WO2025236166A1 - 电池单体、电池及用电装置 - Google Patents

电池单体、电池及用电装置

Info

Publication number
WO2025236166A1
WO2025236166A1 PCT/CN2024/093026 CN2024093026W WO2025236166A1 WO 2025236166 A1 WO2025236166 A1 WO 2025236166A1 CN 2024093026 W CN2024093026 W CN 2024093026W WO 2025236166 A1 WO2025236166 A1 WO 2025236166A1
Authority
WO
WIPO (PCT)
Prior art keywords
wall
pressure relief
groove
battery cell
relief groove
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Pending
Application number
PCT/CN2024/093026
Other languages
English (en)
French (fr)
Inventor
全超
李耀
顾明光
刘思轲
刘双旭
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Contemporary Amperex Technology Co Ltd
Original Assignee
Contemporary Amperex Technology Co Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Contemporary Amperex Technology Co Ltd filed Critical Contemporary Amperex Technology Co Ltd
Priority to CN202480060945.4A priority Critical patent/CN122003767A/zh
Priority to PCT/CN2024/093026 priority patent/WO2025236166A1/zh
Publication of WO2025236166A1 publication Critical patent/WO2025236166A1/zh
Pending legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Classifications

    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M10/00—Secondary cells; Manufacture thereof
    • H01M10/05—Accumulators with non-aqueous electrolyte
    • H01M10/052—Li-accumulators
    • H01M10/0525—Rocking-chair batteries, i.e. batteries with lithium insertion or intercalation in both electrodes; Lithium-ion batteries
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
    • H01M50/10—Primary casings; Jackets or wrappings
    • H01M50/147—Lids or covers
    • H01M50/148—Lids or covers characterised by their shape
    • H01M50/15—Lids or covers characterised by their shape for prismatic or rectangular cells
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
    • H01M50/20—Mountings; Secondary casings or frames; Racks, modules or packs; Suspension devices; Shock absorbers; Transport or carrying devices; Holders
    • H01M50/202—Casings or frames around the primary casing of a single cell or a single battery
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
    • H01M50/20—Mountings; Secondary casings or frames; Racks, modules or packs; Suspension devices; Shock absorbers; Transport or carrying devices; Holders
    • H01M50/249—Mountings; Secondary casings or frames; Racks, modules or packs; Suspension devices; Shock absorbers; Transport or carrying devices; Holders specially adapted for aircraft or vehicles, e.g. cars or trains
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
    • H01M50/30—Arrangements for facilitating escape of gases
    • H01M50/342—Non-re-sealable arrangements
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
    • H01M50/30—Arrangements for facilitating escape of gases
    • H01M50/375—Vent means sensitive to or responsive to temperature

Definitions

  • This application relates to the field of battery technology, and more specifically, to a battery cell, a battery, and an electrical device.
  • a pressure relief structure is typically installed on the outer casing of each cell to release internal pressure. This structure is activated when the internal pressure or temperature reaches a threshold, releasing the pressure within the cell.
  • existing pressure relief structures often prematurely open during use, resulting in poor stability and hindering the improvement of cell lifespan and reliability.
  • This application provides a battery cell, a battery, and an electrical device, which can effectively improve the service life and reliability of the battery cell.
  • a battery cell including a housing, electrode terminals, and an electrode assembly; the housing has a first wall; the electrode terminals are disposed on the first wall; the electrode assembly is housed within the housing, and the electrode assembly is electrically connected to the electrode terminals; wherein, the first wall is provided with a pressure relief groove, the first wall is configured to crack along at least a portion of the pressure relief groove when the battery cell is depressurized, the projection of the pressure relief groove does not overlap with the projection of the electrode terminals along the thickness direction of the first wall, and the thickness of the electrode terminals is greater than the thickness of the first wall.
  • a pressure relief groove is provided on the first wall, so that the first wall can crack along at least part of the pressure relief groove when the battery cell is depressurized, thereby releasing the internal pressure of the battery cell.
  • the thickness of the electrode terminals in the thickness direction of the first wall is greater than the thickness of the first wall, and the projection of the electrode terminals in the thickness direction of the first wall does not overlap with the projection of the pressure relief groove in the thickness direction of the first wall, the battery cell with this structure can set the electrode terminals and the pressure relief structure of the battery cell on the same wall of the outer shell.
  • the electrode terminals can improve the structural rigidity of the first wall, thereby improving the deformation resistance of the first wall.
  • This can alleviate the deformation of the first wall during the use of the battery cell, thereby reducing the strain and strain amplitude in the area of the first wall where the pressure relief groove is provided, and thus reducing the occurrence of low-cycle fatigue in the area of the first wall where the pressure relief groove is provided, thereby reducing the occurrence of fatigue damage in the area of the first wall where the pressure relief groove is provided.
  • This helps to reduce the risk of premature valve opening of the battery cell, thereby improving the service life and reliability of the battery cell.
  • the pressure relief groove and the electrode terminal are arranged along a first direction; wherein, along a second direction, the maximum dimension of the electrode terminal is D1 , the maximum dimension of the first wall is D2 , satisfying 0.4 ⁇ D1 / D2 ⁇ 0.9 , and the thickness direction of the first wall, the first direction, and the second direction are perpendicular to each other.
  • the ratio of the maximum dimension of the electrode terminal in the second direction to the maximum dimension of the first wall in the second direction is 0.4 to 0.9.
  • the ratio of the maximum dimension of the electrode terminal in the second direction to the maximum dimension of the first wall in the second direction is 0.4 to 0.9.
  • the space occupied by the electrode terminal in the second direction of the first wall can be increased. This is beneficial to enhancing the strengthening effect of the electrode terminal on the structural rigidity of the first wall, thereby improving the deformation resistance of the first wall.
  • This phenomenon helps reduce the risk of premature valve opening in battery cells, thereby improving the service life and reliability of battery cells.
  • the ratio of the maximum size of the electrode terminal in the second direction to the maximum size of the first wall in the second direction to be less than or equal to 0.9, the phenomenon of the electrode terminal occupying too much space in the first wall in the second direction can be alleviated, thereby reducing the phenomenon of excessively large openings of the mounting holes for mounting the electrode terminals.
  • the maximum dimension of the electrode terminal is D1
  • the maximum dimension of the first wall is D2 , satisfying that 0.6 ⁇ D1 / D2 ⁇ 0.9.
  • the space occupied by the electrode terminal in the second direction of the first wall can be further increased.
  • This is beneficial to further enhance the strengthening effect of the electrode terminal on the structural rigidity of the first wall, thereby improving the deformation resistance of the first wall.
  • This can further alleviate the deformation phenomenon of the first wall during the use of the battery cell, thereby reducing the strain and strain amplitude in the area of the first wall where the pressure relief groove is provided. In turn, it can further reduce the phenomenon of low-cycle fatigue in the area of the first wall where the pressure relief groove is provided, which is beneficial to further reduce the risk of premature valve opening of the battery cell, thereby improving the service life and reliability of the battery cell.
  • the outer edge of the first wall includes a first edge, the first edge and the pressure relief groove are respectively located on both sides of the electrode terminal in a first direction, the first direction being perpendicular to the thickness direction of the first wall; wherein, along the first direction, the minimum distance between the pressure relief groove and the electrode terminal is L1 , and the minimum distance between the pressure relief groove and the first edge is L2 , satisfying 0.2 ⁇ L1 / L2 ⁇ 0.8 .
  • the ratio of the minimum distance between the pressure relief groove and the electrode terminal in the first direction to the minimum distance between the pressure relief groove and the first edge in the first direction is 0.2 to 0.8.
  • this ratio is set to less than or equal to 0.8, the pressure relief groove is made closer to the electrode terminal in the first direction. This enhances the structural stiffness of the area where the pressure relief groove is located on the first wall, which helps reduce the strain and strain amplitude in this area. This reduces the occurrence of low-cycle fatigue in the area, lowering the risk of premature valve opening in battery cells and effectively improving the overall performance.
  • the ratio of the minimum distance between the pressure relief groove and the electrode terminal in the first direction to the minimum distance between the pressure relief groove and the first edge in the first direction is set to be greater than or equal to 0.2. This mitigates the phenomenon of the pressure relief groove being too close to the electrode terminal. As a result, when the first wall cracks along at least a portion of the pressure relief groove to release the internal pressure of the battery cell, the impact of thermal runaway gas inside the battery cell on the electrode terminal and other components connected to the electrode terminal can be reduced. This reduces the risk of short circuit or thermal diffusion caused by damage to the electrode terminal and other components connected to the electrode terminal, thereby improving the reliability of the battery cell.
  • the minimum distance between the pressure relief groove and the electrode terminal is L1
  • the minimum distance between the pressure relief groove and the first edge is L2 , satisfying 0.2 ⁇ L1 / L2 ⁇ 0.6 .
  • the pressure relief groove can be further close to the electrode terminal in the first direction, thereby further enhancing the strengthening effect of the electrode terminal on the structural rigidity of the area where the pressure relief groove is provided on the first wall. This helps to reduce the strain and strain amplitude in the area where the pressure relief groove is provided on the first wall, thereby further reducing the occurrence of low-cycle fatigue in the area where the pressure relief groove is provided on the first wall, further reducing the risk of premature valve opening of the battery cell, and thus effectively improving the service life and reliability of the battery cell.
  • the pressure relief groove and the electrode terminal are arranged along a first direction, which is perpendicular to the thickness direction of the first wall; wherein, along the first direction, the minimum distance between the pressure relief groove and the electrode terminal is L1 , and the thickness of the portion of the first wall located between the pressure relief groove and the electrode terminal is D, satisfying 3 ⁇ L1 /D ⁇ 30.
  • the ratio of the minimum distance between the pressure relief groove and the electrode terminal in the first direction to the thickness of the portion of the first wall located between the pressure relief groove and the electrode terminal is 3 to 30.
  • this ratio is set to less than or equal to 30, the problem of excessively large minimum distance between the pressure relief groove and the electrode terminal in the first direction and excessively small thickness of the portion of the first wall located between the pressure relief groove and the electrode terminal is alleviated.
  • This enhances the structural stiffness of the area where the pressure relief groove is located on the first wall, thereby reducing the strain and strain amplitude in this area. This reduces the occurrence of low-cycle fatigue in the area, lowering the risk of premature valve opening in the battery cell, and ultimately effectively improving the performance of the battery cell.
  • the ratio of the minimum distance between the pressure relief groove and the electrode terminal in the first direction to the thickness of the portion of the first wall located between the pressure relief groove and the electrode terminal to be greater than or equal to 3
  • the phenomenon of the minimum distance between the pressure relief groove and the electrode terminal in the first direction being too small and the thickness of the portion of the first wall located between the pressure relief groove and the electrode terminal being too large can be alleviated.
  • This can alleviate the phenomenon of excessive waste of the thickness of the first wall, thereby reducing the manufacturing cost of the battery cell.
  • the first wall cracks at least partially along the pressure relief groove to release the internal pressure of the battery cell, the impact of thermal runaway gas inside the battery cell on the electrode terminal and other components connected to the electrode terminal can be reduced. This can reduce the risk of short circuit or thermal diffusion caused by damage to the electrode terminal and other components connected to the electrode terminal, thereby improving the reliability of the battery cell.
  • the minimum distance between the pressure relief groove and the electrode terminal is L1
  • the thickness of the portion of the first wall located between the pressure relief groove and the electrode terminal is D, satisfying that 5 ⁇ L1 / D ⁇ 25.
  • the ratio of the minimum distance between the pressure relief groove and the electrode terminal in the first direction to the thickness of the portion of the first wall located between the pressure relief groove and the electrode terminal is less than or equal to 25
  • the problem of excessively large minimum distance between the pressure relief groove and the electrode terminal in the first direction and excessively small thickness of the portion of the first wall located between the pressure relief groove and the electrode terminal is further alleviated.
  • This is beneficial to further enhance the structural stiffness of the area where the pressure relief groove is located on the first wall, thereby further reducing the strain and strain amplitude in the area where the pressure relief groove is located on the first wall.
  • the ratio of the minimum distance between the pressure relief groove and the electrode terminal in the first direction to the thickness of the portion of the first wall located between the pressure relief groove and the electrode terminal is set to be greater than or equal to 5. This further alleviates the phenomenon that the minimum distance between the pressure relief groove and the electrode terminal in the first direction is too small and the thickness of the portion of the first wall located between the pressure relief groove and the electrode terminal is too large. On the one hand, this can further alleviate the phenomenon of excessive waste of the thickness of the first wall. On the other hand, when the first wall cracks along at least a portion of the pressure relief groove and releases the internal pressure of the battery cell, it can further reduce the impact of thermal runaway gas inside the battery cell on the electrode terminal and other components connected to the electrode terminal.
  • the thickness of the portion of the first wall located between the pressure relief groove and the electrode terminal is D, satisfying 0.8mm ⁇ D ⁇ 4mm.
  • the thickness of the portion of the first wall located between the pressure relief groove and the electrode terminal is greater than or equal to 0.8 mm and less than or equal to 4 mm, on the one hand, the structural strength of the portion of the first wall located between the pressure relief groove and the electrode terminal can be improved, thereby reducing the risk of the first wall breaking or being damaged during use. On the other hand, it can reduce the phenomenon of excessive waste of the thickness of the first wall, which is conducive to reducing the manufacturing difficulty and manufacturing cost of the first wall.
  • the pressure relief groove and the electrode terminal are arranged along a first direction, which is perpendicular to the thickness direction of the first wall; wherein, along the first direction, the minimum distance between the pressure relief groove and the electrode terminal is L1 , which satisfies 10mm ⁇ L1 ⁇ 100mm .
  • the minimum distance between the pressure relief groove and the electrode terminal in the first direction is 10mm to 100mm.
  • the pressure relief groove is closer to the electrode terminal, thereby enhancing the structural rigidity of the area where the pressure relief groove is provided on the first wall. This helps to reduce the strain and strain amplitude in the area where the pressure relief groove is provided on the first wall, thereby reducing the phenomenon of low-cycle fatigue in the area where the pressure relief groove is provided on the first wall, reducing the risk of premature valve opening of the battery cell, and thus effectively improving the service life and reliability of the battery cell.
  • the minimum distance between the pressure relief groove and the electrode terminal in the first direction is set to be greater than or equal to 10mm.
  • the first wall cracks along at least part of the pressure relief groove to release the internal pressure of the battery cell, the impact of thermal runaway gas inside the battery cell on the electrode terminal and other components connected to the electrode terminal can be reduced. This reduces the risk of short circuit or thermal diffusion caused by damage to the electrode terminal and other components connected to the electrode terminal, thereby improving the reliability of the battery cell.
  • the minimum distance between the pressure relief groove and the electrode terminal is L1 , satisfying 15mm ⁇ L1 ⁇ 50mm .
  • the minimum distance between the pressure relief groove and the electrode terminal in the first direction is 15mm to 50mm. On the one hand, this is achieved by...
  • the minimum distance between the pressure relief groove and the electrode terminal in the first direction is further set to less than or equal to 50 mm, so that the pressure relief groove is closer to the electrode terminal. This further enhances the structural rigidity of the area where the pressure relief groove is located on the first wall, which helps to reduce the strain and strain amplitude in the area where the pressure relief groove is located on the first wall. This further reduces the occurrence of low-cycle fatigue in the area where the pressure relief groove is located on the first wall, thereby reducing the risk of premature valve opening in the battery cell. This effectively improves the service life and reliability of the battery cell.
  • the phenomenon of the pressure relief groove being too close to the electrode terminal is further alleviated.
  • This further reduces the impact of thermal runaway gas inside the battery cell on the electrode terminal and other components connected to the electrode terminal when the first wall cracks at least partially along the pressure relief groove to release the internal pressure of the battery cell.
  • This further reduces the risk of short circuit or thermal diffusion caused by damage to the electrode terminal and other components connected to the electrode terminal, thereby improving the reliability of the battery cell.
  • the battery cell includes two electrode terminals, both of which are disposed on the first wall and are spaced apart along a first direction, the first direction being perpendicular to the thickness direction of the first wall; wherein, along the first direction, the pressure relief groove is located between the two electrode terminals.
  • the two electrode terminals can further enhance the structural rigidity of the area where the pressure relief groove is set on the first wall. This helps to reduce the strain and strain amplitude in the area where the pressure relief groove is set on the first wall, thereby further reducing the occurrence of low-cycle fatigue in the area where the pressure relief groove is set on the first wall. This further reduces the risk of premature valve opening in the battery cell and helps to improve the service life and reliability of the battery cell.
  • the minimum distance between the pressure relief groove and the two electrode terminals is equal along the first direction.
  • the regularity of the battery cell structure can be improved, which is conducive to reducing the manufacturing difficulty of the battery cell.
  • the strengthening effect of the two electrode terminals on the structural stiffness of the area where the pressure relief groove is provided on the first wall can be similar, which is conducive to further reducing the strain and strain amplitude of the area where the pressure relief groove is provided on the first wall, so as to alleviate the phenomenon of low cycle fatigue in the area where the pressure relief groove is provided on the first wall, thereby further reducing the risk of premature valve opening of the battery cell.
  • the first wall is provided with mounting holes that penetrate the first wall along its thickness direction, and each mounting hole corresponds to an electrode terminal.
  • Each electrode terminal includes a cylindrical portion, a first limiting portion, and a second limiting portion.
  • the cylindrical portion passes through the mounting holes along the thickness direction of the first wall and connects the first limiting portion and the second limiting portion. Both the first limiting portion and the second limiting portion protrude from the outer peripheral surface of the cylindrical portion.
  • the first limiting portion and the second limiting portion are located on opposite sides of the first wall, and at least a portion of the projections of the first limiting portion and the second limiting portion overlap with the first wall.
  • the electrode terminal is provided with a first limiting part and a second limiting part, as well as a column part connecting the first limiting part and the second limiting part.
  • the column part passes through the mounting hole of the first wall, and the first limiting part and the second limiting part are respectively located on both sides of the first wall and overlap at least part of the first wall, so as to realize the fastening and installation of the electrode terminal on the first wall.
  • the electrode terminal with this structure can improve the structural stability and reliability of the electrode terminal set on the first wall, and further enhance the strengthening effect of the electrode terminal on the structural rigidity of the area of the first wall where the pressure relief groove is provided.
  • the projection of the first wall in the thickness direction of the first wall is rectangular, the dimension of the first wall in the first direction is larger than the dimension of the first wall in the second direction, and the thickness direction of the first wall, the first direction, and the second direction are perpendicular to each other; wherein, the pressure relief groove and the electrode terminal are arranged along the first direction.
  • the first wall is a rectangular structure.
  • the electrode terminal can strengthen the structural stiffness of the first wall in the direction in which the first wall is most prone to deformation, which is conducive to further improving the deformation resistance of the first wall, thereby reducing the strain and strain amplitude in the area of the first wall where the pressure relief groove is set, and thus further reducing the phenomenon of low cycle fatigue in the area of the first wall where the pressure relief groove is set, thereby further reducing the risk of premature valve opening of the battery cell.
  • the housing is cuboid in shape and has two second walls, which are disposed opposite to each other along the second direction and are respectively connected to the two ends of the first wall; wherein, along the second direction, the surface of the second wall facing away from the electrode assembly is the surface with the largest area on the outer surface of the housing.
  • the outer shell is rectangular and has two second walls arranged opposite each other in a second direction.
  • the surface of the second wall facing away from the electrode assembly is the surface with the largest area on the outer surface of the outer shell. This makes the second direction both the width direction of the first wall and the thickness direction of the battery cell. This allows the electrode terminals to strengthen the structural stiffness of the first wall in the direction where the deformation of the first wall is the largest. This is beneficial to further improve the deformation resistance of the first wall and reduce the strain and strain amplitude in the area where the pressure relief groove is provided on the first wall. This can further reduce the phenomenon of low-cycle fatigue in the area where the pressure relief groove is provided on the first wall, and further reduce the risk of premature valve opening of the battery cell.
  • the pressure relief groove is stamped onto the first wall.
  • the forming method of the pressure relief groove on the first wall is simple, which is conducive to reducing the manufacturing cost of battery cells.
  • the pressure relief groove includes multiple levels of grooves arranged sequentially along the thickness direction of the first wall.
  • the pressure relief groove is a groove structure formed by multiple processing steps.
  • the depth of a single processing step can be reduced for the same depth, which helps to reduce the manufacturing difficulty and the demand for manufacturing equipment, thereby reducing manufacturing costs.
  • It can also reduce the forming force on the first wall during a single processing step, which helps to reduce the risk of cracks in the first wall and improve the production quality of battery cells.
  • it can improve the material flow pattern during the formation of the pressure relief groove, which is conducive to the flow of materials generated during the formation of the pressure relief groove, thereby improving the structural consistency of the pressure relief groove.
  • the minimum residual thickness of the pressure relief groove is D3 , which satisfies 0.05mm ⁇ D3 ⁇ 0.3mm .
  • the minimum residual thickness of the pressure relief groove in the thickness direction of the first wall is 0.05mm to 0.3mm.
  • the minimum residual thickness of the pressure relief groove in the thickness direction of the first wall is 0.05mm to 0.3mm.
  • the structural strength of the area where the pressure relief groove is located in the first wall is mitigated, thereby reducing the risk of cracking or damage in the area where the pressure relief groove is located during production, transportation, or normal use.
  • the minimum residual thickness of the pressure relief groove in the thickness direction of the first wall to be less than or equal to 0.3 mm, the problem of the first wall cracking along the pressure relief groove when the battery cell experiences thermal runaway is alleviated. This reduces the burst pressure required for the battery cell to release pressure and open the valve, thereby reducing the risk of explosion caused by excessive pressure relief burst pressure of the battery cell.
  • the battery cell further includes an electrolyte contained within the casing; wherein the electrolyte includes an electrolyte salt, the electrolyte salt including hexafluorophosphate, and the molar concentration of the hexafluorophosphate is less than or equal to 1.1 mol/L.
  • the amount of hydrofluoric acid generated by the battery cell during use can be reduced, thereby reducing the corrosion of the area where the pressure relief groove is provided on the first wall.
  • This can alleviate the situation where the minimum residual thickness of the pressure relief groove is further reduced, thereby reducing the risk of premature cracking or damage to the battery cell due to the decrease in structural strength of the area where the pressure relief groove is provided on the first wall, and further improving the reliability and stability of the battery cell in use.
  • the bottom of the pressure relief groove forms a first weak portion
  • the first wall is configured to split along at least a portion of the first weak portion when the battery cell is depressurized; wherein the first wall is further provided with a guide groove, the bottom of the guide groove forms a second weak portion, and along the thickness direction of the first wall, the projection of the pressure relief groove and the projection of at least one of the guide grooves together define at least one predetermined pressure relief area, and the second weak portion is configured to guide at least a portion of the predetermined pressure relief area to flip over to open at least a portion of the predetermined pressure relief area.
  • a guide groove is also provided on the first wall.
  • the projection of the guide groove and the pressure relief groove along the thickness direction of the first wall defines at least one predetermined pressure relief area on the first wall.
  • the predetermined pressure relief area can be opened after the first wall is at least partially cracked along the pressure relief groove, and can be flipped around the second weak part at the bottom of the guide groove to release the internal pressure of the battery cell.
  • the battery cell with this structure can expand the flip angle of the predetermined pressure relief area after it is opened, thereby effectively increasing the pressure relief area of the battery cell, so as to improve the pressure relief rate of the battery cell when thermal runaway occurs, thereby reducing the risk of fire and explosion caused by untimely pressure relief of the battery cell, which is conducive to improving the reliability of the battery cell.
  • the pressure relief groove and the electrode terminal are arranged along a first direction, and the pressure relief groove and the guide groove are arranged along a second direction, wherein the thickness direction of the first wall, the first direction, and the second direction are perpendicular to each other.
  • the guide groove and the pressure relief groove by setting the guide groove and the pressure relief groove to be arranged along the second direction, such that the guide groove is located on at least one side of the pressure relief groove in the second direction, on the one hand, the influence of the guide groove on the structural rigidity of the first wall in the area between the electrode terminal and the pressure relief groove can be reduced, which is beneficial to improving the strengthening effect of the electrode terminal on the structural rigidity of the area of the first wall where the pressure relief groove is provided.
  • the interference between the pressure relief groove and the guide groove can be reduced, so that the pressure relief groove and the guide groove can be processed separately. It can also alleviate the phenomenon that the first weak part at the bottom of the pressure relief groove tears the second weak part at the bottom of the guide groove when it cracks. It can also improve the effect of the predetermined pressure relief area being flipped around the second weak part after it is opened.
  • the guide groove extends along the first direction, and the two ends of the guide groove extend out of the two ends of the pressure relief groove, respectively, along the first direction.
  • the guide groove is larger than the pressure relief groove in the first direction, so that the predetermined pressure relief area defined by the pressure relief groove can be flipped around the second weak part, and the flipping effect of the predetermined pressure relief area can be improved, thereby increasing the pressure relief area of the battery cell and improving the pressure relief rate of the battery cell when thermal runaway occurs.
  • the guide groove can improve the absorption effect of the excess material extruded from the pressure relief groove of the first wall during the molding process, and can improve the effect of the guide groove in separating the edge of the pressure relief groove and the first wall in the second direction, so as to improve the effect of the guide groove in blocking the deformation energy of the battery cell when the battery cell is subjected to internal and external impact forces.
  • the projection of the guide groove does not overlap with the projection of the electrode terminal along the thickness direction of the first wall.
  • the thickness of the second weak portion is greater than the thickness of the first weak portion along the thickness direction of the first wall.
  • the residual thickness of the guide groove is greater than the residual thickness of the pressure relief groove.
  • the first weak portion includes at least one weak segment
  • the cross-sectional area of the weak segment perpendicular to its extension direction is a first cross-sectional area S1
  • the cross-sectional area of the second weak portion perpendicular to its extension direction is a second cross-sectional area S2 , satisfying that S1 ⁇ S2 .
  • the structural strength of the area where the pressure relief groove is set in the first wall is less than the structural strength of the area where the guide groove is set in the first wall. This facilitates the first wall to preferentially crack along the first weak part at the bottom of the pressure relief groove and release the internal pressure of the battery cell, which helps to alleviate the phenomenon that the pressure relief effect of the battery cell is poor when the first wall cracks from the area where the guide groove is set.
  • the pressure relief groove and the guide groove are respectively disposed on both sides of the first wall along the thickness direction of the first wall.
  • the pressure relief groove includes a first groove segment and two second groove segments.
  • the two second groove segments are arranged opposite each other along a first direction, and the second groove segments and the guide groove are arranged along a second direction.
  • the first groove segment connects the two second groove segments.
  • the thickness direction of the first wall, the first direction, and the second direction are perpendicular to each other.
  • the projections of the first groove segment, the two second groove segments, the extension lines of the two second groove segments, and the guide groove together enclose the predetermined pressure relief area.
  • the projections of the first groove segment, the two second groove segments, the guide groove, and the extension lines of the guide groove together enclose the predetermined pressure relief area.
  • the projections of the first groove segment, the two second groove segments, the extension lines of the two second groove segments, the guide groove, and the extension lines of the guide groove together enclose the predetermined pressure relief area.
  • the battery cell with this structure facilitates the machining of pressure relief grooves on the first wall to form a predetermined pressure relief area, and the predetermined pressure relief area defined by the pressure relief grooves of this structure is easier to rotate around the location of the guide groove. Furthermore, it makes the first and second groove segments... The intersecting points are weaker, making them more prone to cracking and opening the predetermined pressure relief zone for pressure relief.
  • the pressure relief groove includes a first groove segment and a second groove segment, the first groove segment and the second groove segment being connected; wherein, along the thickness direction of the first wall, the projection of the first groove segment, the projection of the extension line of the first groove segment, the projection of the second groove segment, the projection of the extension line of the second groove segment, and the projection of the guide groove together enclose the predetermined pressure relief area; or, along the thickness direction of the first wall, the projection of the first groove segment, the projection of the second groove segment, the projection of the guide groove, and the projection of the extension line of the guide groove together enclose the predetermined pressure relief area; or, along the thickness direction of the first wall, the projection of the first groove segment, the projection of the extension line of the first groove segment, the projection of the second groove segment, the projection of the extension line of the second groove segment, the projection of the guide groove, and the projection of the extension line of the guide groove together enclose the predetermined pressure relief area.
  • the battery cell with this structure can increase the pressure relief area of the battery cell to improve the pressure relief rate of the battery cell.
  • the pressure relief groove is a groove extending along an arcuate trajectory; wherein, along the thickness direction of the first wall, the projection of the pressure relief groove, the projection of the extension line of the pressure relief groove, and the projection of the guide groove together enclose the predetermined pressure relief area; or, along the thickness direction of the first wall, the projection of the pressure relief groove, the projection of the guide groove, and the projection of the extension line of the guide groove together enclose the predetermined pressure relief area; or, along the thickness direction of the first wall, the projection of the pressure relief groove, the projection of the extension line of the pressure relief groove, the projection of the guide groove, and the projection of the extension line of the guide groove together enclose the predetermined pressure relief area.
  • the pressure relief groove as a structure that extends along an arc trajectory, the predetermined pressure relief area is formed on the inner side of the pressure relief groove.
  • the pressure relief groove with this structure is easy to manufacture on the first wall, which helps to reduce the manufacturing difficulty of the battery cell.
  • the guide groove is stamped onto the first wall.
  • the forming method of the guide groove on the first wall is simple, which is conducive to reducing the manufacturing cost of battery cells.
  • the first wall is configured to support the electrode assembly along its thickness direction.
  • the first wall can support the electrode assembly in the thickness direction of the first wall, so that the battery cell can be inverted.
  • this allows the battery cell to adapt to more application scenarios, thereby improving the adaptability of the battery cell.
  • it enables the pressure relief groove and electrode terminals of the battery cell to be located at the bottom of the battery cell, so as to facilitate assembly and release of internal pressure of the battery cell.
  • the housing includes a housing and an end cap; the interior of the housing forms a receiving cavity with an opening for receiving the electrode assembly; the end cap closes the opening; wherein the housing includes the first wall; or, the end cap is the first wall.
  • the battery cell with this structure allows the area where the pressure relief groove is located on the outer casing to be far away from the end cap. This effectively alleviates the stress generated by the connection between the end cap and the housing on the area where the pressure relief groove is located on the first wall, reducing the impact on this area. This, in turn, helps reduce the risk of cracking or structural strength reduction in the area where the pressure relief groove is located under stress, thereby improving the service life and reliability of the battery cell.
  • the battery cell with this structure facilitates the setting of pressure relief grooves and the installation of electrode terminals on the end cap, reducing the manufacturing difficulty of the battery cell and improving its production efficiency.
  • the housing includes a shell and two end caps; the interior of the shell has a receiving cavity for accommodating the electrode assembly, and openings are formed at opposite ends of the shell, with both openings communicating with the receiving cavity; the two end caps respectively close the two openings; wherein one of the two end caps is the first wall; or, the shell includes the first wall.
  • the outer casing has openings at both opposite ends, and two end caps respectively close the two openings.
  • the first wall is one of the two end caps.
  • This structure facilitates the assembly of battery cells from both ends of the casing, reducing manufacturing and assembly difficulties. It also facilitates the installation of pressure relief grooves and electrode terminals on the end caps, further reducing manufacturing difficulty and improving production efficiency.
  • the area with the pressure relief groove is located away from the end caps. This effectively mitigates the stress generated by the connection between the end caps and the casing on the area with the pressure relief groove on the first wall, reducing its impact. This, in turn, reduces the risk of cracking or structural strength reduction in the area with the pressure relief groove under tensile stress, thus improving the battery cell's lifespan and reliability.
  • embodiments of this application also provide a battery, including the aforementioned battery cell.
  • the battery further includes a housing, in which the battery cell is housed, the housing having a bottom plate located at the bottom of the battery cell, the bottom plate being disposed facing the first wall along the thickness direction of the first wall.
  • the battery cell is set up upside down in the box. This allows the pressure relief groove and electrode terminals of the battery cell to be located at the bottom of the battery cell and facing the bottom plate, which facilitates assembly and release of internal pressure of the battery cell. It also mitigates the risk to the user caused by the upward impact of thermal runaway gas released from the battery cell during thermal runaway.
  • embodiments of this application also provide an electrical device, including the aforementioned battery cell or battery, wherein the battery cell is used to provide electrical energy.
  • Figure 1 is a structural schematic diagram of a vehicle provided in some embodiments of this application.
  • FIG. 2 is an exploded view of the battery structure provided in some embodiments of this application.
  • Figure 3 is a schematic diagram of the structure of a battery cell provided in some embodiments of this application.
  • Figure 4 is an exploded view of the structure of a battery cell provided in some embodiments of this application.
  • Figure 5 is a front view of a battery cell facing the pressure relief groove in the thickness direction of the first wall according to some embodiments of this application;
  • Figure 6 is a partial enlarged view of point A of the battery cell shown in Figure 5;
  • Figure 7 is a front view of a battery cell facing the pressure relief groove in the thickness direction of the first wall according to some embodiments of this application;
  • Figure 8 is a partial cross-sectional view of the first wall of the casing of a battery cell provided in some embodiments of this application;
  • Figure 9 is a front view of a battery cell in the thickness direction of the first wall facing the pressure relief groove according to some embodiments of this application;
  • Figure 10 is a front view of a battery cell facing the pressure relief groove in the thickness direction of the first wall according to some other embodiments of this application;
  • Figure 11 is a front view of a battery cell provided in some further embodiments of this application, facing the pressure relief groove in the thickness direction of the first wall.
  • Icons 1000 - Vehicle; 100 - Battery; 10 - Housing; 11 - First Housing Body; 12 - Second Housing Body; 20 - Battery Cell; 21 - Housing; 211 - First Wall; 2111 - Pressure Relief Groove; 2111a - First Groove Segment; 2111b - Second Groove Segment; 2111c - First Weak Point; 2112 - First Edge; 2113 - Predetermined Pressure Relief Area; 2114 - Guide Groove; 2114a - Second Weak Point; 212 - Housing; 2121 - Opening; 213 - End Cap; 214 - Second Wall; 22 - Electrode Terminal; 23 - Electrode Assembly; 231 - Tab; 200 - Controller; 300 - Motor; X - Thickness Direction of First Wall; Y - First Direction; Z - Second Direction.
  • connection should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal communication between two components.
  • connection can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal communication between two components.
  • the term "and/or” is merely a description of the relationship between related objects, indicating that three relationships can exist.
  • a and/or B can represent: A existing alone, A and B existing simultaneously, or B existing alone.
  • the character "/" generally indicates that the preceding and following related objects have an "or" relationship.
  • multiple means two or more (including two).
  • the battery cell can be a secondary battery, which refers to a battery cell that can be recharged to activate the active materials and continue to be used after the battery cell has been discharged.
  • the battery cell can be a lithium-ion battery, sodium-ion battery, sodium-lithium-ion battery, lithium metal battery, sodium metal battery, lithium-sulfur battery, magnesium-ion battery, nickel-metal hydride battery, nickel-cadmium battery, lead-acid battery, etc., and the embodiments of this application are not limited to this.
  • a single battery cell typically includes an electrode assembly.
  • the electrode assembly includes a positive electrode, a negative electrode, and a separator.
  • active ions such as lithium ions
  • the separator positioned between the positive and negative electrodes, prevents short circuits while allowing active ions to pass through.
  • the positive electrode may be a positive electrode sheet, which may include a positive electrode current collector and a positive electrode active material disposed on at least one surface of the positive electrode current collector.
  • the positive current collector has two surfaces opposite each other in its own thickness direction, and the positive active material is disposed on either or both of the two opposite surfaces of the positive current collector.
  • the positive electrode current collector can be a metal foil or a composite current collector.
  • a metal foil it can be aluminum with a silver-plated surface, stainless steel with a silver-plated surface, stainless steel, copper, aluminum, nickel, carbon electrode, carbon, nickel, or titanium, etc.
  • Composite current collectors can include a polymer material base layer and a metal layer.
  • Composite current collectors can be formed by forming a metal material (aluminum, aluminum alloy, nickel, nickel alloy, titanium, titanium alloy, silver and silver alloy, etc.) on a polymer material substrate (such as a substrate of polypropylene, polyethylene terephthalate, polybutylene terephthalate, polystyrene, polyethylene, etc.).
  • the positive electrode active material may include at least one of the following materials: lithium phosphate, lithium transition metal oxide, and their respective modified compounds.
  • lithium phosphate include, but are not limited to, at least one of lithium iron phosphate (such as LiFePO4 (also referred to as LFP)), lithium iron phosphate and carbon composites, lithium manganese phosphate (such as LiMnPO4 ), lithium manganese phosphate and carbon composites, lithium manganese iron phosphate, and lithium manganese iron phosphate and carbon composites.
  • lithium transition metal oxides may include, but are not limited to , lithium cobalt oxides (such as LiCoO2 ), lithium nickel oxides (such as LiNiO2 ), lithium manganese oxides (such as LiMnO2 , LiMn2O4 ), lithium nickel cobalt oxides, lithium manganese cobalt oxides, lithium nickel manganese oxides, lithium nickel cobalt manganese oxides (such as LiNi 1/3 Co 1/3 Mn 1/3 O2 (also abbreviated as NCM 333 ), LiNi 0.5 Co 0.2 Mn 0.3 O2 (also abbreviated as7) At least one of the following: NCM 523 , LiNi 0.5 Co 0.25 Mn 0.25 O 2 (also known as NCM 211 ), LiNi 0.6 Co 0.2 Mn 0.2 O 2 (also known as NCM 622 ), LiNi 0.8 Co 0.1 Mn 0.1 O 2 (also known as NCM 811 ), lithium nickel cobalt aluminum oxides (such as LiNi 0.
  • the positive electrode can be a foamed metal.
  • the foamed metal can be foamed nickel, foamed copper, foamed aluminum, foamed alloys, etc.
  • the surface of the foamed metal may or may not contain a positive electrode active material.
  • lithium source material, potassium metal, or sodium metal can also be filled and/or deposited within the foamed metal, where the lithium source material is lithium metal and/or a lithium-rich material.
  • the negative electrode may be a negative electrode sheet, and the negative electrode sheet may include a negative electrode current collector.
  • the negative electrode current collector can be a metal foil, a foamed metal, or a composite current collector.
  • a metal foil it can be silver-treated aluminum or stainless steel, stainless steel, copper, aluminum, nickel, carbon electrode, nickel, or titanium, etc.
  • Foamed metal can be foamed nickel, foamed copper, foamed aluminum, foamed alloy, etc.
  • Composite current collectors can include a polymer material base layer and a metal layer.
  • Composite current collectors can be formed by forming a metal material (copper, copper alloy, nickel, nickel alloy, titanium, titanium alloy, silver and silver alloy, etc.) on a polymer material substrate (such as a substrate of polypropylene, polyethylene terephthalate, polybutylene terephthalate, polystyrene, polyethylene, etc.).
  • a metal material copper, copper alloy, nickel, nickel alloy, titanium, titanium alloy, silver and silver alloy, etc.
  • a polymer material substrate such as a substrate of polypropylene, polyethylene terephthalate, polybutylene terephthalate, polystyrene, polyethylene, etc.
  • the negative electrode sheet may include a negative electrode current collector and a negative electrode active material disposed on at least one surface of the negative electrode current collector.
  • the negative electrode current collector has two surfaces opposite each other in its own thickness direction, and the negative electrode active material is disposed on either or both of the two opposite surfaces of the negative electrode current collector.
  • the negative electrode active material may be a negative electrode active material known in the art for use in battery cells.
  • the negative electrode active material may include at least one of the following materials: artificial graphite, natural graphite, soft carbon, hard carbon, silicon-based materials, tin-based materials, and lithium titanate, etc.
  • Silicon-based materials may be selected from at least one of elemental silicon, silicon oxide compounds, silicon-carbon composites, silicon-nitrogen composites, and silicon alloys.
  • Tin-based materials may be selected from at least one of elemental tin, tin oxide compounds, and tin alloys.
  • this application is not limited to these materials, and other conventional materials that can be used as battery negative electrode active materials may also be used. These negative electrode active materials may be used alone or in combination of two or more.
  • the positive current collector can be made of aluminum, and the negative current collector can be made of copper.
  • the electrode assembly further includes an isolator disposed between the positive and negative electrodes.
  • the separator is a separator membrane.
  • the separator membrane can be of various types, and any known porous separator membrane with good chemical and mechanical stability can be selected.
  • the material of the separator may include at least one of glass fiber, nonwoven fabric, polyethylene, polypropylene, and polyvinylidene fluoride.
  • the separator may be a single-layer film or a multi-layer composite film. When the separator is a multi-layer composite film, the materials of each layer may be the same or different.
  • the separator may be a separate component located between the positive and negative electrodes, or it may be attached to the surfaces of the positive and negative electrodes.
  • the separator is a solid electrolyte.
  • the solid electrolyte is disposed between the positive and negative electrodes, serving both to transport ions and to isolate the positive and negative electrodes.
  • the battery cell also includes an electrolyte, which acts as a conductor of ions between the positive and negative electrodes.
  • the electrolyte can be liquid, gel-like, or solid. Liquid electrolytes include electrolyte salts and solvents.
  • the electrolyte salt may include at least one of lithium hexafluorophosphate, lithium tetrafluoroborate, lithium perchlorate, lithium hexafluoroarsenate, lithium bis(fluorosulfonyl)imide, lithium bis(trifluoromethanesulfonyl)imide, lithium trifluoromethanesulfonate, lithium difluorophosphate, lithium difluorooxalate borate, lithium dioxalate borate, lithium difluorodioxalate phosphate, and lithium tetrafluorooxalate phosphate.
