CN117941126A

CN117941126A - Battery monomer, battery and electric equipment

Info

Publication number: CN117941126A
Application number: CN202280062035.0A
Authority: CN
Inventors: 范国凌; 杜鑫鑫; 任莹莹; 薛凯元
Original assignee: Contemporary Amperex Technology Co Ltd
Current assignee: Contemporary Amperex Technology Co Ltd
Priority date: 2022-07-27
Filing date: 2022-09-13
Publication date: 2024-04-26
Also published as: CN217562707U; WO2024021248A1

Abstract

The embodiment of the application discloses a battery monomer, a battery and electric equipment. The battery cell includes: a housing; an electrolyte; an electrode assembly, the electrode assembly and the electrolyte being accommodated in the case; and the buffer piece is accommodated in the shell and connected with the electrode assembly, a cavity is formed in the buffer piece, the cavity is isolated from electrolyte, and the buffer piece is used for buffering expansion of the electrode assembly. The technical scheme of the application can improve the performance of the battery.

Description

Battery monomer, battery and electric equipment

Cross Reference to Related Applications

The present application claims priority from chinese patent application 202221954778.2 entitled "battery cell, battery and powered device" filed on month 07, 2022, and the entire contents of which are incorporated herein by reference.

Technical Field

The application relates to the technical field of batteries, in particular to a battery monomer, a battery and electric equipment.

Background

Energy conservation and emission reduction are key to sustainable development of the automobile industry. In this case, the electric vehicle is an important component for sustainable development of the automobile industry due to the advantage of energy conservation and environmental protection. For electric vehicles, battery technology is an important factor for development.

The space utilization rate, the safety performance, the strength, the long-term charge and discharge performance and the like of the battery monomer are critical to the performance of the battery. Therefore, how to improve the performance of the battery is a problem to be solved.

Disclosure of Invention

The embodiment of the application provides a battery monomer, a battery and electric equipment, which can improve the performance of the battery.

In a first aspect, an embodiment of the present application provides a battery cell, including: a housing; an electrolyte; an electrode assembly, the electrode assembly and the electrolyte being accommodated in the case; and the buffer piece is accommodated in the shell and connected with the electrode assembly, a cavity is formed in the buffer piece, the cavity is isolated from the electrolyte, and the buffer piece is used for buffering expansion of the electrode assembly.

In an embodiment of the present application, a battery cell includes a case, an electrode assembly accommodated in the case, an electrolyte, and a buffer member. A buffer member is received in the case and coupled to the electrode assembly, the buffer member being for buffering expansion of the electrode assembly. Because the buffer piece sets up in the free inside of battery, when the inner space of battery is fixed time, can give the free inner space of battery with the space of buffer piece between the free battery of originally setting up in the battery to can improve the space utilization of battery. The inside of the buffer member is provided with a cavity, and the cavity is isolated from the electrolyte, so that the cavity in the buffer member can provide a deformation space for the electrode assembly, the weight energy density of the battery cell is improved, and the temperature difference between the cavity and the electrode assembly or the shell is reduced. Therefore, the technical scheme of the embodiment of the application can improve the performance of the battery.

In one possible implementation, the cavity communicates with the exterior of the housing. In this way, the cavity can exchange heat with the outside of the housing, which is advantageous in reducing the temperature difference between the cavity and the outside of the housing.

In one possible implementation, the cavity is for receiving a fluid to regulate the temperature of the battery cell. In this way, the temperature of the battery cell can be raised or lowered by the fluid in the cavity to reduce the temperature difference between the cavity and the outside of the case or the electrode assembly.

In one possible implementation, the buffer is configured to adjust the thickness by pressure variations of the fluid in the cavity. In the implementation manner, on one hand, the thickness of the cavity can be increased by increasing the pressure of the fluid, so that the gap between the electrode assembly and the shell is reduced or the electrode assembly can be contacted with the shell, the thermal resistance can be reduced, and the heat dissipation efficiency of the battery cell can be improved; on the other hand, the force applied on the electrode assembly by the buffer member can be adjusted by adjusting the thickness of the cavity, so that the stress on the two sides of the electrode assembly in the thickness direction of the buffer member is uniform, the uniform release of the expansion force of the electrode assembly can be realized, the polarization accumulation of the electrode assembly is reduced, and the cycle life and the safety performance of a battery cell are improved.

In one possible implementation, a resilient support structure is disposed within the cavity for cushioning expansion of the electrode assembly. In the use process of the battery cell, the elastic support structure is favorable for further improving the deformability of the buffer piece and providing more expansion space for the electrode assembly.

In one possible implementation, the elastic support structure is parallel to the thickness direction of the cushioning member. In this way, the installation of the elastic support structure is facilitated.

