Battery cell, battery, electrical device, manufacturing method and equipment for battery cell

Abstract

This application relates to a battery cell, a battery, an electrical device, a manufacturing method and equipment of a battery cell, and relates to the field of batteries. This application provides a battery cell, which includes: a housing including a wall portion; an electrode terminal insulatingly mounted on the wall portion; an electrode assembly disposed within the housing, the electrode assembly including a main body and a first tab formed at one end of the main body close to the wall portion; a current collecting member disposed between the electrode assembly and the wall portion, the current collecting member being used to connect the first tab and the electrode terminal; a heat shrinkable film, at least a part of the heat shrinkable film covering the side of the current collecting member facing the wall portion to insulate and isolate the current collecting member and the wall portion. The battery cell of this application has high safety.

Description

Technical Field

[0001] The present application relates to the technical field of batteries, and particularly to a battery cell, a battery, an electrical device, a manufacturing method and equipment for a battery cell. Background Art

[0002] Energy conservation and emission reduction are the keys to the sustainable development of the automotive industry. Electric vehicles have become an important part of the sustainable development of the automotive industry due to their advantages of energy conservation and environmental protection. For electric vehicles, battery technology is an important factor related to their development.

[0003] During the charging and discharging process of the battery, there is a risk of short circuit in the battery cell, which poses a great potential safety hazard. How to reduce the probability of short circuit in the battery cell and improve the safety of the battery cell and the battery is crucial for the development of battery technology. Summary of the Invention

[0004] The purpose of the present application is to provide a battery cell, a battery, an electrical device, a manufacturing method and equipment for a battery cell. The battery cell is not prone to short circuit problems and has high safety.

[0005] In a first aspect, the present application provides a battery cell, including a housing including a wall portion; an electrode terminal insulatedly mounted on the wall portion; an electrode assembly disposed in the housing, the electrode assembly including a main body and a first tab formed at one end of the main body close to the wall portion; a current collector member disposed between the electrode assembly and the wall portion, the current collector member being used to connect the first tab and the electrode terminal; and a heat shrinkable film, at least a part of the heat shrinkable film covering the side of the current collector member facing the wall portion to insulate and isolate the current collector member and the wall portion.

[0006] In the battery cell of the present application, the heat shrinkable film covers the current collector member by heat shrinkage to insulate and isolate the current collector member and the wall portion. The heat shrinkable film has good covering property after heat shrinkage. When the battery cell is interfered by external factors, the heat shrinkable film can still stably cover the current collector member, reducing the risk of short circuit between the current collector member and the wall portion and improving the safety of the battery cell. In addition, the surface of the heat shrinkable film formed by heat shrinkage is relatively flat, not prone to wrinkles, and the thickness of the heat shrinkable film is relatively uniform, reducing the probability that the thickness dimension of the heat shrinkable film increases due to wrinkles, thereby preventing interference between the heat shrinkable film with an oversized thickness dimension and the current collector member, increasing the resistance and difficulty of installing the electrode assembly into the housing, and improving the production efficiency of the battery cell.

[0007] In some embodiments of the present application, the heat shrinkable film extends between the electrode terminal and the current collector member.

[0008] In the above solution, since the heat shrinkable film needs to completely cover the current collector member and extends the heat shrinkable film between the electrode terminal and the current collector member, there is no need to adjust the range of the heat shrinkable film covering the current collector member, which reduces the process difficulty of covering the current collector member with the heat shrinkable film and improves the production efficiency of the battery cell. At the same time, the heat shrinkable film extends between the electrode terminal and the current collector member, and the heat shrinkable film is clamped by the electrode terminal and the current collector member, preventing the heat shrinkable film from not being able to completely cover the current collector member due to problems such as its own heat shrinkage and the expansion of the electrode assembly, improving the stability of the heat shrinkable film covering the current collector member, ensuring that the heat shrinkable film can play a stable insulation and isolation effect on the current collector member and the wall portion, and improving the safety of the battery cell.

[0009] In some embodiments of the present application, there is a gap between the heat shrinkable film and the wall portion.

[0010] In the above solution, a gap is left between the heat shrinkable film and the wall portion to reduce the risk of the potential difference between the wall portion and the current collector member breaking down the heat shrinkable film, that is, to reduce the risk of short circuit of the battery cell and improve the safety of the battery cell.

[0011] In some embodiments of the present application, the heat shrinkable film includes an integrally formed first part and a second part. The first part covers one side of the current collector member facing the wall portion, and the second part covers the outer peripheral surface of the first tab.

[0012] In the above solution, the heat shrinkable film not only covers the current collector member but also covers the outer peripheral surface of the first tab. An insulating film simultaneously plays an insulation and isolation effect between the current collector member and the wall portion and between the first tab and the side wall of the housing, reducing the number of components and making the structure of the battery cell compact.

[0013] In some embodiments of the present application, the current collector member is in a disc shape, the diameter of the current collector member is smaller than the diameter of the first tab, and a step region is formed between the edge of the current collector member and the outer peripheral surface of the first tab. The heat shrinkable film covers the step region.

[0014] In the above solution, on the one hand, the setting of the step region provides enough space for welding the current collector member to the first tab, facilitating the welding of the current collector member to the first tab, improving the production efficiency of the battery cell, and expanding the production capacity of the battery; on the other hand, during the heat shrinkage process of the heat shrinkable film, the step region can absorb the surplus of the heat shrinkable film, reducing the probability of wrinkles appearing during the shrinkage process of the heat shrinkable film and improving the flatness of the heat shrinkable film covering the current collector member.

[0015] In some embodiments of the present application, the heat shrinkable film further includes a third part, and the third part covers the outer peripheral surface of the main body. The third part is integrally formed with the second part.

[0016] In the above solution, on the one hand, the third part wraps the outer peripheral surface of the main body, reducing the risk of short circuit between the outer shell and the main body, reducing the risk of short circuit of the battery cell, and improving the safety of the battery cell. On the other hand, the third part and the second part are integrally formed, and it is not easy for the third part and the second part to overlap, preventing the increase in the thickness dimension of the heat shrink film due to the overlap of the second part and the third part, reducing the probability of local stress concentration caused by the increase in the thickness dimension of the heat shrink film and the extrusion of the outer shell, and further reducing the risk of lithium plating on the electrode due to stress concentration.

[0017] In some embodiments of the present application, the electrode assembly is wound by a pole piece and a separator, and the battery cell further includes a tape, the tape is adhered to the outer peripheral surface of the main body and fixes the winding end of the pole piece and / or the separator, and the third part does not overlap with the tape.

[0018] In the above solution, the third part and the tape do not overlap, preventing the increase in the thickness dimension of the overlapping part due to the overlap of the third part and the tape, and it is not easy to have the problem of local stress concentration caused by the increase in the thickness dimension of this part and the extrusion of the side wall of the outer shell, and further reducing the risk of lithium plating on the electrode due to stress concentration.

[0019] In some embodiments of the present application, the battery cell further includes an elastic layer, the elastic layer is disposed between the wall portion and the heat shrink film, and the elastic layer is used to apply an elastic force along the axial direction of the electrode assembly to the electrode assembly.

[0020] In the above solution, when the battery cell is vibrated, the elastic layer can apply an elastic force along its axial direction to the electrode assembly and the current collector member, further insulating and isolating the current collector member and the wall portion, reducing the risk of short circuit of the battery cell, and improving the safety of the battery cell.

[0021] In some embodiments of the present application, the electrode assembly further includes a second tab, the second tab is formed at one end of the main body away from the wall portion, the second tab has the opposite polarity to the first tab, and the second tab is electrically connected to the wall portion.

[0022] In the above solution, the first tab and the second tab are located at both ends of the electrode assembly, and there is good insulation between the first tab and the second tab, reducing the risk of short circuit of the battery cell, and improving the safety of the battery cell.

[0023] In some embodiments of the present application, the outer shell includes a housing and an end cover, the housing includes a bottom wall and a side wall, the side wall surrounds the bottom wall, one end of the side wall is connected to the bottom wall, the other end of the side wall encloses an opening opposite to the bottom wall, the end cover covers the opening, and the wall portion is the bottom wall or the end cover.

[0024] In the above solution, the second wall and the wall portion define a space for accommodating the electrode assembly, the electrolyte and other structures, and the opening surrounded by the second wall is covered by an end cap to prevent the electrolyte from leaking out of the opening.

[0025] In a second aspect, the present application provides a battery, including the above battery cell.

[0026] In a third aspect, the present application provides an electrical device, including the above battery, and the battery is used to provide electrical energy.

[0027] In a fourth aspect, the present application provides a method for manufacturing a battery cell, including providing a housing and an electrode terminal, the housing includes a wall portion, and the electrode terminal is insulated and installed on the wall portion; providing an electrode assembly, the electrode assembly includes a main body and a first tab, and the first tab is formed at one end of the main body close to the wall portion; providing a current collector member, connecting the current collector member to the first tab; providing a heat shrinkable film, sleeving the heat shrinkable film on the electrode assembly; heating the heat shrinkable film to shrink, and making at least a part of the heat shrinkable film cover the current collector member; placing the electrode assembly and the current collector member covered with the heat shrinkable film into the housing, and making the side of the current collector member covered with the heat shrinkable film face the wall portion to insulate and isolate the current collector member and the wall portion; connecting the current collector member to the electrode terminal.

