Battery monomer, battery and electric equipment

Abstract

The embodiment of the invention provides a battery monomer, a battery and electric equipment, and relates to the technical field of batteries. The battery monomer provided by the embodiment of the invention comprises a shell and a pressure relief nick, the shell is flat, and the shell comprises two first walls which are opposite to each other along the thickness direction of the shell; a pressure relief nick is disposed on at least one of the first walls. According to the battery monomer provided by the embodiment of the invention, the area enclosed by the pressure relief nicks is not limited, meanwhile, the pressure relief nicks are easier to process, and the manufacturing cost is reduced.

Description

Technical Field

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

[0002] Energy conservation and emission reduction are the keys to the sustainable development of the automotive industry. Electric vehicles have become an important part of the sustainable development of the automotive industry due to their advantages of energy conservation and environmental protection. For electric vehicles, battery technology is an important factor related to their development.

[0003] Batteries are widely used in fields such as portable electronic devices, electric transportation vehicles, electric tools, drones, energy storage devices, etc. During the manufacturing process of batteries, the manufacturing cost of batteries is an issue that cannot be ignored. Therefore, how to reduce the manufacturing cost of batteries is an urgent technical problem in battery technology. Summary of the Invention

[0004] The present application provides a battery cell, a battery, and an electrical device. The pressure relief indentation is provided on the large surface, so the processing of the pressure relief indentation is easier, and the manufacturing cost of the battery can be reduced.

[0005] The present application is implemented by the following technical solutions:

[0006] In a first aspect, an embodiment of the present application provides a battery cell, including a housing and a pressure relief indentation. The housing is flat, and along the thickness direction of the housing, the housing includes two opposite first walls; the pressure relief indentation is provided on at least one of the first walls.

[0007] According to the battery cell of the embodiment of the present application, the housing is flat. By providing the pressure relief indentation on at least one of the two first walls opposite to each other in the thickness direction of the housing, the area enclosed by the pressure relief indentation is not restricted, and the area enclosed by the pressure relief indentation and the setting position of the pressure relief indentation can be freely selected. At the same time, since the area of the outer surface of the first wall is large, the processing of the pressure relief indentation is easier, and the manufacturing cost is reduced.

[0008] According to some embodiments of the present application, the pressure relief indentation is a closed annular structure. In the above solution, the structural strength of the part of the housing provided with the pressure relief indentation is more uniform, and when the battery cell undergoes thermal runaway, its high temperature and high pressure resistance capabilities are also improved.

[0009] According to some embodiments of the present application, the pressure relief notch is an unclosed annular structure. In the above solution, after thermal runaway occurs in the battery cell, the crack can be torn along the extension direction of the pressure relief notch. At the same time, due to the existence of the opening, the crack can tear the outer shell along the orientation of the opening, so that the tearing direction and range of the crack are controllable, realizing local valve opening, reducing the probability of tearing the outer shell in a large range. Both the tearing direction and range of the crack are controllable, reducing the damage to the battery cell caused by the uncontrollability of the crack, and also reducing the impact on other battery cells caused by the uncontrollable discharge of high-pressure gas due to the uncontrollable crack.

[0010] According to some embodiments of the present application, the pressure relief notch is located in the central area of the first wall. In the above solution, the area enclosed by the pressure relief notch can be selected as needed. In addition, setting the pressure relief notch at the central position of the first wall can make the processing easier and reduce the processing cost of the pressure relief notch.

[0011] According to some embodiments of the present application, the pressure relief notch is arranged in the corner area of the first wall. In the above solution, the area enclosed by the pressure relief notch is not limited. At the same time, when thermal runaway occurs in the battery cell, the crack tears the first wall along the pressure relief notch. Since the pressure relief notch is arranged in the corner area of the first wall, the crack can only damage the corner area of the first wall, reducing the probability of the crack damaging the first wall in a large range.

[0012] According to some embodiments of the present application, the pressure relief notch includes an arc segment, a first extension segment, and a second extension segment. The arc segment has a first end and a second end. The first extension segment extends from the first end towards the direction close to the central axis of the arc segment, and the second extension segment extends from the second end towards the direction close to the central axis of the arc segment. In the above solution, when thermal runaway occurs in the battery cell and the pressure relief notch is torn, local valve opening can be realized, reducing the probability of tearing the outer shell in a large range. Both the tearing direction and range of the crack are controllable, reducing the damage to the battery cell caused by the uncontrollability of the crack, and also reducing the impact on other battery cells caused by the uncontrollable discharge of high-pressure gas due to the uncontrollable crack.

[0013] According to some embodiments of the present application, the central angle of the arc segment is α, satisfying: 180° ≤ α < 360°. In the above solution, when α ≥ 180°, the area enclosed by the arc segment is sufficient. Thus, when the battery cell undergoes thermal runaway, the crack tears the outer shell along the arc segment, and the crack on the arc segment can enable the high-pressure gas inside the outer shell to be quickly discharged; when α < 360°, the pressure relief notch is an unclosed annular structure with an opening thereon. Thus, the crack can tear the outer shell along the orientation of the opening, making the tearing direction and range of the crack controllable, and further realizing local valve opening of the crack on the outer shell. When 180° ≤ α < 360°, it can not only make the range of the crack tearing along the arc segment sufficient and the high-pressure gas inside the outer shell can be quickly discharged, but also there is an opening on the pressure relief notch, which can guide the tearing direction and range of the crack, and realize local valve opening of the crack on the outer shell.

[0014] According to some embodiments of the present application, the first extension segment is tangent to the arc segment; and / or the second extension segment is tangent to the arc segment. In the above solution, the crack on the arc segment can very smoothly extend and tear along the tangent line at the first end or the second end of the arc segment, reducing the obstruction during the crack tearing process, making the crack tearing smoother and more controllable, and reducing the stress concentration during the tearing process.

[0015] According to some embodiments of the present application, the first extension segment is a straight line segment; and / or the second extension segment is a straight line segment. In the above solution, on the one hand, it is easier to process the first extension segment and / or the second extension segment. On the other hand, the tearing process of the crack on the straight line segment is smoother. Or rather, the straight line segment can better guide the crack to tear along the preset direction, so that the tearing direction and range of the crack are more controllable.

[0016] According to some embodiments of the present application, the end of the first extension segment far from the arc segment and the end of the second extension segment far from the arc segment are spaced apart to form a first opening. In the above solution, the orientation of the first opening directly affects the tearing direction of the crack. For example, if the first opening faces the corner of the first wall, then after the battery cell undergoes thermal runaway, the high-pressure gas will tear the pressure relief notch, and the crack can tear along the direction of the first opening facing the corner. Thus, the tearing direction of the crack can be adjusted by adjusting the orientation of the first opening.

[0017] According to some embodiments of the present application, the pressure relief notch is disposed in the corner area of the first wall and the first opening faces the corner of the first wall. In the above solution, when the battery cell undergoes thermal runaway, the crack can tear the outer shell under the guidance of the pressure relief notch. Since the pressure relief notch is disposed in the corner area of the first wall, the tearing area of the crack also mainly concentrates in the corner area of the first wall, thereby reducing the probability of damage to other areas of the first wall, making it possible to recycle the outer shell after the battery cell undergoes thermal runaway.

[0018] According to some embodiments of the present application, the pressure relief notch includes: a first arc segment and a second arc segment, the first arc segment and the second arc segment are spaced apart in a first direction, and the first arc segment and the second arc segment protrude away from each other; a first straight segment and a second straight segment, the first straight segment is connected to the same-direction ends of the first arc segment and the second arc segment in a second direction, and the second straight segment is connected to the same-direction ends of the first arc segment and the second arc segment in the second direction, and the first direction and the second direction are perpendicular to each other.

[0019] In the above solution, the first arc segment, the first straight segment, the second arc segment and the second straight segment form a runway-shaped structure, and the first arc segment, the first straight segment, the second arc segment and the second straight segment can be sequentially etched by laser.

[0020] According to some embodiments of the present application, the length of the first straight segment or the second straight segment is L 1 , satisfying: 1 mm ≤ L 1 ≤ 40 mm. In the above solution, when L 1 ≥ 1 mm, after the battery cell undergoes thermal runaway, when the crack tears the outer shell along the pressure relief notch, the high-temperature and high-pressure gas inside the outer shell can be quickly discharged. When L 1 ≤ 40 mm, the overall size of the pressure relief notch is not too large, so that the overall structural strength of the outer shell meets the requirements. When 1 mm ≤ L 1 ≤ 40 mm, it can not only quickly discharge the gas inside the outer shell after the battery cell undergoes thermal runaway, but also the overall structural strength of the outer shell meets the requirements.

[0021] According to some embodiments of the present application, satisfying: 5 mm ≤ L 1 ≤ 30 mm. In the above solution, when L 1 ≥ 5 mm, after the battery cell undergoes thermal runaway, when the crack tears the outer shell along the pressure relief notch, the high-temperature and high-pressure gas inside the outer shell can be discharged more quickly. When L 1 ≤ 30 mm, the overall size of the pressure relief notch is not too large, so that the overall structural strength of the outer shell can further meet the requirements. When 5 mm ≤ L1 When it is ≤ 30 mm, it can not only make the gas in the housing be discharged more quickly after thermal runaway of the battery cell occurs, but also further meet the requirements for the overall structural strength of the housing.

