Battery cell, method for manufacturing electrode assembly, battery device, and electric device

Abstract

The application relates to the field of batteries, and provides a battery monomer, a manufacturing method of an electrode assembly, a battery device and a power utilization device. The battery monomer comprises an electrode assembly, and the electrode assembly comprises a positive electrode sheet, a negative electrode sheet, a diaphragm and a support body. The positive electrode sheet, the diaphragm and the negative electrode sheet are wound and arranged at the outer periphery of the support body. The support body is in a ring structure, the outer ring surface of the support body is fixedly connected with the diaphragm, the inner ring surface of the support body is provided with first adhesive particles, the inner ring surface of the support body is self-adhered through the first adhesive particles, and the hardness of the support body is greater than the hardness of the diaphragm. Based on the above structure, in the compaction process, the diaphragm can be hindered from being retracted inward through the support body in a flat structure which supports the inner ring of the diaphragm, the layer gap between the positive electrode sheet and the negative electrode sheet of the inner ring is hindered from being enlarged, the electrode assembly is promoted to be closely attached layer by layer with a small layer gap, the electrode assembly is fully compacted, and the risk of the electrode assembly appearing a pre-pressing opening phenomenon and the like is reduced.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of batteries, and particularly relates to a battery monomer, a manufacturing method of an electrode assembly, a battery device, and a power utilization device. BACKGROUND

[0002] An electrode assembly is a necessary component for an electrochemical reaction in a battery monomer. The electrode assembly includes a positive electrode sheet, a negative electrode sheet, and a separator separating the positive electrode sheet and the negative electrode sheet. The positive electrode sheet, the separator, and the negative electrode sheet are wound and set, and undergo a compaction process and the like, to form a flatly coiled electrode assembly, so that the electrode assembly has a main body region and a bending region arranged at an end side of the main body region. However, because the separator is thin and elastic, in the compaction process, the rebounding force of the corner of the separator at the bending region is relatively large, so that the separator of the inner ring drives the electrode sheet on the inner side to rebound and retract inward, so that the interlayer gap between the positive electrode sheet and the negative electrode sheet of the inner ring is relatively large, so that the electrode assembly is difficult to compact, and the electrode assembly that is not fully compacted has a pre-pressing opening phenomenon. SUMMARY

[0003] Embodiments of the application provide a battery monomer, which aims to solve the problem that an electrode assembly is difficult to be fully compacted, the interlayer gap between the positive electrode sheet and the negative electrode sheet of the inner ring is relatively large, and a pre-pressing opening phenomenon occurs.

[0004] To achieve the above object, the technical scheme adopted by the embodiments of the application is as follows:

[0005] In a first aspect, a battery monomer is provided, which includes at least one electrode assembly, and the electrode assembly includes a positive electrode sheet, a negative electrode sheet, a separator, and a support body.

[0006] The positive electrode sheet, the separator, and the negative electrode sheet are wound and set on the outer periphery of the support body.

[0007] The support body is in a ring structure, the outer ring surface of the support body is fixedly connected with the separator, the inner ring surface of the support body is provided with first adhesive particles, the inner ring surface of the support body is self-adhered through the first adhesive particles, and the hardness of the support body is greater than the hardness of the separator.

[0008] In the battery cell provided by the embodiments of the present application, the electrode assembly can be formed by arranging a support body in the innermost ring in a ring structure and having a first adhesive particle on the inner ring surface, and fixing the separator to the outer ring surface of the support body, and stacking and winding the positive electrode sheet, the separator and the negative electrode sheet around the outer periphery of the support body, so that in the compaction process, the inner ring surface of the support body can be adhered by the first adhesive particle itself, so that the support body can form a flat structure without opening, and the support body can support the inner ring of the separator to prevent the separator of the inner ring (especially the innermost ring) from rebounding and retracting inward. Based on this, the interlayer gap between the positive electrode sheet and the negative electrode sheet of the inner ring (especially the innermost ring) can be prevented from becoming larger, the separator of the innermost ring can be made to adhere to the outer ring surface of the support body, the electrode assembly can be made to adhere layer by layer with a small interlayer gap, and the electrode assembly can be fully compacted. Thus, the risk of the electrode assembly not being fully compacted and causing a pre-pressing opening phenomenon can be reduced, the OH (Outgassing & Hooping, outgassing and hoop effect, i.e. expansion / contraction) misalignment caused by the pre-pressing opening can be reduced, the structural stability of the electrode assembly and the uniformity of the electrochemical reaction can be improved, sufficient restraint can be provided to the electrode sheet to prevent the end of the electrode sheet from moving due to external force, the risk of the positive electrode sheet exceeding the negative electrode sheet due to the movement of the end of the electrode sheet and causing metal precipitation and short circuit phenomenon can be reduced, the risk of affecting the active ion transmission performance due to the large interlayer gap between the positive electrode sheet and the negative electrode sheet and causing metal precipitation during the use of the battery cell can be reduced, the risk of affecting the yield rate due to the falling of external particles along the interlayer gap into the inside of the electrode assembly can be reduced, and the risk of causing a short circuit phenomenon due to the falling of external metal particles along the interlayer gap into the inside of the electrode assembly can be reduced. Thus, the use performance, use reliability and use life of the battery cell can be improved.

[0009] By adopting the above scheme, by making the hardness of the support body greater than the hardness of the diaphragm, the support body can have higher hardness than the diaphragm. Based on this, during the needle pulling of the winding needle and the clamping needle, the high-hardness support body has stronger anti-deformation ability than the diaphragm. When the winding needle / clamping needle is pulled out, it is not easy to twist or sag due to external force pulling, and can maintain the ring shape, so the shape stability is higher. Therefore, it can reduce the contact deformation and friction resistance of the support body and the winding needle / clamping needle, improve the smoothness of the needle pulling operation, reduce the risk of the support body and the diaphragm being pulled away to cause the positive and negative electrode plates to be short-circuited, reduce the risk of the support body and the diaphragm being wrinkled, folded and other defects, reduce the risk of structural damage during the needle pulling process, and reduce the needle pulling problem. And, since the support body has higher hardness than the diaphragm, the flat support body formed by compaction can form a stable "inner ring skeleton" with high hardness, can provide hard support to the inner ring of the diaphragm, can continuously resist the rebound stress of the diaphragm, and can reliably hinder the diaphragm from rebounding and retracting inward, thereby enabling the electrode assembly to be fully compacted, tightly attached layer by layer, and reducing the interlayer gap, and improving the structural stability and structural reliability of the electrode assembly.

[0010] In some embodiments, the first adhesive particles are pressure-sensitive adhesive particles, heat-sensitive adhesive particles, or heat-press synergistic adhesive particles.

[0011] By adopting the above scheme, by making the first adhesive particles pressure-sensitive adhesive particles, heat-sensitive adhesive particles, or heat-press synergistic adhesive particles, the first adhesive particles can be in a low-adhesion state or substantially non-adhesive before the compaction process (including the winding process, the material cutting process, and the material moving process), so that the inner ring surface of the support body is not tightly adhered to the winding needle and the clamping needle by the first adhesive particles. Thus, during the needle pulling of the winding needle and the clamping needle, the risk of the support body and the diaphragm being pulled away to cause the positive and negative electrode plates to be short-circuited due to excessive adhesion can be reduced, the risk of the support body and the diaphragm being wrinkled, folded and other defects due to excessive adhesion can be reduced, the yield of the winding process and the smoothness of the needle pulling operation can be improved, and the needle pulling problem can be reduced. The first adhesive particles can also be activated in terms of temperature and pressure during the compaction process, so that the inner ring surface of the support body can be adhered by the first adhesive particles, and the support body can form a flat structure without opening. The stability and reliability of the structure and shape of the support body after compaction can be improved.

[0012] In some embodiments, the surface roughness of the inner ring surface of the support body is less than the surface roughness of the diaphragm.

[0013] By adopting the above scheme, by making the surface roughness of the inner annular surface of the support body less than that of the diaphragm, the inner annular surface of the support body can be made smoother than the surface of the diaphragm. Based on this, during the needle pulling of the winding needle and the clamping needle, the inner annular surface of the support body has fewer microscopic concave-convex and smaller friction with the contact interface of the winding needle and the clamping needle, and is less likely to generate static electricity due to friction and to cause the inner annular surface of the support body to adhere to the winding needle / clamping needle due to static adsorption. Therefore, the smoothness of the needle pulling operation can be improved, the following property of the support body during needle pulling can be reduced, the risk of the support body and the diaphragm being pulled away to cause the positive and negative electrode plates to be short-circuited can be reduced, the risk of the support body and the diaphragm having defects such as wrinkling and folding can be reduced, the risk of structural damage during the needle pulling process can be reduced, the needle pulling failure can be reduced, and the yield of the electrode assembly can be improved.

[0014] In some embodiments, the thickness of the support body from its outer annular surface to its inner annular surface is 50 μm (microns) to 500 μm.

[0015] By adopting the above scheme, by making the thickness of the support body from its outer annular surface to its inner annular surface 50 μm to 500 μm, the support body has sufficient thickness and strength, which can improve the anti-deformation ability of the support body itself and reduce the risk of deformation or wrinkling of the support body during winding and compaction due to external force. In addition, the basic support ability of the flattened support body can be improved, which can form reliable support for the inner ring of the diaphragm, provide sufficient reaction force to reliably resist the rebound stress of the diaphragm, and reliably hinder the inward rebound and contraction of the diaphragm. Therefore, the electrode assembly can be fully compacted, tightly adhered layer by layer, and the interlayer gap can be reduced, and the structural stability and reliability of the electrode assembly can be improved. In addition, the risk of the support body occupying too much space due to excessive thickness can be reduced, the volume ratio of the support body in the electrode assembly can be reduced, and the energy margin of the battery cell can be squeezed by the support body, thereby maintaining and improving the energy density and group margin of the battery cell. In addition, the risk of the support body excessively occupying the normal expansion space of the electrode assembly due to excessive thickness can be reduced, the risk of the over-thick support body limiting the expansion buffer of the inner ring area can be reduced, the risk of excessive accumulation of expansion force in the later stage of the battery cell cycle can be reduced, and the risk of phenomena such as deformation of the shell, sealing leakage, shell rupture, short circuit, and thermal runaway caused by excessive expansion force can be reduced, thereby maintaining and improving the use reliability and service life of the battery cell.

[0016] In some embodiments, the diameter of the first adhesive particle is 5 μm to 30 μm.

[0017] By adopting the above scheme, by making the diameter of the first adhesive particles 5-30 μm, the risk of agglomeration of the first adhesive particles due to too small particles, too large specific surface area, and too high surface energy can be reduced, the particle dispersibility of the first adhesive particles can be better and not easy to agglomerate, and the uniformity of the adhesive points on the inner ring surface of the support can be improved. The risk of reducing the number of adhesive points due to too large particles, limited contact area, and increased gap between particles can be reduced, and a sufficient number of adhesive points can be formed in the unit area of the inner ring surface of the support. The single first adhesive particle has a moderate contact area and adhesion area. Thus, the adhesion strength of the first adhesive particles can be optimized, the inner ring surface of the support can be effectively self-adhered by the first adhesive particles during the compaction process, and the support can form a stable and non-open flat structure. Furthermore, the influence of the first adhesive particles on the thickness increase of the electrode assembly after compaction can be reduced, the risk of increasing the thickness of the electrode assembly after compaction due to too large particles can be reduced, and thus the energy margin of the battery cell can be reduced. The energy density and group margin of the battery cell can be maintained and improved.

[0018] In some embodiments, the outer ring surface of the support is provided with at least one groove, and the groove depth is less than the thickness of the support from the outer ring surface to the inner ring surface.

[0019] By adopting the above scheme, by providing a groove on the outer ring surface of the support, an infiltration channel for electrolyte can be provided in the inner circle of the electrode assembly (especially between the closely fitted support and the separator) under the condition that the electrode assembly is fully compacted, and the electrolyte can be smoothly diffused and fully penetrated into the inner circle of the electrode assembly. Thus, the problem of slow electrolyte filling speed and poor local infiltration of the inner circle due to close fitting can be improved, and the electrochemical performance of the battery cell can be maintained and improved. Furthermore, the electrolyte storage space can be reserved through the groove to pre-store the electrolyte, and the electrolyte stored in the groove can be released by expansion and extrusion during the later cycle of the battery cell. Thus, the electrolyte can be supplemented and consumed, and the liquid retention capability, cycle performance, and service life of the battery cell can be maintained and improved. Furthermore, based on the groove depth being less than the thickness of the support from the outer ring surface to the inner ring surface, the groove only partially depresses the outer ring surface of the support without damaging the overall continuity of the support. Thus, the structural strength of the annular support can be maintained, the basic support capability of the flat support after compaction can be maintained, and the flat support after compaction can reliably support the inner circle of the separator, resist the rebound stress of the separator, and hinder the inward rebound and contraction of the separator.

[0020] In some embodiments, the at least one groove is a straight groove.

[0021] By adopting the above scheme, by making the groove a straight groove, the extension path of the groove can be simple and free of redundant bends, the flow resistance of the electrolyte in the groove can be reduced, the electrolyte can be directed to transmit and diffuse along the extension direction of the groove, so that the transmission directionality and transmission efficiency of the electrolyte along the groove can be improved, the electrolyte filling speed can be improved, and the wetting effect of the inner ring of the electrode assembly can be improved. Moreover, the "straight line characteristic" of the straight groove can make the flow and storage of the electrolyte in the groove more stable, and can reduce the local liquid accumulation or flow dead angle caused by bending, so that the uniformity of electrolyte wetting and the reliability of storage compensation can be improved. Moreover, the edges of the straight groove are regular, and the stress concentration effect is weaker than that of a curved groove, which can reduce the risk of local fracture of the support body during compaction or cycling caused by the straight groove. Moreover, the straight groove has a simplified processing process and lower processing difficulty, which can improve the processing feasibility, processing convenience and processing consistency.

[0022] In some embodiments, the at least one groove is a ring-shaped groove.

[0023] By adopting the above scheme, by making the groove a ring-shaped groove, a ring-shaped electrolyte channel can be formed on the outer ring surface of the support body via the ring-shaped groove, so that the electrolyte can uniformly diffuse along the ring-shaped path to cover a larger area of the outer ring surface of the support body, thereby reducing the local wetting blind area and improving the uniformity and consistency of electrolyte wetting. Moreover, a ring-shaped storage space can also be formed via the ring-shaped groove, so that the electrolyte is uniformly distributed and stably stored in the ring-shaped groove, and after the battery monomer is cycled, the electrolyte in the ring-shaped groove can be uniformly released along the ring-shaped path under the expansion and extrusion of the electrode assembly, so as to supplement the electrolyte in the ring-shaped groove and the surrounding area, thereby optimizing the cycle life and liquid retention capacity of the battery monomer. Moreover, the closed contour of the ring-shaped groove can make the stress distribution of the edge more symmetrical, and the stress of the ring-shaped groove (especially the circular ring-shaped groove) can be uniformly dispersed along the ring direction, thereby reducing the risk of local fracture of the support body caused by the ring-shaped groove during the compaction process or long-term cycling, and maintaining the overall structural strength of the support body.

[0024] In some embodiments, the at least one groove is an arc-shaped groove.

[0025] By adopting the above scheme, since the extension range of the arc-shaped groove is between the unidirectionality of the linear groove and the full encircling of the ring-shaped groove, the arc-shaped groove can form a wider coverage in a specific radian area, and can guide the electrolyte to the area (such as the area near the corner of the flat support body) in the inner ring where the wetting is prone to be insufficient through the directional extension of the arc shape, so as to improve the local wetting blind area and balance the directionality and coverage range of the electrolyte wetting. Moreover, the curved shape of the arc-shaped groove can form an "arc-shaped storage space" on the outer ring surface of the support body, and after the battery monomer circulates for a long time, the electrolyte stored in the arc-shaped groove can diffuse to the periphery along the arc-shaped path under the extrusion of the electrode assembly, so as to optimize the cycle life and liquid retention capacity of the battery monomer. Moreover, the edge of the arc-shaped groove is a smooth curve transition, and the stress concentration effect is weak, which can reduce the risk of cracking of the support body due to edge stress concentration in the compaction process or long-term circulation.

[0026] In some embodiments, the at least one groove is a point-shaped groove.

[0027] By adopting the above scheme, based on the "point-shaped distribution" characteristics of the point-shaped groove, the point-shaped groove can be arranged in the local area in the inner ring of the electrode assembly where the wetting is prone to be insufficient, that is, the point-shaped groove can be discretely arranged according to the wetting demand in the inner ring to adapt to the improvement of the local wetting short board, so as to accurately supplement the specific wetting blind area and improve the flexibility, accuracy and pertinence of the electrolyte wetting. Moreover, the plurality of discretely distributed point-shaped grooves can form a decentralized electrolyte storage space, so that the electrolyte is stored at different positions on the outer ring surface of the support body. Based on this, in the later stage of the battery monomer circulation, the electrolyte in each point-shaped groove can be released to the peripheral area, which can reduce the problem of concentrated or insufficient electrolyte release caused by uneven local extrusion of a single long groove, so as to improve the balance of electrolyte supplement and facilitate reliable compensation of electrolyte consumption in the circulation process, which helps to maintain the long-term cycle performance of the battery monomer. Moreover, the weakening of the point-shaped groove to the overall strength of the support body is small and dispersed, the edge stress concentration range of a single point-shaped groove is small, and the local cracking risk of the support body caused by the point-shaped groove in the compaction process or long-term circulation can be reduced. Moreover, the processing of the point-shaped groove can be realized through simple processes such as stamping and punching, and the position, number and size of the point-shaped groove can be flexibly adjusted, so the processing feasibility and adaptability are high.

[0028] In some embodiments, the groove width of the groove is 50 μm to 500 μm, and the groove depth of the groove is 50 μm to 500 μm.

[0029] By adopting the above scheme, by making the groove width of the groove 50-500 μm and making the groove depth of the groove 50-500 μm, the groove can form a capillary structure, which can promote the adsorption of the electrolyte in the capillary structure, that is, the adsorption capacity of the electrolyte in the groove can be optimized. Moreover, the capillary phenomenon (driven by the liquid surface tension and the groove wall adhesion) can be mainly relied on to promote the wicking of the electrolyte, that is, to promote the flow of the electrolyte in the groove, which can reduce the risk of capillary blockage caused by too small size, which hinders the flow of the electrolyte, and can reduce the risk of the gravity of the electrolyte exceeding the capillary force caused by too large size, which causes the electrolyte to sink and gather, and hinders the diffusion and infiltration of the electrolyte, thereby balancing and optimizing the infiltration effect and speed of the electrolyte. Moreover, based on the arrangement of the present embodiment, the volume of the groove is moderate, which can store sufficient electrolyte for compensation in the later circulation, and will not weaken the supporting strength and pressure resistance of the support body.

[0030] In some embodiments, the battery cell includes a housing having opposite first and second end walls and a side wall connected between the first and second end walls; an electrode assembly is disposed in the housing, the electrode assembly including a main body portion and a tab extending from the main body portion outward toward the first end wall, the tab being electrically isolated from the side wall, and the electrode assembly being electrically isolated from the second end wall.

[0031] By adopting the above scheme, on the basis of accommodating and protecting the electrode assembly by the housing, the tab of the electrode assembly can be electrically isolated from the side wall, and the electrode assembly can be electrically isolated from the second end wall, so as to reduce the risk of direct contact between the tab and the side wall and between the electrode assembly and the second end wall, thereby maintaining the stable operation of the battery cell and improving the use reliability and service life of the battery cell.

[0032] In some embodiments, a plurality of electrode assemblies are provided, and the plurality of electrode assemblies are arranged side by side along the first direction.

[0033] In each electrode assembly, two electrode assemblies located at both ends along the first direction are first electrode assemblies, the support body of the first electrode assembly is an insulating member, and has a first extension portion extending from the main body portion outward toward the first end wall, and the tabs of the electrode assemblies are located between the two first extension portions and are electrically isolated from the side wall by the two first extension portions.

[0034] By adopting the above scheme, in the case that a plurality of electrode assemblies are arranged side by side along the first direction, the tab of all the electrode assemblies can be constrained between the two first extension portions by forming the two first extension portions of the insulating support bodies of the two first electrode assemblies to extend towards the first end wall to enclose a unified isolation space via the two first extension portions. Based on this, a "enclosing type" insulating protective wall can be formed via the two first extension portions, which physically blocks the tab from deviating towards the side wall due to vibration, deformation, etc., thereby reliably preventing the tab from directly contacting the side wall to form a conductive path, reducing the risk of short circuit caused by direct contact between the tab and the side wall, improving insulation reliability, and improving the use reliability and service life of the battery monomer. Moreover, based on the arrangement of the present embodiment, it is not necessary to separately design an insulating structure for each tab, thereby simplifying the insulation scheme in the multi-tab scenario, reducing independent insulating components, and simplifying and optimizing the structure of the battery monomer. Moreover, the support body itself bears the winding support function of the electrode assembly, and the first extension portion formed by the extension additionally bears the tab isolation function, realizing "one material with multiple functions" and "function reuse". Based on this functional integration, the space reserved for isolating the tab (such as a separate insulating space reserved between the side wall and the tab) can be reduced, thereby helping to compress the internal redundancy of the battery monomer and improve the space utilization and energy density of the battery monomer.

[0035] In some embodiments, the battery monomer includes an insulating shell arranged in the shell, the insulating shell covering the electrode assembly, and the electrode assembly being electrically isolated from the side wall and the second end wall by the insulating shell.

[0036] By adopting the above scheme, an insulating barrier can be constructed by additionally arranging the insulating shell covering the electrode assembly in the shell to uniformly achieve electrical isolation between the electrode assembly and the side wall (especially between the tab and the side wall) and between the electrode assembly and the second end wall, thereby reducing the risk of short circuit caused by direct contact between the electrode assembly and the side wall (especially between the tab and the side wall) and between the electrode assembly and the second end wall, and reducing the risk of multi-path short circuit, thereby improving insulation reliability and improving the use reliability and service life of the battery monomer. Moreover, the present embodiment is compatible with different numbers of electrode assemblies, and it is not necessary to adjust the insulation scheme according to the number of electrode assemblies, nor is it necessary to separately design an insulating structure for each electrode assembly, each tab, and each side of the electrode assembly, thereby improving the universality of the insulation design, simplifying the insulation scheme and reducing independent insulating components, and simplifying and optimizing the structure of the battery monomer.

[0037] In some embodiments, the battery monomer includes a bottom support plate arranged in the shell, the bottom support plate being arranged between the electrode assembly and the second end wall, and the electrode assembly being electrically isolated from the second end wall by the bottom support plate.

[0038] By adopting the above scheme, the electrode assembly can be reliably supported through the bottom supporting plate between the electrode assembly and the second end wall, and the bottom supporting plate can serve as a physical separation layer between the electrode assembly and the second end wall to directly block the conductive contact between the electrode assembly and the second end wall, so as to realize the electrical isolation between the electrode assembly and the second end wall and reduce the risk of short circuit caused by the direct contact between the electrode assembly and the second end wall. In addition, the bottom supporting plate can cover the bottom of the electrode assembly through the flat supporting surface thereof, disperse the pressure, and reduce the risk of insulation damage. Therefore, the insulation reliability can be improved, and the use reliability and service life of the battery cell can be improved. In addition, the present embodiment is compatible with different numbers of electrode assemblies, and there is no need to adjust the insulation scheme according to the number of electrode assemblies or to design an insulation structure for each electrode assembly. Therefore, the insulation design versatility can be improved, the insulation scheme can be simplified, and the number of independent insulation components can be reduced. In addition, the structure of the battery cell can be simplified and optimized.

