Shell, battery monomer, battery and electric equipment

Abstract

The embodiment of the utility model provides a shell, a single battery, a battery and electric equipment, the shell is used for the single battery, and the shell comprises a first wall, a second wall and a first corner part connected with the first wall and the second wall; wherein the first corner part is provided with a weakening groove. According to the shell provided by the embodiment of the invention, the reliability of the battery can be improved.

Description

Technical Field

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

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

[0003] Batteries are widely used in portable electronic devices, electric vehicles, electric tools, drones, energy storage devices and other fields. In the manufacturing process of batteries, the reliability of batteries is an issue that cannot be ignored. Therefore, how to improve the reliability of batteries is a technical problem that needs to be solved urgently in battery technology. Utility Model Content

[0004] The present application provides a housing, a battery cell, a battery and an electrical device, which can improve the reliability of the battery.

[0005] This application is achieved through the following technical solutions:

[0006] In a first aspect, an embodiment of the present application provides a shell for a battery cell, the shell comprising a first wall, a second wall, and a first corner portion connecting the first wall and the second wall; wherein the first corner portion is provided with a weakened groove.

[0007] According to the shell of the embodiment of the present application, by setting a weakened groove at the first corner portion, after one of the first wall and the second wall is greatly deformed due to the expansion of the battery cell, the first corner portion will deform before the other of the first wall and the second wall, so that the first corner portion can absorb part of the expansion energy and reduce the deformation of the other of the first wall and the second wall. As a result, the outer surface of the other of the first wall and the second wall is flat, and glue can be smoothly applied thereon. When the water-cooling plate or heating film is crimped thereon, the thickness consistency of the adhesive tape between it and the water-cooling plate or heating film is good, which improves the thermal conductivity of the water-cooling plate or heating film, thereby improving the reliability of the battery cell.

[0008] According to some embodiments of the present application, the weakened groove is disposed on the inner side of the first corner portion. In the above solution, the weakened groove cannot be seen from the outside of the shell, which improves the aesthetics of the battery cell. In addition, the probability of the structure defining the weakened groove scratching the adjacent battery cell can also be effectively reduced.

[0009] According to some embodiments of the present application, there are two first walls, and the two first walls are arranged opposite to each other along the first direction; there are two second walls, and the two second walls are arranged opposite to each other along the second direction; the first corner portion is arranged between any adjacent first walls and second walls; the weakened groove extends along the third direction; and the first direction, the second direction and the third direction are perpendicular to each other. In the above scheme, the structural strength of the four corners of the shell in the circumferential direction is reduced. After one of the first wall and the second wall undergoes a large deformation due to the expansion of the battery cell, the four corners of the shell in the circumferential direction (i.e., the first corner portion) can absorb part of the energy after the battery cell expands, thereby reducing the deformation amount of the other of the first wall and the second wall.

[0010] According to some embodiments of the present application, the shell is formed with an opening at at least one end in the third direction, and each of the first corner portions is provided with a plurality of the weakened grooves, which are arranged at intervals along the circumference of the opening. In the above scheme, the plurality of weakened grooves can further reduce the structural strength of the first corner portion, making the first corner portion more likely to deform, thereby improving the energy absorption capacity of the first corner portion.

[0011] According to some embodiments of the present application, a support rib is formed between two adjacent weakened grooves, the support rib includes a main section and an end section, the main section and the end section are arranged along the third direction, the end section is closer to the opening than the main section, and the thickness of the end section is less than the thickness of the main section to form a positioning step. In the above scheme, the end cover can be overlapped on the positioning step, which facilitates the positioning of the end cover before the end cover is fixedly connected to the shell, thereby improving the fixing efficiency and connection stability of the end cover and the shell.

[0012] According to some embodiments of the present application, along the third direction, the weakened groove runs through both ends of the first corner portion. In the above solution, the strength of the entire area of ​​the first corner portion along the third direction is weakened, thereby further improving the deformation capacity of the first corner portion and enhancing the energy absorption capacity of the first corner portion.

[0013] According to some embodiments of the present application, the shell further comprises a bottom wall, the first wall, the second wall and the first corner portion surround an opening at one end on the same side in the third direction, and the first wall, the second wall and the first corner portion are connected to the bottom wall at the other end on the same side in the third direction. In the above scheme, the bottom wall and the opening are arranged opposite to each other in the third direction, and the first wall, the second wall and the first corner portion are arranged around the periphery of the bottom wall.

[0014] According to some embodiments of the present application, along the circumference of the opening, the width of the weakened groove is a, which satisfies: 1mm≤a≤3mm. In the above scheme, on the one hand, the first corner portion can be deformed to absorb part of the energy, and on the other hand, the first corner portion can have a certain structural strength, which reduces the probability of damage to the first corner portion during the deformation process, so that the shell can better protect the components inside the shell.

[0015] According to some embodiments of the present application, along the thickness direction of the first corner portion, the depth of the weakened groove is b, which satisfies: 0.1mm≤b≤0.5mm. In the above scheme, on the one hand, the first corner portion can be deformed to absorb part of the energy, and on the other hand, the first corner portion can have a certain structural strength, reducing the probability of damage to the first corner portion during the deformation process, so that the shell can better protect the components inside the shell.

[0016] In a second aspect, an embodiment of the present application further provides a battery cell, comprising: a shell, an electrode assembly and an end cover, wherein the shell is the shell of the above embodiment, and the shell has an opening; the electrode assembly is accommodated in the shell; and the end cover is covered on the opening.

[0017] In a third aspect, an embodiment of the present application further provides a battery, comprising the above-mentioned battery cell.

[0018] In a fourth aspect, an embodiment of the present application further provides an electrical device, comprising the above-mentioned battery cell or the above-mentioned battery, wherein the battery cell or the battery is used to provide electrical energy.

[0019] Additional aspects and advantages of the present application will be given in part in the description below, and in part will become apparent from the description below, or will be learned through the practice of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present application and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying creative work.

