End cap assembly, battery cell and manufacturing method thereof, battery and electrical device

Abstract

The embodiments of the present application relate to the field of batteries, and in particular to an end cap assembly, a battery cell and a method for manufacturing the same, a battery and an electrical device. The end cap assembly includes an end cap for sealing the shell of the battery cell, and an explosion-proof mechanism is provided on the end cap; an adapter, the orthographic projection of the adapter on the first surface of the end cap at least partially overlaps with the orthographic projection of the explosion-proof mechanism on the first surface of the end cap, and the first surface is the surface of the end cap facing the shell; a support is provided between the adapter and the end cap, and the support is made of a high-temperature resistant insulating material, and the support can support the adapter to prevent the adapter from blocking the explosion-proof mechanism when the battery cell is in thermal runaway. The present application adds a support to prevent the adapter from directly abutting against the explosion-proof mechanism and blocking the explosion-proof mechanism when the battery cell is in thermal runaway, thereby ensuring the normal actuation of the explosion-proof mechanism, thereby preventing the battery cell from burning or even exploding when it is in thermal runaway, and ensuring the safety of the battery cell when in use.

Description

Technical Field

[0001] The embodiments of the present application relate to the field of batteries, and in particular to an end cover assembly, a battery cell and a manufacturing method thereof, a battery and an electrical device. Background Art

[0002] With the development of science and technology, batteries have been widely used in portable electronic devices such as mobile phones, digital cameras and laptops, and have broad application prospects in electric vehicles such as electric cars and electric bicycles, and large and medium-sized electric equipment such as energy storage facilities, becoming an important technical means to solve global problems such as energy crisis and environmental pollution.

[0003] The safety of battery use is an important factor in measuring battery performance. In the prior art, the battery cells used to form the battery generally include a shell with openings at both ends, an end cap for closing the openings on the shell, an electrode terminal located on the end cap, and an adapter located on the side of the end cap close to the shell. The adapter is used to electrically connect the electrode terminal and the electrode assembly. In order to improve the safety of battery cells, an explosion-proof mechanism is generally provided on the end cap. The explosion-proof mechanism can discharge the high-temperature and high-pressure emissions generated inside the battery cell when thermal runaway occurs in the battery cell, reduce the pressure inside the battery cell, and prevent the battery cell from exploding in the case of thermal runaway.

[0004] However, the inventors have discovered that in the event of thermal runaway of a battery cell, the explosion-proof mechanism is sometimes difficult to open normally, and the end cover and the shell separate under the high pressure inside the battery cell, which in severe cases may cause explosion risks. Summary of the invention

[0005] In view of the above problems, the present application provides an end cover assembly, a battery cell and a manufacturing method thereof, a battery and an electrical device, which can reduce the possibility of the adapter plate blocking the explosion-proof mechanism, ensure the normal operation of the explosion-proof mechanism of the battery cell in the case of thermal runaway, and improve the safety of the battery cell.

[0006] The first aspect of the present application provides an end cap assembly for a battery cell, comprising:

[0007] An end cover, used to close the shell of the battery cell, the end cover is provided with an explosion-proof mechanism, and the explosion-proof mechanism can be actuated to release the internal pressure of the battery cell when the battery cell has a thermal runaway;

[0008] An adapter is used to electrically connect the electrode assembly of the battery cell and the electrode terminal of the battery cell, wherein the orthographic projection of the adapter on the first surface of the end cover at least partially overlaps with the orthographic projection of the explosion-proof mechanism on the first surface of the end cover, and the first surface is the surface of the end cover facing the shell.

[0009] Wherein, a support member is provided between the adapter and the end cover, and the support member is made of high temperature resistant material. The orthographic projection of the adapter on the first surface at least partially overlaps with the orthographic projection of the support member on the first surface, so that when the battery cell thermally runs away, the support member can support the adapter to prevent the adapter from blocking the explosion-proof mechanism.

[0010] By adopting the above scheme, the support member made of high temperature resistant material is not easy to melt and deform when the battery cell has thermal runaway. Therefore, when the adapter is deformed under thermal runaway conditions, the adapter is blocked by the support member and will not press against the explosion-proof mechanism to block the explosion-proof mechanism. Therefore, when thermal runaway occurs, the high temperature and high pressure emissions in the battery cell can activate the explosion-proof mechanism and be discharged through the explosion-proof mechanism, thereby reducing the possibility of combustion or even explosion of the battery cell and improving the safety of the battery cell when in use.

[0011] In some embodiments, the melting point of the support member is greater than 300°C.

[0012] By adopting the above solution, when the battery cell is in thermal runaway, the maximum temperature of the internal emissions is within 300°C. At this time, the support member will not be deformed due to melting, so that the adapter can be stably supported in thermal runaway to ensure normal exhaust of the explosion-proof mechanism.

[0013] In some embodiments, the support member is made of insulating material.

[0014] By adopting the above solution, the support member will not cause a short circuit problem during use.

[0015] In some embodiments, the support member includes a support block, and the support block is disposed between the adapter and the end cover.

[0016] In some embodiments, an orthographic projection of the support block on the first surface is offset from an orthographic projection of the explosion-proof mechanism on the first surface.

[0017] In some embodiments, an isolation component is provided between the adapter and the end cover, the isolation component is used to insulate the adapter from the end cover, and the support block is fixed on the isolation component.

[0018] By adopting the above solution, the isolation component can not only achieve insulation between the adapter and the end cover, but also fix the position of the support block to prevent the support block from shifting and failing to provide good support for the adapter.

[0019] In some embodiments, a receiving groove is provided on the isolation component, and the support block is disposed in the receiving groove.

[0020] In some embodiments, one side of the receiving groove is provided with an opening for receiving the supporting block.

[0021] In some embodiments, the opening faces the end cover, one end of the support block abuts against the bottom wall of the accommodating groove, and the other end abuts against the end cover;

[0022] Alternatively, the opening faces the adapter, and one end of the support block abuts against the bottom wall of the accommodating groove, and the other end abuts against the adapter.

