Battery monomer, battery and electric device

Abstract

The utility model provides a battery monomer, a battery and a power utilization device. The battery cell comprises a housing and an electrode assembly accommodated in the housing, the housing comprises two first walls opposite to each other in a first direction and two second walls opposite to each other in a second direction, and the first direction and the second direction intersect with each other. The shell further comprises a bent wall, the first wall and the second wall are connected through the bent wall, the bent wall is bent relative to the first wall and the second wall, and a notch is formed in the position, on the outer side of the bent wall, of the shell. According to the invention, the reliability and energy density of the battery can be improved.

Description

Technical Field

[0001] The present application relates to the field of battery technology, and in particular to a battery cell, a battery and an electrical device. Background Art

[0002] With the development of new energy technology, batteries are used more and more widely, for example, in mobile phones, laptops, electric vehicles, electric cars, electric airplanes, electric ships, electric toy cars, electric toy ships, electric toy airplanes and electric tools, etc.

[0003] In batteries, the edges of the battery cell shell are usually rounded, and the radius of the rounded corners is small, so the space between the edges of adjacent battery cells is small. On the one hand, it is easy to form a capillary effect, which is not conducive to the glue coating between the battery cell and the box, affecting the reliability of the battery; on the other hand, the space between adjacent battery cells is difficult to be used by other related components in the battery, making the compactness of the internal structure of the battery low, affecting the energy density of the battery. Therefore, how to effectively improve the reliability and energy density of the battery is an urgent problem to be solved in battery technology. Utility Model Content

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

[0005] In a first aspect, an embodiment of the present application provides a battery cell, the battery cell comprising a shell and an electrode assembly contained in the shell, the shell comprising two first walls opposite to each other in a first direction and two second walls opposite to each other in a second direction, the first direction and the second direction intersecting. The shell further comprises a bent wall, the first wall and the second wall are connected by the bent wall, the bent wall is bent relative to the first wall and the second wall, and the shell forms a notch on the outer side of the bent wall.

[0006] The shell of the battery cell of the above technical solution can form a notch on the outer side of the bent wall, which can increase the space enclosed by the edges of adjacent battery cells in the battery. On the one hand, it can reduce the risk of capillary effect formed in the space enclosed by the edges of adjacent battery cells in the battery, so as to improve the reliability of the battery; on the other hand, the space enclosed by the edges of adjacent battery cells in the battery is larger and can be easily used by other related components in the battery, thereby improving the compactness of the internal structure of the battery to improve the energy density of the battery.

[0007] In some embodiments of the first aspect, a first dimension L1 of the notch along the first direction satisfies the relationship: 3mm≤L1≤30mm, and a second dimension L2 of the notch along the second direction satisfies the relationship: 5mm≤L2≤40mm.

[0008] The above technical solution can increase the gap to improve the reliability and energy density of the battery while taking into account the total power of the battery cell by setting the first size L1 of the gap along the first direction and the second size L2 of the gap along the second direction within the above range.

[0009] In some embodiments of the first aspect, the first dimension L1 satisfies the relationship: 5mm≤L1≤15mm, and the second dimension L2 satisfies the relationship: 7mm≤L2≤20mm, so as to further enhance the reliability of the battery and the balance between the energy density and the total power of the battery cell.

[0010] In some embodiments of the first aspect, the bent wall and the first wall are both flat plate structures, and a first angle a formed between the bent wall and the first wall and pointing to the electrode assembly satisfies the relationship: a>90°.

[0011] By setting the first angle a formed between the bent wall and the first wall and pointing to the electrode assembly within the above-mentioned range, the sharpness of the edge at the connection position of the bent wall and the first wall can be reduced, thereby reducing the risk of the edge formed between the bent wall and the first wall of the battery cell in the battery causing scratches to the adjacent battery cells, thereby further improving the overall reliability of the battery.

[0012] In some embodiments of the first aspect, the first angle a satisfies the relationship: 110°≤a≤160°, so as to further reduce the sharpness of the edge at the connection position between the bending wall and the first wall.

[0013] In some embodiments of the first aspect, the bending wall is bent into an arc shape, and a radius b of the bending wall satisfies the relationship: 4mm≤b≤100mm.

[0014] On the one hand, the above technical solution bends the bending wall into an arc shape, so that the outer surface of the bending wall is relatively rounded, thereby reducing the risk of the bending wall of the battery cell in the battery causing scratches to the adjacent battery cells, so as to further improve the overall reliability of the battery; on the other hand, by setting the radius b of the bending wall within the above range, the gap can be increased to improve the reliability and energy density of the battery, while also reducing the risk of performance degradation of the battery cell due to the bending wall squeezing the electrode assembly.

[0015] In some embodiments of the first aspect, the radius b satisfies the relationship: 8 mm ≤ b ≤ 50 mm, so as to further enhance the reliability of the battery and the balance between the energy density and the performance of the battery cell.

[0016] In some embodiments of the first aspect, the electrode assembly includes a straight region and two bent regions, and the two bent regions are respectively connected to two ends of the straight region along the second direction. In the second direction, both ends of the first wall extend beyond the straight region. The risk of the bent wall squeezing the electrode assembly can be reduced, thereby facilitating the improvement of the reliability of the battery cell.

[0017] In some embodiments of the first aspect, a third dimension c of the bending wall in the first direction and a fourth dimension d of the bending area in the first direction satisfy the relationship: c≥0.1*d.

[0018] The above technical solution sets the third dimension c of the bending wall in the first direction and the fourth dimension d of the bending area in the first direction to satisfy the relationship: c≥0.1*d. This can increase the gap to improve the reliability and energy density of the battery, while also enabling the bending wall to be dynamically adjusted according to the size of the electrode assembly to reduce the risk of the gap formed by the shell on the outside of the bending wall failing due to changes in the overall size of the battery cell, thereby improving the effectiveness of the bending wall.

[0019] In some embodiments of the first aspect, the third dimension c and the fourth dimension d satisfy the relationship: c≤0.25d.

[0020] By setting the third dimension c and the fourth dimension d to satisfy the relationship: c≤0.25d, the risk of the bent wall squeezing the side of the bent area of ​​the electrode assembly close to the first wall can be reduced, thereby facilitating improving the reliability of the battery cell.

[0021] In some embodiments of the first aspect, a fifth dimension e of the bending wall in the second direction and a sixth dimension f of the bending zone in the second direction satisfy the relationship: e≥0.5*f.

[0022] The above technical solution sets the fifth dimension e of the bending wall in the second direction and the sixth dimension f of the bending area in the second direction to satisfy the relationship: e≥0.5*f. This can increase the gap to improve the reliability and energy density of the battery, while also enabling the bending wall to be dynamically adjusted according to the size of the electrode assembly to reduce the risk of the gap formed by the shell on the outside of the bending wall failing due to changes in the overall size of the battery cell, thereby improving the effectiveness of the bending wall.

[0023] In some embodiments of the first aspect, the fifth size e and the sixth size f satisfy the relationship: e≤f.

[0024] By setting the fifth dimension e and the sixth dimension f to satisfy the relationship: e≤f, the risk of the bending wall squeezing the side of the bending area of ​​the electrode assembly close to the second wall can be reduced, which is beneficial to improving the reliability of the battery cell.

[0025] In some embodiments of the first aspect, the bending wall and the bending area are spaced apart, which can further reduce the risk of the bending wall squeezing the bending area of ​​the electrode assembly, thereby facilitating improving the reliability of the battery cell.

[0026] In some embodiments of the first aspect, the bent wall includes a planar segment and two curved segments, one of the two curved segments is connected between the planar segment and the first wall, and the other of the two curved segments is connected between the planar segment and the second wall.

[0027] The sharpness of the edges at the connection positions of the bending wall and the first wall and the bending wall and the second wall can be reduced, thereby reducing the risk of the edges of the battery cells in the battery causing scratches to the adjacent battery cells, thereby further improving the overall reliability of the battery.

