Electrode assembly and battery

Abstract

The electrode assembly comprises a first electrode, a first spacer and a second electrode, the first spacer is arranged between the first electrode and the second electrode, and the first electrode, the first spacer and the second electrode are sequentially stacked and configured to be capable of being rolled in the second direction. Wherein the size of the first spacer in the third direction is gradually reduced along the second direction, so that when the first electrode and the second electrode expand or contract, the deformation quantity of the part, with the small size, of the first spacer in the third direction is small; therefore, the degree of deformation and collapse of the first electrode and the second electrode caused by rapid increase of stress of the parts of the first electrode and the second electrode in the cyclic expansion process of the first electrode and the second electrode is reduced, and meanwhile, the number of cycles of deformation and collapse of the first electrode and the second electrode is reduced; furthermore, the risk of short circuit in the battery is reduced, and the cycle life of the first electrode and the second electrode is prolonged.

Description

Technical Field

[0001] The utility model relates to the technical field of batteries, in particular to an electrode assembly and a battery. Background Art

[0002] The existing battery structure is that the positive electrode, diaphragm, negative electrode, and diaphragm are wound or stacked in sequence. The positive electrode, negative electrode, and diaphragm are required to have a specific alignment structure during the assembly process, and the processing consistency of the electrodes and diaphragms is required to be high. As the battery energy density approaches its limit, the existing technology increases the battery capacity, reduces the number of batteries in the battery pack, and thus reduces the amount of battery shells used. The increase in battery capacity causes the diameter of the single cell to increase, and the corresponding internal cycle expansion stress worsens. Taking cylindrical batteries as an example, since there is a central hole in the core of the cylindrical battery, which is a stress concentration and release area, the increase in battery capacity can easily cause deformation of the electrode interface near the central hole, causing the inner walls of the central hole to contact each other and then poor lithium deposition, which quickly deteriorates the cycle performance. The deterioration of lithium deposition brings the safety risk of internal short circuit. Therefore, how to reduce the internal cycle expansion stress of the battery while increasing the battery capacity to improve battery safety is a technical problem that needs to be solved in battery technology. Utility Model Content

[0003] The main purpose of the utility model is to provide an electrode assembly and a battery, aiming to solve the technical problem.

[0004] To achieve the above objectives, the present invention provides an electrode assembly, comprising:

[0005] A first electrode, comprising a first current collector and a first active coating, wherein the first current collector comprises a first region and a second region adjacently distributed along a first direction, the first active coating being applied to the first region and configured to be electronically conductive with the first current collector, and the second region being adapted for electrical connection to a tab;

[0006] a first spacer disposed on a side of the first active coating layer facing away from the first current collector, the first spacer being configured to have electrical insulation properties, wherein a dimension of the first spacer in a third direction gradually decreases along the second direction, the second direction being perpendicular to the first direction, and the third direction being perpendicular to the first direction and the second direction;

[0007] a second electrode comprising a second current collector and a second active coating coated on at least one side of the second current collector along the third direction, wherein the second active coating is configured to be electronically conductive with the second current collector;

[0008] The first spacer is located between the first electrode and the second electrode, and the first electrode, the first spacer, and the second electrode are sequentially stacked and configured to be able to be rolled up along the second direction at the same time.

[0009] In some embodiments, the dimension T of the first spacer in the third direction and the curvature radius R of each coil formed by rolling the first spacer along the second direction satisfy: T=k / R, where k is the proportional coefficient and the value range of R is 0.02 mm. 2 ~0.1mm 2 .

[0010] In some embodiments, the first separator is configured to be coated on a side of the first active coating layer facing away from the first current collector.

[0011] In some embodiments, a dimension D1 of the first spacer in the first direction and a dimension L1 of the first active coating in the first direction satisfy 0mm≤D1-L1≤5mm, and a side of the first active coating facing away from the second region is aligned with a side of the first region facing away from the second region.

[0012] In some embodiments, a dimension D2 of the first spacer in the second direction and a dimension L2 of the first active coating in the second direction satisfy 0 mm ≤ L2 − D2 ≤ 5 mm.

