CN216085250U

CN216085250U - Battery cell, battery and power consumption device

Info

Publication number: CN216085250U
Application number: CN202122530793.6U
Authority: CN
Inventors: 方堃; 郭志君
Original assignee: Contemporary Amperex Technology Co Ltd
Current assignee: Contemporary Amperex Technology Co Ltd
Priority date: 2021-10-20
Filing date: 2021-10-20
Publication date: 2022-03-18
Anticipated expiration: 2031-10-20

Abstract

The application relates to a battery monomer, battery and power consumption device relates to the battery field. The application provides a battery monomer, battery monomer includes: a housing including a wall portion; an electrode terminal mounted on the wall portion in an insulated manner; the electrode assembly is arranged in the shell and comprises a main body and a first tab, and the first tab is formed at one end of the main body close to the wall part; a current collecting member disposed between the electrode assembly and the wall part, the current collecting member for connecting the first tab and the electrode terminal; and at least one part of the heat-shrinkable film is coated on one side of the current collecting member facing the wall part so as to insulate and separate the current collecting member and the wall part. The battery cell has higher security.

Description

Battery cell, battery and power consumption device

Technical Field

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

Background

Energy conservation and emission reduction are the key points of sustainable development of the automobile industry, and electric vehicles become important components of the sustainable development of the automobile industry due to the advantages of energy conservation and environmental protection. For electric vehicles, battery technology is an important factor in its development.

In the use process of charging and discharging of the battery, the battery monomer has the risk of short circuit, great potential safety hazard exists, how to reduce the probability of short circuit of the battery monomer, and the improvement of the safety of the battery monomer and the battery is of great importance to the development of the battery technology.

SUMMERY OF THE UTILITY MODEL

The application aims at providing a battery cell, a battery and an electric device. The battery monomer is not easy to have the problem of short circuit and has higher safety.

In a first aspect, the present application provides a battery cell comprising a housing comprising a wall portion; an electrode terminal mounted on the wall portion in an insulated manner; the electrode assembly is arranged in the shell and comprises a main body and a first tab, and the first tab is formed at one end of the main body close to the wall part; a current collecting member disposed between the electrode assembly and the wall part, the current collecting member for connecting the first tab and the electrode terminal; and at least one part of the heat-shrinkable film is coated on one side of the current collecting member facing the wall part so as to insulate and separate the current collecting member and the wall part.

According to the battery cell, the heat shrinkage film is coated on the current collecting component in a heat shrinkage mode so as to insulate and isolate the current collecting component and the wall portion. The cladding performance of the thermal shrinkage film after being heated and shrunk is better, when the single battery is interfered by external factors, the thermal shrinkage film can still stably wrap the current collecting component, the risk of short circuit between the current collecting component and the wall portion is reduced, and the safety of the single battery is improved. In addition, the surface of the thermal shrinkage film formed by thermal shrinkage is smooth and not easy to generate wrinkles, the thickness of the thermal shrinkage film is uniform, the probability that the thickness of the thermal shrinkage film is increased due to the wrinkles is reduced, and then the interference of the thickness of the thermal shrinkage film with a flow collecting component is prevented, so that the resistance and the difficulty of the electrode assembly to be installed into the shell are increased, and the production efficiency of the battery monomer is improved.

In some embodiments of the present application, the heat shrink film extends between the electrode terminal and the current collecting member.

In the scheme, the heat-shrinkable film is required to completely coat the current collecting member, and the heat-shrinkable film is extended between the electrode terminal and the current collecting member, so that the range of the current collecting member coated by the heat-shrinkable film is not required to be adjusted, the process difficulty of coating the current collecting member by the heat-shrinkable film is reduced, and the production efficiency of the single battery is improved. Meanwhile, the thermal shrinkage film extends between the electrode terminal and the current collecting member, and is clamped by the electrode terminal and the current collecting member, so that the situation that the thermal shrinkage film cannot be completely coated on the current collecting member due to the problems of self thermal shrinkage, electrode assembly expansion and the like of the thermal shrinkage film is prevented, the stability of the current collecting member coated by the thermal shrinkage film is improved, the thermal shrinkage film can be used for stably insulating and isolating the current collecting member and the wall part, and the safety of a battery monomer is improved.

In some embodiments of the present application, there is a gap between the heat shrink film and the wall.

In the above scheme, a gap is left between the heat-shrinkable film and the wall part, so that the risk that the heat-shrinkable film is broken down by the potential difference between the wall part and the current collecting member is reduced, the risk of short circuit of the battery cell is also reduced, and the safety of the battery cell is improved.

In some embodiments of the present application, the heat-shrinkable film includes a first portion and a second portion, the first portion is wrapped on a side of the current collecting member facing the wall, and the second portion is wrapped on an outer circumferential surface of the first tab.

In the above scheme, the heat-shrinkable film not only covers the current collecting member, but also covers the outer peripheral surface of the first tab, and an insulating and isolating effect is achieved between the current collecting member and the wall portion and between the first tab and the side wall of the housing through an insulating film, so that the number of parts is reduced, and the structure of the single battery is compact.

In some embodiments of the present application, the current collecting member has a disk shape, a diameter of the current collecting member is smaller than a diameter of the first tab, a stepped region is formed between an edge of the current collecting member and an outer circumferential surface of the first tab, and the heat shrinkage film covers the stepped region.

In the above scheme, on one hand, the step area is configured to provide enough space for the current collecting member to be welded to the first tab, so that the current collecting member is conveniently welded to the first tab, the production efficiency of the single battery is improved, and the capacity of the battery is expanded; on the other hand, in the process of thermal shrinkage of the thermal shrinkage film, the step area can absorb the allowance of the thermal shrinkage film, the probability of wrinkles in the process of thermal shrinkage film shrinkage is reduced, and the flatness of the thermal shrinkage film coated on the current collecting component is improved.

In some embodiments of the present application, the heat shrinkable film further includes a third portion, the third portion covers the outer circumferential surface of the main body, and the third portion is integrally formed with the second portion.

In the above scheme, on one hand, the third part coats the outer peripheral surface of the main body, so that the risk of short circuit between the shell and the main body is reduced, the risk of short circuit of the single battery is reduced, and the safety of the single battery is improved; on the other hand, the third part and the second part are integrally formed, the third part and the second part are not easy to overlap, the thickness size of the heat-shrinkable film is prevented from being increased due to the overlapping of the second part and the third part, the probability of local stress concentration caused by the increase of the thickness size of the heat-shrinkable film and the extrusion of the shell is reduced, and the risk of lithium precipitation of the pole piece due to the stress concentration is reduced.

In some embodiments of the present application, the electrode assembly is formed by winding a pole piece and a separator, the battery cell further includes an adhesive tape adhered to an outer circumferential surface of the main body and fixing a winding end of the pole piece and/or the separator, and the third portion does not overlap the adhesive tape.

In the above scheme, the third portion and the adhesive tape are not overlapped, so that the problem that the thickness of the overlapped portion is increased due to the overlapping of the third portion and the adhesive tape is not easy to cause local stress concentration due to the fact that the thickness of the overlapped portion is increased and the side wall of the shell is extruded is solved, and the risk of lithium precipitation of the pole piece caused by stress concentration is reduced.

In some embodiments of the present application, the battery cell further includes an elastic layer disposed between the wall portion and the heat shrinkage film, the elastic layer for applying an elastic force to the electrode assembly in an axial direction of the electrode assembly.

In the above scheme, when the single battery is vibrated, the elastic layer can apply elastic force along the axial direction of the single battery to the electrode assembly and the current collecting component, so that the current collecting component and the wall part are further insulated and isolated, the risk of short circuit of the single battery is reduced, and the safety of the single battery is improved.

In some embodiments of the present application, the electrode assembly further includes a second tab formed at an end of the main body distal from the wall portion, the second tab being opposite in polarity to the first tab, the second tab being electrically connected to the wall portion.

In the above scheme, the first tab and the second tab are located at two ends of the electrode assembly, and the first tab and the second tab have good insulativity, so that the risk of short circuit of the single battery is reduced, and the safety of the single battery is improved.

In some embodiments of the present application, the housing includes a casing body and an end cover, the casing body includes a bottom wall and a side wall, the side wall is enclosed around the bottom wall, one end of the side wall is connected with 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.

In the above aspect, the second wall and the wall portion define a space in which the electrode assembly, the electrolyte, and other structures are housed, and the opening surrounded by the second wall is covered by the end cap to prevent the electrolyte from leaking from the opening.

In a second aspect, the present application provides a battery including the battery cell described above.