  • the solvent may include at least one selected from ethylene carbonate, propylene carbonate, methyl ethyl carbonate, diethyl carbonate, dimethyl carbonate, dipropyl carbonate, methyl propyl carbonate, ethyl propyl carbonate, butyl carbonate, fluoroethylene carbonate, methyl formate, methyl acetate, ethyl acetate, propyl acetate, methyl propionate, ethyl propionate, propyl propionate, methyl butyrate, ethyl butyrate, 1,4-butyrolactone, sulfolane, dimethyl sulfone, methyl ethyl sulfone, and diethyl sulfone.
  • the solvent may also be an ether solvent.
  • Ether solvents may include one or more selected from ethylene glycol dimethyl ether, ethylene glycol diethyl ether, diethylene glycol dimethyl ether, triethylene glycol dimethyl ether, tetraethylene glycol dimethyl ether, 1,3-dioxolane, tetrahydrofuran, methyl tetrahydrofuran, diphenyl ether, and crown ethers.
  • the gel electrolyte includes a polymer as the electrolyte backbone network, combined with an ionic liquid - lithium salt.
  • Solid electrolytes include polymer solid electrolytes, inorganic solid electrolytes, and composite solid electrolytes.
  • polymer solid electrolytes can be polyether (polyoxyethylene), polysiloxane, polycarbonate, polyacrylonitrile, polyvinylidene fluoride, polymethyl methacrylate, monoionic polymers, polyionic liquids-lithium salts, cellulose, etc.
  • inorganic solid electrolytes may include one or more of the following: oxide solid electrolytes (crystalline perovskite, sodium superconducting ion conductor, garnet, amorphous LiPON thin film), sulfide solid electrolytes (crystalline lithium superconducting ion conductor (lithium germanium phosphate sulfide, silver sulfide germanium ore), amorphous sulfides), halide solid electrolytes, nitride solid electrolytes, and hydride solid electrolytes.
  • oxide solid electrolytes crystalline perovskite, sodium superconducting ion conductor, garnet, amorphous LiPON thin film
  • sulfide solid electrolytes crystalline lithium superconducting ion conductor (lithium germanium phosphate sulfide, silver sulfide germanium ore), amorphous sulfides)
  • halide solid electrolytes nitride solid electrolytes, and hydr
  • composite solid electrolytes are formed by adding inorganic solid electrolyte fillers to polymer solid electrolytes.
  • the electrode assembly is a wound structure.
  • the positive and negative electrode sheets are wound into a wound structure.
  • the electrode assembly is a stacked structure.
  • multiple positive and negative electrodes can be set, and multiple positive and multiple negative electrodes can be stacked alternately.
  • multiple positive electrode plates can be provided, and negative electrode plates can be folded to form multiple stacked folded segments, with a positive electrode plate sandwiched between adjacent folded segments.
  • both the positive and negative electrode plates are folded to form multiple stacked folded segments.
  • multiple separators can be provided, each positioned between any adjacent positive or negative electrode plates.
  • the separators can be continuously arranged, either by folding or rolling between any adjacent positive or negative electrode plates.
  • the electrode assembly can be cylindrical, flat, or polygonal, etc.
  • the electrode assembly is provided with tabs that allow current to be drawn from the electrode assembly.
  • the tabs include a positive tab and a negative tab.
  • the battery cell may include a housing.
  • the housing is used to encapsulate components such as electrode assemblies and electrolytes.
  • the housing may be made of steel, aluminum, plastic (such as polypropylene), composite metal (such as copper-aluminum composite), or aluminum-plastic film, etc.
  • a battery cell can be a cylindrical battery cell, a prismatic battery cell, a pouch battery cell, or a battery cell of other shapes.
  • Cylindrical cells include, but are not limited to, prismatic cells, blade-shaped cells, and multi-faceted prism cells, such as hexagonal prism cells.
  • the battery mentioned in the embodiments of this application refers to a single physical module comprising one or more battery cells to provide higher voltage and capacity.
  • the battery can be a battery module, and when there are multiple battery cells, the multiple battery cells are arranged and fixed to form a battery module.
  • the battery can be a battery pack, which includes a housing and individual battery cells, with the individual battery cells or battery modules housed within the housing.
  • the housing may be part of the vehicle's chassis structure.
  • a portion of the housing may be at least a part of the vehicle's floor, or a portion of the housing may be at least a part of the vehicle's crossbeams and longitudinal beams.
  • the battery can be an energy storage device.
  • Energy storage devices include energy storage containers, energy storage cabinets, etc.
  • the development of battery technology must simultaneously consider multiple design factors, such as performance parameters like energy density, cycle life, discharge capacity, and charge/discharge rate.
  • performance parameters like energy density, cycle life, discharge capacity, and charge/discharge rate.
  • battery safety must also be taken into account.
  • a pressure relief structure is usually incorporated into the cell's casing. This structure releases internal pressure, effectively improving the cell's safety.
  • the pressure relief structure can be integrally formed onto the casing using a molding process, meaning it's a weak point on the casing.
  • the pressure relief structure and casing can be separate components, such as welded, snap-fitted, or bonded parts. This allows the pressure relief structure to actuate and open when the internal pressure or temperature of the battery cell reaches a threshold, thus releasing the internal pressure.
  • expansion and contraction occur.
  • a battery cell including a casing, electrode terminals, and electrode assemblies.
  • the casing has a first wall.
  • the electrode terminals are disposed on the first wall.
  • the electrode assemblies are housed within the casing and are electrically connected to the electrode terminals.
  • the first wall is provided with a pressure relief groove, and the first wall is configured to crack along at least a portion of the pressure relief groove when the battery cell is depressurized.
  • the projection of the pressure relief groove does not overlap with the projection of the electrode terminals, and the thickness of the electrode terminals is greater than the thickness of the first wall.
  • a pressure relief groove is provided on the first wall, allowing the first wall to crack along at least part of the groove when the battery cell is depressurized, thereby releasing the internal pressure of the battery cell.
  • the electrode terminals are thicker than the first wall in the thickness direction, and the projection of the electrode terminals onto the first wall in the thickness direction does not overlap with the projection of the pressure relief groove.
  • the electrode terminals enhance the structural rigidity of the first wall, improving its resistance to deformation. This reduces deformation of the first wall during battery cell use, decreasing strain and strain amplitude in the area where the pressure relief groove is located. Consequently, it reduces low-cycle fatigue in the area where the pressure relief groove is located, minimizing fatigue damage and reducing the risk of premature valve opening in the battery cell, thus improving its service life and reliability.
  • the battery cells disclosed in this application can be used, but are not limited to, in electrical devices such as vehicles, ships, or aircraft.
  • a power system for such an electrical device can be constructed using battery cells and batteries disclosed in this application. This helps to alleviate the problem of premature valve opening during battery cell use, thereby improving the service life and reliability of the battery cells.
  • the electrical device can be, but is not limited to, mobile phones, tablets, laptops, electric toys, power tools, electric vehicles, electric cars, ships, spacecraft, etc.
  • Electric toys can include stationary or mobile electric toys, such as game consoles, electric car toys, electric ship toys, and electric airplane toys, etc.
  • Spacecraft can include airplanes, rockets, space shuttles, and spacecraft, etc.
  • FIG. 1 is a structural schematic diagram of a vehicle 1000 provided in some embodiments of this application.
  • the vehicle 1000 can be a gasoline-powered vehicle, a natural gas-powered vehicle, or a new energy vehicle. New energy vehicles can be pure electric vehicles, hybrid electric vehicles, or range-extended electric vehicles, etc.
  • a battery 100 is installed inside the vehicle 1000.
  • the battery 100 can be located at the bottom, front, or rear of the vehicle 1000.
  • the battery 100 can be used to power the vehicle 1000; for example, the battery 100 can serve as the operating power source or general power source for the vehicle 1000.
  • the vehicle 1000 may also include a controller 200 and a motor 300.
  • the controller 200 controls the battery 100 to supply power to the motor 300, for example, to meet the power needs of the vehicle 1000 during startup, navigation, and driving.
  • the battery 100 can not only serve as the operating power or power source for the vehicle 1000, but also as the driving power source for the vehicle 1000, replacing or partially replacing fuel or natural gas to provide driving power for the vehicle 1000.
  • Figure 2 is an exploded view of the battery 100 provided in some embodiments of this application
  • Figure 3 is a schematic diagram of the battery cell 20 provided in some embodiments of this application.
  • the battery 100 includes a housing 10 and a battery cell 20, which is housed within the housing 10.
  • the housing 10 provides assembly space for the battery cell 20, and can adopt various structures.
  • the housing 10 may include a first housing body 11 and a second housing body 12, which overlap each other, and together define an assembly space for accommodating the battery cell 20.
  • the second housing body 12 may be a hollow structure open at one end, and the first housing body 11 may be a plate-like structure, with the first housing body 11 covering the open side of the second housing body 12 so that the first housing body 11 and the second housing body 12 together define the assembly space; alternatively, the first housing body 11 and the second housing body 12 may both be hollow structures open on one side, with the open side of the first housing body 11 covering the open side of the second housing body 12.
  • the box 10 formed by the first box body 11 and the second box body 12 can be of various shapes, such as a cylinder, a cuboid, or a cube.
  • the shape of the box 10 is a cuboid.
  • battery 100 there can be one or more battery cells 20 disposed within housing 10.
  • battery cells 20 When there are multiple battery cells 20 disposed within housing 10, they can be connected in series, in parallel, or in a mixed configuration.
  • a mixed configuration means that multiple battery cells 20 are connected in both series and parallel configurations. Multiple battery cells 20 can be directly connected in series, in parallel, or in a mixed configuration, and then the entire assembly of multiple battery cells 20 is housed within housing 10.
  • battery 100 can also be composed of multiple battery cells 20 first connected in series, in parallel, or in a mixed configuration to form a battery module, and then multiple battery modules are connected in series, in parallel, or in a mixed configuration to form a whole, which is then housed within housing 10.
  • the battery 100 may also include other structures.
  • the battery 100 may also include a busbar for connecting multiple battery cells 20 to achieve electrical connection between the multiple battery cells 20.
  • Each battery cell 20 can be a secondary battery or a primary battery; it can also be a lithium-sulfur battery, a sodium-ion battery, or a magnesium-ion battery, but is not limited to these.
  • the battery cell 20 can be in the form of a cuboid, cylinder, prism, or other shapes. For example, in Figure 3, the battery cell 20 has a cuboid structure.
  • FIG4 is an exploded view of the structure of a battery cell 20 provided in some embodiments of this application
  • FIG5 is a front view of the battery cell 20 provided in some embodiments of this application facing the pressure relief groove 2111 in the thickness direction X of the first wall
  • FIG6 is a partial enlarged view of part A of the battery cell 20 shown in FIG5.
  • This application provides a battery cell 20, which includes a housing 21, electrode terminals 22 and electrode assembly 23.
  • the housing 21 has a first wall 211.
  • the electrode terminals 22 are disposed on the first wall 211.
  • the electrode assembly 23 is housed within the housing 21 and is electrically connected to the electrode terminals 22.
  • the first wall 211 is provided with a pressure relief groove 2111.
  • the first wall 211 is configured to crack along at least part of the pressure relief groove 2111 when the battery cell 20 is depressurized, so as to release the internal pressure of the battery cell 20.
  • the projection of the pressure relief groove 2111 does not overlap with the projection of the electrode terminal 22, and the thickness of the electrode terminal 22 is greater than the thickness of the first wall 211.
  • the outer shell 21 can also be used to contain electrolytes, such as electrolyte solution.
  • the outer shell 21 can have various structural forms, such as a cylinder, cuboid, or prism.
  • the outer shell 21 can be made of various materials, such as copper, iron, aluminum, steel, or aluminum alloy.
  • the housing 21 may include a housing 212 and an end cap 213.
  • the housing 212 has an internal cavity for accommodating the electrode assembly 23 and has an opening 2121. That is, the housing 212 is a hollow structure with an opening 2121 at one end.
  • the end cap 213 covers the opening 2121 of the housing 212 and forms a sealed connection to form a closed space for accommodating the electrode assembly 23 and the electrolyte.
  • the housing 212 includes an integrally formed bottom wall and a side wall.
  • the side wall surrounds the bottom wall, with one end of the side wall connected to the bottom wall and the other end forming an opening 2121.
  • An end cap 213 covers the opening 2121 and is disposed opposite to the bottom wall.
  • the bottom wall and the side wall together define a receiving cavity for accommodating the electrode assembly 23.
  • the first wall 211 which has the pressure relief groove 2111 and the electrode terminal 22, can be the end cap 213 of the outer casing 21 or a wall of the housing 212 of the outer casing 21.
  • the first wall 211 is the end cap 213, that is, the pressure relief groove 2111 is provided on the end cap 213 of the outer casing 21, and correspondingly, the electrode terminal 22 is provided on the end cap 213.
  • the structure of the battery cell 20 is not limited to this.
  • the first wall 211 can also be the bottom wall of the housing 212 that is opposite to the end cap 213 in the thickness direction X of the first wall.
  • the first wall 211 can also be the side wall of the housing 212 that is adjacent to and connected to the end cap 213.
  • the first wall 211 is provided with mounting holes that penetrate the surfaces of both sides of the first wall 211 along the thickness direction X.
  • the mounting holes correspond one-to-one with the electrode terminals 22. At least a portion of the electrode terminals 22 is inserted into the mounting holes or covers the mounting holes along the thickness direction X of the first wall, so that the electrode terminals 22 can be electrically connected to the electrode assembly 23 housed in the housing 21.
  • the first wall 211 is provided with a pressure relief groove 2111, that is, the pressure relief groove 2111 for pressure relief is formed on the first wall 211 by an integral molding process.
  • the pressure relief groove 2111 is a structure formed by machining on the first wall 211, and the bottom wall of the pressure relief groove 2111 is part of the first wall 211.
  • the pressure relief groove 2111 on the first wall 211 can be made by an integral molding process such as stamping or etching.
  • the first wall 211 is configured to crack along at least a portion of the pressure relief groove 2111 when the battery cell 20 is depressurized, so as to release the internal pressure of the battery cell 20. That is, the area of the first wall 211 with the pressure relief groove 2111 forms a weak structure of the first wall 211.
  • This weak structure is a pressure relief structure of the outer shell 21 of the battery cell 20 for releasing the internal pressure of the battery cell 20, so that when the internal pressure or temperature of the battery cell 20 reaches a predetermined value, the first wall 211 can crack along at least a portion of the bottom wall of the pressure relief groove 2111 to release the internal pressure of the battery cell 20.
  • the pressure relief groove 2111 can be disposed on the surface of the first wall 211 facing the electrode assembly 23, or on the surface of the first wall 211 away from the electrode assembly 23.
  • the shape of the pressure relief groove 2111 can be various, such as a strip structure extending along a straight trajectory, a "U”-shaped structure, a “V”-shaped structure, an “S”-shaped structure, an "N”-shaped structure, an "H”-shaped structure, a "Y”-shaped structure, a double “Y”-shaped structure, a rectangular structure, a triangular structure, a circular structure, or an elliptical structure, etc.
  • the pressure relief groove 2111 can be a multi-level groove disposed along the thickness direction X of the first wall, or it can be a single-level groove.
  • the projection of the pressure relief groove 2111 does not overlap with the projection of the electrode terminal 22. That is, in the plane perpendicular to the thickness direction X of the first wall, the orthographic projection of the pressure relief groove 2111 does not overlap with the orthographic projection of the electrode terminal 22.
  • the pressure relief groove 2111 and the electrode terminal 22 are arranged at intervals.
  • the pressure relief groove 2111 is located on one side of the electrode terminal 22 in the first direction Y. That is, the pressure relief groove 2111 and the electrode terminal 22 are arranged along the first direction Y.
  • the battery cell 20 is provided with two electrode terminals 22, and both electrode terminals 22 are provided on the first wall 211, then the two electrode terminals 22 are arranged at intervals along the first direction Y, and the pressure relief groove 2111 is located between the two electrode terminals 22 in the first direction Y.
  • the thickness of the electrode terminal 22 is greater than the thickness of the first wall 211.
  • the overall dimension of the electrode terminal 22 in the thickness direction X of the first wall is greater than the wall thickness of the first wall 211.
  • the electrode assembly 23 When assembling the battery cell 20, the electrode assembly 23 can be placed into the housing 212 first, and the electrolyte can be filled into the housing 212. Then, the end cap 213 can be closed onto the opening 2121 of the housing 212 to complete the assembly of the battery cell 20.
  • the housing 212 can have various shapes, such as a cylinder or a cuboid.
  • the shape of the housing 212 can be determined based on the specific shape of the electrode assembly 23. For example, if the electrode assembly 23 is a cylindrical structure, then the housing 212 can be a cylindrical structure; if the electrode assembly 23 is a cuboid structure, then the housing 212 can be a cylindrical structure. 212 can be a cuboid structure.
  • the end cap 213 can also have various structures, such as a plate-like structure or a hollow structure with one end open. For example, in Figures 3 and 4, the shell 212 is a cuboid structure and the end cap 213 is a rectangular plate-like structure.
  • the outer casing 21 is not limited to the structure described above.
  • the outer casing 21 can also be other structures.
  • the outer casing 21 can include a housing 212 and two end caps 213.
  • the housing 212 is a hollow structure with openings 2121 on opposite sides.
  • One end cap 213 is fitted onto one opening 2121 of the housing 212 and forms a sealed connection to form a closed space for accommodating the electrode assembly 23 and the electrolyte. That is, the housing 212 has openings 2121 on opposite sides, and the two end caps 213 are fitted onto the opposite sides of the housing 212 to close the corresponding openings 2121.
  • the first wall 211 is one of the two end caps 213.
  • the electrode assembly 23 is the component in the battery cell 20 where the electrochemical reaction occurs.
  • the structure of the electrode assembly 23 can be various.
  • the electrode assembly 23 can be a wound structure formed by winding the positive electrode, the separator and the negative electrode, or a stacked structure formed by arranging the positive electrode, the separator and the negative electrode in layers.
  • the separator is a separator membrane
  • the main material of the separator membrane can be selected from at least one of glass fiber, non-woven fabric, polyethylene, polypropylene and polyvinylidene fluoride.
  • a tab 231 is formed at one end of the first wall 211 along the thickness direction X.
  • the tab 231 is used to input or output the positive or negative electrode of the electrode assembly 23 and is used for electrical connection with the electrode terminal 22.
  • the tab 231 of the electrode assembly 23 is a component formed by stacking and connecting the regions of the positive electrode sheet that are not coated with a positive active material layer, or a component formed by stacking and connecting the regions of the negative electrode sheet that are not coated with a negative active material layer.
  • the tab 231 is a component formed by stacking and connecting the regions of the positive electrode sheet that are not coated with a positive active material layer; if the tab 231 is used to output the negative electrode of the electrode assembly 23, then the tab 231 is a component formed by stacking and connecting the regions of the negative electrode sheet that are not coated with a negative active material layer.
  • the material of the tab 231 can be copper or aluminum, etc.
  • the electrode assembly 23 housed within the housing 21 can be one or more.
  • two electrode assemblies 23 are disposed within the housing 21 of the battery cell 20, and the two electrode assemblies 23 are stacked along the second direction Z, that is, the two electrode assemblies 23 are stacked along the thickness direction of the battery cell 20.
  • the electrode assembly 23 housed within the housing 21 can also be one, three, four, five, six, seven, or eight, etc.
  • the thickness direction X of the first wall, the first direction Y, and the second direction Z are mutually perpendicular.
  • the thickness direction X of the first wall is the height direction of the battery cell 20
  • the first direction Y is the length direction of the battery cell 20
  • the second direction Z is the thickness direction of the battery cell 20.
  • the electrode terminal 22 serves to input or output electrical energy of the battery cell 20.
  • the electrode terminal 22 is electrically connected to the tab 231 to input or output electrical energy of the battery cell 20.
  • the electrode terminal 22 is insulated and installed on the first wall 211 of the housing 21, that is, there is no electrical connection between the electrode terminal 22 and the first wall 211 of the housing 21.
  • an insulating element is provided between the electrode terminal 22 and the first wall 211.
  • the insulating element is used to insulate and isolate the electrode terminal 22 and the first wall 211, so as to achieve the insulated installation of the electrode terminal 22 on the first wall 211 of the housing 21.
  • a sealing element is provided between the mounting hole wall of the electrode terminal 22 and the first wall 211. The sealing element is used to seal the gap between the electrode terminal 22 and the mounting hole wall to alleviate the phenomenon of electrolyte leakage from the mounting hole inside the battery cell 20.
  • the battery cell 20 includes two electrode terminals 22, both of which are disposed on the first wall 211.
  • the two electrode terminals 22 are spaced apart along the first direction Y and are located on both sides of the pressure relief groove 2111, that is, the pressure relief groove 2111 is located between the two electrode terminals 22 in the first direction Y.
  • each electrode assembly 23 has two tabs 231, and the polarities of the two tabs 231 are opposite.
  • the two electrode terminals 22 are electrically connected to the two tabs 231 of the electrode assembly 23, respectively, to realize the input or output of the positive and negative electrodes of the battery cell 20.
  • the two electrode terminals 22 may also be disposed on the first wall 211, and the other electrode terminal 22 may be disposed on another wall of the outer casing 21.
  • the electrode terminal 22 can be made of various materials, such as copper, iron, aluminum, steel, or aluminum alloy.
  • the battery cell 20 may also include two current collectors, both of which are disposed within the housing 21. Each current collector is used to connect an electrode terminal 22 and a tab 231 of the same polarity among a plurality of electrode assemblies 23, so as to realize the electrical connection between the electrode terminal 22 and the electrode assembly 23, which helps to reduce the assembly difficulty between the tab 231 and the electrode terminal 22.
  • the material of the current collector can be various, such as copper, iron, aluminum, steel or aluminum alloy.
  • a pressure relief groove 2111 is provided on the first wall 211, so that the first wall 211 can crack along at least part of the pressure relief groove 2111 when the battery cell 20 is depressurized, thereby releasing the internal pressure of the battery cell 20.
  • the electrode terminal 22 is also mounted on the first wall 211, and the thickness of the electrode terminal 22 in the thickness direction X of the first wall is greater than the thickness of the first wall 211. Furthermore, the projection of the electrode terminal 22 in the thickness direction X of the first wall does not overlap with the projection of the pressure relief groove 2111 in the thickness direction X of the first wall. This structure allows the battery cell 20 to incorporate the electrode terminal 22 and the pressure relief structure of the battery cell 20.
  • the structural rigidity of the first wall 211 can be improved through the electrode terminals 22, thereby enhancing the deformation resistance of the first wall 211.
  • This can alleviate the deformation of the first wall 211 during the use of the battery cell 20, thereby reducing the strain and strain amplitude in the area of the first wall 211 where the pressure relief groove 2111 is provided.
  • This can further reduce the occurrence of low-cycle fatigue in the area of the first wall 211 where the pressure relief groove 2111 is provided, thus reducing the risk of fatigue damage in the area of the first wall 211 where the pressure relief groove 2111 is provided. This helps to reduce the risk of premature valve opening in the battery cell 20, thereby improving the service life and reliability of the battery cell 20.
  • the pressure relief groove 2111 and the electrode terminal 22 are arranged along the first direction Y and along the second direction Z.
  • the maximum size of the electrode terminal 22 is D1
  • the maximum size of the first wall 211 is D2 , satisfying that 0.4 ⁇ D1 / D2 ⁇ 0.9 .
  • the thickness direction X of the first wall, the first direction Y, and the second direction Z are perpendicular to each other.
  • the maximum dimension D1 of electrode terminal 22 is the maximum space occupied by electrode terminal 22 in the second direction Z.
  • the projection of electrode terminal 22 onto the thickness direction X of the first wall is rectangular, and the length direction of the projection of electrode terminal 22 onto the thickness direction X of the first wall is the first direction Y. Then, the maximum dimension D1 of electrode terminal 22 is the width of electrode terminal 22 in the second direction Z. Dimensions.
  • the maximum dimension of the first wall 211 is D2, which is the maximum space occupied by the first wall 211 in the second direction Z.
  • the projection of the first wall 211 on the thickness direction X of the first wall is a rectangle, and the length direction of the projection of the first wall 211 on the thickness direction X of the first wall is the first direction Y. Then the maximum dimension of the first wall 211 is D2, which is the width dimension of the first wall 211 in the second direction Z.
  • the electrode terminal 22 may also be of other shapes.
  • FIG7 is a front view of the battery cell 20 provided in some embodiments of the present application facing the pressure relief groove 2111 in the thickness direction X of the first wall.
  • the projection of the electrode terminal 22 in the thickness direction X of the first wall is circular, and the maximum dimension D1 of the electrode terminal 22 is the maximum diameter of the electrode terminal 22.
  • 0.4 ⁇ D1 / D2 ⁇ 0.9 means that the ratio of the maximum dimension D1 of the electrode terminal 22 in the second direction Z to the maximum dimension D2 of the first wall 211 in the second direction Z is between 0.4 and 0.9.
  • the ratio of the maximum dimension D1 of the electrode terminal 22 in the second direction Z to the maximum dimension D2 of the first wall 211 in the second direction Z can be 0.4, 0.42, 0.45, 0.48, 0.5, 0.52, 0.55, 0.6, 0.65, 0.7, 0.75, 0.8, 0.85 or 0.9, etc.
  • a positive electrode slurry was prepared in N-methylpyrrolidone (NMP) by mixing positive electrode active material LiNi 0.7 Co 0.1 Mn 0.1 O 2 , conductive agent Super P, and binder polyvinylidene fluoride (PVDF) with conductive agent Super P.
  • NMP N-methylpyrrolidone
  • the solid content of the positive electrode slurry was 50 wt%, and the mass ratio of LiNi 0.7 Co 0.1 Mn 0.1 O 2 , Super P, and PVDF in the solid composition was 8:1:1.
  • the positive electrode slurry was coated on the upper and lower surfaces of the current collector aluminum foil and dried at 85°C. After cold pressing, the foil was trimmed, cut into sheets, and slit. Finally, it was dried under vacuum at 85°C for 4 hours to produce the positive electrode sheet.
  • Graphite, conductive agent Super P, thickener carboxymethyl cellulose (CMC), and binder styrene-butadiene rubber (SBR) are mixed evenly in deionized water to prepare a negative electrode slurry.
  • the solid content of the negative electrode slurry is 30 wt%, and the mass ratio of graphite, silicon suboxide, Super P, CMC, and binder styrene-butadiene rubber (SBR) in the solid components is 88:7:3:2.
  • the negative electrode slurry is coated on the upper and lower surfaces of the current collector copper foil and dried at 85°C. Then, it is cold-pressed, trimmed, cut into sheets, and slit. Finally, it is dried under vacuum at 120°C for 12 hours to prepare the negative electrode sheet.
  • a 16 ⁇ m polyethylene film was used as the separator.
  • the positive electrode, separator, and negative electrode are stacked in sequence, with the separator positioned between the positive and negative electrodes to isolate them.
  • the electrode assembly 23 is then wound up and placed inside an aluminum shell 21.
  • the electrolyte prepared above is injected into the dried shell 21.
  • the battery cell 20 is then prepared by encapsulation, settling, formation, shaping, and capacity testing.
  • the shell 21 of the battery cell 20 is a cuboid structure, and electrode terminals 22 are installed on the first wall 211 of the shell 21.
  • a pressure relief groove 2111 is provided on the surface of the first wall 211 away from the electrode assembly 23.
  • the pressure relief groove 2111 is "H" shaped and is located on one side of the electrode terminal 22 in the first direction Y.
  • the maximum dimension D1 of the electrode terminal 22 in the second direction Z is 12 mm
  • the maximum dimension D2 of the first wall 211 in the second direction Z is 40 mm, so that the ratio of D1 to D2 is 0.3.
  • the fixture consists of three 10mm steel plates (the first steel plate, the second steel plate, and the third steel plate are arranged in sequence along the second direction Z, and the thickness direction of the first steel plate, the second steel plate, and the third steel plate are all in the second direction Z).
  • the first steel plate and the third steel plate are located at both ends of the fixture and are fixed by bolts.
  • the second steel plate is located between the first steel plate and the third steel plate, and the second steel plate is constrained by the guide rail. The second steel plate can only move in translational direction along its thickness.
  • the battery cell 20 is installed between the first steel plate and the second steel plate (i.e., placed between the first steel plate and the second steel plate in the second direction Z).
  • Support structures are placed between the largest outer surface of one side of the battery cell 20 and the first steel plate, and between the largest outer surface of the other side of the battery cell 20 and the second steel plate (i.e., support structures are placed on both sides of the battery cell 20 in the second direction Z).
  • the support structure can be a heat insulation pad or a water cooling plate (consistent with the material/structure between the battery cells 20 in the actual battery 100).
  • the support structure can be compressed to provide expansion space for the battery cell 20 during charge-discharge cycle aging.
  • the largest outer surface of one side of the battery cell 20 is in contact with the support structure, the first steel plate is in contact with the corresponding support structure, the second steel plate is in contact with the corresponding support structure, and a pressure sensor is provided between the second steel plate and the third steel plate.
  • test procedure shall be carried out in accordance with the "Standard Cycle Life” section 6.4 of "GBT31484-2015 Power Batteries for Electric Vehicles 100 Cycle Life Requirements and Test Methods", and the test cycle cutoff condition shall be changed to "the test shall be stopped when the area where the pressure relief groove 2111 is set on the first wall 211 is damaged".
  • the testing process involves continuously observing the area where the pressure relief groove 2111 is located on the first wall 211 until the area shows signs of damage and leakage. The number of cycles is then recorded as the cycle fatigue count of the battery cell 20.
  • the cycle fatigue count of the battery cell 20 can be used to reasonably predict whether the area where the pressure relief groove 2111 is located on the first wall 211 will crack prematurely during use.
  • Comparative Examples 1-2 and Examples 1-6 show that when the ratio of the maximum dimension D1 of the electrode terminal 22 in the second direction Z to the maximum dimension D2 of the first wall 211 in the second direction Z is less than 0.4, the cycle fatigue number of the battery cell 20 is less than 1000 cycles. This makes the area where the pressure relief groove 2111 of the first wall 211 of the casing 21 is located prone to premature cracking during use, resulting in a short service life of the battery cell 20. However, when the ratio of the maximum dimension D1 of the electrode terminal 22 in the second direction Z to the maximum dimension D2 of the first wall 211 in the second direction Z is greater than or equal to 0.4, the cycle fatigue number of the battery cell 20 can reach more than 1200 cycles.
  • the ratio of the maximum dimension D1 of the electrode terminal 22 in the second direction Z to the maximum dimension D2 of the first wall 211 in the second direction Z is set to be less than or equal to 0.9.
  • the ratio of the maximum dimension of the electrode terminal 22 in the second direction Z to the maximum dimension of the first wall 211 in the second direction Z is 0.4 to 0.9.
  • the ratio of the maximum dimension of the electrode terminal 22 in the second direction Z to the maximum dimension of the first wall 211 in the second direction Z is greater than or equal to 0.4, the space occupied by the electrode terminal 22 in the second direction Z of the first wall 211 can be increased. This is beneficial to enhancing the strengthening effect of the electrode terminal 22 on the structural rigidity of the first wall 211, thereby improving the deformation resistance of the first wall 211.
  • the occurrence of low-cycle fatigue in the region helps reduce the risk of premature valve opening in the battery cell 20, thereby improving the service life and reliability of the battery cell 20.
  • the ratio of the maximum size of the electrode terminal 22 in the second direction Z to the maximum size of the first wall 211 in the second direction Z can be less than or equal to 0.9, the phenomenon that the electrode terminal 22 occupies too much space in the first wall 211 in the second direction Z can be alleviated, thereby reducing the phenomenon that the opening of the mounting hole for mounting the electrode terminal 22 is too large. This can reduce the assembly difficulty of the electrode terminal 22 and the manufacturing difficulty of the mounting hole, thereby reducing the manufacturing difficulty of the battery cell 20. It can also alleviate the phenomenon that the structural strength of the area where the mounting hole is set in the first wall 211 is too low, thereby reducing the risk of the first wall 211 breaking or being damaged during processing, production or use.
  • the maximum size of the electrode terminal 22 is D1
  • the maximum size of the first wall 211 is D2 , which satisfies that 0.6 ⁇ D1 / D2 ⁇ 0.9 .
  • the space occupied by the electrode terminal 22 in the second direction Z of the first wall 211 can be further increased.
  • This is beneficial to further enhance the strengthening effect of the electrode terminal 22 on the structural rigidity of the first wall 211, thereby improving the deformation resistance of the first wall 211.
  • This can further alleviate the deformation phenomenon of the first wall 211 during the use of the battery cell 20, thereby reducing the strain and strain amplitude in the area of the first wall 211 where the pressure relief groove 2111 is provided.
  • This can further reduce the phenomenon of low-cycle fatigue in the area of the first wall 211 where the pressure relief groove 2111 is provided, which is beneficial to further reduce the risk of premature valve opening of the battery cell 20, thereby improving the service life and reliability of the battery cell 20.
  • the outer edge of the first wall 211 includes a first edge 2112.
  • the first edge 2112 and the pressure relief groove 2111 are respectively located on both sides of the electrode terminal 22 in the first direction Y, which is perpendicular to the thickness direction X of the first wall.
  • the minimum distance between the pressure relief groove 2111 and the electrode terminal 22 is L1
  • the minimum distance between the pressure relief groove 2111 and the first edge 2112 is L2 , satisfying that 0.2 ⁇ L1 / L2 ⁇ 0.8.
  • the outer edge of the first wall 211 includes a first edge 2112.
  • the first edge 2112 and the pressure relief groove 2111 are located on both sides of the electrode terminal 22 in the first direction Y. That is, the first edge 2112 is the edge of one side of the first wall 211 in the first direction Y.
  • the pressure relief groove 2111, the electrode terminal 22 and the first edge 2112 are arranged sequentially along the first direction Y.
  • the projection of the first wall 211 on the thickness direction X of the first wall is a rectangle, and the length direction of the projection of the first wall 211 on the thickness direction X of the first wall is the first direction Y.
  • the first edge 2112 is formed at both ends of the first wall 211 on the first direction Y.
  • L2 is the distance on the first direction Y between the area where the electrode terminal 22 is provided between the pressure relief groove 2111 and the first edge 2112.
  • two electrode terminals 22 are provided on the first wall 211, and a pressure relief groove 2111 is provided between the two electrode terminals 22 in the first direction Y.
  • L1 is the distance between the pressure relief groove 2111 and one of the electrode terminals 22 in the first direction Y
  • L2 is the distance between the pressure relief groove 2111 and the area where the corresponding electrode terminal 22 is provided between the first edge 2112 in the first direction Y. That is to say, the values of L1 and L2 are both based on the same electrode terminal 22.
  • the first edge 2112 is the edge of the projection of the first wall 211 on the thickness direction X of the first wall on the first direction Y; if the first wall 211 is the bottom wall of the shell 212, then the first edge 2112 is the outer surface of the shell 212 connected to one end of the first wall 211 on the first direction Y, away from the electrode assembly 23. That is to say, the rounded or chamfered area formed at the edge of the first wall 211 belongs to the first wall 211.
  • the minimum distance L1 between the pressure relief groove 2111 and the electrode terminal 22 is the spacing between the pressure relief groove 2111 and the electrode terminal 22 in the first direction Y.
  • the minimum distance L2 between the pressure relief groove 2111 and the first edge 2112 is the spacing between the pressure relief groove 2111 and the first edge 2112 in the first direction Y.
  • 0.2 ⁇ L 1 /L 2 ⁇ 0.8 means that the ratio of the minimum distance between the pressure relief groove 2111 and the electrode terminal 22 in the first direction Y to the minimum distance between the pressure relief groove 2111 and the first edge 2112 in the first direction Y is 0.2 to 0.8.
  • the ratio of the minimum distance between the pressure relief groove 2111 and the electrode terminal 22 in the first direction Y to the minimum distance between the pressure relief groove 2111 and the first edge 2112 in the first direction Y can be 0.2, 0.22, 0.25, 0.28, 0.3, 0.32, 0.35, 0.4, 0.45, 0.5, 0.55, 0.6, 0.65, 0.7, 0.75 or 0.8, etc.
  • a positive electrode slurry was prepared in N-methylpyrrolidone (NMP) by mixing positive electrode active material LiNi 0.7 Co 0.1 Mn 0.1 O 2 , conductive agent Super P, and binder polyvinylidene fluoride (PVDF) with conductive agent Super P.
  • NMP N-methylpyrrolidone
  • the solid content of the positive electrode slurry was 50 wt%, and the mass ratio of LiNi 0.7 Co 0.1 Mn 0.1 O 2 , Super P, and PVDF in the solid composition was 8:1:1.
  • the positive electrode slurry was coated on the upper and lower surfaces of the current collector aluminum foil and dried at 85°C. After cold pressing, the foil was trimmed, cut into sheets, and slit. Finally, it was dried under vacuum at 85°C for 4 hours to produce the positive electrode sheet.
  • Graphite, conductive agent Super P, thickener carboxymethyl cellulose (CMC), and binder styrene-butadiene rubber (SBR) are mixed evenly in deionized water to prepare a negative electrode slurry.
  • the solid content of the negative electrode slurry is 30 wt%, and the mass ratio of graphite, silicon suboxide, Super P, CMC, and binder styrene-butadiene rubber (SBR) in the solid components is 88:7:3:2.
  • the negative electrode slurry is coated on the upper and lower surfaces of the current collector copper foil and dried at 85°C. Then, it is cold-pressed, trimmed, cut into sheets, and slit. Finally, it is dried under vacuum at 120°C for 12 hours to prepare the negative electrode sheet.
  • a 16 ⁇ m polyethylene film was used as the separator.
  • the positive electrode, separator, and negative electrode are stacked in sequence, with the separator positioned between the positive and negative electrodes to isolate them.
  • the electrode assembly 23 is then wound up and placed inside an aluminum casing 21.
  • the electrolyte prepared above is injected into the dried casing 21.
  • the battery cell 20 is then prepared through encapsulation, settling, formation, shaping, and capacity testing.
  • the casing 21 of the battery cell 20 has a cuboid structure, and electrode terminals 22 are mounted on the first wall 211.
  • a pressure relief groove 2111 is provided on the surface of the first wall 211 facing away from the electrode assembly 23.
  • the pressure relief groove 2111 is H-shaped and located on one side of the electrode terminal 22 in the first direction Y.
  • the minimum distance L1 between the pressure relief groove 2111 and the electrode terminal 22 in the first direction Y is 5 mm, and the minimum distance L1 between the pressure relief groove 2111 and the first edge 2112 in the first direction Y is...
  • the distance L2 is 30mm so that the ratio of L1 to L2 is 0.167.
  • the preparation methods of the battery cells 20 in Comparative Examples 4-5 and Examples 7-11 are the same as those in Comparative Example 3.
  • the difference lies in the minimum distance L1 between the pressure relief groove 2111 and the electrode terminal 22 in the first direction Y and the minimum distance L2 between the pressure relief groove 2111 and the first edge 2112 in the first direction Y, so that the ratio of L1 to L2 is different.
  • the specific situation is shown in Table 2.
  • the fixture consists of three 10mm steel plates (the first steel plate, the second steel plate, and the third steel plate are arranged in sequence along the second direction Z, and the thickness direction of the first steel plate, the second steel plate, and the third steel plate are all in the second direction Z).
  • the first steel plate and the third steel plate are located at both ends of the fixture and are fixed by bolts.
  • the second steel plate is located between the first steel plate and the third steel plate, and the second steel plate is constrained by the guide rail. The second steel plate can only move in translational direction along its thickness.
  • the battery cell 20 is installed between the first steel plate and the second steel plate (i.e., placed between the first steel plate and the second steel plate in the second direction Z).
  • Support structures are placed between the largest outer surface of one side of the battery cell 20 and the first steel plate, and between the largest outer surface of the other side of the battery cell 20 and the second steel plate (i.e., support structures are placed on both sides of the battery cell 20 in the second direction Z).
  • the support structure can be a heat insulation pad or a water cooling plate (consistent with the material/structure between the battery cells 20 in the actual battery 100).
  • the support structure can be compressed to provide expansion space for the battery cell 20 during charge-discharge cycle aging.
  • the largest outer surface of one side of the battery cell 20 is in contact with the support structure, the first steel plate is in contact with the corresponding support structure, the second steel plate is in contact with the corresponding support structure, and a pressure sensor is provided between the second steel plate and the third steel plate.
  • test procedure shall be carried out in accordance with the "Standard Cycle Life” section 6.4 of "GBT31484-2015 Power Batteries for Electric Vehicles 100 Cycle Life Requirements and Test Methods", and the test cycle cutoff condition shall be changed to "the test shall be stopped when the area where the pressure relief groove 2111 is set on the first wall 211 is damaged".
  • the testing process involves continuously observing the area where the pressure relief groove 2111 is located on the first wall 211 until the area shows signs of damage and leakage. The number of cycles is then recorded as the cycle fatigue count of the battery cell 20.
  • the cycle fatigue count of the battery cell 20 can be used to reasonably predict whether the area where the pressure relief groove 2111 is located on the first wall 211 will crack prematurely during use.
  • the ratio of the minimum distance L1 between the pressure relief groove 2111 and the electrode terminal 22 in the first direction Y and the minimum distance L2 between the pressure relief groove 2111 and the first edge 2112 in the first direction Y is also greater than 0.8.
