Battery monomer, battery and electric device

Abstract

The utility model provides a battery monomer, a battery and a power utilization device. The battery monomer comprises an electrode assembly, a shell, a first end cover and a second end cover, the shell is provided with a first opening and a second opening, the first opening and the second opening are located at the two ends of the shell in the first direction respectively, the shell comprises a main body part, a first thickening part and a second thickening part, and the main body part is arranged around the electrode assembly; the first thickening part is connected to the main body part and arranged in the circumferential direction of the first opening, the second thickening part is connected to the main body part and arranged in the circumferential direction of the second opening, the thickness of the first thickening part is larger than that of the main body part, and the thickness of the second thickening part is larger than that of the main body part. The first end cover is connected to the first thickened part and covers the first opening. The second end cover is connected to the second thickened part and covers the second opening. According to the invention, the reliability of the battery monomer can be effectively improved.

Description

Technical Field

[0001] The present application relates to the technical field of batteries, and particularly to a battery cell, a battery, and an electrical device. Background Art

[0002] With the development of new energy technologies, batteries are increasingly widely used, such as in mobile phones, laptops, battery-powered vehicles, electric vehicles, electric airplanes, electric ships, electric toy cars, electric toy ships, electric toy airplanes, and power tools.

[0003] In the development of battery technologies, the reliability of battery cells directly affects the reliability, usage cost, and user experience of end products. Therefore, how to effectively improve the reliability of battery cells is an urgent technical problem in battery technologies. Summary of the Utility Model

[0004] In view of the above problems, the present application provides a battery cell, a battery, and an electrical device, which can effectively improve the reliability of the battery cell.

[0005] In a first aspect, an embodiment of the present application provides a battery cell. The battery cell includes an electrode assembly, a housing, a first end cap, and a second end cap. The housing has a first opening and a second opening, and the first opening and the second opening are respectively located at two ends of the housing along a first direction. The housing includes a main body portion, a first thickened portion, and a second thickened portion. The main body portion surrounds the electrode assembly. The first thickened portion is connected to the main body portion and is arranged along the circumference of the first opening. The second thickened portion is connected to the main body portion and is arranged along the circumference of the second opening. The thickness of the first thickened portion is greater than the thickness of the main body portion, and the thickness of the second thickened portion is greater than the thickness of the main body portion. The first end cap is connected to the first thickened portion and covers the first opening. The second end cap is connected to the second thickened portion and covers the second opening.

[0006] The above technical solution sets a first thickened portion with a relatively thick thickness along the circumference of the first opening on the housing, and connects the first end cap to the first thickened portion. The relatively thick first thickened portion has higher structural strength to improve the structural strength after the first end cap and the housing are combined, and reduce the risk of cracking and failure at the connection position between the first end cap and the housing. By setting a second thickened portion with a relatively thick thickness along the circumference of the second opening on the housing, and connecting the second end cap to the second thickened portion, the relatively thick second thickened portion has higher structural strength to improve the structural strength after the second end cap and the housing are combined, and reduce the risk of cracking and failure at the connection position between the second end cap and the housing. Thus, the reliability of the battery cell can be effectively improved.

[0007] In some embodiments of the first aspect, the first thickened portion protrudes from the inner surface of the main body portion.

[0008] The inner surface of the main body part is the surface of the main body part facing the electrode assembly, and the first thickening part protrudes towards the inside of the housing. When the thickness of the first thickening part is constant, the first thickening part protruding from the inner surface of the main body part can reduce the occupancy rate of the first thickening part in the outer space of the housing, thereby reducing the maximum size of the housing, making full use of the inner space of the housing, and being beneficial to improving the energy density of the battery cell.

[0009] In some embodiments of the first aspect, the first thickening part protrudes relative to the outer surface of the main body part.

[0010] The outer surface of the main body part is the surface of the main body part facing away from the electrode assembly, and the first thickening part protrudes towards the outside of the housing. When the thickness of the first thickening part is constant, the first thickening part protruding from the outer surface of the main body part can reduce the occupancy rate of the first thickening part in the inner space of the housing, thereby reducing the risk of interference between the first thickening part and the electrode assembly, and being beneficial to further improving the reliability of the battery cell.

[0011] In some embodiments of the first aspect, the second thickening part protrudes relative to the inner surface of the main body part.

[0012] The inner surface of the main body part is the surface of the main body part facing the electrode assembly, and the second thickening part protrudes towards the inside of the housing. When the thickness of the second thickening part is constant, the second thickening part protruding from the inner surface of the main body part can reduce the occupancy rate of the second thickening part in the outer space of the housing, thereby reducing the maximum size of the housing, making full use of the inner space of the housing, and being beneficial to improving the energy density of the battery cell.

[0013] In some embodiments of the first aspect, the second thickening part protrudes relative to the outer surface of the main body part.

[0014] The outer surface of the main body part is the surface of the main body part facing away from the electrode assembly, and the second thickening part protrudes towards the outside of the housing. When the thickness of the second thickening part is constant, the second thickening part protruding from the outer surface of the main body part can reduce the occupancy rate of the second thickening part in the inner space of the housing, thereby reducing the risk of interference between the second thickening part and the electrode assembly, and being beneficial to further improving the reliability of the battery cell.

[0015] In some embodiments of the first aspect, the first thickening part surrounds the first opening.

[0016] It can further improve the structural strength after the first end cover is fitted with the housing, thereby further improving the energy density of the battery cell.

[0017] In some embodiments of the first aspect, the second thickening part surrounds the second opening.

[0018] It can further improve the structural strength after the second end cap is fitted with the housing, thereby further increasing the energy density of the battery cell.

[0019] In some embodiments of the first aspect, in the first direction, one end of the first thickened portion close to the electrode assembly extends beyond the first end cap.

[0020] It can further ensure the strength after the first end cap is fitted with the housing, thereby further improving the reliability of the battery cell.

[0021] In some embodiments of the first aspect, in the first direction, one end of the second thickened portion close to the electrode assembly extends beyond the second end cap.

[0022] It can further ensure the strength after the second end cap is fitted with the housing, thereby further improving the reliability of the battery cell.

[0023] In some embodiments of the first aspect, the electrode assembly includes a first electrode tab. The first electrode tab includes a first coating area and a first tab extending from an end of the first coating area in the first direction. The first thickened portion protrudes from the inner surface of the main body portion, and in a direction perpendicular to the first direction, the first coating area does not overlap with the first thickened portion.

[0024] When the first thickened portion protrudes from the inner surface of the main body portion, the first coating area does not overlap with the first thickened portion in a direction perpendicular to the first direction, which can reduce the risk of affecting the electrical performance of the electrode assembly due to interference between the first thickened portion and the first coating area. Thus, while reducing the maximum size of the housing and making full use of the internal space of the housing to increase the energy density of the battery cell, the adverse effect of the first thickened portion on the electrode assembly can be reduced.

[0025] In some embodiments of the first aspect, the electrode assembly further includes a separator. The separator covers the first coating area, and in a direction perpendicular to the first direction, the separator does not overlap with the first thickened portion.

[0026] When the first thickened portion protrudes from the inner surface of the main body portion, the separator does not overlap with the first thickened portion in a direction perpendicular to the first direction, which can reduce the risk of insulation failure between the first electrode tab and the second electrode tab due to interference between the first thickened portion and the separator. Thus, while reducing the maximum size of the housing and making full use of the internal space of the housing to increase the energy density of the battery cell, the adverse effect of the first thickened portion on the electrode assembly can be further reduced.

[0027] In some embodiments of the first aspect, the electrode assembly has a flat area. The flat area includes a plurality of electrode tabs stacked along a second direction, and the first direction intersects the second direction.

[0028] The above technical solution can reduce the influence of the expansion of the electrode assembly itself on the first end cover and the second end cover, thereby further reducing the risk of cracking and failure at the connection position between the first end cover and the housing, and further reducing the risk of cracking and failure at the connection position between the second end cover and the housing.

[0029] In some embodiments of the first aspect, the battery cell further includes a bracket, and the bracket is connected between the first end cover and the electrode assembly. The size of the first thickened portion in the first direction is greater than the size of the second thickened portion in the first direction.

[0030] The provision of a bracket between the first end cover and the electrode assembly also provides a relatively large space between the first end cover and the electrode assembly in the first direction, thereby enabling an increase in the size range of the first thickened portion in the first direction. Thus, by increasing the size of the first thickened portion in the first direction, the above technical solution can further improve the strength of the first end cover after being fitted with the housing.

[0031] In some embodiments of the first aspect, the first end cover includes a first cover body and a first extension portion. The first extension portion is connected to the first cover body and protrudes from a surface of the first cover body close to the housing. At least a part of the first extension portion is located inside the housing and is connected to the first thickened portion, and the first cover body is located outside the housing and is connected to the first thickened portion.

[0032] The introduction of the first extension portion can increase the overall contact area between the first end cover and the first thickened portion, thereby further improving the connection strength between the first end cover and the housing.

[0033] In some embodiments of the first aspect, the second end cover includes a second cover body and a second extension portion. The second extension portion is connected to the second cover body and protrudes from a surface of the second cover body close to the housing. At least a part of the second extension portion is located inside the housing and is connected to the second thickened portion, and the second cover body is located outside the housing and is connected to the second thickened portion.

