WO2023045672A1 - 一种端盖、端盖组件、电池单体、电池及用电设备 - Google Patents

一种端盖、端盖组件、电池单体、电池及用电设备 Download PDF

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Publication number
WO2023045672A1
WO2023045672A1 PCT/CN2022/114233 CN2022114233W WO2023045672A1 WO 2023045672 A1 WO2023045672 A1 WO 2023045672A1 CN 2022114233 W CN2022114233 W CN 2022114233W WO 2023045672 A1 WO2023045672 A1 WO 2023045672A1
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WO
WIPO (PCT)
Prior art keywords
end cap
end cover
groove
wall
pressure relief
Prior art date
Application number
PCT/CN2022/114233
Other languages
English (en)
French (fr)
Inventor
王学辉
顾明光
陈小波
高雄伟
郝浴沧
Original Assignee
宁德时代新能源科技股份有限公司
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 宁德时代新能源科技股份有限公司 filed Critical 宁德时代新能源科技股份有限公司
Priority to EP22871725.2A priority Critical patent/EP4266461A1/en
Priority to KR1020237019297A priority patent/KR20230104270A/ko
Priority to JP2023533708A priority patent/JP2023552192A/ja
Publication of WO2023045672A1 publication Critical patent/WO2023045672A1/zh
Priority to US18/460,716 priority patent/US20230411779A1/en

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    • 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
    • H01M50/3425—Non-re-sealable arrangements in the form of rupturable membranes or weakened parts, e.g. pierced with the aid of a sharp member
    • 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
    • H01M50/102—Primary casings; Jackets or wrappings characterised by their shape or physical structure
    • H01M50/107—Primary casings; Jackets or wrappings characterised by their shape or physical structure having curved cross-section, e.g. round or elliptic
    • 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
    • H01M50/152—Lids or covers characterised by their shape for cells having curved cross-section, e.g. round or elliptic
    • 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
    • H01M50/247—Mountings; Secondary casings or frames; Racks, modules or packs; Suspension devices; Shock absorbers; Transport or carrying devices; Holders specially adapted for portable devices, e.g. mobile phones, computers, hand tools or pacemakers
    • 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
    • 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
    • H01M50/50—Current conducting connections for cells or batteries
    • H01M50/543—Terminals
    • H01M50/547—Terminals characterised by the disposition of the terminals on the cells
    • H01M50/55—Terminals characterised by the disposition of the terminals on the cells on the same side of the cell
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M2220/00—Batteries for particular applications
    • H01M2220/20—Batteries in motive systems, e.g. vehicle, ship, plane
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M2220/00—Batteries for particular applications
    • H01M2220/30—Batteries in portable systems, e.g. mobile phone, laptop
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
    • Y02E60/10—Energy storage using batteries

Definitions

  • the present application relates to the field of battery technology, in particular, to an end cover, an end cover assembly, a battery cell, a battery and electrical equipment.
  • the present application aims to provide an end cover, an end cover assembly, a battery cell, a battery and electrical equipment, so as to improve the safety of the battery.
  • the embodiment of the present application provides an end cover for a battery cell, which includes:
  • Two through holes, passing through the end cap, are used for installing electrode terminals
  • the groove is formed by indenting the surface of the end cap along the thickness direction, and the bottom wall of the groove forms a pressure relief mechanism
  • the weak part is arranged on the pressure relief mechanism, and the pressure relief mechanism is used to release the internal pressure of the battery cell;
  • the depth of the weakened portion decreases gradually.
  • the existing pressure relief mechanism is generally formed independently and then connected to the end cap, and connection defects are prone to occur at the connection part.
  • the pressure relief mechanism is directly formed on the end cap without connection, and there is no problem of connection defects.
  • the thickness of the pressure relief mechanism at the weak part decreases, and the greater the depth of the weak part, the smaller the thickness of the pressure relief mechanism at the weak part.
  • the pressure relief mechanism is used to release the internal pressure of the battery cell, and the pressure relief mechanism can actively Pressure relief can also be passive pressure relief.
  • the pressure relief mechanism is split along the weak part to release the internal pressure of the battery cell.
  • the weak part of the existing pressure relief mechanism easily affects the structural strength of the end cover.
  • the weak part of this application only has the largest local depth, and the depth of other parts decreases. As the depth of the weak part decreases, the thickness of the pressure relief mechanism gradually increases. The structural strength of the pressure relief mechanism is improved, and the structural strength of the end cover is further improved.
  • the end cover expands and deforms, and the perpendicular line of the line connecting the two through holes is the stress deformation center line of the end cover, and the stress of the end cover is relatively concentrated on the stress deformation center line.
  • the maximum depth of the weak part of the pressure relief mechanism is set on the vertical line of the two through holes.
  • the maximum stress on the end cap acts on the maximum depth of the weak part. Ensure that the weak part of the pressure relief mechanism is cracked at the position with the largest depth. After the weak part is cracked, under the action of the internal pressure of the battery cell, the pressure relief mechanism is easy to continue to crack along the weak part, increasing the valve opening area and realizing effective Pressure relief to ensure battery safety.
  • the opening direction of the pressure relief mechanism is limited by the cracking direction of the weak part of the pressure relief mechanism, so that countermeasures can be taken in advance to further improve battery safety.
  • the end cap provided by the present application has no connection defect, the structural strength of the end cap is high, and the pressure relief mechanism on the end cap can release pressure in a controlled direction, and the end cap can effectively improve the safety of the battery.
  • a perpendicular line of a line connecting the two through holes passes through the middle of the weak portion.
  • the deepest position of the weak part is in the middle, and when the internal pressure of the battery cell reaches the threshold value, the pressure relief mechanism splits along the weak part from the middle to both sides, and the valve opening speed of the pressure relief mechanism is fast, which can quickly release pressure to improve safety.
  • the weakened portion is symmetrical about the mid-perpendicular line.
  • the weak portion bears the same force on both sides of the mid-perpendicular line, ensuring that the pressure relief mechanism splits along the weak portion from the middle to both sides, further controlling the valve opening direction of the pressure relief mechanism, and improving safety.
  • the groove is symmetrical about the mid-perpendicular line.
  • the groove is symmetrical about the vertical line, and the weak part is symmetrical about the vertical line, so the pressure relief mechanism is symmetrical about the vertical line, and the structural strength and stress bearing capacity of the pressure relief mechanism on both sides of the vertical line are the same.
  • the valve opening direction of the pressure relief mechanism is more accurate, and the safety is higher.
  • the end cap is circular, the perpendicular line passes through the center of the end cap, and the weak portion extends along the circumference of the end cap.
  • the two parts of the end cover as a whole on both sides of the mid-perpendicular line have the same structural strength and the same bearing capacity, so as to ensure that the stress of the end cover is concentrated on the mid-perpendicular line, and further ensure that the end cover can be lifted from the mid-perpendicular line first.
  • the deepest part of the weak part is cracked to ensure the valve opening direction of the pressure relief mechanism and ensure the safety of the battery.
  • the weak portion is relatively far away from the center of the end cap and close to the edge of the end cap.
  • the center position is deformed greatly, and the edge position is relatively large. The deformation is small. Therefore, under the same valve opening pressure, when the weak part is set close to the edge of the end cover, the depth of the weak part needs to be set relatively large to ensure that the pressure relief mechanism can crack along the weak part under internal pressure. Open to open the valve. Since the overall thickness of the end cover is small, the pressure relief mechanism and the weak part are more refined. When the depth of the weak part is relatively large, the processing difficulty is relatively small and easy to process.
  • the groove includes an arc-shaped wall and a straight wall, the arc-shaped wall is surrounded by the straight wall, and the arc-shaped wall extends along the circumference of the end cap.
  • the groove is set in a bow shape, and when machining the weak portion, the arc-shaped wall can be used as a reference, and the weak portion can be processed along the arc-shaped wall, which is convenient for processing.
  • the valve opening area of the arc shape is larger than that of other shapes, Further improve security.
  • the arc angle enclosed by the arc wall is less than or equal to 180°.
  • the center position of the end cap is not in the groove, so as to ensure the structural strength of the end cap and leave a place for setting other functional components on the end cap.
  • the weakened portion has a first separation distance from the arc-shaped wall.
  • the weak portion and the arc-shaped wall are arranged at intervals, and when the connection position between the arc-shaped wall and the bottom wall of the groove is uneven, the weak portion is not prone to poor molding due to the first spacing distance, ensuring that The weak part is well formed to ensure that the pressure relief mechanism can be split along the weak part.
  • both ends of the weakened portion have a second separation distance from the straight wall.
  • the arc-shaped wall has a third separation distance from the edge of the end cap.
  • the arc-shaped wall of the groove is spaced from the edge of the end cap, so as to improve the structural strength of the edge of the end cap corresponding to the arc-shaped wall.
  • the corners at the connection positions of the arc-shaped wall and the straight wall are rounded corners to alleviate the problem of stress concentration at the corners, so as to prevent the end caps from being damaged at the corners of the grooves when the edges of the end caps are squeezed, improving the Structural strength of end caps.
  • a stepped surface is formed on the side wall of the groove, and the stepped surface extends along the circumferential direction of the groove.
  • the edge of the end cover When the edge of the end cover is squeezed, firstly the side wall above the step surface resists deformation, and then the stress is transmitted through the step surface to the side wall and bottom wall below the step surface, so the above scheme can effectively relieve the extrusion of the edge of the end cover Improve the structural strength of the end cap by eliminating the problem of damage to the weak part.
  • an end cap assembly which includes:
  • An end cap a groove
  • the groove is formed by indenting the surface of the end cap along the thickness direction, the bottom wall of the groove forms a pressure relief mechanism, and the groove includes a groove extending along the circumference of the end cap an arc-shaped wall; and a weakened portion configured to be split when the pressure relief mechanism is actuated, the weakened portion corresponding to the shape of the arc-shaped wall.
  • the end cap assembly provided by the present application has high structural strength, can effectively and directionally controllably open a valve to release pressure, and improve the safety of the battery.
  • the weakened portion is arc-shaped, and along the circumferential extension direction of the arc, the depth of the weakened portion is different.
  • the setting form of the weak part matches the shape of the arc wall, which is convenient for processing; along the circumferential extension direction of the arc, the depth of the weak part is different, which facilitates the cracking of the weak part and the release of the pressure relief mechanism. Release the internal pressure of the battery cell.
  • the end cover assembly further includes an electrode terminal, the electrode terminal includes a straight first wall, and the groove further includes a straight wall connecting two ends of the arc-shaped wall, The first wall is substantially parallel to the straight wall.
  • the first wall is basically parallel to the straight wall.
  • the distance between the groove and the electrode terminal is small, which reduces the space occupation; on the other hand, the cracking direction of the pressure relief mechanism can be restricted. Reduces the risk of contact with electrode terminals following failure of the pressure relief mechanism.
  • the depth of the weakened portion decreases gradually along the extension direction from the middle portion of the arc-shaped wall to both ends.
  • the depth of the weak part adopts the above-mentioned setting method.
  • the weak part splits from the middle of the arc-shaped wall to both ends, limiting the cracking direction of the pressure relief mechanism, so as to facilitate the release.
  • Pressure release mechanism When the pressure relief mechanism is actuated, the weak part splits from the middle of the arc-shaped wall to both ends, limiting the cracking direction of the pressure relief mechanism, so as to facilitate the release. Pressure release mechanism.
  • the end cover assembly further includes two through holes, the through holes are used for installing the electrode terminals, and one side of the vertical line along the line connecting the two through holes is Or on both sides, the depth of the weakened portion gradually decreases in a direction away from the median perpendicular.
  • the deepest position of the weak part is at the mid-perpendicular line, and when the pressure relief mechanism is actuated, the weak part splits from the position corresponding to the mid-perpendicular line to the direction away from the mid-perpendicular line, which facilitates the quick release of the pressure relief mechanism. Pressure relief for increased safety.
  • the embodiment of the present application provides a battery cell, which includes:
  • the end cap closes the opening.
  • the battery cell provided by the present application has an end cover that is not easily damaged, and has a stable overall structure.
  • the pressure relief mechanism on the end cover can effectively and directionally controllably open a valve to release pressure, and has high safety.
  • the groove is disposed on a side of the end cover away from the housing.
  • the groove is recessed from the outer surface of the end cap, and the pressure relief mechanism is far away from the outer surface of the end cap, so that the pressure relief mechanism is not easy to contact other objects and cause damage.
  • the embodiment of the present application provides a battery, which includes the aforementioned end cap or the aforementioned end cap assembly.
  • the battery provided by the present application has the aforementioned battery cells with high safety, so the battery has high safety and stable performance.
  • the embodiment of the present application provides an electric device, which includes the aforementioned battery.
  • the electrical equipment provided by this application uses a battery with high safety and stable performance to achieve stable work.
  • Fig. 1 is a schematic structural diagram of a vehicle provided by an embodiment of the present application.
  • Fig. 2 is an exploded schematic diagram of a battery provided by an embodiment of the present application.
  • Fig. 3 is a schematic structural diagram of a battery module provided by an embodiment of the present application.
  • Fig. 4 is a schematic structural diagram of a battery cell provided by an embodiment of the present application.
  • Fig. 5 is an exploded schematic diagram of a battery cell provided by an embodiment of the present application.
  • Fig. 6 is a schematic plan view of an end cap provided by an embodiment of the present application.