[0028] In a fifth aspect, the present application provides a manufacturing device for a battery cell, including a first providing device for providing a housing and an electrode terminal, the housing includes a wall portion, and the electrode terminal is insulated and installed on the wall portion; a second providing device for providing an electrode assembly, the electrode assembly includes a main body and a first tab, and the first tab is formed at one end of the main body close to the wall portion; a third providing device for providing a current collector member; a fourth providing device for providing a heat shrinkable film and sleeving the heat shrinkable film on the electrode assembly; a first assembling device for connecting the current collector member to the first tab; a heating device for heating the heat shrinkable film to shrink and making at least a part of the heat shrinkable film cover the current collector member; a second assembling device for placing the electrode assembly and the current collector member covered with the heat shrinkable film into the housing, and making the side of the current collector member covered with the heat shrinkable film face the wall portion to insulate and isolate the current collector member and the wall portion; a third assembling device for connecting the current collector member to the electrode terminal. Description of the Drawings

[0029] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required to be used in the embodiments of the present application will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For those of ordinary skill in the art, other drawings can be obtained according to the drawings without creative efforts.

[0030] Figure 1 It is a schematic structural diagram of a vehicle provided by an embodiment of the present application;

[0031] Figure 2 Schematic diagram of the structure of a battery provided by an embodiment of the present application;

[0032] Figure 3 Explosion diagram of a battery cell provided by an embodiment of the present application;

[0033] Figure 4 Cross-sectional view of a battery cell provided by an embodiment of the present application;

[0034] Figure 5 Schematic diagram of the heat shrink film extending between the electrode terminal and the current collector member provided by an embodiment of the present application;

[0035] Figure 6 Schematic diagram of the heat shrink film including a first part and a second part provided by an embodiment of the present application;

[0036] Figure 7 Another schematic diagram of the heat shrink film including a first part and a second part provided by an embodiment of the present application;

[0037] Figure 8 Schematic diagram of the heat shrink film including a third part provided by an embodiment of the present application;

[0038] Figure 9 Schematic diagram of a battery cell provided with an elastic layer according to an embodiment of the present application;

[0039] Figure 10 Schematic diagram of a battery cell provided by an embodiment of the present application;

[0040] Figure 11 Schematic diagram of the manufacturing method of a battery cell provided by the fourth embodiment of the present application;

[0041] Figure 12 Schematic diagram of the manufacturing equipment of a battery cell provided by the fifth embodiment of the present application. [[ID=?]]

[0042] In the drawings, the drawings are not drawn to actual scale.

[0043] Marking description: 10 - battery cell; 11 - housing; 11a - wall portion; 111 - shell; 1111 - bottom wall; 1112 - side wall; 112 - end cap; 12 - electrode terminal; 121 - insulating member; 1211 - elastic layer; 122 - second convex portion; 13 - electrode assembly; 131 - first tab; 132 - main body; 133 - second tab; 14 - current collecting member; 141 - first convex portion; 142 - step region; 15 - heat shrink film; 151 - first part; 152 - second part; 153 - third part; 20 - box body; 21 - first sub - box body; 22 - second sub - box body; 100 - battery; 200 - controller; 300 - motor; 1000 - vehicle; 2000 - manufacturing equipment for battery cells; 2100 - first providing device; 2200 - second providing device; 2300 - third providing device; 2400 - fourth providing device; 2500 - first assembling device; 2600 - heating device; 2700 - second assembling device; 2800 - third assembling device. Detailed implementation manners

[0044] The following further describes the implementation manners of the present application in detail with reference to the drawings and embodiments. The detailed descriptions and drawings of the following embodiments are used to exemplarily illustrate the principle of the present application, but cannot be used to limit the scope of the present application, that is, the present application is not limited to the described embodiments.

[0045] In the description of the present application, it should be noted that unless otherwise specified, the meaning of "a plurality of" is two or more; the orientation or positional relationships indicated by the terms "upper", "lower", "left", "right", "inner", "outer", etc. are only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation to the present application. In addition, the terms "first", "second", "third", etc. are only used for descriptive purposes and cannot be understood as indicating or implying relative importance. "Vertical" is not strictly vertical, but within the allowable error range. "Parallel" is not strictly parallel, but within the allowable error range.

[0046] The orientation terms appearing in the following description are all the directions shown in the drawings, and do not limit the specific structure of the present application. In the description of the present application, it should also be noted that unless otherwise clearly specified and limited, the terms "mounted", "connected", "connected" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be directly connected, or indirectly connected through an intermediate medium. For those of ordinary skill in the art, the specific meanings of the above terms in the present application can be understood according to specific situations.

[0047] In this application, the battery mentioned refers to a single physical module that includes one or more battery cells to provide a higher voltage and capacity. For example, the battery mentioned in this application may include a battery module, a battery pack, etc.

[0048] A battery cell includes an electrode assembly and an electrolyte. The electrode assembly is composed of a positive electrode tab, a negative electrode tab, and a separator. The battery cell mainly works by the movement of metal ions between the positive electrode tab and the negative electrode tab. The positive electrode tab includes a positive electrode current collector and a positive electrode active material layer. The positive electrode active material layer is coated on the surface of the positive electrode current collector. The positive electrode current collector without the coated positive electrode active material layer protrudes from the positive electrode current collector with the coated positive electrode active material layer. The positive electrode current collector without the coated positive electrode active material layer serves as the positive electrode ear. Taking a lithium-ion battery as an example, the material of the positive electrode current collector can be aluminum, and the positive electrode active material can be lithium cobaltate, lithium iron phosphate, ternary lithium, lithium manganate, etc. The negative electrode tab includes a negative electrode current collector and a negative electrode active material layer. The negative electrode active material layer is coated on the surface of the negative electrode current collector. The negative electrode current collector without the coated negative electrode active material layer protrudes from the negative electrode current collector with the coated negative electrode active material layer. The negative electrode current collector without the coated negative electrode active material layer serves as the negative electrode ear. The material of the negative electrode current collector can be copper, and the negative electrode active material can be carbon or silicon, etc. In order to ensure that a large current can pass through without fusing, the number of positive electrode ears is multiple and stacked together, and the number of negative electrode ears is multiple and stacked together. The material of the separator can be PP (Polypropylene) or PE (Polyethylene), etc.

[0049] Currently, from the perspective of the development of the market situation, the application of power batteries is becoming more and more extensive. Power batteries are not only used in energy storage power systems such as hydropower, thermal power, wind power, and solar power stations, but also widely used in electric transportation such as electric bicycles, electric motorcycles, and electric vehicles, as well as in multiple fields such as military equipment and aerospace. With the continuous expansion of the application fields of power batteries, the market demand is also constantly increasing.

[0050] The present inventor has noticed that during the use of a battery, due to external factors such as vibration and collision. Taking an electric vehicle equipped with battery cells and a battery as an example, during the driving of the electric vehicle, according to the different roughness of the road surface, the electric vehicle will experience different degrees of bumps and vibrations. When the electric vehicle passes through road surface defects such as deep pits, cracks, and bumps, the body posture of the electric vehicle will deviate significantly, and the electric vehicle will generate a large amplitude of vibration. In addition, when the electric vehicle collides, whether it is a low-speed collision or a high-speed collision, the battery cells will be greatly disturbed. When the battery cell is vibrated, the electrode assembly and the current collector member located inside the outer shell of the battery cell may move, especially in the axial direction of the electrode assembly, and the current collector member and the electrode assembly are prone to displacement. Further, due to the different polarities of the current collector member and the outer shell, after the current collector member and the electrode assembly move, there is a risk of short circuit between the current collector member and the outer shell. The battery short circuit will release the electric energy stored in the battery cell in the form of heat in a short time, causing thermal runaway, reducing the safety of the battery cell, and posing a great safety hazard.

[0051] In order to reduce the risk of short circuit between the current collector member and the outer shell and improve the safety of the battery cell, the inventor has studied and found that an insulating paper or an insulating tube can be provided between the current collector member and the outer shell to insulate and isolate the current collector member and the outer shell. However, the insulating paper is wrapped around the current collector member by a fitting method, resulting in the insulating paper being easily detached under the interference of vibration and unable to effectively cover the current collector member. In addition, the insulating tube is sleeved on the electrode assembly and wrapped around the current collector member by a folding method. During the folding process of the insulating tube, wrinkles will be generated, and the thickness dimension of the insulating tube at the position of the wrinkles increases. On the one hand, the increase in the thickness dimension of the insulating tube wrapped around the current collector member will reduce the stability of the electrical connection between the current collector member and the electrode terminal; on the other hand, when the thickness of the insulating tube is too large, it will also increase the resistance and difficulty of installing the electrode assembly into the shell, reduce the production efficiency of the battery cell, and thus lead to a low production capacity of the battery, unable to meet the growing market demand for the battery.