[0022] According to some embodiments of the present application, in the second direction, the distance between the first straight line segment and the second straight line segment is W 1 , satisfying: 1 mm ≤ W 1 ≤ 40 mm. In the above solution, when W 1 ≥ 1 mm, after thermal runaway of the battery cell occurs, after the crack tears the housing along the pressure relief notch, the high-temperature and high-pressure gas in the housing can be quickly discharged. When W 1 ≤ 40 mm, the overall size of the pressure relief notch is not too large, so that the overall structural strength of the housing meets the requirements. When 1 mm ≤ W 1 ≤ 40 mm, it can not only make the gas in the housing be quickly discharged after thermal runaway of the battery cell occurs, but also the overall structural strength of the housing meets the requirements.

[0023] According to some embodiments of the present application, satisfying: 1 mm ≤ W 1 ≤ 10 mm. In the above solution, when W 1 ≥ 1 mm, after thermal runaway of the battery cell occurs, after the crack tears the housing along the pressure relief notch, the high-temperature and high-pressure gas in the housing can be quickly discharged. When W 1 ≤ 10 mm, the overall size of the pressure relief notch is not too large, so that the overall structural strength of the housing further meets the requirements. When 1 mm ≤ W 1 ≤ 10 mm, it can not only make the gas in the housing be quickly discharged after thermal runaway of the battery cell occurs, but also the overall structural strength of the housing further meets the requirements.

[0024] According to some embodiments of the present application, the first straight line segment includes a first sub-segment and a second sub-segment. One end of the first sub-segment is connected to the first arc segment, one end of the second sub-segment is connected to the second arc segment, and the other ends of the first sub-segment and the second sub-segment are spaced apart to form a second opening. In the above solution, local valve opening on the side wall can be realized. When thermal runaway occurs inside the battery cell, the gas can tear the housing along the pressure relief notch. At the same time, the area where the second opening is located will not be disconnected from the housing, but guides the gas to continue tearing the housing until the desired tearing effect is achieved. That is to say, the second opening can guide the tearing direction of the crack, making the tearing direction and tearing range of the crack controllable.

[0025] According to some embodiments of the present application, the length of the pressure relief notch is L, and the distance between the first sub-segment and the second sub-segment in the first direction is L 2, satisfying: 0.05 ≤ L 2 / L ≤ 0.8. In the above solution, when L 2 / L ≥ 0.05, the second opening guides the crack to tear the outer shell, so that after the battery cell undergoes thermal runaway, the gas inside the outer shell can be quickly discharged; when L 2 / L ≤ 0.8, it can make the crack tear the outer shell along the orientation of the second opening, and the tearing range will not be too large, reducing the probability of large-scale damage to the outer shell. When 0.05 ≤ L 2 / L ≤ 0.8, not only can the gas inside the outer shell be quickly discharged after the battery cell undergoes thermal runaway, but also the probability of large-scale damage to the outer shell is reduced.

[0026] According to some embodiments of the present application, satisfying: 0.05 ≤ L 2 / L ≤ 0.4. In the above solution, when L 2 / L ≥ 0.05, the second opening guides the crack to tear the outer shell, so that after the battery cell undergoes thermal runaway, the gas inside the outer shell can be quickly discharged; when L 2 / L ≤ 0.4, it can make the crack tear the outer shell along the orientation of the second opening, and the tearing range will not be too large, further reducing the probability of large-scale damage to the outer shell. When 0.05 ≤ L 2 / L ≤ 0.4, not only can the gas inside the outer shell be quickly discharged after the battery cell undergoes thermal runaway, but also the probability of large-scale damage to the outer shell is further reduced.

[0027] According to some embodiments of the present application, the outer shell includes a housing and a cover plate. The housing includes a bottom wall and a peripheral side wall. One end of the peripheral side wall is connected to the outer periphery of the bottom wall, and the other end of the peripheral side wall encloses an opening. The cover plate closes the opening; wherein the first wall is the cover plate or the bottom wall. In the above solution, the outer shell is jointly formed by two separate components - the housing and the cover plate. The housing and the cover plate can be metal parts, and the two can be fixed together by welding.

[0028] In a second aspect, an embodiment of the present application provides a battery, including the above battery cell. Since the battery according to the embodiment of the present application is provided with the above battery cell, the processing of the battery is easier, and the manufacturing cost is reduced.

[0029] In a third aspect, an embodiment of the present application provides an electrical device, including the above battery cell or the above battery, and the battery cell or the battery is used to provide electrical energy. Therefore, the manufacturing difficulty and processing cost of the electrical device are reduced.

[0030] The additional aspects and advantages of the present application will be partially given in the following description, partially become obvious from the following description, or be understood through the practice of the present application. Brief Description of the Drawings

[0031] To more clearly illustrate the technical solutions of the embodiments of the present application, the following will briefly introduce the drawings required for use in the embodiments. It should be understood that the following drawings only show some embodiments of the present application, and therefore should not be regarded as limiting the scope. For those of ordinary skill in the art, without creative efforts, other relevant drawings can also be obtained based on these drawings.

[0032] Figure 1 Schematic diagram of a vehicle provided by an embodiment of the present application;

[0033] Figure 2 Explosion view of a battery provided by an embodiment of the present application;

[0034] Figure 3 Explosion view of a battery cell provided by an embodiment of the present application;

[0035] Figure 4 Schematic diagram of a first wall provided by an embodiment of the present application;

[0036] Figure 5 For Figure 4 Partial enlarged schematic diagram of the circled A;

[0037] Figure 6 Schematic diagram of another first wall provided by an embodiment of the present application;

[0038] Figure 7 Schematic diagram of yet another first wall provided by an embodiment of the present application;

[0039] Figure 8 For Figure 7 Partial enlarged schematic diagram of the circled B;

[0040] Figure 9 Schematic diagram of yet another first wall provided by an embodiment of the present application.

[0041] Icons: Vehicle 1000, Battery 100, Controller 200, Motor 300, Box 10, Battery Cell 20, First Sub-box 11, Second Sub-box 12, Outer Shell 21, Electrode Assembly 22, Electrode Terminal 25, Housing 211, Bottom Wall 211a, Peripheral Side Wall 211b, Cover Plate 212,

[0042] First Wall 212a, First Edge 212a1, Second Edge 212a2,

[0043] Pressure relief notch 213, arc segment 201, first extension segment 202, second extension segment 203, central axis 201a, first opening 201c, first arc segment 204, second arc segment 205, first straight segment 206, second straight segment 207, first sub-segment 206a, second sub-segment 206b, second opening 208. Detailed implementation manners

[0044] To make the objectives, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present application. Apparently, the described embodiments are some, but not all, of the embodiments of the present application. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present application without making creative efforts shall fall within the protection scope of the present application.

[0045] Unless otherwise defined, all technical and scientific terms used in the present application have the same meanings as those commonly understood by those skilled in the technical field to which the present application belongs; the terms used in the description of the present application in the specification are only for the purpose of describing specific embodiments, and are not intended to limit the present application; the terms "including" and "having" and any variations thereof in the specification and claims of the present application and the above drawings are intended to cover non-exclusive inclusion. The terms "first", "second", etc. in the specification and claims of the present application or the above drawings are used to distinguish different objects, rather than to describe a specific order or primary-secondary relationship.

[0046] Referring to "embodiments" in the present application means that specific features, structures or characteristics described in connection with the embodiments can be included in at least one embodiment of the present application. The phrase appears in various positions in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described in the present application can be combined with other embodiments.

[0047] In the description of the present application, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected to", and "attached to" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be directly connected, or indirectly connected through an intermediate medium, and it can be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present application can be understood according to specific circumstances.

[0048] In this application, the term "and / or" is merely a description of the association relationship between associated objects, indicating that there can be three relationships. For example, A and / or B can represent three situations: A exists alone, A and B exist simultaneously, and B exists alone. Additionally, in this application, the character " / " generally indicates that the associated objects before and after are in an "or" relationship.

[0049] In this application, "a plurality of" means two or more (including two). Similarly, "a plurality of groups" means two or more groups (including two groups), and "a plurality of sheets" means two or more sheets (including two sheets).

[0050] In some embodiments, the battery can be a battery module. When there are multiple battery cells, the multiple battery cells are arranged and fixed to form a battery module.

[0051] In some embodiments, the battery can be a battery pack. The battery pack includes a box body and battery cells, and the battery cells or battery modules are accommodated in the box body.

[0052] In some embodiments, the box body can be part of the chassis structure of a vehicle. For example, part of the box body can become at least part of the floor of the vehicle, or part of the box body can become at least part of the crossbeam and longitudinal beam of the vehicle.

[0053] In some embodiments, the battery can be an energy storage device. The energy storage device includes an energy storage container, an energy storage cabinet, etc.

[0054] In the embodiments of this application, the battery cell can be a secondary battery, which refers to a battery cell that can be activated by charging after discharging so as to continue to be used.

[0055] The battery cell can be, but is not limited to, 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-metal hydride battery, a nickel-cadmium battery, a lead-acid battery, etc.