  • Fig. 7 is the A-A sectional view of Fig. 6;
  • Fig. 8 is an enlarged view of part B of Fig. 7;
  • Fig. 9 is a schematic perspective view of an end cap provided by an embodiment of the present application.
  • Fig. 10 is an enlarged view of part C of Fig. 9;
  • Fig. 11 is a schematic plan view of an end cap assembly provided by an embodiment of the present application.
  • Fig. 12 is a schematic plan view of an end cap assembly provided by another embodiment of the present application.
  • Marking instructions 1000-vehicle; 100-battery; 200-motor; 300-controller; 101-box; 1011-first part; 1012-second part; 102-battery module; Component; 12-housing; 121-opening; 13-end cover assembly; 131-end cover; 132-electrode terminal; 1321-first wall 1321; 133-groove; 1331-curved wall; 1333-step surface; 134-pressure relief mechanism; 1341-weak part; 135-through hole; Mid-perpendicular line; ⁇ -thickness direction of end cap; ⁇ -arc angle.
  • multiple refers to more than two (including two), similarly, “multiple groups” refers to more than two groups (including two), and “multiple pieces” refers to It is more than two pieces (including two pieces), unless otherwise clearly and specifically defined.
  • the battery mentioned in the embodiments of the present application refers to a single physical module including one or more battery cells to provide higher voltage and capacity.
  • the battery mentioned in this application may include a battery module or a battery pack, and the like.
  • Batteries generally include a case for enclosing one or more battery cells. The box can prevent liquid or other foreign objects from affecting the charging or discharging of the battery cells.
  • the battery cell includes an electrode assembly and an electrolyte, and the electrode assembly is composed of a positive pole piece, a negative pole piece and a separator.
  • a battery cell works primarily by moving metal ions between the positive and negative pole pieces.
  • the positive electrode sheet includes a positive electrode current collector and a positive electrode active material layer, the positive electrode active material layer is coated on the surface of the positive electrode current collector, and the current collector not coated with the positive electrode active material layer protrudes from the current collector coated with the positive electrode active material layer, The current collector not coated with the positive electrode active material layer is used as the positive electrode tab.
  • the material of the positive electrode current collector can be aluminum, and the positive electrode active material can be lithium cobaltate, lithium iron phosphate, ternary lithium or lithium manganate.
  • the negative electrode sheet includes a negative electrode current collector and a negative electrode active material layer, the negative electrode active material layer is coated on the surface of the negative electrode current collector, and the current collector not coated with the negative electrode active material layer protrudes from the current collector coated with the negative electrode active material layer, The current collector not coated with the negative electrode active material layer is used as the negative electrode tab.
  • the material of the negative electrode current collector may be copper, and the negative electrode active material may be carbon or silicon.
  • the number of positive pole tabs is multiple and stacked together, and the number of negative pole tabs is multiple and stacked together.
  • the material of the diaphragm can be PP or PE, etc.
  • the electrode assembly may be a wound structure or a laminated structure, which is not limited in the embodiment of the present application.
  • the protection measures include at least the switching element, the selection of an appropriate isolation diaphragm material, and the pressure relief mechanism.
  • the switching element refers to an element that can stop charging or discharging the battery when the temperature or resistance inside the battery cell reaches a certain threshold.
  • the separator is used to isolate the positive pole piece and the negative pole piece. When the temperature rises to a certain value, it can automatically dissolve the micron-scale (or even nanoscale) micropores attached to it, so that metal ions cannot pass through the separator. Terminate the internal reaction of the battery cell.
  • the pressure relief mechanism refers to an element or part that is activated to release the internal pressure or temperature when the internal pressure or temperature of the battery cell reaches a predetermined threshold.
  • the threshold design varies according to design requirements. The threshold may depend on the materials of one or more of the positive pole piece, the negative pole piece, the electrolyte and the separator in the battery cell.
  • the "activation" mentioned in this application means that the pressure relief mechanism is activated or activated to a certain state, so that the internal pressure and temperature of the battery cells can be released. Actions by the pressure relief mechanism may include, but are not limited to, at least a portion of the pressure relief mechanism rupture, shatter, be torn, or open, among others.
  • the high-temperature and high-pressure material inside the battery cell will be discharged from the actuated part as discharge.
  • the battery cells can be depressurized under controllable pressure or temperature, thereby avoiding potential more serious accidents.
  • the emissions from battery cells mentioned in this application include but are not limited to: electrolyte, dissolved or split positive and negative electrodes, fragments of separator, high temperature and high pressure gas generated by reaction, flame, etc.
  • the pressure relief mechanism on the battery cell has an important impact on the safety of the battery. For example, when a short circuit, overcharge, etc. occur, it may cause thermal runaway inside the battery cell, resulting in a sudden increase in pressure or temperature. In this case, the internal pressure and temperature can be released to the outside through the actuation of the pressure relief mechanism, so as to prevent the battery cells from exploding and igniting.
  • the pressure relief mechanism can take the form of an explosion-proof valve, gas valve, pressure relief valve or safety valve, etc., and can specifically use a pressure-sensitive or temperature-sensitive element or structure, that is, when the internal pressure or temperature of the battery cell reaches a predetermined threshold When the pressure relief mechanism performs an action or the weak structure provided in the pressure relief mechanism is destroyed, a through hole or channel for internal pressure or temperature release is formed.
  • a passage for pressure relief is generally provided on the end cover, and the pressure relief mechanism is connected to the end cover and closes the passage for pressure relief.
  • the fragments generated by the pressure relief mechanism fly up when the pressure relief mechanism is actuated, and the discharge of the pressure relief mechanism (such as high-temperature and high-pressure gas) during actuation Rush out, etc., and the battery cell is also prone to leakage.
  • the application provides an end cap, the surface of the end cap is recessed along the thickness direction to form a groove, and the bottom wall of the groove forms a pressure relief device.
  • a weak part is set on the pressure relief mechanism, and the pressure relief mechanism is configured to split along the weak part when the internal pressure of the battery cell reaches a threshold value, and two through holes for installing electrode terminals are formed on the end cover, and two The perpendicular line of the line connecting the through holes intersects the weak portion, and the depth of the weak portion gradually decreases along the direction where one or both sides of the perpendicular line connecting the two through holes are away from the perpendicular line.
  • the thickness of the bottom wall of the groove is thinner than that of the end cap, and the bottom wall of the groove with a thinner thickness is used as a pressure relief mechanism, and the pressure relief mechanism is directly formed On the end cover, the pressure relief mechanism and the end cover do not need to be connected, there is no problem of connection defects, and there is no problem of liquid leakage caused by connection defects.
  • a weakened portion is further set on the pressure relief mechanism so that the thickness of the pressure relief mechanism at the weakened portion is further thinned.
  • the weakened portion can be a recess formed on the pressure relief mechanism, and the recess is used to thin the thickness of the pressure relief mechanism (that is, The thickness of the bottom wall of the aforementioned groove), the recess can be a notch, or a groove formed on the pressure relief mechanism by means of extrusion, stamping, integral casting and the like.
  • the overall depth of the weak part of the pressure relief mechanism in the prior art is consistent, but the depth of the weak part of the present application is variable, and the depth of the weak part is the largest only at the intersection of the perpendicular line of the line connecting the two through holes, along the In the direction away from the mid-perpendicular line, the depth of the weak part gradually decreases, so that the thickness of the pressure relief mechanism at the weak part gradually increases, which improves the structural strength of the pressure relief mechanism, thereby improving the structural strength of the end cover.
  • the end cap is not easy to accidentally damage and leak.
  • the end cover expands and deforms.
  • the perpendicular line of the line connecting the two through holes is the stress deformation center line of the end cover.
  • the stress of the end cover is relatively concentrated on the stress deformation center line.
  • the maximum depth of the weak part of the pressure mechanism is set on the perpendicular line of the two through holes.
  • the initial cracking position and cracking direction of the weak part are determined, thereby defining the valve opening direction of the pressure relief mechanism, so as to take countermeasures in advance and relieve the pressure relief mechanism when it is actuated.
  • Safety issues caused by debris flying up and emissions rushing out further improve battery safety.
  • the end cap disclosed in the embodiment of the present application is used for a battery cell, and the battery cell may include a lithium-ion secondary battery, a lithium-ion primary battery, a lithium-sulfur battery, a sodium-lithium-ion battery, a sodium-ion battery, or a magnesium-ion battery.
  • the application embodiments do not limit this.
  • the battery cell can be in the form of a cylinder, a flat body, a cuboid or other shapes, which is not limited in this embodiment of the present application.
  • the battery cell disclosed in this embodiment can be used in electrical equipment such as vehicles, ships, or aircrafts, but is not limited to.
  • the power supply system comprising the battery cells and batteries disclosed in this application can be used to form the electrical equipment, which is beneficial to alleviate the safety risks caused by battery leakage and charging and discharging, and improve the safety of battery performance and battery life.
  • the embodiment of the present application provides an electric device using a battery as a power source.
  • the electric device can be, but not limited to, a mobile phone, a tablet, a notebook computer, an electric toy, an electric tool, a battery car, an electric car, a ship, a spacecraft, and the like.
  • electric toys may include fixed or mobile electric toys, such as game consoles, electric car toys, electric boat toys, electric airplane toys, etc.
  • spacecraft may include airplanes, rockets, space shuttles, spaceships, etc.
  • a vehicle is used as an example of an electric device according to an embodiment of the present application.
  • Figure 1 shows a vehicle 1000 according to an embodiment of the present application.
  • the vehicle 1000 can be a fuel vehicle, a gas vehicle or a new energy vehicle, and the new energy vehicle can be a pure electric vehicle or a hybrid vehicle. Or extended-range cars, etc.
  • a battery 100 , a controller 300 and a motor 200 may be provided inside the vehicle 1000 , and the controller 300 is used to control the battery 100 to supply power to the motor 200 .
  • the battery 100 may be provided at the bottom or front or rear of the vehicle 1000 .
  • the battery 100 can be used for power supply of the vehicle 1000 , for example, the battery 100 can be used as an operating power source of the vehicle 1000 , for a circuit system of the vehicle 1000 , for example, for starting, navigating, and working power requirements of the vehicle 1000 .
  • the battery 100 can not only be used as an operating power source for the vehicle 1000 , but can also be used as a driving power source for the vehicle 1000 , replacing or partially replacing fuel oil or natural gas to provide driving power for the vehicle 1000 .
  • the battery 100 may include a plurality of battery cells 1 , wherein the plurality of battery cells 1 may be connected in series or in parallel or in parallel, and the hybrid connection refers to a mixture of series and parallel connections.
  • the battery 100 may also be called a battery 100 pack.
  • multiple battery cells 1 can be connected in series, parallel or mixed to form a battery module 102 , and then multiple battery modules 102 can be connected in series, parallel or mixed to form a battery 100 . That is to say, a plurality of battery cells 1 may directly form the battery 100 , or may first form the battery module 102 , and the battery module 102 then forms the battery 100 .
  • the battery 100 may include a plurality of battery cells 1 .
  • the battery 100 may further include a box body 101 (or called a cover body), the interior of the box body 101 is a hollow structure, and a plurality of battery cells 1 are accommodated in the box body 101 .
  • the box body 101 may include two parts for accommodating (refer to FIG. 2 ), referred to here as a first part 1011 and a second part 1012 respectively, and the first part 1011 and the second part 1012 are fastened together.
  • the shapes of the first part 1011 and the second part 1012 may be determined according to the combined shape of a plurality of battery cells 1 , and each of the first part 1011 and the second part 1012 may have an opening.
  • both the first part 1011 and the second part 1012 can be hollow cuboids and each has only one face as an open face, the opening of the first part 1011 and the opening of the second part 1012 are arranged oppositely, and the first part 1011 and the second part 1012 are interlocked Combined to form a box 101 with a closed chamber.
  • the first part 1011 and the second part 1012 one may also be a cuboid with an opening, and the other may be a cover structure to close the opening of the cuboid.
  • a plurality of battery cells 1 are combined in parallel, in series or in parallel and placed in the box 101 formed by fastening the first part 1011 and the second part 1012 .
  • the battery 100 may also include other structures.
  • the battery 100 may also include a confluence part, which is used to realize the electrical connection between a plurality of battery cells 1 , such as parallel connection, series connection or mixed connection.
  • the current-combining component can realize the electrical connection between the battery cells 1 by connecting the electrode terminals of the battery cells 1 .
  • the bus member may be fixed to the electrode terminal of the battery cell 1 by welding. The electric energy of the plurality of battery cells 1 can be further drawn out through the case body 101 through the conductive mechanism.
  • the conduction means can also belong to the current-collecting part.
  • the battery cell 1 includes an electrode assembly 11 , a casing 12 and an end cap assembly 13 .
  • the electrode assembly 11 is a part where the electrochemical reaction occurs in the battery cell 1 .
  • One battery cell 1 may contain one or more electrode assemblies 11 .
  • the electrode assembly 11 is mainly formed by winding or laminating a positive pole piece and a negative pole piece, and a separator is usually provided between the positive pole piece and the negative pole piece.
  • the parts of the positive pole piece and the negative pole piece with active material constitute the main body of the electrode assembly 11 , and the parts of the positive pole piece and the negative pole piece without active material respectively form tabs.
  • the positive pole tab and the negative pole tab can be located at one end of the main body together or at two ends of the main body respectively.
  • the casing 12 is a component used to cooperate with the end cap 131 to form the internal environment of the battery cell 1 , wherein the formed internal environment can be used to accommodate the electrode assembly 11 , electrolyte and other components.
