Battery monomer, battery and electric equipment

Abstract

The embodiment of the utility model provides a battery monomer, a battery and electric equipment. The battery monomer comprises an electrode assembly and an insulating part, and the electrode assembly comprises a first pole piece; the insulating part comprises first gummed paper and second gummed paper, and the first gummed paper and the second gummed paper are arranged on the two sides of the first pole piece in the thickness direction respectively; in the width direction of the first pole piece, the first gummed paper is provided with a first end and a second end exceeding the first pole piece, the second gummed paper is provided with a third end and a fourth end exceeding the first pole piece, the first end is connected with the third end, and the second end is connected with the fourth end. According to the technical scheme provided by the invention, the fixing performance of fixing the insulating part on the first pole piece is good, and the risk that the insulating part falls off is reduced, so that the reliability of the single battery can be improved.

Description

Technical Field

[0001] The present application relates to the field of battery technology, and in particular to a battery cell, a battery and an electrical device. Background Art

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

[0003] During the manufacturing process of batteries, the reliability of batteries is an issue that cannot be ignored. Therefore, how to improve the reliability of batteries is a technical problem that needs to be solved urgently in battery technology. Utility Model Content

[0004] The present application provides a battery cell, a battery and an electrical device, which can improve the reliability of the battery cell.

[0005] This application is achieved through the following technical solutions:

[0006] In a first aspect, an embodiment of the present application provides a battery cell, the battery cell comprising an electrode assembly and an insulating member, the electrode assembly comprising a first pole piece; the insulating member comprising a first adhesive tape and a second adhesive tape, the first adhesive tape and the second adhesive tape are respectively arranged on both sides of the thickness direction of the first pole piece; in the width direction of the first pole piece, the first adhesive tape has a first end and a second end extending beyond the first pole piece, the second adhesive tape has a third end and a fourth end extending beyond the first pole piece, the first end is connected to the third end, and the second end is connected to the fourth end.

[0007] In the technical solution of the embodiment of the present application, the first adhesive tape and the second adhesive tape are attached to both sides of the first pole piece in the thickness direction, which protects the first pole piece and reduces the risk of cracking and powdering in the area where the insulating member is attached to the first pole piece, thereby ensuring that the cracked pole piece will not pierce the diaphragm during the cycle of the battery cell. The first and third ends of the first and second adhesive tapes extending beyond the first pole piece are connected, and the second and fourth ends are connected, that is, the ends of the adhesive tapes on both sides of the thickness direction of the first pole piece are sealed and fixed to the first pole piece in a clamping manner, thereby realizing the connection and fixation of the portion of the insulating member extending beyond the first pole piece, and the insulating member has good fixing performance on the first pole piece, reducing the risk of the insulating member falling off, thereby improving the reliability of the battery cell.

[0008] According to some embodiments of the present application, the first end is bonded to the third end, and the second end is bonded to the fourth end.

[0009] In the above scheme, the first end and the third end are bonded together, and the second end and the fourth end are bonded together, so the bonding method is reliable and easy to operate.

[0010] According to some embodiments of the present application, the first adhesive tape includes a first substrate and a first adhesive layer, and the first substrate is bonded to the first pole piece through the first adhesive layer; the second adhesive tape includes a second substrate and a second adhesive layer, and the second substrate is bonded to the first pole piece through the second adhesive layer.

[0011] In the above scheme, the stability of the insulating member on the first pole piece is not high only by connecting the outer ends of the first adhesive tape and the second adhesive tape. In order to further improve the bonding stability of the insulating member on the first pole piece, a first adhesive layer is provided on the first substrate of the first adhesive tape, and the first adhesive tape is bonded to the first pole piece through the first adhesive layer. A second adhesive layer is provided on the second substrate of the second adhesive tape, and the second adhesive tape is bonded to the second pole piece through the second adhesive layer. The overlapping area of ​​the insulating member and the first pole piece is bonded and fixed, and the insulating member is more firmly bonded to the first pole piece.

[0012] According to some embodiments of the present application, the first substrate and the second substrate are porous materials.

[0013] In the above scheme, the first substrate and the second substrate are made of porous materials, which is more conducive to the active ions passing through the pores of the adhesive tape during the charging and discharging process of the battery cell, ensuring that the capacity of the area with the insulating member in the battery cell can be normally exerted.

[0014] According to some embodiments of the present application, the first substrate has a first surface in the thickness direction thereof, the first adhesive layer is arranged on the first surface, the first surface includes a first adhesive coating area coated with the first adhesive layer and a first blank area not coated with the first adhesive layer; the second substrate has a second surface in the thickness direction thereof, the second adhesive layer is arranged on the second surface, the second surface includes a second adhesive coating area coated with the second adhesive layer and a second blank area not coated with the second adhesive layer.

[0015] In the above scheme, a first blank area and a first glue-coated area are formed on the first surface of the first substrate, and a second blank area and a second glue-coated area are formed on the second surface of the second substrate. The first glue-coated area and the second glue-coated area can be used to achieve stable bonding of the first adhesive tape and the second adhesive tape to the first electrode. The provision of the first blank area and the second blank area can not only avoid waste of adhesive layer materials, but also because the substrate is a porous material, no adhesive layer is provided in the first blank area and the second blank area. In this way, during the charging and discharging process of the battery cell, active ions (such as lithium ions) can normally pass through the blank areas on the first and second adhesive tapes where no adhesive layer is provided. Compared with spreading the adhesive layer all over the surface of the substrate, the area for active ions to pass through the insulating component is increased, and the blocking effect of the insulating component on the movement of active ions is reduced, so that the capacity of the battery cell in the area adjacent to the insulating component can be normally exerted.

[0016] According to some embodiments of the present application, the first end and the third end extend beyond the first pole piece by the same distance, and the second end and the fourth end extend beyond the first pole piece by the same distance.

[0017] In the above scheme, the first end and the third end extend beyond the first pole piece by an equal distance, and the second end and the fourth end extend beyond the first pole piece by an equal distance, that is, the first adhesive tape and the second adhesive tape completely overlap, which makes it easier to ensure that the bonding areas at both ends of the insulating member are equal.