[0039] In some embodiments, the battery cell comprises an insulation support arranged in the shell and abutting against one side of the electrode assembly facing the second end wall. The support body of the electrode assembly has a second extension portion extending out of the main body portion, and the second extension portion is connected with the insulation support.

[0040] By adopting the above scheme, on the basis of abutting against and supporting the electrode assembly through the insulation support and realizing the electrical isolation between the electrode assembly and the second end wall, the support body of the electrode assembly can be extended to form a second extension portion. The second extension portion is connected and fixed with the insulation support to form a fixed point between the electrode assembly and the insulation support, so as to fix the electrode assembly relative to the insulation support, stabilize the position and state of the electrode assembly relative to the insulation support, and hinder the electrode assembly from moving relative to the insulation support. Therefore, the structural stability and reliability of the battery cell can be improved. In addition, during the use of the battery cell, the position stability of the electrode assembly is improved, and the risk of movement is reduced. Therefore, the risk of contact and short circuit between the electrode assembly and the second end wall caused by the relative displacement between the electrode assembly and the insulation support can be reduced, and the risk of contact and short circuit between the tab of the electrode assembly and the side wall caused by the position deviation of the tab can be reduced. Therefore, the short circuit risk can be reduced, and the use reliability and service life of the battery cell can be improved.

[0041] In some embodiments, the second extension portion is arranged between the main body portion and the insulation support.

[0042] By adopting the above scheme, by arranging the second extension part between the main body part and the insulating support part in a bent manner, the abutting area and the connecting area of the second extension part and the insulating support part can be increased, so that the connecting strength, the connecting stability and the connecting reliability between the second extension part and the insulating support part can be enhanced, the connecting stability and the connecting reliability between the electrode assembly and the insulating support part can be improved, the position and the state of the electrode assembly relative to the insulating support part can be consolidated, the risk of short circuit can be reduced, and the structural stability, the structural reliability, the use reliability and the service life of the battery monomer can be improved. Moreover, the bent shape can give the second extension part a certain elastic deformation capability. When the battery monomer is subjected to external impact or internal stress (such as expansion and contraction of the electrode assembly during charging and discharging), the bent second extension part can absorb part of the energy through its own deformation, thereby playing a buffering role, so that the stress can be directly transmitted to the main body part or the insulating support part, the risk of structural damage of the electrode assembly due to rigid stress can be reduced, the stress load of the insulating support part can be reduced, and the service life of the insulating support part can be prolonged. Moreover, the bent arrangement can reasonably arrange the second extension part in the limited space between the main body part and the insulating support part. The bent second extension part can be compressed in the space between the main body part and the insulating support part through "folding", so as to adapt to the compact layout requirement inside the shell, and to improve the energy density of the battery monomer.

[0043] In a second aspect, a manufacturing method of an electrode assembly is provided, comprising the following steps:

[0044] The support body is sleeved on the outer periphery of the winding needle, so that the winding needle is expanded and tightly presses the support body. The support body has a ring structure, and the inner ring surface of the support body is provided with first adhesive particles.

[0045] The winding end of the diaphragm is fixedly connected to the outer ring surface of the support body.

[0046] After the diaphragm is wound on the outer periphery of the support body for a preset number of turns, the negative electrode sheet is wound, and in the case that the winding length of the negative electrode sheet exceeds the preset length, the positive electrode sheet is wound, so as to wind the positive electrode sheet, the diaphragm and the negative electrode sheet on the outer periphery of the support body.

[0047] The positive electrode sheet is cut off first, then the negative electrode sheet is cut off, then the diaphragm is cut off, and then the winding is finished to form a winding structure.

[0048] The winding structure is discharged from the winding needle.

[0049] The winding structure is compacted, so that the inner ring surface of the support body is self-adhered through the first adhesive particles, thereby forming a flat electrode assembly.

[0050] By adopting the above scheme, by adopting the electrode assembly manufacturing method provided in the embodiment of the present application, the positive electrode sheet, the separator and the negative electrode sheet can be first wound on the outer periphery of the support body, and the support body, the separator, the negative electrode sheet and the positive electrode sheet jointly form a winding structure; then the winding structure is compacted until the inner annular surface of the support body is self-adhered by the first adhesive particles, so that the support body forms a flat structure without opening, thereby obtaining a flat electrode assembly. Based on this, the electrode assembly with the support body and sufficient compaction provided in the embodiment of the present application can be conveniently and quickly manufactured, and the manufacturability, production convenience, production efficiency, production consistency and production yield of the electrode assembly can be provided.

[0051] In some embodiments, the first adhesive particles are pressure-sensitive adhesive particles, heat-sensitive adhesive particles or heat-press synergistic adhesive particles;

[0052] In the step of sleeving the support body on the outer periphery of the winding needle and expanding and tightly pressing the support body with the winding needle, the first adhesive particles are not activated.

[0053] In the step of compacting the winding structure, the first adhesive particles are activated to adhere to the inner annular surface of the support body.

[0054] By adopting the above scheme, by making the first adhesive particles pressure-sensitive adhesive particles, heat-sensitive adhesive particles or heat-press synergistic adhesive particles, the first adhesive particles can be in a low-adhesion state or substantially without adhesion in the step of sleeving the support body on the outer periphery of the winding needle and expanding and tightly pressing the support body with the winding needle to the step of discharging the winding structure from the winding needle, so that the inner annular surface of the support body is not tightly adhered to the outer surface of the winding needle and the clamping needle by the first adhesive particles, thereby reducing the risk of the support body and the separator being pulled away due to excessive adhesion during the needle extraction of the winding needle and the insertion and extraction of the clamping needle in the step of discharging the winding structure from the winding needle, reducing the risk of the support body and the separator being wrinkled, folded and other defects due to excessive adhesion, thereby improving the yield of the winding process and the smoothness of the needle extraction operation, and reducing the needle extraction problems. Moreover, in the step of compacting the winding structure, the first adhesive particles can be activated based on temperature and pressure, so that the inner annular surface of the support body can be self-adhered by the first adhesive particles, and the support body can form a flat structure without opening, thereby improving the yield of the compaction process, and strengthening the stability and reliability of the structure and morphology of the support body after compaction. Therefore, the manufacturability, production convenience, production efficiency, production consistency and production yield of the electrode assembly can be improved.

[0055] In some embodiments, in the step of fixing the entry winding end of the diaphragm to the outer annular surface of the support body, the entry winding end of the diaphragm is fixedly connected to the outer annular surface of the support body by hot melt connection or ultrasonic welding.

[0056] By using the above scheme, in the step of fixing the entry winding end of the diaphragm to the outer annular surface of the support body, the entry winding end of the diaphragm can be fixedly connected to the outer annular surface of the support body by hot melt connection or ultrasonic welding, which is convenient and fast. Based on this, the connection convenience, connection strength, connection stability, and connection reliability between the entry winding end of the diaphragm and the outer annular surface of the support body can be improved, and the production convenience, production efficiency, and production yield of the electrode assembly can be improved. Moreover, since hot melt connection or ultrasonic welding does not require additional consumables (such as solder, adhesive, etc.), the influence of the residual additional consumables on the structure and performance of the electrode assembly can be reduced, and the forming quality of the electrode assembly can be improved; the influence of the residual additional consumables on the pollution of the electrolyte can be reduced, and the performance of the battery cell can be optimized; and the cost can be reduced.

[0057] In some embodiments, the fixedly connected region between the entry winding end of the diaphragm and the outer annular surface of the support body is a first connection area; along the axial direction of the support body, the size of the first connection area is greater than or equal to 10 mm (millimeters) and less than or equal to the size of the support body.

[0058] By using the above scheme, based on the first connection area, the entry winding end of the diaphragm and the outer annular surface of the support body have sufficient axial connection length and connection area, so that the connection strength, connection stability, and connection reliability between the entry winding end of the diaphragm and the outer annular surface of the support body can be improved, the risk of the diaphragm falling off the support body at the initial winding stage can be reduced, the qualified rate of the step of fixing the entry winding end of the diaphragm to the outer annular surface of the support body can be improved, and the production convenience, production efficiency, and production yield of the electrode assembly can be improved. Moreover, the first connection area does not exceed the axial boundary of the support body, which can reduce the damage influence of the formation of the first connection area on the winding needle, protect the winding needle from damage, maintain the use reliability and service life of the winding needle, and reduce the equipment maintenance cost and downtime risk.

[0059] In some embodiments, the fixedly connected region between the entry winding end of the diaphragm and the outer annular surface of the support body is a first connection area; along the circumferential direction of the support body, the size of the first connection area is greater than or equal to 5 mm and less than or equal to the circumference of the support body.

[0060] By adopting the above scheme, the connection length and area between the entry winding end of the diaphragm and the outer ring surface of the support body can be sufficient based on the first connection area, so that the connection strength, stability and reliability between the entry winding end of the diaphragm and the outer ring surface of the support body can be improved, the risk of the diaphragm falling off the support body at the initial winding stage can be reduced, the yield of the step of fixing and connecting the entry winding end of the diaphragm to the outer ring surface of the support body can be improved, and the production convenience, efficiency and yield of the electrode assembly can be improved.

[0061] In some embodiments, the preset number of turns is 0.5 turns to 1 turn.

[0062] By adopting the above scheme, after the step of fixing and connecting the entry winding end of the diaphragm to the outer ring surface of the support body, the diaphragm can be wound 0.5 turns to 1 turn around the outer periphery of the support body. Based on this, the 0.5 turns to 1 turn of the pre-wound diaphragm can cover at least half of the outer ring surface of the support body, and a "half-wrapped" inner insulating barrier can be formed to insulate and isolate the support body and the pole piece, and the positive pole piece and the negative pole piece, thereby reducing the risk of short circuit, especially reducing the risk of the positive pole piece and the negative pole piece being overlapped and short-circuited due to the end of the pole piece moving out of the insulating isolation range of the diaphragm, and improving the forming quality and production yield of the electrode assembly. Moreover, the initial winding turns of the 0.5 turns to 1 turn of the diaphragm are less, so that the "starting core" (i.e., the support body and the initial diaphragm) of the winding structure has a smaller and more compact volume. Based on this, in the subsequent compaction process, the compact starting core can uniformly transmit pressure to the entire winding structure, thereby reducing the problem of local insufficient compaction due to too many initial winding turns of the diaphragm and too thick starting core, and improving the compaction density and efficiency, and the overall volume energy density of the electrode assembly.

[0063] In some embodiments, the preset length is 2 mm.

[0064] By adopting the above scheme, the positive pole piece can be wound again when the entry winding length of the negative pole piece exceeds 2 mm. Based on this, the negative pole piece can be wound before the positive pole piece, the entry winding length of the negative pole piece can exceed that of the positive pole piece by 2 mm, the entry winding end of the positive pole piece can be reliably covered by the negative pole piece, the design principle of "negative pole piece covering positive pole piece" can be followed, the probability of metal deposition and short circuit can be reduced from the root, and the forming quality and production yield of the electrode assembly can be improved.

[0065] In some embodiments, the number of winding needles is one, and the winding needle maintains a preset position unchanged during winding.

[0066] By adopting the above scheme, the steps of sleeving the support body on the outer periphery of the winding needle, supporting and pressing the support body by the winding needle, and forming the winding structure by winding tail-off, and the step of discharging the winding structure from the winding needle can be performed by using the device with the single winding needle which maintains the preset position unchanged during the winding process. Therefore, the device structure can be simplified, the device complexity and failure rate can be reduced, and the production continuity can be indirectly improved. Moreover, since the winding needle maintains the preset position unchanged and does not need to be switched, the stability and consistency of the winding process can be improved, and thus the forming quality and production yield of the electrode assembly can be improved.

[0067] In some embodiments, the number of winding needles is two, and the two winding needles can rotate around the preset axis to alternately switch between the first station and the second station. In each step of the method for manufacturing the electrode assembly:

[0068] The steps of sleeving the support body on the outer periphery of the winding needle, supporting and pressing the support body by the winding needle, and forming the winding structure by winding tail-off are performed at the first station, and the step of discharging the winding structure from the winding needle is performed at the first station.

[0069] The steps of fixing and connecting the winding-in end of the diaphragm to the outer annular surface of the support body, and cutting off the positive electrode tab and then cutting off the negative electrode tab are performed at the second station.

[0070] The step of cutting off the diaphragm is performed between the second station and the first station.

[0071] By adopting the above scheme, the two winding needles can be alternately used at the first station and the second station, the steps of the winding process of the electrode assembly can be split to different stations to realize alternate operation, the two winding needles can be operated in parallel, the waiting time and production rhythm can be compressed, the idle time of the device can be reduced, the seamless connection can be formed, the production capacity per unit time can be improved (theoretically, one operation cycle can basically complete the winding process of two electrode assemblies, which is close to twice the efficiency of the single winding needle), and the production efficiency can be improved. Moreover, after the steps are split to fixed stations, the operation of each station can be specialized and optimized, each station can perform the corresponding operation with high precision, stability and accuracy, and the operation parameters of each step can be easily standardized, so that the process stability can be optimized, and the consistency and yield of batch production can be improved.

[0072] In some embodiments, when the two winding needles complete the station switching, the diaphragm is lap jointed from the first station to the outer annular surface of the support body located at the second station, the step of fixing and connecting the winding-in end of the diaphragm to the outer annular surface of the support body is performed at the second station, the step of cutting off the diaphragm is performed between the second station and the first station, and the step of forming the winding structure by winding tail-off is performed at the first station.

[0073] By adopting the above scheme, on the basis of two alternating needle positions, through the process design of "the diaphragm is spliced from the first position to the support body of the second position, the diaphragm is fixed in the second position, the diaphragm is cut off between the first position and the second position, and the diaphragm is wound up in the first position", the diaphragm can be seamlessly spliced, the continuity of the diaphragm can be optimized, the diaphragm does not need to be rewound every time, the diaphragm redundancy waste caused by rewinding every time can be reduced, the material utilization rate can be improved, the operation of "fixing the diaphragm in the second position" can be simple based on the continuity of the diaphragm, the process continuity can be improved, and the cooperation of the double-position operation can be strengthened. And the timing connection of the diaphragm splicing, fixing, cutting and ending can make the second position start winding after fixing the diaphragm, and the first position can basically use the cut-off diaphragm to end at the same time, so that the first position and the second position share a time-sharing use of the diaphragm, so that the "ending" of the previous product and the "initial winding" of the subsequent product can be carried out in parallel, and the waiting of the position caused by the conflict of the diaphragm distribution (such as "the previous ending is not completed, and the subsequent winding cannot take the diaphragm") can be reduced, so that the production rhythm can be compressed, and the production efficiency can be improved.

[0074] In some embodiments, the number of needles is three, and the three needles can rotate around a preset axis to make the three needles cyclically alternate in the first position, the second position and the third position, and the three needles are one-to-one corresponding to the first position, the second position and the third position; wherein in each step of the method for manufacturing the electrode assembly:

[0075] The step of sleeving the support body on the outer periphery of the needle to make the needle support and tightly contact the support body is performed in the first position;

[0076] The step of fixing the diaphragm winding end to the outer ring surface of the support body is performed in the second position, and the step of cutting off the positive electrode sheet is performed first, and then the negative electrode sheet is cut off;

[0077] The step of cutting off the diaphragm is performed between the second position and the third position;

[0078] The step of winding and ending to form the winding structure, and the step of discharging the winding structure from the needle are performed in the third position.

[0079] By adopting the above scheme, the three winding needles can be arranged to work in the first station, the second station and the third station in turn, the steps of the winding process of the electrode assembly can be split into three stations to realize alternating operation, the three winding needles can realize parallel operation, the waiting time and production rhythm can be compressed, the idle time of the equipment can be reduced, the seamless connection can be formed, the production capacity per unit time can be improved (theoretically, one operation cycle can basically complete the winding process of three electrode assemblies, which can be close to 3 times the efficiency of single winding needle), and the production efficiency can be improved. Moreover, after splitting the steps into fixed stations, the operation of each station can be professionalized and optimized, each station can perform the corresponding operation with high precision, stability and accuracy, and the operation parameters of each step can be easily standardized, so that the process stability can be optimized, and the consistency and yield of batch production can be improved.

[0080] In some embodiments, the number of winding needles is four, and the four winding needles can rotate around the preset axis, so that the four winding needles are arranged in the first station, the second station, the third station and the fourth station in turn, and the four winding needles are arranged in the first station, the second station, the third station and the fourth station one by one; wherein in each step of the method for manufacturing the electrode assembly:

[0081] The step of sleeving the support body on the outer periphery of the winding needle, so that the winding needle is expanded and tightly presses the support body, is performed in the first station;

[0082] The step of fixing the winding end of the diaphragm to the outer ring surface of the support body is performed in the second station, and the steps of cutting the positive electrode tab and then cutting the negative electrode tab are performed in the second station;

[0083] The step of cutting the diaphragm is performed between the second station and the third station;

[0084] The step of winding and finishing to form the winding structure is performed in the third station;

[0085] The step of discharging the winding structure from the winding needle is performed in the fourth station.

[0086] By adopting the above scheme, the four winding needles can be arranged to work in the first station, the second station, the third station and the fourth station in turn in a cyclic and alternating manner, each step of the winding process of the electrode assembly can be split into four stations to realize alternating operation, the four winding needles can realize parallel operation, the waiting time and production rhythm can be compressed, the idle time of the equipment can be reduced, the seamless connection can be formed, the production capacity per unit time can be improved (theoretically, one operation cycle can basically complete the winding process of four electrode assemblies, which can be close to 4 times the efficiency of single winding needle), and the production efficiency can be improved. Moreover, after splitting the steps into fixed stations, the operation of each station can be professionalized and optimized, each station can perform the corresponding operation with high precision, stability and accuracy, and the operation parameters of each step can be easily standardized, so that the process stability can be optimized, and the consistency and yield of batch production can be improved.

[0087] In a third aspect, a battery device is provided. The battery device includes the battery cell provided in the embodiments of the present application.

[0088] By adopting the above scheme, the battery device can improve the use performance, use reliability and use life by applying the battery cell provided in the embodiments of the present application.

[0089] In a fourth aspect, a power consumption device is provided. The power consumption device includes the battery device provided in the embodiments of the present application, or the battery cell provided in the embodiments of the present application.

[0090] By adopting the above scheme, the power consumption device can improve the use performance, use reliability and use life by applying the battery device or the battery cell provided in the embodiments of the present application. DETAILED DESCRIPTION

[0091] In order to clearly illustrate the technical solutions in the embodiments of the present application, the following will briefly introduce the drawings needed to be used in the embodiments of the present application or the prior art description. Obviously, the drawings in the following description are only some embodiments of the present application, and for those skilled in the art, other drawings can also be obtained from these drawings without creative labor.

[0092] Figure 1 The structural schematic diagram of the vehicle provided in some embodiments of the present application is shown in the figure;

[0093] Figure 2 The exploded schematic diagram of the battery device provided in some embodiments of the present application is shown in the figure;

[0094] Figure 3 The exploded schematic diagram of the battery cell provided in some embodiments of the present application is shown in the figure;

[0095] Figure 4A schematic diagram of the decomposition of a battery cell provided for some embodiments of the present application, wherein the electrode assembly comprises a support body;

[0096] Figure 5 A perspective schematic diagram of an electrode assembly provided for some embodiments of the present application;

[0097] Figure 6 A sectional view of an electrode assembly provided for some embodiments of the present application;

[0098] Figure 7 A Figure 6 magnified view of region A provided;

[0099] Figure 8 A front view of a support body in a compacted state provided for some embodiments of the present application;

[0100] Figure 9 A Figure 8 front view of a support body in an un-compacted state provided;

[0101] Figure 10 A front view of a support body in an un-compacted state provided for some other embodiments of the present application, wherein the outer circumferential surface of the support body is provided with grooves;

[0102] Figure 11 A Figure 10 front view of a support body in a compacted state provided;

[0103] Figure 12 A Figure 11 top view of a support body provided;

[0104] Figure 13 A top view of a support body provided for some other embodiments of the present application, wherein the grooves are straight grooves;

[0105] Figure 14 A top view of a support body provided for some other embodiments of the present application, wherein the grooves are annular grooves;

[0106] Figure 15 A top view of a support body provided for some other embodiments of the present application, wherein part of the grooves are straight grooves and part of the grooves are arc grooves;

[0107] Figure 16 A top view of a support body provided for some other embodiments of the present application, wherein the grooves are point grooves;

[0108] Figure 17 A structural schematic diagram of a battery cell provided for some embodiments of the present application, wherein the battery cell is provided with an insulating shell and is not provided with a bottom supporting plate, and the support body is provided with a first extension and a second extension;

[0109] Figure 18 A structural schematic diagram of a battery cell provided for some embodiments of the present application, wherein the battery cell is provided with a bottom supporting plate and is not provided with an insulating shell, and the supporting body is provided with a first extension part and a second extension part;

[0110] Figure 19 A structural schematic diagram of a battery cell provided for some embodiments of the present application, wherein the battery cell is provided with an insulating shell and a bottom supporting plate, and the supporting body is not provided with a first extension part and a second extension part;

[0111] Figure 20 A flow chart of a manufacturing method of an electrode assembly provided for some embodiments of the present application;

[0112] Figure 21 A structural schematic diagram corresponding to the step of "sleeving the supporting body on the outer periphery of the winding needle, and expanding and tightly pressing the supporting body by the winding needle" provided for some embodiments of the present application;

[0113] Figure 22 A structural schematic diagram corresponding to the step of "fixedly connecting the winding-in end of the diaphragm to the outer annular surface of the supporting body" provided for some embodiments of the present application;

[0114] Figure 23 A structural schematic diagram corresponding to the step of "winding the diaphragm on the outer periphery of the supporting body for a preset number of turns" provided for some embodiments of the present application;

[0115] Figure 24 A structural schematic diagram corresponding to the step of "winding the diaphragm on the outer periphery of the supporting body for a preset number of turns, then winding the negative electrode sheet, and in the case that the winding length of the negative electrode sheet exceeds the preset length, winding the positive electrode sheet, so as to wind the positive electrode sheet, the diaphragm and the negative electrode sheet on the outer periphery of the supporting body" provided for some embodiments of the present application;

[0116] Figure 25 A structural schematic diagram corresponding to the step of "fixedly connecting the winding-in end of the diaphragm to the outer annular surface of the supporting body" provided for some embodiments of the present application, wherein the connecting marks of the first connecting area are in a straight line shape, and the extension direction of the connecting marks is substantially parallel to the axial direction of the supporting body;

[0117] Figure 26 A structural schematic diagram corresponding to the step of "fixedly connecting the winding-in end of the diaphragm to the outer annular surface of the supporting body" provided for some embodiments of the present application, wherein the connecting marks of the first connecting area are in a straight line shape, and the extension direction of the connecting marks is substantially perpendicular to the axial direction of the supporting body;

[0118] Figure 27 A structural schematic diagram corresponding to the step of "fixedly connecting the winding-in end of the diaphragm to the outer annular surface of the supporting body" provided for some embodiments of the present application, wherein the connecting marks of the first connecting area are in a curved line shape;

[0119] Figure 28 The structure diagram corresponding to the step of "fixing and connecting the entry end of the diaphragm to the outer ring surface of the support body" provided by some embodiments of the present application, wherein the connection mark of the first connection area is in the form of a dot;

[0120] Figure 29 The structure diagram of the turret and two winding needles provided by some embodiments of the present application;

[0121] Figure 30 The structure diagram of the turret and three winding needles provided by some embodiments of the present application;

[0122] Figure 31 The structure diagram of the turret and four winding needles provided by some embodiments of the present application.