  • the ratio of 2 is less than or equal to 0.8, the number of cycles of fatigue of the battery cell 20 can approach 1200, thereby reducing the premature cracking of the area where the pressure relief groove 2111 is set on the first wall 211 of the casing 21 during use, which is beneficial to improving the service life of the battery cell 20.
  • the ratio of the minimum distance L1 between the pressure relief groove 2111 and the electrode terminal 22 in the first direction Y and the minimum distance L2 between the pressure relief groove 2111 and the first edge 2112 in the first direction Y is set to be less than or equal to 0.8.
  • the ratio of the minimum distance L1 between the pressure relief groove 2111 and the electrode terminal 22 in the first direction Y and the minimum distance L2 between the pressure relief groove 2111 and the first edge 2112 in the first direction Y is less than or equal to 0.2, although the cycle fatigue number of the battery cell 20 is higher, it will cause the pressure relief groove 2111 and the electrode terminal 22 to be closer together.
  • the thermal runaway gas inside the battery cell 20 is very likely to impact the busbar connected to the electrode terminal 22, thereby causing the insulation layer on the busbar to be damaged.
  • the ratio of the minimum distance L1 between the pressure relief groove 2111 and the electrode terminal 22 in the first direction Y and the minimum distance L2 between the pressure relief groove 2111 and the first edge 2112 in the first direction Y is set to be greater than or equal to 0.2.
  • the ratio of the minimum distance between the pressure relief groove 2111 and the electrode terminal 22 in the first direction Y to the minimum distance between the pressure relief groove 2111 and the first edge 2112 in the first direction Y is 0.2 to 0.8.
  • the ratio of the minimum distance between the pressure relief groove 2111 and the electrode terminal 22 in the first direction Y to the minimum distance between the pressure relief groove 2111 and the first edge 2112 in the first direction Y is less than or equal to 0.8, the pressure relief groove 2111 is closer to the electrode terminal 22 in the first direction Y. This enhances the structural stiffness of the area where the pressure relief groove 2111 is located on the first wall 211, which helps reduce the strain and strain amplitude in this area.
  • the impact of thermal runaway gas inside battery cell 20 on electrode terminal 22 and other components connected to electrode terminal 22 can be reduced. This can reduce the risk of short circuit or thermal diffusion caused by damage to electrode terminal 22 and other components connected to electrode terminal 22, thereby improving the reliability of battery cell 20.
  • the minimum distance between the pressure relief groove 2111 and the electrode terminal 22 is L1
  • the minimum distance between the pressure relief groove 2111 and the first edge 2112 is L2 , which satisfies 0.2 ⁇ L1 / L2 ⁇ 0.6 .
  • the ratio of the minimum distance L1 between the pressure relief groove 2111 and the electrode terminal 22 in the first direction Y and the minimum distance L2 between the pressure relief groove 2111 and the first edge 2112 in the first direction Y is further set to be less than or equal to 0.6 .
  • the pressure relief groove 2111 can be further close to the electrode terminal 22 in the first direction Y, thereby further enhancing the structural stiffness of the area where the pressure relief groove 2111 is provided on the first wall 211.
  • the pressure relief groove 2111 and the electrode terminal 22 are arranged along a first direction Y, which is perpendicular to the thickness direction X of the first wall.
  • first direction Y the minimum distance between the pressure relief groove 2111 and the electrode terminal 22 is L1
  • the thickness of the portion of the first wall 211 located between the pressure relief groove 2111 and the electrode terminal 22 is D, satisfying 3 ⁇ L1 / D ⁇ 30.
  • the thickness D (not shown in the figure) of the portion of the first wall 211 located between the pressure relief groove 2111 and the electrode terminal 22 is the dimension of the portion of the first wall 211 located between the pressure relief groove 2111 and the electrode terminal 22 along the first direction Y in the thickness direction X of the first wall, and is also the wall thickness of the portion of the first wall 211 located between the pressure relief groove 2111 and the electrode terminal 22 in the first direction Y.
  • 3 ⁇ L 1 /D ⁇ 30 means that the ratio of the minimum distance between the pressure relief groove 2111 and the electrode terminal 22 in the first direction Y to the wall thickness of the portion of the first wall 211 located between the pressure relief groove 2111 and the electrode terminal 22 in the first direction Y is 3 to 30.
  • the ratio of the minimum distance between the pressure relief groove 2111 and the electrode terminal 22 in the first direction Y to the wall thickness of the portion of the first wall 211 located between the pressure relief groove 2111 and the electrode terminal 22 in the first direction Y can be 3, 3.5, 4, 4.5, 5, 5.5, 6, 7, 8, 9, 10, 12, 12.5, 15, 16, 18, 20, 21, 22, 25, 26, 28, 29 or 30, etc.
  • a positive electrode slurry was prepared in N-methylpyrrolidone (NMP) by mixing positive electrode active material LiNi 0.7 Co 0.1 Mn 0.1 O 2 , conductive agent Super P, and binder polyvinylidene fluoride (PVDF) with conductive agent Super P.
  • NMP N-methylpyrrolidone
  • the solid content of the positive electrode slurry was 50 wt%, and the mass ratio of LiNi 0.7 Co 0.1 Mn 0.1 O 2 , Super P, and PVDF in the solid composition was 8:1:1.
  • the positive electrode slurry was coated on the upper and lower surfaces of the current collector aluminum foil and dried at 85°C. After cold pressing, the foil was trimmed, cut into sheets, and slit. Finally, it was dried under vacuum at 85°C for 4 hours to produce the positive electrode sheet.
  • Graphite, conductive agent Super P, thickener carboxymethyl cellulose (CMC), and binder styrene-butadiene rubber (SBR) are mixed evenly in deionized water to prepare a negative electrode slurry.
  • the solid content of the negative electrode slurry is 30 wt%, and the mass ratio of graphite, silicon suboxide, Super P, CMC, and binder styrene-butadiene rubber (SBR) in the solid components is 88:7:3:2.
  • the negative electrode slurry is coated on the upper and lower surfaces of the current collector copper foil and dried at 85°C. Then, it is cold-pressed, trimmed, cut into sheets, and slit. Finally, it is dried under vacuum at 120°C for 12 hours to prepare the negative electrode sheet.
  • a 16 ⁇ m polyethylene film was used as the separator.
  • the positive electrode, separator, and negative electrode are stacked in sequence, with the separator positioned between the positive and negative electrodes to isolate them.
  • the electrode assembly 23 is then wound up and placed inside an aluminum casing 21.
  • the electrolyte prepared above is injected into the dried casing 21.
  • the process includes encapsulation, settling, formation, shaping, and capacity testing to complete the fabrication of the battery cell 20.
  • the casing 21 of the battery cell 20 has a cuboid structure, and electrode terminals 22 are mounted on the first wall 211 of the casing 21.
  • a pressure relief groove 2111 is provided on the surface of the first wall 211 facing away from the electrode assembly 23.
  • the pressure relief groove 2111 is H-shaped and located on one side of the electrode terminal 22 in the first direction Y.
  • the minimum distance L between the pressure relief groove 2111 and the electrode terminal 22 in the first direction Y of the battery cell 20 in Comparative Example 6 is... L1 is 28mm, and the thickness D of the portion of the first wall 211 located between the pressure relief groove 2111 and the electrode terminal 22 is 0.8mm, so that the ratio of L1 to D is 35.
  • the preparation method of the battery cell 20 in Examples 12-18 is the same as that in Comparative Example 6.
  • the difference is that the minimum distance L1 between the pressure relief groove 2111 and the electrode terminal 22 in the first direction Y and the thickness D of the portion of the first wall 211 located between the pressure relief groove 2111 and the electrode terminal 22 are different, so that the ratio of L1 to D is different.
  • the specific situation is shown in Table 3.
  • the fixture consists of three 10mm steel plates (the first steel plate, the second steel plate, and the third steel plate are arranged in sequence along the second direction Z, and the thickness direction of the first steel plate, the second steel plate, and the third steel plate are all in the second direction Z).
  • the first steel plate and the third steel plate are located at both ends of the fixture and are fixed by bolts.
  • the second steel plate is located between the first steel plate and the third steel plate, and the second steel plate is constrained by the guide rail. The second steel plate can only move in translational direction along its thickness.
  • the battery cell 20 is installed between the first steel plate and the second steel plate (i.e., placed between the first steel plate and the second steel plate in the second direction Z).
  • Support structures are placed between the largest outer surface of one side of the battery cell 20 and the first steel plate, and between the largest outer surface of the other side of the battery cell 20 and the second steel plate (i.e., support structures are placed on both sides of the battery cell 20 in the second direction Z).
  • the support structure can be a heat insulation pad or a water cooling plate (consistent with the material/structure between the battery cells 20 in the actual battery 100).
  • the support structure can be compressed to provide expansion space for the battery cell 20 during charge-discharge cycle aging.
  • the largest outer surface of one side of the battery cell 20 is in contact with the support structure, the first steel plate is in contact with the corresponding support structure, the second steel plate is in contact with the corresponding support structure, and a pressure sensor is provided between the second steel plate and the third steel plate.
  • test procedure shall be carried out in accordance with the "Standard Cycle Life” section 6.4 of "GBT31484-2015 Power Batteries for Electric Vehicles 100 Cycle Life Requirements and Test Methods", and the test cycle cutoff condition shall be changed to "the test shall be stopped when the area where the pressure relief groove 2111 is set on the first wall 211 is damaged".
  • the testing process involves continuously observing the area where the pressure relief groove 2111 is located on the first wall 211 until the area shows signs of damage and leakage. The number of cycles is then recorded as the cycle fatigue count of the battery cell 20.
  • the cycle fatigue count of the battery cell 20 can be used to reasonably predict whether the area where the pressure relief groove 2111 is located on the first wall 211 will crack prematurely during use.
  • the ratio of the minimum distance L1 between the pressure relief groove 2111 and the electrode terminal 22 in the first direction Y to the thickness D of the portion of the first wall 211 located between the pressure relief groove 2111 and the electrode terminal 22 is less than or equal to 30, the number of cyclic fatigue cycles of the battery cell 20 can approach 1200, thereby reducing the number of cyclic fatigue cycles in the area where the pressure relief groove 2111 is located on the first wall 211 of the casing 21 during use.
  • the occurrence of premature cracking is beneficial to improving the service life of the battery cell 20.
  • the ratio of the minimum distance L1 between the pressure relief groove 2111 and the electrode terminal 22 in the first direction Y and the thickness D of the portion of the first wall 211 located between the pressure relief groove 2111 and the electrode terminal 22 is set to be less than or equal to 30.
  • the ratio of the minimum distance L1 between the pressure relief groove 2111 and the electrode terminal 22 in the first direction Y and the thickness D of the portion of the first wall 211 located between the pressure relief groove 2111 and the electrode terminal 22 is set to be greater than or equal to 3.
  • the ratio of the minimum distance between the pressure relief groove 2111 and the electrode terminal 22 in the first direction Y to the thickness of the portion of the first wall 211 located between the pressure relief groove 2111 and the electrode terminal 22 is 3 to 30.
  • the ratio of the minimum distance between the pressure relief groove 2111 and the electrode terminal 22 in the first direction Y to the thickness of the portion of the first wall 211 located between the pressure relief groove 2111 and the electrode terminal 22 is mitigated.
  • the excessive thickness of the portion of the first wall 211 located between the pressure relief groove 2111 and the electrode terminal 22 is a problem.
  • the ratio of the minimum distance between the pressure relief groove 2111 and the electrode terminal 22 in the first direction Y to the thickness of the portion of the first wall 211 located between the pressure relief groove 2111 and the electrode terminal 22 is greater than or equal to 3
  • the phenomenon of the minimum distance between the pressure relief groove 2111 and the electrode terminal 22 in the first direction Y being too small and the thickness of the portion of the first wall 211 located between the pressure relief groove 2111 and the electrode terminal 22 being too large can be alleviated.
  • This can alleviate the phenomenon of excessive waste of the thickness of the first wall 211, thereby reducing the manufacturing cost of the battery cell 20.
  • the impact of thermal runaway gas inside the battery cell 20 on the electrode terminal 22 and other components connected to the electrode terminal 22 can be reduced. This can reduce the risk of short circuit or thermal diffusion caused by damage to the electrode terminal 22 and other components connected to the electrode terminal 22, thereby improving the reliability of the battery cell 20.
  • the minimum distance between the pressure relief groove 2111 and the electrode terminal 22 is L1
  • the thickness of the portion of the first wall 211 located between the pressure relief groove 2111 and the electrode terminal 22 is D, which satisfies 5 ⁇ L1 /D ⁇ 25.
  • the ratio of the minimum distance L1 between the pressure relief groove 2111 and the electrode terminal 22 in the first direction Y and the thickness D of the portion of the first wall 211 located between the pressure relief groove 2111 and the electrode terminal 22 is further set to be less than or equal to 25.
  • the ratio of the minimum distance L1 between the pressure relief groove 2111 and the electrode terminal 22 in the first direction Y and the thickness D of the portion of the first wall 211 located between the pressure relief groove 2111 and the electrode terminal 22 is less than 5
  • the change in the cycle fatigue number of the battery cell 20 is no longer significant.
  • the ratio of the minimum distance L1 between the pressure relief groove 2111 and the electrode terminal 22 in the first direction Y and the thickness D of the portion of the first wall 211 located between the pressure relief groove 2111 and the electrode terminal 22 is set to be greater than or equal to 5.
  • the ratio of the minimum distance between the pressure relief groove 2111 and the electrode terminal 22 in the first direction Y to the thickness of the portion of the first wall 211 located between the pressure relief groove 2111 and the electrode terminal 22 is set to be greater than or equal to 5.
  • the thickness of the portion of the first wall 211 located between the pressure relief groove 2111 and the electrode terminal 22 is D, satisfying 0.8mm ⁇ D ⁇ 4mm.
  • the thickness D of the portion of the first wall 211 located between the pressure relief groove 2111 and the electrode terminal 22 can be 0.8mm, 0.9mm, 1mm, 1.1mm, 1.2mm, 1.3mm, 1.5mm, 1.8mm, 2mm, 2.2mm, 2.5mm, 3mm, 3.5mm or 4mm, etc.
  • the thickness of the portion of the first wall 211 located between the pressure relief groove 2111 and the electrode terminal 22 is greater than or equal to 0.8 mm and less than or equal to 4 mm, on the one hand, the structural strength of the portion of the first wall 211 located between the pressure relief groove 2111 and the electrode terminal 22 can be improved, thereby reducing the risk of the first wall 211 breaking or being damaged during use. On the other hand, it can reduce the phenomenon of excessive waste of the thickness of the first wall 211, which is beneficial to reducing the manufacturing difficulty and manufacturing cost of the first wall 211.
  • the pressure relief groove 2111 and the electrode terminal 22 are arranged along a first direction Y, which is perpendicular to the thickness direction X of the first wall.
  • the minimum distance between the pressure relief groove 2111 and the electrode terminal 22 is L1 , satisfying 10mm ⁇ L1 ⁇ 100mm.
  • the minimum distance L1 between the pressure relief groove 2111 and the electrode terminal 22 can be 10mm, 12mm, 15mm, 18mm, 20mm, 25mm, 30mm, 35mm, 40mm, 45mm, 50mm, 55mm, 60mm, 65mm, 70mm, 75mm, 80mm, 85mm, 90mm, 95mm or 100mm, etc.
  • the minimum distance between the pressure relief groove 2111 and the electrode terminal 22 in the first direction Y is 10mm to 100mm.
  • the pressure relief groove 2111 is relatively close to the electrode terminal.
  • the diameter is set to be greater than or equal to 10 mm to alleviate the phenomenon that the pressure relief groove 2111 is too close to the electrode terminal 22.
  • the minimum distance between the pressure relief groove 2111 and the electrode terminal 22 is L1 , which satisfies 15mm ⁇ L1 ⁇ 50mm .
  • the minimum distance between the pressure relief groove 2111 and the electrode terminal 22 in the first direction Y is 15mm to 50mm.
  • the pressure relief groove 2111 is brought closer to the electrode terminal 22. This further enhances the structural stiffness of the area where the pressure relief groove 2111 is located on the first wall 211, which helps reduce the strain and strain amplitude in this area. This further reduces the occurrence of low-cycle fatigue in this area, thereby further reducing the risk of premature valve opening in the battery cell 20, and thus effectively...
  • the first wall 211 can further reduce the impact of thermal runaway gas inside the battery cell 20 on the electrode terminal 22 and other components connected to the electrode terminal 22 when at least part of the first wall 211 cracks along the pressure relief groove 2111 to release the internal pressure of the battery cell 20. This can further reduce the risk of short circuit or thermal diffusion caused by damage to the electrode terminal 22 and other components connected to the electrode terminal 22, thereby improving the reliability of the battery cell 20.
  • the battery cell 20 may include two electrode terminals 22, both of which are disposed on a first wall 211 and are spaced apart along a first direction Y, which is perpendicular to the thickness direction X of the first wall.
  • a pressure relief groove 2111 is located between the two electrode terminals 22 along the first direction Y.
  • the pressure relief groove 2111 is located between the two electrode terminals 22. That is to say, one electrode terminal 22, the pressure relief groove 2111, and the other electrode terminal 22 are arranged sequentially along the first direction Y.
  • the first wall 211 may also have only one electrode terminal 22, and the other electrode terminal 22 may be disposed on other walls of the housing 21. That is, the two electrode terminals 22 of the battery cell 20 may be disposed on two different walls of the housing 21.
  • the two electrode terminals 22 can further enhance the structural stiffness of the area of the first wall 211 where the pressure relief groove 2111 is provided. This helps to reduce the strain and strain amplitude of the area of the first wall 211 where the pressure relief groove 2111 is provided, thereby further reducing the occurrence of low-cycle fatigue in the area of the first wall 211 where the pressure relief groove 2111 is provided. This further reduces the risk of premature valve opening in the battery cell 20 and helps to improve the service life and reliability of the battery cell 20.
  • the minimum distance between the pressure relief groove 2111 and the two electrode terminals 22 is equal along the first direction Y. That is, the minimum distance L1 between the pressure relief groove 2111 and any one of the electrode terminals 22 in the first direction Y is the same.
  • the two electrode terminals 22 can achieve similar strengthening effects on the structural stiffness of the area where the pressure relief groove 2111 is provided on the first wall 211. This is conducive to further reducing the strain and strain amplitude of the area where the pressure relief groove 2111 is provided on the first wall 211, so as to alleviate the phenomenon of low-cycle fatigue in the area where the pressure relief groove 2111 is provided on the first wall 211, thereby further reducing the risk of premature valve opening of the battery cell 20.
  • the first wall 211 is provided with mounting holes (not shown in the figure).
  • the mounting holes penetrate the first wall 211 along the thickness direction X, and each mounting hole corresponds to an electrode terminal 22.
  • the electrode terminal 22 includes a cylindrical portion, a first limiting portion, and a second limiting portion (not shown in the figure).
  • the cylindrical portion passes through the mounting holes along the thickness direction X of the first wall, and the cylindrical portion connects the first limiting portion and the second limiting portion. Both the first limiting portion and the second limiting portion protrude from the outer peripheral surface of the cylindrical portion.
  • the first limiting portion and the second limiting portion are located on both sides of the first wall 211, and at least a portion of the projection of the first limiting portion and the projection of the second limiting portion overlaps with the first wall 211.
  • the mounting holes correspond one-to-one with the electrode terminals 22, meaning that each electrode terminal 22 is installed in one mounting hole.
  • the column portion connects the first limiting portion and the second limiting portion. Both the first limiting portion and the second limiting portion protrude from the outer peripheral surface of the column portion. That is, the column portion is a structure that extends along the thickness direction X of the first wall and is inserted into the mounting hole. The two ends of the column portion in the thickness direction X of the first wall are respectively connected to the first limiting portion and the second limiting portion. At the same time, the first limiting portion and the second limiting portion protrude from the outer peripheral surface of the column portion. That is, the projection of the first limiting portion and the second limiting portion in the thickness direction X of the first wall is located on the outside of the column portion.
  • the first limiting part and the second limiting part are respectively located on both sides of the first wall 211, and at least a portion of the projection of the first limiting part and the projection of the second limiting part overlap with the first wall 211. That is, the first limiting part and the second limiting part are respectively located on both sides of the first wall 211 and cooperate to clamp the first wall 211 to fasten the electrode terminal 22 to the first wall 211.
  • an insulating member is provided between the first limiting part and the second limiting part and the first wall 211 so that the electrode terminal 22 is insulated and installed on the first wall 211.
  • the electrode terminal 22 is provided with a first limiting part and a second limiting part, as well as a column part connecting the first limiting part and the second limiting part.
  • the column part passes through the mounting hole of the first wall 211, and the first limiting part and the second limiting part are respectively located on both sides of the first wall 211 and overlap at least part of the first wall 211, so as to fasten and install the electrode terminal 22 on the first wall 211.
  • the electrode terminal 22 with this structure can improve the structural stability and reliability of the electrode terminal 22 on the first wall 211, and further enhance the structural rigidity of the area of the first wall 211 where the pressure relief groove 2111 is provided.
  • the projection of the first wall 211 in the thickness direction X of the first wall is rectangular.
  • the first wall 211 has a larger dimension in the first direction Y than in the second direction Z.
  • the thickness directions X, Y, and Z of the first wall are perpendicular to each other.
  • the pressure relief grooves 2111 and the electrode terminals 22 are arranged along the first direction Y.
  • the projection of the first wall 211 in the thickness direction X is rectangular.
  • the dimension of the first wall 211 in the first direction Y is greater than the dimension of the first wall 211 in the second direction Z. That is to say, the first wall 211 is a rectangular plate structure, and the first direction Y is the length direction of the first wall 211, while the second direction Z is the width direction of the first wall 211.
  • the pressure relief groove 2111 and the electrode terminal 22 are arranged along the first direction Y, that is, the pressure relief groove 2111 and the electrode terminal 22 are arranged along the length direction of the first wall 211.
  • the first wall 211 has a rectangular structure.
  • the difficulty of installing the electrode terminal 22 and setting the pressure relief groove 2111 on the first wall 211 can be reduced, so that the first wall 211 has enough space to set the electrode terminal 22 and the pressure relief groove 2111 in the first direction Y.
  • the electrode terminal 22 can strengthen the structural stiffness of the first wall 211 in the direction in which the first wall 211 is most prone to deformation, which is conducive to further improving the deformation resistance of the first wall 211, thereby reducing the strain and strain amplitude in the area of the first wall 211 where the pressure relief groove 2111 is set, thereby further reducing the phenomenon of low-cycle fatigue in the area of the first wall 211 where the pressure relief groove 2111 is set, and further reducing the risk of premature valve opening of the battery cell 20.
  • the housing 21 is rectangular and has two second walls 214.
  • the two second walls 214 are arranged opposite each other along the second direction Z and are respectively connected to the two ends of the first wall 211.
  • the surface of the second wall 214 facing away from the electrode assembly 23 is the surface with the largest area on the outer surface of the housing 21.
  • the second wall 214 consists of two walls of the outer shell 21 that are respectively connected to the two ends of the first wall 211 in the second direction Z, and the two second walls 214 are arranged at intervals along the second direction Z and are parallel to each other.
  • the surface of the second wall 214 facing away from the electrode assembly 23 is the surface with the largest area on the outer surface of the outer shell 21. That is, the length direction and the width direction of the second wall 214 are the length direction and the width direction of the outer shell 21 of the battery cell 20, respectively, so that the arrangement direction of the two second walls 214 is the thickness direction of the battery cell 20, that is, the second direction Z is the thickness direction of the battery cell 20.
  • the outer shell 21 is cuboid in shape and has two second walls 214 arranged opposite each other in the second direction Z.
  • the surface of the second wall 214 facing away from the electrode assembly 23 is the surface with the largest area on the outer surface of the outer shell 21.
  • This is beneficial to further improve the deformation resistance of the first wall 211 and reduce the strain and strain amplitude in the area where the pressure relief groove 2111 is provided on the first wall 211. This can further reduce the phenomenon of low-cycle fatigue in the area where the pressure relief groove 2111 is provided on the first wall 211, and further reduce the risk of premature valve opening of the battery cell 20.
  • the pressure relief groove 2111 is stamped into the first wall 211. That is, the pressure relief groove 2111 is a groove structure formed in the first wall 211 by a stamping process.
  • the pressure relief groove 2111 formed on the first wall 211 can also be formed by processing techniques such as laser etching or milling.
  • the forming method of the pressure relief groove 2111 on the first wall 211 is simple, which is beneficial to reducing the manufacturing cost of the battery cell 20.
  • FIG8 is a partial cross-sectional view of the first wall 211 of the casing 21 of the battery cell 20 provided in some embodiments of this application.
  • the pressure relief groove 2111 includes a multi-level groove arranged sequentially along the thickness direction X of the first wall. That is, the pressure relief groove 2111 is a multi-level stepped groove structure arranged along the thickness direction X of the first wall, that is, the pressure relief groove 2111 is a stepped groove structure formed by multiple stamping.
  • the pressure relief groove 2111 is a two-stage stepped groove structure, that is, the pressure relief groove 2111 includes two levels of grooves arranged sequentially along the thickness direction X of the first wall.
  • the pressure relief groove 2111 can also be a three-stage stepped groove, a four-stage stepped groove, a five-stage stepped groove, or a six-stage stepped groove, etc.
  • each groove segment is a multi-level stepped groove structure.
  • the pressure relief groove 2111 includes a first groove segment 2111a and two second groove segments 2111b, where both the first groove segment 2111a and the two second groove segments 2111b are multi-level stepped groove structures.
  • the entire pressure relief groove 2111 is a multi-level stepped groove structure.
  • the pressure relief groove 2111 is a groove structure formed by multiple processing steps.
  • the pressure relief groove 2111 can reduce the depth of a single processing step for the same depth, which helps to reduce the manufacturing difficulty and the demand for manufacturing equipment, thereby reducing manufacturing costs. It can also reduce the forming force on the first wall 211 during a single processing step, which helps to reduce the risk of cracks in the first wall 211 and improve the production quality of the battery cell 20.
  • it can improve the material flow pattern during the formation of the pressure relief groove 2111, which is beneficial to the flow of materials generated during the formation of the pressure relief groove 2111 and improves the structural consistency of the pressure relief groove 2111.
  • the minimum residual thickness of the pressure relief groove 2111 along the thickness direction X of the first wall is D3 , which satisfies 0.05mm ⁇ D3 ⁇ 0.3mm .
  • the minimum residual thickness D3 of the pressure relief groove 2111 is the minimum thickness of the area corresponding to the bottom surface of the pressure relief groove 2111 in the thickness direction X of the first wall 211.
  • the bottom of the pressure relief groove 2111 forms a first weak part 2111c
  • the minimum residual thickness D3 of the pressure relief groove 2111 is the minimum thickness D3 of the first weak part 2111c in the thickness direction X of the first wall.
  • the pressure relief groove 2111 has multiple grooves, and the minimum residual thickness D3 of the pressure relief groove 2111 is the thickness of the bottom wall of the deepest first-level groove in the thickness direction X of the first wall of the pressure relief groove 2111.
  • the minimum residual thickness D3 of the pressure relief groove 2111 can be 0.05mm, 0.06mm, 0.07mm, 0.08mm, 0.09mm, 0.1mm, 0.12mm, 0.15mm, 0.16mm, 0.18mm, 0.2mm, 0.22mm, 0.25mm, 0.28mm or 0.3mm, etc.
  • the minimum residual thickness of the pressure relief groove 2111 in the thickness direction X of the first wall is 0.05mm to 0.3mm, which on the one hand...
  • the minimum residual thickness of the pressure relief groove 2111 in the thickness direction X of the first wall is set to be greater than or equal to 0.05 mm to alleviate the phenomenon that the structural strength of the area where the pressure relief groove 2111 is provided in the first wall 211 is too small. This can reduce the risk of cracking or damage in the area where the pressure relief groove 2111 is provided in the first wall 211 during production, transportation or normal use.
  • the minimum residual thickness of the pressure relief groove 2111 in the thickness direction X of the first wall is less than or equal to 0.3 mm, the problem of the difficulty of the first wall 211 cracking along the pressure relief groove 2111 when the battery cell 20 experiences thermal runaway is alleviated. This can reduce the burst pressure required for the battery cell 20 to release pressure and open the valve, thereby reducing the risk of explosion caused by excessive burst pressure of the battery cell 20.
  • the battery cell 20 may further include an electrolyte contained within the housing 21.
  • the electrolyte includes an electrolyte salt, including hexafluorophosphate, wherein the molar concentration of hexafluorophosphate is less than or equal to 1.1 mol/L.
  • the molar concentration of hexafluorophosphate in the electrolyte can be 0.1 mol/L, 0.2 mol/L, 0.25 mol/L, 0.3 mol/L, 0.4 mol/L, 0.5 mol/L, 0.6 mol/L, 0.7 mol/L, 0.8 mol/L, 0.9 mol/L, 1 mol/L, or 1.1 mol/L, etc.
  • hexafluorophosphate in the electrolyte is easily oxidized or reduced during use, generating unstable compounds and acidic substances, such as hydrofluoric acid, which is a common example.
  • Hydrofluoric acid is a highly corrosive inorganic acid that has a strong corrosive effect on the outer shell 21.
  • the amount of hydrofluoric acid generated by the battery cell 20 during use can be reduced, thereby reducing the corrosion of the area where the pressure relief groove 2111 is provided on the first wall 211.
  • a first weak portion 2111c is formed at the bottom of the pressure relief groove 2111, and a first wall 211 is configured to crack along at least a portion of the first weak portion 2111c when the battery cell 20 is depressurized.
  • the first wall 211 is also provided with a guide groove 2114, and a second weak portion 2114a is formed at the bottom of the guide groove 2114.
  • the projection of the pressure relief groove 2111 and the projection of at least one guide groove 2114 together define at least one predetermined pressure relief area 2113.
  • the second weak portion 2114a is configured to guide at least a portion of the predetermined pressure relief area 2113 to flip over, thereby opening at least a portion of the predetermined pressure relief area 2113.
  • the bottom of the pressure relief groove 2111 forms a first weak part 2111c.
  • the first wall 211 is configured to crack along at least part of the first weak part 2111c when the battery cell 20 is depressurized. That is, the bottom wall of the pressure relief groove 2111 is the first weak part 2111c, and the first weak part 2111c is the remaining part of the first wall 211 where the pressure relief groove 2111 is set, so that the first wall 211 can crack along at least part of the bottom wall of the pressure relief groove 2111 when the battery cell 20 is depressurized, thereby releasing the internal pressure of the battery cell 20.
  • the bottom of the guide groove 2114 forms a second weak part 2114a, that is, the bottom wall of the guide groove 2114 is the second weak part 2114a, and the second weak part 2114a is the remaining part of the first wall 211 where the guide groove 2114 is set.
  • the projection of the pressure relief groove 2111 and the projection of at least one guide groove 2114 together define at least one predetermined pressure relief area 2113. That is, at least one predetermined pressure relief area 2113 is formed within the area enclosed by the pressure relief groove 2111 and the guide groove 2114.
  • the pressure relief groove 2111 and the guide groove 2114 define two predetermined pressure relief areas 2113, and the two predetermined pressure relief areas 2113 are arranged at intervals along the second direction Z.
  • the pressure relief groove 2111 is a structure provided along the edge of the predetermined pressure relief area 2113, such that the setting trajectory of the pressure relief groove 2111 is provided along the edge of the predetermined pressure relief area 2113, so that the first wall 211 can be cracked along the edge of the predetermined pressure relief area 2113.
  • the predetermined pressure relief area 2113 is the area enclosed by the projection of the pressure relief groove 2111 on the thickness direction X of the first wall, the projection of the extension line of the pressure relief groove 2111 on the thickness direction X of the first wall, the projection of the guide groove 2114 on the thickness direction X of the first wall, and the projection of the extension of the guide groove 2114 on the thickness direction X of the first wall.
  • the pressure relief groove 2111 may consist of only one groove segment, or it may be a structure formed by connecting multiple groove segments.
  • the pressure relief groove 2111 and the guide groove 2114 may be grooves extending along a straight trajectory, or they may be grooves extending along a non-straight trajectory.
  • the second weak portion 2114a is configured to guide at least a portion of the predetermined pressure relief zone 2113 to flip, thereby opening at least a portion of the predetermined pressure relief zone 2113. That is, after the first wall 211 cracks along the first weak portion 2111c at the bottom of the pressure relief groove 2111 and the predetermined pressure relief zone 2113 is opened, at least a portion of the predetermined pressure relief zone 2113 can be flipped about the second weak portion 2114a as an axis, so that after the predetermined pressure relief zone 2113 is flipped, the interior and exterior of the outer casing 21 can be connected to each other for pressure relief.
  • a guide groove 2114 is also provided on the first wall 211.
  • the projection of the guide groove 2114 and the pressure relief groove 2111 along the thickness direction X of the first wall defines at least one predetermined pressure relief area 2113 on the first wall 211.
  • the predetermined pressure relief area 2113 can be opened after the first wall 211 is at least partially cracked along the pressure relief groove 2111, and can be flipped around the second weak part 2114a at the bottom of the guide groove 2114 to release the internal pressure of the battery cell 20.
  • the battery cell 20 with this structure can expand the flip angle of the predetermined pressure relief area 2113 after it is opened, thereby effectively increasing the pressure relief area of the battery cell 20, thereby improving the pressure relief rate of the battery cell 20 when thermal runaway occurs, and thus reducing the risk of fire and explosion caused by untimely pressure relief of the battery cell 20, which is beneficial to improving the reliability of the battery cell 20.
  • the pressure relief groove 2111 and the electrode terminal 22 are arranged along the first direction Y, and the pressure relief groove 2111 and the guide groove 2114 are arranged along the second direction Z.
  • the thickness direction X of the first wall, the first direction Y, and the second direction Z are perpendicular to each other.
  • the pressure relief groove 2111 and the electrode terminal 22 are arranged along the first direction Y, and the pressure relief groove 2111 and the guide groove 2114 are arranged along the second direction Z. That is, in the second direction Z, at least one side of the pressure relief groove 2111 is provided with the guide groove 2114, and the guide groove 2114 can be a structure that is in contact with or spaced from the pressure relief groove 2111.
  • the pressure relief groove 2111 defines two predetermined pressure relief areas 2113 arranged at intervals along the second direction Z.
  • the pressure relief groove 2111 is provided with guide grooves 2114 on both sides in the second direction Z, such that the pressure relief groove 2111 is located between the two guide grooves 2114 in the second direction Z, and each predetermined pressure relief area 2113 corresponds to one guide groove 2114.
  • the guide groove 2114 and the pressure relief groove 2111 along the second direction Z, such that the guide groove 2114 is located on at least one side of the pressure relief groove 2111 in the second direction Z, the influence of the guide groove 2114 on the structural rigidity of the area of the first wall 211 between the electrode terminal 22 and the pressure relief groove 2111 can be reduced.
  • This is beneficial to improving the strengthening effect of the electrode terminal 22 on the structural rigidity of the area of the first wall 211 where the pressure relief groove 2111 is provided.
  • the interference between the pressure relief groove 2111 and the guide groove 2114 can be reduced, so that the pressure relief groove 2111 and the guide groove 2114 can be processed separately.
  • the phenomenon of 2114a can also enhance the effect of the predetermined pressure relief zone 2113 being opened and then flipping around the second weak part 2114a.
  • the pressure relief groove 2111 and the guide groove 2114 are spaced apart along the second direction Z. That is, the orthographic projections of the pressure relief groove 2111 and the guide groove 2114 in a plane perpendicular to the thickness direction X of the first wall are spaced apart along the second direction Z, such that the projections of the pressure relief groove 2111 and the guide groove 2114 on the thickness direction X of the first wall are spaced apart along the second direction Z.
  • the guide groove 2114 is located on one side of the pressure relief groove 2111 in the second direction Z, and there is a gap between them.
  • the first wall 211 is provided with two guide grooves 2114.
  • the two guide grooves 2114 are arranged at intervals along the second direction Z and are respectively located on both sides of the pressure relief groove 2111 in the second direction Z.
  • the two guide grooves 2114 and the pressure relief groove 2111 are both spaced apart in the second direction Z.
  • the pressure relief groove 2111 and the guide groove 2114 do not contact each other.
  • this can reduce the mutual influence between the pressure relief groove 2111 and the guide groove 2114 during the processing, and can also reduce the stress influence between the area of the first wall 211 where the pressure relief groove 2111 is set and the area of the first wall 211 where the guide groove 2114 is set.
  • the guide groove 2114 extends along the first direction Y, and the two ends of the pressure relief groove 2111 extend from the two ends of the guide groove 2114 along the first direction Y.
  • the two ends of the guide groove 2114 extend to the two ends of the pressure relief groove 2111, that is, the size of the guide groove 2114 in the first direction Y is larger than that of the pressure relief groove 2111, and the two ends of the guide groove 2114 in the first direction Y extend to the two sides of the pressure relief groove 2111.
  • the pressure relief groove 2111 includes a first groove segment 2111a and two second groove segments 2111b
  • the two ends of the guide groove 2114 in the first direction Y extend to the two sides of the two second groove segments 2111b.
  • the projection of the guide groove 2114 is set to extend beyond the two ends of the projection of the pressure relief groove 2111 in its extending direction. This results in the guide groove 2114 having two ends that extend beyond the two ends of the pressure relief groove 2111 in its extending direction.
  • the flipping effect of the pressure zone 2113 can increase the pressure relief area of the battery cell 20, thereby improving the pressure relief rate of the battery cell 20 when thermal runaway occurs.
  • it can improve the absorption effect of the guide groove 2114 on the residual material extruded from the pressure relief groove 2111 of the first wall 211 during the molding process, and can also improve the separation effect of the guide groove 2114 between the pressure relief groove 2111 and the edge of the first wall 211, so as to improve the blocking effect of the guide groove 2114 on the deformation energy of the battery cell 20 when the battery cell 20 is subjected to internal and external impact forces.
  • the projection of the guide groove 2114 does not overlap with the projection of the electrode terminal 22.
  • the interference between the guide groove 2114 and the electrode terminal 22 can be reduced, and the manufacturing difficulty of the battery cell 20 can be reduced.
  • the thickness of the second weak portion 2114a is greater than the thickness of the first weak portion 2111c, that is, the residual thickness of the guide groove 2114 is greater than the residual thickness of the pressure relief groove 2111.
  • the thickness of the bottom wall of the guide groove 2114 is greater than the thickness of the bottom wall of the pressure relief groove 2111. That is, along the thickness direction X of the first wall, the depth of the pressure relief groove 2111 is greater than the depth of the guide groove 2114.
  • the first weak part 2111c includes multiple weak segments, and the bottom wall of each groove segment of the pressure relief groove 2111 is a weak segment of the first weak part 2111c; in an embodiment where the pressure relief groove 2111 includes only one smooth groove segment, the first weak part 2111c includes only one weak segment.
  • the residual thickness of the guide groove 2114 is greater than the residual thickness of the pressure relief groove 2111. This results in the structural strength of the area of the first wall 211 where the pressure relief groove 2111 is located being less than the structural strength of the area of the first wall 211 where the guide groove 2114 is located. This allows the first wall 211 to preferentially crack along the first weak portion 2111c at the bottom of the pressure relief groove 2111 and release the internal pressure of the battery cell 20. This helps to alleviate the phenomenon that the pressure relief effect of the battery cell 20 is poor due to the first wall 211 cracking from the area where the guide groove 2114 is located.
  • the thickness of the second weak portion 2114a is D4 , which satisfies 0.15mm ⁇ D4 ⁇ 0.5mm .
  • the thickness D4 of the second weak part 2114a is the thickness of the area in the thickness direction X of the first wall 211 where the guide groove 2114 is provided and the bottom surface of the guide groove 2114 is corresponding to.
  • the thickness D4 of the second weak portion 2114a is the thickness of the bottom wall of the guide groove 2114 in the thickness direction X of the first wall.
  • the thickness D4 of the second weak portion 2114a is the wall thickness of the bottom wall of the deepest single-stage groove in the thickness direction X of the first wall of the guide groove 2114.
  • the thickness D4 of the second weak portion 2114a can be 0.15mm, 0.16mm, 0.17mm, 0.18mm, 0.19mm, 0.2mm, 0.22mm, 0.25mm, 0.28mm, 0.3mm, 0.35mm, 0.4mm, 0.45mm or 0.5mm, etc.
  • the thickness of the second weak portion 2114a in the thickness direction X of the first wall is 0.15mm to 0.5mm.
  • the thickness of the second weak portion 2114a in the thickness direction X of the first wall is 0.15mm to 0.5mm.
  • the structural strength of the area where the guide groove 2114 is provided on the first wall 211 is improved. This mitigates the phenomenon of accidental cracking of the first wall 211 in the area where the guide groove 2114 is provided when the battery cell 20 experiences thermal runaway, thereby improving the reliability and stability of the battery cell 20.
  • the thickness of the second weak portion 2114a in the thickness direction X of the first wall is set to be greater than or equal to 0.15mm. This mitigates the phenomenon of accidental cracking of the first wall 211 in the area where the guide groove 2114 is provided on the first wall 211 when the battery cell 20 experiences thermal runaway, thereby improving the reliability and stability of the battery cell 20.
  • the thickness of 14a in the thickness direction X of the first wall is set to be less than or equal to 0.5 mm.
  • the first weak portion 2111c includes at least one weak segment, the cross-sectional area of which perpendicular to its extension direction is a first cross-sectional area S1 , and the cross-sectional area of the second weak portion 2114a perpendicular to its extension direction is a second cross-sectional area S2 . So, S 1 ⁇ S 2 .