In one possible implementation, the elastic support structure comprises an elastic support column or an elastic support plate. Therefore, the elastic supporting structure is simple in structure and convenient to process.

In one possible implementation, the elastic support structure is a metallic elastic support structure or a polymeric elastic support structure. In this way, the flexible choice of the type of elastic support structure according to the actual needs is facilitated.

In one possible implementation, the case includes a case having an opening and for accommodating the electrode assembly, and an end cap for covering the opening; the surface of the buffer piece, which faces the end cover, is provided with an inlet and an outlet, and the cavity is communicated with the outside of the shell through the inlet and the outlet. In this way, the cavity of the buffer element is communicated with the outside of the shell through the arrangement of the inlet and the outlet of the buffer element.

In one possible implementation, the end cover is provided with a connection port corresponding to the inlet and outlet, and the inlet and outlet is communicated with the outside of the shell through the connection port. Therefore, the connecting ports corresponding to the inlet and the outlet are arranged on the end cover, and no additional pipeline is needed to be arranged for connecting the inlet and the outlet with the connecting ports.

In one possible implementation, the inlet and outlet include an inlet through which fluid enters the cavity and an outlet through which fluid exits the cavity. Thus, through the arrangement of the inlet and the outlet, the circulating flow of the fluid in the cavity is conveniently realized, and the heat exchange efficiency is improved.

In one possible implementation, the ratio of the size of the buffer member to the size of the battery cell is 1% to 20% in the thickness direction of the buffer member. Thus, the buffer function of the buffer piece and the space utilization rate of the battery cell are convenient to be considered.

In one possible implementation, the battery cell includes a plurality of the electrode assemblies, and the buffer member is disposed between adjacent ones of the electrode assemblies. Thus, the temperature of the electrode assembly is conveniently reduced or increased, and the temperature difference between the electrode assembly and the shell is facilitated.

In one possible implementation, the buffer is an aluminum buffer, an aluminum alloy buffer, or a polymer buffer. Thus, the type of the buffer piece is convenient to flexibly select according to actual requirements.

In one possible implementation, the side of the electrode assembly includes a planar portion, and the buffer member is connected to the planar portion. In this way, the connection between the buffer member and the electrode assembly is facilitated.

In one possible implementation, the planar portion is a surface of the electrode assembly having the largest area. Thus, the uniform release of the expansion force of the electrode assembly is facilitated, and the heat exchange efficiency between the fluid in the cavity and the electrode assembly is improved, so that the heat dissipation efficiency is improved.

In a second aspect, an embodiment of the present application provides a battery including: the battery cell according to any one of the first aspect and its implementation forms; and the box body is used for accommodating the battery cells.

In a third aspect, an embodiment of the present application provides an electric apparatus, including: the battery of the second aspect, the battery is configured to provide electrical energy to the powered device.

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 illustration of a vehicle according to an embodiment of the application;

FIG. 2 is a schematic diagram of a battery according to an embodiment of the application;

Fig. 3 is a schematic structural diagram of a battery cell according to an embodiment of the application;

FIG. 4 is a cross-sectional view of the battery cell of FIG. 3 taken along the direction A-A;

FIG. 5 is a schematic view illustrating a structure of a buffer according to an embodiment of the application;

FIG. 6 is a cross-sectional view of the bumper of FIG. 5 taken along the B-B direction;

FIG. 7 is a cross-sectional view of the bumper of FIG. 5 taken along the direction C-C;

Fig. 8 is a schematic structural view of an electrode assembly according to an embodiment of the present application.

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 indicate an orientation or positional relationship merely for convenience of description and to simplify the description, and do not indicate or imply that the devices or elements in question must have a particular orientation, be constructed and operate in a particular orientation, and therefore should not be construed as limiting the application. Furthermore, the terms "first," "second," "third," 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.

The directional terms appearing in the following description are those directions shown in the drawings and do not limit the specific structure of the application. 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 "and/or" in the present application is merely an association relation describing the association object, and indicates that three kinds of relations may exist, for example, a and/or B may indicate: a exists alone, A and B exist together, and B exists alone. In the present application, the character "/" generally indicates that the front and rear related objects are an or relationship.

In the embodiments of the present application, the same reference numerals denote the same components, and detailed descriptions of the same components are omitted in different embodiments for the sake of brevity. It should be understood that the thickness, length, width, etc. dimensions of the various components in the embodiments of the application shown in the drawings, as well as the overall thickness, length, width, etc. dimensions of the integrated device, are merely illustrative and should not be construed as limiting the application in any way.

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

In the present application, the battery cell may include a lithium ion secondary battery, a lithium ion primary battery, a lithium sulfur battery, a sodium lithium ion battery, a sodium ion battery, a magnesium ion battery, or the like, which is not limited in the embodiment of the present application. The battery cell may be a round body, a flat body, a rectangular parallelepiped, or other shape, etc., which is not limited by the embodiment of the present application. The battery cells are generally classified into three types according to the packaging method: the cylindrical battery cell, the square battery cell and the soft package battery cell are not limited in this embodiment.

