CN223124177U - Battery monomer, battery device, electric equipment and energy storage equipment - Google Patents

Abstract

The embodiment of the present application provides a battery cell, a battery device, an electric device and an energy storage device, which can improve the performance of the battery cell. The battery cell includes: a shell, an electrode assembly, a pressure relief mechanism and an insulating member, the shell includes a receiving cavity, the electrode assembly is received in the receiving cavity, the pressure relief mechanism is arranged on the first wall of the shell, the insulating member is used to wrap at least part of the surface of the electrode assembly facing the shell, the insulating member includes a first connecting portion opposite to the first wall, wherein the melting point of the first connecting portion is lower than the melting point of the remaining portion of the insulating member except the first connecting portion.

Description

Battery monomer, battery device, electric equipment and energy storage equipment

Technical Field

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

Background

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

In addition to improving the electrical performance of battery devices, safety issues are also a non-negligible issue in the development of battery technology, such as thermal runaway issues of the battery cells. If the safety problem of the battery device cannot be guaranteed, the battery device cannot be used, and the service performance of the battery device is reduced. Therefore, how to reduce the risk of thermal runaway diffusion of the battery cell and improve the service performance of the battery cell has become a technical problem to be solved in the art.

Disclosure of utility model

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

In a first aspect, a battery cell is provided, including a housing including a receiving cavity, an electrode assembly received in the receiving cavity, a pressure relief mechanism disposed on a first wall of the housing, an insulating member for wrapping at least a portion of a surface of the electrode assembly facing the housing, the insulating member including a first connection portion opposite to the first wall, wherein a melting point of the first connection portion is smaller than a melting point of a remaining portion of the insulating member other than the first connection portion.

In the embodiment of the application, the insulating part is arranged to wrap at least part of the surface of the electrode assembly facing the shell, and comprises the first connecting part opposite to the first wall where the pressure release mechanism is located, the melting point of the first connecting part is smaller than that of the rest part except the first connecting part of the insulating part, and under the condition that the battery cell is in thermal runaway, namely in the process of increasing the temperature of the interior of the battery cell, the first connecting part is melted earlier than the rest part except the first connecting part of the insulating part, so that an exhaust channel communicated with the pressure release mechanism is formed between the first wall and the surface of the electrode assembly corresponding to the first connecting part, high-temperature and high-pressure gas generated by the electrode assembly is directionally discharged to the exterior of the battery cell through the exhaust channel and the pressure release mechanism, the risk of damaging the rest wall except the first wall of the shell by the high-temperature and high-pressure gas is reduced, and meanwhile, the use performance of the battery cell is improved.

In some implementations, the insulating member further includes a second connection portion connected to the first connection portion, the first connection portion for covering a first surface of the electrode assembly, the second connection portion for covering a second surface of the electrode assembly, the second surface having an area greater than an area of the first surface.

In the embodiment of the application, the insulating part is arranged to further comprise a second connecting part connected with the first connecting part, the first connecting part is used for covering the first surface of the electrode assembly, the second connecting part is used for covering the second surface of the electrode assembly, the area of the second surface is larger than that of the first surface, and under the condition that the battery cell is in thermal runaway, the first connecting part is melted compared with the second connecting part, so that an exhaust channel communicated with the pressure release mechanism is formed between the first wall and the first surface, high-temperature and high-pressure gas generated by the electrode assembly is directionally discharged to the outside of the battery cell through the exhaust channel and the pressure release mechanism, the risk of damaging the wall, opposite to the second surface, of the shell by the high-temperature and high-pressure gas is reduced, namely, the risk of short circuit of the battery cell caused by direct contact between the second surface and the surface of the shell is reduced, and meanwhile, the risk of thermal runaway diffusion is reduced, and the service performance of the battery cell is improved.

In some implementations, the melting point T1 of the first connection portion and the melting point T2 of the second connection portion satisfy that T2/T1 is greater than or equal to 1.5. In this way, in the embodiment of the application, by setting the melting point T1 of the first connecting part and the melting point T2 of the second connecting part to be equal to or greater than 1.5, under the condition that the battery cell is in thermal runaway, the first connecting part can be melted preferentially compared with the second connecting part, so that an exhaust channel communicated with the pressure release mechanism is formed between the first wall and the first surface, and high-temperature and high-pressure gas generated by the electrode assembly is directionally discharged to the outside of the battery cell through the exhaust channel and the pressure release mechanism, the risk of thermal runaway diffusion is reduced, and the service performance of the battery cell is improved.

In some implementations, the first connection portion is provided with a first through hole penetrating the first connection portion in a thickness direction of the first connection portion, the first through hole communicating with the accommodation chamber.

In the embodiment of the application, the first through hole penetrating through the first connecting part along the thickness direction of the first connecting part is arranged on the first connecting part, and is communicated with the accommodating cavity, so that the first connecting part can be quickly melted under the condition that the battery monomer is out of control, an exhaust channel communicated with the pressure release mechanism is formed between the first wall and the first surface, and high-temperature and high-pressure gas generated by the electrode assembly is directionally and quickly discharged to the outside of the battery monomer through the exhaust channel and the pressure release mechanism, the risk of out-of-control diffusion is reduced, and the service performance of the battery monomer is improved.

In some implementations, the first connection portion is provided with a plurality of the first through holes, and the plurality of the first through holes are arranged at intervals along a first direction, and the first direction is perpendicular to a thickness direction of the first connection portion.

In the embodiment of the application, the plurality of first through holes are arranged on the connecting part, and the plurality of first through holes are arranged at intervals along the first direction, and the first direction is perpendicular to the thickness direction of the first connecting part, so that the melting of the first connecting part can be further accelerated under the condition that the battery cell is out of control, an exhaust channel communicated with the pressure release mechanism is formed between the first wall and the first surface, high-temperature and high-pressure gas generated by the electrode assembly is directionally and rapidly discharged to the outside of the battery cell through the exhaust channel and the pressure release mechanism, the risk of out-of-control diffusion is reduced, and the service performance of the battery cell is improved.

In some implementations, the first connection is provided with a zone of weakness configured to melt upon the temperature within the receiving cavity reaching a threshold such that a vent passage is formed between the first surface and the first wall in communication with the pressure relief mechanism.

In the embodiment of the application, the weak area is arranged on the first connecting part and is configured to be melted under the condition that the temperature in the accommodating cavity reaches the threshold value, so that the exhaust channel communicated with the pressure release mechanism is formed between the first surface and the first wall, high-temperature and high-pressure gas generated by the electrode assembly is directionally and rapidly discharged to the outside of the battery cell through the exhaust channel and the pressure release mechanism, the risk of thermal runaway diffusion is reduced, the service performance of the battery cell is improved, and meanwhile, under the condition that thermal runaway does not occur, the risk of short circuit caused by direct contact between the shell and the electrode assembly can be reduced due to the arrangement of the weak area.

In some implementations, the weakened area has a thickness that is less than a thickness of a remaining area of the first connection portion other than the weakened area, and/or the weakened area is provided with a score on a surface perpendicular to a thickness direction of the first connection portion.

In the embodiment of the application, the thickness of the weak area is smaller than that of the rest areas of the first connecting part except the weak area, and/or the weak area is provided with the scores on the surface perpendicular to the thickness direction of the first connecting part, so that when the battery cells are in thermal runaway, the weak area of the first connecting part can be melted preferentially, and the melting of the first connecting part is further accelerated, so that an exhaust channel communicated with the pressure release mechanism is formed between the first wall and the first surface, high-temperature and high-pressure gas generated by the electrode assembly is discharged to the outside of the battery cells through the exhaust channel and the pressure release mechanism, the risk of thermal runaway diffusion is reduced, the service performance of the battery cells is improved, and meanwhile, the weak area is simple in implementation mode, easy to process and manufacture, and the manufacturing cost is reduced.

In some implementations, the electrode assembly is provided with a tab that faces a second wall of the battery cell that is different from the first wall. In this way, in the embodiment of the application, by setting the second wall of the tab facing the battery cell and the first wall to be different, in the case that thermal runaway occurs in the battery cell, a vent channel communicated with the pressure release mechanism can be formed between the first wall and the first surface, so that high-temperature and high-pressure gas generated by the electrode assembly is directionally and rapidly discharged to the outside of the battery cell through the vent channel and the pressure release mechanism, the risk of damage to the tab in the pressure release process is reduced, the risk of thermal runaway diffusion is reduced, and the service performance of the battery cell is improved.