[0023] By adopting the above scheme, the side wall of the accommodating groove limits the position of the support block in the direction perpendicular to the first surface, so that the support block can always be located at the position corresponding to the adapter; and the arrangement in which the two ends of the support block are respectively pressed against the bottom wall and the end cover or the adapter of the accommodating groove can prevent the support block from falling from the opening of the accommodating groove, thereby making it difficult to support the adapter during thermal runaway.

[0024] In some embodiments, the isolation component is made of a high temperature resistant insulating material.

[0025] By adopting the above scheme, the isolation component is not easy to melt during thermal runaway, and it not only plays an insulating role, but also plays a role in supporting the adapter, thereby preventing the adapter from blocking the explosion-proof mechanism.

[0026] In some embodiments, the support block and the isolation component are made of the same material and are integrally formed.

[0027] By adopting the above solution, the support block and the isolation component are processed and formed together, which greatly improves the processing efficiency of the end cover assembly and saves the manufacturing cost of the end cover assembly.

[0028] In some embodiments, the adapter includes a first connecting section, a second connecting section and a third connecting section, the first connecting section is connected to the electrode terminal of the battery cell, the third connecting section is used to connect to the electrode assembly inside the shell of the battery cell, and the second connecting section connects the first connecting section and the third connecting section;

[0029] The orthographic projection of the first connecting segment on the first surface does not overlap with the orthographic projection of the explosion-proof mechanism on the first surface, and the orthographic projection of the third connecting segment on the first surface at least partially overlaps with the orthographic projection of the support member on the first surface, so that when the battery cell thermally runs away, the support member can support the third connecting segment to prevent the third connecting segment from blocking the explosion-proof mechanism.

[0030] By adopting the above solution, the adapter directly supports the third connecting section, so that there is always a gap between the first connecting section and the third connecting section for the emission to pass through when thermal runaway occurs in the battery cell, and the support member is located within the height range between the first connecting section and the third connecting section, and will not occupy additional space inside the shell, thereby reducing the volume of the battery cell and improving the energy density of the battery cell.

[0031] In some embodiments, a through hole is provided on the adapter directly opposite to the explosion-proof mechanism for allowing emissions generated when the battery cell experiences thermal runaway to pass through.

[0032] By adopting the above solution, the exhaust inside the battery cell can reach the explosion-proof mechanism through the through hole and be discharged through the explosion-proof mechanism, further ensuring smooth exhaust inside and outside the battery cell.

[0033] In a second aspect of the present application, a battery cell is provided, comprising an electrode assembly, a housing, and the end cap assembly described in the above embodiment;

[0034] The shell is a hollow cavity with an opening, the electrode assembly is accommodated in the cavity, and the end cap assembly covers the opening of the shell.

[0035] By adopting the above solution, when thermal runaway occurs, the high-temperature and high-pressure emissions in the battery cell can actuate the explosion-proof mechanism and be discharged through the explosion-proof mechanism, preventing the battery cell from burning or even exploding, thereby ensuring the safety of the battery cell when in use.

[0036] According to a third aspect of the present application, a battery is provided, comprising two or more battery cells according to the above-mentioned embodiments.

[0037] By adopting the above scheme, when one of the battery cells experiences thermal runaway, the high-temperature and high-pressure emissions inside it can activate the explosion-proof mechanism and be discharged through the explosion-proof mechanism, preventing the heat from spreading and affecting other battery cells, and preventing the battery from burning or even exploding, thereby ensuring the safety of the battery when in use.

[0038] In a fourth aspect of the present application, there is provided an electrical device, comprising the battery cell of the above embodiment, wherein the battery cell is used to provide electrical energy.

[0039] By adopting the above solution, when the electrical device is powered by the battery, the battery is not likely to explode, and the device is highly safe to use.

[0040] In a fifth aspect of the present application, a method for manufacturing an end cap assembly is provided. The manufactured end cap assembly is used for a battery cell, comprising:

[0041] Providing an end cover, the end cover is used to seal the housing of the battery cell, the end cover is provided with an explosion-proof mechanism, the explosion-proof mechanism can be actuated to release the pressure of the battery cell when the battery cell has a thermal runaway;

[0042] Providing an adapter, the adapter being used to electrically connect the electrode assembly of the battery cell and the electrode terminal of the battery cell, the orthographic projection of the adapter on the first surface of the end cover at least partially overlapping with the orthographic projection of the explosion-proof mechanism on the first surface of the end cover, the first surface being the surface of the end cover facing the housing;

[0043] A support member is provided, the support member is located between the adapter and the end cover, the support member is made of a high temperature resistant insulating material, and the orthographic projection of the adapter on the first surface at least partially overlaps with the orthographic projection of the support member on the first surface, so that when the battery cell thermally runs away, the support member can support the adapter to prevent the adapter from blocking the explosion-proof mechanism.

[0044] In a sixth aspect of the present application, a method for manufacturing a battery cell is provided, comprising:

[0045] Providing a shell, wherein the shell is a hollow cavity with an opening;

[0046] Providing an electrode assembly, and installing the electrode assembly in the cavity of the shell;

[0047] Providing an end cover, the end cover is used to seal the housing of the battery cell, the end cover is provided with an explosion-proof mechanism, and the explosion-proof mechanism can be actuated to release the internal pressure of the battery cell when the battery cell has a thermal runaway;

[0048] Providing an adapter, the adapter being used to electrically connect the electrode assembly of the battery cell and the electrode terminal of the battery cell, the orthographic projection of the adapter on the first surface of the end cover at least partially overlapping with the orthographic projection of the explosion-proof mechanism on the first surface of the end cover, the first surface being the surface of the end cover facing the housing;

[0049] A support member is provided, the support member is located between the adapter and the end cover, the support member is made of a high temperature resistant insulating material, and the orthographic projection of the adapter on the first surface at least partially overlaps with the orthographic projection of the support member on the first surface, so that when the battery cell thermally runs away, the support member can support the adapter to prevent the adapter from blocking the explosion-proof mechanism.

[0050] The above description is only an overview of the technical solution of the embodiment of the present application. In order to more clearly understand the technical means of the embodiment of the present application, it can be implemented in accordance with the contents of the specification. In order to make the above and other purposes, features and advantages of the embodiment of the present application more obvious and easy to understand, the specific implementation methods of the present application are listed below. BRIEF DESCRIPTION OF THE DRAWINGS

[0051] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following is a brief introduction to the drawings required for use in the description of the embodiments. Obviously, the drawings described below are some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0052] Figure 1 It is a schematic diagram of an electrical device according to an embodiment of the present application.