[0018] According to some embodiments of the present application, the distance that the first end extends beyond the first pole piece is equal to the distance that the second end extends beyond the first pole piece.

[0019] In the above solution, the two ends of the first adhesive tape and the two ends of the second adhesive tape that extend beyond the width direction of the first pole piece are made the same in size, which is convenient for processing and manufacturing.

[0020] According to some embodiments of the present application, in the width direction of the first pole piece, the dimension of the first end extending beyond the first pole piece is greater than or equal to 1 mm and less than or equal to 5 mm.

[0021] In the above scheme, the size of the first end exceeding the first pole piece is limited to this range, which can not only ensure that the first adhesive tape and the second adhesive tape have sufficient connection area in the exceeding area, but also facilitate the subsequent detection of whether there is a phenomenon of missing insulation parts in the battery cell, which is convenient for manufacturing. When the size of the first end exceeding the first pole piece is less than 1mm, the bonding area of ​​the first end is small, which affects the bonding strength between the first adhesive tape and the second adhesive tape, and the size of the first end exceeding the first pole piece is small, which is not conducive to the missing insulation part detection. When the size of the first end exceeding the first pole piece is greater than 5mm, not only is the adhesive tape material wasted, but also the assembly space of the battery cell is occupied. In addition, due to the excessive length of the first end, it is easy to interfere with other components during the manufacturing process. For example, the excessive length of the first end is easy to be mistaken for a pole ear, which affects the manufacturing process of the battery cell.

[0022] According to some embodiments of the present application, the electrode assembly is a wound structure, the electrode assembly includes a second pole piece and a diaphragm, the first pole piece and the second pole piece have opposite polarities, and the diaphragm is arranged between the first pole piece and the second pole piece; an insulating member is attached to at least one bending section of the first pole piece.

[0023] In the above scheme, during the shaping process of the battery cell, the pole piece of the battery cell is prone to cracking and powdering at the bent section due to pressure. By attaching an insulating member to at least one bent section of the first pole piece, the first adhesive tape and the second adhesive tape on the insulating member can protect the bent section of the first pole piece, reducing the risk of cracking and powdering in the area of ​​the first pole piece where the insulating member is attached, thereby ensuring that the battery cell will not have cracked pole pieces piercing the diaphragm during the cycle process.

[0024] According to some embodiments of the present application, an insulating member is attached to the innermost bending section of the first pole piece.

[0025] In the above scheme, when the battery cell is shaped, the first pole piece is more prone to cracking and powdering because the innermost bent section of the first pole piece has the largest folding amount. Therefore, an insulating part is attached to the innermost bent section of the first pole piece to protect the innermost bent section of the first pole piece, thereby reducing the risk of cracking and powdering of the first pole piece.

[0026] According to some embodiments of the present application, the first pole piece is a positive pole piece.

[0027] In a second aspect, the present application provides a battery, which includes the battery cell in the above embodiment.

[0028] In a third aspect, the present application provides an electrical device, which includes the battery cell of the above embodiment or the battery of the above embodiment, and the battery cell or the battery is used to provide electrical energy.

[0029] Additional aspects and advantages of the present application will be given in part in the description below, and in part will become apparent from the description below, or will be learned through the practice of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present application and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying creative work.

[0031] Figure 1 A schematic diagram of the structure of a vehicle according to some embodiments of the present application;

[0032] Figure 2 A schematic diagram of the exploded structure of a battery according to some embodiments of the present application;

[0033] Figure 3 A schematic cross-sectional structure diagram of an electrode assembly in a battery cell in some embodiments of the present application;

[0034] Figure 4 A schematic diagram of the insulating member of the first pole piece of some embodiments of the present application during heat sealing;

[0035] Figure 5 This is a schematic structural diagram of the first pole piece before winding in some embodiments of the present application;

[0036] Figure 6 This is a schematic diagram of the structure of adhesive tape according to some embodiments of the present application.

[0037] Icons: 1000-vehicle; 100-battery; 200-controller; 300-motor; 10-housing; 11-first part; 12-second part; 20-battery cell; 22-electrode assembly; 221-first pole piece; 2210-first pole ear; 2211-first bending section; 2212-second bending section; 222-second pole piece; 23-insulating member; 231-first adhesive tape; 2311-first end; 2312-second end; 2313-first substrate; 2314-first surface; 2315-first blank area; 232-second adhesive tape; 2321-third end; 2322-fourth end; 2323-second substrate; 2324-second surface; 24-diaphragm; 400-heating plate. DETAILED DESCRIPTION

[0038] In order to make the purpose, technical solution and advantages of the embodiments of the present application clearer, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0039] Unless otherwise defined, all technical and scientific terms used in this application have the same meaning as those commonly understood by technicians in the technical field of this application; the terms used in the specification of this application are only for the purpose of describing specific embodiments and are not intended to limit this application; the terms "including" and "having" in the specification and claims of this application and the above-mentioned drawings and any variations thereof are intended to cover non-exclusive inclusions. The terms "first", "second", etc. in the specification and claims of this application or the above-mentioned drawings are used to distinguish different objects, rather than to describe a specific order or a primary and secondary relationship.

[0040] Reference to "embodiments" in this application means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present application. The appearance of the phrase in various locations in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described in this application may be combined with other embodiments.

[0041] In the description of this application, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", and "attached" 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 a direct connection, or an indirect connection through an intermediate medium, or it can be the internal communication of two elements. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0042] The term "and / or" in this application is only a description of the association relationship of associated objects, indicating that there can be three relationships. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. In addition, the character " / " in this application generally indicates that the associated objects before and after are in an "or" relationship.

[0043] The term "multiple" as used in this application refers to more than two (including two). Similarly, "multiple groups" refers to more than two groups (including two groups), and "multiple sheets" refers to more than two sheets (including two sheets).

[0044] In some embodiments, the battery may be a battery module. When there are multiple battery cells, the multiple battery cells are arranged and fixed to form a battery module.