[0123] In the drawings, various reference numerals refer to:

[0124] 1 - battery device, 2 - controller, 3 - motor; 100 - battery cell, 200 - case, 201 - first part, 202 - second part; 10 - battery monomer, 11 - shell, 111 - first end wall, 112 - second end wall, 113 - side wall; 12 - electrode assembly, 12a - first electrode assembly, 121 - main body part, 122 - tab, 122a - positive electrode tab, 122b - negative electrode tab, 123 - pole piece, 123a - positive electrode pole piece, 123b - negative electrode pole piece, 124 - diaphragm, 125 - support body, 1251 - first adhesive particle, 1252 - groove, 1252a - straight groove, 1252b - ring groove, 1252c - arc groove, 1252d - dot-shaped groove, 1253 - first extension, 1254 - second extension, 1255 - first connection area, 12551 - connection mark; d1 - thickness of the support body from its outer ring surface to its inner ring surface, d2 - groove depth of the groove, d3 - groove width of the groove, x - first direction; 13 - insulating member; 14 - electrode terminal, 14a - positive electrode terminal, 14b - negative electrode terminal; 15 - adapter, 15a - positive electrode adapter, 15b - negative electrode adapter; 16 - pressure relief mechanism; 17 - insulating shell, 18 - bottom support plate, 19 - insulating support member; 20 - winding needle, y - winding direction, 30 - turret, 31 - first station, 32 - second station, 33 - third station, 34 - fourth station, L - preset length. DETAILED DESCRIPTION

[0125] In order to make the technical problems, technical solutions and beneficial effects of the present application clear, the present application will be described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely intended to explain the present application and are not intended to limit the present application. Unless otherwise specified, all embodiments and optional embodiments of the present application can be combined to form new technical solutions. Unless otherwise specified, all technical features and optional technical features of the present application can be combined to form new technical solutions.

[0126] In the description of the present application, it should be understood that the terms "length", "width", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the purpose of facilitating the description of the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the present application.

[0127] In addition, the terms "first", "second" are only for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined with "first", "second" can explicitly or implicitly include one or more features. In the description of the present application, the meaning of "multiple" is two or more, unless otherwise explicitly specified and limited.

[0128] In the present application, unless otherwise explicitly specified and limited, the terms "mounting", "connection", "connection", "fixing" and the like should be understood in a broad sense, for example, it can be fixedly connected, or it can be detachably connected, or it can be integrated; it can be mechanically connected, or it can be electrically connected; it can be directly connected, or it can be indirectly connected through an intermediate medium; it can be the internal communication of two elements or the interaction relationship between two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0129] The battery cell is the smallest unit for storing and outputting electric energy. Inside the battery cell, at least one electrode assembly is usually provided. The electrode assembly is a necessary component for the electrochemical reaction in the battery cell. The electrode assembly includes a positive electrode sheet, a negative electrode sheet, and a separator separating the positive electrode sheet and the negative electrode sheet. The positive electrode sheet, the separator, and the negative electrode sheet are wound and set, and after processes such as compaction, a flat roll-shaped electrode assembly is formed, so that the electrode assembly has a main body region and a bending region provided at the end side of the main body region.

[0130] However, due to the thin thickness (about 10 microns) and elasticity of the separator, the corner rebound force of the separator at the bending area is large in the compaction process, causing the innermost separator to rebound and retract together with the pole piece on the inner side, resulting in a large interlayer gap between the positive pole piece and the negative pole piece of the innermost ring, making it difficult to compact the electrode assembly (i.e., not compacted), and causing the electrode assembly to be insufficiently compacted to cause pre-pressing opening and other phenomena. Even in some cases, due to design needs, the thickness of the pole piece needs to be increased to improve product competitiveness; however, the larger the thickness of the pole piece, the greater the probability of pre-pressing opening, and the greater the opening of the pre-pressing opening. The "pre-pressing opening" refers to the phenomenon that the interlayer structure (mainly the positive pole piece, the separator, and the negative pole piece) that should be tightly attached after the electrode assembly undergoes the compaction process, has a local or overall gap expansion, delamination, or even warping, similar to the "opening" state.

[0131] If the interlayer gap between the positive pole piece and the negative pole piece is too large, during the use of the battery monomer, especially in the later stage of the cycle after the battery monomer undergoes multiple charge and discharge cycles (i.e., long-term use), it will affect the active ion transmission performance and cause metal precipitation (for example, if the active ion is lithium ion, the metal precipitation phenomenon is lithium precipitation), thereby affecting the use performance, use reliability, and use life of the battery monomer.

[0132] If the electrode assembly has a pre-pressing opening, during the subsequent charge and discharge process, the electrode assembly will cause interlayer misalignment (misalignment) due to expansion / contraction (i.e., OH, Outgassing & Hooping), affecting the structural stability of the electrode assembly, affecting the uniformity of the electrochemical reaction, and affecting the use performance, use reliability, and use life of the battery monomer. Moreover, in the initial design of the electrode assembly, the negative pole piece will exceed the positive pole piece (i.e., "negative excess design", "negative pole covering positive pole"), to reduce the risk of metal precipitation and short circuit; but the pre-pressing opening will make the pole piece lack sufficient restraint, causing the end of the pole piece to easily move due to external forces such as vibration, and if the end of the pole piece moves and causes the positive pole piece to exceed the negative pole piece, it will increase the risk of metal precipitation and short circuit, affecting the use performance, use reliability, and use life of the battery monomer.

[0133] If the electrode assembly is not fully compacted and the interlayer gap is large, external particles such as particles in the environment and particles generated during processing and assembly are likely to fall into the interior of the electrode assembly along the interlayer gap of the electrode assembly, affecting the yield of the electrode assembly. If the external particles that fall into the interior of the electrode assembly are metal particles, they are also likely to cause short circuits, affecting the use performance, use reliability, and use life of the battery monomer.

[0134] Therefore, some embodiments of the present application provide a battery cell, an electrode assembly of which can be formed by arranging a support body in a ring structure with a first adhesive particle on an inner ring surface, and fixedly connecting a separator with an outer ring surface of the support body, and stacking and winding a positive electrode tab, the separator and a negative electrode tab on the outer periphery of the support body, so that in the compaction process, the inner ring surface of the support body can be adhered by the first adhesive particle itself, so that the support body can form a flat structure without opening, and the support body can support the inner ring of the separator to prevent the separator from rebounding and retracting inward, especially the innermost ring. Based on this, the interlayer gap between the positive electrode tab and the negative electrode tab of the inner ring, especially the innermost ring, can be prevented from becoming larger, the separator of the innermost ring can be made to adhere to the outer ring surface of the support body, the electrode assembly can be made to adhere layer by layer with a smaller interlayer gap, and the electrode assembly can be fully compacted. Therefore, the risk of the electrode assembly not being fully compacted and the phenomenon of pre-pressing opening can be reduced, the OH misplacement caused by pre-pressing opening can be reduced, the structural stability of the electrode assembly and the uniformity of the electrochemical reaction can be improved, sufficient restraint can be formed on the electrode tab to prevent the end of the electrode tab from moving due to external force, the risk of the positive electrode tab exceeding the negative electrode tab due to the end of the electrode tab moving and causing metal precipitation and short circuit phenomenon can be reduced, the risk of affecting the active ion transmission performance due to the interlayer gap between the positive electrode tab and the negative electrode tab being too large and causing metal precipitation during the use of the battery cell can be reduced, the risk of foreign particles falling into the electrode assembly along the interlayer gap and affecting the yield can be reduced, and the risk of foreign metal particles falling into the electrode assembly along the interlayer gap and causing short circuit phenomenon can be reduced. Therefore, the use performance, use reliability and use life of the battery cell can be improved.

[0135] The battery cell disclosed in the embodiments of the present application can be used independently, or can be combined with other battery cells to form a modular battery device capable of providing higher voltage and capacity, such as a battery module, a battery pack or a battery pack. The battery cell and the battery device disclosed in the embodiments of the present application can be used in a power consumption device using the battery cell and the battery device as a power source, or in various energy storage systems using the battery cell and the battery device as an energy storage element. The power consumption device can be, but is not limited to, a vehicle, a mobile phone, a portable device, a notebook computer, a ship, a spacecraft, an electric toy and an electric tool, etc. The vehicle can be a fuel car, a gas car or a new energy car, and the new energy car can be a pure electric car, a hybrid car or an extended range car, etc. The spacecraft includes an airplane, a rocket, a space shuttle and a spacecraft, etc. The electric toy includes a fixed or mobile electric toy, such as a game console, an electric car toy, an electric ship toy and an electric plane toy, etc. The electric tool includes a metal cutting electric tool, a grinding electric tool, an assembly electric tool and a railway electric tool, such as a power drill, an electric grinder, an electric wrench, an electric screwdriver, an electric hammer, an impact drill, a concrete vibrator and an electric planer, etc.

[0136] In order to illustrate the technical solutions provided in the present application, the following will be described in detail with reference to specific drawings and examples, and taking a vehicle as an example.

[0137] Please refer to Figure 1 , Figure 1 The structural schematic diagram of a vehicle is provided for some embodiments of the present application. The vehicle can be a fuel automobile, a gas automobile, or a new energy automobile, and the new energy automobile can be a pure electric automobile, a hybrid electric automobile, or a range extended automobile, etc. The vehicle is internally provided with a battery device 1, which can be arranged at the bottom, the head, or the tail of the vehicle. The battery device 1 is used to supply power to the vehicle, for example, the battery device 1 can be used as the operating power source of the vehicle. The vehicle can further include a controller 2 and a motor 3, and the controller 2 is used to control the battery device 1 to supply power to the motor 3, for example, to meet the power demand of the vehicle during starting, navigation, and driving.

[0138] In some embodiments of the present application, the battery device 1 can not only be used as the operating power source of the vehicle, but also be used as the driving power source of the vehicle, to replace or partially replace fuel or natural gas to provide driving power for the vehicle.

[0139] Please refer to Figure 2 , Figure 2 The exploded schematic diagram of the battery device 1 is provided for some embodiments of the present application. The battery device 1 includes a battery cell 100 and a box body 200, and the battery cell 100 is accommodated in the box body 200.

[0140] The box body 200 is used to provide an accommodation space for the battery cell 100 and other components, and the box body 200 can prevent dust, water, and other foreign matters from affecting the battery cell 100 and other components, thereby reducing the influence of external liquids or other foreign matters on the performance of the battery cell 100 and other components, and effectively prolonging the service life of the battery device 1.

[0141] The box body 200 can adopt various structures. In some embodiments, the box body 200 can include a first part 201 and a second part 202, and the first part 201 and the second part 202 are mutually covered. The first part 201 and the second part 202 jointly define an accommodation space for accommodating the battery cell 100. The second part 202 can be a hollow structure with one end open, and the first part 201 can be a plate-shaped structure, which is covered on the open side of the second part 202 to jointly define the accommodation space with the second part 202. The first part 201 and the second part 202 can also be hollow structures with one side open, and the open side of the first part 201 is covered on the open side of the second part 202.

[0142] The box body 200 can have various shapes, such as a cylinder or a cuboid.

[0143] The box 200 can be made of various materials, such as copper, iron, aluminum, stainless steel, aluminum alloy, plastic, etc.

[0144] The battery unit 100 is an energy storage unit capable of converting chemical energy into electrical energy. In the battery device 1, one battery unit 100 can be provided, or at least two battery units 100 can be provided. In the case where at least two battery units 100 are provided, the at least two battery units 100 can be connected in series, in parallel, or in a mixed connection. The mixed connection means that the at least two battery units 100 are connected in series and in parallel.

[0145] The battery unit 100 can include at least two battery cells. The at least two battery cells can be directly connected in series, in parallel, or in a mixed connection, and the whole of the at least two battery cells can be accommodated in the box 200. The battery cell can be a lithium ion secondary battery cell, a lithium-sulfur battery cell, a sodium lithium ion battery cell, a sodium ion battery cell, or a magnesium ion battery cell, etc. The battery cell can be in the shape of a cylinder, a flat body, a cuboid, or other shapes, etc. The battery cell can be packaged in different ways to form a cylindrical battery cell, a square battery cell, or a soft-pack battery cell, etc.

[0146] Alternatively, the battery unit 100 can be a battery module or a battery pack. That is, the at least two battery cells can be connected in series, in parallel, or in a mixed connection to form a modular structure (i.e., a battery module or a battery pack); and the at least two battery modules or battery packs can be connected in series, in parallel, or in a mixed connection to form a whole, which is accommodated in the box 200.

[0147] Of course, the battery device 1 can also include other structures, for example, the battery device 1 can also include a current collecting component (not shown in the figure) for realizing the electrical connection between the at least two battery units 100. For another example, the battery device 1 can also include a power distribution device (not shown in the figure) for serving as a control unit for distributing the energy of the battery device 1 and for high-voltage distribution of the battery device 1.

[0148] Of course, in some embodiments, the battery device 1 can not include the box 200, but the at least two battery cells can be electrically connected and assembled into a whole through necessary fixing structures (such as end plates, side plates, binding belts, etc.) and then assembled into a power consumption device.

[0149] Please refer to Figure 3 , Figure 3 The battery cell 10 provided for some embodiments of the present application is a schematic exploded view. The battery cell 10 is the smallest unit for storing and outputting electrical energy. The battery cell 10 includes an outer shell 11, an electrode assembly 12, an insulating member 13, an electrode terminal 14, an adapter 15, a pressure relief mechanism 16, an electrolyte (not shown in the figure), etc.

[0150] The shell 11 is a component that isolates the internal environment of the battery monomer 10 from the external environment. The internal environment enclosed by the shell 11 can be used to accommodate the electrode assembly 12, the electrolyte and other components. The shell 11 can include a first end wall 111, a second end wall and a side wall 113. The side wall 113 can be in a cylindrical shape, such as a circular cylindrical shape, a rectangular cylindrical shape, a polygonal cylindrical shape and the like. The first end wall 111 and the second end wall are respectively covered on opposite ends of the side wall 113, so that the internal space enclosed by the first end wall 111, the second end wall and the side wall 113 is isolated from the external environment. In some embodiments, the first end wall 111 and the side wall 113 can be integrated, for example, the first end wall 111 and the side wall 113 can form a common connecting surface before other components are put into the shell, and when it is necessary to package the shell 11, the first end wall 111 is covered on the side wall 113; in other embodiments, the first end wall 111 and the side wall 113 can be independent components, the first end wall 111 can be covered on one end opening of the side wall 113, and the first end wall 111 and the side wall 113 can be connected and fixed. Similarly, in some embodiments, the second end wall and the side wall 113 can be independent components, the second end wall can be covered on one end opening of the side wall 113, and the second end wall and the side wall 113 can be connected and fixed; in other embodiments, the second end wall and the side wall 113 can be integrated, for example, the second end wall and the side wall 113 can form a common connecting surface before other components are put into the shell, and when it is necessary to package the shell 11, the second end wall is covered on the side wall 113. In some embodiments, the shape of the first end wall 111 and the shape of the second end wall can be adapted to the shape of the side wall 113. In some embodiments, the first end wall 111, the second end wall and the side wall 113 can be made of a material with certain hardness and strength, so that the shell 11 is not easy to deform when subjected to extrusion and collision, so that the battery monomer 10 can have high structural strength and structural reliability. The material of the first end wall 111, the second end wall and the side wall 113 can be the same or different. The material of the first end wall 111, the second end wall and the side wall 113 can be set as needed, for example, the side wall 113, the first end wall 111 and the second end wall can each be made of copper, iron, aluminum, stainless steel, aluminum alloy, nickel-plated copper, iron-plated copper, copper-nickel composite material, copper-iron composite material and the like as needed.

[0151] The electrode assembly 12 is a component in which electrochemical reactions occur in the battery cell 10. One or at least two electrode assemblies 12 can be included inside the case 11. The electrode assembly 12 includes a positive electrode sheet, a negative electrode sheet, and a separator. The positive electrode sheet and the negative electrode sheet are two sheets of opposite polarity, and the separator separates the positive electrode sheet and the negative electrode sheet. The positive electrode sheet, the separator, and the negative electrode sheet can be processed in a roll shape to form the electrode assembly 12. In the electrode assembly 12, the portions of the two sheets having active materials constitute a main body portion 121 of the electrode assembly 12, and the portions of the two sheets not having active materials each constitute a tab 122. The tab 122 is a current transmission end of the electrode assembly 12 and is used to transmit current. The tab 122 of the positive electrode sheet is a positive electrode tab 122a, and the tab 122 of the negative electrode sheet is a negative electrode tab 122b. The positive electrode tab 122a and the negative electrode tab 122b can be located together at one end of the main body portion 121 or can be located separately at both ends of the main body portion 121.

[0152] The electrolyte is a liquid that infiltrates the electrode assembly 12. The battery cell 10 mainly works by moving active ions between the positive electrode sheet and the negative electrode sheet. When the battery cell 10 is charged, active ions are generated in the positive electrode sheet, and the active ions provided from the positive electrode sheet move to the negative electrode sheet through the pores of the separator via the electrolyte and are embedded in the negative electrode active material of the negative electrode sheet. Conversely, when the battery cell 10 is discharged, the active ions embedded in the negative electrode active material of the negative electrode sheet are released from the negative electrode sheet, and the active ions released from the negative electrode sheet move to the positive electrode sheet through the pores of the separator via the electrolyte and are embedded in the positive electrode active material of the positive electrode sheet. The active ions can be lithium ions, sodium ions, or the like.

[0153] The electrode terminal 14 is a component that is electrically connected to the electrode assembly 12 and is used to output or input electric energy. The electrode terminal 14 includes a positive electrode terminal 14a and a negative electrode terminal 14b. The positive electrode terminal 14a is electrically connected to the positive electrode tab 122a of the electrode assembly 12. The negative electrode terminal 14b is electrically connected to the negative electrode tab 122b of the electrode assembly 12. The electrode terminal 14 can be mounted to the case 11 and stably mounted in position and in state with respect to the case 11. In some embodiments, the electrode terminal 14 can be mounted to the case 11 by a method of crimping a flange.

[0154] The adapter 15 is a current collecting member electrically connected between the tab 122 of the electrode assembly 12 and the corresponding electrode terminal 14. The adapter 15 can also be referred to as an adapter connector, a current collecting plate, or an adapter tab, etc. The adapter 15 has electrically conductive properties and is made of an electrically conductive material. The material of the adapter 15 can include aluminum, an aluminum alloy, copper, a copper alloy, a copper-aluminum alloy, etc. The adapter 15 includes a positive adapter 15a and a negative adapter 15b. The positive tab 122a of the electrode assembly 12 can be electrically connected with the positive electrode terminal 14a through the positive adapter 15a, and the negative tab 122b of the electrode assembly 12 can be electrically connected with the negative electrode terminal 14b through the negative adapter 15b to form a current loop. In some embodiments, the adapter 15 can be connected with the tab 122 of the electrode assembly 12 by welding, abutting, etc. The adapter 15 can be connected with the electrode terminal 14 by welding, abutting, etc. The shape of the adapter 15 can be various, such as square, circular, irregular, etc.

[0155] The insulating member 13 is a component having insulating properties. The insulating member 13 is arranged in the housing 11, and in particular between the electrode assembly 12 and the wall portion (e.g. the first end wall 111) of the housing 11 having the electrode terminal 14. On the basis that the tab 122 of the electrode assembly 12 and the corresponding electrode terminal 14 can be electrically connected, the insulating member 13 can be used to insulate and isolate the electrode assembly 12 and the wall portion of the housing 11 having the electrode terminal 14, so as to reduce the risk of short circuit, current leakage, etc. In addition, the insulating member 13 can also be fixed to the wall portion of the housing 11 having the electrode terminal 14 and abut against the electrode assembly 12, so as to fill the gap between the electrode assembly 12 and the wall portion of the housing 11 and tightly fix the electrode assembly 12, so that the electrode assembly 12 can be prevented from moving or shaking relative to the housing 11 during use of the battery monomer 10, and the structural integrity of the battery monomer 10 can be maintained, and the risk of loosening or deformation of the electrode assembly 12 can be reduced.

[0156] The pressure relief mechanism 16 is arranged on the housing 11, and the pressure relief mechanism 16 can be used to release the internal pressure when the internal pressure (or temperature) of the battery monomer 10 reaches a threshold value. In some cases, the pressure relief mechanism 16 can also be referred to as an explosion-proof valve. In some embodiments, the pressure relief mechanism 16 can be integrally formed with the wall portion (e.g. the first end wall 111, etc.) of the housing 11 for arranging the pressure relief mechanism 16 (i.e. an integral structure), for example, the pressure relief mechanism 16 is a notch arranged on the corresponding wall portion of the housing 11. In other embodiments, the pressure relief mechanism 16 can be separately formed and connected with the corresponding wall portion (e.g. the first end wall 111, etc.) of the housing 11 (i.e. a separate structure).

[0157] Please refer to Figure 4 , Figure 5 , Figure 6 , Figure 7Some embodiments of the present application provide a battery cell 10, which includes at least one electrode assembly 12. The electrode assembly 12 includes a positive electrode tab 123a, a negative electrode tab 123b, a separator 124, and a support 125. The positive electrode tab 123a, the separator 124, and the negative electrode tab 123b are wound around the outer periphery of the support 125. The support 125 has a ring shape. The outer ring surface of the support 125 is fixedly connected with the separator 124. Please refer to Figure 8 , Figure 9 The inner ring surface of the support 125 is provided with first adhesive particles 1251. The inner ring surface of the support 125 is self-adhered via the first adhesive particles 1251.

[0158] It is noted that the electrode assembly 12 is a component in which electrochemical reactions occur in the battery cell 10. One or more electrode assemblies 12 can be provided inside the battery cell 10.

[0159] The electrode assembly 12 includes the positive electrode tab 123a, the negative electrode tab 123b, the separator 124, and the support 125. The positive electrode tab 123a and the negative electrode tab 123b are two electrode tabs 123 with opposite polarities. The separator 124 is an insulating film for separating the positive electrode tab 123a and the negative electrode tab 123b with opposite polarities, so as to prevent the positive electrode tab 123a and the negative electrode tab 123b from directly contacting each other and causing short circuit. The separator 124 has a plurality of pores for allowing active ions to freely penetrate. The material of the separator 124 can be PP (polypropylene), PE (polyethylene), or the like.

[0160] The support 125 has a ring shape. As shown in Figure 6 , Figure 8 , Figure 9 In some embodiments, the support 125 has a closed ring shape. Of course, in other embodiments, the support 125 can have an open ring shape. The support 125 can be an insulating component, for example, can be a plastic piece, a structural piece made of thermosetting material, a porous structure made of insulating material, or the like; or the support 125 can be a conductive component, for example, can be a metal piece, an aluminum plastic film, or the like. For example, in some embodiments, the material of the support 125 can be a polyester film (PET, Polyethylene Terephthalate).

[0161] In the winding process, the support body 125 is in an un-compacted state and has a circular ring structure, and the inner ring surface of the support body 125 is provided with first adhesive particles 1251; the winding end of the diaphragm 124 can be fixedly connected with the outer ring surface of the support body 125, and the fixed connection mode can be hot melt connection, ultrasonic welding or adhesion and the like; the diaphragm 124 can be provided with two, one of which is arranged between the positive electrode plate 123a and the negative electrode plate 123b, and the other is arranged on the side of the negative electrode plate 123b away from the positive electrode plate 123a, or on the side of the positive electrode plate 123a away from the negative electrode plate 123b, so as to realize the laminated arrangement of the positive electrode plate 123a, the diaphragm 124 and the negative electrode plate 123b, and to reliably separate the positive electrode plate 123a and the negative electrode plate 123b by the diaphragm 124 to prevent the positive electrode plate 123a and the negative electrode plate 123b from being in contact and short-circuiting; the positive electrode plate 123a, the diaphragm 124 and the negative electrode plate 123b are laminated and wound on the outer periphery of the support body 125, so that the support body 125 is located in the innermost circle of the electrode assembly 12.