  • the pressure relief groove 2111 includes three groove segments, and the corresponding first weak part 2111c includes three weak segments, with the bottom of each groove segment of the pressure relief groove 2111 forming a weak segment.
  • the first cross-sectional area S1 is the product of the width of the weak segment in the direction perpendicular to the extension direction of the weak segment and the thickness direction X of the first wall, and the thickness of the weak segment in the thickness direction X of the first wall. If the weak segment is a structure extending along the first direction Y, then the first cross-sectional area S1 is the product of the width of the weak segment in the second direction Z and the thickness of the weak segment in the thickness direction X of the first wall; if the weak segment is a structure extending along the second direction Z, then the first cross-sectional area S1 is the product of the width of the weak segment in the first direction Y and the thickness of the weak segment in the thickness direction X of the first wall.
  • the second cross-sectional area S2 is the product of the width of the second weak portion 2114a in the direction perpendicular to the extension direction of the second weak portion 2114a and the thickness direction X of the first wall, and the thickness of the second weak portion 2114a in the thickness direction X of the first wall.
  • the guide groove 2114 is a structure extending along the first direction Y.
  • the second weak portion 2114a formed at the bottom of the guide groove 2114 is a structure extending along the first direction Y. Therefore, the second cross-sectional area S2 is the product of the width of the second weak portion 2114a in the second direction Z and the thickness of the second weak portion 2114a in the thickness direction X of the first wall.
  • the structural strength of the area where the pressure relief groove 2111 is provided on the first wall 211 is less than the structural strength of the area where the guide groove 2114 is provided on the first wall 211.
  • pressure relief groove 2111 and guide groove 2114 are respectively disposed on both sides of the first wall 211. That is, pressure relief groove 2111 and guide groove 2114 are respectively disposed on the surfaces of the first wall 211 on both sides in the thickness direction X of the first wall.
  • the pressure relief groove 2111 may be disposed on the side of the first wall 211 facing the interior of the outer casing 21, and correspondingly, the guide groove 2114 may be disposed on the side of the first wall 211 away from the interior of the outer casing 21.
  • the pressure relief groove 2111 may also be disposed on the side of the first wall 211 away from the interior of the outer casing 21, and correspondingly, the guide groove 2114 may be disposed on the side of the first wall 211 facing the interior of the outer casing 21.
  • the pressure relief groove 2111 and the guide groove 2114 may both be located on the same side of the first wall 211 in the thickness direction X of the first wall.
  • the side surface of the guide groove 2114 is set at an obtuse angle to the bottom surface of the guide groove 2114 to facilitate the forming of the guide groove 2114.
  • the side surface of the pressure relief groove 2111 is set at an obtuse angle to the bottom surface of the pressure relief groove 2111 to facilitate the forming of the pressure relief groove 2111.
  • the pressure relief groove 2111 is a multi-level groove structure arranged along the thickness direction X of the first wall, that is, the pressure relief groove 2111 is a stepped groove structure, and the side surface of each level of the groove is set at an obtuse angle to the bottom surface.
  • a pressure relief groove 2111 is disposed on the side of the first wall 211 facing away from the electrode assembly 23 along the thickness direction X of the first wall. That is, the pressure relief groove 2111 is disposed on the outer surface of the first wall 211 facing away from the interior of the housing 21.
  • the pressure relief groove 2111 is set on the outer surface of the first wall 211, which facilitates the processing of the pressure relief groove 2111 on the first wall 211, thereby reducing the processing difficulty of the pressure relief groove 2111 and improving the production efficiency of the battery cell 20.
  • a guide groove 2114 is disposed on the side of the first wall 211 facing the electrode assembly 23 along the thickness direction X of the first wall. That is, the guide groove 2114 is disposed on the inner surface of the first wall 211 facing the interior of the housing 21.
  • the guide groove 2114 is set on the inner surface of the first wall 211, so that the predetermined pressure relief area 2113 can be flipped to the outside of the outer shell 21 after being opened around the second weak part 2114a at the bottom of the guide groove 2114. This reduces the interference effect of the side of the guide groove 2114 on the predetermined pressure relief area 2113 during the flipping process, which is beneficial to improving the flipping effect of the predetermined pressure relief area 2113.
  • the pressure relief groove 2111 includes a first groove segment 2111a and two second groove segments 2111b.
  • the two second groove segments 2111b are arranged opposite each other along the first direction Y, and the second groove segments 2111b and the guide groove 2114 are arranged along the second direction Z.
  • the first groove segment 2111a connects the two second groove segments 2111b.
  • the thickness direction X of the first wall, the first direction Y and the second direction Z are perpendicular to each other.
  • the projections of the first groove segment 2111a, the two second groove segments 2111b, the projections of the extension lines of the two second groove segments 2111b, and the projection of the guide groove 2114 together enclose the predetermined pressure relief area 2113; or, along the thickness direction X of the first wall, the projections of the first groove segment 2111a, the two second groove segments 2111b, the projection of the guide groove 2114, and the projection of the extension line of the guide groove 2114 together enclose the predetermined pressure relief area 2113; or, along the thickness direction X of the first wall, the projections of the first groove segment 2111a, the two second groove segments 2111b, the projections of the extension lines of the two second groove segments 2111b, the projection of the guide groove 2114, and the projection of the extension line of the guide groove 2114 together enclose the predetermined pressure relief area 2113.
  • the two second slot segments 2111b are arranged opposite each other along the first direction Y, that is, the two second slot segments 2111b are arranged at intervals along the first direction Y.
  • both second slot segments 2111b extend along the second direction Z.
  • the minimum distance L1 between the pressure relief groove 2111 and the electrode terminal 22 in the first direction Y is the same as the minimum distance between the second groove segment 2111b and the electrode terminal 22 in the first direction Y.
  • the minimum distance L2 between the pressure relief groove 2111 and the first edge 2112 in the first direction Y is the same as the minimum distance between the second groove segment 2111b and the first edge 2112 in the first direction Y.
  • the first slot segment 2111a connects to two second slot segments 2111b. That is, the first slot segment 2111a is located between the two second slot segments 2111b in the first direction Y, and the two ends of the first slot segment 2111a are respectively connected to the two second slot segments 2111b.
  • the first slot segment 2111a may also extend two second slot segments 2111b from its two ends in the first direction Y.
  • the predetermined pressure relief zone 2113 is the projection of the first groove segment 2111a onto the thickness direction X of the first wall, and two... The area enclosed by the projection of the second groove segment 2111b onto the thickness direction X of the first wall, the projection of the extension lines of the two second groove segments 2111b onto the thickness direction X of the first wall, and the projection of the guide groove 2114 onto the thickness direction X of the first wall, and the structure in which the first groove segment 2111a and the two second groove segments 2111b are arranged along the edge of the predetermined pressure relief area 2113, so that the predetermined pressure relief area 2113 can be opened with the first groove segment 2111a and the two second groove segments 2111b as the boundary.
  • the part of the first wall 211 located in the predetermined pressure relief area 2113 can be opened with the first groove segment 2111a and the two second groove segments 2111b as the boundary when the battery cell 20 is depressurized, thereby releasing the internal pressure of the battery cell 20.
  • the structure of the battery cell 20 is not limited to this.
  • the predetermined pressure relief area 2113 can also be the area formed by the projection of the first groove segment 2111a on the thickness direction X of the first wall, the projection of the two second groove segments 2111b on the thickness direction X of the first wall, the projection of the guide groove 2114 on the thickness direction X of the first wall, and the projection of the extension line of the guide groove 2114 on the thickness direction X of the first wall.
  • it can be the area formed by the projection of the first groove segment 2111a on the thickness direction X of the first wall, the projection of the two second groove segments 2111b on the thickness direction X of the first wall, the projection of the extension line of the two second groove segments 2111b on the thickness direction X of the first wall, the projection of the guide groove 2114 on the thickness direction X of the first wall, and the projection of the extension line of the guide groove 2114 on the thickness direction X of the first wall.
  • the pressure relief groove 2111 formed by the first groove segment 2111a and the two second groove segments 2111b can be an "H" shaped structure, and two guide grooves 2114 are provided on the first wall 211.
  • the two guide grooves 2114 are respectively located on both sides of the pressure relief groove 2111 in the second direction Z, so as to form two predetermined pressure relief areas 2113 on the first wall 211, and the two predetermined pressure relief areas 2113 are respectively located on both sides of the first groove segment 2111a in the second direction Z.
  • the pressure relief groove 2111 can also be other shapes.
  • one end of the two second groove segments 2111b is respectively connected to both ends of the first groove segment 2111a, so as to enclose and form a predetermined pressure relief area 2113 on the first wall 211, so that the shape of the pressure relief groove 2111 formed by the first groove segment 2111a and the two second groove segments 2111b is a "U" shaped structure.
  • the battery cell 20 with this structure is convenient for processing pressure relief grooves 2111 on the first wall 211 and forming a predetermined pressure relief area 2113.
  • the predetermined pressure relief area 2113 defined by the pressure relief grooves 2111 of this structure is easier to rotate around the position of the guide groove 2114. On the other hand, it makes the intersection of the first groove segment 2111a and the second groove segment 2111b weaker, making it easier to crack and open the predetermined pressure relief area 2113 for pressure relief.
  • the first wall 211 is provided with two guide grooves 2114 along the second direction Z, and the first groove segment 2111a is located between the two guide grooves 2114.
  • the connection positions of the two second groove segments 2111b to the first groove segment 2111a are offset from the two ends of the two second groove segments 2111b, so that a predetermined pressure relief zone 2113 is formed on both sides of the first groove segment 2111a along the second direction Z.
  • connection positions of the two second groove segments 2111b and the first groove segment 2111a are all offset from the two ends of the two second groove segments 2111b. That is, the first groove segment 2111a is connected between the two ends of the second groove segment 2111b, so that the pressure relief groove 2111 formed by the first groove segment 2111a and the two second groove segments 2111b has an approximately "H" shaped structure.
  • each guide groove 2114 is located on both sides of the pressure relief groove 2111. That is, the pressure relief groove 2111 is provided with guide grooves 2114 on both sides of the second direction Z, and each guide groove 2114 corresponds to a predetermined pressure relief area 2113, so that each guide groove 2114 can guide the corresponding predetermined pressure relief area 2113 to flip.
  • the first groove segment 2111a and the two second groove segments 2111b form a pressure relief groove 2111 with an "H"-shaped structure.
  • This allows a predetermined pressure relief area 2113 to be formed on both sides of the first groove segment 2111a of the pressure relief groove 2111.
  • the two predetermined pressure relief areas 2113 can be opened in a split manner to relieve pressure when the battery cell 20 is depressurized, which is beneficial to further increase the pressure relief effect of the battery cell 20 and can effectively improve the pressure relief rate of the battery cell 20.
  • FIG9 is a front view of the battery cell 20 provided in some embodiments of the present application facing the pressure relief groove 2111 in the thickness direction X of the first wall.
  • One end of a second groove segment 2111b is connected to one end of a first groove segment 2111a
  • one end of another second groove segment 2111b is connected to the other end of the first groove segment 2111a. That is, one end of each of the two second groove segments 2111b is connected to both ends of the first groove segment 2111a, so that the pressure relief groove 2111 formed by the first groove segment 2111a and the two second groove segments 2111b has a "U" shaped structure.
  • a second groove segment 2111b, a first groove segment 2111a, and another second groove segment 2111b are arranged in a sequentially connected structure so that the first groove segment 2111a and the two second groove segments 2111b form a pressure relief groove 2111 with a "U"-shaped structure.
  • This helps to reduce the processing difficulty of the pressure relief groove 2111 and also helps to expand the area of the predetermined pressure relief area 2113.
  • the pressure relief area of the battery cell 20 can be increased, thereby improving the pressure relief rate of the battery cell 20.
  • the first groove segment 2111a and the two second groove segments 2111b both extend along a straight trajectory, and the first groove segment 2111a and the two second groove segments 2111b are perpendicular to each other. That is, the extension direction of the first groove segment 2111a is perpendicular to the extension direction of the second groove segments 2111b.
  • the pressure relief groove 2111 formed by the first groove segment 2111a and the two second groove segments 2111b together has a regular "H" shape, and a predetermined pressure relief area 2113 is formed on both sides of the first groove segment 2111a along the second direction Z.
  • the areas of the two predetermined pressure relief areas 2113 can be the same or different.
  • the first groove segment 2111a is a straight line structure extending along the first direction Y
  • the second groove segment 2111b is a straight line structure extending along the second direction Z
  • the first groove segment 2111a is located between the two second groove segments 2111b along the first direction Y.
  • the extension direction of the first groove segment 2111a is the arrangement direction of the two second groove segments 2111b, thereby improving the regularity of the shape of the pressure relief groove 2111, which helps to reduce the processing difficulty of the pressure relief groove 2111, thereby reducing the manufacturing cost of the battery cell 20 and improving the production efficiency of the battery cell 20.
  • FIG10 is a front view of a battery cell 20 in the thickness direction X of the first wall facing the pressure relief groove 2111 according to other embodiments of this application.
  • the pressure relief groove 2111 includes a first groove segment 2111a and a second groove segment 2111b, which are connected.
  • the projection of the first groove segment 2111a, the projection of the extension line of the first groove segment 2111a, the projection of the second groove segment 2111b, the projection of the extension line of the second groove segment 2111b, and the projection of the guide groove 2114 together enclose a predetermined pressure relief area 2113; or, along the thickness direction X of the first wall, the projection of the first groove segment 2111a, the projection of the second groove segment 2111b, the projection of the guide groove 2114, and the projection of the extension line of the guide groove 2114 together enclose a predetermined pressure relief area 2113; or, along the thickness direction X of the first wall, the projection of the first groove segment 2111a, the projection of the second groove segment 2111b, the projection of the guide groove 2114, and the projection of the extension line of the guide groove 2114
  • one end of the first groove segment 2111a and one end of the second groove segment 2111b are connected to form a "V"-shaped pressure relief groove 2111.
  • the pressure relief groove 2111 defines only one predetermined pressure relief area 2113, and the first wall 211 is provided with only one guide groove 2114, which is correspondingly provided with the predetermined pressure relief area 2113.
  • the shape of the pressure relief groove 2111 formed by the interconnection of the first groove segment 2111a and the second groove segment 2111b can also be a "T"-shaped structure, an "L”-shaped structure, or an "X"-shaped structure, etc.
  • the predetermined pressure relief zone 2113 is the area formed by the projection of the first groove segment 2111a on the thickness direction X of the first wall, the projection of the extension line of the first groove segment 2111a on the thickness direction X of the first wall, the projection of the second groove segment 2111b on the thickness direction X of the first wall, the projection of the extension line of the second groove segment 2111b on the thickness direction X of the first wall, and the projection of the guide groove 2114 on the thickness direction X of the first wall.
  • the structure of the battery cell 20 is not limited to this.
  • the predetermined pressure relief area 2113 can also be the area formed by the projection of the first groove segment 2111a on the thickness direction X of the first wall, the projection of the second groove segment 2111b on the thickness direction X of the first wall, the projection of the guide groove 2114 on the thickness direction X of the first wall, and the projection of the extension line of the guide groove 2114 on the thickness direction X of the first wall.
  • it can be the area formed by the projection of the first groove segment 2111a on the thickness direction X of the first wall, the projection of the extension line of the first groove segment 2111a on the thickness direction X of the first wall, the projection of the second groove segment 2111b on the thickness direction X of the first wall, the projection of the extension line of the second groove segment 2111b on the thickness direction X of the first wall, the projection of the guide groove 2114 on the thickness direction X of the first wall, and the projection of the extension line of the guide groove 2114 on the thickness direction X of the first wall.
  • the battery cell 20 with this structure can increase the pressure relief area of the battery cell 20 to improve the pressure relief rate of the battery cell 20.
  • it makes the intersection of the first groove segment 2111a and the second groove segment 2111b weaker, making it easier to crack and open the predetermined pressure relief area 2113 to release the internal pressure of the battery cell 20.
  • FIG11 is a front view of a battery cell 20 provided in further embodiments of this application, facing the pressure relief groove 2111 along the thickness direction X of the first wall.
  • the pressure relief groove 2111 is a groove extending along an arcuate trajectory.
  • the projection of the pressure relief groove 2111, the projection of the extension line of the pressure relief groove 2111, and the projection of the guide groove 2114 together enclose a predetermined pressure relief area 2113; or, along the thickness direction X of the first wall, the projection of the pressure relief groove 2111, the projection of the guide groove 2114, and the projection of the extension line of the guide groove 2114 together enclose a predetermined pressure relief area 2113; or, along the thickness direction X of the first wall, the projection of the pressure relief groove 2111, the projection of the extension line of the pressure relief groove 2111, the projection of the guide groove 2114, and the projection of the extension line of the guide groove 2114 together enclose a predetermined pressure relief area 2113.
  • the pressure relief groove 2111 is a groove that extends along an arc-shaped trajectory. That is to say, the pressure relief groove 2111 includes only a smooth groove segment, and the pressure relief groove 2111 has an arc-shaped groove structure.
  • the predetermined pressure relief area 2113 is the area formed by the projection of the pressure relief groove 2111 on the thickness direction X of the first wall, the projection of the extension line of the pressure relief groove 2111 on the thickness direction X of the first wall, and the projection of the guide groove 2114 on the thickness direction X of the first wall.
  • the structure of the battery cell 20 is not limited to this.
  • the predetermined pressure relief area 2113 may also be the area formed by the projection of the pressure relief groove 2111 on the thickness direction X of the first wall, the projection of the guide groove 2114 on the thickness direction X of the first wall, and the projection of the extension line of the guide groove 2114 on the thickness direction X of the first wall, or it may be the area formed by the projection of the pressure relief groove 2111 on the thickness direction X of the first wall, the projection of the extension line of the pressure relief groove 2111 on the thickness direction X of the first wall, the projection of the guide groove 2114 on the thickness direction X of the first wall, and the projection of the extension line of the guide groove 2114 on the thickness direction X of the first wall.
  • the pressure relief groove 2111 has a "C" shaped structure.
  • the predetermined pressure relief area 2113 is formed on the inner side of the pressure relief groove 2111.
  • the pressure relief groove 2111 with this structure is easy to manufacture on the first wall 211, which helps to reduce the manufacturing difficulty of the battery cell 20.
  • the guide groove 2114 is stamped into the first wall 211. That is, the guide groove 2114 is a groove structure formed in the first wall 211 by a stamping process.
  • the guide groove 2114 formed on the first wall 211 can also be formed by processing techniques such as laser etching or milling.
  • the forming method of the guide groove 2114 on the first wall 211 is simple, which is beneficial to reducing the manufacturing cost of the battery cell 20.
  • the first wall 211 is configured to support the electrode assembly 23 along the thickness direction X of the first wall. That is, in the thickness direction X of the first wall, the first wall 211 of the housing 21 is located at the bottom of the electrode assembly 23, and the thickness direction X of the first wall is the direction of gravity or approximately the direction of gravity.
  • the first wall 211 can support the electrode assembly 23 in the thickness direction X of the first wall, so that the battery cell 20 can be placed upside down.
  • this allows the battery cell 20 to adapt to more usage scenarios, thereby improving the adaptability of the battery cell 20.
  • it enables the pressure relief groove 2111 and the electrode terminal 22 of the battery cell 20 to be located at the bottom of the battery cell 20, so as to facilitate assembly and release of internal pressure of the battery cell 20.
  • the housing 21 may include a housing 212 and an end cap 213.
  • the housing 212 has an internal cavity with an opening 2121 for housing the nanoelectrode assembly 23.
  • the end cap 213 closes the opening 2121 and is a first wall 211.
  • the end cap 213 is the first wall 211, that is, the pressure relief groove 2111 is provided on the end cap 213 of the outer shell 21, and correspondingly, the electrode terminal 22 is also provided on the end cap 213 of the outer shell 21.
  • the battery cell 20 with this structure is convenient to set the pressure relief groove 2111 and install the electrode terminal 22 on the end cap 213, which helps to reduce the manufacturing difficulty of the battery cell 20 and improve the production efficiency of the battery cell 20.
  • the structure of the battery cell 20 is not limited to this; in some embodiments, the battery cell 20 can also have other structures.
  • the housing 21 may include a housing 212 and an end cap 213.
  • the housing 212 has an internal cavity with an opening 2121 for housing the nanoelectrode assembly 23.
  • the end cap 213 closes the opening 2121.
  • the housing 212 includes a first wall 211.
  • the shell 212 includes integrally formed side walls and a bottom wall, meaning that the shell 212 is manufactured using an integral forming process, such as stamping, casting, or extrusion molding.
  • the side walls and bottom wall of the shell 212 are a single, integral structure.
  • the shell 212 includes a first wall 211, which can be the bottom wall of the shell 212 or one of the multiple side walls of the shell 212.
  • the battery cell 20 with this structure can make the area of the outer casing 21 with the pressure relief groove 2111 far away from the end cap 213.
  • This can effectively alleviate the stress generated by the connection between the end cap 213 and the casing 212 on the area of the first wall 211 with the pressure relief groove 2111, thereby reducing the impact on the area of the first wall 211 with the pressure relief groove 2111.
  • This helps to reduce the risk of cracking or structural strength reduction in the area of the first wall 211 with the pressure relief groove 2111 under stress, thereby improving the service life and reliability of the battery cell 20.
  • the outer casing 21 may include a housing 212 and two end caps 213.
  • the housing 212 has an internal cavity for accommodating the electrode assembly 23. Both ends of the housing 212 have openings 2121, and both openings 2121 communicate with the cavity.
  • the two end caps 213 respectively close the two openings 2121.
  • One of the end caps 213 is a first wall 211.
  • the housing 212 of the outer casing 21 has openings 2121 at both opposite ends, and two end caps 213 respectively close the two openings 2121.
  • the first wall 211 is one of the two end caps 213.
  • the battery cell 20 with this structure is easy to assemble from both ends of the housing 212, which helps to reduce the manufacturing and assembly difficulty of the battery cell 20. It also makes it easy to set pressure relief grooves 2111 and install electrode terminals 22 on the end caps 213, which helps to reduce the manufacturing difficulty of the battery cell 20 and improve the production efficiency of the battery cell 20.
  • the structure of the battery cell 20 is not limited to this.
  • the housing 212 may also include a first wall 211, meaning the first wall 211 is one of the walls of the housing 212.
  • This structure allows the area of the outer casing 21 with the pressure relief groove 2111 to be located away from the end caps 213. This effectively mitigates the stress generated by the connection between the end caps 213 and the housing 212 on the area of the first wall 211 with the pressure relief groove 2111, reducing the impact on this area. This, in turn, helps reduce the risk of cracking or structural strength reduction in the area of the first wall 211 with the pressure relief groove 2111 under tensile stress, thereby improving the service life and reliability of the battery cell 20.
  • this application also provides a battery 100, which includes a battery cell 20 of any of the above schemes.
  • the battery 100 may further include a housing 10, in which the battery cell 20 is housed, and the housing 10 has a bottom plate located at the bottom of the battery cell 20, with the bottom plate facing the first wall 211 along the thickness direction X of the first wall.
  • the housing 10 has a bottom plate located at the bottom of the battery cell 20.
  • the bottom plate is a plate of the housing 10 located at the bottom of the battery cell 20 in the thickness direction X of the first wall.
  • the first wall 211 is located opposite to the bottom plate, that is, the first wall 211 is also located at the bottom of the electrode assembly 23 in the thickness direction X of the first wall.
  • the thickness direction X of the first wall is the direction of gravity or approximately the direction of gravity, so that the battery cell 20 is placed upside down in the housing 10 with the end provided with the electrode terminal 22 and the pressure relief groove 2111.
  • the housing 10 may include a first housing body 11 and a second housing body 12, which overlap each other, and together define an assembly space for accommodating the battery cell 20.
  • the base plate is a plate of the second housing body 12.
  • the second box body 12 can be a hollow structure with one end open, and the first box body 11 can be a plate-like structure.
  • the first box body 11 covers the open side of the second box body 12 so that the first box body 11 and the second box body 12 together define the assembly space;
  • the first box body 11 and the second box body 12 can also be hollow structures with one side open, and the open side of the first box body 11 covers the open side of the second box body 12.
  • the box 10 formed by the first box body 11 and the second box body 12 can be of various shapes, such as a cylinder or a cuboid.
  • the box 10 is a cuboid structure.
  • the battery cell 20 disposed within the housing 10 can be one or more.
  • the housing 100 of the battery 100 contains multiple battery cells 20. These multiple battery cells 20 can be connected in series, parallel, or a combination thereof. A combination thereof means that some of the multiple battery cells 20 are connected in series and others in parallel. Multiple battery cells 20 can be directly connected in series, parallel, or a combination thereof, and then the entire assembly of the multiple battery cells 20 is housed within the housing 10.
  • the battery 100 can also be composed of multiple battery cells 20 first connected in series, parallel, or a combination thereof to form a battery module, and then these battery modules are connected in series, parallel, or a combination thereof to form a whole, which is then housed within the housing 10.
  • the battery 100 may also include other structures.
  • the battery 100 may also include a busbar component that connects multiple battery cells 20 to achieve electrical connection between the multiple battery cells 20.
  • the battery 100 may not have a housing 10.
  • the battery 100 includes multiple battery cells 20, and the battery 100 composed of multiple battery cells 20 can be directly mounted onto an electrical device to provide power to the electrical device through the multiple battery cells 20. That is, the housing 10 can be part of the electrical device.
  • the housing 10 can be part of the chassis structure of the vehicle 1000.
  • a portion of the housing 10 can be at least a part of the floor of the vehicle 1000, or a portion of the housing 10 can be at least a part of the crossbeams and longitudinal beams of the vehicle 1000.
  • the battery cell 20 is arranged invertedly inside the housing 10. This allows the pressure relief groove 2111 and the electrode terminal 22 of the battery cell 20 to be located at the bottom of the battery cell 20 and facing the bottom plate, which facilitates assembly and release of internal pressure of the battery cell 20. It also mitigates the risk to the user caused by the upward impact of thermal runaway gas released from the battery cell 20 of the battery 100 during thermal runaway.
  • this application also provides an electrical device, which includes a battery cell 20 or a battery 100 of any of the above schemes, and the battery cell 20 is used to provide electrical energy to the electrical device.
  • the electrical device can be any of the aforementioned devices or systems that use battery cell 20 or battery 100.
  • this application provides a battery cell 20, which includes an outer...
  • the device comprises a housing 21, two electrode terminals 22, and an electrode assembly 23.
  • the housing 21 is rectangular and has a first wall 211.
  • the housing 21 includes a shell 212 and an end cap 213.
  • the shell 212 has an internal cavity with an opening 2121 for accommodating the electrode assembly 23.
  • the end cap 213 closes the opening 2121 and serves as the first wall 211.
  • Both electrode terminals 22 are disposed on the first wall 211.
  • the thickness of the electrode terminals 22 in the thickness direction X of the first wall is greater than the wall thickness of the first wall 211, and they are spaced apart along the first direction Y.
  • the electrode assembly 23 is housed within the housing 21 and is electrically connected to the electrode terminals 22.
  • the first wall 211 is provided with a pressure relief groove 2111, which is formed by stamping on the first wall 211.
  • the pressure relief groove 2111 includes multiple levels of grooves arranged sequentially along the thickness direction X of the first wall.
  • a first weak portion 2111c is formed at the bottom of the pressure relief groove 2111.
  • the first wall 211 is configured to crack along at least part of the first weak portion 2111c when the battery cell 20 is depressurized, so as to release the internal pressure of the battery cell 20.
  • the projection of the pressure relief groove 2111 does not overlap with the projection of the electrode terminal 22.
  • the pressure relief groove 2111 is disposed between two electrode terminals 22.
  • the maximum size of the electrode terminal 22 is D1
  • the maximum size of the first wall 211 is D2 , satisfying 0.6 ⁇ D1 / D2 ⁇ 0.9 .
  • the thickness direction X of the first wall, the first direction Y, and the second direction Z are perpendicular to each other.
  • the outer edge of the first wall 211 includes a first edge 2112.
  • the first edge 2112 and the pressure relief groove 2111 are located on both sides of the electrode terminal 22 in the first direction Y.
  • the minimum distance between the pressure relief groove 2111 and the electrode terminal 22 is L1
  • the minimum distance between the pressure relief groove 2111 and the first edge 2112 is L2 , satisfying 0.2 ⁇ L1 / L2 ⁇ 0.6 and 15mm ⁇ L1 ⁇ 50mm .
  • the thickness of the portion of the first wall 211 located between the pressure relief groove 2111 and the electrode terminal 22 in the first direction Y is D, satisfying 5 ⁇ L1 /D ⁇ 25.
  • the projection of the first wall 211 in the thickness direction X is rectangular.
  • the dimension of the first wall 211 in the first direction Y is larger than the dimension of the first wall 211 in the second direction Z.
  • the outer shell 21 also has two second walls 214, which are arranged opposite each other along the second direction Z and respectively connected to the two ends of the first wall 211.
  • the pressure relief groove 2111 includes a first groove segment 2111a and two second groove segments 2111b.
  • the two second groove segments 2111b are arranged opposite each other along the first direction Y, and the second groove segments 2111b and the guide groove 2114 are arranged along the second direction Z.
  • the first groove segment 2111a connects the two second groove segments 2111b.
  • connection positions of the two second groove segments 2111b and the first groove segment 2111a are all offset from the two ends of the two second groove segments 2111b, so that predetermined pressure relief is formed on both sides of the first groove segment 2111a along the second direction Z.
  • the first wall 211 is provided with two guide grooves 2114, which are stamped into the first wall 211.
  • a second weak portion 2114a is formed at the bottom of the guide groove 2114.
  • the two guide grooves 2114 are located on both sides of the pressure relief groove 2111.
  • the second weak portion 2114a is configured to guide at least a portion of the predetermined pressure relief area 2113 to flip, thereby opening at least a portion of the predetermined pressure relief area 2113.
  • the pressure relief groove 2111 and the guide grooves 2114 are spaced apart along the second direction Z.
  • the first groove segment 2111a and the two second groove segments 2111b both extend along a straight trajectory, and the first groove segment 2111a and the two second groove segments 2111b are perpendicular to each other.
  • the thickness of the second weak portion 2114a is greater than the thickness of the first weak portion 2111c.
  • the first weak portion 2111c includes at least one weak segment, the cross-sectional area of which perpendicular to its extension direction is a first cross-sectional area S1 , and the cross-sectional area of the second weak portion 2114a perpendicular to its extension direction is a second cross-sectional area S2 , satisfying that S1 ⁇ S2 .
  • a pressure relief groove 2111 and a guide groove 2114 are respectively disposed on both sides of the first wall 211, the pressure relief groove 2111 being disposed on the side of the first wall 211 away from the electrode assembly 23, and the guide groove 2114 being disposed on the side of the first wall 211 facing the electrode assembly 23.