[0045] In some embodiments, the battery may be a battery pack, which includes a case and battery cells, wherein the battery cells or battery modules are accommodated in the case.

[0046] In some embodiments, the box body can be used as a part of the chassis structure of the vehicle. For example, part of the box body can become at least a part of the floor of the vehicle, or part of the box body can become at least a part of the cross beam and longitudinal beam of the vehicle.

[0047] In some embodiments, the battery may be an energy storage device, which includes an energy storage container, an energy storage cabinet, and the like.

[0048] In the embodiment of the present application, the battery cell may be a secondary battery. A secondary battery refers to a battery cell that can be continuously used by activating active materials by charging after the battery cell is discharged.

[0049] The battery cells may be, but are not limited to, lithium ion batteries, sodium ion batteries, sodium lithium ion batteries, lithium metal batteries, sodium metal batteries, lithium sulfur batteries, magnesium ion batteries, nickel hydrogen batteries, nickel cadmium batteries, lead storage batteries, etc.

[0050] As an example, the battery cell may be a cylindrical battery cell, a prismatic battery cell, a pouch battery cell, or a battery cell of other shapes, the prismatic battery cell including a square case battery cell.

[0051] A battery cell generally includes an electrode assembly. The electrode assembly includes a positive electrode, a negative electrode, and a separator. During the charge and discharge process of the battery cell, active ions (such as lithium ions) are embedded and removed between the positive electrode and the negative electrode. The separator is set between the positive electrode and the negative electrode to prevent the positive and negative electrodes from short-circuiting, while allowing active ions to pass through.

[0052] In some embodiments, the positive electrode may be a positive electrode sheet, and the positive electrode sheet may include a positive electrode current collector and a positive electrode active material disposed on at least one surface of the positive electrode current collector.

[0053] As an example, the positive electrode current collector has two surfaces facing each other in its thickness direction, and the positive electrode active material is disposed on either or both of the two facing surfaces of the positive electrode current collector.

[0054] As an example, the positive electrode current collector may be a metal foil or a composite current collector. For example, as the metal foil, aluminum with a silver-plated surface, stainless steel with a silver-plated surface, stainless steel, copper, aluminum, nickel, carbon electrode, carbon, nickel or titanium, etc., may be used. The composite current collector may include a polymer material base and a metal layer. The composite current collector may be formed by forming a metal material (aluminum, aluminum alloy, nickel, nickel alloy, titanium, titanium alloy, silver and silver alloy, etc.) on a polymer material substrate (such as a substrate of polypropylene, polyethylene terephthalate, polybutylene terephthalate, polystyrene, polyethylene, etc.).

[0055] As an example, the positive electrode active material may include at least one of the following materials: lithium-containing phosphates, lithium transition metal oxides, and their respective modified compounds. However, the present application is not limited to these materials, and other conventional materials that can be used as positive electrode active materials for batteries may also be used.

[0056] In some embodiments, the negative electrode may be a negative electrode sheet, and the negative electrode sheet may include a negative electrode current collector.

[0057] As an example, the negative electrode current collector may be a metal foil or a composite current collector. For example, as the metal foil, aluminum with a silver-plated surface, stainless steel with a silver-plated surface, stainless steel, copper, aluminum, nickel, carbon electrode, carbon, nickel or titanium, etc. may be used.

[0058] In some embodiments, the negative electrode current collector has two surfaces opposite to each other in its thickness direction, and the negative electrode active material is disposed on any one or both of the two opposite surfaces of the negative electrode current collector.

[0059] As an example, the negative electrode active material may adopt the negative electrode active material for the battery known in the art. As an example, the negative electrode active material may include at least one of the following materials: artificial graphite, natural graphite, soft carbon, hard carbon, silicon-based materials, tin-based materials and lithium titanate, etc. The silicon-based material may be selected from at least one of elemental silicon, silicon oxide compounds, silicon-carbon composites, silicon-nitrogen composites and silicon alloys. The tin-based material may be selected from at least one of elemental tin, tin oxide compounds and tin alloys. However, the present application is not limited to these materials, and other traditional materials that can be used as negative electrode active materials for batteries may also be used. These negative electrode active materials may be used alone or in combination of two or more.

[0060] In some embodiments, the separator is a membrane. The present application has no particular limitation on the type of the membrane, and any known porous membrane with good chemical stability and mechanical stability can be selected.

[0061] As an example, the main material of the separator can be selected from at least one of glass fiber, non-woven fabric, polyethylene, polypropylene, polyvinylidene fluoride, and ceramic. The separator can be a single-layer film or a multi-layer composite film, without special restrictions. When the separator is a multi-layer composite film, the materials of each layer can be the same or different, without special restrictions. The separator can be a separate component located between the positive and negative electrodes, or it can be attached to the surface of the positive and negative electrodes.

[0062] In some embodiments, the separator is a solid electrolyte, which is disposed between the positive electrode and the negative electrode and serves to transmit ions and isolate the positive and negative electrodes.

[0063] In some embodiments, the electrode assembly is a wound structure, wherein the positive electrode sheet and the negative electrode sheet are wound into a wound structure.

[0064] At present, from the perspective of market development, 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 vehicles such as electric bicycles, electric motorcycles, electric cars, as well as military equipment and aerospace and other fields. With the continuous expansion of the application field of power batteries, the market demand is also constantly expanding.

[0065] The development of battery technology must take into account many design factors at the same time, such as energy density, discharge capacity, charge and discharge rate and other performance parameters. In addition, battery reliability must also be considered.

[0066] At present, during the shaping process of the wound electrode assembly, the pole pieces in the electrode assembly are prone to cracking and powdering, especially at the bending section of the pole piece, which leads to low reliability of the battery cell. In order to alleviate the problem of cracking and powdering of the pole piece. In the prior art, the method of applying glue to the bending section of the electrode assembly is usually adopted to solve the problem of pressure cracking and powdering of the bending section of the electrode assembly. However, the bonding effect between the adhesive tape and the surface of the pole piece is poor, which easily causes the adhesive tape to separate from the pole piece, and there is still a problem of low reliability of the battery cell.

