Electrode assembly, manufacturing method and system, battery cell, battery and electrical device

Abstract

The present application relates to an electrode assembly and a manufacturing method and system, a battery cell, a battery and an electrical device. The electrode assembly includes an electrode member, the electrode member includes an electrode member wound along a winding direction; the electrode member includes an electrode body, the electrode body includes an insulating substrate and a conductive layer arranged on the insulating substrate; the conductive layer includes a first part coated with an active material layer and a second part not coated with an active material layer; the second part is N, and the N second parts are arranged at intervals along the winding direction; along the winding direction, the spacing between the Mth and M-1th second parts is L1, and the spacing between the Mth and M+1th second parts is L2; ​​N and M are both positive integers, 2≤M≤N-1, 0.95<L2 / L1<1.05. The embodiments of the present application can improve the overcurrent capacity and safety performance of the electrode assembly.

Description

Technical Field

[0001] The present application relates to the technical field of battery production, and in particular to an electrode assembly and a manufacturing method and system, a battery cell, a battery and an electrical device. Background Art

[0002] Battery cells are widely used in electronic devices, such as mobile phones, laptop computers, electric vehicles, electric cars, electric airplanes, electric ships, electric toy cars, electric toy ships, electric toy airplanes, and electric tools, etc. Battery cells can include nickel-cadmium battery cells, nickel-hydrogen battery cells, lithium-ion battery cells, and secondary alkaline zinc-manganese battery cells, etc. Battery cells include electrode assemblies, in which ions migrate and generate current, and then the current is collected and output.

[0003] In the development of battery technology, how to improve the performance of electrode assemblies is a technical problem that needs to be solved urgently. Summary of the invention

[0004] The present application provides an electrode assembly and a manufacturing method and system, a battery cell, a battery and an electrical device, which can improve the performance of the electrode assembly.

[0005] In the first aspect, the present application proposes an electrode assembly, comprising an electrode component wound along a winding direction; the electrode component comprises an electrode body, the electrode body comprises an insulating substrate and a conductive layer arranged on the insulating substrate; the conductive layer comprises a first part coated with an active material layer and a second part not coated with the active material layer; there are N second parts, and the N second parts are arranged at intervals along the winding direction; along the winding direction, the spacing between the Mth and M-1th second parts is L1, and the spacing between the Mth and M+1th second parts is L2; ​​N and M are both positive integers, 2≤M≤N-1, 0.95<L2 / L1<1.05.

[0006] In the above technical solution, along the winding direction, the spacing between the Mth second part and the M-1th second part is L1, and the spacing between the Mth and M+1th second parts is L2, 0.95<L2 / L1<1.05; during the charging and discharging process of the battery cell, when the active material layer shrinks or expands, due to the small difference between L1 and L2, the force exerted by the insulating matrix on both sides of the second part is basically the same, and the force on the second part is more balanced, thereby ensuring the connection stability between the first part and the second part, improving the structural stability of the electrode assembly, and improving the current carrying capacity and safety performance of the electrode assembly.

[0007] In some embodiments, the second part includes a first conductive part and a second conductive part, the first conductive part is arranged between the second conductive part and the first part, and along the winding direction, the size of the first conductive part is larger than the size of the second conductive part. In the embodiment of the present application, the size of the first conductive part in the winding direction is larger than the size of the second conductive part in the winding direction, so as to increase the connection area between the first part and the second part, thereby increasing the connection strength between the two, improving the structural stability of the battery cell, and further improving the reliability of the battery cell. And because the thickness of the conductive layer is small, the flow area between the first part and the second part is small, which may cause serious heat generation at this place, seriously reducing the performance of the battery cell, and increasing the size of the first conductive part in the winding direction can increase the flow area of ​​the conductive layer at the connection between the first part and the second part, thereby alleviating the heat generation phenomenon at this place during the use of the electrode assembly, thereby further improving the flow capacity and safety performance of the electrode assembly.

[0008] In some embodiments, along the winding direction, the width of the first conductive portion increases in a gradient manner. In the embodiments of the present application, the variation trend of the second portion is relatively regular, which is conducive to processing and manufacturing.

[0009] In some embodiments, the electrode member is provided in multiple circles, and the second part is provided in at least one circle. In the embodiment of the present application, the second part is provided in each circle, and the second part is connected to the conductive structure, so that the accommodation space of the battery cell can be effectively utilized.

[0010] In some embodiments, the electrode member is provided with two second parts on each turn thereof, and the two second parts are respectively provided on both sides of the winding axis of the electrode member. In the embodiment of the present application, two second parts are provided on each turn, and the second parts are used to connect the conductive structure, which can effectively improve the conductivity of the conductive structure as a whole.

[0011] In some embodiments, the electrode component includes a conductive structure connected to the second portion, any second portion of the N second portions is connected to two conductive structures, the conductive structures are arranged to be 2N, and the projections of the 2N conductive structures in a direction perpendicular to the winding axis of the electrode component at least partially overlap. In the embodiment of the present application, the 2N conductive structures are interconnected after being stacked, which can improve the current carrying capacity of the conductive structure.

[0012] In some embodiments, the first part includes a connecting portion and a transition portion, the transition portion is located on both sides of the connecting portion, the connecting portion is extended along the width direction of the conductive structure, and at least a portion of the transition portion is arc-shaped; the second part is arranged at the connecting portion and extends along the width direction of the conductive structure.

[0013] In the embodiment of the present application, the second part is arranged at the connecting part, which can ensure that the conductive structure connected to the second part can be effectively welded when stacked and connected, thereby improving the bonding force between adjacent conductive structures and increasing the contact area between adjacent conductive structures, thereby improving the current carrying capacity.

