Battery cell, battery device, energy storage device, energy storage system and charging network

Abstract

The utility model provides a battery cell, a battery device, an energy storage device, an energy storage system and a charging network. The battery monomer comprises a shell, an electrode assembly and a first insulating part, the shell is provided with a containing cavity, the electrode assembly is contained in the containing cavity, the electrode assembly comprises an electrode main body and a tab, the tab is led out from one end of the electrode main body along a first direction, the shell comprises a first wall, the first wall and the electrode assembly are arranged along a second direction, and the first direction intersects with the second direction. The first insulating part is arranged on the side, facing the electrode body, of the first wall, and in the same plane perpendicular to the second direction, the orthographic projection of the first insulating part is located in the orthographic projection of the electrode body. According to the invention, the reliability of the battery monomer can be effectively improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of batteries, in particular to a battery monomer, a battery device, an energy storage device, an energy storage system and a charging network. BACKGROUND

[0002] With the development of new energy technology, batteries are increasingly widely used, for example, in mobile phones, notebook computers, electric cars, electric vehicles, electric aircraft, electric ships, electric toy cars, electric toy ships, electric toy aircraft and electric tools.

[0003] In the development of battery technology, how to improve the reliability of the battery monomer is a continuous research direction in the battery technology. Utility model content

[0004] In view of the above problems, the present application provides a battery monomer, a battery device, an energy storage device, an energy storage system and a charging network, which can effectively improve the reliability of the battery monomer.

[0005] In a first aspect, the embodiments of the present application provide a battery monomer, which comprises a shell, an electrode assembly and a first insulating piece. The shell has a receiving cavity, and the electrode assembly is received in the receiving cavity. The electrode assembly comprises an electrode body and a tab, and the tab is led out from one end of the electrode body along a first direction. The shell comprises a first wall, and the first wall is arranged along a second direction with the electrode assembly. The first direction intersects the second direction. The first insulating piece is arranged on a side of the first wall facing the electrode body. In the same plane perpendicular to the second direction, the orthographic projection of the first insulating piece is located in the orthographic projection of the electrode body.

[0006] The first insulating piece can play a protective role on the electrode body. On the one hand, the first insulating piece can resist the piercing of the electrode body by a sharp object to some extent, reducing the risk of internal short circuit. On the other hand, even if the electrode body is pierced by a sharp object to produce heat and cause the insulating film to fail, the first insulating piece can still play an insulating role to reduce the current generated by the internal short circuit and reduce the heat generation, thereby reducing the risk of thermal runaway of the battery monomer and improving the reliability of the battery monomer.

[0007] In addition, the first insulating piece is arranged corresponding to the side surface of the electrode body facing the first wall, and the first insulating piece does not exceed the edge of the side surface of the electrode body facing the first wall. This not only can reduce the space occupation of the first insulating piece and improve the energy density of the battery monomer, but also can reduce the risk of interference with the shell during assembly and improve the assembly efficiency and product yield of the battery monomer.

[0008] In some embodiments of the first aspect, in the same plane perpendicular to the second direction, the orthographic projection area S1 of the first insulating piece and the orthographic projection area S2 of the electrode body satisfy the relationship: 5%≤S1 / S2≤80%.

[0009] By setting S1 / S2 to be greater than or equal to 5%, the coverage area of the first insulating piece can be effectively increased to improve the protection effect of the first insulating piece on the electrode body; by setting S1 / S2 to be less than or equal to 80%, the space occupation of the first insulating piece can be reduced to improve the energy density of the battery monomer.

[0010] In some embodiments of the first aspect, the maximum distance between the edge of the orthographic projection of the first insulating piece and the edge of the orthographic projection of the electrode body in the same plane perpendicular to the second direction is 10mm-240mm.

[0011] By setting the maximum distance between the edge of the orthographic projection of the first insulating piece and the edge of the orthographic projection of the electrode body to be greater than or equal to 10mm, the risk of interference between the first insulating piece and the shell during assembly can be reduced to improve the assembly efficiency and product yield of the battery monomer; by setting the maximum distance between the edge of the orthographic projection of the first insulating piece and the edge of the orthographic projection of the electrode body to be less than or equal to 240mm, the coverage area of the first insulating piece can be effectively increased to improve the protection effect of the first insulating piece on the electrode body.

[0012] In some embodiments of the first aspect, the thermal decomposition temperature of the first insulating piece is 400℃-1500℃.

[0013] By setting the thermal decomposition temperature of the first insulating piece to be greater than or equal to 400℃, the protection effect of the first insulating piece on the electrode body can be improved; by setting the thermal decomposition temperature of the first insulating piece to be less than or equal to 1500℃, the difficulty of obtaining the material can be effectively reduced, and the cost can be reduced.

[0014] In some embodiments of the first aspect, the size of the first insulating piece along the second direction is 0.05mm-2mm.

[0015] By setting the size of the first insulating piece along the second direction to be greater than or equal to 0.05mm, the structural reliability of the first insulating piece can be improved to improve the protection effect of the first insulating piece on the electrode body; by setting the size of the first insulating piece along the second direction to be less than or equal to 2mm, the space occupation of the first insulating piece can be reduced to improve the energy density of the battery monomer.

[0016] In some embodiments of the first aspect, the second direction is parallel to the thickness direction of the electrode assembly.

[0017] The above technical solution can better protect the electrode body by the first insulating piece to further improve the reliability of the battery monomer.

[0018] In some embodiments of the first aspect, the electrode body comprises a first electrode tab, a second electrode tab, and a separator, the first electrode tab and the second electrode tab have opposite polarities, and at least part of the separator is arranged between the first electrode tab and the second electrode tab. The thermal decomposition temperature of the first insulating member is greater than the thermal decomposition temperature of the separator.

[0019] The above technical solution can still play an insulating role in the first insulating member even if the separator fails due to heat generated by the electrode body being pierced by a sharp object, so as to reduce the current generated by internal short circuit and reduce heat generation, thereby reducing the risk of thermal runaway of the battery cell and improving the reliability of the battery cell.

[0020] In some embodiments of the first aspect, the first insulating member is arranged between the first wall and the insulating film.

[0021] The above technical solution can reduce the assembly difficulty between the insulating film and the electrode body and improve the flatness of the insulating film on the electrode body.

[0022] In some embodiments of the first aspect, the battery cell further comprises a heat absorbing member, the heat absorbing member is connected to the first insulating member and is arranged along the second direction with the first insulating member, and the heat absorbing member is configured to absorb heat when the temperature of the accommodation cavity reaches a first threshold value.

[0023] The above technical solution can further reduce heat generation when the electrode body is pierced by a sharp object by introducing a heat absorbing member, thereby further reducing the risk of thermal runaway of the battery cell and improving the energy density of the battery cell.

[0024] In some embodiments of the first aspect, the first insulating member is provided with a recess on one side along the second direction, and at least part of the heat absorbing member is arranged in the recess.

[0025] The above technical solution can reduce the occupation of the internal space of the battery cell by the heat absorbing member, which helps to improve the energy density of the battery cell.

[0026] In some embodiments of the first aspect, the battery cell further comprises a buffer member, the buffer member is connected to one side of the first insulating member facing the first wall, and the elastic modulus of the buffer member is less than the elastic modulus of the first insulating member.

[0027] The buffer member has a smaller elastic modulus and a relatively soft texture. When the battery cell is pierced by a sharp object, the buffer member can absorb part of the impact force by deforming itself, thereby playing a certain buffering role, reducing the force of the sharp object acting on the first insulating member and the electrode body, and further improving the reliability of the battery cell.

[0028] In some embodiments of the first aspect, there are multiple electrode assemblies arranged along a second direction, and the battery cell further includes a second insulating member disposed between the electrode bodies of two adjacent electrode assemblies.

[0029] This can further reduce the internal short-circuit current when the electrode assembly is punctured by a sharp object, thereby further reducing heat generation and reducing the risk of thermal runaway of individual battery cells.

[0030] Secondly, this application provides a battery device that includes a battery cell provided in any of the embodiments of the first aspect.