[0056] The 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 extracted back and forth between the positive electrode and the negative electrode. The separator is disposed between the positive electrode and the negative electrode, which can prevent the short circuit between the positive and negative electrodes and at the same time allow the active ions to pass through.

[0057] In some embodiments, the positive electrode can be a positive electrode plate, and the positive electrode plate can include a positive electrode current collector and a positive electrode active material disposed on at least one surface of the positive electrode current collector.

[0058] As an example, the positive electrode current collector has two surfaces opposite to each other in its own thickness direction, and the positive electrode active material is disposed on any one or both of the two opposite surfaces of the positive electrode current collector.

[0059] As an example, the positive electrode current collector can 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. can be used. The composite current collector can include a polymer material base layer and a metal layer. The composite current collector can be formed by forming a metal material (such as 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.).

[0060] As an example, the positive electrode active material can include at least one of the following materials: lithium-containing phosphate, lithium transition metal oxide, and their respective modified compounds. However, the present application is not limited to these materials, and other conventional materials that can be used as the battery positive electrode active material can also be used.

[0061] In some embodiments, the negative electrode can be a negative electrode sheet, and the negative electrode sheet can include a negative electrode current collector.

[0062] As an example, the negative electrode current collector can 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. can be used.

[0063] In some embodiments, the negative electrode current collector has two surfaces opposite to each other in its own thickness direction, and the negative electrode active material is disposed on either one or both of the two opposite surfaces of the negative electrode current collector.

[0064] As an example, the negative electrode active material can be a negative electrode active material for a battery well-known in the art. As an example, the negative electrode active material can include at least one of the following materials: artificial graphite, natural graphite, soft carbon, hard carbon, silicon-based material, tin-based material, and lithium titanate, etc. The silicon-based material can be selected from at least one of elemental silicon, silicon oxide compound, silicon-carbon composite, silicon-nitrogen composite, and silicon alloy. The tin-based material can be selected from at least one of elemental tin, tin oxide compound, and tin alloy. However, the present application is not limited to these materials, and other conventional materials that can be used as the battery negative electrode active material can also be used. These negative electrode active materials can be used alone or in combination of two or more.

[0065] In some embodiments, the separator is a separator membrane. The present application does not have any particular limitation on the type of the separator membrane, and any well-known porous structure separator membrane with good chemical stability and mechanical stability can be selected.

[0066] As an example, the main material of the separator can be selected from at least one of glass fiber, non-woven fabric, polyethylene, polypropylene, polyvinylidene fluoride, and ceramics. The separator can be a single-layer film or a multi-layer composite film, without particular limitation. When the separator is a multi-layer composite film, the materials of each layer can be the same or different, without particular limitation. The separator can be a single component located between the positive and negative electrodes, or can be attached to the surfaces of the positive and negative electrodes.

[0067] In some embodiments, the separator is a solid electrolyte. The solid electrolyte is disposed between the positive electrode and the negative electrode, and simultaneously functions to transport ions and isolate the positive and negative electrodes.

[0068] In some embodiments, the battery cell further includes an electrolyte, and the electrolyte functions to conduct ions between the positive and negative electrodes. The electrolyte can be liquid, gel-like, or solid. Among them, the liquid electrolyte includes an electrolyte salt and a solvent.

[0069] In some embodiments, the electrolyte salt can include at least one of lithium hexafluorophosphate, lithium tetrafluoroborate, lithium perchlorate, lithium hexafluoroarsenate, lithium bis(fluorosulfonyl)imide, lithium bis(trifluoromethanesulfonyl)imide, lithium trifluoromethanesulfonate, lithium difluorophosphate, lithium difluoro(oxalato)borate, lithium bis(oxalato)borate, lithium difluoro bis(oxalato)phosphate, and lithium tetrafluoro(oxalato)phosphate.

[0070] In some embodiments, the solvent can 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, sulfolane, dimethyl sulfone, methyl ethyl sulfone, and diethyl sulfone. The solvent can also be an ether solvent. The ether solvent can include one or more of ethylene glycol dimethyl ether, ethylene glycol diethyl ether, diethylene glycol dimethyl ether, triethylene glycol dimethyl ether, tetraethylene glycol dimethyl ether, 1,3-dioxolane, tetrahydrofuran, methyltetrahydrofuran, diphenyl ether, and crown ether.

[0071] Among them, the gel-like electrolyte includes a polymer as the skeleton network of the electrolyte, and is combined with an ionic liquid-lithium salt.

[0072] Among them, the solid electrolyte includes a polymer solid electrolyte, an inorganic solid electrolyte, and a composite solid electrolyte.

[0073] As an example, the polymer solid electrolyte can be polyether (polyethylene oxide), polysiloxane, polycarbonate, polyacrylonitrile, polyvinylidene fluoride, polymethyl methacrylate, single-ion polymer, poly(ionic liquid)-lithium salt, cellulose, etc.

[0074] As an example, the inorganic solid electrolyte may include one or more of oxide solid electrolytes (crystalline perovskite, sodium superionic conductor, garnet, amorphous LiPON film), sulfide solid electrolytes (crystalline lithium superionic conductor (lithium germanium phosphorus sulfur, argyrodite), amorphous sulfide), and halide solid electrolytes, nitride solid electrolytes, and hydride solid electrolytes.

[0075] As an example, the composite solid electrolyte is formed by adding an inorganic solid electrolyte filler to a polymer solid electrolyte.

[0076] In some embodiments, the electrode assembly has a wound structure. The positive electrode sheet and the negative electrode sheet are wound into a wound structure.

[0077] In some embodiments, the electrode assembly has a laminated structure.

[0078] 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 can be a steel shell, an aluminum shell, a plastic shell (such as polypropylene), a composite metal shell (such as a copper-aluminum composite shell), or an aluminum-plastic film, etc.

[0079] In some embodiments, the housing includes an end cap and a housing body. The housing body is provided with an opening, and the end cap closes the opening to form a sealed space for accommodating substances such as the electrode assembly and the electrolyte. The housing body can be provided with one or more openings. One or more end caps can also be provided.

[0080] In some embodiments, at least one electrode terminal is provided on the housing, and the electrode terminal is electrically connected to the tab of the electrode assembly. The electrode terminal can be directly connected to the tab or indirectly connected to the tab through an adapter. The electrode terminal can be provided on the end cap or on the housing body.

[0081] In some embodiments, an explosion-proof valve is provided on the housing. The explosion-proof valve is used to release the internal pressure of the battery cell.

[0082] As an example, the battery cell can be a cylindrical battery cell, a prismatic battery cell, a soft-pack battery cell, or a battery cell of other shapes. The prismatic battery cell includes a square-shell battery cell, a blade-shaped battery cell, a multi-prismatic battery, and the multi-prismatic battery is, for example, a hexagonal-prismatic battery, etc. There is no particular limitation in the embodiments of the present application.

[0083] The battery mentioned in the embodiments of the present application refers to a single physical module including one or more battery cells to provide a higher voltage and capacity.

[0084] In some embodiments, the battery can be a battery module. When there are multiple battery cells, the multiple battery cells are arranged and fixed to form a battery module.

[0085] In some embodiments, the battery may be a battery pack, which includes a box body and battery cells, and the battery cells or battery modules are accommodated in the box body.

[0086] In some embodiments, the box body may be part of the chassis structure of a vehicle. For example, part of the box body may become at least part of the floor of the vehicle, or part of the box body may become at least part of the cross beams and longitudinal beams of the vehicle.

[0087] In some embodiments, the battery may be an energy storage device. The energy storage device includes an energy storage container, an energy storage electrical cabinet, etc.

[0088] The battery has prominent advantages such as high energy density, low environmental pollution, high power density, long service life, wide application range, and small self-discharge coefficient, and is an important part of the development of new energy today.

[0089] The development of battery technology needs to consider various design factors at the same time. For example, performance parameters such as energy density, discharge capacity, charge and discharge rate, etc. In addition, the assembly efficiency of the battery also needs to be considered.

[0090] The battery cells disclosed in the embodiments of the present application can be used but are not limited to power-consuming devices such as vehicles, ships, or aircraft. The power system of the power-consuming device can be composed of the battery cells, batteries, etc. disclosed in the present application.

[0091] The embodiments of the present application provide a power-consuming device using battery cells as a power source. The power-consuming device can be but is not limited to mobile phones, tablet computers, laptop computers, electric toys, electric tools, electric bicycles, electric motorcycles, electric vehicles, ships, spacecraft, etc. Among them, the electric toy can include fixed or mobile electric toys, such as game consoles, electric vehicle toys, electric ship toys, and electric aircraft toys, etc. The spacecraft can include airplanes, rockets, space shuttles, and spaceships, etc.

[0092] For the convenience of description in the following embodiments, a power-consuming device of an embodiment of the present application is taken as an example of a vehicle 1000 for description.