In a third aspect, the present application provides an electric device comprising the above battery for providing electric energy.

In a fourth aspect, the present application provides a method of manufacturing a battery cell, including providing a case including a wall portion and an electrode terminal mounted to the wall portion in an insulated manner; providing an electrode assembly including a main body and a first tab formed at one end of the main body adjacent to the wall portion; providing a current collecting component, and connecting the current collecting component to the first tab; providing a heat-shrinkable film, and sleeving the heat-shrinkable film on the electrode assembly; heating the heat-shrinkable film to shrink and make at least one part of the heat-shrinkable film cover the current collecting member; placing the electrode assembly and the current collecting member coated with the heat-shrinkable film into a case, and making one side of the current collecting member coated with the heat-shrinkable film face the wall portion to insulate and separate the current collecting member and the wall portion; the current collecting member is connected to the electrode terminal.

In a fifth aspect, the present application provides a manufacturing apparatus of a battery cell, including a first providing device for providing a housing and an electrode terminal, the housing including a wall portion, the electrode terminal being mounted on the wall portion in an insulated manner; a second providing means for providing an electrode assembly including a main body and a first tab formed at one end of the main body adjacent to the wall portion; third supply means for supplying a current collecting member; the fourth providing device is used for providing a heat-shrinkable film, and the heat-shrinkable film is sleeved on the electrode assembly; a first assembly device for connecting the current collecting member to the first tab; the heating device is used for heating the heat-shrinkable film to shrink, and at least one part of the heat-shrinkable film is coated on the current collecting component; a second assembling device which puts the electrode assembly and the current collecting member coated with the heat shrinkage film into the shell, and enables one side of the current collecting member coated with the heat shrinkage film to face the wall part so as to insulate and separate the current collecting member and the wall part; and a third assembling means for connecting the current collecting member to the electrode terminal.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings that are required to be used in the embodiments will be briefly described below, it should be understood that the following drawings only illustrate some embodiments of the present application and therefore should not be considered as limiting the scope, and for those skilled in the art, other related drawings can be obtained from the drawings without inventive effort.

FIG. 1 is a schematic structural diagram of a vehicle according to an embodiment of the present disclosure;

fig. 2 is a schematic structural diagram of a battery according to an embodiment of the present disclosure;

fig. 3 is an exploded view of a battery cell according to an embodiment of the present disclosure;

fig. 4 is a cross-sectional view of a battery cell provided in an embodiment of the present application;

fig. 5 is a schematic view of a heat shrink film provided in accordance with an embodiment of the present application extending between an electrode terminal and a current collecting member;

FIG. 6 is a schematic view of a heat shrink film including a first portion and a second portion provided in accordance with an embodiment of the present application;

FIG. 7 is another schematic view of a heat shrink film including a first portion and a second portion as provided by an embodiment of the present application;

FIG. 8 is a schematic view of a heat shrink film including a third portion as provided by one embodiment of the present application;

fig. 9 is a schematic diagram of a battery cell provided with an elastic layer according to an embodiment of the present disclosure;

fig. 10 is a schematic diagram of a battery cell according to an embodiment of the present disclosure;

fig. 11 is a schematic view of a method for manufacturing a battery cell according to a fourth embodiment of the present application;

fig. 12 is a schematic view of a manufacturing apparatus of a battery cell according to a fifth embodiment of the present application.

Icon: 10-a battery cell; 11-a housing; 11 a-a wall portion; 111-a housing; 1111-bottom wall; 1112-a side wall; 112-an end cap; 12-an electrode terminal; 121-an insulator; 1211-an elastic layer; 122-a second protrusion; 13-an electrode assembly; 131-a first tab; 132-a body; 133-a second tab; 14-a current collecting member; 141-a first projection; 142-a step area; 15-heat-shrinkable film; 151-first part; 152-a second portion; 153-third part; 20-a box body; 21-a first sub-tank; 22-a second sub-tank; 100-a battery; 200-a controller; 300-a motor; 1000-a vehicle; 2000-manufacturing equipment of battery cells; 2100-a first providing device; 2200-a second providing means; 2300-a third providing means; 2400-a fourth providing device; 2500-a first assembly device; 2600-a heating device; 2700-second assembly device; 2800-third assembly means.

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. It is to be understood that the embodiments described are only a few embodiments of the present application and not all embodiments. The components of the embodiments of the present application, generally described and illustrated in the figures herein, can be arranged and designed in a wide variety of different configurations.

In the description of the present application, it should be noted that the terms "inside", "outside", and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings or orientations or positional relationships that the products of the application usually place when using, and are only used for convenience in describing the present application and simplifying the description, but do not indicate or imply that the devices or elements that are referred to must have a specific orientation, be constructed in a specific orientation, and operate, and thus, should not be construed as limiting the present application. Furthermore, the terms "first," "second," and the like are used merely to distinguish one description from another, and are not to be construed as indicating or implying relative importance.

In the description of the present application, it is also to be noted that, unless otherwise explicitly specified or limited, the terms "disposed" and "connected" are to be interpreted broadly, e.g., as being either fixedly connected, detachably connected, or integrally connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meaning of the above terms in the present application can be understood in a specific case by those of ordinary skill in the art.

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

The battery monomer comprises an electrode assembly and electrolyte, wherein the electrode assembly comprises a positive pole piece, a negative pole piece and a diaphragm. The battery cell mainly depends on metal ions to move between the positive pole piece and the negative pole piece to work. The positive pole piece includes anodal mass flow body and anodal active substance layer, and anodal active substance layer coats in anodal mass flow body's surface, and the anodal mass flow body protrusion in the anodal mass flow body that has coated anodal active substance layer of uncoated anodal active substance layer, and the anodal mass flow body that does not coat anodal active substance layer is as anodal utmost point ear. Taking a lithium ion battery as an example, the material of the positive electrode current collector may be aluminum, and the positive electrode active material may be lithium cobaltate, lithium iron phosphate, ternary lithium, lithium manganate, or the like. The negative pole piece includes negative pole mass flow body and negative pole active substance layer, and the negative pole active substance layer coats in the surface of negative pole mass flow body, and the negative pole mass flow body protrusion in the negative pole mass flow body of coating the negative pole active substance layer not coating the negative pole active substance layer, and the negative pole mass flow body of not coating the negative pole active substance layer is as negative pole utmost point ear. The material of the negative electrode current collector may be copper, and the negative electrode active material may be carbon, silicon, or the like. In order to ensure that the fuse is not fused when a large current is passed, the number of the positive electrode tabs is multiple and the positive electrode tabs are stacked together, and the number of the negative electrode tabs is multiple and the negative electrode tabs are stacked together. The material of the diaphragm may be PP (Polypropylene) or PE (Polyethylene).

At present, the application of the power battery is more and more extensive from the development of market situation. The power battery is not only applied to energy storage power supply systems such as hydraulic power, firepower, wind power and solar power stations, but also widely applied to electric vehicles such as electric bicycles, electric motorcycles, electric automobiles and the like, and a plurality of fields such as military equipment and aerospace. With the continuous expansion of the application field of the power battery, the market demand is also continuously expanding.

The present inventors have noted that the battery is disturbed by external factors, such as vibration, impact, etc., during use. Taking an electric vehicle as an example, the electric vehicle is an electric vehicle equipped with a battery cell and a battery, and the electric vehicle may generate jolts and vibrations of different degrees according to different roughness of a road surface during the driving process of the electric vehicle. When the electric automobile passes through road surface defects such as pits, cracks, convex hulls and the like, the posture of the automobile body of the electric automobile is greatly deviated, and the electric automobile generates vibration with a large amplitude. In addition, when the electric vehicle collides, the battery cells are greatly disturbed regardless of a low-speed collision or a high-speed collision. When the battery cell is subjected to vibration, the electrode assembly and the current collecting member located in the case of the battery cell may be moved, and particularly, the current collecting member and the electrode assembly are easily displaced in the axial direction of the electrode assembly. Furthermore, due to the fact that the polarity of the current collecting component is different from that of the shell, after the current collecting component and the electrode assembly shift, the risk of short circuit exists between the current collecting component and the shell, electric energy stored in the single battery can be released in a short time in a heat energy mode due to the short circuit of the battery, thermal runaway is caused, the safety of the single battery is reduced, and great potential safety hazards exist.

