Battery monomer, battery and electric device

Abstract

The utility model provides a battery monomer, a battery and a power utilization device, and belongs to the technical field of batteries. The battery monomer comprises a shell and an end cover, a containing cavity with an opening is formed in the shell, the containing cavity is used for containing an electrode assembly and electrolyte, and the cavity wall face of the containing cavity comprises a first area and a second area. The end cover seals the opening. The first area and the second area are both provided with insulating layers, the thickness of the insulating layer arranged in the first area is smaller than that of the insulating layer arranged in the second area, or only the second area is provided with the insulating layer, and the insulating layers are used for separating the electrolyte and the shell. According to the battery monomer adopting the structure, the corrosion resistance of the shell in the first area is weaker than that of the shell in the second area, so that the shell is preferentially corroded and punctured in the first area compared with the second area, and the corroded and punctured position of the shell in the subsequent use process can be controlled; the phenomenon that corrosion breakdown points of the shell appear at any position is reduced.

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] In recent years, new energy vehicles have developed by leaps and bounds. In the field of electric vehicles, power batteries, as the power source of electric vehicles, play an irreplaceable and important role. With the vigorous promotion of new energy vehicles, the demand for power battery products is also growing. Among them, batteries, as core components of new energy vehicles, have high requirements in terms of reliability and service life.

[0003] In battery technology, a battery cell usually includes an outer shell and an electrode assembly. The outer shell includes a shell and an end cap. The end cap is closed at the opening of the shell, and the electrode assembly and the electrolyte are contained in the shell. However, in the use of existing battery cells, it is very easy for the electrolyte to corrode the shell, causing the shell to be corroded and punctured, resulting in a short service life of the battery cell. The corrosion and puncture point is uncontrollable, resulting in the risk of leakage of the battery cell, and the protection of the battery cell is relatively difficult, which is not conducive to improving the reliability of the battery cell. Utility Model Content

[0004] The embodiments of the present application provide 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, comprising a shell and an end cover; a accommodating chamber with an opening is formed inside the shell, the accommodating chamber is used to accommodate an electrode assembly and an electrolyte, and the cavity wall of the accommodating chamber includes a first area and a second area; the end cover closes the opening; wherein both the first area and the second area are provided with an insulating layer, and the thickness of the insulating layer provided in the first area is less than the thickness of the insulating layer provided in the second area, and the insulating layer is used to separate the electrolyte and the shell; or, only the second area is provided with an insulating layer, and the insulating layer is used to separate the electrolyte and the shell.

[0006] In the above technical solution, an insulating layer is provided on at least part of the wall surface of the accommodating cavity of the shell, so that the insulating layer can separate the electrolyte and the shell to achieve insulation isolation between the shell and the electrode assembly, and can separate the shell and the electrolyte to play a certain protective role on the shell, thereby improving the corrosion resistance of the shell, which is conducive to alleviating the phenomenon of the shell being corroded and broken down by the electrolyte, so as to prolong the time of the shell being corroded and broken down, thereby helping to prolong the service life of the battery cell and improve the reliability of the battery cell, wherein, by dividing the wall surface of the accommodating cavity into a first area and a second area, and the thickness of the insulating layer provided in the first area is less than that of the insulating layer provided in the second area. The thickness of the insulating layer is small or only the second area is provided with an insulating layer, so that the corrosion resistance of the shell in the first area is weaker than that of the shell in the second area, so that the shell will be corroded and broken down preferentially in the first area compared with the second area, so that the position where the shell is corroded and broken down during subsequent use can be controlled to reduce the phenomenon that the corrosion and breakdown points of the shell appear at any position. On the one hand, the shell can be protected at a fixed point or safety measures can be implemented, which is beneficial to reducing the difficulty of subsequent protection of the battery cell. On the other hand, during use, only the first area of ​​the shell needs to be monitored to realize the inspection of the corrosion and breakdown of the battery cell, which is beneficial to reducing the difficulty of detecting and monitoring the battery cell.

[0007] In some embodiments, both the first region and the second region are provided with an insulating layer, and a thickness of the insulating layer provided in the second region is greater than or equal to twice a thickness of the insulating layer provided in the first region.

[0008] In the above technical solution, the thickness of the insulating layer set in the second area is set to be greater than or equal to twice the thickness of the insulating layer set in the first area, so that the thickness of the insulating layer set in the first area is set to be less than or equal to 0.5 times the thickness of the insulating layer set in the second area, so that the corrosion resistance of the shell in the first area is further weaker than the corrosion resistance of the shell in the second area, so as to increase the probability that the position where the shell is corroded and broken down appears in the first area, so that the position where the shell is corroded and broken down in subsequent use can be controlled, so as to reduce the phenomenon that the corrosion breakdown point of the shell appears at any position, which is conducive to further reducing the difficulty of subsequent protection of the battery cell, and is conducive to further reducing the difficulty of detection and monitoring of the battery cell.

[0009] In some embodiments, the first area is circular or elliptical in shape.

[0010] In the above technical solution, by setting the first area to be circular or elliptical, on the one hand, the manufacturing difficulty of the battery cell can be reduced, which is conducive to improving the production efficiency of the battery cell; on the other hand, the subsequent protection and monitoring difficulty of the battery cell can be reduced.

[0011] In some embodiments, the housing further has a pressure relief mechanism, which is located in the first region and configured to release internal pressure of the battery cell.

[0012] In the above technical solution, by arranging the pressure relief mechanism for releasing the internal pressure of the battery cell in the first area, on the one hand, the area corresponding to the pressure relief mechanism is not provided with an insulating layer or the thickness of the insulating layer is small, thereby reducing the influence of the insulating layer on the pressure relief mechanism, so that the pressure relief mechanism can normally release pressure, which is beneficial to improving the reliability of the battery cell; on the other hand, the pressure relief point and the corrosion breakdown point of the battery cell are located in the same area, thereby facilitating the subsequent protection of the battery cell or the implementation of safety measures, without setting multiple protection points, which is beneficial to reducing the difficulty of subsequent protection of the battery cell.

[0013] In some embodiments, the housing includes a wall portion configured to support the electrode assembly; wherein at least a portion of an inner surface of the wall portion facing the accommodating cavity forms the first region.

[0014] In the above technical solution, the first area is formed on the wall portion, and the wall portion is a wall of the shell supporting the electrode assembly, so that after the first area is corroded and punctured, the puncture point of the shell is located at the bottom of the battery cell, thereby reducing the harm to users after the battery cell is corroded and punctured, which is beneficial to improving the reliability of the battery cell.

[0015] In some embodiments, the shell includes a bottom wall and a side wall. Along the thickness direction of the end cover, the bottom wall and the end cover are arranged opposite to each other, and the side wall is arranged around the bottom wall. One end of the side wall is connected to the bottom wall, and the other end is enclosed to form an opening. The side wall and the bottom wall are enclosed to form a accommodating cavity; wherein the bottom wall is a wall portion.

[0016] In the above technical solution, by setting the wall portion as the bottom wall of the shell, on the one hand, the end cover is located on the top of the battery cell, which is helpful to reduce the risk of electrolyte leakage from the connection between the end cover and the shell during the use of the battery cell, so as to improve the reliability of the battery cell; on the other hand, the first area can be away from the end cover, which is helpful to reduce the stress generated by the connection between the end cover and the shell acting on the first area, so as to reduce the impact on the first area.

[0017] In some embodiments, the wall thickness of the end cap is greater than the wall thickness of the housing.

[0018] In the above technical solution, by setting the wall thickness of the end cover to be greater than the wall thickness of the shell, the corrosion resistance of the end cover is greater than that of the shell, so as to alleviate the phenomenon of corrosion resistance of the end cover and enable the shell to be corroded before the end cover, thereby facilitating fixed-point protection of the shell or implementing safety measures.

[0019] In some embodiments, the housing includes a wall portion, and at least a portion of the inner surface of the wall portion facing the accommodating cavity forms a first area; wherein the area of ​​the first area is S1, and the area of ​​the inner surface of the wall portion facing the accommodating cavity is S2, satisfying, 5mm 2 ≤S1≤S2.