[0013] In some embodiments, the first electrode includes a first end and a second end arranged opposite to each other along the second direction, the first active coating and the first spacer are flush at the first end, the first end is the starting point of rolling up the first electrode, the first spacer and the second electrode, and the second end is the end point of rolling up.

[0014] In some embodiments, the first active coating is disposed on two opposite sides of the first current collector along the third direction.

[0015] In some embodiments, a dimension M1 of the second active coating in the first direction and a dimension L1 of the first active coating in the first direction satisfy: 2 mm ≤ L1 − M1 ≤ 5 mm.

[0016] In some embodiments, the electrode assembly further includes a second spacer, which is located on the side of the first electrode or the second electrode facing away from the first spacer, and the second spacer is configured to be the same as the first spacer, and the second spacer is configured to be stacked with the first electrode, the first spacer, and the second electrode and rolled up together along the second direction.

[0017] A second aspect of the present invention further provides a battery, comprising:

[0018] The electrode assembly according to any one of the above embodiments; and

[0019] The housing has a housing space configured to accommodate the electrode assembly.

[0020] Compared with the prior art, the beneficial effects of the present invention are:

[0021] In the technical solution of the present invention, an electrode assembly includes a first electrode, a first separator, and a second electrode, wherein the first separator is disposed between the first electrode and the second electrode, and the first electrode, the first separator, and the second electrode are sequentially stacked and configured to be able to be rolled along a second direction. In particular, along the second direction, the dimension of the first separator in a third direction gradually decreases. Therefore, when the first and second electrodes expand or contract, compared to designing the thickness of the first separator to be equal at all locations, the first separator of the present application has a smaller portion with a smaller dimension in the third direction, thereby reducing the squeezing force on the first and second electrodes located at the center of the roll. This reduces the degree of deformation and collapse of the first and second electrodes caused by the rapid increase in stress at the inner portion during the cyclic expansion of the first and second electrodes, and reduces the number of cycles of deformation and collapse of the first and second electrodes, thereby reducing the risk of internal short circuits in the battery and improving the cycle life of the first and second electrodes. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the structures shown in these drawings without paying any creative work.

[0023] Figure 1 This is a schematic diagram of a battery in one embodiment of the present invention;

[0024] Figure 2 This is a schematic structural diagram of a first electrode or a second electrode at a first viewing angle in one embodiment of the present invention;

[0025] Figure 3 This is a schematic structural diagram of the first electrode in a second viewing angle in one embodiment of the present invention;

[0026] Figure 4 This is a schematic structural diagram of the first electrode in a third viewing angle in one embodiment of the present invention;

[0027] Figure 5 Schematic diagram of the structure of an electrode assembly in one embodiment of the present invention; wherein the electrode assembly includes a first spacer, a first electrode, a second spacer and a second electrode.

[0028] Description of Figure Numbers:

[0029] Battery 10;

[0030] Electrode assembly 100;

[0031] First electrode 110; first current collector 111; first region 1111; second region 1112; first active coating 112; first end 113; second end 114;

[0032] a first spacer 120;

[0033] Second electrode 130; second current collector 131; second active coating 132;

[0034] a second spacer 140;

[0035] Housing 200; Accommodation space 210;

[0036] First direction X; second direction Y; third direction Z.

[0037] The realization of the purpose, functional features and advantages of the present invention will be further explained in conjunction with embodiments and with reference to the accompanying drawings. DETAILED DESCRIPTION

[0038] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0039] See also Figures 2 to 5The present invention provides an electrode assembly 100, comprising a first electrode 110, a first separator 120, and a second electrode 130. The first electrode 110 includes a first current collector 111 and a first active coating 112. The first current collector 111 has a first region 1111 and a second region 1112 arranged along a first direction X. The first active coating 112 covers the first region 1111 and maintains electronic conductivity with the first current collector 111. The second region 1112 is adapted to be electrically connected to a tab. The first separator 120 is disposed on a side of the first active coating 112 away from the first current collector 111 and has electrical insulation properties. The dimension of the first separator 120 gradually decreases along the second direction Y in a third direction Z, thereby reducing expansion stress within the rolled-up electrode assembly 100. The second electrode 130 includes a second current collector 131 and a second active coating 132. The second active coating 132 is coated on one or more sides of the second current collector 131 along the third direction Z and maintains electronic conductivity with the second current collector 131. The first spacer 120 is positioned between the first electrode 110 and the second electrode 130. The first electrode 110, the first spacer 120, and the second electrode 130 are stacked in this order and can be simultaneously rolled up along the second direction Y. The design of the first spacer 120 effectively reduces the inner ring expansion stress of the first electrode 110 and the second electrode 130 during the cycle after rolling up, thereby improving the cycle life and safety of the battery 10. It should be noted that the second direction Y is perpendicular to the first direction X, and the third direction Z is perpendicular to the first direction X and the second direction Y.