[0021] Figure 1 A schematic diagram of a vehicle provided for some embodiments of the present application;

[0022] Figure 2 An exploded view of a battery provided for some embodiments of the present application;

[0023] Figure 3 An exploded view of a battery cell provided for some embodiments of the present application;

[0024] Figure 4 A schematic diagram of a housing along a third direction provided in some embodiments of the present application;

[0025] Figure 5 for Figure 4 A partial enlarged schematic diagram is circled;

[0026] Figure 6 An axonometric view of a housing provided for some embodiments of the present application;

[0027] Figure 7 for Figure 6 The enlarged schematic diagram of the part B is circled;

[0028] Figure 8 for Figure 6 The enlarged schematic diagram of the part B is circled.

[0029] Icon: 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, shell 211, end cover 212, first wall 211a, second wall 211b, first corner portion 211c, support rib 211d, main body section 211d1, end section 211d2, bottom wall 211e, weakened groove 101, opening 102, positioning step 103. DETAILED DESCRIPTION

[0030] In order to make the purpose, technical solution and advantages of the embodiments of the present application clearer, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0031] Unless otherwise defined, all technical and scientific terms used in this application have the same meaning as those commonly understood by technicians in the technical field of this application; the terms used in the specification of this application are only for the purpose of describing specific embodiments and are not intended to limit this application; the terms "including" and "having" in the specification and claims of this application and the above-mentioned drawings and any variations thereof are intended to cover non-exclusive inclusions. The terms "first", "second", etc. in the specification and claims of this application or the above-mentioned drawings are used to distinguish different objects, rather than to describe a specific order or a primary and secondary relationship.

[0032] Reference to "embodiments" in this application means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present application. The appearance of the phrase in various locations in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described in this application may be combined with other embodiments.

[0033] In the description of this application, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", and "attached" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a direct connection, or an indirect connection through an intermediate medium, or it can be the internal communication of two elements. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0034] The term "multiple" as used in this application refers to more than two (including two). Similarly, "multiple groups" refers to more than two groups (including two groups), and "multiple sheets" refers to more than two sheets (including two sheets).

[0035] In some embodiments, the battery may be a battery module. When there are multiple battery cells, the multiple battery cells are arranged and fixed to form a battery module.

[0036] In some embodiments, the battery may be a battery pack, which includes a case and battery cells, wherein the battery cells or battery modules are accommodated in the case.

[0037] In some embodiments, the box body can be used as a part of the chassis structure of the vehicle. For example, part of the box body can become at least a part of the floor of the vehicle, or part of the box body can become at least a part of the cross beam and longitudinal beam of the vehicle.

[0038] In some embodiments, the battery may be an energy storage device, which includes an energy storage container, an energy storage cabinet, and the like.

[0039] In the embodiment of the present application, the battery cell may be a secondary battery. A secondary battery refers to a battery cell that can be continuously used by activating active materials by charging after the battery cell is discharged.

[0040] The battery cells may be, but are not limited to, lithium ion batteries, sodium ion batteries, sodium lithium ion batteries, lithium metal batteries, sodium metal batteries, lithium sulfur batteries, magnesium ion batteries, nickel hydrogen batteries, nickel cadmium batteries, lead storage batteries, etc.

[0041] A battery cell generally includes an electrode assembly. The electrode assembly includes a positive electrode, a negative electrode, and a separator. During the charge and discharge process of the battery cell, active ions (such as lithium ions) are embedded and removed between the positive electrode and the negative electrode. The separator is set between the positive electrode and the negative electrode to prevent the positive and negative electrodes from short-circuiting, while allowing active ions to pass through.

[0042] In some embodiments, the positive electrode may be a positive electrode sheet, and the positive electrode sheet may include a positive electrode current collector and a positive electrode active material disposed on at least one surface of the positive electrode current collector.

[0043] As an example, the positive electrode current collector has two surfaces facing each other in its thickness direction, and the positive electrode active material is disposed on either or both of the two facing surfaces of the positive electrode current collector.

[0044] As an example, the positive electrode current collector may be a metal foil or a composite current collector. For example, as the metal foil, aluminum with a silver-plated surface, stainless steel with a silver-plated surface, stainless steel, copper, aluminum, nickel, carbon electrode, carbon, nickel or titanium, etc., may be used. The composite current collector may include a polymer material base and a metal layer. The composite current collector may be formed by forming a metal material (aluminum, aluminum alloy, nickel, nickel alloy, titanium, titanium alloy, silver and silver alloy, etc.) on a polymer material substrate (such as a substrate of polypropylene, polyethylene terephthalate, polybutylene terephthalate, polystyrene, polyethylene, etc.).

[0045] As an example, the positive electrode active material may include at least one of the following materials: lithium-containing phosphates, lithium transition metal oxides, and their respective modified compounds. However, the present application is not limited to these materials, and other conventional materials that can be used as positive electrode active materials for batteries may also be used.

[0046] In some embodiments, the negative electrode may be a negative electrode sheet, and the negative electrode sheet may include a negative electrode current collector.

[0047] As an example, the negative electrode current collector may be a metal foil or a composite current collector. For example, as the metal foil, aluminum with a silver-plated surface, stainless steel with a silver-plated surface, stainless steel, copper, aluminum, nickel, carbon electrode, carbon, nickel or titanium, etc. may be used.

[0048] In some embodiments, the negative electrode current collector has two surfaces opposite to each other in its thickness direction, and the negative electrode active material is disposed on any one or both of the two opposite surfaces of the negative electrode current collector.

[0049] As an example, the negative electrode active material may adopt the negative electrode active material for the battery known in the art. As an example, the negative electrode active material may include at least one of the following materials: artificial graphite, natural graphite, soft carbon, hard carbon, silicon-based materials, tin-based materials and lithium titanate, etc. The silicon-based material may be selected from at least one of elemental silicon, silicon oxide compounds, silicon-carbon composites, silicon-nitrogen composites and silicon alloys. The tin-based material may be selected from at least one of elemental tin, tin oxide compounds and tin alloys. However, the present application is not limited to these materials, and other traditional materials that can be used as negative electrode active materials for batteries may also be used. These negative electrode active materials may be used alone or in combination of two or more.