[0053] Figure 2 It is a schematic diagram of the exploded structure of a battery according to an embodiment of the present application.

[0054] Figure 3 It is a partially exploded schematic diagram of a battery cell according to an embodiment of the present application.

[0055] Figure 4 It is a schematic diagram of an exploded view of an end cover assembly according to an embodiment of the present application.

[0056] Figure 5 It is a top view of an end cover assembly according to an embodiment of the present application.

[0057] Figure 6 The end cap assembly of one embodiment of the present application is Figure 5 Schematic diagram of the cross-section of the AA surface.

[0058] Figure 7 It is a schematic diagram of an exploded view of an end cover assembly according to another embodiment of the present application.

[0059] Figure 8 The end cap assembly of another embodiment of the present application is Figure 5 Schematic cross-sectional view in the direction shown by plane AA.

[0060] Fig. 9 The end cap assembly of another embodiment of the present application is Figure 5 Schematic cross-sectional view in the direction shown by plane BB.

[0061] Fig.10 It is a manufacturing flow chart of the end cover assembly in one embodiment of the present application.

[0062] Fig.11 It is a manufacturing flow chart of a battery cell in one embodiment of the present application. DETAILED DESCRIPTION

[0063] In order to make the purpose, technical solution and advantages of the embodiments of the present application clearer, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0064] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by technicians in the technical field to which this application belongs; the terms used in the specification of the application are only for the purpose of describing specific embodiments and are not intended to limit this application.

[0065] The terms "including" and "having" and any variations thereof in the specification, claims and drawings of this application are intended to cover but not exclude other contents. The word "a" or "an" does not exclude the existence of a plurality. In the description of this application, unless otherwise specified, the meaning of "plurality" refers to more than two (including two), and similarly, "multiple groups" refers to more than two (including two).

[0066] Reference to "embodiments" herein means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present application. The appearance of the phrase "embodiments" in various locations in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0067] In the description of the present application, it should be noted that, unless otherwise clearly specified and limited, the terms "installation", "connection" and "connection" should be understood in a broad sense. For example, the "connection" or "connection" of a mechanical structure may refer to a physical connection. For example, the physical connection may be a fixed connection, such as a fixed connection through a fixing member, such as a fixed connection through a screw, bolt or other fixing member; the physical connection may also be a detachable connection, such as a mutual snap connection or snap connection; the physical connection may also be an integral connection, such as welding, bonding or integral molding to form a connection for connection. The "connection" or "connection" of a circuit structure may refer to an electrical connection or a signal connection in addition to a physical connection. For example, it may be a direct connection, that is, a physical connection, or it may be an indirect connection through at least one intermediate element, as long as the circuit is connected, or it may be the internal connection of two elements; the signal connection may refer to a signal connection through a media medium, such as a radio wave, in addition to a signal connection through a circuit. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0068] In the description of this specification, it should be understood that the directional words such as "upper" and "lower" described in the embodiments of the present application are described from the perspectives shown in the accompanying drawings and should not be understood as limitations on the embodiments of the present application.

[0069] In addition, the terms "first", "second", etc. in the specification and claims of the present application or the above-mentioned drawings are used to distinguish different objects, rather than to describe a specific order, and may explicitly or implicitly include one or more of the features. The present application is further described in detail below through specific embodiments and in conjunction with the drawings.

[0070] The battery mentioned in the embodiments of the present application refers to a single physical module including one or more battery cells to provide higher voltage and capacity. For example, the battery mentioned in the present application may include a battery module or a battery pack, etc. For the convenience of description, the battery module and the battery pack may be collectively referred to as a battery in this article. The battery generally includes a box for encapsulating one or more battery cells. The box can prevent liquid or other foreign matter from affecting the charging or discharging of the battery cells.

[0071] In the present application, battery cells may include lithium-ion secondary batteries, lithium-ion primary batteries, lithium-sulfur batteries, sodium-lithium-ion batteries, sodium-ion batteries or magnesium-ion batteries, etc., and the embodiments of the present application do not limit this. Battery cells may be cylindrical, flat, rectangular or other shapes, etc., and the embodiments of the present application do not limit this. Battery cells are generally divided into three types according to the packaging method: cylindrical battery cells, square battery cells and soft-pack battery cells, and the embodiments of the present application do not limit this.

[0072] The battery cell includes a housing, an electrode assembly and an electrolyte. The electrode assembly is composed of a positive electrode sheet, a negative electrode sheet and a separator. The battery cell mainly relies on the movement of metal ions between the positive electrode sheet and the negative electrode sheet to work. The positive electrode sheet includes a positive current collector and a positive active material layer. The positive active material layer is coated on the surface of the positive current collector. The current collector not coated with the positive active material layer protrudes from the current collector coated with the positive active material layer. The current collector not coated with the positive active material layer serves as the positive electrode tab. Taking lithium-ion batteries as an example, the material of the positive current collector can be aluminum, and the positive active material can be lithium cobalt oxide, lithium iron phosphate, ternary lithium or lithium manganese oxide, etc. The negative electrode sheet includes a negative current collector and a negative active material layer. The negative active material layer is coated on the surface of the negative current collector. The current collector not coated with the negative active material layer protrudes from the current collector coated with the negative active material layer. The current collector not coated with the negative active material layer serves as the negative electrode tab. The material of the negative current collector can be copper, and the negative active material can be carbon or silicon, etc. In order to ensure that a large current can pass without melting, the number of positive electrode tabs is multiple and stacked together, and the number of negative electrode tabs is multiple and stacked together. The material of the isolation film can be PP or PE. In addition, the electrode assembly can be a winding structure or a laminated structure, and the embodiments of the present application are not limited thereto.

[0073] The shell includes a shell and an end cover assembly. The shell is a hollow cavity structure with an opening. After the electrode assembly is loaded into the shell from the opening, the opening is closed by the end cover assembly to seal the shell to prevent gaseous, liquid or solid substances from flowing between the inside and outside of the shell and affecting the performance of the battery cell.