[0040] It will be appreciated that in some embodiments, the first current collector 111 can be made of aluminum foil or copper foil, and the first active coating layer 112 can be made of a common positive or negative electrode material for lithium-ion batteries 10. For example, the negative electrode material can be graphite, etc. The second current collector 131 can be made of copper foil or aluminum foil, and the second active coating layer 132 can be made of a different material from the first active coating layer 112 to accommodate the different requirements of the battery 10. For example, the positive electrode material can be a lithium-ion battery 10 material, including but not limited to lithium cobalt oxide, lithium manganese oxide, etc. The first separator 120 can be made of other electrically insulating materials such as polypropylene (PP), polyester film (PET), polyethylene (PE), polyimide film (PI), etc., to ensure that the first separator 120 has good electrical insulation and mechanical strength. Electronic conductivity between the first active coating layer 112 and the first current collector 111 can be achieved using a conductive agent, such as carbon black. The gradually decreasing thickness of the first separator 120 helps reduce stress within the battery 10, thereby extending the battery 10 life. In addition, the first active coating 112 and the first current collector 111 can be tightly bonded by processes such as hot pressing to ensure good contact and stability. In some embodiments, the bonding strength between the first active coating 112 and the first current collector 111 can be enhanced by adding auxiliary materials such as adhesives.

[0041] In some embodiments, the dimension T of the first spacer 120 in the third direction Z and the curvature radius R of each coil formed by the first spacer 120 being rolled up along the second direction Y satisfy the relationship: T=k / R, where k is the proportional coefficient, and the value range of R is 0.02mm²~0.1mm². For example, the value of R can be 0.02mm², 0.05mm², 0.07mm², 0.09mm², 0.1mm², etc. It should be noted that the value range of the curvature radius R can also be appropriately adjusted according to the specific size and winding requirements of the electrode assembly 100. It is understandable that in some embodiments, the proportional coefficient k can be set according to the characteristics of the material of the first spacer 120, such as the size and capacity of the battery 10. In other embodiments, the proportional coefficient k can be adjusted according to factors such as the elastic modulus and thickness of the material of the first spacer 120. By adjusting the relationship between the dimension T of the first spacer 120 in the third direction Z and the radius of curvature R, the internal structure of the battery 10 can be optimized, reducing internal stress caused by expansion during cycling, thereby improving the safety and service life of the battery 10. Specifically, as R increases, the dimension T of the first spacer 120 in the third direction Z decreases. Conversely, as R decreases, the dimension T of the first spacer 120 in the third direction Z increases. This design helps ensure the stability and consistency of the battery 10 at different curvature radii, thereby effectively reducing the internal expansion stress of the first and second electrodes 110, 130 during cycling after winding, thereby improving the overall performance of the battery 10.

[0042] In other embodiments, the rolled-up layer can be divided into N segments, and the radius R of each segment can be the curvature radius at the first circle position of the segment, or the radius R of each segment can be the curvature radius of the median circle layer of the segment (it should be noted that after the first electrode 110, the first spacer 120 and the second electrode 130 are stacked and rolled up in sequence, at any position, the first current collector 111, the first active coating 112, the first spacer 120, the second current collector 131 and the second active coating 132 each have a circle layer, so the first spacer 120 can be selected as the median circle layer).

[0043] In some embodiments, the first spacer 120 is configured to be coated on the side of the first active coating 112 facing away from the first current collector 111. It is understood that in some embodiments, the insulating material used for the first spacer 120 can be covered on the surface of the first active coating 112 by a specific coating process, such as spraying, dipping or roller coating. Thus, the first spacer 120 can not only play an insulating role, but also increase the surface flatness of the first active coating 112 and improve the contact quality between the electrodes. The selection of the insulating material used for the first spacer 120 can take into account the chemical stability of the material to ensure that good insulation performance is maintained even in the high voltage environment generated during the charging and discharging process of the battery 10. In some embodiments, the insulating material of the first spacer 120 can also be added with ingredients such as flame retardants to improve fire resistance.