[0050] In some embodiments, the separator is a separator. The present application has no particular limitation on the type of separator, and any known separator with a porous structure having good chemical stability and mechanical stability can be selected.

[0051] As an example, the main material of the separator can be selected from at least one of glass fiber, non-woven fabric, polyethylene, polypropylene, polyvinylidene fluoride, and ceramic. The separator can be a single-layer film or a multi-layer composite film, without special restrictions. When the separator is a multi-layer composite film, the materials of each layer can be the same or different, without special restrictions. The separator can be a separate component located between the positive and negative electrodes, or it can be attached to the surface of the positive and negative electrodes.

[0052] In some embodiments, the separator is a solid electrolyte, which is disposed between the positive electrode and the negative electrode and serves to transmit ions and isolate the positive and negative electrodes.

[0053] In some embodiments, the battery cell further includes an electrolyte, which plays a role in conducting ions between the positive and negative electrodes. The electrolyte can be liquid, gel or solid. Among them, the liquid electrolyte includes an electrolyte salt and a solvent.

[0054] In some embodiments, the electrolyte salt may include at least one of lithium hexafluorophosphate, lithium tetrafluoroborate, lithium perchlorate, lithium hexafluoroarsenate, lithium bisfluorosulfonyl imide, lithium bistrifluoromethanesulfonyl imide, lithium trifluoromethanesulfonate, lithium difluorophosphate, lithium difluorooxalatoborate, lithium dioxalatoborate, lithium difluorodioxalatophosphate, and lithium tetrafluorooxalatophosphate.

[0055] In some embodiments, the solvent may include at least one of ethylene carbonate, propylene carbonate, ethyl methyl carbonate, diethyl carbonate, dimethyl carbonate, dipropyl carbonate, methyl propyl carbonate, ethyl propyl carbonate, butylene carbonate, fluoroethylene carbonate, methyl formate, methyl acetate, ethyl acetate, propyl acetate, methyl propionate, ethyl propionate, propyl propionate, methyl butyrate, ethyl butyrate, 1,4-butyrolactone, cyclopentane, dimethyl sulfone, methyl ethyl sulfone and diethyl sulfone. The solvent may also be an ether solvent. The ether solvent may include one or more of ethylene glycol dimethyl ether, ethylene glycol diethyl ether, diethylene glycol dimethyl ether, triethylene glycol dimethyl ether, tetraethylene glycol dimethyl ether, 1,3-dioxolane, tetrahydrofuran, methyltetrahydrofuran, diphenyl ether and crown ether.

[0056] Among them, the gel electrolyte includes a skeleton network with a polymer as the electrolyte, combined with an ionic liquid-lithium salt.

[0057] Among them, solid electrolytes include polymer solid electrolytes, inorganic solid electrolytes, and composite solid electrolytes.

[0058] As an example, the polymer solid electrolyte may be polyether (polyethylene oxide), polysiloxane, polycarbonate, polyacrylonitrile, polyvinylidene fluoride, polymethyl methacrylate, a single ion polymer, polyionic liquid-lithium salt, cellulose, and the like.

[0059] As an example, the inorganic solid electrolyte may include an oxide solid electrolyte (crystalline perovskite, sodium superconducting ion conductor, garnet, amorphous LiPON film), a sulfide solid electrolyte (crystalline lithium superion conductor (lithium germanium phosphosulfide, silver germanium sulfide), amorphous sulfide) and one or more of a halide solid electrolyte, a nitride solid electrolyte and a hydride solid electrolyte.

[0060] As an example, the composite solid electrolyte is formed by adding an inorganic solid electrolyte filler to a polymer solid electrolyte.

[0061] In some embodiments, the electrode assembly is a wound structure, wherein the positive electrode sheet and the negative electrode sheet are wound into the wound structure.

[0062] In some embodiments, the electrode assembly is a laminate structure.

[0063] In some embodiments, the battery cell may include a housing. The housing is used to encapsulate components such as the electrode assembly and the electrolyte. The housing may be a steel housing, an aluminum housing, a plastic housing (such as polypropylene), a composite metal housing (such as a copper-aluminum composite housing), or an aluminum-plastic film.

[0064] In some embodiments, the housing includes an end cap and a shell, the shell is provided with an opening, and the end cap closes the opening to form a closed space for accommodating substances such as the electrode assembly and the electrolyte. The shell may be provided with one or more openings. One or more end caps may also be provided.

[0065] In some embodiments, at least one electrode terminal is disposed on the housing, and the electrode terminal is electrically connected to the electrode tab of the electrode assembly. The electrode terminal may be directly connected to the electrode tab, or may be indirectly connected to the electrode tab through an adapter. The electrode terminal may be disposed on the end cap, or may be disposed on the housing.

[0066] In some embodiments, an explosion-proof valve is provided on the housing, and the explosion-proof valve is used to release the internal pressure of the battery cell.

[0067] 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 polygonal prismatic battery, such as a hexagonal prismatic battery, etc. There is no particular limitation in the embodiments of the present application.

[0068] The battery mentioned in the embodiments of the present application refers to a single physical module including one or more battery cells to provide higher voltage and capacity.

[0069] In some embodiments, the battery may be a battery module. When there are multiple battery cells, the multiple battery cells are arranged and fixed to form a battery module.

[0070] In some embodiments, the battery may be a battery pack, which includes a case and battery cells, wherein the battery cells or battery modules are accommodated in the case.

[0071] In some embodiments, the box body can be used as a part of the chassis structure of the vehicle. For example, part of the box body can become at least a part of the floor of the vehicle, or part of the box body can become at least a part of the cross beam and longitudinal beam of the vehicle.

