WO2023197133A1 - 电池单体的壳体、电池单体、电池以及用电装置 - Google Patents

电池单体的壳体、电池单体、电池以及用电装置 Download PDF

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Publication number
WO2023197133A1
WO2023197133A1 PCT/CN2022/086247 CN2022086247W WO2023197133A1 WO 2023197133 A1 WO2023197133 A1 WO 2023197133A1 CN 2022086247 W CN2022086247 W CN 2022086247W WO 2023197133 A1 WO2023197133 A1 WO 2023197133A1
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WIPO (PCT)
Prior art keywords
plate
plate part
thickness
along
battery cell
Prior art date
Application number
PCT/CN2022/086247
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English (en)
French (fr)
Inventor
陈威
李川
郭志君
雷育永
郑东来
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.)
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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 CN202280007140.4A priority Critical patent/CN117223159A/zh
Priority to PCT/CN2022/086247 priority patent/WO2023197133A1/zh
Publication of WO2023197133A1 publication Critical patent/WO2023197133A1/zh

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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
    • H01M50/20—Mountings; Secondary casings or frames; Racks, modules or packs; Suspension devices; Shock absorbers; Transport or carrying devices; Holders
    • H01M50/204—Racks, modules or packs for multiple batteries or multiple cells
    • H01M50/207—Racks, modules or packs for multiple batteries or multiple cells characterised by their shape
    • H01M50/209—Racks, modules or packs for multiple batteries or multiple cells characterised by their shape adapted for prismatic or rectangular cells
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
    • H01M50/20—Mountings; Secondary casings or frames; Racks, modules or packs; Suspension devices; Shock absorbers; Transport or carrying devices; Holders
    • H01M50/249—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
    • 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, and more specifically, to a battery cell casing, a battery cell, a battery and an electrical device.
  • Battery cells are widely used in electronic devices, such as mobile phones, laptops, battery cars, electric cars, electric airplanes, electric ships, electric toy cars, electric toy ships, electric toy airplanes, electric tools, etc.
  • the battery cells may include cadmium-nickel battery cells, nickel-hydrogen battery cells, lithium-ion battery cells, secondary alkaline zinc-manganese battery cells, etc.
  • the present application provides a battery cell casing, a battery cell, a battery and an electrical device, which can improve the energy density of the battery cell.
  • embodiments of the present application provide a casing for a battery cell, and the end of the casing along a first direction has an opening.
  • the shell includes a first side plate, a second side plate and a first connecting plate.
  • the first side plate and the second side plate are arranged along the circumference of the opening.
  • the first connecting plate is connected between the first side plate and the second side plate. space, and at least part of the first connecting plate is arc-shaped.
  • the first side plate includes a first plate part, a second plate part and a third plate part.
  • the second plate part is connected between the first plate part and the first connecting plate.
  • the third plate part is located near the opening of the first plate part. side.
  • the thickness of the first plate part is smaller than the thickness of the second plate part and the thickness of the third plate part.
  • the above technical solution can reduce the thickness of the first plate portion of the first side plate to increase the internal space of the casing and reserve more space for the electrode assembly and the electrolyte, thereby increasing the energy density of the battery cell and improving The charge and discharge performance of the battery cell.
  • the arc-shaped part of the first connecting plate can release stress and reduce stress concentration during the molding process of the shell; the thickness of the second plate part is greater than the thickness of the first plate part, so that the second plate part close to the first connecting plate has The strength is higher than that of the first plate part, which reduces the risk of cracking of the second plate part when the battery cell is subjected to external impact, and provides safety. Since the thickness of the third plate part is greater than the thickness of the first plate part, the third plate part can be used to connect with the end cover of the battery cell to improve the connection strength between the case and the end cover, reduce the risk of cracking of the case, and improve safety.
  • the second plate part is directly connected to the third plate part to increase the overall strength of the first side plate and reduce the risk of cracking of the first side plate.
  • the thickness of the second plate part is equal to the thickness of the third plate part to reduce the difficulty of molding the housing.
  • the thickness of the first plate part is T1
  • the thickness of the second plate part is T2
  • T1 and T2 satisfy: 0.05mm ⁇ T2-T1 ⁇ 1mm.
  • T1 When the value of T1 is determined, the larger T2 is, the higher the strength of the second plate part is, but the internal space of the shell is smaller; when the value of T1 is determined, the smaller T2 is, the lower the strength of the second plate part is, but the The internal space of the shell is larger.
  • T2 the larger T1 is, the higher the strength of the first plate part is, but the internal space of the shell is smaller; when the value of T2 is determined, the smaller T1 is, the lower the strength of the first plate part is, but the internal space of the shell is smaller.
  • the internal space of the shell is larger.
  • the above technical solution limits the value of T2-T1 to 0.05mm-1mm to balance the strength of the shell and the capacity of the shell.
  • T1 and T2 satisfy: 0.1mm ⁇ T2-T1 ⁇ 0.7mm.
  • the thickness T1 of the first plate portion is 0.1 mm-0.8 mm.
  • the thickness T2 of the second plate portion is 0.4mm-1.5mm.
  • the first side panel further includes a first transition portion connected between the first panel portion and the second panel portion.
  • the thickness of the first transition portion gradually increases in the direction from the first plate portion to the second plate portion.
  • the first transition portion by providing the first transition portion, a smooth transition can be achieved between the first plate portion and the second plate portion, reducing the difficulty of molding the housing, reducing stress concentration, and reducing the risk of cracking of the first side plate.
  • the first plate portion and the second plate portion are arranged along a second direction, the second direction being perpendicular to the first direction.
  • the size of the second plate part along the second direction is L1
  • the size of the first transition part along the second direction is L2.
  • L1 and L2 satisfy: 0.2 ⁇ L1/L2 ⁇ 5.
  • the dimension L1 of the second plate portion along the second direction is 0.5mm-10mm
  • the dimension L2 of the first transition portion along the second direction is 0.5mm-10mm
  • an end of the first plate part facing away from the third plate part is flush with an end of the second plate part facing away from the third plate part.
  • the second plate part may separate the first plate part and the first connecting plate to reduce the risk of cracking of the first plate part.
  • the housing further includes a third side plate and a second connecting plate.
  • the third side plate and the opening are arranged oppositely along the first direction, the second connecting plate is connected between the first side plate and the third side plate, and at least part of the second connecting plate is arc-shaped. The first plate part is directly connected to the second connecting plate.
  • the arc-shaped portion of the second connecting plate can release stress during the molding process of the housing and reduce stress concentration.
  • the first plate part is directly connected to the second connecting plate, which can reduce the step at the connection between the first plate part and the second connecting plate, reduce the risk of local pressure on the electrode assembly, and improve the performance of the electrode assembly.
  • the housing includes two first side plates and two second side plates, the two second side plates are oppositely arranged along the second direction, the two first side plates are oppositely arranged along the third direction, and the second side panels are arranged oppositely along the third direction.
  • the first direction, the second direction and the third direction are perpendicular to each other.
  • the adjacent first side plate and the second side plate are connected through a first connecting plate.
  • the first side plate has two second plate portions, and the two second plate portions are respectively provided on both sides of the first plate portion along the second direction.
  • the two first connecting plates are connected to the first plate part through two second plate parts respectively.
  • the second plate part has higher strength and can withstand the pressure from the first plate part. transfers stress across the connecting plate, thereby reducing the risk of cracking and providing safety.
  • the size of the first side panel along the second direction is greater than the size of the second side panel along the third direction.
  • the first side plate has a larger area than the second side plate, the area where the first side plate can be thinned is larger, which can effectively increase the internal space of the casing and improve battery performance.
  • the capacity of the unit since the first side plate has a larger area than the second side plate, the area where the first side plate can be thinned is larger, which can effectively increase the internal space of the casing and improve battery performance. The capacity of the unit.
  • the second plate portion and the third plate portion protrude from the inner surface of the first plate portion.
  • the outer surfaces of the first plate part, the second plate part and the third plate part are flush to ensure the flatness of the outer surface of the first side plate and improve the appearance of the casing.
  • the first side plate further includes a second transition portion connected between the first plate portion and the third plate portion.
  • the thickness of the second transition portion gradually increases in the direction from the first plate portion to the third plate portion.
  • the second transition part can achieve a smooth transition between the first plate part and the third plate part, reducing the difficulty of shell molding, reducing stress concentration, and reducing the risk of cracking of the first side plate.
  • the size of the third plate portion along the first direction is L3
  • the size of the second transition portion along the first direction is L4
  • L3 and L4 satisfy: 0.3 ⁇ L3/L4 ⁇ 3.
  • the dimension L3 of the third plate portion along the first direction is 0.3mm-10mm, and the dimension L4 of the second transition portion along the first direction is 0.3mm-10mm.
  • the second side plate is provided with a recess, and the recess is recessed from an end surface of the second side plate along the first direction.
  • the thickness of the portion of the second side plate corresponding to the side surface of the recess is greater than the thickness of the first plate portion.
  • the bottom surface of the recess can be used to support the end cap of the battery cell, and can limit the end cap when it extends into the casing to prevent the end cap from excessively extending into the casing.
  • the part of the second side plate corresponding to the side of the recess can be used to connect with the end cover. Even if a recess is provided on the second side plate in this embodiment, the strength of the part of the second side plate corresponding to the side of the recess can be ensured. Reduces the risk of second side panel cracking.
  • one end of the third plate portion close to the first plate portion exceeds the bottom surface of the recessed portion.
  • the bottom surface of the recess is used to support the end cap and limit the position of the end cap.
  • the end of the third plate part close to the first plate part exceeds the bottom surface of the recess, so that the end of the third plate part close to the first plate part exceeds the end cover, thereby ensuring the connection of the first side plate. Due to the strength of the end cover, it reduces the risk of cracking of the first side plate and improves safety.
  • embodiments of the present application provide a battery cell, including a case, an electrode assembly and an end cap provided in any embodiment of the first aspect.
  • the electrode assembly is accommodated in the housing, and a gap is provided between the electrode assembly and the second plate portion in the thickness direction of the first side plate.
  • the end cap is used to cover the opening and is connected to the third plate part.
  • the gap between the electrode assembly and the second plate part can reduce the risk of the second plate part squeezing the electrode assembly, reduce stress concentration, and improve the charge and discharge performance of the electrode assembly. Since the thickness of the third plate part is greater than the thickness of the first plate part, the third plate part can be used to connect with the end cover to improve the connection strength between the housing and the end cover, reduce the risk of cracking of the housing, and improve safety.
  • the third plate portion is used to weld with the end cap and form a welded portion. In the first direction, one end of the third plate portion close to the first plate portion exceeds the welding portion.
  • the electrode assembly is a rolled structure and includes a straight region and a bent region.
  • the bent region is connected to an end of the straight region along the second direction, and the first direction, the second direction and the thickness direction are in pairs. vertical.
  • the first plate part covers at least part of the straight area
  • the second plate part covers at least part of the bending area
  • a gap is formed between the second plate part and the bending area.
  • the second plate part can use the space reserved in the bending zone to ensure its own thickness and reduce the pressure of the second plate part to squeeze the electrode. Component Risks.
  • the third plate part in the thickness direction, does not overlap with the straight area, and the third plate part does not overlap with the bending area, so as to reduce the risk of the third plate part squeezing the bending area and the straight area, Reduce stress concentration and improve the charge and discharge performance of electrode components.
  • the battery cell further includes an insulating member, and the insulating member is disposed on a side of the end cover facing the flat area and offset against the flat area. In a direction away from the end cap, a surface of the insulating member that abuts the flat area extends beyond an end of the first plate portion facing the third plate portion.
  • the insulating member can insulate the end cap and the flat area to reduce the risk of the end cap connecting the positive and negative electrode plates in the flat area and improve safety.
  • the insulating member offsets the flat area along the first direction to reduce the shaking amplitude of the flat area when the battery cell vibrates, reduces the risk of misalignment of the positive and negative electrode plates, and improves the charge and discharge performance of the electrode assembly.
  • the insulating member can limit the position of the flat area along the first direction to reduce the possibility of the flat area colliding with the third plate when the battery cell vibrates, thereby reducing the risk of cracking of the third plate.
  • embodiments of the present application provide a battery, including a plurality of battery cells provided in any embodiment of the second aspect.
  • embodiments of the present application provide an electrical device, including the battery cell provided in any embodiment of the second aspect, and the battery cell is used to provide electric energy.
  • Figure 1 is a schematic structural diagram of a vehicle provided by some embodiments of the present application.
  • FIG. 2 is an exploded schematic diagram of a battery provided by some embodiments of the present application.
  • FIG 3 is a schematic structural diagram of the battery module shown in Figure 2;
  • Figure 4 is an exploded schematic diagram of a battery cell provided by some embodiments of the present application.
  • Figure 5 is a schematic structural diagram of a housing provided by some embodiments of the present application.
  • Figure 6 is an enlarged schematic view of the housing shown in Figure 5 at circular frame A;
  • Figure 7 is a schematic cross-sectional view of the housing shown in Figure 5;
  • Figure 8 is an enlarged schematic diagram of Figure 7 at circular frame B;
  • Figure 9 is another schematic cross-sectional view of the housing shown in Figure 5;
  • Figure 10 is an enlarged schematic diagram of Figure 7 at circular frame C;
  • Figure 11 is another schematic cross-sectional view of the housing shown in Figure 5;
  • Figure 12 is a schematic structural diagram of a housing provided by other embodiments of the present application.
  • Figure 13 is an enlarged schematic view of the housing shown in Figure 12 at the circular frame D;
  • Figure 14 is a schematic cross-sectional view of a battery cell provided by some embodiments of the present application.