  • the casing 12 and the end cover 131 can be independent components, and the opening 121 can be provided on the casing 12 , and the internal environment of the battery cell 1 can be formed by making the end cover 131 cover the opening 121 .
  • the end cover 131 and the housing 12 can also be integrated. Specifically, the end cover 131 and the housing 12 can form a common connecting surface before other components are inserted into the housing. When the inside of the housing 12 needs to be encapsulated , then make the end cover 131 cover the housing 12 .
  • the housing 12 can be in various shapes and sizes, such as cuboid, cylinder, hexagonal prism and so on. Specifically, the shape of the casing 12 can be determined according to the specific shape and size of the electrode assembly 11 .
  • the housing 12 can be made of various materials, such as copper, iron, aluminum, stainless steel, aluminum alloy, plastic, etc., which is not particularly limited in this embodiment of the present application.
  • the end cover assembly 13 refers to a component that fits at the opening 121 of the casing 12 to isolate the internal environment of the battery cell 1 from the external environment.
  • the end cover assembly 13 includes an end cover 131 , an electrode terminal 132 , a pressure relief mechanism 134 and other functional components, wherein the end cover 131 is used to connect the casing 12 to close the opening 121 .
  • the shape of the end cap 131 can be adapted to the shape of the housing 12 to match the housing 12 .
  • the end cap 131 can be made of a material (such as aluminum alloy) with a certain hardness and strength, so that the end cap 131 is not easily deformed when it is squeezed and collided, so that the battery cell 1 can have a higher Structural strength and safety performance can also be improved.
  • the material of the end cover 131 may also be various, for example, copper, iron, aluminum, stainless steel, aluminum alloy, plastic, etc., which is not particularly limited in this embodiment of the present application.
  • an insulator can be provided inside the end cover 131 , and the insulator can be used to isolate the electrical connection components in the housing 12 from the end cover 131 to reduce the risk of short circuit.
  • the insulating member may be plastic, rubber or the like.
  • the electrode terminal 132 is disposed on the end cap 131 , and the electrode terminal 132 can be used to electrically connect with the tab of the electrode assembly 11 for outputting or inputting electric energy of the battery cell 1 .
  • the pressure relief mechanism 134 is disposed on the end cover 131 for releasing the internal pressure when the internal pressure or temperature of the battery cell 1 reaches a threshold value.
  • the present application provides an end cover 131 for the battery cell 1 (as shown in FIG. 5 ).
  • the end cover 131 is provided with a groove 133 and two through holes 135.
  • the groove 133 is formed by indenting the surface of the end cover 131 along the thickness direction.
  • the bottom wall of the groove 133 forms a pressure relief mechanism 134.
  • the pressure relief mechanism 134 is configured to split along the weak part 1341 when the internal pressure of the battery cell 1 reaches a threshold value; two through holes 135 run through the end cap 131 for installing the electrode terminal 132, along the two through holes One side or both sides of the vertical line ⁇ of the connection line 135 is away from the direction of the vertical line ⁇ , and the depth of the weak portion 1341 gradually decreases.
  • the ⁇ direction is the thickness direction of the end cap, and the concave direction of the groove 133 and the depth direction of the weak portion 1341 are both along the thickness direction ⁇ of the end cap.
  • the pressure relief mechanism 134 is used to release the internal pressure of the battery cell 1 , and the pressure relief mechanism 134 can actively or passively relieve the pressure.
  • the pressure relief mechanism 134 is a passive pressure relief mechanism, for example, the pressure relief mechanism 134 is configured to rupture along the weak portion 1341 when the internal pressure of the battery cell 1 reaches a threshold.
  • the thickness of the bottom wall of the groove 133 is thinner than the thickness of the end cover 131, and the bottom wall of the thinner groove 133 is used as the pressure relief mechanism 134, also That is, when the internal pressure of the battery cell 1 reaches a threshold value, the bottom wall of the groove 133 is broken to release the internal pressure.
  • the groove 133 can be formed by cutting on the end cover 131, or it can be integrally cast with the end cover 131, or it can be formed by stamping the groove 133 and the end cover 131 at one time, or the groove 133 can be formed by stamping raw materials first. The end cap 131 is then formed by stamping.
  • the weak portion 1341 is a recess formed on the pressure relief mechanism 134, that is, another groove 133 formed on the bottom wall of the groove 133 (for ease of distinction, hereinafter referred to as the second groove),
  • the bottom wall of the groove 133 is recessed from the surface along the thickness direction ⁇ of the end cap to form a second groove, and the second groove reduces the thickness of the bottom wall of the groove 133 (that is, reduces the thickness of the pressure relief mechanism 134 ).
  • the second groove can be a score provided on the surface of the pressure relief mechanism 134 , or can be formed by secondary stamping on the pressure relief mechanism 134 , or integrally formed when casting the end cover 131 .
  • the weakened portion 1341 is used to define the preferential destruction position of the pressure relief mechanism 134 .
  • the pressure relief mechanism 134 is preferentially destroyed from the weakened portion 1341 to release the internal pressure.
  • the connection of 135 is sealed to avoid liquid leakage.
  • an insulator is provided at the connection between each electrode terminal 132 and the through hole 135 , so as to prevent the end cap 131 from being electrified, and reduce the potential safety hazard of a short circuit caused by electrification of the end cap 131 .
  • the polarities of the two electrode terminals 132 may be the same or different.
  • the end cap 131 When the internal pressure of the battery cell 1 increases, the end cap 131 will be squeezed or even expanded and deformed.
  • the structural strength of the end cap 131 at the through hole 135 is relatively low, and the perpendicular line between the two through holes 135 ⁇ is the stress-deformation centerline of the end cap 131 , that is, on the perpendicular line ⁇ of the line connecting the two through holes 135 , the stress of the end cap 131 is relatively concentrated.
  • the perpendicular line ⁇ refers to the perpendicular bisector of the line segment, that is, the perpendicular line drawn by the midpoint of the line passing through the two through holes 135 .
  • connection line of two through holes 135 refers to the connection line of the centroids of two through holes 135, when two through holes 135 are circular, the connection line of two through holes 135 is the circle center of two through holes 135 connection.
  • the perpendicular line ⁇ of the line connecting the two through holes 135 passes through the weak portion 1341, that is, the perpendicular line ⁇ intersects the weak portion 1341, and there is an intersection point between the perpendicular line ⁇ and the weak portion 1341 , the weakened portion 1341 is configured to have the largest depth at the intersection point, and the depth of the weakened portion 1341 decreases toward one or both sides of the mid-perpendicular line ⁇ in a direction away from the mid-perpendicular line ⁇ , in other words, along the direction of the weakened portion 1341 In the extension direction of , the farther away from the intersection point of the weakened portion 1341 and the vertical line ⁇ , the smaller the depth of the weakened portion 1341 is, and the greater the remaining thickness of the pressure relief mechanism 134 after being thinned by the weakened portion 1341 is.
  • a weakened portion 1341 with gradually changing depth is provided on the pressure relief mechanism 134, and the deepest position of the weakened portion 1341 is set on the perpendicular line ⁇ of the line connecting the two through holes 135
  • the overall strength of the end cover 131 is relatively high, and there is no connection defect between the pressure relief mechanism 134 and the end cover 131, which effectively alleviates the problem of liquid leakage; it also ensures that the pressure relief mechanism 134 on the end cover 131 can crack from the deepest position of the weak part 1341.
  • the pressure relief mechanism 134 is effectively actuated under the internal pressure; and the pressure relief mechanism 134 is further split along the weak portion 1341 under the internal pressure of the battery cell 1 to expand the valve opening area, and the pressure relief mechanism 134 is limited.
  • the valve opening position and direction of the pressure relief mechanism 134 are controllable, which is convenient for pre-preparation for the pressure relief mechanism 134, such as setting protection in the direction of relief of the pressure relief mechanism 134, Therefore, the safety of the battery 100 is improved.
  • the channel connecting the inside and the outside of the battery cell 1 formed after the pressure relief mechanism 134 is split is used to discharge the discharge.
  • the valve opening area mentioned in this application refers to the flow cross-sectional area of the channel.
  • the perpendicular line ⁇ of the line connecting the two through holes 135 passes through the middle of the weak portion 1341 .
  • the extension direction of the weak portion 1341 forms a certain angle with the vertical line ⁇ , and the intersection point of the weak portion 1341 and the vertical line ⁇ is at the midpoint of the extension direction of the weak portion 1341 .
  • the pressure relief mechanism 134 Since the deepest position of the weak portion 1341 is in the middle, when the internal pressure of the battery cell 1 reaches the threshold value, the pressure relief mechanism 134 is split synchronously along the weak portion 1341 from the middle to both sides, and the valve opening speed of the pressure relief mechanism 134 is fast, so that The battery cell 1 releases pressure quickly to improve safety.
  • the weakened portion 1341 is symmetrical about the mid-perpendicular line ⁇ .
  • the intersection of the weak portion 1341 and the vertical line ⁇ is at the midpoint of the extension direction of the weak portion 1341 , and the extension direction of the weak portion 1341 is perpendicular to the vertical line ⁇ , so that the weak portion 1341 is symmetrical about the vertical line ⁇ .
  • the stress distribution on both sides of the stress concentration line is similar, and the weak portion 1341 bears the same force on both sides of the mid-perpendicular line ⁇ , ensuring that the pressure relief mechanism 134 cracks from the middle to both sides along the weak portion 1341 open, to further control the valve opening direction of the pressure relief mechanism 134 to improve safety.
  • the groove 133 is symmetrical about the perpendicular line ⁇ .
  • the pressure relief mechanism 134 is symmetrical about the vertical line ⁇ , and the structural strength of the pressure relief mechanism 134 on both sides of the vertical line ⁇ is the same,
  • the stress bearing capacity is consistent, ensuring that when the internal pressure of the battery cell 1 reaches the threshold value, the pressure relief mechanism 134 is simultaneously opened from the intersection point of the weak part 1341 and the vertical line ⁇ to both sides of the vertical line ⁇ , and the valve is opened.
  • the direction is more accurate, the valve opening speed is faster, and the safety is higher.
  • the end cap 131 is circular, the vertical line ⁇ passes through the center of the end cap 131 , and the weak portion 1341 extends along the circumference of the end cap 131 .
  • two through holes 135 are symmetrically arranged on the circular end cover 131, the vertical line ⁇ of the connection line of the two through holes 135 passes through the center of circle of the circular end cover 131, and the two through holes 135 It is symmetrical about the perpendicular ⁇ .
  • the weakened portion 1341 extends along the circumference of the end cover 131 , that is, the weakened portion 1341 extends along an arc, and the center of the arc coincides with the center of the circular end cover 131 .
  • the coincidence mentioned in this application may be complete coincidence; it may also be that the center of the arc near the center of the end cap 131 is in a state of close coincidence.
  • the end cover 131 is symmetrical about the vertical line ⁇ as a whole, and the two parts of the end cover 131 on both sides of the vertical line ⁇ have the same structural strength and the same bearing capacity, ensuring that the stress of the end cover 131 is concentrated on the vertical line ⁇ , to further ensure that the end cover 131 can be split from the deepest position of the weak portion 1341 on the mid-perpendicular line ⁇ , and further ensure the valve opening direction of the pressure relief mechanism 134 .
  • the deformation at the center (circle center) is larger, and the deformation at the edge is smaller. Since the weak portion 1341 extends along the circumferential direction of the end cover 131, the weak portion 1341 is relatively closer to the edge of the end cover 131 and relatively farther away from the center of the end cover 131. When the weak portion 1341 is close to the edge of the end cover 131 with less deformation, Under the same valve opening pressure, the depth of the weak portion 1341 needs to be set relatively large, so as to ensure that the weak portion 1341 can be broken. Since the overall thickness of the end cover 131 is small, the pressure relief mechanism 134 and the weak portion 1341 are finer, requiring higher processing precision. By setting the depth of the weak portion 1341 relatively large, the processing difficulty is effectively reduced.
  • the groove 133 includes an arc-shaped wall 1331 and a straight wall 1332 , the arc-shaped wall 1331 and the straight wall 1332 are enclosed, and the arc-shaped wall 1331 extends along the circumference of the end cover 131 .
  • the projection of the arc-shaped wall 1331 on the end cover 131 is an arc, and the center of the arc coincides with the center of the circle of the end cover 131 .
  • the coincidence mentioned in this application may be complete coincidence; it may also be that the center of the arc is close to the state of coincidence near the center of the end cap 131 .
  • the projection of the straight wall 1332 on the end cover 131 is a straight line, and the two ends of the straight line are connected with the two ends of the arc to form a bow. That is, the projection shape of the groove 133 on the end cover 131 is arcuate, or the shape of the groove 133 is arcuate.
  • the arc-shaped wall 1331 is used as a reference, and the weak portion 1341 can be processed along the arc-shaped wall 1331, which is convenient for processing.
  • the pressure relief mechanism 134 After the pressure relief mechanism 134 is split along the weak portion 1341, the pressure relief mechanism 134 is connected to the straight wall 1332, so as to prevent the pressure relief mechanism 134 from flying up after being damaged.
  • the opening direction of the pressure relief mechanism 134 faces the edge direction of the end cover 131, limiting The discharge discharges toward the edge of the end cap 131 .
  • the groove 133 can also be set in other shapes, such as a waist shape, the waist shape has two arc-shaped walls 1331 extending along the circumference of the end cover 131, and one of the arc-shaped walls 1331 is relatively close to the end cover 131 The center of the other arc-shaped wall 1331 is relatively close to the edge of the end cover 131 .