In some implementations, the electrode assembly includes two tabs disposed opposite to each other, the two tabs respectively facing the two second walls disposed opposite to the battery cell, and the first wall connects the two second walls.

In the embodiment of the application, the electrode assembly is arranged to comprise two oppositely arranged lugs, the two oppositely arranged lugs face two second walls of the battery cell respectively, the first wall is connected with the two second walls, and under the condition that the battery cell is in thermal runaway, an exhaust channel communicated with the pressure release mechanism can be formed between the first wall and the first surface, so that high-temperature and high-pressure gas generated by the electrode assembly is directionally and rapidly discharged to the outside of the battery cell through the exhaust channel and the pressure release mechanism, the damage risk of the two lugs in the pressure release process is reduced, the risk of thermal runaway diffusion is reduced, and the service performance of the battery cell is improved.

In some implementations, the housing includes two first openings disposed opposite to each other, the battery cell includes two end caps disposed opposite to each other, the two end caps are respectively used to cover the two first openings, and the end cap is the second wall.

In the embodiment of the application, the shell is arranged to comprise two first openings which are oppositely arranged, the battery cell comprises two end covers which are oppositely arranged, the two end covers are respectively used for covering the two first openings, the end covers are the second walls, and under the condition that the battery cell is in thermal runaway, an exhaust channel which is communicated with the pressure release mechanism can be formed between the first walls and the first surface, so that high-temperature and high-pressure gas generated by the electrode assembly is directionally and rapidly discharged to the outside of the battery cell through the exhaust channel and the pressure release mechanism, the damage risk of the pressure release process to the two electrode lugs and the end covers is reduced, the risk of thermal runaway diffusion is reduced, and the service performance of the battery cell is improved.

In some implementations, a surface of the second connection portion near a side of the first connection portion is provided with a connection region, the first connection portion is fixedly connected with the connection region, and at least a partial orthographic projection of the first connection portion covers an orthographic projection of the connection region on a plane perpendicular to a thickness direction of the first connection portion.

In the embodiment of the application, the first connecting part is fixedly connected with the connecting area, and at least part of the orthographic projection of the first connecting part covers the orthographic projection of the connecting area on the plane vertical to the thickness direction of the first connecting part, so that the first connecting part and the second connecting part are conveniently and fixedly connected, the connecting mode is simple and feasible, the processing and manufacturing efficiency of the insulating part can be effectively improved, and the manufacturing cost is reduced.

In some implementations, the first connection portion is an at least partially overlapping double-layer structure that is stacked along a thickness direction of the first connection portion.

According to the embodiment of the application, the first connecting part is arranged into the double-layer structure which is at least partially overlapped, and the double-layer structure is arranged in a lamination manner along the thickness direction of the first connecting part, so that an exhaust channel with a large space communicated with the pressure release mechanism is formed between the first wall and the first surface under the condition that the thermal runaway of the battery unit occurs, high-temperature and high-pressure gas generated by the electrode assembly is directionally and rapidly discharged to the outside of the battery unit through the exhaust channel and the pressure release mechanism, the risk of thermal runaway diffusion is effectively reduced, and the service performance of the battery unit is improved.

In some implementations, the thickness D1 of the first connection portion satisfies 0.1 mm≤D1≤5 mm. Thus, in the embodiment of the application, by setting the thickness D1 of the first connecting portion to be greater than or equal to 0.1mm and less than or equal to 5mm, in the case that thermal runaway occurs in the battery cell, an exhaust channel with enough space communicated with the pressure release mechanism is formed between the first wall and the first surface, so that high-temperature and high-pressure gas generated by the electrode assembly is directionally and rapidly discharged to the outside of the battery cell through the exhaust channel and the pressure release mechanism, the risk of thermal runaway diffusion is effectively reduced, the service performance of the battery cell is improved, and the structural strength of the insulating piece and the energy density of the battery cell are simultaneously considered.

In some implementations, the thickness D2 of the second connection portion satisfies 0.05mm < D2 < 0.5mm. Thus, in the embodiment of the application, the thickness D2 of the second connecting portion is set to be greater than or equal to 0.05mm and less than or equal to 0.5mm, so that the structural strength of the insulating member and the energy density of the battery cell are both considered.

In a second aspect, a battery device is provided, including a plurality of battery cells, where the battery cells are the battery cells in the first aspect or the implementation manners thereof.

In a third aspect, a powered device is provided, comprising a battery arrangement as described in the second aspect, for providing electrical energy to the powered device.

In some implementations, the powered device may be a vehicle, a vessel, a spacecraft, or the like.

In a fourth aspect, there is provided an energy storage device comprising a battery arrangement as described in the second aspect for storing electrical energy for the energy storage device.

Drawings

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

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

Fig. 2 is a schematic structural diagram of a battery device according to an embodiment of the present application.

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

Fig. 4 is an exploded view of a battery cell according to another embodiment of the present application.

Fig. 5 is a schematic structural view of an insulating member according to an embodiment of the present application.

Fig. 6 is a schematic structural view of an insulating member according to another embodiment of the present application.

Fig. 7 is a schematic structural diagram of a battery cell according to another embodiment of the present application.

Fig. 8 is a schematic cross-sectional view of a battery cell according to an embodiment of the present application.

Fig. 9 is a schematic cross-sectional view of a battery cell according to another embodiment of the present application.

Fig. 10 is a schematic structural diagram of a first connection portion according to an embodiment of the present application.

Fig. 11 is a schematic structural view of a first connection portion according to another embodiment of the present application.

Fig. 12 is a schematic view showing a partially exploded structure of an insulating member according to an embodiment of the present application.

The reference numerals describe 1-vehicle, 10-battery device, 20-battery cell, 30-controller, 40-motor, 111-first portion, 112-second portion, 112 a-bottom plate, 112 b-side plate, 21-case, 22-electrode assembly, 211-case, 212-end cap, 213-pressure release mechanism, 222-tab, 222 a-positive tab, 222 b-negative tab, 214-electrode terminal, 214 a-positive electrode terminal, 214 b-negative electrode terminal, 23-connection member, 24-insulator, 25-receiving cavity, 50-first wall, 510-first connection, 520-second connection, 521-first sub-connection, 510 a-second sub-connection, 510 b-third sub-connection, 511-first through hole, 512-weak area, 610-first surface, 620-second surface, 60-first opening, 70-second wall, 530-connection area, 540-third connection.

Detailed Description

For the purpose of making the objects, technical solutions and advantages of the embodiments of the present application more apparent, the technical solutions of the embodiments of the present application will be clearly described below with reference to the accompanying drawings in the embodiments of the present application, and it is apparent that the described embodiments are some embodiments of the present application, but not all embodiments of the present application. All other embodiments, which can be made by those skilled in the art based on the embodiments of the application without making any inventive effort, are intended to be within the scope of the application.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs, the terms used in this description are for the purpose of describing particular embodiments only and are not intended to be limiting of the application, and the terms "comprising" and "having" and any variations thereof in the description of the application and the claims and the above description of the drawings are intended to cover non-exclusive inclusions. The terms first, second and the like in the description and in the claims or in the above-described figures, are used for distinguishing between different objects and not necessarily for describing a particular sequential or chronological order.

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

In the description of the present application, it should be noted that, unless explicitly specified and limited otherwise, the terms "mounted," "connected," and "attached" are to be construed broadly, and may be, for example, fixedly connected, detachably connected, or integrally connected, directly connected, indirectly connected through an intermediary, or may be in communication with the interior of two elements. The specific meaning of the above terms in the present application can be understood by those of ordinary skill in the art according to the specific circumstances.

The term "and/or" in the present application is merely an association relation describing the association object, and indicates that three kinds of relations may exist, for example, a and/or B may indicate that a exists alone, while a and B exist together, and B exists alone. In the present application, the character "/" generally indicates that the front and rear related objects are an or relationship.

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

The term "plurality" as used herein means two or more (including two), and similarly, "plural sets" means two or more (including two), and "plural sheets" means two or more (including two).

In the embodiment of the application, the battery cell can be a secondary battery, and the secondary battery refers to a battery cell which can activate the active material in a charging mode to continue to use after the battery cell discharges. The battery device in the embodiment of the application may also be referred to as a battery.

The battery cell may be a lithium ion battery, a sodium lithium ion battery, a lithium metal battery, a sodium metal battery, a lithium sulfur battery, a magnesium ion battery, a nickel hydrogen battery, a nickel cadmium battery, a lead storage battery, etc., which is not limited by the embodiment of the application.