[0028] In some embodiments of the first aspect, a groove is provided on the bending wall, and the groove is recessed relative to a surface of the bending wall facing away from the electrode assembly.

[0029] The above technical solution can further increase the gap formed by the shell on the outer side of the bent wall by setting a groove on the bent wall. On the other hand, it can also improve the structural strength of the bent wall to further improve the reliability of the battery.

[0030] In a second aspect, the present application provides a battery, which includes a battery cell provided by any embodiment of the first aspect.

[0031] In some embodiments of the second aspect, the battery further comprises a box body, wherein the plurality of battery cells are accommodated in the box body. The box body comprises a bottom plate, wherein the plurality of battery cells are bonded to the bottom plate.

[0032] The shell of the battery cell of the above technical solution can form a notch on the outer side of the bent wall, which can increase the space enclosed between the edges of adjacent battery cells in the battery, thereby reducing the risk of capillary effect forming in the space enclosed between the edges of adjacent battery cells in the battery, thereby improving the reliability of the battery.

[0033] In some embodiments of the second aspect, the battery further comprises a heat exchange assembly, the heat exchange assembly comprising a current collector and a plurality of heat exchange plates, the plurality of heat exchange plates are connected to the current collector and are spaced apart along the first direction, the battery cells are arranged between adjacent heat exchange plates, the current collector is located on one side of the plurality of battery cells along the second direction, and a portion of the current collector extends into the gap.

[0034] The shell of the battery cell can form a notch on the outside of the bent wall, which can increase the space enclosed between the edges of adjacent battery cells in the battery. Part of the current collector extends into the notch, thereby improving the compactness between the current collector and the battery cell and improving the utilization efficiency of the internal space of the battery, thereby increasing the energy density of the battery.

[0035] In a third aspect, the present application provides an electrical device, comprising a battery provided by any embodiment of the second aspect, and the battery is used to provide electrical energy.

[0036] The above description is only an overview of the technical solution of the present application. In order to more clearly understand the technical means of the present application, it can be implemented in accordance with the contents of the specification. In order to make the above and other purposes, features and advantages of the present application more obvious and easy to understand, the specific implementation methods of the present application are listed below. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Various other advantages and benefits will become apparent to those of ordinary skill in the art by reading the detailed description of the preferred embodiments below. The accompanying drawings are only for the purpose of illustrating the preferred embodiments and are not to be considered as limiting the present application. Also, the same reference symbols are used throughout the accompanying drawings to represent the same components. In the accompanying drawings:

[0038] Figure 1 A schematic diagram of the structure of a vehicle provided in some embodiments of the present application;

[0039] Figure 2 A schematic diagram of an exploded structure of a battery provided in some embodiments of the present application;

[0040] Figure 3 A schematic diagram of the structure of a battery module provided in some embodiments of the present application;

[0041] Figure 4 A schematic diagram of a three-dimensional structure of a battery cell provided in some embodiments of the present application;

[0042] Figure 5 A schematic cross-sectional structure diagram of a battery cell provided in some embodiments of the present application;

[0043] Figure 6 A schematic cross-sectional structure diagram of another battery cell provided in some embodiments of the present application;

[0044] Figure 7 A schematic cross-sectional structure diagram of another battery cell provided in some embodiments of the present application;

[0045] Figure 8 A schematic cross-sectional structure diagram of another battery cell provided in some embodiments of the present application;

[0046] Fig. 9 A schematic cross-sectional structure diagram of another battery cell provided in some embodiments of the present application;

[0047] Fig.10 for Fig. 9 A schematic diagram of the local enlarged structure at H;

[0048] Fig.11 A schematic diagram of a three-dimensional structure of another battery cell provided in some embodiments of the present application;

[0049] Fig.12 A schematic diagram of the partial structure of a battery provided in some embodiments of the present application.

[0050] The reference numerals in the specific implementation manner are as follows:

[0051] 1. Vehicle; 2. Battery; 3. Controller; 4. Motor; 5. Box; 51. Bottom plate; 5a. First box part; 5b. Second box part; 5c. Accommodation space; 6. Battery module; 7. Battery cell; 8. Heat exchange assembly; 81. Current collector; 82. Heat exchange plate;

[0052] 10. Shell; 11. First wall; 12. Second wall; 13. Bend wall; 131. Plane section; 132. Bend section; 20. Electrode assembly; 21. Straight area; 22. Bend area; 30. Notch; 40. Groove; X. First direction; Y. Second direction. DETAILED DESCRIPTION

[0053] In order to make the purpose, technical solution and advantages of the embodiments of the present application clearer, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0054] Unless otherwise defined, all technical and scientific terms used in this application have the same meaning as those commonly understood by technicians in the technical field to which this application belongs; the terms used in the specification of this application are only for the purpose of describing specific embodiments and are not intended to limit this application; the terms "including" and "having" and any variations thereof in the specification and claims of this application and the above-mentioned drawings are intended to cover non-exclusive inclusions. The terms "first", "second", etc. in the specification and claims of this application or the above-mentioned drawings are used to distinguish different objects, rather than to describe a specific order or a primary and secondary relationship.

[0055] Reference to "embodiment" in this application means that a particular feature, structure, or characteristic described in conjunction with the embodiment may be included in at least one embodiment of the present application. The appearance of the phrase in various places in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments.

[0056] In the description of this application, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", and "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 a direct connection, or an indirect connection through an intermediate medium, or it can be the internal communication of two elements. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0057] The term "and / or" in this application is only a description of the association relationship of associated objects, indicating that there can be three relationships. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. In addition, the character " / " in this application generally indicates that the associated objects before and after are in an "or" relationship.

[0058] In the embodiments of the present application, the same reference numerals represent the same components, and for the sake of brevity, detailed descriptions of the same components are omitted in different embodiments. It should be understood that the thickness, length, width and other dimensions of various components in the embodiments of the present application shown in the drawings, as well as the overall thickness, length, width and other dimensions of the integrated device are only exemplary descriptions and should not constitute any limitation to the present application.

[0059] The term "plurality" used in the present application refers to two or more (including two).

[0060] In the present application, the term "parallel" includes not only the absolutely parallel situation, but also the roughly parallel situation conventionally recognized in engineering; meanwhile, "vertical" includes not only the absolutely vertical situation, but also the roughly vertical situation conventionally recognized in engineering.

[0061] In the embodiment of the present application, the battery cell may be a secondary battery cell, which refers to a battery cell that can be continuously used by activating active materials by charging after the battery cell is discharged.

[0062] The battery cells may be lithium-ion battery cells, sodium-ion battery cells, sodium-lithium-ion battery cells, lithium metal battery cells, sodium metal battery cells, lithium-sulfur battery cells, magnesium-ion battery cells, nickel-hydrogen battery cells, nickel-cadmium battery cells, lead-acid battery cells, etc.

[0063] A battery cell generally includes an electrode assembly. The electrode assembly includes a positive electrode and a negative electrode. During the charge and discharge process of the battery cell, active ions (such as lithium ions) are inserted and removed back and forth between the positive electrode and the negative electrode.

[0064] In some embodiments, the electrode assembly further includes a separator, which is disposed between the positive electrode and the negative electrode to prevent the positive and negative electrodes from short-circuiting while allowing active ions to pass through.

[0065] In some embodiments, the positive electrode may be a positive electrode sheet, and the positive electrode sheet may 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.

[0066] As an example, the positive electrode current collector has two surfaces facing each other in its thickness direction, and the positive electrode active material layer is disposed on any one or both of the two facing surfaces of the positive electrode current collector.