[0052] Based on the above considerations, in order to reduce the risk of short circuit between the current collector member and the outer shell, the inventor has designed a battery cell through in-depth research. The outer shell includes a wall portion (located at one end of the outer shell), and one side of the current collector member facing the wall portion is wrapped with a heat-shrinkable film to insulate and isolate the current collector member and the wall portion. The heat-shrinkable film is wrapped around the current collector member by heat shrinkage. After heat shrinkage, the heat-shrinkable film has good wrapping properties. At the same time, after heat shrinkage, the heat-shrinkable film can be wrapped around the current collector member more smoothly and stably, and is not prone to generating wrinkles.

[0053] In such a battery cell, after the heat-shrinkable film is heated and shrinks, it wraps around the current collector member flatly and stably. Even if the battery cell is interfered by external factors, causing the current collector member to move, the heat-shrinkable film can still stably wrap around the current collector member, and play an insulating and isolating role between the current collector member and the wall portion, reducing the risk of short circuit between the current collector member and the wall portion, and improving the safety of the battery cell.

[0054] The battery cell disclosed in the embodiments of the present application can be but is not limited to being used in power-consuming devices such as vehicles, ships or aircraft. A power supply system of the power-consuming device can be composed of the battery cell, battery, etc. disclosed in the present application. In this way, it is beneficial to reduce the risk of short circuit between the current collector member and the wall portion in the battery cell, and improve the safety of the battery cell and the battery.

[0055] The embodiments of the present application provide a power-consuming device using a battery as a power source. The power-consuming device can be but is not limited to a mobile phone, a tablet computer, a laptop computer, an electric toy, an electric tool, a battery car, an electric vehicle, a ship, a spacecraft, etc. Among them, the electric toy can include a fixed or mobile electric toy, for example, a game console, an electric vehicle toy, an electric ship toy and an electric aircraft toy, etc. The spacecraft can include an airplane, a rocket, a space shuttle and a spaceship, etc.

[0056] For the convenience of description in the following embodiments, a power-consuming device of the embodiments of the present application is taken as an example of a vehicle for description.

[0057] As Figure 1 shown, Figure 1 is a schematic structural diagram of a vehicle 1000 provided by some embodiments of the present application. The vehicle 1000 can be a fuel vehicle, a gas vehicle or a new energy vehicle. The new energy vehicle can be a pure electric vehicle, a hybrid electric vehicle or an extended-range electric vehicle, etc. A battery 100 is disposed inside the vehicle 1000. The battery 100 can be disposed at the bottom, head or tail of the vehicle 1000. The battery 100 can be used for power supply of the vehicle 1000. For example, the battery 100 can be used as an operating power source of the vehicle 1000. The vehicle 1000 can further include a controller 200 and a motor 300. The controller 200 is used to control the battery 100 to supply power to the motor 300. For example, it is used for the working power requirements during the start, navigation and driving of the vehicle 1000.

[0058] In some embodiments of the present application, the battery 100 can not only be used as an operating power source of the vehicle 1000, but also be used as a driving power source of the vehicle 1000, replacing or partially replacing fuel or natural gas to provide driving power for the vehicle 1000.

[0059] As Figure 2 shown, Figure 2Schematic diagram of the structure of the battery 100 provided by some embodiments of the present application. The battery 100 includes a box body 20 and battery cells 10, and the battery cells 10 are accommodated in the box body 20. Among them, the box body 20 is used to provide an accommodation space for the battery cells 10, and the box body 20 can adopt various structures. In some embodiments, the box body 20 may include a first sub-box body 21 and a second sub-box body 22, the first sub-box body 21 and the second sub-box body 22 are covered with each other, and the first sub-box body 21 and the second sub-box body 22 jointly define an accommodation space for accommodating the battery cells 10. The second sub-box body 22 may be a hollow structure with one end open, the first sub-box body 21 may be a plate-like structure, and the first sub-box body 21 covers the open side of the second sub-box body 22 so that the first sub-box body 21 and the second sub-box body 22 jointly define an accommodation space; the first sub-box body 21 and the second sub-box body 22 may also both be hollow structures with one side open, and the open side of the first sub-box body 21 covers the open side of the second sub-box body 22. Of course, the box body 20 formed by the first sub-box body 21 and the second sub-box body 22 may be of various shapes, such as a cylinder, a cuboid, etc.

[0060] In the battery 100, there may be multiple battery cells 10, and the multiple battery cells 10 can be connected in series, in parallel, or in a mixed connection. A mixed connection means that there are both series and parallel connections among the multiple battery cells 10. The multiple battery cells 10 can be directly connected in series, in parallel, or in a mixed connection together, and then the whole formed by the multiple battery cells 10 is accommodated in the box body 20; of course, the battery 100 can also be that multiple battery cells 10 are first connected in series, in parallel, or in a mixed connection to form a battery module form, and then multiple battery modules are connected in series, in parallel, or in a mixed connection to form a whole and are accommodated in the box body 20. The battery 100 may further include other structures. For example, the battery 100 may further include a busbar component for realizing the electrical connection between the multiple battery cells 10.

[0061] Among them, each battery cell 10 can be a secondary battery or a primary battery; it can also be a lithium-sulfur battery, a sodium-ion battery, or a magnesium-ion battery, but is not limited thereto. The battery cell 10 can be in the shape of a cylinder, a flat body, a cuboid, or other shapes, etc.

[0062] As Figure 3 shown, Figure 3 An exploded view of the battery cell 10 provided by some embodiments of the present application. The battery cell 10 refers to the smallest unit that makes up the battery 100. As Figure 3 shown, the battery cell 10 includes a housing 11, an electrode assembly 13, and other functional components.

[0063] The housing 11 is a component for forming the internal environment of the battery cell 10. The internal environment formed by the housing 11 can be used to accommodate the electrode assembly 13, the electrolyte, and other components. The housing 11 can be of various shapes and sizes, such as cylindrical, cuboid, hexagonal prism, etc. Specifically, the shape of the housing 11 can be determined according to the specific shape and size of the electrode assembly 13. The material of the housing 11 can be various, such as copper, iron, aluminum, stainless steel, aluminum alloy, etc.

[0064] The electrode assembly 13 is a component in the battery cell 10 where an electrochemical reaction occurs. The housing 11 can contain one or more electrode assemblies 13. The electrode assembly 13 is mainly formed by winding or laminating a positive electrode plate and a negative electrode plate, and usually a separator is provided between the positive electrode plate and the negative electrode plate. The parts of the positive electrode plate and the negative electrode plate with active materials constitute the main body 132 of the electrode assembly 13, and the parts of the positive electrode plate and the negative electrode plate without active materials respectively constitute the electrode tabs. The positive electrode tab and the negative electrode tab can be located together at one end of the main body 132 or separately at both ends of the main body 132. During the charging and discharging process of the battery 100, the positive active material and the negative active material react with the electrolyte, and the electrode tabs are connected to the electrode terminals 12 to form a current loop.

[0065] As Figure 4 shown, Figure 4 is a cross-sectional view of the battery cell 10 according to some embodiments of the present application. The present application provides a battery cell 10, which includes a housing 11, an electrode terminal 12, an electrode assembly 13, a current collector member 14, and a heat shrinkable film 15. The housing 11 includes a wall portion 11a, and the electrode terminal 12 is insulatingly mounted on the wall portion 11a. The electrode assembly 13 is disposed inside the housing 11. The electrode assembly 13 includes a main body 132 and a first electrode tab 131, and the first electrode tab 131 is formed at one end of the main body 132 close to the wall portion 11a. The current collector member 14 is disposed between the electrode assembly 13 and the wall portion 11a, and the current collector member 14 is used to connect the first electrode tab 131 and the electrode terminal 12. At least a part of the heat shrinkable film 15 covers the side of the current collector member 14 facing the wall portion 11a to insulate and isolate the current collector member 14 and the wall portion 11a.

[0066] The electrode terminal 12 is insulatingly mounted on the wall portion 11a. Since the polarities between the electrode terminal 12 and the housing 11 are different, that is, the polarities between the electrode terminal 12 and the wall portion 11a are different (for example, in some embodiments of the present application, the electrode terminal 12 is positively charged and the wall portion 11a is negatively charged), therefore, insulation should be provided between the electrode terminal 12 and the wall portion 11a to prevent the electrode terminal 12 from being electrically connected to the wall portion 11a, which may cause a short circuit problem in the battery cell 10, thereby ensuring high safety of the battery cell 10, the battery 100, and the electrical device.

[0067] Specifically, as Figure 4 shown, an insulating member 121 can be provided between the electrode terminal 12 and the wall portion 11a. The insulating member 121 is used to isolate the electrode terminal 12 and the wall portion 11a to reduce the risk of short circuit. Among them, the material of the insulating member 121 can be plastic, such as PVC (Polyvinyl Chloride), PP (Polypropylene), etc. Or, the material of the insulating member 121 can also be rubber, such as butyl rubber, styrene-butadiene rubber, silicone rubber, etc. Or, the insulating member 121 can also be a fiber material, such as NOMEX (aromatic polyamide / Nomex) insulating paper. NOMEX insulating paper is mainly composed of meta-aramid fibers and has good insulation performance, as well as good heat resistance and corrosion resistance.