[0044] See also Figure 3 In some embodiments, the dimension D1 of the first separator 120 in the first direction X and the dimension L1 of the first active coating layer 112 in the first direction X satisfy 0 mm ≤ D1 - L1 ≤ 5 mm. For example, the difference in the dimensions of the first separator 120 and the first active coating layer 112 in the first direction X can be 0 mm, 0.5 mm, 1.5 mm, 2 mm, 3.5 mm, 4 mm, 5 mm, etc. Preferably, 0.2 mm ≤ D1 - L1 ≤ 2 mm. Furthermore, the side of the first active coating layer 112 facing away from the second region 1112 is aligned with the side of the first region 1111 facing away from the second region 1112. This ensures a dimensional match between the first separator 120 and the first active coating layer 112, allowing the first separator 120 to precisely cover the first active coating layer 112, ensuring stability and consistency of the electrode assembly 100 during winding, and preventing contact and short circuiting between the first electrode 110 and the second electrode 130. Furthermore, since the dimensional difference between the first active coating 112 and the first separator 120 in the first direction X does not exceed 5 mm, the first separator 120 ensures good fit with the first active coating 112, avoiding unnecessary gaps caused by excessive dimensional differences. This helps the first separator 120 effectively cover and shield the first active coating 112 during the winding process, preventing the first active coating 112 from contacting and short-circuiting with the second active coating 132. This reduces the risk of internal short circuits caused by interlayer misalignment while also ensuring the lightweight design of the battery 10. The alignment design between the first active coating 112 and the first region 1111 ensures effective contact between the first active coating 112 and the first current collector 111, improving energy density while preventing the first active coating 112 from protruding from the first current collector 111 and contacting other structural components, which can cause short circuits. This is beneficial for improving the performance of the electrode assembly 100.

[0045] See also Figure 4In some embodiments, the dimension D2 of the first spacer 120 in the second direction Y and the dimension L2 of the first active coating 112 in the second direction Y satisfy 0mm≤L2-D2≤5mm. For example, the size difference between the first spacer 120 and the first active coating 112 in the second direction Y can be 0mm, 1mm, 2.5mm, 3mm, 4mm, 5mm, etc. Ensure that the first spacer 120 and the first active coating 112 have a good fit in the second direction Y to avoid unnecessary gaps or overlaps. This ensures the stability and consistency of the first spacer 120 and the first active coating 112 during the winding process, thereby improving the overall performance and cycle stability of the battery 10. It should be noted that the size difference between the first active coating 112 and the first spacer 120 can be achieved through precise coating and cutting processes.

[0046] To further enhance the fit between the first separator 120 and the first active coating 112, the surface roughness of the first separator 120 can be adjusted to increase friction, thereby improving contact stability between the two. For example, by creating a microscopic concave-convex structure on the surface of the first separator 120, the friction between the first separator 120 and the first active coating 112 can be effectively increased, maintaining good contact even when the electrode assembly 100 is squeezed during winding. Furthermore, an additional adhesive layer can be introduced to further enhance the fit between the first separator 120 and the first active coating 112, thereby improving the performance of the entire electrode assembly 100.