[0031] Thirdly, this application provides an electrical device for an energy storage device, which includes a plurality of battery cells provided in any embodiment of the first aspect or a plurality of battery devices provided in any embodiment of the second aspect, wherein the battery cells or battery devices are used to store or provide electrical energy.

[0032] Fourthly, this application provides an energy storage system, which includes an energy conversion system and an energy storage device provided in any embodiment of the third aspect, wherein the energy conversion system is connected to the energy storage device to convert the current input to the energy storage device or output from the energy storage device into energy.

[0033] Fifthly, this application provides a charging network, which includes a charging pile and an energy storage device provided in any embodiment of the third aspect or an energy storage system provided in any embodiment of the fourth aspect, wherein the energy storage device is used to provide electrical energy to the charging pile.

[0034] The above description is only an overview of the technical solution of this application. In order to better understand the technical means of this application and to implement it in accordance with the contents of the specification, and to make the above and other objects, features and advantages of this application more obvious and understandable, the following are specific embodiments of this application. Attached Figure Description

[0035] Various other advantages and benefits will become apparent to those skilled in the art upon reading the following detailed description of preferred embodiments. The accompanying drawings are for illustrative purposes only and are not intended to limit the scope of this application. Furthermore, the same reference numerals denote the same parts throughout the drawings. In the drawings:

[0036] Figure 1 This is a schematic diagram of the charging network structure in some embodiments of this application;

[0037] Figure 2 This is a schematic diagram of the energy storage system in some embodiments of this application;

[0038] Figure 3 This is an exploded structural diagram of a battery device provided in some embodiments of this application;

[0039] Figure 4 A structural diagram of a battery module provided by some embodiments of the present application;

[0040] Figure 5 A structural diagram of a battery cell provided by some embodiments of the present application;

[0041] Figure 6 A structural diagram of a battery cell provided by some embodiments of the present application, viewed from one side in a first direction;

[0042] Figure 7 A structural diagram of a battery cell provided by some embodiments of the present application, viewed from one side in a second direction; Figure 6 A structural diagram of a battery cell provided by some embodiments of the present application, viewed from one side in a second direction;

[0043] Figure 8 A structural diagram of a battery cell provided by some embodiments of the present application, viewed from one side in a second direction;

[0044] Figure 9 A structural diagram of a battery cell provided by some embodiments of the present application, viewed from one side in a second direction;

[0045] Figure 10 A structural diagram of a battery cell provided by some embodiments of the present application, viewed from one side in a second direction; Figure 9 A structural diagram of a battery cell provided by some embodiments of the present application, viewed from one side in a second direction;

[0046] Figure 11 A structural diagram of a battery cell provided by some embodiments of the present application, viewed from one side in a second direction; Figure 10 A structural diagram of a battery cell provided by some embodiments of the present application, viewed from one side in a second direction;

[0047] Figure 12 A structural diagram of a battery cell provided by some embodiments of the present application, viewed from one side in a second direction;

[0048] Figure 13 A structural diagram of a battery cell provided by some embodiments of the present application, viewed from one side in a second direction; Figure 12 A structural diagram of a battery cell provided by some embodiments of the present application, viewed from one side in a second direction;

[0049] Figure 14 A structural diagram of a battery cell provided by some embodiments of the present application, viewed from one side in a first direction;

[0050] Figure 15 A structural diagram of a battery cell provided by some embodiments of the present application, viewed from one side in a second direction; Figure 14 A structural diagram of a battery cell provided by some embodiments of the present application, viewed from one side in a second direction.

[0051] Reference signs in the detailed description of the embodiments are as follows:

[0052] 100, energy storage device; 200, energy conversion system; 300, power generation device; 400, charging pile; 500, connector;

[0053] 2, battery device; 5, box; 5a, first box; 5b, second box; 6, battery module; 7, battery cell;

[0054] 10, housing; 11, accommodating cavity; 12, first wall;

[0055] 20, electrode assembly; 21, electrode body; 22, tab;

[0056] 30, first insulating member;

[0057] 40, heat absorbing member; 50, buffering member; 60, second insulating member;

[0058] X, first direction; Y, second direction. DETAILED DESCRIPTION

[0059] In order to make the objects, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only some of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative work fall within the scope of protection of the present application.

[0060] Unless otherwise defined, all technical and scientific terms used in the present application have the same meaning as commonly understood by one of ordinary skill in the art to which the present application belongs; the terms used in the specification of the present application are only for the purpose of describing specific embodiments and are not intended to limit the present application; the terms "include" and "have" and any variations thereof in the specification and claims of the present application and the above description of drawings are intended to cover non-exclusive inclusion. The terms "first", "second" and the like in the specification and claims of the present application and the above description of drawings are used to distinguish different objects, rather than to describe a particular order or primary and secondary relationship.

[0061] In the present application, the phrase "embodiment" means that the specific features, structures or characteristics described in connection with the embodiment can be included in at least one embodiment of the present application. The appearance of this phrase at various places in the specification does not necessarily mean the same embodiment, nor is it an independent or alternative embodiment to the other embodiments.

[0062] In the description of the present application, it should be noted that unless otherwise explicitly specified and limited, the terms "mounting", "connection", "connecting", "attachment" should be understood in a broad sense, for example, it can be fixed connection, or detachable connection, or integral connection; it can be direct connection, or indirect connection through an intermediate medium, or internal communication of two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0063] The term "and / or" in the present application only describes the association relationship of the associated objects, which means that there can be three relationships, for example, A and / or B can mean that A exists alone, A and B exist together, and B exists alone. In addition, the character " / " in the present application generally represents that the front and rear associated objects have an "or" relationship.

[0064] In the embodiments of the present application, the same reference signs represent the same components, and for the sake of brevity, the detailed description of the same components is omitted in different embodiments. It should be understood that the thickness, length, width and other dimensions of various components in the embodiments of the present application shown in the drawings, as well as the overall thickness, length, width and other dimensions of the integrated device, are only exemplary and should not constitute any limitation on the present application.

[0065] "Multiple" appearing in the present application means two or more (including two).

[0066] The term "parallel" in the present application not only includes the case of absolute parallel, but also includes the case of approximate parallel which is generally recognized in engineering; at the same time, "perpendicular" also not only includes the case of absolute perpendicular, but also includes the case of approximate perpendicular which is generally recognized in engineering.

[0067] With the development of new energy technology, batteries are increasingly widely used, such as in mobile phones, notebook computers, electric vehicles, electric cars, electric aircraft, electric ships, electric toy cars, electric toy ships, electric toy aircraft and electric tools.

[0068] In the development of battery technology, how to improve the reliability of battery monomers is a continuous research direction in battery technology.

[0069] In the use process of the battery monomer, the electrode assembly is easily punctured by a sharp object, which can cause internal short circuit and heat generation. The high temperature inside the battery monomer can cause the isolation member to shrink, thereby further aggravating the internal short circuit, which can easily cause severe thermal runaway, seriously affecting the reliability of the battery monomer.

[0070] Based on the above considerations, the application designs a battery monomer, which comprises a shell, an electrode assembly, an insulating film and a first insulating piece. The shell has a containing cavity, and the electrode assembly is contained in the containing cavity. The electrode assembly comprises an electrode body and a tab, and the tab is led out from one end of the electrode body along a first direction. The shell comprises a first wall, and the first wall is arranged along a second direction with the electrode assembly. The first direction intersects the second direction. The insulating film is wrapped on the outer surface of the electrode body, and the first insulating piece is arranged on the side of the first wall facing the electrode body. In the same plane perpendicular to the second direction, the orthographic projection of the first insulating piece is located in the orthographic projection of the electrode body, and the thermal decomposition temperature of the first insulating piece is greater than the thermal decomposition temperature of the insulating film.

[0071] The first insulating piece can protect the electrode body. On the one hand, the first insulating piece can resist the piercing of the electrode body by sharp objects to some extent, reducing the risk of internal short circuit. On the other hand, even if the electrode body is pierced by a sharp object to generate heat and cause the insulating film to fail, the first insulating piece can still play an insulating role to reduce the current generated by the internal short circuit and reduce heat generation, thereby reducing the risk of thermal runaway of the battery monomer and improving the reliability of the battery monomer.