[0068] The current collector member 14 is used to connect the first tab 131 and the electrode terminal 12 means that both the first tab 131 and the electrode terminal 12 are connected to the current collector member 14, and the electrical connection between the first tab 131 and the electrode terminal 12 is achieved through the current collector member 14.

[0069] The heat shrinkable film 15 is made of a heat shrinkable material. The heat shrinkable material is a kind of polymer shape memory material, which is a material obtained by radiation processing of polymer materials. Ordinary polymer materials, such as polyethylene, polyvinyl chloride, etc., are usually linear structures. The linear polymer materials are transformed into network structures under the radiation of radiation sources such as electron accelerators. Such network polymer materials obtained by radiation processing are heat shrinkable materials. The heat shrinkable materials have a unique shape memory effect. The heat shrinkable materials that have been expanded and cooled and shaped can shrink back to the initial shape when heated. By using the shape memory effect of the heat shrinkable materials, the heat shrinkable materials can be made into heat shrinkable pipes, heat shrinkable films or heat shrinkable special-shaped materials, etc. During use, the heat shrinkable materials are heated to make them shrink. The shrunk heat shrinkable materials form the heat shrinkable film 15, which is flat and tightly covers the outer surface of the object, and plays roles such as insulation, sealing and protection for the object it covers.

[0070] Furthermore, at least a part of the heat shrinkable film 15 covers the side of the current collector member 14 facing the wall portion 11a means that a tubular or film-shaped heat shrinkable material is arranged on the current collector member 14, and the heat shrinkable material is heated to make it shrink to form the heat shrinkable film 15. The heat shrinkable film 15 is flat and tightly covers the side of the current collector member 14 facing the wall portion 11a to insulate and isolate the current collector member 14 and the wall portion 11a.

[0071] It should be noted that, as Figure 4As shown in the figure, the fact that the heat-shrinkable film 15 covers one side of the current collector member 14 facing the wall portion 11a does not mean that the heat-shrinkable film 15 completely covers one side of the current collector member 14 facing the wall portion 11a. If the heat-shrinkable film 15 completely covers one side of the current collector member 14 facing the wall portion 11a, the heat-shrinkable film 15 will insulate and isolate between the electrode terminal 12 and the current collector member 14, while electrical connection is required between the electrode terminal 12 and the current collector member 14, that is, there should be a part where the electrode terminal 12 and the current collector member 14 abut and contact each other. Specifically, it is sufficient that the heat-shrinkable film 15 covers the part of the current collector member 14 corresponding to the wall portion 11a.

[0072] In addition, as Figure 4 shown in the figure, part of the electrode terminal 12 is located between the wall portion 11a and the current collector member 14, that is, the projection of the wall portion 11a on the current collector member 14 overlaps with the projection of the part of the electrode terminal 12 located between the wall portion 11a and the current collector member 14 on the current collector member 14. Since electrical connection is required between the electrode terminal 12 and the current collector member 14 and insulation isolation is not needed, therefore, the heat-shrinkable film 15 also does not need to cover the projection part of the part of the electrode terminal 12 located between the wall portion 11a and the current collector member 14 on the current collector member 14 (this part is located within the projection of the wall portion 11a on the current collector member 14). It can be understood that no matter in what way the heat-shrinkable film 15 covers one side of the current collector member 14 facing the wall portion 11a, as long as the heat-shrinkable film 15 can achieve insulation isolation between the current collector member 14 and the wall portion 11a and ensure stable electrical connection between the current collector member 14 and the electrode terminal 12.

[0073] For the battery cell 10 of the present application, the heat-shrinkable film 15 covers the current collector member 14 by heat shrinkage to play a role in insulating and isolating the current collector member 14 and the wall portion 11a. The heat-shrinkable film 15 has good covering property after heat shrinkage. When the battery cell 10 is interfered by external factors and externally disturbed, the heat-shrinkable film 15 can still cover the current collector member 14 relatively stably, reducing the risk of short circuit between the current collector member 14 and the wall portion 11a and improving the safety of the battery cell 10. In addition, the surface of the heat-shrinkable film 15 formed by heat shrinkage is relatively flat, not easy to generate wrinkles, and the thickness of the heat-shrinkable film 15 is uniform, reducing the probability that the thickness dimension of the heat-shrinkable film 15 increases due to wrinkles, preventing interference between the heat-shrinkable film 15 with too large thickness dimension and the current collector member 14, and increasing the resistance and difficulty of installing the electrode assembly 13 into the shell, and improving the production efficiency of the battery cell 10.

[0074] As Figure 5 shown in the figure, Figure 5 is a schematic diagram of the heat-shrinkable film 15 extending between the electrode terminal 12 and the current collector member 14 in some embodiments of the present application. In some embodiments of the present application, the heat-shrinkable film 15 extends between the electrode terminal 12 and the current collector member 14.

[0075] On the one hand, a part of the heat-shrinkable film 15 extends between the electrode terminal 12 and the current collector member 14, and the heat-shrinkable film 15 is clamped and pressed by the electrode terminal 12 and the current collector member 14 to prevent the heat-shrinkable film 15 from moving around and failing to completely cover the portion of the current collector member 14 corresponding to the wall portion 11a, reducing the risk of short circuit between the current collector member 14 and the wall portion 11a and ensuring a high level of safety for the battery cell 10. In addition, since the heat-shrinkable film 15 needs to completely cover the current collector member 14, extending the heat-shrinkable film 15 between the electrode terminal 12 and the current collector member 14 can reduce the precision requirements for covering the heat-shrinkable film 15, thereby reducing the process difficulty of covering the current collector member 14 with the heat-shrinkable film 15.

[0076] On the other hand, during the use of the battery cell 10, heat will be generated, and the temperature of the battery cell 10 will rise. This will not only heat the heat-shrinkable film 15 and cause the heat-shrinkable film 15 to further contract, but also the electrode assembly 13 will expand outwards, and the heat-shrinkable film 15 cannot completely cover the current collector member 14, and thus cannot play an insulating and isolating role between the current collector member 14 and the wall portion 11a, resulting in a risk of short circuit between the current collector member 14 and the wall portion 11a. Therefore, by the setting method of extending the heat-shrinkable film 15 between the electrode terminal 12 and the current collector member 14, even if the temperature of the battery cell 10 rises and causes a further shrinking trend of the heat-shrinkable film 15, due to the clamping and pressing of the heat-shrinkable film 15 by the electrode terminal 12 and the current collector member 14, the portion of the heat-shrinkable film 15 covering the current collector member 14 will not shift due to contraction, that is, the heat-shrinkable film 15 can stably cover the portion of the current collector member 14 corresponding to the wall portion 11a, ensuring that the current collector member 14 and the wall portion 11a are in an insulating and isolating state, reducing the risk of short circuit between the current collector member 14 and the wall portion 11a, and ensuring a high level of safety for the battery cell 10.

[0077] In some other embodiments of the present application, the heat-shrinkable film 15 may not extend between the electrode terminal 12 and the current collector member 14, that is, the projection of the portion of the electrode terminal 12 located between the current collector member 14 and the wall portion 11a on the current collector member 14 does not overlap with the projection of the heat-shrinkable film 15 on the current collector member 14.

[0078] Furthermore, when the heat-shrinkable film 15 extends between the electrode terminal 12 and the current collector member 14, due to the certain thickness of the heat-shrinkable film 15, there will be a certain gap between the electrode terminal 12 and the current collector member 14. The electrode terminal 12 and the current collector member 14 should be in contact and in a stable electrical connection state to ensure that the battery cell 10 forms a stable circuit, and thus ensure that the battery cell 10 supplies power stably. However, the gap between the electrode terminal 12 and the current collector member 14 will destroy the stability of the electrical connection between the electrode terminal 12 and the current collector member 14, and even cause a situation where the battery cell 10 cannot form a circuit and cannot supply power.

[0079] Therefore, as Figure 5 shown, in some embodiments of the present application, in order to ensure a stable electrical connection between the current collector member 14 and the electrode terminal 12, the portion of the current collector member 14 for connecting to the electrode terminal 12 can protrude towards the electrode terminal 12 to form a first convex portion 141, so that the current collector member 14 and the electrode terminal 12 can maintain contact and have a stable electrical connection.

[0080] Furthermore, as Figure 5 shown, when the current collector member 14 is formed with the first convex portion 141, in order to ensure that when the heat shrinkable film 15 extends between the electrode terminal 12 and the current collector member 14, the electrode terminal 12 and the current collector member 14 can clamp the heat shrinkable film 15, the portion of the electrode terminal 12 for cooperating with the current collector member 14 to clamp the heat shrinkable film 15 can be formed with a second convex portion 122 extending towards the current collector member 14. Through the arrangement of the first convex portion 141 and the second convex portion 122, while ensuring that the current collector member 14 is stably electrically connected to the electrode terminal 12 through the first convex portion 141, it is ensured that the electrode terminal 12 can cooperate with the current collector member 14 through the second convex portion 122 to clamp the heat shrinkable film 15 extending between the electrode terminal 12 and the current collector member 14.