[0074] The end cap assembly has an electrode terminal, which extends from the inside to the outside of the end cap assembly, and includes a positive terminal and a negative terminal. The positive terminal is electrically connected to the positive electrode tab via an adapter, that is, one end of the adapter is connected to the electrode terminal, and the other end is connected to the positive electrode tab; the negative terminal is electrically connected to the negative electrode tab via an adapter, that is, one end of the adapter is connected to the negative terminal, and the other end is connected to the negative electrode tab, thereby realizing the conduction of current inside and outside the battery cell.

[0075] The development of battery technology must take into account many design factors at the same time, such as energy density, cycle life, discharge capacity, charge and discharge rate and other performance parameters. In addition, battery safety must also be considered. One of the important factors affecting battery safety is thermal runaway.

[0076] During the use of the battery, when one of the battery cells encounters external short circuit, overcharge, puncture, plate impact, etc., the battery cell is prone to thermal runaway. When thermal runaway occurs, the battery cell will release emissions. The emissions include one or more of high-temperature flue gas, volatilized high-temperature electrolyte, dissolved or split positive and negative electrode plates, fragments of isolation membrane, high-temperature and high-pressure gas produced by the reaction, flame, etc. If these emissions are not discharged in time, the temperature and pressure inside the battery cell will continue to rise, and even an explosion may occur.

[0077] For this reason, when designing a battery cell, an explosion-proof mechanism is provided on the end cover of the battery cell. An explosion-proof mechanism refers to an element or component that can be actuated to discharge the internal pressure and / or internal material of the battery cell when the internal pressure or internal temperature of the battery cell reaches a predetermined threshold. The explosion-proof mechanism can specifically take the form of an explosion-proof valve, such as an air valve, a pressure relief valve or a safety valve, and can specifically take the form of a pressure-sensitive or temperature-sensitive element or structure, that is, when the internal pressure or temperature of the battery cell reaches a predetermined threshold, the explosion-proof mechanism performs an action or the weak structure provided in the explosion-proof mechanism is destroyed, thereby forming an opening or channel for internal pressure discharge. The threshold referred to in this application may be a pressure threshold or a temperature threshold, and the design of the threshold varies according to different design requirements, for example, the threshold may be designed or determined according to the internal pressure or internal temperature value of the battery cell that is considered to be dangerous or out of control. In addition, the threshold may, for example, depend on one or more of the materials used in the positive electrode sheet, the negative electrode sheet, the electrolyte and the separator in the battery cell.

[0078] The "activation" mentioned in this application means that the explosion-proof mechanism produces an action or is activated to a certain state, so that the internal pressure of the battery cell can be released. The action produced by the explosion-proof mechanism may include but is not limited to: at least a part of the explosion-proof mechanism is ruptured, broken, torn or opened, etc. When the explosion-proof mechanism is actuated, the high-temperature and high-pressure substances inside the battery cell will be discharged from the actuated part as emissions. In this way, the battery cell can be depressurized under controllable pressure or temperature, thereby avoiding potential more serious accidents.

[0079] In order to ensure that the explosion-proof mechanism can be activated to an actuated state in a timely manner by emissions when thermal runaway occurs, a certain space is usually reserved between the adapter and the explosion-proof mechanism for the emissions generated during thermal runaway to pass through.

[0080] However, in the actual use of the battery, the emissions generated by thermal runaway of the battery cell cannot be discharged in time through the explosion-proof mechanism, causing the end cap of the battery cell to separate from the shell under high pressure, thereby causing the risk of battery fire or explosion. After long-term research, the inventor found that this problem is caused by the fact that when thermal runaway occurs, the temperature inside the shell rises sharply, and the pole ears and adapters of the electrode assembly are deformed under the influence of internal temperature and air pressure and move closer to the explosion-proof mechanism, causing the explosion-proof mechanism to be blocked by the adapter and difficult to be activated to the actuated state by the emissions, resulting in the continuous increase of internal air pressure or temperature, and the connection between the end cap assembly and the shell is separated.

[0081] In view of this, an embodiment of the present application provides an end cover assembly for a battery cell, by arranging a support member on the end cover assembly, the support member is located between the adapter and the explosion-proof mechanism, and the support member is made of high temperature resistant material, so that it is not easy to melt and deform when thermal runaway occurs in the battery cell, and supports the adapter when the adapter is deformed, thereby reducing the possibility of the adapter blocking the explosion-proof mechanism, so that the explosion-proof mechanism can be activated to an actuated state to discharge emissions inside the battery cell when thermal runaway occurs in the battery cell, thereby reducing the possibility of explosion of the battery cell and improving the safety of the battery cell during use.

[0082] The battery cells in the embodiments of the present application can be applied to various batteries, and the battery can also be suitable for various devices using batteries, such as mobile phones, portable devices, laptop computers, electric vehicles, electric toys, electric tools, electric vehicles, ships and spacecraft, etc. For example, spacecraft include airplanes, rockets, space shuttles and spacecraft, etc., but are not limited to this.

[0083] like Figure 1 As shown, it is a schematic diagram of the structure of an electric device provided in one embodiment of the present application. The electric device is a car as an example for explanation. The car can be a fuel car, a gas car or a new energy car. The new energy car can be a pure electric car, a hybrid car or an extended-range car, etc. The car includes a battery 200, a controller 210 and a motor 220. The battery 200 is used to supply power to the controller 210 and the motor 220 as the operating power supply and driving power supply of the car. For example, the battery 200 is used for the working power demand during the start, navigation and operation of the car. For example, the battery 200 supplies power to the controller 210, the controller 210 controls the battery 200 to supply power to the motor 220, and the motor 220 receives and uses the power of the battery 200 as the driving power supply of the car, replacing or partially replacing fuel or natural gas to provide driving power for the car.

[0084] In order to meet different power requirements, the battery 200 may include a plurality of battery cells 100, wherein the plurality of battery cells 100 may be connected in series, in parallel, or in hybrid connection, wherein hybrid connection refers to a mixture of series connection and parallel connection. Optionally, the plurality of battery cells 100 may be connected in series, in parallel, or in hybrid connection to form a battery module, and the plurality of battery modules may be connected in series, in parallel, or in hybrid connection to form the battery 200. In other words, the plurality of battery cells 100 may be directly formed into the battery 200, or may be first formed into a battery module, and the battery module may then be formed into the battery 200.