In order to reduce the risk of short circuit between the current collecting member and the case and improve the safety of the battery cell, the inventors have studied and found that an insulating paper or an insulating tube may be disposed between the current collecting member and the case to insulate and separate the current collecting member and the case. However, since the current collecting member is covered with the insulating paper by bonding, the insulating paper itself is likely to fall off under the influence of vibration, and thus the current collecting member cannot be effectively covered. In addition, the insulating tube is sleeved on the electrode assembly and is wrapped on the current collecting component in a folding mode, wrinkles are generated in the folding process of the insulating tube, and the thickness of the insulating tube is increased at the positions of the wrinkles. On the one hand, the increase in the thickness dimension of the insulating tube covering the current collecting member may decrease the stability of the electrical connection between the current collecting member and the electrode terminal; on the other hand, when the thickness of the insulating tube is too large, the resistance and difficulty of installing the electrode assembly into the shell are increased, the production efficiency of the single battery is reduced, the productivity of the battery is low, and the ever-increasing requirements of the market on the battery cannot be met.

In view of the above, in order to reduce the risk of short circuit between the current collecting member and the case, the inventors have conducted extensive studies to design a battery cell in which the case includes a wall portion (at one end of the case) and a side of the current collecting member facing the wall portion is covered with a heat-shrinkable film to insulate and separate the current collecting member and the wall portion. The heat-shrinkable film is coated on the current collecting component in a heat shrinkage mode, the coating performance of the heat-shrinkable film after being heated and shrunk is good, and meanwhile, the heat-shrinkable film can be coated on the current collecting component smoothly and stably after being heated and shrunk, and wrinkles are not easy to generate.

In the single battery, the thermal shrinkage film is more smoothly and stably coated on the current collecting member after being heated and shrunk, and even if the single battery is interfered by external factors to cause the current collecting member to move, the thermal shrinkage film can still be stably coated on the current collecting member, and plays an insulating and isolating role on the current collecting member and the wall part, so that the risk of short circuit between the current collecting member and the wall part is reduced, and the safety of the single battery is improved.

The battery cell disclosed in the embodiment of the application can be used in electric devices such as vehicles, ships or aircrafts, but not limited thereto. The power supply system comprising the battery monomer, the battery and the like disclosed by the application can be used, so that the risk of short circuit between the current collecting component and the wall part in the battery monomer is reduced, and the safety of the battery monomer and the battery is improved.

The embodiment of the application provides an electric device using a battery as a power supply, wherein the electric device can be but is not limited to a mobile phone, a tablet, a notebook computer, an electric toy, an electric tool, a battery car, an electric automobile, a ship, a spacecraft and the like. The electric toy may include a stationary or mobile electric toy, such as a game machine, an electric car toy, an electric ship toy, an electric airplane toy, and the like, and the spacecraft may include an airplane, a rocket, a space shuttle, a spacecraft, and the like.

For convenience of description, the following embodiments are described by taking an electric device of the embodiments of the present application as an example of a vehicle.

As shown in fig. 1, fig. 1 is a schematic structural diagram of a vehicle 1000 according to some embodiments of the present application. The vehicle 1000 may be a fuel automobile, a gas automobile, or a new energy automobile, and the new energy automobile may be a pure electric automobile, a hybrid electric automobile, or a range-extended automobile, etc. The battery 100 is provided inside the vehicle 1000, and the battery 100 may be provided at the bottom or the head or the tail of the vehicle 1000. The battery 100 may be used for power supply of the vehicle 1000, for example, the battery 100 may serve as an operation power source of the vehicle 1000. The vehicle 1000 may further include a controller 200 and a motor 300, the controller 200 being configured to control the battery 100 to supply power to the motor 300, for example, for starting, navigation, and operational power requirements while the vehicle 1000 is traveling.

In some embodiments of the present application, the battery 100 may be used not only as an operating power source of the vehicle 1000, but also as a driving power source of the vehicle 1000, instead of or in part of fuel or natural gas, to provide driving power for the vehicle 1000.

As shown in fig. 2, fig. 2 is a schematic structural diagram of a battery 100 according to some embodiments of the present disclosure. The battery 100 includes a case 20 and a battery cell 10, and the battery cell 10 is accommodated in the case 20. The case 20 is used to provide a receiving space for the battery cell 10, and the case 20 may have various structures. In some embodiments, the case 20 may include a first sub-case 21 and a second sub-case 22, the first sub-case 21 and the second sub-case 22 cover each other, and the first sub-case 21 and the second sub-case 22 together define a receiving space for receiving the battery cell 10. The second sub-box 22 may be a hollow structure with an opening at one end, the first sub-box 21 may be a plate-shaped structure, and the first sub-box 21 covers the opening side of the second sub-box 22, so that the first sub-box 21 and the second sub-box 22 define an accommodating space together; the first sub-box 21 and the second sub-box 22 may be both hollow structures with one side open, and the open side of the first sub-box 21 covers the open side of the second sub-box 22. Of course, the case 20 formed by the first sub-case 21 and the second sub-case 22 may have various shapes, such as a cylinder, a rectangular parallelepiped, and the like.

In the battery 100, the number of the battery cells 10 may be multiple, and the multiple battery cells 10 may be connected in series or in parallel or in series-parallel, where in series-parallel refers to that the multiple battery cells 10 are connected in series or in parallel. The plurality of single batteries 10 can be directly connected in series or in parallel or in series-parallel, and the whole formed by the plurality of single batteries 10 is accommodated in the box body 20; of course, the battery 100 may also be formed by connecting a plurality of battery cells 10 in series, in parallel, or in series-parallel to form a battery module, and then connecting a plurality of battery modules in series, in parallel, or in series-parallel to form a whole, and accommodating the whole in the case 20. The battery 100 may further include other structures, for example, the battery 100 may further include a bus member for achieving electrical connection between the plurality of battery cells 10.

Wherein, each battery cell 10 may be a secondary battery or a primary battery; but is not limited to, a lithium sulfur battery, a sodium ion battery, or a magnesium ion battery. The battery cell 10 may be cylindrical, flat, rectangular parallelepiped, or other shape.

As shown in fig. 3, fig. 3 is an exploded view of a battery cell 10 according to some embodiments of the present disclosure. The battery cell 10 refers to the smallest unit constituting the battery 100. As shown in fig. 3, the battery cell 10 includes a case 11, an electrode assembly 13, and other functional components.

The case 11 is an assembly for forming an internal environment of the battery cell 10, wherein the internal environment formed by the case 11 may be used to house the electrode assembly 13, an electrolyte, and other components. The housing 11 may be of various shapes and various sizes, such as cylindrical, rectangular parallelepiped, hexagonal prism, etc. Specifically, the shape of the case 11 may be determined according to the specific shape and size of the electrode assembly 13. The material of the housing 11 may be various materials, such as copper, iron, aluminum, stainless steel, aluminum alloy, etc.

The electrode assembly 13 is a part in which electrochemical reactions occur in the battery cell 10. One or more electrode assemblies 13 may be contained within the housing 11. The electrode assembly 13 is mainly formed by winding or stacking a positive electrode tab and a negative electrode tab, and a separator is usually provided between the positive electrode tab and the negative electrode tab. The portions of the positive and negative electrode sheets having active materials constitute the main body 132 of the electrode assembly 13, and the portions of the positive and negative electrode sheets having no active materials constitute tabs, respectively. The positive and negative electrode tabs may be located together at one end of the main body 132 portion or separately at both ends of the main body 132 portion. During the charge and discharge of the battery 100, the positive and negative active materials react with the electrolyte, and the tabs are connected to the electrode terminals 12 to form a current loop.

As shown in fig. 4, fig. 4 is a cross-sectional view of a battery cell 10 according to some embodiments of the present application. The present application provides a battery cell 10, the battery cell 10 including a case 11, an electrode terminal 12, an electrode assembly 13, a current collecting member 14, and a heat shrinkage film 15. The case 11 includes a wall portion 11a, and the electrode terminal 12 is mounted on the wall portion 11a in an insulated manner. The electrode assembly 13 is disposed in the case 11, and 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 near the wall portion 11 a. A current collecting member 14 is disposed between the electrode assembly 13 and the wall portion 11a, and the current collecting member 14 serves to connect the first tab 131 and the electrode terminal 12. At least a portion of the heat shrinkable film 15 covers the side of the current collecting member 14 facing the wall portion 11a to insulate and separate the current collecting member 14 and the wall portion 11 a.

The electrode terminal 12 is insulated from the wall 11a, and because the polarity between the electrode terminal 12 and the housing 11 is different, that is, the polarity between the electrode terminal 12 and the wall 11a is different (for example, in some embodiments of the present application, the electrode terminal 12 is positively charged, and the wall 11a is negatively charged), the electrode terminal 12 and the wall 11a should be insulated from each other to prevent the electrode terminal 12 and the wall 11a from being electrically connected to cause a short circuit of the battery cell 10, thereby ensuring high safety of the battery cell 10, the battery 100 and the electric device.