[0162] In the compacting process, the inner ring surface of the support body 125 is adhered by the first adhesive particles 1251 itself, so that the inner ring of the support body 125 has no opening, and the support body 125 forms a flat structure; the flat support body 125 can support the inner circle of the diaphragm 124, can hinder the inward rebound and shrinkage of the diaphragm 124 of the inner circle (especially the innermost circle), can hinder the increase of the interlayer gap between the positive electrode plate 123a and the negative electrode plate 123b of the inner circle (especially the innermost circle), can make the diaphragm 124 of the innermost circle tightly adhere to the outer ring surface of the support body 125, can make the electrode assembly 12 tightly adhere layer by layer with small interlayer gap, and can make the electrode assembly 12 fully compacted.

[0163] In the compacting process, the inner ring surface of the support body 125 is adhered by the first adhesive particles 1251 itself, so that the inner ring of the support body 125 has no opening, and the support body 125 forms a flat structure; the flat support body 125 can support the inner circle of the diaphragm 124, can hinder the inward rebound and shrinkage of the diaphragm 124 of the inner circle (especially the innermost circle), can hinder the increase of the interlayer gap between the positive electrode plate 123a and the negative electrode plate 123b of the inner circle (especially the innermost circle), can make the diaphragm 124 of the innermost circle tightly adhere to the outer ring surface of the support body 125, can make the electrode assembly 12 tightly adhere layer by layer with small interlayer gap, and can make the electrode assembly 12 fully compacted.

[0164] The surface of the separator 124 can or can not have third adhesive particles (not shown in the figure). In the case where the surface of the separator 124 has the third adhesive particles, in the compaction process, the innermost circle of the separator 124 can also be adhered to the outer ring surface of the support 125 via the third adhesive particles, and each circle of the separator 124 can also be adhered to the adjacent pole piece 123 via the third adhesive particles, so that the close-fitting degree of the electrode assembly 12 can be improved, the interlayer gap of the electrode assembly 12 can be reduced, and the electrode assembly 12 can be compacted tightly. It should be further noted that in the case where the electrode assembly 12 is not provided with the support 125 and the surface of the separator 124 has the third adhesive particles, in the compaction process, due to the thin thickness, elasticity and large corner rebound force of the separator 124, the innermost circle of the separator 124 (especially the loose end of the innermost circle of the separator 124) will rebound and retract inward, so that the innermost circle of the separator 124 cannot be adhered via the third adhesive particles like the support 125, that is, the problem of “the electrode assembly 12 is difficult to be compacted sufficiently, the interlayer gap between the positive pole piece 123a and the negative pole piece 123b of the innermost circle is large, and the pre-pressing opening phenomenon occurs” still exists.

[0165] In the electrode assembly 12, the part of the two pole pieces 123 having the active material constitutes the main body part 121 of the electrode assembly 12, and the part of the two pole pieces 123 not having the active material constitutes the tab 122 respectively, and the tab 122 is the current transmission end of the electrode assembly 12 and is used for transmitting current. The tab 122 of the positive pole piece 123a is the positive tab 122a, and the tab 122 of the negative pole piece 123b is the negative tab 122b. The positive tab 122a and the negative tab 122b can be located on the same side of the support 125 (as shown in FIG. 1), or can be located on the two sides of the support 125 respectively. Figure 5

[0166] ​In summary, in the battery monomer 10 provided by the embodiments of the present application, the electrode assembly 12 can be fixedly connected with the support 125 through the inner annular surface of the support 125 having the first adhesive particles 1251 in a ring structure, and the diaphragm 124 is fixedly connected with the outer annular surface of the support 125, and the positive electrode tab 123a, the diaphragm 124 and the negative electrode tab 123b are stacked and wound around the outer periphery of the support 125, so that in the compaction process, the inner annular surface of the support 125 can be adhered by the first adhesive particles 1251 itself, so that the support 125 can form a flat structure without opening, and the support 125 can support the inner circle of the diaphragm 124 to prevent the diaphragm 124 of the inner circle (especially the innermost circle) from rebounding and retracting inward. Based on this, the interlayer gap between the positive electrode tab 123a and the negative electrode tab 123b of the inner circle (especially the innermost circle) can be prevented from becoming larger, the diaphragm 124 of the innermost circle can be caused to tightly adhere to the outer annular surface of the support 125, the electrode assembly 12 can be caused to tightly adhere layer by layer with a smaller interlayer gap, and the electrode assembly 12 can be fully compacted. Thus, the risk of the electrode assembly 12 appearing to be pre-pressed with an opening due to insufficient compaction can be reduced, the OH dislocation caused by the pre-pressed opening can be reduced, the structural stability of the electrode assembly 12 and the uniformity of the electrochemical reaction can be improved, sufficient restraint can be formed on the electrode tab 123 to prevent the end of the electrode tab 123 from moving due to external force, the risk of the positive electrode tab 123a exceeding the negative electrode tab 123b to cause metal precipitation and short circuit due to the movement of the end of the electrode tab 123 can be reduced, the risk of affecting the active ion transmission performance and causing metal precipitation during the use of the battery monomer 10 due to the excessive interlayer gap between the positive electrode tab 123a and the negative electrode tab 123b can be reduced, the risk of affecting the yield rate due to the falling of external particles into the electrode assembly 12 along the interlayer gap can be reduced, and the risk of causing a short circuit due to the falling of external metal particles into the electrode assembly 12 along the interlayer gap can be reduced. Thus, the use performance, use reliability and use life of the battery monomer 10 can be improved.

[0167] Please refer to Figure 6 、 Figure 7 、 Figure 9 In some embodiments of the present application, the first adhesive particles 1251 are pressure-sensitive adhesive particles, heat-sensitive adhesive particles or heat-pressing synergistic adhesive particles.

[0168] It should be noted that the pressure-sensitive adhesive particles are adhesive particles that are triggered to adhere by pressure, and are in a low-adhesive state or substantially have no adhesion at normal temperature, and can deform, diffuse and tightly adhere to the contact surface under the state of applying pressure to achieve adhesion by intermolecular forces (such as van der Waals forces). If the first adhesive particles 1251 are pressure-sensitive adhesive particles, the first adhesive particles 1251 can be in a low-adhesive state or substantially have no adhesion in the winding process, so that the inner annular surface of the support body 125 cannot be tightly adhered to the winding needle and the clamping needle through the first adhesive particles 1251; the first adhesive particles 1251 can be activated to have adhesion in the compaction process due to bearing pressure, so that the inner annular surface of the support body 125 can be adhered by the first adhesive particles 1251 itself, and the support body 125 can form a flat structure without opening. For example, the pressure-sensitive adhesive particles can be PCS (Pressure Sensitive Coating / Adhesive, pressure-sensitive coating / pressure-sensitive adhesive) adhesive particles (such as acrylate pressure-sensitive adhesive particles, etc.), butyl rubber particles, etc. The winding needle is a component for assisting the winding of the electrode assembly 12, and the clamping needle is a component for clamping, transferring, etc. of the pre-formed electrode assembly 12.

[0169] The heat-sensitive adhesive particles are adhesive particles that are triggered to adhere by temperature change, and can be in a non-adhesive state or a low-adhesive state at normal temperature, and can be softened, melted and activated to have adhesion when the temperature is increased to a specific threshold (softening point or melting point), and can form stable adhesion after cooling and solidification. If the first adhesive particles 1251 are heat-sensitive adhesive particles, the first adhesive particles 1251 can have no adhesion or be in a low-adhesive state in the winding process, so that the inner annular surface of the support body 125 cannot be tightly adhered to the winding needle and the clamping needle through the first adhesive particles 1251; the first adhesive particles 1251 can be activated to have adhesion in the compaction process due to temperature increase, so that the inner annular surface of the support body 125 can be adhered by the first adhesive particles 1251 itself, and the support body 125 can form a flat structure without opening. For example, the heat-sensitive adhesive particles can be hot melt adhesive particles (such as ethylene-vinyl acetate (EVA) adhesive particles, etc.), wax composite particles, etc.

[0170] The hot-pressing synergic adhesive particle is an adhesive particle that requires the joint action of temperature and pressure to trigger adhesion. In the case of separate heating or separate pressure, the adhesion effect of the hot-pressing synergic adhesive particle is weak. Under the joint action of temperature and pressure, the hot-pressing synergic adhesive particle can be softened, flowed and fully infiltrated into the contact surface, and then form a high-strength adhesion after cooling. If the first adhesive particle 1251 is a hot-pressing synergic adhesive particle, the first adhesive particle 1251 can be in a low-adhesion state or substantially have no adhesion in the winding process, so that the inner annular surface of the support body 125 cannot be tightly adhered to the winding needle and the clamping needle through the first adhesive particle 1251. The first adhesive particle 1251 can be activated in the compaction process due to the bearing pressure and the temperature rise, so that the inner annular surface of the support body 125 can be adhered by the first adhesive particle 1251 itself, and the support body 125 can form a flat structure without opening. For example, the hot-pressing synergic adhesive particle can be a polyurethane hot-melt pressure-sensitive adhesive particle, an epoxy-phenolic composite particle, etc.

[0171] By adopting the above scheme, by making the first adhesive particle 1251 a pressure-sensitive adhesive particle, a heat-sensitive adhesive particle or a hot-pressing synergic adhesive particle, the first adhesive particle 1251 can be in a low-adhesion state or substantially have no adhesion before the compaction process (including the winding process, the material cutting process and the material moving process), so that the inner annular surface of the support body 125 cannot be tightly adhered to the winding needle and the clamping needle through the first adhesive particle 1251, thereby reducing the risk of the support body 125 and the separator 124 being pulled away due to excessive adhesion force during the pulling of the winding needle and the clamping needle, causing the positive electrode plate 123a and the negative electrode plate 123b to be short-circuited, reducing the risk of the support body 125 and the separator 124 being wrinkled, folded and other defects due to excessive adhesion force, improving the yield of the winding process and the smoothness of the pulling operation, and reducing the pulling failure problem. In the compaction process, the first adhesive particle 1251 can be activated based on temperature and pressure, so that the inner annular surface of the support body 125 can be adhered by the first adhesive particle 1251 itself, the support body 125 can form a flat structure without opening, and the stability and reliability of the structure and form of the support body 125 after compaction can be strengthened.

[0172] Please refer to Figure 6 、 Figure 7 In some embodiments of the present application, the hardness of the support body 125 is greater than the hardness of the separator 124.

[0173] It should be noted that the hardness of the support body 125 is greater than the hardness of the diaphragm 124, that is, the support body 125 is harder than the diaphragm 124, and the support body 125 is made of a relatively hard material. The hardness of the support body 125 refers to the overall hardness of the support body 125, mainly the annular part of the support body 125, not just the hardness of the first adhesive particles 1251. The hardness of the support body 125 and the hardness of the diaphragm 124 can be measured by nanoindentation method, that is, a diamond indenter of a nanoindenter is pressed into the surface of the support body 125 (or the diaphragm 124) with a very small load (μN level), the load-displacement curve is recorded, and the hardness value (hardness value = maximum load / indentation projection area) is calculated. This method can accurately measure the local hardness of the support body 125 (or the diaphragm 124) and reduce the "penetration effect" of the macro method.

[0174] By using the above scheme, by making the hardness of the support body 125 greater than the hardness of the diaphragm 124, the support body 125 can have higher hardness than the diaphragm 124. Based on this, during the needle pulling of the winding needle and the clamping needle, the self anti-deformation ability of the high-hardness support body 125 is stronger than that of the diaphragm 124, and the support body 125 is not easy to twist or sag due to external force pulling during the pulling of the winding needle / clamping needle, and can maintain the annular shape and have high shape stability, thereby reducing the contact deformation and friction resistance between the support body 125 and the winding needle / clamping needle, improving the smoothness of the needle pulling operation, reducing the risk of the support body 125 and the diaphragm 124 being pulled away and causing the positive and negative electrode plates 123a and 123b to be short-circuited, reducing the risk of the support body 125 and the diaphragm 124 being wrinkled, folded and other defects, reducing the risk of structural damage during the needle pulling process, and reducing the risk of needle pulling problems. And because the support body 125 has higher hardness than the diaphragm 124, the flat support body 125 formed by compaction can form a stable "inner ring skeleton" with high hardness, can provide hard support to the inner ring of the diaphragm 124, can continuously resist the rebound stress of the diaphragm 124, and can reliably hinder the diaphragm 124 from rebounding and retracting inward, thereby enabling the electrode assembly 12 to be fully compacted, tightly attached layer by layer, and reducing the interlayer gap, and improving the structural stability and reliability of the electrode assembly 12.

[0175] Please refer to Figure 6 、 Figure 7 In some embodiments of the present application, the surface roughness of the inner annular surface of the support body 125 is less than the surface roughness of the diaphragm 124.

[0176] It should be noted that the surface roughness of the diaphragm 124 is large due to the presence of many particles (such as ceramic powder, etc.) on the surface of the diaphragm 124. Since the inner annular surface of the support body 125 is provided with the first adhesive particles 1251 (and substantially no other particles), and since the inner annular surface of the support body 125 is the main contact interface with the winding needle and the clamping needle, the surface roughness of the inner annular surface of the support body 125 can be designed to be smaller than the surface roughness of the diaphragm 124, so that the inner annular surface of the support body 125 is not completely smooth but smoother than the surface of the diaphragm 124. The surface roughness can be measured by a laser scanning method (non-contact measurement method), that is, by using the principle of laser interference, the laser beam is irradiated on the measured surface (i.e. the inner annular surface of the support body 125 and the surface of the diaphragm 124), the interference signal of the reflected light is received and converted into surface profile data, so that the roughness information of a large area surface can be quickly obtained.

[0177] By using the above scheme, by making the surface roughness of the inner annular surface of the support body 125 smaller than the surface roughness of the diaphragm 124, the inner annular surface of the support body 125 is smoother than the surface of the diaphragm 124. Based on this, during the pulling of the winding needle and the clamping needle, the contact interface between the inner annular surface of the support body 125 and the winding needle and the clamping needle has fewer microscopic concave-convexes and smaller friction with the winding needle and the clamping needle, and is less likely to generate static electricity due to friction and less likely to cause the inner annular surface of the support body 125 to be adhered to the winding needle and the clamping needle due to static electricity, thereby improving the smoothness of the pulling operation, reducing the followability of the support body 125 during pulling, reducing the risk of the support body 125 and the diaphragm 124 being pulled away and causing the positive electrode plate 123a and the negative electrode plate 123b to be short-circuited, reducing the risk of the support body 125 and the diaphragm 124 being wrinkled or folded, reducing the risk of structural damage during the pulling process, reducing the pulling defects, improving the yield of the electrode assembly 12.

[0178] Please refer to Figure 4 , Figure 6 , Figure 7 , Figure 9 In some embodiments of the present application, the thickness d1 of the support body from its outer annular surface to its inner annular surface is 50 μm to 500 μm.

[0179] It should be noted that the thickness d1 of the support body from its outer annular surface to its inner annular surface is 50-500 μm, i.e., the thickness d1 of the support body from its outer annular surface to its inner annular surface is greater than or equal to 50 μm and less than or equal to 500 μm, for example, it can be 50 μm, 100 μm, 150 μm, 200 μm, 250 μm, 300 μm, 350 μm, 400 μm, 450 μm, 500 μm, etc. Wherein, the thickness d1 of the support body from its outer annular surface to its inner annular surface can be measured by image analysis method, for example, the cross-sectional image of the support body 125 can be taken by scanning electron microscope (SEM), and after calibrating the scale by image analysis software (such as Image-Pro Plus), the vertical distance of the outer annular surface and the inner annular surface in the radial direction is directly measured to obtain the thickness d1 of the support body from its outer annular surface to its inner annular surface.

[0180] By adopting the above scheme, by making the thickness d1 of the support body from its outer annular surface to its inner annular surface 50-500 μm, the support body 125 has sufficient thickness and sufficient strength, based on which, the anti-deformation ability of the support body 125 itself can be improved, and the risk of deformation or wrinkling of the support body 125 in the winding and compaction process due to external force can be reduced; the basic supporting ability of the flattened support body 125 can also be improved, which can enable the flattened support body 125 to reliably support the inner circle of the diaphragm 124, provide sufficient reaction force to reliably resist the rebound stress of the diaphragm 124, and reliably hinder the inward rebound and shrinkage of the diaphragm 124; thereby the electrode assembly 12 can be fully compacted, tightly adhered layer by layer, and the interlayer gap can be reduced, and the structural stability and reliability of the electrode assembly 12 can be improved. Moreover, the risk of the support body 125 occupying too much space due to excessive thickness can be reduced, the volume ratio of the support body 125 in the electrode assembly 12 can be reduced, and the energy margin of the battery monomer 10 can be squeezed by the support body 125, thereby the energy density and group margin of the battery monomer 10 can be maintained and improved. Moreover, the risk of the support body 125 excessively occupying the normal expansion space of the electrode assembly 12 due to excessive thickness can be reduced, the risk of the over-thick support body 125 limiting the expansion buffer of the inner circle area can be reduced, the risk of excessive accumulation of expansion force in the later stage of the battery monomer 10 cycle can be reduced, and the risk of deformation of the shell 11, sealing leakage, rupture of the shell 11, short circuit, thermal runaway, etc. caused by excessive expansion force can be reduced, thereby the use reliability and service life of the battery monomer 10 can be maintained and improved.

[0181] Please refer to Figure 4 , Figure 6 , Figure 9 In some embodiments of the present application, the diameter of the first adhesive particle 1251 is 5-30 μm.

[0182] It should be noted that the diameter of the first adhesive particles 1251 (i.e., particle diameter) is 5-30 μm, i.e., the diameter of the first adhesive particles 1251 is greater than or equal to 5 μm and less than or equal to 30 μm, for example, it can be 5 μm, 10 μm, 15 μm, 20 μm, 25 μm, 30 μm, etc. Wherein, the diameter of the first adhesive particles 1251 can be measured by a scanning electron microscope (SEM) method, and the steps can be referred to as follows: a small amount of sample containing the first adhesive particles 1251 is peeled off from the inner annular surface of the support 125 and dispersed on a conductive substrate (such as a carbon film slide); if the particles are prone to agglomeration, ultrasonic dispersion can be used for auxiliary dispersion; a clear image of the particles is obtained by SEM, and the size measurement tool (such as a ruler calibrated directly) of the device is used to measure the diameter of a plurality of particles, and the average value or distribution range is taken to obtain the diameter of the first adhesive particles 1251.

[0183] By adopting the above scheme, by making the diameter of the first adhesive particles 1251 5-30 μm, the risk of agglomeration of the first adhesive particles 1251 due to too small particles, too large specific surface area, and too high surface energy can be reduced, the particle dispersibility of the first adhesive particles 1251 can be improved, and the first adhesive particles 1251 are not prone to agglomeration, the uniformity of the bonding point distribution of the inner annular surface of the support 125 can be improved; the risk of reducing the number of bonding points due to too large particles, limited contact area, and increased gap between particles can be reduced, a sufficient number of bonding points in a unit area of the inner annular surface of the support 125 can be formed, and the single first adhesive particle 1251 has a moderate contact area and bonding area; thereby the bonding strength of the first adhesive particles 1251 can be optimized, the inner annular surface of the support 125 can be effectively bonded by the first adhesive particles 1251 during the compaction process, and the support 125 can form a stable flat structure without opening. Moreover, the influence of the first adhesive particles 1251 on the thickness increase of the electrode assembly 12 after compaction can be reduced, the risk of increasing the thickness of the electrode assembly 12 after compaction due to too large particles can be reduced, thereby the energy margin of the battery monomer 10 can be reduced by the support 125 and the first adhesive particles 1251 thereof, and the energy density and group margin of the battery monomer 10 can be maintained and improved.

[0184] Please refer to Figure 10 , Figure 11 , Figure 12 In some embodiments of the present application, the outer annular surface of the support 125 is provided with at least one groove 1252, and the groove depth d2 of the groove is less than the thickness d1 of the support from its outer annular surface to its inner annular surface.

[0185] It should be noted that the outer annular surface of the support 125 is provided with at least one groove 1252, and the groove 1252 can be a straight groove 1252a (such as Figure 13As shown), zigzag grooves, curved grooves (e.g., annular groove 1252b (as shown) Figure 14 As shown), arc-shaped groove 1252c (as shown) Figure 15 As shown), wavy grooves, etc.), dotted grooves 1252d (such as...) Figure 16 (as shown in the figure). When multiple grooves 1252 are provided, the multiple grooves 1252 can be flexibly arranged on the outer ring surface of the support body 125, such as horizontal and vertical intersections, matrix array distribution, equal spacing, unequal spacing, etc.; the shape and size of the multiple grooves 1252 can be the same or different. The groove depth d2 is less than the thickness d1 of the support body from its outer ring surface to its inner ring surface, that is, the groove 1252 does not penetrate the support body 125 along its groove depth direction.

[0186] By adopting the above solution, and by providing a groove 1252 on the outer ring surface of the support 125, the electrode assembly 12 can be fully compacted, and the electrode assembly 12 can be positioned within the inner ring of the electrode assembly 12 (especially between the tightly fitted support 125 and the diaphragm 124, such as...). Figure 6 , Figure 7 (As shown) provides an electrolyte wetting channel, enabling the electrolyte to diffuse smoothly and fully penetrate into the inner ring of the electrode assembly 12. This improves the problem of slow electrolyte filling speed and poor local wetting of the inner ring caused by the tight fit of the inner ring, and can maintain and improve the battery cell 10 (such as...). Figure 4 The electrochemical performance (shown) is improved. Furthermore, the groove 1252 can reserve electrolyte storage space to pre-store electrolyte. During the later stages of battery cell 10 cycling, the electrolyte stored in the groove 1252 is released through expansion and compression, thereby replenishing the electrolyte, compensating for consumption, and maintaining and improving the electrolyte retention capacity, cycle performance, and service life of the battery cell 10. Moreover, since the groove depth d2 is less than the thickness d1 of the support body from its outer ring surface to its inner ring surface, the groove 1252 is only partially recessed on the outer ring surface of the support body 125, without disrupting the overall continuity of the support body 125. This maintains the structural strength of the annular support body 125, maintains the basic support capacity of the compacted flat support body 125, and enables the compacted flat support body 125 to reliably support the inner ring of the separator 124, resisting the rebound stress of the separator 124 and preventing the separator 124 from rebounding or shrinking inward.

[0187] Of course, such as Figure 8 , Figure 9 As shown, in other embodiments, the outer ring surface of the support 125 may not have a groove 1252.

[0188] Please see Figure 6 , Figure 12 , Figure 13 , Figure 15In some embodiments of the present application, the at least one groove 1252 is a straight groove 1252a.

[0189] It should be noted that the at least one groove 1252 is a straight groove 1252a, and the extension direction of the straight groove 1252a can be parallel to the axial direction of the support body 125, or can be parallel to the circumferential direction of the support body 125, or can intersect the axial direction of the support body 125 and the circumferential direction of the support body 125. The axial direction of the support body 125 is the extension direction of the central axis of the support body 125, and the circumferential direction of the support body 125 is the surrounding direction of the outer ring surface of the support body 125.