[0014] In some embodiments, the connection portion includes a first connection portion and a second connection portion that are arranged opposite to each other; the first connection portion and the second connection portion are respectively arranged on both sides of the winding axis of the electrode component, and the second part is arranged on the first connection portion and / or the second connection portion.

[0015] In the embodiment of the present application, when the second part is arranged at the first connection part or the second connection part, the number of the conductive structures connected to the second part is relatively small, which can reduce the thickness of the multiple conductive structures after stacking and improve the energy density of the battery cell. When the second part is arranged at the first connection part and the second connection part, the conductive structure connected to the second part is also arranged at the first connection part and the second connection part, and the number of the conductive structures is relatively increased, which can effectively improve the overall conductivity of the multiple conductive structures.

[0016] In a second aspect, an embodiment of the present application provides a battery cell, comprising an electrode assembly as provided in any embodiment of the first aspect and a housing for accommodating the electrode assembly.

[0017] In a third aspect, an embodiment of the present application provides a battery, comprising a plurality of battery cells provided in the embodiment of the second aspect.

[0018] In a fourth aspect, an embodiment of the present application provides an electrical device, comprising a battery as provided in the embodiment of the third aspect, wherein the battery is used to provide electrical energy.

[0019] In a fifth aspect, an embodiment of the present application provides a method for manufacturing an electrode assembly, comprising: providing an electrode body, the electrode body comprising an insulating substrate and a conductive layer arranged on the insulating substrate, the conductive layer comprising a first part and a second part; winding the electrode body along a winding direction; wherein, there are N second parts, and along the winding direction, the N second parts are spaced apart, and the spacing between the Mth and M-1th second parts is L1, and the spacing between the Mth and M+1th second parts is L2, N and M are both positive integers, 2≤M≤N-1, 0.95<L2 / L1<1.05.

[0020] In a sixth aspect, an embodiment of the present application provides a manufacturing system for an electrode assembly, comprising: a first providing device for providing an electrode body, the electrode body comprising an insulating substrate and a conductive layer arranged on the surface of the insulating substrate, the conductive layer comprising a first part and a second part; a winding device for winding the electrode body along a winding direction; wherein, there are N second parts, and along the winding direction, the N second parts are spaced apart, and the spacing between the Mth and M-1th second parts is L1, and the spacing between the Mth and M+1th second parts is L2, N and M are both positive integers, 2≤M≤N-1, 0.95<L2 / L1<1.05. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] The features, advantages and technical effects of exemplary embodiments of the present application will be described below with reference to the accompanying drawings.

[0022] Figure 1 is a schematic diagram of the structure of a vehicle provided in some embodiments of the present application;

[0023] Figure 2 is a schematic diagram of the exploded structure of a battery provided in some embodiments of the present application;

[0024] Figure 3 yes Figure 2 A schematic diagram of the structure of the battery module shown;

[0025] Figure 4 is a schematic diagram of the exploded structure of a battery cell provided in some embodiments of the present application;

[0026] Figure 5 is a schematic cross-sectional view of an electrode assembly provided in some embodiments of the present application;

[0027] Figure 6 is a schematic diagram of the structure of the electrode components of the electrode assembly provided in some embodiments of the present application after winding;

[0028] Figure 7 is a schematic structural diagram of an electrode component of an electrode assembly provided in some embodiments of the present application in an unfolded state;

[0029] Figure 8 yes Figure 7 A schematic cross-sectional view of the electrode member shown along line AA;

[0030] Fig. 9 is a schematic flow chart of a method for manufacturing an electrode assembly provided in some embodiments of the present application;

[0031] Fig.10 is a schematic block diagram of a manufacturing system for an electrode assembly provided in some embodiments of the present application;

[0032] In the drawings, the drawings are not necessarily drawn to scale.

[0033] Among them, the reference numerals in the figure are:

[0034] 1. Vehicle; 2. Battery; 3. Controller; 4. Motor; 5. Box; 51. First box portion; 52. Second box portion; 53. Accommodation space; 6. Battery module; 7. Battery cell; 10. Electrode assembly; 11. Isolator; 13. Current collecting member; 20. Housing assembly; 21. Shell; 22. Cover assembly; 221. Electrode terminal; 223. End cap;

[0035] 8. Electrode components;

[0036] 9. electrode body; 91. insulating substrate; 92. conductive layer; 921. first part; 9211. connecting part; 9211a. first connecting part; 9211b. second connecting part; 9212. transition part; 922. second part; 9221. first conductive part; 9222. second conductive part;

[0037] 93. Active material layer;

[0038] 12. Conductive structure;

[0039] 1000. Manufacturing system; 100. First providing device; 200. Winding device. DETAILED DESCRIPTION

[0040] The following detailed description and drawings of the embodiments of the present application are used to illustrate the principles of the present application, but cannot be used to limit the scope of the present application, that is, the present application is not limited to the described embodiments.

[0041] 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 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.

[0042] Unless otherwise defined, all technical and scientific terms used in this application have the same meanings 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.

[0043] Reference to "embodiment" in this application means that a particular feature, structure, or characteristic described in conjunction with the embodiment may be included in at least one embodiment of the present application. The appearance of the phrase in various places 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.

[0044] 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.

[0045] 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.

[0046] In the embodiments of the present application, the same reference numerals represent the same components, and for the sake of brevity, detailed descriptions of the same components are omitted in different embodiments. It should be understood that the thickness, length, width and other dimensions of various components in the embodiments of the present application shown in the drawings, as well as the overall thickness, length, width and other dimensions of the integrated device are only exemplary descriptions and should not constitute any limitation to the present application.

[0047] The term "plurality" used in the present application refers to two or more (including two).