[0020] In the above technical solution, the first area is formed on the wall of the shell, and the area of ​​the first area of ​​the shell is set to be greater than or equal to 5mm 2 and is less than or equal to the area of ​​the inner surface of the wall facing the accommodating cavity. On the one hand, the area of ​​the first region is set to be greater than or equal to 5 mm 2 , so as to facilitate the formation and manufacture of the first area, which is conducive to reducing the manufacturing difficulty of the battery cell, and is convenient for subsequent monitoring or inspection of the first area, which is conducive to reducing the detection difficulty and monitoring difficulty of the battery cell. On the other hand, the area of ​​the first area is set to be less than or equal to the area of ​​the inner surface of the wall facing the accommodating cavity, so as to alleviate the phenomenon that the shell is corroded and broken down in a large range or appears on other walls of the shell during use, so as to facilitate fixed-point protection of the shell or implementation of safety measures, which is conducive to reducing the subsequent protection difficulty of the battery cell, and thus reducing the detection difficulty and monitoring difficulty of the battery cell while taking into account the subsequent protection difficulty of the battery cell.

[0021] In some embodiments, the thickness of the insulating layer disposed in the second region is D, satisfying 1 μm≤D≤500 μm.

[0022] In the above technical solution, the thickness of the insulating layer set in the second area is 1μm to 500μm. On the one hand, by setting the thickness of the insulating layer set in the second area to be greater than or equal to 1μm, the protection effect of the insulating layer on the second area of ​​the shell can be improved, and the effect of the insulating layer in insulating and isolating the electrode assembly and the second area of ​​the shell can be improved, thereby effectively improving the corrosion resistance of the second area of ​​the shell, which is beneficial to extending the service life of the battery cell, and can reduce the risk of short circuit between the electrode assembly and the shell, which is beneficial to improving the reliability of the battery cell. On the other hand, by setting the thickness of the insulating layer set in the second area to be less than or equal to 500μm, the difficulty of setting the insulating layer on the second area of ​​the shell can be reduced, and the space occupied by the insulating layer can be reduced, which is beneficial to improving the internal space utilization of the battery cell, so as to improve the energy density of the battery cell, thereby improving the service life and reliability of the battery cell while taking into account the energy density of the battery cell.

[0023] In some embodiments, the thickness of the insulating layer disposed in the second region is D, satisfying 10 μm≤D≤200 μm.

[0024] In the above technical solution, the thickness of the insulating layer set in the second area is 10μm to 200μm. On the one hand, by setting the thickness of the insulating layer set in the second area to be greater than or equal to 10μm, the protection effect of the insulating layer on the second area of ​​the shell can be further improved, and the effect of the insulating layer in insulating and isolating the electrode assembly and the second area of ​​the shell can be further improved, so that the corrosion resistance of the second area of ​​the shell can be further improved, which is beneficial to extending the service life of the battery cell, and can further reduce the risk of short circuit between the electrode assembly and the shell, which is beneficial to improving the reliability of the battery cell. On the other hand, by setting the thickness of the insulating layer set in the second area to be less than or equal to 200μm, the difficulty of setting the insulating layer on the second area of ​​the shell can be further reduced, and the space occupied by the insulating layer can be further reduced, which is beneficial to further improve the internal space utilization of the battery cell, so as to improve the energy density of the battery cell, thereby improving the service life and reliability of the battery cell while taking into account the energy density of the battery cell.

[0025] In some embodiments, the insulating layer is made of polyimide.

[0026] In the above technical solution, by setting the material of the insulating layer to polyimide, the insulating layer has good resistance to electrolyte corrosion, which is beneficial to improving the service life of the insulating layer, thereby further improving the corrosion resistance of the shell, and helping to alleviate the phenomenon of the shell being corroded and broken down by the electrolyte, so as to extend the time of the shell being corroded and broken down, thereby further improving the service life and reliability of the battery cell.

[0027] In a second aspect, an embodiment of the present application further provides a battery, comprising the above-mentioned battery cell.

[0028] In a third aspect, an embodiment of the present application further provides an electrical device, comprising the above-mentioned battery cell, wherein the battery cell is used to provide electrical energy. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present application and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying creative work.

[0030] Figure 1 A schematic diagram of the structure of a vehicle provided in some embodiments of the present application;

[0031] Figure 2 An exploded view of the structure of a battery provided in some embodiments of the present application;

[0032] Figure 3 A schematic diagram of the structure of a battery cell provided in some embodiments of the present application;

[0033] Figure 4 An exploded view of the structure of a battery cell provided in some embodiments of the present application;

[0034] Figure 5 A schematic diagram of the structure of a housing provided in some embodiments of the present application;

[0035] Figure 6 A cross-sectional view of a housing provided for some embodiments of the present application;

[0036] Figure 7 A partial cross-sectional view of a housing provided for some embodiments of the present application;

[0037] Figure 8 A cross-sectional view of a housing provided for some other embodiments of the present application;

[0038] Fig. 9 A partial cross-sectional view of a housing provided for some other embodiments of the present application;

[0039] Fig.10 A top view of a housing provided for some embodiments of the present application.

[0040] Icons: 1000-vehicle; 100-battery; 10-casing; 11-first casing body; 12-second casing body; 20-battery cell; 21-casing; 211-opening; 212-accommodating chamber; 213-first area; 214-second area; 215-insulating layer; 216-notched groove; 217-wall; 218-bottom wall; 219-side wall; 22-end cover; 23-electrode assembly; 231-ear; 24-electrode terminal; 25-current collecting member; 26-pressure relief mechanism; 200-controller; 300-motor; X-thickness direction of the end cover. DETAILED DESCRIPTION

[0041] 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 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.

[0042] Unless otherwise defined, all technical and scientific terms used in this application have the same meanings as those commonly understood by technicians in the technical field of this application; 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" in the specification and claims of this application and the above-mentioned drawings and any variations thereof 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.

[0043] 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.

[0044] 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.

[0045] 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.

[0046] 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.

[0047] The term "plurality" used in the present application refers to two or more (including two).

[0048] In the embodiment of the present application, the battery cell may be a secondary battery. A secondary battery refers to a battery cell that can be continuously used by activating active materials by charging after the battery cell is discharged.

[0049] The battery cell can be a lithium ion battery, a sodium ion battery, a sodium lithium ion battery, a lithium metal battery, a sodium metal battery, a lithium sulfur battery, a magnesium ion battery, a nickel hydrogen battery, a nickel cadmium battery, a lead storage battery, etc., which is not limited in the embodiments of the present application.

[0050] A battery cell generally includes an electrode assembly. The electrode assembly includes a positive electrode, a negative electrode, and a separator. During the charge and discharge process of the battery cell, active ions (such as lithium ions) are embedded and removed between the positive electrode and the negative electrode. The separator is set 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.

[0051] 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 disposed on at least one surface of the positive electrode current collector.

[0052] As an example, the positive electrode current collector has two surfaces facing each other in its thickness direction, and the positive electrode active material is disposed on either or both of the two facing surfaces of the positive electrode current collector.

[0053] As an example, the positive electrode current collector may be a metal foil or a composite current collector. For example, as the metal foil, aluminum with a silver-plated surface, stainless steel with a silver-plated surface, stainless steel, copper, aluminum, nickel, carbon electrode, carbon, nickel or titanium, etc. 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 a substrate of polypropylene, polyethylene terephthalate, polybutylene terephthalate, polystyrene, polyethylene, etc.).

[0054] As an example, 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. However, the present application is not limited to these materials, and 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, at least one of 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 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 / 3O2 (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 0.85 Co 0.15 Al 0.05 O2) and its modified compounds, etc.

[0055] In some embodiments, the positive electrode may be a foamed metal. The foamed metal may be a nickel foam, a copper foam, an aluminum foam, an alloy foam, etc. When the foamed metal is used as the positive electrode, the positive electrode active material may not be provided on the surface of the foamed metal, but of course, the positive electrode active material may also be provided. As an example, a lithium source material, potassium metal or sodium metal may also be filled or / and deposited in the foamed metal, and the lithium source material is lithium metal and / or a lithium-rich material.

[0056] In some embodiments, the negative electrode may be a negative electrode sheet, and the negative electrode sheet may include a negative electrode current collector.