[0190] For example, as shown in some embodiments, the outer ring surface of the support body 125 is provided with a plurality of straight grooves 1252a, and the extension directions of some of the straight grooves 1252a are parallel to the axial direction of the support body 125, and the extension directions of the other straight grooves 1252a are parallel to the circumferential direction of the support body 125, thereby forming a cross layout. Figure 12 For example, as shown in some embodiments, the outer ring surface of the support body 125 is provided with a plurality of straight grooves 1252a, and the extension directions of some of the straight grooves 1252a are parallel to the axial direction of the support body 125, and the extension directions of the other straight grooves 1252a are parallel to the circumferential direction of the support body 125, thereby forming a cross layout.

[0191] Figure 13 For example, as shown in some embodiments, the outer ring surface of the support body 125 is provided with a plurality of straight grooves 1252a, and the extension directions of some of the straight grooves 1252a are parallel to the axial direction of the support body 125, and the extension directions of the other straight grooves 1252a are parallel to the circumferential direction of the support body 125, thereby forming a cross layout.

[0192] By adopting the above scheme, by making the groove 1252 a straight groove 1252a, the extension path of the groove 1252 can be simple and free of redundant bending, which can reduce the flow resistance of the electrolyte in the groove 1252, and can promote the directional transmission and directional diffusion of the electrolyte along the extension direction of the groove 1252, thereby improving the transmission directionality and transmission efficiency of the electrolyte along the groove 1252, improving the electrolyte filling speed, and improving the wetting effect of the inner ring of the electrode assembly 12. Moreover, the "straight line characteristic" of the straight groove 1252a can promote the flow and storage of the electrolyte in the groove, and can reduce the local liquid accumulation or flow dead angle caused by bending, thereby improving the uniformity of electrolyte wetting and the reliability of storage compensation. Moreover, the edges of the straight groove 1252a are regular, and the stress concentration effect is weaker than that of a curved groove, which can reduce the risk of local fracture of the support body 125 caused by the straight groove 1252a during compaction or cycling. Moreover, the processing technology of the straight groove 1252a is simplified, and the processing difficulty is relatively low, which can improve the processing feasibility, processing convenience and processing consistency.

[0193] Please refer to Figure 4 , Figure 6 , Figure 14 ​In some embodiments of the present application, the at least one groove 1252 is a ring-shaped groove 1252b.

[0194] It should be noted that the at least one groove 1252 is a ring-shaped groove 1252b. In some embodiments, the groove 1252 is ring-shaped in a top view of the outer surface of the support body 125, for example, circular ring-shaped, polygonal ring-shaped, etc. In some embodiments, the groove 1252 is ring-shaped along the circumferential direction of the support body 125. For example, as shown in FIG. 12, in some embodiments, the plurality of ring-shaped grooves 1252b are arranged in a matrix array in a top view of the outer surface of the support body 125. Figure 14

[0195] By adopting the above scheme, by making the groove 1252 a ring-shaped groove 1252b, a circumferential electrolyte channel can be formed in the outer surface of the support body 125 via the ring-shaped groove 1252b, so that the electrolyte can uniformly diffuse along the ring-shaped path and cover a larger area of the outer surface of the support body 125, thereby reducing the local immersion blind area and improving the uniformity and consistency of electrolyte immersion. In addition, a circumferential storage space can also be formed via the ring-shaped groove 1252b, so that the electrolyte is uniformly distributed and stably stored in the ring-shaped groove 1252b. In the later stage of the cycle of the battery cell 10, under the expansion and extrusion of the electrode assembly 12, the electrolyte in the ring-shaped groove 1252b can be uniformly released along the ring-shaped path, so as to supplement the electrolyte in the ring-shaped groove 1252b and the surrounding area, thereby optimizing the cycle life and liquid retention capacity of the battery cell 10. In addition, the closed profile of the ring-shaped groove 1252b can make the stress distribution of the edge more symmetrical, and the stress of the ring-shaped groove 1252b (especially the circular ring-shaped groove) can be uniformly dispersed along the circumferential direction, thereby reducing the risk of local fracture of the support body 125 caused by the ring-shaped groove 1252b in the compaction process or long-term cycle, and maintaining the overall structural strength of the support body 125.

[0196] Please refer to Figure 4 、 Figure 6 、 Figure 15 In some embodiments of the present application, the at least one groove 1252 is an arc-shaped groove 1252c.

[0197] It should be noted that the at least one groove 1252 is an arc-shaped groove 1252c, i.e., the groove 1252 is arc-shaped in a top view of the outer surface of the support body 125, for example, semicircular arc-shaped, etc.

[0198] ​By adopting the above scheme, since the extension range of the arc-shaped groove 1252c is between the unidirectionality of the straight groove 1252a and the full-circumferentiality of the annular groove 1252b, the arc-shaped groove 1252c can form a wider coverage in a specific arc region, and can guide the electrolyte to the area prone to insufficient wetting in the inner ring (such as the area near the corner of the flat support 125) through the directional extension of the arc shape, thereby improving the local wetting blind area and balancing the directionality and coverage of the electrolyte wetting. Moreover, the curved shape of the arc-shaped groove 1252c can form an "arc-shaped storage space" on the outer surface of the support 125, and after the cycle of the battery monomer 10, under the expansion and extrusion of the electrode assembly 12, the electrolyte stored in the arc-shaped groove 1252c can diffuse to the periphery along the arc-shaped path, thereby optimizing the cycle life and liquid retention capacity of the battery monomer 10. Moreover, the edge of the arc-shaped groove 1252c is a smooth curve transition, and the stress concentration effect is weak, which can reduce the risk of cracking of the support 125 due to edge stress concentration in the compaction process or long-term cycle.

[0199] Please refer to Figure 4 、 Figure 6 、 Figure 16 In some embodiments of the present application, at least one groove 1252 is a point-shaped groove 1252d.

[0200] It should be noted that at least one groove 1252 is a point-shaped groove 1252d, that is, the groove 1252 is point-shaped, such as circular point-shaped, polygonal point-shaped, etc., similar to a hole structure, under the visual angle of viewing the outer surface of the support 125. For example, as shown in Figure 16 In some embodiments, the plurality of point-shaped grooves 1252d are arranged in a matrix array under the visual angle of viewing the outer surface of the support 125.

[0201] By adopting the above scheme, based on the "point distribution" characteristic of the dotted groove 1252d, the dotted groove 1252d can be set in local areas in the inner ring of the electrode assembly 12 where insufficient wetting is likely to occur. That is, the dotted groove 1252d can be discretized according to the wetting requirements of the inner ring to adapt to the improvement of local wetting shortcomings, thereby achieving precise replenishment of specific wetting blind areas and improving the flexibility, accuracy and targeting of electrolyte wetting. Furthermore, the multiple discretely distributed dot-shaped grooves 1252d can form a decentralized electrolyte storage space, ensuring that electrolyte is stored at different positions on the outer ring surface of the support 125. Based on this, in the later stages of battery cell 10 cycling, as the electrode assembly 12 expands and compresses, the electrolyte in each dot-shaped groove 1252d can be released to the surrounding area. This reduces the problem of concentrated or insufficient electrolyte release caused by uneven local compression in a single long groove, thereby improving the uniformity of electrolyte replenishment. It facilitates reliable compensation for electrolyte consumption during cycling and helps maintain the long-term cycling performance of the battery cell 10. In addition, the dot-shaped grooves 1252d have a small and dispersed weakening effect on the overall strength of the support 125, and the edge stress concentration range of a single dot-shaped groove 1252d is small, which can reduce the risk of local fracture of the support 125 due to the dot-shaped grooves 1252d during the compaction process or long-term cycling. Furthermore, the dotted groove 1252d can be processed through simple processes such as stamping and drilling. The position, quantity, and size of the dotted groove 1252d can be flexibly adjusted, making it highly feasible and adaptable to various processing requirements.

[0202] It should be noted that when the outer ring surface of the support 125 has multiple grooves 1252, the aforementioned straight grooves 1252a, annular grooves 1252b, arc-shaped grooves 1252c, and dotted grooves 1252d can be selected or arbitrarily combined. For example, such as Figure 15 As shown, in some embodiments, a half-area of ​​the outer annular surface of the support body 125 is provided with four straight grooves 1252a and four arc-shaped grooves 1252c. The extending directions of the straight grooves 1252a intersect the axial direction and the circumferential direction of the support body 125. The four straight grooves 1252a are combined in pairs, and the two pairs of straight grooves 1252a intersect each other to form an "X" shape. The two sets of straight grooves 1252a are arranged adjacent to each other and connected to each other. The four arc-shaped grooves 1252c are combined in pairs, with one set of arc-shaped grooves 1252c located on one side of the four straight grooves 1252a and the other set of arc-shaped grooves 1252c located on the other side of the four straight grooves 1252a. The two sets of arc-shaped grooves 1252c are connected in sequence to form an "m" shape and are connected between two straight grooves 1252a.

[0203] Of course, in other embodiments, the groove 1252 may be in other forms, such as a zigzag groove, a wavy groove, or a curved groove, etc.

[0204] Please see Figure 10In some embodiments of the present application, the groove width d3 of the groove is 50-500 μm, and the groove depth d2 of the groove is 50-500 μm.

[0205] It should be noted that the groove width d3 of the groove is 50-500 μm, i.e., the groove width d3 of the groove is greater than or equal to 50 μm and less than or equal to 500 μm, for example, it can be 50 μm, 100 μm, 150 μm, 200 μm, 250 μm, 300 μm, 350 μm, 400 μm, 450 μm, 500 μm, etc. The groove width d3 of the groove can be measured by a scanning electron microscope (SEM), i.e., the edge of the groove 1252 can be clearly displayed by electronic imaging, and the groove width d3 can be directly read by using the scale function of the SEM.

[0206] The groove depth d2 of the groove is 50-500 μm, i.e., the groove width d3 of the groove is greater than or equal to 50 μm and less than or equal to 500 μm, for example, it can be 50 μm, 100 μm, 150 μm, 200 μm, 250 μm, 300 μm, 350 μm, 400 μm, 450 μm, 500 μm, etc. The groove width d3 of the groove and the groove depth d2 of the groove are in the same range, but the specific values can be the same or different. The groove depth d2 of the groove can be measured by a laser confocal microscope, i.e., the surface of the groove 1252 can be scanned by laser to generate a three-dimensional topography map, and the vertical height difference between the bottom of the groove 1252 and the outer ring surface can be directly read to obtain the groove depth d2 of the groove.

[0207] By using the above scheme, by making the groove width d3 of the groove 50-500 μm and the groove depth d2 of the groove 50-500 μm, the groove 1252 can form a capillary structure, which can promote the adsorption of the electrolyte by the groove 1252 in a capillary structure, i.e., the adsorption capacity of the electrolyte by the groove 1252 can be optimized. Moreover, the capillary phenomenon (driven by the surface tension of the liquid and the adhesion of the groove 1252 wall) can be mainly relied on to promote the wicking of the electrolyte, i.e., to promote the flow of the electrolyte in the groove 1252, which can reduce the risk of capillary blockage due to too small size, thereby hindering the flow of the electrolyte, and can reduce the risk of the gravity of the electrolyte exceeding the capillary force due to too large size, thereby causing the electrolyte to sink and gather, hindering the diffusion and infiltration of the electrolyte, thereby balancing and optimizing the infiltration effect and speed of the electrolyte. Moreover, based on the settings of the present embodiment, the volume of the groove 1252 is moderate, which can store sufficient electrolyte for compensation in the later circulation period, and will not weaken the supporting strength and pressure resistance of the support body 125.

[0208] Please refer to Figure 4 , Figure 17 , Figure 18 , Figure 19In some embodiments of the present application, the battery cell 10 includes a housing 11 having opposite first and second end walls 111 and 112 and a side wall 113 connecting between the first and second end walls 111 and 112. The electrode assembly 12 is disposed within the housing 11, and the electrode assembly 12 includes a main body portion 121 and a tab 122 extending out of the main body portion 121 toward the first end wall 111, the tab 122 being electrically isolated from the side wall 113, and the electrode assembly 12 being electrically isolated from the second end wall 112.

[0209] It is noted that the housing 11 is a component for isolating the internal environment of the battery cell 10 from the external environment. The internal environment enclosed by the housing 11 can be used to accommodate components such as the electrode assembly 12 and electrolyte. The housing 11 can include the side wall 113, the first end wall 111 and the second end wall 112. The side wall 113 can be in a cylindrical shape, such as a circular cylindrical shape, a rectangular cylindrical shape, a polygonal cylindrical shape, etc. The first and second end walls 111 and 112 are respectively capped on opposite ends of the side wall 113, so that the internal space enclosed by the side wall 113, the first end wall 111 and the second end wall 112 is isolated from the external environment. In addition, other relevant descriptions of the housing 11 and its side wall 113, first end wall 111 and second end wall 112 can be referred to the foregoing, and will not be repeated here.

[0210] The electrode assembly 12 is disposed within the housing 11, and the electrode assembly 12 includes the main body portion 121 and the tab 122 extending out of the main body portion 121 toward the first end wall 111, the tab 122 being a current transmission end of the electrode assembly 12 for transmitting current. In addition, other relevant descriptions of the electrode assembly 12 and its main body portion 121 and tab 122 can be referred to the foregoing, and will not be repeated here.

[0211] The tab 122 is electrically isolated from the side wall 113 to reduce the risk of short circuit caused by direct contact between the tab 122 and the side wall 113. The tab 122 can be electrically isolated from the side wall 113 by, but not limited to, the insulating member 13, the support body 125, the insulating shell 17 and other insulating components.

[0212] The electrode assembly 12 is electrically isolated from the second end wall 112 to reduce the risk of short circuit caused by direct contact between the electrode assembly 12 and the second end wall 112. The electrode assembly 12 can be electrically isolated from the second end wall 112 by, but not limited to, the insulating shell 17, the bottom support plate 18 and other insulating components.

[0213] By adopting the above scheme, on the basis of accommodating and protecting the electrode assembly 12 by the shell 11, the risk of short circuit caused by direct contact between the tab 122 and the side wall 113 and between the electrode assembly 12 and the second end wall 112 can be reduced by electrically isolating the tab 122 of the electrode assembly 12 from the side wall 113 and electrically isolating the electrode assembly 12 from the second end wall 112. Thus, the stable operation of the battery monomer 10 can be maintained, and the use reliability and service life of the battery monomer 10 can be improved.

[0214] Please refer to Figure 4 、 Figure 17 、 Figure 18 In some embodiments of the present application, the electrode assembly 12 is provided in a plurality, and the plurality of electrode assemblies 12 are arranged side by side along the first direction x. Among the electrode assemblies 12, the two electrode assemblies 12 located at both ends along the first direction x are first electrode assemblies 12a, the support body 125 of the first electrode assembly 12a is an insulating member, and has a first extension 1253 extending to the outside of the main body 121 towards the first end wall 111, and the tabs 122 of each electrode assembly 12 are located between the two first extensions 1253 and are electrically isolated from the side wall 113 by the two first extensions 1253.

[0215] It should be noted that the present embodiment is applicable to the case where the electrode assembly 12 is provided in a plurality. Inside the shell 11, the plurality of electrode assemblies 12 can be arranged side by side along the first direction x, and the first direction x can correspond to the thickness direction of the electrode assembly 12.

[0216] Among the electrode assemblies 12, the two electrode assemblies 12 located at both ends along the first direction x are first electrode assemblies 12a, for example, as shown in Figure 17As shown, if the electrode assembly 12 is provided with two, the two electrode assemblies 12 are the first electrode assembly 12a; for example, if the electrode assembly 12 is provided with three, the two electrode assemblies 12 located at the two ends along the first direction x are the first electrode assembly 12a, and the electrode assembly 12 located in the middle is not the first electrode assembly 12a; and so on. The support body 125 of the first electrode assembly 12a is an insulating component and has insulating properties, for example, the material of the support body 125 of the first electrode assembly 12a can be a polyester film (polyethylene terephthalate, PET, Polyethylene Terephthalate) or the like. The support body 125 of the first electrode assembly 12a has a first extension 1253 extending out of the main body 121 towards the first end wall 111, and the first extension 1253 can be in abutting or spaced relationship with the first end wall 111. Since the first electrode assembly 12 is provided with two, the first extension 1253 is also provided with two. The tab 122 of each electrode assembly 12 can be located between the two first extensions 1253, so that the tab 122 of each electrode assembly 12 can be electrically isolated from the side wall 113 by the two first extensions 1253.

[0217] By adopting the above scheme, in the case where a plurality of electrode assemblies 12 are arranged side by side along the first direction x, the tabs 122 of all the electrode assemblies 12 can be constrained between the two first extensions 1253 by forming the insulating support bodies 125 of the two first electrode assemblies 12a to extend towards the first end wall 111 to form the first extensions 1253, and enclosing a unified isolation space via the two first extensions 1253. Based on this, a "enclosing type" insulating protective wall can be formed via the two first extensions 1253, which can physically block the tabs 122 from being offset to the side wall 113 due to vibration, deformation, etc., thereby reliably preventing the tabs 122 from directly contacting the side wall 113 to form a conductive path, reducing the risk of short circuit caused by direct contact between the tabs 122 and the side wall 113, improving insulation reliability, and improving the use reliability and service life of the battery monomer 10. Moreover, based on the arrangement of the present embodiment, there is no need to design an insulating structure for each tab 122 individually, thereby simplifying the insulation scheme in the multi-tab 122 scenario, reducing the number of independent insulating components, and simplifying and optimizing the structure of the battery monomer 10. Moreover, the support body 125 itself bears the winding support function of the electrode assembly 12, and the first extension 1253 formed by the extension additionally bears the isolation function of the tab 122, achieving "one material with multiple functions" and "function reuse". Based on this functional integration, the space reserved for isolating the tabs 122 (such as a separate insulating space reserved between the side wall 113 and the tabs 122) can be reduced, thereby helping to compress the internal redundancy of the battery monomer 10 and improve the space utilization and energy density of the battery monomer 10.

[0218] Please refer toFigure 4 、 Figure 17 、 Figure 19 In some embodiments of the present application, the battery cell 10 comprises an insulating shell 17 arranged in the outer shell 11, the insulating shell 17 is arranged outside the electrode assembly 12, and the electrode assembly 12 is electrically isolated from the side wall 113 and the second end wall 112 through the insulating shell 17.

[0219] It should be noted that the present embodiment is applicable to the case of "one electrode assembly 12", and also applicable to the case of "multiple electrode assemblies 12".

[0220] The insulating shell 17 is arranged in the outer shell 11, and the insulating shell 17 is a shell-shaped structure with insulating properties with an open top. The electrode assembly 12 is contained in the insulating shell 17, so that the insulating shell 17 is arranged outside the electrode assembly 12, especially the part of the electrode assembly 12 except the top (i.e. the circumferential side and the bottom of the electrode assembly 12). The insulating shell 17 is made of insulating material and has insulating properties. The insulating shell 17 is used to insulate and isolate the electrode assembly 12 from the side wall 113 and the second end wall 112, so as to achieve electrical isolation between the electrode assembly 12 and the side wall 113 (especially between the tab 122 and the side wall 113), and between the electrode assembly 12 and the second end wall 112, and reduce the risk of direct contact and short circuit between the electrode assembly 12 and the side wall 113 (especially between the tab 122 and the side wall 113), and between the electrode assembly 12 and the second end wall 112. The insulating shell 17 can be made of inorganic insulating material, such as silicon oxide, silicon nitride, aluminum oxide, aluminum nitride, etc. The insulating shell 17 can also be made of organic insulating material, such as polyimide, polyethylene, polyvinylidene fluoride, polytetrafluoroethylene, etc.

[0221] By adopting the above scheme, an insulating shell 17 is added in the outer shell 11 to cover the electrode assembly 12, and an overall and comprehensive insulating barrier is constructed, so as to uniformly achieve electrical isolation between the electrode assembly 12 and the side wall 113 (especially between the tab 122 and the side wall 113), and between the electrode assembly 12 and the second end wall 112, and reduce the risk of direct contact and short circuit between the electrode assembly 12 and the side wall 113 (especially between the tab 122 and the side wall 113), and between the electrode assembly 12 and the second end wall 112, and reduce the risk of multi-path short circuit, thereby improving the insulation reliability, and improving the use reliability and service life of the battery cell 10. Moreover, the present embodiment is compatible with different numbers of electrode assemblies 12, and there is no need to adjust the insulation scheme according to the number of electrode assemblies 12, and there is no need to design an insulating structure for each electrode assembly 12, each tab 122, and multiple side edges of the electrode assembly 12, thereby improving the generality of the insulation design, simplifying the insulation scheme, and reducing independent insulating components, and simplifying and optimizing the structure of the battery cell 10.

[0222] It should be noted that the present embodiment and the previous embodiment can be set alternatively or in combination to achieve electrical isolation between the tab 122 and the side wall 113. As shown in Figure 17 some embodiments, the electrical isolation between the tab 122 and the side wall 113 can be achieved by the insulating shell 17 and the two first extension parts 1253 together. In this way, the insulation reliability between the tab 122 and the side wall 113 can be improved, and the use reliability and service life of the battery monomer 10 can be improved. As shown in Figure 18 some other embodiments, the electrical isolation between the tab 122 and the side wall 113 can be achieved by the two first extension parts 1253 only. Since the electrode assembly 12 itself can be electrically isolated from the side wall 113 based on the diaphragm 124, the insulating shell 17 covering the electrode assembly 12 can be omitted. In this way, the occupied space of the insulating shell 17 can be saved, and the space utilization of the battery monomer 10 in the first direction x and the second direction can be improved, thereby improving the volumetric energy density of the battery monomer 10, wherein the second direction is a direction perpendicular to the first direction x and the thickness direction of the first end wall 111. As shown in Figure 19 some other embodiments, the electrical isolation between the tab 122 and the side wall 113 can be achieved by the insulating shell 17 only, and the two first extension parts 1253 can be omitted. In this way, the occupied space of the two first extension parts 1253 can be saved, and the saved space can be used to store electrolyte, thereby improving the ion conduction efficiency, optimizing the rate performance, cycle life and long-term stability of the battery monomer 10, and the application range of this case is wider, which can be applied to the case of “one electrode assembly 12” or “multiple electrode assemblies 12”, and the case of “flexible layout of the tab 122 on any side of the support 125”.

[0223] Please refer to Figure 18 , Figure 19 In some embodiments of the present application, the battery monomer 10 includes a bottom support plate 18 arranged in the shell 11, and the bottom support plate 18 is arranged between the electrode assembly 12 and the second end wall 112, and the electrode assembly 12 is electrically isolated from the second end wall 112 through the bottom support plate 18.

[0224] It should be noted that the present embodiment is applicable to the case of “one electrode assembly 12” and the case of “multiple electrode assemblies 12”.

[0225] The bottom support plate 18 is arranged in the shell 11 and between the electrode assembly 12 and the second end wall 112. The bottom support plate 18 is made of insulating material and has insulating performance. The bottom support plate 18 can provide reliable support to the electrode assembly 12 and be insulated between the electrode assembly 12 and the second end wall 112.

[0226] By adopting the above scheme, by additionally arranging the bottom supporting plate 18 between the electrode assembly 12 and the second end wall 112, reliable support can be provided to the electrode assembly 12 via the bottom supporting plate 18, and the bottom supporting plate 18 serves as a physical separation layer between the electrode assembly 12 and the second end wall 112 to directly block the conductive contact between the electrode assembly 12 and the second end wall 112, so as to realize the electrical isolation between the electrode assembly 12 and the second end wall 112 and reduce the risk of short circuit caused by the direct contact between the electrode assembly 12 and the second end wall 112. In addition, the bottom supporting plate 18 can cover the bottom of the electrode assembly 12 through its flat support surface to disperse the pressure and reduce the risk of insulation damage. Therefore, the insulation reliability can be improved, and the use reliability and service life of the battery monomer 10 can be improved. In addition, the present embodiment is compatible with different numbers of electrode assemblies 12, and there is no need to adjust the insulation scheme according to the number of electrode assemblies 12, and there is no need to design an insulation structure for each electrode assembly 12. Therefore, the insulation design versatility can be improved, the insulation scheme can be simplified, and the number of independent insulation components can be reduced, so that the structure of the battery monomer 10 can be simplified and optimized.