Specifically, as shown in fig. 4, an insulating member 121 may be disposed between the electrode terminal 12 and the wall portion 11a, and the insulating member 121 serves to isolate the electrode terminal 12 from the wall portion 11a to reduce the risk of short circuit. The insulating member 121 may be made of plastic, such as PVC (Polyvinyl Chloride), PP (Polypropylene), etc., or the insulating member 121 may be made of rubber, such as butyl rubber, styrene butadiene rubber, silicon rubber, etc., or the insulating member 121 may be made of fiber, such as NOMEX (aromatic polyamide/NOMEX) insulating paper, which is mainly made of meta-aramid fiber and has good insulating property, heat resistance and corrosion resistance.

The current collecting member 14 is used to connect the first tab 131 and the electrode terminal 12, that is, the first tab 131 and the electrode terminal 12 are both connected to the current collecting member 14, and the first tab 131 and the electrode terminal 12 are electrically connected through the current collecting member 14.

The heat shrinkable film 15 is made of a heat shrinkable material, which is a polymer shape memory material obtained by radiation processing of a polymer material. Common polymer materials such as polyethylene and polyvinyl chloride are generally linear structures, and the polymer materials with the linear structures are converted into net structures under the radiation action of radioactive sources such as an electron accelerator. The heat shrinkable material has unique shape memory effect, and can be shrunk and restored to the original shape after being heated after being expanded, cooled and shaped. The heat-shrinkable material can be made into a heat-shrinkable tube material, a heat-shrinkable film material or a heat-shrinkable special-shaped material by utilizing the shape memory effect of the heat-shrinkable material, and the heat-shrinkable material is heated to shrink in the using process, the shrunk heat-shrinkable material forms the heat-shrinkable film 15, and the heat-shrinkable film is flatly and compactly coated on the outer surface of an object, and plays roles of insulating, sealing, protecting and the like on the coated object.

Further, the heat-shrinkable film 15 is formed by providing a heat-shrinkable material in a tubular or film shape to the current collecting member 14, heating and shrinking the heat-shrinkable material to form the heat-shrinkable film 15, and the heat-shrinkable film 15 is coated on the side of the current collecting member 14 facing the wall portion 11a in a flat and compact manner to insulate and isolate the current collecting member 14 from the wall portion 11 a.

It should be noted that, as shown in fig. 4, the heat-shrinkable film 15 covering the side of the current collecting member 14 facing the wall 11a does not mean that the heat-shrinkable film 15 completely covers the side of the current collecting member 14 facing the wall 11a, if the heat-shrinkable film 15 completely covers the side of the current collecting member 14 facing the wall 11a, the heat-shrinkable film 15 will insulate and isolate the electrode terminal 12 and the current collecting member 14, and the electrode terminal 12 and the current collecting member 14 need to be electrically connected, that is, the electrode terminal 12 and the current collecting member 14 should have portions that are in contact with each other. Specifically, the heat-shrinkable film 15 may cover a portion of the current collecting member 14 corresponding to the wall portion 11 a.

Further, as shown in fig. 4, the partial electrode terminal 12 is located between the wall portion 11a and the current collecting member 14, that is, the projection of the wall portion 11a on the current collecting member 14 overlaps with the projection of the partial electrode terminal 12 located between the wall portion 11a and the current collecting member 14 on the current collecting member 14, and since the electrode terminal 12 and the current collecting member 14 are electrically connected without insulation, the heat-shrinkable film 15 also does not need to cover the projection portion of the partial electrode terminal 12 on the current collecting member 14 located between the wall portion 11a and the current collecting member 14 (the portion is located within the projection of the wall portion 11a on the current collecting member 14). It is understood that, no matter how the heat-shrinkable film 15 is coated on the side of the current collecting member 14 facing the wall portion 11a, the heat-shrinkable film 15 may be any film as long as it can achieve insulation isolation between the current collecting member 14 and the wall portion 11a and ensure stable electrical connection between the current collecting member 14 and the electrode terminal 12.

In the battery cell 10 of the present application, the heat shrinkable film 15 is wrapped around the current collecting member 14 so as to be shrunk by heat, thereby insulating and isolating the current collecting member 14 and the wall portion 11 a. The heat-shrinkable film 15 has good coating performance after being heated and shrunk, and when the single battery 10 is interfered by external factors and disturbed externally, the heat-shrinkable film 15 can still stably coat the current collecting member 14, so that the risk of short circuit between the current collecting member 14 and the wall part 11a is reduced, and the safety of the single battery 10 is improved. In addition, the surface of the heat-shrinkable film 15 formed by heat shrinkage is smooth, wrinkles are not easy to generate, the thickness of the heat-shrinkable film 15 is uniform, the probability that the thickness of the heat-shrinkable film 15 is increased due to the wrinkles is reduced, the interference of the overlarge thickness of the heat-shrinkable film 15 and the current collecting component 14 is prevented, the resistance and difficulty of the electrode assembly 13 in the shell are increased, and the production efficiency of the battery cell 10 is improved.

As shown in fig. 5, fig. 5 is a schematic view illustrating the heat shrinkage film 15 of some embodiments of the present application extending between the electrode terminal 12 and the current collecting member 14. In some embodiments of the present application, the heat shrink film 15 extends between the electrode terminal 12 and the current collecting member 14.

On one hand, a part of the heat-shrinkable film 15 extends between the electrode terminal 12 and the current collecting member 14, and the heat-shrinkable film 15 is clamped and pressed by the electrode terminal 12 and the current collecting member 14, so that the heat-shrinkable film 15 is prevented from moving and cannot be completely coated on the part, corresponding to the wall part 11a, of the current collecting member 14, the risk of short circuit between the current collecting member 14 and the wall part 11a is reduced, and the high safety of the battery cell 10 is ensured. In addition, since the heat-shrinkable film 15 needs to be completely coated on the current collecting member 14, the heat-shrinkable film 15 is extended between the electrode terminal 12 and the current collecting member 14, so that the precision requirement for coating the heat-shrinkable film 15 can be reduced, and the process difficulty for coating the heat-shrinkable film 15 by the current collecting member 14 is further reduced.

On the other hand, since the battery cell 10 generates heat during use, the temperature of the battery cell 10 will rise, and not only will the heat-shrinkable film 15 be heated to further shrink the heat-shrinkable film 15, but also the electrode assembly 13 will expand outward, and the heat-shrinkable film 15 cannot completely cover the current collecting member 14, and cannot insulate and isolate the current collecting member 14 and the wall portion 11a, so that there is a risk of short circuit between the current collecting member 14 and the wall portion 11 a. Therefore, by the arrangement mode of extending the heat-shrinkable film 15 between the electrode terminal 12 and the current collecting member 14, even if the temperature of the battery cell 10 rises, which causes the heat-shrinkable film 15 to tend to shrink further, since the electrode terminal 12 and the current collecting member 14 clamp and press the heat-shrinkable film 15, the part of the heat-shrinkable film 15, which is wrapped around the current collecting member 14, does not shift due to shrinkage, i.e., the heat-shrinkable film 15 can be stably wrapped around the part of the current collecting member 14, which corresponds to the wall part 11a, so that the current collecting member 14 and the wall part 11a are in an insulated and isolated state, the risk of short circuit between the current collecting member 14 and the wall part 11a is reduced, and the battery cell 10 is ensured to have high safety.

In some other embodiments of the present application, the heat-shrinkable film 15 may also not extend between the electrode terminal 12 and the current collecting member 14, i.e., the projection of the portion of the electrode terminal 12 between the current collecting member 14 and the wall portion 11a on the current collecting member 14 does not overlap with the projection of the heat-shrinkable film 15 on the current collecting member 14.

Further, when the heat shrinkage film 15 extends between the electrode terminal 12 and the current collecting member 14, a certain gap may exist between the electrode terminal 12 and the current collecting member 14 due to the thickness of the heat shrinkage film 15. The electrode terminal 12 and the current collecting member 14 should be in a state of contact and stable electrical connection to ensure that the battery cell 10 forms a stable circuit and thus the battery cell 10 supplies power stably, and the gap between the electrode terminal 12 and the current collecting member 14 will destroy the stability of the electrical connection between the electrode terminal 12 and the current collecting member 14, even if the battery cell 10 cannot form a circuit and cannot supply power.

Therefore, as shown in fig. 5, in some embodiments of the present application, in order to ensure stable electrical connection between the current collecting member 14 and the electrode terminal 12, a portion of the current collecting member 14 for connection with the electrode terminal 12 may be protruded toward the electrode terminal 12 and form a first protrusion 141 to enable contact and stable electrical connection between the current collecting member 14 and the electrode terminal 12.