[0034] The introduction of the second extension portion can increase the overall contact area between the second end cover and the second thickened portion, thereby further improving the connection strength between the second end cover and the housing.

[0035] In some embodiments of the first aspect, the battery cell further includes a pressure relief mechanism. The housing includes two relatively arranged first side plates, and the pressure relief mechanism is arranged on one of the two first side plates.

[0036] Compared with the first end cover and the second end cover, the area of the first side plate is relatively large. Thus, arranging the pressure relief mechanism on the first side plate can reduce the difficulty of arranging the pressure relief mechanism.

[0037] In some embodiments of the first aspect, a weld seam is provided on the other of the two first side plates.

[0038] By arranging the weld seam on the first side plate without the pressure relief mechanism among the two first side plates, the influence of the weld seam on the pressure relief mechanism can be reduced, thereby improving the reliability of the pressure relief mechanism.

[0039] In some embodiments of the first aspect, the main body portion and the first thickened portion are of an integrally formed structure.

[0040] On the one hand, there is no need to connect the main body portion and the first thickened portion through an additional connection process, which simplifies the manufacturing process flow. At the same time, compared with connecting the main body portion and the first thickened portion through an additional connection process, the connection between the main body portion and the first thickened portion in an integrated structure has higher connection firmness.

[0041] In some embodiments of the first aspect, the main body portion and the second thickened portion are of an integrally formed structure.

[0042] On the one hand, there is no need to connect the main body portion and the second thickened portion through an additional connection process, which simplifies the manufacturing process flow. At the same time, compared with connecting the main body portion and the second thickened portion through an additional connection process, the connection between the main body portion and the second thickened portion in an integrated structure has higher connection firmness.

[0043] In some embodiments of the first aspect, the first end cap is welded to the housing. The welding has high reliability, is convenient and fast, and has low cost.

[0044] In some embodiments of the first aspect, the second end cap is welded to the housing. The welding has high reliability, is convenient and fast, and has low cost.

[0045] In the second aspect, the present application provides a battery, which includes the battery cell provided in any embodiment of the first aspect.

[0046] In some embodiments of the second aspect, a plurality of battery cells are sequentially arranged in contact with each other along the second direction. The first thickened portion protrudes from the inner surface of the main body portion, the second thickened portion protrudes from the inner surface of the main body portion, and the first direction intersects with the second direction.

[0047] When a plurality of battery cells are sequentially arranged in contact with each other along the second direction, the first thickened portion protrudes from the inner surface of the main body portion, and the second thickened portion protrudes from the inner surface of the main body portion, so that the first thickened portion and the second thickened portion will not cause a gap between two adjacent battery cells, which can improve the structural compactness of the battery, thereby being beneficial to improving the overall energy density of the battery.

[0048] In some embodiments of the second aspect, a plurality of battery cells are arranged at intervals along a second direction. A first thickening portion protrudes relative to the outer surface of the main body portion, and a second thickening portion protrudes relative to the outer surface of the main body portion. The first direction and the second direction intersect. The battery cell further includes a separating member disposed between the main body portions of two adjacent battery cells, and in the second direction, the separating member does not overlap with the first thickening portion, and the separating member does not overlap with the second thickening portion.

[0049] In the above technical solution, by disposing the separating member between the main body portions of two adjacent battery cells, on the one hand, the accommodation space jointly formed by the first thickening portion and the second thickening portion of two adjacent battery cells can be fully utilized to improve the space utilization rate of the battery, making the structure of the battery more compact and reliable, which is beneficial to improving the energy density of the battery. On the other hand, the displacement of the separating member can be restricted by the first thickening portion and the second thickening portion, improving the reliability of the battery. In addition, in the second direction, the separating member does not overlap with the first thickening portion, and the separating member does not overlap with the second thickening portion, which can reduce the risk of the first thickening portion and the second thickening portion interfering with the separating member and causing damage to the separating member.

[0050] In a third aspect, the present application provides an electrical device, which includes the battery provided in any one of the embodiments of the first aspect, and the battery is used to provide electrical energy.

[0051] The above description is only an overview of the technical solution of the present application. In order to be able to understand the technical means of the present application more clearly, it can be implemented according to the content of the specification. And in order to make the above and other purposes, features and advantages of the present application more obvious and understandable, the specific embodiments of the present application are specifically exemplified below. BRIEF DESCRIPTION OF THE DRAWINGS

[0052] By reading the following detailed description of the preferred embodiments, various other advantages and benefits will become clear to those of ordinary skill in the art. The drawings are only for the purpose of showing the preferred embodiments and are not considered to be a limitation of the present application. And throughout the drawings, the same reference numerals are used to represent the same components. In the drawings:

[0053] Figure 1 is a schematic structural diagram of a vehicle provided in some embodiments of the present application;

[0054] Figure 2 is an exploded structural diagram of a battery provided in some embodiments of the present application;

[0055] Figure 3 is a schematic structural diagram of a battery module provided in some embodiments of the present application;

[0056] Figure 4 is a schematic three-dimensional structural diagram of a battery cell provided in some embodiments of the present application;

[0057] Figure 5 is Figure 4 Schematic diagram of the explosion structure of the battery cell shown;

[0058] Figure 6 is Figure 4 Schematic diagram of the side view structure of the battery cell shown;

[0059] Figure 7 is Figure 6 Schematic diagram of the sectional structure along A-A;

[0060] Figure 8 is Figure 7 Schematic diagram of the enlarged local structure at F of;

[0061] Figure 9 is Figure 7 Schematic diagram of the enlarged local structure at H of;

[0062] Figure 10 Front view structure diagram of another battery cell provided by some embodiments of the present application;

[0063] Figure 11 is Figure 10 Schematic diagram of the enlarged local structure at G of;

[0064] Figure 12 is Figure 10 Schematic diagram of the enlarged local structure at K of;

[0065] Figure 13 Local structure diagram of a battery provided by some embodiments of the present application;

[0066] Figure 14 is Figure 13 Schematic diagram of the enlarged local structure at M of;

[0067] Figure 15 is Figure 13 Schematic diagram of the enlarged local structure at N of.

[0068] The reference numerals in the specific embodiments are as follows:

[0069] 1. Vehicle; 2. Battery; 3. Controller; 4. Motor; 5. Box body; 5a. First box body part; 5b. Second box body part; 5c. Accommodating space; 6. Battery module; 7. Battery cell;

[0070] 10. Electrode assembly; 20. Housing; 21a. First opening; 21b. Second opening; 22. Main body; 23a. First thickened part; 23b. Second thickened part; 24. First side plate; 30a. First end cap; 30b. Second end cap; 31. First cap main body; 32. First extension part; 33. Second cap main body; 34. Second extension part; 40. Bracket; 50. Pressure relief mechanism; 60. Partition member; X. First direction; Y. Second direction. Detailed implementation manners

[0071] To make the objectives, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present application. Apparently, the described embodiments are some but not all of the embodiments of the present application. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present application without creative efforts shall fall within the scope of protection of the present application.

[0072] Unless otherwise defined, all technical and scientific terms used in the present application have the same meaning as commonly understood by those skilled in the technical field to which the present application belongs; the terms used in the description of the present application are only for the purpose of describing specific embodiments and are not intended to limit the present application; the terms "including" and "having" and any variations thereof in the description and claims of the present application and the above drawings are intended to cover non-exclusive inclusion. The terms "first", "second", etc. in the description and claims of the present application or the above drawings are used to distinguish different objects and not to describe a specific order or primary-secondary relationship.

[0073] Referring to "embodiments" in the present application means that specific features, structures or characteristics described in connection with the embodiments can be included in at least one embodiment of the present application. The phrase appears in various places in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment mutually exclusive with other embodiments.

[0074] In the description of the present application, it should be noted that unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "attached" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be directly connected, or indirectly connected through an intermediate medium, and it can be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present application can be understood according to specific situations.

[0075] In this application, the term "and / or" is merely a description of the relationship between associated objects, indicating that there can be three relationships. For example, A and / or B can represent: A exists alone, A and B exist simultaneously, and B exists alone. Additionally, in this application, the character " / " generally indicates that the associated objects before and after are in an "or" relationship.

[0076] In the embodiments of this application, the same reference numerals represent the same components. For the sake of brevity, in different embodiments, the detailed description of the same components is omitted. It should be understood that the thickness, length, width, etc. of various components shown in the drawings in the embodiments of this application, as well as the overall thickness, length, width, etc. of the integrated device, are only for illustrative purposes and should not constitute any limitation to this application.

[0077] The term "a plurality of" as used in this application refers to two or more (including two).

[0078] In this application, the term "parallel" includes not only the case of absolute parallelism but also the case of approximately parallel as conventionally understood in engineering; at the same time, "perpendicular" also includes not only the case of absolute perpendicularity but also the case of approximately perpendicular as conventionally understood in engineering.

[0079] In the embodiments of this application, the battery cell can be a secondary battery cell, which refers to a battery cell that can be activated by charging after discharging so that the active material can be used continuously.