[0048] In the present application, battery cells may include lithium-ion secondary battery cells, lithium-ion primary battery cells, lithium-sulfur battery cells, sodium-lithium-ion battery cells, sodium-ion battery cells or magnesium-ion battery cells, etc., and the embodiments of the present application do not limit this. Battery cells may be cylindrical, flat, rectangular or other shapes, etc., and the embodiments of the present application do not limit this. Battery cells are generally divided into the following types according to the packaging method: cylindrical battery cells, square battery cells, etc., and the embodiments of the present application do not limit this.

[0049] The battery mentioned in the embodiments of the present application refers to a single physical module including one or more battery cells to provide higher voltage and capacity. For example, the battery mentioned in the present application may include a battery module or a battery pack. The battery generally includes a box for encapsulating one or more battery cells. The box can prevent liquid or other foreign matter from affecting the charging or discharging of the battery cells.

[0050] The battery cell includes an electrode assembly and an electrolyte, and the electrode assembly includes a first electrode member, a second electrode member, and a separator located between the first electrode member and the second electrode member. The electrode assembly is wound by the first electrode member, the separator, and the second electrode member. The polarity of the first electrode member and the second electrode member is different. Exemplarily, the first electrode member is a positive electrode member, and correspondingly, the second electrode member is a negative electrode member. Of course, the first electrode member can also be a negative electrode member, and correspondingly, the second electrode member is a positive electrode member. The battery cell mainly relies on the movement of metal ions between the first electrode member and the second electrode member to work. The material of the separator can be PP (polypropylene) or PE (polyethylene), etc.

[0051] The positive electrode component includes a positive electrode body and a positive conductive structure. The positive electrode body is a laminated structure, including an insulating substrate and a positive conductive layer disposed on the surface of the insulating substrate, part of the positive conductive layer is coated with a positive active material layer, and the positive conductive structure is not coated with the positive active material layer. Taking a lithium-ion battery as an example, the material of the positive conductive layer can be aluminum, the positive active material layer includes a positive active material, and the positive active material can be lithium cobalt oxide, lithium iron phosphate, ternary lithium or lithium manganese oxide, etc. The negative electrode component includes a negative electrode body and a negative conductive structure. The negative electrode body is a laminated structure, including an insulating substrate and a negative conductive layer disposed on the surface of the insulating substrate, part of the negative conductive layer is coated with a negative active material layer, and the negative conductive structure is not coated with a negative active material layer. The material of the negative conductive layer can be copper, the negative active material layer includes a negative active material, and the negative active material can be carbon or silicon, etc. In order to ensure that a large current can pass without melting, the number of positive electrode conductive structures is multiple and they are stacked together, and the number of negative electrode conductive structures is multiple and they are stacked together.

[0052] The battery cell may also include a housing assembly, which has a receiving cavity inside, and the receiving cavity is a closed space provided by the housing assembly for the electrode assembly and the electrolyte. The housing assembly includes a shell and a cover assembly, the shell is a hollow structure with one side open, and the cover assembly covers the opening of the shell and forms a sealed connection to form a receiving cavity for accommodating the electrode assembly and the electrolyte.

[0053] The development of battery technology must take into account many design factors at the same time, such as energy density, cycle life, discharge capacity, charge and discharge rate and other performance parameters. In addition, the safety performance of battery cells must also be considered.

[0054] The inventors found that during the charge and discharge process of the battery cell, the active material layer of the electrode assembly will shrink or expand. Since the insulating matrix is ​​usually made of organic polymer materials, the ductility of the insulating matrix is ​​good; the conductive structure is usually made of metal materials, which has poor ductility compared to the insulating matrix, and the conductive structure is not easy to stretch. Due to the difference in ductility between the insulating matrix and the conductive structure, when the active material layer shrinks or expands, the insulating matrix will give a certain force to the conductive structure. When the forces on both sides of the conductive structure are different, the conductive structure may be torn or the insulating matrix may be wrinkled. The conductive structure is torn, resulting in at least partial rupture between the conductive structure and the conductive layer. It is difficult for the conductive structure to lead out the current generated by the electrode assembly, and the current carrying capacity of the electrode assembly is poor; and the torn conductive structure may pierce the separator and conduct the positive and negative electrodes, causing safety risks. The wrinkles of the insulating matrix will cause the bonding force between the insulating matrix and the conductive layer to decrease, thereby causing the current carrying capacity of the electrode assembly to decrease.

[0055] In view of this, the inventors proposed a technical solution, in which an electrode assembly includes an electrode component, the electrode component includes an electrode body and a conductive structure, the electrode body includes an insulating substrate and a conductive layer arranged on the surface of the insulating substrate, the conductive layer includes a first part and a second part extending from the first part, the first part is coated with an active material layer, the second part is not coated with the active material layer, and the second part is connected to the conductive structure; the second parts are arranged in N numbers, the electrode component is wound along a winding direction, and the N second parts are arranged at intervals along the winding direction; along the winding direction, the spacing between the Mth second part and the M-1th second part is L1, and the spacing between the Mth and M+1th second parts is L2; ​​wherein N and M are both positive integers, 2≤M≤N-1, 0.95<L2 / L1<1.05. For an electrode assembly with such a structure, during the process of charging and discharging the battery cell, the forces acting on both sides of the second part are basically the same. Since the second part is connected to the conductive structure and stacked, the forces acting on both sides of the conductive structure are basically the same, which can effectively prevent the conductive structure from being torn or the insulating substrate from being wrinkled. The structure of the electrode assembly is stable, thereby improving the safety performance and current carrying capacity of the electrode assembly.

[0056] The technical solutions described in the embodiments of the present application are applicable to batteries and electrical devices using batteries.