[0057] As an example, the negative electrode current collector may be a metal foil, a foamed metal or a composite current collector. For example, as the metal foil, aluminum or stainless steel treated with silver, stainless steel, copper, aluminum, nickel, carbon electrode, nickel or titanium, etc. may be used. The foamed metal may be a nickel foam, a copper foam, an aluminum foam, an alloy foam, 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 a substrate of polypropylene, polyethylene terephthalate, polybutylene terephthalate, polystyrene, polyethylene, etc.).

[0058] As an example, the negative electrode sheet may include a negative electrode current collector and a negative electrode active material disposed on at least one surface of the negative electrode current collector.

[0059] As an example, the negative electrode current collector has two surfaces facing each other in its thickness direction, and the negative electrode active material is disposed on either or both of the two facing surfaces of the negative electrode current collector.

[0060] 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. However, the present application is not limited to these materials, and 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.

[0061] 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.

[0062] In some embodiments, the electrode assembly further includes a separator disposed between the positive electrode and the negative electrode.

[0063] In some embodiments, the separator is a separator membrane. There may be many types of separator membranes, and any known porous separator membrane with good chemical stability and mechanical stability may be selected.

[0064] As an example, the material of the separator may include at least one of glass fiber, non-woven fabric, polyethylene, polypropylene and polyvinylidene fluoride. The separator may be a single-layer film or a multi-layer composite film. When the separator is a multi-layer composite film, the materials of each layer may be the same or different. The separator may be a separate component located between the positive and negative electrodes, or may be attached to the surface of the positive and negative electrodes.

[0065] In some embodiments, the separator is a solid electrolyte, which is disposed between the positive electrode and the negative electrode and serves to transmit ions and isolate the positive and negative electrodes.

[0066] In some embodiments, the battery cell further includes an electrolyte, which plays a role in conducting ions between the positive and negative electrodes. The electrolyte can be liquid, gel or solid. Among them, the liquid electrolyte includes an electrolyte salt and a solvent.

[0067] In some embodiments, the electrolyte salt may include at least one of lithium hexafluorophosphate, lithium tetrafluoroborate, lithium perchlorate, lithium hexafluoroarsenate, lithium bisfluorosulfonyl imide, lithium bistrifluoromethanesulfonyl imide, lithium trifluoromethanesulfonate, lithium difluorophosphate, lithium difluorooxalatoborate, lithium dioxalatoborate, lithium difluorodioxalatophosphate, and lithium tetrafluorooxalatophosphate.

[0068] In some embodiments, the solvent may include 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 may also be an ether solvent. The ether solvent may 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.

[0069] Among them, the gel electrolyte includes a skeleton network with a polymer as the electrolyte, combined with an ionic liquid-lithium salt.

[0070] Among them, solid electrolytes include polymer solid electrolytes, inorganic solid electrolytes, and composite solid electrolytes.

[0071] 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.

[0072] As an example, the inorganic solid electrolyte may include 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.

[0073] As an example, the composite solid electrolyte is formed by adding an inorganic solid electrolyte filler to a polymer solid electrolyte.

[0074] In some embodiments, the electrode assembly is a wound structure, wherein the positive electrode sheet and the negative electrode sheet are wound into the wound structure.

[0075] In some embodiments, the electrode assembly is a laminate structure.

[0076] 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.

[0077] 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.

[0078] 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.

[0079] 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.

[0080] 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.

[0081] In some embodiments, the shape of the electrode assembly can be cylindrical, flat, or polygonal.

[0082] 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.

[0083] 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.

[0084] 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 but is not limited to a square-shell battery cell, a blade-shaped battery cell, a polygonal battery, such as a hexagonal battery, etc.

[0085] 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.

[0086] 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.

[0087] 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.

[0088] 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.

[0089] In some embodiments, the battery may be an energy storage device, which includes an energy storage container, an energy storage cabinet, and the like.

[0090] Batteries have outstanding advantages such as high energy density, low environmental pollution, high power density, long service life, wide adaptability, and low self-discharge coefficient. They are an important part of the development of new energy today. The development of battery technology must consider many design factors at the same time, such as energy density, cycle life, discharge capacity, charge and discharge rate and other performance parameters. In addition, the safety of the battery also needs to be considered.

[0091] For a general battery cell, the battery cell includes a shell and an electrode assembly and an electrolyte contained in the shell. The shell includes a shell and an end cap. The shell forms a receiving cavity with an opening inside. The electrode assembly and the electrolyte are both contained in the receiving cavity. The end cap covers the opening of the shell. In the related art, in order to reduce the risk of short circuit between the electrode assembly and the shell, an insulating film is usually coated on the outer side of the electrode assembly to insulate and isolate the electrode assembly and the shell through the insulating film, thereby reducing the risk of internal short circuit of the battery cell. However, in a battery cell of this structure, the electrolyte contained in the receiving cavity will directly contact the inner surface of the shell. During long-term use or when a short circuit occurs in the battery cell, it is easy to cause the shell to be electrochemically corroded and punctured, resulting in a short service life of the battery cell. The corrosion puncture point of the shell can occur at any position of the shell, making the corrosion puncture point of the shell uncontrollable, thereby causing the battery cell to have the risk of leakage, etc., and the subsequent protection of the battery cell is difficult, which is not conducive to improving the reliability of the battery cell.

[0092] Based on the above considerations, in order to solve the problems of low service life and reliability of battery cells, an embodiment of the present application provides a battery cell, which includes a shell and an end cover. A receiving cavity with an opening is formed inside the shell, and the receiving cavity is used to receive the electrode assembly and the electrolyte. The cavity wall of the receiving cavity includes a first area and a second area. The end cover closes the opening. Both the first area and the second area are provided with an insulating layer, and the thickness of the insulating layer provided in the first area is less than the thickness of the insulating layer provided in the second area. The insulating layer is used to separate the electrolyte and the shell, or only the second area is provided with an insulating layer, and the insulating layer is used to separate the electrolyte and the shell.

[0093] In a battery cell of this structure, an insulating layer is provided on at least part of the wall surface of the housing cavity of the shell, so that the insulating layer can separate the electrolyte and the shell to achieve insulation isolation between the shell and the electrode assembly, and can separate the shell and the electrolyte to provide a certain degree of protection for the shell, thereby improving the corrosion resistance of the shell, helping to alleviate the phenomenon of the shell being corroded and punctured by the electrolyte, thereby extending the time for the shell to be corroded and punctured, and further helping to extend the service life of the battery cell and improve the reliability of the battery cell, wherein the wall surface of the housing cavity is divided into a first area and a second area, and the thickness of the insulating layer provided in the first area is smaller than the thickness of the insulating layer provided in the second area. The thickness of the layer or only sets an insulating layer in the second area makes the corrosion resistance of the shell in the first area weaker than that of the shell in the second area, so that the shell will be corroded and broken down preferentially in the first area compared with the second area, so that the position where the shell is corroded and broken down during subsequent use can be controlled to reduce the phenomenon that the corrosion breakdown point of the shell appears at any position. On the one hand, the shell can be protected at a fixed point or safety measures can be implemented, which is beneficial to reducing the difficulty of subsequent protection of the battery cell. On the other hand, during use, only the first area of ​​the shell needs to be monitored to realize the corrosion and breakdown of the battery cell. Check, which is beneficial to reduce the difficulty of detection and monitoring of the battery cell.

[0094] The battery cell disclosed in the embodiment of the present application can be used, but not limited to, in electrical devices such as vehicles, ships or aircraft. A power supply system comprising the battery cell and battery disclosed in the present application can be used to form the electrical device, which is helpful to alleviate the problem that the shell of the battery cell is easily corroded and punctured and the puncture point is uncontrollable, thereby improving the service life and reliability of the battery cell.

[0095] The embodiment of the present application provides an electric device using a battery as a power source, and the electric device may be, but is not limited to, a mobile phone, a tablet, a laptop, an electric toy, an electric tool, a battery car, an electric car, a ship, a spacecraft, etc. Among them, the electric toy may include a fixed or mobile electric toy, such as a game console, an electric car toy, an electric ship toy, and an electric airplane toy, etc., and the spacecraft may include an airplane, a rocket, a space shuttle, and a spacecraft, etc.