Reference to a battery in accordance with an embodiment of the present application refers to a single physical module that includes one or more battery cells to provide higher voltage and capacity. For example, the battery referred to in the present application may include a battery module or a battery pack, or the like. The battery generally includes a case for enclosing one or more battery cells. The case body can prevent liquid or other foreign matters from affecting the charge or discharge of the battery cells.

To meet different power demands, a battery may include a plurality of battery cells, where the plurality of battery cells may be connected in series or parallel or a series-parallel connection, which refers to a mixture of series and parallel. Alternatively, a plurality of battery units may be connected in series or in parallel or in series to form a battery module, and then a plurality of battery modules may be connected in series or in parallel or in series to form a battery. That is, a plurality of battery cells may be directly assembled into a battery, or may be assembled into a battery module first, and the battery module may be assembled into a battery. The battery is further arranged in the electric equipment to provide electric energy for the electric equipment.

The development of battery technology is taking into consideration various design factors such as energy density, cycle life, discharge capacity, charge-discharge rate, safety, etc. The buffer member in the battery is generally disposed between the battery cells to buffer the battery cells, but such arrangement is complicated to assemble and is disadvantageous in improving the utilization of the internal space of the battery. The buffer piece is arranged in the battery monomer, so that the problems can be improved to a certain extent, but in the use process of the battery monomer, more heat is accumulated in the battery monomer, the conventional buffer piece has larger thermal resistance, the heat dissipation of the battery monomer is not facilitated, and a larger temperature difference exists between the inner part of the battery monomer and the outer surface of the battery monomer. On one hand, the temperature of the battery cell is increased due to the heat accumulated in the battery cell, so that the safety of the battery cell is not improved; on the other hand, the temperature difference between the inside of the battery cell and the outer surface of the battery cell is unfavorable for the selection of the charging strategy of the battery, and influences the charging and discharging performance. It follows that the internal arrangement of the battery cells is critical to the performance of the battery. Therefore, how to provide a battery cell to improve the performance of the battery is a urgent problem to be solved.

In view of this, an embodiment of the present application provides a battery cell including a case, an electrode assembly received in the case, an electrolyte, and a buffer member. A buffer member is received in the case and coupled to the electrode assembly, the buffer member being for buffering expansion of the electrode assembly. Because the buffer piece sets up in the free inside of battery, when the inner space of battery is fixed time, can give the free inner space of battery with the space of buffer piece between the free battery of originally setting up in the battery to can improve the space utilization of battery. The inside of the buffer member is provided with a cavity, and the cavity is isolated from the electrolyte, so that the cavity in the buffer member can provide a deformation space for the electrode assembly, thereby being beneficial to improving the weight energy density of the battery cell and reducing the temperature difference between the cavity and the electrode assembly or the shell. Therefore, the technical scheme of the embodiment of the application can improve the performance of the battery.

The technical solutions described in the embodiments of the present application are applicable to various devices using batteries, for example, mobile phones, portable devices, notebook computers, battery cars, electric toys, electric tools, electric vehicles, ships, spacecraft, and the like, and for example, spacecraft include airplanes, rockets, space shuttles, spacecraft, and the like.

It should be understood that the technical solutions described in the embodiments of the present application are not limited to the above-described devices, but may be applied to all devices using batteries, but for simplicity of description, the following embodiments are described by taking an electric vehicle as an example.

For example, as shown in fig. 1, a schematic structural diagram of a vehicle 1 according to an embodiment of the present application is shown, where the vehicle 1 may be a fuel-oil vehicle, a gas-fired 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. The vehicle 1 may be provided with a motor 40, a controller 30 and a battery 10, the controller 30 being arranged to control the battery 10 to supply power to the motor 40. For example, 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, e.g. the battery 10 may be used as an operating power source for the vehicle 1, for electrical circuitry of the vehicle 1, e.g. for start-up, navigation and operational power requirements of the vehicle 1. In another embodiment of the present application, the battery 10 may be used not only 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 supply driving power to the vehicle 1.

To meet different power usage requirements, the battery 10 may include a plurality of battery cells. For example, as shown in fig. 2, a battery 10 according to an embodiment of the present application may include a plurality of battery cells 20. The battery 10 may further include a case 11, in which the case 11 has a hollow structure, and the plurality of battery cells 20 are accommodated in the case 11. For example, a plurality of battery cells 20 are connected in parallel or in series-parallel combination with each other and then placed in the case 11.