[0227] It should be noted that the present embodiment and the previous embodiment can be set alternatively or in combination to realize the electrical isolation between the electrode assembly 12 and the second end wall 112. As shown in FIG. 1B, in some embodiments, the electrical isolation between the electrode assembly 12 and the second end wall 112 can be realized only by the insulating shell 17, and the bottom supporting plate 18 is omitted. By such arrangement, the occupied space of the bottom supporting plate 18 can be saved, the space utilization of the battery monomer 10 in the thickness direction of the first end wall 111 can be improved, and the energy density of the battery monomer 10 can be improved. Figure 17 Figure 18 As shown in FIG. 1C, in another embodiment, the electrical isolation between the electrode assembly 12 and the second end wall 112 can be realized only by the bottom supporting plate 18, and the insulating shell 17 is omitted. By such arrangement, the occupied space of the insulating shell 17 can be saved, the space utilization of the battery monomer 10 in the first direction x and the second direction can be improved, so that the volumetric energy density of the battery monomer 10 can be improved, wherein the second direction is a direction perpendicular to the first direction x and the thickness direction of the first end wall 111. Figure 19 As shown in FIG. 1D, in another embodiment, the electrical isolation between the electrode assembly 12 and the second end wall 112 can be realized by the insulating shell 17 and the bottom supporting plate 18. By such arrangement, the insulation reliability between the electrode assembly 12 and the second end wall 112 can be improved, and the use reliability and service life of the battery monomer 10 can be improved.

[0228] ​Since the two first extensions 1253 and the insulating shell 17 can be used for electrical isolation between the tab 122 and the side wall 113, and since the insulating shell 17 and the base plate 18 can be used for electrical isolation between the electrode assembly 12 and the second end wall 112, the two first extensions 1253, the insulating shell 17, and the base plate 18 can be combined into five schemes to achieve electrical isolation between the tab 122 and the side wall 113, and between the electrode assembly 12 and the second end wall 112. For example... Figure 17 As shown, in some embodiments, electrical isolation between the tab 122 and the sidewall 113 can be achieved jointly by the insulating shell 17 and the two first extensions 1253, and electrical isolation between the electrode assembly 12 and the second end wall 112 can be achieved solely by the insulating shell 17, omitting the bottom support plate 18. This configuration improves insulation reliability, enhances the reliability and lifespan of the battery cell 10, and saves the space occupied by the bottom support plate 18, thereby improving the space utilization of the battery cell 10 in the thickness direction of the first end wall 111 and increasing the energy density of the battery cell 10. Figure 18 As shown, in some other embodiments, electrical isolation between the tab 122 and the sidewall 113 can be achieved solely through the two first extensions 1253, and electrical isolation between the electrode assembly 12 and the second endwall 112 can be achieved solely through the bottom support plate 18, omitting the insulating shell 17. This arrangement saves space occupied by the insulating shell 17, improving the space utilization of the battery cell 10 in the first direction x and the second direction, thereby increasing the volumetric energy density of the battery cell 10. The second direction is perpendicular to both the first direction x and the thickness direction of the first endwall 111. Figure 19As shown, in some other embodiments, electrical isolation between the tab 122 and the sidewall 113 can be achieved solely through the insulating shell 17, and electrical isolation between the electrode assembly 12 and the second endwall 112 can be achieved jointly through the insulating shell 17 and the bottom plate 18. Furthermore, the two first extensions 1253 are omitted. This arrangement saves the space occupied by the two first extensions 1253, and the freed-up space can be used to store electrolyte, thereby improving ion conduction efficiency and optimizing the rate performance, cycle life, and long-term stability of the battery cell 10. Additionally, the insulating shell 17 and the bottom plate 18 can improve the insulation reliability between the electrode assembly 12 and the second endwall 112, thereby enhancing the reliability and service life of the battery cell 10. In other embodiments, electrical isolation between the tab 122 and the sidewall 113 can be achieved by the insulating shell 17 and the two first extensions 1253, and electrical isolation between the electrode assembly 12 and the second endwall 112 can be achieved by the insulating shell 17 and the bottom plate 18. This configuration can improve the insulation reliability between the tab 122 and the sidewall 113, and between the electrode assembly 12 and the second endwall 112, thereby improving the reliability and service life of the battery cell 10. In other embodiments, electrical isolation between the tab 122 and the sidewall 113, as well as electrical isolation between the electrode assembly 12 and the second endwall 112, can be achieved solely through the insulating shell 17. This arrangement saves the space occupied by the two first extensions 1253, and the freed-up space can be used to store electrolyte, thereby improving ion conduction efficiency and optimizing the rate performance, cycle life, and long-term stability of the battery cell 10. It also saves the space occupied by the bottom plate 18, which can improve the space utilization rate of the battery cell 10 in the thickness direction of the first endwall 111 and improve the energy density of the battery cell 10.

[0229] Please see Figure 17 , Figure 18 In some embodiments of this application, the battery cell 10 includes an insulating support 19 disposed within the housing 11. The insulating support 19 abuts against the side of the electrode assembly 12 facing the second end wall 112. The support body 125 of the electrode assembly 12 has a second extension 1254 extending out of the main body 121. The second extension 1254 is connected to the insulating support 19.

[0230] It should be noted that the insulating support 19 is disposed inside the housing 11, between the electrode assembly 12 and the second end wall 112, and in contact with the side of the electrode assembly 12 facing the second end wall 112. The insulating support 19 is made of insulating material and has insulating properties.

[0231] In the embodiment in which the electrical isolation between the electrode assembly 12 and the second end wall 112 is achieved only by the insulating shell 17, and in the embodiment in which the electrical isolation between the electrode assembly 12 and the second end wall 112 is achieved by the insulating shell 17 and the bottom support plate 18 together, since the portion of the insulating shell 17 located between the electrode assembly 12 and the second end wall 112 is in abutting contact with the electrode assembly 12, the portion of the insulating shell 17 located between the electrode assembly 12 and the second end wall 112 is the insulating support 19.

[0232] In the embodiment in which the electrical isolation between the electrode assembly 12 and the second end wall 112 is achieved only by the bottom support plate 18, since the bottom support plate 18 is in abutting contact with the side of the electrode assembly 12 facing the second end wall 112, the bottom support plate 18 is the insulating support 19.

[0233] The support body 125 of the electrode assembly 12 can have a second extension 1254 extending out of the main body 121 towards the insulating support 19, and the second extension 1254 is connected and fixed with the insulating support 19, so that the electrode assembly 12 is fixed relative to the insulating support 19, and the position and state of the electrode assembly 12 relative to the insulating support 19 are stabilized. The connection between the second extension 1254 and the insulating support 19 can be achieved by hot melting, ultrasonic welding, or adhesion, etc. The present embodiment is applicable to the case where the electrode assembly 12 is provided with one, and is also applicable to the case where the electrode assembly 12 is provided with multiple.

[0234] By adopting the above scheme, on the basis of abutting supporting the electrode assembly 12 by the insulating support 19 and achieving the electrical isolation between the electrode assembly 12 and the second end wall 112, the support body 125 of the electrode assembly 12 can be extended to form a second extension 1254, and the second extension 1254 is connected and fixed with the insulating support 19, so as to form a fixed point between the electrode assembly 12 and the insulating support 19, to facilitate the fixation of the electrode assembly 12 relative to the insulating support 19, to stabilize the position and state of the electrode assembly 12 relative to the insulating support 19, and to hinder the electrode assembly 12 from moving relative to the insulating support 19, so as to improve the structural stability and reliability of the battery monomer 10. During the use of the battery monomer 10, since the position stability of the electrode assembly 12 is improved and the risk of movement is reduced, the risk of contact short circuit between the electrode assembly 12 and the second end wall 112 caused by the relative displacement between the electrode assembly 12 and the insulating support 19 is reduced, and the risk of contact short circuit between the tab 122 of the electrode assembly 12 and the side wall 113 caused by the position deviation of the tab 122 is reduced, so as to reduce the risk of short circuit and improve the use reliability and service life of the battery monomer 10.

[0235] Of course, in other embodiments, the support body 125 of the electrode assembly 12 can omit the second extension 1254. In this way, the space occupied by the second extension 1254 can be saved, and the saved space can be used to store electrolyte, thereby improving ion conduction efficiency and optimizing the rate performance, cycle life, and long-term stability of the battery monomer 10.

[0236] Please refer to Figure 17 , Figure 18 In some embodiments of the present application, the second extension 1254 is bent and arranged between the main body 121 and the insulating support 19.

[0237] It should be noted that the second extension 1254 is first bent between the main body 121 and the insulating support 19, and then connected and fixed with the insulating support 19.

[0238] By adopting the above scheme, by bending the second extension 1254 between the main body 121 and the insulating support 19, the contact area and the connection area of the second extension 1254 and the insulating support 19 can be increased, thereby the connection strength, the connection stability, and the connection reliability between the second extension 1254 and the insulating support 19 can be enhanced, the connection stability and the connection reliability between the electrode assembly 12 and the insulating support 19 can be improved, the position and the state of the electrode assembly 12 relative to the insulating support 19 can be consolidated, the risk of short circuit can be reduced, and the structural stability, the structural reliability, the use reliability, and the service life of the battery monomer 10 can be improved. Moreover, the bending form can give the second extension 1254 a certain elastic deformation capability. When the battery monomer 10 is subjected to external impact or internal stress (such as expansion and contraction of the electrode assembly 12 during charging and discharging), the bent second extension 1254 can absorb part of the energy through its own deformation, thereby playing a buffering role, so that the stress can be directly transmitted to the main body 121 or the insulating support 19, the risk of structural damage of the electrode assembly 12 due to rigid stress can be reduced, and the stress load of the insulating support 19 can be reduced to prolong the service life of the insulating support 19. Moreover, the bending arrangement can reasonably arrange the second extension 1254 in the limited space between the main body 121 and the insulating support 19, and the bent second extension 1254 can be compressed in the space between the main body 121 and the insulating support 19, which can adapt to the compact layout requirement inside the shell 11, and is conducive to improving the energy density of the battery monomer 10.

[0239] Of course, in other embodiments, the second extension 1254 can not be bent and arranged, and can be directly connected with the insulating support 19.

[0240] Please refer to Figure 4 , Figure 5 , Figure 6 , Figure 7 ,Figure 10 、 Figure 11 、 Figure 12 、 Figure 17 In some embodiments, the battery cell 10 includes a housing 11, an electrode assembly 12 disposed within the housing 11, and an insulating case 17 disposed within the housing 11.

[0241] The electrode assembly 12 comprises a positive electrode tab 123a, a negative electrode tab 123b, a separator 124 and a support body 125. The support body 125 is a closed ring structure, the outer ring surface of the support body 125 is fixedly connected with the separator 124, and the positive electrode tab 123a, the separator 124 and the negative electrode tab 123b are wound around the outer periphery of the support body 125. The inner ring surface of the support body 125 is provided with first adhesive particles 1251, the first adhesive particles 1251 are pressure-sensitive adhesive particles, heat-sensitive adhesive particles or heat-pressing synergistic adhesive particles, and the diameter of the first adhesive particles 1251 is 5-30 microns. The hardness of the support body 125 is greater than the hardness of the separator 124. The surface roughness of the inner ring surface of the support body 125 is less than the surface roughness of the separator 124. The thickness d1 of the support body from its outer ring surface to its inner ring surface is 50-500 microns. Based on the above structure, the first adhesive particles 1251 are in a low-adhesive state or substantially have no adhesion before the compaction process (including the winding process, the cutting process and the moving process), so that the inner ring surface of the support body 125 will not be tightly adhered to the winding needle and the clamping needle through the first adhesive particles 1251, thereby reducing the risk that the support body 125 and the separator 124 are pulled away due to excessive adhesion during the pulling of the winding needle and the clamping needle, causing the positive electrode tab 123a and the negative electrode tab 123b to be short-circuited, reducing the risk that the support body 125 and the separator 124 are wrinkled, folded and other defects due to excessive adhesion, improving the qualified rate of the winding process and the smoothness of the pulling operation, and reducing the pulling failure problem.Furthermore, the first adhesive particles 1251 can activate their viscosity based on temperature and pressure during the compaction process, allowing the inner ring surface of the support 125 to adhere to itself via the first adhesive particles 1251. This enables the support 125 to form a flat structure without openings, allowing the support 125 to support the inner ring of the diaphragm 124 and preventing the inner ring (especially the innermost ring) of the diaphragm 124 from rebounding or shrinking inwards. Based on this, it can prevent the interlayer gap between the positive electrode 123a and the negative electrode 123b in the inner ring (especially the innermost ring) from increasing, and can cause the innermost diaphragm 124 to adhere tightly to the outer ring surface of the support 125. This can cause the electrode assembly 12 to adhere tightly ring by ring with small interlayer gaps, and can cause the electrode assembly 12 to be fully compacted. Therefore, it can reduce the occurrence of pre-compression openings in the electrode assembly 12 due to insufficient compaction. The pre-compression opening reduces the risk of OH displacement, improves the structural stability and electrochemical reaction uniformity of the electrode assembly 12, provides sufficient constraint force to the electrode 123 to prevent the end of the electrode 123 from moving due to external force, reduces the risk of metal deposition and short circuits caused by the positive electrode 123a exceeding the negative electrode 123b due to end movement of the electrode 123, reduces the risk of metal deposition and short circuits caused by excessive interlayer gaps between the positive electrode 123a and the negative electrode 123b affecting the active ion transport performance, and reduces the risk of metal deposition during the use of the battery cell 10. It also reduces the risk of external particles falling into the electrode assembly 12 along the interlayer gaps, affecting the yield, and reduces the risk of short circuits caused by external metal particles falling into the electrode assembly 12 along the interlayer gaps. Therefore, the performance, reliability, and service life of the battery cell 10 can be improved.

[0242] The outer annular surface of the support body 125 is provided with a plurality of grooves 1252, the groove depth d2 of the grooves is less than the thickness d1 of the support body from its outer annular surface to its inner annular surface, the groove width d3 of the grooves is 50-500 μm, and the groove depth d2 of the grooves is 50-500 μm. Among the plurality of grooves 1252, a part of the grooves 1252 are straight grooves 1252a whose extension direction is parallel to the axial direction of the support body 125, and a part of the grooves 1252 are straight grooves 1252a whose extension direction is parallel to the circumferential direction of the support body 125, forming a cross layout. Based on the above structure, in the case of sufficient compaction of the electrode assembly 12, the grooves 1252 can provide a wetting channel for the electrolyte in the inner circle of the electrode assembly 12 (especially between the closely fitted support body 125 and the separator 124), so as to enable the electrolyte to diffuse smoothly and permeate fully to the inner circle of the electrode assembly 12, thereby improving the problem of slow electrolyte filling speed and poor local wetting in the inner circle caused by close fitting, and maintaining and improving the electrochemical performance of the battery monomer 10. Moreover, the grooves 1252 can reserve electrolyte storage space to pre-store electrolyte, and release the electrolyte stored in the grooves 1252 by swelling and extrusion in the later stage of the battery monomer 10 cycle, so as to supplement the electrolyte, compensate for consumption, maintain and improve the liquid retention capacity, cycle performance and service life of the battery monomer 10. Moreover, the grooves 1252 are only locally recessed on the outer annular surface of the support body 125, without damaging the overall continuity of the support body 125, so as to maintain the structural strength of the annular support body 125, maintain the basic support capacity of the flattened support body 125, and enable the flattened support body 125 to reliably support the inner circle of the separator 124, resist the rebound stress of the separator 124, and hinder the inward rebound and shrinkage of the separator 124.

[0243] The shell 11 has opposite first and second end walls 111 and 112 and a side wall 113 connected between the first and second end walls 111 and 112. The electrode assembly 12 includes a main body portion 121 and a tab 122 extending out of the main body portion 121 toward the first end wall 111. Two electrode assemblies 12 are provided, and the two electrode assemblies 12 are arranged side by side along the first direction x. The two electrode assemblies 12 are both first electrode assemblies 12a. The support body 125 of the first electrode assembly 12a is an insulating member. The support body 125 of the first electrode assembly 12a has a first extension portion 1253 extending out of the main body portion 121 toward the first end wall 111. The tabs 122 of the two electrode assemblies 12 are located between the two first extension portions 1253. An insulating shell 17 covers the outside of the two electrode assemblies 12. Based on the above structure, the electrical isolation between the tabs 122 and the side wall 113 can be achieved by the insulating shell 17 and the two first extension portions 1253 together. The electrical isolation between the electrode assembly 12 and the second end wall 112 can be achieved by the insulating shell 17. Based on this, the risk of direct contact and short circuit between the tabs 122 and the side wall 113 and between the electrode assembly 12 and the second end wall 112 can be reduced. The insulation reliability can be improved. The use reliability and service life of the battery monomer 10 can be improved. The bottom support plate 18 can be omitted. The occupied space of the bottom support plate 18 can be saved. The space utilization rate of the battery monomer 10 in the thickness direction of the first end wall 111 can be improved. The energy density of the battery monomer 10 can be improved.

[0244] Since the portion of the insulating shell 17 located between the electrode assembly 12 and the second end wall 112 is in abutting contact with the electrode assembly 12, the portion of the insulating shell 17 located between the electrode assembly 12 and the second end wall 112 is an insulating support 19. The support body 125 of the electrode assembly 12 has a second extension portion 1254 extending out of the main body portion 121. The second extension portion 1254 is arranged in a bent manner between the main body portion 121 and the insulating support 19 and is connected with the insulating support 19. Based on the above structure, the second extension portion 1254 can be connected and fixed with the insulating support 19, thereby forming a fixed point between the electrode assembly 12 and the insulating support 19. The electrode assembly 12 is fixed relative to the insulating support 19. The position and state of the electrode assembly 12 relative to the insulating support 19 are stable. The electrode assembly 12 is prevented from moving relative to the insulating support 19. Therefore, the structural stability and structural reliability of the battery monomer 10 can be improved. During use of the battery monomer 10, since the position stability of the electrode assembly 12 is improved and the risk of movement is reduced, the risk of contact and short circuit between the electrode assembly 12 and the second end wall 112 due to relative displacement between the electrode assembly 12 and the insulating support 19 can be reduced. The risk of contact and short circuit between the tab 122 of the electrode assembly 12 and the side wall 113 due to position deviation of the tab 122 can be reduced. Therefore, the risk of short circuit can be reduced. The use reliability and service life of the battery monomer 10 can be improved.

[0245] Please refer to Figure 20 、 Figure 6 、 Figure 7 、 Figure 9 Some embodiments of the present application provide a manufacturing method of an electrode assembly 12 for manufacturing the electrode assembly 12 provided by the embodiments of the present application with a support body 125. Please refer to Figure 21 、 Figure 22 、 Figure 23 、 Figure 24 The manufacturing method of the electrode assembly 12 comprises the following steps:

[0246] S1, the support body 125 is sleeved on the outer periphery of the winding needle 20, so that the winding needle 20 is expanded and tightly pressed against the support body 125. Wherein, the support body 125 is annular structure, the inner ring surface of the support body 125 is provided with first adhesive particles 1251. It should be noted that, as shown in Figure 21 , since the support body 125 is annular structure, the support body 125 can be sleeved on the outer periphery of the winding needle 20, at this time, the support body 125 is basically in the form of a ring; then, the winding needle 20 is expanded outward and tightly pressed against the support body 125, so that the feeding of the support body 125 can be realized, and the position and state of the support body 125 on the winding needle 20 can be basically stabilized. In some embodiments, before the process of "sleeving the support body 125 on the outer periphery of the winding needle 20", the winding needle 20 can be retracted first, so as to facilitate the process of "sleeving the support body 125 on the outer periphery of the winding needle 20" behind the turret 30; after the process of "expanding the winding needle 20 and tightly pressing the support body 125", the winding needle 20 can be reset to extend out, so as to facilitate the subsequent steps. Wherein, the inner ring surface of the support body 125 is provided with first adhesive particles 1251, after the process of "sleeving the support body 125 on the outer periphery of the winding needle 20", the inner ring surface of the support body 125 will contact the outer peripheral surface of the winding needle 20, the inner ring surface of the support body 125 may be slightly bonded or basically not bonded with the outer peripheral surface of the winding needle 20 through the first adhesive particles 1251, basically not affecting the execution of the subsequent step of "feeding the winding structure from the winding needle 20". Wherein, the winding needle 20 is a component for assisting the winding and forming of the electrode assembly 12, and the turret 30 is a component for installing and supporting the winding needle 20.

[0247] S2, the entry end of the diaphragm 124 is fixedly connected to the outer ring surface of the support body 125. It should be noted that, as shown in Figure 22 , after the feeding of the support body 125 is completed, the diaphragm 124 can be wound first, and the entry end of the diaphragm 124 is fixedly connected to the outer ring surface of the support body 125, so as to provide a stable starting point for the subsequent winding, promote the synchronous movement of the diaphragm 124 and the support body 125, and reduce the deviation in the initial winding stage, wherein the fixed connection mode can adopt hot melt connection, ultrasonic welding or adhesion and the like.

[0248] S3, after winding the separator 124 around the outer periphery of the support 125 by a predetermined number of turns, the negative electrode tab 123b is wound in, and in a case where the length of the negative electrode tab 123b wound in exceeds a predetermined length L, the positive electrode tab 123a is wound in, so that the positive electrode tab 123a, the separator 124, and the negative electrode tab 123b are wound around the outer periphery of the support 125. Note that, as shown in FIG. 6B, the positive electrode tab 123a is wound in so as to be positioned on the outer periphery of the support 125. Figure 23 , Figure 24As shown, after the entry end of the diaphragm 124 is fixedly connected to the outer ring surface of the support body 125, the diaphragm 124 can be wound around the outer periphery of the support body 125 for a preset number of turns, so that the pre-wound diaphragm 124 can form a longer inner circle insulation barrier between the support body 125 and the pole piece 123, and between the positive pole piece 123a and the negative pole piece 123b, thereby reducing the risk of short circuit, especially reducing the risk of short circuit caused by the end of the pole piece 123 moving out of the insulation isolation range of the diaphragm 124, causing the positive pole piece 123a and the negative pole piece 123b to overlap and short circuit. The preset number of turns can be an integer (e.g. 1 turn, 2 turns, etc.) or a fraction (e.g. 0.5 turns, 0.75 turns, 1.5 turns, etc.). After the diaphragm 124 is wound around the outer periphery of the support body 125 for a preset number of turns, the negative pole piece 123b is wound, and after the length of the negative pole piece 123b exceeds the preset length L, the positive pole piece 123a is wound. Based on this, the negative pole piece 123b can be wound before the positive pole piece 123a, the entry end of the positive pole piece 123a can be covered by the negative pole piece 123b, and the design principle of "the negative pole piece 123b covering the positive pole piece 123a" can be followed to reduce the probability of metal deposition and short circuit from the root. The preset length L can be an integer (e.g. 1 mm, 2 mm, 3 mm, etc.) or a fraction (e.g. 1.5 mm, 2.5 mm, 3.5 mm, etc.). Two diaphragms 124 can be provided, one of which is arranged between the positive pole piece 123a and the negative pole piece 123b, and the other is arranged on the side of the negative pole piece 123b away from the positive pole piece 123a, or on the side of the positive pole piece 123a away from the negative pole piece 123b, to achieve the laminated arrangement of the positive pole piece 123a, the diaphragm 124 and the negative pole piece 123b, and to reliably separate the positive pole piece 123a and the negative pole piece 123b by the diaphragm 124 to prevent the positive pole piece 123a and the negative pole piece 123b from contacting and short circuiting. After the diaphragm 124 is wound, only the diaphragm 124 is wound around the outer periphery of the support body 125 before the negative pole piece 123b is wound. After the negative pole piece 123b is wound, the negative pole piece 123b and the diaphragm 124 are wound together around the outer periphery of the support body 125 before the positive pole piece 123a is wound. After the positive pole piece 123a is wound, the positive pole piece 123a, the diaphragm 124 and the negative pole piece 123b are wound together around the outer periphery of the support body 125. The winding direction y remains unchanged during the winding.