  • Figure 15 is another schematic cross-sectional view of a battery cell provided by some embodiments of the present application.
  • Figure 16 is an enlarged schematic diagram of Figure 15 at the circular frame E;
  • Figure 17 is a schematic cross-sectional view of an electrode assembly of a battery cell provided by some embodiments of the present application.
  • Figure 18 is a schematic structural diagram of the first side plate of the housing provided by some embodiments of the present application.
  • Electrode assembly 11. Main body; 111. Straight area; 112. Bending area; 12. Poles; 10a, first pole piece; 10b, second pole piece; 10c, separator;
  • Second transition part 22. Two side plates; 221, recess; 221a, side; 221b, bottom surface; 222, thinned area; 23, first connecting plate; 24, third side plate; 25, second connecting plate; 20a, opening;
  • G gap
  • W welding part
  • X first direction
  • Y second direction
  • Z third direction.
  • an embodiment means that a particular feature, structure or characteristic described in connection with the embodiment may be included in at least one embodiment of the application.
  • the appearances of this phrase in various places in the specification are not necessarily all referring to the same embodiment, nor are separate or alternative embodiments mutually exclusive of other embodiments.
  • connection should be understood in a broad sense.
  • connection can be a fixed connection, It can also be detachably connected or integrally connected; it can be directly connected or indirectly connected through an intermediate medium; it can be internal communication between two components.
  • connection can be a fixed connection
  • connection can also be detachably connected or integrally connected; it can be directly connected or indirectly connected through an intermediate medium; it can be internal communication between two components.
  • connection can also be detachably connected or integrally connected; it can be directly connected or indirectly connected through an intermediate medium; it can be internal communication between two components.
  • “Plural” appearing in this application means two or more (including two).
  • parallel includes not only the absolutely parallel situation, but also the roughly parallel situation that is conventionally recognized in engineering; at the same time, the term “perpendicular” includes not only the absolutely vertical situation, but also the roughly parallel situation that is conventionally recognized in engineering. vertical situation.
  • battery cells may include lithium ion secondary battery cells, lithium ion primary battery cells, lithium sulfur battery cells, sodium lithium ion battery cells, sodium ion battery cells or magnesium ion battery cells, etc.,
  • the embodiments of the present application are not limited to this.
  • the battery mentioned in the embodiments of this 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 be a battery module or a battery pack.
  • Batteries generally include a box for packaging one or more battery cells. The box can prevent liquid or other foreign matter from affecting the charging or discharging of the battery cells.
  • the battery cell includes an electrode assembly and an electrolyte.
  • the electrode assembly includes a positive electrode piece, a negative electrode piece and a separator. Battery cells mainly rely on the movement of metal ions between the positive and negative electrodes to work.
  • 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.
  • the positive electrode current collector includes a positive electrode current collector and a positive electrode tab.
  • the positive electrode current collector is coated with the positive electrode active material layer.
  • the positive electrode tab is not coated with the positive electrode active material layer.
  • the material of the cathode current collector can be aluminum, and the cathode active material layer includes cathode active materials.
  • the cathode active material can be lithium cobalt oxide, lithium iron phosphate, ternary lithium or lithium manganate, etc.
  • the negative electrode sheet includes a negative electrode current collector and a negative electrode active material layer, and the negative electrode active material layer is coated on the surface of the negative electrode current collector; the negative electrode current collector includes a negative electrode current collector and a negative electrode tab, and the negative electrode current collector is coated with the negative electrode active material layer , the negative electrode tab is not coated with the negative electrode active material layer.
  • the negative electrode current collector may be made of copper, and the negative electrode active material layer may include a negative electrode active material.
  • the negative electrode active material may be carbon or silicon.
  • the material of the isolator can be PP (polypropylene, polypropylene) or PE (polyethylene, polyethylene), etc.
  • the battery cell also includes a casing and an end cover.
  • the casing has an opening.
  • the end cover covers the opening and is sealingly connected to form a sealed space for accommodating the electrode assembly and the electrolyte.
  • the inventor tried to reduce the overall wall thickness of the casing to increase the internal space of the casing, increase the energy density of the battery cells, and improve the charge and discharge performance of the battery cells.
  • the part of the shell close to the opening needs to be connected to the end cover. If the thickness of the shell is reduced, the connection strength between the shell and the end cover may be affected; affected by the end cover, the part of the shell close to the opening needs to be connected to the end cover. Some are also prone to the risk of cracking.
  • the shell and the end cover are connected by welding. After welding, the shell will form a heat-affected zone near the molten pool. The heat-affected zone will be affected by residual thermal stress, resulting in a heat-affected zone.
  • the strength is lower than that of other areas; if the thickness of the casing is reduced, then when the heat-affected zone is squeezed during the use of the battery cell, the casing may crack in the heat-affected zone, resulting in electrolysis fluid leakage, causing battery cell failure and causing safety risks.
  • the inventor also found that during the molding process of the casing, residual stress is easy to occur at the corners of the casing; if the thickness of the casing is reduced, when the battery cell is subjected to external impact, the area near the corners of the casing is prone to cracking. This can lead to electrolyte leakage, battery cell failure, and safety risks.
  • embodiments of the present application provide a technical solution, which thins some areas of the casing to increase the internal space of the casing, improve the energy density of the battery cells, and ensure the safety of the part of the casing close to the opening.
  • the strength and strength of the parts close to the corners reduce the risk of shell cracking, improve sealing, and reduce safety hazards.
  • Electrical devices can be vehicles, cell phones, portable devices, laptops, ships, spacecraft, electric toys and power tools, etc.
  • Vehicles can be fuel vehicles, gas vehicles or new energy vehicles, and new energy vehicles can be pure electric vehicles, hybrid vehicles or extended-range vehicles, etc.
  • spacecraft include aircraft, rockets, space shuttles, spaceships, etc.
  • electric toys include fixed Type or mobile electric toys, such as game consoles, electric car toys, electric ship toys and electric airplane toys, etc.
  • electric tools include metal cutting electric tools, grinding electric tools, assembly electric tools and railway electric tools, for example, Electric drills, electric grinders, electric wrenches, electric screwdrivers, electric hammers, impact drills, concrete vibrators, planers and more.
  • Electric drills Electric grinders, electric wrenches, electric screwdrivers, electric hammers, impact drills, concrete vibrators, planers and more.
  • the following embodiments take the electrical device as a vehicle as an example.
  • Figure 1 is a schematic structural diagram of a vehicle provided by some embodiments of the present application.
  • a battery 2 is provided inside the vehicle 1 , and the battery 2 can be provided at the bottom, head, or tail of the vehicle 1 .
  • the battery 2 may be used to power the vehicle 1 , for example, the battery 2 may be used as an operating power source for the vehicle 1 .
  • the vehicle 1 may also include a controller 3 and a motor 4.
  • the controller 3 is used to control the battery 2 to provide power to the motor 4, for example, to meet the power requirements for starting, navigation and driving of the vehicle 1.
  • the battery 2 can not only be used as the operating power supply of the vehicle 1, but also can be used as the driving power supply of the vehicle 1, replacing or partially replacing fuel or natural gas to provide driving power for the vehicle 1.
  • Figure 2 is an exploded schematic diagram of a battery provided by some embodiments of the present application.
  • the battery 2 includes a case 5 and a battery cell (not shown in FIG. 2 ), and the battery cell is accommodated in the case 5 .
  • the box 5 is used to accommodate battery cells, and the box 5 can be of various structures.
  • the box body 5 may include a first box body part 5a and a second box body part 5b.
  • the first box body part 5a and the second box body part 5b cover each other.
  • the first box body part 5a and the second box body part 5b cover each other.
  • the two box portions 5b jointly define an accommodating space 5c for accommodating battery cells.
  • the second box part 5b can be a hollow structure with one end open, and the first box part 5a is a plate-like structure.
  • the first box part 5a is covered with the open side of the second box part 5b to form a receiving space 5c.
  • the box body 5; the first box body part 5a and the second box body part 5b can also be a hollow structure with one side open, and the opening side of the first box body part 5a is covered with the opening side of the second box body part 5b , to form a box 5 having an accommodation space 5c.
  • the first box part 5a and the second box part 5b can be in various shapes, such as cylinder, rectangular parallelepiped, etc.
  • a sealing member may also be provided between the first box part 5a and the second box part 5b, such as sealant, sealing ring, etc. .
  • the first box part 5a can also be called an upper box cover, and the second box part 5b can also be called a lower box.
  • the battery 2 there may be one battery cell or a plurality of battery cells. If there are multiple battery cells, the multiple battery cells can be connected in series, in parallel, or in mixed connection. Mixed connection means that multiple battery cells are connected in series and in parallel. Multiple battery cells can be directly connected in series or parallel or mixed together, and then the whole composed of multiple battery cells can be accommodated in the box 5; of course, multiple battery cells can also be connected in series or parallel first or A battery module 6 is formed by a mixed connection, and multiple battery modules 6 are connected in series, parallel, or mixed to form a whole, and are accommodated in the box 5 .
  • FIG. 3 is a schematic structural diagram of the battery module shown in FIG. 2 .
  • the plurality of battery cells 7 are first connected in series, parallel, or mixed to form the battery module 6 .
  • a plurality of battery modules 6 are connected in series, parallel, or mixed to form a whole, and are accommodated in the box.
  • the plurality of battery cells 7 in the battery module 6 can be electrically connected through bus components to achieve parallel, series or mixed connection of the plurality of battery cells 7 in the battery module 6 .
  • Figure 4 is an exploded schematic diagram of a battery cell provided by some embodiments of the present application.
  • the battery cell 7 includes an electrode assembly 10 , a case 20 and an end cap 30 .
  • the casing 20 has a hollow structure, and an accommodation cavity for accommodating the electrode assembly 10 and the electrolyte is formed inside.
  • the housing 20 can be in various shapes, such as rectangular parallelepiped, hexagonal prism, etc.
  • the shape of the housing 20 can be determined according to the specific shape of the electrode assembly 10 . For example, if the electrode assembly 10 has a rectangular parallelepiped structure, a rectangular parallelepiped shell can be used.
  • the end cap 30 is sealingly connected to the housing 20 to form a sealed space for accommodating the electrode assembly 10 and the electrolyte.
  • the end cap 30 is connected to the housing 20 by welding. Welding can achieve sealing and fixation between the end cover 30 and the housing 20 at the same time.
  • the housing 20 has an opening 20 a at one end along the first direction X, and the end cover 30 is provided as one and covers the opening 20 a of the housing 20 . In other examples, both ends of the housing 20 along the first direction
  • the first direction X is parallel to the thickness direction of the end cap 30 .
  • the electrode assembly 10 is the core component for realizing the charging and discharging functions of the battery cell 7. It includes a first pole piece, a second pole piece and a separator. The first pole piece and the second pole piece have opposite polarities. The separator is used to The first pole piece and the second pole piece are insulated and isolated. The electrode assembly 10 mainly relies on the movement of metal ions between the first pole piece and the second pole piece to work.
  • One of the first pole piece and the second pole piece is a positive pole piece, and the other one of the first pole piece and the second pole piece is a negative pole piece.
  • the electrode assembly 10 may be a rolled structure, a laminated structure, or other structures. There may be one or more first pole pieces, and there may be one or more second pole pieces. The number of the first pole pieces and the second pole pieces can be determined according to the structure of the electrode assembly 10 .
  • Electrode assembly 10 There may be one electrode assembly 10 or multiple electrode components 10 , which is not limited in this embodiment.
  • the battery cell 7 further includes two electrode terminals 40 installed on the end cover 30 .
  • the two electrode terminals 40 are respectively used to electrically connect the first pole piece and the second pole piece to connect the electrode assembly 10
  • the generated electrical energy is exported.
  • the electrode assembly 10 includes a main body 11 and tabs 12 connected to the main body 11 .
  • the main body part 11 is the electricity generating part of the electrode assembly 10, and the active material inside the body part 11 is used to cause an electrochemical reaction with the electrolyte, etc., to generate a charge and discharge process.
  • the tabs 12 are led out from the end of the main body 11 and are used to connect with the electrode terminals 40 to lead out the electric energy generated by the main body 11 .
  • the main body part 11 includes a positive electrode current collecting part, a positive electrode active material layer, a negative electrode current collecting part, a negative electrode active material layer and a separator.
  • the tab 12 includes a positive electrode tab and a negative electrode tab.
  • Figure 5 is a schematic structural diagram of a housing provided in some embodiments of the present application
  • Figure 6 is an enlarged schematic diagram of the housing shown in Figure 5 at circular frame A
  • Figure 7 is a schematic cross-sectional view of the housing shown in Figure 5
  • Figure 8 is an enlarged schematic view of the circular frame B in Figure 7
  • Figure 9 is another sectional schematic view of the housing shown in Figure 5.
  • an embodiment of the present application provides a housing 20 .
  • the end of the housing 20 along the first direction X has an opening 20 a.
  • the housing 20 includes a first side plate 21, a second side plate 22 and a first connecting plate 23.
  • the first side plate 21 and the second side plate 22 are arranged along the circumferential direction of the opening 20a.
  • the first connecting plate 23 is connected to the first connecting plate 23. Between the side plate 21 and the second side plate 22, at least part of the first connecting plate 23 is arc-shaped.
  • the first side plate 21 includes a first plate part 211, a second plate part 212 and a third plate part 213.
  • the second plate part 212 is connected between the first plate part 211 and the first connecting plate 23.