[0072] In some embodiments, the battery may be an energy storage device, which includes an energy storage container, an energy storage cabinet, and the like.

[0073] Batteries have outstanding advantages such as high energy density, low environmental pollution, high power density, long service life, wide adaptability, and small self-discharge coefficient. They are an important part of the development of new energy today.

[0074] The development of battery technology must take into account multiple design factors at the same time, such as performance parameters such as energy density, discharge capacity, charge and discharge rate, and also the assembly efficiency of the battery.

[0075] In the field of battery technology, in order to increase the energy density of the battery cell, the thickness of the shell can be reduced, which also leads to the shell thickness becoming thinner and thinner. For example, after multiple rectangular battery cells are stacked into groups, the large surfaces of the shell are relatively arranged in the stacking direction. Since the battery cells will expand during use, the large surface will be under greater pressure. Since the thickness of the shell is relatively thin, the small surface of the shell will bulge and deform under the action of torque after the large surface is under pressure. Specifically, after the battery cells are stacked into groups, due to the expansion of the battery cells, not only the large surface will undergo a certain deformation, but the small surface will also bulge and deform due to the extrusion effect.

[0076] It should be noted that the large surface of the shell is the two side walls of the shell peripheral wall in the thickness direction, and the small surface of the shell is the side wall of the shell peripheral wall adjacent to the large surface. One end of the shell peripheral wall defines an opening, and the end cover cooperates with one end of the shell peripheral wall to seal the opening.

[0077] When multiple battery cells are stacked in groups, the following problems may occur due to the large deformation of the small surface of the shell:

[0078] The small surface of the shell needs to be pasted with a heating film, but the severely deformed small surface is uneven. When the heating film is pasted, a gap is very likely to appear between the heating film and the small surface, and effective pressure cannot be applied, thus affecting the pressing effect of the heating film. In addition, since the small surface of the shell is raised and its own area is small, even if the heating film is bonded to the small surface of the shell, the adhesive layer will creep and break during the raising process of the small surface, resulting in failure or even destruction of the bonding interface.

[0079] When multiple small faces are attached to the water cooling plate, since the middle area of ​​the small face along the thickness direction of the battery cell is more protruding than the two end areas of the small face along the thickness direction of the battery cell, the thickness of the glue layer between the small face and the water cooling plate is uneven. The thickness of the glue layer between the middle area of ​​the small face and the water cooling plate is small, and the thickness of the glue layer between the two end areas of the small face and the water cooling plate is large, which affects the uniformity of thermal conductivity and further affects the cooling effect.

[0080] Of course, when multiple small surfaces are attached by the water cooling plate, since the middle area of ​​the small surface is protruding compared to the two end areas, and the protruding curvature of multiple small surfaces cannot be guaranteed to be consistent, when the same amount of glue is coated on the small surface and the water cooling plate is pressed onto the small surface, the glue pressing area of ​​multiple small surfaces fluctuates greatly and the glue pressing area may be inconsistent, which further affects the water cooling effect of the small surface.

[0081] To this end, the present application provides a shell for a battery cell, the shell having a first wall, a second wall and a first corner portion connecting the first wall and the second wall, and the first corner portion is provided with a weakened groove.

[0082] The battery cells disclosed in the embodiments of the present application can be used, but not limited to, in electrical equipment such as vehicles, ships or aircraft. The power supply system of the electrical equipment can be composed of the battery cells and batteries disclosed in the present application.

[0083] The embodiment of the present application provides an electric device using a battery cell as a power source, and the electric device may be, but is not limited to, a mobile phone, a tablet computer, a laptop computer, an electric toy, an electric tool, an electric bicycle, an electric motorcycle, an electric car, a ship, a spacecraft, etc. Among them, the electric toy may include a fixed or mobile electric toy, for example, a game console, an electric car toy, an electric ship toy, an electric airplane toy, etc., and the spacecraft may include an airplane, a rocket, a space shuttle, a spacecraft, etc.

[0084] For the convenience of description, the following embodiments are described by taking a vehicle 1000 as an example of an electrical device in an embodiment of the present application.

[0085] Please refer to Figure 1 , Figure 1 Schematic diagram of a vehicle provided for the first embodiment of the present application. Vehicle 1000 may be a fuel vehicle, a gas vehicle or a new energy vehicle, and the new energy vehicle may be a pure electric vehicle, a hybrid vehicle or an extended-range vehicle, etc. A battery 100 is provided inside the vehicle 1000, and the battery 100 may be provided at the bottom, head or tail of the vehicle 1000. The battery 100 may be used to power the vehicle 1000, for example, the battery 100 may be used as an operating power source for the vehicle 1000, for the circuit system of the vehicle 1000, for example, for the working power requirements during the startup, navigation and operation of the vehicle 1000.

[0086] The vehicle 1000 may further include a controller 200 and a motor 300 , wherein the controller 200 is used to control the battery 100 to supply power to the motor 300 , for example, to meet the power requirements of starting, navigating, and driving the vehicle 1000 .

[0087] In some embodiments of the present application, the battery 100 can not only serve as an operating power source for the vehicle 1000, but also serve as a driving power source for the vehicle 1000, replacing or partially replacing fuel or natural gas to provide driving power for the vehicle 1000.

[0088] Please refer to Figure 2 , Figure 2An exploded diagram of a battery provided in the first embodiment of the present application. The battery 100 includes a case 10 and a battery cell 20, and the battery cell 20 is contained in the case 10. Among them, the case 10 is used to provide a storage space for the battery cell 20, and the case 10 can adopt a variety of structures. In some embodiments, the case 10 may include a first sub-case 11 and a second sub-case 12, and the first sub-case 11 and the second sub-case 12 cover each other, and the first sub-case 11 and the second sub-case 12 jointly define a storage space for accommodating the battery cell 20. The second sub-case 12 may be a hollow structure with one end open, and the first sub-case 11 may be a plate-like structure, and the first sub-case 11 covers the open side of the second sub-case 12, so that the first sub-case 11 and the second sub-case 12 jointly define a storage space; the first sub-case 11 and the second sub-case 12 may also be hollow structures with one side open, and the open side of the first sub-case 11 covers the open side of the second sub-case 12.