[0067] Based on the above considerations, in order to achieve the bonding stability of the tape on the pole piece, the present application designs a battery cell, in which the first pole piece in the battery cell is affixed with the first tape and the second tape on both sides in the thickness direction, and the first tape and the second tape are connected at both ends extending beyond the first pole piece respectively.

[0068] In such a battery cell, the adhesive tapes on both sides of the electrode in the thickness direction extend beyond the end of the first electrode and are connected, so that the first adhesive tape and the second adhesive tape are fixed to the first electrode in a clamping manner. The insulating part is fixed to the first electrode with good fixing performance, reducing the risk of the insulating part falling off, thereby improving the reliability of the battery cell.

[0069] The battery cells disclosed in the embodiments of the present application can be used, but not limited to, in electrical equipment such as vehicles, ships or aircraft. The power supply system of the electrical equipment can be composed of the battery cells and batteries disclosed in the present application.

[0070] The embodiment of the present application provides an electric device using a battery as a power source, and the electric device may be, but is not limited to, a mobile phone, a tablet, a laptop, an electric toy, an electric tool, a battery car, an electric car, a ship, a spacecraft, etc. Among them, the electric toy may include a fixed or mobile electric toy, for example, a game console, an electric car toy, an electric ship toy, an electric airplane toy, etc., and the spacecraft may include an airplane, a rocket, a space shuttle, a spacecraft, etc.

[0071] For the convenience of description, the following embodiments are described by taking a vehicle as an example of an electrical device in an embodiment of the present application.

[0072] Please refer to Figure 1 , Figure 1A schematic diagram of the structure of a vehicle 1000 provided for some embodiments of the present application. The vehicle 1000 may be a fuel vehicle, a gas vehicle or a new energy vehicle, and the new energy vehicle may be a pure electric vehicle, a hybrid vehicle or an extended-range vehicle, etc. A battery 100 is provided inside the vehicle 1000, and the battery 100 may be provided at the bottom, head or tail of the vehicle 1000. The battery 100 may be used to power the vehicle 1000, for example, the battery 100 may be used as an operating power source for the vehicle 1000. The vehicle 1000 may also include a controller 200 and a motor 300, and the controller 200 is used to control the battery 100 to power the motor 300, for example, for starting, navigating and driving the vehicle 1000.

[0073] In some embodiments of the present application, the battery 100 can not only serve as an operating power source for the vehicle 1000, but also serve as a driving power source for the vehicle 1000, replacing or partially replacing fuel or natural gas to provide driving power for the vehicle 1000.

[0074] Please refer to Figure 2 , Figure 2 An exploded view of a battery 100 provided in some embodiments of the present application. The battery 100 includes a box 10 and a battery cell 20, and the battery cell 20 is contained in the box 10. Among them, the box 10 is used to provide a storage space for the battery cell 20, and the box 10 can adopt a variety of structures. In some embodiments, the box 10 may include a first part 11 and a second part 12, the first part 11 and the second part 12 cover each other, and the first part 11 and the second part 12 jointly define a storage space for accommodating the battery cell 20. The second part 12 may be a hollow structure with one end open, the first part 11 may be a plate-like structure, and the first part 11 covers the open side of the second part 12, so that the first part 11 and the second part 12 jointly define a storage space; the first part 11 and the second part 12 may also be hollow structures with one side open, and the open side of the first part 11 covers the open side of the second part 12. Of course, the box 10 formed by the first part 11 and the second part 12 may be in a variety of shapes, such as a cylinder, a cuboid, etc.

[0075] In the battery 100, there may be multiple battery cells 20, and the multiple battery cells 20 may be connected in series, in parallel, or in a mixed connection. A mixed connection means that the multiple battery cells 20 are both connected in series and in parallel. The multiple battery cells 20 may be directly connected in series, in parallel, or in a mixed connection, and then the whole formed by the multiple battery cells 20 is accommodated in the box 10; of course, the battery 100 may also be a battery module formed by connecting multiple battery cells 20 in series, in parallel, or in a mixed connection, and then the multiple battery modules are connected in series, in parallel, or in a mixed connection to form a whole, and accommodated in the box 10. The battery 100 may also include other structures, for example, the battery 100 may also include a busbar component for realizing electrical connection between the multiple battery cells 20.

[0076] Each battery cell 20 may be a secondary battery or a primary battery; it may also be a lithium-sulfur battery, a sodium-ion battery or a magnesium-ion battery.

[0077] The battery cell 20 refers to the smallest unit constituting the battery and includes an end cap, a housing, an electrode assembly and other functional components.

[0078] The end cap refers to a component that covers the opening of the shell to isolate the internal environment of the battery cell 20 from the external environment. Without limitation, the shape of the end cap can be adapted to the shape of the shell to match the shell. Optionally, the end cap can be made of a material with a certain hardness and strength (such as aluminum alloy), so that the end cap is not easily deformed when squeezed and collided, so that the battery cell can have a higher structural strength and reliability can also be improved. Functional components such as electrode terminals can be provided on the end cap. The electrode terminal can be used to electrically connect to the electrode assembly for output or input of electrical energy of the battery cell 20. The material of the end cap can also be a variety of materials, such as copper, iron, aluminum, stainless steel, aluminum alloy, plastic, etc., and the embodiments of the present application do not impose special restrictions on this. In some embodiments, an insulating structure can also be provided on the inner side of the end cap, and the insulating structure can be used to isolate the electrical connection components in the shell from the end cap to reduce the risk of short circuit. Exemplarily, the insulating structure can be plastic, rubber, etc.

[0079] The electrode assembly is a component in the battery cell 20 where an electrochemical reaction occurs. One or more electrode assemblies may be contained in the housing. The electrode assembly is mainly formed by winding or stacking the positive electrode sheet and the negative electrode sheet, and a diaphragm is usually provided between the positive electrode sheet and the negative electrode sheet, and the diaphragm is used to separate the positive electrode sheet and the negative electrode sheet to avoid short circuits between the positive electrode sheet and the negative electrode sheet. The parts of the positive electrode sheet and the negative electrode sheet with active materials constitute the main body of the electrode assembly, and the parts of the positive electrode sheet and the negative electrode sheet without active materials each constitute a lug. The positive electrode lug and the negative electrode lug may be located together at one end of the main body or respectively at both ends of the main body.