  • the weakened portion 1341 is processed along the arc-shaped wall 1331 near the edge of the end cover 131, so that after the pressure relief mechanism 134 is split along the weakened portion 1341, the pressure relief mechanism 134 is connected to the arc-shaped wall near the center of the end cap 131 1331 , prevent the pressure relief mechanism 134 from flying up after being damaged, and the opening direction of the pressure relief mechanism 134 faces the edge direction of the end cover 131 , limiting the release of the discharge to the edge direction of the end cover 131 .
  • the bow shape When the length of the weak portion 1341 is constant, the bow shape has a larger valve opening area than the waist shape, which can further improve safety. Under the condition that the valve opening area is constant, the arched shape has a shorter extension length along the edge of the end cap 131 than the waist shape, and the groove 133 has little influence on the structural strength of the end cap 131, so the structure of the arched end cap 131 is set Higher strength.
  • the arc angle ⁇ enclosed by the arc wall 1331 is less than or equal to 180°.
  • FIG. 6 shows the arc angle ⁇ surrounded by the arched arc wall 1331.
  • the weak portion 1341 and the arc-shaped wall 1331 have a first separation distance L1.
  • the weak portion 1341 is not disposed close to the connecting position between the arc wall 1331 and the bottom wall of the groove 133 , but there is a first distance L1 between the weak portion 1341 and the arc wall 1331 .
  • the first spacing distance L1 >1mm.
  • the connection position between the arc-shaped wall 1331 and the bottom wall of the groove 133 is uneven, the shape of the weak portion 1341 is not easily affected due to the setting of the first distance L1, so that the weak portion 1341 is prevented from being poorly formed, and the weak portion 1341 is guaranteed to be formed. Good, ensure that the pressure relief mechanism 134 can be split along the weak portion 1341 .
  • the groove 133 is allowed to have a certain processing error, so as to prevent the position of the weak portion 1341 from being outside the groove 133 due to the processing error.
  • the two ends of the weak portion 1341 and the straight wall 1332 have a second separation distance L2.
  • the two ends of the weak portion 1341 do not extend to the connection position between the straight wall 1332 and the bottom wall of the groove 133, but a second interval is provided between the two ends of the weak portion 1341 and the straight wall 1332 Distance L2.
  • the second spacing distance L2 ⁇ 0.5mm.
  • the two ends of the weak portion 1341 and the straight wall 1332 have a second distance L2
  • the edge of the end cover 131 is squeezed, it is not easy to transmit the deformation to the weak portion 1341 through the straight wall 1332, and the weak portion 1341 is not easy to crack.
  • the structural strength of the end cap 131 is high, and when the internal pressure of the battery cell 1 does not reach the threshold value, the pressure relief mechanism 134 is not easy to accidentally rupture along the weak portion 1341 .
  • the arc wall 1331 has a third separation distance L3 from the edge of the end cover 131 .
  • a third distance L3 is set between the arc wall 1331 of the groove 133 and the edge of the end cover 131 to ensure the structural strength of the edge of the end cover 131 corresponding to the arc wall 1331 .
  • the third spacing distance L3 >3mm.
  • the corners at the connection positions of the arc-shaped wall 1331 and the straight wall 1332 are rounded to realize the arc transition between the arc-shaped wall 1331 and the straight wall 1332 .
  • the problem of stress concentration at the corners of the arc-shaped wall 1331 and the straight wall 1332 is alleviated, so that when the edge of the end cover 131 is squeezed, the end cover 131 falls out of the groove.
  • the corner of 133 is damaged, which improves the structural strength of the end cover 131.
  • a stepped surface 1333 is formed on the sidewall of the groove 133 , and the stepped surface 1333 extends along the circumference of the groove 133 .
  • the side wall of the groove 133 includes an arcuate wall 1331 and a straight wall 1332, as shown in Figure 9 and Figure 10, the step surface 1333 is perpendicular to the arcuate wall 1331 and the straight wall 1332, and on the thickness direction ⁇ of the end cap, the The side wall formed by the curved wall 1331 and the straight wall 1332 is divided into upper and lower parts, wherein the side wall of the upper part and the side wall of the lower part are staggered, and the opening area of the groove 133 is larger than the area of the bottom wall of the groove 133 . In other embodiments, the opening area of the groove 133 may also be smaller than the area of the bottom wall of the groove 133 .
  • the step surface 1333 By setting the step surface 1333, if the edge of the end cover 131 is pressed towards the center of the circle, firstly the side wall of the upper part resists deformation, and then the stress is transmitted to the side wall of the lower part through the step surface 1333, and then to the side wall of the lower part.
  • the bottom wall can effectively alleviate the impact of the edge of the end cover 131 on the weak portion 1341 , so as to prevent the weak portion 1341 from being damaged when the internal pressure of the battery cell 1 does not reach a threshold, and improve the structural strength of the end cover 131 .
  • the embodiment of the present application provides an end cap assembly 13, which includes the end cap 131 and the electrode terminal 132 described in any of the above solutions.
  • the two electrode terminals 132 are disposed in the two through holes 135 of the end cap 131 to lead out the electric energy of the battery cell 1 or to charge the electric energy into the battery cell 1 .
  • the embodiment of the present application provides an end cover assembly 13, and the end cover assembly 13 includes an end cover 131, a groove 133 and a weak portion 1341.
  • the groove 133 is formed by indenting the surface of the end cover 131 along the thickness direction ⁇ , the bottom wall of the groove 133 forms the pressure relief mechanism 134 , and the groove 133 includes an arc-shaped wall 1331 extending along the circumferential direction of the end cover 131 .
  • the weakened portion 1341 is configured to be split when the pressure relief mechanism 134 is actuated, and the weakened portion 1341 is set corresponding to the shape of the arc-shaped wall 1331 .
  • the outline of the end cover 131 is circular, the arc-shaped wall 1331 extends along the circumference of the end cover 131, the pressure relief mechanism 134 is formed on the bottom wall of the groove 133, the weak part 1341 is arranged on the pressure relief mechanism 134, the weak part 1341 and The shape of the arc wall 1331 is set correspondingly.
  • the weak portion 1341 is a recess formed on the pressure relief mechanism 134, that is, another groove formed on the bottom wall of the groove 133 (for ease of distinction, hereinafter referred to as the second groove), the bottom wall of the groove 133
  • the second groove is formed by indenting the surface along the thickness direction ⁇ of the end cap 131 , and the second groove reduces the thickness of the bottom wall of the groove 133 (that is, reduces the thickness of the pressure relief mechanism 134 ).
  • the weak portion 1341 can be a notch provided on the surface of the pressure relief mechanism 134 , or can be formed by secondary stamping on the pressure relief mechanism 134 , or integrally formed when the end cover 131 is cast.
  • the weakened portion 1341 is used to define the preferential destruction position of the pressure relief mechanism 134.
  • the pressure relief mechanism 134 is activated, and the pressure relief mechanism 134 is preferentially split from the weakened portion 1341 to Release internal pressure.
  • the pressure relief mechanism 134 is split along the weak portion 1341 to expand the valve opening area. Under the condition that the initial damage position and the subsequent cracking direction of the pressure relief mechanism 134 are limited, the valve opening position and direction of the pressure relief mechanism 134 are controllable, which is convenient for
  • the pressure relief mechanism 134 is prepared in advance, for example, a protection is provided in the discharge direction of the pressure relief mechanism 134 , so as to improve the safety of the battery 100 .
  • the channel connecting the inside and the outside of the battery cell 1 formed after the pressure relief mechanism 134 is split is used to discharge the discharge.
  • the valve opening area mentioned in this application refers to the flow cross-sectional area of the channel.
  • the end cover assembly 13 provided in the present application has high structural strength, and can effectively and directionally controllably open a valve to release pressure, thereby improving the safety of the battery 100 .
  • the weakened portion 1341 is arc-shaped, and the depths of the weakened portion 1341 are different along the circumferential extension direction of the arc.
  • the weakened part 1341 is arc-shaped, and is arranged corresponding to the shape of the arc-shaped wall 1331, which is convenient for processing and forming.
  • the depth of the weak portion 1341 is different, so that the weak portion splits in an arc, which is convenient for the pressure relief mechanism to release the internal pressure of the battery cell.
  • the end cover assembly 13 further includes an electrode terminal 132, the electrode terminal 132 includes a straight first wall 1321, and the groove 133 also includes a flat wall connecting the two ends of the arc-shaped wall 1331.
  • the straight wall 1332 , the first wall 1321 is substantially parallel to the straight wall 1332 .
  • the first wall 1321 is a wall of the electrode terminal 132 which is substantially parallel to the straight wall 1332 of the groove 133 .
  • the first wall 1321 being substantially parallel to the straight wall 1332 means that the first wall 1321 is parallel to the straight wall 1332 , or the angle between the first wall 1321 and the straight wall 1332 is relatively small (eg less than 5°).
  • the first wall 1321 may be a wall of the electrode terminal 132 close to the groove 133 , and the first wall 1321 is closer to the groove 133 than other walls of the electrode terminal 132 .
  • the first wall 1321 is substantially parallel to the straight wall 1332.
  • the distance between the groove 133 and the electrode terminal 132 is small, which reduces space occupation; The risk of contacting the electrode terminal 132 after the pressure relief mechanism 134 is broken.
  • the depth of the weakened portion 1341 decreases gradually along the extension direction from the middle portion of the arc-shaped wall 1331 to both ends.
  • the depth of the weakened portion 1341 adopts the above-mentioned setting method.
  • the weakened portion 1341 is split from the middle of the arc-shaped wall 1331 to both ends, limiting the cracking of the pressure relief mechanism 134 Direction, so that the pressure relief mechanism 134 releases pressure.
  • the end cover assembly 13 further includes two through holes 135 for installing the electrode terminals 132 , and the center of the connecting line along the two through holes 135 is On one side or both sides of the vertical line ⁇ , the depth of the weak portion 1341 gradually decreases in a direction away from the middle vertical line ⁇ .
  • the depth of the weakened portion 1341 can be gradually reduced; or, along the vertical line of the line connecting the two through holes 135 The depth of the weak portion 1341 can gradually decrease in the direction away from the vertical line ⁇ on both sides of the line ⁇ .
  • the deepest position of the weak portion 1341 is at the vertical line ⁇ .
  • the weak portion 1341 splits from the position corresponding to the vertical line ⁇ to the direction away from the vertical line ⁇ . , it is convenient for the pressure relief mechanism 134 to quickly release pressure, and improve safety.
  • the embodiment of the present application provides a battery cell 1 , and the battery cell 1 includes a housing 12 and the aforementioned end cover assembly 13 .
  • the housing 12 has an opening, and the end cover 131 closes the opening.
  • the groove 133 is disposed on a side of the end cover 131 away from the housing 12 .
  • the groove 133 is recessed from the outer surface of the end cover 131 , so that the pressure relief mechanism 134 is away from the outer surface of the end cover 131 , and the pressure relief mechanism 134 is not easy to contact other objects and cause damage.
  • the outer surface of the end cover 131 mentioned here refers to the surface of the end cover 131 facing away from the housing 12 .
  • the end cap assembly 13 of the battery cell 1 further includes a protective film 136 covering the opening of the groove 133 to protect the pressure relief mechanism 134 .
  • the embodiment of the present application provides a battery 100 , and the battery 100 includes the aforementioned battery cells 1 .
  • the embodiment of the present application provides a battery 100 , and the battery 100 includes the aforementioned end cap 131 or the aforementioned end cap assembly 13 .
  • the embodiment of the present application provides an electric device, which includes the aforementioned battery 100 .
  • the powered device may be any of the aforementioned devices or systems using the battery 100 .
  • the present application provides an end cover 131, the end cover 131 is circular, and the end cover 131 is provided with two through holes 135 for installing the electrode terminals 132.
  • the two through holes 135 are arranged symmetrically about the center of the end cover 131, and the perpendicular line ⁇ of the line connecting the two through holes 135 passes through the center of the end cover 131.
  • the end cover 131 is also provided with a groove 133, which is symmetrical about the vertical line ⁇ .
  • the side wall of groove 133 comprises arc wall 1331 and straight wall 1332, and the two ends of arc wall 1331 are connected with the two ends of straight wall 1332, and the side wall of groove 133 is surrounded to form arch, and arc wall 1331
  • the arc transition with the straight wall 1332 makes the corner of the side wall of the groove 133 be a rounded corner.
  • the arc-shaped wall 1331 extends along the circumferential direction of the end cover 131 , and the arc-shaped wall 1331 is separated from the edge of the end cover 131 by a third distance L3 , and the third distance L3 is 3.5 mm.
  • the groove 133 is formed by recessing the surface of the casing 12 of the end cover 131 away from the battery cell 1 along the thickness direction, so that the thickness of the bottom wall of the groove 133 is thinner than that of the end cover 131, and the bottom wall of the groove 133 acts as a leak.
  • the pressure mechanism 134 and the pressure relief mechanism 134 are provided with a weak portion 1341, which is a second groove or notch formed by stamping, and the bottom wall of the groove 133 is further thinned at the weak portion 1341.
  • the weak portion 1341 is symmetrical about the vertical line ⁇ , and the depth of the weak portion 1341 is set in the form of a continuous gradient.
  • the weak portion 1341 is the deepest at the intersection with the vertical line ⁇ .