[0067] As an example, the positive electrode current collector may be a metal foil or a composite current collector. For example, as the metal foil, stainless steel, copper, aluminum, nickel, silver-surface-treated aluminum, silver-surface-treated stainless steel, carbon electrode, carbon, nickel or titanium, etc. may be used. The composite current collector may include a polymer material base and a metal layer. The composite current collector may be formed by forming a metal material (aluminum, aluminum alloy, nickel, nickel alloy, titanium, titanium alloy, silver and silver alloy, etc.) on a polymer material substrate (such as polypropylene, polyethylene terephthalate, polybutylene terephthalate, polystyrene, polyethylene, etc.).

[0068] As an example, the positive electrode active material layer includes a positive electrode active material. The positive electrode active material may include at least one of the following materials: lithium-containing phosphates, lithium transition metal oxides and their respective modified compounds. Other traditional materials that can be used as positive electrode active materials for batteries can also be used. These positive electrode active materials can be used alone or in combination of two or more. Among them, examples of lithium-containing phosphates may include, but are not limited to, lithium iron phosphate (such as LiFePO4 (also referred to as LFP)), a composite material of lithium iron phosphate and carbon, lithium manganese phosphate (such as LiMnPO4), a composite material of lithium manganese phosphate and carbon, lithium iron manganese phosphate, and at least one of a composite material of lithium iron manganese phosphate and carbon. Examples of lithium transition metal oxides may include, but are not limited to, lithium cobalt oxide (such as LiCoO2), lithium nickel oxide (such as LiNiO2), lithium manganese oxide (such as LiMnO2, LiMn2O4), lithium nickel cobalt oxide, lithium manganese cobalt oxide, lithium nickel manganese oxide, lithium nickel cobalt manganese oxide (such as LiNi 1 / 3 Co 1 / 3 Mn 1 / 3 O2 (also referred to as NCM 333 )、LiNi 0.5 Co 0.2 Mn 0.3 O2 (also referred to as NCM 523 )、LiNi 0.5 Co 0.25 Mn 0.25 O2 (also referred to as NCM 211 )、LiNi 0.6 Co 0.2 Mn 0.2 O2 (also referred to as NCM 622 )、LiNi 0.8 Co 0.1 Mn 0.1 O2 (also referred to as NCM 811 ), lithium nickel cobalt aluminum oxide (such as LiNi 0.80 Co 0.15 Al 0.05 O2) and its modified compounds, etc.

[0069] In some embodiments, the positive electrode may be carbon foam or metal foam. The metal foam may be nickel foam, copper foam, aluminum foam or alloy foam. When the metal foam is used as the positive electrode, the positive electrode active material may not be provided on the surface of the metal foam, but the positive electrode active material may also be provided. As an example, lithium source material, potassium metal or sodium metal may be filled or / and deposited in the metal foam, and the lithium source material is lithium metal and / or lithium-rich material.

[0070] In some embodiments, the negative electrode may be a negative electrode sheet, and the negative electrode sheet may 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.

[0071] As an example, the negative electrode current collector may be a metal foil, a foamed metal, a foamed carbon or a composite current collector. For example, as a metal foil, stainless steel, copper, aluminum, nickel, silver-surface-treated aluminum, silver-surface-treated stainless steel, a carbon electrode, carbon, nickel or titanium, etc. may be used. The foamed metal may be a foamed nickel, a foamed copper, a foamed aluminum or a foamed alloy, etc. The composite current collector may include a polymer material base and a metal layer. The composite current collector may be formed by forming a metal material (copper, copper alloy, nickel, nickel alloy, titanium, titanium alloy, silver and silver alloy, etc.) on a polymer material substrate (such as polypropylene, polyethylene terephthalate, polybutylene terephthalate, polystyrene, polyethylene, etc.).

[0072] As an example, the negative electrode active material may adopt the negative electrode active material for battery cells known in the art. As an example, the negative electrode active material may include at least one of the following materials: artificial graphite, natural graphite, soft carbon, hard carbon, silicon-based materials, tin-based materials, lithium titanate, etc. The silicon-based material may be selected from at least one of elemental silicon, silicon oxide compounds, silicon-carbon composites, silicon-nitrogen composites, and silicon alloys. The tin-based material may be selected from at least one of elemental tin, tin oxide compounds, and tin alloys. Other traditional materials that can be used as negative electrode active materials for batteries may also be used. These negative electrode active materials may be used alone or in combination of two or more.

[0073] In some embodiments, the negative electrode may be foamed carbon or foamed metal. The foamed metal may be foamed nickel, foamed copper, foamed aluminum or foamed alloy, etc. When the foamed metal is used as the negative electrode sheet, the surface of the foamed metal may not be provided with a negative electrode active material, but of course, a negative electrode active material may also be provided.

[0074] As an example, a lithium source material, potassium metal or sodium metal may be filled or / and deposited in the negative electrode current collector, and the lithium source material is lithium metal and / or lithium-rich material.

[0075] In some embodiments, the material of the positive electrode current collector may be aluminum, and the material of the negative electrode current collector may be copper.

[0076] In some embodiments, the electrode assembly further includes a separator disposed between the positive electrode sheet and the negative electrode sheet.

[0077] In some embodiments, the separator is a separator. The present application has no particular limitation on the type of separator, and any known separator with a porous structure having good chemical stability and mechanical stability can be selected.

[0078] As an example, the main material of the separator can be selected from at least one of glass fiber, non-woven fabric, polyethylene, polypropylene, polyvinylidene fluoride, and ceramic. The separator can be a single-layer film or a multi-layer composite film, without special restrictions. When the separator is a multi-layer composite film, the materials of each layer can be the same or different, without special restrictions. The separator can be a separate component located between the positive and negative electrodes, or it can be attached to the surface of the positive and negative electrodes.

[0079] In some embodiments, the separator is a solid electrolyte, which is disposed between the positive electrode sheet and the negative electrode sheet and plays the role of transmitting ions and isolating the positive and negative electrodes.

[0080] In some embodiments, the battery cell further includes an electrolyte, which acts as a conductor of ions between the positive and negative electrodes. The present application has no specific restrictions on the type of electrolyte, which can be selected according to needs. The electrolyte can be liquid, gel or solid.

[0081] In some embodiments, the liquid electrolyte includes an electrolyte salt and a solvent.

[0082] 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 difluorooxalatoborate, lithium dioxalatoborate, lithium difluorodioxalatophosphate, and lithium tetrafluorooxalatophosphate.

[0083] 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, cyclopentane, dimethyl sulfone, methyl ethyl sulfone and diethyl sulfone. The solvent can also be selected from ether solvents. Ether solvents 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.

[0084] The gel electrolyte includes a polymer-based electrolyte skeleton network combined with an ionic liquid-lithium salt.

[0085] Solid electrolytes include polymer solid electrolytes, inorganic solid electrolytes, and composite solid electrolytes.

[0086] As an example, the polymer solid electrolyte may be polyether (polyethylene oxide), polysiloxane, polycarbonate, polyacrylonitrile, polyvinylidene fluoride, polymethyl methacrylate, a single ion polymer, polyionic liquid-lithium salt, cellulose, and the like.

[0087] As an example, the inorganic solid electrolyte can be an oxide solid electrolyte (crystalline perovskite, sodium superconducting ion conductor, garnet, amorphous LiPON film), a sulfide solid electrolyte (crystalline lithium superion conductor (lithium germanium phosphosulfide, silver germanium sulfide), amorphous sulfide) and one or more of a halide solid electrolyte, a nitride solid electrolyte and a hydride solid electrolyte.

[0088] As an example, the composite solid electrolyte is formed by adding an inorganic solid electrolyte filler to a polymer solid electrolyte.

[0089] In some embodiments, the electrode assembly is a wound structure, wherein the positive electrode sheet and the negative electrode sheet are wound into a wound structure.

[0090] In some embodiments, the electrode assembly is a laminate structure.