[0249] S4, cut off the positive electrode sheet 123a first, and then cut off the negative electrode sheet 123b. It should be noted that the positive electrode sheet 123a is cut off before the negative electrode sheet 123b, so that the tail end of the positive electrode sheet 123a is also covered by the negative electrode sheet 123b, the winding length of the negative electrode sheet 123b is greater than that of the positive electrode sheet 123a, the design principle of "the negative electrode sheet 123b covering the positive electrode sheet 123a" can be followed, and the probability of metal deposition and short circuit can be reduced from the root. During this period, the winding action is not stopped.

[0250] S5, cut off the diaphragm 124. It should be noted that the diaphragm 124 is cut off after the negative electrode sheet 123b, so that the diaphragm 124 reliably separates the positive electrode sheet 123a and the negative electrode sheet 123b to prevent the positive electrode sheet 123a and the negative electrode sheet 123b from contacting and short circuiting. During this period, the winding action is not stopped.

[0251] S6, winding is completed to form a winding structure. It should be noted that after cutting off the diaphragm 124, winding is completed, so that the support 125, the diaphragm 124, the negative electrode sheet 123b and the positive electrode sheet 123a together form a winding structure, which is an intermediate form of the electrode assembly 12. One winding operation of one winding structure is completed on one winding needle 20, without interrupting the winding operation and replacing the winding needle 20.

[0252] S7, the winding structure is discharged from the winding needle 20. It should be noted that the winding structure completed by winding is discharged from the winding needle 20. In some embodiments, the winding structure can be clamped from the winding needle 20 by a clamping needle, and transferred to a pre-pressing device.

[0253] S8, compact the winding structure, so that the inner annular surface of the support 125 is adhered by the first adhesive particles 1251 itself, thereby forming a flat electrode assembly 12. It should be noted that after the winding structure is discharged, a compacting process can be performed on the winding structure to flatten the winding structure by compacting until the inner annular surface of the support 125 is adhered by the first adhesive particles 1251 itself, so that the support 125 forms a flat structure without opening. In this way, a flat electrode assembly 12 can be obtained, and the shape conversion from "cylindrical winding structure" to "flat electrode assembly 12" can be realized. In some embodiments, the winding structure can be compacted by the pre-pressing device, or even stretched by the clamping needle cooperating with the pre-pressing device.

[0254] By adopting the above scheme, by adopting the manufacturing method of the electrode assembly 12 provided in the embodiments of the present application, the positive electrode tab 123a, the separator 124 and the negative electrode tab 123b can be first wound on the outer periphery of the support body 125, and the support body 125, the separator 124, the negative electrode tab 123b and the positive electrode tab 123a are collectively formed into a winding structure; then the winding structure is compacted until the inner annular surface of the support body 125 is adhered by the first adhesive particles 1251 themselves, so that the support body 125 forms a flat structure without opening, thereby obtaining a flat electrode assembly 12. Based on this, the electrode assembly 12 provided in the embodiments of the present application with the support body 125 and sufficient compaction can be conveniently and quickly manufactured, and the manufacturability, production convenience, production efficiency, production consistency and production yield of the electrode assembly 12 can be provided.

[0255] Please refer to Figure 9 , Figure 20 , Figure 21 In some embodiments of the present application, the first adhesive particles 1251 are pressure-sensitive adhesive particles, heat-sensitive adhesive particles or heat-pressing synergistic adhesive particles. In the steps of sleeving the support body 125 on the outer periphery of the winding needle 20 to expand and tightly press the support body 125 (i.e. S1) to the step of discharging the winding structure from the winding needle 20 (i.e. S7), the first adhesive particles 1251 are not activated. Please refer to Figure 6 , Figure 7 In the step of compacting the winding structure (i.e. S8), the first adhesive particles 1251 are activated to adhere the inner annular surface of the support body 125 by the first adhesive particles 1251 themselves.

[0256] It should be noted that the related description of the pressure-sensitive adhesive particles, the heat-sensitive adhesive particles and the heat-pressing synergistic adhesive particles can be referred to the foregoing, which will not be repeated here.

[0257] It should be further noted that in each step of the manufacturing method of the electrode assembly 12:

[0258] In the steps of sleeving the support body 125 on the outer periphery of the winding needle 20 to expand and tightly press the support body 125 (i.e. S1) to the step of discharging the winding structure from the winding needle 20 (i.e. S7), the first adhesive particles 1251 are not activated, so that the first adhesive particles 1251 are in a low-adhesion state or basically have no adhesion, and the inner annular surface of the support body 125 will not be tightly adhered by the first adhesive particles 1251 and the outer peripheral surface of the winding needle 20 and the clamping needle.

[0259] In the step of compacting the winding structure (i.e. S8), the first adhesive particles 1251 can be activated based on temperature and pressure, so that the inner annular surface of the support body 125 can be adhered by the first adhesive particles 1251 themselves, and the support body 125 can form a flat structure without opening.

[0260] By adopting the above scheme, by making the first adhesive particles 1251 be pressure-sensitive adhesive particles, heat-sensitive adhesive particles or heat-press synergistic adhesive particles, the first adhesive particles 1251 can be in a low-adhesive state or substantially no adhesive state without being activated in the step (i.e. S1) of "sleeving the support body 125 on the outer periphery of the winding needle 20, expanding and tightly pressing the support body 125 by the winding needle 20" to the step (i.e. S7) of "stripping the winding structure from the winding needle 20", so that the inner annular surface of the support body 125 cannot be tightly adhered to the outer peripheral surface of the winding needle 20 and the clamping needle via the first adhesive particles 1251, thereby reducing the risk of the support body 125 and the diaphragm 124 being pulled away due to excessive adhesive force during the stripping of the winding needle 20 in the step (i.e. S7) of "stripping the winding structure from the winding needle 20", and the insertion and stripping of the clamping needle, reducing the risk of the support body 125 and the diaphragm 124 being wrinkled, folded and other defects due to excessive adhesive force, thereby improving the yield of the winding process and the smoothness of the stripping operation, and reducing the stripping problem. And in the step (i.e. S8) of compacting the winding structure, the first adhesive particles 1251 can be activated based on temperature and pressure, so that the inner annular surface of the support body 125 can be adhered via the first adhesive particles 1251 itself, so that the support body 125 can form a flat structure without opening, thereby improving the yield of the compacting process, and strengthening the stability and reliability of the structure and form of the support body 125 after compacting. Therefore, the manufacturability, production convenience, production efficiency, production consistency, production yield of the electrode assembly 12 can be improved.

[0261] Please refer to Figure 20 , Figure 22 , Figure 4 In some embodiments of the present application, in the step (i.e. S2) of fixing and connecting the winding end of the diaphragm 124 to the outer annular surface of the support body 125, the winding end of the diaphragm 124 is fixedly connected to the outer annular surface of the support body 125 by hot melt connection or ultrasonic welding.

[0262] By adopting the above scheme, in the step (i.e., S2) of "fixing and connecting the winding-in end of the diaphragm 124 to the outer ring surface of the support body 125", the hot melt connection or ultrasonic welding mode can be adopted to conveniently and quickly realize the fixed connection between the winding-in end of the diaphragm 124 and the outer ring surface of the support body 125. Based on this, the connection convenience, connection strength, connection stability, connection reliability between the winding-in end of the diaphragm 124 and the outer ring surface of the support body 125 can be improved, and the production convenience, production efficiency, and production yield of the electrode assembly 12 can be improved. Moreover, since the hot melt connection or ultrasonic welding mode does not require additional consumables (such as solder, adhesive, etc.), the influence of the residual additional consumables on the structure and performance of the electrode assembly 12 can be reduced, and the forming quality of the electrode assembly 12 can be improved; the influence of the residual additional consumables on the pollution of the electrolyte can be reduced, and the performance of the battery cell 10 can be optimized; and the cost can be reduced.

[0263] Of course, in other embodiments, other modes (such as bonding, etc.) can be adopted to realize the fixed connection between the winding-in end of the diaphragm 124 and the outer ring surface of the support body 125.

[0264] Please refer to Figure 20 , Figure 22 , Figure 6 In some embodiments of the present application, the fixed connection region between the winding-in end of the diaphragm 124 and the outer ring surface of the support body 125 is the first connection area 1255. The size (i.e., d4) of the first connection area 1255 along the axial direction of the support body 125 is greater than or equal to 10 mm and less than or equal to the size (i.e., d5) of the support body 125.

[0265] It should be noted that in the step (i.e., S2) of "fixing and connecting the winding-in end of the diaphragm 124 to the outer ring surface of the support body 125", the fixed connection region between the winding-in end of the diaphragm 124 and the outer ring surface of the support body 125 is the first connection area 1255. The form of the connection mark 12551 of the first connection area 1255 can be flexibly set as needed, for example, it can be in a checkered pattern (as shown in Figure 22 , a stripe pattern extending along the axial direction of the support body 125 (as shown in Figure 25 , a stripe pattern extending along the circumferential direction of the support body 125 (as shown in Figure 26 , a curved pattern arranged in a curved extension (as shown in Figure 27 , a dot pattern (as shown in Figure 28 , etc.

[0266] In the axial direction of the support body 125, the size (i.e., d4) of the first connecting area 1255 is greater than or equal to 10 mm and less than or equal to the size (i.e., d5) of the support body 125, that is, the size (i.e., d4) of the first connecting area 1255 cannot exceed the size (i.e., d5) of the support body 125; if the size of the diaphragm 124 is less than the size (i.e., d5) of the support body 125, the size (i.e., d4) of the first connecting area 1255 is allowed to exceed the size of the diaphragm 124 but cannot exceed the size (i.e., d5) of the support body 125.

[0267] By adopting the above scheme, the diaphragm 124 can have sufficient axial connecting length and connecting area between the winding-in end and the outer ring surface of the support body 125 based on the first connecting area 1255, so that the connecting strength, stability and reliability between the winding-in end of the diaphragm 124 and the outer ring surface of the support body 125 can be improved, the risk of the diaphragm 124 falling off the support body 125 at the initial stage of winding can be reduced, the yield of the step (i.e., S2) of fixing and connecting the winding-in end of the diaphragm 124 to the outer ring surface of the support body 125 can be improved, and the production convenience, efficiency and yield of the electrode assembly 12 can be improved. Moreover, the first connecting area 1255 does not exceed the axial boundary of the support body 125, the formation of the first connecting area 1255 can reduce the damage to the winding needle 20, the winding needle 20 can be protected from damage, the use reliability and service life of the winding needle 20 can be maintained, and the equipment maintenance cost and downtime risk can be reduced.

[0268] Please refer to Figure 20 , Figure 22 , Figure 6 In some embodiments of the present application, the fixed connection area between the winding-in end of the diaphragm 124 and the outer ring surface of the support body 125 is the first connecting area 1255. In the circumferential direction of the support body 125, the size (i.e., d6) of the first connecting area 1255 is greater than or equal to 5 mm and less than or equal to the circumference of the support body 125.

[0269] It should be noted that in the step (i.e., S2) of fixing and connecting the winding-in end of the diaphragm 124 to the outer ring surface of the support body 125, the fixed connection area between the winding-in end of the diaphragm 124 and the outer ring surface of the support body 125 is the first connecting area 1255. In the circumferential direction of the support body 125, the size (i.e., d6) of the first connecting area 1255 is greater than or equal to 5 mm and less than or equal to the circumference of the support body 125, that is, the first connecting area 1255 at most forms one turn around the support body 125.

[0270] By adopting the above scheme, the first connecting area 1255 can be used to connect the winding-in end of the diaphragm 124 and the outer ring surface of the support body 125, so that the circumferential connection length and area between the winding-in end of the diaphragm 124 and the outer ring surface of the support body 125 are sufficient, thereby improving the connection strength, stability and reliability between the winding-in end of the diaphragm 124 and the outer ring surface of the support body 125, reducing the risk of the diaphragm 124 falling off the support body 125 at the initial winding stage, improving the yield of the step of fixing and connecting the winding-in end of the diaphragm 124 to the outer ring surface of the support body 125 (i.e., S2), and improving the production convenience, efficiency and yield of the electrode assembly 12.

[0271] Please refer to Figure 20 、 Figure 23 、 Figure 24 In some embodiments of the present application, the preset number of turns is 0.5 turns to 1 turn.

[0272] It should be noted that in the step of winding the diaphragm 124 around the outer periphery of the support body 125 by a preset number of turns, then winding the negative electrode tab 123b, and then winding the positive electrode tab 123a when the winding length of the negative electrode tab 123b exceeds the preset length L (i.e., S3), the diaphragm 124 is wound around the outer periphery of the support body 125 for 0.5 turns to 1 turn.

[0273] By adopting the above scheme, after the step of fixing and connecting the winding-in end of the diaphragm 124 to the outer ring surface of the support body 125 (i.e., S2), the diaphragm 124 can be first wound around the outer periphery of the support body 125 for 0.5 turns to 1 turn. Based on this, the pre-wound 0.5 turns to 1 turn of the diaphragm 124 can cover at least half of the outer ring surface of the support body 125, forming a "half-wrapped" inner insulating barrier to insulate and isolate the support body 125 and the tabs 123, as well as the positive electrode tab 123a and the negative electrode tab 123b, thereby reducing the risk of short circuit, especially the risk of the tabs 123 exceeding the insulating isolation range of the diaphragm 124 due to the end displacement of the tabs 123, causing the positive electrode tab 123a and the negative electrode tab 123b to be short-circuited, and improving the forming quality and yield of the electrode assembly 12. Moreover, the initial winding turns of the diaphragm 124 are 0.5 turns to 1 turn, which can make the "starting core" (i.e., the support body 125 and the initial diaphragm 124) of the winding structure smaller and more compact. Based on this, in the subsequent compaction process, the compact starting core can uniformly transmit pressure to the entire winding structure, thereby reducing the problem of local compaction deficiency caused by excessive initial winding turns of the diaphragm 124 and excessive thickness of the starting core, thereby improving the compaction density and efficiency, and improving the overall volumetric energy density of the electrode assembly 12 (as shown in FIG. 1). Figure 6

[0274] ​Of course, in other embodiments, the preset number of turns can be other integers or decimals.

[0275] Referring to Figure 20 , Figure 24 , Figure 6 In some embodiments of the present application, the preset length L is 2 mm.

[0276] It should be noted that in the step (i.e., S3) of “after winding the separator 124 around the outer periphery of the support 125 for a preset number of turns, then winding the negative electrode tab 123b, in the case where the winding length of the negative electrode tab 123b exceeds the preset length L, then winding the positive electrode tab 123a, so as to wind the positive electrode tab 123a, the separator 124 and the negative electrode tab 123b around the outer periphery of the support 125”, in the case where the winding length of the negative electrode tab 123b exceeds 2 mm, then winding the positive electrode tab 123a.

[0277] By adopting the above scheme, the positive electrode tab 123a can be wound in the case where the winding length of the negative electrode tab 123b exceeds 2 mm. Based on this, the negative electrode tab 123b can be wound prior to the positive electrode tab 123a, the winding length of the negative electrode tab 123b can exceed 2 mm of the positive electrode tab 123a, the winding end of the positive electrode tab 123a can be reliably covered by the negative electrode tab 123b, the design principle of “the negative electrode tab 123b covering the positive electrode tab 123a” can be followed, the probability of metal deposition and short circuit can be reduced from the root, and the forming quality and production yield of the electrode assembly 12 can be improved.

[0278] Of course, in other embodiments, the preset length L can be other integers or decimals.

[0279] Referring to Figure 20 , Figure 21 , Figure 6 In some embodiments of the present application, the number of winding needles 20 is one, and the winding needle 20 maintains a preset position unchanged during the winding process.

[0280] It should be noted that only one winding needle 20 is provided, and in one work cycle, one winding needle 20 can perform the winding process of one electrode assembly 12, the winding process includes the step (i.e., S1) of “sleeving the support 125 around the outer periphery of the winding needle 20, so as to expand and tightly abut the support 125 by the winding needle 20” to the step (i.e., S7) of “stripping the winding structure from the winding needle 20”, and the winding needle 20 maintains a preset position unchanged during the winding process.

[0281] By adopting the above scheme, the steps (i.e., S1) of "sleeving the support body 125 on the outer periphery of the winding needle 20, and expanding and tightly pressing the support body 125 by the winding needle 20" to the step (i.e., S7) of "discharging the winding structure from the winding needle 20" can be performed by using the device of "single winding needle and the winding needle 20 maintaining the preset position unchanged during the winding process". Based on this, the device structure can be simplified, the device complexity and failure rate can be reduced, and the production continuity can be indirectly improved. Moreover, since the winding needle 20 maintains the preset position unchanged and does not need to be switched, the stability and consistency of the winding process can be improved, so that the forming quality and production yield of the electrode assembly 12 can be improved.

[0282] Please refer to Figure 20 、 Figure 24 、 Figure 29 、 Figure 6 In some embodiments of the present application, the number of winding needles 20 is two, and the two winding needles 20 can rotate around the preset axis to alternately switch the two winding needles 20 between the first station 31 and the second station 32. Among them, in the steps of the manufacturing method of the electrode assembly 12, the steps (i.e., S1) of "sleeving the support body 125 on the outer periphery of the winding needle 20, and expanding and tightly pressing the support body 125 by the winding needle 20", the step (i.e., S6) of "performing winding and forming a winding structure", and the step (i.e., S7) of "discharging the winding structure from the winding needle 20" are performed at the first station 31; the steps (i.e., S2) of "fixing the inlet end of the diaphragm 124 to the outer surface of the support body 125" to the step (i.e., S4) of "cutting the positive electrode sheet 123a first, and then cutting the negative electrode sheet 123b" are performed at the second station 32; and the step (i.e., S5) of cutting the diaphragm 124 is performed between the second station 32 and the first station 31.

[0283] It should be noted that the turret 30 is provided with two winding needles 20, and the two winding needles 20 are correspondingly located at the first station 31 and the second station 32. Under the driving of the turret 30, the two winding needles 20 can rotate around the preset axis to alternately exchange positions, so that the two winding needles 20 are alternately switched between the first station 31 and the second station 32, that is, the winding needle 20 originally at the first station 31 is switched to the second station 32, and the winding needle 20 originally at the second station 32 is switched to the first station 31. Among them, the preset axis corresponds to the central axis of the turret 30.

[0284] In one operation cycle (i.e., the period of one rotation of the winding needle 20 around the preset axis), one winding needle 20 can perform a winding process of one electrode assembly 12, and two winding needles 20 can one-to-one perform winding processes of two electrode assemblies 12. The winding process includes the steps (i.e., S1) of "sleeving the support body 125 on the outer periphery of the winding needle 20, and expanding and tightly pressing the support body 125 by the winding needle 20" to the step (i.e., S7) of "discharging the winding structure from the winding needle 20".

[0285] For each winding needle 20, when the winding needle 20 is located at the first station 31, the step of “wrapping the support body 125 around the outer periphery of the winding needle 20 to expand and tightly press the support body 125” (i.e., S1) is performed; when the winding needle 20 is switched from the first station 31 to the second station 32, the steps of “fixing the inlet end of the diaphragm 124 to the outer surface of the support body 125” (i.e., S2) to “cutting the positive electrode tab 123a first and then the negative electrode tab 123b” (i.e., S4) are performed; when the winding needle 20 is switched from the second station 32 to the first station 31, the step of cutting the diaphragm 124 between the second station 32 and the first station 31 (i.e., S5) is performed, and then the steps of “performing winding finishing to form a winding structure” (i.e., S6) and “discharging the winding structure from the winding needle 20” (i.e., S7) are performed at the first station 31; thus, the winding needle 20 can complete the winding process of one electrode assembly 12.

[0286] For the two winding needles 20, the winding needle 20 located at the first station 31 processes the “finishing and discharging” of the previous product and the “support body 125 feeding” of the subsequent product, and the winding needle 20 located at the second station 32 processes the “winding of the diaphragm 124 and the electrode tab 123”, and the actions of the two winding needles 20 at the two stations are performed in parallel, which can compress the waiting time and eliminate the idle period of the single winding needle mode.

[0287] By adopting the above scheme, the winding process of the electrode assembly 12 can be divided into steps (i.e., S1-S7) and performed alternately at the first station 31 and the second station 32, which can enable the two winding needles 20 to perform parallel operations, compress the waiting time and production rhythm, eliminate the idle period of the single winding needle mode, reduce the idle time of the equipment, form “seamless connection”, improve the production capacity per unit time (theoretically, one operation cycle can basically complete the winding process of two electrode assemblies 12, which can be close to twice the efficiency of the single winding needle), and improve the production efficiency. Moreover, after the steps are divided into fixed stations, the operations at each station can be specialized and optimized, each station can perform the corresponding operation with high precision, stability and accuracy, and the operation parameters of each step can be easily standardized, thereby optimizing the process stability and improving the consistency and yield of batch production.

[0288] Please refer to Figure 20 , Figure 24 , Figure 29 , Figure 6In some embodiments of the present application, in the case that the two winding needles 20 complete the station switching, the diaphragm 124 is overlapped from the first station 31 to the outer ring surface of the support body 125 located in the second station 32, and then the step of "fixing the winding-in end of the diaphragm 124 to the outer ring surface of the support body 125" is performed in the second station 32 (i.e. S2), then the step of cutting the diaphragm 124 is performed between the second station 32 and the first station 31 (i.e. S5), and then the step of winding up and forming the winding structure is performed in the first station 31 (i.e. S6).

[0289] It should be noted that in the case that the two winding needles 20 complete the station switching, i.e. in the case that the winding needle 20 originally in the first station 31 is switched to the second station 32, and the winding needle 20 originally in the second station 32 is switched to the first station 31, the diaphragm 124 will be overlapped from the first station 31 to the outer ring surface of the support body 125 located in the second station 32; in this state, the step of "fixing the winding-in end of the diaphragm 124 to the outer ring surface of the support body 125" can be performed first in the second station 32 (i.e. S2, which is not the same step in the winding process of the same electrode assembly 12 as the S5 step and the S6 step described below), so as to facilitate the fixed connection between the diaphragm 124 and the support body 125 of the next product; then the step of cutting the diaphragm 124 is performed between the second station 32 and the first station 31 (i.e. S5, which is the same step in the winding process of the same electrode assembly 12 as the S6 step described below), so as to cut and separate the diaphragm 124 in the first station 31 and the second station 32; then the step of "winding up and forming the winding structure" is performed in the first station 31 (i.e. S6), so as to complete the winding up of the previous product.