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

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

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

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

As an example, the positive electrode active material may include at least one of lithium-containing phosphates, lithium transition metal oxides, and their respective modified compounds. However, the present application is not limited to these materials, and other conventional materials that can be used as a battery positive electrode active material may be used. These positive electrode active materials may be used alone or in combination of two or more. Examples of the lithium-containing phosphate may include, but are not limited to, at least one of lithium iron phosphate (such as LiFePO ₄ (which may also be referred to simply as LFP)), a composite of lithium iron phosphate and carbon, lithium manganese phosphate (such as LiMnPO ₄), a composite of lithium manganese phosphate and carbon, lithium manganese phosphate, and a composite of lithium manganese phosphate and carbon.

As an example, the positive electrode active material may include at least one of a sodium transition metal oxide, a polyanion-type compound, and a prussian blue-type compound.

In some implementations, the sodium transition metal oxide can be a doped modified sodium transition metal oxide, and the doping modification of the sodium transition metal oxide can include at least one of a sodium site doping modification, an oxygen site doping modification, a transition metal site doping modification, and a surface cladding modification.

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

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

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

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

In some implementations, the battery cells in embodiments of the application may be non-negative sodium secondary batteries.

The negative electrode-free sodium secondary battery is a battery cell in which a negative electrode active material layer is not actively provided on the negative electrode side during the production of the battery cell, and for example, a sodium metal or a carbonaceous active material layer is not provided at the negative electrode by a process such as coating or deposition during the production of the battery cell to form the negative electrode active material layer. When the lithium ion battery is charged for the first time, electrons are obtained from the sodium ion at the anode side to deposit on the surface of the current collector to form a sodium metal phase, and when the lithium ion battery is discharged, metal sodium can be converted into sodium ions to return to the anode, so that the circulation charge and discharge are realized. The non-negative sodium secondary battery cell can obtain a higher energy density due to the absence of the negative electrode active material layer, compared to other sodium secondary batteries.

In some implementations, to improve cell performance, the negative side of a non-negative sodium secondary battery may be provided with some functional coating, such as carbonaceous materials, metal oxides, alloys, etc., to improve the conductivity of the negative current collector and to improve the uniformity of deposited sodium metal.

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

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

In some embodiments, the electrode assembly further includes a separator disposed between the positive electrode and the negative electrode.

In some embodiments, the separator is a separator film. The type of the separator is not particularly limited, and any known porous separator having good chemical stability and mechanical stability can be used.

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

In some embodiments, the separator is a solid state electrolyte. The solid electrolyte is arranged between the anode and the cathode and plays roles in transmitting ions and isolating the anode and the cathode.

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

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

In some embodiments, the battery cell may include a housing. The case is used to encapsulate the electrode assembly, the electrolyte, and the like. The shell can be a steel shell, an aluminum shell, a plastic shell (such as polypropylene), a composite metal shell (such as a copper-aluminum composite shell), an aluminum-plastic film or the like. The housing includes a shell and an end cap.

As examples, the battery cell may be a cylindrical battery cell, a prismatic battery cell, a pouch battery cell, or other shaped battery cell, including a square-case battery cell, a blade-shaped battery cell, a polygonal-prismatic battery cell, such as a hexagonal-prismatic battery cell, or the like.

In order to meet different power requirements, the battery device in the embodiment of the application may include a plurality of battery cells, where the plurality of battery cells may be connected in series or parallel or in series-parallel, and the series-parallel refers to a mixture of series and parallel. In some implementations, a plurality of battery cells may be first connected in series or parallel or series-parallel to form a battery module, and then connected in series or parallel or series-parallel to form a battery. That is, a plurality of battery cells may be directly assembled into a battery device, or may be assembled into a battery module first, and the battery module may be assembled into a battery device. The battery device is further arranged in the electric equipment to provide electric energy for the electric equipment.

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

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

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

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

The development of battery technology is to consider various design factors, such as energy density, cycle life, discharge capacity, charge-discharge rate, and other performance parameters. In addition to improving the electrical performance of batteries, safety issues are also a non-negligible issue in the development of battery technology. If the safety problem of the battery device cannot be guaranteed, the battery device cannot be used, and the service performance of the battery device is reduced. Currently, with the increase of the demands of consumers for the endurance mileage of electric vehicles, the capacity and the energy density of the battery device become very important performance indexes. The energy density of the battery device is directly related to the positive and negative electrode materials, and a higher energy density requires a cathode active material having a higher Ni content or an anode active material having a higher Si content, but as the content of these elements increases, the safety margin of the battery device also deteriorates. Therefore, how to design the battery cell to realize directional pressure release of the battery cell, reduce the risk of thermal runaway diffusion, and improve the service performance of the battery device has become a technical problem to be solved in the art.

The embodiment of the application provides a battery unit, a battery device, electric equipment and energy storage equipment, wherein the battery unit comprises a shell, an electrode assembly, a pressure relief mechanism and an insulating piece, the shell comprises a containing cavity, the electrode assembly is contained in the containing cavity, the pressure relief mechanism is arranged on a first wall of the shell, the insulating piece is used for wrapping at least part of the surface of the electrode assembly, which faces the shell, the insulating piece comprises a first connecting portion opposite to the first wall, and the melting point of the first connecting portion is smaller than that of the rest part of the insulating piece except the first connecting portion. Thus, in the embodiment of the application, the insulating part is arranged to wrap at least part of the surface of the electrode assembly facing the shell, and comprises the first connecting part opposite to the first wall where the pressure release mechanism is located, the melting point of the first connecting part is smaller than that of the rest part except the first connecting part of the insulating part, and in the case of thermal runaway of the battery cell, namely in the process of temperature rise of the interior of the battery cell, the first connecting part is melted earlier than the rest part except the first connecting part of the insulating part, so that an exhaust channel communicated with the pressure release mechanism is formed between the first wall and the surface of the electrode assembly corresponding to the first connecting part, high-temperature and high-pressure gas generated by the electrode assembly is directionally discharged to the outside of the battery cell through the exhaust channel and the pressure release mechanism, the risk of damaging the rest wall except the first wall of the shell by the high-temperature and high-pressure gas is reduced, and meanwhile, the risk of thermal runaway diffusion is reduced, and thus the service performance of the battery cell is improved.

The technical scheme described by the embodiment of the application is suitable for various electric equipment using a battery device.

The electric equipment can be vehicles, mobile phones, portable equipment, notebook computers, ships, spacecrafts, electric toys, electric tools and the like. The vehicle may be a fuel oil vehicle, a gas vehicle or a new energy vehicle, the new energy vehicle may be a pure electric vehicle, a hybrid vehicle or a range-extended vehicle, etc., the spacecraft includes an airplane, a rocket, a space plane, a spacecraft, etc., the electric toy includes a fixed or movable electric toy such as a game machine, an electric vehicle toy, an electric ship toy, an electric plane toy, etc., and the electric tool includes a metal cutting electric tool, a grinding electric tool, an assembling electric tool, a railway electric tool such as an electric drill, an electric grinder, an electric wrench, an electric screwdriver, an electric hammer, an impact electric drill, a concrete vibrator, an electric planer, etc. The embodiment of the application does not limit the electric equipment in particular.

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

For example, as shown in fig. 1, a schematic structural diagram of a vehicle 1 according to an embodiment of the present application is shown, where the vehicle 1 may be a fuel-oil vehicle, a gas-fired vehicle or a new energy vehicle, and the new energy vehicle may be a pure electric vehicle, a hybrid vehicle or an extended range vehicle. The motor 40, the controller 30 and the battery device 10 may be provided in the vehicle 1, and the controller 30 is configured to control the battery device 10 to supply power to the motor 40. For example, the battery device 10 may be provided at the bottom or the head or the tail of the vehicle 1. The battery device 10 may be used for power supply of the vehicle 1, for example, the battery device 10 may be used as an operating power source of the vehicle 1, for the circuitry of the vehicle 1, for example, for the start-up, navigation and operational power requirements of the vehicle 1. In another embodiment of the present application, the battery device 10 may not only serve as an operating power source for the vehicle 1, but also as a driving power source for the vehicle 1, instead of or in part instead of fuel oil or natural gas, to supply driving power to the vehicle 1.