[0091] As an example, a plurality of positive electrode sheets and a plurality of negative electrode sheets may be provided respectively, and the plurality of positive electrode sheets and the plurality of negative electrode sheets may be alternately stacked.

[0092] As an example, a plurality of positive electrode sheets may be provided, and the negative electrode sheet may be folded to form a plurality of stacked folded segments, with a positive electrode sheet being sandwiched between adjacent folded segments.

[0093] As an example, both the positive electrode sheet and the negative electrode sheet are folded to form a plurality of folded sections that are stacked.

[0094] As an example, a plurality of separators may be provided, each of which is provided between any adjacent positive electrode sheets or negative electrode sheets.

[0095] As an example, the separator may be disposed continuously, and may be disposed between any adjacent positive electrode sheets or negative electrode sheets by folding or winding.

[0096] In some embodiments, the shape of the electrode assembly can be cylindrical, flat, or polygonal.

[0097] In some embodiments, the electrode assembly is provided with tabs, which can lead current out of the electrode assembly. The tabs include a positive tab and a negative tab.

[0098] 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 housing, an aluminum housing, a plastic housing (such as polypropylene), a composite metal housing (such as a copper-aluminum composite housing), or an aluminum-plastic film.

[0099] 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 polygonal battery, such as a hexagonal battery.

[0100] The battery mentioned in the embodiments of the present application refers to a single physical module including one or more battery cells to provide higher voltage and capacity.

[0101] 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.

[0102] In some embodiments, the battery may be a battery pack, which includes a case and battery cells, wherein the battery cells or battery modules are accommodated in the case.

[0103] In some embodiments, the box body can be used as a part of the chassis structure of the vehicle. For example, part of the box body can become at least a part of the floor of the vehicle, or part of the box body can become at least a part of the cross beam and longitudinal beam of the vehicle.

[0104] In some embodiments, the battery may be an energy storage device, which includes an energy storage container, an energy storage cabinet, and the like.

[0105] With the development of new energy technology, batteries are used more and more widely, for example, in mobile phones, laptops, electric vehicles, electric cars, electric airplanes, electric ships, electric toy cars, electric toy ships, electric toy airplanes and electric tools, etc.

[0106] In batteries, the edges of the battery cell shell are usually rounded, and the radius of the rounded corners is small, so that the space between the edges of adjacent battery cells is small. On the one hand, if the space between the edges of adjacent battery cells is too small, it is easy to form a capillary effect, and the structural glue between the battery cell and the box will extend to the end cover of the battery cell through the space surrounded by the edges, which is not conducive to the glue coating between the battery cell and the box, affecting the reliability of the battery. On the other hand, if the space between the edges of adjacent battery cells is too small, it will be difficult to be used by other related components in the battery, making the compactness of the internal structure of the battery low, affecting the energy density of the battery.

[0107] Based on the above considerations, the present application designs a battery cell, which includes a shell and an electrode assembly contained in the shell, wherein the shell includes two first walls opposite to each other along a first direction and two second walls opposite to each other along a second direction, wherein the first direction and the second direction intersect. The shell also includes a bent wall, wherein the first wall and the second wall are connected by the bent wall, the bent wall is bent relative to both the first wall and the second wall, and the shell forms a notch on the outer side of the bent wall.

[0108] The shell of the battery cell in the above technical solution can form a notch on the outside of the bent wall, which can increase the space enclosed by the edges of adjacent battery cells in the battery. On the one hand, it can reduce the risk of capillary effect formed in the space enclosed by the edges of adjacent battery cells in the battery, so as to improve the reliability of the battery; on the other hand, the space enclosed by the edges of adjacent battery cells in the battery is larger and can be easily utilized by other related components in the battery, thereby improving the compactness of the internal structure of the battery to improve the energy density of the battery.

[0109] The technical solutions described in the embodiments of the present application are applicable to batteries and electrical devices using batteries.

[0110] Electrical devices may be, but are not limited to, vehicles, mobile phones, portable devices, laptops, ships, spacecraft, electric toys, and electric tools, etc. Vehicles may be, but are not limited to, fuel vehicles, gas vehicles, or new energy vehicles, and new energy vehicles may be, but are not limited to, pure electric vehicles, hybrid vehicles, or extended-range vehicles, etc.; spacecraft include, but are not limited to, airplanes, rockets, space shuttles, and spacecraft, etc.; electric toys include, but are not limited to, fixed or mobile electric toys, such as game consoles, electric car toys, electric ship toys, and electric airplane toys, etc.; electric tools include, but are not limited to, metal cutting electric tools, grinding electric tools, assembly electric tools, and railway electric tools, such as electric drills, electric grinders, electric wrenches, electric screwdrivers, electric hammers, impact drills, concrete vibrators, and electric planers, etc.

[0111] It should be understood that the technical solutions described in the embodiments of the present application are not limited to the batteries and electrical equipment described above, but can also be applied to all batteries including battery boxes and electrical equipment using batteries. However, for the sake of simplicity, the following embodiments are described using electric vehicles as examples.

[0112] Figure 1 A schematic diagram of the structure of a vehicle provided for some embodiments of the present application.

[0113] Continue to refer Figure 1 The vehicle 1 is provided with a battery 2 inside, and the battery 2 can be provided at the bottom, head, or tail of the vehicle 1. The battery 2 can be used for powering the vehicle 1, for example, the battery 2 can be used as an operating power source for the vehicle 1.

[0114] The vehicle 1 may further include a controller 3 and a motor 4 , wherein the controller 3 is used to control the battery 2 to supply power to the motor 4 , for example, to meet the power requirements of starting, navigating, and driving the vehicle 1 .

[0115] In some embodiments of the present application, the battery 2 can not only serve as an operating power source for the vehicle 1, but also serve as a driving power source for the vehicle 1, replacing or partially replacing fuel or natural gas to provide driving power for the vehicle 1.

[0116] Figure 2 An exploded schematic diagram of a battery provided for some embodiments of the present application.

[0117] Continue to refer Figure 2 The battery 2 includes a box body 5 and a battery cell, and the battery cell is accommodated in the box body 5.

[0118] The box 5 is used to accommodate the battery cells, and the box 5 can be of various structures. In some embodiments, the box 5 can include a first box portion 5a and a second box portion 5b, the first box portion 5a and the second box portion 5b cover each other, and the first box portion 5a and the second box portion 5b jointly define a storage space 5c for accommodating the battery cells. The second box portion 5b can be a hollow structure with an opening at one end, the first box portion 5a is a plate-like structure, and the first box portion 5a covers the opening side of the second box portion 5b to form a box 5 with a storage space 5c; the first box portion 5a and the second box portion 5b can also be hollow structures with an opening at one side, and the opening side of the first box portion 5a covers the opening side of the second box portion 5b to form a box 5 with a storage space 5c. Of course, the first box portion 5a and the second box portion 5b can be of various shapes, such as a cylinder, a cuboid, etc.

[0119] In order to improve the sealing performance after the first box body 5a and the second box body 5b are connected, a sealing member, such as a sealant, a sealing ring, etc., may also be provided between the first box body 5a and the second box body 5b.

[0120] Assuming that the first box body portion 5a covers the top of the second box body portion 5b, the first box body portion 5a can also be called an upper box cover, and the second box body portion 5b can also be called a lower box.

[0121] In the battery 2, there can be one or more battery cells. If there are multiple battery cells, the multiple battery cells can be connected in series, in parallel, or in mixed connection. Mixed connection means that the multiple battery cells are both connected in series and in parallel. The multiple battery cells can be directly connected in series, in parallel, or in mixed connection, and then the whole formed by the multiple battery cells is accommodated in the box 5; of course, multiple battery cells can also be connected in series, in parallel, or in mixed connection to form a battery module 6, and the multiple battery modules 6 are then connected in series, in parallel, or in mixed connection to form a whole, and accommodated in the box 5.