[0047] See also Figure 4In some embodiments, the first electrode 110 includes a first end 113 and a second end 114 disposed opposite each other along the second direction Y. The first active coating layer 112 and the first separator 120 are aligned at the first end 113. The first end 113 is the starting point for winding the first electrode 110, the first separator 120, and the second electrode 130, and the second end 114 is the end point for winding. This design ensures that the first active coating layer 112 and the first separator 120 are precisely aligned during the winding process, thereby ensuring the continuity and consistency of the winding process. It also ensures that the first separator 120 is always located between the first electrode 110 and the second electrode 130, preventing contact and short circuiting between the two. When the first active coating layer 112 and the first separator 120 are aligned at the first end 113, they can effectively prevent misalignment during the winding process, avoiding the risk of internal short circuits, thereby improving the reliability and safety of the electrode assembly 100. Because the first active coating layer 112 and the first spacer 120 are flush at the first end 113, there is a 0-5 mm difference between the first active coating layer 112 and the first spacer 120 at the second end 114. When the first electrode 110 and the first spacer 120 are rolled up, the first active coating layer 112 and the second end 114 of the first spacer 120 are nearly flush at the end of the roll-up. It should be noted that during the actual roll-up process, the first electrode 110, located on the inner side relative to the first spacer 120, will gradually lag behind the first spacer 120 due to relative movement between the first electrode 110 and the first spacer 120. However, the 0-5 mm difference between the first active coating layer 112 and the first spacer 120 in the second direction Y before roll-up can compensate for the lag between the first electrode 110 and the first spacer 120 during the roll-up process. Therefore, after the winding is completed, the first electrode 110 and the second end 114 of the first separator 120 can be in a nearly flush state at the end of the winding.

[0048] In order to further improve the stability during the winding process and the overall performance of the electrode assembly 100, a special positioning structure can be used to ensure that the first active coating 112 and the first separator 120 are positioned more accurately at the first end 113. For example, positioning protrusions are provided at the edge positions of the first active coating 112 and the first separator 120. These protrusions can play an alignment role at the beginning of winding, ensuring that the first active coating 112 and the edge of the first separator 120 completely overlap. In this way, not only can the deviation that may occur during the winding process be reduced, but the yield and service life of the electrode assembly 100 can also be improved. In addition, the material selection of the first active coating 112 and the first separator 120 can be selected from materials with higher elasticity, so that the first electrode 110 can better adapt to deformation during the winding process, thereby further improving the overall performance of the electrode assembly 100.

[0049] See also Figure 3 and Figure 4 In some embodiments, the first active coating 112 is provided on both sides of the first current collector 111 that are opposite to each other along the third direction Z. This double-sided coating design enables the first electrode 110 to participate in the electrochemical reaction more evenly in the thickness direction, which helps to improve the energy density and cycle stability of the battery 10. In other words, the first active coating 112 is coated on both sides of the first current collector 111, ensuring that both sides of the first electrode 110 can effectively participate in the charge and discharge process, thereby improving the overall performance of the battery 10. Since the first active coating 112 is distributed on both sides of the first current collector 111, the effective reaction area is increased, thereby improving the specific capacity of the electrode.

[0050] To further enhance the overall performance of the electrode assembly 100, a conductive additive is introduced into the material of the first active coating layer 112 to improve the electron transport path between the active material particles, thereby enhancing the rate capability of the battery 10. Furthermore, the stability of the entire electrode assembly 100 during use can be ensured by controlling the uniformity of the first active coating layer 112 distribution on both sides of the first current collector 111. For example, by precisely controlling the coating process to ensure that the thickness difference of the first active coating layer 112 on both sides does not exceed ±10%, this ensures good electrochemical performance while avoiding local overheating within the battery 10 caused by uneven thickness.

[0051] It is understood that in some embodiments, the first active coating 112 can be a positive electrode active coating or a negative electrode active coating, depending on the material of the first current collector 111. The first current collector 111 can be made of metal materials such as aluminum foil or copper foil to ensure good electrical conductivity. The material of the first active coating 112 can be selected according to the type of battery 10. For example, the positive electrode active coating of the lithium-ion battery 10 can be lithium cobalt oxide, nickel manganese cobalt oxide, etc., while the negative electrode active coating can be graphite or silicon carbon composite material, etc. In other embodiments, the same active material can be used on both sides of the first active coating 112, or different active materials can be used according to the design requirements of the battery 10 to achieve better performance.

[0052] In some embodiments, the dimension M1 of the second active coating layer 132 in the first direction X and the dimension L1 of the first active coating layer 112 in the first direction X satisfy the following relationship: 2 mm ≤ L1 - M1 ≤ 5 mm. For example, the dimension difference between the first active coating layer 112 and the second active coating layer 132 in the first direction X can be 2 mm, 2.5 mm, 3 mm, 4 mm, 4.5 mm, 5 mm, etc. This dimension difference ensures sufficient spacing between the first electrode 110 and the second electrode 130 during the winding process, preventing short circuits caused by contact between the first electrode 110 and the second electrode 130 during cycling. By controlling the dimension difference between the second active coating layer 132 and the first active coating layer 112 in the first direction X, the structure of the electrode assembly 100 is optimized, improving the safety and cycling performance of the battery 10. The material selection for the second active coating layer 132 can be determined based on the type and performance requirements of the battery 10 and can be the same as or different from that of the first active coating layer 112.