To meet different power requirements, the battery device 10 according to the embodiment of the present application may include at least one battery cell group, where the battery cell group includes a plurality of battery cells, and the plurality of battery cells may be electrically connected in series or parallel or in series-parallel to form the battery device 10, where series-parallel refers to a mixture of series and parallel. The battery device 10 may also be referred to as a battery pack. For example, a plurality of battery cells may be first assembled into a battery module by series connection or parallel connection or series-parallel connection, and then assembled into the battery device 10 by series connection or parallel connection or series-parallel connection. That is, a plurality of battery cells may be directly assembled into the battery device 10, or the battery module may be assembled first and then assembled into the battery device 10.

For example, as shown in fig. 2, the battery device 10 may include a plurality of battery cells 20, which is a schematic structural view of the battery device 10 according to an embodiment of the present application. The battery device 10 may further include a case 11 (or called a cover), in which the case 11 has a hollow structure, and a plurality of battery cells 20 are accommodated in the case 11. For example, a plurality of battery cells 20 are connected in parallel or in series-parallel combination with each other and then placed in the case 11.

As shown in fig. 2, the housing 11 may include two portions, referred to herein as a first portion 111 and a second portion 112, respectively, with the first portion 111 and the second portion 112 snap-fit together. The shape of the first portion 111 and the second portion 112 may be determined according to the shape of the combination of the plurality of battery cells 20, and each of the first portion 111 and the second portion 112 may have one opening. For example, each of the first portion 111 and the second portion 112 may be a hollow rectangular parallelepiped and each has only one surface as an open surface, the opening of the first portion 111 and the opening of the second portion 112 are disposed opposite to each other, and the first portion 111 and the second portion 112 are fastened to each other to form the case 11 having a closed chamber. The case may include a bottom plate 112a, side plates 112b, and beams, among others. The plurality of battery cells 20 are connected in parallel or in series-parallel combination and then placed in the box 11 formed by buckling the first part 111 and the second part 112.

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

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

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

Fig. 3 is a schematic structural diagram of a battery cell 20 according to an embodiment of the application, and fig. 4 is a schematic exploded structural diagram of the battery cell 20 according to another embodiment of the application. As shown in fig. 3 and 4, the battery cell 20 of the embodiment of the present application may include a case 21 having a closed receiving space and an electrode assembly 22 disposed in the receiving space within the case 21. The housing 21 may include a housing 211 having a hollow structure with at least one opening, and an end cap 212 for being fastened to the housing 211 to form the housing 21 having a closed accommodating space.

In some embodiments, the end cap 212 may be a plate-like structure for covering the opening of the housing 211. In other embodiments, the end cap 212 is similar in structure to the housing 211, i.e., the housing 211 and the end cap 212 are hollow structures having one opening that interfaces to form the housing 21 with a closed receiving space.

It should be understood that if the end cap 212 is a plate-shaped structure, the housing 211 may have a hollow structure with one or more ends open, for example, if the housing 211 has a hollow structure with one end open, the end cap 212 may be provided as one, and if the housing 211 has a hollow structure with two opposite ends open, the end caps 212 may be provided as two, and the two end caps 212 respectively cover the openings at the two ends of the housing 211.

The housing 21 may be of various shapes, such as a cylinder, a cuboid, or other polyhedron. As shown in fig. 3 and 4, in the embodiment of the present application, the case 21 is mainly described as an example of a rectangular parallelepiped structure.

It should be appreciated that the end cap 212 of the present embodiment is configured to cooperate with the housing 211 to isolate the internal environment of the battery cell 20 from the external environment. The shape of the end cap 212 may be adapted to the shape of the housing 211, and as shown in fig. 3 and 4, the housing 211 has a rectangular parallelepiped structure, and the end cap 212 has a rectangular plate-like structure adapted to the housing 211.

In some embodiments, the housing 211 may be a hollow structure having at least one end formed with an opening, and the end cap 212 may be shaped to fit the shape of the housing 211, and the end cap 212 is used to cover the opening of the housing 211, so that the case 21 insulates the internal environment of the battery cell 20 from the external environment. If the housing 211 has a hollow structure with one end formed to be open, the end cap 212 may be provided as one.

The material of the housing 211 according to the embodiment of the present application may include one or more materials, for example, copper, iron, aluminum, steel, aluminum alloy, etc. The material of the end cap 212 may also be one or more, and may include copper, iron, aluminum, steel, aluminum alloy, etc., for example. The material of the end cap 212 may be the same as or different from the material of the housing 211, and the material of the different walls of the housing 211 may be the same or different.

The end cap 212 of the embodiment of the present application may be any wall of the housing 21, for example, the end cap 212 may be a wall with the largest area, or a wall with the smallest area, or may be other walls, where the embodiment of the present application is not limited thereto. Alternatively, the end cap 212 may have other structures, for example, the end cap 212 may have a groove structure with an opening, so that the opening of the end cap 212 covers the opening of the housing 211, which is not limited thereto.

It should be appreciated that the battery cell 20 also includes an electrode terminal 214. The electrode terminal 214 of the embodiment of the present application is used to electrically connect with the electrode assembly 22 inside the battery cell 20 to output the electric power of the battery cell 20. As shown in fig. 3 to 4, the battery cell 20 may include at least two electrode terminals 214, and the at least two electrode terminals 214 may include at least one positive electrode terminal 214a and at least one negative electrode terminal 214b, the positive electrode terminal 214a being for electrical connection with the positive electrode tab 222a of the electrode assembly 22, and the negative electrode terminal 214b being for electrical connection with the negative electrode tab 222b of the electrode assembly 22. The positive electrode terminal 214a and the positive electrode tab 222a may be directly connected or indirectly connected, and the negative electrode terminal 214b and the negative electrode tab 222b may be directly connected or indirectly connected. Illustratively, the positive electrode terminal 214a may be electrically connected to the positive electrode tab 222a by one of the connection members 23, and the negative electrode terminal 214b may be electrically connected to the negative electrode tab 222b by one of the connection members 23. It should be understood that in the embodiment of the present application, the positive tab 222a and the negative tab 222b may be collectively referred to as the tabs 222.

In the embodiment of the present application, the wall of the case 211 and the wall of the end cap 212 are both referred to as the wall of the battery cell 20, wherein for the rectangular parallelepiped type battery cell 20 shown in fig. 3 and 4, the wall of the case 211 includes a bottom wall and four side walls. The case 211 is determined according to the shape of the combined one or more electrode assemblies 22, for example, the case 211 may be a hollow rectangular parallelepiped or square or cylindrical body, and one face of the case 211 has an opening so that one or more electrode assemblies 22 may be placed in the case 211. For example, when the housing 211 is a hollow rectangular parallelepiped or square, one of the planes of the housing 211 is an opening surface, i.e., the plane has no wall body so that the inside and outside of the housing 211 communicate. When the housing 211 may be a hollow cylinder, the end surface of the housing 211 is an open surface, i.e., the end surface has no wall body so that the inside and outside of the housing 211 communicate. End cap 212 covers the opening and is connected to housing 211 to form a closed cavity in which electrode assembly 22 is placed. The housing 211 is filled with an electrolyte, such as an electrolyte solution.

In the battery cell 20, the electrode assembly 22 is a component of the battery cell 20 in which an electrochemical reaction occurs, and the electrode assembly 22 in the case 211 may be provided in one or more cases according to actual use requirements. For example, as shown in fig. 4, 2 electrode assemblies 22 are provided in the battery cell 20. The electrode assembly 22 may have a cylindrical shape, a rectangular parallelepiped shape, or the like, and if the electrode assembly 22 has a cylindrical structure, the case 211 may have a cylindrical structure, and if the electrode assembly 22 has a rectangular parallelepiped structure, the case 211 may have a rectangular parallelepiped structure.

In the battery cell 20, the electrode assembly 22 is a component of the battery cell 20 in which an electrochemical reaction occurs, and the electrode assembly 22 in the case 211 may be provided in one or more cases according to actual use requirements. For example, as shown in fig. 4, 2 electrode assemblies 22 are provided in the battery cell 20. The electrode assembly 22 may have a cylindrical shape, a rectangular parallelepiped shape, or the like, and if the electrode assembly 22 has a cylindrical structure, the case 211 may have a cylindrical structure, and if the electrode assembly 22 has a rectangular parallelepiped structure, the case 211 may have a rectangular parallelepiped structure. In an embodiment of the present application, the material of the housing 211 may include copper, iron, aluminum, steel, aluminum alloy, etc.