[0080] The present application embodiment provides a battery cell, please refer to Figure 3 , Figure 4 and Figure 5 , Figure 3 A schematic cross-sectional structure diagram of an electrode assembly in a battery cell in some embodiments of the present application; Figure 4 A schematic diagram of the insulating member of the first pole piece of some embodiments of the present application during heat sealing; Figure 5 The schematic diagram of the structure of the first pole piece before winding of some embodiments of the present application. The battery cell 20 includes an electrode assembly 22 and an insulating member 23, wherein the electrode assembly 22 includes a first pole piece 221; the insulating member 23 includes a first adhesive tape 231 and a second adhesive tape 232, and the first adhesive tape 231 and the second adhesive tape 232 are respectively arranged on both sides of the thickness direction of the first pole piece 221; in the width direction X of the first pole piece 221, the first adhesive tape 231 has a first end 2311 and a second end 2312 that extend beyond the first pole piece 221, and the second adhesive tape 232 has a third end 2321 and a fourth end 2322 that extend beyond the first pole piece 221, the first end 2311 is connected to the third end 2321, and the second end 2312 is connected to the fourth end 2322.

[0081] The insulating member 23 is a component that does not have a conductive property. The material of the insulating member 23 may be selected from at least one of glass fiber, non-woven fabric, polyethylene, polypropylene, polyvinylidene fluoride, and ceramics.

[0082] The width direction X of the first pole piece 221 is Figure 5 The first end 2311 refers to one end of the first adhesive tape 231 in the length direction. The second end 2312 refers to the other end of the first adhesive tape 231 along the length direction thereof opposite to the first end 2311. The first end 2311 and the second end 2312 are located at two ends of the first adhesive tape 231 in the length direction thereof.

[0083] The third end 2321 refers to one end of the second adhesive tape 232 in the length direction, and the fourth end 2322 refers to the other end of the second adhesive tape 232 along its length direction opposite to the third end 2321. The third end 2321 and the fourth end 2322 are respectively located at the two ends of the second adhesive tape 232 in the length direction.

[0084] The first end 2311 and the third end 2321 may be connected by bonding or other methods, such as ultrasonic welding, or by inserting a fixing piece through the overlapping portion of the first end 2311 and the third end 2321 of the first adhesive tape 231 and the second adhesive tape 232, and connecting the first adhesive tape and the second adhesive tape using the fixing piece.

[0085] Similarly, the second end 2312 and the fourth end 2322 may be connected by bonding or other methods, such as ultrasonic welding, or by inserting a fixing piece through the overlapping portion of the second end 2312 and the fourth end 2322 of the first adhesive tape 231 and the second adhesive tape 232, and connecting the first adhesive tape 231 and the second adhesive tape 232 using the fixing piece.

[0086] In the technical solution of the embodiment of the present application, the first adhesive tape 231 and the second adhesive tape 232 are attached to both sides of the first pole piece 221 in the thickness direction, which protects the first pole piece 221 and reduces the risk of cracking and powdering in the area of ​​the first pole piece 221 where the insulating member 23 is attached, thereby ensuring that the battery cell 20 will not have a cracked pole piece piercing the diaphragm 24 during the cycle process. The first end 2311 and the third end 2321 of the first adhesive tape 231 and the second adhesive tape 232 extending beyond the first pole piece 221 are connected, and the second end 2312 and the fourth end 2322 are connected, that is, the two ends of the adhesive tape on both sides of the thickness direction of the first pole piece 221 are fixed to the first pole piece 221 in a clamping manner, so that the connection and fixation of the portion of the insulating member 23 extending beyond the first pole piece 221 is achieved, and the fixing performance of the insulating member 23 on the first pole piece 221 is good, reducing the risk of the insulating member 23 falling off, thereby improving the reliability of the battery cell 20.

[0087] In some embodiments of the present application, the first end 2311 and the third end 2321 are bonded, and the second end 2312 and the fourth end 2322 are bonded.

[0088] The first end 2311 and the third end 2321 can be hot-melt bonded, and the second end 2312 and the fourth end 2322 can be hot-melt bonded. Specifically, a hot-melt adhesive layer is provided on the facing surfaces of the first end 2311 and / or the third end 2321, and a hot-melt adhesive layer is provided on the facing surfaces of the second end 2312 and / or the fourth end 2322. During bonding, only the insulating member 23 needs to be hot-pressed, and the hot-melt adhesive layer melts, thereby achieving heat sealing of the outer side of the insulating member 23, and the insulating member 23 has stronger adhesion to the first pole piece 221.

[0089] The hot melt adhesive layer is composed of hot melt adhesive, which is a plastic adhesive. Its physical state changes with temperature within a certain temperature range, while its chemical properties remain unchanged. It is non-toxic and tasteless and is an environmentally friendly chemical product. The hot melt temperature range can be controlled at 80-160°C. The hot melt temperature is preferably 90-100°C, which can ensure the adhesion of the hot melt adhesive layer without affecting the porosity of the substrate. When the hot melt temperature is lower than 80°C, it will affect the adhesion of the hot melt adhesive layer, which may easily cause the insulating member 23 and the first pole piece 221 to fall off.

[0090] Please refer to Figure 4 , Figure 4Schematic diagram of the insulating member of the first pole piece of some embodiments of the present application during heat sealing. When heat sealing the insulating member 23, two heating plates 400 are respectively located at the ends of the first adhesive tape 231 and the second adhesive tape 232 in the insulating member 23 extending outside the first pole piece 221, and the first end 2311 and the third end 2321, as well as the second end 2312 and the fourth end 2322 are heat-pressed by the heating plate 400 to complete the heat sealing of the insulating member 23 on the first pole piece 221. During heat sealing, the distance d between the heating plate 400 and the first pole piece 221 is 1-3 mm.