Alternatively, the battery 10 may further include other structures, which are not described in detail herein. For example, the battery 10 may further include a bus member for making electrical connection between the plurality of battery cells 20, such as parallel or series-parallel connection. Specifically, the bus member may realize electrical connection between the battery cells 20 by connecting electrode terminals of the battery cells 20. Further, the bus member may be fixed to the electrode terminals of the battery cells 20 by welding. The electrical energy of the plurality of battery cells 20 may be further drawn through the housing by a conductive mechanism. Alternatively, the conductive means may also belong to the bus bar member.

The number of battery cells 20 may be set to any number according to different power requirements. The plurality of battery cells 20 may be connected in series, parallel, or series-parallel to achieve a larger capacity or power. Since the number of battery cells 20 included in each battery 10 may be large, the battery cells 20 may be arranged in groups for easy installation, and each group of battery cells 20 constitutes a battery module. The number of battery cells 20 included in the battery module is not limited, and may be set according to requirements. The battery may include a plurality of battery modules, which may be connected in series, parallel, or series-parallel.

Fig. 3 is a schematic structural view of a battery cell according to an embodiment of the present application, and fig. 4 is a sectional view of the battery cell in fig. 3 along A-A direction. As shown in conjunction with fig. 3 and 4, in one embodiment of the present application, the battery cell 20 includes a case 21, an electrolyte, an electrode assembly 22, and a buffer member 25.

In the battery cell 20, a case 21 serves to accommodate an electrolyte, an electrode assembly 22, and a buffer 25. The case 21 is dependent on the shape of the one or more electrode assemblies 22 combined, and for example, the case 21 may be a hollow rectangular parallelepiped or square or cylindrical body.

The electrode assembly 22 may be composed of a positive electrode sheet, a negative electrode sheet, and a separator. The battery cell 20 operates primarily by means of metal ions moving between the positive and negative electrode tabs. The separator is used for separating the positive plate from the negative plate, and the separator can be made of polypropylene or polyethylene and the like.

The positive plate comprises a positive electrode current collector and a positive electrode active material layer, wherein the positive electrode active material layer is coated on the surface of the positive electrode current collector, the current collector without the positive electrode active material layer protrudes out of the current collector coated with the positive electrode active material layer, and the current collector without the positive electrode active material layer is used as a positive electrode lug. Taking a lithium ion battery as an example, the material of the positive electrode current collector may be aluminum, and the positive electrode active material may be lithium cobaltate, lithium iron phosphate, ternary lithium, lithium manganate or the like.

The negative electrode sheet comprises a negative electrode current collector and a negative electrode active material layer, wherein the negative electrode active material layer is coated on the surface of the negative electrode current collector, the current collector without the negative electrode active material layer protrudes out of the current collector with the coated negative electrode active material layer, and the current collector without the negative electrode active material layer is used as a negative electrode tab. The material of the negative electrode current collector may be copper, and the negative electrode active material may be carbon, silicon, or the like. In order to ensure that the high current is passed without fusing, the number of positive electrode lugs is multiple and stacked together, and the number of negative electrode lugs is multiple and stacked together.

The electrode assembly 22 may be a roll-to-roll structure or a laminate structure, and embodiments of the present application are not particularly limited thereto.

In the battery cell 20, the electrode assemblies 22 may be provided in a single unit, or in a plurality, according to actual use requirements, as shown in fig. 3, 2 individual electrode assemblies 22 are provided in the battery cell 20.

The electrolyte is provided inside the case 21, and serves to transfer ions between the positive electrode sheet and the negative electrode sheet. The electrolyte may be liquid, gel or all solid, and the kind of the electrolyte is not particularly limited in the present application and may be selected according to the need.

The buffer member 25 is accommodated in the case 21 and is connected to the electrode assembly 22. The buffer member 25 may be directly connected to the electrode assembly 22 or may be indirectly connected to the electrode assembly 22. Since the buffer member 25 is disposed inside the battery cells 20, when the internal space of the battery 10 is fixed, the space of the buffer member 25 between the battery cells 20 originally disposed in the battery 10 can be yielded to the internal space of the battery cells 20, thereby improving the space utilization of the battery 10.

The buffer 25 is provided inside with a cavity 251, and the cavity 251 is isolated from the electrolyte. The cavity 251 in the buffer member 25 is elastically deformed when subjected to an external force, for example, the cavity 251 is compressed when subjected to a pressure. In one aspect, cavity 251 within buffer 25 may provide space for expansion of electrode assembly 22; on the other hand, the provision of the cavity 251 is advantageous in reducing the weight of the buffer member 25, thereby being advantageous in improving the gravimetric energy density of the battery cell 20; in still another aspect, the provision of the cavity 251 is advantageous in reducing the thermal resistance of the buffer member 25, thereby advantageously reducing the temperature difference between the cavity 251 and the electrode assembly 22 or the case 21.