[0089] In the battery 100, there may be multiple battery cells 20, and the multiple battery cells 20 may be connected in series, in parallel, or in a mixed connection. A mixed connection means that the multiple battery cells 20 are both connected in series and in parallel. The multiple battery cells 20 may be directly connected in series, in parallel, or in a mixed connection, and then the whole formed by the multiple battery cells 20 is accommodated in the box 10; of course, the battery 100 may also be a battery module formed by connecting multiple battery cells 20 in series, in parallel, or in a mixed connection, and then the multiple battery modules are connected in series, in parallel, or in a mixed connection to form a whole, and accommodated in the box 10. The battery 100 may also include other structures, for example, the battery 100 may also include a busbar component for realizing electrical connection between the multiple battery cells 20.

[0090] The battery cell 20 may be a secondary battery or a primary battery; the battery cell 20 may also be a lithium-sulfur battery, a sodium-ion battery or a magnesium-ion battery, but is not limited thereto.

[0091] Please refer to Figure 3 , Figure 3 An exploded view of a battery cell provided in some embodiments of the present application. Figure 3 As shown, the battery cell 20 includes a housing 21, an electrode assembly 22 and an electrode terminal 25. The housing 21 includes a shell 211 and an end cap 212. The shell 211 has an opening, and the end cap 212 closes the opening to isolate the internal environment of the battery cell 20 from the external environment.

[0092] The shell 211 is a component used to cooperate with the end cap 212 to form the internal environment of the battery cell 20, wherein the formed internal environment can be used to accommodate the electrode assembly 22, the electrolyte and other components. The shell 211 and the end cap 212 can be independent components. The shell 211 can be of various shapes and sizes. Specifically, the shape of the shell 211 can be determined according to the specific shape and size of the electrode assembly 22. The material of the shell 211 can be various, such as copper, iron, aluminum, stainless steel, aluminum alloy, plastic, etc.

[0093] The end cap 212 refers to a component that covers the opening of the shell 211 to isolate the internal environment of the battery cell 20 from the external environment. Without limitation, the shape of the end cap 212 can be adapted to the shape of the shell 211 to match the shell 211. Optionally, the end cap 212 can be made of a material with a certain hardness and strength (such as aluminum alloy), so that the end cap 212 is not easily deformed when squeezed and collided, so that the battery cell 20 can have a higher structural strength and reliability can also be improved. Functional components such as electrode terminals can be provided on the end cap 212. The electrode terminal can be used to electrically connect to the electrode assembly 22 for outputting or inputting electrical energy of the battery cell 20. The material of the end cap 212 can also be a variety of materials, such as copper, iron, aluminum, stainless steel, aluminum alloy, plastic, etc., and the embodiment of the present application does not impose special restrictions on this. In some embodiments, an insulating structure can also be provided on the inner side of the end cap 212, and the insulating structure can be used to isolate the electrical connection components in the shell 211 from the end cap 212 to reduce the risk of short circuit. Exemplarily, the insulating structure may be plastic, rubber, or the like.

[0094] The electrode assembly 22 is a component in the battery cell 20 where electrochemical reactions occur. One or more electrode assemblies 22 may be included in the housing 211. The electrode assembly 22 is mainly formed by winding or stacking the positive electrode sheet and the negative electrode sheet, and a separator is usually provided between the positive electrode sheet and the negative electrode sheet, and the separator is used to separate the positive electrode sheet and the negative electrode sheet to avoid short circuits between the positive electrode sheet and the negative electrode sheet. The parts of the positive electrode sheet and the negative electrode sheet with active materials constitute the main body of the electrode assembly, and the parts of the positive electrode sheet and the negative electrode sheet without active materials each constitute a pole ear. The positive pole ear and the negative pole ear may be located together at one end of the main body or respectively at both ends of the main body. During the charge and discharge process of the battery, the positive active material and the negative active material react with the electrolyte, and the pole ears connect the electrode terminals to form a current loop.

[0095] like Figure 4-Figure 7 As shown, the housing 211 according to the embodiment of the present application can be used for the battery cell 20, that is, the housing 211 is a part of the battery cell 20. The housing 211 can define a receiving space inside, and the receiving space can be used to receive the electrode assembly 22.

[0096] The housing 211 includes a first wall 211 a , a second wall 211 b , and a first corner portion 211 c , and the first wall 211 a and the second wall 211 b are connected by the first corner portion 211 c .

[0097] The housing 211 of the embodiment of the present application may have an opening 102, and the electrode assembly 22 may be placed in the accommodation space defined by the housing 211 through the opening 102. The first wall 211a, the second wall 211b, and the end of the first corner portion 211c on the same side may surround the above-mentioned opening 102, and the end cover 212 may cooperate with the first wall 211a, the second wall 211b, and the end of the first corner portion 211c on the same side, so that the end cover 212 seals the opening 102.

[0098] The first wall 211a and the second wall 211b may both be flat plate structures, and the first corner portion 211c may be an arc-shaped plate structure. For example, the first wall 211a and the second wall 211b connected by the first corner portion 211c may be orthogonal to each other.

[0099] The shell 211 may be an integrally formed part, the shell 211 may be a metal part, and of course the shell 211 may also be a non-metal part, for example, the shell 211 may be made of a plastic part or a composite material part.

[0100] During the use of the battery cell 20 , the pressure inside the housing 211 may change, and the first wall 211 a and / or the second wall 211 b may be deformed.