[0093] Please refer to Figure 1 , Figure 1 which is a schematic diagram of the vehicle provided by the first embodiment of the present application. The vehicle 1000 can be a fuel vehicle, a gas vehicle, or a new energy vehicle. The new energy vehicle can be a pure electric vehicle, a hybrid vehicle, or an extended-range vehicle, etc. A battery 100 is arranged inside the vehicle 1000, and the battery 100 can be arranged at the bottom, head, or tail of the vehicle 1000. The battery 100 can be used for power supply of the vehicle 1000. For example, the battery 100 can be used as the operating power source of the vehicle 1000 and is used for the circuit system of the vehicle 1000, such as for the working power consumption requirements during the start, navigation, and operation of the vehicle 1000.

[0094] The vehicle 1000 may further include a controller 200 and a motor 300. The controller 200 is used to control the battery 100 to supply power to the motor 300. For example, it is used for the working power requirements during the start, navigation, and driving of the vehicle 1000.

[0095] In some embodiments of the present application, the battery 100 can not only be used as the operating power source of the vehicle 1000, but also as the driving power source of the vehicle 1000, replacing or partially replacing fuel or natural gas to provide driving power for the vehicle 1000.

[0096] Please refer to Figure 2 , Figure 2 , which is an exploded view of the battery provided in the first embodiment of the present application. The battery 100 includes a box body 10 and battery cells 20. The battery cells 20 are accommodated in the box body 10. Among them, the box body 10 is used to provide an accommodation space for the battery cells 20, and the box body 10 can adopt various structures. In some embodiments, the box body 10 may include a first sub-box body 11 and a second sub-box body 12. The first sub-box body 11 and the second sub-box body 12 cover each other, and the first sub-box body 11 and the second sub-box body 12 jointly define an accommodation space for accommodating the battery cells 20. The second sub-box body 12 may be a hollow structure with one end open, and the first sub-box body 11 may be a plate-like structure. The first sub-box body 11 covers the open side of the second sub-box body 12 so that the first sub-box body 11 and the second sub-box body 12 jointly define an accommodation space; the first sub-box body 11 and the second sub-box body 12 may also both be hollow structures with one side open, and the open side of the first sub-box body 11 covers the open side of the second sub-box body 12.

[0097] In the battery 100, there may be multiple battery cells 20. The multiple battery cells 20 can be connected in series, in parallel, or in a series-parallel combination. A series-parallel combination means that there are both series and parallel connections among the multiple battery cells 20. The multiple battery cells 20 can be directly connected in series, in parallel, or in a series-parallel combination together, and then the whole formed by the multiple battery cells 20 is accommodated in the box body 10; of course, the battery 100 can also be that multiple battery cells 20 are first connected in series, in parallel, or in a series-parallel combination to form a battery module form, and then multiple battery modules are connected in series, in parallel, or in a series-parallel combination to form a whole and are accommodated in the box body 10. The battery 100 may further include other structures. For example, the battery 100 may further include a busbar component for realizing the electrical connection among the multiple battery cells 20.

[0098] Among them, the battery cell 20 can be a secondary battery or a primary battery; the battery cell 20 can also be a lithium-sulfur battery, a sodium-ion battery, or a magnesium-ion battery, but is not limited thereto.

[0099] Please refer to Figure 3 , Figure 3 , which is an exploded view of the battery cell provided in some embodiments of the present application. AsFigure 3 As shown in Figure 3 , the battery cell 20 includes a housing 21, an electrode assembly 22, and electrode terminals 25. The housing 21 includes a housing body 211 and a cover plate 212. The housing body 211 has an opening, and the cover plate 212 closes the opening to isolate the internal environment of the battery cell 20 from the external environment.

[0100] The housing body 211 is a component for cooperating with the cover plate 212 to form the internal environment of the battery cell 20. Among them, the formed internal environment can be used to accommodate the electrode assembly 22, the electrolyte, and other components. The housing body 211 and the cover plate 212 can be independent components. The housing body 211 can be of various shapes and sizes. Specifically, the shape of the housing body 211 can be determined according to the specific shape and size of the electrode assembly 22. The material of the housing body 211 can be various, such as copper, iron, aluminum, stainless steel, aluminum alloy, plastic, etc.

[0101] The cover plate 212 is a component that covers the opening of the housing body 211 to isolate the internal environment of the battery cell 20 from the external environment. Without limitation, the shape of the cover plate 212 can be adapted to the shape of the housing body 211 to cooperate with the housing body 211. Optionally, the cover plate 212 can be made of a material with a certain hardness and strength (such as aluminum alloy). In this way, the cover plate 212 is not easily deformed when subjected to extrusion and collision, enabling the battery cell 20 to have higher structural strength and improved reliability. Functional components such as electrode terminals can be provided on the cover plate 212. The electrode terminals can be used for electrically connecting to the electrode assembly 22 to output or input the electrical energy of the battery cell 20. The material of the cover plate 212 can also be various, such as copper, iron, aluminum, stainless steel, aluminum alloy, plastic, etc., and the embodiments of the present application do not make special restrictions on this. In some embodiments, an insulating structure can also be provided on the inner side of the cover plate 212. The insulating structure can be used to isolate the electrical connection components in the housing body 211 from the cover plate 212 to reduce the risk of short circuit. Exemplarily, the insulating structure can be plastic, rubber, etc.

[0102] The electrode assembly 22 is a component in the battery cell 20 where an electrochemical reaction occurs. One or more electrode assemblies 22 can be included in the housing body 211. The electrode assembly 22 is mainly formed by winding or laminating a positive electrode plate and a negative electrode plate. And generally, a separator is provided between the positive electrode plate and the negative electrode plate. The separator is used to separate the positive electrode plate and the negative electrode plate to prevent internal short circuit between the positive electrode plate and the negative electrode plate. The parts of the positive electrode plate and the negative electrode plate with active substances constitute the main body of the electrode assembly. The parts of the positive electrode plate and the negative electrode plate without active substances respectively constitute the electrode tabs. The positive electrode tab and the negative electrode tab can be located at one end of the main body together or at both ends of the main body respectively. During the charging and discharging process of the battery, the positive active substance and the negative active substance react with the electrolyte, and the electrode tabs are connected to the electrode terminals to form a current loop.

[0103] In the related art, in a square flat battery, the pressure relief mechanism is generally arranged on the side wall with a relatively narrow width. On the one hand, there are also electrode terminals arranged on the side wall, and the pressure relief mechanism may have problems such as limited area to avoid interference with the electrode terminals. On the other hand, even if there are no electrode terminals on the side wall where the pressure relief mechanism is arranged, due to the overall narrowness of the side wall, the area of the pressure relief mechanism is still limited, resulting in unsmooth exhaust when the battery is out of thermal control.

[0104] In addition, since the pressure relief mechanism is arranged on the side wall with a relatively narrow width, when processing the pressure relief mechanism on this side wall (for example, the pressure relief notch processed by laser etching), the processing difficulty is relatively large, resulting in an increase in manufacturing cost.

[0105] Therefore, the present application provides a battery cell, and the area enclosed by the pressure relief notch of this battery cell is not limited, and the processing difficulty is reduced.

[0106] The battery cell according to the embodiment of the present application may include a housing 21 and a pressure relief notch 213.

[0107] As Figure 3 、 Figure 4 and Figure 7 shown, the housing 21 can isolate the external environment and the internal environment of the battery cell. The housing 21 can be a metal part, and of course it can also be an insulating part.

[0108] The housing 21 can define an accommodation space, and an electrode assembly and an electrolyte for infiltrating the electrode assembly can be accommodated in the accommodation space.

[0109] In the embodiment of the present application, the housing 21 is flat, so the housing 21 has large surface side walls and small surface side walls. Generally, there are two large surface side walls and they are opposite in the thickness direction of the housing 21, and the two large surface side walls are connected by small surface side walls. The housing 21 is configured to be flat, which can enable multiple battery cells to be stacked in the thickness direction, facilitating the storage and installation of multiple battery elevators.

[0110] In some embodiments of the present application, along the thickness direction of the housing 21, the housing 21 includes two first walls 212a opposite to each other.

[0111] It can be understood that since the housing 21 is flat, the dimension in the thickness direction of the housing 21 is smaller than the dimension in the width direction of the housing 21, and the dimension in the thickness direction of the housing 21 is smaller than the dimension in the length direction of the housing 21.

[0112] Two first walls 212a are opposite to each other in the thickness direction of the outer shell 21. Therefore, the area of the outer surface of the first wall 212a is larger than that of the other side walls. Therefore, the area enclosed by the pressure relief notch 213 provided on the first wall 212a with the largest outer surface area is not limited, and a pressure relief notch 213 with a suitable area can be processed as required. In addition, by providing the pressure relief notch 213 on the first wall 212a with the largest outer surface area, it is easier to process the pressure relief notch 213, thereby reducing the manufacturing cost of the pressure relief notch 213.

[0113] In some embodiments of the present application, the pressure relief notch 213 is provided on at least one of the first walls 212a. That is to say, only one of the two first walls 212a may be provided with the pressure relief notch 213, or each of the two first walls 212a may be provided with the pressure relief notch 213.

[0114] The structural strength of the part of the first wall 212a where the pressure relief notch 213 is provided is smaller than that of other parts. Therefore, after the battery cell undergoes thermal runaway, the pressure relief notch 213 will tear first, so as to quickly discharge the high-pressure gas in the outer shell 21.