[0080] The battery cell can be a lithium-ion battery cell, a sodium-ion battery cell, a sodium-lithium-ion battery cell, a lithium-metal battery cell, a sodium-metal battery cell, a lithium-sulfur battery cell, a magnesium-ion battery cell, a nickel-metal hydride battery cell, a nickel-cadmium battery cell, a lead-acid battery cell, etc., and the embodiments of this application are not limited thereto.

[0081] The battery cell generally includes an electrode assembly. The electrode assembly includes a positive electrode and a negative electrode. During the charging and discharging process of the battery cell, active ions (such as lithium ions) are embedded and extracted back and forth between the positive electrode and the negative electrode.

[0082] In some embodiments, the electrode assembly further includes a separator, which is disposed between the positive electrode and the negative electrode, can play a role in preventing short circuit between the positive and negative electrodes, and at the same time allows active ions to pass through.

[0083] In some embodiments, the positive electrode can be a positive electrode sheet, and the positive electrode sheet can include a positive electrode current collector and a positive electrode active material layer disposed on at least one surface of the positive electrode current collector.

[0084] In some embodiments, the negative electrode can be a negative electrode sheet, and the negative electrode sheet can include a negative electrode current collector and a negative electrode active material layer disposed on at least one surface of the negative electrode current collector.

[0085] In some embodiments, the battery cell further includes an electrolyte, which plays a role in conducting ions between the positive and negative electrodes. The present application does not specifically limit the type of electrolyte, and it can be selected according to requirements. The electrolyte can be liquid, gel-like, or solid-state.

[0086] In some embodiments, the liquid electrolyte includes an electrolyte salt and a solvent.

[0087] In some embodiments, the electrolyte salt can be selected from at least one of lithium hexafluorophosphate, lithium tetrafluoroborate, lithium perchlorate, lithium hexafluoroarsenate, lithium bis(fluorosulfonyl)imide, lithium bis(trifluoromethanesulfonyl)imide, lithium trifluoromethanesulfonate, lithium difluorophosphate, lithium difluoro(oxalato)borate, lithium bis(oxalato)borate, lithium difluoro bis(oxalato)phosphate, and lithium tetrafluoro(oxalato)phosphate.

[0088] In some embodiments, the solvent can be selected from at least one of ethylene carbonate, propylene carbonate, ethyl methyl carbonate, diethyl carbonate, dimethyl carbonate, dipropyl carbonate, methyl propyl carbonate, ethyl propyl carbonate, butylene carbonate, fluoroethylene carbonate, methyl formate, methyl acetate, ethyl acetate, propyl acetate, methyl propionate, ethyl propionate, propyl propionate, methyl butyrate, ethyl butyrate, 1,4-butyrolactone, sulfolane, dimethyl sulfone, methyl ethyl sulfone, and diethyl sulfone. The solvent can also be an ether solvent. The ether solvent can include one or more of ethylene glycol dimethyl ether, ethylene glycol diethyl ether, diethylene glycol dimethyl ether, triethylene glycol dimethyl ether, tetraethylene glycol dimethyl ether, 1,3-dioxolane, tetrahydrofuran, methyltetrahydrofuran, diphenyl ether, and crown ether.

[0089] The gel-like electrolyte includes a polymer as the skeletal network of the electrolyte, combined with an ionic liquid-lithium salt.

[0090] The solid-state electrolyte includes a polymer solid-state electrolyte, an inorganic solid-state electrolyte, and a composite solid-state electrolyte.

[0091] As an example, the polymer solid-state electrolyte can be polyether (polyethylene oxide), polysiloxane, polycarbonate, polyacrylonitrile, polyvinylidene fluoride, polymethyl methacrylate, single-ion polymer, poly(ionic liquid)-lithium salt, cellulose, etc.

[0092] As an example, the inorganic solid-state electrolyte can be an oxide solid electrolyte (crystalline perovskite, sodium superionic conductor, garnet, amorphous LiPON film), a sulfide solid electrolyte (crystalline lithium superionic conductor (lithium germanium phosphorus sulfur, argyrodite), amorphous sulfide), and one or more of a halide solid electrolyte, a nitride solid electrolyte, and a hydride solid electrolyte.

[0093] As an example, the composite solid-state electrolyte is formed by adding an inorganic solid-state electrolyte filler to the polymer solid electrolyte.

[0094] In some embodiments, the electrode assembly has a wound structure. The positive electrode sheet and the negative electrode sheet are wound into a wound structure.

[0095] In some embodiments, the electrode assembly has a stacked structure.

[0096] As an example, multiple positive electrode sheets and multiple negative electrode sheets may be provided respectively, and the multiple positive electrode sheets and the multiple negative electrode sheets are alternately stacked.

[0097] As an example, multiple positive electrode sheets may be provided, and the negative electrode sheet is folded to form multiple stacked folding segments, and a positive electrode sheet is clamped between adjacent folding segments.

[0098] As an example, both the positive electrode sheet and the negative electrode sheet are folded to form multiple stacked folding segments.

[0099] As an example, multiple separators may be provided and are respectively disposed between any adjacent positive electrode sheet or negative electrode sheet.

[0100] As an example, the separators may be continuously provided and are disposed between any adjacent positive electrode sheet or negative electrode sheet by folding or winding.

[0101] In some embodiments, the shape of the electrode assembly may be cylindrical, flat, prismatic, or the like.

[0102] In some embodiments, the electrode assembly is provided with tabs, and the tabs can conduct current out of the electrode assembly. The tabs include a positive tab and a negative tab.

[0103] In some embodiments, the battery cell may include a housing. The housing is used to encapsulate components such as the electrode assembly and the electrolyte. The housing may be a steel shell, an aluminum shell, a plastic shell (such as polypropylene), a composite metal shell (such as a copper-aluminum composite housing), or an aluminum-plastic film, or the like.

[0104] As an example, the battery cell may be a cylindrical battery cell, a prismatic battery cell, a soft-pack battery cell, or a battery cell of other shapes. The prismatic battery cell includes a square-shell battery cell, a blade-shaped battery cell, a multi-prismatic battery, and the multi-prismatic battery is, for example, a hexagonal-prismatic battery, etc.

[0105] The battery mentioned in the embodiments of the present application refers to a single physical module including one or more battery cells to provide a higher voltage and capacity.

[0106] In some embodiments, the battery may be a battery module. When there are multiple battery cells, the multiple battery cells are arranged and fixed to form a battery module.

[0107] In some embodiments, the battery may be a battery pack. The battery pack includes a box body and battery cells, and the battery cells or the battery module are accommodated in the box body.

[0108] In some embodiments, the box body can be part of the chassis structure of a vehicle. For example, a part of the box body can form at least a part of the floor of the vehicle, or a part of the box body can form at least a part of the cross beams and longitudinal beams of the vehicle.

[0109] In some embodiments, the battery can be an energy storage device. The energy storage device includes an energy storage container, an energy storage electrical cabinet, etc.

[0110] With the development of new energy technologies, batteries are more and more widely used, such as in mobile phones, laptop computers, battery cars, electric vehicles, electric airplanes, electric ships, electric toy cars, electric toy ships, electric toy airplanes, and electric tools, etc.

[0111] In the development of battery technologies, the reliability of battery cells will directly affect the reliability, usage cost, and user experience of end products. After the end cap of a battery cell is welded to the housing, a heat affected zone often forms near the weld pool. The heat affected zone is subjected to the action of residual thermal stress, resulting in the strength of the heat affected zone being lower than that of other regions. During the use of the battery cell, when the heat affected zone is squeezed or vibrated, the housing is prone to cracking in the heat affected zone, resulting in electrolyte leakage and causing the battery cell to fail, thus seriously affecting the reliability of the battery cell.

[0112] Based on the above considerations, the embodiments of the present application provide a battery cell. The battery cell includes an electrode assembly, a housing, a first end cap, and a second end cap. The housing has a first opening and a second opening, and the first opening and the second opening are respectively located at both ends of the housing along a first direction. The housing includes a main body portion, a first thickening portion, and a second thickening portion. The main body portion surrounds the electrode assembly. The first thickening portion is connected to the main body portion and is arranged along the circumference of the first opening. The second thickening portion is connected to the main body portion and is arranged along the circumference of the second opening. The thickness of the first thickening portion is greater than the thickness of the main body portion, and the thickness of the second thickening portion is greater than the thickness of the main body portion. The first end cap is connected to the first thickening portion and covers the first opening. The second end cap is connected to the second thickening portion and covers the second opening.

[0113] The above technical solution sets a first thickening portion with a relatively thick thickness along the circumference of the first opening on the housing, and connects the first end cap to the first thickening portion. The first thickening portion with a relatively thick thickness has higher structural strength, so as to improve the structural strength after the cooperation of the first end cap and the housing, and reduce the risk of cracking and failure at the connection position between the first end cap and the housing. By setting a second thickening portion with a relatively thick thickness along the circumference of the second opening on the housing, and connecting the second end cap to the second thickening portion, the second thickening portion with a relatively thick thickness has higher structural strength, so as to improve the structural strength after the cooperation of the second end cap and the housing, and reduce the risk of cracking and failure at the connection position between the second end cap and the housing. Thereby, the reliability of the battery cell can be effectively improved.

[0114] The technical solutions described in the embodiments of this application are applicable to batteries and electrical devices using batteries.