[0122] Figure 3 for Figure 2 Schematic diagram of the structure of the battery module shown.

[0123] In some embodiments, referring to the figure, there are multiple battery cells 7, and the multiple battery cells 7 are first connected in series, parallel or mixed to form a battery module 6. The multiple battery modules 6 are then connected in series, parallel or mixed to form a whole, and are accommodated in the box.

[0124] The multiple battery cells 7 in the battery module 6 can be electrically connected through a busbar component to achieve parallel connection, series connection or mixed connection of the multiple battery cells 7 in the battery module 6 .

[0125] Figure 4 A schematic diagram of a three-dimensional structure of a battery cell provided in some embodiments of the present application. Figure 5 A schematic diagram of the cross-sectional structure of a battery cell provided in some embodiments of the present application.

[0126] Continue to refer Figures 4 to 5 The embodiment of the present application provides a battery cell 7, the battery cell 7 includes a shell 10 and an electrode assembly 20 accommodated in the shell 10, the shell 10 includes two first walls 11 opposite to each other along a first direction X and two second walls 12 opposite to each other along a second direction Y, the first direction X and the second direction Y intersect. The shell 10 also includes a bent wall 13, the first wall 11 and the second wall 12 are connected by the bent wall 13, the bent wall 13 is bent relative to the first wall 11 and the second wall 12, and the shell 10 forms a notch 30 on the outer side of the bent wall 13.

[0127] Exemplarily, the housing 10 is a component for forming an internal environment of the battery cell 7. The formed internal environment can be used to accommodate the electrode assembly 20, electrolyte and other components. Optionally, the housing 10 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.

[0128] The electrode assembly 20 is a component in the battery cell 7 where electrochemical reactions occur. The electrode assembly 20 is mainly formed by winding or stacking positive and negative electrode sheets, and a separator is usually provided between the positive and negative electrode sheets. The parts of the positive and negative electrode sheets with active materials constitute the main body of the electrode assembly 20, and the parts of the positive and negative electrode sheets without active materials each constitute a tab. The positive tab and the negative tab may be located together at one end of the main body or at both ends of the main body respectively. During the charge and discharge process of the battery 2, the positive active material and the negative active material react with the electrolyte, and the tabs connect the electrode terminals to form a current loop.

[0129] The bending of the bending wall 13 relative to the first wall 11 means that an angle not equal to 180 degrees can be formed between the bending wall 13 and the first wall 11 , and the bending of the bending wall 13 relative to the second wall 12 means that an angle not equal to 180 degrees can be formed between the bending wall 13 and the second wall 12 .

[0130] The notch 30 formed on the outer side of the bent wall 13 of the housing 10 refers to the space surrounded by the extended imaginary portion of the first wall 11 along the second direction Y, the extended imaginary portion of the second wall 12 along the first direction X, and the bent wall 13. The extended imaginary portion of the first wall 11 along the second direction Y can be understood as the imaginary portion of the first wall 11 that continues to extend along the second direction Y outside its main body, and the extended imaginary portion of the second wall 12 along the first direction X can be understood as the imaginary portion of the second wall 12 that continues to extend along the first direction X outside its main body.

[0131] Optionally, the bending wall 13 may be detachably connected between the first wall 11 and the second wall 12, or may be integrally provided on the first wall 11 and the second wall 12. The bending wall 13 may be directly connected to the first wall 11 and the second wall 12, or may be restricted to the first wall 11 and the second wall 12 by other components. As an example, the connection method of the bending wall 13 to the first wall 11 and the second wall 12 may be, but is not limited to, bolt connection, welding, riveting, clamping or bonding.

[0132] As an example, the bending wall 13 and the first wall 11 are an integrally formed structure. On the one hand, there is no need to connect the bending wall 13 and the first wall 11 through an additional connection process, which simplifies the manufacturing process. On the other hand, compared with connecting the bending wall 13 and the first wall 11 through an additional connection process, the bending wall 13 and the first wall 11 in an integrated structure have a higher connection firmness. As another example, the bending wall 13 and the second wall 12 are an integrally formed structure. As yet another example, the bending wall 13, the first wall 11 and the second wall 12 are an integrally formed structure, which can further simplify the manufacturing process and further improve the structural strength of the shell 10.

[0133] It should be noted that in the current battery 2, the edges of the outer shell of the battery cell 7 are usually rounded, and the radius of the rounded corners is small, so that the space enclosed between the edges of adjacent battery cells 7 is small. On the one hand, if the space enclosed between the edges of adjacent battery cells 7 is too small, it is easy to form a capillary effect, and the structural glue between the battery cell 7 and the box 5 will extend to the end cover of the battery cell 7 through the space enclosed by the edges, which is not conducive to the glue coating between the battery cell 7 and the box 5, affecting the reliability of the battery 2. On the other hand, if the space enclosed between the edges of adjacent battery cells 7 is too small, it will be difficult to be used by other related components in the battery 2, making the compactness of the internal structure of the battery 2 low, affecting the energy density of the battery 2.

[0134] In this way, the shell 10 of the battery cell 7 of the above technical solution can form a notch 30 on the outside of the bent wall 13, which can increase the space enclosed by the edges of adjacent battery cells 7 in the battery 2. On the one hand, it can reduce the risk of capillary effect formed in the space enclosed by the edges of adjacent battery cells 7 in the battery 2, so as to improve the reliability of the battery 2; on the other hand, the space enclosed by the edges of adjacent battery cells 7 in the battery 2 is larger and can be easily used by other related components in the battery 2, thereby improving the compactness of the internal structure of the battery 2 and improving the energy density of the battery 2.

[0135] In some embodiments, a first dimension L1 of the notch 30 along the first direction X satisfies the relationship: 3 mm ≤ L1 ≤ 30 mm, and a second dimension L2 of the notch 30 along the second direction Y satisfies the relationship: 5 mm ≤ L2 ≤ 40 mm.

[0136] As an example, the first dimension L1 of the notch 30 along the first direction X can be but is not limited to 3mm, 4mm, 5mm, 6mm, 7mm, 8mm, 9mm, 10mm, 11mm, 12mm, 13mm, 14mm, 15mm, 16mm, 17mm, 18mm, 19mm, 20mm, 21mm, 22mm, 23mm, 24mm, 25mm, 26mm, 27mm, 28mm, 29mm, 30mm, etc.

[0137] The second dimension L2 of the notch 30 along the second direction Y may be, but is not limited to, 5mm, 6mm, 7mm, 8mm, 9mm, 10mm, 11mm, 12mm, 13mm, 14mm, 15mm, 16mm, 17mm, 18mm, 19mm, 20mm, 21mm, 22mm, 23mm, 24mm, 25mm, 26mm, 27mm, 28mm, 29mm, 30mm, 31mm, 32mm, 33mm, 34mm, 35mm, 36mm, 37mm, 38mm, 39mm, 40mm, etc.

[0138] It is understandable that the size of the notch 30 is inversely proportional to the size of the internal space of the housing 10. The larger the notch 30, the smaller the internal space of the housing 10; the smaller the notch 30, the larger the internal space of the housing 10. The size of the notch 30 is proportional to the size of the space enclosed between the edges of the adjacent battery cells 7 in the battery 2. The size of the internal space of the housing 10 is proportional to the total power of the battery cells 7.

[0139] The above technical solution can increase the gap 30 to improve the reliability and energy density of the battery 2 while taking into account the total power of the battery cell 7 by setting the first size L1 of the gap 30 along the first direction X and the second size L2 of the gap 30 along the second direction Y within the above range.

[0140] Furthermore, the first dimension L1 satisfies the relationship: 5 mm ≤ L1 ≤ 15 mm, and the second dimension L2 satisfies the relationship: 7 mm ≤ L2 ≤ 20 mm, so as to further enhance the reliability of the battery 2 and the balance between the energy density and the total power of the battery cell 7 .