Further, as shown in fig. 5, when the current collecting member 14 is formed with the first protrusion 141, in order to ensure that the heat-shrinkable film 15 extends between the electrode terminal 12 and the current collecting member 14, the electrode terminal 12 and the current collecting member 14 can sandwich the heat-shrinkable film 15, a portion of the electrode terminal 12 for sandwiching the heat-shrinkable film 15 in cooperation with the current collecting member 14 may be formed with the second protrusion 122 extending toward the current collecting member 14. By the provision of the first and

second protrusions

141 and 122, while ensuring stable electrical connection of the current collecting member 14 to the electrode terminal 12 through the first protrusion 141, it is ensured that the electrode terminal 12 can sandwich the heat-shrinkable film 15 extending to the front of the electrode terminal 12 and the current collecting member 14 together with the current collecting member 14 through the second protrusion 122.

According to the arrangement mode, the heat-shrinkable film 15 extends to the position between the electrode terminal 12 and the current collecting member 14, the range of the current collecting member 14 coated by the heat-shrinkable film 15 is not required to be adjusted, the process difficulty of coating the current collecting member 14 by the heat-shrinkable film 15 is reduced, and the production efficiency of the single battery 10 is improved. Meanwhile, the heat-shrinkable film 15 extends to a position between the electrode terminal 12 and the current collecting member 14, the electrode terminal 12 and the current collecting member 14 can clamp the heat-shrinkable film 15, the heat-shrinkable film 15 is prevented from being heated and shrunk, the electrode assembly 13 expands and the like, so that the heat-shrinkable film 15 cannot be completely coated on the current collecting member 14, the stability of coating the heat-shrinkable film 15 on the current collecting member 14 is improved, and the safety of the battery cell 10 is improved.

As shown in fig. 4 and 5, in some embodiments of the present application, there is a gap between the heat shrink film 15 and the wall portion 11a, i.e., the heat shrink film 15 is not in contact with the wall portion 11 a.

The heat-shrinkable film 15 is coated on the side of the current collecting member 14 facing the wall portion 11a, and it is understood that the heat-shrinkable film 15 is in close contact with the outer surface of the current collecting member 14 facing the wall portion 11 a. Further, the polarity of the current collecting member 14 is different from that of the wall 11a, and there is a potential difference between the current collecting member 14 and the wall 11a, and although the heat-shrinkable film 15 itself has better insulation property and can insulate and separate the current collecting member 14 and the wall 11a, since the thickness of the heat-shrinkable film 15 is thin, there is a risk that the potential difference between the current collecting member 14 and the wall 11a breaks through the heat-shrinkable film 15 when the heat-shrinkable film 15 contacts the wall 11a, and therefore, a certain gap should be formed between the heat-shrinkable film 15 and the wall 11a to prevent the heat-shrinkable film 15 from breaking through due to too close distance between the current collecting member 14 and the wall 11a, and the current collecting member 14 and the wall 11a are conducted and short-circuited.

In other embodiments of the present application, when the thickness of the heat shrinkage film 15 is thick, the potential difference between the current collecting member 14 and the wall portion 11a is not sufficient to break through the heat shrinkage film 15, and at this time, no gap may be provided between the heat shrinkage film 15 and the wall portion 11a, that is, the heat shrinkage film 15 may abut against the wall portion 11 a. It is understood that the heat shrink film 15 may be provided to insulate and separate the current collecting member 14 from the wall portion 11 a.

In this arrangement, because a certain potential difference exists between the wall portion 11a and the current collecting member 14, if the heat-shrinkable film 15 is in contact with the wall portion 11a, there is a risk that the potential difference between the wall portion 11a and the current collecting member 14 breaks down the heat-shrinkable film 15, and therefore, a gap is left between the heat-shrinkable film 15 and the wall portion 11a, so as to reduce the risk of short circuit between the wall portion 11a and the current collecting member 14, that is, reduce the risk of short circuit of the battery cell 10, and improve the safety of the battery cell 10.

As shown in fig. 6, fig. 6 is a schematic view of heat shrink film 15 including first portion 151 and second portion 152 according to some embodiments of the present application. In some embodiments of the present application, the heat-shrinkable film 15 includes a first portion 151 and a second portion 152 that are integrally formed, the first portion 151 is wrapped around the side of the current collecting member 14 facing the wall portion 11a, and the second portion 152 is wrapped around the outer circumferential surface of the first tab 131.

The first tab 131 is electrically connected to the current collecting member 14, and the polarities of the first tab 131 and the current collecting member 14 are the same, that is, the polarities of the first tab 131 and the housing 11 are different, so that the first tab 131 and the housing 11 need to be isolated in an insulating manner to prevent the first tab 131 from being electrically connected to the housing 11 to cause a short circuit, thereby reducing the risk of the short circuit of the battery cell 10 and ensuring that the battery cell 10, the battery 100 and the electric device have higher safety.

As shown in fig. 6, the current collecting member 14 is disposed between the first tab 131 and the wall 11a, that is, the current collecting member 14 is disposed on the end surface of the first tab 131 facing the wall 11a, and the first portion 151 of the heat shrinkable film 15 is wrapped on the side of the current collecting member 14 facing the wall 11a, that is, the end surface of the first tab 131 facing the wall 11a is insulated from the housing 11. Further, as shown in fig. 6, 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 to cause short circuit, the outer peripheral surface of the first tab 131 should also be insulated from the housing 11, and therefore, the heat shrinkable film 15 is provided to include a first portion 151 and a second portion 152, and the outer peripheral surface of the first tab 131 is covered by the second portion 152 on the side of the current collecting member 14 facing the wall portion 11a covered by the first portion 151, so as to insulate the outer peripheral surface of the first tab 131 from the inner peripheral wall of the housing 11.

Specifically, as shown in FIG. 6, in some embodiments of the present application, first portion 151 and second portion 152 of heat shrink film 15 are integrally formed. The heat shrinkable film 15 formed by integrally forming the first portion 151 and the second portion 152 has good covering capability, can completely cover one side of the current collecting member 14 facing the wall part 11a, the outer peripheral surface of the first tab 131 and the corner positions of the current collecting member 14 and the first tab 131, has good insulation effect between the current collecting member 14 and the first tab 131 and the housing 11, and is not easy to cause the problem of short circuit between the current collecting member 14 or the first tab 131 and the housing 11 due to the insufficient covering of the heat shrinkable film 15.

As shown in fig. 6, the corner positions of the current collecting member 14 and the first tab 131 refer to the corner of the current collecting member 14 itself, the corner of the first tab 131 itself, and the corner formed between the current collecting member 14 and the first tab 131. Specifically, the corner of the current collecting member 14 itself is a corner between the side of the current collecting member 14 facing the wall portion 11a and the outer peripheral surface of the current collecting member 14, the corner of the first tab 131 itself is a 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 collecting member 14 and the first tab 131 is a corner formed between the outer peripheral surface of the current collecting member 14 and the side of the first tab 131 facing the wall portion 11 a.

Further, the heat shrinkable film 15 formed by integrally forming the first portion 151 and the second portion 152 is easy to form and has high production efficiency. No adjustment of the area covered by first portion 151 and second portion 152 is required during the heating of heat shrink 15. It can be understood that the integrally formed heat shrinkable film 15 can be naturally adhered to and coated on the portion of the battery cell 10 that needs to be coated with the heat shrinkable film 15 without intervention after being heated and shrunk. Therefore, the production efficiency of the battery cell 10 provided with the integrally formed heat-shrinkable film 15 is high, and the productivity of the battery 100 is further increased, so that the demand of the market for the increasing productivity of the battery 100 can be met.

In other embodiments of the present application, the first portion 151 and the second portion 152 of the heat shrinkable film 15 may be provided separately, for example, the first portion 151 may be a sheet-shaped circular ring and may be coated on the side of the current collecting member 14 facing the wall portion 11a, and the second portion 152 may be a cylindrical circular ring and may be coated on the outer peripheral surface of the first tab 131.

In this arrangement, the heat-shrinkable film 15 covers not only the current collecting member 14 but also the outer peripheral surface of the first tab 131, and the heat-shrinkable film 15 simultaneously insulates and isolates the current collecting member 14 from the wall portion 11a and the first tab 131 from the side wall of the housing 11, thereby reducing the number of parts and enabling the structure of the battery cell 10 to be compact.