[0115] The electrical devices can be vehicles, mobile phones, portable devices, laptop computers, ships, spacecraft, electric toys, and electric tools, etc. The vehicle can be a fuel vehicle, a gas vehicle, or a new energy vehicle. The new energy vehicle can be a pure electric vehicle, a hybrid electric vehicle, or an extended-range electric vehicle, etc.; the spacecraft includes airplanes, rockets, space shuttles, and spaceships, etc.; the electric toys include stationary or mobile electric toys, for example, game consoles, electric vehicle toys, electric ship toys, and electric airplane toys, etc.; the electric tools include metal cutting electric tools, grinding electric tools, assembly electric tools, and electric tools for railways, for example, electric drills, electric grinders, electric wrenches, electric screwdrivers, electric hammers, impact electric drills, concrete vibrators, and electric planers, etc. The embodiments of this application do not impose special restrictions on the above-mentioned electrical devices.

[0116] It should be understood that the technical solutions described in the embodiments of this application are not only limited to the batteries and electrical devices described above, but can also be applicable to all batteries including battery boxes and electrical devices using batteries. However, for the sake of simplicity of description, the following embodiments will be described by taking an electric vehicle as an example.

[0117] Figure 1 It is a schematic structural diagram of a vehicle provided in some embodiments of this application.

[0118] Continue to refer to Figure 1 , inside the vehicle 1, there is a battery 2, and the battery 2 can be arranged at the bottom, head, or tail of the vehicle 1. The battery 2 can be used to supply power to the vehicle 1. For example, the battery 2 can be used as the operating power source of the vehicle 1.

[0119] The vehicle 1 may further include a controller 3 and a motor 4. The controller 3 is used to control the battery 2 to supply power to the motor 4. For example, it is used for the working power requirements during the start, navigation, and driving of the vehicle 1.

[0120] In some embodiments of this application, the battery 2 can not only be used as the operating power source of the vehicle 1, but also be used as the driving power source of the vehicle 1, replacing or partially replacing fuel or natural gas to provide driving power for the vehicle 1.

[0121] Figure 2 It is an exploded structural diagram of a battery provided in some embodiments of this application.

[0122] Continue to refer to Figure 2 , the battery 2 includes a box body 5 and battery cells, and the battery cells are accommodated in the box body 5.

[0123] The housing 5 is used to accommodate battery cells, and the housing 5 can have various structures. In some embodiments, the housing 5 can include a first housing part 5a and a second housing part 5b. The first housing part 5a and the second housing part 5b cover each other, and the first housing part 5a and the second housing part 5b jointly define an accommodation space 5c for accommodating battery cells. The second housing part 5b can be a hollow structure with an open end, and the first housing part 5a is a plate-like structure. The first housing part 5a covers the open side of the second housing part 5b to form the housing 5 with the accommodation space 5c. Both the first housing part 5a and the second housing part 5b can also be hollow structures with an open side, and the open side of the first housing part 5a covers the open side of the second housing part 5b to form the housing 5 with the accommodation space 5c. Of course, the first housing part 5a and the second housing part 5b can have various shapes, such as a cylinder, a cuboid, etc.

[0124] To improve the sealing performance after the connection between the first housing part 5a and the second housing part 5b, a sealing member can also be provided between the first housing part 5a and the second housing part 5b, such as sealant, sealing ring, etc.

[0125] Assume that the first housing part 5a covers the top of the second housing part 5b. The first housing part 5a can also be called the upper cover, and the second housing part 5b can also be called the lower housing.

[0126] In the battery 2, there can be one or multiple battery cells. If there are multiple battery cells, the multiple battery cells can be connected in series, parallel, or in a mixed connection. A mixed connection means that there are both series and parallel connections among the multiple battery cells. The multiple battery cells can be directly connected in series, parallel, or in a mixed connection together, and then the whole formed by the multiple battery cells is accommodated in the housing 5. Of course, it can also be that multiple battery cells are first connected in series, parallel, or in a mixed connection to form a battery module 6, and then multiple battery modules 6 are connected in series, parallel, or in a mixed connection to form a whole and are accommodated in the housing 5.

[0127] Figure 3 This is a schematic structural diagram of a battery module provided by some embodiments of the present application.

[0128] In some embodiments, referring to the figure continuously, there are multiple battery cells 7. The multiple battery cells 7 are first connected in series, parallel, or in a mixed connection to form a battery module 6. Then multiple battery modules 6 are connected in series, parallel, or in a mixed connection to form a whole and are accommodated in the housing.

[0129] The multiple battery cells 7 in the battery module 6 can be electrically connected through a busbar component to achieve parallel, series, or mixed connection of the multiple battery cells 7 in the battery module 6.

[0130] Figure 4 This is a schematic three-dimensional structural diagram of a battery cell provided by some embodiments of the present application. Figure 5 ForFigure 4 Exploded structural schematic diagram of the battery cell shown Figure 6 is Figure 4 Side view structural schematic diagram of the battery cell shown Figure 7 is Figure 6 Cross-sectional structural schematic diagram along A-A Figure 8 is Figure 7 Local enlarged structural schematic diagram at F of Figure 9 is Figure 7 Local enlarged structural schematic diagram at H of Figure 10 Front view structural schematic diagram of another battery cell provided by some embodiments of the present application Figure 11 is Figure 10 Local enlarged structural schematic diagram at G of Figure 12 is Figure 10 Local enlarged structural schematic diagram at K of

[0131] Referring to Figures 4 to 12 , embodiments of the present application provide a battery cell 7. The battery cell 7 includes an electrode assembly 10, a housing 20, a first end cap 30a, and a second end cap 30b. The housing 20 has a first opening 21a and a second opening 21b. The first opening 21a and the second opening 21b are respectively located at two ends of the housing 20 along the first direction X. The housing 20 includes a main body portion 22, a first thickened portion 23a, and a second thickened portion 23b. The main body portion 22 surrounds the electrode assembly 10. The first thickened portion 23a is connected to the main body portion 22 and is arranged along the circumference of the first opening 21a. The second thickened portion 23b is connected to the main body portion 22 and is arranged along the circumference of the second opening 21b. The thickness of the first thickened portion 23a is greater than the thickness of the main body portion 22. The thickness of the second thickened portion 23b is greater than the thickness of the main body portion 22. The first end cap 30a is connected to the first thickened portion 23a and covers the first opening 21a. The second end cap 30b is connected to the second thickened portion 23b and covers the second opening 21b.

[0132] Exemplarily, the end cap refers to a component that covers the opening of the housing 20 to isolate the internal environment of the battery cell 7 from the external environment. Optionally, the shape of the end cap can be adapted to the shape of the housing 20 to cooperate with the housing 20. Optionally, the end cap can be made of a material with a certain hardness and strength (such as aluminum alloy). In this way, the end cap is not easily deformed when subjected to extrusion and collision, enabling the battery cell 7 to have higher structural strength and improved reliability. Functional components such as terminal groups can be provided on the end cap. The material of the end cap can also be various. For example, the end cap can be, but is not limited to, made of metal or non-metal materials. For example, the metal material can be copper, aluminum, or stainless steel, etc.; the non-metal material can be polyethylene, polypropylene, or polyvinyl chloride, etc.

[0133] The housing 20 is a component for cooperating with the end cap to form the internal environment of the battery cell 7. Among them, the formed internal environment can be used to accommodate the electrode assembly 10, the electrolyte, and other components. The housing 20 and the end cap can be independent components. An opening can be provided on the housing 20, and the end cap is covered at the opening to form the internal environment of the battery cell 7. Optionally, the end cap and the housing 20 can also be integrated. Specifically, the end cap and the housing 20 can first form a common connection surface before other components are put into the housing, and when it is necessary to encapsulate the inside of the housing 20, the end cap is then covered on the housing 20. The housing 20 can be of various shapes and sizes, such as cuboid, cylindrical, hexagonal prism, etc. Specifically, the shape of the housing 20 can be determined according to the specific shape and size of the electrode assembly 10. The material of the housing 20 can be various. For example, the housing 20 can be but not limited to being made of metal or non-metal materials. For example, the metal materials can be copper, aluminum, or stainless steel, etc.; the non-metal materials can be polyethylene, polypropylene, or polyvinyl chloride, etc.

[0134] The electrode assembly 10 is the core component for the battery cell 7 to achieve the charge and discharge functions. The electrode assembly 10 can be a wound structure, a stacked structure, or other structures. The electrode assembly 10 can be one or multiple.

[0135] In the embodiment of the present application, the housing 20 has a first opening 21a and a second opening 21b. The first opening 21a and the second opening 21b are respectively located at both ends of the housing 20 along the first direction X. The first end cap 30a is covered at the first opening 21a of the housing 20, and the second end cap 30b is covered at the second opening 21b of the housing 20 to isolate the internal environment of the battery cell 7 from the external environment.

[0136] The first end cap 30a and the second end cap 30b can be made of the same material or different materials. As an example, the first end cap 30a and the second end cap 30b are made of the same material, which is beneficial to simplifying the preparation process and reducing costs.

[0137] In some examples, the first thickening portion 23a is arranged along the circumference of the first opening 21a and surrounds part of the first opening 21a, which is beneficial to taking into account the reliability and energy density of the battery cell 7.