  • the third plate part 213 Located on the side of the first plate portion 211 close to the opening 20a.
  • the thickness of the first plate part 211 is smaller than the thickness of the second plate part 212 and the thickness of the third plate part 213 .
  • the housing 20 may be provided with the opening 20a only at one end along the first direction X, or may be provided with openings 20a at both ends along the first direction X.
  • first side plate 21 and the second side plate 22 are generally plate-like structures parallel to the first direction X.
  • first side plate 21 There may be one first side plate 21 or multiple first side plates 21 , and the number thereof may be set according to the shape of the housing 20 .
  • second side plate 22 There may be one second side plate 22 or multiple second side plates 22 , and the number thereof may be set according to the shape of the housing 20 .
  • the first connecting plate 23 can be bent into an arc shape as a whole, or only partially bent into an arc shape. In some examples, the first connecting plate 23 is bent into an arc shape.
  • the third plate part 213 may be disposed on one side of the first plate part 211 along the first direction X, or may be disposed on both sides of the first plate part 211 along the first direction X.
  • the first plate part 211 is connected to the second plate part 212.
  • the first plate part 211 may be directly connected to the second plate part 212 , or may be indirectly connected to the second plate part 212 via other parts of the first side plate 21 .
  • the first plate part 211 is connected to the third plate part 213.
  • the first plate part 211 may be directly connected to the third plate part 213 , or may be indirectly connected to the third plate part 213 via other parts of the first side plate 21 .
  • the second plate part 212 is connected to the third plate part 213.
  • the second plate part 212 may be directly connected to the third plate part 213 , or may be indirectly connected to the third plate part 213 via other parts of the first side plate 21 .
  • the thickness of the second plate part 212 and the thickness of the third plate part 213 are both greater than the thickness of the first plate part 211 .
  • the embodiment of the present application does not limit the thickness relationship between the second plate part 212 and the third plate part 213 .
  • the thickness of the second plate part 212 may be greater than, equal to, or less than the thickness of the third plate part 213 .
  • This embodiment can reduce the thickness of the first plate portion 211 of the first side plate 21 to increase the internal space of the case 20 and reserve more space for the electrode assembly 10 and the electrolyte, thereby increasing the battery cell 7
  • the energy density improves the charging and discharging performance of the battery cell 7.
  • the arc-shaped part of the first connecting plate 23 can release stress and reduce stress concentration during the molding process of the housing 20; the thickness of the second plate part 212 is greater than the thickness of the first plate part 211, so that the parts close to the first connecting plate 23
  • the second plate part 212 has a higher strength than the first plate part 211, which reduces the risk of the second plate part 212 cracking when the battery cell 7 is impacted by an external impact, thereby providing safety.
  • the third plate part 213 can be used to connect with the end cover 30 of the battery cell 7 to improve the connection strength between the case 20 and the end cover 30 and reduce the The risk of housing 20 cracking increases safety.
  • the second plate part 212 is directly connected to the third plate part 213 to improve the overall strength of the first side plate 21 and reduce the risk of cracking of the first side plate 21 .
  • the thickness of the second plate part 212 is equal to the thickness of the third plate part 213 to reduce the difficulty of molding the housing 20 .
  • the thickness of the first plate part 211 is T1
  • the thickness of the second plate part 212 is T2
  • T1 and T2 satisfy: 0.05mm ⁇ T2-T1 ⁇ 1mm.
  • T1 When the value of T1 is determined, the larger T2 is, the higher the strength of the second plate part 212 is, but the internal space of the housing 20 is smaller; when the value of T1 is determined, the smaller T2 is, the stronger the strength of the second plate part 212 is. lower, but the internal space of the housing 20 is larger.
  • T2 the larger T1 is, the higher the strength of the first plate part 211 is, but the internal space of the housing 20 is smaller; when the value of T2 is determined, the smaller T1 is, the stronger the strength of the first plate part 211 is. lower, but the internal space of the housing 20 is larger.
  • this embodiment limits the value of T2-T1 to 0.05mm-1mm.
  • the value of T2-T1 may be 0.05mm, 0.1mm, 0.2mm, 0.5mm, 0.7mm, 0.9mm, or 1mm.
  • T1 and T2 satisfy: 0.1mm ⁇ T2-T1 ⁇ 0.7mm.
  • the thickness T1 of the first plate portion 211 is 0.1mm-0.8mm.
  • the thickness T1 of the first plate portion 211 is limited to 0.1mm-0.8mm to balance the strength of the case 20 and the energy density of the battery cell 7 .
  • the thickness T1 of the first plate part 211 is 0.1 mm, 0.3 mm, 0.5 mm, 0.7 mm or 0.8 mm.
  • the thickness T2 of the second plate portion 212 is 0.4mm-1.5mm.
  • the thickness T1 of the second plate portion 212 is limited to 0.4mm-1.5mm to balance the strength of the case 20 and the energy density of the battery cell 7 .
  • the thickness T2 of the second plate portion 212 is 0.4mm, 0.5mm, 0.8mm, 1mm, 1.2mm or 1.5mm.
  • the first side plate 21 further includes a first transition portion 214 connected between the first plate portion 211 and the second plate portion 212 .
  • the thickness of the first transition part 214 gradually increases.
  • first transition portion 214 by providing the first transition portion 214, a smooth transition can be achieved between the first plate portion 211 and the second plate portion 212, thereby reducing the difficulty of molding the housing 20, reducing stress concentration, and reducing the risk of cracking of the first side plate 21. risk.
  • the inner surface of the first transition portion 214 may be a bevel or a cambered surface.
  • the thickness of the end of the first transition part 214 connected to the second plate part 212 is equal to the thickness of the second plate part 212
  • the thickness of the end of the first transition part 214 connected to the first plate part 211 is equal to The thickness of the first plate portion 211.
  • the first plate part 211, the second plate part 212, and the third plate part 213 are all flat plate structures with uniform thickness.
  • the first plate part 211 and the second plate part 212 are arranged along the second direction Y, and the second direction Y is perpendicular to the first direction X.
  • the size of the second plate portion 212 along the second direction Y is L1
  • the size of the first transition portion 214 along the second direction Y is L2
  • L1 and L2 satisfy: 0.2 ⁇ L1/L2 ⁇ 5.
  • the value of L1+L2 is constant, the smaller the value of L1/L2, the greater the force transmitted to the first transition part 214 during the molding process of the housing 20, and the higher the risk of cracking of the first transition part 214; in When the value of L1+L2 is constant, the larger the value of L1/L2, the steeper the transition surface of the first transition part 214, the more obvious the step formed between the first plate part 211 and the second plate part 212, and the shell 20 is formed The higher the difficulty. In the embodiment of the present application, the value of L1/L2 is limited to 0.2-5 to balance the molding difficulty and strength of the housing 20.
  • the value of L1/L2 is 0.2, 0.4, 0.5, 1, 2, 2.5 or 5.
  • the dimension L1 of the second plate portion 212 along the second direction Y is 0.5mm-10mm.
  • L1 is 0.5mm, 1mm, 2mm, 5mm, 8mm or 10mm.
  • the dimension L2 of the first transition portion 214 along the second direction Y is 0.5 mm-10 mm.
  • L2 is 0.5mm, 1mm, 2mm, 5mm, 8mm or 10mm.
  • the housing 20 includes two first side plates 21 and two second side plates 22.
  • the two second side plates 22 are oppositely arranged along the second direction Y.
  • the two first side plates 21 are arranged along the second direction Y.
  • the three directions Z are arranged oppositely, and the first direction X, the second direction Y and the third direction Z are perpendicular to each other.
  • the adjacent first side plate 21 and the second side plate 22 are connected through a first connecting plate 23 .
  • the first side plate 21 has two second plate portions 212 , and the two second plate portions 212 are respectively provided on both sides of the first plate portion 211 along the second direction Y.
  • This embodiment does not limit the area of the first side plate 21 and the area of the second side plate 22.
  • the area of the first side plate 21 may be greater than, equal to, or smaller than the area of the second side plate 22.
  • the two first side plates 21 and the two second side plates 22 are alternately arranged along the circumferential direction of the opening 20a.
  • there may be four first connecting plates 23 and each first connecting plate 23 connects the adjacent first side plate 21 and the second side plate 22 .
  • the two first connecting plates 23 are respectively connected to the first plate part 211 through two second plate parts 212.
  • the second plate part 212 has higher strength and can withstand the pressure from the first plate part 212. The stress is transferred on the connecting plate 23, thereby reducing the risk of cracking and providing safety.
  • the size of the first side plate 21 along the second direction Y is larger than the size of the second side plate 22 along the third direction Z.
  • the first side plate 21 has a larger area than the second side plate 22, the area where the first side plate 21 can be thinned is larger, which can effectively increase the internal space of the casing 20 and improve battery cell efficiency.
  • the second plate portion 212 and the third plate portion 213 protrude from the inner surface of the first plate portion 211 .
  • the outer surfaces of the first plate portion 211 , the second plate portion 212 and the third plate portion 213 are flush.
  • the outer surface of the first plate part 211 is the surface of the first plate part 211 that is away from the electrode assembly 10
  • the outer surface of the second plate part 212 is the surface of the second plate part 212 that is away from the electrode assembly 10
  • the outer surface of the third plate part 213 is The outer surface is the surface of the second plate portion 212 facing away from the electrode assembly 10 .
  • This embodiment can ensure the flatness of the outer surface of the first side plate 21 and improve the appearance of the housing 20 .
  • the first side plate 21 further includes a second transition portion 215 connected between the first plate portion 211 and the third plate portion 213 .
  • the thickness of the second transition part 215 gradually increases.
  • the second transition part 215 can achieve a smooth transition between the first plate part 211 and the third plate part 213, reducing the difficulty of molding the housing 20, reducing stress concentration, and reducing the risk of cracking of the first side plate 21.
  • the second transition portion 215 is connected to the first transition portion 214 .
  • the inner surface of the second transition portion 215 facing the electrode assembly 10 may be a bevel or a curved surface.
  • the thickness of one end of the second transition part 215 connected to the third plate part 213 is equal to the thickness of the third plate part 213
  • the thickness of one end of the second transition part 215 connected to the first plate part 211 is equal to the thickness of the first plate part 211 thickness.
  • the size of the third plate portion 213 along the first direction X is L3
  • the size of the second transition portion 215 along the first direction X is L4, and L3 and L4 satisfy: 0.3 ⁇ L3/L4 ⁇ 3.
  • the smaller the value of L3/L4 the smaller the area of the first side plate 21 used to connect to the end cover 30, and the lower the connection strength between the housing 20 and the end cover 30.
  • the embodiment of the present application limits the value of L3/L4 to 0.3-3 to balance the molding difficulty of the housing 20 and the connection strength between the housing 20 and the end cover 30 .
  • the value of L3/L4 is 0.3, 0.5, 0.8, 1, 2 or 3.
  • the dimension L3 of the third plate portion 213 along the first direction X is 0.3mm-10mm.
  • L3 is 0.3mm, 0.5mm, 1mm, 2mm, 5mm, 8mm or 10mm.
  • the dimension L4 of the second transition portion 215 along the first direction X is 0.3 mm-10 mm.
  • L4 is 0.3mm, 0.5mm, 1mm, 2mm, 5mm, 8mm or 10mm.
  • the second side plate 22 is provided with a recess 221 that is recessed from an end surface of the second side plate 22 along the first direction X.
  • the thickness of the portion of the second side plate 22 corresponding to the side surface 221 a of the recessed portion 221 is greater than the thickness of the first plate portion 211 .
  • the bottom surface 221b of the recess 221 can be used to support the end cap 30 and limit the end cap 30 when it extends into the housing 20 to prevent the end cap 30 from excessively extending into the housing 20 .
  • the portion of the second side plate 22 corresponding to the side surface 221a of the recess 221 can be used to connect with the end cover 30. Even if the recess 221 is provided on the second side plate 22 in this embodiment, the connection between the second side plate 22 and the recess can be ensured.
  • the partial strength corresponding to the side 221a of 221 reduces the risk of cracking of the second side plate 22 .
  • the bottom surface 221b of the recess 221 may be flat.
  • the included angle between the bottom surface 221b of the recessed part 221 and the side surface 221a of the recessed part 221 may be 80°-170°.
  • the portion of the second side plate 22 corresponding to the side surface 221 a of the recess 221 is welded to the end cover 30 .
  • the first connecting plate 23 is also provided with a recess, and the recess of the first connecting plate 23 is recessed from the end surface of the first connecting plate 23 along the first direction X.
  • the recessed portion of the first connecting plate 23 communicates with the recessed portion 221 of the second side plate 22 .
  • one end of the third plate portion 213 close to the first plate portion 211 exceeds the bottom surface 221b of the recessed portion 221 .
  • the bottom surface 221b of the recess 221 is used to support the end cap 30 and limit the position of the end cap 30 .
  • the end of the third plate part 213 close to the first plate part 211 exceeds the bottom surface 221b of the recess 221, so that the end of the third plate part 213 close to the first plate part 211 exceeds the end cover 30, thereby
  • the strength of the part of the first side plate 21 connected to the end cover 30 is ensured, the risk of cracking of the first side plate 21 is reduced, and the safety is improved.
  • the second side plate 22 has an inner surface facing the electrode assembly 10 , and the inner surface of the second side plate 22 is connected to the bottom surface 221 b of the recess 221 .
  • the inner surface of the second side plate 22 is flat, and no recessed structure is provided on the inner surface of the second side plate 22 .