  • the depth of the weak portion 1341 It decreases gradually towards both sides of the vertical line ⁇ .
  • the stress of the end cover 131 on the vertical line ⁇ is relatively concentrated, and on the entire pressure relief mechanism 134, the intersection of the weak portion 1341 and the vertical line ⁇ has the thinnest thickness but is stressed. Maximum, to achieve the effect of fixed-point destruction, to ensure that the pressure relief mechanism 134 is broken from the intersection point.
  • the pressure relief mechanism 134 is further cracked along the weak part 1341, and the pressure relief mechanism 134 is still broken after cracking. It is connected with the straight wall 1332 to prevent the pressure relief mechanism 134 from flying up after being damaged, and restricts the discharge to the edge of the end cover 131 to improve safety.
  • a stepped surface 1333 is formed on the side wall of the groove 133, and the stepped surface 1333 divides the side wall of the groove 133 into upper and lower parts along the thickness direction ⁇ of the end cover.
  • the side wall of the upper part is staggered from the side wall of the lower part, and the groove
  • the opening area of the groove 133 is larger than the bottom wall area of the groove 133, so as to facilitate discharge of the discharge.

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Abstract

本申请涉及一种端盖、端盖组件、电池单体、电池及用电设备。端盖包括：两个通孔，贯穿端盖，用于安装电极端子；凹槽，凹槽由端盖的表面沿厚度方向凹陷形成，凹槽的底壁形成泄压机构；薄弱部，设置于泄压机构上，泄压机构被配置为在电池单体的内部压力达到阈值时沿薄弱部裂开；其中，沿两个通孔的连线的中垂线的一侧或两侧远离中垂线的方向，薄弱部的深度逐渐减小。本申请提供的端盖不存在连接缺陷，端盖的结构强度较高，端盖上的泄压机构能够方向可控地泄压，该端盖能够有效提高电池的安全性。

Description

一种端盖、端盖组件、电池单体、电池及用电设备
相关申请的交叉引用
本申请要求享有于2021年09月24日提交的名称为“一种端盖、端盖组件、电池单体、电池及用电设备”的中国专利申请202122325362.6的优先权，该申请的全部内容通过引用并入本文中。
技术领域
本申请涉及电池技术领域，具体而言，涉及一种端盖、端盖组件、电池单体、电池及用电设备。
背景技术
在追求节能减排的大环境下，电动车辆由于节能环保的优势，成为汽车产业的发展新趋势，是汽车产业可持续发展的重要组成部分。电动车辆使用中，以及在其他用电设备使用中，其所携带的电池在充放电过程中，若出现内压异常升高容易出现安全问题，而电池的安全性关乎设备安全和使用者人身安全，如何提高电池的安全性是重要的研发方向。
发明内容
本申请旨在提供一种端盖、端盖组件、电池单体、电池及用电设备，以提高电池的安全性。
本申请的实施例是这样实现的：
第一方面，本申请实施例提供一种端盖，用于电池单体，其包括：
两个通孔，贯穿所述端盖，用于安装电极端子；
凹槽，所述凹槽由所述端盖的表面沿厚度方向凹陷形成，所述凹槽的底壁形成泄压机构；
薄弱部，设置于所述泄压机构上，所述泄压机构用于泄放所述电池单体的内部压力；
其中，沿所述两个通孔的连线的中垂线的一侧或两侧远离所述中垂线的方向，所述薄弱部的深度逐渐减小。
现有泄压机构一般是独立成型后连接在端盖上，连接部位容易出现连接缺陷，本申请提供的端盖，泄压机构直接成型在端盖上，无需连接，不存在连接缺陷问题。泄压机构在薄弱部处的厚度减小，薄弱部的深度越大，泄压机构在薄弱部处的厚度越小，泄压机构用于泄放电池单体的内部压力，泄压机构可以主动泄压，也可以被动泄压，可选地，电池单体的内部压力达到阈值时，泄压机构沿薄弱部裂开，以泄放电池单体的内部压力。
现有泄压机构上的薄弱部容易影响端盖的结构强度，本申请的薄弱部仅局部深度最大，其余部位深度减小，随着薄弱部的深度减小，泄压机构的厚度逐渐增加，提 高了泄压机构的结构强度，进而提高了端盖的结构强度。
由于电池单体的内部压力增大时，端盖膨胀变形，两个通孔的连线的中垂线为端盖的应力变形中心线，在应力变形中心线上端盖的应力相对集中，通过将泄压机构的薄弱部的深度最大位置设置在两个通孔的中垂线上，当电池单体的内部压力达到阈值时，端盖的受到的最大应力作用在薄弱部的深度最大的位置，保证泄压机构的薄弱部在深度最大的位置处裂开，薄弱部裂开后，在电池单体的内部压力作用下，泄压机构易于沿薄弱部继续裂开，增加开阀面积，实现有效泄压，保证电池安全性。泄压机构沿薄弱部裂开的方向限定了泄压机构的开阀方向，以便提前做好应对措施，进一步提高电池安全性。
因此，本申请提供的端盖不存在连接缺陷，端盖的结构强度较高，端盖上的泄压机构能够方向可控地泄压，该端盖能够有效提高电池的安全性。
在本申请的一些实施例中，所述两个通孔的连线的中垂线经过所述薄弱部的中部。
在上述技术方案中，薄弱部的最深位置在中部，在电池单体的内部压力达到阈值时泄压机构沿薄弱部由中部向两侧裂开，泄压机构的开阀速度快，能够快速泄压，提高安全性。
在本申请的一些实施例中，所述薄弱部关于所述中垂线对称。
在上述技术方案中，薄弱部在中垂线两侧的受力一致，保证泄压机构沿薄弱部由中部向两侧裂开，进一步控制泄压机构的开阀方向，提高安全性。
在本申请的一些实施例中，所述凹槽关于所述中垂线对称。
在上述技术方案中，凹槽关于中垂线对称、薄弱部关于中垂线对称，则泄压机构关于中垂线对称，泄压机构在中垂线两侧的结构强度一致，应力承受能力一致，保证泄压机构在电池单体的内压达到阈值时两侧同步开启，泄压机构的开阀方向更准确，安全性更高。
在本申请的一些实施例中，所述端盖为圆形，所述中垂线经过所述端盖的圆心，所述薄弱部沿所述端盖的周向延伸。
在上述技术方案中，端盖整体在中垂线的两侧的两个部分结构强度一致，承受能力一致，确保端盖的应力集中在中垂线上，进一步保证端盖能够先从中垂线上的薄弱部的最深位置处裂开，确保泄压机构的开阀方向，保证电池安全性。
另外，通过使薄弱部沿端盖的周向延伸，使得薄弱部相对远离端盖的中心而靠近端盖的边缘，而圆形的端盖受内压作用变形时中心位置变形较大、边缘位置变形较小，因此，同等开阀压力下，薄弱部设置在靠近端盖的边缘的位置时，薄弱部的深度需要设置的相对较大，以保证泄压机构能够在内压下沿薄弱部裂开实现开阀。由于端盖整体厚度小，泄压机构、薄弱部则更为精细，薄弱部的深度相对较大时，加工难度较小，便于加工。
在本申请的一些实施例中，所述凹槽包括弧形壁和平直壁，所述弧形壁与所述平直壁围合，所述弧形壁沿所述端盖的周向延伸。
在上述技术方案中，凹槽设置为弓形，加工薄弱部时，能够以弧形壁作为基准，沿弧形壁加工薄弱部即可，加工方便。并且，相对于同样具有弧形部的腰形或其他形状，在薄弱部的长度一定的情况下，也即弧形壁的长度一定的情况下，弓形相对于其 他形状的开阀面积更大，进一步提高安全性。
在本申请的一些实施例中，所述弧形壁所包围的弧形角小于等于180°。
在上述技术方案中，端盖的中心位置不在凹槽中，保证端盖的结构强度，并为在端盖上设置其他功能部件余留位置。
在本申请的一些实施例中，所述薄弱部与所述弧形壁具有第一间隔距离。
在上述技术方案中，薄弱部与弧形壁间隔设置，弧形壁与凹槽的底壁的连接位置不平整时，由于设有第一间隔距离，薄弱部不容易出现成型不良的问题，确保薄弱部成型良好，保证泄压机构能够沿薄弱部裂开。
在本申请的一些实施例中，所述薄弱部的两端与所述平直壁具有第二间隔距离。
在上述技术方案中，端盖的边缘受挤压时，不容易通过平直壁将变形传递至薄弱部，薄弱部不容易裂开，端盖的结构强度高，电池单体的内压没有达到阈值时，泄压机构不容易沿薄弱部裂开，保证端盖正常使用。
在本申请的一些实施例中，所述弧形壁与所述端盖的边缘具有第三间隔距离。
在上述技术方案中，凹槽的弧形壁与端盖的边缘间隔，提高端盖对应弧形壁处的边缘的结构强度。
在本申请的一些实施例中，所述弧形壁和所述平直壁之间圆弧过渡。
在上述技术方案中，弧形壁和平直壁的连接位置的转角为圆角，缓解转角处应力集中的问题，以免端盖的边缘受挤压时，端盖从凹槽的转角处损坏，提高端盖的结构强度。
在本申请的一些实施例中，所述凹槽的侧壁上形成有台阶面，所述台阶面沿所述凹槽的周向延伸。
端盖边缘受挤压时，首先是台阶面以上的侧壁抵抗变形，其次应力才会通过台阶面传导台阶面以下的侧壁和底壁，因此上述方案能够有效缓解端盖的边缘受挤压导致薄弱部损坏的问题，提高端盖的结构强度。
第二方面，本申请实施例提供一种端盖组件，其包括：
端盖；凹槽，所述凹槽由所述端盖的表面沿厚度方向凹陷形成，所述凹槽的底壁形成泄压机构，所述凹槽包括沿所述端盖的周向延伸的弧形壁；和薄弱部，被配置为在所述泄压机构致动时可以裂开，所述薄弱部与所述弧形壁的形状对应设置。
本申请提供的端盖组件，结构强度高，能够有效且方向可控地开阀泄压，提高电池的安全性。
在本申请的一些实施例中，所述薄弱部为弧形，沿所述弧形的周向延伸方向，所述薄弱部的深度尺寸不同。
在上述技术方案中，薄弱部的设置形式与弧形壁的形状相匹配，便于加工；沿弧形的周向延伸方向，薄弱部的深度尺寸不同，便于薄弱部裂开，便于泄压机构泄放电池单体的内部压力。
在本申请的一些实施例中，所述端盖组件还包括电极端子，所述电极端子包括平直的第一壁，所述凹槽还包括连接所述弧形壁的两端的平直壁，所述第一壁基本平行于所述平直壁。
在上述技术方案中，第一壁基本平行于平直壁，一方面，凹槽与电极端子之间的距离较小，减小空间占用；另一方面，可以限制泄压机构的裂开方向，降低泄压机 构破坏后与电极端子接触的风险。
在本申请的一些实施例中，沿所述弧形壁的中间部分向两端的延伸方向，所述薄弱部的深度逐渐减小。
在上述技术方案中，薄弱部的深度采用上述的设置方式，当泄压机构致动时，薄弱部由弧形壁的中间向两端裂开，限制泄压机构的裂开方向，以便于泄压机构泄压。
在本申请的一些实施例中，所述端盖组件还包括两个通孔，所述通孔用于安装所述电极端子，沿所述两个通孔的连线的中垂线的一侧或两侧，向远离所述中垂线的方向，所述薄弱部的深度逐渐减小。
在上述技术方案中，薄弱部的最深位置在中垂线处，在泄压机构致动时，薄弱部由与中垂线对应的位置向远离中垂线的方向裂开，便于泄压机构快速泄压，提高安全性。
第三方面，本申请实施例提供一种电池单体，其包括：
壳体，具有开口；和
如前所述的端盖组件，所述端盖封闭所述开口。
本申请提供的电池单体，其端盖不容易损坏，整体结构稳定，其端盖上的泄压机构能够有效且方向可控地开阀泄压，安全性高。
在本申请的一些实施例中，所述凹槽设置于所述端盖的背离所述壳体的一侧。
在上述技术方案中，凹槽从端盖的外表面凹陷成型，泄压机构远离端盖的外表面，泄压机构不容易接触其他物体导致损坏。
第四方面，本申请实施例提供一种电池，其包括前述的端盖或前述的端盖组件。
本申请提供的电池具有前述的安全性较高的电池单体，故电池的安全性较高，性能稳定。
第五方面，本申请实施例提供一种用电设备，其包括前述的电池。
本申请提供的用电设备，采用安全性高、性能稳定的电池，实现稳定工作。
附图说明
为了更清楚地说明本申请实施例的技术方案，下面将对本申请实施例中所需要使用的附图作简单地介绍，显而易见地，下面所描述的附图仅仅是本申请的一些实施例，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，还可以根据附图获得其他的附图。