As shown in fig. 6 and 7, fig. 7 is another schematic view of a heat shrink film 15 including a first portion 151 and a second portion 152 according to some embodiments of the present application. In some embodiments of the present application, the current collecting member 14 has a disk shape, the diameter of the current collecting member 14 is smaller than that of the first tab 131, a stepped region 142 is formed between the edge of the current collecting member 14 and the outer circumferential surface of the first tab 131, and the heat shrinkage film 15 covers the stepped region 142.

Wherein the edge of the current collecting member 14 refers to the outer circumferential surface of the current collecting member 14.

As shown in fig. 6 and 7, the edge of the current collecting member 14 forms a stepped region 142 with the outer circumferential surface of the first tab 131, it being understood that the current collecting member 14 is disposed between the electrode assembly 13 and the wall portion 11a, i.e., the current collecting member 14 is disposed between the first tab 131 and the wall portion 11a, i.e., the side of the current collecting member 14 facing the wall portion 11a is closer to the wall portion 11a than the side of the first tab 131 facing the wall portion 11 a; meanwhile, the diameter of the current collecting member 14 is smaller than that of the first tab 131, i.e., the projection of the current collecting member 14 on the first tab 131 is located inside the first tab 131, and thus a stepped structure, i.e., a stepped region 142, will be formed between the outer circumferential surface of the current collecting member 14 (the edge of the current collecting member 14) and the outer circumferential surface of the first tab 131.

On one hand, the current collecting member 14 is connected to the first tab 131 by welding, and the step area 142 provides an adequate area for welding between the current collecting member 14 and the first tab 131, so that the difficulty in welding between the current collecting member 14 and the first tab 131 can be effectively reduced, the welding efficiency is improved, and further, the production efficiency of the single battery 10 is improved, thereby expanding the capacity of the battery 100 and meeting the demand of the market on the capacity of the battery 100.

On the other hand, in order to ensure that the heat-shrinkable film 15 can completely cover the current collecting member 14 and the first tab 131, so as to insulate and isolate the current collecting member 14 and the first tab 131 from the housing 11, the heat-shrinkable film 15 should be provided with a certain margin, and the margin of the heat-shrinkable film 15 is prone to wrinkle during the process of heat shrinkage of the heat-shrinkable film 15. Meanwhile, the heat-shrinkable film 15 is affected by factors such as the flatness of the surface covered by the heat-shrinkable film 15 and the shape of the portion covered by the heat-shrinkable film 15 during heat shrinkage, for example, the outer surface of the current collecting member 14 facing the wall portion 11a is not an absolute plane but an uneven profile, and when the heat-shrinkable film 15 is covered on the current collecting member 14, the surface of the heat-shrinkable film 15 may also be wrinkled. The generation of wrinkles not only affects the coating quality of the heat-shrinkable film 15, but also may cause the problem that the single battery 10 cannot be packaged because the thickness of the position where the heat-shrinkable film 15 is wrinkled is increased, thereby generating waste products and reducing the qualification rate of the single battery 10 in the production process. Therefore, in order to reduce the possibility of wrinkles occurring during heat shrinkage of the heat shrinkable film 15, a region for absorbing the margin of the heat shrinkable film 15 should be provided at the portion covered with the heat shrinkable film 15. The step area 142 is arranged so that the step area 142 can be used for absorbing the allowance of the heat shrinkable film 15, thereby reducing the probability of wrinkles occurring in the heat shrinkable film 15 during the heat shrinkage process.

When the heat-shrinkable film 15 covers the current collecting member 14 and the first tab 131 with the stepped region 142 formed between the current collecting member 14 and the first tab 131, in some embodiments of the present application, as shown in fig. 6, the heat-shrinkable film 15 may be across the stepped region 142, i.e., the heat-shrinkable film 15 does not abut the outer peripheral surface of the current collecting member 14 and the end surface of the first tab 131 facing the wall portion 11 a; in other embodiments of the present application, as shown in fig. 7, the heat shrinkage film 15 may also be shrunk and adhered to the outer circumferential surface of the current collecting member 14 and the end surface of the first tab 131 facing the wall portion 11 a.

In this arrangement, the stepped region 142 is arranged between the current collecting member 14 and the first tab 131, on one hand, the stepped region 142 provides enough space for welding the current collecting member 14 to the first tab 131, so that the welding between the current collecting member 14 and the first tab 131 is facilitated, the production efficiency of the single battery 10 is improved, and the capacity of the battery 100 is expanded; on the other hand, in the process of the heat shrinkage film 15 being heated and shrunk, the step area 142 can absorb the allowance of the heat shrinkage film 15, the probability of the wrinkle occurring in the shrinking process of the heat shrinkage film 15 is reduced, and the flatness of the heat shrinkage film 15 coated on the current collecting member 14 is improved.

As shown in fig. 8, fig. 8 is a schematic view of the heat shrink film 15 including a third portion 153 of some embodiments of the present application. In some embodiments of the present application, the heat shrinkable film 15 further includes a third portion 153, the third portion 153 covers the outer circumferential surface of the main body 132, and the third portion 153 is integrally formed with the second portion 152.

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 adjacent to the wall portion 11 a. Therefore, in order to prevent a short circuit between the main body 132 and the housing 11 while covering the outer circumferential surface of the first tab 131 with the second portion 152, the outer circumferential surface of the main body 132 and the inner wall of the housing 11 should be insulated from each other. Therefore, the third portion 153 is disposed on the heat shrinkable film 15, and the outer peripheral surface of the main body 132 is covered by the third portion 153, so as to achieve insulation between the main body 132 and the housing 11.

When the third portion 153 and the second portion 152 of the heat shrinkable film 15 are integrally formed, the continuity between the second portion 152 and the third portion 153 is good, the second portion 152 and the third portion 153 are heated and shrunk, a gap is not easy to be formed between the second portion 152 and the third portion 153, it is ensured that the second portion 152 and the third portion 153 can completely coat the first tab 131, the body and a transition region between the first tab 131 and the body, the probability of short circuit of the battery cell 10 is further reduced, and further, the safety of the battery cell 10, the battery 100 and an electric device is improved. Meanwhile, because the second part 152 and the third part 153 are integrally formed, a mutually overlapped area cannot be formed between the second part 152 and the third part 153 after being heated and shrunk, the problem that the thickness of the heat-shrinkable film 15 is locally increased due to the overlapping of the second part 152 and the third part 153, and stress concentration occurs at the position where the thickness of the heat-shrinkable film 15 is increased is solved, and the risk of lithium precipitation caused by the stress concentration at the local position is reduced.

In addition, the third portion 153 and the second portion 152 are integrally formed, and when the third portion 153 is sleeved on the outer peripheral surface of the body, the second portion 152 is correspondingly sleeved on the outer peripheral surface of the first tab 131. Then, the thermal shrinkage film 15 is heated, and the second portion 152 and the third portion 153 can be shrunk and correspondingly closely attached to and cover the outer peripheral surface of the first tab 131 and the outer peripheral surface of the body, so that the assembly and production of the single battery 10 are facilitated, and the single battery 10 has high production efficiency.

Further, as shown in fig. 8, the first portion 151, the second portion 152 and the third portion 153 are sequentially connected and integrally formed, so as to further improve the integrity of the heat shrinkable film 15, on one hand, the risk of short circuit of the battery cell 10 is reduced, and the safety performance of the battery cell 10 is improved, on the other hand, the connection positions of the first portion 151 and the second portion 152 and the connection positions of the second portion 152 and the third portion are prevented from being overlapped with each other, the thicknesses of the positions of the heat shrinkable film 15 are uniform and consistent, the problem of stress concentration is not easy to occur, and further, the risk of lithium precipitation caused by stress concentration is reduced.

In this arrangement, on one hand, the third portion 153 covers the outer peripheral surface of the main body 132, so that the risk of short circuit between the housing 11 and the main body 132 is reduced, that is, the risk of short circuit of the single battery 10 is reduced, and the safety of the single battery 10 is improved; on the other hand, the third portion 153 and the second portion 152 are integrally formed, the third portion 153 and the second portion 152 are not easily overlapped, the increase of the thickness of the heat-shrinkable film 15 caused by the overlapping of the second portion 152 and the third portion 153 is prevented, the probability of local stress concentration caused by the extrusion of the heat-shrinkable film 15 and the shell 11 due to the increase of the thickness is reduced, and the risk of lithium precipitation of the electrode due to the stress concentration is further reduced.

In some embodiments of the present application, the electrode assembly 13 is formed by winding a pole piece and a separator, the battery cell 10 further includes an adhesive tape adhered to the outer circumferential surface of the main body 132 and fixing the wound head and tail sections of the pole piece and/or the separator, and the third portion 153 does not overlap the adhesive tape.