[0085] For example, Figure 2 As shown, it is a schematic diagram of the structure of a battery 200 provided by an embodiment of the present application. The battery 200 may include more than two battery cells 100. In addition, the battery 200 also includes a first box 201, a second box 202 and a third box 203, wherein the third box 203 may be a shell structure with openings at both ends, and the first box 201 and the second box 202 are respectively buckled on the openings at both ends of the third box 203 to form a closed space for accommodating the battery cells 100. After a plurality of battery cells 100 are electrically connected in series, in parallel or in a mixed manner to form a battery module, each battery module is then connected in series, in parallel or in a mixed manner to achieve a larger current or voltage. Optionally, the first box 201, the second box 202 and the third box 203 may be metal or plastic, for example, the first box 201, the second box 202 and the third box 203 are all aluminum or aluminum alloy.

[0086] In one embodiment, a plurality of battery cells 100 are placed in a vertical direction and arranged in a space enclosed by the first box 201, the second box 202 and the third box 203. In some embodiments, the first box 201, the second box 202 and the third box 203 are sealed and connected.

[0087] Of course, the structure of the box is not limited thereto, and may also be other structures, for example, the structure of the two openings is interlocked to form a closed space to accommodate the battery cell 100 .

[0088] like Figure 3 , which is a partially exploded structural schematic diagram of a battery cell 100 disclosed in one embodiment of the present application, wherein the battery cell 100 may be a secondary battery or a primary battery, such as a lithium-ion secondary battery, a lithium-ion primary battery, a lithium-sulfur battery, a sodium-lithium-ion battery, or a magnesium-ion battery, but is not limited thereto. The battery cell 100 may be cylindrical, flat, rectangular, or in other shapes, etc. In this example of the present application, the battery cell 100 is a cylindrical body for illustration.

[0089] The battery cell 100 includes a housing 10 and an electrode assembly 20 placed in the housing 10. The housing 10 may be made of metal material or plastic. Optionally, the housing 10 is made of aluminum or aluminum alloy. The housing 10 has an opening, which may be located on an end surface of the housing 10. For example, the housing 10 includes two openings, which are respectively located on two end surfaces of the cylindrical housing 10, that is, the two end surfaces of the housing 10 do not have end walls, so that the inside and outside of the housing 10 are connected, so that the electrode assembly 20 can be installed in the housing 10 from any opening.

[0090] The electrode assembly 20 is formed by stacking or winding a positive electrode sheet, a negative electrode sheet and a separator, the separator is sandwiched between the positive electrode sheet and the negative electrode sheet, the electrode assembly 20 has a positive electrode ear and a negative electrode ear, the positive electrode ear and the negative electrode ear are respectively opposite to one of the openings, and the opening is covered with an end cover assembly 30, the end cover assembly 30 is sealed with the shell 10 at the opening of the shell 10 to form a hollow cavity, after the electrode assembly 20 is placed in the shell 10, the shell 10 is filled with electrolyte and sealed.

[0091] like Figure 4 As shown, Figure 4 for Figure 3 The schematic diagram of the exploded structure of the middle end cap assembly 30, the end cap assembly 30 includes an end cap 31, an isolation component 34, an electrode terminal 32 and an adapter 35. The electrode terminal 32 on the end cap assembly 30 corresponding to the positive electrode tab of the electrode assembly 20 is the positive terminal, and the electrode terminal 32 on the end cap assembly 30 corresponding to the negative electrode tab of the electrode assembly 20 is the negative terminal. The positive electrode tab of the electrode assembly 20 is electrically connected to the positive terminal, and the negative electrode tab of the electrode assembly 20 is electrically connected to the negative terminal.

[0092] The end cap 31 is substantially in the shape of a plate, and has a first surface 31a and a second surface 31b, wherein the first surface 31a is the surface facing the housing 10, and the second surface 31b is the surface facing away from the housing 10, and the isolation component 34, the electrode terminal 32 and the adapter 35 are all located on the side where the first surface 31a is located. The end cap 31 can be made of metal or plastic, and optionally, the end cap 31 is made of aluminum or aluminum alloy, and is sealed and connected to the opening of the housing 10 by welding.

[0093] The end cap 31 is provided with two through terminal holes, and the isolation component 34 and the adapter 35 are provided with through holes corresponding to the terminal holes. The two electrode terminals 32 pass through the through holes and the terminal holes, and are riveted to a rivet block 37 on the second surface of the end cap 31. An insulating member 39 is sandwiched between the rivet block 37 and the end cap 31 for insulation between the electrode terminal 32 and the end cap 31. A sealing ring 38 is provided between the outer wall of the electrode terminal 32 and the inner wall of the terminal hole. The sealing of the terminal hole can be achieved by compressing the sealing ring 38, and at the same time, the electrode terminal 32 can be more firmly combined with the terminal hole.

[0094] An explosion-proof mechanism 33 is provided on the end cover 31, and the explosion-proof mechanism 33 can be actuated to release the internal pressure of the battery cell 100 when the battery cell 100 is in thermal runaway. For example, the explosion-proof mechanism 33 can be a part of the weak area of ​​the end cover 31, or an explosion-proof through hole 331 can be provided on the end cover 31, and an explosion-proof plate 332 is arranged on the end cover 31 and seals the explosion-proof through hole 331, and the explosion-proof plate 332 can be destroyed by the emissions generated inside the battery cell 100 when thermal runaway occurs.

[0095] For example, the strength of the weak area or explosion-proof plate 332 can be reduced by reducing the thickness of the weak area or explosion-proof plate 332, so that the weak area or explosion-proof plate 332 is more easily damaged by the discharge than other areas of the end cover 31. The second surface of the explosion-proof mechanism 33 close to the end cover 31 is provided with a patch 333, which covers the explosion-proof through hole 331 to prevent the explosion-proof plate 332 from being damaged by external forces. At the same time, the patch 333 can be pushed open by the discharge inside the battery cell 100 in the case of thermal runaway to allow the discharge to flow out.