[0091] By bonding the first end 2311 and the third end 2321 , and bonding the second end 2312 and the fourth end 2322 , the bonding method is reliable and easy to operate.

[0092] According to some embodiments of the present application, the first adhesive tape 231 includes a first substrate 2313 and a first adhesive layer, and the first substrate 2313 is bonded to the first pole piece 221 through the first adhesive layer; the second adhesive tape 232 includes a second substrate 2323 and a second adhesive layer, and the second substrate 2323 is bonded to the first pole piece 221 through the second adhesive layer.

[0093] The first adhesive layer and the second adhesive layer can be PVDF (polyvinylidene difluoride) or maleic anhydride modified polypropylene. When the first adhesive layer and the second adhesive layer are PVDF, a single layer of island-shaped PVDF particles are sprayed on the corresponding substrate. When it is necessary to fix the insulating member 23 on the first pole piece 221, the first adhesive tape 231 and the second adhesive tape 232 in the hot-pressed insulating member 23 are extended to the corresponding ends of the first pole piece 221. After the PVDF is heated and melted, the first adhesive tape 231 and the second adhesive tape 232 in the thickness direction of the first pole piece 221 are bonded.

[0094] Only by connecting the outer ends of the first adhesive tape 231 and the second adhesive tape 232, the stability of the insulating member 23 on the first pole piece 221 is not high. In order to further improve the bonding stability of the insulating member 23 on the first pole piece 221, a first adhesive layer is provided on the first substrate 2313 of the first adhesive tape 231, and the first adhesive tape 231 is bonded to the first pole piece 221 through the first adhesive layer. A second adhesive layer is provided on the second substrate 2323 of the second adhesive tape 232, and the second adhesive tape 232 is bonded to the second pole piece 222 through the second adhesive layer. The overlapping area of ​​the insulating member 23 and the first pole piece 221 is bonded and fixed, and the insulating member 23 is more firmly bonded to the first pole piece 221.

[0095] According to some embodiments of the present application, the first substrate 2313 and the second substrate 2323 are porous materials. The porous material here means that the material has more tiny pores, which can filter larger particles but allow metal ions to pass through.

[0096] The materials of the first substrate 2313 and the second substrate 2323 can be polypropylene, polyethylene or non-woven fabrics. Polypropylene, referred to as PP, is a polymer formed by polyaddition reaction of propylene. Polypropylene is a thermoplastic synthetic resin with excellent performance and is a colorless, translucent, thermoplastic, lightweight general-purpose plastic. Polyethylene (PE) is a thermoplastic resin obtained by polymerization reaction of ethylene monomers. Non-woven fabrics are also called non-woven fabrics, needle-punched cotton, needle-punched non-woven fabrics, etc. They are made of polyester fiber and polyester fiber (referred to as PET) and are made by needle-punching process.

[0097] The first substrate 2313 and the second substrate 2323 are made of porous materials, which is more conducive to the active ions to penetrate the pores of the adhesive tape during the charging and discharging process of the battery cell 20, thereby ensuring that the capacity of the area where the insulating member 23 is attached in the battery cell 20 can be normally exerted.

[0098] According to some embodiments of this application, please refer to Figure 4 , Figure 5 and Figure 6 The first substrate 2313 has a first surface 2314 in its thickness direction, the first adhesive layer is arranged on the first surface 2314, and the first surface 2314 includes a first adhesive coating area coated with the first adhesive layer and a first blank area 2315 not coated with the first adhesive layer; the second substrate 2323 has a second surface 2324 in its thickness direction, the second adhesive layer is arranged on the second surface 2324, and the second surface 2324 includes a second adhesive coating area coated with the second adhesive layer and a second blank area not coated with the second adhesive layer.

[0099] The first adhesive layer may include a plurality of first sub-adhesive layers, which are spaced apart on the first surface 2314, and a first blank area 2315 is formed between two adjacent first sub-adhesive layers. The second adhesive layer may include a plurality of second sub-adhesive layers, which are spaced apart on the first surface 2314, and a second blank area is formed between two adjacent second sub-adhesive layers.

[0100] By forming a first blank area 2315 and a first glue coating area on the first surface 2314 of the first substrate 2313, and forming a second blank area and a second glue coating area on the second surface 2324 of the second substrate 2323, the first glue coating area and the second glue coating area can be used to achieve stable bonding of the first adhesive tape 231 and the second adhesive tape 232 to the first electrode 221. The provision of the first blank area 2315 and the second blank area can not only avoid waste of adhesive layer materials, but also because the substrate is a porous material, no adhesive layer is provided in the first blank area 2315 and the second blank area. In this way, during the charging and discharging process of the battery cell 20, active ions (such as lithium ions) can normally pass through the blank areas on the first adhesive tape 231 and the second adhesive tape 232 where no adhesive layer is provided. Compared with spreading the adhesive layer all over the surface of the substrate, the area where the active ions pass through the insulating member 23 is increased, and the blocking effect of the insulating member 23 on the movement of active ions is reduced, so that the capacity of the area of ​​the battery cell adjacent to the insulating member 23 can be normally exerted.

[0101] The distances that the first end 2311 and the third end 2321 extend beyond the first pole piece 221 may also be unequal, and the distances that the second end 2312 and the fourth end 2322 extend beyond the first pole piece 221 may also be unequal, depending on actual conditions.

[0102] According to some embodiments of the present application, the first end 2311 and the third end 2321 extend beyond the first pole piece 221 by the same distance, and the second end 2312 and the fourth end 2322 extend beyond the first pole piece 221 by the same distance.

[0103] The first end 2311 and the third end 2321 extend beyond the first pole piece 221 by the same distance, which means that the first adhesive tape 231 and the second adhesive tape 232 extend beyond the first pole piece 221 in the width direction X and are aligned with each other. The second end 2312 and the fourth end 2322 extend beyond the first pole piece 221 by the same distance, which means that the first adhesive tape 231 and the second adhesive tape 232 extend beyond the first pole piece 221 in the width direction X and are also aligned with each other.