The buffer 25 serves to buffer expansion of the electrode assembly 22. The electrode assembly 22 applies pressure to the cushion 25 when inflated, and the cushion 25 applies an opposite pressure to the electrode assembly 22 after compressed. The surface of the electrode assembly 22 in contact with or connected to the buffer member 25 may be subjected to a force in a proper range as a whole due to the buffer member 25, which is advantageous in achieving uniform release of the expansion force of the electrode assembly 22.

The shape of the buffer member 25 may be a rectangular parallelepiped shape or a shape adapted to the electrode assembly 22, to which the embodiment of the present application is not particularly limited.

The embodiment of the present application provides a battery cell 20, and the battery cell 20 includes a case 21, an electrode assembly 22 accommodated in the case 21, an electrolyte, and a buffer member 25. A buffer member 25 is accommodated in the case 21 and coupled to the electrode assembly 22, and the buffer member 25 serves to buffer expansion of the electrode assembly 22. Since the buffer member 25 is disposed inside the battery cells 20, when the internal space of the battery 10 is fixed, the space of the buffer member 25 between the battery cells 20 originally disposed in the battery 10 can be yielded to the internal space of the battery cells 20, thereby improving the space utilization of the battery 10. The buffer member 25 is provided at the inside thereof with a cavity 251, the cavity 251 being isolated from the electrolyte, so that the cavity 251 in the buffer member 25 can provide a space for the electrode assembly 22 to deform, increase the gravimetric energy density of the battery cell 20, and reduce the temperature difference between the cavity 251 and the electrode assembly 22 or the case 21. Therefore, the technical scheme of the embodiment of the application can improve the performance of the battery 10.

In one embodiment of the present application, the cavity 251 communicates with the outside of the housing 21.

The outside of the case 21 may also refer to the outside of the battery cell 20, that is, the cavity 251 communicates with the external environment outside the case 21.

In this embodiment, the cavity 251 may exchange heat with the external environment, for example, when the temperature of the cavity 251 is high, the cavity 251 may radiate heat to the external environment to lower the temperature of the cavity 251, so that the temperature difference between the cavity 251 and the electrode assembly 22 and the case 21 may be further reduced.

The temperature difference affects the charge and discharge performance of the battery. For example, the temperature difference results in the presence of a low temperature region for which the dynamics are poor and a high temperature region (relative to the low temperature region) for which a smaller charge current is required, which affects the charge speed of the battery.

In one embodiment of the present application, cavity 251 is used to contain a fluid to regulate the temperature of cell 20.

Alternatively, the fluid may be circulated to achieve better temperature regulation. Alternatively, the fluid may be a gas or a liquid, such as water, a mixture of water and ethanol, a refrigerant, or air, or the like.

In this embodiment, the fluid in the cavity 251 may further cool or warm the cavity 251 and the area around the cavity 251 inside the battery cell 20, so as to adjust the temperature of the cavity 251 and the area around the cavity. In this way, the temperature difference between the case 21 and the electrode assembly 22 and the cavity 251 can be reduced during the cooling or heating of the battery cell 20 using the thermal management member.

In one embodiment of the application, the buffer 25 is configured to adjust the thickness by pressure changes of the fluid in the cavity 251.

The thickness of the buffer 25 may refer to the size of the buffer 25 in the thickness direction of the buffer 25, for example, the x-direction.

In this embodiment, the thickness of the buffer 25 may be adjusted by pressurizing the fluid. For example, in the case where the fluid pressure increases, the dimension of the buffer member 25 in the thickness direction becomes large, so that the space occupied by the buffer member 25 becomes large, the gap between the electrode assembly 22 and the case 21 becomes small, and even the electrode assembly 22 contacts the case 21. Thus, it is advantageous to reduce the thermal resistance between the electrode assembly 22 and the case 21, improve the heat dissipation efficiency, and effectively reduce the temperature of the electrode assembly 22.

In this embodiment, the thickness of the buffer 25 may also be adjusted by depressurizing the fluid. As the battery cell 20 is used, the size of the electrode assembly 22 becomes larger relative to the earlier use period of the battery cell 20, and the gap between the electrode assembly 22 and the case 21 becomes smaller. At this time, the size of the buffer member 25 may be changed by adjusting the pressure of the fluid, for example, by decreasing the pressure of the fluid to change the state in which the electrode assembly 22 and the case 21 are pressed against each other to the state in which the electrode assembly 22 is just in contact with the case 21.