[0101] The first corner portion 211c is provided with a weakening groove 101, so that the structural strength of the first corner portion 211c of the embodiment of the present application is weaker than that of the existing first corner portion. Therefore, after one of the first wall 211a and the second wall 211b undergoes a large deformation due to the expansion of the battery cell 20, the first corner portion 211c will deform before the other of the first wall 211a and the second wall 211b, so that the first corner portion 211c can absorb part of the expansion energy and reduce the deformation of the other of the first wall 211a and the second wall 211b.

[0102] For example, the area of ​​the outer surface of the first wall 211 a is greater than the area of ​​the outer surface of the second wall 211 b , the first wall 211 a is a large surface of the shell 211 , and the second wall 211 b is a small surface of the shell 211 .

[0103] During the use of the battery cell 20 , the battery cell 20 will expand and the shell 211 will deform. Since the first wall 211a is a large surface and the first wall 211a is a side wall of the shell 211 in the thickness direction, the large surface will be subjected to greater pressure and thus deform.

[0104] A weakening groove 101 is provided on the first corner portion 211c, so the first corner portion 211c will be more easily deformed, absorbing at least part of the energy transferred from the first wall 211a to the second wall 211b, that is, the first corner portion 211c will deform before the second wall 211b, thereby reducing the deformation of the second wall 211b.

[0105] Since the deformation of the second wall 211b is reduced, the size of the middle area of ​​the second wall 211b protruding from the two end areas of the second wall 211b in the thickness direction of the shell 211 is also reduced. Therefore, the outer surface of the second wall 211b is flat, and glue can be smoothly applied on the second wall 211b. When the water-cooling plate is pressed on the second wall 211b, the glue pressing area of ​​multiple second walls 211b has small fluctuation and high consistency.

[0106] In addition, whether the small surface is attached with a heating film or a water-cooling plate, since the small surface no longer protrudes outward or the size of the protrusion is smaller, the small surface is relatively flat, and the thickness of the glue layer between the small surface and the heating film or the water-cooling plate is consistent, thereby improving the thermal conductivity of the water-cooling plate or the heating film.

[0107] It should be noted that the weakened groove 101 of the embodiment of the present application may not penetrate the first corner portion 211c in the thickness direction of the first corner portion 211c, and the weakened groove 101 may be a long strip structure or a circular or rectangular structure.

[0108] After the first corner portion 211 c is deformed by pressure, the radius of the fillet of the first corner portion 211 c becomes smaller, thereby absorbing deformation energy and reducing the deformation amount of the small surface.

[0109] In some embodiments of the present application, Figure 5 , Figure 7 and Figure 8 As shown, the weakened groove 101 is disposed on the inner side of the first corner portion 211c. It should be noted that the "inside" here refers to the direction toward the inner middle area of ​​the housing 211, and the "outside" refers to the direction away from the inner middle area of ​​the housing 211.

[0110] Since the weakened groove 101 of the embodiment of the present application is disposed on the inner side of the first corner portion 211 c , the weakened groove 101 cannot be seen from the outer side of the shell 211 , thereby improving the aesthetics of the battery cell 20 .

[0111] In addition, if the weakened groove 101 is disposed on the outer side of the first corner portion 211c, the structure defining the weakened groove 101 may scratch the adjacent battery cells 20. Therefore, disposing the weakened groove 101 on the inner side of the first corner portion 211c can reduce the probability of the above problem.

[0112] In some embodiments of the present application, Figure 4 and Figure 6 As shown, there are two first walls 211 a , and the two first walls 211 a are arranged opposite to each other along the first direction X. The two first walls 211 a are spaced apart in the first direction X and opposite to each other.

[0113] There are two second walls 211 b , and the two second walls 211 b are arranged opposite to each other along the second direction Y. The two second walls 211 b are spaced apart and opposite to each other in the second direction Y. The first direction X and the second direction Y are perpendicular to each other.

[0114] A first corner portion 211c is disposed between any adjacent first walls 211a and second walls 211b. That is, any adjacent first walls 211a and second walls 211b are connected via the corresponding first corner portions 211c.

[0115] The number of the first corner portions 211 c is four, and the four first corner portions 211 c are respectively disposed at four corners of the housing 211 in the circumferential direction.

[0116] It should be noted that the circumference of the housing 211 may refer to the circumference of the opening 102 sealed by the end cover 212 .

[0117] Since the first corner portion 211c is arranged on the weakened groove 101, the structural strength of the four circumferential corners of the shell 211 is reduced. After one of the first wall 211a and the second wall 211b is greatly deformed due to the expansion of the battery cell 20, the four circumferential corners of the shell 211 (that is, the first corner portion 211c) can absorb part of the energy after the battery cell 20 expands, thereby reducing the deformation of the other one of the first wall 211a and the second wall 211b.

[0118] The weakened groove 101 extends along the third direction Z, and the first direction X, the second direction Y and the third direction Z are perpendicular to each other. Therefore, after one of the first wall 211a and the second wall 211b is greatly deformed due to the expansion of the battery cell 20, the first corner portion 211c can be deformed, and the two adjacent supporting ribs 211d defining the weakened groove 101 can be close to each other, so that the rounded arc of the outer surface of the first corner portion 211c is reduced, absorbing part of the energy that should be transmitted to the other of the first wall 211a and the second wall 211b, and reducing the deformation of the other of the first wall 211a and the second wall 211b.

[0119] The weakened groove 101 of the present application extends along the third direction Z, which can further reduce the structural strength of the first corner portion 211 c and facilitate the first corner portion 211 c to deform and absorb energy.

[0120] According to some embodiments of the present application, Figure 5, Figure 7 and Figure 8 As shown, the housing 211 is formed with an opening 102 at at least one end in the third direction Z. The battery cell 20 may further include an end cover 212 , which may cooperate with the housing 211 to seal the opening 102 .

[0121] Each first corner portion 211c is provided with a plurality of weakened grooves 101, and the plurality of weakened grooves 101 are arranged at intervals along the circumference of the opening 102. Thus, the plurality of weakened grooves 101 can further reduce the structural strength of the first corner portion 211c, making the first corner portion 211c more likely to deform, thereby improving the energy absorption capacity of the first corner portion 211c.