图1为本申请一实施例提供的车辆的结构示意图；
图2为本申请一实施例提供的电池的分解示意图；
图3为本申请一实施例提供的电池模块的结构示意图；
图4为本申请一实施例提供的电池单体的结构示意图；
图5为本申请一实施例提供的电池单体的分解示意图；
图6为本申请一实施例提供的端盖的平面示意图；
图7为图6的A-A剖面图；
图8为图7的B部分放大图；
图9为本申请一实施例提供的端盖的立体示意图；
图10为图9的C部分放大图；
图11为本申请一实施例提供的端盖组件的平面示意图；
图12为本申请另一实施例提供的端盖组件的平面示意图；
在附图中，附图并未按照实际的比例绘制。
标记说明：1000-车辆；100-电池；200-马达；300-控制器；101-箱体；1011-第一部分；1012-第二部分；102-电池模块；1-电池单体；11-电极组件；12-壳体；121-开口；13-端盖组件；131-端盖；132-电极端子；1321-第一壁1321；133-凹槽；1331-弧形壁；1332-平直壁；1333-台阶面；134-泄压机构；1341-薄弱部；135-通孔；136-防护膜；L1-第一间隔距离；L2-第二间隔距离；L3-第三间隔距离；α-中垂线；β-端盖的厚度方向；γ-弧形角。
具体实施方式
下面将结合附图对本申请技术方案的实施例进行详细的描述。以下实施例仅用于更加清楚地说明本申请的技术方案，因此只作为示例，而不能以此来限制本申请的保护范围。
除非另有定义，本文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；本文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。
在本申请实施例的描述中，技术术语“第一”“第二”等仅用于区别不同对象，而不能理解为指示或暗示相对重要性或者隐含指明所指示的技术特征的数量、特定顺序或主次关系。在本申请实施例的描述中，“多个”的含义是两个以上，除非另有明确具体的限定。
在本文中提及“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。本领域技术人员显式地和隐式地理解的是，本文所描述的实施例可以与其它实施例相结合。
在本申请实施例的描述中，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，本文中字符“/”，一般表示前后关联对象是一种“或”的关系。
在本申请实施例的描述中，术语“多个”指的是两个以上(包括两个)，同理，“多组”指的是两组以上(包括两组)，“多片”指的是两片以上(包括两片)，除非另有明确具体的限定。
在本申请实施例的描述中，技术术语“中心”“纵向”“横向”“长度”“宽度”“厚度”“上”“下”“前”“后”“左”“右”“竖直”“水平”“顶”“底”“内”“外”“顺时针”“逆时针”“轴向”“径向”“周向”等指示的方位或位置关系为基于附图所示的方位或位置关系，仅是为了便于描述本申请实施例和简化描述，而不是指示或暗示所指的装置或元件必须具有特定的方位、以特定的方位构造和操作，因此不能理解为对本申请实施例的限制。
在本申请实施例的描述中，除非另有明确的规定和限定，技术术语“安装” “相连”“连接”“固定”等术语应做广义理解，例如，可以是固定连接，也可以是可拆卸连接，或成一体；也可以是机械连接，也可以是电连接；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或两个元件的相互作用关系。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实施例中的具体含义。
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。例如，本申请中所提到的电池可以包括电池模块或电池包等。电池一般包括用于封装一个或多个电池单体的箱体。箱体可以避免液体或其他异物影响电池单体的充电或放电。
电池单体包括电极组件和电解液，电极组件由正极极片、负极极片和隔离膜组成。电池单体主要依靠金属离子在正极极片和负极极片之间移动来工作。正极极片包括正极集流体和正极活性物质层，正极活性物质层涂覆于正极集流体的表面，未涂敷正极活性物质层的集流体凸出于已涂覆正极活性物质层的集流体，未涂敷正极活性物质层的集流体作为正极极耳。以锂离子电池为例，正极集流体的材料可以为铝，正极活性物质可以为钴酸锂、磷酸铁锂、三元锂或锰酸锂等。负极极片包括负极集流体和负极活性物质层，负极活性物质层涂覆于负极集流体的表面，未涂敷负极活性物质层的集流体凸出于已涂覆负极活性物质层的集流体，未涂敷负极活性物质层的集流体作为负极极耳。负极集流体的材料可以为铜，负极活性物质可以为碳或硅等。为了保证通过大电流而不发生熔断，正极极耳的数量为多个且层叠在一起，负极极耳的数量为多个且层叠在一起。隔膜的材质可以为PP或PE等。此外，电极组件可以是卷绕式结构，也可以是叠片式结构，本申请实施例并不限于此。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。
对于电池单体来说，主要的安全危险来自于充电和放电过程，同时还有适宜的环境温度设计，为了有效地避免不必要的损失，对电池单体一般会有至少三重保护措施。具体而言，保护措施至少包括开关元件、选择适当的隔离膜材料以及泄压机构。开关元件是指电池单体内的温度或者电阻达到一定阈值时而能够使电池停止充电或者放电的元件。隔离膜用于隔离正极极片和负极极片，可以在温度上升到一定数值时自动溶解掉附着在其上的微米级(甚至纳米级)微孔，从而使金属离子不能在隔离膜上通过，终止电池单体的内部反应。
泄压机构是指电池单体的内部压力或温度达到预定阈值时致动以泄放内部压力或温度的元件或部件。该阈值设计根据设计需求不同而不同。所述阈值可能取决于电池单体中的正极极片、负极极片、电解液和隔离膜中一种或几种的材料。本申请中所提到的“致动”是指泄压机构产生动作或被激活至一定的状态，从而使得电池单体的内部压力及温度得以被泄放。泄压机构产生的动作可以包括但不限于：泄压机构中的至少一部分破裂、破碎、被撕裂或者打开，等等。泄压机构在致动时，电池单体的内部的高温高压物质作为排放物会从致动的部位向外排出。以此方式能够在可控压力或温度的情况下使电池单体发生泄压，从而避免潜在的更严重的事故发生。本申请中所提到的来自电池单体的排放物包括但不限于：电解液、被溶解或分裂的正负极极片、隔离膜的碎片、反应产生的高温高压气体、火焰，等等。
电池单体上的泄压机构对电池的安全性有着重要影响。例如，当发生短路、过充等现象时，可能会导致电池单体内部发生热失控从而压力或温度骤升。这种情况下通过泄压机构致动可以将内部压力及温度向外释放，以防止电池单体爆炸、起火。泄压机构可以采用诸如防爆阀、气阀、泄压阀或安全阀等的形式，并可以具体采用压敏或温敏的元件或构造，即，当电池单体的内部压力或温度达到预定阈值时，泄压机构执行动作或者泄压机构中设有的薄弱结构被破坏，从而形成可供内部压力或温度泄放的贯通口或通道。
目前一般是在端盖上设置用于泄压的通道，泄压机构连接在端盖上并封闭泄压的通道。然而现有电池单体在设置泄压机构后，仍然存在一定安全风险，例如，泄压机构在致动时产生的碎片飞起，泄压机构在致动时的排放物(如高温高压气体)冲出等等，并且电池单体还容易出现漏液的情况。进一步研究发现，端盖由于需要开设设置泄压机构的通道导致结构强度降低，端盖容易受损而导致漏液，而且泄压机构与端盖的连接部位容易出现连接缺陷，导致连接不严密而漏液，例如泄压机构与端盖的焊缝出现气泡、裂纹等。
鉴于此，为解决泄压机构致动导致的安全问题和漏液导致的安全问题，本申请提供一种端盖，端盖的表面沿厚度方向凹陷形成凹槽，凹槽的底壁形成泄压机构，泄压机构上设置薄弱部，泄压机构被配置为在电池单体的内部压力达到阈值时沿薄弱部裂开，端盖上形成有两个用于安装电极端子的通孔，两个通孔的连线的中垂线与薄弱部相交，沿两个通孔的连线的中垂线的一侧或两侧远离中垂线的方向，薄弱部的深度逐渐减小。
本申请提供的端盖，通过在端盖上设置凹槽，凹槽的底壁厚度比端盖的厚度薄，将厚度较薄的凹槽的底壁作为泄压机构，该泄压机构直接成型在端盖上，泄压机构与端盖无需连接，不存在连接缺陷问题，不会出现连接缺陷导致的漏液问题。
泄压机构上进一步设置薄弱部，使得泄压机构在薄弱部处的厚度进一步减薄，薄弱部可以为形成在泄压机构上的凹部，该凹部用于减薄泄压机构的厚度(也即前述凹槽的底壁的厚度)，该凹部可以为刻痕，也可以为通过挤压、冲压、一体铸造成型等方式在泄压机构上形成的槽体。现有技术中泄压机构的薄弱部整体深度一致，而本申请的薄弱部的深度是变化的，薄弱部仅在与两个通孔的连线的中垂线的相交位置处深度最大，沿远离该中垂线的方向上，薄弱部的深度逐渐减小，使得泄压机构在薄弱部处的厚度逐渐增加，提高了泄压机构的结构强度，进而提高了端盖的结构强度，在电池单体的内压未达到阈值时，端盖不容易意外损坏而漏液。
电池单体的内部压力增大时，端盖膨胀变形，两个通孔的连线的中垂线为端盖的应力变形中心线，在应力变形中心线上端盖的应力相对集中，通过将泄压机构的薄弱部的深度最大位置设置在两个通孔的中垂线上，当电池单体的内部压力达到阈值时，端盖的受到的最大应力作用在薄弱部的深度最大的位置，保证泄压机构的薄弱部在深度最大的位置处裂开，薄弱部裂开后，在电池单体的内部压力作用下，泄压机构易于沿薄弱部继续裂开，扩大开阀面积，实现有效泄压，保证电池安全性。
并且，通过设置薄弱部的深度，确定了薄弱部的初始裂开位置和裂开的方向，从而限定出泄压机构的开阀方向，以便提前做好应对措施，缓解泄压机构在致动时碎片飞起、排放物冲出导致的安全问题，进一步提高电池安全性。
本申请实施例公开的端盖，用于电池单体，电池单体可以包括锂离子二次电池、锂离子一次电池、锂硫电池、钠锂离子电池、钠离子电池或镁离子电池等，本申请实施例对此并不限定。电池单体可呈圆柱体、扁平体、长方体或其它形状等，本申请实施例对此也不限定。
本实施例公开的电池单体可以但不限于用于车辆、船舶或飞行器等用电设备中。可以使用具备本申请公开的电池单体、电池等组成该用电设备的电源系统，这样，有利于缓解电池漏液和充放电导致的安全风险，提升电池性能的安全性和电池寿命。
本申请实施例提供一种使用电池作为电源的用电设备，用电设备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设备为车辆为例进行说明。
例如，如图1所示，图1示出了本申请一实施例的一种车辆1000，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的内部可以设置电池100、控制器300以及马达200，控制器300用来控制电池100为马达200的供电。例如，在车辆1000的底部或车头或车尾可以设置电池100。电池100可以用于车辆1000的供电，例如，电池100可以作为车辆1000的操作电源，用于车辆1000的电路系统，例如，用于车辆1000的启动、导航和运行时的工作用电需求。在本申请的另一实施例中，电池100不仅仅可以作为车辆1000的操作电源，还可以作为车辆1000的驱动电源，替代或部分地替代燃油或天然气为车辆1000提供驱动动力。
为了满足不同的使用电力需求，电池100可以包括多个电池单体1，其中，多个电池单体1之间可以串联或并联或混联，混联是指串联和并联的混合。电池100也可以称为电池100包。可选地，请结合图2和图3所示，多个电池单体1可以先串联或并联或混联组成电池模块102，多个电池模块102再串联或并联或混联组成电池100。也就是说，多个电池单体1可以直接组成电池100，也可以先组成电池模块102，电池模块102再组成电池100。
电池100可以包括多个电池单体1。电池100还可以包括箱体101(或称罩体)，箱体101内部为中空结构，多个电池单体1容纳于箱体101内。箱体101可以包括两个用于容纳的部分(可参照图2)，这里分别称为第一部分1011和第二部分1012，第一部分1011和第二部分1012扣合在一起。第一部分1011和第二部分1012的形状可以根据多个电池单体1组合的形状而定，第一部分1011和第二部分1012可以均具有一个开口。例如，第一部分1011和第二部分1012均可以为中空长方体且各自只有一个面为开口面，第一部分1011的开口和第二部分1012的开口相对设置，并且第一部分1011和第二部分1012相互扣合形成具有封闭腔室的箱体101。第一部分1011和第二部分1012中，也可以一者为具有开口的长方体，另一者为盖板结构以封闭长方体的开口。多个电池单体1相互并联或串联或混联组合后置于第一部分1011和第二部分1012扣合后形成的箱体101内。
可选地，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，汇流部件用于实现多个电池单体1之间的电连接，例如并联或串联或混联。具体地，汇流部件可通过连接电池单体1的电极端子实现电池单体1之间的电连接。进一步地，汇流部件可通过焊接固定于电池单体1的电极端子。多个电池单体1的电能可进一步通过导电机构穿过箱体101而引出。可选地，导电机构也可属于汇流部件。