[0141] As an example, the first dimension L1 of the notch 30 along the first direction X may be, but is not limited to, 5 mm, 5.5 mm, 6.5 mm, 7.5 mm, 8.5 mm, 9.5 mm, 10.5 mm, 11.5 mm, 12.5 mm, 13.5 mm, 14.5 mm, 15 mm, etc.

[0142] The second dimension L2 of the notch 30 along the second direction Y may be, but is not limited to, 7 mm, 7.5 mm, 8.5 mm, 9.5 mm, 10.5 mm, 11.5 mm, 12.5 mm, 13.5 mm, 14.5 mm, 15.5 mm, 16.5 mm, 17.5 mm, 18.5 mm, 19.5 mm, 20 mm, etc.

[0143] In some embodiments, the bent wall 13 and the first wall 11 are both flat plate structures, and a first angle a formed between the bent wall 13 and the first wall 11 and pointing toward the electrode assembly 20 satisfies the relationship: a>90°.

[0144] As an example, the first angle a can be but is not limited to 95°, 100°, 105°, 110°, 115°, 120°, 125°, 130°, 135°, 140°, 145°, 150°, 155°, 160°, 165°, 170°, 175°, etc.

[0145] By setting the first angle a formed between the bent wall 13 and the first wall 11 and pointing to the electrode assembly 20 within the above-mentioned range, the sharpness of the edge at the connection position of the bent wall 13 and the first wall 11 can be reduced, thereby reducing the risk of the edge formed between the bent wall 13 and the first wall 11 of the battery cell 7 in the battery 2 causing scratches to the adjacent battery cells 7, thereby further improving the overall reliability of the battery 2.

[0146] Furthermore, the first angle a satisfies the relationship: 110°≤a≤160°, so as to further reduce the sharpness of the edge at the connection position between the bending wall 13 and the first wall 11 .

[0147] As an example, the first angle a can be but is not limited to 110°, 113°, 115°, 117°, 120°, 123°, 125°, 127°, 130°, 133°, 135°, 137°, 140°, 143°, 145°, 147°, 150°, 153°, 155°, 157°, 160°, etc.

[0148] In some optional embodiments, the bent wall 13 and the second wall 12 are both flat plate structures, and a second angle k formed between the bent wall 13 and the second wall 12 and directed toward the electrode assembly 20 satisfies the relationship: b>90°.

[0149] As an example, the second angle k can be but is not limited to 95°, 100°, 105°, 110°, 115°, 120°, 125°, 130°, 135°, 140°, 145°, 150°, 155°, 160°, 165°, 170°, 175°, etc.

[0150] By setting the second angle k formed between the bent wall 13 and the second wall 12 and pointing to the electrode assembly 20 within the above-mentioned range, the sharpness of the edge at the connection position between the bent wall 13 and the second wall 12 can be reduced, thereby reducing the risk of the edge formed between the bent wall 13 and the second wall 12 of the battery cell 7 in the battery 2 causing scratches to the adjacent battery cell 7, thereby further improving the overall reliability of the battery 2.

[0151] Furthermore, the second angle k satisfies the relationship: 110°≤a≤160°, so as to further reduce the sharpness of the edge at the connection position between the bending wall 13 and the second wall 12 .

[0152] As an example, the second angle k can be but is not limited to 110°, 113°, 115°, 117°, 120°, 123°, 125°, 127°, 130°, 133°, 135°, 137°, 140°, 143°, 145°, 147°, 150°, 153°, 155°, 157°, 160°, etc.

[0153] In some embodiments, the first angle a and the second angle k are the same to improve the overall regularity of the housing 10 of the battery cell 7 .

[0154] Figure 6 A schematic cross-sectional structure diagram of another battery cell 7 provided in some embodiments of the present application.

[0155] Continue to refer Figure 6In some embodiments, the bending wall 13 is bent into an arc shape, and the radius b of the bending wall 13 satisfies the relationship: 4mm≤b≤100mm. It should be noted that since the bending wall 13 has a certain thickness, the arc-shaped bending wall 13 has an inner diameter and an outer diameter, and the radius b of the bending wall 13 refers to the outer diameter of the bending wall 13.

[0156] As an example, the radius b of the bending wall 13 can be but is not limited to 4mm, 5mm, 6mm, 7mm, 8mm, 9mm, 10mm, 15mm, 20mm, 25mm, 30mm, 35mm, 40mm, 45mm, 50mm, 55mm, 60mm, 65mm, 70mm, 75mm, 80mm, 85mm, 90mm, 95mm, 100mm, etc.

[0157] It can be understood that the larger the radius of the bending wall 13, the larger the gap 30 is, and the smaller the distance between the bending wall 13 and the electrode assembly 20 is; the smaller the radius of the bending wall 13, the smaller the gap 30 is, and the larger the distance between the bending wall 13 and the electrode assembly 20 is.

[0158] On the one hand, the above technical scheme bends the bending wall 13 into an arc shape, so that the outer surface of the bending wall 13 is relatively rounded, thereby reducing the risk of the bending wall 13 of the battery cell 7 in the battery 2 causing scratches to the adjacent battery cell 7, so as to further improve the overall reliability of the battery 2; on the other hand, by setting the radius b of the bending wall 13 within the above range, the notch 30 can be increased to improve the reliability and energy density of the battery 2, while also reducing the risk of performance degradation of the battery cell 7 due to the bending wall 13 squeezing the electrode assembly 20.

[0159] Furthermore, the radius b of the bending wall 13 satisfies the relationship: 8 mm ≤ b ≤ 50 mm, so as to further enhance the balance between the reliability and energy density of the battery 2 and the performance of the battery cell 7 .

[0160] As an example, the radius b of the bending wall 13 can be but is not limited to 8mm, 8.5mm, 9mm, 9.5mm, 10mm, 10.5mm, 11mm, 12mm, 13mm, 14mm, 15mm, 16mm, 17mm, 18mm, 19mm, 20mm, 23mm, 25mm, 27mm, 30mm, 33mm, 35mm, 37mm, 40mm, 43mm, 45mm, 47mm, 50mm, etc.

[0161] Figure 7 This is a schematic cross-sectional structure diagram of another battery cell 7 provided in some embodiments of the present application. Figure 8This is a schematic cross-sectional structure diagram of another battery cell 7 provided in some embodiments of the present application.

[0162] Continue to refer Figure 7 and Figure 8 In some embodiments, the electrode assembly 20 includes a straight region 21 and two bent regions 22, and the two bent regions 22 are respectively connected to the two ends of the straight region 21 along the second direction Y. In the second direction Y, both ends of the first wall 11 exceed the straight region 21. The risk of the bent wall 13 squeezing the electrode assembly 20 can be reduced, thereby facilitating the improvement of the reliability of the battery cell 7.

[0163] In some embodiments, a third dimension c of the bending wall 13 in the first direction X and a fourth dimension d of the bending area 22 in the first direction X satisfy the relationship: c≥0.1*d.

[0164] As an example, the third dimension c of the bending wall 13 in the first direction X can be but is not limited to 0.1d, 0.2d, 0.3d, 0.4d, 0.5d, 0.6d, 0.7d, 0.8d, 0.9d, d, 1.5d, 2d, 2.5d, 3d, etc.

[0165] It can be understood that, when the size of the bending wall 13 in the second direction Y remains unchanged, the larger the third size c of the bending wall 13 in the first direction X, the larger the notch 30 formed by the shell 10 on the outside of the bending wall 13. In addition, the larger the fourth size d of the bending area 22 in the first direction X, the larger the size of the electrode assembly 20 in the first direction X, so that the size of the battery cell 7 as a whole in the first direction X is also larger. Due to the proportional relationship between the third size c and the fourth size d, as the size of the battery cell 7 as a whole in the first direction X increases, the notch 30 formed by the shell 10 on the outside of the bending wall 13 will also increase accordingly.