[0096] The isolation component 34 is arranged on the first surface 31a of the end cover 31, and is made of an insulating material, generally made of plastic, plastic glue and other materials, to separate the end cover 31 and the electrode assembly 20 to reduce the risk of short circuit. A discharge port 341 is opened on the isolation component 34 for the discharge to pass through, and the discharge port 341 is arranged directly opposite to the explosion-proof mechanism 33.

[0097] Combination Figure 3 and Figure 4 The adapter 35 is located between the electrode assembly 20 and the isolation component 34, one end of which is connected to the electrode terminal 32, and the other end is used to connect to the positive electrode tab or the negative electrode tab of the electrode assembly 20, so as to realize the electrical connection between the electrode assembly 20 and the electrode terminal 32. Due to the limitation of the internal space of the battery cell 100, the orthographic projection of the adapter 35 on the first surface of the end cover 31 usually overlaps at least partially with the orthographic projection of the explosion-proof mechanism 33 on the first surface of the end cover 31.

[0098] During the use of the battery cell 100, if the battery cell 100 is overcharged, impacted, etc., the electrode assembly 20 short-circuits and generates a large amount of gas and heat. This situation is called thermal runaway of the battery cell 100. In the case of thermal runaway, after the high-temperature and high-pressure emissions in the battery cell 100 accumulate to a certain extent in the shell, they will destroy the explosion-proof mechanism 33 and be discharged from the explosion-proof mechanism 33, that is, the explosion-proof mechanism 33 is actuated. The actuation of the explosion-proof mechanism 33 prevents the continuous accumulation of emissions and the occurrence of combustion, explosion and other accidents.

[0099] However, since the battery cell 100 is in a state of thermal runaway, the temperature and air pressure inside it increase, causing the adapter 35 to deform toward the end cover 31, and the isolation component 34 will melt and soften at this time, making it difficult to support the adapter 35, causing the adapter 35 to continue to deform and press against the explosion-proof mechanism 33, thereby blocking the explosion-proof mechanism 33, making it difficult for the explosion-proof mechanism 33 to be destroyed by the emissions in the battery cell 100 and to relieve the pressure on the battery cell 100, thereby causing an explosion risk.

[0100] To solve the above problems, refer to Figure 4 In one embodiment of the present application, a support member 36 is provided between the adapter 35 and the end cover 31. The support member 36 is made of a high temperature resistant material, such as ceramic, mica, high temperature resistant resin, etc. The support member 36 may be annular, U-shaped, prismatic, cylindrical or irregular, and is not limited here. The number of the support members 36 may be one or more, as long as the orthographic projection of the adapter 35 on the first surface and the orthographic projection of the support member 36 on the first surface at least partially overlap, so that when the battery cell 100 is in thermal runaway, the support member 36 can support the adapter 35 to prevent the adapter 35 from blocking the explosion-proof mechanism 33.

[0101] In one embodiment, the melting point of the support member 36 is greater than 300°C, thereby ensuring that the support member 36 will not be melted and deformed by the emissions during thermal runaway, so that when the adapter 35 is deformed, the adapter 35 will not directly abut against the explosion-proof mechanism 33 and block the explosion-proof mechanism 33. Therefore, when thermal runaway occurs, the high-temperature and high-pressure emissions in the battery cell 100 can activate the explosion-proof mechanism 33 and be discharged through the explosion-proof mechanism 33, preventing the battery cell 100 from burning or even exploding, thereby improving the safety of the battery cell 100 when in use.

[0102] In one embodiment, the support member 36 is supported by an insulating material to avoid the problem of the support member 36 causing a short circuit during use.

[0103] In one embodiment, the support member 36 includes a support block, which is disposed between the adapter 35 and the end cover 31, for example, Figure 4 As shown, there are two groups of support blocks, each group includes two arc-shaped support blocks, and the orthographic projection of the support blocks on the first surface is staggered with the orthographic projection of the explosion-proof mechanism 33 on the first surface to ensure that the explosion-proof mechanism 33 can be destroyed to discharge gas during thermal runaway. For example, the support blocks can be fixed on the isolation component 34 to prevent the support blocks from shifting and failing to form a good support for the adapter 35, or affecting the actuation of the explosion-proof mechanism 33. The specific fixing method of the support blocks will be described in the following embodiments.

[0104] like Figure 4As shown, in one embodiment, a receiving groove 40 is provided on the isolation component 34, and the support block is disposed in the receiving groove 40. One side of the receiving groove 40 has an opening so that the support block can be inserted from the opening, that is, part of the support block is not wrapped by the groove wall of the receiving groove 40. In this case, the positioning of the support block is facilitated.

[0105] For example, Figure 4 , Figure 5 and Figure 6 As shown, the opening of the accommodating groove 40 faces the end cover 31, one end of the support block abuts against the bottom wall of the accommodating groove 40, and the other end abuts against the end cover 31. Figure 5 is a top view of the end cover assembly 30, Figure 6 A cross-sectional schematic diagram is shown when the accommodating groove 40 opens toward the end cover 31 .

[0106] For example, Figure 7 As shown, Figure 7 The exploded schematic diagram of the end cover assembly 30 illustrates the state where the support block is located on the side of the isolation component 34 close to the adapter 35. At this time, the opening of the accommodating groove 40 faces the adapter 35, one end of the support block is against the bottom wall of the accommodating groove 40, and the other end is against the adapter 35.

[0107] The above two opening modes of the accommodating grooves 40 enable the side walls of the accommodating grooves 40 to limit the position of the support block in the direction perpendicular to the first surface, so that the support block can always be located at the position corresponding to the adapter 35, and form a stable support for the adapter 35 without restricting the actuation of the explosion-proof mechanism 33; and the arrangement in which the two ends of the support block are respectively pressed against the bottom wall of the accommodating groove 40 and the end cover 31 or the adapter 35 can prevent the support block from falling from the opening of the accommodating groove 40, thereby making it difficult to support the adapter 35 during thermal runaway.

[0108] like Figure 8 As shown, in another embodiment, the support block is glued and fixed on the isolation component 34. The support block can be glued on the side of the isolation component 34 facing the end cover 31, or on the side of the isolation component 34 facing the adapter 35. For example, heat-resistant glue can be used for gluing. This method of fixing the support block can also achieve the situation that the support block is displaced and difficult to support the adapter 35 during thermal runaway. Figure 8 The figure shows a state where the support block is glued and fixed to the side of the isolation component 34 facing the adapter 35 .