In this embodiment, the adjustment of the thickness of cushioning member 25 may be accomplished by a change in the pressure of the fluid within cavity 251. On the one hand, by adjusting the thickness of the buffer member 25, it is advantageous to reduce the thermal resistance between the electrode assembly 22 and the case 21, and to improve the heat dissipation efficiency. On the other hand, the stress of the first surface and the second surface of the electrode assembly 22, which may be the surfaces of the electrode assembly 22 in contact with the buffer member 25, may be made uniform and constant, i.e., the stress of the first surface and the second surface of the electrode assembly 22 in contact with the case 21; thus, the accumulation of polarization of the electrode assembly 22 caused by suspending one of the first surface and the second surface can be avoided, the occurrence of phenomena such as lithium precipitation and the like caused by the accumulation of polarization can be avoided, and the safety performance, long-term charge and discharge performance, capacity and the like of the battery can be ensured. Wherein, the suspending of the first surface may mean that the first surface is not contacted with the buffer member 25, and the second surface is contacted with the housing 21; the suspension of the second surface may mean that the second surface is not in contact with the housing 21 and the first surface is in contact with the buffer 25.

Fig. 5 is a schematic structural view of a buffer member according to an embodiment of the present application, fig. 6 is a cross-sectional view of the buffer member in the direction B-B of fig. 5, and fig. 7 is a cross-sectional view of the buffer member in the direction C-C of fig. 5. In one embodiment, as shown in connection with fig. 5-7, a flexible support structure 252 is disposed within cavity 251, with flexible support structure 252 being used to cushion expansion of electrode assembly 22. The provision of the elastic support structure 252 is advantageous for further improving the deformability of the buffer member 25 during use of the battery cell 20, and for providing more expansion space to the electrode assembly 22.

In one embodiment, the resilient support structure 252 is parallel to the thickness direction of the bumper 25.

The elastic support structure 252 is parallel to the thickness direction of the cushion 25, which can be said to be the elastic support structure 252 extends in the thickness direction of the cushion 25. In this way, installation of the resilient support structure 252 is facilitated.

Optionally, a plurality of resilient support structures 252 are disposed within cavity 251. The plurality of elastic support structures 252 may be spaced apart in the height direction of the battery cell 20, for example, in the z-direction in the drawing.

Optionally, a plurality of resilient support structures 252 are disposed parallel to one another. Alternatively, a plurality of resilient support structures 252 may be connected to one another at an angle. The arrangement of the elastic support structure 252 may be specifically set according to actual needs, which is not specifically limited by the present application.

In one embodiment, elastomeric support structure 252 includes elastomeric support columns or elastomeric support plates. Thus, the flexible support structure 252 is simple in structure and convenient to machine.

In one embodiment, the resilient support structure 252 is a metallic resilient support structure or a polymeric resilient support structure. In this way, the flexible choice of the type of elastic support structure according to the actual needs is facilitated.

The material of the polymeric elastic support structure is a polymer, which may also be referred to as a high molecular weight compound, such as polypropylene. In the embodiment of the present application, the elastic supporting structure 252 may also be made of other polymer compounds that can be elastically deformed, which is not limited herein.

Alternatively, the elastic support structure 252 may be made of other elastic materials, so long as elastic deformation of the elastic support structure 252 is achieved.

In one embodiment, the case 21 includes a case 211 having an opening and for accommodating the electrode assembly 22, and an end cap 212 for covering the opening; wherein the surface of the buffer member 25 facing the end cap 212 is provided with an inlet/outlet 253, and the cavity 251 communicates with the outside of the housing 21 through the inlet/outlet 253.

One of the faces of the case 211 has an opening so that one or more electrode assemblies 22 may be placed inside the case 211. For example, when the housing 211 is a hollow rectangular parallelepiped or square, one of the planes of the housing 211 is an opening surface, i.e., the plane has no wall body so that the inside and outside of the housing 211 communicate. When the housing 211 may be a hollow cylinder, the end surface of the housing 211 is an open surface, i.e., the end surface has no wall body so that the inside and outside of the housing 211 communicate. End cap 212 covers the opening and is connected to housing 211 to form a closed cavity in which electrode assembly 22 is placed.

Alternatively, both sides of the housing 211 have openings. For example, the housing 211 has two openings disposed opposite to each other, and two end caps are respectively used to cover the two openings.

The end cap 212 may be provided with electrode terminals 214, the electrode terminals 214 being a positive electrode terminal 214a and a negative electrode terminal 214b, respectively. The end cap 212 is generally in the shape of a flat plate, and two electrode terminals 214 are fixed to the flat plate surface of the end cap 212. Each electrode terminal 214 may be provided with a connection member, one for each, between the end cap 212 and the electrode assembly 22 for electrically connecting the electrode assembly 22 and the electrode terminal 214.

In this embodiment, the surface of the buffer member 25 facing the end cap 212 is provided with an inlet/outlet 253, and the cavity 251 communicates with the outside of the housing 21 through the inlet/outlet 253. In this way, the communication between the cavity 251 of the damper 25 and the outside of the housing 21 is achieved by the provision of the inlet/outlet 253 of the damper 25.