[0057] The electrical device may be a vehicle, a mobile phone, a portable device, a laptop computer, a ship, a spacecraft, an electric toy, an electric tool, and the like. The vehicle 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, and the like; the spacecraft may include an airplane, a rocket, a space shuttle, and a spacecraft, and the like; the electric toy may include a fixed or mobile electric toy, such as a game console, an electric car toy, an electric ship toy, and an electric airplane toy, and the like; the electric tool may include a metal cutting electric tool, a grinding electric tool, an assembly electric tool, and an electric tool for railways, such as an electric drill, an electric grinder, an electric wrench, an electric screwdriver, an electric hammer, an impact drill, a concrete vibrator, and an electric planer, and the like. The embodiments of the present application do not impose any special restrictions on the above-mentioned electrical devices.

[0058] For the convenience of description, the following embodiments are described by taking the electric device as a vehicle as an example.

[0059] Figure 1 Schematic diagram of the structure of a vehicle provided by some embodiments of the present application. Figure 1 As shown, a battery 2 is disposed inside the vehicle 1, and the battery 2 may be disposed at the bottom, head, or tail of the vehicle 1. The battery 2 may be used to power the vehicle 1, for example, the battery 2 may be used as an operating power source for the vehicle 1.

[0060] The vehicle 1 may further include a controller 3 and a motor 4 , wherein the controller 3 is used to control the battery 2 to supply power to the motor 4 , for example, to meet the power requirements of starting, navigating, and driving the vehicle 1 .

[0061] In some embodiments of the present application, the battery 2 can not only serve as an operating power source for the vehicle 1, but also serve as a driving power source for the vehicle 1, replacing or partially replacing fuel or natural gas to provide driving power for the vehicle 1.

[0062] Figure 2 Schematic diagram of the exploded structure of the battery provided in some embodiments of the present application. Figure 2 As shown, the battery 2 includes a box 5 and a battery cell ( Figure 2 The battery cells are contained in the box body 5.

[0063] The box 5 is used to accommodate the battery cells, and the box 5 can be of various structures. In some embodiments, the box 5 can include a first box portion 51 and a second box portion 52, the first box portion 51 and the second box portion 52 cover each other, and the first box portion 51 and the second box portion 52 jointly define a storage space 53 for accommodating the battery cells. The second box portion 52 can be a hollow structure with one end open, the first box portion 51 is a plate-like structure, and the first box portion 51 covers the open side of the second box portion 52 to form a box 5 with a storage space 53; the first box portion 51 and the second box portion 52 can also be hollow structures with one side open, and the open side of the first box portion 51 covers the open side of the second box portion 52 to form a box 5 with a storage space 53. Of course, the first box portion 51 and the second box portion 52 can be of various shapes, such as a cylinder, a cuboid, etc.

[0064] In order to improve the sealing performance after the first box body 51 and the second box body 52 are connected, a sealing member, such as a sealant, a sealing ring, etc., may also be provided between the first box body 51 and the second box body 52 .

[0065] Assuming that the first box body portion 51 covers the top of the second box body portion 52 , the first box body portion 51 can also be referred to as an upper box cover, and the second box body portion 52 can also be referred to as a lower box body.

[0066] In the battery 2, there can be one or more battery cells. If there are multiple battery cells, the multiple battery cells can be connected in series, in parallel, or in mixed connection. Mixed connection means that the multiple battery cells are both connected in series and in parallel. The multiple battery cells can be directly connected in series, in parallel, or in mixed connection, and then the whole formed by the multiple battery cells is accommodated in the box 5; of course, multiple battery cells can also be connected in series, in parallel, or in mixed connection to form a battery module 6, and the multiple battery modules 6 are then connected in series, in parallel, or in mixed connection to form a whole, and accommodated in the box 5.

[0067] Figure 3 yes Figure 2 The schematic diagram of the battery module is shown in FIG. Figure 3 As shown, in some embodiments, there are multiple battery cells 7, and the multiple battery cells 7 are first connected in series, in parallel, or in mixed connection to form a battery module 6. The multiple battery modules 6 are then connected in series, in parallel, or in mixed connection to form a whole, and are accommodated in a box.

[0068] The multiple battery cells 7 in the battery module 6 can be electrically connected through a busbar component to achieve parallel connection, series connection or mixed connection of the multiple battery cells 7 in the battery module 6 .

[0069] Figure 4 Schematic diagram of the exploded structure of a battery cell provided in some embodiments of the present application. Figure 4 As shown, the battery cell 7 provided in the embodiment of the present application includes an electrode assembly 10 and a housing assembly 20 , and the electrode assembly 10 is accommodated in the housing assembly 20 .

[0070] In some embodiments, the housing component 20 can also be used to contain electrolyte, such as electrolyte. The housing component 20 can be in various structural forms.

[0071] In some embodiments, the housing assembly 20 may include a shell 21 and a cover assembly 22, wherein the shell 21 is a hollow structure with one side open, and the cover assembly 22 covers the opening of the shell 21 and forms a sealed connection to form a housing cavity for accommodating the electrode assembly 10 and the electrolyte.

[0072] The shell 21 can be in various shapes, such as a cylinder, a cuboid, etc. The shape of the shell 21 can be determined according to the specific shape of the electrode assembly 10. For example, if the electrode assembly 10 is a cylindrical structure, a cylindrical shell can be selected; if the electrode assembly 10 is a cuboid structure, a cuboid shell can be selected.

[0073] In some embodiments, the cover assembly 22 includes an end cover 223, and the end cover 223 covers the opening of the housing 21. The end cover 223 can be a variety of structures, for example, the end cover 223 is a plate-like structure, a hollow structure with one end open, etc. Figure 4 In the embodiment, the shell 21 is a rectangular parallelepiped structure, the end cover 223 is a plate-shaped structure, and the end cover 223 covers the opening at the top of the shell 21.