[0166] In this way, the above technical scheme sets the third dimension c of the bending wall 13 in the first direction X and the fourth dimension d of the bending zone 22 in the first direction X to satisfy the relationship: c≥0.1*d. This can increase the gap 30 to improve the reliability and energy density of the battery 2, while also enabling the bending wall 13 to be dynamically adjusted according to the size of the electrode assembly 20, so as to reduce the risk of failure of the function of the gap 30 formed by the shell 10 on the outside of the bending wall 13 due to changes in the overall size of the battery cell 7, thereby improving the effectiveness of the bending wall 13.

[0167] Furthermore, the third dimension c and the fourth dimension d also satisfy the relationship: c≤0.25d.

[0168] As an example, the third dimension c of the bending wall 13 in the first direction X can be but is not limited to 0.1d, 0.11d, 0.12d, 0.13d, 0.14d, 0.15d, 0.16d, 0.17d, 0.18d, 0.19d, 0.2d, 0.21d, 0.22d, 0.23d, 0.24d, 0.25d, etc.

[0169] It can be understood that, when the size of the bending wall 13 in the second direction Y remains unchanged, the larger the third size c of the bending wall 13 in the first direction X is, the smaller the angle formed between the bending wall 13 and the first wall 11 will be, that is, the distance between the bending wall 13 and the side of the bending area 22 of the electrode assembly 20 close to the first wall 11 will be.

[0170] In this way, by setting the third dimension c and the fourth dimension d to satisfy the relationship: c≤0.25d, the risk of the bending wall 13 squeezing the side of the bending area 22 of the electrode assembly 20 close to the first wall 11 can be reduced, which is beneficial to improving the reliability of the battery cell 7.

[0171] In some embodiments, a fifth dimension e of the bending wall 13 in the second direction Y and a sixth dimension f of the bending area 22 in the second direction Y satisfy the relationship: e≥0.5*f.

[0172] As an example, the fifth dimension e of the bending wall 13 in the second direction Y can be but is not limited to 0.5f, 0.6f, 0.7f, 0.8f, 0.9f, f, 1.2f, 1.4f, 1.6f, 1.7f, 1.8f, 1.9f, 2f, 2.5f, 3f, 3.5f, 4f, etc.

[0173] It can be understood that, when the size of the bending wall 13 in the first direction X remains unchanged, the larger the fifth size e of the bending wall 13 in the second direction Y, the larger the notch 30 formed by the shell 10 on the outside of the bending wall 13. In addition, the larger the sixth size f of the bending area 22 in the second direction Y, the larger the size of the electrode assembly 20 in the second direction Y, so that the size of the battery cell 7 as a whole in the second direction Y is also larger. Due to the proportional relationship between the fifth size e and the sixth size f, as the size of the battery cell 7 as a whole in the second direction Y increases, the notch 30 formed by the shell 10 on the outside of the bending wall 13 will also increase accordingly.

[0174] In this way, the above technical scheme sets the fifth dimension e of the bending wall 13 in the second direction Y and the sixth dimension f of the bending zone 22 in the second direction Y to satisfy the relationship: e≥0.5*f. This can increase the gap 30 to improve the reliability and energy density of the battery 2, while also enabling the bending wall 13 to be dynamically adjusted according to the size of the electrode assembly 20, so as to reduce the risk of failure of the function of the gap 30 formed by the shell 10 on the outside of the bending wall 13 due to changes in the overall size of the battery cell 7, thereby improving the effectiveness of the bending wall 13.

[0175] Further, the fifth dimension e and the sixth dimension f satisfy the relationship: e≤f.

[0176] As an example, the fifth dimension e of the bending wall 13 in the second direction Y can be but is not limited to 0.5f, 0.52f, 0.54f, 0.56f, 0.58f, 0.6f, 0.62f, 0.64f, 0.66f, 0.68f, 0.7f, 0.72f, 0.74f, 0.76f, 0.78f, 0.8f, 0.82f, 0.84f, 0.86f, 0.88f, 0.9f, 0.92f, 0.94f, 0.96f, 0.98f, f, etc.

[0177] It can be understood that, when the size of the bending wall 13 in the first direction X remains unchanged, the larger the fifth size e of the bending wall 13 in the second direction Y is, the smaller the angle formed between the bending wall 13 and the second wall 12 will be, that is, the distance between the bending wall 13 and the side of the bending area 22 of the electrode assembly 20 close to the second wall 12 will be.

[0178] In this way, by setting the fifth dimension e and the sixth dimension f to satisfy the relationship: e≤f, the risk of the bending wall 13 squeezing the bending area 22 of the electrode assembly 20 on the side close to the second wall 12 can be reduced, which is beneficial to improving the reliability of the battery cell 7.

[0179] In some embodiments, the bending wall 13 and the bending area 22 are spaced apart from each other, which can further reduce the risk of the bending wall 13 squeezing the bending area 22 of the electrode assembly 20 , thereby facilitating improving the reliability of the battery cell 7 .

[0180] Fig. 9 A schematic cross-sectional structure diagram of another battery 2 cell provided in some embodiments of the present application is shown. Fig.10 for Fig. 9 Schematic diagram of the local enlarged structure at H.

[0181] Continue to refer Figures 9 and 10In some embodiments, the bent wall 13 includes a planar segment 131 and two curved segments 132 , one of the two curved segments 132 is connected between the planar segment 131 and the first wall 11 , and the other of the two curved segments 132 is connected between the planar segment 131 and the second wall 12 .

[0182] Exemplarily, the plane section 131 is a flat plate structure, and the curved section 132 is an arc structure. The plane section 131 is connected to the first wall 11 and the second wall 12 respectively through two curved sections 132, which can reduce the sharpness of the edges at the connection position of the bent wall 13 and the first wall 11 and the edges at the connection position of the bent wall 13 and the second wall 12, thereby reducing the risk of the edges of the battery cells 7 in the battery 2 causing scratches to the battery cells 7 adjacent thereto, so as to further improve the overall reliability of the battery 2.

[0183] Optionally, the curved section 132 and the plane section 131 are integrally formed. On the one hand, there is no need to connect the curved section 132 and the plane section 131 through an additional connection process, which simplifies the manufacturing process. On the other hand, compared with connecting the curved section 132 and the plane section 131 through an additional connection process, the curved section 132 and the plane section 131 in an integral structure have a higher connection firmness.

[0184] Fig.11 This is a schematic diagram of a three-dimensional structure of another battery 2 cell provided in some embodiments of the present application.

[0185] Continue to refer Fig.11 In some embodiments, a groove 40 is provided on the bending wall 13 , and the groove 40 is recessed relative to a surface of the bending wall 13 facing away from the electrode assembly 20 .

[0186] Exemplarily, the groove 40 has a certain accommodation space, which can further increase the notch 30 formed by the housing 10 on the outer side of the bent wall 13. The groove 40 can also form a concave-convex structure on the side of the bent wall 13 facing away from the electrode assembly 20, which is beneficial to improve the structural strength of the bent wall 13.

[0187] Optionally, the number of the grooves 40 may be one or more. As an example, when the number of the grooves 40 is plural, the plurality of grooves 40 are distributed in an array.

[0188] Optionally, the bending wall 13 may be an integrally formed groove 40 , which can simplify the process and help reduce costs.

[0189] Along the thickness direction of the bending wall 13 , the projection shape of the groove 40 may be, but is not limited to, a rectangle, a circle, a trapezoid, an ellipse or a triangle, etc., and may be selected according to the actual application environment.

[0190] The above technical solution can further increase the gap 30 formed by the shell 10 on the outer side of the bent wall 13 by setting the groove 40 on the bent wall 13, on the one hand; on the other hand, it can also improve the structural strength of the bent wall 13 to further improve the reliability of the battery 2.