[0122] There is a support rib 211d between two adjacent weakened grooves 101. When the first corner portion 211c is subjected to extrusion force, the two adjacent support ribs 211d approach each other, and the first corner portion 211c is deformed, so that the fillet radius of the outer side of the first corner portion 211c is reduced.

[0123] In some embodiments of the present application, the outer surface of the first wall 211a is larger than the outer surface of the second wall 211b, so the first wall 211a is a large surface and the second wall 211b is a small surface. During the use of the battery cell 20, the battery cell 20 will expand, and the large surface will be deformed by the pressure inside the shell 211. Under the action of the large surface torque or the internal pressure of the shell 211, the first corner portion 211c will deform, and the two supporting ribs 211d defining the weakened groove 101 will move closer to each other, so that the first corner portion 211c will deform before the small surface, absorb deformation energy, and reduce the deformation amount of the small surface.

[0124] In some embodiments of the present application, Figure 7 As shown, a support rib 211d is formed between two adjacent weakened grooves 101. It is understandable that the support rib 211d is naturally obtained during the molding process of the shell 211 or after the weakened groove 101 is machined on the inner side of the shell 211.

[0125] Along the circumferential direction of the opening 102 , two side surfaces of the support rib 211 d that are opposite to each other are respectively a portion of the inner side surfaces of two adjacent weakened grooves 101 .

[0126] The supporting rib 211d includes a main section 211d1 and an end section 211d2, the main section 211d1 and the end section 211d2 are connected to each other, and the main section 211d1 and the end section 211d2 are arranged along the third direction Z.

[0127] The end section 211d2 is closer to the opening 102 than the main section 211d1, and the thickness of the end section 211d2 is less than that of the main section 211d1 to form a positioning step 103. Thus, the end cover 212 can overlap the positioning step 103, which facilitates the positioning of the end cover 212 before the end cover 212 is fixedly connected to the housing 211, thereby improving the fixing efficiency and connection stability of the end cover 212 and the housing 211.

[0128] It is understandable that steps may also be provided on the first wall 211a and the second wall 211b. Along the third direction Z, the steps on the first wall 211a and the second wall 211b remain flush with the positioning steps 103, thereby improving the positioning stability of the end cover 212.

[0129] According to some embodiments of the present application, the number of the weakened grooves 101 may be 2-5, and thus the number of the supporting ribs 211d is at least 1.

[0130] In some embodiments of the present application, the weakening groove 101 passes through both ends of the first corner portion 211c along the third direction Z. Thus, the strength of the entire region of the first corner portion 211c along the third direction Z is weakened, thereby further improving the deformation capacity of the first corner portion 211c and the energy absorption capacity of the first corner portion 211c.

[0131] After one of the first wall 211a and the second wall 211b undergoes a significant deformation due to the expansion of the battery cell 20, the first corner portion 211c can be more easily deformed, and the two adjacent support ribs 211d that define the weakened groove 101 can be close to each other, so that the radius of the outer surface of the first corner portion 211c will be reduced, absorbing the energy that should be transferred to the other of the first wall 211a and the second wall 211b, thereby reducing the deformation of the other of the first wall 211a and the second wall 211b.

[0132] In some embodiments of the present application, Figure 6 As shown, the housing 211 further includes a bottom wall 211e, and the first wall 211a, the second wall 211b, and the first corner portion 211c form an opening 102 at one end on the same side in the third direction Z. The first wall 211a, the second wall 211b, and the first corner portion 211c are connected to the bottom wall 211e at the other end on the same side in the third direction Z. The bottom wall 211e and the opening 102 are arranged opposite to each other in the third direction Z, and the first wall 211a, the second wall 211b, and the first corner portion 211c are arranged around the periphery of the bottom wall 211e.

[0133] The housing 211 in the embodiment of the present application has only one opening 102 , and therefore the battery cell 20 of the present application only needs one end cover 212 , and the end cover 212 can seal the above-mentioned opening 102 .

[0134] The bottom wall 211 e , the two first walls 211 a , the two second walls 211 b and the plurality of first corner portions 211 c may be an integrally formed part, thereby improving the production efficiency of the housing 211 .

[0135] According to some embodiments of the present application, Figure 8 As shown, along the circumference of the opening 102 , the width of the weakening groove 101 is a, satisfying: 1 mm ≤ a ≤ 3 mm.

[0136] The present application limits the width of the weakened groove 101 to the above-mentioned range. On the one hand, it can enable the first corner portion 211c to deform to absorb part of the energy. On the other hand, it can enable the first corner portion 211c to have a certain structural strength, thereby reducing the probability of damage to the first corner portion 211c during the deformation process, so that the shell 211 can better protect the devices inside the shell 211.

[0137] For example, the width of the weakened groove 101 may be 1 mm, 1.2 mm, 1.4 mm, 1.6 mm, 1.8 mm, 2 mm, 2.2 mm, 2.4 mm, 2.6 mm, 2.8 mm, and 3 mm.

[0138] It should be noted that the above-mentioned width value of the weakening groove 101 is only a specific example of the present application. As long as the width value of the weakening groove 101 meets the above-mentioned range, it is within the protection scope of the present application.

[0139] In some embodiments of the present application, Figure 8 As shown, along the thickness direction of the first corner portion 211 c , the depth of the weakened groove 101 is b, satisfying: 0.1 mm ≤ b ≤ 0.5 mm.

[0140] The present application limits the depth of the weakened groove 101 to the above-mentioned range. On the one hand, it can enable the first corner portion 211c to deform to absorb part of the energy. On the other hand, it can enable the first corner portion 211c to have a certain structural strength, thereby reducing the probability of damage to the first corner portion 211c during the deformation process, so that the shell 211 can better protect the devices inside the shell 211.