[0096] For the convenience of description, the following embodiments are described by taking a vehicle as an example of an electrical device in an embodiment of the present application.

[0097] Please refer to Figure 1 , Figure 1A schematic diagram of the structure of a vehicle 1000 provided for some embodiments of the present application. The vehicle 1000 may be a fuel vehicle, a gas vehicle or a new energy vehicle, and the new energy vehicle may be a pure electric vehicle, a hybrid vehicle or an extended-range vehicle, etc. A battery 100 is provided inside the vehicle 1000, and the battery 100 may be provided at the bottom of the vehicle 1000, or at the head of the vehicle 1000, or at the tail of the vehicle 1000. The battery 100 may be used to power the vehicle 1000, for example, the battery 100 may be used as an operating power source or a power source for the vehicle 1000, etc. The vehicle 1000 may also include a controller 200 and a motor 300, and the controller 200 is used to control the battery 100 to power the motor 300, for example, for the starting, navigation and working power requirements of the vehicle 1000 during driving.

[0098] In some embodiments of the present application, the battery 100 can not only serve as an operating power source or a use power source for the vehicle 1000, but also serve as a driving power source for the vehicle 1000, replacing or partially replacing fuel or natural gas to provide driving power for the vehicle 1000.

[0099] Please refer to Figure 2 and Figure 3 , Figure 2 The structure explosion diagram of the battery 100 provided in some embodiments of the present application is shown in FIG. Figure 3 The schematic diagram of the structure of the battery cell 20 provided in some embodiments of the present application is as follows. The battery 100 comprises a box body 10 and a battery cell 20 , and the battery cell 20 is used to be accommodated in the box body 10 .

[0100] The box body 10 is used to provide an assembly space for the battery cell 20, and the box body 10 can adopt a variety of structures. In some embodiments, the box body 10 may include a first box body 11 and a second box body 12, the first box body 11 and the second box body 12 cover each other, and the first box body 11 and the second box body 12 jointly define an assembly space for accommodating the battery cell 20. The second box body 12 may be a hollow structure with one end open, and the first box body 11 may be a plate-like structure, and the first box body 11 covers the open side of the second box body 12, so that the first box body 11 and the second box body 12 jointly define an assembly space; the first box body 11 and the second box body 12 may also be hollow structures with one side open, and the open side of the first box body 11 covers the open side of the second box body 12.

[0101] Of course, the box body 10 formed by the first box body 11 and the second box body 12 can be in various shapes, such as a cylinder, a cuboid or a cube. Figure 2 In the embodiment, the box body 10 is in the shape of a rectangular parallelepiped.

[0102] In the battery 100, the battery cell 20 disposed in the box 10 may be one or more. When there are more than one battery cell 20 disposed in the box 10, the multiple battery cells 20 may be connected in series, in parallel, or in mixed connection. Mixed connection means that the multiple battery cells 20 are both connected in series and in parallel. The multiple battery cells 20 may be directly connected in series, in parallel, or in mixed connection, and then the whole formed by the multiple battery cells 20 may be accommodated in the box 10; of course, the battery 100 may also be a battery module formed by connecting multiple battery cells 20 in series, in parallel, or in mixed connection, and then the multiple battery modules may be connected in series, in parallel, or in mixed connection to form a whole, and then the whole may be accommodated in the box 10.

[0103] In some embodiments, the battery 100 may further include other structures. For example, the battery 100 may further include a busbar component, which is used to connect the plurality of battery cells 20 to achieve electrical connection between the plurality of battery cells 20 .

[0104] Each battery cell 20 may be a secondary battery or a primary battery; it may also be a lithium-sulfur battery, a sodium-ion battery or a magnesium-ion battery, but is not limited thereto. The battery cell 20 may be in a rectangular parallelepiped, a cylinder, a prism or other shapes. For example, Figure 3 In the figure, the battery cell 20 is a rectangular parallelepiped structure.

[0105] According to some embodiments of the present application, referring to Figure 3 , and please refer to Figure 4 , Figure 5 , Figure 6 and Figure 7 , Figure 4 This is an exploded view of the structure of the battery cell 20 provided in some embodiments of the present application. Figure 5 This is a schematic diagram of the structure of the housing 21 provided in some embodiments of the present application. Figure 6 A cross-sectional view of a housing 21 provided in some embodiments of the present application, Figure 7 A partial cross-sectional view of a shell 21 provided in some embodiments of the present application. The present application provides a battery cell 20, which includes a shell 21 and an end cover 22. A receiving cavity 212 with an opening 211 is formed inside the shell 21. The receiving cavity 212 is used to receive an electrode assembly 23 and an electrolyte. The cavity wall of the receiving cavity 212 includes a first region 213 and a second region 214. The end cover 22 closes the opening 211. Both the first region 213 and the second region 214 are provided with an insulating layer 215, and the thickness of the insulating layer 215 provided in the first region 213 is less than the thickness of the insulating layer 215 provided in the second region 214. The insulating layer 215 is used to separate the electrolyte and the shell 21.

[0106] Among them, the cavity wall surface of the accommodating cavity 212 includes a first area 213 and a second area 214, that is, the inner surface of the accommodating cavity 212 of the shell 21 is divided into the first area 213 and the second area 214 as a whole, and an insulating layer 215 is provided on the first area 213 and the second area 214, and the thickness of the insulating layer 215 in the first area 213 is smaller than the thickness of the insulating layer 215 in the second area 214.

[0107] Exemplarily, the insulating layer 215 serves to separate the electrolyte from the shell 21 and to insulate and isolate the electrode assembly 23 from the shell 21 . The insulating member may be made of various materials, such as polyimide, epoxy resin, and the like.

[0108] Optionally, the insulating layer 215 may be disposed on the first region 213 and the second region 214 by various processing techniques. For example, the insulating layer 215 may be disposed on the first region 213 and the second region 214 by processing techniques such as electrophoresis or spraying.

[0109] Of course, the structure of the battery cell 20 is not limited to this. In some embodiments, Figure 8 and Fig. 9 , Figure 8 The cross-sectional view of the housing 21 provided in some other embodiments of the present application is as follows: Fig. 9 A partial cross-sectional view of a shell 21 provided for some other embodiments of the present application. The cavity wall surface of the accommodating cavity 212 of the shell 21 includes a first area 213 and a second area 214, and only the second area 214 is provided with an insulating layer 215, and the insulating layer 215 is used to separate the electrolyte and the shell 21. In other words, the first area 213 of the shell 21 is not provided with an insulating layer 215, and the insulating layer 215 is only provided on the second area 214 of the shell 21, that is, the thickness of the insulating layer 215 provided in the first area 213 is 0μm, which is equivalent to the insulating layer 215 having a through hole formed at the position corresponding to the first area 213 of the shell 21, and the through hole passes through both sides of the insulating layer 215.

[0110] In some embodiments, see Figure 4 As shown, the battery cell 20 may further include an electrode assembly 23, which is accommodated in the accommodating cavity 212. The electrode assembly 23 is a component in the battery cell 20 where an electrochemical reaction occurs. The structure of the electrode assembly 23 may be various. For example, the electrode assembly 23 may be a wound structure formed by winding a positive electrode sheet, an isolating member, and a negative electrode sheet, or may be a stacked structure formed by stacking a positive electrode sheet, an isolating member, and a negative electrode sheet.

[0111] Exemplarily, the isolation member is an isolation membrane, and a main material of the isolation membrane may be selected from at least one of glass fiber, non-woven fabric, polyethylene, polypropylene and polyvinylidene fluoride.

[0112] Optionally, the electrode assembly 23 accommodated in the accommodation cavity 212 may be one or more. Figure 4 In the embodiment, two electrode assemblies 23 are disposed inside the battery cell 20, and the two electrode assemblies 23 are stacked along the thickness direction thereof, that is, the two electrode assemblies 23 are stacked along the thickness direction of the battery cell 20. Of course, in other embodiments, the number of electrode assemblies 23 accommodated in the accommodation cavity 212 may be one, three, four, five, six, seven or eight.

[0113] The shell formed by the shell 21 and the end cap 22 can also be used to contain electrolyte, etc. The shell formed by the shell 21 and the end cap 22 can be in various structural forms, such as a cylinder or a cuboid, etc. Similarly, the shell 21 and the end cap 22 can also be made of various materials, such as aluminum or aluminum alloy, etc.

