CN219959089U

CN219959089U - Battery cell, battery and electricity utilization device

Info

Publication number: CN219959089U
Application number: CN202322054835.2U
Authority: CN
Inventors: 聂鹏茹; 陈威; 陈祖贵; 陈宽仪; 粟泽龙
Original assignee: Contemporary Amperex Technology Co Ltd
Current assignee: Contemporary Amperex Technology Co Ltd
Priority date: 2023-08-02
Filing date: 2023-08-02
Publication date: 2023-11-03
Anticipated expiration: 2033-08-02

Abstract

The application provides a battery cell, a battery and an electric device. The battery cell includes a case, an electrode terminal, and an electrode assembly; the shell is provided with a containing cavity, the shell comprises a first wall and a second wall, the second wall is connected with the first wall, at least one bulge is arranged on one side of the second wall facing the containing cavity, and one side of the second wall facing away from the containing cavity is flat; the electrode terminal is arranged on the first wall; the electrode assembly is accommodated in the accommodating chamber. The battery monomer provided by the application is beneficial to ensuring that the battery monomer has higher heat exchange rate and is timely and efficiently heated or cooled on the premise of reducing the risk of wrinkling of the pole piece of the electrode assembly and further reducing the risk of lithium precipitation of the electrode assembly, so that the reliability of the battery monomer is improved.

Description

Battery cell, battery and electricity utilization device

Technical Field

The present application relates to the field of battery technologies, and in particular, to a battery cell, a battery, and an electric device.

Background

Batteries are widely used in electronic devices such as cellular phones, notebook computers, battery cars, electric vehicles, electric airplanes, electric ships, electric toy vehicles, electric toy ships, electric toy airplanes, electric tools, and the like.

In the development of battery cell technology, in addition to improving the service performance of the battery cell, the reliability of the battery cell is also a problem to be considered. Therefore, how to improve the reliability of the battery cell is a continuous improvement in the battery cell technology.

Disclosure of Invention

The embodiment of the utility model provides a battery cell, a battery and an electricity utilization device, which can improve the reliability of the battery cell.

In a first aspect, the present utility model provides a battery cell including a case, an electrode terminal, and an electrode assembly; the shell is provided with a containing cavity, the shell comprises a first wall and a second wall, the second wall is connected with the first wall, at least one bulge is arranged on one side of the second wall facing the containing cavity, and one side of the second wall facing away from the containing cavity is flat; the electrode terminal is arranged on the first wall; the electrode assembly is accommodated in the accommodating chamber.

According to the battery monomer provided by the embodiment of the utility model, at least one bulge is arranged on one side of the second wall facing the accommodating cavity, and one side of the second wall facing away from the accommodating cavity is in a straight shape, so that a certain binding force can be provided for expansion of the electrode assembly by the bulge in the process of expanding the electrode assembly, the risk of wrinkling of a pole piece of the electrode assembly is reduced, and the side of the second wall facing away from the accommodating cavity is in a straight shape.

In some embodiments, an electrode assembly includes an electrode body and a tab that is led out from an end of the electrode body in a first direction; the absolute value |h1-h2| of the minimum distance difference of the at least one protrusion to both ends of the electrode body in the first direction satisfies: the h is more than or equal to 0 and less than or equal to |h1-h2| and less than or equal to 5mm. The electrode assembly is beneficial to realizing that at least one bulge corresponds to the central area of the electrode body as much as possible, so that the binding force can be provided for the expansion of the electrode assembly through the at least one bulge in the process of the initial expansion of the electrode assembly, and the risk of wrinkling of the electrode assembly pole pieces is further reduced.

In some embodiments, the side of the second wall facing the receiving chamber is provided with a plurality of protrusions. In the expansion process of the electrode assembly, corresponding binding force can be provided for expansion of different parts of the electrode assembly through different bulges, so that the risk of free expansion of the electrode assembly is further reduced, and the risk of wrinkling of the electrode assembly in the expansion process is further reduced.

In some embodiments, at least one of the protrusions is curved toward one side of the electrode assembly. Therefore, in the expansion process of the electrode assembly, the electrode assembly is gradually contacted with the raised arc-shaped surface, the binding force born by each part of the expansion of the electrode assembly is relatively uniform, and the risk of wrinkling of the electrode assembly in the expansion process is further reduced.

In some embodiments, the electrode assembly abuts at least one protrusion. When the electrode assembly begins to expand, the bulge can provide certain binding force for the electrode assembly, and in the whole process of expanding the electrode assembly, the bulge can provide certain binding force for the electrode assembly, so that the risk of wrinkling of the electrode assembly in the expanding process is reduced, the distance between the bulge and the electrode assembly is reduced, the volume of a battery is reduced, and the energy density of the battery is improved.

In some embodiments, the protrusion includes an insulating buffer provided on a side of the second wall facing the receiving cavity. Not only can provide certain constraint power for the inflation of electrode assembly to reduce the risk that electrode assembly takes place the fold at the in-process of inflation, can also reduce the risk that electrode assembly produced deformation because of constraint power is too big at the in-process of inflation, be favorable to further reducing the risk that electrode assembly takes place to separate lithium, and then improve battery monomer's reliability.