[0138] In some examples, the second thickening portion 23b is arranged along the circumference of the second opening 21b and surrounds part of the second opening 21b, which is beneficial to taking into account the reliability and energy density of the battery cell 7.

[0139] In some examples, the first thickening portion 23a is arranged along the circumference of the first opening 21a and surrounds the entire first opening 21a, which can greatly improve the structural strength after the first end cap 30a is fitted with the housing 20.

[0140] In some examples, the second thickening portion 23b is arranged along the circumferential direction of the second opening 21b and surrounds the entire second opening 21b, which can greatly improve the structural strength after the cooperation between the second end cap 30b and the housing 20.

[0141] In some examples, the main body portion 22, the first thickening portion 23a, and the second thickening portion 23b are integrally formed by stamping on the housing 20.

[0142] In some examples, the main body portion 22, the first thickening portion 23a, and the second thickening portion 23b are formed independently. The first thickening portion 23a and the second thickening portion 23b are fixedly connected to the main body portion 22 through a connecting process. Optionally, the connection manner between the first end cap 30a and the first thickening portion 23a can be but is not limited to welding, bolt connection, bonding, snap connection, or riveting, etc., and can be selected according to the actual application environment. Optionally, the connection manner between the second end cap 30b and the second thickening portion 23b can be but is not limited to welding, bolt connection, bonding, snap connection, or riveting, etc., and can be selected according to the actual application environment.

[0143] The first end cap 30a is hermetically connected to the first thickening portion 23a, and the second end cap 30b is hermetically connected to the second thickening portion 23b to form a sealed space for accommodating the electrode assembly 10 and the electrolyte. Exemplarily, the first end cap 30a is welded to the first thickening portion 23a, and the second end cap 30b is welded to the second thickening portion 23b. Welding can simultaneously achieve the sealing and fixing between the first end cap 30a and the first thickening portion 23a, and achieve the sealing and fixing between the second end cap 30b and the second thickening portion 23b, which helps to reduce the structural complexity of the battery cell 7.

[0144] The thickness of the first thickening portion 23a is greater than the thickness of the main body portion 22, so that the first thickening portion 23a has higher strength. The first thickening portion 23a can protrude from the inner surface of the main body portion 22, can protrude from the outer surface of the main body portion 22, or can protrude from both the inner surface and the outer surface of the main body portion 22.

[0145] The thickness of the second thickening portion 23b is greater than the thickness of the main body portion 22, so that the second thickening portion 23b has higher strength. The second thickening portion 23b can protrude from the inner surface of the main body portion 22, can protrude from the outer surface of the main body portion 22, or can protrude from both the inner surface and the outer surface of the main body portion 22.

[0146] In the above technical solution, a relatively thick first thickening portion 23a is provided along the circumferential direction of the first opening 21a on the housing 20, and the first end cover 30a is connected to the first thickening portion 23a. The relatively thick first thickening portion 23a has higher structural strength, so as to improve the structural strength after the first end cover 30a is fitted with the housing 20, and reduce the risk of cracking and failure at the connection position between the first end cover 30a and the housing 20. By providing a relatively thick second thickening portion 23b along the circumferential direction of the second opening 21b on the housing 20, and connecting the second end cover 30b to the second thickening portion 23b, the relatively thick second thickening portion 23b has higher structural strength, so as to improve the structural strength after the second end cover 30b is fitted with the housing 20, and reduce the risk of cracking and failure at the connection position between the second end cover 30b and the housing 20. Thereby, the reliability of the battery cell 7 can be effectively improved.

[0147] In the embodiment of the present application, only the thicknesses of the first thickening portion 23a and the second thickening portion 23b are increased. Compared with the solution of increasing the thickness of the housing 20 as a whole, this embodiment can reduce the weight of the housing 20 and improve the energy density of the battery cell 7.

[0148] In some embodiments, the housing 20 further includes a first transition portion, and the first transition portion is connected between the main body portion 22 and the first thickening portion 23a. In the first direction X and in the direction from the housing 20 to the first end cover 30a, the thickness of the first transition portion gradually increases. It can reduce the sudden change in thickness between the main body portion 22 and the first thickening portion 23a, thereby reducing the risk of stress concentration and improving the reliability of the housing 20.

[0149] In some embodiments, the housing 20 further includes a second transition portion, and the second transition portion is connected between the main body portion 22 and the second thickening portion 23b. In the first direction X and in the direction from the housing 20 to the second end cover 30b, the thickness of the second transition portion gradually increases. It can reduce the sudden change in thickness between the main body portion 22 and the second thickening portion 23b, thereby reducing the risk of stress concentration and improving the reliability of the housing 20.

[0150] In some embodiments, the first thickening portion 23a protrudes from the inner surface of the main body portion 22.

[0151] The inner surface of the main body portion 22 is the surface of the main body portion 22 facing the electrode assembly 10, and the first thickening portion 23a is provided to protrude toward the inside of the housing 20. When the thickness of the first thickening portion 23a is fixed, the first thickening portion 23a protruding from the inner surface of the main body portion 22 can reduce the occupancy rate of the outer space of the housing 20 by the first thickening portion 23a, and further reduce the maximum size of the housing 20, making full use of the inner space of the housing 20, which is beneficial to improving the energy density of the battery cell 7.

[0152] In some embodiments, the first thickened portion 23a protrudes relative to the inner surface of the main body portion 22, and the outer surface of the main body portion 22 is flush with the outer surface of the first thickened portion 23a. This can improve the flatness of the outer surface of the housing 20 and enhance the appearance of the housing 20.

[0153] In some embodiments, the first thickened portion 23a protrudes relative to the outer surface of the main body portion 22.

[0154] The outer surface of the main body portion 22 is the surface of the main body portion 22 facing away from the electrode assembly 10, and the first thickened portion 23a protrudes towards the outside of the housing 20. When the thickness of the first thickened portion 23a is fixed, the first thickened portion 23a protruding from the outer surface of the main body portion 22 can reduce the occupancy rate of the inner space of the housing 20 by the first thickened portion 23a, thereby reducing the risk of interference between the first thickened portion 23a and the electrode assembly 10, which is beneficial to further improving the reliability of the battery cell 7.

[0155] In some embodiments, the second thickened portion 23b protrudes relative to the inner surface of the main body portion 22.

[0156] The inner surface of the main body portion 22 is the surface of the main body portion 22 facing the electrode assembly 10, and the second thickened portion 23b protrudes towards the inside of the housing 20. When the thickness of the second thickened portion 23b is fixed, the second thickened portion 23b protruding from the inner surface of the main body portion 22 can reduce the occupancy rate of the outer space of the housing 20 by the second thickened portion 23b, thereby reducing the maximum size of the housing 20 and making full use of the inner space of the housing 20, which is beneficial to improving the energy density of the battery cell 7.

[0157] In some embodiments, the second thickened portion 23b protrudes relative to the inner surface of the main body portion 22, and the outer surface of the main body portion 22 is flush with the outer surface of the second thickened portion 23b. This can improve the flatness of the outer surface of the housing 20 and enhance the appearance of the housing 20.

[0158] In some embodiments, the second thickened portion 23b protrudes relative to the outer surface of the main body portion 22.

[0159] The outer surface of the main body portion 22 is the surface of the main body portion 22 facing away from the electrode assembly 10, and the second thickened portion 23b protrudes towards the outside of the housing 20. When the thickness of the second thickened portion 23b is fixed, the second thickened portion 23b protruding from the outer surface of the main body portion 22 can reduce the occupancy rate of the inner space of the housing 20 by the second thickened portion 23b, thereby reducing the risk of interference between the second thickened portion 23b and the electrode assembly 10, which is beneficial to further improving the reliability of the battery cell 7.

[0160] In some embodiments, the first thickened portion 23a is disposed around the first opening 21a.

[0161] The first thickening portion 23a surrounds the first opening 21a for one week, which can further improve the structural strength after the cooperation between the first end cover 30a and the housing 20, thereby further improving the energy density of the battery cell 7.

[0162] In some embodiments, the second thickening portion 23b is arranged to surround the second opening 21b.

[0163] The second thickening portion 23b surrounds the second opening 21b for one week, which can further improve the structural strength after the cooperation between the second end cover 30b and the housing 20, thereby further improving the energy density of the battery cell 7.

[0164] In some embodiments, in the first direction X, one end of the first thickening portion 23a close to the electrode assembly 10 extends beyond the first end cover 30a.

[0165] The first thickening portion 23a is used to connect with the first end cover 30a to form a first connection portion. In the first direction X, one end of the first thickening portion 23a close to the electrode assembly 10 extends beyond the first end cover 30a, which can make the first connection portion located within the range of the first thickening portion 23a, thereby further ensuring the improvement of the strength after the cooperation between the first end cover 30a and the housing 20, and further improving the reliability of the battery cell 7.

[0166] In some embodiments, in the first direction X, one end of the second thickening portion 23b close to the electrode assembly 10 extends beyond the second end cover 30b.

[0167] The second thickening portion 23b is used to connect with the second end cover 30b to form a second connection portion. In the first direction X, one end of the second thickening portion 23b close to the electrode assembly 10 extends beyond the second end cover 30b, which can make the second connection portion located within the range of the second thickening portion 23b, thereby further ensuring the improvement of the strength after the cooperation between the second end cover 30b and the housing 20, and further improving the reliability of the battery cell 7.