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  • Sealing Battery Cases Or Jackets (AREA)
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Abstract

本申请提供了一种电池单体、电池及用电装置，属于电池技术领域。其中，电池单体包括外壳、电极端子和电极组件。外壳具有第一壁。电极端子设置于第一壁。电极组件容纳于外壳内，电极组件与电极端子电连接。第一壁设置有泄压槽，第一壁被配置为在电池单体泄压时能够沿着至少部分泄压槽裂开，沿第一壁的厚度方向，泄压槽的投影与电极端子的投影不重叠，且电极端子的厚度大于第一壁的厚度。通过电极端子能够提升第一壁的结构刚度，以提升第一壁的抗变形能力，从而能够减少第一壁设置有泄压槽的区域在使用过程中的应变和应变幅，进而能够减少第一壁设置有泄压槽的区域出现低周疲劳的现象，有利于降低电池单体出现提前开阀的风险。

Description

电池单体、电池及用电装置 技术领域
本申请涉及电池技术领域，具体而言，涉及一种电池单体、电池及用电装置。
背景技术
近些年，新能源汽车有了飞跃式的发展，在电动汽车领域，动力电池作为电动汽车的动力源，起着不可替代的重要作用。随着新能源汽车的大力推广，对动力电池产品的需求也日益增长，其中，电池作为新能源汽车核心零部件在使用可靠性方面和使用寿命方面均有着较高的要求。
在电池技术中，为了保证电池单体的安全性，一般会在电池单体的外壳上设置用于泄放电池单体内部压力的泄压结构，使得在电池单体内部压力或温度达到阈值时，泄压结构能够致动以泄放电池单体内部的压力。然而，现有的电池单体的泄压结构在使用过程中常常出现提前致动开阀的现象，以造成电池单体的使用稳定性较差，从而不利于提升电池单体的使用寿命和使用可靠性。
发明内容
本申请实施例提供一种电池单体、电池及用电装置，能够有效提升电池单体的使用寿命和使用可靠性。
第一方面，本申请实施例提供一种电池单体，包括外壳、电极端子和电极组件；所述外壳具有第一壁；所述电极端子设置于所述第一壁；所述电极组件容纳于所述外壳内，所述电极组件与所述电极端子电连接；其中，所述第一壁设置有泄压槽，所述第一壁被配置为在所述电池单体泄压时能够沿着至少部分所述泄压槽裂开，沿所述第一壁的厚度方向，所述泄压槽的投影与所述电极端子的投影不重叠，且所述电极端子的厚度大于所述第一壁的厚度。
在上述技术方案中，第一壁上设置有泄压槽，使得第一壁在电池单体泄压时能够沿着至少部分泄压槽裂开，以实现对电池单体的内部压力进行泄放，其中，通过将电极端子也装配于第一壁上，电极端子在第一壁的厚度方向上的厚度大于第一壁的厚度，且电极端子在第一壁的厚度方向上的投影与泄压槽在第一壁的厚度方向上的投影不重叠，使得这种结构的电池单体能够将电极端子和电池单体用于泄压的结构设置于外壳的同一个壁上，从而通过电极端子能够提升第一壁的结构刚度，以提升第一壁的抗变形能力，使得在电池单体的使用过程中能够缓解第一壁的变形现象，以减少第一壁设置有泄压槽的区域的应变和应变幅，进而能够减少第一壁设置有泄压槽的区域出现低周疲劳的现象，以减少第一壁设置有泄压槽的区域出现疲劳损坏的现象，有利于降低电池单体出现提前开阀的风险，以提升电池单体的使用寿命和使用可靠性。
在一些实施例中，所述泄压槽与所述电极端子沿第一方向排布；其中，沿第二方向，所述电极端子的最大尺寸为D1，所述第一壁的最大尺寸为D2，满足，0.4≤D1/D2≤0.9，所述第一壁的厚度方向、所述第一方向和所述第二方向两两垂直。
在上述技术方案中，电极端子在第二方向上的最大尺寸与第一壁在第二方向上的最大尺寸的比值为0.4到0.9，一方面通过将电极端子在第二方向上的最大尺寸与第一壁在第二方向上的最大尺寸的比值设置为大于或等于0.4能够提升电极端子在第二方向上占用第一壁的空间大小，有利于提升电极端子对第一壁的结构刚度的加强作用，以提升第一壁的抗变形能力，使得在电池单体的使用过程中能够缓解第一壁的变形现象，以减少第一壁设置有泄压槽的区域的应变和应变幅，进而能够减少第一壁设置有泄压槽的区域出现低周疲劳的现象，有利于降低电池单体出现提前开阀的风险，以提升电池单体的使用寿命和使用可靠性，另一方面通过将电极端子在第二方向上的最大尺寸与第一壁在第二方向上的最大尺寸的比值设置为小于或等于0.9能够缓解电极端子在第二方向上占用第一壁的空间过大的现象，以减少用于安装电极端子的安装孔的开孔过大的现象，从而能够降低电极端子的装配难度和安装孔的制造难度，以降低电池单体的制造难度，且能够缓解第一壁设置安装孔的区域的结构强度太低的现象，以降低第一壁在加工生产或使用过程中出现断裂或损坏的风险。
在一些实施例中，沿第二方向，所述电极端子的最大尺寸为D1，所述第一壁的最大尺寸为D2，满足，0.6≤D1/D2≤0.9。
在上述技术方案中，通过将电极端子在第二方向上的最大尺寸与第一壁在第二方向上的最大尺寸的比值进一步设置为大于或等于0.6能够进一步提升电极端子在第二方向上占用第一壁的空间大小，有利于进一步提升电极端子对第一壁的结构刚度的加强作用，以提升第一壁的抗变形能力，使得在电池单体的使用过程中能够进一步缓解第一壁的变形现象，以减少第一壁设置有泄压槽的区域的应变和应变幅，进而能够进一步减少第一壁设置有泄压槽的区域出现低周疲劳的现象，有利于进一步降低电池单体出现提前开阀的风险，以提升电池单体的使用寿命和使用可靠性。
在一些实施例中，所述第一壁的外边缘包括第一边缘，所述第一边缘和所述泄压槽在第一方向上分别位于所述电极端子的两侧，所述第一方向垂直于所述第一壁的厚度方向；其中，沿所述第一方向，所述泄压槽与所述电极端子的最小距离为L1，所述泄压槽与所述第一边缘的最小距离为L2，满足，0.2≤L1/L2≤0.8。
在上述技术方案中，泄压槽与电极端子在第一方向上的最小距离与泄压槽与第一边缘在第一方向上的最小距离的比值为0.2到0.8，一方面通过将泄压槽与电极端子在第一方向上的最小距离与泄压槽与第一边缘在第一方向上的最小距离的比值设置为小于或等于0.8，使得泄压槽在第一方向上更接近电极端子，以提升电极端子对第一壁设置有泄压槽的区域的结构刚度的加强作用，有利于减少第一壁设置有泄压槽的区域的应变和应变幅，从而能够减少第一壁设置有泄压槽的区域出现低周疲劳的现象，以降低电池单体出现提前开阀的风险，进而能够有效提升电 池单体的使用寿命和使用可靠性，另一方面通过将泄压槽与电极端子在第一方向上的最小距离与泄压槽与第一边缘在第一方向上的最小距离的比值设置为大于或等于0.2，以缓解泄压槽过度靠近电极端子的现象，从而在第一壁沿着泄压槽的至少部分裂开并泄放电池单体的内部压力时能够减少电池单体内部的热失控气体对电极端子以及连接于电极端子上的其他部件的冲击现象，进而能够降低因电极端子以及连接于电极端子上的其他部件损坏而带来的短接风险或热扩散风险，以提升电池单体的使用可靠性。
在一些实施例中，沿所述第一方向，所述泄压槽与所述电极端子的最小距离为L1，所述泄压槽与所述第一边缘的最小距离为L2，满足，0.2≤L1/L2≤0.6。
在上述技术方案中，通过将泄压槽与电极端子在第一方向上的最小距离与泄压槽与第一边缘在第一方向上的最小距离的比值进一步设置为小于或等于0.6，使得泄压槽在第一方向上能够进一步接近电极端子，以进一步提升电极端子对第一壁设置有泄压槽的区域的结构刚度的加强作用，有利于减少第一壁设置有泄压槽的区域的应变和应变幅，从而能够进一步减少第一壁设置有泄压槽的区域出现低周疲劳的现象，以进一步降低电池单体出现提前开阀的风险，进而能够有效提升电池单体的使用寿命和使用可靠性。
在一些实施例中，所述泄压槽与所述电极端子沿第一方向排布，所述第一方向垂直于所述第一壁的厚度方向；其中，沿所述第一方向，所述泄压槽与所述电极端子的最小距离为L1，所述第一壁位于所述泄压槽和所述电极端子之间的部分的厚度为D，满足，3≤L1/D≤30。
在上述技术方案中，泄压槽与电极端子在第一方向上的最小距离和第一壁位于泄压槽和电极端子之间的部分的厚度的比值为3到30，一方面通过将泄压槽与电极端子在第一方向上的最小距离和第一壁位于泄压槽和电极端子之间的部分的厚度的比值设置为小于或等于30，以缓解泄压槽与电极端子在第一方向上的最小距离过大且第一壁位于泄压槽和电极端子之间的部分的厚度过小的现象，有利于提升电极端子和第一壁对第一壁设置有泄压槽的区域的结构刚度的加强作用，以减少第一壁设置有泄压槽的区域的应变和应变幅，从而能够减少第一壁设置有泄压槽的区域出现低周疲劳的现象，以降低电池单体出现提前开阀的风险，进而能够有效提升电池单体的使用寿命和使用可靠性，另一方面通过将泄压槽与电极端子在第一方向上的最小距离和第一壁位于泄压槽和电极端子之间的部分的厚度的比值设置为大于或等于3，以缓解泄压槽与电极端子在第一方向上的最小距离过小且第一壁位于泄压槽和电极端子之间的部分的厚度过大的现象，从而能够缓解第一壁的厚度出现过度浪费的现象，以降低电池单体的制造成本，且在第一壁沿着泄压槽的至少部分裂开并泄放电池单体的内部压力时能够减少电池单体内部的热失控气体对电极端子以及连接于电极端子上的其他部件的冲击现象，进而能够降低因电极端子以及连接于电极端子上的其他部件损坏而带来的短接风险或热扩散风险，以提升电池单体的使用可靠性。
在一些实施例中，沿所述第一方向，所述泄压槽与所述电极端子的最小距离为L1，所述第一壁位于所述泄压槽和所述电极端子之间的部分的厚度为D，满足，5≤L1/D≤25。
在上述技术方案中，通过将泄压槽与电极端子在第一方向上的最小距离和第一壁位于泄压槽和电极端子之间的部分的厚度的比值设置为小于或等于25，以进一步缓解泄压槽与电极端子在第一方向上的最小距离过大且第一壁位于泄压槽和电极端子之间的部分的厚度过小的现象，有利于进一步提升电极端子和第一壁对第一壁设置有泄压槽的区域的结构刚度的加强作用，以进一步减少第一壁设置有泄压槽的区域的应变和应变幅，从而能够有效减少第一壁设置有泄压槽的区域出现低周疲劳的现象，以进一步降低电池单体出现提前开阀的风险，同样地，通过将泄压槽与电极端子在第一方向上的最小距离和第一壁位于泄压槽和电极端子之间的部分的厚度的比值设置为大于或等于5，以进一步缓解泄压槽与电极端子在第一方向上的最小距离过小且第一壁位于泄压槽和电极端子之间的部分的厚度过大的现象，一方面能够进一步缓解第一壁的厚度出现过度浪费的现象，另一方面在第一壁沿着泄压槽的至少部分裂开并泄放电池单体的内部压力时能够进一步减少电池单体内部的热失控气体对电极端子以及连接于电极端子上的其他部件的冲击现象。
在一些实施例中，所述第一壁位于所述泄压槽和所述电极端子之间的部分的厚度为D，满足，0.8mm≤D≤4mm。
在上述技术方案中，通过将第一壁位于泄压槽和电极端子之间的部分的厚度设置为大于或等于0.8mm，且小于或等于4mm，一方面能够提升第一壁位于泄压槽和电极端子之间的部分的结构强度，以降低第一壁在使用过程中出现断裂或破损的风险，另一方面能够减少第一壁的厚度出现过度浪费的现象，有利于降低第一壁的制造难度和制造成本。
在一些实施例中，所述泄压槽与所述电极端子沿第一方向排布，所述第一方向垂直于所述第一壁的厚度方向；其中，沿所述第一方向，所述泄压槽与所述电极端子的最小距离为L1，满足，10mm≤L1≤100mm。
在上述技术方案中，泄压槽与电极端子在第一方向上的最小距离10mm到100mm，一方面通过将泄压槽与电极端子在第一方向上的最小距离设置为小于或等于100mm，使得泄压槽较为靠近电极端子，以提升电极端子对第一壁设置有泄压槽的区域的结构刚度的加强作用，有利于减少第一壁设置有泄压槽的区域的应变和应变幅，从而能够减少第一壁设置有泄压槽的区域出现低周疲劳的现象，以降低电池单体出现提前开阀的风险，进而能够有效提升电池单体的使用寿命和使用可靠性，另一方面通过将泄压槽与电极端子在第一方向上的最小距离设置为大于或等于10mm，以缓解泄压槽过度靠近电极端子的现象，从而在第一壁沿着泄压槽的至少部分裂开并泄放电池单体的内部压力时能够减少电池单体内部的热失控气体对电极端子以及连接于电极端子上的其他部件的冲击现象，进而能够降低因电极端子以及连接于电极端子上的其他部件损坏而带来的短接风险或热扩散风险，以提升电池单体的使用可靠性。
在一些实施例中，沿所述第一方向，所述泄压槽与所述电极端子的最小距离为L1，满足，15mm≤L1≤50mm。
在上述技术方案中，泄压槽与电极端子在第一方向上的最小距离15mm到50mm，一方面通过将泄压槽 与电极端子在第一方向上的最小距离进一步设置为小于或等于50mm，使得泄压槽更为靠近电极端子，以进一步提升电极端子对第一壁设置有泄压槽的区域的结构刚度的加强作用，有利于减少第一壁设置有泄压槽的区域的应变和应变幅，从而能够进一步减少第一壁设置有泄压槽的区域出现低周疲劳的现象，以进一步降低电池单体出现提前开阀的风险，进而能够有效提升电池单体的使用寿命和使用可靠性，另一方面通过将泄压槽与电极端子在第一方向上的最小距离进一步设置为大于或等于15mm，以进一步缓解泄压槽过度靠近电极端子的现象，从而在第一壁沿着泄压槽的至少部分裂开并泄放电池单体的内部压力时能够进一步减少电池单体内部的热失控气体对电极端子以及连接于电极端子上的其他部件的冲击现象，进而能够进一步降低因电极端子以及连接于电极端子上的其他部件损坏而带来的短接风险或热扩散风险，以提升电池单体的使用可靠性。
在一些实施例中，所述电池单体包括两个所述电极端子，两个所述电极端子均设置于所述第一壁上，且两个所述电极端子沿第一方向间隔排布，所述第一方向垂直于所述第一壁的厚度方向；其中，沿所述第一方向，所述泄压槽位于两个所述电极端子之间。
在上述技术方案中，通过将电池单体的两个电极端子均设置于第一壁上，且将泄压槽在第一方向上设置于两个电极端子之间，以使两个电极端子能够进一步提升对第一壁设置有泄压槽的区域的结构刚度的加强作用，有利于减少第一壁设置有泄压槽的区域的应变和应变幅，从而能够进一步减少第一壁设置有泄压槽的区域出现低周疲劳的现象，以进一步降低电池单体出现提前开阀的风险，有利于提升电池单体的使用寿命和使用可靠性。
在一些实施例中，沿所述第一方向，所述泄压槽与两个所述电极端子之间的最小距离相等。
在上述技术方案中，通过将泄压槽在第一方向上与两个电极端子之间的间距设置为相等的结构，一方面能够提升电池单体的结构的规整度，有利于降低电池单体的制造难度，另一方面能够实现两个电极端子对第一壁设置有泄压槽的区域的结构刚度的加强效果相近，有利于进一步减少第一壁设置有泄压槽的区域的应变和应变幅，以缓解第一壁设置有泄压槽的区域出现低周疲劳的现象，从而能够进一步降低电池单体出现提前开阀的风险。
在一些实施例中，所述第一壁设置有安装孔，所述安装孔沿所述第一壁的厚度方向贯穿所述第一壁，所述安装孔与所述电极端子一一对应；其中，所述电极端子包括柱体部、第一限位部和第二限位部，所述柱体部沿所述第一壁的厚度方向穿设于所述安装孔内，且所述柱体部连接所述第一限位部和所述第二限位部，所述第一限位部和所述第二限位部均凸出于所述柱体部的外周面，沿所述第一壁的厚度方向，所述第一限位部和所述第二限位部分别位于所述第一壁的两侧，且所述第一限位部的投影和所述第二限位部的投影的至少部分与所述第一壁重叠。
在上述技术方案中，电极端子设置有第一限位部和第二限位部以及连接第一限位部和第二限位部的柱体部，柱体部穿设于第一壁的安装孔内，且第一限位部和第二限位部分别位于第一壁的两侧并与第一壁的至少部分重叠，以实现将电极端子紧固和安装于第一壁上，采用这种结构的电极端子一方面能够提升电极端子设置在第一壁上的结构稳定性和可靠性，另一方面能够进一步提升电极端子对第一壁设置有泄压槽的区域的结构刚度的加强效果。
在一些实施例中，所述第一壁在所述第一壁的厚度方向上的投影呈长方形，所述第一壁在第一方向上的尺寸大于所述第一壁在第二方向上的尺寸，所述第一壁的厚度方向、所述第一方向和所述第二方向两两垂直；其中，所述泄压槽与所述电极端子沿所述第一方向排布。
在上述技术方案中，第一壁为长方形结构，通过将泄压槽和电极端子的排布方向设置为与第一壁的长度方向一致，一方面能够降低在第一壁上安装电极端子和设置泄压槽的难度，使得第一壁在第一方向上具有足够的空间设置电极端子和泄压槽，另一方面使得电极端子能够对第一壁在第一壁最容易产生变形的方向上进行结构刚度的加强，有利于进一步提升第一壁的抗变形能力，以减少第一壁设置有泄压槽的区域的应变和应变幅，从而能够进一步减少第一壁设置有泄压槽的区域出现低周疲劳的现象，以进一步降低电池单体出现提前开阀的风险。
在一些实施例中，所述外壳呈长方体状，所述外壳还具有两个第二壁，两个所述第二壁沿所述第二方向相对设置且分别连接于所述第一壁的两端；其中，沿所述第二方向，所述第二壁背离所述电极组件的表面为所述外壳的外表面中面积最大的面。
在上述技术方案中，外壳为长方体状，外壳还具有在第二方向上相对设置的两个第二壁，且第二壁背离电极组件的表面为外壳的外表面中面积最大的面，使得第二方向既为第一壁的宽度方向，也为电池单体的厚度方向，从而实现电极端子能够对第一壁在第一壁出现变形量最大的方向上进行结构刚度的加强，有利于进一步提升第一壁的抗变形能力，以减少第一壁设置有泄压槽的区域的应变和应变幅，从而能够进一步减少第一壁设置有泄压槽的区域出现低周疲劳的现象，以进一步降低电池单体出现提前开阀的风险。
在一些实施例中，所述泄压槽冲压成型于所述第一壁。
在上述技术方案中，通过将泄压槽设置为冲压成型于第一壁上的结构，使得泄压槽在第一壁上的成型方式简单，有利于降低电池单体的制造成本。
在一些实施例中，所述泄压槽包括沿所述第一壁的厚度方向依次排布的多级槽。
在上述技术方案中，通过将泄压槽设置为沿第一壁的厚度方向设置的多级阶梯槽结构，以使泄压槽为多次加工形成的凹槽结构，采用这种结构的泄压槽在同等深度的情况下一方面能够降低泄压槽单次加工的深度，有利于降低泄压槽的制造难度和对制造设备的需求，以降低制造成本，且能够减小第一壁在泄压槽单次加工时所受到的成型力，有利于降低第一壁产生裂纹的风险，以提高电池单体的生产质量，另一方面能够改善泄压槽在形成过程中的流料形态，有利于在形成泄压槽时所产生物料的进行流动，以提升泄压槽的结构的一致性。
在一些实施例中，沿所述第一壁的厚度方向，所述泄压槽的最小残余厚度为D3，满足，0.05mm≤D3≤0.3mm。
在上述技术方案中，泄压槽在第一壁的厚度方向上的最小残余厚度为0.05mm到0.3mm，一方面通过将泄压槽在第一壁的厚度方向上的最小残余厚设置为大于或等于0.05mm，以缓解第一壁设置有泄压槽的区域的结构强度过小的现象，从而能够降低第一壁设置有泄压槽的区域在生产、运输或正常使用情况下出现开裂或损坏等风 险，另一方面通过将泄压槽在第一壁的厚度方向上的最小残余厚设置为小于或等于0.3mm，以缓解第一壁在电池单体发生热失控时沿着泄压槽裂开的难度较大的问题，从而能够降低电池单体泄压开阀所需的爆破压，以降低电池单体因泄压爆破压过大而引发的爆炸风险。
在一些实施例中，所述电池单体还包括电解液，所述电解液容纳于所述外壳内；其中，所述电解液包括电解质盐，所述电解质盐包括六氟磷酸盐，所述六氟磷酸盐的摩尔浓度小于或等于1.1mol/L。
在上述技术方案中，通过将电解液中的六氟磷酸盐的摩尔浓度设置为小于或等于1.1mol/L，以缓解电池单体在使用过程中产生的氢氟酸的量，从而能够减少第一壁设置有泄压槽的区域被腐蚀的现象，以缓解泄压槽的最小残余厚度进一步减小的情况，进而能够降低电池单体因第一壁设置有泄压槽的区域的结构强度下降而出现提前开裂或损坏的风险，以进一步提升电池单体的使用可靠性和使用稳定性。
在一些实施例中，所述泄压槽的底部形成第一薄弱部，所述第一壁被配置为在所述电池单体泄压时能够沿着至少部分所述第一薄弱部裂开；其中，所述第一壁还设置有引导槽，所述引导槽的底部形成第二薄弱部，沿所述第一壁的厚度方向，所述泄压槽的投影和至少一个所述引导槽的投影共同限定出至少一个预定泄压区，所述第二薄弱部被配置为引导所述预定泄压区的至少部分翻转，以打开所述预定泄压区的至少部分。
在上述技术方案中，第一壁上还设置有引导槽，引导槽和泄压槽沿第一壁的厚度方向的投影在第一壁上限定出至少一个预定泄压区，且预定泄压区在第一壁沿着泄压槽的至少部分裂开后能够被打开，并能够绕着引导槽底部的第二薄弱部进行翻转，以泄放电池单体的内部压力，采用这种结构的电池单体能够实现在预定泄压区被打开后扩大预定泄压区的翻转角度，从而有效能够增加电池单体的泄压面积，以提升电池单体在发生热失控时的泄压速率，进而能够降低电池单体因泄压不及时而引发起火爆炸等风险，有利于提升电池单体的使用可靠性。
在一些实施例中，所述泄压槽与所述电极端子沿第一方向排布，所述泄压槽与所述引导槽沿第二方向排布，所述第一壁的厚度方向、所述第一方向和所述第二方向两两垂直。
在上述技术方案中，通过将引导槽和泄压槽设置为沿第二方向排布的结构，使得引导槽位于泄压槽在第二方向上的至少一侧，一方面能够减少引导槽对第一壁位于电极端子与泄压槽之间的区域的结构刚度的影响，有利于提升电极端子对第一壁设置有泄压槽的区域的结构刚度的加强效果，另一方面能够减少泄压槽与引导槽之间的干涉影响，以便于分别对泄压槽和引导槽进行加工，且能够缓解泄压槽底部的第一薄弱部在裂开时撕裂引导槽底部的第二薄弱部的现象，还能够提升预定泄压区被打开后绕着第二薄弱部进行翻转的效果。
在一些实施例中，所述引导槽沿所述第一方向延伸，沿所述第一方向，所述引导槽的两端分别延伸出所述泄压槽的两个端部。
在上述技术方案中，通过将引导槽设置为沿第一方向延伸且在第一方向上的两端分别超出泄压槽的两个端部的结构，一方面使得引导槽在第一方向上的尺寸大于泄压槽，以便于泄压槽限定的预定泄压区绕着第二薄弱部进行翻转，且能够提升预定泄压区的翻转效果，从而能够增加电池单体的泄压面积，以提升电池单体在发生热失控时的泄压速率，另一方面能够提升引导槽对第一壁的泄压槽在成型过程中挤出的余料的吸收效果，且能够提升引导槽在第二方向上对泄压槽和第一壁的边缘进行分隔的效果，以提高引导槽在电池单体受到内外冲击作用力时对电池单体的变形能量的阻挡效果。
在一些实施例中，沿所述第一壁的厚度方向，所述引导槽的投影与所述电极端子的投影不重叠。
在上述技术方案中，通过将引导槽和电极端子在第一壁的厚度方向上的投影设置为互不重叠的结构，从而能够减少引导槽和电极端子之间的干涉影响，且有利于降低电池单体的制造难度。
在一些实施例中，沿所述第一壁的厚度方向，所述第二薄弱部的厚度大于所述第一薄弱部的厚度。
在上述技术方案中，通过将第二薄弱部在第一壁的厚度方向上的厚度设置为大于第一薄弱部在第一壁的厚度方向上的厚度，以使引导槽的残余厚度大于泄压槽的残余厚度，使得第一壁设置泄压槽的区域的结构强度小于第一壁设置引导槽的区域的结构强度，以便于第一壁能够优先沿着泄压槽底部的第一薄弱部进行裂开并泄放电池单体的内部压力，从而有利于缓解第一壁从设置引导槽的区域裂开而造成电池单体的泄压效果不佳的现象。
在一些实施例中，所述第一薄弱部包括至少一个薄弱段，所述薄弱段垂直于其延伸方向的横截面积为第一截面积S1，所述第二薄弱部垂直于其延伸方向的横截面积为第二截面积S2，满足，S1＜S2。
在上述技术方案中，通过将第一薄弱部的薄弱段垂直于其延伸方向的横截面的面积设置为小于第二薄弱部垂直于其延伸方向的横截面的面积，以使第一壁设置泄压槽的区域的结构强度小于第一壁设置引导槽的区域的结构强度，从而便于第一壁能够优先沿着泄压槽底部的第一薄弱部进行裂开并泄放电池单体的内部压力，有利于缓解第一壁从设置引导槽的区域裂开而造成电池单体的泄压效果不佳的现象。
在一些实施例中，沿所述第一壁的厚度方向，所述泄压槽和所述引导槽分别设置于所述第一壁的两侧。
在上述技术方案中，通过将泄压槽和引导槽分别设置于第一壁在第一壁的厚度方向上的两侧，从而便于在第一壁的两侧分别对泄压槽和引导槽进行加工，有利于减少泄压槽和引导槽在加工过程中的相互影响。
在一些实施例中，所述泄压槽包括第一槽段和两个第二槽段，两个所述第二槽段沿第一方向相对设置，且所述第二槽段与所述引导槽沿第二方向排布，所述第一槽段连接两个所述第二槽段，所述第一壁的厚度方向、所述第一方向和所述第二方向两两垂直；沿所述第一壁的厚度方向，所述第一槽段的投影、两个所述第二槽段的投影、两个所述第二槽段的延长线的投影和所述引导槽的投影共同围合出所述预定泄压区；或，沿所述第一壁的厚度方向，所述第一槽段的投影、两个所述第二槽段的投影、所述引导槽的投影和所述引导槽的延长线的投影共同围合出所述预定泄压区；或，沿所述第一壁的厚度方向，所述第一槽段的投影、两个所述第二槽段的投影、两个所述第二槽段的延长线的投影、所述引导槽的投影和所述引导槽的延长线的投影共同围合出所述预定泄压区。
在上述技术方案中，采用这种结构的电池单体一方面便于在第一壁上加工泄压槽并形成预定泄压区，且这种结构的泄压槽限定的预定泄压区更容易绕着引导槽所在的位置进行翻转，另一方面使得第一槽段和第二槽段的 相交位置更薄弱，更容易裂开并打开预定泄压区进行泄压。
在一些实施例中，所述泄压槽包括第一槽段和第二槽段，所述第一槽段和所述第二槽段相连；其中，沿所述第一壁的厚度方向，所述第一槽段的投影、所述第一槽段的延长线的投影、所述第二槽段的投影、所述第二槽段的延长线的投影和所述引导槽的投影共同围合出所述预定泄压区；或，沿所述第一壁的厚度方向，所述第一槽段的投影、所述第二槽段的投影、所述引导槽的投影和所述引导槽的延长线的投影共同围合出所述预定泄压区；或，沿所述第一壁的厚度方向，所述第一槽段的投影、所述第一槽段的延长线的投影、所述第二槽段的投影、所述第二槽段的延长线的投影、所述引导槽的投影和所述引导槽的延长线的投影共同围合出所述预定泄压区。
在上述技术方案中，通过将泄压槽设置为包括相互连接的第一槽段和第二槽段，采用这种结构的电池单体一方面能够增大电池单体的泄压面积，以提高电池单体的泄压速率，另一方面使得第一槽段和第二槽段的相交位置更薄弱，更容易裂开并打开预定泄压区泄放电池单体的内部压力。
在一些实施例中，所述泄压槽为沿弧形轨迹延伸的槽；其中，沿所述第一壁的厚度方向，所述泄压槽的投影、所述泄压槽的延长线的投影和所述引导槽的投影共同围合出所述预定泄压区；或，沿所述第一壁的厚度方向，所述泄压槽的投影、所述引导槽的投影和所述引导槽的延长线的投影共同围合出所述预定泄压区；或，沿所述第一壁的厚度方向，所述泄压槽的投影、所述泄压槽的延长线的投影、所述引导槽的投影和所述引导槽的延长线的投影共同围合出所述预定泄压区。
在上述技术方案中，通过将泄压槽设置为沿弧形轨迹延伸的结构，以使预定泄压区形成于泄压槽的内侧，采用这种结构的泄压槽便于在第一壁上制造成型，有利于降低电池单体的制造难度。
在一些实施例中，所述引导槽冲压成型于所述第一壁。
在上述技术方案中，通过将引导槽设置为冲压成型于第一壁上的结构，使得引导槽在第一壁上的成型方式简单，有利于降低电池单体的制造成本。
在一些实施例中，沿所述第一壁的厚度方向，所述第一壁被配置为支撑所述电极组件。
在上述技术方案中，第一壁能够在第一壁的厚度方向上支撑电极组件，使得电池单体为能够倒置放置的结构，一方面使得电池单体能够适应更多的使用场景，以提升电池单体的适应范围，另一方面能够实现电池单体的泄压槽和电极端子均位于电池单体的底部，以便于装配和电池单体的内部压力的泄放。
在一些实施例中，所述外壳包括壳体和端盖；所述壳体的内部形成具有开口的容纳腔，所述容纳腔用于容纳所述电极组件；所述端盖封闭所述开口；其中，所述壳体包括所述第一壁；或，所述端盖为所述第一壁。
在上述技术方案中，通过将外壳的第一壁设置为壳体的一个壁，采用这种结构的电池单体能够使得外壳设置有泄压槽的区域远离端盖，从而能够有效缓解端盖与壳体相互连接产生的应力作用在第一壁设置有泄压槽的区域上的现象，以减少对第一壁设置有泄压槽的区域造成的影响，进而有利于降低第一壁设置有泄压槽的区域在应力的拉扯作用下出现开裂或结构强度下降的风险，以提升电池单体的使用寿命和使用可靠性。通过将外壳的第一壁设置为外壳用于封闭开口的端盖，采用这种结构的电池单体便于在端盖上设置泄压槽和安装电极端子，有利于降低电池单体的制造难度，以提升电池单体的生产效率。
在一些实施例中，所述外壳包括壳体和两个端盖；所述壳体的内部形成有容纳腔，所述容纳腔用于容纳所述电极组件，所述壳体相对的两端均形成有开口，且两个所述开口均与所述容纳腔连通；两个所述端盖分别封闭两个所述开口；其中，两个所述端盖中的一个所述端盖为所述第一壁；或，所述壳体包括所述第一壁。
在上述技术方案中，外壳的壳体在相对的两端上均设置有开口的结构，且两个端盖分别封闭两个开口，第一壁为两个端盖中的一个端盖，采用这种结构的电池单体便于对电池单体从壳体的两端分别进行装配，有利于降低电池单体的制造难度和装配难度，且便于在端盖上设置泄压槽和安装电极端子，有利于降低电池单体的制造难度，以提升电池单体的生产效率。通过将外壳的第一壁设置为壳体的一个壁，采用这种结构的电池单体能够使得外壳设置有泄压槽的区域远离端盖，从而能够有效缓解端盖与壳体相互连接产生的应力作用在第一壁设置有泄压槽的区域上的现象，以减少对第一壁设置有泄压槽的区域造成的影响，进而有利于降低第一壁设置有泄压槽的区域在应力的拉扯作用下出现开裂或结构强度下降的风险，以提升电池单体的使用寿命和使用可靠性。
第二方面，本申请实施例还提供一种电池，包括上述的电池单体。
在一些实施例中，所述电池还包括箱体，所述电池单体容纳于所述箱体内，所述箱体具有位于所述电池单体的底部的底板，沿所述第一壁的厚度方向，所述底板与所述第一壁面向设置。
在上述技术方案中，通过将箱体的底板与电池单体的第一壁在第一壁的厚度方向上面向设置，使得电池单体为倒置设置于箱体内的结构，从而能够实现电池单体的泄压槽和电极端子均位于电池单体的底部且面向底板设置，以便于装配和电池单体的内部压力的泄放，且能够缓解电池的电池单体在热失控时泄放的热失控气体向上冲击对使用者造成的风险。
第三方面，本申请实施例还提供一种用电装置，包括上述的电池单体或电池，所述电池单体用于提供电能。
附图说明
为了更清楚地说明本申请实施例的技术方案，下面将对实施例中所需要使用的附图作简单地介绍，应当理解，以下附图仅示出了本申请的某些实施例，因此不应被看作是对范围的限定，对于本领域普通技术人员来讲，在不付出创造性劳动的前提下，还可以根据这些附图获得其他相关的附图。
图1为本申请一些实施例提供的车辆的结构示意图；
图2为本申请一些实施例提供的电池的结构爆炸图；
图3为本申请一些实施例提供的电池单体的结构示意图；
图4为本申请一些实施例提供的电池单体的结构爆炸图；
图5为本申请一些实施例提供的电池单体在第一壁的厚度方向上面向泄压槽的正视图；
图6为图5所示的电池单体的A处的局部放大图；
图7为本申请又一些实施例提供的电池单体在第一壁的厚度方向上面向泄压槽的正视图；
图8为本申请一些实施例提供的电池单体的外壳的第一壁的局部剖视图；
图9为本申请再一些实施例提供的电池单体在第一壁的厚度方向上面向泄压槽的正视图；
图10为本申请另一些实施例提供的电池单体在第一壁的厚度方向上面向泄压槽的正视图；
图11为本申请再又一些实施例提供的电池单体在第一壁的厚度方向上面向泄压槽的正视图。
图标：1000-车辆；100-电池；10-箱体；11-第一箱本体；12-第二箱本体；20-电池单体；21-外壳；211-第一壁；2111-泄压槽；2111a-第一槽段；2111b-第二槽段；2111c-第一薄弱部；2112-第一边缘；2113-预定泄压区；2114-引导槽；2114a-第二薄弱部；212-壳体；2121-开口；213-端盖；214-第二壁；22-电极端子；23-电极组件；231-极耳；200-控制器；300-马达；X-第一壁的厚度方向；Y-第一方向；Z-第二方向。
具体实施方式
为使本申请实施例的目的、技术方案和优点更加清楚，下面将结合本申请实施例中的附图，对本申请实施例中的技术方案进行清楚地描述，显然，所描述的实施例是本申请一部分实施例，而不是全部的实施例。基于本申请中的实施例，本领域普通技术人员在没有作出创造性劳动前提下所获得的所有其他实施例，都属于本申请保护的范围。
除非另有定义，本申请所使用的所有的技术和科学术语与属于本申请的技术领域的技术人员通常理解的含义相同；本申请中在申请的说明书中所使用的术语只是为了描述具体的实施例的目的，不是旨在于限制本申请；本申请的说明书和权利要求书及上述附图说明中的术语“包括”和“具有”以及它们的任何变形，意图在于覆盖不排他的包含。本申请的说明书和权利要求书或上述附图中的术语“第一”、“第二”等是用于区别不同对象，而不是用于描述特定顺序或主次关系。
在本申请中提及“实施例”意味着，结合实施例描述的特定特征、结构或特性可以包含在本申请的至少一个实施例中。在说明书中的各个位置出现该短语并不一定均是指相同的实施例，也不是与其它实施例互斥的独立的或备选的实施例。
在本申请的描述中，需要说明的是，除非另有明确的规定和限定，术语“安装”、“相连”、“连接”、“附接”应做广义理解，例如，可以是固定连接，也可以是可拆卸连接，或一体地连接；可以是直接相连，也可以通过中间媒介间接相连，可以是两个元件内部的连通。对于本领域的普通技术人员而言，可以根据具体情况理解上述术语在本申请中的具体含义。
本申请中术语“和/或”，仅仅是一种描述关联对象的关联关系，表示可以存在三种关系，例如，A和/或B，可以表示：单独存在A，同时存在A和B，单独存在B这三种情况。另外，本申请中字符“/”，一般表示前后关联对象是一种“或”的关系。
在本申请的实施例中，相同的附图标记表示相同的部件，并且为了简洁，在不同实施例中，省略对相同部件的详细说明。应理解，附图示出的本申请实施例中的各种部件的厚度、长宽等尺寸，以及集成装置的整体厚度、长宽等尺寸仅为示例性说明，而不应对本申请构成任何限定。
本申请中出现的“多个”指的是两个以上(包括两个)。
本申请实施例中，电池单体可以为二次电池，二次电池是指在电池单体放电后可通过充电的方式使活性材料激活而继续使用的电池单体。
电池单体可以为锂离子电池、钠离子电池、钠锂离子电池、锂金属电池、钠金属电池、锂硫电池、镁离子电池、镍氢电池、镍镉电池、铅蓄电池等，本申请实施例对此并不限定。
电池单体一般包括电极组件。电极组件包括正极、负极以及隔离件。在电池单体充放电过程中，活性离子(例如锂离子)在正极和负极之间往返嵌入和脱出。隔离件设置在正极和负极之间，可以起到防止正负极短路的作用，同时可以使活性离子通过。
在一些实施例中，正极可以为正极片，正极片可以包括正极集流体以及设置在正极集流体至少一个表面的正极活性材料。
作为示例，正极集流体具有在其自身厚度方向相对的两个表面，正极活性材料设置在正极集流体相对的两个表面的任意一者或两者上。
作为示例，正极集流体可采用金属箔片或复合集流体。例如，作为金属箔片，可采用表面镀银处理的铝、表面镀银处理的不锈钢、不锈钢、铜、铝、镍、炭精电极、碳、镍或钛等。复合集流体可包括高分子材料基层和金属层。复合集流体可通过将金属材料(铝、铝合金、镍、镍合金、钛、钛合金、银及银合金等)形成在高分子材料基材(如聚丙烯、聚对苯二甲酸乙二醇酯、聚对苯二甲酸丁二醇酯、聚苯乙烯、聚乙烯等的基材)上而形成。
作为示例，正极活性材料可包括以下材料中的至少一种：含锂磷酸盐、锂过渡金属氧化物及其各自的改性化合物。但本申请并不限定于这些材料，还可以使用其他可被用作电池正极活性材料的传统材料。这些正极活性材料可以仅单独使用一种，也可以将两种以上组合使用。其中，含锂磷酸盐的示例可包括但不限于磷酸铁锂(如LiFePO4(也可以简称为LFP))、磷酸铁锂与碳的复合材料、磷酸锰锂(如LiMnPO4)、磷酸锰锂与碳的复合材料、磷酸锰铁锂、磷酸锰铁锂与碳的复合材料中的至少一种。锂过渡金属氧化物的示例可包括但不限于锂钴氧化物(如LiCoO2)、锂镍氧化物(如LiNiO2)、锂锰氧化物(如LiMnO2、LiMn2O4)、锂镍钴氧化物、锂锰钴氧化物、锂镍锰氧化物、锂镍钴锰氧化物(如LiNi1/3Co1/3Mn1/3O2(也可以简称为NCM333)、LiNi0.5Co0.2Mn0.3O2(也可以简称为 NCM523)、LiNi0.5Co0.25Mn0.25O2(也可以简称为NCM211)、LiNi0.6Co0.2Mn0.2O2(也可以简称为NCM622)、LiNi0.8Co0.1Mn0.1O2(也可以简称为NCM811)、锂镍钴铝氧化物(如LiNi0.85Co0.15Al0.05O2)及其改性化合物等中的至少一种。
在一些实施例中，正极可以采用泡沫金属。泡沫金属可以为泡沫镍、泡沫铜、泡沫铝、泡沫合金等。泡沫金属作为正极时，泡沫金属表面可以不设置正极活性材料，当然也可以设置正极活性材料。作为示例，在泡沫金属内还可以填充或/和沉积有锂源材料、钾金属或钠金属，锂源材料为锂金属和/或富锂材料。
在一些实施例中，负极可以为负极片，负极片可以包括负极集流体。
作为示例，负极集流体可采用金属箔片、泡沫金属或复合集流体。例如，作为金属箔片，可以采用银表面处理的铝或不锈钢、不锈钢、铜、铝、镍、炭精电极、镍或钛等。泡沫金属可以为泡沫镍、泡沫铜、泡沫铝、泡沫合金等。复合集流体可包括高分子材料基层和金属层。复合集流体可通过将金属材料(铜、铜合金、镍、镍合金、钛、钛合金、银及银合金等)形成在高分子材料基材(如聚丙烯、聚对苯二甲酸乙二醇酯、聚对苯二甲酸丁二醇酯、聚苯乙烯、聚乙烯等的基材)上而形成。
作为示例，负极片可以包括负极集流体以及设置在负极集流体至少一个表面上的负极活性材料。
作为示例，负极集流体具有在其自身厚度方向相对的两个表面，负极活性材料设置在负极集流体相对的两个表面中的任意一者或两者上。
作为示例，负极活性材料可采用本领域公知的用于电池单体的负极活性材料。作为示例，负极活性材料可包括以下材料中的至少一种：人造石墨、天然石墨、软炭、硬炭、硅基材料、锡基材料和钛酸锂等。硅基材料可选自单质硅、硅氧化合物、硅碳复合物、硅氮复合物以及硅合金中的至少一种。锡基材料可选自单质锡、锡氧化合物以及锡合金中的至少一种。但本申请并不限定于这些材料，还可以使用其他可被用作电池负极活性材料的传统材料。这些负极活性材料可以仅单独使用一种，也可以将两种以上组合使用。
在一些实施例中，正极集流体的材料可以为铝，负极集流体的材料可以为铜。
在一些实施方式中，电极组件还包括隔离件，隔离件设置在正极和负极之间。
在一些实施方式中，隔离件为隔离膜。隔离膜的种类可以是多种，可以选用任意公知的具有良好的化学稳定性和机械稳定性的多孔结构隔离膜。
作为示例，隔离膜的材质可以包括玻璃纤维、无纺布、聚乙烯、聚丙烯及聚偏二氟乙烯中的至少一种。隔离膜可以是单层薄膜，也可以是多层复合薄膜。在隔离膜为多层复合薄膜时，各层的材料可以相同或不同。隔离件可以是单独的一个部件位于正负极之间，也可以附着在正负极的表面。
在一些实施方式中，隔离件为固态电解质。固态电解质设于正极和负极之间，同时起到传输离子和隔离正负极的作用。
在一些实施方式中，电池单体还包括电解质，电解质在正、负极之间起到传导离子的作用。电解质可以是液态的、凝胶态的或固态的。其中，液态电解质包括电解质盐和溶剂。
在一些实施方式中，电解质盐可以包括六氟磷酸锂、四氟硼酸锂、高氯酸锂、六氟砷酸锂、双氟磺酰亚胺锂、双三氟甲磺酰亚胺锂、三氟甲磺酸锂、二氟磷酸锂、二氟草酸硼酸锂、二草酸硼酸锂、二氟二草酸磷酸锂及四氟草酸磷酸锂中的至少一种。
在一些实施方式中，溶剂可以包括碳酸亚乙酯、碳酸亚丙酯、碳酸甲乙酯、碳酸二乙酯、碳酸二甲酯、碳酸二丙酯、碳酸甲丙酯、碳酸乙丙酯、碳酸亚丁酯、氟代碳酸亚乙酯、甲酸甲酯、乙酸甲酯、乙酸乙酯、乙酸丙酯、丙酸甲酯、丙酸乙酯、丙酸丙酯、丁酸甲酯、丁酸乙酯、1,4-丁内酯、环丁砜、二甲砜、甲乙砜及二乙砜中的至少一种。溶剂也可选醚类溶剂。醚类溶剂可以包括乙二醇二甲醚、乙二醇二乙醚、二乙二醇二甲醚、三乙二醇二甲醚、四乙二醇二甲醚、1,3-二氧戊环、四氢呋喃、甲基四氢呋喃、二苯醚及冠醚中的一种或多种。
其中，凝胶态电解质包括以聚合物作为电解质的骨架网络，搭配离子液体-锂盐。
其中，固态电解质包括聚合物固态电解质、无机固态电解质、复合固态电解质。
作为示例，聚合物固态电解质可以为聚醚(聚氧化乙烯)、聚硅氧烷、聚碳酸酯、聚丙烯腈、聚偏氟乙烯、聚甲基丙烯酸甲酯、单离子聚合物、聚离子液体-锂盐、纤维素等。
作为示例，无机固态电解质可以包括氧化物固体电解质(晶态的钙钛矿、钠超导离子导体、石榴石、非晶态的LiPON薄膜)、硫化物固体电解质(晶态的锂超离子导体(锂锗磷硫、硫银锗矿)、非晶体硫化物)以及卤化物固体电解质、氮化物固体电解质及氢化物固体电解质中的一种或多种。
作为示例，复合固态电解质通过在聚合物固体电解质中增加无机固态电解质填料形成。
在一些实施方式中，电极组件为卷绕结构。正极片、负极片卷绕成卷绕结构。
在一些实施方式中，电极组件为叠片结构。
作为示例，正极片、负极片可分别设置多个，多个正极片和多个负极片交替层叠设置。
作为示例，正极片可设置多个，负极片折叠形成多个层叠设置的折叠段，相邻的折叠段之间夹持一个正极片。
作为示例，正极片和负极片均折叠形成多个层叠设置的折叠段。
作为示例，隔离件可设置多个，分别设置在任意相邻的正极片或负极片之间。
作为示例，隔离件可连续地设置，通过折叠或者卷绕方式设置在任意相邻的正极片或负极片之间。
在一些实施方式中，电极组件的形状可以为圆柱状，扁平状或多棱柱状等。