In one embodiment, the end cap 212 is provided with a connection port 2121 corresponding to the inlet port 253, and the inlet port 253 communicates with the outside of the housing 21 through the connection port 2121. Thus, by providing the connection port 2121 corresponding to the inlet/outlet 253 on the end cap 212, no additional pipe is required to connect the inlet/outlet 253 and the connection port 2121, and the battery cell 20 is simple in structure and convenient to manufacture and assemble.

In one embodiment, the inlet/outlet 253 includes an inlet 2531 and an outlet 2532, and fluid enters the cavity 251 of the bumper 25 through the inlet 2531 and exits the cavity 251 of the bumper 25 through the outlet 2532. Thus, by providing inlet 2531 and outlet 2532, a circulating flow of fluid within cavity 251 is facilitated, which is beneficial to improving efficiency of heat exchange.

Alternatively, the shape and size of the inlet 2531 and the outlet 2532 may be specifically set according to actual requirements, which is not specifically limited by the embodiment of the present application.

In one embodiment, the ratio of the size of the buffer member 25 to the size of the battery cell 20 is 1% to 20% in the thickness direction of the buffer member 25.

The size of the buffer 25 may be L1 and the size of the battery cell 20 may be L2 in the thickness direction of the buffer 25. When the ratio of L1 to L2 is less than 1%, the thickness of the buffer member 25 is too small, and it is difficult to achieve the buffering action of the buffer member 25; when the ratio of L1 to L2 is greater than 20%, the thickness of the buffer member 25 is excessively large, occupying more space, which is disadvantageous for the improvement of the space utilization rate of the battery cell 20 and the increase of the volumetric energy density.

In this embodiment, the ratio of the size of the buffer member 25 to the size of the battery cell 20 is 1% to 20% in the thickness direction of the buffer member 25, so that both the buffer effect of the buffer member 25 and the space utilization of the battery cell 20 are facilitated.

Alternatively, the ratio of the dimension L1 of the buffer member 25 to the dimension L2 of the battery cell 20 is 5% to 10%.

Alternatively, the ratio of L1 to L2 may be specifically set according to the actual situation.

In one embodiment, the battery cell 20 includes a plurality of electrode assemblies 22, and the buffer member 25 is disposed between adjacent electrode assemblies 22. In this way, it is convenient to cool or warm the electrode assembly 22, which is advantageous in reducing the temperature difference between the electrode assembly 22 and the case 21.

Optionally, a buffer member 25 is further provided between the electrode assembly 22 and the case 21, which is advantageous in further reducing the temperature difference between the electrode assembly 22 and the case 21 and improving the rate of temperature increase or decrease to the battery cell 20.

In one embodiment, the bumper 25 is an aluminum bumper, an aluminum alloy bumper, or a polymer bumper. This facilitates flexible choice of the type of cushioning member 25 according to actual needs.

The buffer 25 is a polymer buffer, and may refer to that the material of the buffer 25 is a polymer (or a high molecular compound), such as polypropylene, polyethylene, and the like. The specific type of polymer in the embodiment of the present application is not particularly limited as long as the cushioning effect of the cushioning member 25 and the effect of isolating the electrolyte can be achieved.

Optionally, the buffer member 25 is an aluminum buffer member, so that the buffer member 25 may have a better heat conducting property. Alternatively, the buffer member 25 may be made of other materials that are excellent in heat conductive properties and do not absorb the electrolyte.

Fig. 8 is a schematic structural view of an electrode assembly according to an embodiment of the present application. In one embodiment, as shown in fig. 8, the side of the electrode assembly 22 includes a planar portion 27, and the buffer member 25 is connected to the planar portion 27.

The electrode assembly 22 includes side surfaces and end surfaces. For example, the electrode assembly 22 includes two end surfaces disposed opposite and parallel to the end cap 212, and the side surfaces of the electrode assembly 22 are connected to the two end surfaces, respectively.

Fig. 8 shows a schematic cross-sectional view of an electrode assembly 22. The electrode assembly 22 may include a planar portion 27 and a curved portion 28. The planar portion 27 and the curved portion 28 may be interconnected to form the electrode assembly 22. The electrode assembly 22 may be a rolled configuration.

Alternatively, the electrode assembly 22 may not include a curved portion, but only a planar portion, which is not particularly limited by the embodiment of the present application.

In this embodiment, the flat portion 27 is connected to the electrode assembly 22, thereby facilitating the connection between the buffer member 25 and the electrode assembly 22.

In one embodiment, planar portion 27 is the surface of electrode assembly 22 that has the greatest area. In this way, it is advantageous to achieve uniform release of the expansion force of the electrode assembly 22, and at the same time, to increase the heat exchange area between the electrode assembly 22 and the buffer 25, and it is possible to improve the heat exchange efficiency between the fluid in the cavity 251 and the electrode assembly 22, for example, it is possible to improve the heat dissipation efficiency inside the battery cell 20.