[0072] In addition, the first insulating piece is arranged corresponding to the side surface of the electrode body facing the first wall, and the first insulating piece does not exceed the edge of the side surface of the electrode body facing the first wall. This not only can reduce the space occupation of the first insulating piece and improve the energy density of the battery monomer, but also can reduce the risk of interference with the shell during assembly and improve the assembly efficiency and product yield of the battery monomer.

[0073] Figure 1 For the structure diagram of the charging network in some embodiments of the application, Figure 2 For the structure diagram of the energy storage system in some embodiments of the application.

[0074] As Figure 1 and Figure 2 shown, the embodiments of the application provide a charging network, which comprises a charging pile 400 and an energy storage device 100. The charging pile 400 is electrically connected with the energy storage device 100, and the energy storage device 100 is used to provide electric energy for the charging pile 400. The charging pile 400 and the battery device in the energy storage device 100 are electrically connected through a cable, and the battery device can provide the electric energy stored by itself to the charging pile 400. The charging pile 400 has one or more connectors 500, which are used to connect with an electric equipment (such as a vehicle), so that the electric equipment can be charged.

[0075] The energy storage device 100 can be located inside the charging pile (for example, a charging and storage integrated machine), or can be located outside the charging pile.

[0076] In some embodiments, the energy storage system can include one or more energy storage devices 100 and a power converter system 200 for connecting between a power generation device 300 or a power grid or a load and the energy storage device 100. The power generation device 300 is configured to generate electric power, the energy storage device 100 is configured to store electric power, and the power converter system 200 is configured to convert electric power input to or output from the energy storage device 100. The electric power generated by the power generation device 300 can be stored in the energy storage device 100 through the power converter system 200, and the electric power stored in the energy storage device 100 can be output to a load or a power grid through the power converter system 200. As an example, the power generation device 300 can be a solar panel, a hydroelectric power generation device, a thermal power generation device, a wind power generation device, etc. The specific type of the power generation device 300 is not limited in the present application.

[0077] In some embodiments, the charging network can include a charging pile 400 and an energy storage system, and the charging pile 400 is electrically connected to the energy storage device 100 in the energy storage system.

[0078] The energy storage device 100 provided in the embodiments of the present application includes one or more battery clusters to improve the voltage and capacity of the energy storage device 100. The battery cluster can include a plurality of battery devices connected in series through a busbar component to improve the voltage of the energy storage device 100. When the energy storage device 100 includes a plurality of battery clusters, the plurality of battery clusters are connected in parallel to improve the capacity of the energy storage device 100.

[0079] The energy storage device 100 can be used in an energy storage power station, a wind power generation system, a solar power generation system, a mobile power system, or a temporary power supply system, etc. The energy storage device 100 can store electric power as needed and output the electric power at an appropriate time. For example, the energy storage device 100 can store electric power during a low electricity consumption period and provide electric power to relevant users or electric devices during a high electricity consumption period. The energy storage system provided in the embodiments of the present application can be any power system that needs to use the energy storage device 100.

[0080] In some embodiments, the energy storage device 100 is an energy storage container or an energy storage cabinet.

[0081] In some embodiments, the energy storage device 100 can include a cabinet body and one or more battery clusters, and the battery clusters are accommodated in the cabinet body.

[0082] In some embodiments, the energy storage device 100 can include a thermal management module, a master control module, a general control module, a power distribution module, a fire-fighting module, etc.

[0083] As an example, the thermal management module can include a liquid cooling unit that provides a coolant through a pipe to each battery device for regulating the temperature of the battery cells.

[0084] As an example, the master module can serve as a battery management unit of the battery cluster for monitoring and managing the battery cluster. The master module can monitor information such as current, voltage, power, or temperature of the battery cluster. For example, the charging and discharging current, voltage, etc. of the battery cluster can be controlled. The master module includes a slave battery management unit (SBMU), a fuse module, etc.

[0085] As an example, the master module can serve as a battery management unit of the battery cluster for monitoring and managing the battery cluster. The master module can monitor information such as current, voltage, power, or temperature of the battery cluster. For example, the charging and discharging current, voltage, etc. of the battery cluster can be controlled. The master module includes a slave battery management unit (SBMU), a fuse module, etc.

[0086] As an example, the fire extinguishing system includes a control panel, a detector, an alarm device, etc. for detecting, alarming, or extinguishing the energy storage system.

[0087] As an example, the power distribution device can be used to distribute power to the power consumption module of the energy storage device 100.

[0088] Figure 3 An exploded view of a battery device according to some embodiments of the present application.

[0089] In some embodiments, the battery device 2 can include one or more battery cell assemblies for providing voltage and capacity.

[0090] The battery cell assembly can include a plurality of battery cells (not shown) connected in series, in parallel, or in a mixed connection through a busbar. Figure 3 The mixed connection means that there are both series and parallel connections among the plurality of battery cells.

[0091] The battery cell can be a secondary battery cell, which means that the battery cell can be activated by charging after discharging.

[0092] As an example, the battery cell can be a lithium-ion battery cell, a sodium-ion battery cell, a sodium-lithium-ion battery cell, a lithium-metal battery cell, a sodium-metal battery cell, a lithium-sulfur battery cell, a magnesium-ion battery cell, a nickel-hydrogen battery cell, a nickel-cadmium battery cell, a lead-acid battery cell, or the like.

[0093] As an example, the battery cell can be a prismatic battery cell, a pouch battery cell, or a battery cell of other shapes, the prismatic battery cell including a square battery cell, a blade battery cell, a multi-prismatic battery cell, such as a hexagonal battery cell, or the like.

[0094] In some embodiments, the battery cell assembly is generally formed by arranging a plurality of battery cells; as an example, the battery cell assembly can be a battery module 6, which is formed by arranging and fixing a plurality of battery cells into one independent module. As an example, the battery module 6 can be formed by bundling a plurality of battery cells by a cable tie.

[0095] In some embodiments, the battery device 2 can be a battery pack, which includes a case 5 and one or more battery cell assemblies housed in the case 5. As an example, the battery cell assembly can be a battery module 6, which can be housed in the case by fixing the battery module 6 in the case. As an example, the battery cell assembly can also be housed in the case by fixing a plurality of battery cells directly in the case.

[0096] In some embodiments, the case 5 for housing the battery cells can be of various structures.

[0097] In some embodiments, the case 5 can include a first case 5a and a second case 5b. The first case 5a and the second case 5b are coupled so that an enclosed space is formed inside the case 5 to receive the battery cell assembly. The enclosed here means covered or closed, which can be sealed or unsealed. The first case can be a top cover or a bottom plate.

[0098] In some embodiments, the case 5 can include a top cover, a frame, and a bottom plate. The top cover and the bottom plate are respectively connected with the frame so that an enclosed space is formed inside the case to receive the battery cell assembly. As an example, the frame can include a plurality of side beams.

[0099] In some embodiments, the case 5 can be part of the chassis structure of a vehicle. For example, part of the case 5 can be at least part of the floor of the vehicle, or part of the case 5 can be at least part of the cross beam and the longitudinal beam of the vehicle.

[0100] In some embodiments, the battery device 2 can be an energy storage device.

[0101] The energy storage device can be used in an energy storage power station, a wind power system, a solar power system, a mobile power system, or a temporary power supply system, etc. The energy storage device can store electric energy as needed and output the electric energy at an appropriate time. For example, the energy storage device can store electric energy during a low electricity consumption period and provide electric energy for relevant users or electric equipment during a high electricity consumption period.

[0102] In some embodiments, the energy storage device includes an energy storage container, an energy storage cabinet, etc.

[0103] Figure 4 A structural schematic diagram of a battery module provided by some embodiments of the present application.

[0104] In some embodiments, as shown in Figure 4 The plurality of battery cells 7 are connected in series, in parallel, or in a mixed manner to form a battery module 6. A plurality of battery modules 6 are connected in series, in parallel, or in a mixed manner to form an entire system and are accommodated in a box.