[0290] By adopting the above scheme, on the basis of two winding needles 20 alternating stations, through the process design of "the diaphragm 124 is overlapped from the first station 31 to the support body 125 of the second station 32-the second station 32 fixes the winding end of the diaphragm 124-the diaphragm 124 is cut off between the first station 31 and the second station 32-the first station 31 winding end", the seamless overlap of the diaphragm 124 can be realized, the continuity of the diaphragm 124 can be optimized, the diaphragm 124 does not need to be rewound every time, the redundant waste of the diaphragm 124 caused by rewinding every time can be reduced, the material utilization rate can be improved, the operation of "the second station 32 fixes the winding end of the diaphragm 124" can be simple based on the continuity of the diaphragm 124, the process continuity can be improved, and the cooperation of the double-station operation can be strengthened. And the timing connection of the overlap, fixation, cutting and end of the diaphragm 124 can make the second station 32 start winding after fixing the diaphragm 124, and the first station 31 can basically simultaneously use the cut-off diaphragm 124 to end, so that the first station 31 and the second station 32 share the time-sharing use of a piece of diaphragm 124, so that the "end" of the previous product and the "initial winding" of the subsequent product can be carried out in parallel, which can reduce the waiting of the station caused by the conflict of the diaphragm 124 distribution (such as "the previous end is not completed, and the subsequent winding cannot take the diaphragm 124"), thereby the production rhythm can be compressed, and the production efficiency can be improved.

[0291] Please refer to Figure 20 、 Figure 24 、 Figure 30 、 Figure 6 In some embodiments of the present application, the number of winding needles 20 is three, and the three winding needles 20 can rotate around a predetermined axis to make the three winding needles 20 cyclically alternate in the first station 31, the second station 32 and the third station 33, and the three winding needles 20 correspond to the first station 31, the second station 32 and the third station 33 one by one. Among them, in each step of the method for manufacturing the electrode assembly 12: the step of "sleeving the support body 125 on the outer periphery of the winding needle 20, so that the winding needle 20 is expanded and tightly presses the support body 125" (i.e. S1) is carried out in the first station 31; the steps of "fixing the winding end of the diaphragm 124 to the outer ring surface of the support body 125" (i.e. S2) to "cutting the positive electrode sheet 123a first, and then cutting the negative electrode sheet 123b" (i.e. S4) are carried out in the second station 32; the step of cutting the diaphragm 124 (i.e. S5) is carried out between the second station 32 and the third station 33; the steps of "carrying out winding end to form a winding structure" (i.e. S6), and "discharging the winding structure from the winding needle 20" (i.e. S7) are carried out in the third station 33.

[0292] It should be noted that the turret 30 is provided with three winding needles 20, and the three winding needles 20 are correspondingly located at the first station 31, the second station 32 and the third station 33. Under the driving of the turret 30, the three winding needles 20 can rotate around the preset axis line, so that the three winding needles 20 are alternately positioned in sequence and circularly, and each winding needle 20 is switched among the first station 31, the second station 32 and the third station 33 in sequence and circularly, that is, the winding needle 20 originally at the first station 31 is switched to the second station 32, the winding needle 20 originally at the second station 32 is switched to the third station 33, and the winding needle 20 originally at the third station 33 is switched to the first station 31. The preset axis line corresponds to the central axis line of the turret 30.

[0293] In one operation cycle (i.e. in a cycle in which the winding needle 20 rotates around the preset axis line), one winding needle 20 can perform a winding process of one electrode assembly 12, and the three winding needles 20 can perform the winding processes of the three electrode assemblies 12 one by one. The winding process includes steps (i.e. S1) of “sleeving the support body 125 on the outer periphery of the winding needle 20 to expand and tightly abut the support body 125” to steps (i.e. S7) of “discharging the winding structure from the winding needle 20”.

[0294] For each winding needle 20, the step (i.e. S1) of “sleeving the support body 125 on the outer periphery of the winding needle 20 to expand and tightly abut the support body 125” is performed when the winding needle 20 is at the first station 31; the steps (i.e. S2) of “fixing the inlet winding end of the diaphragm 124 to the outer ring surface of the support body 125” to the step (i.e. S4) of “cutting the positive electrode tab 123a first and then cutting the negative electrode tab 123b” are performed when the winding needle 20 is switched from the first station 31 to the second station 32; the step (i.e. S5) of cutting the diaphragm 124 is performed between the second station 32 and the third station 33 when the winding needle 20 is switched from the second station 32 to the third station 33, and the steps (i.e. S6) of “performing winding finishing to form a winding structure” and (i.e. S7) of “discharging the winding structure from the winding needle 20” are performed at the third station 33; thus, the winding needle 20 can complete the winding process of one electrode assembly 12.

[0295] For the three winding needles 20, the winding needle 20 at the first station 31 processes the “support body 125 feeding”, the winding needle 20 at the second station 32 processes the “diaphragm 124 and tab 123 winding”, and the winding needle 20 at the third station 33 processes the “finishing and discharging”. The actions of the three winding needles 20 at the three stations are performed in parallel, which can compress the waiting time and eliminate the idle period of “starting the next one after completing one product” in the single winding needle mode.

[0296] By adopting the above scheme, the three winding needles 20 can be arranged to work in the first station 31, the second station 32 and the third station 33 in turn, the steps (i.e., S1-S7) of the winding process of the electrode assembly 12 can be split into three stations to realize alternate operation, the three winding needles 20 can realize parallel operation, the waiting time and production rhythm can be compressed, the idle time of the equipment can be reduced, the seamless connection can be formed, the production capacity per unit time can be improved (theoretically, one operation cycle can basically complete the winding process of three electrode assemblies 12, which can be close to 3 times the efficiency of single winding needle), and the production efficiency can be improved. Moreover, after splitting the steps into fixed stations, the operation of each station can be professionalized and optimized, each station can perform the corresponding operation with high precision, stability and accuracy, and the operation parameters of each step can be easily standardized, thereby the process stability can be optimized, and the consistency and yield of batch production can be improved.

[0297] Please refer to Figure 20 、 Figure 24 、 Figure 31 、 Figure 6 In some embodiments of the present application, the number of winding needles 20 is four, and the four winding needles 20 can rotate around the preset axis to make the four winding needles 20 work in the first station 31, the second station 32, the third station 33 and the fourth station 34 in turn, and the four winding needles 20 are one-to-one corresponding to the first station 31, the second station 32, the third station 33 and the fourth station 34. Among them, in the steps of the manufacturing method of the electrode assembly 12, the step of “sleeving the support body 125 on the outer periphery of the winding needle 20 to make the winding needle 20 support and tightly connect the support body 125” (i.e., S1) is performed in the first station 31; the step of “fixing the inlet winding end of the diaphragm 124 to the outer ring surface of the support body 125” (i.e., S2) to the step of “cutting off the positive electrode sheet 123a first, and then cutting off the negative electrode sheet 123b” (i.e., S4) are performed in the second station 32; the step of cutting off the diaphragm 124 (i.e., S5) is performed between the second station 32 and the third station 33; the step of “performing winding and forming a winding structure” (i.e., S6) is performed in the third station 33; and the step of “stripping the winding structure from the winding needle 20” (i.e., S7) is performed in the fourth station 34.

[0298] It should be noted that the turret 30 is provided with four winding needles 20, and the four winding needles 20 are one-to-one corresponding to the first station 31, the second station 32, the third station 33 and the fourth station 34. Under the driving of the turret 30, the four winding needles 20 can rotate around the preset axis, so that the four winding needles 20 are alternately positioned in turn and circularly, and each winding needle 20 is switched among the first station 31, the second station 32, the third station 33 and the fourth station 34 in turn and circularly, that is, the winding needle 20 originally in the first station 31 is switched to the second station 32, the winding needle 20 originally in the second station 32 is switched to the third station 33, the winding needle 20 originally in the third station 33 is switched to the fourth station 34, and the winding needle 20 originally in the fourth station 34 is switched to the first station 31. The preset axis corresponds to the central axis of the turret 30.

[0299] In one operation cycle (i.e. in a cycle in which the winding needle 20 rotates around the preset axis once), one winding needle 20 can perform the winding process of one electrode assembly 12, and the four winding needles 20 can one-to-one perform the winding processes of the four electrode assemblies 12, and the winding process includes the step (i.e. S1) of “sleeving the support body 125 on the outer periphery of the winding needle 20 to expand and tightly abut the support body 125” to the step (i.e. S7) of “stripping the winding structure from the winding needle 20”.

[0300] For each winding needle 20, the step (i.e. S1) of “sleeving the support body 125 on the outer periphery of the winding needle 20 to expand and tightly abut the support body 125” is performed when the winding needle 20 is in the first station 31; the steps (i.e. S2 to S4) of “fixing the entry end of the diaphragm 124 to the outer surface of the support body 125” to “cutting the positive electrode tab 123a first and then the negative electrode tab 123b” are performed when the winding needle 20 is switched from the first station 31 to the second station 32; the step (i.e. S5) of cutting the diaphragm 124 is performed between the second station 32 and the third station 33 when the winding needle 20 is switched from the second station 32 to the third station 33, and the step (i.e. S6) of “performing winding finishing to form a winding structure” is performed at the third station 33; the step (i.e. S7) of “stripping the winding structure from the winding needle 20” is performed when the winding needle 20 is switched from the third station 33 to the fourth station 34; thus, the winding needle 20 can complete the winding process of one electrode assembly 12.

[0301] For the four winding needles 20, the winding needle 20 located at the first station 31 processes "support body 125 feeding", the winding needle 20 located at the second station 32 processes "diaphragm 124 and pole piece 123 winding", the winding needle 20 located at the third station 33 processes "finishing", and the winding needle 20 located at the fourth station 34 processes "discharging". The actions of the four winding needles 20 at the four stations are carried out in parallel, the waiting time can be compressed, and the idle period of "finishing one product before starting the next" in the single winding needle mode can be eliminated.

[0302] By adopting the above scheme, the winding process steps (i.e., S1-S7) of the electrode assembly 12 can be split into four stations to realize alternating operation by adopting the scheme that the four winding needles 20 sequentially circulate and alternate at the first station 31, the second station 32, the third station 33, and the fourth station 34. The four winding needles 20 can realize parallel operation, the waiting time and production rhythm can be compressed, the idle period of "finishing one product before starting the next" in the single winding needle mode can be eliminated, the equipment idle time can be reduced, "seamless connection" can be formed, the production capacity per unit time can be improved (theoretically, one operation cycle can basically complete the winding process of four electrode assemblies 12, which can be close to 4 times the efficiency of a single winding needle), and the production efficiency can be improved. Moreover, after splitting the steps into fixed stations, the operation of each station can be specialized and optimized, each station can perform the corresponding operation with high precision, stability, and accuracy, and the operation parameters of each step can be easily standardized, thereby optimizing the process stability and improving the consistency and yield of batch production.

[0303] Please refer to Figure 20 、 Figure 24 、 Figure 30 、 Figure 31 In some embodiments of the present application, in the case that the three (or four) winding needles 20 complete a station switching, the diaphragm 124 is lap jointed from the third station 33 to the outer ring surface of the support body 125 located at the second station 32. The step of "fixing and connecting the winding end of the diaphragm 124 to the outer ring surface of the support body 125" is performed at the second station 32 (i.e., S2), the step of cutting the diaphragm 124 is performed between the second station 32 and the third station 33 (i.e., S5), and the step of "performing winding finishing to form a winding structure" is performed at the third station 33 (i.e., S6).

[0304] It should be noted that the present embodiment is applicable to the case of "three winding needles 20", and is also applicable to the case of "four winding needles 20".

[0305] In the case that the three (or four) winding needles 20 complete a station switching once, the diaphragm 124 will be overlapped from the third station 33 to the outer ring surface of the support body 125 located in the second station 32; in this state, the step of "fixing the winding end of the diaphragm 124 to the outer ring surface of the support body 125" can be performed first in the second station 32 (i.e. S2, which is not the same as the steps in the winding process of the electrode assembly 12 (such as Figure 6 the electrode assembly 12 described below S5 step and S6 step) to facilitate the fixed connection between the diaphragm 124 and the support body 125 of the next product; then the step of cutting the diaphragm 124 is performed between the second station 32 and the third station 33 (i.e. S5, which is the same as the winding process of the electrode assembly 12 in the step described below S6 step) to cut and separate the diaphragm 124 of the third station 33 and the second station 32; then the step of "winding and forming a winding structure" is performed in the third station 33 (i.e. S6) to complete the winding of the previous product.

[0306] By adopting the above scheme, on the basis of the three (or four) winding needles 20 alternating stations, through the process design of "the diaphragm 124 is overlapped from the third station 33 to the support body 125 of the second station 32 - the second station 32 fixes the winding end of the diaphragm 124 - the diaphragm 124 is cut between the third station 33 and the second station 32 - the third station 33 winds up", the diaphragm 124 can be seamlessly overlapped, the continuity of the diaphragm 124 can be optimized, the diaphragm 124 does not need to be rewound every time, the redundancy and waste of the diaphragm 124 caused by rewinding every time can be reduced, the material utilization rate can be improved, the operation of "the second station 32 fixes the winding end of the diaphragm 124" can be simple based on the continuity of the diaphragm 124, the process continuity can be improved, and the cooperation of the double-station operation can be strengthened. Moreover, the timing connection of the overlapping, fixing, cutting and ending of the diaphragm 124 can enable the second station 32 to start winding after fixing the diaphragm 124, and the third station 33 can basically simultaneously use the cut diaphragm 124 to end, so that the third station 33 and the second station 32 share a time-sharing use of a section of diaphragm 124, so that the "ending" of the previous product and the "initial winding" of the next product can be performed in parallel, which can reduce the station waiting caused by the allocation conflict of the diaphragm 124 (such as "the previous ending is not completed, and the next winding cannot take the diaphragm 124"), thereby the production cycle can be compressed, and the production efficiency can be improved.

[0307] Of course, in other embodiments, the number of winding needles 20 can be five or more, so as to refine and split each step (i.e. S1-S7) of the winding process of the electrode assembly 12 to each station, so as to realize alternating operation and parallel operation.

[0308] Please refer to Figure 1 , Figure 4Some embodiments of the present application provide a battery device 1, which comprises the battery cell 10 provided by the embodiments of the present application.

[0309] By adopting the above scheme, the battery device 1 can improve the use performance, use reliability and use life by applying the battery cell 10 provided by the embodiments of the present application.

[0310] Please refer to Figure 1 , Figure 4 Some embodiments of the present application provide a battery device 1, which comprises the battery cell 10 provided by the embodiments of the present application.

[0311] By adopting the above scheme, the battery device 1 can improve the use performance, use reliability and use life by applying the battery cell 10 provided by the embodiments of the present application.

[0312] The above is only optional embodiments of the present application, and is not intended to limit the present application. For those skilled in the art, the present application can have various changes and modifications. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the scope of claims of the present application.

Claims

1. A battery cell, characterized by, The battery cell comprises at least one electrode assembly, the electrode assembly comprising a positive electrode sheet, a negative electrode sheet, a separator and a support body; The positive electrode sheet, the separator and the negative electrode sheet are wound and arranged on the outer periphery of the support body; The support body is in a ring structure, the outer ring surface of the support body is fixedly connected with the separator, the inner ring surface of the support body is provided with first adhesive particles, and the inner ring surface of the support body is self-adhered through the first adhesive particles, so that the support body forms a flat structure; the hardness of the support body is greater than the hardness of the separator, so that the anti-deformation ability of the support body is stronger than the anti-deformation ability of the separator; the outer ring surface of the support body is provided with at least one groove, and the groove depth of the groove is less than the thickness of the support body from the outer ring surface to the inner ring surface thereof.

2. The battery cell of claim 1, wherein, The first adhesive particles are pressure-sensitive adhesive particles, heat-sensitive adhesive particles or hot-pressing synergistic adhesive particles.

3. The battery cell of claim 1, wherein, The surface roughness of the inner ring surface of the support body is less than the surface roughness of the separator.

4. The battery cell of claim 1, wherein, The thickness of the support body from the outer ring surface to the inner ring surface thereof is 50 μm to 500 μm.

5. The battery cell of claim 1, wherein, The diameter of the first adhesive particles is 5 μm to 30 μm.

6. The battery cell of any one of claims 1-5, wherein, At least one of the grooves is a straight groove; and / or, at least one of the grooves is a ring groove; and / or, at least one of the grooves is an arc-shaped groove; and / or, at least one of the grooves is a point-shaped groove.

7. The battery cell of any one of claims 1-5, wherein, The groove width of the groove is 50 μm to 500 μm, and the groove depth of the groove is 50 μm to 500 μm.

8. The battery cell of any one of claims 1-5, wherein, The battery cell comprises a housing having opposite first and second end walls and a side wall connected between the first and second end walls; the electrode assembly is arranged in the housing, and the electrode assembly comprises a main body portion and a tab extending outward from the main body portion toward the first end wall, the tab being electrically isolated from the side wall, and the electrode assembly being electrically isolated from the second end wall.

9. The battery cell of claim 8, wherein the cathode comprises a lithium metal oxide. A plurality of the electrode assemblies are arranged side by side along a first direction; In each of the electrode assemblies, two electrode assemblies located at both ends along the first direction are first electrode assemblies, the support bodies of the first electrode assemblies are insulating members and have first extension portions extending outward from the main body portions toward the first end wall, and the tabs of each electrode assembly are located between the two first extension portions and are electrically isolated from the side wall through the two first extension portions.

10. The battery cell as described in claim 8, characterized in that, The battery cell comprises an insulating shell arranged in the housing, the insulating shell covering the electrode assembly, and the electrode assembly being electrically isolated from the side wall and the second end wall through the insulating shell.

11. The battery cell as described in claim 8, characterized in that, The battery cell comprises a bottom support plate arranged in the housing, the bottom support plate being arranged between the electrode assembly and the second end wall, and the electrode assembly being electrically isolated from the second end wall through the bottom support plate.

12. The battery cell as described in claim 8, characterized in that, The battery cell comprises an insulating support member arranged in the housing, the insulating support member abutting against one side of the electrode assembly toward the second end wall, and the support body of the electrode assembly having a second extension portion extending outward from the main body portion, the second extension portion being connected with the insulating support member.

13. The battery cell as described in claim 12, characterized in that, The second extension is arranged between the main body and the insulating support.

14. A method of making an electrode assembly, comprising: The method comprises the following steps: The support body is sleeved on the outer periphery of the winding needle, and the winding needle is expanded and tightly pressed against the support body, wherein the support body is annular, the inner annular surface of the support body is provided with first adhesive particles, and the outer annular surface of the support body is provided with at least one groove, the groove depth is smaller than the thickness of the support body from the outer annular surface to the inner annular surface; The entry end of the diaphragm is fixedly connected to the outer annular surface of the support body, wherein the hardness of the support body is greater than the hardness of the diaphragm, so that the anti-deformation ability of the support body is stronger than the anti-deformation ability of the diaphragm; After the diaphragm is wound on the outer periphery of the support body for a preset number of turns, the negative electrode sheet is wound, and when the winding length of the negative electrode sheet exceeds the preset length, the positive electrode sheet is wound, so as to wind the positive electrode sheet, the diaphragm and the negative electrode sheet on the outer periphery of the support body; The positive electrode sheet is cut first, then the negative electrode sheet is cut, then the diaphragm is cut, and finally the winding is completed to form a winding structure; The winding structure is discharged from the winding needle; The winding structure is compacted, so that the inner annular surface of the support body is self-adhered through the first adhesive particles, thereby forming a flat electrode assembly.

15. The method of manufacturing an electrode assembly of claim 14, wherein, The first adhesive particles are pressure-sensitive adhesive particles, heat-sensitive adhesive particles or heat-pressing synergistic adhesive particles; In the steps of sleeving the support body on the outer periphery of the winding needle, expanding and tightly pressing the winding needle against the support body, and discharging the winding structure from the winding needle, the first adhesive particles are not activated; In the step of compacting the winding structure, the first adhesive particles are activated, so that the inner annular surface of the support body is self-adhered through the first adhesive particles.

16. The method of making an electrode assembly of claim 14, wherein, In the step of fixedly connecting the entry end of the diaphragm to the outer annular surface of the support body, the entry end of the diaphragm is fixedly connected to the outer annular surface of the support body by hot melting or ultrasonic welding.

17. The method of making an electrode assembly of claim 14, wherein, The fixed connection area of the entry end of the diaphragm to the outer annular surface of the support body is a first connection area; Along the axial direction of the support body, the size of the first connection area is greater than or equal to 10 mm and less than or equal to the size of the support body; And / or, along the circumferential direction of the support body, the size of the first connection area is greater than or equal to 5 mm and less than or equal to the circumference of the support body.

18. The method of making an electrode assembly of claim 14, wherein, The preset number of turns is 0.5 turns to 1 turn.

19. The method of making an electrode assembly of claim 14, wherein, The preset length is 2 mm.

20. The method of making an electrode assembly of any one of claims 14-19, wherein, The number of winding needles is one, and the winding needle maintains a preset position unchanged during winding.

21. The method of making an electrode assembly of any one of claims 14-19, wherein, The number of winding needles is two, and the two winding needles can rotate around a preset axis to alternately switch between a first station and a second station; wherein in each step of the electrode assembly manufacturing method: The steps of sleeving the support body on the outer periphery of the winding needle, expanding and tightly pressing the winding needle against the support body, and discharging the winding structure from the winding needle are performed in the first station. The step of fixing the entry winding end of the diaphragm to the outer ring surface of the support body to the step of cutting off the positive electrode tab first and then cutting off the negative electrode tab are performed in the second station. The step of cutting off the diaphragm is performed between the second station and the first station.

22. The method of making an electrode assembly of claim 21, wherein, In the case that the two winding needles complete station switching, the diaphragm is lap jointed to the outer ring surface of the support body in the second station, the step of fixing the entry winding end of the diaphragm to the outer ring surface of the support body is performed in the second station first, the step of cutting off the diaphragm is performed between the second station and the first station, and the step of winding and ending to form the winding structure is performed in the first station.

23. The method of making an electrode assembly of any one of claims 14-19, wherein, The number of the winding needles is three, the three winding needles can rotate around a preset axis, so that the three winding needles are cyclically and alternately arranged in the first station, the second station and the third station, and the three winding needles are one-to-one corresponding to the first station, the second station and the third station; wherein, in each step of the method for manufacturing the electrode assembly: The step of sleeving the support body on the outer periphery of the winding needle, so that the winding needle is expanded and tightly abuts against the support body is performed in the first station; The step of fixing the entry winding end of the diaphragm to the outer ring surface of the support body to the step of cutting off the positive electrode tab first and then cutting off the negative electrode tab are performed in the second station; The step of cutting off the diaphragm is performed between the second station and the third station; The step of winding and ending to form the winding structure and the step of discharging the winding structure from the winding needle are performed in the third station.

24. The method of making an electrode assembly of any one of claims 14-19, wherein, The number of the winding needles is four, the four winding needles can rotate around a preset axis, so that the four winding needles are cyclically and alternately arranged in the first station, the second station, the third station and the fourth station, and the four winding needles are one-to-one corresponding to the first station, the second station, the third station and the fourth station; wherein, in each step of the method for manufacturing the electrode assembly: The step of sleeving the support body on the outer periphery of the winding needle, so that the winding needle is expanded and tightly abuts against the support body is performed in the first station; The step of fixing the entry winding end of the diaphragm to the outer ring surface of the support body to the step of cutting off the positive electrode tab first and then cutting off the negative electrode tab are performed in the second station; The step of cutting off the diaphragm is performed between the second station and the third station; The step of winding and ending to form the winding structure is performed in the third station; The step of discharging the winding structure from the winding needle is performed in the fourth station.

25. A battery device, characterized by The battery device comprises the battery cell as claimed in any one of claims 1-13.

26. An electrical device, comprising: The electric device comprises the battery device as claimed in claim 25, or the battery cell as claimed in any one of claims 1-13.

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