[0115] The pressure relief notch 213 is generally a groove structure, and the cross-sectional shape of the pressure relief notch 213 can be semicircular, trapezoidal or other shapes. The present application does not limit the specific shape of the cross-section of the pressure relief notch 213.

[0116] According to the battery cell of the embodiment of the present application, the outer shell 21 is flat. By providing the pressure relief notch 213 on at least one of the two first walls 212a opposite to each other in the thickness direction of the housing, the area enclosed by the pressure relief notch 213 is not limited, and the area enclosed by the pressure relief notch 213 and the setting position of the pressure relief notch 213 can be freely selected. At the same time, since the area of the outer surface of the first wall 212a is large, the processing of the pressure relief notch 213 is easier, and the manufacturing cost is reduced.

[0117] In some embodiments of the present application, as Figure 9 shown, the pressure relief notch 213 is a closed annular structure. That is to say, the pressure relief notch 213 is a continuous structure with the head and tail connected, and there is no opening on the pressure relief notch 213. Thus, the structural strength of the part of the outer shell 21 provided with the pressure relief notch 213 is more uniform, and its high temperature and high pressure resistance are also improved when the battery cell undergoes thermal runaway.

[0118] The shape of the pressure relief notch 213 can be circular, racetrack-shaped, polygonal or other special-shaped structures. As long as it is a head-and-tail connected annular structure, it is within the protection scope of the present application.

[0119] In some embodiments of the present application, as Figure 4, Figure 6 and Figure 7 As shown, the pressure relief notch 213 is an unclosed annular structure. That is to say, the pressure relief notch 213 does not connect end to end, and the two ends of the pressure relief notch 213 in the length direction are spaced apart, so there is an opening on the pressure relief notch 213. Thus, after the battery cell undergoes thermal runaway, the crack can tear along the extension direction of the pressure relief notch 213. At the same time, due to the existence of the opening, the crack can tear the outer shell 21 along the orientation of the opening, so that the tearing direction and tearing range of the crack are controllable, realizing local valve opening, reducing the probability of tearing the outer shell 21 in a large range, the tearing direction and tearing range of the crack are both controllable, reducing the damage to the battery cell caused by the uncontrollability of the crack, and also reducing the impact on other battery cells caused by the disorderly discharge of high-pressure gas due to the uncontrollability of the crack.

[0120] In some embodiments of the present application, as Figure 4 and Figure 7 shown, the pressure relief notch 213 is arranged in the central area of the first wall 212a. Thus, the area enclosed by the pressure relief notch 213 can be selected as needed. In addition, arranging the pressure relief notch 213 at the central position of the first wall 212a can make the processing easier and reduce the processing cost of the pressure relief notch 213.

[0121] According to some embodiments of the present application, as Figure 6 shown, the pressure relief notch 213 is arranged in the corner area of the first wall 212a. Thus, the area enclosed by the pressure relief notch 213 is not limited. At the same time, when the battery cell undergoes thermal runaway, the crack tears the first wall 212a along the pressure relief notch 213. Since the pressure relief notch 213 is arranged in the corner area of the first wall 212a, the crack can only damage the corner area of the first wall 212a, reducing the probability of the crack damaging the first wall 212a in a large range.

[0122] In some embodiments of the present application, as Figure 5 shown, the pressure relief notch 213 includes an arc segment 201. As the name implies, the arc segment 201 is not a complete circle, but an arc segment corresponding to the central angle of a certain circle. The central angle and radius of the arc segment 201 can be adjusted as needed.

[0123] The arc segment 201 has a first end and a second end, and the first end and the second end are the two ends of the arc segment 201 in the length direction.

[0124] The pressure relief notch 213 further includes a first extension segment 202. The first extension segment 202 can be a straight line segment, an arc segment or other special-shaped line segments (for example, serpentine, etc.). The specific type of the first extension segment 202 is not limited here.

[0125] The first extension section 202 can be connected to the first end, and the first extension section 202 can extend from the first end towards the direction close to the central axis 201a of the arc section 201.

[0126] It should be noted that the central axis 201a of the arc section 201 can divide the arc section 201 into two sub-arc sections, and the two sub-arc sections are symmetric about the central axis 201a of the arc section 201.

[0127] Thus, the extension line of the first extension section 202 extending towards the direction away from the arc section 201 will eventually intersect with the central axis 201a of the arc section 201.

[0128] The pressure relief notch 213 further includes a second extension section 203. The second extension section 203 can be a straight line section, an arc section or other special-shaped line sections (for example, serpentine, etc.), and the specific type of the second extension section 203 is not limited here.

[0129] The second extension section 203 can be connected to the second end, and the second extension section 203 can extend from the second end towards the direction close to the central axis 201a of the arc section 201.

[0130] Thus, the extension line of the second extension section 203 extending towards the direction away from the arc section 201 will eventually intersect with the central axis 201a of the arc section 201.

[0131] The first extension section 202 and the second extension section 203 can also be symmetric about the central axis 201a of the arc section 201. Of course, the first extension section 202 and the second extension section 203 can also be asymmetric about the central axis 201a of the arc section 201, as long as it is ensured that the first extension section 202 extends from the first end towards the direction close to the central axis 201a of the arc section 201 and the second extension section 203 extends from the second end towards the direction close to the central axis 201a of the arc section 201.

[0132] According to the battery cell 20 of the embodiment of the present application, the pressure relief notch 213 includes an arc segment 201, a first extension segment 202, and a second extension segment 203. By extending the first extension segment 202 from the first end towards the central axis 201a of the arc segment 201 and extending the second extension segment 203 from the second end towards the central axis 201a of the arc segment 201, the arc segment 201 can reduce the stress concentration during the processing of the pressure relief notch 213. When the battery cell 20 undergoes thermal runaway and the internal high-pressure gas tears the pressure relief notch 213, the first extension segment 202 and the second extension segment 203 can guide the crack towards the central axis 201a of the arc segment 201. Thus, the first extension segment 202 and the second extension segment 203 can guide the crack on the outer shell 21 to gradually converge, making the size of the torn part on the outer shell 21 controllable. Of course, the first extension segment 202 and the second extension segment 203 can also make the tearing direction of the crack controllable. Therefore, after the battery cell 20 undergoes thermal runaway and the pressure relief notch 213 is torn, local valve opening can be achieved, reducing the probability of tearing the outer shell 21 over a large area. The tearing direction and the tearing range of the crack are both controllable, reducing the damage to the battery cell 20 caused by the uncontrollability of the crack and also reducing the impact on other battery cells 20 caused by the unordered discharge of high-pressure gas due to the uncontrollability of the crack.

[0133] In some embodiments of the present application, as Figure 5 shown, the central angle of the arc segment 201 is α, satisfying: 180° ≤ α < 360°. For example, the central angle can be 180°, 200°, 220°, 240°, 260°, 280°, 300°, 320°, 340°, 350°.

[0134] The present application does not limit the specific value of the central angle of the arc segment 201, as long as it is ensured that the central angle of the arc segment 201 is within the above range.

[0135] When α ≥ 180°, the area enclosed by the arc segment 201 is sufficient. Thus, when the battery cell 20 undergoes thermal runaway, the crack tears the outer shell 21 along the arc segment 201, and the crack on the arc segment 201 can quickly discharge the high-pressure gas inside the outer shell 21; when α < 360°, the pressure relief notch 213 is an unclosed annular structure with an opening on the pressure relief notch 213. Thus, the crack can tear the outer shell along the direction of the opening, making the tearing direction and the tearing range of the crack controllable, and further achieving local valve opening of the crack on the outer shell 21. When 180° ≤ α < 360°, both the range of the crack torn along the arc segment 201 is sufficient and the high-pressure gas inside the outer shell 21 can be quickly discharged, and at the same time, there is an opening on the pressure relief notch 213, which can guide the tearing direction and the tearing range of the crack, achieving local valve opening of the crack on the outer shell 21.

[0136] In some embodiments of the present application, 210° ≤ α ≤ 330°. For example, the central angle α of the arc segment 201 can be 210°, 240°, 245°, 250°, 255°, 260°, 265°, 270°, 275°, 280°, 285°, 290°, 295°, 300°, 330°.

[0137] When α ≥ 210°, the area enclosed by the arc segment 201 is further increased. Thus, when the battery cell 20 undergoes thermal runaway, the crack tears the outer shell 21 along the arc segment 201, and the tearing range of the crack enables the high-pressure gas inside the outer shell 21 to be discharged more quickly; when α ≤ 330°, the pressure relief notch 213 is an unclosed annular structure, and there is an opening on the pressure relief notch 213 with a larger opening range. Thus, the crack can tear the outer shell along the orientation of the opening. Not only is the tearing direction and tearing range of the crack controllable, but also the tearing range of the crack is larger. Furthermore, the high-pressure gas inside the outer shell 21 can be discharged more quickly. When 210° ≤ α ≤ 330°, the discharge speed of the high-pressure gas inside the outer shell 21 can be further increased. At the same time, the opening size on the arc segment 201 is larger, so that the crack can be guided to have a larger tearing range on the outer shell 21. Thus, the opening can not only guide the tearing direction and tearing range of the crack, but also further increase the discharge speed of the high-pressure gas inside the outer shell 21.