[0105] The plurality of battery cells 7 in the battery module 6 can be electrically connected through busbar components to realize parallel connection, series connection, or mixed connection of the plurality of battery cells 7 in the battery module 6. The busbar components can be one or more, and each busbar component is used to electrically connect at least two battery cells 7.

[0106] The battery cell provided by the embodiments of the present application includes a shell and an electrode assembly accommodated in the shell.

[0107] In some embodiments, the shell can be a steel shell, an aluminum shell, or a composite metal shell (such as a copper-aluminum composite shell), etc.

[0108] The shell can be a hollow structure, and an accommodation cavity for accommodating the electrode assembly and the electrolyte is formed in the shell.

[0109] In some embodiments, the shell of the battery cell is a cylindrical shell, a square shell, a prismatic shell, or a shell of other shapes.

[0110] The shell can be in various shapes and sizes, such as a cuboid or a cylinder. Specifically, the shape of the shell can be determined according to the specific shape and size of the electrode assembly. The material of the shell can be various, such as copper, iron, aluminum, stainless steel, aluminum alloy, etc.

[0111] The shape of the end cover can be adapted to the shape of the shell to fit the shell. The material of the end cover can be the same as or different from the material of the shell. Alternatively, the end cover can be made of a material with certain hardness and strength (such as copper, iron, aluminum, stainless steel, aluminum alloy, etc.), so that the end cover is not easy to deform when subjected to extrusion and collision, and the battery cell can have higher strength and reliability.

[0112] The end cap is connected to the case by welding, adhesion, clamping, or other means.

[0113] The electrode assembly is a component in which electrochemical reactions occur in the battery cell. One or more electrode assemblies can be included in the case.

[0114] In some embodiments, the electrode assembly includes a positive electrode sheet and a negative electrode sheet, the positive electrode sheet being opposite in polarity to the negative electrode sheet.

[0115] In some embodiments, the positive electrode sheet can include a positive electrode current collector and a positive electrode film layer disposed on at least one surface of the positive electrode current collector.

[0116] As an example, the positive electrode current collector has two surfaces opposite in the thickness direction thereof, and the positive electrode film layer is disposed on either one or both of the two opposite surfaces of the positive electrode current collector.

[0117] As an example, the positive electrode current collector can employ a metal foil, a conductive polymer material, a carbon material, or a composite current collector. For example, as the metal foil, a pure metal, an alloy, a surface-treated metal, including but not limited to stainless steel, copper, aluminum, nickel, a nickel alloy, titanium, or silver, etc. can be employed. The composite current collector can include a polymer material base layer and a metal layer. The composite current collector can be formed by forming a metal material (aluminum, an aluminum alloy, nickel, a nickel alloy, titanium, a titanium alloy, silver, and a silver alloy, etc.) on a polymer material base material (such as a base material of polypropylene, polyethylene terephthalate, polybutylene terephthalate, polystyrene, polyethylene, etc.).

[0118] As an example, the positive electrode film layer includes a positive electrode active material, which can include at least one of a lithium-containing phosphate, a lithium transition metal oxide, and a modified compound of each thereof. However, the present application is not limited to these materials, and other conventional materials that can be used as a battery positive electrode active material can also be used. These positive electrode active materials can be used alone only one or two or more can be used in combination. Examples of the lithium-containing phosphate can include, but are not limited to, at least one of lithium iron phosphate (such as LiFeP04 (which can also be referred to as LFP)), a composite material of lithium iron phosphate and carbon, lithium manganese phosphate (such as LiMnP04), a composite material of lithium manganese phosphate and carbon, lithium manganese iron phosphate, and a composite material of lithium manganese iron phosphate and carbon. Examples of the lithium transition metal oxide can include, but are not limited to, at least one of lithium cobalt oxide (such as LiCo02), lithium nickel oxide (such as LiNi02), lithium manganese oxide (such as LiMn02, LiMn204), lithium nickel cobalt oxide, lithium manganese cobalt oxide, lithium nickel manganese oxide, lithium nickel cobalt manganese oxide (such as LiNi 1 / 3 Co 1 / 3 Mn 1 / 3 O2 (which can also be referred to as NCM 333 ), LiNi 0.5Co 0.2 Mn 0.3 O2(also referred to as NCM 523 ), LiNi 0.5 Co 0.25 Mn 0.25 O2(also referred to as NCM 211 ), LiNi 0.6 Co 0.2 Mn 0.2 O2(also referred to as NCM 622 ), LiNi 0.8 Co 0.1 Mn 0.1 O2(also referred to as NCM 811 ), lithium nickel cobalt aluminum oxide (such as LiNi 0.8 Co 0.15 Al 0.05 O2), and modified compounds thereof. The modified compounds refer to substances obtained by modification means such as doping or coating on the basis of the above-mentioned substances.

[0119] In some embodiments, the negative electrode sheet can include a negative electrode current collector.

[0120] As an example, the negative electrode current collector can adopt a metal foil, a conductive polymer material, a carbon material, or a composite current collector. For example, as the metal foil, a pure metal, an alloy, a surface-treated metal, including but not limited to stainless steel, copper, aluminum, nickel, nickel alloy, titanium, or silver, etc. can be adopted. The composite current collector can include a polymer material base layer and a metal layer. The composite current collector can be formed by forming a metal material (copper, copper alloy, nickel, nickel alloy, titanium, titanium alloy, silver, and silver alloy, etc.) on a polymer material base material (such as a base material of polypropylene, polyethylene terephthalate, polybutylene terephthalate, polystyrene, polyethylene, etc.).

[0121] As an example, the negative electrode sheet can include a negative electrode current collector and a negative electrode film layer disposed on at least one surface of the negative electrode current collector.

[0122] As an example, the negative electrode current collector has two opposite surfaces in the thickness direction of itself, and the negative electrode film layer is disposed on any one or both of the two opposite surfaces of the negative electrode current collector.

[0123] As an example, the negative electrode film layer includes a negative electrode active material, which can employ a negative electrode active material for a battery cell known in the art. As an example, the negative electrode active material can include at least one of artificial graphite, natural graphite, soft carbon, hard carbon, silicon-based material, tin-based material, and lithium titanate, etc. The silicon-based material can be selected from at least one of elemental silicon, silicon oxide compound, silicon-carbon composite, silicon-nitrogen composite, and silicon alloy. The tin-based material can be selected from at least one of elemental tin, tin oxide compound, and tin alloy. However, the present application is not limited to these materials, and other conventional materials that can be used as a negative electrode active material for a battery cell can also be used. These negative electrode active materials can be used alone or in combination of two or more.

[0124] In some embodiments, the material of the positive electrode current collector can be aluminum, and the material of the negative electrode current collector can be copper.

[0125] In some embodiments, the electrode assembly further includes a solid-state electrolyte. The solid-state electrolyte is disposed between the positive electrode sheet and the negative electrode sheet, and functions to transport ions and separate the positive electrode and the negative electrode.

[0126] In some embodiments, the solid-state electrolyte includes a polymer solid-state electrolyte, an inorganic solid-state electrolyte, a composite solid-state electrolyte.

[0127] As an example, the polymer of the polymer solid-state electrolyte can include polyether (polyethylene oxide), polysiloxane, polycarbonate, polyacrylonitrile, polyvinylidene fluoride, polymethyl methacrylate, a single-ion polymer, a polyionic liquid, cellulose, etc.

[0128] As an example, the inorganic solid-state electrolyte can be one or more of an oxide solid electrolyte (crystalline perovskite, sodium superionic conductor, garnet, amorphous LiPON thin film), a sulfide solid electrolyte (crystalline lithium superionic conductor (lithium germanium phosphorus sulfide, argyrodite), amorphous sulfide), a halide solid electrolyte, a nitride solid electrolyte, and a hydride solid electrolyte.

[0129] As an example, the composite solid-state electrolyte is formed by adding an inorganic solid-state electrolyte filler to a polymer solid-state electrolyte.