  • FIG. 10 is an enlarged schematic view of the circular frame C in FIG. 7 ;
  • FIG. 11 is another sectional schematic view of the housing shown in FIG. 5 .
  • the second plate part 212 can separate the first plate part 211 and the first connecting plate 23 to reduce the risk of cracking of the first plate part 211.
  • the third plate part 213 and the two second plate parts 212 form a U-shaped structure, and the first plate part 211 is located in an area enclosed by the U-shaped structure.
  • the housing 20 further includes a third side plate 24 and a second connection plate 25 .
  • the third side plate 24 and the opening 20a are arranged oppositely along the first direction X.
  • the second connecting plate 25 is connected between the first side plate 21 and the third side plate 24, and at least part of the second connecting plate 25 is arc-shaped.
  • the first plate part 211 is directly connected to the second connecting plate 25 .
  • the arc-shaped portion of the second connecting plate 25 can release stress during the molding process of the housing 20 and reduce stress concentration.
  • the first plate part 211 is directly connected to the second connecting plate 25, which can reduce the step at the connection between the first plate part 211 and the second connecting plate 25, reduce the risk of local pressure on the electrode assembly 10, and improve the performance of the electrode assembly 10 .
  • the thickness of the end portion of the second connecting plate 25 that is directly connected to the first plate portion 211 is equal to the thickness of the first plate portion 211 to provide a smooth transition between the first plate portion 211 and the second connecting plate 25 . , reducing the risk of steps forming at the connection between the first plate portion 211 and the second connecting plate 25 .
  • Figure 12 is a schematic structural diagram of a housing provided by other embodiments of the present application;
  • Figure 13 is an enlarged schematic diagram of the housing shown in Figure 12 at the circular frame D.
  • the second side plate 22 is provided with a thinned area 222 in the middle to increase the internal space of the housing 20 .
  • the first side plate 21 has a flat plate structure.
  • Figure 14 is a schematic cross-sectional view of a battery cell provided by some embodiments of the present application
  • Figure 15 is another schematic cross-sectional view of a battery cell provided by some embodiments of the present application
  • Figure 16 is a schematic cross-sectional view of the battery cell in Figure 15 at circular frame E Enlarged schematic diagram
  • Figure 17 is a schematic cross-sectional view of an electrode assembly of a battery cell provided by some embodiments of the present application.
  • the battery cell 7 in the embodiment of the present application includes a case 20 , an electrode assembly 10 and an end cap 30 .
  • the housing 20 may be the housing 20 of any of the above embodiments.
  • the electrode assembly 10 is accommodated in the housing 20 , and a gap G is provided between the electrode assembly 10 and the second plate portion 212 in the thickness direction of the first side plate 21 .
  • the end cap 30 is used to cover the opening 20 a and is connected to the third plate part 213 .
  • the gap G between the electrode assembly 10 and the second plate part 212 can reduce the risk of the second plate part 212 squeezing the electrode assembly 10, reduce stress concentration, and improve the charge and discharge performance of the electrode assembly 10. Since the thickness of the third plate part 213 is greater than the thickness of the first plate part 211, the third plate part 213 can be used to connect with the end cover 30 to improve the connection strength between the housing 20 and the end cover 30 and reduce the risk of cracking of the housing 20. risks and improve safety.
  • the thickness direction of the first side plate 21 is parallel to the third direction Z.
  • the third plate portion 213 is used to weld with the end cover 30 and form the welding portion W. In the first direction X, one end of the third plate portion 213 close to the first plate portion 211 exceeds the welding portion W.
  • the thickness of the third plate part 213 close to the opening 20a is increased, and the end of the third plate part 213 close to the first plate part 211 exceeds the welding part W to ensure that the first side plate 21 is in the welding part W.
  • the strength of the nearby area reduces the risk of cracking of the first side panel 21 and improves safety.
  • the electrode assembly 10 includes a first pole piece 10a, a separator 10c, and a second pole piece 10b.
  • the separator 10c is used to insulate the first pole piece 10a and the second pole piece 10b.
  • the first pole piece 10a, the separator and the second pole piece 10b can be sequentially stacked and wound more than two times to form the electrode assembly 10.
  • the electrode assembly 10 is flat.
  • the electrode assembly 10 is a rolled structure and includes a straight region 111 and a bent region 112.
  • the bent region 112 is connected to the end of the straight region 111 along the second direction Y.
  • the first direction The two directions Y and the thickness direction are perpendicular to each other.
  • the first plate part 211 covers at least part of the straight area 111
  • the second plate part 212 covers at least part of the bending area 112
  • a gap G is formed between the second plate part 212 and the bending area 112 .
  • the thickness direction is parallel to the third direction Z.
  • each pole piece located in the straight area 111 is generally in a straight state; the part of each pole piece located in the bending area 112 is generally in a bent state.
  • the part of the pole piece located in the bending area 112 can be an arc. shape.
  • the second plate part 212 can use the space reserved by the bending area 112 to ensure its own thickness and reduce the thickness of the second plate part 212 . There is a risk of portion 212 squeezing electrode assembly 10 .
  • the second plate portion 212 does not overlap the straight region 111 in the thickness direction.
  • the main body 11 of the electrode assembly 10 includes a straight area 111 and a bent area 112, and the tabs 12 are led out from the straight area 111.
  • the projection of the active material layer (including the positive active material layer and the negative active material layer) in the flat area 111 is located within the projection of the first plate portion 211 .
  • the third plate portion 213 does not overlap with the flat area 111 in the thickness direction, so as to reduce the risk of the third plate portion 213 squeezing the flat area 111 and reduce stress concentration on the flat area 111 .
  • the third plate portion 213 does not overlap with the bending area 112 in the thickness direction, so as to reduce the risk of the third plate portion 213 squeezing the bending area 112 and reduce the stress concentration on the bending area 112 .
  • the battery cell 7 further includes an insulating member 50 , which is disposed on a side of the end cover 30 facing the flat area 111 and offset against the flat area 111 .
  • the surface of the insulating member 50 that abuts the flat area 111 extends beyond the end of the first plate portion 211 facing the third plate portion 213 .
  • the insulating member 50 can insulate the end cap 30 from the flat area 111 to reduce the risk that the end cap 30 conducts the positive and negative electrode plates in the flat area 111 and improve safety.
  • the insulating member 50 offsets the flat area 111 along the first direction X to reduce the shaking amplitude of the flat area 111 when the battery cell 7 vibrates, thereby reducing the risk of misalignment of the positive and negative electrode plates and improving the charge and discharge performance of the electrode assembly 10 .
  • the insulating member 50 can limit the position of the flat area 111 along the first direction .
  • the present application also provides a battery including a plurality of battery cells according to any of the above embodiments.
  • the present application also provides an electrical device, including the battery cell of any of the above embodiments, and the battery cell is used to provide electrical energy to the electrical device.
  • the power-consuming device can be any of the aforementioned devices or systems using battery cells.
  • the present application provides a square housing 20 , and the end of the housing 20 along the first direction X has an opening 20 a.
  • the housing 20 includes two first side plates 21, two second side plates 22 and four first connecting plates 23.
  • the two first side plates 21 and the two second side plates 22 alternate along the circumferential direction of the opening 20a.
  • the adjacent first side plate 21 and the second side plate 22 are connected through a first connecting plate 23 .
  • At least part of the first connecting plate 23 is arc-shaped.
  • the first side plate 21 includes a first plate part 211, two second plate parts 212 and a third plate part 213; the two second plate parts 212 are respectively located on both sides of the first plate part 211, and each second plate part 212 Connected between the first plate portion 211 and the corresponding first connecting plate 23 .
  • the third plate part 213 is located on the side of the first plate part 211 close to the opening 20a.
  • the thickness of the second plate part 212 is equal to the thickness of the third plate part 213 , and the thickness of the second plate part 212 is greater than the thickness of the first plate part 211 .
  • the first side panel 21 also includes a first transition portion 214 and a second transition portion 215 .
  • the first transition part 214 is connected between the first plate part 211 and the second plate part 212; along the direction from the first plate part 211 to the second plate part 212, the thickness of the first transition part 214 gradually increases.
  • the second transition portion 215 is connected between the first plate portion 211 and the third plate portion 213 . Along the direction from the first plate part 211 to the third plate part 213, the thickness of the second transition part 215 gradually increases.
  • Embodiment 1 can be prepared according to the following steps:
  • step (VI) as shown in FIGS. 5 and 18 , the size of the housing 20 along the first direction X is 115 mm, the size along the second direction Y is 237.5 mm, and the size along the third direction Z is 32 mm.
  • the housing 20 includes two first side plates 21 oppositely arranged along the third direction Z.
  • the dimension D1 of each first side plate 21 along the first direction X is 113 mm, and the dimension D2 along the second direction Y is 230 mm.
  • the first side plate 21 includes a first plate part 211, two second plate parts 212 and a third plate part 213.
  • the third plate part 213 is located on the side of the first plate part 211 close to the opening along the first direction X.
  • Two The second plate portions 212 are respectively located on both sides of the first plate portion 211 along the second direction Y, and the two second plate portions 212 and the third plate portion 213 form a U-shaped structure.
  • the dimension D3 of the first plate part 211 along the first direction X is 103 mm.
  • the dimension D4 of the first plate part 211 along the second direction Y is 220 mm.
  • the dimension L1 of the second plate part 212 along the second direction Y is 5 mm.
  • the dimension L3 of the plate portion 213 along the first direction X is 10 mm.
  • the thickness T1 of the first plate part 211 along the third direction Z is 0.5 mm
  • the thickness T2 of the second plate part 212 along the third direction Z is 0.7 mm
  • the thickness of the third plate part 213 is equal to the thickness of the second plate part 212 .
  • Example 2 The preparation method of the battery cell of Example 2 is similar to that of Example 1, except that T2 is 0.51 mm.
  • Example 3 The preparation method of the battery cell of Example 3 is as in Example 1, except that T2 is 0.55 mm.
  • Example 4 The preparation method of the battery cell of Example 4 is as in Example 1, except that T2 is 0.9 mm.
  • Example 5 The preparation method of the battery cell of Example 5 is similar to that of Example 1, except that T2 is 1 mm.
  • Example 6 The preparation method of the battery cell of Example 6 is as in Example 1, except that T2 is 1.2 mm.
  • Example 7 The preparation method of the battery cell of Example 7 is similar to that of Example 1, except that T2 is 1.5 mm.
  • Comparative Example 1 The preparation method of the battery cell in Comparative Example 1 is as in Example 1, except that the overall thickness of the first side plate in Comparative Example 1 is 0.5 mm.
  • the battery cells are charged at a rate of 1C, discharged at a rate of 1C, and a full-charge-discharge cycle test is performed until the capacity of the battery cells decays to 80% of the initial capacity; the battery cells are placed in a vacuum.
  • the vacuum box was evacuated. After 5 hours, an organic gas tester (VOC tester, model ppbRAE-3000) was used to detect the content of organic gases in the vacuum box to determine whether the battery cells were leaking.
  • VOC tester model ppbRAE-3000
  • making the thickness of the second plate part greater than the thickness of the first plate part can reduce the risk of shell cracking and improve the sealing and safety of the battery cells.