在一些实施方式中，电极组件设有极耳，极耳可以将电流从电极组件导出。极耳包括正极耳和负极耳。
在一些实施方式中，电池单体可以包括外壳。外壳用于封装电极组件及电解质等部件。外壳可以为钢壳、铝壳、塑料壳(如聚丙烯)、复合金属壳(如铜铝复合外壳)或铝塑膜等。
作为示例，电池单体可以为圆柱形电池单体、棱柱电池单体、软包电池单体或其它形状的电池单体，棱 柱电池单体包括但不限于方壳电池单体、刀片形电池单体、多棱柱电池，多棱柱电池例如为六棱柱电池等。
本申请的实施例所提到的电池是指包括一个或多个电池单体以提供更高的电压和容量的单一的物理模块。
在一些实施例中，电池可以为电池模块，电池单体有多个时，多个电池单体排列并固定形成一个电池模块。
在一些实施例中，电池可以为电池包，电池包包括箱体和电池单体，电池单体或电池模块容纳于箱体中。
在一些实施例中，箱体可以作为车辆的底盘结构的一部分。例如，箱体的部分可以成为车辆的地板的至少一部分，或者，箱体的部分可以成为车辆的横梁和纵梁的至少一部分。
在一些实施例中，电池可以为储能装置。储能装置包括储能集装箱、储能电柜等。
电池具有能量密度高、环境污染小、功率密度大、使用寿命长、适应范围广、自放电系数小等突出的优点，是现今新能源发展的重要组成部分。电池技术的发展要同时考虑多方面的设计因素，例如，能量密度、循环寿命、放电容量、充放电倍率等性能参数，另外，还需要考虑电池的安全性。
对于一般的电池单体而言，为了保证电池单体的使用安全性，通常会在电池单体的外壳上设置泄压结构，以通过泄压结构泄放电池单体的内部压力，从而能够有效提升电池单体的使用安全性。在相关技术中，泄压结构可以采用一体成型工艺形成于外壳上，即泄压结构为外壳上形成有薄弱结构的区域，泄压结构与外壳也可以是分体设置的结构，比如，泄压结构可以是通过焊接、卡接或粘接等方式连接于外壳上的泄压部件等，使得电池单体的内部压力或温度达到阈值时泄压结构能够致动并打开，以泄压电池单体的内部压力。然而，在电池单体循环充放电过程中会出现膨胀和收缩的现象，而电池单体膨胀和收缩产生的变形会传递至外壳设置有泄压结构的壁上，使得外壳设置有泄压结构的壁出现变形等现象，从而造成第一壁上设置的泄压结构会产生较大的应变和应变幅，以使第一壁上设置的泄压结构出现低周疲劳的现象，进而导致第一壁上设置的泄压结构的使用稳定性较差，容易造成电池单体在使用过程中出现提前致动泄压的现象，不利于提升电池单体的使用寿命以及使用可靠性。
基于以上考虑，为了解决电池单体的使用寿命较短且使用可靠性较低的问题，本申请实施例提供了一种电池单体，电池单体包括外壳、电极端子和电极组件。外壳具有第一壁。电极端子设置于第一壁。电极组件容纳于外壳内，电极组件与电极端子电连接。第一壁设置有泄压槽，第一壁被配置为在电池单体泄压时能够沿着至少部分泄压槽裂开，沿第一壁的厚度方向，泄压槽的投影与电极端子的投影不重叠，且电极端子的厚度大于第一壁的厚度。
在这种结构的电池单体中，第一壁上设置有泄压槽，使得第一壁在电池单体泄压时能够沿着至少部分泄压槽裂开，以实现对电池单体的内部压力进行泄放，其中，通过将电极端子也装配于第一壁上，电极端子在第一壁的厚度方向上的厚度大于第一壁的厚度，且电极端子在第一壁的厚度方向上的投影与泄压槽在第一壁的厚度方向上的投影不重叠，使得这种结构的电池单体能够将电极端子和电池单体用于泄压的结构设置于外壳的同一个壁上，从而通过电极端子能够提升第一壁的结构刚度，以提升第一壁的抗变形能力，使得在电池单体的使用过程中能够缓解第一壁的变形现象，以减少第一壁设置有泄压槽的区域的应变和应变幅，进而能够减少第一壁设置有泄压槽的区域出现低周疲劳的现象，以减少第一壁设置有泄压槽的区域出现疲劳损坏的现象，有利于降低电池单体出现提前开阀的风险，以提升电池单体的使用寿命和使用可靠性。
本申请实施例公开的电池单体可以但不限用于车辆、船舶或飞行器等用电装置中。可以使用具备本申请公开的电池单体、电池等组成该用电装置的电源系统，这样，有利于缓解电池单体在使用过程中出现提前致动开阀的问题，以提升电池单体的使用寿命以及使用可靠性。
本申请实施例提供一种使用电池作为电源的用电装置，用电装置可以为但不限于手机、平板、笔记本电脑、电动玩具、电动工具、电瓶车、电动汽车、轮船、航天器等等。其中，电动玩具可以包括固定式或移动式的电动玩具，例如，游戏机、电动汽车玩具、电动轮船玩具和电动飞机玩具等等，航天器可以包括飞机、火箭、航天飞机和宇宙飞船等等。
以下实施例为了方便说明，以本申请一实施例的一种用电装置为车辆为例进行说明。
请参照图1，图1为本申请一些实施例提供的车辆1000的结构示意图。车辆1000可以为燃油汽车、燃气汽车或新能源汽车，新能源汽车可以是纯电动汽车、混合动力汽车或增程式汽车等。车辆1000的内部设置有电池100，电池100可以设置在车辆1000的底部，也可以设置在车辆1000的头部，还可以设置在车辆1000的尾部。电池100可以用于车辆1000的进行供电，例如，电池100可以作为车辆1000的操作电源或使用电源等。车辆1000还可以包括控制器200和马达300，控制器200用来控制电池100为马达300供电，例如，用于车辆1000的启动、导航和行驶时的工作用电需求。
在本申请一些实施例中，电池100不仅可以作为车辆1000的操作电源或使用电源，还可以作为车辆1000的驱动电源，代替或部分地代替燃油或天然气为车辆1000提供驱动动力。
请参照图2和图3，图2为本申请一些实施例提供的电池100的结构爆炸图，图3为本申请一些实施例提供的电池单体20的结构示意图。电池100包括箱体10和电池单体20，电池单体20用于容纳于箱体10内。
其中，箱体10用于为电池单体20提供装配空间，箱体10可以采用多种结构。在一些实施例中，箱体10可以包括第一箱本体11和第二箱本体12，第一箱本体11与第二箱本体12相互盖合，第一箱本体11和第二箱本体12共同限定出用于容纳电池单体20的装配空间。第二箱本体12可以为一端开放的空心结构，第一箱本体11可以为板状结构，第一箱本体11盖合于第二箱本体12的开放侧，以使第一箱本体11与第二箱本体12共同限定出装配空间；第一箱本体11和第二箱本体12也可以是均为一侧开放的空心结构，第一箱本体11的开放侧盖合于第二箱本体12的开放侧。
当然，第一箱本体11和第二箱本体12形成的箱体10可以是多种形状，比如，圆柱体、长方体或正方体等。示例性地，在图2中，箱体10的形状为长方体。
在电池100中，设置于箱体10内的电池单体20可以是一个，也可以是多个。当设置于箱体10内的电池单体20为多个时，多个电池单体20之间可以是串联或并联或混联，混联是指多个电池单体20中既有串联又有并联。多个电池单体20之间可直接串联或并联或混联在一起，再将多个电池单体20构成的整体容纳于箱体10内；当然，电池100也可以是多个电池单体20先串联或并联或混联组成电池模块形式，多个电池模块再串联或并联或混联形成一个整体，并整体容纳于箱体10内。
在一些实施例中，电池100还可以包括其他结构，例如，该电池100还可以包括汇流部件，汇流部件用于连接多个电池单体20，以实现多个电池单体20之间的电连接。
其中，每个电池单体20可以为二次电池或一次电池；还可以是锂硫电池、钠离子电池或镁离子电池，但并不局限于此。电池单体20可以呈长方体、圆柱体、棱柱体或其它形状等。示例性地，在图3中，电池单体20为长方体结构。
根据本申请的一些实施例，参照图3，并请进一步参照图4、图5和图6，图4为本申请一些实施例提供的电池单体20的结构爆炸图，图5为本申请一些实施例提供的电池单体20在第一壁的厚度方向X上面向泄压槽2111的正视图，图6为图5所示的电池单体20的A处的局部放大图。本申请提供了一种电池单体20，电池单体20包括外壳21、电极端子22和电极组件23。外壳21具有第一壁211。电极端子22设置于第一壁211。电极组件23容纳于外壳21内，电极组件23与电极端子22电连接。第一壁211设置有泄压槽2111，第一壁211被配置为在电池单体20泄压时能够沿着至少部分泄压槽2111裂开，以泄放电池单体20的内部压力，沿第一壁的厚度方向X，泄压槽2111的投影与电极端子22的投影不重叠，且电极端子22的厚度大于第一壁211的厚度。
其中，外壳21还可以用于容纳电解质，例如，电解液。外壳21可以是多种结构形式，比如，圆柱体、长方体或棱柱结构等。同样地，外壳21的材质也可以是多种，比如，铜、铁、铝、钢或铝合金等。
在一些实施例中，外壳21可以包括壳体212和端盖213，壳体212的内部形成有容纳腔，容纳腔用于容纳电极组件23，且容纳腔具有开口2121，也就是说，壳体212为一端开口2121的空心结构，端盖213盖合于壳体212的开口2121处并形成密封连接，以形成用于容纳电极组件23和电解质的密闭空间。
可选地，壳体212包括一体成型的底壁和侧壁，侧壁围设于底壁的周围，侧壁的一端与底壁相连，另一端围合形成开口2121，端盖213盖合于开口2121且与底壁相对设置，底壁和侧壁共同限定出用于容纳电极组件23的容纳腔。
需要说明的是，设置有泄压槽2111和安装有电极端子22的第一壁211可以是外壳21的端盖213，也可以是外壳21的壳体212的一个壁。示例性地，在图3和图4中，第一壁211为端盖213，即泄压槽2111设置于外壳21的端盖213上，对应地，电极端子22设置于端盖213上，当然，电池单体20的结构并不局限于此，在其他实施例中，第一壁211也可以为壳体212在第一壁的厚度方向X上与端盖213相对设置的底壁，第一壁211还可以是壳体212与端盖213相邻且相互连接的侧壁。
其中，第一壁211设置有安装孔，安装孔沿第一壁的厚度方向X贯穿第一壁211的两侧的表面，安装孔与电极端子22一一对应，电极端子22的至少部分插设于安装孔内或沿第一壁的厚度方向X覆盖安装孔，以使电极端子22能够与容纳于外壳21内的电极组件23电连接。
第一壁211设置有泄压槽2111，即第一壁211上通过一体成型工艺形成有用于泄压的泄压槽2111，也就是说，泄压槽2111为在第一壁211上加工形成的结构，且泄压槽2111的槽底壁为第一壁211的一部分，比如，第一壁211上的泄压槽2111可以通过冲压或刻蚀等一体成型工艺制成。
第一壁211被配置为在电池单体20泄压时能够沿着至少部分泄压槽2111裂开，以泄放电池单体20的内部压力，也就是说，第一壁211设置有泄压槽2111的区域形成第一壁211的薄弱结构，该薄弱结构为电池单体20的外壳21用于泄放电池单体20的内部压力的泄压结构，使得在电池单体20的内部压力或温度达到预定值时第一壁211能够沿着泄压槽2111的槽底壁的至少部分裂开，以泄放电池单体20的内部压力。
可选地，泄压槽2111可以是设置于第一壁211面向电极组件23的一侧的表面上，也可以是设置于第一壁211背离电极组件23的一侧的表面上，同样地，泄压槽2111的形状也可以是多种，比如，泄压槽2111可以是沿直线轨迹延伸的条形结构、“U”形结构、“V”形结构、“S”形结构、“N”形结构、“H”形结构、“Y”形结构、双“Y”形结构、矩形结构、三角形结构、圆形结构或椭圆形结构等。此外，泄压槽2111可以是沿第一壁的厚度方向X设置的多级槽，也可以是仅为一级槽。
沿第一壁的厚度方向X，泄压槽2111的投影与电极端子22的投影不重叠，即在垂直于第一壁的厚度方向X的平面内，泄压槽2111的正投影与电极端子22的正投影不重叠，也就是说，在垂直于第一壁的厚度方向X的方向上，泄压槽2111与电极端子22间隔排布，示例性地，在图5中，泄压槽2111在第一方向Y上位于电极端子22的一侧，即泄压槽2111与电极端子22沿第一方向Y排布，需要说明的是，在电池单体20设置有两个电极端子22，且两个电极端子22均设置于第一壁211上的结构，则两个电极端子22为沿第一方向Y间隔排布的结构，且泄压槽2111在第一方向Y上位于两个电极端子22之间。
电极端子22的厚度大于第一壁211的厚度，也就是说，电极端子22在第一壁的厚度方向X上的整体尺寸大于第一壁211的壁厚。
在组装电池单体20时，可以先将电极组件23放入壳体212内，并向壳体212内填充电解液，之后再将端盖213盖合于壳体212的开口2121，以完成电池单体20的组装。
壳体212可以是多种形状，比如，圆柱体、长方体等。壳体212的形状可根据电极组件23的具体形状来确定。比如，若电极组件23为圆柱体结构，则壳体212可选用圆柱体结构；若电极组件23为长方体结构，则壳体 212可选用长方体结构。当然，端盖213也可以是多种结构，比如，端盖213为板状结构或一端开放的空心结构等。示例性地，在图3和图4中，壳体212为长方体结构，端盖213为矩形板状结构。
当然，可理解地，外壳21并不仅仅局限于上述结构，外壳21也可以是其他结构，比如，外壳21可以包括壳体212和两个端盖213，壳体212为相对的两侧开口2121的空心结构，一个端盖213对应盖合于壳体212的一个开口2121处并形成密封连接，以形成用于容纳电极组件23和电解质的密闭空间，也就是说，壳体212在相对的两侧上均形成有开口2121，且两个端盖213分别盖合于壳体212的两侧，以封闭对应的开口2121，对应地，第一壁211为两个端盖213中的一个端盖213。
需要说明的是，电极组件23是电池单体20中发生电化学反应的部件，电极组件23的结构可以是多种，比如，电极组件23可以是由正极片、隔离件和负极片通过卷绕形成的卷绕式结构，也可以是由正极片、隔离件和负极片通过层叠布置形成的层叠式结构。
示例性地，隔离件为隔离膜，隔离膜的主要材质可选自玻璃纤维、无纺布、聚乙烯、聚丙烯以及聚偏二氟乙烯中的至少一种。
其中，电极组件23在第一壁的厚度方向X上靠近第一壁211的一端形成有极耳231，极耳231用于输入或输出电极组件23的正极或负极，极耳231用于与电极端子22电连接。需要说明的是，电极组件23的极耳231为正极片上未涂覆正极活性物质层的区域相互层叠连接形成的部件或负极片上未涂覆负极活性物质层的区域相互层叠连接形成的部件。若极耳231用于输出电极组件23的正极，则极耳231为正极片上未涂覆正极活性物质层的区域相互层叠连接形成的部件；若极耳231用于输出电极组件23的负极，则极耳231为负极片上未涂覆负极活性物质层的区域相互层叠连接形成的部件。
示例性地，极耳231的材质可以是铜或铝等。
可选地，容纳于外壳21内的电极组件23可以是一个，也可以是多个。示例性地，在图4中，电池单体20的外壳21内设置有两个电极组件23，两个电极组件23沿第二方向Z层叠设置，也就是说，两个电极组件23沿电池单体20的厚度方向层叠设置。当然，在其他实施例中，容纳于外壳21内的电极组件23也可以为一个、三个、四个、五个、六个、七个或八个等。需要说明的是，第一壁的厚度方向X、第一方向Y和第二方向Z两两垂直，第一壁的厚度方向X为电池单体20的高度方向，第一方向Y为电池单体20的长度方向，第二方向Z为电池单体20的厚度方向。
在本申请实施例中，电极端子22起到输入或输出电池单体20的电能的作用，电极端子22与极耳231电连接，以输入或输出电池单体20的电能。
需要说明的是，电极端子22绝缘安装于外壳21的第一壁211上，即电极端子22与外壳21的第一壁211之间未形成电连接，也就是说，电极端子22与第一壁211之间设置有绝缘件，绝缘件用于绝缘隔离电极端子22和第一壁211，以实现电极端子22绝缘安装于外壳21的第一壁211上，且电极端子22和第一壁211的安装孔的孔壁面之间还设置有密封件，密封件用于密封电极端子22和安装孔的孔壁面之间的间隙，以缓解电池单体20内部的电解液从安装孔处泄漏的现象。
其中，在图4和图5中，电池单体20包括两个电极端子22，两个电极端子22均设置于第一壁211上，两个电极端子22沿第一方向Y间隔排布且分别位于泄压槽2111的两侧，即泄压槽2111在第一方向Y上位于两个电极端子22之间，对应地，每个电极组件23具有两个极耳231，且两个极耳231的极性相反，两个电极端子22分别与电极组件23的两个极耳231电连接，以实现电池单体20的正极和负极的输入或输出。需要说明的是，在其他实施例中，两个电极端子22也可以是仅一个电极端子22设置于第一壁211上，另一个电极端子22设置于外壳21的其他壁上。
可选地，电极端子22的材质也可以是多种，比如，电极端子22的材质可以是铜、铁、铝、钢或铝合金等。
在一些实施例中，电池单体20还可以包括两个集流构件，两个集流构件均设置于外壳21内，每个集流构件用于连接一个电极端子22和多个电极组件23中极性相同的极耳231，以实现电极端子22与电极组件23之间的电连接，有利于降低极耳231与电极端子22之间的装配难度。
示例性地，集流构件的材质也可以是多种，比如，集流构件的材质可以是铜、铁、铝、钢或铝合金等。
在本实施例中，第一壁211上设置有泄压槽2111，使得第一壁211在电池单体20泄压时能够沿着至少部分泄压槽2111裂开，以实现对电池单体20的内部压力进行泄放，其中，通过将电极端子22也装配于第一壁211上，电极端子22在第一壁的厚度方向X上的厚度大于第一壁211的厚度，且电极端子22在第一壁的厚度方向X上的投影与泄压槽2111在第一壁的厚度方向X上的投影不重叠，使得这种结构的电池单体20能够将电极端子22和电池单体20用于泄压的结构设置于外壳21的同一个壁上，从而通过电极端子22能够提升第一壁211的结构刚度，以提升第一壁211的抗变形能力，使得在电池单体20的使用过程中能够缓解第一壁211的变形现象，以减少第一壁211设置有泄压槽2111的区域的应变和应变幅，进而能够减少第一壁211设置有泄压槽2111的区域出现低周疲劳的现象，以减少第一壁211设置有泄压槽2111的区域出现疲劳损坏的现象，有利于降低电池单体20出现提前开阀的风险，以提升电池单体20的使用寿命和使用可靠性。
根据本申请的一些实施例，参见图5所示，泄压槽2111与电极端子22沿第一方向Y排布，沿第二方向Z，电极端子22的最大尺寸为D1，第一壁211的最大尺寸为D2，满足，0.4≤D1/D2≤0.9，第一壁的厚度方向X、第一方向Y和第二方向Z两两垂直。
其中，电极端子22的最大尺寸D1为电极端子22在第二方向Z上占用的最大空间。
示例性地，在图5中，电极端子22在第一壁的厚度方向X上的投影为长方形，且电极端子22在第一壁的厚度方向X上的投影的长度方向为第一方向Y，则电极端子22的最大尺寸D1为电极端子22在第二方向Z上的宽 度尺寸。
第一壁211的最大尺寸为D2为第一壁211在第二方向Z上占用的最大空间。
示例性地，在图5中，第一壁211在第一壁的厚度方向X上的投影为长方形，且第一壁211在第一壁的厚度方向X上的投影的长度方向为第一方向Y，则第一壁211的最大尺寸为D2为第一壁211在第二方向Z上的宽度尺寸。
需要说明的是，在其他实施例中，电极端子22也可以是其他形状，比如，参照图7，图7为本申请又一些实施例提供的电池单体20在第一壁的厚度方向X上面向泄压槽2111的正视图，电极端子22在第一壁的厚度方向X上的投影为圆形，则电极端子22的最大尺寸D1为电极端子22的最大直径。
0.4≤D1/D2≤0.9，是指电极端子22在第二方向Z上的最大尺寸D1与第一壁211在第二方向Z上的最大尺寸D2的比值在0.4到0.9。
示例性地，电极端子22在第二方向Z上的最大尺寸D1与第一壁211在第二方向Z上的最大尺寸D2的比值可以为0.4、0.42、0.45、0.48、0.5、0.52、0.55、0.6、0.65、0.7、0.75、0.8、0.85或0.9等。
为了使本申请实施例所解决的技术问题、技术方案及有益效果更加清楚，以下将结合对比例1-2和实施例1-6进行进一步详细说明。显然，所描述的实施例仅仅是本申请一部分实施例，而不是全部的实施例。以下对至少一个示例性实施例的描述实际上仅仅是说明性的，决不作为对本申请及其应用的任何限制。基于本申请中的实施例，本领域普通技术人员在没有付出创造性劳动前提下所获得的所有其他实施例都属于本申请保护的范围。
对比例1
1)正极片的制备
将正极活性材料LiNi0.7Co0.1Mn0.1O2、导电剂Super P、粘结剂聚偏二氟乙烯(PVDF)在N-甲基吡咯烷酮(NMP)中制成正极浆料，其中正极浆料中固体含量为50wt％，固体成分中LiNi0.7Co0.1Mn0.1O2、Super P、PVDF的质量比为8:1:1，将正极浆料涂布在集流体铝箔的上下表面并在85℃下烘干后进行冷压，然后进行切边、裁片、分条后，在85℃的真空条件下烘干4h，制成正极片。
2)负极片的制备
将石墨与导电剂Super P、增稠剂羧甲基纤维素(CMC)、粘接剂丁苯橡胶(SBR)在去离子水中混合均匀，制成负极浆料，其中负极浆料中固体含量为30wt％，固体成分中石墨、氧化亚硅、Super P、CMC及粘接剂丁苯橡胶(SBR)的质量比为88:7:3:2，将负极浆料涂布在集流体铜箔上下表面并在85℃下烘干，然后进行冷压、切边、裁片、分条后，在120℃真空条件下烘干12h，制成负极片。
3)电解质的制备
在氩气气氛手套箱中(H2O<0.1ppm，O2<0.1ppm)，将充分干燥的电解质盐LiPF6溶解于混合溶剂(混合溶剂包括碳酸乙烯酯(EC)和碳酸二乙酯(DEC)，并且碳酸乙烯酯(EC)和碳酸二乙酯(DEC)按照质量比50:50混合)中，混合均匀后获得浓度为1mol/L的液态电解质。
4)隔离件
以16μm的聚乙烯膜作为隔离件。
5)电池单体20的制备
将正极片、隔离件、负极片按顺序叠好，使隔离件处于正负极片中间起到隔离正负极的作用，卷绕得到电极组件23，将电极组件23置于铝制的外壳21内，将上述制备的电解质注入到干燥后的外壳21内，封装、静置、化成、整形、容量测试等，完成电池单体20的制备，电池单体20的外壳21为长方体结构，并在外壳21的第一壁211上安装电极端子22并在第一壁211背离电极组件23的一侧的表面上设置泄压槽2111，泄压槽2111呈“H”形形状，且泄压槽2111为在第一方向Y上位于电极端子22的一侧，其中，对比例1的电池单体20的电极端子22在第二方向Z上的最大尺寸D1为12mm，且第一壁211在第二方向Z上的最大尺寸D2为40mm，以使D1与D2的比值为0.3。
对比例2和实施例1-6的电池单体20的制备方法同于对比例1，区别在于电极端子22在第二方向Z上的最大尺寸D1和第一壁211在第二方向Z上的最大尺寸D2不同，以使D1与D2的比值不同，具体情况如表1所示。
下面通过对比例1-2和实施例1-6对电极端子22在第二方向Z上的最大尺寸D1和第一壁211在第二方向Z上的最大尺寸D2的比值在不同情况下对电池单体20进行实验，以获取电池单体20的循环疲劳次数，具体实验方法和步骤如下：
(1)准备专用测试夹具，具体地，夹具由三片10mm的钢板组成(沿第二方向Z依次排布的第一钢板、第二钢板和第三钢板，且第一钢板、第二钢板和第三钢板的厚度方向均为第二方向Z)，第一钢板、第三钢板位于夹具两端，由螺栓连接固定，第二钢板位于第一钢板和第三钢板之间，且第二钢板通过导轨约束，第二钢板只能沿其厚度方向平移活动；
(2)将电池单体20安装在第一钢板和第二钢板之间(即第二方向Z放置于第一钢板和第二钢板之间)，电池单体20一侧最大的外表面与第一钢板之间以及电池单体20另一侧最大的外表面与第二钢板之间均放置支撑结构(即电池单体20在第二方向Z上的两侧均放置有支撑结构)，支撑结构可以为隔热垫或者水冷板(与实际电池100内电池单体20之间的材料/结构保持一致)，支撑结构可以被压缩，为电池单体20在充放电循环老化过程中提供膨胀空间；电池单体20一侧最大的外表面与支撑结构贴合，第一钢板与对应的支撑结构贴合，第二钢板与对应的支撑结构贴合，第二钢板和第三钢板之间设有压力传感器；
(3)通过调节螺栓的预紧力，以调节第二钢板的位置，观察压力传感器，使得电池单体20受到初始挤压力为2000N，并将电池单体20的两个电极端子22连接到专用的电池100充放电设备上；
(4)将电池单体20和夹具放置到25±2℃恒温环境中，使电池单体20达到温度平衡后开启测试；
(5)测试步骤参照《GBT31484-2015电动汽车用动力蓄电池100循环寿命要求及试验方法》中6.4章节“标准循环寿命”执行，且将测试循环截止条件更改为“直至第一壁211设置泄压槽2111的区域出现破损则停止测试”。
具体而言，按照如下步骤测试：
a、以1I1(A)电流放电至2.8V；
b、搁置不低于30min；
c、按照《GBT31484-2015电动汽车用动力蓄电池100循环寿命要求及试验方法》6.1.1.3方法充电；
d、搁置不低于30min；
e、以1I1(A)电流放电至2.8V；
f、按照b～e循环，直至第一壁211设置泄压槽2111的区域出现破损则停止测试。
即测试过程持续观察第一壁211设置泄压槽2111的区域，直至第一壁211设置泄压槽2111的区域出现破损漏液，则记录循环次数为电池单体20的循环疲劳次数，其中，电池单体20的循环疲劳次数越多，说明第一壁211设置泄压槽2111的区域在长期使用过程中出现提前开裂的概率较小，使用寿命就越长，从而能够通过电池单体20的循环疲劳次数进行合理预测第一壁211设置泄压槽2111的区域在使用过程中出现提前开裂的情况。
其中，对比例1-2和实施例1-6的实验结果如下表1所示。
表1
参见表1所示，综合对比例1-2和实施例1-6的实验结果可知，在电极端子22在第二方向Z上的最大尺寸D1和第一壁211在第二方向Z上的最大尺寸D2的比值小于0.4时，电池单体20的循环疲劳次数不足1000次，使得外壳21的第一壁211设置泄压槽2111的区域在使用过程中极容易出现提前开裂的现象，由此造成电池单体20在使用过程中的使用寿命较短，而在电极端子22在第二方向Z上的最大尺寸D1和第一壁211在第二方向Z上的最大尺寸D2的比值大于或等于0.4时，电池单体20的循环疲劳次数能够达到1200次以上，从而能够减少外壳21的第一壁211设置泄压槽2111的区域在使用过程中出现提前开裂等现象，有利于提升电池单体20的使用寿命，因此，将电极端子22在第二方向Z上的最大尺寸D1和第一壁211在第二方向Z上的最大尺寸D2的比值设置为大于或等于0.4。
同样地，在电极端子22在第二方向Z上的最大尺寸D1和第一壁211在第二方向Z上的最大尺寸D2的比值大于0.9后，虽然电池单体20的循环疲劳次数更高，但是会导致电极端子22在第二方向Z上靠近第一壁211的外边缘，且会导致第一壁211用于安装电极端子22的安装孔过大，安装孔的孔壁面已经接近第一壁211的外边缘，造成第一壁211装配电极端子22的区域的结构强度较低，极容易在运输、生产和使用中发生破坏，因此，将电极端子22在第二方向Z上的最大尺寸D1和第一壁211在第二方向Z上的最大尺寸D2的比值设置为小于或等于0.9。
在本实施例中，电极端子22在第二方向Z上的最大尺寸与第一壁211在第二方向Z上的最大尺寸的比值为0.4到0.9，一方面通过将电极端子22在第二方向Z上的最大尺寸与第一壁211在第二方向Z上的最大尺寸的比值设置为大于或等于0.4能够提升电极端子22在第二方向Z上占用第一壁211的空间大小，有利于提升电极端子22对第一壁211的结构刚度的加强作用，以提升第一壁211的抗变形能力，使得在电池单体20的使用过程中能够缓解第一壁211的变形现象，以减少第一壁211设置有泄压槽2111的区域的应变和应变幅，进而能够减少第一壁211设置有泄压槽2111的区域出现低周疲劳的现象，有利于降低电池单体20出现提前开阀的风险，以提升电池单体20的使用寿命和使用可靠性，另一方面通过将电极端子22在第二方向Z上的最大尺寸与第一壁211在第二方向Z上的最大尺寸的比值设置为小于或等于0.9能够缓解电极端子22在第二方向Z上占用第一壁211的空间过大的现象，以减少用于安装电极端子22的安装孔的开孔过大的现象，从而能够降低电极端子22的装配难度和安装孔的制造难度，以降低电池单体20的制造难度，且能够缓解第一壁211设置安装孔的区域的结构强度太低的现象，以降低第一壁211在加工生产或使用过程中出现断裂或损坏的风险。
根据本申请的一些实施例，请继续参见图5所示，沿第二方向Z，电极端子22的最大尺寸为D1，第一壁211的最大尺寸为D2，满足，0.6≤D1/D2≤0.9。
其中，请继续参见表1所示，并综合对比例1-2和实施例1-6的实验结果可知，在电极端子22在第二方向Z上的最大尺寸D1和第一壁211在第二方向Z上的最大尺寸D2的比值大于或等于0.6时，电池单体20的循环疲劳次数能够达到1500次以上，从而能够进一步减少外壳21的第一壁211设置泄压槽2111的区域在使用过程中出现提前开裂等现象，有利于提升电池单体20的使用寿命，因此，将电极端子22在第二方向Z上的最大尺寸D1和第一壁211在第二方向Z上的最大尺寸D2的比值进一步设置为大于或等于0.6。
在本实施例中，通过将电极端子22在第二方向Z上的最大尺寸与第一壁211在第二方向Z上的最大尺寸的比值进一步设置为大于或等于0.6能够进一步提升电极端子22在第二方向Z上占用第一壁211的空间大小，有利于进一步提升电极端子22对第一壁211的结构刚度的加强作用，以提升第一壁211的抗变形能力，使得在电池单体20的使用过程中能够进一步缓解第一壁211的变形现象，以减少第一壁211设置有泄压槽2111的区域的应变和应变幅，进而能够进一步减少第一壁211设置有泄压槽2111的区域出现低周疲劳的现象，有利于进一步降低电池单体20出现提前开阀的风险，以提升电池单体20的使用寿命和使用可靠性。
根据本申请的一些实施例，参见图5以及图7所示，第一壁211的外边缘包括第一边缘2112，第一边缘2112和泄压槽2111在第一方向Y上分别位于电极端子22的两侧，第一方向Y垂直于第一壁的厚度方向X。沿第一方向Y，泄压槽2111与电极端子22的最小距离为L1，泄压槽2111与第一边缘2112的最小距离为L2，满足，0.2≤L1/L2≤0.8。
其中，第一壁211的外边缘包括第一边缘2112，第一边缘2112和泄压槽2111在第一方向Y上分别位于电极端子22的两侧，也就是说，第一边缘2112为第一壁211在第一方向Y上的一侧的边缘，泄压槽2111、电极端子22和第一边缘2112沿第一方向Y依次排布。
示例性地，在图5中，第一壁211在第一壁的厚度方向X上的投影为长方形，且第一壁211在第一壁的厚度方向X上的投影的长度方向为第一方向Y，则第一壁211在第一方向Y上的两端均形成有第一边缘2112，在这种实施例中，则L2取泄压槽2111与第一边缘2112之间设置有电极端子22的区域在第一方向Y上的距离。
在图5中，在第一壁211上设置有两个电极端子22，泄压槽2111在第一方向Y上设置于两个电极端子22之间，且第一壁211在第一方向Y上的两端均形成有第一边缘2112的实施中，则L1取泄压槽2111与其中一个电极端子22在第一方向Y上的距离，而L2取泄压槽2111与第一边缘2112之间设置有对应的电极端子22的区域在第一方向Y上的距离，也就是说，L1和L2的取值均基于同一个电极端子22。
需要说明的是，若第一壁211为外壳21的端盖213，则第一边缘2112为第一壁211在第一壁的厚度方向X上的投影在第一方向Y上的边缘；若第一壁211为壳体212的底壁，则第一边缘2112为壳体212在第一方向Y上连接于第一壁211的一端的壁背离电极组件23的外表面，也就是说，第一壁211的边缘处形成的圆角区域或倒角区域均属于第一壁211。
泄压槽2111与电极端子22的最小距离L1为泄压槽2111和电极端子22在第一方向Y上的间距。
泄压槽2111与第一边缘2112的最小距离L2为泄压槽2111与第一边缘2112在第一方向Y上的间距。
0.2≤L1/L2≤0.8，是指泄压槽2111与电极端子22在第一方向Y上的最小距离和泄压槽2111与第一边缘2112在第一方向Y上的最小距离的比值为0.2到0.8。
示例性地，泄压槽2111与电极端子22在第一方向Y上的最小距离和泄压槽2111与第一边缘2112在第一方向Y上的最小距离的比值可以为0.2、0.22、0.25、0.28、0.3、0.32、0.35、0.4、0.45、0.5、0.55、0.6、0.65、0.7、0.75或0.8等。
为了使本申请实施例所解决的技术问题、技术方案及有益效果更加清楚，以下将结合对比例3-5和实施例7-11进行进一步详细说明。显然，所描述的实施例仅仅是本申请一部分实施例，而不是全部的实施例。以下对至少一个示例性实施例的描述实际上仅仅是说明性的，决不作为对本申请及其应用的任何限制。基于本申请中的实施例，本领域普通技术人员在没有付出创造性劳动前提下所获得的所有其他实施例都属于本申请保护的范围。
对比例3
1)正极片的制备
将正极活性材料LiNi0.7Co0.1Mn0.1O2、导电剂Super P、粘结剂聚偏二氟乙烯(PVDF)在N-甲基吡咯烷酮(NMP)中制成正极浆料，其中正极浆料中固体含量为50wt％，固体成分中LiNi0.7Co0.1Mn0.1O2、Super P、PVDF的质量比为8:1:1，将正极浆料涂布在集流体铝箔的上下表面并在85℃下烘干后进行冷压，然后进行切边、裁片、分条后，在85℃的真空条件下烘干4h，制成正极片。
2)负极片的制备
将石墨与导电剂Super P、增稠剂羧甲基纤维素(CMC)、粘接剂丁苯橡胶(SBR)在去离子水中混合均匀，制成负极浆料，其中负极浆料中固体含量为30wt％，固体成分中石墨、氧化亚硅、Super P、CMC及粘接剂丁苯橡胶(SBR)的质量比为88:7:3:2，将负极浆料涂布在集流体铜箔上下表面并在85℃下烘干，然后进行冷压、切边、裁片、分条后，在120℃真空条件下烘干12h，制成负极片。
3)电解质的制备
在氩气气氛手套箱中(H2O<0.1ppm，O2<0.1ppm)，将充分干燥的电解质盐LiPF6溶解于混合溶剂(混合溶剂包括碳酸乙烯酯(EC)和碳酸二乙酯(DEC)，并且碳酸乙烯酯(EC)和碳酸二乙酯(DEC)按照质量比50:50混合)中，混合均匀后获得浓度为1mol/L的液态电解质。
4)隔离件
以16μm的聚乙烯膜作为隔离件。
5)电池单体20的制备
将正极片、隔离件、负极片按顺序叠好，使隔离件处于正负极片中间起到隔离正负极的作用，卷绕得到电极组件23，将电极组件23置于铝制的外壳21内，将上述制备的电解质注入到干燥后的外壳21内，封装、静置、化成、整形、容量测试等，完成电池单体20的制备，电池单体20的外壳21为长方体结构，并在外壳21的第一壁211上安装电极端子22并在第一壁211背离电极组件23的一侧的表面上设置泄压槽2111，泄压槽2111呈“H”形形状，且泄压槽2111为在第一方向Y上位于电极端子22的一侧，其中，对比例3的电池单体20的泄压槽2111与电极端子22在第一方向Y上的最小距离L1为5mm，且泄压槽2111与第一边缘2112在第一方向Y上的最小 距离L2为30mm，以使L1与L2的比值为0.167。
对比例4-5和实施例7-11的电池单体20的制备方法同于对比例3，区别在于泄压槽2111与电极端子22在第一方向Y上的最小距离L1和泄压槽2111与第一边缘2112在第一方向Y上的最小距离L2不同，以使L1与L2的比值不同，具体情况如表2所示。
下面通过对比例3-5和实施例7-11对泄压槽2111与电极端子22在第一方向Y上的最小距离L1和泄压槽2111与第一边缘2112在第一方向Y上的最小距离L2的比值在不同情况下对电池单体20进行实验，以获取电池单体20的循环疲劳次数，具体实验方法和步骤如下：
(1)准备专用测试夹具，具体地，夹具由三片10mm的钢板组成(沿第二方向Z依次排布的第一钢板、第二钢板和第三钢板，且第一钢板、第二钢板和第三钢板的厚度方向均为第二方向Z)，第一钢板、第三钢板位于夹具两端，由螺栓连接固定，第二钢板位于第一钢板和第三钢板之间，且第二钢板通过导轨约束，第二钢板只能沿其厚度方向平移活动；
(2)将电池单体20安装在第一钢板和第二钢板之间(即第二方向Z放置于第一钢板和第二钢板之间)，电池单体20一侧最大的外表面与第一钢板之间以及电池单体20另一侧最大的外表面与第二钢板之间均放置支撑结构(即电池单体20在第二方向Z上的两侧均放置有支撑结构)，支撑结构可以为隔热垫或者水冷板(与实际电池100内电池单体20之间的材料/结构保持一致)，支撑结构可以被压缩，为电池单体20在充放电循环老化过程中提供膨胀空间；电池单体20一侧最大的外表面与支撑结构贴合，第一钢板与对应的支撑结构贴合，第二钢板与对应的支撑结构贴合，第二钢板和第三钢板之间设有压力传感器；
(3)通过调节螺栓的预紧力，以调节第二钢板的位置，观察压力传感器，使得电池单体20受到初始挤压力为2000N，并将电池单体20的两个电极端子22连接到专用的电池100充放电设备上；
(4)将电池单体20和夹具放置到25±2℃恒温环境中，使电池单体20达到温度平衡后开启测试；
(5)测试步骤参照《GBT31484-2015电动汽车用动力蓄电池100循环寿命要求及试验方法》中6.4章节“标准循环寿命”执行，且将测试循环截止条件更改为“直至第一壁211设置泄压槽2111的区域出现破损则停止测试”。
具体而言，按照如下步骤测试：
a、以1I1(A)电流放电至2.8V；
b、搁置不低于30min；
c、按照《GBT31484-2015电动汽车用动力蓄电池100循环寿命要求及试验方法》6.1.1.3方法充电；
d、搁置不低于30min；
e、以1I1(A)电流放电至2.8V；
f、按照b～e循环，直至第一壁211设置泄压槽2111的区域出现破损则停止测试。
即测试过程持续观察第一壁211设置泄压槽2111的区域，直至第一壁211设置泄压槽2111的区域出现破损漏液，则记录循环次数为电池单体20的循环疲劳次数，其中，电池单体20的循环疲劳次数越多，说明第一壁211设置泄压槽2111的区域在长期使用过程中出现提前开裂的概率较小，使用寿命就越长，从而能够通过电池单体20的循环疲劳次数进行合理预测第一壁211设置泄压槽2111的区域在使用过程中出现提前开裂的情况。
其中，对比例3-5和实施例7-11的实验结果如下表2所示。
表2
参见表2所示，综合对比例3-5和实施例7-11的实验结果可知，在泄压槽2111与电极端子22在第一方向Y上的最小距离L1和泄压槽2111与第一边缘2112在第一方向Y上的最小距离L2的比值大于0.8时，电池单体20的循环疲劳次数不足1000次，使得外壳21的第一壁211设置泄压槽2111的区域在使用过程中极容易出现提前开裂的现象，由此造成电池单体20在使用过程中的使用寿命较短，而在泄压槽2111与电极端子22在第一方向Y上的最小距离L1和泄压槽2111与第一边缘2112在第一方向Y上的最小距离L2的比值小于或等于0.8时，电池单体20的循环疲劳次数能够接近1200次，从而能够减少外壳21的第一壁211设置泄压槽2111的区域在使用过程中出现提前开裂等现象，有利于提升电池单体20的使用寿命，因此，将泄压槽2111与电极端子22在第一方向Y上的最小距离L1和泄压槽2111与第一边缘2112在第一方向Y上的最小距离L2的比值设置为小于或等于0.8。
同样地，在泄压槽2111与电极端子22在第一方向Y上的最小距离L1和泄压槽2111与第一边缘2112在第一方向Y上的最小距离L2的比值小于或等于0.2后，虽然电池单体20的循环疲劳次数更高，但是会导致泄压槽2111与电极端子22较为接近，使得第一壁211在沿着泄压槽2111裂开并泄放电池单体20的内部压力时，电池单体20内部的热失控气体极容易对连接于电极端子22上的汇流部件进行冲击，从而会造成汇流部件上的绝缘层被破 坏，以导致短路并导致热扩散，因此，将泄压槽2111与电极端子22在第一方向Y上的最小距离L1和泄压槽2111与第一边缘2112在第一方向Y上的最小距离L2的比值设置为大于或等于0.2。
在本实施例中，泄压槽2111与电极端子22在第一方向Y上的最小距离与泄压槽2111与第一边缘2112在第一方向Y上的最小距离的比值为0.2到0.8，一方面通过将泄压槽2111与电极端子22在第一方向Y上的最小距离与泄压槽2111与第一边缘2112在第一方向Y上的最小距离的比值设置为小于或等于0.8，使得泄压槽2111在第一方向Y上更接近电极端子22，以提升电极端子22对第一壁211设置有泄压槽2111的区域的结构刚度的加强作用，有利于减少第一壁211设置有泄压槽2111的区域的应变和应变幅，从而能够减少第一壁211设置有泄压槽2111的区域出现低周疲劳的现象，以降低电池单体20出现提前开阀的风险，进而能够有效提升电池单体20的使用寿命和使用可靠性，另一方面通过将泄压槽2111与电极端子22在第一方向Y上的最小距离与泄压槽2111与第一边缘2112在第一方向Y上的最小距离的比值设置为大于或等于0.2，以缓解泄压槽2111过度靠近电极端子22的现象，从而在第一壁211沿着泄压槽2111的至少部分裂开并泄放电池单体20的内部压力时能够减少电池单体20内部的热失控气体对电极端子22以及连接于电极端子22上的其他部件的冲击现象，进而能够降低因电极端子22以及连接于电极端子22上的其他部件损坏而带来的短接风险或热扩散风险，以提升电池单体20的使用可靠性。