[0109] In another embodiment, the support block may be fixed on the isolation component 34 by injection molding.

[0110] In another embodiment, the isolation component 34 is made of a high-temperature resistant insulating material, such as ceramic, mica, high-temperature resistant resin, etc. The material of the isolation component 34 may be the same as that of the support block, or may be different from the material of the support block. The support block may be fixed to the isolation component 34 in the same manner as the support block in any of the above embodiments. At this time, the isolation component 34 is not easy to melt during thermal runaway, and it not only serves as an insulator, but also serves to support the adapter 35, thereby further reducing the possibility of the adapter 35 blocking the explosion-proof mechanism 33.

[0111] like Fig. 9 As shown, in one embodiment, when the support block and the isolation component 34 are made of the same material, that is, high-temperature resistant material, in order to facilitate processing and assembly, the support block and the isolation component 34 can be formed in one piece, thereby greatly improving the processing efficiency of the end cover assembly 30 and saving the manufacturing cost of the end cover assembly 30.

[0112] In the above-mentioned embodiments of the present application, the adapter 35 includes a first connecting section 351, a second connecting section 352 and a third connecting section 353. The first connecting section 351 is connected to the electrode terminal 32 of the battery cell 100, and the third connecting section 353 is used to connect to the electrode assembly 20 inside the shell 10 of the battery cell 100. The second connecting section 352 connects the first connecting section 351 and the third connecting section 353. For example, the first connecting section 351, the second connecting section 352, and the third connecting section 353 can be bent from the same elastic metal sheet.

[0113] In order to save space inside the battery cell 100, Figure 8 and Fig. 9 As shown, it can be specifically configured that the orthographic projection of the first connecting segment 351 on the first surface does not overlap with the orthographic projection of the explosion-proof mechanism 33 on the first surface, and the orthographic projection of the third connecting segment 353 on the first surface at least partially overlaps with the orthographic projection of the support member 36 on the first surface, so that when the battery cell 100 thermally runs away, the support member 36 can support the third connecting segment 353 to prevent the third connecting segment 353 from blocking the explosion-proof mechanism 33.

[0114] The third connecting section 353 is directly supported by the adapter 35, so that there is always a gap between the first connecting section 351 and the third connecting section 353 to allow emissions from the battery cell 100 to pass through when thermal runaway occurs. In addition, the support member 36 is located within the height range between the first connecting section 351 and the third connecting section 353. Therefore, the setting of the support member 36 will not occupy additional space inside the shell 10, thereby reducing the volume of the battery cell 100 and improving the energy density of the battery cell 100.

[0115] like Figure 4 and Figure 7As shown, in some embodiments, a through hole is provided on the adapter 35 directly opposite the explosion-proof mechanism 33 for the passage of emissions generated when the battery cell 100 experiences thermal runaway. The through hole can be specifically arranged on the third connecting section 353. The emissions inside the battery cell 100 can pass through the through hole to reach the explosion-proof mechanism 33 and be discharged through the explosion-proof mechanism 33, further ensuring smooth exhaust when the battery cell 100 experiences thermal runaway.

[0116] In summary, the above-mentioned embodiment of the present application arranges a support member 36 made of high-temperature resistant material on the end cover assembly 30, and sets a specific position between the support member 36 and the adapter 35, so that when the end cover assembly 30 is used for the battery cell 100, the support member 36 can support the adapter 35 to reduce the possibility of the adapter 35 blocking the explosion-proof mechanism 33, so that the explosion-proof mechanism 33 can be activated to an actuated state to discharge the emissions inside the battery cell 100 when the battery cell 100 has a thermal runaway, so that the explosion-proof mechanism 33 can reduce the possibility of the battery cell 100 exploding when the battery cell 100 has a thermal runaway, thereby improving the safety of the battery cell 100 during use.

[0117] In addition, another aspect of the present application provides a method for manufacturing an end cap assembly 30, wherein the manufactured end cap assembly 30 is used to seal the opening of the housing 10 of the battery cell 100, such as Fig.10 As shown, the method includes:

[0118] S410 : providing an end cover 31 , the end cover 31 being used to seal the housing 10 of the battery cell 100 , and an explosion-proof mechanism 33 being provided on the end cover 31 , and the explosion-proof mechanism 33 being actuated to release the pressure of the battery cell 100 when the battery cell 100 is in thermal runaway.

[0119] S420: Provide an adapter 35, which is used to electrically connect the electrode assembly 20 of the battery cell 100 and the electrode terminal 32 of the battery cell 100, and the orthographic projection of the adapter 35 on the first surface 31a of the end cover 31 at least partially overlaps with the orthographic projection of the explosion-proof mechanism 33 on the first surface 31a of the end cover 31, and the first surface 31a is the surface of the end cover 31 facing the shell 10.

[0120] S430: Provide a support member 36, which is located between the adapter 35 and the end cover 31. The support member 36 is made of a high-temperature resistant insulating material. The orthographic projection of the adapter 35 on the first surface at least partially overlaps with the orthographic projection of the support member 36 on the first surface 31a, so that when the battery cell 100 thermally runs away, the support member 36 can support the adapter 35 to prevent the adapter 35 from blocking the explosion-proof mechanism 33.

[0121] It should be noted that in the manufacturing method of the above-mentioned end cover assembly 30, the order of the various steps is not completely in accordance with the above-mentioned arrangement order. In the actual process of manufacturing the end cover assembly 30, the order of the above-mentioned steps can be adjusted according to the actual situation, or performed simultaneously, or other steps can be added to manufacture other components of the end cover assembly 30, so as to finally obtain the required end cover assembly 30, specifically refer to the embodiment of the end cover assembly 30.

[0122] In another aspect of the present application, a method for manufacturing a battery cell 100 is provided. Fig.11 As shown, the method includes:

[0123] S510: Provide a shell 10, where the shell 10 is a hollow cavity with an opening.

[0124] S520: providing an electrode assembly 20 , and installing the electrode assembly 20 in the cavity of the shell 10 .