[0168] In some embodiments, the electrode assembly 10 includes a first electrode tab. The first electrode tab includes a first coating area and a first tab led out from an end of the first coating area along the first direction X. The first thickening portion 23a protrudes relative to the inner surface of the main body portion 22. In the direction perpendicular to the first direction X, the first coating area does not overlap with the first thickening portion 23a.

[0169] Exemplarily, the electrode assembly 10 further includes a second electrode tab. The polarities of the first electrode tab and the second electrode tab are opposite. The electrode assembly 10 mainly works by the movement of metal ions between the first electrode tab and the second electrode tab. One of the first electrode tab and the second electrode tab is a positive electrode tab, and the other is a negative electrode tab.

[0170] The first electrode tab can be one or more, and the second electrode tab can be one or more. The number of the first electrode tab and the second electrode tab can be determined according to the structure of the electrode assembly 10.

[0171] In some examples, the first electrode tab is a negative electrode tab and the second electrode tab is a positive electrode tab.

[0172] The first coating area is the electricity generation part of the first electrode tab, and the active material inside it is used to carry out an electrochemical reaction with the electrolyte, etc., to generate a charge and discharge process. The first tab is led out from the end of the first coating area along the first direction X and is used to conduct out the electric energy generated by the first coating area. The first coating area includes a current collector part and an active material layer.

[0173] When the first thickening part 23a protrudes from the inner surface of the main body part 22, the first coating area and the first thickening part 23a do not overlap in the direction perpendicular to the first direction X, which can reduce the risk of affecting the electrical performance of the electrode assembly 10 due to interference between the first thickening part 23a and the first coating area. Thus, while reducing the maximum size of the housing 20 and making full use of the internal space of the housing 20 to improve the energy density of the battery cell 7, the adverse effect of the first thickening part 23a on the electrode assembly 10 can be reduced.

[0174] In some embodiments, the second thickening part 23b protrudes from the inner surface of the main body part 22, and in the direction perpendicular to the first direction X, the first coating area and the second thickening part 23b do not overlap.

[0175] When the second thickening part 23b protrudes from the inner surface of the main body part 22, the first coating area and the second thickening part 23b do not overlap in the direction perpendicular to the first direction X, which can reduce the risk of affecting the electrical performance of the electrode assembly 10 due to interference between the second thickening part 23b and the first coating area. Thus, while reducing the maximum size of the housing 20 and making full use of the internal space of the housing 20 to improve the energy density of the battery cell 7, the adverse effect of the second thickening part 23b on the electrode assembly 10 can be reduced.

[0176] In some embodiments, the electrode assembly 10 further includes a separator, the separator covers the first coating area, and in the direction perpendicular to the first direction X, the separator does not overlap with the first thickening part 23a.

[0177] Exemplarily, the second electrode tab includes a second coating area and a second tab led out from the end of the second coating area along the first direction X. The separator is used to insulate and isolate the first coating area of the first electrode tab and the second coating area of the second electrode tab. The material of the separator can be, but is not limited to, polypropylene or polyethylene, etc.

[0178] When the first thickening portion 23a protrudes from the inner surface of the main body portion 22, the separator does not overlap with the first thickening portion 23a in the direction perpendicular to the first direction X, which can reduce the risk of insulation failure between the first and second electrode plates caused by interference between the first thickening portion 23a and the separator. Thus, while reducing the maximum size of the housing 20 and making full use of the internal space of the housing 20 to improve the energy density of the battery cell 7, the adverse effect of the first thickening portion 23a on the electrode assembly 10 can be further reduced.

[0179] In some embodiments, in the direction perpendicular to the first direction X, the separator does not overlap with the second thickening portion 23b.

[0180] When the second thickening portion 23b protrudes from the inner surface of the main body portion 22, the separator does not overlap with the second thickening portion 23b in the direction perpendicular to the first direction X, which can reduce the risk of insulation failure between the first and second electrode plates caused by interference between the second thickening portion 23b and the separator. Thus, while reducing the maximum size of the housing 20 and making full use of the internal space of the housing 20 to improve the energy density of the battery cell 7, the adverse effect of the second thickening portion 23b on the electrode assembly 10 can be further reduced.

[0181] In some embodiments, the electrode assembly 10 has a flat region, and the flat region includes a plurality of electrode plates stacked along the second direction Y, and the first direction X intersects with the second direction Y.

[0182] Exemplarily, the second direction Y can be understood as the thickness direction of the electrode assembly 10. During the cyclic use of the battery cell 7, the electrode assembly 10 will expand to a certain extent along the second direction Y.

[0183] In some examples, the electrode assembly 10 is a wound structure, the first and second electrode plates are wound into a wound structure, and the wound electrode assembly 10 includes a flat region and a bent region. The bent region is connected to one end of the flat region in the third direction, and the first direction X, the second direction Y, and the third direction are perpendicular to each other pairwise. The first and second electrode plates located in the flat region are alternately stacked along the second direction Y.

[0184] In some examples, the electrode assembly 10 is a stacked structure, the first and second electrode plates are alternately stacked along the second direction Y, and the overall shape of the stacked electrode assembly 10 is a flat structure. That is to say, the overall stacked electrode assembly 10 can be used as the flat region.

[0185] The above technical solutions can reduce the influence of the expansion of the electrode assembly 10 itself on the first end cap 30a and the second end cap 30b, thereby further reducing the risk of cracking and failure at the connection position between the first end cap 30a and the housing 20, and further reducing the risk of cracking and failure at the connection position between the second end cap 30b and the housing 20.

[0186] In some embodiments, the battery cell 7 further includes a bracket 40, and the bracket 40 is connected between the first end cap 30a and the electrode assembly 10. The size of the first thickened portion 23a in the first direction X is greater than the size of the second thickened portion 23b in the first direction X.

[0187] The bracket 40 may be entirely located between the first end cap 30a and the electrode assembly 10, or only a part of it may be located between the first end cap 30a and the electrode assembly 10. The bracket 40 may be independent of the first end cap 30a, and the first end cap 30a and the electrode assembly 10 clamp and fix the bracket 40. The bracket 40 may also be fixedly connected to the first end cap 30a. For example, the bracket 40 may be fixedly connected to the first end cap 30a by, but not limited to, connection methods such as welding, bonding, snap connection, bolt connection, or riveting.

[0188] When the battery cell 7 is subjected to an external impact, the bracket 40 can limit the vibration of the electrode assembly 10, thereby reducing the tensile force on the tab of the electrode assembly 10, reducing the risk of tab tearing, and improving the reliability of the battery cell 77.

[0189] Optionally, the bracket 40 may be made of an insulating material such as polyethylene, polypropylene, polyvinyl chloride, or rubber, so as to reduce the risk of the first end cap 30a conducting the positive and negative electrodes of the electrode assembly 10 and improve the reliability.

[0190] The provision of the bracket 40 between the first end cap 30a and the electrode assembly 10 also allows for a larger space between the first end cap 30a and the electrode assembly 10 in the first direction X, thereby enabling an increase in the size range of the first thickened portion 23a in the first direction X. In this way, the above technical solution can further improve the strength of the first end cap 30a after it is fitted with the housing 20 by increasing the size of the first thickened portion 23a in the first direction X.

[0191] Optionally, the bracket 40 and the first end cap 30a are an integrally formed structure.

[0192] On the one hand, there is no need to connect the bracket 40 and the first end cap 30a through an additional connection process, which simplifies the manufacturing process flow. At the same time, compared with connecting the bracket 40 and the first end cap 30a through an additional connection process, the connection between the integrally formed bracket 40 and the first end cap 30a has a higher connection strength.

[0193] In some embodiments, the battery cell 7 further includes a first insulating member and a second insulating member. The first insulating member is connected to the side of the first end cap 30a close to the electrode assembly 10, and the second insulating member is connected to the side of the second end cap 30b close to the electrode assembly 10.

[0194] In some embodiments, the first end cap 30a includes a first cap body 31 and a first extension portion 32. The first extension portion 32 is connected to the first cap body 31 and protrudes from a side surface of the first cap body 31 close to the housing 20. At least a part of the first extension portion 32 is located inside the housing 20 and is connected to the first thickened portion 23a, and the first cap body 31 is located outside the housing 20 and is connected to the first thickened portion 23a.

[0195] Both the first cap body 31 and the first extension portion 32 are connected to the first thickened portion 23a. The first extension portion 32 extends along the first direction X. The introduction of the first extension portion 32 can increase the overall contact area between the first end cap 30a and the first thickened portion 23a, thereby further improving the connection strength between the first end cap 30a and the housing 20. As an example, both the first cap body 31 and the first extension portion 32 are welded to the first thickened portion 23a.

[0196] Optionally, the first cap body 31 and the first extension portion 32 are of an integrally formed structure. On the one hand, there is no need to connect the first cap body 31 and the first extension portion 32 through an additional connection process, which simplifies the manufacturing process flow. At the same time, compared with connecting the first cap body 31 and the first extension portion 32 through an additional connection process, the first cap body 31 and the first extension portion 32 in an integral structure have higher connection firmness.