The electrode assembly 13 is formed by winding a pole piece and a diaphragm, wherein 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 the diaphragm. Further, the active material-containing portions of the positive and negative electrode plates constitute the main body 132, and the active material-free portions of the positive and negative electrode plates are used to constitute positive and negative electrode tabs, respectively. For example, the first tab 131 is formed of a portion of the positive electrode tab having no active material.

Since the electrode assembly 13 is formed by winding the pole piece and the diaphragm, the pole piece and the diaphragm have a tendency to expand outward, and the pole piece and the diaphragm should be tightened and fixed in order to prevent the pole piece and the diaphragm from expanding and prevent the pole piece and the diaphragm from being in direct contact with the case 11 after expansion to cause short circuit. For example, tape may be adhered to the outer peripheral surface of the main body 132 and the wound trailing end of the pole piece and/or membrane secured by the tape to prevent outward expansion of the pole piece and membrane.

The winding ending refers to the ending part of the outermost layer in the winding process of the pole piece and the diaphragm, and can also be understood as the winding end of the pole piece and the diaphragm. Meanwhile, when the tape is adhered to the outer circumferential surface of the main body 132, the tape should be insulated in order to prevent the pole piece at the outermost layer of the main body 132 from being short-circuited with the housing 11, and for example, the tape may be a polyvinyl chloride-based insulating tape, a polyolefin-based insulating tape, or the like.

Further, since the adhesive tape is used to adhere to the outer peripheral surface of the main body 132, and the third portion 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 portion 153 of the heat-shrinkable film 15 from overlapping with the adhesive tape to cause stress concentration, and further reduce the risk of lithium deposition due to gravity concentration, the third portion 153 of the heat-shrinkable film 15 and the adhesive tape should cover the outer peripheral surface of the main body 132 at different positions, that is, the third portion 153 and the adhesive tape should not overlap.

According to the arrangement mode, the third part 153 is not overlapped with the adhesive tape, the thickness of the overlapped part is prevented from being increased due to the overlapping of the third part 153 and the adhesive tape, the problem that local position stress concentration is caused due to the fact that the thickness of the part is increased and the part is extruded with the side wall of the shell 11 is not prone to occurring, and then the risk of lithium precipitation of the pole piece due to stress concentration is reduced.

The problem that the thickness is increased due to the overlapping of the third portion 153 and the adhesive tape is not easy to occur, the stress concentration at a local position due to the increase of the thickness is prevented, and the risk of lithium precipitation of the electrode due to the stress concentration is reduced.

As shown in fig. 9, fig. 9 is a schematic view of the battery cell 10 of some embodiments of the present application provided with the elastic layer 1211. In some embodiments of the present application, the battery cell 10 further includes an elastic layer 1211, the elastic layer 1211 being disposed between the wall portion 11a and the heat shrinkage film 15, the elastic layer 1211 serving to apply an elastic force to the electrode assembly 13 in the axial direction of the electrode assembly 13, that is, to the current collecting member 14 in the axial direction of the electrode assembly 13.

As shown in fig. 9, in some embodiments of the present application, the insulating member 121 extending between the heat shrinkage film 15 and the wall portion 11a may serve as the elastic layer 1211 of the battery cell 10, and provide the electrode assembly 13 with an elastic force in the axial direction of the electrode assembly 13.

Further, when the insulating member 121 extending between the wall portion 11a and the heat shrinkable film 15 is used as the elastic layer 1211, a certain gap may be formed between the elastic layer 1211 and the heat shrinkable film 15 to prevent a gap from occurring between the electrode terminal 12 and the current collecting member 14, thereby ensuring that the electrode terminal 12 and the current collecting member 14 can be stably abutted and electrically connected.

Of course, the elastic layer 1211 may abut against the heat shrinkable film 15 to further limit the position of the electrode assembly 13 and reduce the possibility of the electrode assembly 13 moving in the axial direction thereof, while ensuring stable electrical connection between the electrode terminal 12 and the current collecting member 14. At this time, in order to enable the elastic layer 1211 to abut against the heat shrinkable film 15, a projection protruding toward the heat shrinkable film 15 may be formed at a portion of the insulating member 121 extending between the wall portion 11a and the heat shrinkable film 15, that is, a portion of the insulating member 121 as the elastic layer 1211, and abut against the heat shrinkable film 15 through the projection. Specifically, the projection may be annular, or the projection may be plural, and the plural projections are spaced around the axis of the electrode assembly 13.

Note that, when the portion of the insulating member 121 extending between the wall portion 11a and the heat shrinkage film 15 is used as the elastic layer 1211, the insulating member 121 should have certain elasticity, and the material of the insulating member 121 may be rubber, such as butyl rubber, styrene butadiene rubber, silicon rubber, and the like.

In other embodiments of the present application, the elastic layer 1211 may also be a separate component in the battery cell 10, in which case, two ends of the elastic layer 1211 in the axial direction of the electrode assembly 13 are respectively abutted against the wall portion 11a and the heat shrinkage film 15, so as to limit the electrode assembly 13 and reduce the possibility of the electrode assembly 13 moving in the axial direction.

With this arrangement, when the single battery 10 is vibrated, the elastic layer 1211 can apply an elastic force to the electrode assembly 13 and the current collecting member 14 along the axial direction thereof, and further insulate and isolate the current collecting member 14 and the wall portion 11a, thereby reducing the risk of short circuit of the single battery 10 and improving the safety of the single battery 10.

As shown in fig. 10, fig. 10 is a schematic view of a battery cell 10 of 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 an end of the main body 132 away from the wall portion 11a, the second tab 133 is opposite in polarity to the first tab 131, and the second tab 133 is electrically connected to the wall portion 11 a.

As shown in fig. 10, the first tab 131 is located at one end of the electrode assembly 13 toward 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, i.e., the first tab 131 and the second tab 133 are respectively formed at both ends of the body 132 of the electrode assembly 13.

The first tab 131 is opposite in polarity to the second tab 133, and for example, the first tab 131 is a positive tab of the electrode assembly 13, is formed of a portion of the positive tab having no active material, and is electrically connected to the current collecting member 14 and the electrode terminal 12, and the second tab 133 is a negative tab of the electrode assembly 13, is formed of a portion of the negative tab having no active material, and is electrically connected to the case 11.

According to the arrangement mode, the first lug 131 and the second lug 133 are located at two ends of the electrode assembly 13, and the first lug 131 and the second lug 133 have good insulativity, so that the risk of short circuit of the single battery 10 is reduced, and the safety of the single battery 10 is improved.

As shown in fig. 10, in some embodiments of the present application, the housing 11 includes a casing 111 and an end cover 112, the casing 111 includes a bottom wall 1111 and a side wall 1112, the side wall 1112 is enclosed around the bottom wall 1111, one end of the side wall 1112 is connected to the bottom wall 1111, one end of the side wall 1112 encloses an opening opposite to the bottom wall 1111, the end cover 112 covers the opening, and the wall 11a is the bottom wall 1111 or the end cover 112.

The bottom wall 1111 and the side wall 1112 may be integrally formed, or the bottom wall 1111 and the side wall 1112 may be separately disposed and connected by welding, clamping, or the like. In particular, the sidewall 1112 can be cylindrical, such as a cylinder or prism.

The other end of the side wall 1112 opposite to the bottom wall 1111 encloses an opening from which the current collecting member 14 and the electrode assembly 13 can be mounted into the case 111. After the electrode assembly 13 is fitted into the case 111, the opening is covered with the end cap 112 to close the opening. Further, when the housing 11 needs to be filled with electrolyte and the end cap 112 covers the opening, a sealing member, such as a sealing ring or a gasket, may be disposed between the end cap 112 and the sidewall 1112 to improve the sealing performance of the end cap 112 covering the opening and prevent the electrolyte from leaking from the housing 11.

Wall 11a being either bottom wall 1111 or end cap 112 includes two cases: in one case, the wall 11a is a bottom wall 1111; alternatively, the wall 11a is an end cap 112. In the embodiment in which the wall portion 11a is the bottom wall 1111, the current collecting member 14 faces the bottom wall 1111 after the electrode assembly 13 is mounted in the case 111. A heat shrink film 15 is located between the bottom wall 1111 and the current collecting member 14. In the embodiment where the wall portion 11a is the end cap 112, after the electrode assembly 13 is fitted into the case 111, the current collecting member 14 faces the end cap 112, and the heat shrinkable film 15 is located between the end cap 112 and the current collecting member 14.