[0114] The housing 21 has an accommodating cavity 212 with an opening 211 formed inside. That is, the housing 21 is a hollow structure with an opening 211 formed at at least one end. Figure 4 and Figure 5 In the embodiment, the shell 21 has an opening 211 formed at only one end in the thickness direction X of the end cover, and the end cover 22 covers the opening 211 of the shell 21 and forms a sealed connection to form a sealed space for accommodating the electrode assembly 23 and the electrolyte.

[0115] Exemplarily, the end cover 22 covers the opening 211 of the shell 21 , and the end cover 22 is connected to the shell 21 by welding.

[0116] When assembling the battery cell 20 , the electrode assembly 23 may be placed in the housing 21 first, and the housing 21 may be filled with electrolyte. Then, the end cap 22 may be covered on the opening 211 of the housing 21 to complete the assembly of the battery cell 20 .

[0117] The shell 21 can be in various shapes, such as a cylinder, a cuboid, or a prism structure. The shape of the shell 21 can be determined according to the specific shape of the electrode assembly 23. For example, if the electrode assembly 23 is a cylindrical structure, a shell 21 with a cylindrical structure can be selected; if the electrode assembly 23 is a cuboid structure, a shell 21 with a cuboid structure can be selected. Of course, the structure of the end cap 22 can also be various, such as the end cap 22 being a plate-like structure or a hollow structure with one end open. For example, in Figure 4 and Figure 5 In the embodiment, the shell 21 is a rectangular parallelepiped structure, and the end cover 22 is a rectangular plate structure.

[0118] Of course, it is understandable that the battery cell 20 is not limited to the above structure. For example, the battery cell 20 may include a shell 21 and two end covers 22. The shell 21 is a hollow structure with openings 211 on opposite sides. One end cover 22 corresponds to an opening 211 of the shell 21 and forms a sealed connection to form an enclosed space for accommodating the electrode assembly 23 and the electrolyte. That is, the shell 21 is formed with openings 211 on opposite sides, and the two end covers 22 are respectively covered on both sides of the shell 21 to close the corresponding openings 211.

[0119] In some embodiments, see Figure 4 As shown, the battery cell 20 may further include an electrode terminal 24 , which is insulated and mounted on the end cover 22 , and is electrically connected to the electrode assembly 23 to output or input electrical energy of the battery cell 20 .

[0120] It should be noted that the electrode terminal 24 is insulated and installed on the end cover 22 , that is, no electrical connection is formed between the electrode terminal 24 and the end cover 22 .

[0121] Among them, Figure 3 and Figure 4 In the embodiment, the battery cell 20 includes two electrode terminals 24, and correspondingly, each electrode assembly 23 has two pole ears 231, and the polarities of the two pole ears 231 are opposite. The two electrode terminals 24 are electrically connected to the two pole ears 231 of the electrode assembly 23, respectively, so as to realize the input or output of the positive electrode and the negative electrode of the battery cell 20. It should be noted that the pole ears 231 of the electrode assembly 23 are components formed by mutually stacking and connecting the regions on the positive electrode sheet that are not coated with the positive electrode active material layer, or components formed by mutually stacking and connecting the regions on the negative electrode sheet that are not coated with the negative electrode active material layer. If the pole ears 231 are used to output the positive electrode of the electrode assembly 23, the pole ears 231 are components formed by mutually stacking and connecting the regions on the positive electrode sheet that are not coated with the positive electrode active material layer; if the pole ears 231 are used to output the negative electrode of the electrode assembly 23, the pole ears 231 are components formed by mutually stacking and connecting the regions on the negative electrode sheet that are not coated with the negative electrode active material layer.

[0122] Exemplarily, the electrode terminal 24 may be made of a variety of materials. For example, the electrode terminal 24 may be made of copper, iron, aluminum, steel, or aluminum alloy.

[0123] For example, in Figure 3 and Figure 4 In the embodiment, the two electrode terminals 24 are both mounted on the end cap 22. Of course, the structure of the battery cell 20 is not limited thereto. In other embodiments, the two electrode terminals 24 may be both mounted on the housing 21. Similarly, one electrode terminal 24 may be mounted on the housing 21 and the other electrode terminal 24 may be mounted on the end cap 22.

[0124] In some embodiments, see Figure 4 As shown, the battery cell 20 may also include two current collecting components 25, both of which are arranged in the shell 21, and each current collecting component 25 is used to connect an electrode terminal 24 and a plurality of electrode lugs 231 with the same polarity in the electrode assemblies 23 to achieve electrical connection between the electrode terminal 24 and the electrode assembly 23, which is beneficial to reduce the difficulty of assembly between the lug 231 and the electrode terminal 24.

[0125] Exemplarily, the material of the current collecting component 25 may be various, for example, the material of the current collecting component 25 may be copper, iron, aluminum, steel or aluminum alloy.

[0126] In the present embodiment, an insulating layer 215 is provided on at least a portion of the cavity wall surface of the accommodating cavity 212 of the shell 21, so that the insulating layer 215 can separate the electrolyte and the shell 21, so as to realize the insulation isolation between the shell 21 and the electrode assembly 23, and can separate the shell 21 and the electrolyte, so as to play a certain protective role on the shell 21, thereby improving the corrosion resistance of the shell 21, which is conducive to alleviating the phenomenon that the shell 21 is corroded and broken down by the electrolyte, so as to prolong the time that the shell 21 is corroded and broken down, and further helps to prolong the service life of the battery cell 20 and improve the reliability of the battery cell 20, wherein, by dividing the cavity wall surface of the accommodating cavity 212 into a first area 213 and a second area 214, and the thickness of the insulating layer 215 provided in the first area 213 is less than the thickness of the insulating layer 215 provided in the second area 214. The thickness of layer 215 or the insulating layer 215 is only set in the second area 214, so that the corrosion resistance of the shell 21 in the first area 213 is weaker than the corrosion resistance of the shell 21 in the second area 214, so that the shell 21 will be corroded and broken down preferentially in the first area 213 compared with the second area 214, so that the position where the shell 21 is corroded and broken down during subsequent use can be controlled to reduce the phenomenon that the corrosion and breakdown points of the shell 21 appear at any position. On the one hand, the shell 21 can be protected at a fixed point or safety measures can be implemented, which is beneficial to reducing the difficulty of subsequent protection of the battery cell 20. On the other hand, during use, only the first area 213 of the shell 21 needs to be monitored to realize the inspection of the corrosion and breakdown of the battery cell 20, which is beneficial to reducing the difficulty of detection and monitoring of the battery cell 20.

[0127] According to some embodiments of the present application, see Figure 6 and Figure 7As shown, both the first region 213 and the second region 214 are provided with an insulating layer 215, and the thickness of the insulating layer 215 provided in the second region 214 is greater than or equal to twice the thickness of the insulating layer 215 provided in the first region 213, that is, the thickness of the insulating layer 215 provided in the first region 213 is H, and the thickness of the insulating layer 215 provided in the second region 214 is D, satisfying that H≤0.5D.

[0128] The housing 21 has a plurality of walls, and the thickness of the insulating layer 215 disposed in the first region 213 is H, which is the dimension of the insulating layer 215 disposed in the first region 213 in the thickness direction of the corresponding wall. Similarly, the thickness of the insulating layer 215 disposed in the second region 214 is D, which is the dimension of the insulating layer 215 disposed in the second region 214 in the thickness direction of the corresponding wall.

[0129] Exemplarily, the thickness H of the insulating layer 215 set in the first region 213 can be 0.1 times, 0.15 times, 0.2 times, 0.25 times, 0.3 times, 1 / 3 times, 0.35 times, 0.4 times, 0.45 times or 0.5 times the thickness D of the insulating layer 215 set in the second region 214.