[0081] With this setting method, the heat shrinkable film 15 extends between the electrode terminal 12 and the current collector member 14, without the need to adjust the range of the heat shrinkable film 15 covering the current collector member 14, reducing the process difficulty of covering the current collector member 14 with the heat shrinkable film 15 and improving the production efficiency of the battery cell 10. At the same time, when the heat shrinkable film 15 extends between the electrode terminal 12 and the current collector member 14, the electrode terminal 12 and the current collector member 14 can clamp the heat shrinkable film 15, preventing problems such as the heat shrinkable film 15 shrinking due to heat and the electrode assembly 13 expanding, which may cause the heat shrinkable film 15 to not completely cover the current collector member 14, improving the stability of the heat shrinkable film 15 covering the current collector member 14 and enhancing the safety of the battery cell 10.

[0082] As Figure 4 and Figure 5 shown, in some embodiments of the present application, there is a gap between the heat shrinkable film 15 and the wall portion 11a, that is, the heat shrinkable film 15 does not contact the wall portion 11a.

[0083] The heat-shrinkable film 15 is coated on one side of the current collector member 14 facing the wall portion 11a. It can be understood that the heat-shrinkable film 15 is closely attached to the outer surface of the current collector member 14 facing the wall portion 11a. Further, the polarities between the current collector member 14 and the wall portion 11a are different, and there is an electric potential difference between the current collector member 14 and the wall portion 11a. Although the heat-shrinkable film 15 itself has good insulation properties and can insulate and isolate the current collector member 14 and the wall portion 11a, due to the relatively thin thickness of the heat-shrinkable film 15, when the heat-shrinkable film 15 contacts the wall portion 11a, there is a risk that the electric potential difference between the current collector member 14 and the wall portion 11a will break down the heat-shrinkable film 15. Therefore, there should be a certain gap between the heat-shrinkable film 15 and the wall portion 11a to prevent the distance between the current collector member 14 and the wall portion 11a from being too close and breaking down the heat-shrinkable film 15, resulting in the conduction and short circuit of the current collector member 14 and the wall portion 11a.

[0084] In some other embodiments of the present application, when the thickness of the heat-shrinkable film 15 is relatively thick, the electric potential difference between the current collector member 14 and the wall portion 11a is not sufficient to break down the heat-shrinkable film 15. At this time, a gap may not be provided between the heat-shrinkable film 15 and the wall portion 11a, that is, the heat-shrinkable film 15 may also be in contact with the wall portion 11a. It can be understood that it is sufficient that the heat-shrinkable film 15 can insulate and isolate the current collector member 14 and the wall portion 11a.

[0085] In this setting method, since there is a certain electric potential difference between the wall portion 11a and the current collector member 14, if the heat-shrinkable film 15 contacts the wall portion 11a, there is a risk that the electric potential difference between the wall portion 11a and the current collector member 14 will break down the heat-shrinkable film 15. Therefore, a gap is left between the heat-shrinkable film 15 and the wall portion 11a to reduce the risk of short circuit between the wall portion 11a and the current collector member 14, that is, to reduce the risk of short circuit of the battery cell 10, and improve the safety of the battery cell 10.

[0086] As Figure 6 shown, Figure 6 is a schematic diagram of the heat-shrinkable film 15 including a first part 151 and a second part 152 in some embodiments of the present application. In some embodiments of the present application, the heat-shrinkable film 15 includes an integrally formed first part 151 and a second part 152. The first part 151 is coated on one side of the current collector member 14 facing the wall portion 11a, and the second part 152 is coated on the outer peripheral surface of the first pole ear 131.

[0087] The first pole ear 131 is electrically connected to the current collector member 14, and the first pole ear 131 and the current collector member 14 have the same polarity, that is, the first pole ear 131 and the outer casing 11 have different polarities. Therefore, insulation isolation is required between the first pole ear 131 and the outer casing 11 to prevent the first pole ear 131 from being electrically connected to the outer casing 11 and short-circuiting, reducing the risk of short circuit of the battery cell 10, and ensuring that the battery cell 10, the battery 100 and the electrical device have high safety.

[0088] Among them, as Figure 6 shown, the current collector member 14 is disposed between the first tab 131 and the wall portion 11a, that is, the current collector member 14 is disposed on the end face of the first tab 131 facing the wall portion 11a. By covering the first part 151 of the heat shrink film 15 on the side of the current collector member 14 facing the wall portion 11a, the insulation isolation between the end face of the first tab 131 facing the wall portion 11a and the housing 11 is achieved. Further, as Figure 6 shown, in order to prevent the outer peripheral surface of the first tab 131 from being electrically connected to the inner peripheral wall of the housing 11, resulting in a short circuit, the outer peripheral surface of the first tab 131 and the housing 11 should also be insulated from each other. Therefore, the heat shrink film 15 is provided to include a first part 151 and a second part 152. On the basis of covering the first part 151 on the side of the current collector member 14 facing the wall portion 11a, the second part 152 is used to cover the outer peripheral surface of the first tab 131 to insulate the outer peripheral surface of the first tab 131 and the inner peripheral wall of the housing 11.

[0089] Specifically, as Figure 6 shown, in some embodiments of the present application, the first part 151 and the second part 152 of the heat shrink film 15 are integrally formed. The heat shrink film 15 integrally formed by the first part 151 and the second part 152 has good covering ability and can completely cover the side of the current collector member 14 facing the wall portion 11a, the outer peripheral surface of the first tab 131, and the corner positions of the current collector member 14 and the first tab 131. There is a good insulation effect between the current collector member 14 and the first tab 131 and the housing 11, and it is not easy to have the problem that the current collector member 14 or the first tab 131 is short-circuited with the housing 11 due to the incomplete covering of the heat shrink film 15.

[0090] Among them, as Figure 6 shown, the corner positions of the current collector member 14 and the first tab 131 refer to the corner of the current collector member 14 itself, the corner of the first tab 131 itself, and the corner formed between the current collector member 14 and the first tab 131. Specifically, the corner of the current collector member 14 itself is the corner between the side of the current collector member 14 facing the wall portion 11a and the outer peripheral surface of the current collector member 14, the corner of the first tab 131 itself is the corner between the side of the first tab 131 facing the wall portion 11a and the outer peripheral surface of the first tab 131, and the corner formed between the current collector member 14 and the first tab 131 is the corner formed between the outer peripheral surface of the current collector member 14 and the side of the first tab 131 facing the wall portion 11a.

[0091] Further, the shrink film 15 integrally formed by the first part 151 and the second part 152 is easy to form and has a high production efficiency. During the heating process of the shrink film 15, it is not necessary to adjust the parts covered by the first part 151 and the second part 152. It can be understood that after the integrally formed shrink film 15 shrinks when heated, without intervention, it can naturally adhere to and cover the part of the battery cell 10 that needs to be covered with the shrink film 15. Therefore, the production efficiency of the battery cell 10 provided with the integrally formed shrink film 15 is relatively high, thereby expanding the production capacity of the battery 100 to meet the increasing demand of the market for the production capacity of the battery 100.

[0092] In some other embodiments of the present application, the first part 151 and the second part 152 of the shrink film 15 can also be separately arranged. For example, the first part 151 is a sheet-shaped ring and is covered on one side of the current collector member 14 facing the wall portion 11a, and the second part 152 is a cylindrical ring and is covered on the outer peripheral surface of the first tab 131.

[0093] In this setting method, the shrink film 15 is not only covered on the current collector member 14, but also on the outer peripheral surface of the first tab 131. Through one shrink film 15, the insulation between the current collector member 14 and the wall portion 11a and between the first tab 131 and the side wall of the housing 11 is simultaneously achieved, reducing the number of components and making the structure of the battery cell 10 compact.

[0094] Such as Figure 6 and Figure 7 shown, Figure 7 Another schematic diagram of the shrink film 15 including the first part 151 and the second part 152 in some embodiments of the present application. In some embodiments of the present application, the current collector member 14 is in a disc shape, the diameter of the current collector member 14 is smaller than the diameter of the first tab 131, and a step area 142 is formed between the edge of the current collector member 14 and the outer peripheral surface of the first tab 131, and the shrink film 15 covers the step area 142.

[0095] Wherein, the edge of the current collector member 14 refers to the outer peripheral surface of the current collector member 14.

[0096] Such as Figure 6 and Figure 7As shown, a stepped area 142 is formed between the edge of the current collector member 14 and the outer peripheral surface of the first tab 131. It can be understood that the current collector member 14 is disposed between the electrode assembly 13 and the wall portion 11a, that is, the current collector member 14 is disposed between the first tab 131 and the wall portion 11a. In other words, the side surface of the current collector member 14 facing the wall portion 11a is closer to the wall portion 11a than the side surface of the first tab 131 facing the wall portion 11a. At the same time, the diameter of the current collector member 14 is smaller than the diameter of the first tab 131, that is, the projection of the current collector member 14 on the first tab 131 is located within the first tab 131. Therefore, a stepped structure, that is, the stepped area 142, will be formed between the outer peripheral surface (the edge of the current collector member 14) of the current collector member 14 and the outer peripheral surface of the first tab 131.