[0074] The end cap 223 may be made of an insulating material (e.g., plastic) or a conductive material (e.g., metal). When the end cap 223 is made of a metal material, the cap assembly 22 may further include an insulating member, which is located on a side of the end cap 223 facing the electrode assembly 10 to insulate and separate the end cap 223 from the electrode assembly 10.

[0075] In some embodiments, the cap assembly 22 may further include an electrode terminal 221, which is mounted on the end cap 223. There are two electrode terminals 221, which are respectively defined as a positive electrode terminal and a negative electrode terminal, and both the positive electrode terminal and the negative electrode terminal are used to be electrically connected to the electrode assembly 10 to output the electric energy generated by the electrode assembly 10.

[0076] In other embodiments, the housing assembly 20 may also be other structures, for example, the housing assembly 20 includes a shell 21 and two cover assemblies 22, the shell 21 is a hollow structure with two opposite openings, and one cover assembly 22 is correspondingly covered at one opening of the shell 21 and forms a sealed connection to form a receiving cavity for accommodating the electrode assembly 10 and the electrolyte. In this structure, one cover assembly 22 may be provided with two electrode terminals 221, while the other cover assembly 22 may not be provided with an electrode terminal 221, or each of the two cover assemblies 22 may be provided with one electrode terminal 221.

[0077] In the battery cell 7, the electrode assembly 10 contained in the housing assembly 20 may be one or more. Figure 4 In the embodiment, there are four electrode assemblies 10.

[0078] The electrode assembly 10 includes a positive electrode component, a negative electrode component and a separator. The electrode assembly 10 may be a wound electrode assembly. The positive electrode component, the negative electrode component and the separator are all strip-shaped structures. In the embodiment of the present application, the positive electrode component, the negative electrode component and the negative electrode sheet may be stacked in sequence and wound more than two times to form the electrode assembly 10.

[0079] From the appearance of the electrode assembly 10, the electrode assembly 10 includes an electrode member 8, and the electrode member 8 includes an electrode body 9 and a conductive structure 12 connected to the electrode body 9. Exemplarily, the conductive structure 12 extends from one end of the electrode body 9 close to the cap assembly 22.

[0080] In some embodiments, there are two conductive structures 12, which are respectively defined as a positive conductive structure and a negative conductive structure. The positive conductive structure and the negative conductive structure can extend from the same end of the electrode body 9, or can extend from opposite ends of the electrode body 9.

[0081] The electrode body 9 is the core part of the electrode assembly 10 to realize the charging and discharging functions, and the conductive structure 12 is used to lead out the current generated by the electrode body 9. The electrode body 9 includes an insulating substrate, a conductive layer, and an active material layer.

[0082] The conductive structure 12 is used to be electrically connected to the electrode terminal 221. The conductive structure 12 can be directly connected to the electrode terminal by welding or the like, or can be indirectly connected to the electrode terminal 221 by other components. For example, the battery cell 7 further includes a current collecting component 13, which is used to electrically connect the electrode terminal 221 and the conductive structure 12. There are two current collecting components 13, and the two current collecting components 13 are respectively defined as a positive current collecting component and a negative current collecting component. The positive current collecting component is used to electrically connect the positive electrode terminal and the positive conductive structure, and the negative current collecting component is used to electrically connect the negative electrode terminal and the negative conductive structure.

[0083] It should be noted that at least one of the positive electrode component and the negative electrode component adopts the structure of the electrode component in any of the following embodiments, that is, only the positive electrode component or the negative electrode component may be the structure of the following electrode component, or both may be the structure of the following electrode component. It should be noted that when both are the structure of the following electrode component, the polarities of the two are opposite. Exemplarily, the positive electrode component adopts the structure of the following electrode component, and the negative electrode component may adopt the structure of a conventional electrode component, or may adopt the structure of the following electrode component.

[0084] Figure 5 It is a schematic cross-sectional view of an electrode assembly provided in some embodiments of the present application. Figure 6 It is a schematic diagram of the structure of the electrode components of the electrode assembly provided in some embodiments of the present application after winding. Figure 7 is a schematic structural diagram of an electrode component of an electrode assembly provided in some embodiments of the present application in an unfolded state; Figure 8 yes Figure 7 The electrode component shown is a schematic cross-sectional view taken along line AA.

[0085] like Figures 5 to 8 As shown, in some embodiments, the electrode assembly 10 includes an electrode member 8 wound along a winding direction X, the electrode member 8 includes an electrode body 9, the electrode body 9 includes an insulating substrate 91 and a conductive layer 92 arranged on the insulating substrate 91, the conductive layer 92 includes a first portion 921 coated with an active material layer 93 and a second portion 922 not coated with the active material layer 93, the second portions 922 are N in number, and the N second portions 922 are arranged at intervals along the winding direction X; along the winding direction X, the spacing between the Mth second portion 922 and the M-1th second portion 922 is L1, and the spacing between the Mth and M+1th second portions 922 is L2; ​​wherein N and M are both positive integers, 2≤M≤N-1, 0.95<L2 / L1<1.05.

[0086] Figures 5 to 8The X direction shown in the figure represents the winding direction of the electrode component 8, the winding direction X represents the direction of winding from the inside to the outside, the Y direction represents the width direction of the conductive structure 12, K represents the winding axis of the electrode component 8, and the Z direction represents the direction perpendicular to the winding axis of the electrode component 8.

[0087] The electrode assembly 10 is a wound electrode assembly, which includes an electrode component 8 and an electrode component with opposite polarity to the electrode component 8 and an isolation member 11 . The two electrode components are isolated by the isolation member 11 and are wound more than two times to form the electrode assembly 10 .