[0141] For example, the depth of the weakened groove 101 may be 0.1 mm, 0.15 mm, 0.2 mm, 0.25 mm, 0.3 mm, 0.35 mm, 0.4 mm, 0.45 mm, or 0.5 mm.

[0142] It should be noted that the depth value of the weakened groove 101 is only a specific example of the present application. As long as the depth value of the weakened groove 101 meets the above range, it is within the protection scope of the present application.

[0143] According to some embodiments of the present application, the outer surface area of ​​the first wall 211a is greater than the outer surface area of ​​the second wall 211b. When multiple battery cells 20 are stacked, the multiple first walls 211a face each other in the stacking direction of the multiple battery cells 20.

[0144] During the use of the battery cell 20, the battery cell 20 will expand. At this time, the large surface is under greater pressure. In the design of the battery cell 20, the large surface is allowed to deform, thereby reducing the problem of tearing the shell 211 due to the inability to release the internal pressure of the battery cell 20.

[0145] In the embodiment of the present application, a weakening groove 101 is provided on the first corner portion 211c, so that the structural strength of the first corner portion 211c is reduced. Therefore, the first corner portion 211c will deform after being compressed, absorb energy, reduce the torque transmitted to the small face, and thus reduce the deformation of the small face.

[0146] The battery cell 20 according to the embodiment of the present application is briefly described below.

[0147] The battery cell 20 according to the embodiment of the present application may include a shell 211 , an electrode assembly 22 and an end cover 212 of the above embodiment. The shell 211 has an opening 102 , the electrode assembly 22 is accommodated in the shell 211 , and the end cover 212 covers the opening 102 .

[0148] Since the end cover 212 can seal the opening 102 , the end cover 212 and the shell 211 define a receiving space, and the receiving space can be used to accommodate the electrode assembly 22 .

[0149] According to the embodiment of the present application, the battery cell 20 has the shell 211 in the above-mentioned embodiment. After one of the first wall 211a and the second wall 211b is greatly deformed due to the expansion of the battery cell 20, the first corner portion 211c will deform the other of the first wall 211a and the second wall 211b first, so that the first corner portion 211c can absorb part of the expansion energy, reduce the deformation amount of the other of the first wall 211a and the second wall 211b, improve the consistency of the thickness of the glue layer between the heat exchange component (for example, a water cooling plate or a heating film) attached to the other of the first wall 211a and the second wall 211b and the other of the first wall 211a and the second wall 211b, thereby improving the heat exchange effect between the heat exchange component and the other of the first wall 211a and the second wall 211b, and improving the reliability of the battery.

[0150] The battery 100 according to the embodiment of the present application is briefly described below.

[0151] The battery 100 according to the embodiment of the present application includes the battery cell 20 of the above embodiment. Since the battery 100 according to the embodiment of the present application includes the above battery cell 20, the reliability of the battery 100 is significantly improved.

[0152] The following is a brief description of the electrical equipment in the embodiments of the present application.

[0153] The electric device according to the embodiment of the present application includes the battery cell 20 or the battery 100 of the above-mentioned embodiment. Since the electric device according to the embodiment of the present application has the above-mentioned battery cell 20 or the battery 100, the reliability of the electric device is improved, and the probability of the electric device being unable to be used or affecting the use experience of the electric device due to insufficient stability of the battery cell 20 or the battery 100 is reduced.

[0154] Although the present application has been described with reference to preferred embodiments, various modifications may be made thereto and parts thereof may be replaced with equivalents without departing from the scope of the present application. In particular, the various technical features mentioned in the various embodiments may be combined in any manner as long as there are no structural conflicts. The present application is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

Claims

1. A housing for a battery cell, characterized in that: The housing comprises a first wall, a second wall and a first corner portion connecting the first wall and the second wall; Wherein, the first corner portion is provided with a weakening groove.

2. The housing according to claim 1, characterized in that The weakened groove is arranged on the inner side surface of the first corner portion.

3. The housing according to claim 2, characterized in that: There are two first walls, and the two first walls are arranged opposite to each other along a first direction. There are two second walls, and the two second walls are arranged opposite to each other along a second direction. The first corner portion is arranged between any adjacent first walls and second walls. The weakened groove extends along a third direction, and the first direction, the second direction and the third direction are perpendicular to each other.

4. The housing according to claim 3, characterized in that: An opening is formed at at least one end of the shell in the third direction, and each of the first corner portions is provided with a plurality of the weakened grooves, which are arranged at intervals along the circumference of the opening.

5. The housing according to claim 4, characterized in that: A support rib is formed between two adjacent weakened grooves, and the support rib includes a main section and an end section. The main section and the end section are arranged along the third direction. The end section is closer to the opening than the main section, and the thickness of the end section is smaller than the thickness of the main section to form a positioning step.

6. The housing according to claim 3, characterized in that: Along the third direction, the weakened groove passes through both ends of the first corner portion.

7. The housing according to claim 3, characterized in that: The shell also includes a bottom wall, the first wall, the second wall and the first corner portion form an opening at one end on the same side of the third direction, and the first wall, the second wall and the first corner portion are connected to the bottom wall at the other end on the same side of the third direction.

8. The housing according to claim 7, characterized in that Along the circumference of the opening, the width of the weakened groove is a, satisfying: 1mm≤a≤3mm.

9. The housing according to claim 1, characterized in that Along the thickness direction of the first corner portion, the depth of the weakened groove is b, satisfying: 0.1 mm≤b≤0.5 mm.

10. A battery cell, characterized in that: include: The housing according to any one of claims 1 to 9, wherein the housing has an opening; an electrode assembly, contained in the housing; An end cover is arranged on the opening.

11. A battery, characterized in that: The battery cell comprises the battery cell according to claim 10.

12. An electrical device, characterized in that: The invention comprises the battery cell according to claim 10 or the battery according to claim 11, wherein the battery cell or the battery is used to provide electrical energy.

Images