根据本申请的一些实施例，请继续参见图5和图7所示，沿第一方向Y，泄压槽2111与电极端子22的最小距离为L1，泄压槽2111与第一边缘2112的最小距离为L2，满足，0.2≤L1/L2≤0.6。
其中，请继续参见表2所示，并综合对比例3-5和实施例7-11的实验结果可知，在泄压槽2111与电极端子22在第一方向Y上的最小距离L1和泄压槽2111与第一边缘2112在第一方向Y上的最小距离L2的比值小于或等于0.6时，电池单体20的循环疲劳次数能够达到1500次以上，从而能够进一步减少外壳21的第一壁211设置泄压槽2111的区域在使用过程中出现提前开裂等现象，有利于提升电池单体20的使用寿命，因此，将泄压槽2111与电极端子22在第一方向Y上的最小距离L1和泄压槽2111与第一边缘2112在第一方向Y上的最小距离L2的比值进一步设置为小于或等于0.6。
在本实施例中，通过将泄压槽2111与电极端子22在第一方向Y上的最小距离与泄压槽2111与第一边缘2112在第一方向Y上的最小距离的比值进一步设置为小于或等于0.6，使得泄压槽2111在第一方向Y上能够进一步接近电极端子22，以进一步提升电极端子22对第一壁211设置有泄压槽2111的区域的结构刚度的加强作用，有利于减少第一壁211设置有泄压槽2111的区域的应变和应变幅，从而能够进一步减少第一壁211设置有泄压槽2111的区域出现低周疲劳的现象，以进一步降低电池单体20出现提前开阀的风险，进而能够有效提升电池单体20的使用寿命和使用可靠性。
根据本申请的一些实施例，参见图5以及图7所示，泄压槽2111与电极端子22沿第一方向Y排布，第一方向Y垂直于第一壁的厚度方向X。沿第一方向Y，泄压槽2111与电极端子22的最小距离为L1，第一壁211位于泄压槽2111和电极端子22之间的部分的厚度为D，满足，3≤L1/D≤30。
其中，第一壁211位于泄压槽2111和电极端子22之间的部分的厚度为D(图中未示出)为第一壁211沿第一方向Y位于泄压槽2111和电极端子22之间的部分在第一壁的厚度方向X上的尺寸，也为第一壁211在第一方向Y上位于泄压槽2111和电极端子22之间的部分的壁厚。
3≤L1/D≤30，是指泄压槽2111与电极端子22在第一方向Y上的最小距离和第一壁211在第一方向Y上位于泄压槽2111和电极端子22之间的部分的壁厚的比值为3到30。
示例性地，泄压槽2111与电极端子22在第一方向Y上的最小距离和第一壁211在第一方向Y上位于泄压槽2111和电极端子22之间的部分的壁厚的比值可以为3、3.5、4、4.5、5、5.5、6、7、8、9、10、12、12.5、15、16、18、20、21、22、25、26、28、29或30等。
为了使本申请实施例所解决的技术问题、技术方案及有益效果更加清楚，以下将结合对比例6和实施例12-18进行进一步详细说明。显然，所描述的实施例仅仅是本申请一部分实施例，而不是全部的实施例。以下对至少一个示例性实施例的描述实际上仅仅是说明性的，决不作为对本申请及其应用的任何限制。基于本申请中的实施例，本领域普通技术人员在没有付出创造性劳动前提下所获得的所有其他实施例都属于本申请保护的范围。
对比例6
1)正极片的制备
将正极活性材料LiNi0.7Co0.1Mn0.1O2、导电剂Super P、粘结剂聚偏二氟乙烯(PVDF)在N-甲基吡咯烷酮(NMP)中制成正极浆料，其中正极浆料中固体含量为50wt％，固体成分中LiNi0.7Co0.1Mn0.1O2、Super P、PVDF的质量比为8:1:1，将正极浆料涂布在集流体铝箔的上下表面并在85℃下烘干后进行冷压，然后进行切边、裁片、分条后，在85℃的真空条件下烘干4h，制成正极片。
2)负极片的制备
将石墨与导电剂Super P、增稠剂羧甲基纤维素(CMC)、粘接剂丁苯橡胶(SBR)在去离子水中混合均匀，制成负极浆料，其中负极浆料中固体含量为30wt％，固体成分中石墨、氧化亚硅、Super P、CMC及粘接剂丁苯橡胶(SBR)的质量比为88:7:3:2，将负极浆料涂布在集流体铜箔上下表面并在85℃下烘干，然后进行冷压、切边、裁片、分条后，在120℃真空条件下烘干12h，制成负极片。
3)电解质的制备
在氩气气氛手套箱中(H2O<0.1ppm，O2<0.1ppm)，将充分干燥的电解质盐LiPF6溶解于混合溶剂(混合溶剂包括碳酸乙烯酯(EC)和碳酸二乙酯(DEC)，并且碳酸乙烯酯(EC)和碳酸二乙酯(DEC)按照质量比50:50混合)中，混合均匀后获得浓度为1mol/L的液态电解质。
4)隔离件
以16μm的聚乙烯膜作为隔离件。
5)电池单体20的制备
将正极片、隔离件、负极片按顺序叠好，使隔离件处于正负极片中间起到隔离正负极的作用，卷绕得到电极组件23，将电极组件23置于铝制的外壳21内，将上述制备的电解质注入到干燥后的外壳21内，封装、静置、化成、整形、容量测试等，完成电池单体20的制备，电池单体20的外壳21为长方体结构，并在外壳21的第一壁211上安装电极端子22并在第一壁211背离电极组件23的一侧的表面上设置泄压槽2111，泄压槽2111呈“H”形形状，且泄压槽2111为在第一方向Y上位于电极端子22的一侧，其中，对比例6的电池单体20的泄压槽2111与电极端子22在第一方向Y上的最小距离L1为28mm，且第一壁211位于泄压槽2111和电极端子22之间的部分的厚度D为0.8mm，以使L1与D的比值为35。
实施例12-18的电池单体20的制备方法同于对比例6，区别在于泄压槽2111与电极端子22在第一方向Y上的最小距离L1和第一壁211位于泄压槽2111和电极端子22之间的部分的厚度D不同，以使L1与D的比值不同，具体情况如表3所示。
下面通过对比例6和实施例12-18对泄压槽2111与电极端子22在第一方向Y上的最小距离L1和第一壁211位于泄压槽2111和电极端子22之间的部分的厚度D的比值在不同情况下对电池单体20进行实验，以获取电池单体20的循环疲劳次数，具体实验方法和步骤如下：
(1)准备专用测试夹具，具体地，夹具由三片10mm的钢板组成(沿第二方向Z依次排布的第一钢板、第二钢板和第三钢板，且第一钢板、第二钢板和第三钢板的厚度方向均为第二方向Z)，第一钢板、第三钢板位于夹具两端，由螺栓连接固定，第二钢板位于第一钢板和第三钢板之间，且第二钢板通过导轨约束，第二钢板只能沿其厚度方向平移活动；
(2)将电池单体20安装在第一钢板和第二钢板之间(即第二方向Z放置于第一钢板和第二钢板之间)，电池单体20一侧最大的外表面与第一钢板之间以及电池单体20另一侧最大的外表面与第二钢板之间均放置支撑结构(即电池单体20在第二方向Z上的两侧均放置有支撑结构)，支撑结构可以为隔热垫或者水冷板(与实际电池100内电池单体20之间的材料/结构保持一致)，支撑结构可以被压缩，为电池单体20在充放电循环老化过程中提供膨胀空间；电池单体20一侧最大的外表面与支撑结构贴合，第一钢板与对应的支撑结构贴合，第二钢板与对应的支撑结构贴合，第二钢板和第三钢板之间设有压力传感器；
(3)通过调节螺栓的预紧力，以调节第二钢板的位置，观察压力传感器，使得电池单体20受到初始挤压力为2000N，并将电池单体20的两个电极端子22连接到专用的电池100充放电设备上；
(4)将电池单体20和夹具放置到25±2℃恒温环境中，使电池单体20达到温度平衡后开启测试；
(5)测试步骤参照《GBT31484-2015电动汽车用动力蓄电池100循环寿命要求及试验方法》中6.4章节“标准循环寿命”执行，且将测试循环截止条件更改为“直至第一壁211设置泄压槽2111的区域出现破损则停止测试”。
具体而言，按照如下步骤测试：
a、以1I1(A)电流放电至2.8V；
b、搁置不低于30min；
c、按照《GBT31484-2015电动汽车用动力蓄电池100循环寿命要求及试验方法》6.1.1.3方法充电；
d、搁置不低于30min；
e、以1I1(A)电流放电至2.8V；
f、按照b～e循环，直至第一壁211设置泄压槽2111的区域出现破损则停止测试。
即测试过程持续观察第一壁211设置泄压槽2111的区域，直至第一壁211设置泄压槽2111的区域出现破损漏液，则记录循环次数为电池单体20的循环疲劳次数，其中，电池单体20的循环疲劳次数越多，说明第一壁211设置泄压槽2111的区域在长期使用过程中出现提前开裂的概率较小，使用寿命就越长，从而能够通过电池单体20的循环疲劳次数进行合理预测第一壁211设置泄压槽2111的区域在使用过程中出现提前开裂的情况。
其中，对比例6和实施例12-18的实验结果如下表3所示。
表3
参见表3所示，综合对比例6和实施例12-18的实验结果可知，在泄压槽2111与电极端子22在第一方向Y上的最小距离L1和第一壁211位于泄压槽2111和电极端子22之间的部分的厚度D的比值位35时，电池单体20的循环疲劳次数不足1000次，使得外壳21的第一壁211设置泄压槽2111的区域在使用过程中极容易出现提前开裂的现象，由此造成电池单体20在使用过程中的使用寿命较短，而在泄压槽2111与电极端子22在第一方向Y上的最小距离L1和第一壁211位于泄压槽2111和电极端子22之间的部分的厚度D的比值小于或等于30时，电池单体20的循环疲劳次数能够接近1200次，从而能够减少外壳21的第一壁211设置泄压槽2111的区域在使用过程 中出现提前开裂等现象，有利于提升电池单体20的使用寿命，因此，将泄压槽2111与电极端子22在第一方向Y上的最小距离L1和第一壁211位于泄压槽2111和电极端子22之间的部分的厚度D的比值设置为小于或等于30。
同样地，基于表3可以看出，在泄压槽2111与电极端子22在第一方向Y上的最小距离L1和第一壁211位于泄压槽2111和电极端子22之间的部分的厚度D的比值越小，甚至比值达到3时，电池单体20的循环疲劳次数变化已不再明显，但是泄压槽2111与电极端子22在第一方向Y上的最小距离会越来越小，反之第一壁211位于泄压槽2111和电极端子22之间的部分的厚度会越来越大，因此，为减少过度浪费的现象，将泄压槽2111与电极端子22在第一方向Y上的最小距离L1和第一壁211位于泄压槽2111和电极端子22之间的部分的厚度D的比值设置为大于或等于3。
在本实施例中，泄压槽2111与电极端子22在第一方向Y上的最小距离和第一壁211位于泄压槽2111和电极端子22之间的部分的厚度的比值为3到30，一方面通过将泄压槽2111与电极端子22在第一方向Y上的最小距离和第一壁211位于泄压槽2111和电极端子22之间的部分的厚度的比值设置为小于或等于30，以缓解泄压槽2111与电极端子22在第一方向Y上的最小距离过大且第一壁211位于泄压槽2111和电极端子22之间的部分的厚度过小的现象，有利于提升电极端子22和第一壁211对第一壁211设置有泄压槽2111的区域的结构刚度的加强作用，以减少第一壁211设置有泄压槽2111的区域的应变和应变幅，从而能够减少第一壁211设置有泄压槽2111的区域出现低周疲劳的现象，以降低电池单体20出现提前开阀的风险，进而能够有效提升电池单体20的使用寿命和使用可靠性，另一方面通过将泄压槽2111与电极端子22在第一方向Y上的最小距离和第一壁211位于泄压槽2111和电极端子22之间的部分的厚度的比值设置为大于或等于3，以缓解泄压槽2111与电极端子22在第一方向Y上的最小距离过小且第一壁211位于泄压槽2111和电极端子22之间的部分的厚度过大的现象，从而能够缓解第一壁211的厚度出现过度浪费的现象，以降低电池单体20的制造成本，且在第一壁211沿着泄压槽2111的至少部分裂开并泄放电池单体20的内部压力时能够减少电池单体20内部的热失控气体对电极端子22以及连接于电极端子22上的其他部件的冲击现象，进而能够降低因电极端子22以及连接于电极端子22上的其他部件损坏而带来的短接风险或热扩散风险，以提升电池单体20的使用可靠性。
根据本申请的一些实施例，请继续参见图5和图7所示，沿第一方向Y，泄压槽2111与电极端子22的最小距离为L1，第一壁211位于泄压槽2111和电极端子22之间的部分的厚度为D，满足，5≤L1/D≤25。
其中，请继续参见表3所示，并综合对比例6和实施例12-18的实验结果可知，在泄压槽2111与电极端子22在第一方向Y上的最小距离L1和第一壁211位于泄压槽2111和电极端子22之间的部分的厚度D的比值小于或等于25时，电池单体20的循环疲劳次数能够达到1500次以上，从而能够进一步减少外壳21的第一壁211设置泄压槽2111的区域在使用过程中出现提前开裂等现象，有利于提升电池单体20的使用寿命，因此，将泄压槽2111与电极端子22在第一方向Y上的最小距离L1和第一壁211位于泄压槽2111和电极端子22之间的部分的厚度D的比值进一步设置为小于或等于25。而在泄压槽2111与电极端子22在第一方向Y上的最小距离L1和第一壁211位于泄压槽2111和电极端子22之间的部分的厚度D的比值小于5以后，电池单体20的循环疲劳次数变化已不再明显，因此，为减少过度浪费的现象，将泄压槽2111与电极端子22在第一方向Y上的最小距离L1和第一壁211位于泄压槽2111和电极端子22之间的部分的厚度D的比值设置为大于或等于5。
在本实施例中，通过将泄压槽2111与电极端子22在第一方向Y上的最小距离和第一壁211位于泄压槽2111和电极端子22之间的部分的厚度的比值设置为小于或等于25，以进一步缓解泄压槽2111与电极端子22在第一方向Y上的最小距离过大且第一壁211位于泄压槽2111和电极端子22之间的部分的厚度过小的现象，有利于进一步提升电极端子22和第一壁211对第一壁211设置有泄压槽2111的区域的结构刚度的加强作用，以进一步减少第一壁211设置有泄压槽2111的区域的应变和应变幅，从而能够有效减少第一壁211设置有泄压槽2111的区域出现低周疲劳的现象，以进一步降低电池单体20出现提前开阀的风险，同样地，通过将泄压槽2111与电极端子22在第一方向Y上的最小距离和第一壁211位于泄压槽2111和电极端子22之间的部分的厚度的比值设置为大于或等于5，以进一步缓解泄压槽2111与电极端子22在第一方向Y上的最小距离过小且第一壁211位于泄压槽2111和电极端子22之间的部分的厚度过大的现象，一方面能够进一步缓解第一壁211的厚度出现过度浪费的现象，另一方面在第一壁211沿着泄压槽2111的至少部分裂开并泄放电池单体20的内部压力时能够进一步减少电池单体20内部的热失控气体对电极端子22以及连接于电极端子22上的其他部件的冲击现象。
在一些实施例中，第一壁211位于泄压槽2111和电极端子22之间的部分的厚度为D，满足，0.8mm≤D≤4mm。
示例性地，第一壁211位于泄压槽2111和电极端子22之间的部分的厚度D可以是0.8mm、0.9mm、1mm、1.1mm、1.2mm、1.3mm、1.5mm、1.8mm、2mm、2.2mm、2.5mm、3mm、3.5mm或4mm等。
在本实施例中，通过将第一壁211位于泄压槽2111和电极端子22之间的部分的厚度设置为大于或等于0.8mm，且小于或等于4mm，一方面能够提升第一壁211位于泄压槽2111和电极端子22之间的部分的结构强度，以降低第一壁211在使用过程中出现断裂或破损的风险，另一方面能够减少第一壁211的厚度出现过度浪费的现象，有利于降低第一壁211的制造难度和制造成本。
根据本申请的一些实施例，参见图5以及图7所示，泄压槽2111与电极端子22沿第一方向Y排布，第一方向Y垂直于第一壁的厚度方向X。沿第一方向Y，泄压槽2111与电极端子22的最小距离为L1，满足，10mm≤L1≤100mm。
示例性地，泄压槽2111与电极端子22的最小距离L1可以为10mm、12mm、15mm、18mm、20mm、25mm、30mm、35mm、40mm、45mm、50mm、55mm、60mm、65mm、70mm、75mm、80mm、85mm、90mm、95mm或100mm等。
在本实施例中，泄压槽2111与电极端子22在第一方向Y上的最小距离10mm到100mm，一方面通过将泄压槽2111与电极端子22在第一方向Y上的最小距离设置为小于或等于100mm，使得泄压槽2111较为靠近电极端子 22，以提升电极端子22对第一壁211设置有泄压槽2111的区域的结构刚度的加强作用，有利于减少第一壁211设置有泄压槽2111的区域的应变和应变幅，从而能够减少第一壁211设置有泄压槽2111的区域出现低周疲劳的现象，以降低电池单体20出现提前开阀的风险，进而能够有效提升电池单体20的使用寿命和使用可靠性，另一方面通过将泄压槽2111与电极端子22在第一方向Y上的最小距离设置为大于或等于10mm，以缓解泄压槽2111过度靠近电极端子22的现象，从而在第一壁211沿着泄压槽2111的至少部分裂开并泄放电池单体20的内部压力时能够减少电池单体20内部的热失控气体对电极端子22以及连接于电极端子22上的其他部件的冲击现象，进而能够降低因电极端子22以及连接于电极端子22上的其他部件损坏而带来的短接风险或热扩散风险，以提升电池单体20的使用可靠性。
在一些实施例中，请继续参见图5和图7所示，沿第一方向Y，泄压槽2111与电极端子22的最小距离为L1，满足，15mm≤L1≤50mm。
在本实施例中，泄压槽2111与电极端子22在第一方向Y上的最小距离15mm到50mm，一方面通过将泄压槽2111与电极端子22在第一方向Y上的最小距离进一步设置为小于或等于50mm，使得泄压槽2111更为靠近电极端子22，以进一步提升电极端子22对第一壁211设置有泄压槽2111的区域的结构刚度的加强作用，有利于减少第一壁211设置有泄压槽2111的区域的应变和应变幅，从而能够进一步减少第一壁211设置有泄压槽2111的区域出现低周疲劳的现象，以进一步降低电池单体20出现提前开阀的风险，进而能够有效提升电池单体20的使用寿命和使用可靠性，另一方面通过将泄压槽2111与电极端子22在第一方向Y上的最小距离进一步设置为大于或等于15mm，以进一步缓解泄压槽2111过度靠近电极端子22的现象，从而在第一壁211沿着泄压槽2111的至少部分裂开并泄放电池单体20的内部压力时能够进一步减少电池单体20内部的热失控气体对电极端子22以及连接于电极端子22上的其他部件的冲击现象，进而能够进一步降低因电极端子22以及连接于电极端子22上的其他部件损坏而带来的短接风险或热扩散风险，以提升电池单体20的使用可靠性。
根据本申请的一些实施例，参见图3、图4和图5所示，电池单体20可以包括两个电极端子22，两个电极端子22均设置于第一壁211上，且两个电极端子22沿第一方向Y间隔排布，第一方向Y垂直于第一壁的厚度方向X。沿第一方向Y，泄压槽2111位于两个电极端子22之间。
其中，沿第一方向Y，泄压槽2111位于两个电极端子22之间，也就是说，一个电极端子22、泄压槽2111和另一个电极端子22为沿第一方向Y依次排布的结构。
需要说明的是，在其他实施例中，第一壁211上也可以是仅设置有一个电极端子22，另一个电极端子22设置于外壳21的其他壁上，也就是说，电池单体20的两个电极端子22分别设置于外壳21不同的两个壁上。
在本实施例中，通过将电池单体20的两个电极端子22均设置于第一壁211上，且将泄压槽2111在第一方向Y上设置于两个电极端子22之间，以使两个电极端子22能够进一步提升对第一壁211设置有泄压槽2111的区域的结构刚度的加强作用，有利于减少第一壁211设置有泄压槽2111的区域的应变和应变幅，从而能够进一步减少第一壁211设置有泄压槽2111的区域出现低周疲劳的现象，以进一步降低电池单体20出现提前开阀的风险，有利于提升电池单体20的使用寿命和使用可靠性。
根据本申请的一些实施例，参见图5以及图7所示，沿第一方向Y，泄压槽2111与两个电极端子22之间的最小距离相等。也就是说，泄压槽2111与任意一个电极端子22在第一方向Y上的最小距离L1均相同。
在本实施例中，通过将泄压槽2111在第一方向Y上与两个电极端子22之间的间距设置为相等的结构，一方面能够提升电池单体20的结构的规整度，有利于降低电池单体20的制造难度，另一方面能够实现两个电极端子22对第一壁211设置有泄压槽2111的区域的结构刚度的加强效果相近，有利于进一步减少第一壁211设置有泄压槽2111的区域的应变和应变幅，以缓解第一壁211设置有泄压槽2111的区域出现低周疲劳的现象，从而能够进一步降低电池单体20出现提前开阀的风险。
根据本申请的一些实施例，第一壁211设置有安装孔(图中未示出)，安装孔沿第一壁的厚度方向X贯穿第一壁211，安装孔与电极端子22一一对应。电极端子22包括柱体部、第一限位部和第二限位部(图中未示出)，柱体部沿第一壁的厚度方向X穿设于安装孔内，且柱体部连接第一限位部和第二限位部，第一限位部和第二限位部均凸出于柱体部的外周面，沿第一壁的厚度方向X，第一限位部和第二限位部分别位于第一壁211的两侧，且第一限位部的投影和第二限位部的投影的至少部分与第一壁211重叠。
其中，安装孔与电极端子22一一对应，即每个电极端子22安装于一个安装孔内。
柱体部连接第一限位部和第二限位部，第一限位部和第二限位部均凸出于柱体部的外周面，也就是说，柱体部为沿第一壁的厚度方向X延伸并插设于安装孔内的结构，且柱体部在第一壁的厚度方向X上的两端分别连接第一限位部和第二限位部，同时第一限位部和第二限位部凸出于柱体部的外周面，即第一限位部和第二限位部在第一壁的厚度方向X上的投影的部分位于柱体部的外侧。
第一限位部和第二限位部分别位于第一壁211的两侧，且第一限位部的投影和第二限位部的投影的至少部分与第一壁211重叠，也就是说，第一限位部和第二限位部为分别位于第一壁211的两侧且配合夹持第一壁211的结构，以将电极端子22紧固于第一壁211上，示例性地，第一限位部和第二限位部与第一壁211之间均设置有绝缘件，以使电极端子22为绝缘安装于第一壁211上的结构。
在本实施例中，电极端子22设置有第一限位部和第二限位部以及连接第一限位部和第二限位部的柱体部，柱体部穿设于第一壁211的安装孔内，且第一限位部和第二限位部分别位于第一壁211的两侧并与第一壁211的至少部分重叠，以实现将电极端子22紧固和安装于第一壁211上，采用这种结构的电极端子22一方面能够提升电极端子22设置在第一壁211上的结构稳定性和可靠性，另一方面能够进一步提升电极端子22对第一壁211设置有泄压槽2111的区域的结构刚度的加强效果。
根据本申请的一些实施例，参见图4和图5所示，第一壁211在第一壁的厚度方向X上的投影呈长方 形，第一壁211在第一方向Y上的尺寸大于第一壁211在第二方向Z上的尺寸，第一壁的厚度方向X、第一方向Y和第二方向Z两两垂直。泄压槽2111与电极端子22沿第一方向Y排布。
其中，第一壁211在第一壁的厚度方向X上的投影呈长方形，第一壁211在第一方向Y上的尺寸大于第一壁211在第二方向Z上的尺寸，也就是说，第一壁211为矩形板状结构，且第一方向Y为第一壁211的长度方向，而第二方向Z为第一壁211的宽度方向。
泄压槽2111与电极端子22沿第一方向Y排布，即泄压槽2111与电极端子22为沿第一壁211的长度方向设置的结构。
在本实施例中，第一壁211为长方形结构，通过将泄压槽2111和电极端子22的排布方向设置为与第一壁211的长度方向一致，一方面能够降低在第一壁211上安装电极端子22和设置泄压槽2111的难度，使得第一壁211在第一方向Y上具有足够的空间设置电极端子22和泄压槽2111，另一方面使得电极端子22能够对第一壁211在第一壁211最容易产生变形的方向上进行结构刚度的加强，有利于进一步提升第一壁211的抗变形能力，以减少第一壁211设置有泄压槽2111的区域的应变和应变幅，从而能够进一步减少第一壁211设置有泄压槽2111的区域出现低周疲劳的现象，以进一步降低电池单体20出现提前开阀的风险。
在一些实施例中，参见图3、图4和图5所示，外壳21呈长方体状，外壳21还具有两个第二壁214，两个第二壁214沿第二方向Z相对设置且分别连接于第一壁211的两端。沿第二方向Z，第二壁214背离电极组件23的表面为外壳21的外表面中面积最大的面。
其中，第二壁214为外壳21在第二方向Z上分别连接于第一壁211的两端的两个壁，且两个第二壁214为沿第二方向Z间隔排布的结构并相互平行。
第二壁214背离电极组件23的表面为外壳21的外表面中面积最大的面，也就是说，第二壁214的长度方向和宽度方向分别为电池单体20的外壳21的长度方向和宽度方向，使得两个第二壁214的排布方向为电池单体20的厚度方向，即第二方向Z为电池单体20的厚度方向。
在本实施例中，外壳21为长方体状，外壳21还具有在第二方向Z上相对设置的两个第二壁214，且第二壁214背离电极组件23的表面为外壳21的外表面中面积最大的面，使得第二方向Z既为第一壁211的宽度方向，也为电池单体20的厚度方向，从而实现电极端子22能够对第一壁211在第一壁211出现变形量最大的方向上进行结构刚度的加强，有利于进一步提升第一壁211的抗变形能力，以减少第一壁211设置有泄压槽2111的区域的应变和应变幅，从而能够进一步减少第一壁211设置有泄压槽2111的区域出现低周疲劳的现象，以进一步降低电池单体20出现提前开阀的风险。
根据本申请的一些实施例，泄压槽2111冲压成型于第一壁211。也就是说，泄压槽2111为第一壁211通过冲压工艺形成于的凹槽结构。
需要说明的是，在其他实施例中，形成于第一壁211上的泄压槽2111还可以通过激光刻蚀或铣削等加工工艺形成。
在本实施例中，通过将泄压槽2111设置为冲压成型于第一壁211上的结构，使得泄压槽2111在第一壁211上的成型方式简单，有利于降低电池单体20的制造成本。
根据本申请的一些实施例，参照图6，并请进一步参照图8，图8为本申请一些实施例提供的电池单体20的外壳21的第一壁211的局部剖视图。泄压槽2111包括沿第一壁的厚度方向X依次排布的多级槽。也就是说，泄压槽2111为沿第一壁的厚度方向X排布的多级阶梯槽结构，即泄压槽2111为通过多次冲压形成的阶梯槽结构。
示例性地，在图8中，泄压槽2111为二级阶梯槽结构，即泄压槽2111包括沿第一壁的厚度方向X依次排布的两级槽，当然，在其他实施例中，泄压槽2111也可以为三级阶梯槽、四级阶梯槽、五级阶梯槽或六级阶梯槽等。
需要说明的是，在泄压槽2111包括多个槽段的实施例中，每个槽段均为多级阶梯槽结构，示例性地，在图6中，泄压槽2111包括第一槽段2111a和两个第二槽段2111b，则第一槽段2111a和两个第二槽段2111b均为多级阶梯槽结构。当然，在泄压槽2111整体为沿平滑轨迹延伸的曲线、环线或直线等结构中，则泄压槽2111整体均为多级阶梯槽结构。
在本实施例中，通过将泄压槽2111设置为沿第一壁的厚度方向X设置的多级阶梯槽结构，以使泄压槽2111为多次加工形成的凹槽结构，采用这种结构的泄压槽2111在同等深度的情况下一方面能够降低泄压槽2111单次加工的深度，有利于降低泄压槽2111的制造难度和对制造设备的需求，以降低制造成本，且能够减小第一壁211在泄压槽2111单次加工时所受到的成型力，有利于降低第一壁211产生裂纹的风险，以提高电池单体20的生产质量，另一方面能够改善泄压槽2111在形成过程中的流料形态，有利于在形成泄压槽2111时所产生物料的进行流动，以提升泄压槽2111的结构的一致性。
在一些实施例中，参见图8所示，沿第一壁的厚度方向X，泄压槽2111的最小残余厚度为D3，满足，0.05mm≤D3≤0.3mm。
其中，泄压槽2111的最小残余厚度D3为第一壁211设置有泄压槽2111且泄压槽2111的槽底面对应的区域在第一壁的厚度方向X上的最小厚度。在图8中，泄压槽2111的底部形成第一薄弱部2111c，泄压槽2111的最小残余厚度D3则为第一薄弱部2111c在第一壁的厚度方向X上的最小厚度为D3。
示例性地，在图8中，泄压槽2111的多级槽，则泄压槽2111的最小残余厚度D3为泄压槽2111在第一壁的厚度方向X上最深的一级槽的槽底壁的厚度。
示例性地，泄压槽2111的最小残余厚度D3可以是0.05mm、0.06mm、0.07mm、0.08mm、0.09mm、0.1mm、0.12mm、0.15mm、0.16mm、0.18mm、0.2mm、0.22mm、0.25mm、0.28mm或0.3mm等。
在本实施例中，泄压槽2111在第一壁的厚度方向X上的最小残余厚度为0.05mm到0.3mm，一方面通过 将泄压槽2111在第一壁的厚度方向X上的最小残余厚设置为大于或等于0.05mm，以缓解第一壁211设置有泄压槽2111的区域的结构强度过小的现象，从而能够降低第一壁211设置有泄压槽2111的区域在生产、运输或正常使用情况下出现开裂或损坏等风险，另一方面通过将泄压槽2111在第一壁的厚度方向X上的最小残余厚设置为小于或等于0.3mm，以缓解第一壁211在电池单体20发生热失控时沿着泄压槽2111裂开的难度较大的问题，从而能够降低电池单体20泄压开阀所需的爆破压，以降低电池单体20因泄压爆破压过大而引发的爆炸风险。
在一些实施例中，电池单体20还可以包括电解液，电解液容纳于外壳21内。电解液包括电解质盐，电解质盐包括六氟磷酸盐，六氟磷酸盐的摩尔浓度小于或等于1.1mol/L。
示例性地，电解液中的六氟磷酸盐的摩尔浓度可以是0.1mol/L、0.2mol/L、0.25mol/L、0.3mol/L、0.4mol/L、0.5mol/L、0.6mol/L、0.7mol/L、0.8mol/L、0.9mol/L、1mol/L或1.1mol/L等。
需要说明的是，电解液中的六氟磷酸盐在使用过程中容易被氧化或还原，生成不稳定的化合物及酸性物质，例如氢氟酸是常见的一种，而氢氟酸是一种高度腐蚀性的无机酸，对外壳21有很强的腐蚀作用。
在本实施例中，通过将电解液中的六氟磷酸盐的摩尔浓度设置为小于或等于1.1mol/L，以缓解电池单体20在使用过程中产生的氢氟酸的量，从而能够减少第一壁211设置有泄压槽2111的区域被腐蚀的现象，以缓解泄压槽2111的最小残余厚度进一步减小的情况，进而能够降低电池单体20因第一壁211设置有泄压槽2111的区域的结构强度下降而出现提前开裂或损坏的风险，以进一步提升电池单体20的使用可靠性和使用稳定性。
根据本申请的一些实施例，参见图5、图6和图8所示，泄压槽2111的底部形成第一薄弱部2111c，第一壁211被配置为在电池单体20泄压时能够沿着至少部分第一薄弱部2111c裂开。第一壁211还设置有引导槽2114，引导槽2114的底部形成第二薄弱部2114a，沿第一壁的厚度方向X，泄压槽2111的投影和至少一个引导槽2114的投影共同限定出至少一个预定泄压区2113，第二薄弱部2114a被配置为引导预定泄压区2113的至少部分翻转，以打开预定泄压区2113的至少部分。
其中，泄压槽2111的底部形成第一薄弱部2111c，第一壁211被配置为在电池单体20泄压时能够沿着至少部分第一薄弱部2111c裂开，也就是说，泄压槽2111的槽底壁为第一薄弱部2111c，第一薄弱部2111c为第一壁211设置泄压槽2111的残余部分，使得第一壁211在电池单体20泄压时能够沿着泄压槽2111的槽底壁的至少部分裂开，从而泄放电池单体20的内部压力。
引导槽2114的底部形成第二薄弱部2114a，也就是说，引导槽2114的槽底壁为第二薄弱部2114a，第二薄弱部2114a为第一壁211设置引导槽2114的残余部分。
沿第一壁的厚度方向X，泄压槽2111的投影和至少一个引导槽2114的投影共同限定出至少一个预定泄压区2113，即泄压槽2111和引导槽2114围合形成的区域内形成至少一个预定泄压区2113，示例性地，在图6中，泄压槽2111和引导槽2114限定出两个预定泄压区2113，且两个预定泄压区2113沿第二方向Z间隔排布。其中，泄压槽2111为沿着预定泄压区2113的边缘设置的结构，使得泄压槽2111的设置轨迹为沿着预定泄压区2113的边缘设置，使得第一壁211能够沿着预定泄压区2113的边缘裂开。
需要说明的是，在泄压槽2111和引导槽2114相互间隔且互不接触的实施例中，则预定泄压区2113为泄压槽2111在第一壁的厚度方向X上的投影、泄压槽2111的延长线在第一壁的厚度方向X上的投影、引导槽2114在第一壁的厚度方向X上的投影以及引导槽2114的延长在第一壁的厚度方向X上的投影共同围合形成的区域。可选地，泄压槽2111可以是仅包括一个槽段，也可以是由多个槽段连接形成的结构，同样地，泄压槽2111和引导槽2114可以是沿直线轨迹延伸的槽，也可以是沿非直线轨迹延伸的槽。
第二薄弱部2114a被配置为引导预定泄压区2113的至少部分翻转，以打开预定泄压区2113的至少部分，也就是说，在第一壁211沿着泄压槽2111底部的第一薄弱部2111c裂开并使得预定泄压区2113被打开后，预定泄压区2113的至少一部分能够以第二薄弱部2114a为轴进行翻转，以便于预定泄压区2113翻转后使得外壳21的内部和外壳21的外部相互连通后进行泄压。
在本实施例中，第一壁211上还设置有引导槽2114，引导槽2114和泄压槽2111沿第一壁的厚度方向X的投影在第一壁211上限定出至少一个预定泄压区2113，且预定泄压区2113在第一壁211沿着泄压槽2111的至少部分裂开后能够被打开，并能够绕着引导槽2114底部的第二薄弱部2114a进行翻转，以泄放电池单体20的内部压力，采用这种结构的电池单体20能够实现在预定泄压区2113被打开后扩大预定泄压区2113的翻转角度，从而有效能够增加电池单体20的泄压面积，以提升电池单体20在发生热失控时的泄压速率，进而能够降低电池单体20因泄压不及时而引发起火爆炸等风险，有利于提升电池单体20的使用可靠性。
根据本申请的一些实施例，参见图6和图8所示，泄压槽2111与电极端子22沿第一方向Y排布，泄压槽2111与引导槽2114沿第二方向Z排布，第一壁的厚度方向X、第一方向Y和第二方向Z两两垂直。
其中，泄压槽2111与电极端子22沿第一方向Y排布，泄压槽2111与引导槽2114沿第二方向Z排布，也就是说，在第二方向Z上，泄压槽2111的至少一侧设置有引导槽2114，且引导槽2114可以是与泄压槽2111接触或间隔设置的结构。
示例性地，在图6中，泄压槽2111限定出沿第二方向Z间隔排布的两个预定泄压区2113，对应地，泄压槽2111在第二方向Z上的两侧均设置有引导槽2114，使得泄压槽2111在第二方向Z上位于两个引导槽2114之间，且每个预定泄压区2113对应一个引导槽2114。
在本实施例中，通过将引导槽2114和泄压槽2111设置为沿第二方向Z排布的结构，使得引导槽2114位于泄压槽2111在第二方向Z上的至少一侧，一方面能够减少引导槽2114对第一壁211位于电极端子22与泄压槽2111之间的区域的结构刚度的影响，有利于提升电极端子22对第一壁211设置有泄压槽2111的区域的结构刚度的加强效果，另一方面能够减少泄压槽2111与引导槽2114之间的干涉影响，以便于分别对泄压槽2111和引导槽2114进行加工，且能够缓解泄压槽2111底部的第一薄弱部2111c在裂开时撕裂引导槽2114底部的第二薄弱部 2114a的现象，还能够提升预定泄压区2113被打开后绕着第二薄弱部2114a进行翻转的效果。
在一些实施例中，参见图5和图6所示，泄压槽2111与引导槽2114沿第二方向Z间隔设置。即泄压槽2111和引导槽2114在垂直于第一壁的厚度方向X的平面内的正投影沿第二方向Z间隔排布，使得泄压槽2111在第一壁的厚度方向X上的投影与引导槽2114在第一壁的厚度方向X上的投影沿第二方向Z间隔设置，也就是说，引导槽2114在第二方向Z上位于泄压槽2111的一侧，且两者之间存在间隙。
示例性地，在图6中，第一壁211设置有两个引导槽2114，两个引导槽2114沿第二方向Z间隔排布且分别位于泄压槽2111在第二方向Z上的两侧，两个引导槽2114与泄压槽2111在第二方向Z上均间隔设置。
在本实施例中，通过将泄压槽2111和引导槽2114设置为沿第二方向Z间隔排布的结构，使得泄压槽2111与引导槽2114之间未接触，一方面能够减少泄压槽2111和引导槽2114在加工过程中的相互影响，且能够减少第一壁211设置泄压槽2111的区域与第一壁211设置引导槽2114的区域之间的应力影响，另一方面能够进一步缓解泄压槽2111底部的第一薄弱部2111c在裂开时撕裂引导槽2114底部的第二薄弱部2114a的现象，从而有利于提升预定泄压区2113绕着第二薄弱部2114a进行翻转的效果。
根据本申请的一些实施例，参见图5和图6所示，引导槽2114沿第一方向Y延伸，沿第一方向Y，引导槽2114的两端分别延伸出泄压槽2111的两个端部。
其中，沿第一方向Y，引导槽2114的两端分别延伸出泄压槽2111的两个端部，即引导槽2114在第一方向Y上的尺寸大于泄压槽2111，且引导槽2114在第一方向Y上的两端分别延伸出泄压槽2111的两侧，也就是说，在泄压槽2111包括第一槽段2111a和两个第二槽段2111b的实施例中，引导槽2114在第一方向Y上的两端分别延伸出两个第二槽段2111b的两侧。
在本实施例中，沿第一壁的厚度方向X，通过将引导槽2114的投影在其延伸方向上设置为分别延伸出泄压槽2111的投影的两个端部，使得引导槽2114为在其延伸方向上的两端分别超出泄压槽2111的两个端部的结构，一方面使得引导槽2114在其延伸方向上的尺寸大于泄压槽2111，以便于泄压槽2111限定的预定泄压区2113绕着第二薄弱部2114a进行翻转，且能够提升预定泄压区2113的翻转效果，从而能够增加电池单体20的泄压面积，以提升电池单体20在发生热失控时的泄压速率，另一方面能够提升引导槽2114对第一壁211的泄压槽2111在成型过程中挤出的余料的吸收效果，且能够提升引导槽2114在泄压槽2111和第一壁211的边缘之间的分隔效果，以提高引导槽2114在电池单体20受到内外冲击作用力时对电池单体20的变形能量的阻挡效果。
在一些实施例中，沿第一壁的厚度方向X，引导槽2114的投影与电极端子22的投影不重叠。
在本实施例中，通过将引导槽2114和电极端子22在第一壁的厚度方向X上的投影设置为互不重叠的结构，从而能够减少引导槽2114和电极端子22之间的干涉影响，且有利于降低电池单体20的制造难度。
根据本申请的一些实施例，参见图6和图8所示，沿第一壁的厚度方向X，第二薄弱部2114a的厚度大于第一薄弱部2111c的厚度，即引导槽2114的残余厚度大于泄压槽2111的残余厚度，也就是说，在第一壁的厚度方向X上，引导槽2114的槽底壁的厚度大于泄压槽2111的槽底壁的厚度，即在第一壁的厚度方向X上，泄压槽2111的槽深大于引导槽2114的槽深。
需要说明的是，若泄压槽2111包括多个平滑的槽段的实施例中，则第一薄弱部2111c包括多个薄弱段，泄压槽2111的每个槽段的槽底壁为第一薄弱部2111c的一个薄弱段；若泄压槽2111仅包括一个平滑的槽段的实施例中，则第一薄弱部2111c仅包括一个薄弱段。
在本实施例中，通过将第二薄弱部2114a在第一壁的厚度方向X上的厚度设置为大于第一薄弱部2111c在第一壁的厚度方向X上的厚度，以使引导槽2114的残余厚度大于泄压槽2111的残余厚度，使得第一壁211设置泄压槽2111的区域的结构强度小于第一壁211设置引导槽2114的区域的结构强度，以便于第一壁211能够优先沿着泄压槽2111底部的第一薄弱部2111c进行裂开并泄放电池单体20的内部压力，从而有利于缓解第一壁211从设置引导槽2114的区域裂开而造成电池单体20的泄压效果不佳的现象。
在一些实施例中，请继续参见图6和图8所示，沿第一壁的厚度方向X，第二薄弱部2114a的厚度为D4，满足，0.15mm≤D4≤0.5mm。
其中，第二薄弱部2114a的厚度D4为第一壁211设置有引导槽2114且引导槽2114的槽底面对应的区域在第一壁的厚度方向X上的厚度。
示例性地，在图8中，引导槽2114为一级槽，则第二薄弱部2114a的厚度D4为引导槽2114在第一壁的厚度方向X上的槽底壁的厚度。当然，若泄压槽2111为多级槽的结构，第二薄弱部2114a的厚度D4为引导槽2114在第一壁的厚度方向X上最深的一级槽的槽底壁的壁厚。
示例性地，第二薄弱部2114a的厚度D4可以是0.15mm、0.16mm、0.17mm、0.18mm、0.19mm、0.2mm、0.22mm、0.25mm、0.28mm、0.3mm、0.35mm、0.4mm、0.45mm或0.5mm等。
在本实施例中，第二薄弱部2114a在第一壁的厚度方向X上的厚度为0.15mm到0.5mm，一方面通过将第二薄弱部2114a在第一壁的厚度方向X上的厚度设置为大于或等于0.15mm，以提升第一壁211设置有引导槽2114的区域的结构强度，从而在电池单体20发生热失控时缓解第一壁211出现在设置引导槽2114的区域误开裂的现象，以提升电池单体20的使用可靠性和稳定性，另一方面通过将第二薄弱部2114a在第一壁的厚度方向X上的厚度设置为小于或等于0.5mm，以缓解第二薄弱部2114a的厚度过大而造成预定泄压区2113被打开后绕着第二薄弱部2114a进行翻转的效果不佳的现象，从而能够进一步扩大预定泄压区2113的翻转角度，以增加电池单体20的泄压面积，有利于提升电池单体20在发生热失控时的泄压速率，进而能够降低电池单体20因泄压不及时而引发起火爆炸等风险，以提升电池单体20的使用可靠性。