[0088] The electrode component 8 includes an electrode body 9 and a conductive structure 12 . The electrode body 9 is the core part of the electrode assembly 10 for realizing the charging and discharging functions, and the conductive structure 12 is used to lead out the current generated by the electrode body 9 .

[0089] The material of the insulating matrix 91 includes one or more of a polymer material and a polymer-based composite material. The polymer-based composite material includes a polymer material and an additive, and the additive is at least one of an inorganic non-metallic material and a metal material. The polymer material includes, but is not limited to, at least one of polyamide, polyimide, polyethylene terephthalate, polybutylene terephthalate, and polyethylene naphthalate. The inorganic non-metallic material includes one or more of a carbon-based material, aluminum oxide, silicon dioxide, silicon nitride, silicon carbide, boron nitride, silicate, and titanium oxide. The metal material includes one or more of magnesium, calcium, strontium, lead, zinc, tin, antimony, bismuth, silver, and ruthenium.

[0090] The conductive layer 92 may be disposed on only one side of the insulating substrate 91, or may be disposed on both sides of the insulating substrate 91. The conductive layer 92 may be formed on the insulating substrate 91 by at least one of mechanical rolling, bonding, vapor deposition, electroless plating, and electroplating, wherein vapor deposition or electroplating may be selected, that is, the conductive layer 92 may be a vapor deposition layer or an electroplating layer, so that the conductive layer 92 and the insulating substrate 91 can be closely bonded, and the insulating substrate 91 can effectively play a supporting and protective role on the conductive layer 92.

[0091] The conductive structure 12 and the second part 922 can be connected by welding or bonding. For example, the conductive structure 12 can be connected to the second part 922 by ultrasonic welding or conductive adhesive bonding. Conductive structures 12 can be set on both sides of the second part 922, that is, one second part 922 corresponds to two conductive structures 12, and accordingly, N second parts 922 correspond to 2N conductive structures 12.

[0092] In the embodiment of the present application, along the winding direction X, the spacing between the Mth second part 922 and the M-1th second part 922 is L1, and the spacing between the Mth and M+1th second parts 922 is L2, and 0.95<L2 / L1<1.05. During the charging and discharging process of the battery cell, when the active material layer 93 shrinks or expands, due to the small difference between L1 and L2, the insulating substrate 91 exerts substantially the same force on both sides of the second part 922, and the force on the second part 922 is relatively balanced, thereby ensuring the connection stability between the first part 921 and the second part 922, and improving the structural stability of the electrode assembly 10, thereby improving the current capacity and safety performance of the electrode assembly 10.

[0093] like Figure 5 As shown, in the embodiment of the present application, the electrode component 8 is wound multiple times to form an electrode assembly 10. The wound electrode assembly 10 includes a straight area and a turning area. The straight area is parallel to the width direction Y of the conductive structure 12, and the turning areas are located on both sides of the straight area.

[0094] In some embodiments, the first portion 921 includes a connecting portion 9211 and a transition portion 9212, the transition portion 9212 is located on both sides of the connecting portion 9211, the connecting portion 9211 is extended along the width direction Y of the conductive structure 12, and at least part of the transition portion 9212 is arc-shaped; the second portion 922 is arranged on the connecting portion 9211 and extends along the width direction Y of the conductive structure 12.

[0095] In the embodiment of the present application, the second portion 922 is disposed on the connecting portion 9211, that is, the second portion 922 is disposed in the straight area, and the conductive structure 12 connected to the second portion 922 is also located in the straight area, and the width direction Y of the conductive structure 12 is the same as the extension direction of the connecting portion 9211, both of which are the Y direction.

[0096] The second part 922 is arranged at the connection part 9211, which can ensure that the conductive structure 12 connected to the second part 922 can be effectively welded when stacked and connected, thereby improving the bonding force between adjacent conductive structures 12, and increasing the contact area between adjacent conductive structures 12, which can improve the current carrying capacity. The second part 922 is not arranged at the transition part 9212, which can avoid stress concentration problems, prevent the second part 922 from breaking due to stress concentration problems, and improve the reliability of the second part 922; accordingly, the conductive structure 12 connected to the second part 922 is not arranged at the transition part 9212, which can effectively prevent the conductive structure 12 from breaking due to stress concentration problems, thereby improving the reliability of the conductive structure 12.

[0097] Please continue reading Figure 5In some embodiments, the connecting portion 9211 includes a first connecting portion 9211a and a second connecting portion 9211b that are arranged opposite to each other; the first connecting portion 9211a and the second connecting portion 9211b are respectively arranged on both sides of the reel axis K of the electrode member 8, and the second portion 922 is arranged on the first connecting portion 9211a and / or the second connecting portion 9211b.

[0098] Under the condition of ensuring the current carrying capacity of the conductive structure 12, when the second part 922 is arranged on the first connecting part 9211a or the second connecting part 9211b, the number of conductive structures 12 connected to the second part 922 is relatively small, which can reduce the thickness of the multiple conductive structures 12 after stacking, thereby reducing the space occupied by the conductive structure 12 and improving the energy density of the battery cell.

[0099] When the second part 922 is arranged on the first connecting part 9211a and the second connecting part 9211b, the conductive structure 12 connected to the second part 922 is also arranged on the first connecting part 9211a and the second connecting part 9211b. The number of the conductive structures 12 is relatively increased, which can effectively improve the overall conductivity of the multiple conductive structures 12.

[0100] In some embodiments, the positive electrode component adopts the electrode component 8 of any of the above embodiments, which can significantly improve the current capacity and conductivity of the positive electrode conductive structure. Of course, the negative electrode component can adopt the electrode component 8 of any of the above embodiments, which can also significantly improve the current capacity and conductivity of the negative electrode conductive structure.