Abstract

本申请实施例提供一种电池单体的壳体、电池单体、电池以及用电装置。壳体沿第一方向的端部具有开口。壳体包括第一侧板、第二侧板以及第一连接板，第一侧板和第二侧板沿开口的周向布置，第一连接板连接于第一侧板和第二侧板之间，且第一连接板的至少部分为弧形。第一侧板包括第一板部、第二板部和第三板部，第二板部连接于第一板部和第一连接板之间，第三板部位于第一板部的靠近开口的一侧。第一板部的厚度小于第二板部的厚度以及第三板部的厚度。本申请实施例可以增大壳体的内部空间，提高电池单体的能量密度，降低壳体开裂的风险，提高安全性。

Description

电池单体的壳体、电池单体、电池以及用电装置 技术领域
本申请涉及电池技术领域，并且更具体地，涉及一种电池单体的壳体、电池单体、电池以及用电装置。
背景技术
电池单体广泛用于电子设备，例如手机、笔记本电脑、电瓶车、电动汽车、电动飞机、电动轮船、电动玩具汽车、电动玩具轮船、电动玩具飞机和电动工具等等。电池单体可以包括镉镍电池单体、氢镍电池单体、锂离子电池单体和二次碱性锌锰电池单体等。
在电池技术的发展中，如何提高电池单体的能量密度，是电池技术中一个重要的研究方向。
发明内容
本申请提供了一种电池单体的壳体、电池单体、电池以及用电装置，其能提高电池单体的能量密度。
第一方面，本申请实施例提供了一种电池单体的壳体，壳体沿第一方向的端部具有开口。壳体包括第一侧板、第二侧板以及第一连接板，第一侧板和第二侧板沿开口的周向布置，第一连接板连接于第一侧板和第二侧板之间，且第一连接板的至少部分为弧形。第一侧板包括第一板部、第二板部和第三板部，第二板部连接于第一板部和第一连接板之间，第三板部位于第一板部的靠近开口的一侧。第一板部的厚度小于第二板部的厚度以及第三板部的厚度。
上述技术方案可减小第一侧板的第一板部的厚度，以增大壳体的内部空间，为电极组件和电解液预留更多的空间，从而提高电池单体的能量密度，改善电池单体的充放电性能。第一连接板的弧形部分可以在壳体的成型过程中释放应力，降低应力集中；第二板部的厚度大于第一板部的厚度，以使靠近第一连接板的第二板部具有高于第一板部的强度，降低第二板部在电池单体受到外部冲击时开裂的风险，提供安全性。由于第三板部的厚度大于第一板部的厚度，所以第三板部可用于与电池单体的端盖连接，以提高壳体与端盖的连接强度，降低壳体开裂的风险，提高安全性。
在一些实施方式中，第二板部直接连接于第三板部，以提高第一侧板的整体强度，降低第一侧板开裂的风险。
在一些实施方式中，第二板部的厚度等于第三板部的厚度，以降低壳体的成型 难度。
在一些实施方式中，第一板部的厚度为T1，第二板部的厚度为T2，T1和T2满足：0.05mm≤T2-T1≤1mm。
在T1的值确定时，T2越大，第二板部的强度越高，但壳体的内部空间越小；在T1的值确定时，T2越小，第二板部的强度越低，但壳体的内部空间越大。在T2的值确定时，T1越大，第一板部的强度越高，但壳体的内部空间越小；在T2的值确定时，T1越小，第一板部的强度越低，但壳体的内部空间越大。上述技术方案将T2-T1的值限定在0.05mm-1mm，以平衡壳体的强度和壳体的容量。
在一些实施方式中，T1和T2满足：0.1mm≤T2-T1≤0.7mm。
在一些实施方式中，第一板部的厚度T1为0.1mm-0.8mm。
在一些实施方式中，第二板部的厚度T2为0.4mm-1.5mm。
在一些实施方式中，第一侧板还包括第一过渡部，第一过渡部连接于第一板部和第二板部之间。沿第一板部指向第二板部的方向，第一过渡部的厚度逐渐增大。
上述技术方案中，通过设置第一过渡部，可以在第一板部和第二板部之间实现平滑过渡，降低壳体成型难度，减小应力集中，降低第一侧板开裂的风险。
在一些实施方式中，第一板部和第二板部沿第二方向布置，第二方向垂直于第一方向。第二板部沿第二方向的尺寸为L1，第一过渡部沿第二方向的尺寸为L2，L1与L2满足：0.2≤L1/L2≤5。
在L1+L2的值一定时，L1/L2的值越小，在壳体成型过程中传递到第一过渡部上的作用力越大，第一过渡部开裂的风险越高；在L1+L2的值一定时，L1/L2的值越大，第一过渡部的过渡面越陡峭，第一板部和第二板部之间形成的台阶越明显，壳体成型的难度越高。上述技术方案将L1/L2的值限定在0.2-5，以平衡壳体的成型难度和强度。
在一些实施方式中，第二板部沿第二方向的尺寸L1为0.5mm-10mm，第一过渡部沿第二方向的尺寸L2为0.5mm-10mm。
在一些实施方式中，在第一方向上，第一板部的背离第三板部的一端与第二板部的背离第三板部的一端齐平。第二板部可以将第一板部和第一连接板隔开，以降低第一板部开裂的风险。
在一些实施方式中，壳体还包括第三侧板和第二连接板。第三侧板和开口沿第一方向相对设置，第二连接板连接于第一侧板和第三侧板之间，且第二连接板的至少部分为弧形。第一板部直接连接于第二连接板。
上述技术方案中，第二连接板的弧形部分可以在壳体的成型过程中释放应力，降低应力集中。第一板部直接连接于第二连接板，这样可以减小第一板部与第二连接板连接处的台阶，降低电极组件局部受压的风险，改善电极组件的性能。
在一些实施方式中，壳体包括两个第一侧板和两个第二侧板，两个第二侧板沿第二方向相对设置，两个第一侧板沿第三方向相对设置，第一方向、第二方向和第三方向两两垂直。相邻的第一侧板和第二侧板通过第一连接板连接。第一侧板的第二板部设置为两个，两个第二板部分别设于第一板部沿第二方向的两侧。
上述技术方案中，两个第一连接板分别通过两个第二板部连接于第一板部，在 壳体的成型过程中，第二板部具有较高的强度，其可以承受从第一连接板上传递的应力，从而降低开裂风险，提供安全性。
在一些实施方式中，第一侧板沿第二方向的尺寸大于第二侧板沿第三方向的尺寸。
上述技术方案中，由于第一侧板相较于第二侧板具有较大的面积，所以第一侧板能够减薄的区域较大，这样可以有效地增大壳体的内部空间，提高电池单体的容量。
在一些实施方式中，第二板部和第三板部凸出于第一板部的内表面。
在一些实施方式中，第一板部的外表面、第二板部的外表面和第三板部的外表面齐平，以保证第一侧板的外表面的平整性，改善壳体的外观。
在一些实施方式中，第一侧板还包括第二过渡部，第二过渡部连接于第一板部和第三板部之间。沿第一板部指向第三板部的方向，第二过渡部的厚度逐渐增大。
上述技术方案中，第二过渡部可以在第一板部和第三板部之间实现平滑过渡，降低壳体成型难度，减小应力集中，降低第一侧板开裂的风险。
在一些实施方式中，第三板部沿第一方向的尺寸为L3，第二过渡部沿第一方向的尺寸为L4，L3与L4满足：0.3≤L3/L4≤3。
在L3+L4的值一定时，L3/L4的值越小，第一侧板的用于与端盖相连的区域越小，壳体与端盖的连接强度越低，在装配壳体和端盖的过程中传递到第二过渡部的作用力越大，第二过渡部开裂的风险越高；在L3+L4的值一定时，L3/L4的值越大，第二过渡部的过渡面越陡峭，第一板部和第三板部之间形成的台阶越明显，壳体成型的难度越高。上述技术方案将L3/L4的值限定在0.3-3，以平衡壳体的成型难度以及壳体与端盖之间的连接强度。
在一些实施方式中，第三板部沿第一方向的尺寸L3为0.3mm-10mm，第二过渡部沿第一方向的尺寸L4为0.3mm-10mm。
在一些实施方式中，第二侧板设有凹部，凹部从第二侧板的沿第一方向的端面凹陷。第二侧板的与凹部的侧面对应的部分的厚度大于第一板部的厚度。
上述技术方案中，凹部的底面可用于支撑电池单体的端盖，并能够在端盖伸入壳体的过程中对端盖进行限位，避免端盖过度地伸入壳体内。第二侧板的与凹部的侧面对应的部分可用于与端盖连接，即使本实施例在第二侧板上开设了凹部，也能够保证第二侧板的与凹部的侧面对应的部分强度，降低第二侧板开裂的风险。
在一些实施方式中，在第一方向上，第三板部的靠近第一板部的一端超出凹部的底面。
上述技术方案中，凹部的底面用于支撑端盖并限制端盖的位置。在本实施例中，第三板部的靠近第一板部的一端超出凹部的底面，这样可以使第三板部的靠近第一板部的一端超出端盖，从而保证第一侧板的连接于端盖的部分的强度，降低第一侧板开裂的风险，提高安全性。
第二方面，本申请实施例提供了一种电池单体，包括第一方面任一实施方式提供的壳体、电极组件以及端盖。电极组件容纳于壳体内，在第一侧板的厚度方向上，电极组件与第二板部之间设有间隙。端盖用于盖合开口并连接于第三板部。
上述技术方案中，电极组件与第二板部之间的间隙可以降低第二板部挤压电极组件的风险，减小应力集中，改善电极组件的充放电性能。由于第三板部的厚度大于第一板部的厚度，所以第三板部可用于与端盖连接，以提高壳体与端盖的连接强度，降低壳体开裂的风险，提高安全性。
在一些实施方式中，第三板部用于与端盖焊接并形成焊接部。在第一方向上，第三板部的靠近第一板部的一端超出焊接部。
上述技术方案中，在形成焊接部之后，第三板部的靠近焊接部的区域会残留热应力。本实施例通过增大靠近开口的第三板部的厚度，并使第三板部的靠近第一板部的一端超出焊接部，以保证第一侧板在焊接部附近的区域的强度，降低第一侧板开裂的风险，提高安全性。
在一些实施方式中，电极组件为卷绕结构且包括平直区和弯折区，弯折区连接于平直区沿第二方向的端部，第一方向、第二方向和厚度方向两两垂直。在厚度方向上，第一板部覆盖平直区的至少部分，第二板部覆盖弯折区的至少部分，且第二板部与弯折区之间形成间隙。
上述技术方案中，由于弯折区在厚度方向上占用的空间较小，因此，第二板部可以利用弯折区预留出的空间来保证自身的厚度，并降低第二板部挤压电极组件的风险。
在一些实施方式中，在厚度方向上，第三板部与平直区不重叠，第三板部与弯折区不重叠，以降低第三板部挤压弯折区和平直区的风险，减小应力集中，改善电极组件的充放电性能。
在一些实施方式中，电池单体还包括绝缘构件，绝缘构件设置于端盖的面向平直区的一侧并与平直区相抵。沿背离端盖的方向，绝缘构件的与平直区的相抵的表面超出第一板部的面向第三板部的端部。
上述技术方案中，绝缘构件能够将端盖和平直区绝缘隔离，以降低端盖将平直区中的正负极片导通的风险，提高安全性。绝缘构件与平直区沿第一方向相抵，以在电池单体震动时减小平直区晃动幅度，降低正负极片错位的风险，改善电极组件的充放电性能。绝缘构件能够限制平直区沿第一方向的位置，以减小平直区在电池单体震动时碰撞第三板部的可能性，降低第三板部开裂的风险。
第三方面，本申请实施例提供了一种电池，包括多个第二方面任一实施方式提供的电池单体。
第四方面，本申请实施例提供了一种用电装置，包括第二方面任一实施方式提供的电池单体，电池单体用于提供电能。
附图说明
为了更清楚地说明本申请实施例的技术方案，下面将对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为本申请一些实施例提供的车辆的结构示意图；
图2为本申请一些实施例提供的电池的爆炸示意图；
图3为图2所示的电池模块的结构示意图；
图4为本申请一些实施例提供的电池单体的爆炸示意图；
图5为本申请一些实施例提供的壳体的结构示意图；
图6为图5所示的壳体在圆框A处的放大示意图；
图7为图5所示的壳体的一剖视示意图；
图8为图7在圆框B处的放大示意图；
图9为图5所示的壳体的另一剖视示意图；
图10为图7在圆框C处的放大示意图；
图11为图5所示的壳体的又一剖视示意图；
图12为本申请另一些实施例提供的壳体的结构示意图；
图13为图12所示的壳体在圆框D处的放大示意图；
图14为本申请一些实施例提供的电池单体的一剖视示意图；
图15为本申请一些实施例提供的电池单体的另一剖视示意图；
图16为图15在圆框E处的放大示意图；
图17为本申请一些实施例提供的电池单体的电极组件的剖视示意图；
图18为本申请一些实施例提供的壳体的第一侧板的结构示意图。
具体实施方式的附图标记如下：
1、车辆；2、电池；3、控制器；4、马达；5、箱体；5a、第一箱体部；5b、第二箱体部；5c、容纳空间；6、电池模块；7、电池单体；
10、电极组件；11、主体部；111、平直区；112、弯折区；12、极耳；10a、第一极片；10b、第二极片；10c、隔离件；
20、壳体；21、第一侧板；211、第一板部；212、第二板部；213、第三板部；214、第一过渡部；215、第二过渡部；22、第二侧板；221、凹部；221a、侧面；221b、底面；222、减薄区；23、第一连接板；24、第三侧板；25、第二连接板；20a、开口；
30、端盖；40、电极端子；50、绝缘构件；
G、间隙；W、焊接部；X、第一方向；Y、第二方向；Z、第三方向。
具体实施方式
为使本申请实施例的目的、技术方案和优点更加清楚，下面将结合本申请实施例中的附图，对本申请实施例中的技术方案进行清楚地描述，显然，所描述的实施例是本申请一部分实施例，而不是全部的实施例。基于本申请中的实施例，本领域普通技术人员在没有作出创造性劳动前提下所获得的所有其他实施例，都属于本申请保护的范围。
除非另有定义，本申请所使用的所有的技术和科学术语与属于本申请的技术领 域的技术人员通常理解的含义相同；本申请中在申请的说明书中所使用的术语只是为了描述具体的实施例的目的，不是旨在于限制本申请；本申请的说明书和权利要求书及上述附图说明中的术语“包括”和“具有”以及它们的任何变形，意图在于覆盖不排他的包含。本申请的说明书和权利要求书或上述附图中的术语“第一”、“第二”等是用于区别不同对象，而不是用于描述特定顺序或主次关系。
在本申请中提及“实施例”意味着，结合实施例描述的特定特征、结构或特性可以包含在本申请的至少一个实施例中。在说明书中的各个位置出现该短语并不一定均是指相同的实施例，也不是与其它实施例互斥的独立的或备选的实施例。