下面针对任意一个电池单体1进行详细描述，如图4和图5所示，电池单体1包括电极组件11、壳体12和端盖组件13。
电极组件11是电池单体1中发生电化学反应的部件。一个电池单体1可以包含一个或多个电极组件11。电极组件11主要由正极极片和负极极片卷绕或层叠放置形成，并且通常在正极极片与负极极片之间设有隔膜。正极极片和负极极片具有活性物质的部分构成电极组件11的主体部，正极极片和负极极片不具有活性物质的部分各自构成极耳。正极极耳和负极极耳可以共同位于主体部的一端或是分别位于主体部的两端。在电池100的充放电过程中，正极活性物质和负极活性物质与电解液发生反应，极耳连接电极端子132以形成电流回路。
壳体12是用于配合端盖131以形成电池单体1的内部环境的组件，其中，形成的内部环境可以用于容纳电极组件11、电解液以及其他部件。壳体12和端盖131可以是独立的部件，可以于壳体12上设置开口121，通过使端盖131盖合开口121以形成电池单体1的内部环境。不限地，也可以使端盖131和壳体12一体化，具体地，端盖131和壳体12可以在其他部件入壳前先形成一个共同的连接面，当需要封装壳体12的内部时，再使端盖131盖合壳体12。壳体12可以是多种形状和多种尺寸的，例如长方体形、圆柱体形、六棱柱形等。具体地，壳体12的形状可以根据电极组件11的具体形状和尺寸大小来确定。壳体12的材质可以是多种，比如，铜、铁、铝、不锈钢、铝合金、塑胶等，本申请实施例对此不作特殊限制。
端盖组件13是指配合于壳体12的开口121处以将电池单体1的内部环境隔绝于外部环境的部件。端盖组件13包括端盖131、电极端子132、泄压机构134及其他功能部件，其中端盖131用于连接壳体12以封闭开口121。不限地，端盖131的形状可以与壳体12的形状相适应以配合壳体12。可选地，端盖131可以由具有一定硬度和强度的材质(如铝合金)制成，这样，端盖131在受挤压碰撞时就不易发生形变，使电池单体1能够具备更高的结构强度，安全性能也可以有所提高。端盖131的材质也可以是多种的，比如，铜、铁、铝、不锈钢、铝合金、塑胶等，本申请实施例对此不作特殊限制。在一些实施例中，在端盖131的内侧还可以设置有绝缘件，绝缘件可以用于隔离壳体12内的电连接部件与端盖131，以降低短路的风险。示例性的，绝缘件可以是塑料、橡胶等。电极端子132设置于端盖131，电极端子132可以用于与电极组件11的极耳电连接，以用于输出或输入电池单体1的电能。泄压机构134设置于端盖131，用于在电池单体1的内部压力或温度达到阈值时泄放内部压力。
根据本申请的一些实施例，如图6、图7和图8所示，本申请提供了一种端盖131，用于电池单体1(如图5所示)。端盖131上设有凹槽133和两个通孔135，凹槽133由端盖131的表面沿厚度方向凹陷形成，凹槽133的底壁形成泄压机构134，泄压机构134上设置薄弱部1341，泄压机构134被配置为在电池单体1的内部压力达到阈值时沿薄弱部1341裂开；两个通孔135贯穿端盖131，用于安装电极端子132， 沿两个通孔135的连线的中垂线α的一侧或两侧远离中垂线α的方向，薄弱部1341的深度逐渐减小。
如图中所示，β方向为端盖的厚度方向，凹槽133的凹陷方向、薄弱部1341的深度方向均沿端盖的厚度方向β。
泄压机构134用于泄放电池单体1的内部压力，泄压机构134可以主动泄压，也可以被动泄压。可选地，泄压机构134为被动泄压，例如，泄压机构134被配置为在电池单体1的内部压力达到阈值时沿薄弱部1341裂开。
如图7所示，通过在端盖131上设置凹槽133，凹槽133的底壁厚度比端盖131的厚度薄，该厚度较薄的凹槽133的底壁作为泄压机构134，也即在电池单体1的内部压力达到阈值时，凹槽133的底壁破坏以泄放内压。凹槽133可以是在端盖131上通过切削等方式成型，也可以是与端盖131一体铸造成型，还可以是凹槽133与端盖131一次冲压成型，或者先冲压原料形成凹槽133、再冲压形成端盖131。
如图8所示，薄弱部1341为形成在泄压机构134上的凹部，也即在凹槽133的底壁上形成的另一凹槽133(为便于区分，以下称第二凹槽)，凹槽133的底壁由表面沿端盖的厚度方向β凹陷形成第二凹槽，第二凹槽减薄凹槽133的底壁的厚度(也即减薄泄压机构134的厚度)。第二凹槽可以为在泄压机构134的表面设置的刻痕，也可以通过在泄压机构134上二次冲压形成，或者在铸造端盖131时一体成型。薄弱部1341用于限定泄压机构134的优先破坏位置，在电池单体1的内部压力达到阈值时，泄压机构134优先从薄弱部1341破坏以泄放内压。
端盖131上的两个通孔135，两个通孔135沿端盖的厚度方向β贯穿端盖131，两个电极端子132分别安装于两个通孔135，每个电极端子132与通孔135的连接处密封，以避免漏液。可选地，每个电极端子132与通孔135的连接处设置绝缘件，以免端盖131带电，减少端盖131带电导致短路的安全隐患。两个电极端子132的极性可以相同，也可以不同。
电池单体1的内部压力增大时，端盖131会受到挤压甚至膨胀变形，端盖131在通孔135处的结构强度相对较低，且两个通孔135的连线的中垂线α为端盖131的应力变形中心线，也就是说，在两个通孔135的连线的中垂线α上，端盖131的应力相对集中。中垂线α是指线段的垂直平分线，也即，过两个通孔135的连线的中点所作的垂线。不限地，两个通孔135的形状为圆形，其他实施例中两个通孔135也可以是其他形状。两个通孔135的连线是指两个通孔135的形心的连线，如两个通孔135为圆形时，两个通孔135的连线为两个通孔135的圆心的连线。
两个通孔135的连线的中垂线α(以下简称中垂线α)经过薄弱部1341，也即中垂线α与薄弱部1341相交，中垂线α与薄弱部1341之间具有交点，薄弱部1341被配置为在交点处的深度最大，且薄弱部1341的深度向中垂线α的一侧或两侧沿远离中垂线α的方向减小，换句话说，沿薄弱部1341的延伸方向上，越远离薄弱部1341与中垂线α的交点，薄弱部1341的深度越小，泄压机构134被薄弱部1341所减薄后剩余的厚度越大。
通过在端盖131上直接形成泄压机构134，在泄压机构134上设置深度渐变的薄弱部1341，并将薄弱部1341的最深位置设置在两个通孔135的连线的中垂线α上，端盖131整体强度较高，泄压机构134与端盖131不存在连接缺陷，有效缓解漏液问 题；还保证端盖131上的泄压机构134能够从薄弱部1341的最深位置定点裂开，以确保泄压机构134在内压下有效致动；并且泄压机构134在电池单体1的内压下进一步地沿薄弱部1341裂开，以扩大开阀面积，在限定了泄压机构134的初始破坏位置和后续裂开方向情况下，泄压机构134的开阀位置和方向可控，便于针对泄压机构134预先准备，如在泄压机构134的泄放方向上设置防护，从而提高电池100的安全性。泄压机构134裂开后形成的连通电池单体1内部和外部的通道，用于泄放排放物，本申请中所说的开阀面积是指该通道的流通截面积。
根据本申请的一些实施例，两个通孔135的连线的中垂线α经过薄弱部1341的中部。
如前所述，薄弱部1341的延伸方向与中垂线α成一定角度，薄弱部1341与中垂线α的交点在薄弱部1341的延伸方向的中点位置。
由于薄弱部1341的最深位置在中部，在电池单体1的内部压力达到阈值时，泄压机构134沿薄弱部1341由中部向两侧同步裂开，泄压机构134的开阀速度快，使电池单体1快速泄压，提高安全性。
根据本申请的一些实施例，薄弱部1341关于中垂线α对称。
薄弱部1341与中垂线α的交点在薄弱部1341的延伸方向的中点位置，薄弱部1341的延伸方向与中垂线α垂直，使得薄弱部1341关于中垂线α对称。
由于中垂线α是应力集中线，应力集中线两侧的应力分布相近，薄弱部1341在中垂线α两侧的受力一致，保证泄压机构134沿薄弱部1341由中部向两侧裂开，进一步控制泄压机构134的开阀方向，提高安全性。
根据本申请的一些实施例中，凹槽133关于中垂线α对称。
通过使凹槽133关于中垂线α对称，进一步保证端盖131的应力集中位置在中垂线α上，进一步保证泄压机构134从薄弱部1341与中垂线α的交点处破坏，控制开阀位置。当凹槽133关于中垂线α对称，且薄弱部1341关于中垂线α对称时，泄压机构134关于中垂线α对称，泄压机构134在中垂线α两侧的结构强度一致，应力承受能力一致，保证泄压机构134在电池单体1的内压达到阈值时，泄压机构134从薄弱部1341与中垂线α的交点向中垂线α的两侧同步开启，开阀方向更准确、开阀速度更快，安全性更高。
根据本申请的一些实施例，端盖131为圆形，中垂线α经过端盖131的圆心，薄弱部1341沿端盖131的周向延伸。
请再参照图6，两个通孔135对称布置在圆形的端盖131上，两个通孔135的连线的中垂线α经过圆形的端盖131的圆心，两个通孔135关于中垂线α对称。薄弱部1341沿端盖131的周向延伸，也即，薄弱部1341沿弧形方向延伸，弧形的圆心与圆形的端盖131的圆心重合。本申请所说的重合，可以是完全重合；也可以是弧形的圆心在端盖131的圆心的附近呈接近重合的状态。
通过上述设置，端盖131整体关于中垂线α对称，端盖131在中垂线α的两侧的两个部分的结构强度一致，承受能力一致，确保端盖131的应力集中在中垂线α上，进一步保证端盖131能够先从中垂线α上的薄弱部1341的最深位置处裂开，进一步保证泄压机构134的开阀方向。
圆形的端盖131受内压作用变形时中心位置(圆心处)变形较大、边缘位 置变形较小。由于薄弱部1341沿端盖131的周向延伸，薄弱部1341相对更靠近端盖131的边缘，相对更远离端盖131的中心位置，薄弱部1341靠近变形较小的端盖131的边缘时，同等开阀压力下，薄弱部1341的深度需要设置的相对较大，以保证薄弱部1341能够裂开。由于端盖131整体厚度小，泄压机构134、薄弱部1341则更为精细，对于加工精度要求较高，通过将薄弱部1341的深度设置得相对较大，有效减小加工难度。
根据本申请的一些实施例，凹槽133包括弧形壁1331和平直壁1332，弧形壁1331与平直壁1332围合，弧形壁1331沿端盖131的周向延伸。
请再参照图6所示，弧形壁1331在端盖131上的投影为弧线，弧线的圆心与圆形的端盖131的圆心重合。本申请所说的重合，可以是完全重合；也可以是弧线的圆心在端盖131的圆心的附近呈接近重合的状态。平直壁1332在端盖131上的投影为直线段，直线段的两端连接弧线的两端，形成弓形。也即，凹槽133在端盖131上的投影形状为弓形，或者说凹槽133的形状为弓形。
加工薄弱部1341时，如通过刻划、冲压等方式在泄压机构134上加工薄弱部1341时，以弧形壁1331作为基准，沿弧形壁1331加工薄弱部1341即可，加工方便。
泄压机构134沿薄弱部1341裂开后，泄压机构134与平直壁1332连接，以防泄压机构134破坏后飞起，泄压机构134的开口方向朝向端盖131的边缘方向，限定排放物向端盖131的边缘方向泄放。
在其他实施例中，凹槽133还可以设置为其他形状，例如腰形，腰形具有两个沿端盖131的周向延伸的弧形壁1331，其中一个弧形壁1331相对靠近端盖131的中心，另一个弧形壁1331相对靠近端盖131的边缘。可选地，沿靠近端盖131的边缘的弧形壁1331加工薄弱部1341，以使泄压机构134沿薄弱部1341裂开后，泄压机构134连接于靠近端盖131中心的弧形壁1331，防止泄压机构134破坏后飞起，且泄压机构134的开口方向朝向端盖131的边缘方向，限定排放物向端盖131的边缘方向泄放。
在薄弱部1341的长度一定的情况下，弓形相比腰形的开阀面积更大，能够进一步提高安全性。在开阀面积一定的情况下，弓形相比腰形，其沿端盖131的边缘的延伸长度更小，凹槽133对于端盖131的结构强度影响较小，设置弓形的端盖131的结构强度更高。
根据本申请的一些实施例，弧形壁1331所包围的弧形角γ小于等于180°。
请再参照图6，图中示出了弓形的弧形壁1331的包围的弧形角γ，通过使弧形角γ≤180°，使端盖131的中心位置不在凹槽133中，保证端盖131的结构强度，并为在端盖131上设置其他功能部件余留位置。
根据本申请的一些实施例，薄弱部1341与弧形壁1331具有第一间隔距离L1。
请再参照图6，薄弱部1341不是贴紧弧形壁1331与凹槽133的底壁的连接位置设置，而是使薄弱部1341与弧形壁1331之间具有第一间隔距离L1。可选地，第一间隔距离L1＞1mm。
弧形壁1331与凹槽133的底壁的连接位置不平整时，由于设置第一间隔距 离L1薄弱部1341的形状不容易受到影响，避免薄弱部1341出现成型不良的问题，确保薄弱部1341成型良好，保证泄压机构134能够沿薄弱部1341裂开。
通过设置第一间隔距离L1，还容许凹槽133具有一定的加工误差，避免由于加工误差，薄弱部1341的位置处于凹槽133以外。