[0138] In some embodiments of the present application, as Figure 5 shown, the first extension segment 202 can be tangent to the arc segment 201. That is to say, the first extension segment 202 coincides with the tangent line at the first end. Thus, the crack on the arc segment 201 can very smoothly extend and tear along the tangent line at the first end of the arc segment 201, reducing the obstruction during the crack tearing process, making the crack tearing smoother and more controllable, and reducing the stress concentration during the tearing process.

[0139] It can be understood that the first extension segment 202 can be an arc segment or a straight line segment. The present application does not limit the line type of the first extension segment 202, as long as it is ensured that the first extension segment 202 is tangent to the arc segment 201.

[0140] In some embodiments of the present application, as Figure 5 shown, the second extension segment 203 can be tangent to the arc segment 201. That is to say, the second extension segment 203 coincides with the tangent line at the second end. Thus, the crack on the arc segment 201 can very smoothly extend and tear along the tangent line at the second end of the arc segment 201, reducing the obstruction during the crack tearing process, making the crack tearing smoother and more controllable, and reducing the stress concentration during the tearing process.

[0141] It can be understood that the second extension segment 203 can be an arc segment or a straight segment. The present application does not limit the type of the line segment of the second extension segment 203, as long as it is ensured that the second extension segment 203 is tangent to the arc segment 201.

[0142] According to some embodiments of the present application, such as Figure 5 shown, the first extension segment 202 is a straight segment. Structuring the first extension segment 202 as a straight segment can, on the one hand, make the processing of the first extension segment 202 easier. On the other hand, the tearing process of the crack on the straight segment is smoother. Or rather, the straight segment can better guide the crack to tear along the preset direction, so that the tearing direction and tearing range of the crack are more controllable.

[0143] According to some embodiments of the present application, the second extension segment 203 is a straight segment. Structuring the second extension segment 203 as a straight segment can, on the one hand, make the processing of the second extension segment 203 easier. On the other hand, the tearing process of the crack on the straight segment is smoother. Or rather, the straight segment can better guide the crack to tear along the preset direction, so that the tearing direction and tearing range of the crack are more controllable.

[0144] In some embodiments of the present application, such as Figure 4 and Figure 5 shown, one end of the first extension segment 202 far from the arc segment 201 and one end of the second extension segment 203 far from the arc segment 201 are spaced apart to form a first opening 201c. That is to say, one end of the first extension segment 202 far from the arc segment 201 and one end of the second extension segment 203 far from the arc segment 201 are not connected to each other, so as to ensure that the pressure relief notch 213 is in an unclosed state.

[0145] Generally speaking, the orientation of the first opening 201c directly affects the tearing direction of the crack. For example, if the first opening 201c faces the corner of the first wall 212a, then after the battery cell 20 is thermally out of control, the high-pressure gas will tear the pressure relief notch 213, and the crack can tear along the direction of the first opening 201c facing the corner. Therefore, the orientation of the first opening 201c can be adjusted to adjust the tearing direction of the crack.

[0146] In some embodiments of the present application, such as Figure 6As shown, the pressure relief notch 213 is provided in the corner area of the first wall 212a. By providing the pressure relief notch 213 in the corner area of the first wall 212a, when the battery cell 20 undergoes thermal runaway, the crack can tear the outer shell 21 under the guidance of the pressure relief notch 213. Since the pressure relief notch 213 is provided in the corner area of the first wall 212a, the tearing area of the crack also mainly concentrates in the corner area of the first wall 212a, thereby reducing the probability of damage to other areas of the first wall 212a by the crack, making it possible to recycle the outer shell 21 after the battery cell 20 undergoes thermal runaway.

[0147] In some embodiments of the present application, the first opening 201c on the pressure relief notch 213 faces the corner of the first wall 212a. Thus, when the crack tears the outer shell 21 along the pressure relief notch 213, it can tear along the orientation of the first opening 201c, that is, the tearing direction of the crack faces the corner of the first wall 212a, thereby reducing the probability of the crack moving towards the middle area of the first wall 212a and reducing the probability of the first wall 212a being completely torn, making it possible to recycle the outer shell 21.

[0148] In some embodiments of the present application, as Figure 5 shown, the radius of the arc segment 201a is R, satisfying: 1 mm ≤ R ≤ 20 mm.

[0149] For example, the radius of the arc segment 201a can be 1 mm, 3 mm, 5 mm, 7 mm, 9 mm, 11 mm, 13 mm, 15 mm, 17 mm, 19 mm, 20 mm.

[0150] The present application does not limit the specific value of the radius of the arc segment 201a. As long as the radius of the arc segment 201a is within the above range, it is within the protection scope of the present application.

[0151] When R ≥ 1 mm, after the crack tears along the arc segment 201a, it can meet the pressure relief requirement of the battery cell 20 during thermal runaway; when R ≤ 20 mm, the range of the arc segment 201a is not too large, so that the overall structural strength of the outer shell 21 meets the requirements. When 1 mm ≤ R ≤ 20 mm, it can not only meet the pressure relief requirement of the battery cell 20 during thermal runaway, but also make the range of the pressure relief notch 213 not too large and the overall structural strength of the outer shell 21 meet the requirements.

[0152] In some embodiments of the present application, as Figure 4 shown, the length of the straight line segment is S 1 , satisfying: 0 < S 1 ≤ 20 mm. For example, the length of the straight line segment can be 1 mm, 3 mm, 5 mm, 7 mm, 9 mm, 11 mm, 13 mm, 15 mm, 17 mm, 19 mm, 20 mm.

[0153] It should be noted that the length of the straight line segment is the length when the first extended segment 202 is constructed as a straight line, or the length when the second extended segment 203 is a straight line.

[0154] The present application does not limit the length of the straight line segment. As long as the radius of the straight line segment is within the above range, it is within the protection scope of the present application.

[0155] When S 1 > 0, after the crack tears along the straight line segment, the pressure relief requirement of the battery cell 20 during thermal runaway can be satisfied; when S 1 ≤ 20 mm, the range of the straight line segment is not too large, so that the overall structural strength of the outer shell 21 meets the requirements. When 0 < S 1 ≤ 20 mm, it can not only meet the pressure relief requirement of the battery cell 20 during thermal runaway, but also prevent the range of the pressure relief notch 213 from being too large to affect the overall structural strength of the outer shell 21.

[0156] In some embodiments of the present application, 0 < S 1 / R ≤ 2. For example, S 1 / R can be 0.05, 0.1, 0.15, 0.2, 0.25, 0.3, 0.35, 0.4, 0.45, 0.5, 0.55, 0.6, 0.7, 0.8, 0.9, 1.0, 1.1, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, 1.9, 2.0.

[0157] The present application does not limit the specific value of S 1 / R. As long as S 1 / R is within the above range, it is within the protection scope of the present application.

[0158] S 1 / R represents the degree of radius extension of the straight line segment relative to the arc segment. The larger S 1 / R is, the more the radius of the straight line segment extends compared to the arc segment. The smaller S 1 / R is, the less the radius of the straight line segment extends compared to the arc segment.

[0159] When S 1 / R > 0, the straight line segment can extend from one end of the arc segment. The straight line segment can guide the crack to tear the outer shell 21. After the crack tears along the straight line segment, the pressure relief requirement of the battery cell 20 during thermal runaway can be satisfied; when S 1 / R ≤ 2, so that the length of the straight line segment is not too long, thereby controlling the range of the pressure relief notch 213 and making the overall structural strength of the outer shell 21 meet the requirements. When 0 < S 1When / R ≤ 2, it can not only ensure that the straight line segment has enough length to guide the tearing direction and range of the crack, but also alleviate the excessive negative impact on the structural strength of the outer shell 21 due to the overlong extension of the straight line segment resulting in too large a range of the pressure relief notch 213.

[0160] According to some embodiments of the present application, as Figure 6 shown, the first wall 212a includes a first edge 212a1 and a second edge 212a2, and the first edge 212a1 and the second edge 212a2 intersect to form a corner of the first wall 212a.

[0161] The shortest distance between the center of the pressure relief notch 213 and the first edge 212a1 is S 2 , and the length of the second edge 212a2 is S, satisfying: 0 < S 2 <S / 2;

[0162] The shortest distance between the center of the pressure relief notch 213 and the second edge 212a2 is T 1 , and the length of the first edge 212a1 is T, satisfying: 0 < T 1 <T / 2.

[0163] Thus, the center of the pressure relief notch 213 is close to a corner defined by the first edge 212a1 and the second edge 212a2. Thus, the tearing area of the crack also mainly concentrates in the corner area of the first wall 212a, so that the probability of damage to other areas of the first wall 212a can be reduced, making it possible to recycle the outer shell 21 after the battery cell 20 undergoes thermal runaway.

[0164] In some embodiments of the present application, as Figure 6 shown, the shortest distance between the end of the first extension segment 202 far from the arc segment 201a and the first edge 212a1 is S 3 , and the length of the second edge 212a2 is S, satisfying: 0 < S 3 <S / 2; the shortest distance between the end of the second extension segment 203 far from the arc segment 201a and the second edge 212a2 is T 2 , and the length of the first edge 212a1 is T, satisfying: 0 < T 2 <T / 2.