[0053] To further enhance the performance of the electrode assembly 100, additives with specific functions can be added to the second active coating layer 132. For example, highly conductive materials such as graphene nanosheets can be added to improve electron conduction efficiency, or nanoparticles with specialized morphologies can be added to enhance the coating's stability. By precisely controlling parameters such as coating speed and drying temperature, the difference between the size M1 of the second active coating layer 132 and the size L1 of the first active coating layer 112 can be maintained within a range of 2 to 5 mm, thereby achieving optimal electrochemical performance.

[0054] See also Figure 5 In some embodiments, the electrode assembly 100 further includes a second separator 140. The second separator 140 is located on a side of the first electrode 110 or the second electrode 130 facing away from the first separator 120. The second separator 140 is configured identically to the first separator 120 and is configured to be stacked with the first electrode 110, the first separator 120, and the second electrode 130 and to be rolled together in the second direction Y. The second separator 140 works together with the first separator 120 to ensure sufficient insulation distance between the first electrode 110 and the second electrode 130, preventing short circuits during the charge and discharge process of the battery 10. The second separator 140 is designed to have the same dimensions as the first separator 120, ensuring stability and consistency of the electrode assembly 100 during the rolling process. The first separator 120 and the second separator 140 are rolled together in the second direction Y, forming a stable electrode assembly 100 structure, which helps improve the cycle performance and safety of the battery 10.

[0055] The material of the second spacer 140 can be an electrically insulating material different from that of the first spacer 120, such as a polyester film or a polyimide film. These materials have high mechanical strength and high temperature resistance, and can better adapt to the operating environment within the battery 10. At the same time, the thickness of the second spacer 140 can be adjusted in a similar manner to the thickness of the first spacer 120 to more effectively balance the pressure within the electrode assembly 100 and further reduce the expansion stress within the electrode assembly 100 after winding. This allows the second spacer 140 to better cooperate with the first spacer 120 to achieve optimal stress release and reduce the probability of deformation and collapse of the electrode assembly 100 due to expansion stress. In other embodiments, the second spacer 140 can adopt a multi-layer structure design to enhance its insulation performance and mechanical stability.

[0056] See also Figures 1 to 5 The second aspect of the present invention further provides a battery 10, which includes the electrode assembly 100 described in any of the above-mentioned embodiments and examples, and a shell 200, wherein the shell 200 has a storage space 210, and the storage space 210 is configured to accommodate the electrode assembly 100. The shell 200 ensures the installation and sealing of the electrode assembly 100 and protects the electrode assembly 100 from the influence of the external environment. In some embodiments, the storage space 210 can be cylindrical, and the outline shape of the battery 10 can be cylindrical or other shapes. By adopting the above-mentioned electrode assembly 100, the battery 10 can effectively reduce the expansion stress inside the battery 10 and improve the cycle stability and safety of the battery 10. The material of the shell 200 can be made of materials such as aluminum-plastic film or metal shell, and the specific material can be selected according to the application requirements of the battery 10. The storage space 210 of the shell 200 can tightly accommodate the electrode assembly 100, ensuring the stability and reliability of the battery 10 during use.

[0057] The design of the shell 200 can also consider the use of high-strength lightweight materials, such as aluminum alloy or carbon fiber composite materials, to reduce the overall weight of the battery 10 while ensuring sufficient strength to protect the electrode assembly 100 from external impact. The shell 200 can be provided with a heat dissipation structure, such as a heat sink or a heat pipe, to help the battery 10 dissipate the heat generated during operation, thereby improving the thermal management capability of the battery 10 and further improving the safety and service life of the battery 10. The shell 200 can be integrated with a safety valve to release gas when the internal pressure of the battery 10 is too high, thereby improving safety. The shell 200 can be specially coated or treated to improve its corrosion resistance and wear resistance.