[0097] On the one hand, the current collector member 14 is connected to the first tab 131 by welding. The setting of the stepped area 142 provides a sufficient area for welding between the current collector member 14 and the first tab 131, which can effectively reduce the difficulty of welding between the current collector member 14 and the first tab 131, improve the welding efficiency, and then improve the production efficiency of the battery cell 10 to expand the production capacity of the battery 100 and meet the market demand for the production capacity of the battery 100.

[0098] On the other hand, in order to ensure that the heat shrinkable film 15 can completely cover the parts of the current collector member 14 and the first tab 131 that need to be covered, so that both the current collector member 14 and the first tab 131 are insulated from the outer shell 11, the heat shrinkable film 15 should be provided with a certain margin. The margin of the heat shrinkable film 15 is very likely to generate wrinkles during the process of heat shrinkage of the heat shrinkable film 15. At the same time, during the process of heat shrinkage of the heat shrinkable film 15, affected by factors such as the flatness of the surface covered by the heat shrinkable film 15 and the shape of the covered part of the heat shrinkable film 15. For example, the outer surface of the current collector member 14 facing the wall portion 11a is not an absolute plane but an uneven surface. When the heat shrinkable film 15 covers the current collector member 14, the surface of the heat shrinkable film 15 may also generate wrinkles. The generation of wrinkles will not only affect the covering quality of the heat shrinkable film 15, but may even cause problems such as the battery cell 10 being unable to be encapsulated due to the increased thickness at the position where the heat shrinkable film 15 has wrinkles, resulting in waste products and reducing the qualified rate during the production process of the battery cell 10. Therefore, in order to reduce the probability of wrinkles appearing during the heat shrinkage process of the heat shrinkable film 15, an area for absorbing the margin of the heat shrinkable film 15 should be provided in the covered part of the heat shrinkable film 15. The setting of the stepped area 142 enables the stepped area 142 to absorb the margin of the heat shrinkable film 15, thereby reducing the probability of wrinkles appearing during the heat shrinkage process of the heat shrinkable film 15.

[0099] When the heat shrinkable film 15 covers the current collector member 14 and the first tab 131, and a stepped area 142 is formed between the current collector member 14 and the first tab 131, in some embodiments of the present application, such asFigure 6 As shown, the heat-shrinkable film 15 can span the step area 142, that is, the heat-shrinkable film 15 does not adhere to the outer peripheral surface of the current collector member 14 and the end surface of the first tab 131 facing the wall portion 11a; in some other embodiments of the present application, as Figure 7 shown, the heat-shrinkable film 15 can also be shrunk and adhered to the outer peripheral surface of the current collector member 14 and the end surface of the first tab 131 facing the wall portion 11a.

[0100] In this setting method, by providing the step area 142 between the current collector member 14 and the first tab 131, on the one hand, the setting of the step area 142 provides sufficient space for welding the current collector member 14 to the first tab 131, facilitating the welding between the current collector member 14 and the first tab 131, improving the production efficiency of the battery cell 10, and expanding the production capacity of the battery 100; on the other hand, during the heat shrinkage process of the heat-shrinkable film 15, the step area 142 can absorb the excess of the heat-shrinkable film 15, reducing the probability of wrinkles appearing during the shrinkage process of the heat-shrinkable film 15, and improving the flatness of the heat-shrinkable film 15 covering the current collector member 14.

[0101] such as Figure 8 shown, Figure 8 is a schematic diagram of the heat-shrinkable film 15 including a third part 153 in some embodiments of the present application. In some embodiments of the present application, the heat-shrinkable film 15 further includes a third part 153, and the third part 153 covers the outer peripheral surface of the main body 132, and the third part 153 is integrally formed with the second part 152.

[0102] The electrode assembly 13 includes a main body 132 and a first tab 131, and the first tab 131 is formed at one end of the main body 132 close to the wall portion 11a. Therefore, on the basis of covering the outer peripheral surface of the first tab 131 with the second part 152, in order to prevent short circuit between the main body 132 and the housing 11, insulation isolation should also be carried out between the outer peripheral surface of the main body 132 and the inner wall of the housing 11. Therefore, a third part 153 is provided on the heat-shrinkable film 15, and the third part 153 covers the outer peripheral surface of the main body 132 to achieve insulation isolation between the main body 132 and the housing 11.

[0103] When the third part 153 and the second part 152 of the heat-shrinkable film 15 are integrally formed, the continuity between the second part 152 and the third part 153 is good. During the heat-shrinking process of the second part 152 and the third part 153, it is not easy to form a gap between the second part 152 and the third part 153, ensuring that the second part 152 and the third part 153 can completely cover the first tab 131, the body, and the transition region between the first tab 131 and the body, further reducing the probability of short circuit in the battery cell 10, and thus improving the safety of the battery cell 10, the battery 100, and the electrical device. At the same time, because the second part 152 and the third part 153 are integrally formed, there will be no overlapping area between the second part 152 and the third part 153 after heat shrinkage, preventing the local thickness of the heat-shrinkable film 15 from increasing due to the overlap of the second part 152 and the third part 153, and avoiding the problem of stress concentration at the position where the thickness of the heat-shrinkable film 15 increases, thereby reducing the risk of lithium plating due to local stress concentration.

[0104] In addition, since the third part 153 and the second part 152 are integrally formed, when the third part 153 is sleeved on the outer peripheral surface of the body, the second part 152 is also correspondingly sleeved on the outer peripheral surface of the first tab 131. Then, when the heat-shrinkable film 15 is heated, the second part 152 and the third part 153 can shrink and correspondingly tightly cover the outer peripheral surface of the first tab 131 and the outer peripheral surface of the body, facilitating the assembly production of the battery cell 10 and making the battery cell 10 have a high production efficiency.

[0105] Furthermore, as Figure 8 shown, the first part 151, the second part 152, and the third part 153 are connected in sequence and integrally formed to further improve the integrity of the heat-shrinkable film 15. On the one hand, the risk of short circuit in the battery cell 10 is reduced, and the safety performance of the battery cell 10 is improved. On the other hand, it prevents the connection positions between the first part 151 and the second part 152 and between the second part 152 and the third part from overlapping, and the thickness of each position of the heat-shrinkable film 15 is relatively uniform and consistent, not easy to have the problem of stress concentration, thereby reducing the risk of lithium plating caused by stress concentration.

[0106] In this setting method, on the one hand, the third part 153 wraps the outer peripheral surface of the main body 132, reducing the risk of short circuit between the outer shell 11 and the main body 132, that is, reducing the risk of short circuit of the battery cell 10 and improving the safety of the battery cell 10. On the other hand, the third part 153 and the second part 152 are integrally formed, and it is not easy for the third part 153 and the second part 152 to overlap, preventing the thickness dimension of the heat shrink film 15 from increasing due to the overlap of the second part 152 and the third part 153, reducing the probability of local stress concentration caused by the increase in the thickness dimension of the heat shrink film 15 and the extrusion with the outer shell 11, and further reducing the risk of lithium plating on the electrode due to stress concentration.

[0107] In some embodiments of the present application, the electrode assembly 13 is wound by a pole piece and a separator. The battery cell 10 further includes a tape, and the tape is bonded to the outer peripheral surface of the main body 132 to fix the winding head and tail sections of the pole piece and / or the separator, and the third part 153 does not overlap with the tape.

[0108] The electrode assembly 13 is wound by a pole piece and a separator. Among them, the pole piece includes a positive pole piece and a negative pole piece, and the positive pole piece and the negative pole piece are isolated by a separator. Further, the parts of the positive pole piece and the negative pole piece with active materials constitute the main body 132, and the parts of the positive pole piece and the negative pole piece without active materials are respectively used to constitute the positive pole tab and the negative pole tab. For example, the first pole tab 131 is constituted by the part of the positive pole piece without active material.

[0109] Since the electrode assembly 13 is wound by a pole piece and a separator, the pole piece and the separator have a tendency to expand outwards. In order to prevent the pole piece and the separator from expanding, and to prevent the pole piece and the separator from directly contacting the outer shell 11 after expansion, resulting in a short circuit, the pole piece and the separator should be tightened and fixed. For example, the tape can be bonded to the outer peripheral surface of the main body 132, and the winding head and tail ends of the pole piece and / or the separator are fixed by the tape to prevent the pole piece and the separator from expanding outwards.

[0110] The winding head and tail ends refer to the outermost finishing parts during the winding process of the pole piece and the separator, and can also be understood as the ends of the winding of the pole piece and the separator. At the same time, when the tape is bonded to the outer peripheral surface of the main body 132, in order to prevent the pole piece on the outermost layer of the main body 132 from short-circuiting with the outer shell 11, the tape should be insulated. For example, the tape can be a polyvinyl chloride-based insulating tape, or a polyolefin-based insulating tape, etc.

[0111] Further, since the tape is used to adhere to the outer peripheral surface of the main body 132, and the third part 153 of the heat-shrinkable film 15 is also used to cover the outer peripheral surface of the main body 132, in order to prevent the third part 153 of the heat-shrinkable film 15 from overlapping with the tape and causing stress concentration problems, thereby reducing the risk of lithium plating due to gravitational concentration, the third part 153 of the heat-shrinkable film 15 and the tape should cover different positions of the outer peripheral surface of the main body 132, that is, the third part 153 does not overlap with the tape.