[0197] The first cap body 31 and the first extension portion 32 can be made of the same material or different materials. As an example, the first cap body 31 and the first extension portion 32 are made of the same material, which is beneficial to simplifying the preparation process and reducing costs.

[0198] In some embodiments, the second end cap 30b includes a second cap body 33 and a second extension portion 34. The second extension portion 34 is connected to the second cap body 33 and protrudes from a side surface of the second cap body 33 close to the housing 20. At least a part of the second extension portion 34 is located inside the housing 20 and is connected to the second thickened portion 23b, and the second cap body 33 is located outside the housing 20 and is connected to the second thickened portion 23b.

[0199] Both the second cap body 33 and the second extension portion 34 are connected to the second thickened portion 23b. The second extension portion 34 extends along the first direction X. The introduction of the second extension portion 34 can increase the overall contact area between the second end cap 30b and the second thickened portion 23b, thereby further improving the connection strength between the second end cap 30b and the housing 20. As an example, both the second cap body 33 and the second extension portion 34 are welded to the second thickened portion 23b.

[0200] Optionally, the second cover body 33 and the second extension portion 34 are integrally formed structures. On the one hand, there is no need to connect the second cover body 33 and the second extension portion 34 through an additional connection process, which simplifies the manufacturing process flow. At the same time, compared with connecting the second cover body 33 and the second extension portion 34 through an additional connection process, the second cover body 33 and the second extension portion 34 in an integral structure have higher connection firmness.

[0201] The second cover body 33 and the second extension portion 34 can be made of the same material or different materials. As an example, the second cover body 33 and the second extension portion 34 are made of the same material, which is beneficial to simplifying the preparation process and reducing costs.

[0202] In some embodiments, the battery cell 7 further includes a pressure relief mechanism 50, the housing 20 includes two oppositely arranged first side plates 24, and the pressure relief mechanism 50 is disposed on one of the two first side plates 24.

[0203] The pressure relief mechanism 50 refers to an element or component that actuates to release the internal pressure or temperature when the internal pressure or temperature of the battery cell 7 reaches a predetermined threshold. This threshold design varies according to different design requirements and may depend on one or several materials among the positive electrode plate, negative electrode plate, electrolyte, and separator in the battery cell 7. The pressure relief mechanism 50 can adopt forms such as an explosion-proof valve, a gas valve, a pressure relief valve, or a safety valve, and can specifically adopt a pressure-sensitive or temperature-sensitive element or structure, that is, when the internal pressure or temperature of the battery cell 7 reaches a predetermined threshold, the pressure relief mechanism 50 performs an action or a weak structure provided in the pressure relief mechanism 50 is damaged, thereby forming an opening or channel for the internal pressure or temperature to be released.

[0204] Relative to the first end cap 30a and the second end cap 30b, the area of the first side plate 24 is larger. Thus, disposing the pressure relief mechanism 50 on the first side plate 24 can reduce the difficulty of setting the pressure relief mechanism 50.

[0205] In some embodiments, components such as a liquid injection hole and an electrode terminal are provided on the first end cap 30a. Disposing the pressure relief mechanism 50 on the first side plate 24 can create space for components such as the liquid injection hole and the electrode terminal, thereby facilitating the optimization of the layout of other components on the first end cap 30a.

[0206] In some embodiments, components such as a liquid injection hole and an electrode terminal are provided on the second end cap 30b. Disposing the pressure relief mechanism 50 on the first side plate 24 can create space for components such as the liquid injection hole and the electrode terminal, thereby facilitating the optimization of the layout of other components on the second end cap 30b.

[0207] In some embodiments, a weld seam is provided on the other one of the two first side plates 24. Since a pressure relief mechanism 50 is provided on one of the two first side plates 24, by arranging the weld seam on the first side plate 24 without the pressure relief mechanism 50 among the two first side plates 24, the influence of the weld seam on the pressure relief mechanism 50 can be reduced, thereby improving the reliability of the pressure relief mechanism 50.

[0208] In some embodiments, the main body portion 22 and the first thickening portion 23a are of an integrally formed structure.

[0209] On the one hand, there is no need to connect the main body portion 22 and the first thickening portion 23a through an additional connection process, which simplifies the manufacturing process flow. At the same time, compared with connecting the main body portion 22 and the first thickening portion 23a through an additional connection process, the connection between the main body portion 22 and the first thickening portion 23a in an integral structure has higher connection firmness.

[0210] In some embodiments, the main body portion 22 and the second thickening portion 23b are of an integrally formed structure.

[0211] On the one hand, there is no need to connect the main body portion 22 and the second thickening portion 23b through an additional connection process, which simplifies the manufacturing process flow. At the same time, compared with connecting the main body portion 22 and the second thickening portion 23b through an additional connection process, the connection between the main body portion 22 and the second thickening portion 23b in an integral structure has higher connection firmness.

[0212] In some embodiments, the first end cover 30a is welded to the housing 20. The welding has high reliability, is convenient and fast, and has low cost.

[0213] In some embodiments, the second end cover 30b is welded to the housing 20. The welding has high reliability, is convenient and fast, and has low cost.

[0214] According to some embodiments of the present application, the present application further provides a battery, including the battery cell 7 of any one of the above solutions.

[0215] In some embodiments, a plurality of battery cells 7 are sequentially arranged in contact with each other along the second direction Y. The first thickening portion 23a protrudes from the inner surface of the main body portion 22, the second thickening portion 23b protrudes from the inner surface of the main body portion 22, and the first direction X intersects with the second direction Y.

[0216] The meaning of arranging a plurality of battery cells 7 in sequence along the second direction Y is that partial outer surfaces of the housings 20 of two adjacent battery cells 7 among the plurality of battery cells 7 are mutually attached along the second direction Y. Thus, in the case where the plurality of battery cells 7 are arranged in sequence along the second direction Y, the first thickening portion 23a protrudes relative to the inner surface of the main body portion 22, and the second thickening portion 23b protrudes relative to the inner surface of the main body portion 22, such that the first thickening portion 23a and the second thickening portion 23b will not cause a gap to be generated between two adjacent battery cells 7, and the structural compactness of the battery can be improved, thereby being beneficial to improving the overall energy density of the battery.

[0217] As an example, the plurality of battery cells 7 may be, but are not limited to, two battery cells 7, three battery cells 7, four battery cells 7, or more battery cells 7.

[0218] Figure 13 FIG. is a schematic diagram of a partial structure of a battery provided by some embodiments of the present application. Figure 14 is Figure 13 a schematic diagram of a partially enlarged structure at M of Figure 15 is Figure 13 a schematic diagram of a partially enlarged structure at N of

[0219] Continuing to refer to Figures 13 to 15 , in some embodiments, the plurality of battery cells 7 are arranged at intervals along the second direction Y, the first thickening portion 23a protrudes relative to the outer surface of the main body portion 22, the second thickening portion 23b protrudes relative to the outer surface of the main body portion 22, and the first direction X intersects with the second direction Y. The battery cell 7 further includes a partition member 60, the partition member 60 is disposed between the main body portions 22 of two adjacent battery cells 7, and in the second direction Y, the partition member 60 does not overlap with the first thickening portion 23a, and the partition member 60 does not overlap with the second thickening portion 23b.

[0220] Exemplarily, the partition member 60 is a component in the battery for assisting in electrical connection, buffering, strengthening, and temperature regulation of the battery cell 7. Exemplarily, the partition member 60 may be, but is not limited to, a buffer pad, a thermal management component, or a strengthening component.

[0221] The first thickening portion 23a protrudes relative to the outer surface of the main body portion 22, the second thickening portion 23b protrudes relative to the outer surface of the main body portion 22, and the first thickening portion 23a and the second thickening portion 23b of two adjacent battery cells 7 along the second direction Y can jointly form an accommodation space.

[0222] In some examples, a part of the separating member 60 is received in the receiving space. That is to say, a part of the separating member 60 is disposed between the main bodies 22 of two adjacent battery cells 7, and another part is located between the first thickening portions 23a of two adjacent battery cells 7, and / or between the second thickening portions 23b of two adjacent battery cells 7.

[0223] In other examples, the separating member 60 is completely received in the receiving space. That is to say, the separating member 60 is disposed between the main bodies 22 of two adjacent battery cells 7, and in the second direction Y, the separating member 60 does not overlap with the first thickening portion 23a, and the separating member 60 does not overlap with the second thickening portion 23b.

[0224] Optionally, the separating member 60 includes a buffer pad. At least a part of the buffer pad is made of an elastic material, such as rubber or other materials. The buffer pad is a rubber structure with a compression amount, which can reduce the collision and damage between the battery cells 7. It should be noted that the buffer pad provided in the embodiments of the present application can also be replaced with a heat insulation pad, a heat conduction pad or other pad-shaped or plate-shaped structures with a cooling function or a heating function, which can be selected according to the actual application environment.