In some embodiments, the battery cell has at least two second walls disposed opposite each other. In the expansion process of the electrode assembly, at least two opposite bulges provide opposite binding force for the electrode assembly, so that the electrode assembly is favorable for being relatively balanced in stress in the expansion process, and the risk of dislocation of the electrode assembly in the expansion process is reduced.

In some embodiments, an electrode assembly includes an electrode body and a tab that is led out from an end of the electrode body in a first direction; the electrode body is provided with two first surfaces opposite to each other along the second direction and two second surfaces opposite to each other along the third direction, the first directions, the second directions and the third directions are intersected with each other, the first surfaces are connected with the two second surfaces, and the area of the first surfaces is larger than that of the second surfaces; the second wall is located on at least one side of the housing in at least a second direction. The second wall can provide a certain binding force for the expansion of the electrode assembly during the expansion of the electrode assembly in the second direction, so that the risk of wrinkling of the electrode assembly during the expansion is greatly reduced.

In some embodiments, two second walls are disposed opposite in the second direction and the other two second walls are disposed opposite in the third direction. Therefore, the corresponding bulges are propped against the corresponding bulges no matter which direction the electrode assembly expands around the electrode assembly, so that binding force along all directions is provided for the electrode assembly, and the risk of wrinkling of the electrode assembly in the expansion process is further reduced.

In a second aspect, an embodiment of the present application provides a battery, including a battery cell provided in any one of the embodiments above.

The battery provided by the embodiment of the application has the same technical effects due to the adoption of the battery monomer provided by any one of the embodiments, and is not described herein.

In some embodiments, the battery further comprises a heat exchange member in engagement with at least a portion of the at least one second wall for exchanging heat with the battery cells through the second wall. The second wall deviates from the one side of holding the chamber and is straight form, then is favorable to increasing the area of heat exchange piece and second wall laminating to improve the heat exchange efficiency of two, so, be favorable to in time, high-efficient heating or the heat dissipation to the battery monomer, so that the battery monomer has suitable operating temperature, be favorable to improving the free reliability of battery.

In a third aspect, an embodiment of the present application provides an electrical device, including a battery unit provided in the foregoing embodiment, or a battery provided in the foregoing embodiment, where the battery unit or the battery is used to provide electrical energy.

The power utilization device provided by the embodiment of the application has the same technical effects due to the adoption of the battery provided by the embodiment, and is not described in detail herein.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings that are needed in the embodiments of the present application will be briefly described below, and it is obvious that the drawings described below are only some embodiments of the present application, and other drawings may be obtained according to the drawings without inventive effort for a person skilled in the art.

Fig. 1 is a schematic structural view of a vehicle according to an embodiment of the present application;

fig. 2 is a schematic structural view of a battery according to an embodiment of the present application;

fig. 3 is a schematic structural view of a battery module in a battery according to an embodiment of the present application;

fig. 4 is a schematic diagram of an explosion structure of a battery cell according to an embodiment of the present application;

FIG. 5 is a schematic cross-sectional view of a battery cell according to an embodiment of the present application;

fig. 6 is a schematic view showing another cross-sectional structure of a battery cell according to an embodiment of the present application;

fig. 7 is a schematic view illustrating a further cross-sectional structure of a battery cell according to an embodiment of the present application.

In the drawings, the drawings are not necessarily to scale.

Marking:

1. a vehicle; 1a, a motor; 1b, a controller;

10. a battery; 11. a first box portion; 12. a second box portion;

20. a battery module;

30. a battery cell;

31. a housing; 31a, a receiving cavity; 311. a first wall; 312. a second wall; 313. a protrusion; 313a, an insulating buffer;

32. an electrode assembly; 321. an electrode body; 3211. a first surface; 3212. a second surface; 322. a tab;

33. an electrode terminal;

x, a first direction; y, second direction; z, third direction.

Detailed Description

Embodiments of the present application are described in further detail below with reference to the accompanying drawings and examples. The following detailed description of the embodiments and the accompanying drawings are provided to illustrate the principles of the application and are not intended to limit the scope of the application, i.e., the application is not limited to the embodiments described.

In the description of the present application, it is to be noted that, unless otherwise indicated, the meaning of "plurality" is two or more; the terms "upper," "lower," "left," "right," "inner," "outer," and the like are merely used for convenience in describing the present application and to simplify the description, and do not denote or imply that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and thus are not to be construed as limiting the present application. Furthermore, the terms "first," "second," and the like are used for descriptive purposes only and are not to be construed as indicating or implying relative importance. The "vertical" is not strictly vertical but is within the allowable error range. "parallel" is not strictly parallel but is within the tolerance of the error.

Reference in the specification to "an embodiment" means that a particular feature, structure, or characteristic described in connection with the embodiment may be included in at least one embodiment of the application. The appearances of such phrases in various places in the specification are not necessarily all referring to the same embodiment, nor are separate or alternative embodiments mutually exclusive of other embodiments. Those of skill in the art will explicitly and implicitly appreciate that the described embodiments of the application may be combined with other embodiments.

In the description of the present application, it should also be noted that, unless explicitly specified and limited otherwise, the terms "mounted," "connected," and "connected" are to be construed broadly, and may be either fixedly connected, detachably connected, or integrally connected, for example; can be directly connected or indirectly connected through an intermediate medium. The specific meaning of the above terms in the present application can be understood as appropriate by those of ordinary skill in the art.