[0058] It should be noted that if the embodiments of the present invention involve directional indications (such as up, down, left, right, front, back, etc.), such directional indications are only used to explain the relative position relationship, movement status, etc. between the various components in a certain specific posture. If the specific posture changes, the directional indication will also change accordingly.

[0059] In addition, if there are descriptions involving "first", "second", etc. in the embodiments of the present invention, the descriptions of "first", "second", etc. are only for descriptive purposes and cannot be understood as indicating or suggesting their relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features limited to "first" and "second" may explicitly or implicitly include at least one of such features. In addition, if "and / or", "and / or" or "and / or" appear in the full text, its meaning includes three parallel solutions. Taking "A and / or B" as an example, it includes solution A, solution B, or solutions that satisfy both A and B. In addition, the technical solutions between the various embodiments can be combined with each other, but it must be based on the ability of ordinary technicians in this field to implement. When the combination of technical solutions is mutually contradictory or cannot be implemented, it should be deemed that such a combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0060] The above are only preferred embodiments of the present invention and do not limit the patent scope of the present invention. All equivalent structural transformations made by using the contents of the present invention specification and drawings under the utility model concept, or direct / indirect application in other related technical fields are included in the patent protection scope of the present invention.

Claims

1. An electrode assembly, characterized in that: include: A first electrode, comprising a first current collector and a first active coating, wherein the first current collector comprises a first region and a second region adjacently distributed along a first direction, the first active coating being applied to the first region and configured to be electronically conductive with the first current collector, and the second region being adapted for electrical connection to a tab; a first spacer disposed on a side of the first active coating layer facing away from the first current collector, the first spacer being configured to have electrical insulation properties, wherein a dimension of the first spacer in a third direction gradually decreases along the second direction, the second direction being perpendicular to the first direction, and the third direction being perpendicular to the first direction and the second direction; a second electrode comprising a second current collector and a second active coating coated on at least one side of the second current collector along the third direction, wherein the second active coating is configured to be electronically conductive with the second current collector; The first spacer is located between the first electrode and the second electrode, and the first electrode, the first spacer, and the second electrode are sequentially stacked and configured to be able to be rolled up along the second direction at the same time.

2. The electrode assembly according to claim 1, wherein The dimension T of the first spacer in the third direction and the curvature radius R of each coil formed by the first spacer rolled up in the second direction satisfy: T=k / R, where k is the proportional coefficient and the value range of R is 0.02mm 2 ~0.1mm 2 .

3. The electrode assembly according to claim 1, wherein The first separator is configured to be coated on a side of the first active coating layer facing away from the first current collector.

4. The electrode assembly according to claim 1, wherein A dimension D1 of the first spacer in the first direction and a dimension L1 of the first active coating in the first direction satisfy 0mm≤D1-L1≤5mm, and a side of the first active coating facing away from the second region is aligned with a side of the first region facing away from the second region.

5. The electrode assembly according to claim 1, wherein A dimension D2 of the first spacer in the second direction and a dimension L2 of the first active coating in the second direction satisfy 0 mm ≤ L2 − D2 ≤ 5 mm.

6. The electrode assembly according to claim 5, wherein: The first electrode includes a first end and a second end arranged opposite to each other along the second direction, the first active coating and the first spacer are flush at the first end, the first end is the starting point of rolling up the first electrode, the first spacer and the second electrode, and the second end is the end point of rolling up.

7. The electrode assembly according to claim 1, wherein The first active coating is provided on both opposite sides of the first current collector along the third direction.

8. The electrode assembly according to claim 1, wherein A dimension M1 of the second active coating layer in the first direction and a dimension L1 of the first active coating layer in the first direction satisfy the following: 2 mm ≤ L1 − M1 ≤ 5 mm.

9. The electrode assembly according to claim 1, wherein: The electrode assembly also includes a second spacer, which is located on the side of the first electrode or the second electrode away from the first spacer. The second spacer is configured to be the same as the first spacer, and the second spacer is configured to be stacked with the first electrode, the first spacer and the second electrode and rolled up together along the second direction.

10. A battery, characterized in that: include: The electrode assembly according to any one of claims 1 to 9; as well as The housing has a housing space configured to accommodate the electrode assembly.

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