在本申请的描述中，需要说明的是，除非另有明确的规定和限定，术语“安装”、“相连”、“连接”、“附接”应做广义理解，例如，可以是固定连接，也可以是可拆卸连接，或一体地连接；可以是直接相连，也可以通过中间媒介间接相连，可以是两个元件内部的连通。对于本领域的普通技术人员而言，可以根据具体情况理解上述术语在本申请中的具体含义。
本申请中术语“和/或”，仅仅是一种描述关联对象的关联关系，表示可以存在三种关系，例如，A和/或B，可以表示：单独存在A，同时存在A和B，单独存在B这三种情况。另外，本申请中字符“/”，一般表示前后关联对象是一种“或”的关系。
在本申请的实施例中，相同的附图标记表示相同的部件，并且为了简洁，在不同实施例中，省略对相同部件的详细说明。应理解，附图示出的本申请实施例中的各种部件的厚度、长宽等尺寸，以及集成装置的整体厚度、长宽等尺寸仅为示例性说明，而不应对本申请构成任何限定。
本申请中出现的“多个”指的是两个以上(包括两个)。
本申请中术语“平行”不仅包括绝对平行的情况，也包括了工程上常规认知的大致平行的情况；同时，“垂直”也不仅包括绝对垂直的情况，还包括工程上常规认知的大致垂直的情况。
本申请中，电池单体可以包括锂离子二次电池单体、锂离子一次电池单体、锂硫电池单体、钠锂离子电池单体、钠离子电池单体或镁离子电池单体等，本申请实施例对此并不限定。
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是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，电极组件包括正极极片、负极极片和隔离件。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；正极集流体包括正极集流部和正极极耳，正极集流部涂覆有正极活性物质层，正极极耳未涂覆正极活性物质层。以锂离子电池为例，正极集流体的材料可以为铝，正极活性物质层包括正极活性物质，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； 负极集流体包括负极集流部和负极极耳，负极集流部涂覆有负极活性物质层，负极极耳未涂覆负极活性物质层。负极集流体的材料可以为铜，负极活性物质层包括负极活性物质，负极活性物质可以为碳或硅等。隔离件的材质可以为PP(polypropylene，聚丙烯)或PE(polyethylene，聚乙烯)等。
电池单体还包括壳体和端盖，壳体具有开口，端盖盖合于开口并密封连接，以形成用于容纳电极组件和电解液的密封空间。
发明人尝试整体减小壳体的壁厚，以增大壳体的内部空间，提高电池单体的能量密度，改善电池单体的充放电性能。
发明人发现，壳体的靠近开口的部分需要连接于端盖，如果减小了壳体的厚度，可能会影响壳体与端盖的连接强度；受端盖的影响，壳体的靠近开口的部分也容易出现开裂的风险。例如，在相关技术中，壳体和端盖通过焊接的方式相连，在焊接后，壳体会在熔池的附近形成热影响区，热影响区内会受到残余热应力的作用，导致热影响区的强度相对于其它区域的强度偏低；如果减小了壳体的厚度，那么当热影响区在电池单体的使用过程中受到挤压时，壳体可能会在热影响区开裂，导致电解液泄漏，造成电池单体失效，引发安全风险。
发明人还发现，在壳体的成型过程中，壳体的拐角处容易残留应力；如果减小壳体的厚度，那么在电池单体受到外部冲击时，壳体的靠近拐角的区域容易开裂，导致电解液泄漏，造成电池单体失效，引发安全风险。
鉴于此，本申请实施例提供了一种技术方案，其减薄壳体的部分区域，以增大壳体的内部空间，提高电池单体的能量密度，并保证壳体的靠近开口的部分的强度和靠近拐角的部分的强度，降低壳体开裂风险，改善密封性，降低安全隐患。
本申请实施例描述的技术方案适用于电池以及使用电池的用电装置。
用电装置可以是车辆、手机、便携式设备、笔记本电脑、轮船、航天器、电动玩具和电动工具等等。车辆可以是燃油汽车、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；航天器包括飞机、火箭、航天飞机和宇宙飞船等等；电动玩具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；电动工具包括金属切削电动工具、研磨电动工具、装配电动工具和铁道用电动工具，例如，电钻、电动砂轮机、电动扳手、电动螺丝刀、电锤、冲击电钻、混凝土振动器和电刨等等。本申请实施例对上述用电装置不做特殊限制。
以下实施例为了方便说明，以用电装置为车辆为例进行说明。
图1为本申请一些实施例提供的车辆的结构示意图。
如图1所示，车辆1的内部设置有电池2，电池2可以设置在车辆1的底部或头部或尾部。电池2可以用于车辆1的供电，例如，电池2可以作为车辆1的操作电源。
车辆1还可以包括控制器3和马达4，控制器3用来控制电池2为马达4供电，例如，用于车辆1的启动、导航和行驶时的工作用电需求。
在本申请一些实施例中，电池2不仅仅可以作为车辆1的操作电源，还可以作 为车辆1的驱动电源，代替或部分地代替燃油或天然气为车辆1提供驱动动力。
图2为本申请一些实施例提供的电池的爆炸示意图。
如图2所示，电池2包括箱体5和电池单体(图2未示出)，电池单体容纳于箱体5内。
箱体5用于容纳电池单体，箱体5可以是多种结构。在一些实施例中，箱体5可以包括第一箱体部5a和第二箱体部5b，第一箱体部5a与第二箱体部5b相互盖合，第一箱体部5a和第二箱体部5b共同限定出用于容纳电池单体的容纳空间5c。第二箱体部5b可以是一端开口的空心结构，第一箱体部5a为板状结构，第一箱体部5a盖合于第二箱体部5b的开口侧，以形成具有容纳空间5c的箱体5；第一箱体部5a和第二箱体部5b也均可以是一侧开口的空心结构，第一箱体部5a的开口侧盖合于第二箱体部5b的开口侧，以形成具有容纳空间5c的箱体5。当然，第一箱体部5a和第二箱体部5b可以是多种形状，比如，圆柱体、长方体等。
为提高第一箱体部5a与第二箱体部5b连接后的密封性，第一箱体部5a与第二箱体部5b之间也可以设置密封件，比如，密封胶、密封圈等。
假设第一箱体部5a盖合于第二箱体部5b的顶部，第一箱体部5a亦可称之为上箱盖，第二箱体部5b亦可称之为下箱体。
在电池2中，电池单体可以是一个，也可以是多个。若电池单体为多个，多个电池单体之间可串联或并联或混联，混联是指多个电池单体中既有串联又有并联。多个电池单体之间可直接串联或并联或混联在一起，再将多个电池单体构成的整体容纳于箱体5内；当然，也可以是多个电池单体先串联或并联或混联组成电池模块6，多个电池模块6再串联或并联或混联形成一个整体，并容纳于箱体5内。
图3为图2所示的电池模块的结构示意图。
如图3所示，在一些实施例中，电池单体7为多个，多个电池单体7先串联或并联或混联组成电池模块6。多个电池模块6再串联或并联或混联形成一个整体，并容纳于箱体内。
电池模块6中的多个电池单体7之间可通过汇流部件实现电连接，以实现电池模块6中的多个电池单体7的并联或串联或混联。
图4为本申请一些实施例提供的电池单体的爆炸示意图；
如图4所示，电池单体7包括电极组件10、壳体20和端盖30。壳体20沿第一方向X的端部具有开口20a，电极组件10容纳于壳体20内，端盖30用于盖合开口20a。
壳体20为空心结构，其内部形成用于容纳电极组件10和电解液的容纳腔。壳体20可以是多种形状，比如，长方体、六棱柱等。壳体20的形状可根据电极组件10的具体形状来确定。比如，若电极组件10为长方体结构，则可选用长方体壳体。
端盖30与壳体20密封连接，以形成用于容纳电极组件10和电解液的密封空间。示例性地，端盖30通过焊接与壳体20相连接。焊接可以同时实现端盖30与壳体20之间的密封和固定。
在一些示例中，壳体20沿第一方向X的一端具有开口20a，端盖30设置为一个并盖合于壳体20的开口20a。在另一些示例中，壳体20沿第一方向X的两端均具有 开口20a，端盖30设置为两个，两个端盖30分别盖合于壳体20的两个开口20a。
示例性地，第一方向X平行于端盖30的厚度方向。
电极组件10为电池单体7实现充放电功能的核心部件，其包括第一极片、第二极片和隔离件，第一极片和第二极片的极性相反，隔离件用于将第一极片和第二极片绝缘隔离。电极组件10主要依靠金属离子在第一极片和第二极片之间移动来工作。
第一极片和第二极片中的一者为正极极片，第一极片和第二极片中的另一者为负极极片。
电极组件10可以为卷绕式结构、叠片式结构或其它结构。第一极片可以为一个或多个，第二极片可以为一个或多个。第一极片和第二极片的数量可根据电极组件10的结构确定。
电极组件10可以为一个，也可以为多个，本实施例对此不作限制。
在一些实施例中，电池单体7还包括安装于端盖30的两个电极端子40，两个电极端子40分别用于与第一极片和第二极片电连接，以将电极组件10产生的电能导出。
在一些实施例中，电极组件10包括主体部11和连接于主体部11的极耳12。主体部11为电极组件10的电生成部，其内部的活性物质用于与电解液等发生电化学反应，以产生充放电过程。极耳12从主体部11的端部引出，并用于与电极端子40连接，以将主体部11产生的电能导出。
主体部11包括正极集流部、正极活性物质层、负极集流部、负极活性物质层和隔离件，极耳12包括正极极耳和负极极耳。
图5为本申请一些实施例提供的壳体的结构示意图；图6为图5所示的壳体在圆框A处的放大示意图；图7为图5所示的壳体的一剖视示意图；图8为图7在圆框B处的放大示意图；图9为图5所示的壳体的另一剖视示意图。
如图5至图9所示，本申请实施例提供了一种壳体20，壳体20沿第一方向X的端部具有开口20a。壳体20包括第一侧板21、第二侧板22以及第一连接板23，第一侧板21和第二侧板22沿开口20a的周向布置，第一连接板23连接于第一侧板21和第二侧板22之间，且第一连接板23的至少部分为弧形。第一侧板21包括第一板部211、第二板部212和第三板部213，第二板部212连接于第一板部211和第一连接板23之间，第三板部213位于第一板部211的靠近开口20a的一侧。第一板部211的厚度小于第二板部212的厚度以及第三板部213的厚度。
壳体20可以仅在沿第一方向X的一端设开口20a，也可以在沿第一方向X的两端均设开口20a。
示例性地，第一侧板21和第二侧板22大体为平行于第一方向X的板状结构。
第一侧板21可以为一个，也可以为多个，其数量可根据壳体20的形状设置。第二侧板22可以为一个，也可以为多个，其数量可根据壳体20的形状设置。
第一连接板23可以整体弯折为弧形，也可以仅部分弯折为弧形。在一些示例中，第一连接板23弯折为圆弧形。
根据开口20a的数量和位置，第三板部213可以设置于第一板部211沿第一方 向X的一侧，也可以设置于第一板部211沿第一方向X的两侧。
第一板部211连接于第二板部212。第一板部211可以直接连接于第二板部212，也可以经由第一侧板21的其它部分间接地连接于第二板部212。
第一板部211连接于第三板部213。第一板部211可以直接连接于第三板部213，也可以经由第一侧板21的其它部分间接地连接于第三板部213。
第二板部212连接于第三板部213。第二板部212可以直接连接于第三板部213，也可以经由第一侧板21的其它部分间接地连接于第三板部213。
第二板部212的厚度和第三板部213的厚度均大于第一板部211的厚度。本申请实施例对第二板部212和第三板部213之间的厚度关系不作限定，第二板部212的厚度可以大于、等于或小于第三板部213的厚度。
本实施例可减小第一侧板21的第一板部211的厚度，以增大壳体20的内部空间，为电极组件10和电解液预留更多的空间，从而提高电池单体7的能量密度，改善电池单体7的充放电性能。第一连接板23的弧形部分可以在壳体20的成型过程中释放应力，降低应力集中；第二板部212的厚度大于第一板部211的厚度，以使靠近第一连接板23的第二板部212具有高于第一板部211的强度，降低第二板部212在电池单体7受到外部冲击时开裂的风险，提供安全性。由于第三板部213的厚度大于第一板部211的厚度，所以第三板部213可用于与电池单体7的端盖30连接，以提高壳体20与端盖30的连接强度，降低壳体20开裂的风险，提高安全性。
在一些实施例中，第二板部212直接连接于第三板部213，以提高第一侧板21的整体强度，降低第一侧板21开裂的风险。
在一些实施例中，第二板部212的厚度等于第三板部213的厚度，以降低壳体20的成型难度。
在一些实施例中，第一板部211的厚度为T1，第二板部212的厚度为T2，T1和T2满足：0.05mm≤T2-T1≤1mm。
在T1的值确定时，T2越大，第二板部212的强度越高，但壳体20的内部空间越小；在T1的值确定时，T2越小，第二板部212的强度越低，但壳体20的内部空间越大。在T2的值确定时，T1越大，第一板部211的强度越高，但壳体20的内部空间越小；在T2的值确定时，T1越小，第一板部211的强度越低，但壳体20的内部空间越大。为了平衡壳体20的强度和壳体20的容量，本实施例将T2-T1的值限定在0.05mm-1mm。
在一些实施例中，T2-T1的值可为0.05mm、0.1mm、0.2mm、0.5mm、0.7mm、0.9mm或1mm。
在一些实施例中，T1和T2满足：0.1mm≤T2-T1≤0.7mm。
在一些实施例中，第一板部211的厚度T1为0.1mm-0.8mm。T1的值越小，第一板部211的强度越低，在电池单体7受到外部冲击时开裂的风险越高；T1的值越大，第一板部211的重量和占用的空间越大，电池单体7的能量密度越低。本实施例将第一板部211的厚度T1限定在0.1mm-0.8mm，以平衡壳体20的强度和电池单体7的能量密度。