The term "plurality" as used herein refers to two or more (including two).

In the present application, the battery cells may include a lithium ion secondary battery cell, a lithium ion primary battery cell, a lithium sulfur battery cell, a sodium lithium ion battery cell, a sodium ion battery cell, or a magnesium ion battery cell, which is not limited in the embodiment of the present application. The battery cell may be in a cylindrical shape, a flat shape, a rectangular parallelepiped shape, or other shapes, which is not limited in this embodiment of the application.

The battery referred to by embodiments of the present application may include one or more battery cells to provide a single physical module of higher voltage and capacity. When a plurality of battery cells are provided, the plurality of battery cells are connected in series, in parallel or in series-parallel through the converging component.

In some embodiments, the battery may be a battery module; when a plurality of battery cells are provided, the plurality of battery cells are arranged and fixed to form a battery module.

In some embodiments, the battery may be a battery pack including a case and a battery cell, the battery cell or battery module being housed in the case.

In some embodiments, the tank may be part of the chassis structure of the vehicle. For example, a portion of the tank may become at least a portion of the floor of the vehicle, or a portion of the tank may become at least a portion of the cross member and the side member of the vehicle.

In some embodiments, the battery may be an energy storage device. The energy storage device comprises an energy storage container, an energy storage electric cabinet and the like.

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 of the battery cell, active ions (e.g., lithium ions) are inserted and extracted back and forth between the positive electrode and the negative electrode. The isolating film is arranged between the positive electrode and the negative electrode, can play a role in preventing the positive electrode and the negative electrode from being short-circuited, and can enable active ions to pass through.

In some embodiments, the positive electrode may be a positive electrode sheet, which 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.

As an example, the positive electrode current collector has two surfaces opposing in its own thickness direction, and the positive electrode active material is provided on either or both of the two surfaces opposing the positive electrode current collector.

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

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 a battery positive electrode active material may be used. These positive electrode active materials may be used alone or in combination of two or more.

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

In some embodiments, the negative electrode may be a negative electrode tab, which may include a negative electrode current collector.

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

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

As an example, the anode current collector has two surfaces opposing in its own thickness direction, and the anode active material is provided on either or both of the two surfaces opposing the anode current collector.

As an example, a negative active material for a battery cell, which is well known in the art, may be used. As an example, the anode active material may include at least one of the following materials: artificial graphite, natural graphite, soft carbon, hard carbon, silicon-based materials, tin-based materials, lithium titanate, and the like.

In some embodiments, the negative electrode may be carbon foam or metal foam. The foam metal can be foam nickel, foam copper, foam aluminum or foam alloy. When the foam metal is used as the negative electrode sheet, the surface of the foam metal does not need to be provided with a negative electrode active material, and the surface of the foam metal can be provided with the negative electrode active material.

As an example, a lithium source material, which is a lithium metal and/or a lithium-rich material, potassium metal, or sodium metal, may also be filled and/or deposited within the negative electrode current collector.

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

In some embodiments, the electrode assembly further includes a separator disposed between the positive electrode and the negative electrode. The type of the separator is not particularly limited, and any known porous separator having good chemical stability and mechanical stability can be used.

As an example, the main material of the separator may be at least one selected from glass fiber, non-woven fabric, polyethylene, polypropylene, polyvinylidene fluoride, and ceramic.

In some embodiments, the battery cell further includes an electrolyte that serves to conduct ions between the positive and negative electrodes. The application is not particularly limited in the kind of electrolyte, and may be selected according to the need. The electrolyte may be liquid, gel or solid.

In some embodiments, the electrode assembly is a rolled structure. The positive plate and the negative plate are wound into a winding structure.

In some embodiments, the electrode assembly is a lamination stack.

The positive plate and the negative plate can be respectively arranged in a plurality, and the positive plates and the negative plates are alternately laminated.

As an example, a plurality of positive electrode sheets may be provided, and the negative electrode sheets are folded to form a plurality of folded sections arranged in a stacked manner, with one positive electrode sheet sandwiched between adjacent folded sections.

As an example, the positive and negative electrode sheets are each folded to form a plurality of folded sections in a stacked arrangement.

As an example, the separator may be provided in plurality, respectively between any adjacent positive electrode sheet or negative electrode sheet.

As an example, the separator may be continuously provided, being disposed between any adjacent positive or negative electrode sheets by folding or winding.

In some embodiments, the electrode assembly may have a cylindrical shape, a flat shape, a polygonal column shape, or the like.

In some embodiments, the electrode assembly is provided with tabs that can conduct current away from the electrode assembly. The tab includes a positive tab and a negative tab.

The battery cell further includes a case inside which a receiving chamber for receiving the electrode assembly is formed. The case may protect the electrode assembly from the outside to prevent foreign substances from affecting the charge or discharge of the electrode assembly.

In the related art, there is a gap between the electrode assembly of the battery cell and the case, and the gaps of the respective parts are substantially the same to reserve a space for expansion of the electrode assembly. However, in the process of cyclic operation of the battery cell, when the electrode assembly just begins to expand, the shell has no binding force on the electrode assembly, and the pole piece of the electrode assembly freely expands, so that the phenomenon that the pole piece is wrinkled is easily caused, and the reliability of the battery cell is seriously affected.