[0130] In some embodiments, the electrode assembly can be a wound structure, a stacked structure, or a hybrid structure of a wound structure and a stacked structure.

[0131] In some embodiments, the electrode assembly is a wound structure. The positive electrode sheet and the negative electrode sheet are wound to form the wound structure.

[0132] In some embodiments, the electrode assembly is a stacked structure.

[0133] As an example, a plurality of positive electrode sheets and a plurality of negative electrode sheets can be alternately stacked. As an example, a plurality of positive electrode sheets can be provided, and a negative electrode sheet can be folded to form a plurality of folded segments which are stacked. One positive electrode sheet can be clamped between adjacent folded segments.

[0134] As an example, a plurality of positive electrode sheets and a plurality of negative electrode sheets can be alternately stacked. As an example, a plurality of positive electrode sheets can be provided, and a negative electrode sheet can be folded to form a plurality of folded segments which are stacked. One positive electrode sheet can be clamped between adjacent folded segments.

[0135] In some embodiments, the electrode assembly can have a cylindrical shape, a flat shape, or a polygonal shape.

[0136] In some embodiments, the positive electrode current collector can include a positive electrode tab, and the negative electrode current collector can include a negative electrode tab. The positive electrode tab and the negative electrode tab can be used to transmit electric current. As an example, at least a portion of the positive electrode tab can not be coated with the positive electrode film layer, and at least a portion of the negative electrode tab can not be coated with the negative electrode film layer.

[0137] In some embodiments, the electrode assembly can have a cylindrical shape, a flat shape, or a polygonal shape.

[0138] In some embodiments, the electrode assembly can have a cylindrical shape, a flat shape, or a polygonal shape.

[0139] In some embodiments, the electrode assembly can include an electrode body. As an example, the electrode body can include the positive electrode film layer, a portion of the positive electrode current collector covered with the positive electrode film layer, the negative electrode film layer, and a portion of the negative electrode current collector covered with the negative electrode film layer.

[0140] The positive electrode tab and the negative electrode tab can be drawn from the same end of the electrode body, or can be drawn from opposite ends of the electrode body, respectively.

[0141] In some embodiments, the battery cell can include a positive electrode lead and a negative electrode lead. The positive electrode lead can be electrically connected to the positive electrode sheet, and the negative electrode lead can be electrically connected to the negative electrode sheet.

[0142] The positive electrode lead and the negative electrode lead can be used to electrically connect to an external circuit to charge or discharge the battery cell.

[0143] In some embodiments, the positive electrode lead can include a positive electrode terminal. At least a portion of the positive electrode terminal can be exposed to the outside of the battery cell to facilitate connection to a busbar member.

[0144] As an example, the positive electrode terminal can be a separately formed member which is mounted to the housing. Alternatively, the positive electrode terminal can also be a part of the housing.

[0145] In some examples, the positive terminal is directly connected to the positive tab; in other examples, the positive terminal and the positive tab are indirectly connected by other conductive structures, such as a positive adapter.

[0146] In some embodiments, the positive terminal is connected to the end cap by welding, riveting, clamping or other means.

[0147] In some embodiments, the negative lead-out portion includes a negative terminal. At least a portion of the negative terminal is exposed to the outside of the battery cell, to facilitate connection with the bus member.

[0148] As an example, the negative terminal can be a separately formed component that is mounted to the housing. Alternatively, the negative terminal can also be part of the housing.

[0149] In some examples, the negative terminal is directly connected to the negative tab; in other examples, the negative lead-out portion further includes other conductive structures, such as a negative adapter, that connect the negative terminal and the negative tab.

[0150] In some embodiments, the negative terminal is connected to the end cap by welding, riveting, clamping or other means.

[0151] Figure 5 A perspective structural schematic diagram of a battery cell according to some embodiments of the present application, Figure 6 A structural schematic diagram of a battery cell according to some embodiments of the present application, viewed from one side in a first direction, Figure 7 A structural schematic diagram of a battery cell according to some embodiments of the present application, Figure 6 A structural schematic diagram of a battery cell according to some embodiments of the present application, viewed from one side in a second direction, Figure 8 A structural schematic diagram of a battery cell according to some embodiments of the present application,

[0152] With reference to Figure 5 to Figure 8 According to some embodiments of the present application, a battery cell 7 is provided, the battery cell 7 including a housing 10, an electrode assembly 20, an insulating film and a first insulating member 30. The housing 10 has a receiving cavity 11, and the electrode assembly 20 is received in the receiving cavity 11. The electrode assembly 20 includes an electrode body 21 and a tab 22, the tab 22 being led out from one end of the electrode body 21 in a first direction X. The housing 10 includes a first wall 12, and the first wall 12 is arranged with the electrode assembly 20 in a second direction Y, the first direction X intersecting the second direction Y. The insulating film is wrapped around an outer surface of the electrode body 21, and the first insulating member 30 is arranged on a side of the first wall 12 facing the electrode body 21. In the same plane perpendicular to the second direction Y, a positive projection of the first insulating member 30 is located within a positive projection of the electrode body 21, and a thermal decomposition temperature of the first insulating member 30 is greater than a thermal decomposition temperature of the insulating film.

[0153] The first insulating piece 30 has good high-temperature resistance and insulation performance, and is mainly used to improve the puncture resistance of the battery monomer 7.

[0154] Exemplarily, the first insulating piece 30 can be a sheet structure or a film structure.

[0155] Optionally, the material of the first insulating piece 30 can be, but is not limited to, polyimide, polyphenylene sulfide, polytetrafluoroethylene, or ceramic material, etc.

[0156] In the same plane perpendicular to the second direction Y, the orthographic projection of the first insulating piece 30 is located in the orthographic projection of the electrode body 21. In other words, the first insulating piece 30 is arranged corresponding to the side surface of the electrode body 21 facing the first wall 12, and the first insulating piece 30 does not exceed the edge of the side surface of the electrode body 21 facing the first wall 12.

[0157] The first insulating piece 30 can be connected to at least one of the first wall 12 and the electrode body 21, or can be arranged spaced apart from the first wall 12 and / or the electrode body 21.

[0158] The thermal decomposition temperature refers to the temperature threshold at which a material begins to chemically decompose and significantly loses weight during heating. When the temperature exceeds this threshold, the structure of the material changes, leading to a decrease in performance or failure.

[0159] The first insulating piece 30 can protect the electrode body 21. On the one hand, the first insulating piece 30 can resist the puncture of the electrode body 21 by sharp objects to some extent, reducing the risk of internal short circuit. On the other hand, even if the electrode body 21 is punctured by a sharp object and the insulation film fails due to heat generation, the first insulating piece 30 can still play an insulating role to reduce the current generated by internal short circuit and reduce heat generation, thereby reducing the risk of thermal runaway of the battery monomer 7 and improving the reliability of the battery monomer 7.

[0160] In addition, the first insulating piece 30 is arranged corresponding to the side surface of the electrode body 21 facing the first wall 12, and the first insulating piece 30 does not exceed the edge of the side surface of the electrode body 21 facing the first wall 12. This not only reduces the space occupation of the first insulating piece 30 and improves the energy density of the battery monomer 7, but also reduces the risk of interference with the shell 10 during assembly and improves the assembly efficiency and product yield of the battery monomer 7.

[0161] In some embodiments, the first insulating piece 30 can be connected to the first wall 12.

[0162] The first insulating member 30 can be directly connected to the first wall 12 or can be limited on the first wall 12 by other components. As an example, the connection mode of the first insulating member 30 to the first wall 12 can be, but is not limited to, bolting, riveting, clamping, or bonding, etc.

[0163] In some embodiments, the first insulating member 30 can be connected to the electrode body 21.

[0164] The first insulating member 30 can be directly connected to the electrode body 21 or can be limited on the electrode body 21 by other components. As an example, the connection mode of the first insulating member 30 to the electrode body 21 can be bonding.

[0165] In some embodiments, the first direction X is perpendicular to the second direction Y.