可选地，第一板部211的厚度T1为0.1mm、0.3mm、0.5mm、0.7mm或0.8mm。
在一些实施例中，第二板部212的厚度T2为0.4mm-1.5mm。T2的值越小，第二板部212的强度越低，在电池单体7受到外部冲击时开裂的风险越高；T2的值越大，第二板部212的重量和占用的空间越大，电池单体7的能量密度越低。本实施例将第二板部212的厚度T1限定在0.4mm-1.5mm，以平衡壳体20的强度和电池单体7的能量密度。
可选地，第二板部212的厚度T2为0.4mm、0.5mm、0.8mm、1mm、1.2mm或1.5mm。
在一些实施例中，第一侧板21还包括第一过渡部214，第一过渡部214连接于第一板部211和第二板部212之间。沿第一板部211指向第二板部212的方向，第一过渡部214的厚度逐渐增大。
本实施例通过设置第一过渡部214，可以在第一板部211和第二板部212之间实现平滑过渡，降低壳体20成型难度，减小应力集中，降低第一侧板21开裂的风险。
在一些实施例中，第一过渡部214的内表面可以是斜面或弧面。
在一些实施例中，第一过渡部214的连接于第二板部212的一端的厚度等于第二板部212的厚度，第一过渡部214的连接于第一板部211的一端的厚度等于第一板部211的厚度。
在一些实施例中，第一板部211、第二板部212、第三板部213均为厚度均匀的平板结构。
在一些实施例中，第一板部211和第二板部212沿第二方向Y布置，第二方向Y垂直于第一方向X。第二板部212沿第二方向Y的尺寸为L1，第一过渡部214沿第二方向Y的尺寸为L2，L1与L2满足：0.2≤L1/L2≤5。
在L1+L2的值一定时，L1/L2的值越小，在壳体20成型过程中传递到第一过渡部214上的作用力越大，第一过渡部214开裂的风险越高；在L1+L2的值一定时，L1/L2的值越大，第一过渡部214的过渡面越陡峭，第一板部211和第二板部212之间形成的台阶越明显，壳体20成型的难度越高。本申请实施例将L1/L2的值限定在0.2-5，以平衡壳体20的成型难度和强度。
可选地，L1/L2的值为0.2、0.4、0.5、1、2、2.5或5。
在一些实施例中，第二板部212沿第二方向Y的尺寸L1为0.5mm-10mm。可选地，L1为0.5mm、1mm、2mm、5mm、8mm或10mm。
在一些实施例中，第一过渡部214沿第二方向Y的尺寸L2为0.5mm-10mm。可选地，L2为0.5mm、1mm、2mm、5mm、8mm或10mm。
在一些实施例中，壳体20包括两个第一侧板21和两个第二侧板22，两个第二侧板22沿第二方向Y相对设置，两个第一侧板21沿第三方向Z相对设置，第一方向X、第二方向Y和第三方向Z两两垂直。相邻的第一侧板21和第二侧板22通过第一连接板23连接。第一侧板21的第二板部212设置为两个，两个第二板部212分别设于第一板部211沿第二方向Y的两侧。
本实施例对第一侧板21的面积和第二侧板22的面积不作限定，第一侧板21的 面积可以大于、等于或小于第二侧板22的面积。
两个第一侧板21和两个第二侧板22沿开口20a的周向交替设置。示例性地，第一连接板23可为四个，各第一连接板23连接相邻的第一侧板21和第二侧板22。
两个第一连接板23分别通过两个第二板部212连接于第一板部211，在壳体20的成型过程中，第二板部212具有较高的强度，其可以承受从第一连接板23上传递的应力，从而降低开裂风险，提供安全性。
在一些实施例中，第一侧板21沿第二方向Y的尺寸大于第二侧板22沿第三方向Z的尺寸。
由于第一侧板21相较于第二侧板22具有较大的面积，所以第一侧板21能够减薄的区域较大，这样可以有效地增大壳体20的内部空间，提高电池单体7的容量。
在一些实施例中，第二板部212和第三板部213凸出于第一板部211的内表面。
在一些实施例中，第一板部211的外表面、第二板部212的外表面和第三板部213的外表面齐平。
第一板部211的外表面为第一板部211的背离电极组件10的表面，第二板部212的外表面为第二板部212的背离电极组件10的表面，第三板部213的外表面为第二板部212的背离电极组件10的表面。
本实施例可以保证第一侧板21的外表面的平整性，改善壳体20的外观。
在一些实施例中，第一侧板21还包括第二过渡部215，第二过渡部215连接于第一板部211和第三板部213之间。沿第一板部211指向第三板部213的方向，第二过渡部215的厚度逐渐增大。
第二过渡部215可以在第一板部211和第三板部213之间实现平滑过渡，降低壳体20成型难度，减小应力集中，降低第一侧板21开裂的风险。
在一些实施例中，第二过渡部215连接于第一过渡部214。
在一些实施例中，第二过渡部215的面向电极组件10的内表面可以是斜面或弧面。
第二过渡部215的连接于第三板部213的一端的厚度等于第三板部213的厚度，第二过渡部215的连接于第一板部211的一端的厚度等于第一板部211的厚度。
在一些实施例中，第三板部213沿第一方向X的尺寸为L3，第二过渡部215沿第一方向X的尺寸为L4，L3与L4满足：0.3≤L3/L4≤3。
在L3+L4的值一定时，L3/L4的值越小，第一侧板21的用于与端盖30相连的区域越小，壳体20与端盖30的连接强度越低，在装配壳体20和端盖30的过程中传递到第二过渡部215的作用力越大，第二过渡部215开裂的风险越高；在L3+L4的值一定时，L3/L4的值越大，第二过渡部215的过渡面越陡峭，第一板部211和第三板部213之间形成的台阶越明显，壳体20成型的难度越高。本申请实施例将L3/L4的值限定在0.3-3，以平衡壳体20的成型难度以及壳体20与端盖30之间的连接强度。
可选地，L3/L4的值为0.3、0.5、0.8、1、2或3。
在一些实施例中，第三板部213沿第一方向X的尺寸L3为0.3mm-10mm。可选地，L3为0.3mm、0.5mm、1mm、2mm、5mm、8mm或10mm。
在一些实施例中，第二过渡部215沿第一方向X的尺寸L4为0.3mm-10mm。可选地，L4为0.3mm、0.5mm、1mm、2mm、5mm、8mm或10mm。
在一些实施例中，第二侧板22设有凹部221，凹部221从第二侧板22的沿第一方向X的端面凹陷。第二侧板22的与凹部221的侧面221a对应的部分的厚度大于第一板部211的厚度。
凹部221的底面221b可用于支撑端盖30，并能够在端盖30伸入壳体20的过程中对端盖30进行限位，避免端盖30过度地伸入壳体20内。第二侧板22的与凹部221的侧面221a对应的部分可用于与端盖30连接，即使本实施例在第二侧板22上开设了凹部221，也能够保证第二侧板22的与凹部221的侧面221a对应的部分强度，降低第二侧板22开裂的风险。
在一些实施例中，凹部221的底面221b可为平面。凹部221的底面221b和凹部221的侧面221a之间的夹角可为80°-170°。
在一些实施例中，第二侧板22的与凹部221的侧面221a对应的部分焊接于端盖30。
在一些实施例中，第一连接板23上也设有凹部，第一连接板23的凹部从第一连接板23沿第一方向X的端面凹陷。示例性地，第一连接板23的凹部与第二侧板22的凹部221连通。
在一些实施例中，在第一方向X上，第三板部213的靠近第一板部211的一端超出凹部221的底面221b。
凹部221的底面221b用于支撑端盖30并限制端盖30的位置。在本实施例中，第三板部213的靠近第一板部211的一端超出凹部221的底面221b，这样可以使第三板部213的靠近第一板部211的一端超出端盖30，从而保证第一侧板21的连接于端盖30的部分的强度，降低第一侧板21开裂的风险，提高安全性。
第二侧板22具有面向电极组件10的内表面，第二侧板22的内表面连接于凹部221的底面221b。示例性地，第二侧板22的内表面为平面，且第二侧板22的内表面上未设置凹陷结构。
图10为图7在圆框C处的放大示意图；图11为图5所示的壳体的又一剖视示意图。
如图10和图11所示，在一些实施例中，在第一方向X上，第一板部211的背离第三板部213的一端与第二板部212的背离第三板部213的一端齐平。第二板部212可以将第一板部211和第一连接板23隔开，以降低第一板部211开裂的风险。
在一些实施例中，第三板部213和两个第二板部212形成U形结构，而第一板部211位于U形结构围成的区域内。
在一些实施例中，壳体20还包括第三侧板24和第二连接板25。第三侧板24和开口20a沿第一方向X相对设置，第二连接板25连接于第一侧板21和第三侧板24之间，且第二连接板25的至少部分为弧形。第一板部211直接连接于第二连接板25。
第二连接板25的弧形部分可以在壳体20的成型过程中释放应力，降低应力集中。第一板部211直接连接于第二连接板25，这样可以减小第一板部211与第二连接 板25连接处的台阶，降低电极组件10局部受压的风险，改善电极组件10的性能。
在一些实施例中，第二连接板25与第一板部211直接相连的端部的厚度等于第一板部211的厚度，以使第一板部211与第二连接板25连接处平滑过渡，降低第一板部211与第二连接板25连接处形成台阶的风险。
图12为本申请另一些实施例提供的壳体的结构示意图；图13为图12所示的壳体在圆框D处的放大示意图。
如图12和图13所示，在一些实施例中，第二侧板22在中部设置减薄区222，以增大壳体20的内部空间。可选地，第一侧板21为平板结构。
图14为本申请一些实施例提供的电池单体的一剖视示意图；图15为本申请一些实施例提供的电池单体的另一剖视示意图；图16为图15在圆框E处的放大示意图；图17为本申请一些实施例提供的电池单体的电极组件的剖视示意图。
如图14至图17所示，本申请实施例的电池单体7包括壳体20、电极组件10和端盖30。壳体20可为上述任一实施例的壳体20。电极组件10容纳于壳体20内，在第一侧板21的厚度方向上，电极组件10与第二板部212之间设有间隙G。端盖30用于盖合开口20a并连接于第三板部213。
电极组件10与第二板部212之间的间隙G可以降低第二板部212挤压电极组件10的风险，减小应力集中，改善电极组件10的充放电性能。由于第三板部213的厚度大于第一板部211的厚度，所以第三板部213可用于与端盖30连接，以提高壳体20与端盖30的连接强度，降低壳体20开裂的风险，提高安全性。
在一些实施例中，第一侧板21的厚度方向平行于第三方向Z。
在一些实施例中，第三板部213用于与端盖30焊接并形成焊接部W。在第一方向X上，第三板部213的靠近第一板部211的一端超出焊接部W。
在形成焊接部W之后，第三板部213的靠近焊接部W的区域会残留热应力。本实施例通过增大靠近开口20a的第三板部213的厚度，并使第三板部213的靠近第一板部211的一端超出焊接部W，以保证第一侧板21在焊接部W附近的区域的强度，降低第一侧板21开裂的风险，提高安全性。
在一些实施例中，电极组件10包括第一极片10a、隔离件10c和第二极片10b，隔离件10c用于将第一极片10a和第二极片10b绝缘隔离。本实施例可以将第一极片10a、隔离件和第二极片10b依次层叠并卷绕两圈以上以形成电极组件10。电极组件10呈扁平状。
在一些实施例中，电极组件10为卷绕结构且包括平直区111和弯折区112，弯折区112连接于平直区111沿第二方向Y的端部，第一方向X、第二方向Y和厚度方向两两垂直。在厚度方向上，第一板部211覆盖平直区111的至少部分，第二板部212覆盖弯折区112的至少部分，且第二板部212与弯折区112之间形成间隙G。厚度方向平行于第三方向Z。
各极片的位于平直区111的部分大体呈平直状态；各极片的位于弯折区112的部分大体呈弯折状态，例如，极片的位于弯折区112的部分可为圆弧状。
由于弯折区112呈弯折状态，其在厚度方向上占用的空间较小，因此，第二板 部212可以利用弯折区112预留出的空间来保证自身的厚度，并降低第二板部212挤压电极组件10的风险。
在一些实施例中，在厚度方向上，第二板部212不与平直区111重叠。
在一些实施例中，电极组件10的主体部11包括平直区111和弯折区112，极耳12从平直区111引出。
在一些实施例中，在厚度方向上，平直区111中的活性物质层(包括正极活性物质层和负极活性物质层)的投影位于第一板部211的投影内。
在一些实施例中，在厚度方向上，第三板部213与平直区111不重叠，以降低第三板部213挤压平直区111的风险，减小平直区111上的应力集中。
在一些实施例中，在厚度方向上，第三板部213与弯折区112不重叠，以降低第三板部213挤压弯折区112的风险，减小弯折区112上的应力集中。
在一些实施例中，电池单体7还包括绝缘构件50，绝缘构件50设置于端盖30的面向平直区111的一侧并与平直区111相抵。沿背离端盖30的方向，绝缘构件50的与平直区111的相抵的表面超出第一板部211的面向第三板部213的端部。
绝缘构件50能够将端盖30和平直区111绝缘隔离，以降低端盖30将平直区111中的正负极片导通的风险，提高安全性。绝缘构件50与平直区111沿第一方向X相抵，以在电池单体7震动时减小平直区111晃动幅度，降低正负极片错位的风险，改善电极组件10的充放电性能。绝缘构件50能够限制平直区111沿第一方向X的位置，以减小平直区111在电池单体7震动时碰撞第三板部213的可能性，降低第三板部213开裂的风险。
根据本申请的一些实施例，本申请还提供了一种电池，包括多个以上任一实施例的电池单体。
根据本申请的一些实施例，本申请还提供了一种用电装置，包括以上任一实施例的电池单体，电池单体用于为用电装置提供电能。用电装置可以是前述任一应用电池单体的设备或系统。