The embodiment of the present application provides a battery cell 20, which battery cell 20 includes a case 21, an electrode assembly 22 accommodated in the case 21, an electrolyte, and a buffer member 25. The buffer member 25 is received in the case 21 and connected to the electrode assembly 22, the buffer member 25 serves to buffer expansion of the electrode assembly 22, the buffer member 25 is internally provided with a cavity 251, the cavity 251 is isolated from an electrolyte and communicates with the outside of the case 21, and the cavity 251 serves to receive a fluid to regulate the temperature of the battery cell 20. The cavity 251 in the buffer member 25 may provide a space for the electrode assembly 22 to deform, increase the weight energy density of the battery cell 20, and reduce the temperature difference between the cavity 251 and the electrode assembly 22 or the case 21. Therefore, the technical scheme of the embodiment of the application can improve the performance of the battery 10.

It should be understood that, in the embodiments of the present application, relevant portions may be referred to each other, and will not be described in detail for brevity.

An embodiment of the present application provides a battery 10 including: the battery cell 20 of any of the above embodiments; and a case 11, the case 11 accommodating the battery cells 20.

The embodiment of the application provides electric equipment, which comprises the following components: the battery 10 in the embodiment of the application, the battery 10 is used for providing electric energy for the electric equipment.

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. In particular, the technical features mentioned in the respective embodiments may be combined in any manner as 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

A battery cell (20), characterized by comprising:

a housing (21);

an electrolyte;

An electrode assembly (22), the electrode assembly (22) and the electrolyte being housed in the case (21);

And a buffer member (25), the buffer member (25) being accommodated in the housing (21) and connected with the electrode assembly (22), a cavity (251) being provided inside the buffer member (25), the cavity (251) being isolated from the electrolyte, the buffer member (25) being configured to buffer expansion of the electrode assembly (22).
The battery cell (20) of claim 1, wherein the cavity (251) communicates with an exterior of the housing (21).
The battery cell (20) of claim 1, wherein the cavity (251) is configured to contain a fluid to regulate a temperature of the battery cell (20).
The battery cell (20) of claim 3, wherein the buffer (25) is configured to adjust thickness by pressure variation of the fluid in the cavity (251).
The battery cell (20) of claim 1, wherein a resilient support structure (252) is disposed within the cavity (251), the resilient support structure (252) being configured to cushion expansion of the electrode assembly (22).
The battery cell (20) of claim 5, wherein the resilient support structure (252) is parallel to a thickness direction of the buffer (25).
The battery cell (20) of claim 5, wherein the resilient support structure (252) comprises an elastomeric support column or a resilient support plate.
The battery cell (20) of claim 5, wherein the elastic support structure (252) is a metallic elastic support structure or a polymeric elastic support structure.
The battery cell (20) of any one of claims 1 to 8, wherein the housing (21) comprises a case (211) and an end cap (212), the case (211) having an opening and being for receiving the electrode assembly (22), the end cap (212) being for covering the opening;

Wherein, the surface of the buffer member (25) facing the end cover (212) is provided with an inlet and an outlet (253), and the cavity (251) is communicated with the outside of the shell (21) through the inlet and the outlet (253).
The battery cell (20) according to claim 9, wherein the end cap (212) is provided with a connection port (2121) corresponding to the inlet/outlet port (253), and the inlet/outlet port (253) communicates with the outside of the housing (21) through the connection port (2121).
The battery cell (20) of claim 9, wherein the inlet (253) includes an inlet (2531) and an outlet (2532), fluid entering the cavity (251) through the inlet (2531) and exiting the cavity (251) through the outlet (2532).
The battery cell (20) according to any one of claims 1 to 8, wherein a ratio of a size of the buffer member (25) to a size of the battery cell (20) is 1% to 20% in a thickness direction of the buffer member (25).
The battery cell (20) of any one of claims 1 to 8, wherein the battery cell (20) comprises a plurality of the electrode assemblies (22), the buffer member (25) being disposed between adjacent ones of the electrode assemblies (22).
The battery cell (20) of any of claims 1 to 8, wherein the buffer (25) is an aluminum buffer, an aluminum alloy buffer, or a polymer buffer.
The battery cell (20) of any one of claims 1 to 8, wherein a side of the electrode assembly (22) includes a planar portion (27), the buffer (25) being connected with the planar portion (27).
The battery cell (20) of claim 15, wherein the planar portion (27) is a surface of the electrode assembly (22) that has a largest area.
A battery (10), characterized by comprising:

The battery cell (20) according to any one of claims 1 to 16;

-a casing (11), said casing (11) being adapted to house said battery cells (20).
A powered device, comprising: the battery (10) according to claim 17, the battery (10) being adapted to provide electrical energy to the powered device.