A pressure release mechanism 213 may also be provided on the battery cell 20. The pressure release mechanism 213 is used to actuate to release the internal pressure or temperature of the battery cell 20 when the internal pressure or temperature reaches a threshold.

The pressure relief mechanism 213 may be a variety of possible pressure relief mechanisms 213. For example, the pressure relief mechanism 213 may be a temperature-sensitive pressure relief mechanism configured to melt when the internal temperature of the battery cell 20 provided with the pressure relief mechanism 213 reaches a threshold value, and/or the pressure relief mechanism 213 may be a pressure-sensitive pressure relief mechanism configured to rupture when the internal air pressure of the battery cell 20 provided with the pressure relief mechanism 213 reaches a threshold value.

In some implementations, an insulating member 24 may be further disposed in the battery cell 20, the insulating member 24 being disposed in an accommodating space of the case 211, and the insulating member 24 may be a hollow structure having one or more ends formed with an opening, and the accommodating space in the hollow structure is used to accommodate the electrode assembly 22 to improve the insulating performance of the battery cell 20.

Fig. 5 shows a schematic structural view of an insulating member 24 according to an embodiment of the present application. Fig. 6 shows a schematic structural view of an insulating member 24 according to another embodiment of the present application. Fig. 7 is a schematic structural diagram of a battery cell 20 according to another embodiment of the present application. Fig. 8 shows a schematic cross-sectional view of a battery cell 20 according to an embodiment of the application. Fig. 9 shows a schematic cross-sectional view of a battery cell 20 according to another embodiment of the present application. Illustratively, the cross-sectional schematic view shown in fig. 8 may be a cross-sectional schematic view of the battery cell 20 shown in fig. 7 along a direction perpendicular to the direction Y, and the cross-sectional schematic view shown in fig. 8 may be a cross-sectional schematic view of the battery cell 20 shown in fig. 7 along a direction perpendicular to the direction X.

It should be understood that, for convenience of description, in the embodiment of the present application, the direction X may be the length direction or the width direction of the battery cell 20, which is perpendicular to the direction Z and the direction Y, or the direction X may also be the length direction of the housing 211, in the embodiment of the present application, the direction X may be the third direction, the direction Y may be the width direction of the battery cell 20, which is perpendicular to the direction Z and the direction X, in the embodiment of the present application, the direction Y may be the second direction, the direction Z may be the height direction of the battery cell 20, which is perpendicular to the direction X and the direction Y, or the direction Z may also be the height direction of the housing 211, as shown in fig. 7 to 9. Illustratively, where the direction X is the length direction of the housing 211, the direction Y is the width direction of the housing 211.

In some implementations, as shown in fig. 5 to 9, the battery cell 20 includes a case 211, an electrode assembly 22, a pressure relief mechanism 213, and an insulating member 24, the case 211 includes a receiving cavity 25, the electrode assembly 22 is received in the receiving cavity 25, the pressure relief mechanism 213 is disposed on a first wall 50 of the case 211, the insulating member 24 is used to wrap at least a portion of a surface of the electrode assembly 22 facing the case 211, the insulating member 24 includes a first connection part 510 opposite to the first wall 50, wherein a melting point of the first connection part 510 is less than a melting point of the rest of the insulating member 24 except the first connection part 510.

It should be understood that the housing 211 of the battery cell 20 according to the embodiment of the present application may have any polyhedral structure, that is, the housing 211 may include a plurality of walls, and the first wall 50 is any one of the walls of the housing 211, that is, the pressure release mechanism 213 may be located on any one of the walls of the housing 211.

Illustratively, in some implementations, the first wall 50 includes, but is not limited to, an example in which the first wall 50 may be a wall of the housing 211 having a minimum area, the first wall 50 may be a wall of the battery cell 20 provided with the pressure relief mechanism 213, the first wall 50 may be a wall adjacent to a wall of the battery cell 20 provided with the electrode terminal 214, and the first wall may be a wall opposite to the wall of the battery cell 20 provided with the electrode terminal 214.

It should also be appreciated that the housing 211 may include a receiving cavity 25 that is either open or closed, for example, where the receiving cavity 25 is open, an end of the receiving cavity 25 may be provided with at least one opening for sealing connection with the end cap 212.

It should also be appreciated that the use of the insulating member 24 in the embodiments of the present application to wrap at least a portion of the surface of the electrode assembly 22 facing the housing 211 may mean that the insulating member 24 can wrap a portion or all of the surface of the electrode assembly 22 facing the housing 211 without affecting the performance of the electrode assembly 22, so as to reduce the risk of shorting the battery device 10 due to direct contact between the electrode assembly 22 and the housing 211.

It should also be appreciated that as shown in fig. 5 and 6, two different insulating members 24 are shown in schematic structural views before or in an unused state of the electrode assembly 22, respectively. The insulation part 24 shown in fig. 5 comprises a first connecting portion 510, which is fixedly connected to another part of the insulation part 24, for example, to an edge region of a second connecting portion 520, after being bent. For example, the first connection part 510 may be adhesively connected or thermally fused to the edge region of the second connection part 520, i.e., the surface of the first connection part 510 adjacent to the second connection part 520 may be thermally fused to the surface of the first sub-connection part 521 adjacent to the first connection part 510. The first connection portion 510 in the insulating member 24 shown in fig. 6 includes two sub-connection portions, namely, a second sub-connection portion 510a and a third sub-connection portion 510b, at least portions of the second sub-connection portion 510a and the third sub-connection portion 510b are stacked on a plane perpendicular to the thickness direction of the first connection portion 510, that is, on a plane perpendicular to the thickness direction of the first connection portion 510, the orthographic projections of the second sub-connection portion 510a and the third sub-connection portion 510b may be completely overlapped or partially overlapped, and the second sub-connection portion 510a and the third sub-connection portion 510b may be adhesively connected or thermally fused.

It should also be understood that the pressure relief mechanism 213 of an embodiment of the present application refers to an element or component that actuates to relieve the internal pressure or temperature of the battery cell 20 when the internal pressure or temperature reaches a predetermined threshold. The threshold design varies according to design requirements. The threshold may depend on the material of one or more of the positive electrode tab, the negative electrode tab, the electrolyte, and the separator in the battery cell 20.

The term "actuated" as used herein refers to the pressure relief mechanism 213 being activated or activated to a state such that the internal pressure and temperature of the battery cell 20 is relieved. The action by pressure relief mechanism 213 may include, but is not limited to, at least a portion of pressure relief mechanism 213 breaking, crushing, tearing or opening, etc. During actuation, the pressure relief mechanism 213 will expel the high temperature, high pressure material inside the battery cell 20 as a discharge out of the actuated site. In this way, the pressure and temperature of the battery cells 20 can be relieved under controlled pressure or temperature conditions, thereby avoiding potentially more serious accidents.

Emissions from the battery cell 20 referred to in the embodiments of the present application include, but are not limited to, electrolyte, dissolved or split positive and negative electrode tabs, fragments of the insulator 24, high temperature and pressure gases generated by the reaction, flames, and the like.

Illustratively, the pressure relief mechanism 213 may be disposed on the bottom wall of the battery cell 20, for example, the pressure relief mechanism may be disposed on the bottom wall of the housing 211. The pressure relief mechanism 213 may be a variety of possible pressure relief mechanisms 213. For example, the pressure relief mechanism 213 may be a temperature-sensitive pressure relief mechanism configured to melt when the internal temperature of the battery cell 20 provided with the pressure relief mechanism 213 reaches a threshold value, and/or the pressure relief mechanism 213 may be a pressure-sensitive pressure relief mechanism configured to rupture when the internal air pressure of the battery cell 20 provided with the pressure relief mechanism 213 reaches a threshold value.

It should also be appreciated that in the embodiment of the present application, the insulating member 24 may be formed separately, in which a connection region needs to be reserved in a region of the remaining connection portion connected to the first connection portion 510 adjacent to the first connection portion 510 during the process of wrapping the insulating member 24 around the electrode assembly 22, the first connection portion 510 is thermally fused to the remaining connection portion through the connection region, and then the thermally fused insulating member 24 is bent to wrap the surface of the electrode assembly 22 facing the case 211, and the wrapped first connection portion 510 is disposed opposite to the first wall 50.