In view of this, the embodiment of the application provides a technical scheme, which is characterized in that the shell is provided with a first wall and a second wall, at least one protrusion is arranged on one side of the second wall facing the accommodating cavity, and one side of the second wall facing away from the accommodating cavity is straight, so that the electrode assembly can provide a certain binding force for the electrode assembly through the protrusion in the expansion process, which is beneficial to reducing the risk of wrinkling of the electrode assembly, and simultaneously, is convenient for cooling the battery cell and is beneficial to ensuring the heat dissipation performance of the battery cell.

The technical scheme described by the embodiment of the application is suitable for a battery cell, a battery comprising the battery cell and an electric device using the battery.

The electric device may be a vehicle, a mobile phone, a portable device, a notebook computer, a ship, a spacecraft, an electric toy, an electric tool, or the like. The vehicle can be a fuel oil vehicle, a fuel gas vehicle or a new energy vehicle, and the new energy vehicle can be a pure electric vehicle, a hybrid electric vehicle or a range-extended vehicle; spacecraft including airplanes, rockets, space planes, spacecraft, and the like; the electric toy includes fixed or mobile electric toys, such as a game machine, an electric car toy, an electric ship toy, and an electric airplane toy; power tools include metal cutting power tools, grinding power tools, assembly power tools, and railroad power tools, such as electric drills, electric grinders, electric wrenches, electric screwdrivers, electric hammers, impact drills, concrete shakers, and electric planers, among others. The embodiment of the application does not limit the electric device in particular.

For convenience of explanation, the following examples will be described taking an electric device as an example of a vehicle.

As shown in fig. 1, a battery 10 is provided inside a vehicle 1. The battery 10 may be provided at the bottom or the head or the tail of the vehicle 1. The battery 10 may be used for power supply of the vehicle 1, for example, the battery 10 may serve as an operating power source of the vehicle 1.

The vehicle 1 may further include a controller 1b and a motor 1a. The controller 1b is used to control the battery 10 to supply power to the motor 1a, for example, for operating power requirements at start-up, navigation and travel of the vehicle 1.

In some embodiments of the application, the battery 10 may not only serve as an operating power source for the vehicle 1, but also as a driving power source for the vehicle 1, instead of or in part instead of fuel oil or natural gas, to provide driving power for the vehicle 1.

Referring to fig. 2, the battery 10 includes a battery cell (not shown in fig. 2). The battery 10 may further include a case for accommodating the battery cells.

The box is used for holding battery monomer, and the box can be multiple structural style. In some embodiments, the housing may include a first housing portion 11 and a second housing portion 12. The first housing part 11 and the second housing part 12 are mutually covered. The first and second casing parts 11 and 12 together define an accommodating space for accommodating the battery cells. The second case 12 may have a hollow structure with one end opened, the first case 11 has a plate-like structure, and the first case 11 is covered on the opening side of the second case 12 to form a case having an accommodation space; the first housing part 11 and the second housing part 12 may each have a hollow structure with one side opened. The open side of the first casing part 11 is closed to the open side of the second casing part 12 to form a casing having an accommodation space. Of course, the first and second case portions 11 and 12 may be of various shapes, such as a cylinder, a rectangular parallelepiped, or the like.

In order to improve the sealing property after the first casing part 11 and the second casing part 12 are connected, a sealing member, such as a sealant, a sealing ring, or the like, may be further provided between the first casing part 11 and the second casing part 12.

Assuming that the first housing part 11 is covered with the second housing part 12, the first housing part 11 may also be referred to as an upper case cover, and the second housing part 12 may also be referred to as a lower case.

In the battery 10, the number of battery cells may be one or more. If the number of the battery cells is multiple, the battery cells can be connected in series, in parallel or in series-parallel. The series-parallel connection refers to that a plurality of battery monomers are connected in series or in parallel. The plurality of battery cells can be directly connected in series or in parallel or in series-parallel, and then the whole formed by the plurality of battery cells is accommodated in the box body, or the plurality of battery cells can be connected in series or in parallel or in series-parallel to form the battery module 20. The plurality of battery modules 20 are then connected in series or parallel or a series-parallel combination to form a unit and are accommodated in a case.

In some embodiments, in the battery module 20, the battery cells are plural. The plurality of battery cells are first connected in series or parallel or a series-parallel combination to form the battery module 20. The plurality of battery modules 20 are then connected in series or parallel or a series-parallel combination to form a unit and are accommodated in a case.

In some embodiments, electrical connection between the plurality of battery cells in the battery module 20 may be achieved through a bus bar component to achieve parallel or series-parallel connection of the plurality of battery cells in the battery module 20.

Referring to fig. 4, a battery cell 30 according to an embodiment of the application includes an electrode assembly 32 and a housing 31, wherein the housing 31 has a receiving cavity 31a, and the electrode assembly 32 is received in the receiving cavity 31 a.

In assembling the battery cell 30, the electrode assembly 32 may be placed in the receiving chamber 31a, the first wall 311 may be covered with the second wall 312, and then an electrolyte may be injected into the receiving chamber 31a through an electrolyte injection port formed in the first wall 311.

In some embodiments, the housing 31 may also be used to contain an electrolyte, such as an electrolyte. The housing 31 may take a variety of structural forms.