[0130] In this embodiment, the thickness of the insulating layer 215 set in the second area 214 is set to be greater than or equal to twice the thickness of the insulating layer 215 set in the first area 213, so that the thickness of the insulating layer 215 set in the first area 213 is set to be less than or equal to 0.5 times the thickness of the insulating layer 215 set in the second area 214, so that the corrosion resistance of the shell 21 in the first area 213 is further weaker than the corrosion resistance of the shell 21 in the second area 214, so as to increase the probability that the position where the shell 21 is corroded and broken down appears in the first area 213, so that the position where the shell 21 is corroded and broken down in subsequent use can be controlled, so as to reduce the phenomenon that the corrosion breakdown point of the shell 21 appears at any position, which is beneficial to further reduce the subsequent protection difficulty of the battery cell 20, and is beneficial to further reduce the detection difficulty and monitoring difficulty of the battery cell 20.

[0131] According to some embodiments of the present application, referring to Fig.10 , Fig.10 In the top view of the housing 21 provided in some embodiments of the present application, the shape of the first area 213 is circular or elliptical.

[0132] Exemplarily, the shape of the first region 213 is circular, and in other embodiments, the shape of the first region 213 may also be elliptical. Of course, the structure of the battery cell 20 is not limited thereto, and in some embodiments, the shape of the first region 213 may also be a polygonal structure such as a triangle, rectangle, pentagon or hexagon.

[0133] In this embodiment, by setting the first area 213 to be circular or elliptical, on the one hand, the manufacturing difficulty of the battery cell 20 can be reduced, which is beneficial to improving the production efficiency of the battery cell 20; on the other hand, the subsequent protection and monitoring difficulty of the battery cell 20 can be reduced.

[0134] According to some embodiments of the present application, see Figure 6 , Figure 7 , Figure 8 and Fig. 9 As shown, the housing 21 further has a pressure relief mechanism 26 , which is located in the first region 213 and is configured to release the internal pressure of the battery cell 20 .

[0135] The pressure relief mechanism 26 is located in the first area 213 , that is, in the thickness direction of the pressure relief mechanism 26 , the projection of the pressure relief mechanism 26 is located in the first area 213 .

[0136] The pressure relief mechanism 26 is used to release the pressure inside the battery cell 20 when the internal pressure or temperature of the battery cell 20 reaches a predetermined value. The pressure relief mechanism 26 can have various structures. Optionally, the pressure relief mechanism 26 and the housing 21 can be an integral structure or a separate structure.

[0137] For example, in Figure 7 and Fig. 9 In the embodiment, the pressure relief mechanism 26 and the shell 21 are an integrally formed structure, that is, the pressure relief mechanism 26 and the shell 21 are an integral structure, and the pressure relief mechanism 26 is a region on the shell 21 where a weak structure is formed. For example, a notched groove 216 is provided on the shell 21, and a region on the shell 21 where the notched groove 216 is provided forms a weak structure. Correspondingly, a groove bottom wall 218 of the notched groove 216 is the pressure relief mechanism 26. That is, the shell 21 is provided with a notched groove 216 in a portion corresponding to the first region 213, and a projection of the notched groove 216 in its depth direction is located within the first region 213. Figure 7 and Fig. 9 In the embodiment, the notched groove 216 is disposed on the surface of the housing 21 on the side away from the accommodating cavity 212 , so as to facilitate the arrangement of the notched groove 216 and the arrangement of the insulating layer 215 on the first region 213 .

[0138] Of course, in other embodiments, the pressure relief mechanism 26 and the shell 21 may also be a separate structure, that is, the pressure relief mechanism 26 and the shell 21 are a split structure, and the pressure relief mechanism 26 can be connected to the shell 21 by welding or the like. That is to say, the part of the shell 21 corresponding to the first area 213 is provided with a pressure relief hole, and the pressure relief mechanism 26 is connected to the shell 21 and covers the pressure relief hole. Correspondingly, the pressure relief mechanism 26 may be a pressure relief component such as an explosion-proof valve, an explosion-proof disk, an air valve, a pressure relief valve or a safety valve.

[0139] It should be noted that, in other embodiments, the pressure relief mechanism 26 may also be disposed on the end cover 22 of the battery cell 20 .

[0140] In this embodiment, by setting the pressure relief mechanism 26 for releasing the internal pressure of the battery cell 20 in the first area 213, on the one hand, the area corresponding to the pressure relief mechanism 26 is not provided with the insulating layer 215 or the thickness of the insulating layer 215 is relatively small, thereby reducing the influence of the insulating layer 215 on the pressure relief mechanism 26, so that the pressure relief mechanism 26 can normally release pressure, which is beneficial to improving the reliability of the battery cell 20. On the other hand, the pressure relief point and the corrosion breakdown point of the battery cell 20 are located in the same area, which is convenient for subsequent protection of the battery cell 20 or implementation of safety measures, without setting multiple protection points, which is beneficial to reducing the difficulty of subsequent protection of the battery cell 20.

[0141] According to some embodiments of the present application, see Figure 4 , Figure 5 and Figure 6 As shown, the housing 21 may include a wall portion 217 configured to support the electrode assembly 23 , and the first region 213 is formed on an inner surface of the wall portion 217 facing the accommodating cavity 212 .

[0142] Among them, the wall portion 217 is configured to support the electrode assembly 23, that is, after the electrode assembly 23 is accommodated in the accommodating cavity 212 of the shell 21, the wall portion 217 of the shell 21 is located at the lower side of the electrode assembly 23 in the direction of gravity, so that the electrode assembly 23 can be placed on the wall portion 217, and correspondingly, the wall portion 217 can support the electrode assembly 23.

[0143] The first region 213 is formed on the inner surface of the wall portion 217 facing the accommodating cavity 212 , that is, at least a portion of the inner surface of the wall portion 217 facing the accommodating cavity 212 forms the first region 213 .

[0144] In this embodiment, the first area 213 is formed on the wall portion 217, and the wall portion 217 is a wall of the shell 21 supporting the electrode assembly 23, so that after the first area 213 is corroded and punctured, the puncture point of the shell 21 is located at the bottom of the battery cell 20, thereby reducing the harm to users after the battery cell 20 is corroded and punctured, which is beneficial to improving the reliability of the battery cell 20.

[0145] In some embodiments, see Figure 3 , Figure 4 and Figure 5As shown, the housing 21 may include a bottom wall 218 and a side wall 219. Along the thickness direction X of the end cover, the bottom wall 218 is arranged opposite to the end cover 22, and the side wall 219 is arranged around the bottom wall 218. One end of the side wall 219 is connected to the bottom wall 218, and the other end is enclosed to form an opening 211. The side wall 219 and the bottom wall 218 are enclosed to form a receiving cavity 212, and the bottom wall 218 is a wall portion 217. In other words, the first area 213 is formed on the inner surface of the bottom wall 218 of the housing 21 facing the receiving cavity 212. Of course, in other embodiments, the wall portion 217 may also be a wall in the side wall 219 of the housing 21.

[0146] The bottom wall 218 and the side wall 219 are integrally formed structures, that is, the housing 21 is made by an integral forming process, such as stamping or casting.

[0147] In this embodiment, by setting the wall portion 217 as the bottom wall 218 of the shell 21, on the one hand, the end cover 22 is located on the top of the battery cell 20, which helps to reduce the risk of electrolyte leakage from the connection between the end cover 22 and the shell 21 during the use of the battery cell 20, thereby improving the reliability of the battery cell 20. On the other hand, the first area 213 can be away from the end cover 22, which helps to reduce the stress generated by the connection between the end cover 22 and the shell 21 acting on the first area 213, thereby reducing the impact on the first area 213.

[0148] According to some embodiments of the present application, see Figure 4 As shown, the wall thickness of the end cover 22 is greater than the wall thickness of the shell 21, that is, the dimension of the end cover 22 in the thickness direction is greater than the thickness of any wall of the shell 21, that is, the dimension of the end cover 22 in the thickness direction is greater than the thickness of the bottom wall 218 of the shell 21, and greater than the thickness of the side wall 219 of the shell 21.

[0149] In this embodiment, by setting the wall thickness of the end cover 22 to be greater than the wall thickness of the shell 21, the corrosion resistance of the end cover 22 is greater than that of the shell 21, so as to alleviate the phenomenon of corrosion and breakdown of the end cover 22, and enable the shell 21 to be corroded and broken down before the end cover 22, thereby facilitating fixed-point protection of the shell 21 or implementing safety measures.