It should also be appreciated that in some implementations, as shown in fig. 5, the insulating member 24 may include a first connection portion 510, a second connection portion 520, and a third connection portion 540, wherein the first connection portion 510 and the second connection portion 520 are connected by heat fusion, the third connection portion 540 is disposed between the two second connection portions 520, the third connection portion 540 may be integrally formed with the two second connection portions 520 or separately formed, for example, in the case that the third connection portion 540 is separately formed with the two second connection portions 520, an edge area of the third connection portion 540 adjacent to the two second connection portions 520 is heat-fused with the two second connection portions 520.

In the embodiment of the present application, by providing the insulating member 24 to wrap at least a portion of the surface of the electrode assembly 22 facing the case 211, and the insulating member 24 includes the first connection part 510 opposite to the first wall 50 where the pressure relief mechanism 213 is located, the melting point of the first connection part 510 is smaller than that of the rest of the insulating member 24 except for the first connection part 510, in the case that the thermal runaway occurs in the battery cell 20, i.e., in the process that the temperature of the interior of the battery cell 20 increases, the first connection part 510 melts earlier than the rest of the insulating member 24 except for the first connection part 510, so that the exhaust passage communicating with the pressure relief mechanism 213 is formed between the first wall 50 and the surface of the electrode assembly 22 corresponding to the first connection part 510, so that the high-temperature and high-pressure gas generated by the electrode assembly 22 is directionally discharged to the outside of the battery cell 20 through the exhaust passage and the pressure relief mechanism 213, the risk of damaging the rest of the case 211 except for the first wall 50 due to the thermal runaway is reduced, and the thermal runaway performance of the battery cell 20 is improved.

In some implementations, as shown in fig. 5 to 9, the insulating member 24 further includes a second connection part 520 connected to the first connection part 510, the first connection part 510 for covering the first surface 610 of the electrode assembly 22, the second connection part 520 for covering the second surface 620 of the electrode assembly 22, and the second surface 620 has an area larger than that of the first surface 610.

It should be appreciated that in the case where thermal runaway of the battery cell 20 occurs, since the melting point of the first connection part 510 is smaller, the first connection part 510 is preferentially melted compared to the second connection part 520, and the second connection part 520 is slowly melted or is not melted throughout the thermal runaway process, so that the second surface 620 of the electrode assembly 22 does not contact the case 211, reducing the risk of short circuits caused by direct contact between the second surface 620 of the electrode assembly 22 and the case 211.

It should also be understood that the first connection part 510 is used to cover the first surface 610 of the electrode assembly 22, and may mean that the projected area of the first connection part 510 is greater than or equal to the projected area of the first surface 610 of the electrode assembly 22 on a plane perpendicular to the thickness direction of the first connection part 510. The second connection part 520 is used to cover the second surface 620 of the electrode assembly 22, and may mean that the projected area of the second connection part 520 is greater than or equal to the projected area of the second surface 620 of the electrode assembly 22 on a plane perpendicular to the thickness direction of the second connection part 520.

In the embodiment of the present application, by providing the insulating member 24 to include the second connection part 520 connected to the first connection part 510, and the first connection part 510 is used to cover the first surface 610 of the electrode assembly 22, the second connection part 520 is used to cover the second surface 620 of the electrode assembly 22, the area of the second surface 620 is larger than that of the first surface 610, and in the case that the thermal runaway occurs in the battery cell 20, the first connection part 510 melts earlier than the second connection part 520, so as to form the vent channel communicating with the pressure release mechanism 213 between the first wall 50 and the first surface 610, so that the high-temperature and high-pressure gas generated by the electrode assembly 22 is directionally discharged to the outside of the battery cell 20 through the vent channel and the pressure release mechanism 213, the risk of damaging the wall opposite to the second surface 620 of the case 211 by the high-temperature and high-pressure gas is reduced, that is, the risk of the direct contact between the second surface 620 and the surface of the case 211 causing the short circuit of the battery cell 20 is reduced, and the thermal runaway diffusion occurs risk of the thermal runaway occurs is reduced, thereby improving the performance of the battery cell 20.

In some implementations, the melting point T1 of the first connecting portion 510 and the melting point T2 of the second connecting portion 520 satisfy that T2/T1. Gtoreq.1.5. Thus, in the embodiment of the application, by setting the melting point T1 of the first connecting portion 510 and the melting point T2 of the second connecting portion 520 to be T2/T1 not less than 1.5, in the case that thermal runaway occurs in the battery cell 20, the first connecting portion 510 can be melted preferentially compared with the second connecting portion 520, so that an exhaust channel communicated with the pressure release mechanism 213 is formed between the first wall 50 and the first surface 610, and high-temperature and high-pressure gas generated by the electrode assembly 22 is discharged to the outside of the battery cell 20 through the exhaust channel and the pressure release mechanism 213 in a directional manner, the risk of thermal runaway diffusion is reduced, and thus the service performance of the battery cell 20 is improved.

In other implementations, the melting point T1 of the first connecting portion 510 and the melting point T2 of the second connecting portion 520 also satisfy that T2/T1. Gtoreq.2.

Fig. 10 is a schematic structural diagram of a first connection portion 510 according to an embodiment of the present application.

In some implementations, the first connection part 510 is provided with a first through hole 511 penetrating the first connection part 510 in a thickness direction of the first connection part 510, and the first through hole 511 communicates with the receiving chamber 25.

It should be understood that the shape of the first through hole 511 may be set according to actual requirements, for example, the shape of the first through hole 511 may be circular, elliptical, polygonal, rectangular, etc. on a plane perpendicular to the thickness direction of the first connection portion 510. It should also be appreciated that the aperture size of the first through hole 511 may be set according to actual requirements, which is not limited by the embodiment of the present application as an example.

In the embodiment of the present application, by providing the first through hole 511 penetrating the first connection part 510 along the thickness direction of the first connection part 510 on the first connection part 510, the first through hole 511 is communicated with the accommodating cavity 25, and in case of thermal runaway of the battery cell 20, the first connection part 510 can be quickly melted, so that an exhaust channel communicated with the pressure release mechanism 213 is formed between the first wall 50 and the first surface 610, and the high-temperature and high-pressure gas generated by the electrode assembly 22 is quickly discharged to the outside of the battery cell 20 through the exhaust channel and the pressure release mechanism 213 in a directional manner, thereby reducing the risk of thermal runaway diffusion, and improving the service performance of the battery cell 20.

In some implementations, the first connection part 510 is provided with a plurality of the first through holes 511, and the plurality of the first through holes 511 are arranged at intervals along a first direction, which is perpendicular to a thickness direction of the first connection part 510.

It should be understood that, in the embodiment of the present application, the plurality of first connection portions 510 may be arranged at equal intervals or at unequal intervals along the first direction, specifically, in the first direction, the distance between any two adjacent first connection portions 510 in the plurality of first connection portions 510 may be set according to actual requirements, which is not limited by the embodiment of the present application.

In the embodiment of the present application, by providing the plurality of first through holes 511 on the connection portion 510, and arranging the plurality of first through holes 511 at intervals along the first direction, where the first direction is perpendicular to the thickness direction of the first connection portion, in the case that thermal runaway occurs in the battery cell 20, the melting of the first connection portion 510 can be further accelerated, so that a vent channel communicating with the pressure release mechanism 213 is formed between the first wall 50 and the first surface 610, so that the high-temperature and high-pressure gas generated by the electrode assembly 22 is directionally and rapidly discharged to the outside of the battery cell 20 through the vent channel and the pressure release mechanism 213, thereby reducing the risk of thermal runaway diffusion, and improving the service performance of the battery cell 20.

Fig. 11 is a schematic structural diagram of a first connection portion 510 according to another embodiment of the present application.

In some implementations, as shown in fig. 11, the first connection 510 is provided with a weakened area 512, the weakened area 512 being configured to melt upon the temperature within the receiving chamber 25 reaching a threshold value, such that a vent passage is formed between the first surface 610 and the first wall 50 in communication with the pressure relief mechanism 213.

It should be appreciated that the above-mentioned temperature threshold may be set according to practical needs, for example, in the case that the temperature in the accommodating cavity 25 reaches the threshold, the weakened area 512 on the first connecting portion 510 is melted preferentially, and a vent channel communicating with the pressure release mechanism 213 is formed between the first surface 610 and the first wall 50, so that the high-temperature and high-pressure gas generated by the electrode assembly 22 is discharged to the outside of the battery cell 20 through the vent channel and the pressure release mechanism 213 in a directional and rapid manner, thereby reducing the risk of thermal runaway diffusion.