The housing 31 may be of various shapes, such as a cylinder, a rectangular parallelepiped, etc. The shape of the case 31 may be determined according to the specific shape of the electrode assembly 32. For example, if the electrode assembly 32 has a cylindrical structure, the case 31 may alternatively have a cylindrical structure. If the electrode assembly 32 has a rectangular parallelepiped structure, the case 31 may alternatively have a rectangular parallelepiped structure. In fig. 4, the case and the electrode assembly 32 are each exemplarily rectangular parallelepiped in structure.

The material of the housing 31 may be various, such as copper, iron, aluminum, stainless steel, aluminum alloy, etc., which is not particularly limited in the embodiment of the present application.

The electrode assembly 32 accommodated in the case 31 may be one or more. In fig. 4, the number of electrode assemblies 32 accommodated in the case 31 is two.

As shown in fig. 4 and 5, the battery cell 30 provided according to the present application includes a case 31, an electrode terminal 33, and an electrode assembly 32, the case 31 having a receiving cavity 31a, the case 31 including a first wall 311 and a second wall 312, the second wall 312 being connected to the first wall 311, the second wall 312 being provided with at least one protrusion 313 on a side facing the receiving cavity 31a, the second wall 312 being flat on a side facing away from the receiving cavity 31 a. The electrode terminal 33 is provided on the first wall 311, and the electrode assembly 32 is accommodated in the accommodation chamber 31 a.

The electrode terminals 33 are disposed on the first walls 311, and thus the first walls 311 may be end caps of the battery cells 30, and the case 31 may have one or more first walls 311 according to the form of the battery cells 30, and when the battery cells 30 have two first walls 311, the two first walls 311 may be disposed opposite to each other, and two electrode terminals 33 may be disposed on the two first walls 311, respectively, and two ends of the electrode assembly 32 may be protruded from the tabs 322.

The second wall 312 is connected with the first wall 311, and then the second wall 312 may intersect with the first wall 311, the battery cell 30 may be a cylindrical battery cell 30 or a prismatic battery cell 30, the second wall 312 is cylindrical in the case where the battery cell 30 is a cylindrical battery cell 30, and the second wall 312 of the case 31 may be sheet-shaped in the case where the battery cell 30 is a prismatic battery cell 30, and the case 31 may have one, two, or more second walls 312.

The side of the second wall 312 facing the receiving chamber 31a is provided with at least one protrusion 313, and then the side of one second wall 312 facing the receiving chamber 31a may be provided with one or more protrusions 313, and adjacent two protrusions 313 may be spaced apart from each other, or adjacent two protrusions 313 may be disposed adjacent to each other.

Alternatively, the protrusion 313 may have a regular or irregular shape, and, for example, a side of the protrusion 313 facing the electrode assembly 32 may have a flat plane, or the protrusion 313 may have an arc shape facing the electrode assembly 32.

The protrusion 313 is provided at a side of the second wall 312 facing the receiving chamber 31a, and the protrusion 313 and the second wall 312 may be integrally formed, or the protrusion 313 and the second wall 312 may be separately formed and the protrusion 313 may be connected to the side of the second wall 312 facing the receiving chamber 31a by welding or bonding.

Alternatively, the protrusion 313 may be elastic, or the protrusion 313 may be inelastic.

At least a portion of the surface of the electrode assembly 32 opposite to the protrusion 313 may be flat, and thus, since the electrode assembly 32 expands during the cyclic charge and discharge, the surface of the electrode assembly 32 opposite to the protrusion 313 may be flat only in one state during the cyclic charge and discharge of the electrode assembly 32, but may not be flat in other states.

Illustratively, in the wound electrode assembly, the electrode assembly 32 is formed through a cold pressing process after being wound, at this time, the surface of the electrode assembly 32 opposite to the protrusion 313 is flat, while the surface of the electrode assembly 32 opposite to the protrusion 313 is curved due to expansion during the formation process of the electrode assembly 32, and then at least a portion of the surface of the electrode assembly 32 opposite to the protrusion 313 is deformed to be flat by restoration during the discharge process or in a full discharge state of the electrode assembly 32.

The protrusions 313 are provided at the side of the second wall 312 facing the receiving chamber 31a, and then the distances between the electrode assemblies 32 corresponding to the different positions of the second wall 312 and the second wall 312 or between the electrode assemblies 32 and the protrusions 313 are different, and then the group margins of the battery cells 30 corresponding to the different positions of the second wall 312 are different. In this way, by reducing the gap between the protrusion 313 or the second wall 312 and the electrode assembly 32, during the expansion of the electrode assembly 32, the electrode assembly 32 gradually contacts and abuts against the protrusion 313, so that the protrusion 313 provides a certain binding force to the electrode assembly 32, which is beneficial to reducing the risk of wrinkling of the electrode assembly 32 during the expansion.

The side of the second wall 312 facing away from the accommodating cavity 31a is straight, and the second wall 312 can be flat, so that after the battery cell 30 forms the battery 10, the side of the second wall 312 facing away from the accommodating cavity 31a can be attached to the relevant heat exchange component, so as to ensure the heat exchange rate of the battery cell 30, timely and efficiently heat up or cool down the battery cell 30, and facilitate the normal operation of the battery cell 30.