根据本申请的一些实施例，参见图6和图8所示，第一薄弱部2111c包括至少一个薄弱段，薄弱段垂直于其延伸方向的横截面积为第一截面积S1，第二薄弱部2114a垂直于其延伸方向的横截面积为第二截面积S2，满 足，S1＜S2。
示例性地，在图6中，泄压槽2111包括三个槽段，则对应第一薄弱部2111c包括三个薄弱段，泄压槽2111的每个槽段的底部形成一个薄弱段。
其中，第一截面积S1为薄弱段在垂直于薄弱段的延伸方向和第一壁的厚度方向X的方向上的宽度与薄弱段在第一壁的厚度方向X上的厚度的乘积。若薄弱段为沿第一方向Y延伸的结构，则第一截面积S1为薄弱段在第二方向Z上的宽度与薄弱段在第一壁的厚度方向X上的厚度的乘积；若薄弱段为沿第二方向Z延伸的结构，则第一截面积S1为薄弱段在第一方向Y上的宽度与薄弱段在第一壁的厚度方向X上的厚度的乘积。
第二截面积S2为第二薄弱部2114a在垂直于第二薄弱部2114a的延伸方向和第一壁的厚度方向X的方向上的宽度与第二薄弱部2114a在第一壁的厚度方向X上的厚度的乘积。示例性地，在图6中，引导槽2114为沿第一方向Y延伸的结构，对应地，引导槽2114底部形成的第二薄弱部2114a为沿第一方向Y延伸的结构，则第二截面积S2为第二薄弱部2114a在第二方向Z上的宽度与第二薄弱部2114a在第一壁的厚度方向X上的厚度的乘积。
在本实施例中，通过将第一薄弱部2111c的薄弱段垂直于其延伸方向的横截面的面积设置为小于第二薄弱部2114a垂直于其延伸方向的横截面的面积，以使第一壁211设置泄压槽2111的区域的结构强度小于第一壁211设置引导槽2114的区域的结构强度，从而便于第一壁211能够优先沿着泄压槽2111底部的第一薄弱部2111c进行裂开并泄放电池单体20的内部压力，有利于缓解第一壁211从设置引导槽2114的区域裂开而造成电池单体20的泄压效果不佳的现象。
根据本申请的一些实施例，参见图6和图8所示，沿第一壁的厚度方向X，泄压槽2111和引导槽2114分别设置于第一壁211的两侧。也就是说，泄压槽2111和引导槽2114分别设置于第一壁211在第一壁的厚度方向X上的两侧的表面上。
可选地，泄压槽2111可以是设置于第一壁211面向外壳21内部的一侧上，对应地，引导槽2114设置于第一壁211背离外壳21内部的一侧上，当然，泄压槽2111也可以是设置于第一壁211背离外壳21内部的一侧上，对应地，引导槽2114设置于第一壁211面向外壳21内部的一侧上。在其他实施例中，也可以是泄压槽2111和引导槽2114均位于第一壁211在第一壁的厚度方向X上的同一侧上。
示例性地，在图8中，引导槽2114的槽侧面与引导槽2114的槽底面呈钝角设置，以便于加工形成引导槽2114。同样地，泄压槽2111的槽侧面与泄压槽2111的槽底面呈钝角设置，以便于加工形成泄压槽2111。在图8中，泄压槽2111为沿第一壁的厚度方向X设置的多级槽结构，即泄压槽2111为阶梯槽结构，每一级槽的槽侧面与槽底面均呈钝角设置。
在本实施例中，通过将泄压槽2111和引导槽2114分别设置于第一壁211在第一壁的厚度方向X上的两侧，从而便于在第一壁211的两侧分别对泄压槽2111和引导槽2114进行加工，有利于减少泄压槽2111和引导槽2114在加工过程中的相互影响。
在一些实施例中，请继续参见图6和图8所示，沿第一壁的厚度方向X，泄压槽2111设置于第一壁211背离电极组件23的一侧。也就是说，泄压槽2111设置于第一壁211背离外壳21内部的外表面上。
在本实施例中，通过将泄压槽2111设置于第一壁211背离电极组件23的一侧上，使得泄压槽2111设置于第一壁211的外表面上，从而便于在第一壁211上加工形成泄压槽2111，有利于降低泄压槽2111的加工难度，以提升电池单体20的生产效率。
在一些实施例中，请继续参见图6和图8所示，沿第一壁的厚度方向X，引导槽2114设置于第一壁211面向电极组件23的一侧。也就是说，引导槽2114设置于第一壁211面向外壳21内部的内表面上。
在本实施例中，通过将引导槽2114设置于第一壁211面向电极组件23的一侧上，使得引导槽2114设置于第一壁211的内表面上，以便于预定泄压区2113在被打开绕着引导槽2114底部的第二薄弱部2114a向外壳21的外侧进行翻转，从而能够减少引导槽2114的槽侧面对预定泄压区2113在翻转过程中造成的干涉影响，有利于提升预定泄压区2113的翻转效果。
根据本申请的一些实施例，参见图5和图6以及图7所示，泄压槽2111包括第一槽段2111a和两个第二槽段2111b，两个第二槽段2111b沿第一方向Y相对设置，且第二槽段2111b与引导槽2114沿第二方向Z排布，第一槽段2111a连接两个第二槽段2111b，第一壁的厚度方向X、第一方向Y和第二方向Z两两垂直。沿第一壁的厚度方向X，第一槽段2111a的投影、两个第二槽段2111b的投影、两个第二槽段2111b的延长线的投影和引导槽2114的投影共同围合出预定泄压区2113；或，沿第一壁的厚度方向X，第一槽段2111a的投影、两个第二槽段2111b的投影、引导槽2114的投影和引导槽2114的延长线的投影共同围合出预定泄压区2113；或，沿第一壁的厚度方向X，第一槽段2111a的投影、两个第二槽段2111b的投影、两个第二槽段2111b的延长线的投影、引导槽2114的投影和引导槽2114的延长线的投影共同围合出预定泄压区2113。
其中，两个第二槽段2111b沿第一方向Y相对设置，也就是说，两个第二槽段2111b沿第一方向Y间隔排布。示例性地，在图6和图7中，两个第二槽段2111b均沿第二方向Z延伸。
需要说明的是，在泄压槽2111包括第一槽段2111a和两个第二槽段2111b的实施例中，参见图5所示，泄压槽2111与电极端子22在第一方向Y上的最小距离L1则为第二槽段2111b与电极端子22在第一方向Y上的最小距离，同样地，泄压槽2111与第一边缘2112在第一方向Y上的最小距离L2则为第二槽段2111b与第一边缘2112在第一方向Y上的最小距离。
第一槽段2111a连接两个第二槽段2111b，也就是说，第一槽段2111a在第一方向Y上位于两个第二槽段2111b之间，且第一槽段2111a的两端分别连接于两个第二槽段2111b，当然，在其他实施例中，第一槽段2111a也可以在第一方向Y上的两端分别延伸出两个第二槽段2111b。
示例性地，在图6和图7中，预定泄压区2113为第一槽段2111a在第一壁的厚度方向X上的投影、两个 第二槽段2111b在第一壁的厚度方向X上的投影、两个第二槽段2111b的延长线在第一壁的厚度方向X上的投影和引导槽2114在第一壁的厚度方向X上的投影共同围合的区域，且第一槽段2111a和两个第二槽段2111b为沿着预定泄压区2113的边缘设置的结构，以使预定泄压区2113能够以第一槽段2111a和两个第二槽段2111b为边界打开，也就是说，第一壁211位于预定泄压区2113的部分在电池单体20泄压时能够以第一槽段2111a和两个第二槽段2111b为边界打开，从而泄放电池单体20的内部压力。当然，电池单体20的结构并不仅仅局限于此，在其他实施例中，预定泄压区2113也可以是第一槽段2111a在第一壁的厚度方向X上的投影、两个第二槽段2111b在第一壁的厚度方向X上的投影、引导槽2114在第一壁的厚度方向X上的投影和引导槽2114的延长线在第一壁的厚度方向X上的投影共同围合形成的区域，还可以是第一槽段2111a在第一壁的厚度方向X上的投影、两个第二槽段2111b在第一壁的厚度方向X上的投影、两个第二槽段2111b的延长线在第一壁的厚度方向X上的投影、引导槽2114在第一壁的厚度方向X上的投影和引导槽2114的延长线在第一壁的厚度方向X上的投影共同围合形成的区域。
可选地，参见图5和图6所示，第一槽段2111a和两个第二槽段2111b共同形成的泄压槽2111的形状可以是“H”形结构，且第一壁211上设置有两个引导槽2114，两个引导槽2114分别在第二方向Z上分别位于泄压槽2111的两侧，以在第一壁211上形成两个预定泄压区2113，且两个预定泄压区2113在第二方向Z上分别位于第一槽段2111a的两侧。当然，在其他实施例中，泄压槽2111还可以是其他形状，比如，两个第二槽段2111b的一端分别连接于第一槽段2111a的两端，以使在第一壁211上围合形成一个预定泄压区2113，使得第一槽段2111a和两个第二槽段2111b共同形成的泄压槽2111的形状为“U”形结构。
在本实施例中，采用这种结构的电池单体20一方面便于在第一壁211上加工泄压槽2111并形成预定泄压区2113，且这种结构的泄压槽2111限定的预定泄压区2113更容易绕着引导槽2114所在的位置进行翻转，另一方面使得第一槽段2111a和第二槽段2111b的相交位置更薄弱，更容易裂开并打开预定泄压区2113进行泄压。
在一些实施例中，请继续参见图5和图6所示，第一壁211设置有两个引导槽2114，沿第二方向Z，第一槽段2111a位于两个引导槽2114之间。两个第二槽段2111b与第一槽段2111a的连接位置均偏离两个第二槽段2111b的两端，以在第一槽段2111a沿第二方向Z的两侧均形成有预定泄压区2113。
其中，两个第二槽段2111b与第一槽段2111a的连接位置均偏离两个第二槽段2111b的两端，也就是说，第一槽段2111a连接于第二槽段2111b的两端之间，以使第一槽段2111a和两个第二槽段2111b共同形成的泄压槽2111的形状为近似“H”形的结构，从而使得泄压槽2111和引导槽2114在第一壁211上限定出两个预定泄压区2113，且两个预定泄压区2113在第二方向Z上分别位于第一槽段2111a的两侧。
沿第二方向Z，两个引导槽2114分别位于泄压槽2111的两侧，也就是说，泄压槽2111在第二方向Z上的两侧均设置有引导槽2114，且每个引导槽2114对应一个预定泄压区2113设置，使得每个引导槽2114能够引导对应的预定泄压区2113进行翻转。
在本实施例中，通过将两个第二槽段2111b与第一槽段2111a的连接位置均设置为位于对应的第二槽段2111b的两端之间，以使第一槽段2111a和两个第二槽段2111b构成类似“H”形结构的泄压槽2111，使得在泄压槽2111的第一槽段2111a的两侧均能够形成预定泄压区2113，且两个预定泄压区2113在电池单体20泄压时能够以对开的方式打开进行泄压，有利于进一步增加电池单体20的泄压效果，可有效提升电池单体20的泄压速率。
在一些实施例中，参照图9，图9为本申请再一些实施例提供的电池单体20在第一壁的厚度方向X上面向泄压槽2111的正视图。一个第二槽段2111b的一端与第一槽段2111a的一端相连，另一个第二槽段2111b的一端与第一槽段2111a的另一端相连。也就是说，两个第二槽段2111b的一端分别连接于第一槽段2111a的两端，使得第一槽段2111a和两个第二槽段2111b共同形成的泄压槽2111的形状为“U”形结构。
在本实施例中，通过一个第二槽段2111b、第一槽段2111a和另一个第二槽段2111b设置为依次连接的结构，以使第一槽段2111a和两个第二槽段2111b构成类似“U”形结构的泄压槽2111，有利于降低泄压槽2111的加工难度，且有利于扩大预定泄压区2113的面积，从而在预定泄压区2113被打开后能够增加电池单体20的泄压面积，以提升电池单体20的泄压速率。
根据本申请的一些实施例，参见图5以及图9所示，第一槽段2111a和两个第二槽段2111b均沿直线轨迹延伸，第一槽段2111a与两个第二槽段2111b均垂直。也就是说，第一槽段2111a的延伸方向垂直于第二槽段2111b的延伸方向。
需要说明的是，在两个第二槽段2111b与第一槽段2111a的连接位置均偏离两个第二槽段2111b的两端的实施例中，则使得第一槽段2111a与两个第二槽段2111b共同形成的泄压槽2111的形状为规则的“H”形的结构，并在第一槽段2111a沿第二方向Z的两侧均形成有预定泄压区2113，当然，两个预定泄压区2113的面积可以相同，也可以不相同。
示例性地，第一槽段2111a为沿第一方向Y延伸的直线结构，第二槽段2111b为沿第二方向Z延伸的直线结构，且第一槽段2111a沿第一方向Y位于两个第二槽段2111b之间。
在本实施例中，通过将两个第二槽段2111b设置为均垂直于第一槽段2111a，使得第一槽段2111a的延伸方向为两个第二槽段2111b的排布方向，从而能够提升泄压槽2111的形状的规则度，有利于降低泄压槽2111的加工难度，以降低电池单体20的制造成本，并能够提升电池单体20的生产效率。
根据本申请的一些实施例，参照图10，图10为本申请另一些实施例提供的电池单体20在第一壁的厚度方向X上面向泄压槽2111的正视图。泄压槽2111包括第一槽段2111a和第二槽段2111b，第一槽段2111a和第二槽段2111b相连。沿第一壁的厚度方向X，第一槽段2111a的投影、第一槽段2111a的延长线的投影、第二槽段2111b的投影、第二槽段2111b的延长线的投影和引导槽2114的投影共同围合出预定泄压区2113；或，沿第一壁的厚度方向X，第一槽段2111a的投影、第二槽段2111b的投影、引导槽2114的投影和引导槽2114的延长线的投 影共同围合出预定泄压区2113；或，沿第一壁的厚度方向X，第一槽段2111a的投影、第一槽段2111a的延长线的投影、第二槽段2111b的投影、第二槽段2111b的延长线的投影、引导槽2114的投影和引导槽2114的延长线的投影共同围合出预定泄压区2113。
其中，第一槽段2111a的一端和第二槽段2111b的一端相连，以使第一槽段2111a和第二槽段2111b形成“V”形结构的泄压槽2111，对应地，泄压槽2111仅限定出一个预定泄压区2113，且第一壁211仅设置有一个引导槽2114，且引导槽2114与预定泄压区2113对应设置。当然，在其他实施例中，第一槽段2111a和第二槽段2111b相互连接形成的泄压槽2111的形状也可以是“T”形结构、“L”形结构或“X”形结构等。
示例性地，在图10中，预定泄压区2113为第一槽段2111a在第一壁的厚度方向X上的投影、第一槽段2111a的延长线在第一壁的厚度方向X上的投影、第二槽段2111b在第一壁的厚度方向X上的投影、第二槽段2111b的延长线在第一壁的厚度方向X上的投影和引导槽2114在第一壁的厚度方向X上的投影共同围合形成的区域。当然，电池单体20的结构并不仅仅局限于此，在其他实施例中，预定泄压区2113也可以是第一槽段2111a在第一壁的厚度方向X上的投影、第二槽段2111b在第一壁的厚度方向X上的投影、引导槽2114在第一壁的厚度方向X上的投影和引导槽2114的延长线在第一壁的厚度方向X上的投影共同围合形成的区域，还可以是第一槽段2111a在第一壁的厚度方向X上的投影、第一槽段2111a的延长线在第一壁的厚度方向X上的投影、第二槽段2111b在第一壁的厚度方向X上的投影、第二槽段2111b的延长线在第一壁的厚度方向X上的投影、引导槽2114在第一壁的厚度方向X上的投影和引导槽2114的延长线在第一壁的厚度方向X上的投影共同围合形成的区域。
在本实施例中，通过将泄压槽2111设置为包括相互连接的第一槽段2111a和第二槽段2111b，这种结构的电池单体20一方面能够增大电池单体20的泄压面积，以提高电池单体20的泄压速率，另一方面使得第一槽段2111a和第二槽段2111b的相交位置更薄弱，更容易裂开并打开预定泄压区2113泄放电池单体20的内部压力。
根据本申请的一些实施例，参照图11，图11为本申请再又一些实施例提供的电池单体20在第一壁的厚度方向X上面向泄压槽2111的正视图。泄压槽2111为沿弧形轨迹延伸的槽。沿第一壁的厚度方向X，泄压槽2111的投影、泄压槽2111的延长线的投影和引导槽2114的投影共同围合出预定泄压区2113；或，沿第一壁的厚度方向X，泄压槽2111的投影、引导槽2114的投影和引导槽2114的延长线的投影共同围合出预定泄压区2113；或，沿第一壁的厚度方向X，泄压槽2111的投影、泄压槽2111的延长线的投影、引导槽2114的投影和引导槽2114的延长线的投影共同围合出预定泄压区2113。
其中，泄压槽2111为沿弧形轨迹延伸的槽，也就是说，泄压槽2111仅包括一个光滑的槽段，且泄压槽2111为弧形槽结构。
示例性地，在图11中，预定泄压区2113为泄压槽2111在第一壁的厚度方向X上的投影、泄压槽2111的延长线在第一壁的厚度方向X上的投影和引导槽2114在第一壁的厚度方向X上的投影共同围合形成的区域。当然，电池单体20的结构并不仅仅局限于此，在其他实施例中，预定泄压区2113也可以是泄压槽2111在第一壁的厚度方向X上的投影、引导槽2114在第一壁的厚度方向X上的投影和引导槽2114的延长线在第一壁的厚度方向X上的投影共同围合形成的区域，还可以是泄压槽2111在第一壁的厚度方向X上的投影、泄压槽2111的延长线在第一壁的厚度方向X上的投影、引导槽2114在第一壁的厚度方向X上的投影和引导槽2114的延长线在第一壁的厚度方向X上的投影共同围合形成的区域。
示例性地，在图11中，泄压槽2111的形状为“C”形结构。
在本实施例中，通过将泄压槽2111设置为沿弧形轨迹延伸的结构，以使预定泄压区2113形成于泄压槽2111的内侧，采用这种结构的泄压槽2111便于在第一壁211上制造成型，有利于降低电池单体20的制造难度。
在一些实施例中，引导槽2114冲压成型于第一壁211。也就是说，引导槽2114为第一壁211通过冲压工艺形成于的凹槽结构。
需要说明的是，在其他实施例中，形成于第一壁211上的引导槽2114还可以通过激光刻蚀或铣削等加工工艺形成。
在本实施例中，通过将引导槽2114设置为冲压成型于第一壁211上的结构，使得引导槽2114在第一壁211上的成型方式简单，有利于降低电池单体20的制造成本。
根据本申请的一些实施例，沿第一壁的厚度方向X，第一壁211被配置为支撑电极组件23。也就是说，在第一壁的厚度方向X上，外壳21的第一壁211位于电极组件23的底部，且第一壁的厚度方向X为重力方向或近似重力方向。
在本实施例中，第一壁211能够在第一壁的厚度方向X上支撑电极组件23，使得电池单体20为能够倒置放置的结构，一方面使得电池单体20能够适应更多的使用场景，以提升电池单体20的适应范围，另一方面能够实现电池单体20的泄压槽2111和电极端子22均位于电池单体20的底部，以便于装配和电池单体20的内部压力的泄放。
根据本申请的一些实施例，参见图3和图4所示，外壳21可以包括壳体212和端盖213，壳体212的内部形成具有开口2121的容纳腔，容纳腔用于容。纳电极组件23，端盖213封闭开口2121，端盖213为第一壁211。
其中，端盖213为第一壁211，也就是说，泄压槽2111设置于外壳21的端盖213上，对应地，电极端子22也设置于外壳21的端盖213上。
在本实施例中，通过将外壳21的第一壁211设置为外壳21用于封闭开口2121的端盖213，采用这种结构的电池单体20便于在端盖213上设置泄压槽2111和安装电极端子22，有利于降低电池单体20的制造难度，以提升电池单体20的生产效率。
需要说明的是，电池单体20的结构并不局限于此，在一些实施例中，电池单体20还可以是其他结构， 比如，外壳21可以包括壳体212和端盖213，壳体212的内部形成具有开口2121的容纳腔，容纳腔用于容。纳电极组件23，端盖213封闭开口2121，壳体212包括第一壁211。
其中，壳体212包括一体成型的侧壁和底壁，即壳体212为采用一体成型工艺加工制成，比如，冲压、铸造或挤出成型等一体成型工艺，也就是说，壳体212的侧壁和底壁为一体式结构。对应地，壳体212包括第一壁211，也就是说，第一壁211可以是壳体212的底壁，也可以是壳体212的侧壁的多个壁中的一个壁。
在本实施例中，通过将外壳21的第一壁211设置为壳体212的一个壁，采用这种结构的电池单体20能够使得外壳21设置有泄压槽2111的区域远离端盖213，从而能够有效缓解端盖213与壳体212相互连接产生的应力作用在第一壁211设置有泄压槽2111的区域上的现象，以减少对第一壁211设置有泄压槽2111的区域造成的影响，进而有利于降低第一壁211设置有泄压槽2111的区域在应力的拉扯作用下出现开裂或结构强度下降的风险，以提升电池单体20的使用寿命和使用可靠性。
需要说明的是，电池单体20的结构还可以是多种，在一些实施例中，外壳21可以包括壳体212和两个端盖213，壳体212的内部形成有容纳腔，容纳腔用于容纳电极组件23，壳体212相对的两端均形成有开口2121，且两个开口2121均与容纳腔连通，两个端盖213分别封闭两个开口2121，两个端盖213中的一个端盖213为第一壁211。
在本实施例中，外壳21的壳体212在相对的两端上均设置有开口2121的结构，且两个端盖213分别封闭两个开口2121，第一壁211为两个端盖213中的一个端盖213，采用这种结构的电池单体20便于对电池单体20从壳体212的两端分别进行装配，有利于降低电池单体20的制造难度和装配难度，且便于在端盖213上设置泄压槽2111和安装电极端子22，有利于降低电池单体20的制造难度，以提升电池单体20的生产效率。
当然，电池单体20的结构并不局限于此，在外壳21包括壳体212和两个端盖213的实施例中，也可以是壳体212包括第一壁211，即第一壁211为壳体212中的一个壁。采用这种结构的电池单体20能够使得外壳21设置有泄压槽2111的区域远离端盖213，从而能够有效缓解端盖213与壳体212相互连接产生的应力作用在第一壁211设置有泄压槽2111的区域上的现象，以减少对第一壁211设置有泄压槽2111的区域造成的影响，进而有利于降低第一壁211设置有泄压槽2111的区域在应力的拉扯作用下出现开裂或结构强度下降的风险，以提升电池单体20的使用寿命和使用可靠性。
根据本申请的一些实施例，本申请还提供了一种电池100，电池100包括以上任一方案的电池单体20。
在一些实施例中，参见图2所示，电池100还可以包括箱体10，电池单体20容纳于箱体10内，箱体10具有位于电池单体20的底部的底板，沿第一壁的厚度方向X，底板与第一壁211面向设置。
其中，箱体10具有位于电池单体20的底部的底板，沿第一壁的厚度方向X，底板与第一壁211面向设置，也就是说，底板为箱体10在第一壁的厚度方向X上位于电池单体20的底部的一个板，且第一壁211与底板相对设置，即第一壁211在第一壁的厚度方向X上也位于电极组件23的底部，且第一壁的厚度方向X为重力方向或近似重力方向，使得电池单体20为设置有电极端子22和泄压槽2111的一端倒置放置于箱体10内。
可选地，箱体10可以包括第一箱本体11和第二箱本体12，第一箱本体11与第二箱本体12相互盖合，第一箱本体11和第二箱本体12共同限定出用于容纳电池单体20的装配空间。示例性地，在图2中，底板为第二箱本体12的一个板体。
可选地，第二箱本体12可以为一端开放的空心结构，第一箱本体11可以为板状结构，第一箱本体11盖合于第二箱本体12的开放侧，以使第一箱本体11与第二箱本体12共同限定出装配空间；第一箱本体11和第二箱本体12也可以是均为一侧开放的空心结构，第一箱本体11的开放侧盖合于第二箱本体12的开放侧。
当然，第一箱本体11和第二箱本体12形成的箱体10可以是多种形状，比如，圆柱体或长方体等。示例性地，在图2中，箱体10为长方体结构。
可选地，设置于箱体10内的电池单体20可以是一个，也可以是多个。示例性地，在图2中，电池100的箱体10内设置有多个电池单体20，多个电池单体20之间可以是串联或并联或混联，混联是指多个电池单体20中既有串联又有并联。多个电池单体20之间可直接串联或并联或混联在一起，再将多个电池单体20构成的整体容纳于箱体10内；当然，电池100也可以是多个电池单体20先串联或并联或混联组成电池模块形式，多个电池模块再串联或并联或混联形成一个整体，并容纳于箱体10内。
其中，电池100还可以包括其他结构，例如，该电池100还可以包括汇流部件，汇流部件连接多个电池单体20，以实现多个电池单体20之间的电连接。
需要说明的是，在一些实施例中，电池100也可以不设置箱体10，电池100包括多个电池单体20，而由多个电池单体20组成的电池100可以直接装配至用电装置上，以通过多个电池单体20为用电装置提供电能。也就是说，箱体10可以作为用电装置的一部分。用电装置以车辆1000为例，箱体10可以作为车辆1000的底盘结构的一部分，例如，箱体10的部分可以成为车辆1000的地板的至少一部分，或者，箱体10的部分可以成为车辆1000的横梁和纵梁的至少一部分。
在本实施例中，通过将箱体10的底板与电池单体20的第一壁211在第一壁的厚度方向X上面向设置，使得电池单体20为倒置设置于箱体10内的结构，从而能够实现电池单体20的泄压槽2111和电极端子22均位于电池单体20的底部且面向底板设置，以便于装配和电池单体20的内部压力的泄放，且能够缓解电池100的电池单体20在热失控时泄放的热失控气体向上冲击对使用者造成的风险。
根据本申请的一些实施例，本申请还提供了一种用电装置，用电装置包括以上任一方案的电池单体20或电池100，并且电池单体20用于为用电装置提供电能。
其中，用电装置可以是前述任一应用电池单体20或电池100的设备或系统。
根据本申请的一些实施例，参见图3至图8所示，本申请提供了一种电池单体20，电池单体20包括外 壳21、两个电极端子22和电极组件23。外壳21呈长方体状，外壳21具有第一壁211，外壳21包括壳体212和端盖213，壳体212的内部形成具有开口2121的容纳腔，容纳腔用于容纳电极组件23，端盖213封闭开口2121，端盖213为第一壁211。两个电极端子22均设置于第一壁211上，电极端子22在第一壁的厚度方向X上的厚度大于第一壁211的壁厚，且沿第一方向Y间隔排布。电极组件23容纳于外壳21内，电极组件23与电极端子22电连接。第一壁211设置有泄压槽2111，泄压槽2111冲压形成于第一壁211上，泄压槽2111包括沿第一壁的厚度方向X依次排布的多级槽，泄压槽2111的底部形成第一薄弱部2111c，第一壁211被配置为在电池单体20泄压时能够沿着至少部分第一薄弱部2111c裂开，以泄放电池单体20的内部压力。沿第一壁的厚度方向X，泄压槽2111的投影与电极端子22的投影不重叠。沿第一方向Y，泄压槽2111设置于两个电极端子22之间。沿第二方向Z，电极端子22的最大尺寸为D1，第一壁211的最大尺寸为D2，满足，0.6≤D1/D2≤0.9，第一壁的厚度方向X、第一方向Y和第二方向Z两两垂直。第一壁211的外边缘包括第一边缘2112，第一边缘2112和泄压槽2111在第一方向Y上分别位于电极端子22的两侧，沿第一方向Y，泄压槽2111与电极端子22的最小距离为L1，泄压槽2111与第一边缘2112的最小距离为L2，满足，0.2≤L1/L2≤0.6，15mm≤L1≤50mm。第一壁211在第一方向Y上位于泄压槽2111和电极端子22之间的部分的厚度为D，满足，5≤L1/D≤25。第一壁211在第一壁的厚度方向X上的投影呈长方形，第一壁211在第一方向Y上的尺寸大于第一壁211在第二方向Z上的尺寸，且外壳21还具有两个第二壁214，两个第二壁214沿第二方向Z相对设置且分别连接于第一壁211的两端，沿第二方向Z，第二壁214背离电极组件23的表面为外壳21的外表面中面积最大的面。泄压槽2111包括第一槽段2111a和两个第二槽段2111b，两个第二槽段2111b沿第一方向Y相对设置，且第二槽段2111b与引导槽2114沿第二方向Z排布，第一槽段2111a连接两个第二槽段2111b，两个第二槽段2111b与第一槽段2111a的连接位置均偏离两个第二槽段2111b的两端，以在第一槽段2111a沿第二方向Z的两侧均形成有预定泄压区2113，第一壁211设置有两个引导槽2114，引导槽2114冲压形成于第一壁211上，引导槽2114的底部形成第二薄弱部2114a，沿第二方向Z，两个引导槽2114分别位于泄压槽2111的两侧，第二薄弱部2114a被配置为引导预定泄压区2113的至少部分翻转，以打开预定泄压区2113的至少部分，泄压槽2111与引导槽2114沿第二方向Z间隔设置。第一槽段2111a和两个第二槽段2111b均沿直线轨迹延伸，第一槽段2111a与两个第二槽段2111b均垂直。沿第一壁的厚度方向X，第二薄弱部2114a的厚度大于第一薄弱部2111c的厚度。第一薄弱部2111c包括至少一个薄弱段，薄弱段垂直于其延伸方向的横截面积为第一截面积S1，第二薄弱部2114a垂直于其延伸方向的横截面积为第二截面积S2，满足，S1＜S2。沿第一壁的厚度方向X，泄压槽2111和引导槽2114分别设置于第一壁211的两侧，泄压槽2111设置于第一壁211背离电极组件23的一侧，引导槽2114设置于第一壁211面向电极组件23的一侧。
需要说明的是，在不冲突的情况下，本申请中的实施例及实施例中的特征可以相互结合。
以上仅为本申请的优选实施例而已，并不用于限制本申请，对于本领域的技术人员来说，本申请可以有各种更改和变化。凡在本申请的精神和原则之内，所作的任何修改、等同替换、改进等，均应包含在本申请的保护范围之内。

Claims (36)

  1. 一种电池单体，包括：
    外壳，具有第一壁；
    电极端子，设置于所述第一壁；以及
    电极组件，容纳于所述外壳内，所述电极组件与所述电极端子电连接；
    其中，所述第一壁设置有泄压槽，所述第一壁被配置为在所述电池单体泄压时能够沿着至少部分所述泄压槽裂开，沿所述第一壁的厚度方向，所述泄压槽的投影与所述电极端子的投影不重叠，且所述电极端子的厚度大于所述第一壁的厚度。
  2. 根据权利要求1所述的电池单体，其中，所述泄压槽与所述电极端子沿第一方向排布；
    其中，沿第二方向，所述电极端子的最大尺寸为D1，所述第一壁的最大尺寸为D2，满足，0.4≤D1/D2≤0.9，所述第一壁的厚度方向、所述第一方向和所述第二方向两两垂直。
  3. 根据权利要求2所述的电池单体，其中，0.6≤D1/D2≤0.9。
  4. 根据权利要求1-3中任一项所述的电池单体，其中，所述第一壁的外边缘包括第一边缘，所述第一边缘和所述泄压槽在第一方向上分别位于所述电极端子的两侧，所述第一方向垂直于所述第一壁的厚度方向；
    其中，沿所述第一方向，所述泄压槽与所述电极端子的最小距离为L1，所述泄压槽与所述第一边缘的最小距离为L2，满足，0.2≤L1/L2≤0.8。
  5. 根据权利要求4所述的电池单体，其中，0.2≤L1/L2≤0.6。
  6. 根据权利要求1-5中任一项所述的电池单体，其中，所述泄压槽与所述电极端子沿第一方向排布，所述第一方向垂直于所述第一壁的厚度方向；
    其中，沿所述第一方向，所述泄压槽与所述电极端子的最小距离为L1，所述第一壁位于所述泄压槽和所述电极端子之间的部分的厚度为D，满足，3≤L1/D≤30。
  7. 根据权利要求6所述的电池单体，其中，5≤L1/D≤25。
  8. 根据权利要求6或7所述的电池单体，其中，0.8mm≤D≤4mm。
  9. 根据权利要求1-8中任一项所述的电池单体，其中，所述泄压槽与所述电极端子沿第一方向排布，所述第一方向垂直于所述第一壁的厚度方向；
    其中，沿所述第一方向，所述泄压槽与所述电极端子的最小距离为L1，满足，10mm≤L1≤100mm。
  10. 根据权利要求9所述的电池单体，其中，15mm≤L1≤50mm。
  11. 根据权利要求1-10中任一项所述的电池单体，其中，所述电池单体包括两个所述电极端子，两个所述电极端子均设置于所述第一壁上，且两个所述电极端子沿第一方向间隔排布，所述第一方向垂直于所述第一壁的厚度方向；
    其中，沿所述第一方向，所述泄压槽位于两个所述电极端子之间。
  12. 根据权利要求11所述的电池单体，其中，沿所述第一方向，所述泄压槽与两个所述电极端子之间的最小距离相等。
  13. 根据权利要求1-12中任一项所述的电池单体，其中，所述第一壁设置有安装孔，所述安装孔沿所述第一壁的厚度方向贯穿所述第一壁，所述安装孔与所述电极端子一一对应；
    其中，所述电极端子包括柱体部、第一限位部和第二限位部，所述柱体部沿所述第一壁的厚度方向穿设于所述安装孔内，且所述柱体部连接所述第一限位部和所述第二限位部，所述第一限位部和所述第二限位部均凸出于所述柱体部的外周面，沿所述第一壁的厚度方向，所述第一限位部和所述第二限位部分别位于所述第一壁的两侧，且所述第一限位部的投影和所述第二限位部的投影的至少部分与所述第一壁重叠。
  14. 根据权利要求1-13中任一项所述的电池单体，其中，所述第一壁在所述第一壁的厚度方向上的投影呈长方形，所述第一壁在第一方向上的尺寸大于所述第一壁在第二方向上的尺寸，所述第一壁的厚度方向、所述第一方向和所述第二方向两两垂直；
    其中，所述泄压槽与所述电极端子沿所述第一方向排布。
  15. 根据权利要求14所述的电池单体，其中，所述外壳呈长方体状，所述外壳还具有两个第二壁，两个所述第二壁沿所述第二方向相对设置且分别连接于所述第一壁的两端；
    其中，沿所述第二方向，所述第二壁背离所述电极组件的表面为所述外壳的外表面中面积最大的面。
  16. 根据权利要求1-15中任一项所述的电池单体，其中，所述泄压槽冲压成型于所述第一壁。
  17. 根据权利要求1-16中任一项所述的电池单体，其中，所述泄压槽包括沿所述第一壁的厚度方向依次排布的多级槽。
  18. 根据权利要求1-17中任一项所述的电池单体，其中，沿所述第一壁的厚度方向，所述泄压槽的最小残余厚度为D3，满足，0.05mm≤D3≤0.3mm。
  19. 根据权利要求18所述的电池单体，其中，所述电池单体还包括电解液，所述电解液容纳于所述外壳内；
    其中，所述电解液包括电解质盐，所述电解质盐包括六氟磷酸盐，所述六氟磷酸盐的摩尔浓度小于或等于1.1mol/L。
  20. 根据权利要求1-19中任一项所述的电池单体，其中，所述泄压槽的底部形成第一薄弱部，所述第一壁被配置为在所述电池单体泄压时能够沿着至少部分所述第一薄弱部裂开；
    其中，所述第一壁还设置有引导槽，所述引导槽的底部形成第二薄弱部，沿所述第一壁的厚度方向，所述泄压槽的投影和至少一个所述引导槽的投影共同限定出至少一个预定泄压区，所述第二薄弱部被配置为引导所述预定泄压区的至少部分翻转，以打开所述预定泄压区的至少部分。
  21. 根据权利要求20所述的电池单体，其中，所述泄压槽与所述电极端子沿第一方向排布，所述泄压槽与所述引导槽沿第二方向排布，所述第一壁的厚度方向、所述第一方向和所述第二方向两两垂直。
  22. 根据权利要求21所述的电池单体，其中，所述引导槽沿所述第一方向延伸，沿所述第一方向，所述引导槽的两端分别延伸出所述泄压槽的两个端部。
  23. 根据权利要求22所述的电池单体，其中，沿所述第一壁的厚度方向，所述引导槽的投影与所述电极端子的投影不重叠。
  24. 根据权利要求20-23中任一项所述的电池单体，其中，沿所述第一壁的厚度方向，所述第二薄弱部的厚度大于所述第一薄弱部的厚度。
  25. 根据权利要求20-24中任一项所述的电池单体，其中，所述第一薄弱部包括至少一个薄弱段，所述薄弱段垂直于其延伸方向的横截面积为第一截面积S1，所述第二薄弱部垂直于其延伸方向的横截面积为第二截面积S2，满足，S1＜S2。
  26. 根据权利要求20-25中任一项所述的电池单体，其中，沿所述第一壁的厚度方向，所述泄压槽和所述引导槽分别设置于所述第一壁的两侧。
  27. 根据权利要求20-26中任一项所述的电池单体，其中，所述泄压槽包括第一槽段和两个第二槽段，两个所述第二槽段沿第一方向相对设置，且所述第二槽段与所述引导槽沿第二方向排布，所述第一槽段连接两个所述第二槽段，所述第一壁的厚度方向、所述第一方向和所述第二方向两两垂直；
    其中，沿所述第一壁的厚度方向，所述第一槽段的投影、两个所述第二槽段的投影、两个所述第二槽段的延长线的投影和所述引导槽的投影共同围合出所述预定泄压区；或
    沿所述第一壁的厚度方向，所述第一槽段的投影、两个所述第二槽段的投影、所述引导槽的投影和所述引导槽的延长线的投影共同围合出所述预定泄压区；或
    沿所述第一壁的厚度方向，所述第一槽段的投影、两个所述第二槽段的投影、两个所述第二槽段的延长线的投影、所述引导槽的投影和所述引导槽的延长线的投影共同围合出所述预定泄压区。
  28. 根据权利要求20-26中任一项所述的电池单体，其中，所述泄压槽包括第一槽段和第二槽段，所述第一槽段和所述第二槽段相连；
    其中，沿所述第一壁的厚度方向，所述第一槽段的投影、所述第一槽段的延长线的投影、所述第二槽段的投影、所述第二槽段的延长线的投影和所述引导槽的投影共同围合出所述预定泄压区；或
    沿所述第一壁的厚度方向，所述第一槽段的投影、所述第二槽段的投影、所述引导槽的投影和所述引导槽的延长线的投影共同围合出所述预定泄压区；或
    沿所述第一壁的厚度方向，所述第一槽段的投影、所述第一槽段的延长线的投影、所述第二槽段的投影、所述第二槽段的延长线的投影、所述引导槽的投影和所述引导槽的延长线的投影共同围合出所述预定泄压区。
  29. 根据权利要求20-26中任一项所述的电池单体，其中，所述泄压槽为沿弧形轨迹延伸的槽；
    其中，沿所述第一壁的厚度方向，所述泄压槽的投影、所述泄压槽的延长线的投影和所述引导槽的投影共同围合出所述预定泄压区；或
    沿所述第一壁的厚度方向，所述泄压槽的投影、所述引导槽的投影和所述引导槽的延长线的投影共同围合出所述预定泄压区；或
    沿所述第一壁的厚度方向，所述泄压槽的投影、所述泄压槽的延长线的投影、所述引导槽的投影和所述引导槽的延长线的投影共同围合出所述预定泄压区。
  30. 根据权利要求20-29中任一项所述的电池单体，其中，所述引导槽冲压成型于所述第一壁。
  31. 根据权利要求1-30中任一项所述的电池单体，其中，所述第一壁的厚度方向，所述第一壁被配置为支撑所述电极组件。
  32. 根据权利要求1-31中任一项所述的电池单体，其中，所述外壳包括：
    壳体，内部形成具有开口的容纳腔，所述容纳腔用于容纳所述电极组件；
    端盖，封闭所述开口；
    其中，所述壳体包括所述第一壁；或
    所述端盖为所述第一壁。
  33. 根据权利要求1-31中任一项所述的电池单体，其中，所述外壳包括：
    壳体，内部形成有容纳腔，所述容纳腔用于容纳所述电极组件，所述壳体相对的两端均形成有开口，且两个所述开口均与所述容纳腔连通；
    两个端盖，分别封闭两个所述开口；
    其中，两个所述端盖中的一个所述端盖为所述第一壁；或
    所述壳体包括所述第一壁。
  34. 一种电池，包括如权利要求1-33中任一项所述的电池单体。
  35. 根据权利要求34所述的电池，其中，所述电池还包括箱体，所述电池单体容纳于所述箱体内，所述箱体具有位于所述电池单体的底部的底板，沿所述第一壁的厚度方向，所述底板与所述第一壁面向设置。
  36. 一种用电装置，包括如权利要求1-33中任一项所述的电池单体或权利要求34-35中任一项所述的电池，所述电池单体用于提供电能。
PCT/CN2024/093026 2024-05-14 2024-05-14 电池单体、电池及用电装置 Pending WO2025236166A1 (zh)

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CN115458880A (zh) * 2022-11-11 2022-12-09 深圳海润新能源科技有限公司 端盖组件、储能装置以及用电设备
CN218300006U (zh) * 2022-04-24 2023-01-13 宁德时代新能源科技股份有限公司 用于电池单体的外壳、电池单体、电池及用电装置
CN116207412A (zh) * 2023-01-31 2023-06-02 湖北亿纬动力有限公司 一种电池、电池模组以及用电设备
CN116345057A (zh) * 2023-05-26 2023-06-27 宁德时代新能源科技股份有限公司 电池单体、电池及用电装置

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CN218300006U (zh) * 2022-04-24 2023-01-13 宁德时代新能源科技股份有限公司 用于电池单体的外壳、电池单体、电池及用电装置
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