[0104] The first end 2311 and the third end 2321 extend beyond the first pole piece 221 by the same distance, and the second end 2312 and the fourth end 2322 extend beyond the first pole piece 221 by the same distance, that is, the first adhesive tape 231 and the second adhesive tape 232 completely overlap, which makes it easier to ensure that the bonding areas at both ends of the insulating member 23 are equal.

[0105] According to some embodiments of the present application, the distance that the first end 2311 extends beyond the first pole piece 221 is equal to the distance that the second end 2312 extends beyond the first pole piece 221 .

[0106] The distance that the first end 2311 extends beyond the first pole piece 221 is equal to the distance that the second end 2312 extends beyond the first pole piece 221 , which means that the amount of extension of the insulating member 23 at both ends of the first pole piece 221 in the width direction X is equal.

[0107] The two ends of the first adhesive tape 231 and the second adhesive tape 232 are arranged to have the same size beyond the two ends of the first pole piece 221 in the width direction, so as to facilitate processing and manufacturing.

[0108] According to some embodiments of the present application, in the width direction X of the first pole piece 221 , the first end 2311 extends beyond the first pole piece 221 by a dimension greater than or equal to 1 mm and less than or equal to 5 mm.

[0109] The dimension of the first end 2311 beyond the first pole piece 221 can be any value of 1 mm to 5 mm. The dimension of the first end 2311 beyond the first pole piece 221 can be: 1.2 mm, 1.5 mm, 1.8 mm, 2.0 mm, 2.2 mm, 3.2 mm, 4.2 mm, 4.5 mm or 4.8 mm, etc. Similarly, the dimension of the second end 2312 beyond the first pole piece 221 can also be any value of 1 mm to 5 mm.

[0110] Limiting the size of the first end 2311 beyond the first pole piece 221 to within this range can ensure that the first adhesive tape 231 and the second adhesive tape 232 have sufficient connection area in the excess area, and can also facilitate subsequent detection of whether the insulating member 23 of the battery cell is missing, thereby facilitating manufacturing.

[0111] When the first end 2311 exceeds the first pole piece 221 by less than 1 mm, the bonding area of ​​the first end 2311 is small, which affects the bonding strength between the first adhesive tape 231 and the second adhesive tape 232 . In addition, the first end 2311 exceeds the first pole piece 221 by a small amount, which is not conducive to the missing detection of the insulating member 23 .

[0112] When the first end 2311 exceeds the first pole piece 221 by more than 5 mm, not only is the adhesive tape material wasted, but also the assembly space of the battery cell is occupied. In addition, since the first end 2311 exceeds the first pole piece 221 by too long, it is easy to interfere with other components during the manufacturing process. For example, the first end 2311 exceeds the first pole piece 221 by too long and is easily detected and mistaken for the first pole ear 2210 of the first pole piece 221, affecting the manufacturing process of the battery cell.

[0113] According to some embodiments of the present application, the electrode assembly 22 is a wound structure, and the electrode assembly 22 includes a second pole piece 222 and a diaphragm 24. The first pole piece 221 and the second pole piece 222 have opposite polarities, and the diaphragm 24 is arranged between the first pole piece 221 and the second pole piece 222; an insulating member 23 is attached to at least one bending section of the first pole piece 221.

[0114] The electrode assembly 22 is a winding structure, which is wound by a fixed winding needle. The first pole piece 221 and the second pole piece 222 are respectively one of a positive pole piece and a negative pole piece. The diaphragm 24 is arranged between the first pole piece 221 and the second pole piece 222, which can prevent the first pole piece 221 and the second pole piece 222 from short-circuiting and allow active ions to pass through. The main body of the electrode assembly 22 includes a straight section and a bent section, and the bent section is connected to one end of the straight section. The first pole piece 221 of the straight section extends along a straight track, and the pole piece of the bent section extends along a bent track.

[0115] During the shaping process of the electrode assembly 22, the electrode pieces of the electrode assembly 22 are prone to cracking and powdering at the compressed bending sections. The insulating member 23 is attached to at least one bending section of the first pole piece 221. The first adhesive tape 231 and the second adhesive tape 232 on the insulating member 23 can protect the bending section of the first pole piece 221, reducing the risk of cracking and powdering in the area of ​​the first pole piece 221 where the insulating member 23 is attached, thereby ensuring that the cracked pole piece of the battery cell will not pierce the diaphragm 24 during the cycle.

[0116] According to some embodiments of the present application, an insulating member 23 is attached to the innermost bending section of the first pole piece 221 .

[0117] When the electrode assembly 22 is wound, the bending section of the first pole piece 221 in the innermost circle of the electrode assembly 22 is subjected to the greatest force, and the bending section in the innermost circle is most prone to cracking and powdering.

[0118] In this embodiment, the insulating member 23 is disposed at the first bending segment 2211 and the second bending segment 2212 of the innermost circle of the first pole piece 221 , that is, the first bending segment 2211 and the second bending segment 2212 are two bending segments formed by the first circle of the first pole piece 221 when it is wound.

[0119] When the electrode assembly 22 is being shaped, since the innermost bending section of the first pole piece 221 has the largest folding amount, the first pole piece 221 is more likely to crack and shed. Therefore, an insulating part 23 is attached to the innermost bending section of the first pole piece 221 to protect the innermost bending section of the first pole piece 221, thereby reducing the risk of cracking and shedding of the first pole piece 221.

[0120] The first electrode piece 221 may be a positive electrode piece or a negative electrode piece.

[0121] According to some embodiments of the present application, the first pole piece 221 is a positive pole piece.

[0122] In a second aspect, the present application provides a battery, which includes the battery cell 20 in the above embodiment.

[0123] In a third aspect, the present application provides an electrical device, which includes the battery cell 20 of the above embodiment or the battery of the above embodiment, and the battery cell 20 or the battery is used to provide electrical energy.