The electrode assembly 32 may be a wound electrode assembly, or the electrode assembly 32 may be a laminated electrode assembly.

According to the battery cell 30 provided by the embodiment of the application, at least one protrusion 313 is arranged on one side of the second wall 312 facing the accommodating cavity 31a, and one side of the second wall 312 facing away from the accommodating cavity 31a is straight, so that a certain binding force can be provided for expansion of the electrode assembly 32 by using the protrusion 313 in the process of expansion of the electrode assembly 32, the risk of wrinkling of a pole piece of the electrode assembly 32 is reduced, and the contact area between the second wall 312 and related heat exchange components is favorably increased after the battery cell 30 is assembled into the battery 10 due to the straight side of the second wall 312 facing away from the accommodating cavity 31a, the risk of wrinkling of the pole piece of the electrode assembly 32 is favorably reduced, and further, the battery cell 30 is favorably ensured to have a higher heat exchange rate on the premise of reducing the risk of lithium precipitation of the electrode assembly 32, and the battery cell 30 is timely and efficiently heated or cooled, so that the reliability of the battery cell 30 is favorably improved.

As shown in fig. 5 and 6, in some embodiments, the electrode assembly 32 includes an electrode body 321 and a tab 322, the tab 322 being led out from an end of the electrode body 321 in the first direction X. The absolute value |h1-h2| of the minimum distance difference of the at least one protrusion 313 to both ends of the electrode body 321 in the first direction X satisfies: the h is more than or equal to 0 and less than or equal to |h1-h2| and less than or equal to 5mm.

Alternatively, the tab 322 may be drawn out from one or both ends of the electrode body 321 according to different structural patterns of the battery cell 30.

The minimum distance of the protrusion 313 to the end of the electrode body 321 in the first direction X may be the minimum distance of the edge of the protrusion 313 near the corresponding end of the electrode body 321 to the corresponding end.

Setting 0.ltoreq.h1-h2.ltoreq.5 mm, then alternatively, |h1-h2| may be 0, 0.5mm, 1mm, 1.5mm, 2mm, 2.5mm, 3mm, 3.5mm, 4mm, 4.5mm, 5mm or the like,

it will be appreciated that the electrode assembly 32 is first expanded during expansion, the maximum value of |h1-h2| is set to 5mm near the central region of the electrode assembly 32, i.e., at least one protrusion 313 is provided corresponding to the central region of the electrode body 321, so that a binding force can be provided to the expansion of the electrode assembly 32 by the at least one protrusion 313 during the initial expansion of the electrode assembly 32.

Accordingly, the inventors have found through systematic analysis and long-term practice that setting 0.ltoreq.h1-h2.ltoreq.5 mm is advantageous in achieving that the at least one protrusion 313 corresponds as much as possible to the central region of the electrode body 321, so that during the initial expansion of the electrode assembly 32, a binding force can be provided to the expansion of the electrode assembly 32 by the at least one protrusion 313, which is advantageous in further reducing the risk of wrinkling of the electrode sheet of the electrode assembly 32.

As shown in fig. 5, in some embodiments, the side of the second wall 312 facing the accommodation chamber 31a is provided with a plurality of protrusions 313.

Alternatively, the plurality of protrusions 313 may be spaced apart, or the plurality of protrusions 313 may abut each other such that different positions of the second wall 312 correspond to different group margins.

It will be appreciated that the side of the second wall 312 facing the accommodating cavity 31a is provided with a plurality of protrusions 313, and during the expansion of the electrode assembly 32, corresponding binding forces can be provided for the expansion of different portions of the electrode assembly 32 by different protrusions 313, so as to further reduce the risk of free expansion of the electrode assembly 32, and facilitate further reducing the risk of wrinkling of the electrode assembly 32 during the expansion.

With continued reference to fig. 5, in some embodiments, at least one protrusion 313 is curved toward a side of the electrode assembly 32.

The expansion force of the electrode assembly 32 is not uniformly distributed in the expansion process, and at least one protrusion 313 is arranged to be arc-shaped towards one side of the electrode assembly 32, so that the specific arc shape of the protrusion 313 can be arranged according to the expansion force distribution of the electrode assembly 32 in the expansion process, the electrode assembly 32 is gradually contacted with the arc-shaped surface of the protrusion 313 in the expansion process of the electrode assembly 32, the constraint force born by each part of the electrode assembly 32 in the expansion process is relatively uniform, and the risk of wrinkling of the electrode assembly 32 in the expansion process is further reduced.

In some embodiments, electrode assembly 32 abuts at least one protrusion 313.

In this way, the at least one protrusion 313 contacts and abuts against the electrode assembly 32, and when the electrode assembly 32 begins to expand, the protrusion 313 can provide a certain binding force for the electrode assembly 32, and in the whole process of expanding the electrode assembly 32, the protrusion 313 can provide a certain binding force for the electrode assembly 32, which is beneficial to further reducing the risk of wrinkling of the electrode assembly 32 during the expanding process.

In addition, the protrusion 313 is abutted against the electrode assembly 32, which is beneficial to reducing the interval between the protrusion 313 and the electrode assembly 32, thereby being beneficial to reducing the volume of the battery cell 30 and improving the energy density of the battery cell 30.