[0225] Optionally, the separating member 60 includes a thermal management member. The thermal management member is inserted between the main bodies 22 of two adjacent battery cells 7. The thermal management member is a hollow structure with a thermal management channel inside. The thermal management channel can allow fluids such as coolant to pass through to exchange heat with the battery cells 7, so as to maintain the temperature of the battery cells 7 within a normal range, reduce the occurrence probability of thermal runaway, and improve the reliability of the battery. Specifically, the thermal management member is a cooling plate. In other embodiments, it can also be a heat conduction plate or other structures that can adjust the temperature of the battery cells 7. Through the above technical solution, the thermal management member can be received between the main bodies 22 of two adjacent battery cells 7, which can not only improve the space utilization rate of the battery, but also help reduce and alleviate the thermal runaway of the battery cells 7 and improve the reliability of the battery cells 7.

[0226] Optionally, the separating member 60 includes a reinforcing member. The reinforcing member is a structure that can strengthen the strength of the entire battery structure and improve the reliability and stability of the battery cells 7. The reinforcing member can be a reinforcing plate. In some embodiments, the reinforcing plate can be connected to one or more battery cells 7, for example, by gluing, to strengthen the structure of the battery cells 7 or the battery module formed by the battery cells 7. In other embodiments, the reinforcing member may not be directly connected to the battery cells 7.

[0227] In the above technical solution, by disposing the partition member 60 between the main bodies 22 of two adjacent battery cells 7, on the one hand, the accommodation space jointly formed by the first thickening portion 23a and the second thickening portion 23b of two adjacent battery cells 7 can be fully utilized to improve the space utilization rate of the battery, making the structure of the battery more compact and reliable, which is beneficial to improving the energy density of the battery. On the other hand, the displacement of the partition member 60 can be restricted by the first thickening portion 23a and the second thickening portion 23b, improving the reliability of the battery. In addition, in the second direction Y, the partition member 60 does not overlap with the first thickening portion 23a, and the partition member 60 does not overlap with the second thickening portion 23b, which can reduce the risk that the first thickening portion 23a and the second thickening portion 23b interfere with the partition member 60 and cause damage to the partition member 60.

[0228] According to some embodiments of the present application, the present application further provides an electrical device, including the battery of any of the above solutions, and the battery is used to provide electrical energy.

[0229] To better understand the battery cell 7 provided in the embodiments of the present application, based on the same inventive concept, embodiments of the above battery cell 7 in actual applications are provided herein for description.

[0230] The embodiments of the present application provide a battery cell 7, which includes an electrode assembly 10, a housing 20, a first end cap 30a and a second end cap 30b. The housing 20 has a first opening 21a and a second opening 21b. The first opening 21a and the second opening 21b are respectively located at two ends of the housing 20 along the first direction X. The housing 20 includes a main body portion 22, a first thickening portion 23a and a second thickening portion 23b. The main body portion 22 surrounds the electrode assembly 10. The first thickening portion 23a is connected to the main body portion 22 and is disposed along the circumference of the first opening 21a. The second thickening portion 23b is connected to the main body portion 22 and is disposed along the circumference of the second opening 21b. The thickness of the first thickening portion 23a is greater than the thickness of the main body portion 22, and the thickness of the second thickening portion 23b is greater than the thickness of the main body portion 22. The first end cap 30a is connected to the first thickening portion 23a and covers the first opening 21a. The second end cap 30b is connected to the second thickening portion 23b and covers the second opening 21b.

[0231] In the above technical solution, a relatively thick first thickening portion 23a is provided along the circumferential direction of the first opening 21a on the housing 20, and the first end cover 30a is connected to the first thickening portion 23a. The relatively thick first thickening portion 23a has higher structural strength to improve the structural strength after the first end cover 30a is fitted with the housing 20, and reduce the risk of cracking and failure at the connection position between the first end cover 30a and the housing 20. By providing a relatively thick second thickening portion 23b along the circumferential direction of the second opening 21b on the housing 20, and connecting the second end cover 30b to the second thickening portion 23b, the relatively thick second thickening portion 23b has higher structural strength to improve the structural strength after the second end cover 30b is fitted with the housing 20, and reduce the risk of cracking and failure at the connection position between the second end cover 30b and the housing 20. Thus, the reliability of the battery cell 7 can be effectively improved.

[0232] In the embodiment of the present application, only the thicknesses of the first thickening portion 23a and the second thickening portion 23b are increased. Compared with the solution of increasing the thickness of the entire housing 20, this embodiment can reduce the weight of the housing 20 and improve the energy density of the battery cell 7.

[0233] It should be noted that, without conflict, the embodiments in the present application and the features in the embodiments can be combined with each other.

[0234] Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them; although the present application has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that: they can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements on some or all of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present application, and they should all be covered within the scope of the claims and the specification of the present application. In particular, as long as there is no structural conflict, the various technical features mentioned in each embodiment can be combined in any way. The present application is not limited to the specific embodiments disclosed in the text, but includes all technical solutions falling within the scope of the claims.

Claims

1. A battery cell, characterized in that: include: Electrode assembly; A shell having a first opening and a second opening, wherein the first opening and the second opening are respectively located at two ends of the shell along a first direction, the shell comprising a main body, a first thickened portion and a second thickened portion, the main body being arranged around the electrode assembly, the first thickened portion being connected to the main body and arranged along the circumference of the first opening, the second thickened portion being connected to the main body and arranged along the circumference of the second opening, the thickness of the first thickened portion being greater than the thickness of the main body, and the thickness of the second thickened portion being greater than the thickness of the main body; A first end cover, connected to the first thickened portion and covering the first opening; A second end cover is connected to the second thickened portion and covers the second opening.

2. The battery cell according to claim 1, characterized in that: The first thickened portion protrudes relative to the inner surface of the main body; and / or, The first thickened portion protrudes relative to an outer surface of the main body portion.

3. The battery cell according to claim 1, characterized in that: The second thickened portion protrudes relative to the inner surface of the main body; and / or, The second thickened portion protrudes relative to an outer surface of the main body portion.

4. The battery cell according to claim 1, characterized in that: The first thickened portion is arranged around the first opening; and / or, The second thickened portion is disposed around the second opening.

5. The battery cell according to claim 1, characterized in that: In the first direction, one end of the first thickened portion close to the electrode assembly exceeds the first end cover; and / or, In the first direction, one end of the second thickened portion close to the electrode assembly exceeds the second end cover.

6. The battery cell according to claim 1, characterized in that: The electrode assembly includes a first pole piece, the first pole piece includes a first coating area and a first pole ear extending from an end of the first coating area along the first direction; The first thickened portion protrudes relative to the inner surface of the main body portion, and the first coating area does not overlap with the first thickened portion in a direction perpendicular to the first direction.

7. The battery cell according to claim 6, characterized in that: The electrode assembly further includes a separator, which covers the first coating region, and in a direction perpendicular to the first direction, the separator does not overlap with the first thickened portion.

8. The battery cell according to claim 1, characterized in that: The electrode assembly has a straight region, and the straight region includes a plurality of pole pieces stacked along a second direction, and the first direction intersects with the second direction.

9. The battery cell according to claim 1, characterized in that: The battery cell further includes a bracket connected between the first end cover and the electrode assembly; A size of the first thickened portion in the first direction is greater than a size of the second thickened portion in the first direction.

10. The battery cell according to claim 1, characterized in that: The first end cover comprises a first cover body and a first extension portion, the first extension portion is connected to the first cover body and protrudes from a side surface of the first cover body close to the shell, at least part of the first extension portion is located inside the shell and connected to the first thickened portion, and the first cover body is located outside the shell and connected to the first thickened portion; and / or, The second end cover includes a second cover body and a second extension portion, the second extension portion is connected to the second cover body and protrudes from a side surface of the second cover body close to the shell, at least part of the second extension portion is located inside the shell and connected to the second thickened portion, and the second cover body is located outside the shell and connected to the second thickened portion.

11. The battery cell according to claim 1, characterized in that: The battery cell further includes a pressure relief mechanism, the housing includes two first side plates that are oppositely disposed, and the pressure relief mechanism is disposed on one of the two first side plates.

12. The battery cell according to claim 11, characterized in that: The other of the two first side plates is provided with a weld seam.

13. The battery cell according to claim 1, characterized in that: The main body and the first thickened portion are an integrally formed structure; and / or, The main body and the second thickened portion are an integrally formed structure.

14. The battery cell according to any one of claims 1 to 13, characterized in that: The first end cover is welded to the shell; and / or, The second end cover is welded to the shell.

15. A battery, characterized in that: The invention comprises a plurality of battery cells according to any one of claims 1 to 14.

16. The battery according to claim 15, characterized in that The plurality of battery cells are sequentially arranged in affixed relation along a second direction, the first thickened portion protrudes relative to the inner surface of the main body, the second thickened portion protrudes relative to the inner surface of the main body, and the first direction intersects with the second direction.

17. The battery according to claim 15, characterized in that The plurality of battery cells are arranged at intervals along a second direction, the first thickened portion protrudes relative to the outer surface of the main body, the second thickened portion protrudes relative to the outer surface of the main body, and the first direction and the second direction intersect; The battery cell further includes a partition component, which is disposed between the main body portions of two adjacent battery cells, and in the second direction, the partition component does not overlap with the first thickened portion, and the partition component does not overlap with the second thickened portion.

18. An electrical device, characterized in that: The invention comprises a battery as claimed in any one of claims 15 to 17, wherein the battery is used to provide electrical energy.

Images