[0112] In this setting method, the third part 153 and the tape do not overlap, preventing the thickness dimension of the overlapping part from increasing due to the overlap of the third part 153 and the tape, and it is not easy to have problems of local stress concentration caused by the extrusion of the side wall of the housing 11 due to the increase in the thickness dimension of this part, thereby reducing the risk of lithium plating of the electrode due to stress concentration.

[0113] It is not easy to have problems of increased thickness due to the overlap of the third part 153 and the tape, preventing local stress concentration due to the increase in thickness, and thereby reducing the risk of lithium plating of the electrode due to stress concentration.

[0114] As Figure 9 shown, Figure 9 is a schematic diagram of the battery cell 10 provided with the elastic layer 1211 in some embodiments of the present application. In some embodiments of the present application, the battery cell 10 further includes an elastic layer 1211, and the elastic layer 1211 is disposed between the wall portion 11a and the heat-shrinkable film 15. The elastic layer 1211 is used to apply an elastic force along the axial direction of the electrode assembly 13 to the electrode assembly 13, that is, to apply an elastic force along the axial direction of the electrode assembly 13 to the current collector member 14.

[0115] As Figure 9 shown, in some embodiments of the present application, the insulating member 121 is extended between the heat-shrinkable film 15 and the wall portion 11a. The insulating member 121 extended between the wall portion 11a and the heat-shrinkable film 15 can be used as the elastic layer 1211 of the battery cell 10 and provide an elastic force along the axial direction of the electrode assembly 13 to the electrode assembly 13.

[0116] Further, when the insulating member 121 extended between the wall portion 11a and the heat-shrinkable film 15 is used as the elastic layer 1211, there can be a certain gap between the elastic layer 1211 and the heat-shrinkable film 15 to prevent a gap from appearing between the electrode terminal 12 and the current collector member 14, thereby ensuring that the electrode terminal 12 and the current collector member 14 can stably abut and be electrically connected.

[0117] Of course, on the basis of ensuring the stable electrical connection between the electrode terminal 12 and the current collector member 14, the elastic layer 1211 can also abut against the heat-shrinkable film 15 to further limit the electrode assembly 13 and reduce the probability of the electrode assembly 13 moving axially. At this time, in order to enable the elastic layer 1211 to abut against the heat-shrinkable film 15, a protrusion protruding towards the heat-shrinkable film 15 can be formed on the part of the insulating member 121 extending between the wall portion 11a and the heat-shrinkable film 15, that is, the part of the insulating member 121 serving as the elastic layer 1211, and the protrusion abuts against the heat-shrinkable film 15. Specifically, the protrusion can be annular, or there can be multiple protrusions, and the multiple protrusions are spaced apart around the axis of the electrode assembly 13.

[0118] It should be noted that when the part of the insulating member 121 extending between the wall portion 11a and the heat-shrinkable film 15 is used as the elastic layer 1211, the insulating member 121 should have a certain elasticity. At this time, the material of the insulating member 121 can be rubber, such as butyl rubber, styrene-butadiene rubber, silicone rubber, etc.

[0119] In some other embodiments of the present application, the elastic layer 1211 can also be an independent component in the battery cell 10. At this time, both ends of the elastic layer 1211 along the axis of the electrode assembly 13 abut against the wall portion 11a and the heat-shrinkable film 15 respectively to limit the electrode assembly 13 and reduce the probability of the electrode assembly 13 moving axially.

[0120] In this setting mode, when the battery cell 10 is vibrated, the elastic layer 1211 can apply an elastic force along its axis to the electrode assembly 13 and the current collector member 14, further insulating and isolating the current collector member 14 and the wall portion 11a, reducing the risk of short circuit of the battery cell 10, and improving the safety of the battery cell 10.

[0121] As Figure 10 shown, Figure 10 is a schematic diagram of the battery cell 10 according to some embodiments of the present application. In some embodiments of the present application, the electrode assembly 13 further includes a second tab 133. The second tab 133 is formed at one end of the main body 132 away from the wall portion 11a. The second tab 133 has a polarity opposite to that of the first tab 131, and the second tab 133 is electrically connected to the wall portion 11a.

[0122] As Figure 10 shown, the first tab 131 is located at one end of the electrode assembly 13 facing the wall portion 11a, and the second tab 133 is located at one end of the electrode assembly 13 away from the wall portion 11a, that is, the first tab 131 and the second tab 133 are respectively formed at both ends of the main body 132 of the electrode assembly 13.

[0123] The first tab 131 and the second tab 133 have opposite polarities. For example, the first tab 131 is the positive tab of the electrode assembly 13, which is formed by the part of the positive electrode tab without active material and is electrically connected to the current collector member 14 and the electrode terminal 12. The second tab 133 is the negative tab of the electrode assembly 13, which is formed by the part of the negative electrode tab without active material and is electrically connected to the housing 11.

[0124] In this setting manner, the first tab 131 and the second tab 133 are located at both ends of the electrode assembly 13, and there is good insulation between the first tab 131 and the second tab 133, reducing the risk of short circuit of the battery cell 10 and improving the safety of the battery cell 10.

[0125] As Figure 10 shown, in some embodiments of the present application, the housing 11 includes a housing body 111 and an end cap 112. The housing body 111 includes a bottom wall 1111 and a side wall 1112. The side wall 1112 surrounds the bottom wall 1111. One end of the side wall 1112 is connected to the bottom wall 1111, and one end of the side wall 1112 forms an opening opposite to the bottom wall 1111. The end cap 112 covers the opening, and the wall portion 11a is the bottom wall 1111 or the end cap 112.

[0126] Wherein, the bottom wall 1111 and the side wall 1112 can be integrally formed, or the bottom wall 1111 and the side wall 1112 can also be separately provided and connected by welding, clamping and other means. Specifically, the side wall 1112 can be columnar, such as a cylinder or a prism.

[0127] The other end of the side wall 1112 opposite to the bottom wall 1111 forms an opening, and the current collector member 14 and the electrode assembly 13 can be installed and inserted into the housing body 111 from the opening. After the electrode assembly 13 is loaded into the housing body 111, the opening is covered by the end cap 112 to seal the opening. Further, the electrolyte needs to be filled into the housing 11. When the end cap 112 covers the opening, a seal, such as a sealing ring or a gasket, can be provided between the end cap 112 and the side wall 1112 to improve the sealing performance of the end cap 16 covering the opening and prevent the electrolyte from leaking from the housing 11.

[0128] The wall portion 11a is the bottom wall 1111 or the end cap 112. In some embodiments of the present application, after the electrode assembly 13 is loaded into the housing body 111, the current collector member 14 faces the bottom wall 1111. At this time, the bottom wall 1111 is the wall portion 11a, and the first insulating member 15 is disposed between the bottom wall 1111 and the current collector member 14. In some other embodiments of the present application, after the electrode assembly 13 is loaded into the housing body 111, the current collector member 14 faces the end cap 112. At this time, the end cap 112 is the wall portion 11a, and the first insulating member 15 is disposed between the end cap 112 and the current collector member 14.

[0129] In this setting method, the side wall 1112 and the wall portion 11a define a space for accommodating the electrode assembly 13, the electrolyte and other structures, and the end cover 16 covers the opening surrounded by the side wall 1112, ensuring the sealing of the outer shell.

[0130] In a second aspect, the present application further provides a battery 100, including the above-mentioned battery cell 10. Since in the battery cell 10, the current collector member 14 and the wall portion 11a are insulated from each other by the heat-shrinkable film 15, the problem of short circuit between the current collector member 14 and the wall portion 11a is prevented, the probability of short circuit of the battery cell 10 is reduced, and thus the safety of the battery 100 is improved.

[0131] In a third aspect, the present application further provides an electrical device, including the above-mentioned battery 100, and the battery 100 is used to provide electrical energy for the electrical device to operate.

[0132] In a fourth aspect, as Figure 11 shown, Figure 11 is a schematic diagram of a manufacturing method of a battery cell provided in some embodiments of the present application. The present application also provides a manufacturing method of a battery cell. Specifically, the manufacturing method of the battery cell is as follows:

[0133] S100. Provide an outer shell 11 and an electrode terminal 12. The outer shell 11 includes a wall portion 11a, and the electrode terminal 12 is insulatingly installed on the wall portion 11a;

[0134] S200. Provide an electrode assembly 13. The electrode assembly 13 includes a main body 132 and a first tab 131, and the first tab 131 is formed at one end of the main body 132 close to the wall portion 11a;

[0135] S300. Provide a current collector member 14 and connect the current collector member 14 to the first tab 131;

[0136] S400. Provide a heat-shrinkable film 15 and sleuth the heat-shrinkable film 15 on the electrode assembly 13;

[0137] S500. Heat the heat-shrinkable film 15 to shrink, and make at least a part of the heat-shrinkable film 15 cover the current collector member 14;

[0138] S600. Place the electrode assembly 13 and the current collector member 14 covered with the heat-shrinkable film 15 into the outer shell 11, and make the side of the current collector member 14 covered with the heat-shrinkable film 15 face the wall portion 11a, so as to insulate and isolate the current collector member 14 and the wall portion 11a;

[0139] S700. Connect the current collector member 14 to the electrode terminal 12.