[0166] In some embodiments, the number of the first walls 12 is two, and the two first walls 12 are oppositely arranged along the second direction Y, and each first wall 12 is provided with a first insulating member 30 on the side facing the electrode body 21.

[0167] In some embodiments, in the same plane perpendicular to the second direction Y, the area S1 of the orthographic projection of the first insulating member 30 and the area S2 of the orthographic projection of the electrode body 21 satisfy the relationship: 5%≤S1 / S2≤80%.

[0168] As an example, S1 / S2 can be, but is not limited to, 5%, 10%, 20%, 40%, 60%, 80%, etc.

[0169] By setting S1 / S2 to be greater than or equal to 5%, the coverage area of the first insulating member 30 can be effectively improved to improve the protection effect of the first insulating member 30 on the electrode body 21; by setting S1 / S2 to be less than or equal to 80%, the space occupation of the first insulating member 30 can be reduced to improve the energy density of the battery monomer 7.

[0170] In some embodiments, in the same plane perpendicular to the second direction Y, the area S1 of the orthographic projection of the first insulating member 30 and the area S2 of the orthographic projection of the electrode body 21 satisfy the relationship: 10%≤S1 / S2≤60%. The protection effect of the first insulating member 30 and the energy density of the battery monomer 7 can be further considered.

[0171] As an example, S1 / S2 can be, but is not limited to, 10%, 15%, 30%, 50%, 55%, 60%, etc.

[0172] In some embodiments, in the same plane perpendicular to the second direction Y, the maximum distance between the edge of the orthographic projection of the first insulating member 30 and the edge of the orthographic projection of the electrode body 21 is: 10mm-240mm.

[0173] As an example, the maximum distance between the edge of the orthographic projection of the first insulating member 30 and the edge of the orthographic projection of the electrode body 21 can be, but is not limited to, 10 mm, 30 mm, 50 mm, 100 mm, 150 mm, 240 mm, etc.

[0174] By setting the maximum distance between the edge of the orthographic projection of the first insulating member 30 and the edge of the orthographic projection of the electrode body 21 to be greater than or equal to 10 mm, the risk of the first insulating member 30 interfering with the shell 10 during assembly can be reduced, thereby improving the assembly efficiency and product yield of the battery monomer 7; by setting the maximum distance between the edge of the orthographic projection of the first insulating member 30 and the edge of the orthographic projection of the electrode body 21 to be less than or equal to 240 mm, the coverage area of the first insulating member 30 can be effectively improved, thereby improving the protection effect of the first insulating member 30 on the electrode body 21.

[0175] In some embodiments, the maximum distance between the edge of the orthographic projection of the first insulating member 30 and the edge of the orthographic projection of the electrode body 21 in the same plane perpendicular to the second direction Y is: 15 mm-100 mm. The protection effect of the first insulating member 30 and the assembly efficiency and product yield of the battery monomer 7 can be further considered.

[0176] As an example, the maximum distance between the edge of the orthographic projection of the first insulating member 30 and the edge of the orthographic projection of the electrode body 21 can be, but is not limited to, 15 mm, 25 mm, 30 mm, 60 mm, 90 mm, 100 mm, etc.

[0177] In some embodiments, the thermal decomposition temperature of the first insulating member 30 is: 400℃-1500℃.

[0178] The thermal decomposition temperature refers to the temperature threshold at which the material begins to chemically decompose and significantly loses weight during heating. When the temperature exceeds this threshold, the structure of the first insulating member 30 changes, resulting in a decrease or failure in its performance.

[0179] As an example, the thermal decomposition temperature of the first insulating member 30 can be, but is not limited to, 400℃, 500℃, 600℃, 800℃, 1000℃, 1200℃, 1500℃, etc.

[0180] By setting the thermal decomposition temperature of the first insulating member 30 to be greater than or equal to 400℃, the protection effect of the first insulating member 30 on the electrode body 21 can be improved; by setting the thermal decomposition temperature of the first insulating member 30 to be less than or equal to 1500℃, the difficulty of obtaining the material can be effectively reduced, thereby reducing the cost.

[0181] As an example, the thermal decomposition temperature of the first insulating member 30 can be tested in accordance with the national standard GB / T 33047.1-2016 “Plastics - Thermogravimetry (TG) - Part 1: General principles” or GB / T 27761-2011 “Determination of thermal stability of solid materials by thermogravimetry”.

[0182] As an example, simply speaking, a sample of the first insulating member 30 can be heated in a nitrogen or air environment at a fixed heating rate (such as 10℃ / min), and the mass change is recorded. The temperature corresponding to a 5% loss of mass of the sample of the first insulating member 30 is the thermal decomposition temperature.

[0183] In some embodiments, the thermal decomposition temperature of the first insulating member 30 is 500℃-1000℃. This can further take into account the protection effect and cost of the first insulating member 30.

[0184] As an example, the thermal decomposition temperature of the first insulating member 30 can be, but is not limited to, 500℃, 600℃, 700℃, 800℃, 900℃, 1000℃, etc.

[0185] In some embodiments, the size of the first insulating member 30 along the second direction Y is 0.05mm-2mm.

[0186] As an example, the size of the first insulating member 30 along the second direction Y can be, but is not limited to, 0.05mm, 0.1mm, 0.5mm, 1mm, 1.5mm, 2mm, etc.

[0187] As an example, the size of the first insulating member 30 along the second direction Y can be, but is not limited to, 0.05mm, 0.1mm, 0.5mm, 1mm, 1.5mm, 2mm, etc.

[0188] By setting the size of the first insulating member 30 along the second direction Y to be greater than or equal to 0.05mm, the structural reliability of the first insulating member 30 can be improved, so as to improve the protection effect of the first insulating member 30 on the electrode body 21. By setting the size of the first insulating member 30 along the second direction Y to be less than or equal to 2mm, the space occupation of the first insulating member 30 can be reduced, so as to improve the energy density of the battery monomer 7.

[0189] In some embodiments, the size of the first insulating member 30 along the second direction Y is 0.1mm-0.2mm. This can further take into account the protection effect of the first insulating member 30 and the energy density of the battery monomer 7.

[0190] As an example, the size of the first insulating member 30 along the second direction Y can be, but is not limited to, 0.1mm, 0.12mm, 0.14mm, 0.16mm, 0.18mm, 0.2mm, etc.

[0191] In some embodiments, the first insulating member 30 is bonded to the electrode body 21.

[0192] In some embodiments, the first insulating member 30 is bonded to the insulating film.

[0193] In some embodiments, the first insulating member 30 has a peel strength of 0.1 N / mm to 1.5 N / mm.

[0194] For example, the peel strength of the first insulating member 30 can be, but is not limited to, 0.1 N / mm, 0.5 N / mm, 0.8 N / mm, 1 N / mm, 1.5 N / mm, etc.

[0195] In some embodiments, the second direction Y is parallel to the thickness direction of the electrode assembly 20. That is, the first wall 12 is arranged opposite to the large face of the electrode body 21, and the first insulating member 30 is arranged between the first wall 12 and the large face of the electrode body 21.

[0196] It can be understood that the large face side of the electrode body 21 is more likely to be punctured by a sharp object. Therefore, the above technical solution can better protect the electrode body 21 by the first insulating member 30, so as to further improve the reliability of the battery monomer 7.

[0197] In some embodiments, the electrode body 21 includes a first electrode tab, a second electrode tab, and a separator, the first electrode tab and the second electrode tab having opposite polarities, and at least part of the separator is arranged between the first electrode tab and the second electrode tab. The thermal decomposition temperature of the first insulating member 30 is greater than the thermal decomposition temperature of the separator.

[0198] One of the first electrode tab and the second electrode tab is a positive electrode tab, and the other is a negative electrode tab.

[0199] The above technical solution can still play an insulating role by the first insulating member 30 to reduce the current generated by internal short circuit and reduce heat generation even in the case that the separator fails due to heat generated by the puncture of the electrode body 21 by a sharp object, thereby reducing the risk of thermal runaway of the battery monomer 7 and improving the reliability of the battery monomer 7.