[0165] One end of the first extension segment 202 far from the arc segment 201a is spaced apart from one end of the second extension segment 203 far from the arc segment 201a, thereby forming a first opening 201c. Since the shortest distance between one end of the first extension segment 202 far from the arc segment 201a and the first edge 212a1 satisfies the above conditions, and the length of the second edge 212a2, and the shortest distance between one end of the second extension segment 203 far from the arc segment 201a and the second edge 212a2 satisfies the above conditions, and the length of the first edge 212a1, the first opening 201c faces the corner formed by the first edge 212a1 and the second edge 212a2.

[0166] Thus, when the crack tears the housing 21 along the pressure relief notch 213, it can tear along the orientation of the first opening 201c, that is, the tearing direction of the crack faces the corner of the first wall 212a, thereby reducing the probability that the crack moves towards the middle area of the first wall 212a and reducing the probability that the first wall 212a is completely torn, so that the housing 21 can be recycled.

[0167] In some embodiments of the present application, as Figures 7 - 9 shown, the pressure relief notch 213 can be configured as a racetrack-shaped structure. The pressure relief notch 213 can include a first arc segment 204, a second arc segment 205, a first straight segment 206, and a second straight segment 207. The central angles of the first arc segment 204 and the second arc segment 205 can both be 180°. The first arc segment 204 and the second arc segment 205 are spaced apart in the first direction X. The first arc segment 204 and the second arc segment 205 protrude away from each other. That is to say, the openings formed by the first arc segment 204 and the second arc segment 205 face each other.

[0168] The first straight segment 206 and the second straight segment 207 are spaced apart in the second direction Y. The first straight segment 206 is connected to the same-direction ends of the first arc segment 204 and the second arc segment 205 in the second direction Y. The second straight segment 207 is connected to the same-direction ends of the first arc segment 204 and the second arc segment 205 in the second direction Y. The first direction X and the second direction Y are perpendicular to each other.

[0169] Thus, the first arc segment 204, the first straight segment 206, the second arc segment 205, and the second straight segment 207 form a racetrack-shaped structure, and the first arc segment 204, the first straight segment 206, the second arc segment 205, and the second straight segment 207 can be sequentially etched by laser.

[0170] In some embodiments of the present application, the length of the first straight segment 206 or the second straight segment 207 is L 1 , satisfying: 1 mm ≤ L 1≤40 mm. For example, the length of the first straight line segment 206 or the second straight line segment 207 can be 1 mm, 4 mm, 8 mm, 12 mm, 16 mm, 20 mm, 24 mm, 28 mm, 32 mm, 36 mm, 40 mm. This application does not limit the specific value of the length of the first straight line segment 206 or the second straight line segment 207. As long as the length of the first straight line segment 206 or the second straight line segment 207 meets the above range, it is within the protection scope of this application.

[0171] When L 1 ≥1 mm, after thermal runaway occurs in the battery cell 20, when the crack tears the outer shell 21 along the pressure relief notch 213, the high-temperature and high-pressure gas inside the outer shell 21 can be quickly discharged. When L 1 ≤40 mm, the overall size of the pressure relief notch 213 will not be too large, so that the overall structural strength of the outer shell 21 meets the requirements. When 1 mm ≤ L 1 ≤40 mm, it can not only make the gas inside the outer shell 21 be quickly discharged after thermal runaway occurs in the battery cell 20, but also the overall structural strength of the outer shell 21 meets the requirements.

[0172] In some embodiments of this application, the length of the first straight line segment 206 or the second straight line segment 207 is L 1 , satisfying: 5 mm ≤ L 1 ≤30 mm. For example, the length of the first straight line segment 206 or the second straight line segment 207 can be 5 mm, 7 mm, 10 mm, 13 mm, 15 mm, 17 mm, 20 mm, 23 mm, 25 mm, 27 mm, 30 mm. This application does not limit the specific value of the length of the first straight line segment 206 or the second straight line segment 207. As long as the length of the first straight line segment 206 or the second straight line segment 207 meets the above range, it is within the protection scope of this application.

[0173] When L 1 ≥5 mm, after thermal runaway occurs in the battery cell 20, when the crack tears the outer shell 21 along the pressure relief notch 213, the high-temperature and high-pressure gas inside the outer shell 21 can be discharged more quickly. When L 1 ≤30 mm, the overall size of the pressure relief notch 213 will not be too large, so that the overall structural strength of the outer shell 21 can further meet the requirements. When 5 mm ≤ L 1 ≤30 mm, it can not only make the gas inside the outer shell 21 be discharged more quickly after thermal runaway occurs in the battery cell 20, but also the overall structural strength of the outer shell 21 further meets the requirements.

[0174] In some embodiments of this application, in the second direction Y, the distance between the first straight line segment 206 and the second straight line segment 207 is W 1 , satisfying: 1 mm ≤ W1 ≤40 mm. The first straight line segment 206 and the second straight line segment 207 may both extend along the first direction X, so that the first straight line segment 206 and the second straight line segment 207 are parallel to each other. For example, the distance between the first straight line segment 206 and the second straight line segment 207 may be 1 mm, 5 mm, 10 mm, 15 mm, 20 mm, 25 mm, 30 mm, 35 mm, 40 mm. The present application does not limit the specific value of the distance between the first straight line segment 206 and the second straight line segment 207, as long as the distance between the first straight line segment 206 and the second straight line segment 207 meets the above range, it is within the protection scope of the present application.

[0175] When W 1 ≥1 mm, after thermal runaway occurs in the battery cell 20, after the crack tears the outer shell 21 along the pressure relief notch 213, the high-temperature and high-pressure gas in the outer shell 21 can be quickly discharged. When W 1 ≤40 mm, the overall size of the pressure relief notch 213 will not be too large, so that the overall structural strength of the outer shell 21 meets the requirements. When 1 mm ≤ W 1 ≤40 mm, the gas in the outer shell 21 can be quickly discharged after thermal runaway occurs in the battery cell 20, and at the same time the overall structural strength of the outer shell 21 also meets the requirements.

[0176] In some embodiments of the present application, in the second direction Y, the distance between the first straight line segment 206 and the second straight line segment 207 is W 1 , satisfying: 1 mm ≤ W 1 ≤10 mm. The first straight line segment 206 and the second straight line segment 207 may both extend along the first direction X, so that the first straight line segment 206 and the second straight line segment 207 are parallel to each other. For example, the distance between the first straight line segment 206 and the second straight line segment 207 may be 1 mm, 2 mm, 3 mm, 4 mm, 5 mm, 6 mm, 7 mm, 8 mm, 9 mm, 10 mm. The present application does not limit the specific value of the distance between the first straight line segment 206 and the second straight line segment 207, as long as the distance between the first straight line segment 206 and the second straight line segment 207 meets the above range, it is within the protection scope of the present application.

[0177] When W 1 ≥1 mm, after thermal runaway occurs in the battery cell 20, after the crack tears the outer shell 21 along the pressure relief notch 213, the high-temperature and high-pressure gas in the outer shell 21 can be quickly discharged. When W 1 ≤10 mm, the overall size of the pressure relief notch 213 will not be too large, so that the overall structural strength of the outer shell 21 further meets the requirements. When 1 mm ≤ W 1When it is ≤ 10 mm, it can not only enable the gas in the housing 21 to be quickly discharged after the battery cell 20 undergoes thermal runaway, but also further meet the requirements for the overall structural strength of the housing 21.

[0178] In some embodiments of the present application, as Figure 8 shown, the first straight segment 206 includes a first sub-segment 206a and a second sub-segment 206b. One end of the first sub-segment 206a is connected to the first arc segment 204, and one end of the second sub-segment 206b is connected to the second arc segment 205. The other end of the first sub-segment 206a and the other end of the second sub-segment 206b are spaced apart to form a second opening 208. That is to say, although the pressure relief notch 213 is also in a runway shape structure, it is not a closed runway shape structure, and there is an unclosed area on the first straight segment 206. Thus, local valve opening can be realized on the housing 21. When thermal runaway occurs inside the battery cell 20, the gas can tear the housing 21 along the pressure relief notch 213. At the same time, the area where the second opening 208 is located will not be disconnected from the housing 21, but will guide the gas to continue tearing the housing 21 until the desired tearing effect is achieved. That is to say, the second opening 208 can guide the tearing direction of the crack, making the tearing direction and range of the crack controllable.

[0179] In some embodiments of the present application, the length of the pressure relief notch 213 is L, and the distance between the first sub-segment 206a and the second sub-segment 206b in the first direction X is L 2 , satisfying: 0.05 ≤ L 2 / L ≤ 0.8. For example, the ratio of the distance between the first sub-segment 206a and the second sub-segment 206b in the first direction X to the length of the pressure relief notch 213 can be 0.05, 0.1, 0.15, 0.2, 0.25, 0.3, 0.35, 0.4, 0.45, 0.5, 0.55, 0.6, 0.65, 0.7, 0.75, 0.8. The present application does not limit the specific value of the ratio of the distance between the first sub-segment 206a and the second sub-segment 206b in the first direction X to the length of the pressure relief notch 213. As long as the ratio of the distance between the first sub-segment 206a and the second sub-segment 206b in the first direction X to the length of the pressure relief notch 213 satisfies the above range, it is within the protection scope of the present application.