根据本申请的一些实施例，薄弱部1341的两端与平直壁1332具有第二间隔距离L2。
请再参照图6，薄弱部1341的两端不延伸至平直壁1332与凹槽133的底壁的连接位置，而是使薄弱部1341的两端与平直壁1332之间具有第二间隔距离L2。可选地，第二间隔距离L2≥0.5mm。
由于薄弱部1341的两端与平直壁1332具有第二间隔距离L2，端盖131的边缘受挤压时，不容易通过平直壁1332将变形传递至薄弱部1341，薄弱部1341不容易裂开，端盖131的结构强度高，在电池单体1的内压没有达到阈值时，泄压机构134不容易沿薄弱部1341意外裂开。
根据本申请的一些实施例，弧形壁1331与端盖131的边缘具有第三间隔距离L3。
请再参照图6，凹槽133的弧形壁1331与端盖131的边缘设置第三间隔距离L3，以保证端盖131对应弧形壁1331处的边缘的结构强度。可选地，第三间隔距离L3＞3mm。
根据本申请的一些实施例，弧形壁1331和平直壁1332之间圆弧过渡。
请再参照图6，弧形壁1331和平直壁1332的连接位置的转角为圆角，以实现弧形壁1331和平直壁1332圆弧过渡。
通过将弧形壁1331和平直壁1332设置为圆弧过渡，缓解弧形壁1331和平直壁1332的转角处应力集中的问题，以免端盖131的边缘受挤压时，端盖131从凹槽133的转角处损坏，提高端盖131的结构强度。
根据本申请的一些实施例，凹槽133的侧壁上形成有台阶面1333，台阶面1333沿凹槽133的周向延伸。
凹槽133的侧壁包括弧形壁1331和平直壁1332，如图9和图10所示，台阶面1333垂直于弧形壁1331和平直壁1332，并在端盖的厚度方向β上，将弧形壁1331和平直壁1332构成的侧壁分成上下两部分，其中上部分的侧壁与下部分的侧壁错开，凹槽133的开口面积大于凹槽133的底壁面积。在其他实施例中，也可以是凹槽133的开口面积小于凹槽133的底壁面积。
通过设置台阶面1333，若端盖131边缘受到朝向圆心的挤压力，首先是上部分的侧壁抵抗变形，其次应力才会通过台阶面1333传导至下部分的侧壁，进而才会传导至底壁，有效缓解端盖131边缘受挤压对薄弱部1341的影响，以免电池单体1的内部压力未达到阈值情况下破坏薄弱部1341，提高端盖131的结构强度。
根据本申请的一些实施例，如图11所示，本申请实施例提供一种端盖组件13，端盖组件13包括以上任一方案所述的端盖131和电极端子132。两个电极端子132设置于端盖131的两个通孔135中，以将电池单体1的电能导出，或向电池单体1内充入电能。
根据本申请的一些实施例，如图11所示，本申请实施例提供一种端盖组件 13，端盖组件13包括端盖131、凹槽133和薄弱部1341。凹槽133由端盖131的表面沿厚度方向β凹陷形成，凹槽133的底壁形成泄压机构134，凹槽133包括沿端盖131的周向延伸的弧形壁1331。薄弱部1341被配置为在泄压机构134致动时可以裂开，薄弱部1341与弧形壁1331的形状对应设置。
端盖131的轮廓呈圆形，弧形壁1331沿端盖131的周向延伸，泄压机构134形成于凹槽133的底壁，薄弱部1341设置于泄压机构134上，薄弱部1341与弧形壁1331的形状对应设置。
薄弱部1341为形成在泄压机构134上的凹部，也即，在凹槽133的底壁上形成的另一凹槽(为了便于区分，以下简称第二凹槽)，凹槽133的底壁由表面沿端盖131的厚度方向β凹陷形成第二凹槽，第二凹槽减薄凹槽133的底壁的厚度(也即减薄泄压机构134的厚度)。薄弱部1341可以为在泄压机构134的表面设置的刻痕，也可以通过在泄压机构134上二次冲压形成，或者在铸造端盖131时一体成型。薄弱部1341用于限定泄压机构134的优先破坏位置，可选地，在电池单体1的内部压力达到阈值时，泄压机构134致动，泄压机构134优先从薄弱部1341裂开以泄放内压。
泄压机构134沿薄弱部1341裂开，扩大开阀面积，在限定了泄压机构134的初始破坏位置和后续裂开方向情况下，泄压机构134的开阀位置和方向可控，便于针对泄压机构134预先准备，如在泄压机构134的泄放方向上设置防护，从而提高电池100的安全性。泄压机构134裂开后形成的连通电池单体1内部和外部的通道，用于泄放排放物，本申请中所说的开阀面积是指该通道的流通截面积。
本申请提供的端盖组件13，结构强度高，能够有效且方向可控地开阀泄压，提高电池100的安全性。
根据本申请的一些实施例，如图11所示，薄弱部1341为弧形，沿弧形的周向延伸方向，薄弱部1341的深度尺寸不同。
薄弱部1341为弧形，且与弧形壁1331的形状对应设置，便于加工成型。
沿弧形的周向延伸方向，薄弱部1341的深度尺寸不同，使得薄弱部呈弧形裂开，便于泄压机构泄放电池单体的内部压力。
根据本申请的一些实施例，如图11所示，端盖组件13还包括电极端子132，电极端子132包括平直的第一壁1321，凹槽133还包括连接弧形壁1331的两端的平直壁1332，第一壁1321基本平行于平直壁1332。
第一壁1321为电极端子132的一个壁，该壁与凹槽133的平直壁1332基本平行。第一壁1321基本平行于平直壁1332是指，第一壁1321与平直壁1332平行，或者第一壁1321与平直壁1332之间的角度较小(如小于5°)。
第一壁1321可以为电极端子132的靠近凹槽133的壁，第一壁1321相对于电极端子132的其他壁更靠近凹槽133。
第一壁1321基本平行于平直壁1332，一方面，凹槽133与电极端子132之间的距离较小，减小空间占用；另一方面，可以限制泄压机构134的裂开方向，降低泄压机构134破坏后与电极端子132接触的风险。
根据本申请的一些实施例，沿弧形壁1331的中间部分向两端的延伸方向，薄弱部1341的深度逐渐减小。
在上述技术方案中，薄弱部1341的深度采用上述的设置方式，当泄压机构 134致动时，薄弱部1341由弧形壁1331的中间向两端裂开，限制泄压机构134的裂开方向，以便于泄压机构134泄压。
根据本申请的一些实施例，如图6和图11所示，端盖组件13还包括两个通孔135，通孔135用于安装电极端子132，沿两个通孔135的连线的中垂线α的一侧或两侧，向远离中垂线α的方向，薄弱部1341的深度逐渐减小。
沿两个通孔135的连线的中垂线α的一侧向远离中垂线α的方向，薄弱部1341的深度可以逐渐减小；或者，沿两个通孔135的连线的中垂线α的两侧向远离中垂线α的方向，薄弱部1341的深度可以逐渐减小。
在上述技术方案中，薄弱部1341的最深位置在中垂线α处，在泄压机构134致动时，薄弱部1341由与中垂线α对应的位置向远离中垂线α的方向裂开，便于泄压机构134快速泄压，提高安全性。
根据本申请的一些实施例，如图4、图5和图11所示，本申请实施例提供一种电池单体1，电池单体1包括壳体12和前述的端盖组件13。壳体12上具有开口，端盖131封闭该开口。
根据本申请的一些实施例，凹槽133设置于端盖131的背离壳体12的一侧。
凹槽133从端盖131的外表面凹陷成型，以使泄压机构134远离端盖131的外表面，泄压机构134不容易接触其他物体导致损坏。这里所说的端盖131的外表面是指端盖131背离壳体12的一侧的表面。
在一些实施例中，如图12所示，电池单体1的端盖组件13还包括防护膜136，防护膜136覆盖凹槽133的开口，以保护泄压机构134。
根据本申请的一些实施例，本申请实施例提供一种电池100，电池100包括前述的电池单体1。
根据本申请的一些实施例，本申请实施例提供一种电池100，电池100包括前述的端盖131或前述的端盖组件13。
根据本申请的一些实施例，本申请实施例提供一种用电设备，其包括前述的电池100。
用电设备可以是前述任一应用电池100的设备或系统。
根据本申请的一些实施例，参见图6-图10，本申请提供一种端盖131，端盖131为圆形，端盖131设有两个用于安装电极端子132的通孔135，两个通孔135关于端盖131的圆心对称布置，两个通孔135的连线的中垂线α过端盖131的圆心。
端盖131还设有凹槽133，凹槽133关于中垂线α对称。凹槽133的侧壁包括弧形壁1331和平直壁1332，弧形壁1331的两端与平直壁1332的两端连接，使凹槽133的侧壁围合形成弓形，且弧形壁1331和平直壁1332圆弧过渡，使得凹槽133的侧壁的转角为圆角。弧形壁1331沿端盖131的周向延伸，弧形壁1331与端盖131的边缘间隔第三间隔距离L3，第三间隔距离L3为3.5mm。凹槽133由端盖131背离电池单体1的壳体12的表面沿厚度方向凹陷形成，以使凹槽133的底壁厚度相对端盖131的厚度减薄，凹槽133的底壁作为泄压机构134，泄压机构134上设置薄弱部1341，薄弱部1341为冲压形成的第二凹槽或刻痕，凹槽133的底壁的薄弱部1341处进一步减薄。薄弱部1341关于中垂线α对称，薄弱部1341的深度设置为连续渐变的形式，薄弱部1341在与中垂线α的交点处最深，沿远离中垂线α的方向，薄弱部1341的深 度向中垂线α的两侧逐渐减小。当电池单体1的内部压力达到阈值时，端盖131在中垂线α上的应力相对集中，整个泄压机构134上，薄弱部1341与中垂线α的交点处厚度最薄但受力最大，起到定点破坏的效果，保证泄压机构134从交点处破裂，在电池单体1的内压作用下，泄压机构134进一步沿薄弱部1341裂开，泄压机构134裂开后仍与平直壁1332连接，以防泄压机构134破坏后飞起，并限定排放物向端盖131的边缘方向泄放，提高安全性。
凹槽133的侧壁上形成有台阶面1333，台阶面1333将凹槽133的侧壁沿端盖的厚度方向β分成上下两部分，上部分的侧壁与下部分的侧壁错开，凹槽133的开口面积大于凹槽133的底壁面积，以便于排放物泄放。
以上所述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 (17)

  1. 一种端盖，用于电池单体，包括：
    两个通孔，贯穿所述端盖，用于安装电极端子；
    凹槽，所述凹槽由所述端盖的表面沿厚度方向凹陷形成，所述凹槽的底壁形成泄压机构；
    薄弱部，设置于所述泄压机构上，所述泄压机构用于泄放所述电池单体的内部压力；
    其中，沿所述两个通孔的连线的中垂线的一侧或两侧远离所述中垂线的方向，所述薄弱部的深度逐渐减小。
  2. 根据权利要求1所述的端盖，其中，所述两个通孔的连线的中垂线经过所述薄弱部的中部。
  3. 根据权利要求2所述的端盖，其中，所述薄弱部关于所述中垂线对称。
  4. 根据权利要求2或3所述的端盖，其中，所述凹槽关于所述中垂线对称。
  5. 根据权利要求2-4中任一项所述的端盖，其中，所述端盖为圆形，所述中垂线经过所述端盖的圆心，所述薄弱部沿所述端盖的周向延伸。
  6. 根据权利要求1-5中任一项所述的端盖，其中，所述凹槽包括弧形壁和平直壁，所述弧形壁与所述平直壁围合，所述弧形壁沿所述端盖的周向延伸。
  7. 根据权利要求6所述的端盖，其中，所述弧形壁所包围的弧形角小于等于180°。
  8. 根据权利要求6或7所述的端盖，其中，所述薄弱部与所述弧形壁具有第一间隔距离；和/或
    所述薄弱部的两端与所述平直壁具有第二间隔距离；和/或
    所述弧形壁与所述端盖的边缘具有第三间隔距离。
  9. 根据权利要求6或7所述的端盖，其中，所述弧形壁和所述平直壁之间圆弧过渡。
  10. 根据权利要求1-9中任一项所述的端盖，其中，所述凹槽的侧壁上形成有台阶面，所述台阶面沿所述凹槽的周向延伸。
  11. 一种端盖组件，包括：
    端盖；
    凹槽，所述凹槽由所述端盖的表面沿厚度方向凹陷形成，所述凹槽的底壁形成泄压机构，所述凹槽包括沿所述端盖的周向延伸的弧形壁；和
    薄弱部，被配置为在所述泄压机构致动时可以裂开，所述薄弱部与所述弧形壁的形状对应设置。
  12. 根据权利要求11所述的端盖组件，其中，所述薄弱部为弧形，沿所述弧形的周向延伸方向，所述薄弱部的深度尺寸不同。
  13. 根据权利要求11或12所述的端盖组件，其中，所述端盖组件还包括电极端子，所述电极端子包括平直的第一壁，所述凹槽还包括连接所述弧形壁的两端的平直壁，所述第一壁基本平行于所述平直壁。
  14. 根据权利要求13所述的端盖组件，其中，沿所述弧形壁的中间部分向两端的延伸方向，所述薄弱部的深度逐渐减小。
  15. 根据权利要求13-14中任一项所述的端盖组件，其中，所述端盖组件还包括两个通孔，所述通孔用于安装所述电极端子，沿所述两个通孔的连线的中垂线的一侧或两侧，向远离所述中垂线的方向，所述薄弱部的深度逐渐减小。
  16. 一种电池，包括权利要求1-10中任一项所述的端盖，或包括权利要求11-15中任一项所述的端盖组件。
  17. 一种用电设备，包括权利要求16所述的电池。
PCT/CN2022/114233 2021-09-24 2022-08-23 一种端盖、端盖组件、电池单体、电池及用电设备 WO2023045672A1 (zh)

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