[0125] S530 : providing an end cover 31 , the end cover 31 is used to seal the housing 10 of the battery cell 100 , and an explosion-proof mechanism 33 is provided on the end cover 31 , and the explosion-proof mechanism 33 can be actuated to release the internal pressure of the battery cell 100 when the battery cell 100 has thermal runaway.

[0126] S540: Provide an adapter 35, which is used to electrically connect the electrode assembly 20 of the battery cell 100 and the electrode terminal 32 of the battery cell 100, and the orthographic projection of the adapter 35 on the first surface 31a of the end cover 31 at least partially overlaps with the orthographic projection of the explosion-proof mechanism 33 on the first surface 31a of the end cover 31, and the first surface is the surface of the end cover 31 facing the shell 10.

[0127] S550: Provide a support member 36, which is located between the adapter 35 and the end cover 31. The support member 36 is made of a high-temperature resistant insulating material. The orthographic projection of the adapter 35 on the first surface 31a at least partially overlaps with the orthographic projection of the support member 36 on the first surface 31a, so that when the battery cell 100 thermally runs away, the support member 36 can support the adapter 35 to prevent the adapter 35 from blocking the explosion-proof mechanism 33.

[0128] The order of the above steps is not necessarily in accordance with the above arrangement order. In the actual process of manufacturing the battery cell 100, the order of the above steps can be adjusted according to the actual situation, or performed simultaneously, or other steps can be added to manufacture other components of the battery cell 100, so as to finally obtain the required battery cell 100. Please refer to the embodiment of the battery cell 100 for details.

[0129] In addition, any method that can manufacture related components and connect related components falls within the protection scope of the embodiments of the present application, and the embodiments of the present application will not be described in detail here.

[0130] The features of the above-mentioned protected subjects and embodiments of the present application can refer to each other. If the structure permits, those skilled in the art can also flexibly combine the technical features in different embodiments to form more embodiments.

[0131] The above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present application.

Claims

1. An end cap assembly for a battery cell (100), comprising: an end cover (31) for sealing the housing (10) of the battery cell (100), the end cover (31) being provided with an explosion-proof mechanism (33), the explosion-proof mechanism (33) being capable of being actuated to release the internal pressure of the battery cell (100) when the battery cell (100) is in thermal runaway; an adapter (35) for electrically connecting the electrode assembly (20) of the battery cell (100) and the electrode terminal (32) of the battery cell (100), wherein the orthographic projection of the adapter (35) on the first surface (31a) of the end cover (31) at least partially overlaps with the orthographic projection of the explosion-proof mechanism (33) on the first surface (31a) of the end cover (31), and the first surface (31a) is the surface of the end cover (31) facing the housing (10); A support member (36) is provided between the adapter (35) and the end cover (31); the support member (36) is made of a high temperature resistant material; an orthographic projection of the adapter (35) on the first surface (31a) and an orthographic projection of the support member (36) on the first surface (31a) at least partially overlap, so that when the battery cell (100) is in thermal runaway, the support member (36) can support the adapter (35).

2. The end cap assembly according to claim 1, wherein: The melting point of the support member (36) is greater than 300°C.

3. The end cap assembly according to claim 1, wherein: The support member (36) is made of insulating material.

4. The end cap assembly according to claim 1, wherein: The support member (36) comprises a support block, and the support block is arranged between the adapter (35) and the end cover (31).

5. The end cap assembly according to claim 4, wherein: The orthographic projection of the support block on the first surface (31a) is offset from the orthographic projection of the explosion-proof mechanism (33) on the first surface (31a).

6. The end cap assembly according to claim 4, wherein: An isolation component (34) is provided between the adapter (35) and the end cover (31), and the isolation component (34) is used to insulate the adapter (35) from the end cover (31). The support block is fixed on the isolation component (34).

7. The end cap assembly according to claim 6, wherein: The isolation component (34) is provided with a receiving groove (40), and the support block is arranged in the receiving groove (40).

8. The end cap assembly according to claim 7, wherein: One side of the accommodating groove (40) is provided with an opening for receiving the supporting block.

9. The end cap assembly according to claim 8, wherein: The opening faces the end cover (31), one end of the support block abuts against the bottom wall of the accommodating groove (40), and the other end abuts against the end cover (31); Alternatively, the opening faces the adapter (35), one end of the support block abuts against the bottom wall of the accommodating groove (40), and the other end abuts against the adapter (35).

10. The end cap assembly according to claim 9, wherein: The isolation component (34) is made of high temperature resistant insulating material.

11. The end cap assembly according to claim 10, wherein: The support block and the isolation component (34) are made of the same material and are integrally formed.

12. The end cap assembly according to claim 6, wherein: At least a portion of the transition member and at least a portion of the isolation member are separated from each other by a gap along a direction perpendicular to the first surface.

13. The end cap assembly of claim 1, wherein: The adapter (35) comprises a first connecting section (351), a second connecting section (352) and a third connecting section (353), wherein the first connecting section (351) is connected to the electrode terminal (32) of the battery cell (100), the third connecting section (353) is used to connect to the electrode assembly (20) inside the housing (10) of the battery cell (100), and the second connecting section (352) connects the first connecting section (351) and the third connecting section (353); The orthographic projection of the first connecting section (351) on the first surface does not overlap with the orthographic projection of the explosion-proof mechanism (33) on the first surface, and the orthographic projection of the third connecting section (353) on the first surface at least partially overlaps with the orthographic projection of the support member (36) on the first surface, so that when the battery cell (100) is thermally runaway, the support member (36) can support the third connecting section (353) to prevent the third connecting section (353) from blocking the explosion-proof mechanism (33).

14. The end cap assembly according to any one of claims 1 to 13, wherein: The adapter (35) is provided with a through hole facing the explosion-proof mechanism (33) for the emission generated when the battery cell (100) experiences thermal runaway to pass through.

15. A battery cell, wherein: It comprises an electrode assembly (20), a shell (10) and an end cap assembly (30) according to any one of claims 1 to 14; The shell (10) is a hollow cavity with an opening, the electrode assembly (20) is accommodated in the cavity, and the end cover assembly (30) covers the opening of the shell (10).

16. A battery, wherein: The battery comprises two or more battery cells (100) as claimed in claim 15.

17. An electrical device, wherein: The battery cell (100) according to claim 15 is used to provide electrical energy.

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