[0200] For example, the thermal decomposition temperature of the separator can be tested according to the national standard GB / T33047.1-2016 "Plastics - Determination of thermal stability by thermogravimetry (TG) - Part 1: General principles" or GB / T27761-2011 "Determination of thermal stability of solid materials by thermogravimetry".

[0201] In some embodiments, the separator is a separator film. The type of the separator film is not particularly limited in the present application, and any known porous structure separator film with good chemical stability and mechanical stability can be selected.

[0202] As an example, the main material of the separator film can be selected from at least one of glass fiber, non-woven fabric, polyethylene, polypropylene, and polyvinylidene fluoride. The separator film can be a single layer film or a multi-layer composite film, and is not particularly limited. When the separator film is a multi-layer composite film, the materials of the respective layers can be the same or different, and are not particularly limited. The separator can be a separate component located between the positive and negative electrodes, or can be attached to the surface of the positive and negative electrodes. An inorganic particle coating, an organic particle coating, or an organic / inorganic composite coating can be applied to the surface of the separator film.

[0203] In some embodiments, the separator is a solid-state electrolyte. The solid-state electrolyte is disposed between the positive electrode and the negative electrode, and functions to transport ions and separate the positive electrode and the negative electrode.

[0204] In some embodiments, the first insulating member 30 is disposed between the first wall 12 and the insulating film.

[0205] The above technical solution can reduce the assembly difficulty between the insulating film and the electrode body 21, and improve the flatness of the insulating film on the electrode body 21.

[0206] Figure 9 Another structure schematic view of the electrode assembly of the battery cell provided by some embodiments of the present application and the first insulating member along a side view in a second direction, Figure 10 For Figure 9 A cross-sectional structure schematic view along B-B, Figure 11 For Figure 10 A structure schematic view of the first insulating member along a side view in a second direction.

[0207] Continuing to refer to Figure 9 to Figure 11 In some embodiments, the battery cell 7 further includes a heat absorbing member 40 connected to the first insulating member 30 and disposed along the second direction Y with the first insulating member 30, and the heat absorbing member 40 is configured to absorb heat when the temperature of the accommodation cavity 11 reaches a first threshold value.

[0208] Illustratively, the heat absorbing member 40 can absorb the heat in the accommodation cavity 11 when the temperature of the accommodation cavity 11 reaches the first threshold value by a chemical heat absorption method, i.e., by using a material to absorb heat through endothermic decomposition or endothermic reaction at high temperature. For example, carbonate decomposition endothermic or fluorine-containing polymer decomposition endothermic, etc.

[0209] The heat absorbing member 40 can also absorb the heat in the accommodation cavity 11 when the temperature of the accommodation cavity 11 reaches the first threshold value by a thermal desorption method, i.e., by using a material to absorb heat through chemical bond rupture at high temperature. For example, organic gel material or phenolic resin, etc.

[0210] The heat-absorbing member 40 can be arranged on the side of the first insulating member 30 facing the first wall 12, or on the side of the first insulating member 30 facing the electrode body 21.

[0211] The heat-absorbing member 40 can be directly connected to the first insulating member 30, or can be limited on the first insulating member 30 by other components. As an example, the heat-absorbing member 40 can be connected to the first insulating member 30 by, but not limited to, riveting, clamping, or bonding.

[0212] Optionally, the heat-absorbing member 40 can be, but is not limited to, a plate-shaped structure, a film layer-shaped structure, or a block-shaped structure.

[0213] The above technical solution can further reduce the heat generation when the electrode body 21 is pierced by a sharp object by introducing the heat-absorbing member 40, thereby further reducing the risk of thermal runaway of the battery monomer 7 and improving the energy density of the battery monomer 7.

[0214] Exemplarily, the first threshold value can be a temperature value or a temperature interval.

[0215] For example, the first threshold value can be, but is not limited to, 100℃, 110℃, 120℃, 130℃, 140℃, 150℃, 160℃, etc.

[0216] In some embodiments, the heat-absorbing member 40 can include a phase change body connected to the first insulating member 30 and arranged along the second direction Y with the first insulating member 30, and the phase change body is configured to generate a phase change and absorb heat when the temperature of the accommodation cavity 11 reaches the first threshold value.

[0217] Exemplarily, the phase change body can be at least one of paraffin, fatty acid, hydrated salt, inorganic salt eutectic, metal alloy phase change material, polymer phase change material, or composite microcapsule structure thereof.

[0218] In some embodiments, the electrode body 21 includes a first electrode sheet, a second electrode sheet, and a separator, the first electrode sheet and the second electrode sheet have opposite polarities, and at least part of the separator is arranged between the first electrode sheet and the second electrode sheet. The first threshold value is less than the thermal decomposition temperature of the separator.

[0219] In some embodiments, the first insulating member 30 is provided with a recess on one side along the second direction Y, and at least part of the heat-absorbing member 40 is arranged in the recess.

[0220] The recess can be arranged on the side of the first insulating member 30 facing the first wall 12, or on the side of the first insulating member 30 facing the electrode body 21.

[0221] The heat-absorbing member 40 can be partially arranged in the recess, or can be entirely accommodated in the recess.

[0222] The technical solution can reduce the occupation of the heat-absorbing member 40 to the internal space of the battery monomer 7, and help to improve the energy density of the battery monomer 7.

[0223] In some embodiments, the heat-absorbing member 40 has a ring structure, and the heat-absorbing member 40 is arranged along the circumferential edge of the first insulating member 30. The central region of the first insulating member 30 can be avoided, so that the first insulating member 30 can better protect the central region of the electrode body 21 which is more likely to be punctured.

[0224] In some embodiments, the number of heat-absorbing members 40 is multiple, and the multiple heat-absorbing members 40 are arranged along the circumferential edge of the first insulating member 30. The central region of the first insulating member 30 can be avoided, so that the first insulating member 30 can better protect the central region of the electrode body 21 which is more likely to be punctured.

[0225] Figure 12 Figure 6 is a structural schematic diagram of a side view of the electrode assembly of the battery monomer in the second direction cooperating with the first insulating member according to another embodiment of the present application, Figure 13 Figure 7 is a structural schematic diagram of a side view of the electrode assembly of the battery monomer in the second direction cooperating with the first insulating member according to another embodiment of the present application, Figure 12 Figure 8 is a sectional structural schematic diagram along C-C.

[0226] Continuing to refer to Figure 12 to Figure 13 In some embodiments, the battery monomer 7 further comprises a buffer member 50 connected to one side of the first insulating member 30 facing the first wall 12, and the elastic modulus of the buffer member 50 is less than that of the first insulating member 30.

[0227] The buffer member 50 can be directly connected with the first insulating member 30, or can be limited on the first insulating member 30 through other components. As an example, the connection mode of the buffer member 50 and the first insulating member 30 can be, but is not limited to, riveting, clamping or bonding, etc.

[0228] The buffer member 50 has a small elastic modulus and a relatively soft texture. When the battery monomer 7 is punctured by a sharp object, the buffer member 50 can absorb part of the impact force by deforming itself, thereby playing a certain buffering role, so as to reduce the force of the sharp object on the first insulating member 30 and the electrode body 21, thereby further improving the reliability of the battery monomer 7.

[0229] Optionally, the buffer member 50 can be, but is not limited to, made of silica gel, foam or rubber, etc.

[0230] Optionally, the buffer member 50 can be, but is not limited to, a sheet-shaped structure, a film layer-shaped structure or a block-shaped structure, etc.

[0231] As an example, the elastic modulus of the buffer member 50 and the first insulating member 30 can refer to the national standard GB / T22315 2008 Metallic Materials - Test Methods for Determination of Young's Modulus and Modulus of Transverse Rupture.

[0232] Figure 14 Another structural schematic view of a battery cell from a side view in a first direction according to some embodiments of the present application, Figure 15 Figure 14 A cross-sectional structural schematic view along D-D.

[0233] With reference to the foregoing Figure 14 to Figure 15 In some embodiments, the number of electrode bodies 21 is plural, the plural electrode bodies 21 are arranged along a second direction Y, and the battery cell 7 further comprises a second insulating member 60 arranged between two adjacent electrode bodies 21.