[0124] According to some embodiments of this application, please refer to Figure 3 and Figure 4 The battery cell 20 includes an electrode assembly 22 and an insulating member 23. The electrode assembly 22 is a wound structure. The electrode assembly 22 includes a first pole piece 221, a second pole piece 222 and a diaphragm 24. The first pole piece 221 and the second pole piece 222 have opposite polarities. The diaphragm 24 is arranged between the first pole piece 221 and the second pole piece 222. The insulating member 23 is attached to at least one bending section of the first pole piece 221.

[0125] The insulating member 23 includes a first adhesive tape 231 and a second adhesive tape 232, which are respectively arranged on both sides of the thickness direction of the first pole piece 221; in the width direction of the first pole piece 221, the first adhesive tape 231 has a first end 2311 and a second end 2312 that extend beyond the first pole piece 221, and the second adhesive tape 232 has a third end 2321 and a fourth end 2322 that extend beyond the first pole piece 221, the first end 2311 and the third end 2321 are bonded, and the second end 2312 and the fourth end 2322 are bonded. The first adhesive tape 231 includes a first substrate 2313 and a first adhesive layer, and the first substrate 2313 is bonded to the first pole piece 221 through the first adhesive layer; the second adhesive tape 232 includes a second substrate 2323 and a second adhesive layer, and the second substrate 2323 is bonded to the first pole piece 221 through the second adhesive layer, and the first substrate 2313 and the second substrate 2323 are porous materials.

[0126] During the shaping process of the electrode assembly 22, the pole pieces of the battery cell 20 are prone to cracking and powdering at the bent sections due to pressure. The insulating member 23 is affixed to at least one bent section of the first pole piece 221. The first adhesive tape 231 and the second adhesive tape 232 on the insulating member 23 can protect the bent section of the first pole piece 221, reducing the risk of cracking and powdering in the area of ​​the first pole piece 221 where the insulating member 23 is affixed, thereby ensuring that the battery cell 20 will not have cracked pole pieces piercing the diaphragm 24 during the cycle process.

[0127] The first end 2311 and the third end 2321 of the first adhesive tape 231 and the second adhesive tape 232 extending beyond the first pole piece 221 are connected, and the second end 2312 and the fourth end 2322 are connected, that is, the two ends of the adhesive tape on both sides of the thickness direction of the first pole piece 221 are sealed and fixed to the first pole piece 221 in a clamping manner, thereby realizing the connection and fixation of the portion of the insulating member 23 extending beyond the first pole piece 221. The insulating member 23 has good fixing performance on the first pole piece 221, which reduces the risk of the insulating member 23 falling off, thereby improving the reliability of the battery cell 20.

[0128] The first substrate 2313 and the second substrate 2323 are made of porous materials, which is more conducive to the active ions to penetrate the pores of the adhesive tape during the charging and discharging process of the battery cell, thereby ensuring that the capacity of the area where the insulating member 23 is attached in the battery cell 20 can be normally exerted.

[0129] Although the present application has been described with reference to preferred embodiments, various modifications may be made thereto and parts thereof may be replaced with equivalents without departing from the scope of the present application. In particular, the various technical features mentioned in the various embodiments may be combined in any manner as long as there are no structural conflicts. The present application is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

Claims

1. A battery cell, characterized in that: include: An electrode assembly, comprising a first pole piece; An insulating member includes a first adhesive tape and a second adhesive tape, wherein the first adhesive tape and the second adhesive tape are respectively arranged on both sides of the first pole piece in the thickness direction; in the width direction of the first pole piece, the first adhesive tape has a first end and a second end extending beyond the first pole piece, and the second adhesive tape has a third end and a fourth end extending beyond the first pole piece, the first end is connected to the third end, and the second end is connected to the fourth end.

2. The battery cell according to claim 1, characterized in that: The first end is bonded to the third end, and the second end is bonded to the fourth end.

3. The battery cell according to claim 1, characterized in that: The first adhesive tape includes a first substrate and a first adhesive layer, and the first substrate is bonded to the first pole piece through the first adhesive layer; the second adhesive tape includes a second substrate and a second adhesive layer, and the second substrate is bonded to the first pole piece through the second adhesive layer.

4. The battery cell according to claim 3, characterized in that: The first substrate and the second substrate are made of porous materials.

5. The battery cell according to claim 4, characterized in that: The first substrate has a first surface in a thickness direction thereof, the first adhesive layer is disposed on the first surface, and the first surface includes a first adhesive coating area coated with the first adhesive layer and a first blank area not coated with the first adhesive layer; The second substrate has a second surface in the thickness direction thereof, the second adhesive layer is arranged on the second surface, and the second surface includes a second adhesive coating area coated with the second adhesive layer and a second blank area not coated with the second adhesive layer.

6. The battery cell according to claim 1, characterized in that: The first end and the third end extend beyond the first pole piece by the same distance, and the second end and the fourth end extend beyond the first pole piece by the same distance.

7. The battery cell according to claim 6, characterized in that: The distance that the first end extends beyond the first pole piece is equal to the distance that the second end extends beyond the first pole piece.

8. The battery cell according to claim 7, characterized in that: In the width direction of the first pole piece, the first end extends beyond the first pole piece by a dimension greater than or equal to 1 mm and less than or equal to 5 mm.

9. The battery cell according to any one of claims 1 to 8, characterized in that: The electrode assembly is a wound structure, and includes a second pole piece and a diaphragm. The first pole piece and the second pole piece have opposite polarities, and the diaphragm is arranged between the first pole piece and the second pole piece. The insulating member is attached to at least one bending section of the first pole piece.

10. The battery cell according to claim 9, characterized in that: The insulating member is attached to the innermost bending section of the first pole piece.

11. The battery cell according to claim 9, characterized in that: The first pole piece is a positive pole piece.

12. A battery, characterized in that: The invention comprises a battery cell as claimed in any one of claims 1 to 11.

13. An electrical equipment, characterized in that: The invention comprises the battery cell according to any one of claims 1 to 11 or the battery according to claim 12, wherein the battery cell or the battery is used to provide electrical energy.

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