[0150] According to some embodiments of the present application, referring to Figure 5 , Figure 6 and Fig.10 The housing 21 may include a wall portion 217, at least part of the inner surface of the wall portion 217 facing the accommodating cavity 212 forms a first region 213, the area of ​​the first region 213 is S1, and the area of ​​the inner surface of the wall portion 217 facing the accommodating cavity 212 is S2, satisfying 5mm 2 ≤S1≤S2.

[0151] In which, the shell 21 may include a wall portion 217, and at least a portion of the inner surface of the wall portion 217 facing the accommodating cavity 212 forms a first area 213, that is, the wall portion 217 is one of the multiple walls of the shell 21, and the inner surface of the wall portion 217 facing the accommodating cavity 212 can be the first area 213 as a whole, or only a part of the area can be the first area 213, that is, the first area 213 is formed on the inner surface of the wall portion 217 facing the accommodating cavity 212.

[0152] Exemplarily, a portion of the inner surface of the wall portion 217 facing the accommodating cavity 212 forms the first area 213 .

[0153] Optionally, the wall portion 217 may be a bottom wall 218 of the shell 21 disposed opposite to the end cover 22 in the thickness direction X of the end cover, or may be one of the side walls 219 of the shell 21 .

[0154] For example, the area of ​​the first region 213 may be 5 mm 2 , 5.5mm 2 、6mm 2 、6.5mm 2 , 7mm 2 , 7.5mm 2 , 8mm 2 , 8.5mm 2 , 9mm 2 、9.5mm 2 , 10mm 2 , 10.5mm 2 、11mm 2 or 12mm 2 wait.

[0155] In this embodiment, the first region 213 is formed on the wall portion 217, and the area of ​​the first region 213 of the housing 21 is set to be greater than or equal to 5 mm. 2 and is smaller than or equal to the area of ​​the inner surface of the wall portion 217 facing the accommodating cavity 212. On the one hand, the area of ​​the first region 213 is set to be greater than or equal to 5 mm 2, so as to facilitate the formation and manufacture of the first area, which is conducive to reducing the manufacturing difficulty of the battery cell 20, and is convenient for subsequent monitoring or inspection of the first area 213, which is conducive to reducing the detection difficulty and monitoring difficulty of the battery cell 20. On the other hand, the area of ​​the first area 213 is set to be less than or equal to the area of ​​the inner surface of the wall portion 217 facing the accommodating cavity 212, so as to alleviate the phenomenon that the shell 21 is corroded and broken down in a large range or appears on other walls of the shell during use, so as to facilitate the fixed-point protection or implementation of safety measures for the shell 21, which is conducive to reducing the subsequent protection difficulty of the battery cell 20, and further, while reducing the detection difficulty and monitoring difficulty of the battery cell 20, it can also take into account the subsequent protection difficulty of the battery cell 20.

[0156] According to some embodiments of the present application, see Figure 7 and Fig. 9 As shown, the thickness of the insulating layer 215 disposed in the second region 214 is D, which satisfies 1 μm≤D≤500 μm.

[0157] Exemplarily, the thickness D of the insulating layer 215 disposed in the second region 214 may be 1 μm, 5 μm, 10 μm, 15 μm, 20 μm, 25 μm, 30 μm, 40 μm, 50 μm, 60 μm, 80 μm, 100 μm, 120 μm, 150 μm, 180 μm, 200 μm, 250 μm, 300 μm, 350 μm, 400 μm, 450 μm or 500 μm, etc.

[0158] In this embodiment, the thickness of the insulating layer 215 provided in the second region 214 is 1 μm to 500 μm. On the one hand, by setting the thickness of the insulating layer 215 provided in the second region 214 to be greater than or equal to 1 μm, the protective effect of the insulating layer 215 on the second region 214 of the shell 21 is improved, and the effect of the insulating layer 215 insulating and isolating the electrode assembly 23 and the second region 214 of the shell 21 can be improved, thereby effectively improving the corrosion resistance of the second region 214 of the shell 21, which is beneficial to prolonging the service life of the battery cell 20, and can reduce the electrode assembly 23. The risk of short circuit between the shell 21 is beneficial to improving the reliability of the battery cell 20. On the other hand, by setting the thickness of the insulating layer 215 set in the second area 214 to be less than or equal to 500μm, the difficulty of setting the insulating layer 215 on the second area 214 of the shell 21 is reduced, and the space occupied by the insulating layer 215 can be reduced, which is beneficial to improving the internal space utilization of the battery cell 20, so as to improve the energy density of the battery cell 20, and further improve the service life and reliability of the battery cell 20 while taking into account the energy density of the battery cell 20.

[0159] In some embodiments, see Figure 7 and Fig. 9 As shown, the thickness of the insulating layer 215 disposed in the second region 214 is D, which satisfies 10 μm≤D≤200 μm.

[0160] In this embodiment, the thickness of the insulating layer 215 provided in the second region 214 is 10 μm to 200 μm. On the one hand, by setting the thickness of the insulating layer 215 provided in the second region 214 to be greater than or equal to 10 μm, the protective effect of the insulating layer 215 on the second region 214 of the shell 21 can be further improved, and the effect of the insulating layer 215 insulating and isolating the electrode assembly 23 and the second region 214 of the shell 21 can be further improved, so that the corrosion resistance of the second region 214 of the shell 21 can be further improved, which is beneficial to prolonging the service life of the battery cell 20, and can further reduce the electrode assembly 2 3 and the shell 21, which is beneficial to improving the reliability of the battery cell 20. On the other hand, by setting the thickness of the insulating layer 215 provided in the second area 214 to be less than or equal to 200 μm, the difficulty of providing the insulating layer 215 on the second area 214 of the shell 21 is further reduced, and the space occupied by the insulating layer 215 can be further reduced, which is beneficial to further improve the internal space utilization of the battery cell 20, so as to improve the energy density of the battery cell 20, thereby improving the service life and reliability of the battery cell 20 while taking into account the energy density of the battery cell 20.

[0161] According to some embodiments of the present application, the material of the insulating layer 215 is polyimide.

[0162] In this embodiment, by setting the material of the insulating layer 215 to polyimide, the insulating layer 215 has good resistance to electrolyte corrosion, which is beneficial to improving the service life of the insulating layer 215, thereby further improving the corrosion resistance of the shell 21, and helping to alleviate the phenomenon of the shell 21 being corroded and broken down by the electrolyte, thereby extending the time when the shell 21 is corroded and broken down, and further improving the service life and reliability of the battery cell 20.

[0163] According to some embodiments of the present application, the present application further provides a battery 100, and the battery 100 includes a battery cell 20 of any of the above schemes.

[0164] Among them, see Figure 2 As shown, the battery 100 may further include a housing 10 , in which the battery cells 20 are accommodated.

[0165] In some embodiments, the box body 10 may include a first box body 11 and a second box body 12 . The first box body 11 and the second box body 12 cover each other, and the first box body 11 and the second box body 12 jointly define an assembly space for accommodating the battery cells 20 .

[0166] Optionally, the second box body 12 can be a hollow structure with one end open, and the first box body 11 can be a plate-like structure. The first box body 11 covers the open side of the second box body 12, so that the first box body 11 and the second box body 12 jointly define an assembly space; the first box body 11 and the second box body 12 can also be hollow structures both with one side open, and the open side of the first box body 11 covers the open side of the second box body 12.

[0167] Of course, the box body 10 formed by the first box body 11 and the second box body 12 can be in various shapes, such as a cylinder or a cuboid. Figure 2 In the embodiment, the box body 10 is a rectangular parallelepiped structure.

[0168] Optionally, the number of battery cells 20 disposed in the box body 10 may be one or more. Figure 2 In the embodiment, a plurality of battery cells 20 are arranged in the box 10 of the battery 100, and the plurality of battery cells 20 can be connected in series, in parallel or in a mixed connection. The mixed connection means that the plurality of battery cells 20 are both connected in series and in parallel. The plurality of battery cells 20 can be directly connected in series, in parallel or in a mixed connection, and then the whole formed by the plurality of battery cells 20 is accommodated in the box 10; of course, the battery 100 can also be a battery module formed by first connecting the plurality of battery cells 20 in series, in parallel or in a mixed connection, and then the plurality of battery modules are connected in series, in parallel or in a mixed connection to form a whole, and then accommodated in the box 10.