[0101] Please continue reading Figure 5 In some embodiments, one of the positive electrode member and the negative electrode member adopts the electrode member 8, and the other adopts the conventional electrode member. The projection of the second part 922 of the electrode member 8 in the thickness direction Z of the conductive structure 12 and the projection of the first part of the conventional electrode member in the thickness direction Z of the conductive structure 12 at least partially overlap. The second part 922 of the electrode member 8 will not significantly increase the height of the electrode assembly 10, thereby increasing the space occupancy rate in the height direction, which is beneficial to increasing the energy density of the battery cell. Exemplarily, the projection of the first conductive part 9221 of the electrode member 8 in the Z direction and the projection of the first part of the conventional electrode member in the Z direction at least partially overlap, or even overlap. The provision of the first conductive part 9221 will not increase the height of the electrode assembly 10, which is beneficial to increasing the space occupancy rate.

[0102] like Figure 6 As shown, in some embodiments, the electrode member 8 is provided in multiple circles, and the second part 922 is provided in at least one circle. In the embodiment of the present application, the second part 922 is provided in each circle, and the second part 922 is connected to the conductive structure 12, which can effectively utilize the accommodation space of the battery cell.

[0103] Please continue reading Figure 6 In some embodiments, the electrode component 8 is provided with two second parts 922 on each turn thereof, and the two second parts 922 are respectively provided on both sides of the winding axis K of the electrode component 8. Two second parts 922 are provided on each turn, and the two second parts 922 are respectively connected to the conductive structure 12, which can increase the number of the conductive structures 12 and improve the overall conductive performance of the conductive structure 12.

[0104] In some embodiments, the electrode member 8 includes a conductive structure 12 connected to the second portion 922, any one of the N second portions 922 is connected to two conductive structures 12, the conductive structures 12 are arranged as 2N, and the projections of the 2N conductive structures 12 in a direction perpendicular to the winding axis K of the electrode member 8 at least partially overlap. Any two conductive structures 12 are stacked and connected to each other, which can improve the current carrying capacity of the conductive structure 12.

[0105] like Figure 7 and Figure 8 As shown, in some embodiments, the second part 922 includes a first conductive part 9221 and a second conductive part 9222, and the first conductive part 9221 is disposed between the second conductive part 9222 and the first part 921. Along the winding direction X, the size of the first conductive part 9221 is larger than the size of the second conductive part 9222. In the embodiment of the present application, the size of the first conductive part 9221 in the winding direction X is larger than the size of the second conductive part 9222 in the winding direction X, so as to increase the connection area between the first part 921 and the second part 922, thereby increasing the connection strength between the two, improving the structural stability of the battery cell, and further improving the reliability of the battery cell. In addition, due to the small thickness of the conductive layer 92, the flow area of ​​the first part 921 and the second part 922 is small, which may cause serious heat generation at this location, seriously reducing the performance of the battery cell, and increasing the size of the first conductive part 9221 in the winding direction X can increase the flow area of ​​the conductive layer 92 at the connection between the first part 921 and the second part 922, thereby alleviating the heat generation phenomenon at this location during the use of the battery cell, and improving the performance of the battery cell.

[0106] In the embodiment of the present application, the conductive structure 12 may be at least partially disposed on the second conductive portion 9222 , and the conductive structure 12 and the second conductive portion 9222 may be connected by welding or bonding.

[0107] The N second parts 922 include N first conductive parts 9221, that is, each second part 922 includes a first conductive part 9221, and the spacing between the Mth and M-1th first conductive parts 9221 of the N first conductive parts 9221 is L1, and the spacing between the Mth and M+1th first conductive parts 9221 is L2, wherein 0.95<L2 / L1<1.05. The first conductive part 9221 is used to connect the first part 921 and the second conductive part 9222, that is, the first conductive part 9221 is directly connected to the insulating substrate 91. During the process of charging and discharging of the battery cell, when the active material layer 93 shrinks or expands, the forces acting on both sides of the first conductive part 9221 by the insulating substrate 91 are basically the same, and the forces on both sides of the first conductive part 9221 are balanced, which can improve the connection stability between the first conductive part 9221 and the first part 921, and then improve the structural stability of the electrode assembly 10, thereby further improving the current capacity and safety performance of the electrode assembly 10.

[0108] In some embodiments, the width of the first conductive portion 9221 increases gradually along the winding direction X. The variation pattern of the first conductive portion 9221 is conducive to production and processing.

[0109] Fig. 9 It is a schematic flow chart of a method for manufacturing an electrode assembly provided in some embodiments of the present application.

[0110] like Fig. 9 As shown, the embodiment of the present application also provides a method for manufacturing an electrode assembly, comprising:

[0111] S100, providing an electrode body, the electrode body comprising an insulating substrate and a conductive layer disposed on the insulating substrate, the conductive layer comprising a first portion and a second portion;

[0112] S200, winding the electrode body along a winding direction;

[0113] Among them, there are N second parts, and along the winding direction, the N second parts are arranged at intervals, and the spacing between the Mth and M-1th second parts is L1, and the spacing between the Mth and M+1th second parts is L2, N and M are both positive integers, 2≤M≤N-1, 0.95<L2 / L1<1.05.

[0114] It should be noted that the relevant structure of the electrode assembly manufactured by the above-mentioned electrode assembly manufacturing method can refer to the electrode assembly provided in the above-mentioned embodiments.

[0115] When assembling an electrode assembly based on the manufacturing method of the electrode assembly, it is not necessary to perform the steps in sequence. That is, the steps may be performed in the order mentioned in the embodiment, or in a different order from the order mentioned in the embodiment, or several steps may be performed simultaneously. For example, steps S100 and S200 may be performed in any order and may be performed simultaneously.