In the embodiment of the present application, the weak area 512 is disposed on the first connection part 510, and the weak area 512 is configured to be melted when the temperature in the receiving chamber 25 reaches the threshold value, so that the vent passage communicating with the pressure release mechanism 213 is formed between the first surface 610 and the first wall 50, thereby enabling the high-temperature and high-pressure gas generated by the electrode assembly 22 to be directionally and rapidly discharged to the outside of the battery cell 20 through the vent passage and the pressure release mechanism 213, reducing the risk of thermal runaway diffusion, thereby improving the use performance of the battery cell 20, and simultaneously, the weak area 512 is also disposed to reduce the risk of short circuit caused by direct contact between the case 211 and the electrode assembly 22 in the case that thermal runaway does not occur.

In some implementations, the thickness of the weakened area 512 is smaller than the thickness of the remaining area of the first connection part 510 excluding the weakened area, and/or the weakened area 512 is provided with a score on a surface perpendicular to the thickness direction of the first connection part 510.

It should be appreciated that in the embodiment of the present application, the shape of the weak area 512 may be set according to practical needs, and illustratively, the shape of the weak area 512 includes, but is not limited to, a circle, an ellipse, a rectangle, and a regular polygon, which are not limited thereto by the embodiment of the present application.

It should also be appreciated that the number of weakened areas 512 provided on the area of the first connection 510 corresponding to the first wall 50 may be provided according to actual requirements, for example, the number of weakened areas 512 may be one or more.

It will also be appreciated that the weakened area 512 may also be provided with a thickness that is smaller than the thickness of the rest of the first connection portion 510, as the weakened area 512 is thinner compared to the rest of the first connection portion 510, the weakened area 512 preferably melts in case the temperature in the receiving chamber 25 reaches a threshold value. It should also be appreciated that in embodiments of the present application, the shape of the score of the weakened area 512 disposed perpendicular to the surface of the first connection part 510 in the thickness direction may be configured according to actual needs, and the score may include, but is not limited to, cross score, mi Zi score, i-score, for example.

In the embodiment of the present application, by setting the thickness of the weak area 512 to be smaller than the thickness of the remaining area of the first connection part 510 excluding the weak area 512 and/or providing the weak area 512 with scores on the surface perpendicular to the thickness direction of the first connection part 510, in case that thermal runaway occurs in the battery cell 20, it is possible to preferentially melt at the weak area 512 of the first connection part 510 and further accelerate the melting of the first connection part 510, so that an exhaust passage communicating with the pressure release mechanism 213 is formed between the first wall 50 and the first surface 610, so that the high-temperature and high-pressure gas generated by the electrode assembly 22 is directionally and rapidly discharged to the outside of the battery cell 20 through the exhaust passage and the pressure release mechanism 213, thereby improving the use performance of the battery cell 20, while the weak area 512 is simple in implementation, easy to manufacture, and manufacturing cost is reduced.

In some implementations, as shown in fig. 7-9, the electrode assembly 22 is provided with tabs 222, the tabs 222 facing the second wall 70 of the battery cell 20, the second wall 70 being different from the first wall 50. Thus, in the embodiment of the present application, by setting the tab 222 differently toward the second wall 70 and the first wall 50 of the battery cell 20, in the case that thermal runaway occurs in the battery cell 20, a vent channel communicating with the pressure release mechanism 213 can be formed between the first wall 50 and the first surface 610, so that the high-temperature and high-pressure gas generated by the electrode assembly 22 is directionally and rapidly discharged to the outside of the battery cell 20 through the vent channel and the pressure release mechanism 213, the risk of damage to the tab 222 during the pressure release process is reduced, and the risk of thermal runaway diffusion is reduced, thereby improving the service performance of the battery cell 20.

In some implementations, as shown in fig. 8 and 9, the electrode assembly 22 includes two tabs 222 disposed opposite to each other, the two tabs 222 respectively face two second walls 70 disposed opposite to the battery cells 20, and the first wall 50 connects the two second walls 70.

In the embodiment of the present application, by arranging the electrode assembly 22 to include two tabs 222 disposed opposite to each other, and two second walls 70 disposed opposite to each other with the two tabs 222 facing the battery cells 20, the first wall 50 is connected to the two second walls 70, and in the case of thermal runaway of the battery cells 20, a vent channel communicating with the pressure release mechanism 213 can be formed between the first wall 50 and the first surface 610, so that the high-temperature and high-pressure gas generated by the electrode assembly 22 is directionally and rapidly discharged to the outside of the battery cells 20 through the vent channel and the pressure release mechanism 213, the risk of damage to the two tabs 222 in the pressure release process is reduced, and the risk of thermal runaway diffusion is reduced, thereby improving the service performance of the battery cells 20.

In some implementations, as shown in fig. 4, 7 and 9, the housing 211 includes two first openings 60 disposed opposite to each other, the battery cell 20 includes two end caps 212 disposed opposite to each other, the two end caps 212 are respectively configured to cover the two first openings 60, and the end cap 212 is the second wall 70.

In the embodiment of the present application, by arranging the housing 211 to include two first openings 60 disposed opposite to each other, the battery cell 20 includes two end caps 212 disposed opposite to each other, the two end caps 212 are respectively used to cover the two first openings 60, the end caps 212 are the second walls 70, and in the case that thermal runaway occurs in the battery cell 20, an exhaust channel communicating with the pressure release mechanism 213 can be formed between the first walls 50 and the first surfaces 610, so that the high-temperature and high-pressure gas generated by the electrode assembly 22 is directionally and rapidly discharged to the outside of the battery cell 20 through the exhaust channel and the pressure release mechanism 213, the risk of damage to the two tabs 222 and the end caps 212 in the pressure release process is reduced, and the risk of thermal runaway diffusion occurs is reduced, thereby improving the service performance of the battery cell 20.

Fig. 12 is a partially exploded view of an insulator 24 according to an embodiment of the present application.

In some implementations, as shown in fig. 12, a surface of the second connection portion 520 near a side of the first connection portion 510 is provided with a connection region 530, the first connection portion 510 is fixedly connected with the connection region 530, and at least a partial orthographic projection of the first connection portion 510 covers an orthographic projection of the connection region 530 on a plane perpendicular to a thickness direction of the first connection portion 510.

It should be understood that, in an embodiment of the present application, on a plane perpendicular to the thickness direction of the first connection portion 510, the orthographic projection of at least part of the first connection portion 510 covering the connection region 530 may mean that the orthographic projection of at least part of the first connection portion 510 has an area greater than or equal to that of the orthographic projection of the connection region 530. It should also be understood that the first connection portion 510 is fixedly connected to the connection region 530, which may mean that at least a portion of the surface of the first connection portion 510 facing the connection region 530 is thermally fused or adhesively connected to the surface of the connection region 530 facing the first connection portion 510. In the case where the first connection part 510 is fixedly connected with the second connection part 520, the first connection part 510 is bent with respect to the second connection part 520 to wrap at least a portion of the surface of the electrode assembly 22 facing the case 211.

In the embodiment of the application, the first connection portion 510 is fixedly connected with the connection region 530, and at least a part of the front projection of the first connection portion 510 covers the front projection of the connection region 530 on a plane perpendicular to the thickness direction of the first connection portion 510, so that the first connection portion 510 and the second connection portion 520 are fixedly connected, and the connection manner is simple and feasible, so that the processing and manufacturing efficiency of the insulating member 24 can be effectively improved, and the manufacturing cost can be reduced.

In some implementations, the first connection portion 510 is an at least partially overlapping double-layer structure that is stacked along a thickness direction of the first connection portion 510.

Illustratively, the first connecting portion 510 is a double-layered structure that is at least partially overlapped, and may mean that the first connecting portion 510 is formed by bending the insulating member 24 shown in fig. 6. That is, the first connection part 510 may be stacked by two connection parts, for example, the second sub-connection part 510a and the third connection part 510b shown in fig. 6, and the second sub-connection part 510a and the third connection part 510b may be completely overlapped or partially overlapped, in the case where the second sub-connection part 510a and the third connection part 510b are partially overlapped, an overlapped region thereof is disposed opposite to the first wall 50, and the overlapped first connection part 510 can provide a large thickness to form an exhaust passage having a large space communicating with the pressure relief mechanism 213 between the first wall 50 and the first surface 610 of the case 211 in the case where thermal runaway of the battery cell 20 occurs.