[0169] The battery 100 may further include other structures. For example, the battery 100 may further include a busbar component, which connects the plurality of battery cells 20 to achieve electrical connection between the plurality of battery cells 20 .

[0170] It should be noted that, in some embodiments, the battery 100 may not be provided with a box 10, and the battery 100 includes a plurality of battery cells 20, and the battery 100 composed of a plurality of battery cells 20 may be directly assembled on an electrical device to provide electrical energy to the electrical device through the plurality of battery cells 20. In other words, the box 10 may be used as a part of the electrical device. Taking the vehicle 1000 as an example of the electrical device, the box 10 may be used as a part of the chassis structure of the vehicle 1000, for example, a part of the box 10 may become at least a part of the floor of the vehicle 1000, or a part of the box 10 may become at least a part of the crossbeam and longitudinal beam of the vehicle 1000.

[0171] According to some embodiments of the present application, the present application further provides an electrical device, which includes a battery cell 20 according to any of the above schemes, and the battery cell 20 is used to provide electrical energy to the electrical device.

[0172] The electrical device may be any of the aforementioned devices or systems using the battery cell 20 .

[0173] According to some embodiments of the present application, see Figures 3 to 7 as well as Fig.10 As shown, the present application provides a battery cell 20, which includes a housing 21, an electrode assembly 23, an end cap 22 and a pressure relief mechanism 26. The housing 21 has an accommodating cavity 212 with an opening 211 formed inside, the accommodating cavity 212 is used to accommodate the electrode assembly 23 and the electrolyte, the cavity wall of the accommodating cavity 212 includes a first area 213 and a second area 214, and the end cap 22 closes the opening 211. The shell 21 includes a bottom wall 218 and a side wall 219. Along the thickness direction X of the end cover, the bottom wall 218 is arranged opposite to the end cover 22, and the side wall 219 is arranged around the bottom wall 218. One end of the side wall 219 is connected to the bottom wall 218, and the other end is surrounded to form an opening 211. The side wall 219 and the bottom wall 218 are surrounded to form a accommodating cavity 212. The wall portion 217 is configured to support the electrode assembly 23. The portion of the bottom wall 218 facing the inner surface of the accommodating cavity 212 in the thickness direction X of the end cover forms a first area 213. The shape of the first area 213 is circular or elliptical. The portion of the cavity wall surface of the accommodating cavity 212 except the first area 213 is the second area 214, and the second area 214 surrounds the outer periphery of the first area 213. The first region 213 and the second region 214 are both provided with an insulating layer 215. The thickness of the insulating layer 215 provided in the first region 213 is less than the thickness of the insulating layer 215 provided in the second region 214. The insulating layer 215 is used to separate the electrolyte and the shell 21. The thickness of the insulating layer 215 provided in the first region 213 is H, and the thickness of the insulating layer 215 provided in the second region 214 is D, which satisfies H≤0.5D, 1μm≤D≤500μm, and further, 10μm≤D≤200μm. The area of ​​the first region 213 is S1, and the area of ​​the inner surface of the wall portion 217 facing the accommodating cavity 212 is S2, which satisfies 5mm 2 ≤S1≤S2. The pressure relief mechanism 26 is located in the first region 213 , and is configured to release the internal pressure of the battery cell 20 .

[0174] According to some embodiments of the present application, see Figures 8 to 9As shown, the present application provides a battery cell 20, which includes a housing 21, an electrode assembly 23, an end cap 22 and a pressure relief mechanism 26. The housing 21 has an accommodating cavity 212 with an opening 211 formed inside, the accommodating cavity 212 is used to accommodate the electrode assembly 23 and the electrolyte, the cavity wall of the accommodating cavity 212 includes a first area 213 and a second area 214, and the end cap 22 closes the opening 211. The shell 21 includes a bottom wall 218 and a side wall 219. Along the thickness direction X of the end cover, the bottom wall 218 is arranged opposite to the end cover 22, and the side wall 219 is arranged around the bottom wall 218. One end of the side wall 219 is connected to the bottom wall 218, and the other end is surrounded to form an opening 211. The side wall 219 and the bottom wall 218 are surrounded to form a accommodating cavity 212. The wall portion 217 is configured to support the electrode assembly 23. The portion of the inner surface of the bottom wall 218 facing the accommodating cavity 212 in the thickness direction X of the end cover forms a first area 213. The shape of the first area 213 is circular or elliptical. The cavity wall surface of the accommodating cavity 212 except the first area 213 is the second area 214. The second area 214 surrounds the outer periphery of the first area 213. Only the second area 214 is provided with an insulating layer 215. The insulating layer 215 is used to separate the electrolyte and the shell 21. The first area 213 is not provided with an insulating layer 215. The thickness of the insulating layer 215 disposed in the second region 214 is D, which satisfies 1 μm ≤ D ≤ 500 μm, and further, 10 μm ≤ D ≤ 200 μm. The area of ​​the first region 213 is S1, and the area of ​​the inner surface of the wall portion 217 facing the accommodating cavity 212 is S2, which satisfies 5 mm 2 ≤S1≤S2. The pressure relief mechanism 26 is located in the first region 213 , and is configured to release the internal pressure of the battery cell 20 .

[0175] 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.

[0176] The above are only preferred embodiments of the present application and are not intended to limit the present application. For those skilled in the art, the present application may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A battery cell, characterized in that: include: A housing having an opening formed therein, wherein the housing is used to accommodate the electrode assembly and the electrolyte, and a wall surface of the housing includes a first area and a second area; as well as an end cap for closing the opening; Wherein, both the first region and the second region are provided with an insulating layer, and the thickness of the insulating layer provided in the first region is less than the thickness of the insulating layer provided in the second region, and the insulating layer is used to separate the electrolyte and the shell; or Only the second region is provided with an insulating layer, and the insulating layer is used to separate the electrolyte and the shell.

2. The battery cell according to claim 1, characterized in that: The insulating layer is disposed in both the first region and the second region, and a thickness of the insulating layer disposed in the second region is greater than or equal to twice a thickness of the insulating layer disposed in the first region.

3. The battery cell according to claim 1, characterized in that: The first area is in a circular or elliptical shape.

4. The battery cell according to claim 1, characterized in that: The housing further has a pressure relief mechanism, which is located in the first region and configured to release internal pressure of the battery cell.

5. The battery cell according to any one of claims 1 to 4, characterized in that: The housing includes a wall portion configured to support the electrode assembly; Wherein, at least a portion of the inner surface of the wall portion facing the accommodating cavity forms the first area.

6. The battery cell according to claim 5, characterized in that: The housing comprises a bottom wall and a side wall. Along the thickness direction of the end cover, the bottom wall is arranged opposite to the end cover, the side wall is arranged around the bottom wall, one end of the side wall is connected to the bottom wall, and the other end is enclosed to form the opening, and the side wall and the bottom wall are enclosed to form the accommodating cavity; Wherein, the bottom wall is the wall portion.

7. The battery cell according to claim 1, characterized in that: The wall thickness of the end cover is greater than the wall thickness of the shell.

8. The battery cell according to claim 1, characterized in that: The housing comprises a wall portion, at least a portion of an inner surface of the wall portion facing the accommodating cavity forming the first area; The area of ​​the first region is S1, the area of ​​the inner surface of the wall facing the accommodating cavity is S2, and the area of ​​the first region is S1, and the area of ​​the inner surface of the wall facing the accommodating cavity is S2, which satisfies the following conditions: 5 mm 2 ≤S1≤S2.

9. The battery cell according to claim 1, characterized in that: The thickness of the insulating layer disposed in the second region is D, which satisfies 1 μm≤D≤500 μm.

10. The battery cell according to claim 9, characterized in that: 10μm≤D≤200μm.

11. The battery cell according to claim 1, characterized in that: The insulating layer is made of polyimide.

12. A battery, characterized in that: The invention comprises a battery cell as claimed in any one of claims 1 to 11.

13. An electrical device, characterized in that: The invention comprises a battery cell as claimed in any one of claims 1 to 11, wherein the battery cell is used to provide electrical energy.

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