[0180] When L 2 / L ≥ 0.05, the second opening 208 guides the crack to tear the housing 21, so that after the battery cell 20 undergoes thermal runaway, the gas in the housing 21 can be quickly discharged; when L 2 / L ≤ 0.8, it can make the crack tear the housing 21 along the orientation of the second opening 208, and the tearing range will not be too large, reducing the probability of large-scale damage to the housing 21. When 0.05 ≤ L 2When / L ≤ 0.8, after the battery cell 20 undergoes thermal runaway, the gas inside the housing 21 can be quickly discharged outward, and at the same time, the probability of the housing 21 being damaged on a large scale is reduced.

[0181] In some embodiments of the present application, the length of the pressure relief notch 213 is L, and the distance between the first sub-segment 206a and the second sub-segment 206b in the first direction X is L 2 , satisfying: 0.05 ≤ L 2 / L ≤ 0.4. For example, the ratio of the distance between the first sub-segment 206a and the second sub-segment 206b in the first direction X to the length of the pressure relief notch 213 can be 0.05, 0.08, 0.12, 0.16, 0.2, 0.24, 0.28, 0.32, 0.4. The present application does not limit the specific value of the ratio of the distance between the first sub-segment 206a and the second sub-segment 206b in the first direction X to the length of the pressure relief notch 213. As long as the ratio of the distance between the first sub-segment 206a and the second sub-segment 206b in the first direction X to the length of the pressure relief notch 213 satisfies the above range, it is within the protection scope of the present application.

[0182] When L 2 / L ≥ 0.05, the second opening 208 guides the crack to tear the housing 21, so that after the battery cell 20 undergoes thermal runaway, the gas inside the housing 21 can be quickly discharged; when L 2 / L ≤ 0.4, it can make the crack tear the housing 21 along the orientation of the second opening 208, and the tearing range will not be too large, further reducing the probability of the housing 21 being damaged on a large scale. When 0.05 ≤ L 2 / L ≤ 0.4, after the battery cell 20 undergoes thermal runaway, the gas inside the housing 21 can be quickly discharged outward, and at the same time, the probability of the housing 21 being damaged on a large scale is further reduced.

[0183] In some embodiments of the present application, as Figure 3 shown, the housing 21 includes a housing body 211 and a cover plate 212. The housing body 211 includes a bottom wall 211a and a peripheral side wall 211b. One end of the peripheral side wall 211b is connected to the outer periphery of the bottom wall 211a, and the other end of the peripheral side wall 211b encloses an opening. The cover plate 212 closes the opening, wherein the first wall 212a is the cover plate 212 or the bottom wall 211a.

[0184] That is to say, the outer shell 21 is jointly formed by two split components, namely a housing 211 and a cover plate 212. The housing 211 and the cover plate 212 can be metal parts, and the two can be fixed together by welding. The first wall 212a is the cover plate 212 or the bottom wall 211a. Therefore, the pressure relief notch 201 is provided on the cover plate 212 or the bottom wall 211a. For example, if the battery cell 20 is flat and the cover plate 212 and the bottom wall 211a are opposite in the thickness direction, the pressure relief notch 201 is provided on the large surface of the outer shell 21.

[0185] In some embodiments of the present application, the outer shell 21 is made of stainless steel, and the pressure relief notch 201 can be processed and formed by laser etching. Of course, the pressure relief notch 201 can also be formed by stamping. The present application does not limit the forming method of the pressure relief notch 201.

[0186] In some embodiments of the present application, the cross-sectional shape of the pressure relief notch 201 can be trapezoidal. Among the two parallel sides of the trapezoid, the longer side is located at the opening 203 of the groove of the pressure relief notch 201. The length of the shorter side among the two parallel sides can be 0.05 mm - 1.0 mm, and the bottom angle of the trapezoid (the angle between the bottom wall and the peripheral wall of the trapezoidal groove) can be 30° - 60°.

[0187] The cross-section of the pressure relief notch 201 is trapezoidal, with better consistency and less stress concentration. Of course, the cross-section of the pressure relief notch 201 can also be triangular, arc-shaped or rectangular.

[0188] The battery of the embodiment of the present application will be briefly described below.

[0189] The battery according to the embodiment of the present application includes the battery cell 20 of the above embodiment. Since the battery according to the embodiment of the present application is provided with the above battery cell 20, the processing of the battery is easier and the manufacturing cost is reduced.

[0190] The electrical equipment of the embodiment of the present application will be briefly described below.

[0191] The electrical equipment according to the embodiment of the present application includes the above battery. Since the electrical equipment according to the embodiment of the present application is provided with the above battery, the manufacturing difficulty and processing cost of the electrical equipment are reduced.

[0192] Although the present application has been described with reference to the preferred embodiments, various improvements can be made to it and components therein can be replaced with equivalents without departing from the scope of the present application. In particular, as long as there is no structural conflict, the technical features mentioned in each embodiment can be combined in any way. The present application is not limited to the specific embodiments disclosed in the text, but includes all technical solutions falling within the scope of the claims.

Claims

1. A battery cell, characterized in that, comprising: a housing, the housing being flat, and along the thickness direction of the housing, the housing includes two opposite first walls; a pressure relief notch, the pressure relief notch being provided on at least one of the first walls.

2. The battery cell according to claim 1, characterized in that, the pressure relief notch is a closed annular structure.

3. The battery cell according to claim 1, characterized in that, the pressure relief notch is an unclosed annular structure.

4. The battery cell according to claim 1, characterized in that, the pressure relief notch is located in the central region of the first wall.

5. The battery cell according to claim 1, characterized in that, the pressure relief notch is provided in the corner region of the first wall.

6. The battery cell according to claim 1, characterized in that, the pressure relief notch includes an arc segment, a first extension segment and a second extension segment, the arc segment has a first end and a second end, the first extension segment extends from the first end towards the direction close to the central axis of the arc segment, and the second extension segment extends from the second end towards the direction close to the central axis of the arc segment.

7. The battery cell according to claim 6, characterized in that, the central angle of the arc segment is α, satisfying: 180°≤α<360°.

8. The battery cell according to claim 6, characterized in that, the first extension segment is tangent to the arc segment; and / or the second extension segment is tangent to the arc segment.

9. The battery cell according to claim 6, characterized in that, the first extension segment is a straight line segment; and / or the second extension segment is a straight line segment.

10. The battery cell according to claim 6, characterized in that, one end of the first extension segment far from the arc segment and one end of the second extension segment far from the arc segment are spaced apart to form a first opening.

11. The battery cell according to claim 10, characterized in that, the pressure relief notch is provided in the corner region of the first wall and the first opening faces the corner of the first wall.

12. The battery cell according to claim 1, characterized in that, the pressure relief notch includes: a first arc segment and a second arc segment, the first arc segment and the second arc segment are spaced apart in a first direction, and the first arc segment and the second arc segment protrude away from each other; a first straight line segment and a second straight line segment, the first straight line segment is connected to the same-direction ends of the first arc segment and the second arc segment in a second direction, and the second straight line segment is connected to the same-direction ends of the first arc segment and the second arc segment in the second direction, and the first direction and the second direction are perpendicular to each other.

13. The battery cell according to claim 12, characterized in that, The length of the first straight line segment or the second straight line segment is L 1 , satisfying: 1 mm ≤ L 1 ≤ 40 mm.

14. The battery cell according to claim 13, characterized in that, Satisfy: 5mm ≤ L 1 ≤ 30mm.

15. The battery cell according to claim 12, characterized in that, In the second direction, the distance between the first straight line segment and the second straight line segment is W 1 , satisfying: 1 mm ≤ W 1 ≤ 40 mm.

16. The battery cell according to claim 15, characterized in that, Satisfy: 1mm ≤ W 1 ≤ 10mm.

17. The battery cell according to claim 12, characterized in that, The first straight line segment includes a first sub-segment and a second sub-segment. One end of the first sub-segment is connected to the first arc segment, and one end of the second sub-segment is connected to the second arc segment. The other ends of the first sub-segment and the second sub-segment are spaced apart to form a second opening.

18. The battery cell according to claim 17, characterized in that The length of the pressure relief notch is L, and the distance between the first sub-segment and the second sub-segment in the first direction is L 2 , satisfying: 0.05 ≤ L 2 / L ≤ 0.8 19. The battery cell according to claim 18, characterized in that Satisfy: 0.05 ≤ L 2 / L ≤ 0.

4.

20. The battery cell according to claim 1, characterized in that the housing includes a housing body and a cover plate. The housing body includes a bottom wall and a peripheral side wall. One end of the peripheral side wall is connected to the outer peripheral edge of the bottom wall, and the other end of the peripheral side wall encloses an opening. The cover plate closes the opening; wherein the first wall is the cover plate or the bottom wall.

21. A battery, characterized in that it includes the battery cell according to any one of claims 1-20.

22. An electrical device, characterized in that it includes the battery cell according to any one of claims 1-20 or the battery according to claim 21, and the battery cell or the battery is used to provide electrical energy.

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