[0234] The current of internal short circuit when the electrode assembly 20 is punctured by a sharp object can be further reduced, thereby further reducing heat generation and reducing the risk of thermal runaway of the battery cell 7.

[0235] The second insulating member 60 can have the same structural features as the first insulating member 30, and the structural details of the second insulating member 60 can refer to the foregoing first insulating member 30, which will not be described here.

[0236] In some embodiments, the battery cell 7 comprises two electrode bodies 21, each electrode body 21 is provided with a first insulating member 30 on the side facing the first wall 12, and each electrode body 21 is provided with a second insulating member 60 on the side away from the first wall 12.

[0237] In some embodiments, the orthographic projections of two second insulating members 60 between two adjacent electrode assemblies 20 are arranged with a spacing in the same plane perpendicular to the second direction Y. This helps to reduce the overall space occupation of the second insulating member 60 along the second direction Y, and helps to improve the energy density of the battery cell 7.

[0238] In some embodiments, the orthographic projection of the first insulating member 30 and the orthographic projection of the second insulating member 60 at least partially overlap in the same plane perpendicular to the second direction Y.

[0239] In some embodiments, the thermal conductivity of the second insulating member 60 is less than that of the first insulating member 30. This can reduce the heat conduction between two adjacent electrode assemblies 20, thereby reducing the thermal influence between two adjacent electrode assemblies 20.

[0240] According to some embodiments of the present application, the present application further provides a battery device comprising the battery cell 7 of any of the above solutions.

[0241] ​According to some embodiments of the present application, the present application also provides a power-using device comprising the battery cell 7 or the battery device of any of the above solutions, and the battery cell 7 or the battery device is used for storing or providing electric energy.

[0242] If not specifically stated, all the embodiments and optional embodiments of the present application can be combined with each other to form new technical solutions. All the technical features and optional technical features of the present application can be combined with each other to form new technical solutions.

[0243] In order to better understand the battery cell 7 provided by the embodiments of the present application, based on the same inventive concept, an embodiment of the above battery cell 7 in actual application is provided for description.

[0244] The embodiments of the present application provide a battery cell 7, the battery cell 7 comprises a shell 10, an electrode assembly 20, an insulating film and a first insulating piece 30, the shell 10 has a containing cavity 11, the electrode assembly 20 is contained in the containing cavity 11, the electrode assembly 20 comprises an electrode main body 21 and a tab 22, the tab 22 is led out from one end of the electrode main body 21 along a first direction X, the shell 10 comprises a first wall 12, the first wall 12 is arranged along a second direction Y with the electrode assembly 20, and the first direction X intersects with the second direction Y. The insulating film is wrapped on the outer surface of the electrode main body 21, and the first insulating piece 30 is arranged on the side of the first wall 12 facing the electrode main body 21. In the same plane perpendicular to the second direction Y, the orthographic projection of the first insulating piece 30 is located in the orthographic projection of the electrode main body 21. The thermal decomposition temperature of the first insulating piece 30 is greater than the thermal decomposition temperature of the insulating film, and the thermal decomposition temperature of the first insulating piece 30 is 400-1500℃.

[0245] The first insulating piece 30 can play a protective role on the electrode main body 21. On the one hand, the first insulating piece 30 can resist the piercing of the electrode main body 21 by sharp objects to a certain extent, reducing the risk of internal short circuit. On the other hand, even if the insulating film fails due to the heat generated by the piercing of the electrode main body 21 by sharp objects, the first insulating piece 30 can still play an insulating role to reduce the current generated by the internal short circuit and reduce the heat generation, thereby reducing the risk of thermal runaway of the battery cell 7 and improving the reliability of the battery cell 7.

[0246] In addition, the first insulating piece 30 is arranged corresponding to the side surface of the electrode main body 21 facing the first wall 12, and the first insulating piece 30 does not exceed the edge of the side surface of the electrode main body 21 facing the first wall 12. This not only can reduce the space occupation of the first insulating piece 30 and improve the energy density of the battery cell 7, but also can reduce the risk of interference with the shell 10 during assembly and improve the assembly efficiency and product yield of the battery cell 7.

[0247] It should be noted that the embodiments and features of the embodiments in the present application can be combined with each other without conflict.

[0248] Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the present application, but not to limit them; although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand: it can still modify the technical solutions recorded in the foregoing embodiments, or make equivalent replacement for part or all of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present application, and they should be covered in the scope of the claims and the description of the present application. Especially, as long as there is no structural conflict, each technical feature mentioned in each embodiment can be combined in any way. The present application is not limited to the specific embodiments disclosed in the text, but includes all technical solutions falling within the scope of the claims.

Claims

1. A battery cell, characterized by, The battery monomer comprises: a housing having a receiving cavity; an electrode assembly accommodated in the receiving cavity, the electrode assembly comprising an electrode body and a tab, the tab being led out from one end of the electrode body in a first direction, the housing comprising a first wall, the first wall being arranged with the electrode assembly in a second direction, the first direction intersecting the second direction; an insulation film covering at least part of the outer surface of the electrode body; a first insulation member arranged on the side of the first wall facing the electrode body in the second direction, the orthographic projection of the first insulation member being located within the orthographic projection of the electrode body, the thermal decomposition temperature of the first insulation member being greater than the thermal decomposition temperature of the insulation film.

2. The battery cell of claim 1, wherein, In the same plane perpendicular to the second direction, the orthographic projection area S1 of the first insulation member and the orthographic projection area S2 of the electrode body satisfy the relationship: 5%≤S1 / S2≤80%.

3. The battery cell of claim 1, wherein, In the same plane perpendicular to the second direction, the maximum distance between the edge of the orthographic projection of the first insulation member and the edge of the orthographic projection of the electrode body is: 10mm-240mm.

4. The battery cell of claim 1, wherein, The thermal decomposition temperature of the first insulation member is: 400℃-1500℃.

5. The battery cell of claim 1, wherein, The dimension of the first insulation member in the second direction is: 0.05mm-2mm.

6. The battery cell of claim 1, wherein, The second direction is parallel to the thickness direction of the electrode assembly.

7. The battery cell of claim 1, wherein, The electrode body comprises a first pole piece, a second pole piece and a separator, the first pole piece and the second pole piece having opposite polarities, at least part of the separator being arranged between the first pole piece and the second pole piece; The thermal decomposition temperature of the first insulation member is greater than the thermal decomposition temperature of the separator.

8. The battery cell of claim 1, wherein, The first insulation member is arranged between the first wall and the insulation film.

9. The battery cell of claim 1, wherein, The battery monomer further comprises a heat absorption member connected to the first insulation member and arranged with the first insulation member in the second direction, the heat absorption member being configured to absorb heat when the temperature of the receiving cavity reaches a first threshold value.

10. The battery cell of claim 9, wherein, One side of the first insulation member in the second direction is provided with a recess, at least part of the heat absorption member being arranged in the recess.

11. The battery cell of claim 1, wherein, The battery monomer further comprises a buffer member connected to the side of the first insulation member facing the first wall, the elastic modulus of the buffer member being less than the elastic modulus of the first insulation member.

12. The battery cell of claim 1, wherein, The number of electrode assemblies is multiple, and multiple electrode assemblies are arranged in the second direction, the battery monomer further comprising a second insulation member arranged between the electrode bodies of two adjacent electrode assemblies.

13. A battery device characterized by comprising: A plurality of battery monomers as claimed in any one of claims 1-12.

14. An energy storage device, characterized by A plurality of battery monomers as claimed in any one of claims 1-12 or a plurality of battery devices as claimed in claim 13 are used to store or provide electrical energy.

15. An energy storage system characterized by, An energy conversion system and an energy storage device as claimed in claim 14 are connected, the energy conversion system being used to convert the current input to or output from the energy storage device.

16. A charging network characterized in that, comprising a charging post and an energy storage device as claimed in claim 14 or an energy storage system as claimed in claim 15, the energy storage device being used to provide electrical energy for the charging post.

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