In this arrangement, the side wall 1112 and the wall 11a define a space for accommodating the electrode assembly 13, the electrolyte and other structures, and the opening defined by the side wall 1112 is covered by the end cap 112, thereby ensuring the sealing performance of the case.

In a second aspect, the present application also provides a battery 100 including the battery cell 10 described above. In the single battery 10, the current collecting member 14 and the wall part 11a are insulated and isolated by the heat shrinkable film 15, so that the problem of short circuit between the current collecting member 14 and the wall part 11a is prevented, the probability of short circuit of the single battery 10 is reduced, and the safety of the battery 100 is improved.

In a third aspect, the present application further provides an electric device, including the battery 100 described above, where the battery 100 is used for providing electric energy to operate the electric device.

In a fourth aspect, as shown in fig. 11, fig. 11 is a schematic diagram of a method for manufacturing a battery cell according to some embodiments of the present application. The application also provides a manufacturing method of the battery monomer. Specifically, the method for manufacturing the battery cell comprises the following steps:

s100, providing a shell 11 and an electrode terminal 12, wherein the shell 11 comprises a wall part 11a, and the electrode terminal 12 is mounted on the wall part 11a in an insulating mode;

s200, providing an electrode assembly 13, wherein the electrode assembly 13 comprises 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 a wall part 11 a;

s300, providing a current collecting component 14, and connecting the current collecting component 14 to a first pole lug 131;

s400, providing a heat-shrinkable film 15, and sleeving the heat-shrinkable film 15 on the electrode assembly 13;

s500, heating the heat-shrinkable film 15 to shrink, and enabling at least one part of the heat-shrinkable film 15 to be coated on the current collecting member 14;

s600, placing the electrode assembly 13 and the current collecting member 14 coated with the heat-shrinkable film 15 into the case 11 with the side of the current collecting member 14 coated with the heat-shrinkable film 15 facing the wall portion 11a, and insulating and isolating the current collecting member 14 and the wall portion 11 a;

s700. the current collecting member 14 is connected to the electrode terminal 12.

The method for manufacturing the battery cell is merely illustrative of the production process of the battery cell 10, and does not show the specific sequence of the production process of the battery cell 10.

In a fifth aspect, as shown in fig. 12, fig. 12 is a schematic view of a manufacturing apparatus 2000 of a battery cell according to some embodiments of the present application. The present application further provides a single cell manufacturing apparatus 2000 for manufacturing the single cell 10. The manufacturing apparatus 2000 of the 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.

Specifically, as shown in fig. 12, the first supply device 2100 is configured to supply a housing 11 and an electrode terminal 12, the housing 11 includes a wall portion 11a, and the electrode terminal 12 is mounted on the wall portion 11a in an insulated manner. The second providing device 2200 is for providing an electrode assembly 13, the electrode assembly 13 including a main body 132 and a first tab 131, the first tab 131 being formed at one end of the main body 132 near the wall portion 11 a. The third providing device 2300 is used to provide the current collecting member 14. The fourth providing device 2400 is used for providing the heat shrinkage film 15, and sleeving the heat shrinkage film 15 on the electrode assembly 13. The first assembly device 2500 is used to connect the current collecting member 14 to the first tab 131. The heating device 2600 is used to heat the heat-shrinkable film 15 to shrink it, and to coat at least a portion of the heat-shrinkable film 15 on the current collecting member 14. The second assembling device 2700 is for placing the electrode assembly 13 and the current collecting member 14 coated with the heat shrinkage film 15 into the case 11 with the side of the current collecting member 14 coated with the heat shrinkage film 15 facing the wall portion 11a to insulate and separate the current collecting member 14 and the wall portion 11 a. The third assembling device 2800 is used to connect the current collecting member 14 to the electrode terminal 12.

In some embodiments of the present application, as shown in fig. 3-10, the present application provides a battery cell 10 including a case 11, an electrode terminal 12, an electrode assembly 13, a current collecting member 14, and a heat shrinkage film 15. The housing 11 includes a wall portion 11a and a side wall 1112, and an insulator 121 is provided between the electrode terminal 12 and the wall portion 11a to insulate the electrode terminal 12 from the wall portion 11 a. An electrode assembly 13 is disposed within the can 11, the electrode assembly 13 including a first tab 131, a body 132, and a second tab 133, the first tab 131 being electrically connected to the current collecting member 14, and the second tab 133 being electrically connected to the can 11. The current collecting member 14 is disposed between the electrode assembly 13 and the wall portion 11a, the current collecting member 14 serves to connect the first tab 131 and the electrode terminal 12, and a portion of the current collecting member 14 connected to the electrode terminal 12 is formed with a first protrusion 141 so that the current collecting member 14 is electrically connected to the electrode terminal 12. The heat-shrinkable film 15 includes a first portion 151, a second portion 152, and a third portion 153, which are integrally formed and connected in sequence, the first portion 151 is wrapped around the current collecting member 14 on a side facing the wall 11a, the second portion 152 is wrapped around the outer circumferential surface of the first tab 131, and the third portion 153 is wrapped around the outer circumferential surface of the body 132, so that the current collecting member 14, the first tab 131, and the body 132 are insulated and isolated from the case 11. The current collecting member 14 has a diameter smaller than that of the first tab 131, and a stepped region 142 is formed between the current collecting member 14 and the first tab 131, and the stepped region 142 is used to absorb the margin during the shrinkage of the heat shrinkable film 15. The portion of the insulating member 121 extending between the wall portion 11a and the heat shrink film 15 constitutes an elastic layer 1211, and the elastic layer 1211 is used to apply an elastic force to the electrode assembly 13 in the axial direction of the electrode assembly 13. The end of the side wall 1112 remote from the wall portion 11a encloses an opening, and the end cap 112 is used to cover the opening.

It should be noted that the features of the embodiments in the present application may be combined with each other without conflict.

The above description is only a preferred embodiment of the present application and is not intended to limit the present application, and various modifications and changes may be made by those skilled in the art. Any modification, equivalent replacement, improvement and the like made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A battery cell, comprising:

a housing including a wall portion;

an electrode terminal mounted on the wall portion in an insulated manner;

an electrode assembly disposed within the case, the electrode assembly including a main body and a first tab formed at one end of the main body adjacent to the wall portion;

a current collecting member disposed between the electrode assembly and the wall part, the current collecting member for connecting the first tab and the electrode terminal;

at least one part of the heat-shrinkable film is coated on one side of the current collecting member facing the wall part so as to insulate and separate the current collecting member and the wall part.

2. The battery cell as recited in claim 1 wherein the heat shrink film extends between the electrode terminal and the current collecting member.

3. The battery cell according to claim 1 or 2, wherein a gap is provided between the heat-shrinkable film and the wall portion.

4. The battery cell as recited in claim 1, wherein the heat-shrinkable film includes a first portion and a second portion that are integrally formed, the first portion wrapping a side of the current collecting member facing the wall portion, and the second portion wrapping an outer circumferential surface of the first tab.

5. The battery cell as recited in claim 4, wherein the current collecting member has a disk shape, a diameter of the current collecting member is smaller than a diameter of the first tab, a stepped region is formed between an edge of the current collecting member and an outer circumferential surface of the first tab, and the heat-shrinkable film covers the stepped region.

6. The battery cell as recited in claim 4 wherein the heat shrink film further comprises a third portion that wraps around the outer peripheral surface of the body, the third portion being integrally formed with the second portion.

7. The battery cell as recited in claim 6, wherein the electrode assembly is formed by winding a pole piece and a separator, the battery cell further comprises an adhesive tape that is adhered to the outer circumferential surface of the main body and fixes a winding end of the pole piece and/or the separator, and the third portion does not overlap the adhesive tape.

8. The battery cell according to claim 1, further comprising an elastic layer disposed between the wall portion and the heat shrink film, the elastic layer configured to apply an elastic force to the electrode assembly in an axial direction of the electrode assembly.

9. The battery cell as recited in claim 1 wherein the electrode assembly further comprises a second tab formed at an end of the body distal from the wall portion, the second tab being opposite in polarity to the first tab, the second tab being electrically connected to the wall portion.

10. The battery cell as recited in claim 9 wherein the housing comprises a casing and an end cap, the casing comprising a bottom wall and a side wall, the side wall being disposed around the bottom wall, one end of the side wall being connected to the bottom wall, the other end of the side wall defining an opening opposite the bottom wall, the end cap covering the opening, the wall being the bottom wall or the end cap.

11. A battery comprising a cell according to any one of claims 1 to 10.

12. An electrical device comprising a battery as claimed in claim 11 for providing electrical energy.