[0140] It should be noted that the above manufacturing method of the battery cell is only a schematic representation of the production process of the battery cell 10 and does not represent the specific sequence in the production process of the battery cell 10.

[0141] In a fifth aspect, as Figure 12 shown, Figure 12 is a schematic diagram of a manufacturing apparatus 2000 for a battery cell according to some embodiments of the present application. The present application also provides a manufacturing apparatus 2000 for a battery cell, which is used for manufacturing the above battery cell 10. The manufacturing apparatus 2000 for a battery cell includes a first providing device 2100, a second providing device 2200, a third providing device 2300, a fourth providing device 2400, a first assembling device 2500, a heating device 2600, a second assembling device 2700, and a third assembling device 2800.

[0142] Specifically, as Figure 12 shown, the first providing device 2100 is used to provide the housing 11 and the electrode terminal 12. The housing 11 includes a wall portion 11a, and the electrode terminal 12 is insulatingly mounted on the wall portion 11a. The second providing device 2200 is used to provide the electrode assembly 13. The electrode assembly 13 includes a main body 132 and a first tab 131. The first tab 131 is formed at one end of the main body 132 close to the wall portion 11a. The third providing device 2300 is used to provide the current collector member 14. The fourth providing device 2400 is used to provide the heat shrink film 15 and sleuth the heat shrink film 15 on the electrode assembly 13. The first assembling device 2500 is used to connect the current collector member 14 to the first tab 131. The heating device 2600 is used to heat the heat shrink film 15 to make it shrink, and at least a part of the heat shrink film 15 covers the current collector member 14. The second assembling device 2700 is used to place the electrode assembly 13 and the current collector member 14 covered with the heat shrink film 15 into the housing 11, and make the side of the current collector member 14 covered with the heat shrink film 15 face the wall portion 11a, so as to insulate and isolate the current collector member 14 and the wall portion 11a. The third assembling device 2800 is used to connect the current collector member 14 to the electrode terminal 12.

[0143] In some embodiments of the present application, as Figures 3 - 10As shown, the present application provides a battery cell 10, which includes a housing 11, an electrode terminal 12, an electrode assembly 13, a current collector member 14, and a heat shrink film 15. The housing 11 includes a wall portion 11a and a side wall 1112. An insulating member 121 is disposed between the electrode terminal 12 and the wall portion 11a to insulate and mount the electrode terminal 12 on the wall portion 11a. The electrode assembly 13 is disposed within the housing 11. The electrode assembly 13 includes a first tab 131, a main body 132, and a second tab 133. The first tab 131 is electrically connected to the current collector member 14, and the second tab 133 is electrically connected to the housing 11. The current collector member 14 is disposed between the electrode assembly 13 and the wall portion 11a. The current collector member 14 is used to connect the first tab 131 and the electrode terminal 12. A first protrusion 141 is formed at a portion of the current collector member 14 connected to the electrode terminal 12 to facilitate the electrical connection between the current collector member 14 and the electrode terminal 12. The heat shrink film 15 includes a first portion 151, a second portion 152, and a third portion 153 that are integrally formed and connected in sequence. The first portion 151 covers a side of the current collector member 14 facing the wall portion 11a. The second portion 152 covers an outer peripheral surface of the first tab 131. The third portion 153 covers an outer peripheral surface of the main body 132 to insulate and isolate the current collector member 14, the first tab 131, and the main body 132 from the housing 11. The diameter of the current collector member 14 is smaller than the diameter of the first tab 131. A stepped area 142 is formed between the current collector member 14 and the first tab 131. The stepped area 142 is used to absorb the surplus during the shrinkage process of the heat shrink film 15. A portion of the insulating member 121 extending between the wall portion 11a and the heat shrink film 15 constitutes an elastic layer 1211. The elastic layer 1211 is used to apply an elastic force along the axial direction of the electrode assembly 13 to the electrode assembly 13. One end of the side wall 1112 away from the wall portion 11a encloses an opening, and an end cap 16 is used to cover the opening.

[0144] Although the present application has been described with reference to the preferred embodiments, various improvements can be made to it and components therein can be replaced with equivalents without departing from the scope of the present application. In particular, as long as there is no structural conflict, the various technical features mentioned in each embodiment can be combined in any manner. The present application is not limited to the specific embodiments disclosed in the text, but includes all technical solutions falling within the scope of the claims.

Claims

1. A battery cell, characterized in that, Comprising: A housing including a wall portion; An electrode terminal insulatedly mounted on the wall portion; An electrode assembly disposed within the housing, the electrode assembly including a main body and a first tab, the first tab being formed at one end of the main body close to the wall portion; A current collector member disposed between the electrode assembly and the wall portion, the current collector member being configured to connect the first tab and the electrode terminal; A heat shrink film, at least a part of the heat shrink film covering one side of a part of the current collector member facing the wall portion to insulatively isolate the current collector member and the wall portion; The heat shrink film extending between the electrode terminal and the current collector member.

2. The battery cell according to claim 1, characterized in that Wherein, There is a gap between the heat shrink film and the wall portion.

3. The battery cell according to claim 1 or 2, characterized in that Wherein, The heat shrink film includes an integrally formed first part and a second part, the first part covering one side of the current collector member facing the wall portion, and the second part covering the outer peripheral surface of the first tab.

4. The battery cell according to claim 3, wherein Wherein, The current collector member is disc-shaped, the diameter of the current collector member being smaller than the diameter of the first tab, a step region being formed between the edge of the current collector member and the outer peripheral surface of the first tab, and the heat shrink film covering the step region.

5. The battery cell according to claim 3, wherein Wherein, The heat shrink film further includes a third part covering the outer peripheral surface of the main body, the third part being integrally formed with the second part.

6. The battery cell according to claim 5, wherein Wherein, The electrode assembly is formed by winding a pole piece and a separator, the battery cell further including a tape adhesively bonded to the outer peripheral surface of the main body and fixing the winding end of the pole piece and / or the separator, and the third part not overlapping with the tape.

7. The battery cell according to claim 1 or 2, characterized in that Wherein, The battery cell further includes an elastic layer disposed between the wall portion and the heat shrink film, the elastic layer being configured to apply an elastic force along the axial direction of the electrode assembly to the electrode assembly.

8. The battery cell according to claim 1 or 2, characterized in that Wherein, The electrode assembly further includes a second tab formed at one end of the main body away from the wall portion, the second tab having a polarity opposite to that of the first tab, and the second tab being electrically connected to the wall portion.

9. The battery cell according to claim 1 or 2, characterized in that Wherein, The housing includes a housing body and an end cap, the housing body including a bottom wall and a side wall, the side wall surrounding the bottom wall, one end of the side wall being connected to the bottom wall, the other end of the side wall enclosing an opening opposite to the bottom wall, and the end cap covering the opening, and the wall portion being the bottom wall or the end cap.

10. A battery, characterized in that Wherein, Including the battery cell according to any one of claims 1-9.

11. An electrical device, characterized in that Wherein, Including the battery according to claim 10, the battery being configured to provide electrical energy.

12. A manufacturing method of a battery cell, characterized in that Wherein, comprising: Providing a housing and an electrode terminal, the housing including a wall portion, and the electrode terminal being insulatedly mounted on the wall portion; Providing an electrode assembly including a main body and a first tab, the first tab being formed at one end of the main body close to the wall portion; Providing a current collector member and connecting the current collector member to the first tab; Providing a heat shrink film and sleeving the heat shrink film on the electrode assembly, the heat shrink film extending between the electrode terminal and the current collector member; Heat the heat-shrinkable film to shrink it, and cause at least a part of the heat-shrinkable film to cover one side of a part of the current collector member facing the wall portion; Place the electrode assembly and the current collector member covered with the heat-shrinkable film into the housing, and cause one side of the portion of the current collector member covered with the heat-shrinkable film to face the wall portion, so as to insulate and isolate the current collector member and the wall portion; Connect the current collector member to the electrode terminal.

13. A manufacturing device for a battery cell, characterized in that Among them, it includes: A first providing device for providing a housing and an electrode terminal, the housing including a wall portion, and the electrode terminal being insulatively mounted on the wall portion; A second providing device for providing an electrode assembly, the electrode assembly including a main body and a first tab, the first tab being formed at one end of the main body close to the wall portion; A third providing device for providing a current collector member; A fourth providing device for providing a heat-shrinkable film and sleeving the heat-shrinkable film on the electrode assembly; A first assembling device for connecting the current collector member to the first tab, and the heat-shrinkable film extending between the electrode terminal and the current collector member; A heating device for heating the heat-shrinkable film to shrink it, and causing at least a part of the heat-shrinkable film to cover one side of a part of the current collector member facing the wall portion; A second assembling device for placing the electrode assembly and the current collector member covered with the heat-shrinkable film into the housing, and causing one side of the portion of the current collector member covered with the heat-shrinkable film to face the wall portion, so as to insulate and isolate the current collector member and the wall portion; A third assembling device for connecting the current collector member to the electrode terminal.

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