As shown in fig. 6, in some embodiments, the protrusion 313 includes an insulating buffer 313a, and the insulating buffer 313a is provided on a side of the second wall 312 facing the accommodating chamber 31 a.

The insulating buffer 313a is provided at a side of the second wall 312 facing the receiving chamber 31a, and the insulating buffer 313a may be adhesively coupled to the second wall 312, or the insulating buffer 313a may be only interposed between the electrode assembly 32 and the second wall 312.

The insulating buffer member 313a has an insulating property and can generate a certain deformation, and in the process of expanding the electrode assembly 32, the insulating buffer member 313a not only can provide a certain binding force for the expansion of the electrode assembly 32, but also can provide a certain buffer for the expansion deformation of the electrode assembly 32 by generating a certain deformation, so that the electrode assembly 32 is at risk of deformation due to overlarge binding force.

Therefore, the protrusion 313 includes the insulating buffer 313a, which not only can provide a certain binding force for the expansion of the electrode assembly 32, so as to reduce the risk of wrinkling of the electrode assembly 32 during the expansion process, but also can reduce the risk of deformation of the electrode assembly 32 due to excessive binding force during the expansion process, thereby being beneficial to further reducing the risk of lithium precipitation of the electrode assembly 32 and further improving the reliability of the battery cell 30.

As shown in fig. 5-6, in some embodiments, the battery cell 30 has at least two second walls 312, the at least two second walls 312 being disposed opposite.

During expansion of the electrode assembly 32, the electrode assembly 32 is generally expanded in two opposite directions, and by providing at least two second walls 312 opposite to each other, at least two opposite protrusions 313 provide opposite binding forces to the electrode assembly 32 during expansion of the electrode assembly 32, which is beneficial to relatively balancing stress of the electrode assembly 32 during expansion and reducing the risk of dislocation of the electrode assembly 32 during expansion.

Alternatively, in the case where the battery cell 30 has a square shape, the electrode assembly 32 may have two first surfaces 3211 opposite in the second direction YY and two second surfaces 3212 opposite in the third direction Z, where the second direction Y and the third direction Z intersect. Alternatively, the second wall 312 may be disposed on at least one side of the housing 31 in the second direction Y, or the second wall 312 may be disposed on at least one side of the housing 31 in the third direction Z, and of course, the second wall 312 may be disposed on at least one side of the housing 31 in the second direction Y and at least one side in the third direction Z.

As shown in fig. 5 and 6, in some embodiments, the electrode assembly 32 includes an electrode body 321 and a tab 322, the tab 322 being led out from an end of the electrode body 321 in the first direction X; the electrode body 321 has two first surfaces 3211 opposite along the second direction Y and two second surfaces 3212 opposite along the third direction Z, the first direction X, the second direction Y and the third direction Z intersect each other, the first surfaces 3211 connect the two second surfaces 3212, and an area of the first surfaces 3211 is larger than an area of the second surfaces 3212; the second wall 312 is located on at least one side of the housing 31 at least along the second direction Y.

The area of the first surface 3211 of the electrode assembly 32 is larger than the area of the second surface 3212, and if two first surfaces 3211 are disposed opposite to each other in the second direction Y, the areas of two opposite walls of the casing 31 in the second direction Y are larger, and the second wall 312 is disposed on at least one side of the casing 31 in the second direction Y, that is, the second wall 312 is disposed as a wall portion having a larger area of the casing 31.

Alternatively, the second wall 312 may be provided on either side of the housing 31 in the second direction Y, or the second wall 312 may be provided on both sides of the housing 31 in the second direction Y.

During expansion of the electrode assembly 32, because the area of the first surface 3211 is larger, the expansion of the electrode assembly 32 along the second direction Y is larger, and the second wall 312 is disposed on at least one side of the casing 31 along the second direction Y, so that during expansion of the electrode assembly 32 along the second direction Y, the second wall 312 can provide a certain binding force for expansion of the electrode assembly 32, so as to greatly reduce the risk of wrinkling of the electrode assembly 32 during expansion.

As shown in fig. 5-7, in some embodiments, two second walls 312 are disposed opposite along the second direction Y, and the other two second walls 312 are disposed opposite along the third direction Z.

Thus, around the electrode assembly 32, no matter in which direction the electrode assembly 32 is expanded, the corresponding protrusion 313 is pressed against the electrode assembly 32 to provide binding force for the electrode assembly 32 along each direction, which is beneficial to further reducing the risk of wrinkling of the electrode assembly 32 during the expansion process.

The battery 10 provided according to the embodiment of the present application includes the battery cell 30 provided in any of the above embodiments.

The battery 10 provided in the embodiment of the present application has the same technical effects due to the use of the battery cell 30 provided in any one of the embodiments, and will not be described herein.

In some embodiments, the battery 10 further includes a heat exchange member that conforms to at least a portion of the at least one second wall 312 to exchange heat with the battery cells 30 through the second wall 312.

The heat exchange member can exchange heat with the battery cell 30 to heat or cool the battery cell 30, for example, when the battery cell 30 works under cold conditions, the battery cell 30 can be heated by the heat exchange assembly, and when the battery cell 30 works, the battery cell 30 can be cooled by the heat exchange member along with the temperature rise of the battery cell 30, so as to prevent the further temperature rise of the battery cell 30, which is beneficial to ensuring the reliability of the battery cell 30.