In the embodiment of the present application, by arranging the first connection part 510 as a double-layer structure that at least partially overlaps and is stacked in the thickness direction of the first connection part 510, in the case that thermal runaway occurs in the battery cell 20, so that an exhaust passage having a large space communicating with the pressure release mechanism 213 is formed between the first wall 50 and the first surface 610, high-temperature and high-pressure gas generated by the electrode assembly 22 is directionally and rapidly discharged to the outside of the battery cell 20 through the exhaust passage and the pressure release mechanism 213, and the risk of thermal runaway diffusion is effectively reduced, thereby improving the service performance of the battery cell 20.

In some implementations, as shown in FIGS. 8 and 9, the thickness D1 of the first connection portion 510 satisfies 0.1 mm≤D1≤5 mm.

The thickness D1 of the first connection portion 510 may be set to be, for example, 0.1mm, 0.2mm, 0.3mm, 0.4mm, 0.5mm, 0.6mm, 0.7mm, 0.8mm, 0.9mm, 1mm, 2mm, 3mm, 4mm, 5mm, etc., or a value thereof within a range obtained by combining any two of the above values.

In the embodiment of the present application, by setting the thickness D1 of the first connection part 510 to be greater than or equal to 0.1mm and less than or equal to 5mm, in case that thermal runaway occurs in the battery cell 20, so that an exhaust passage having a sufficient space communicating with the pressure relief mechanism 213 is formed between the first wall 50 and the first surface 610, high-temperature and high-pressure gas generated from the electrode assembly 22 is directionally and rapidly discharged to the outside of the battery cell 20 through the exhaust passage and the pressure relief mechanism 213, and the risk of thermal runaway diffusion is effectively reduced, thereby improving the use performance of the battery cell 20 while simultaneously compromising the structural strength of the insulating member 24 and the energy density of the battery cell 20.

In other implementations, the thickness D1 of the first connection portion 510 satisfies 1mm D1 3mm.

In some implementations, as shown in FIG. 9, the thickness D2 of the second connection 520 satisfies 0.05mm < D2 < 0.5mm.

The thickness D2 of the second connection part 520 may be set to be, for example, 0.05mm, 0.06mm, 0.07mm, 0.08mm, 0.09mm, 0.1mm, 0.2mm, 0.3mm, 0.4mm, 0.5mm, etc., or a value thereof within a range obtained by combining any two of the above values.

In the embodiment of the present application, the thickness D2 of the second connection part is set to be greater than or equal to 0.05mm and less than or equal to 0.5mm to achieve both the structural strength of the insulating member 24 and the energy density of the battery cell 20.

In other implementations, the thickness D2 of the second connection 520 satisfies 0.08mm D2 0.2mm.

Referring again to fig. 5 to 12, there is provided a battery cell 20, the battery cell 20 including a case 211, an electrode assembly 22, a pressure relief mechanism 213, and an insulating member 24, the case 211 including a receiving cavity 25, the electrode assembly 22 being received in the receiving cavity 25, the pressure relief mechanism 213 being disposed on a first wall 50 of the case 211, the insulating member 24 being for wrapping at least a portion of a surface of the electrode assembly 22 facing the case 211, the insulating member 24 including a first connection part 510 opposite to the first wall 50, wherein a melting point of the first connection part 510 is less than a melting point of the remaining portion of the insulating member 24 excluding the first connection part 510. The insulating member 24 further includes a second connection part 520 connected to the first connection part 510, the first connection part 510 being for covering the first surface 610 of the electrode assembly 22, the second connection part 520 being for covering the second surface 620 of the electrode assembly 22, the second surface 620 having an area larger than that of the first surface 610. The melting point T1 of the first connecting portion 510 and the melting point T2 of the second connecting portion 520 satisfy that T2/T1 is not less than 1.5. The first connection part 510 is provided with a first through hole 511 penetrating the first connection part 510 in a thickness direction of the first connection part 510, and the first through hole 511 communicates with the receiving chamber 25.

The embodiment of the application also provides a battery device 10, which comprises a plurality of battery cells 20, wherein the battery cells 20 are the battery cells 20 in any of the embodiments.

The embodiment of the application also provides electric equipment, which comprises the battery device 10 in any embodiment, wherein the battery device 10 is used for providing electric energy for the electric equipment. Specifically, the electric device may be the vehicle 1 shown in fig. 1, or may be any electric device using the battery device 10.

The embodiment of the application also provides an energy storage device, which comprises the battery device 10 in any of the above embodiments, wherein the battery device 10 is used for storing electric energy for the energy storage device.

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

Claims (17)

1. A battery cell, comprising:

A housing (211) comprising a receiving cavity (25);

an electrode assembly (22) accommodated in the accommodation chamber (25);

A pressure relief mechanism (213), the pressure relief mechanism (213) being provided to a first wall (50) of the housing (211);

An insulator (24) for wrapping at least a portion of a surface of the electrode assembly (22) facing the housing (211), the insulator (24) including a first connection portion (510) opposite the first wall (50);

Wherein the melting point of the first connection portion (510) is smaller than the melting point of the rest of the insulating member (24) except for the first connection portion (510).

2. The battery cell of claim 1, wherein the insulator (24) further comprises a second connection portion (520) connected to the first connection portion (510), the first connection portion (510) for covering a first surface (610) of the electrode assembly (22), the second connection portion (520) for covering a second surface (620) of the electrode assembly (22), the second surface (620) having an area greater than an area of the first surface (610).

3. The battery cell according to claim 2, wherein the melting point T1 of the first connecting portion (510) and the melting point T2 of the second connecting portion (520) satisfy T2/T1 being equal to or greater than 1.5.

4. The battery cell according to claim 2, wherein the first connection portion (510) is provided with a first through hole (511) penetrating the first connection portion (510) in a thickness direction of the first connection portion (510), the first through hole (511) communicating with the accommodation chamber (25).

5. The battery cell according to claim 4, wherein the first connection part (510) is provided with a plurality of the first through holes (511), the plurality of the first through holes (511) being arranged at intervals along a first direction, the first direction being perpendicular to a thickness direction of the first connection part (510).

6. The battery cell according to claim 2, wherein the first connection (510) is provided with a weakened area (512), the weakened area (512) being configured to melt in case the temperature within the receiving chamber (25) reaches a threshold value, such that a vent channel is formed between the first surface (610) and the first wall (50) in communication with the pressure relief mechanism (213).

7. The battery cell according to claim 6, wherein the thickness of the weakened area (512) is smaller than the thickness of the remaining area of the first connection part (510) excluding the weakened area (512), and/or the weakened area (512) is provided with a score on a surface perpendicular to the thickness direction of the first connection part (510).

8. The battery cell of claim 2, wherein the electrode assembly (22) is provided with a tab (222), the tab (222) being directed towards a second wall (70) of the battery cell, the second wall (70) being different from the first wall (50).

9. The battery cell of claim 8, wherein the electrode assembly (22) includes two tabs (222) disposed opposite each other, the two tabs (222) respectively facing the two second walls (70) disposed opposite the battery cell, the first wall (50) connecting the two second walls (70).

10. The battery cell of claim 9, wherein the housing (211) includes two first openings (60) disposed opposite each other, the battery cell includes two end caps (212) disposed opposite each other, the two end caps (212) respectively cover the two first openings (60), and the end caps (212) are the second walls (70).

11. The battery cell according to claim 2, wherein a surface of the second connection part (520) near one side of the first connection part (510) is provided with a connection region (530), the first connection part (510) is fixedly connected with the connection region (530), and at least a partial orthographic projection of the first connection part (510) covers an orthographic projection of the connection region (530) on a plane perpendicular to a thickness direction of the first connection part (510).

12. The battery cell according to any one of claims 1 to 11, wherein the first connection portion (510) is an at least partially overlapping double-layered structure, the double-layered structure being stacked in a thickness direction of the first connection portion.

13. The battery cell according to any one of claims 2 to 11, wherein the thickness D1 of the first connection portion (510) satisfies 0.1mm ∈d1 ∈5mm.

14. The battery cell according to any one of claims 2 to 11, wherein the thickness D2 of the second connection portion (520) satisfies 0.05mm ∈d2 ∈0.5mm.

15. A battery device, characterized by comprising:

A plurality of battery cells, the battery cells being as defined in any one of claims 1 to 14.

16. A powered device comprising the battery assembly of claim 15, wherein the battery assembly is configured to provide power to the powered device.

17. An energy storage device according to claim 15, comprising battery means for storing electrical energy for said energy storage device.