根据本申请的一些实施例，参见图5至图10，本申请提供了一种方形的壳体20，壳体20沿第一方向X的端部具有开口20a。壳体20包括两个第一侧板21、两个第二侧板22以及四个第一连接板23，两个第一侧板21和两个第二侧板22沿开口20a的周向交替布置，相邻的第一侧板21和第二侧板22通过一个第一连接板23连接。第一连接板23的至少部分为弧形。
第一侧板21包括第一板部211、两个第二板部212和第三板部213；两个第二板部212分别位于第一板部211的两侧，各第二板部212连接于第一板部211和对应的第一连接板23之间。第三板部213位于第一板部211的靠近开口20a的一侧。第二板部212的厚度等于第三板部213的厚度，且第二板部212的厚度大于第一板部211的厚度。
第一侧板21还包括第一过渡部214和第二过渡部215。第一过渡部214连接于第一板部211和第二板部212之间；沿第一板部211指向第二板部212的方向，第一过渡部214的厚度逐渐增大。第二过渡部215连接于第一板部211和第三板部213之间。 沿第一板部211指向第三板部213的方向，第二过渡部215的厚度逐渐增大。
以下结合实施例进一步说明本申请。
为了使本申请的发明目的、技术方案和有益技术效果更加清晰，以下结合实施例进一步详细描述本申请。但是，应当理解的是，本申请的实施例仅仅是为了解释本申请，并非为了限制本申请，且本申请的实施例并不局限于说明书中给出的实施例。实施例中未注明具体实验条件或操作条件的按常规条件制作，或按材料供应商推荐的条件制作。
实施例1可按照下述步骤制备：
(i)将正极活性物质NCM523、导电剂乙炔黑、粘结剂PVDF按质量比96:2:2进行混合，加入溶剂NMP，在真空搅拌机作用下搅拌至体系呈均一状，获得正极浆料；将正极浆料均匀涂覆在铝箔上，室温晾干后转移至烘箱继续干燥，然后经过冷压、分切、裁片得到第一极片。
(ii)将负极活性物质石墨或石墨与其它活性物质按不同质量比得到的混合物、导电剂乙炔黑、增稠剂CMC、粘结剂SBR按质量比96.4:1:1.2:1.4进行混合，加入溶剂去离子水，在真空搅拌机作用下搅拌至体系呈均一状，获得负极浆料；将负极浆料均匀涂覆在铜箔上，室温晾干后转移至烘箱继续干燥，然后经过冷压、分切、裁片得到第二极片。
(iii)将碳酸乙烯酯(EC)、碳酸甲乙酯(EMC)、碳酸二乙酯(DEC)按照按体积比1:1:1进行混合得到有机溶剂，接着将充分干燥的锂盐LiPF6溶解于混合后的有机溶剂中，配制成浓度为1mol/L的电解液。
(iv)以12μm厚的聚丙烯膜作为隔离件。
(v)将第一极片、隔离件及第二极片层叠在一起并卷绕为多圈，卷绕后再压平为扁平状，以制备出电极组件。
(Ⅵ)将电极组件装入方形壳体，并焊接壳体和端盖；然后经过注液、静置、化成、整形等工序，获得电池单体。
在步骤(Ⅵ)中，如图5和图18所示，壳体20沿第一方向X的尺寸为115mm，沿第二方向Y的尺寸为237.5mm，沿第三方向Z的尺寸为32mm。壳体20包括沿第三方向Z相对设置的两个第一侧板21，各第一侧板21沿第一方向X的尺寸D1为113mm，沿第二方向Y的尺寸D2为230mm。
第一侧板21包括第一板部211、两个第二板部212和第三板部213，第三板部213位于第一板部211沿第一方向X靠近开口的一侧，两个第二板部212分别位于第一板部211沿第二方向Y的两侧，两个第二板部212和第三板部213形成U形结构。第一板部211沿第一方向X的尺寸D3为103mm，第一板部211沿第二方向Y的尺寸D4为220mm，第二板部212沿第二方向Y的尺寸L1为5mm，第三板部213沿第一方向X的尺寸L3为10mm。第一板部211沿第三方向Z的厚度T1为0.5mm，第二板部212沿第三方向Z的厚度T2为0.7mm，第三板部213的厚度等于第二板部212的厚度。
实施例2：实施例2的电池单体的制备方法参照实施例1，不同之处在于T2为0.51mm。
实施例3：实施例3的电池单体的制备方法参照实施例1，不同之处在于T2为0.55mm。
实施例4：实施例4的电池单体的制备方法参照实施例1，不同之处在于T2为0.9mm。
实施例5：实施例5的电池单体的制备方法参照实施例1，不同之处在于T2为1mm。
实施例6：实施例6的电池单体的制备方法参照实施例1，不同之处在于T2为1.2mm。
实施例7：实施例7的电池单体的制备方法参照实施例1，不同之处在于T2为1.5mm。
对比例1：对比例1的电池单体的制备方法参照实施例1，不同之处在于，对比例1的第一侧板整体厚度为0.5mm。
实施例1-7和对比例1均制备100个电池单体，并对各电池单体进行密封性测试。
具体地，在常温环境下，将电池单体以1C倍率充电、以1C倍率放电，进行满充满放循环测试，直至电池单体的容量衰减至初始容量的80％；将电池单体放入真空箱内，并对真空箱进行抽真空，5个小时后，利用有机气体测试仪(VOC tester，型号ppbRAE-3000)检测真空箱中有机气体的含量，以判断电池单体是否出现泄漏。
实施例1-7和对比示例1的评估结果示出于表1中。
表1
Figure PCTCN2022086247-appb-000001
参照实施例1-7和对比例1，使第二板部的厚度大于第一板部的厚度，可减小壳体开裂的风险，提高电池单体的密封性和安全性。
需要说明的是，在不冲突的情况下，本申请中的实施例及实施例中的特征可以相互组合。
最后应说明的是：以上实施例仅用以说明本申请的技术方案，而非对其限制；尽管参照前述实施例对本申请进行了详细的说明，本领域的普通技术人员应当理解：其依然可以对前述各实施例所记载的技术方案进行修改，或者对其中部分技术特征进行等同替换，但这些修改或者替换，并不使相应技术方案的本质脱离本申请各实施例技术方案的精神和范围。

Claims (26)

  1. 一种电池单体的壳体，沿第一方向的端部具有开口；所述壳体包括第一侧板、第二侧板以及第一连接板，所述第一侧板和所述第二侧板沿所述开口的周向布置，所述第一连接板连接于所述第一侧板和所述第二侧板之间，且所述第一连接板的至少部分为弧形；
    所述第一侧板包括第一板部、第二板部和第三板部，所述第二板部连接于所述第一板部和所述第一连接板之间，所述第三板部位于所述第一板部的靠近所述开口的一侧；
    所述第一板部的厚度小于所述第二板部的厚度以及所述第三板部的厚度。
  2. 根据权利要求1所述的壳体，其中，所述第二板部直接连接于所述第三板部。
  3. 根据权利要求1或2所述的壳体，其中，所述第二板部的厚度等于所述第三板部的厚度。
  4. 根据权利要求1-3任一项所述的壳体，其中，所述第一板部的厚度为T1，所述第二板部的厚度为T2，T1和T2满足：0.05mm≤T2-T1≤1mm。
  5. 根据权利要求4所述的壳体，其中，T1和T2满足：0.1mm≤T2-T1≤0.7mm。
  6. 根据权利要求4或5所述的壳体，其中，所述第一板部的厚度T1为0.1mm-0.8mm，所述第二板部的厚度T2为0.4mm-1.5mm。
  7. 根据权利要求1-6任一项所述的壳体，其中，所述第一侧板还包括第一过渡部，所述第一过渡部连接于所述第一板部和所述第二板部之间；
    沿所述第一板部指向所述第二板部的方向，所述第一过渡部的厚度逐渐增大。
  8. 根据权利要求7所述的壳体，其中，所述第一板部和所述第二板部沿第二方向布置，所述第二方向垂直于所述第一方向；
    所述第二板部沿所述第二方向的尺寸为L1，所述第一过渡部沿所述第二方向的尺寸为L2，L1与L2满足：0.2≤L1/L2≤5。
  9. 根据权利要求8所述的壳体，其中，所述第二板部沿所述第二方向的尺寸L1为0.5mm-10mm，所述第一过渡部沿所述第二方向的尺寸L2为0.5mm-10mm。
  10. 根据权利要求1-9任一项所述的壳体，其中，在所述第一方向上，所述第一板部的背离所述第三板部的一端与所述第二板部的背离所述第三板部的一端齐平。
  11. 根据权利要求1-10任一项所述的壳体，还包括第三侧板和第二连接板；
    所述第三侧板和所述开口沿所述第一方向相对设置，所述第二连接板连接于所述第一侧板和所述第三侧板之间，且所述第二连接板的至少部分为弧形；
    所述第一板部直接连接于所述第二连接板。
  12. 根据权利要求1-11任一项所述的壳体，包括两个所述第一侧板和两个所述第二侧板，两个所述第二侧板沿第二方向相对设置，两个所述第一侧板沿第三方向相对设置，所述第一方向、所述第二方向和所述第三方向两两垂直；
    相邻的所述第一侧板和所述第二侧板通过所述第一连接板连接；
    所述第一侧板的所述第二板部设置为两个，两个所述第二板部分别设于所述第一板部沿所述第二方向的两侧。
  13. 根据权利要求12所述的壳体，其中，所述第一侧板沿所述第二方向的尺寸大于所述第二侧板沿所述第三方向的尺寸。
  14. 根据权利要求1-13任一项所述的壳体，其中，所述第一板部的外表面、所述第二板部的外表面和所述第三板部的外表面齐平；
    所述第二板部和所述第三板部凸出于所述第一板部的内表面。
  15. 根据权利要求1-14任一项所述的壳体，其中，所述第一侧板还包括第二过渡部，所述第二过渡部连接于所述第一板部和所述第三板部之间；
    沿所述第一板部指向所述第三板部的方向，所述第二过渡部的厚度逐渐增大。
  16. 根据权利要求15所述的壳体，其中，所述第三板部沿所述第一方向的尺寸为L3，所述第二过渡部沿所述第一方向的尺寸为L4，L3与L4满足：0.3≤L3/L4≤3。
  17. 根据权利要求16所述的壳体，其中，所述第三板部沿所述第一方向的尺寸L3为0.3mm-10mm，所述第二过渡部沿所述第一方向的尺寸L4为0.3mm-10mm。
  18. 根据权利要求1-17任一项所述的壳体，其中，所述第二侧板设有凹部，所述凹部从所述第二侧板的沿所述第一方向的端面凹陷；
    所述第二侧板的与所述凹部的侧面对应的部分的厚度大于所述第一板部的厚度。
  19. 根据权利要求18所述的壳体，其中，在所述第一方向上，所述第三板部的靠近所述第一板部的一端超出所述凹部的底面。
  20. 一种电池单体，包括：
    根据权利要求1-19任一项所述的壳体；
    电极组件，容纳于所述壳体内，在所述第一侧板的厚度方向上，所述电极组件与所述第二板部之间设有间隙；以及
    端盖，用于盖合所述开口并连接于所述第三板部。
  21. 根据权利要求20所述的电池单体，其中，所述第三板部用于与所述端盖焊接并形成焊接部；在所述第一方向上，所述第三板部的靠近所述第一板部的一端超出所述焊接部。
  22. 根据权利要求20或21所述的电池单体，其中，所述电极组件为卷绕结构且包括平直区和弯折区，所述弯折区连接于所述平直区沿第二方向的端部，所述第一方向、所述第二方向和所述厚度方向两两垂直；
    在所述厚度方向上，所述第一板部覆盖所述平直区的至少部分，所述第二板部覆盖所述弯折区的至少部分，且所述第二板部与所述弯折区之间形成间隙。
  23. 根据权利要求22所述的电池单体，其中，在所述厚度方向上，所述第三板部与所述平直区不重叠，所述第三板部与所述弯折区不重叠。
  24. 根据权利要求22或23所述的电池单体，还包括绝缘构件，所述绝缘构件设置于所述端盖的面向平直区的一侧并与所述平直区相抵；
    沿背离所述端盖的方向，所述绝缘构件的与所述平直区的相抵的表面超出所述第一板部的面向所述第三板部的端部。
  25. 一种电池，包括多个根据权利要求1-24中任一项所述的电池单体。
  26. 一种用电装置，包括根据权利要求1-24中任一项所述的电池单体，所述电池单体用于提供电能。
PCT/CN2022/086247 2022-04-12 2022-04-12 电池单体的壳体、电池单体、电池以及用电装置 WO2023197133A1 (zh)

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Publication number Priority date Publication date Assignee Title
CN206516680U (zh) * 2017-01-20 2017-09-22 深圳市瑞德丰精密制造有限公司 壳体的减重结构和电池
CN209401692U (zh) * 2019-01-25 2019-09-17 宁德时代新能源科技股份有限公司 二次电池
CN209766480U (zh) * 2019-03-21 2019-12-10 合肥国轩高科动力能源有限公司 一种锂电池轻量化壳体
CN212571170U (zh) * 2020-08-19 2021-02-19 江苏塔菲尔新能源科技股份有限公司 一种电芯壳体和电池
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Publication number Priority date Publication date Assignee Title
CN206516680U (zh) * 2017-01-20 2017-09-22 深圳市瑞德丰精密制造有限公司 壳体的减重结构和电池
CN209401692U (zh) * 2019-01-25 2019-09-17 宁德时代新能源科技股份有限公司 二次电池
CN209766480U (zh) * 2019-03-21 2019-12-10 合肥国轩高科动力能源有限公司 一种锂电池轻量化壳体
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