Because the side of the second wall 312 facing away from the accommodating cavity 31a is straight, the area of the heat exchange member attached to the second wall 312 is increased, so as to improve the heat exchange efficiency of the heat exchange member and the second wall, and thus, the battery unit 30 is heated or radiated in time and efficiently, so that the battery unit 30 has a proper working temperature, and the reliability of the battery unit 30 is improved.

The power utilization device provided according to the embodiment of the present application includes the battery 10 provided in the above embodiment or the battery cell 30 provided in the above embodiment, and the battery 10 or the battery cell 30 is used for providing electric energy.

The power utilization device provided by the embodiment of the application has the same technical effects due to the adoption of the battery 10 or the battery cell 30 provided by the embodiment of the application, and is not repeated here.

As shown in fig. 4 to 7, the battery cell 30 provided according to the embodiment of the present application includes a case 31, electrode terminals 33, and an electrode assembly 32. The housing 31 has a housing cavity 31a, the housing 31 includes a first wall 311 and a second wall 312, the second wall 312 is connected to the first wall 311, at least one protrusion 313 is disposed on a side of the second wall 312 facing the housing cavity 31a, and a side of the second wall 312 facing away from the housing cavity 31a is flat. The electrode terminal 33 is disposed on the first wall 311, the electrode assembly 32 is accommodated in the accommodating cavity 31a, the electrode assembly 32 includes an electrode body 321 and a tab 322, and the tab 322 is led out from an end of the electrode body 321 along the first direction X. The absolute value |h1-h2| of the minimum distance difference of the at least one protrusion 313 to both ends of the electrode body 321 in the first direction X satisfies: the h is more than or equal to 0 and less than or equal to |h1-h2| and less than or equal to 5mm. The second wall 312 is provided at a side facing the receiving chamber 31a with a plurality of protrusions 313, at least one protrusion 313 is curved toward the electrode assembly 32, and the electrode assembly 32 abuts against the at least one protrusion 313. The protrusion 313 includes an insulating buffer 313a, and the insulating buffer 313a is provided on a side of the second wall 312 facing the accommodating chamber 31 a. The electrode body 321 has two first surfaces 3211 opposite along the second direction Y and two second surfaces 3212 opposite along the third direction Z, the first direction X, the second direction Y and the third direction Z intersect each other two by two, the first surfaces 3211 connect the two second surfaces 3212, and the area of the first surfaces 3211 is larger than the area of the second surfaces 3212. Two second walls 312 are disposed opposite to each other along the second direction Y, and the other two second walls 312 are disposed opposite to each other along the third direction Z.

While the application has been described with reference to a preferred embodiment, various modifications may be made and equivalents may be substituted for elements thereof without departing from the scope of the application, and in particular, the technical features set forth in the various embodiments may be combined in any manner so long as there is no structural conflict. The present application is not limited to the specific embodiments disclosed herein, but encompasses all technical solutions falling within the scope of the claims.

Claims

1. A battery cell, comprising:

the shell is provided with a containing cavity, the shell comprises a first wall and a second wall, the second wall is connected with the first wall, at least one protrusion is arranged on one side of the second wall facing the containing cavity, and one side of the second wall facing away from the containing cavity is flat;

an electrode terminal provided on the first wall;

and an electrode assembly accommodated in the accommodating chamber.

2. The battery cell of claim 1, wherein the electrode assembly comprises an electrode body and a tab, the tab being led out from an end of the electrode body in a first direction; the absolute value |h1-h2| of the minimum difference in distance of at least one of the protrusions to both ends of the electrode body in the first direction satisfies: the h is more than or equal to 0 and less than or equal to |h1-h2| and less than or equal to 5mm.

3. The battery cell of claim 1, wherein a side of the second wall facing the receiving cavity is provided with a plurality of the protrusions.

4. The battery cell of claim 1, wherein at least one of the protrusions is curved toward a side of the electrode assembly.

5. The battery cell of claim 1, wherein the electrode assembly abuts at least one of the protrusions.

6. The battery cell of claim 1, wherein the protrusion includes an insulating buffer disposed on a side of the second wall facing the receiving cavity.

7. The cell of claim 1, wherein the cell has at least two of the second walls, the at least two of the second walls being disposed opposite each other.

8. The battery cell according to any one of claims 1 to 7, wherein the electrode assembly includes an electrode body and a tab, the tab being led out from an end of the electrode body in a first direction; the electrode body is provided with two first surfaces opposite to each other along a second direction and two second surfaces opposite to each other along a third direction, the first direction, the second direction and the third direction are intersected in pairs, the first surfaces are connected with the two second surfaces, and the area of the first surfaces is larger than that of the second surfaces; the second wall is located on at least one side of the housing at least along the second direction.

9. The battery cell of claim 8, wherein two of the second walls are disposed opposite each other in the second direction and two of the second walls are disposed opposite each other in the third direction.

10. A battery comprising a battery cell according to any one of claims 1 to 9.

11. The battery of claim 10, further comprising a heat exchange member in engagement with at least a portion of at least one of the second walls to exchange heat with the battery cells through the second wall.

12. An electrical device comprising a battery cell according to any one of claims 1 to 9 or a battery according to claim 10 or 11, said battery cell or said battery being adapted to provide electrical energy.