[0116] Fig.10 It is a schematic block diagram of a manufacturing system of an electrode assembly provided in some embodiments of the present application.

[0117] like Fig.10 As shown, an embodiment of the present application also provides a manufacturing system for an electrode assembly, and the manufacturing system 1000 includes: a first providing device 100, used to provide an electrode body, the electrode body includes an insulating substrate and a conductive layer arranged on the surface of the insulating substrate, and the conductive layer includes a first part and a second part; a winding device 200, used to wind the electrode body along a winding direction; wherein, there are N second parts, and along the winding direction X, the N second parts are arranged at intervals, and the spacing between the Mth and the M-1th second parts is L1, and the spacing between the Mth and the M+1th second parts is L2, N and M are both positive integers, 2≤M≤N-1, 0.95<L2 / L1<1.05.

[0118] The relevant structure of the electrode assembly manufactured by the above-mentioned manufacturing system can refer to the electrode assembly provided in the above-mentioned embodiments.

[0119] 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 is no structural conflict. 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. An electrode assembly, characterized in that: The invention comprises an electrode member wound along a winding direction; the electrode member comprises an electrode body, the electrode body comprises an insulating substrate and a conductive layer disposed on the insulating substrate; the conductive layer comprises a first portion coated with an active material layer and a second portion not coated with the active material layer; There are N second parts, and the N second parts are arranged at intervals along the winding direction; The second part includes a first conductive part and a second conductive part, the first conductive part is arranged between the second conductive part and the first part, and along the winding direction, the size of the first conductive part is larger than the size of the second conductive part, The N second parts include N first conductive parts, and along the winding direction, the spacing between the Mth and M-1th first conductive parts is L1, and the spacing between the Mth and M+1th first conductive parts is L2, wherein N and M are both positive integers, 2≤M≤N-1, 0.95<L2 / L1<1.05, The electrode member includes a conductive structure connected to the second portion, the conductive structure being configured to be electrically connected to an electrode terminal.

2. The electrode assembly according to claim 1, characterized in that: Along the winding direction, the size of the first conductive portion increases gradually.

3. The electrode assembly according to claim 1, characterized in that: The electrode member is provided in a plurality of circles, and the second portion is provided in at least one circle.

4. The electrode assembly according to claim 3, characterized in that: The electrode component is provided with two second parts on each turn thereof, and the two second parts are respectively provided on both sides of the winding axis of the electrode component.

5. The electrode assembly according to claim 1, characterized in that: Any of the N second parts is connected to two of the conductive structures, and the conductive structures are arranged to be 2N in number, and the projections of the 2N conductive structures in a direction perpendicular to the winding axis of the electrode component at least partially overlap.

6. The electrode assembly according to claim 5, characterized in that: The first portion includes a connecting portion and a transition portion, wherein the transition portion is located at two sides of the connecting portion, the connecting portion is formed by extending along the width direction of the conductive structure, and at least a portion of the transition portion is arc-shaped; The second portion is disposed at the connecting portion and extends along a width direction of the conductive structure.

7. The electrode assembly according to claim 6, characterized in that: The connecting portion includes a first connecting portion and a second connecting portion which are arranged opposite to each other, wherein the first connecting portion and the second connecting portion are respectively arranged on both sides of the winding axis of the electrode member; The second portion is arranged at the first connecting portion and / or the second connecting portion.

8. A battery cell, characterized in that: It comprises the electrode assembly according to any one of claims 1 to 7 and a casing for accommodating the electrode assembly.

9. A battery, characterized in that: The invention comprises a plurality of battery cells as claimed in claim 8.

10. An electrical device, characterized in that: Comprising a battery as claimed in claim 9, the battery is used to provide electrical energy.

11. A method for manufacturing an electrode assembly, characterized in that: include: Providing an electrode body, the electrode body comprising an insulating substrate and a conductive layer disposed on the insulating substrate, the conductive layer comprising a first portion and a second portion; Winding the electrode body along a winding direction; in, There are N second parts, and the N second parts are arranged at intervals along the winding direction. The second part includes a first conductive part and a second conductive part. The first conductive part is arranged between the second conductive part and the first part. Along the winding direction, the size of the first conductive part is larger than the size of the second conductive part. The N second parts include N first conductive parts, and along the winding direction, the spacing between the Mth and M-1th first conductive parts is L1, and the spacing between the Mth and M+1th first conductive parts is L2, wherein N and M are both positive integers, 2≤M≤N-1, 0.95<L2 / L1<1.05, The electrode assembly further includes a conductive structure connected to the second portion, wherein the conductive structure is configured to be electrically connected to an electrode terminal.

12. A system for manufacturing an electrode assembly, characterized in that: include: A first providing device is used to provide an electrode body, wherein the electrode body comprises an insulating substrate and a conductive layer disposed on a surface of the insulating substrate, wherein the conductive layer comprises a first portion and a second portion; A winding device, used for winding the electrode body along a winding direction; in, There are N second parts, and the N second parts are arranged at intervals along the winding direction. The second part includes a first conductive part and a second conductive part. The first conductive part is arranged between the second conductive part and the first part. Along the winding direction, the size of the first conductive part is larger than the size of the second conductive part. The N second parts include N first conductive parts, and along the winding direction, the spacing between the Mth and M-1th first conductive parts is L1, and the spacing between the Mth and M+1th first conductive parts is L2, wherein N and M are both positive integers, 2≤M≤N-1, 0.95<L2 / L1<1.05, The electrode assembly further includes a conductive structure connected to the second portion, wherein the conductive structure is configured to be electrically connected to an electrode terminal.

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