[0191] According to some embodiments of the present application, the present application further provides a battery 2, comprising a plurality of battery cells 7 according to any of the above schemes.

[0192] Fig.12 A schematic diagram of the partial structure of a battery 2 provided in some embodiments of the present application.

[0193] Continue to refer Fig.12 In some embodiments, the battery 2 further includes a box body 5, and a plurality of battery cells 7 are accommodated in the box body 5. The box body 5 includes a bottom plate 51, and the plurality of battery cells 7 are bonded to the bottom plate 51.

[0194] It should be noted that multiple battery cells 7 are bonded to the bottom plate 51 of the box body 5 by structural adhesive. If the space enclosed by the edges of adjacent battery cells 7 is small, a capillary effect is easily formed, and the structural adhesive between the battery cells 7 and the box body 5 will extend to the end cover of the battery cells 7 through the space enclosed by the edges, which is not conducive to the coating of glue between the battery cells 7 and the box body 5, affecting the reliability of the battery 2.

[0195] In this way, the shell 10 of the battery cell 7 of the above technical solution can form a notch 30 on the outside of the bending wall 13, which can increase the space enclosed by the edges of adjacent battery cells 7 in the battery 2, thereby reducing the risk of capillary effect forming in the space enclosed by the edges of adjacent battery cells 7 in the battery 2, thereby improving the reliability of the battery 2.

[0196] In some embodiments, the battery 2 further includes a heat exchange assembly 8, which includes a current collector 81 and a plurality of heat exchange plates 82, wherein the plurality of heat exchange plates 82 are connected to the current collector 81 and are spaced apart along the first direction X, and battery cells 7 are disposed between adjacent heat exchange plates 82. The current collector 81 is located on one side of the plurality of battery cells 7 along the second direction Y, and a portion of the current collector 81 extends into the notch 30.

[0197] The shell 10 of the battery cell 7 can form a notch 30 on the outer side of the bent wall 13, which can increase the space enclosed between the edges of adjacent battery cells 7 in the battery 2. Part of the current collector 81 extends into the notch 30, thereby improving the compactness between the current collector 81 and the battery cell 7 and improving the utilization efficiency of the internal space of the battery 2, thereby increasing the energy density of the battery 2.

[0198] According to some embodiments of the present application, the present application further provides an electrical device, comprising a battery 2 according to any of the above schemes, wherein the battery 2 is used only to provide electrical energy.

[0199] In order to better understand the battery cell 7 provided in the embodiment of the present application, based on the same inventive concept, an embodiment of the above-mentioned battery cell 7 in actual application is provided here for illustration.

[0200] The embodiment of the present application provides a battery cell 7, which includes a housing 10 and an electrode assembly 20 contained in the housing 10, wherein the housing 10 includes two first walls 11 opposite to each other along a first direction X and two second walls 12 opposite to each other along a second direction Y, wherein the first direction X intersects with the second direction Y. The housing 10 also includes a bent wall 13, wherein the first wall 11 and the second wall 12 are connected by the bent wall 13, the bent wall 13 is bent relative to both the first wall 11 and the second wall 12, and the housing 10 forms a notch 30 on the outer side of the bent wall 13.

[0201] The shell 10 of the battery cell 7 of the above technical solution can form a notch 30 on the outer side of the bent wall 13, which can increase the space enclosed by the edges of adjacent battery cells 7 in the battery 2. On the one hand, it can reduce the risk of capillary effect formed in the space enclosed by the edges of adjacent battery cells 7 in the battery 2, so as to improve the reliability of the battery 2; on the other hand, the space enclosed by the edges of adjacent battery cells 7 in the battery 2 is larger and can be easily used by other related components in the battery 2, thereby improving the compactness of the internal structure of the battery 2 and improving the energy density of the battery 2.

[0202] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present application may be combined with each other.

[0203] 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 aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein by equivalents; 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 included in the scope of the claims and specification of the present application. In particular, as long as there is no structural conflict, the various technical features mentioned in the various embodiments can be combined in any way. The present application is not limited to the specific embodiments disclosed herein, but includes all technical solutions that fall within the scope of the claims.

Claims

1. A battery cell, characterized in that: The invention comprises a shell and an electrode assembly contained in the shell, wherein the shell comprises two first walls opposite to each other in a first direction and two second walls opposite to each other in a second direction, wherein the first direction and the second direction intersect each other; The shell further includes a bending wall, the first wall and the second wall are connected by the bending wall, the bending wall is bent relative to the first wall and the second wall, and the shell forms a notch on the outer side of the bending wall.

2. The battery cell according to claim 1, characterized in that: A first dimension L1 of the notch along the first direction satisfies the relationship: 3mm≤L1≤30mm, and a second dimension L2 of the notch along the second direction satisfies the relationship: 5mm≤L2≤40mm.

3. The battery cell according to claim 2, characterized in that: The first size L1 satisfies the relationship: 5mm≤L1≤15mm, and the second size L2 satisfies the relationship: 7mm≤L2≤20mm.

4. The battery cell according to claim 1, characterized in that: The bent wall and the first wall are both flat plate structures, and a first angle a formed between the bent wall and the first wall and directed toward the electrode assembly satisfies the relationship: a>90°.

5. The battery cell according to claim 4, characterized in that: The first angle a satisfies the relationship: 110°≤a≤160°.

6. The battery cell according to claim 1, characterized in that: The bending wall is bent into an arc shape, and a radius b of the bending wall satisfies the relationship: 4mm≤b≤100mm.

7. The battery cell according to claim 6, characterized in that: The radius b satisfies the relationship: 8mm≤b≤50mm.

8. The battery cell according to any one of claims 1 to 7, characterized in that: The electrode assembly includes a straight area and two bending areas, and the two bending areas are respectively connected to two ends of the straight area along the second direction; In the second direction, both ends of the first wall extend beyond the straight area.

9. The battery cell according to claim 8, characterized in that: A third dimension c of the bending wall in the first direction and a fourth dimension d of the bending area in the first direction satisfy the relationship: c≥0.1*d.

10. The battery cell according to claim 9, characterized in that: The third dimension c and the fourth dimension d satisfy the relationship: c≤0.25d.

11. The battery cell according to claim 8, characterized in that: A fifth dimension e of the bending wall in the second direction and a sixth dimension f of the bending area in the second direction satisfy the relationship: e≥0.5*f.

12. The battery cell according to claim 11, characterized in that: The fifth size e and the sixth size f satisfy the relationship: e≤f.

13. The battery cell according to claim 8, characterized in that: The bending wall is spaced apart from the bending area.

14. The battery cell according to any one of claims 1 to 7, characterized in that: The bent wall includes a plane segment and two curved segments, one of the two curved segments is connected between the plane segment and the first wall, and the other of the two curved segments is connected between the plane segment and the second wall.

15. The battery cell according to any one of claims 1 to 7, characterized in that: The bending wall is provided with a groove, and the groove is recessed relative to a surface of the bending wall facing away from the electrode assembly.

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

17. The battery according to claim 16, characterized in that The battery further comprises a box, wherein the plurality of battery cells are accommodated in the box; The box body includes a bottom plate, and the plurality of battery cells are bonded to the bottom plate.

18. The battery according to claim 16, characterized in that The battery further includes a heat exchange assembly, the heat exchange assembly includes a current collector and a plurality of heat exchange plates, the plurality of heat exchange plates are connected to the current collector and are arranged at intervals along the first direction, and the battery cells are arranged between adjacent heat exchange plates; The current collector is located at one side of the plurality of battery cells along the second direction, and a portion of the current collector extends into the gap.

19. An electrical device, characterized in that: The invention comprises a battery as claimed in any one of claims 16 to 18, wherein the battery is used to provide electrical energy.

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