Battery monomer, manufacturing method of electrode assembly, battery device and power utilization device

Abstract

The invention 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 pole piece, a negative pole piece, a diaphragm and a support body. And the positive pole piece, the diaphragm and the negative pole piece are wound on the periphery of the support body. The supporting body is of an annular structure, the outer ring face of the supporting body is fixedly connected with the diaphragm, first bonding particles are arranged on the inner ring face of the supporting body, the inner ring face of the supporting body adheres to the diaphragm through the first bonding particles, and the hardness of the supporting body is larger than that of the diaphragm. Based on the structure, in the compaction process, the support body forming the flat structure can be supported on the inner ring of the diaphragm to prevent the diaphragm from retracting inwards and prevent the interlayer gap between the positive pole piece and the negative pole piece of the inner ring from increasing, so that the electrode assembly is tightly attached circle by circle while the interlayer gap is relatively small, and the electrode assembly is fully compacted; and the risk of prepressing opening and the like of the electrode assembly is reduced.

Description

Technical Field

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

[0002] The electrode assembly is an essential component for the electrochemical reaction to occur in a battery cell. The electrode assembly includes a positive electrode sheet, a negative electrode sheet, and a separator that separates the positive electrode sheet from the negative electrode sheet. The positive electrode sheet, the separator, and the negative electrode sheet are wound and then undergo post-processing such as compaction to form a flat rolled electrode assembly, so that the electrode assembly has a main body area and a bending area provided at the end side of the main body area. However, since the separator is thin and elastic, during the compaction process, the rebound force of the corner of the separator at the bending area will be relatively large, causing the inner circle of the separator to drive the electrode sheet located inside it to rebound and retract inward, causing the interlayer gap between the positive electrode sheet and the negative electrode sheet in the inner circle to become larger, making it difficult to compact the electrode assembly, and causing the electrode assembly that is not fully compacted to have pre-compression opening and other phenomena. Summary of the Invention

[0003] The embodiment of the present application provides a battery cell, which aims to solve the problem that the electrode assembly is difficult to fully compact, the interlayer gap between the positive and negative electrode sheets in the inner circle is large, and pre-compression opening occurs.

[0004] To achieve the above objectives, the technical solutions adopted in the embodiments of the present application are: In a first aspect, a battery cell is provided, the battery cell comprising at least one electrode assembly, the electrode assembly comprising a positive electrode sheet, a negative electrode sheet, a separator, and a support; The positive electrode sheet, the separator and the negative electrode sheet are wound around the outer periphery of the support body; The support body is an annular structure, the outer ring surface of the support body is fixedly connected to 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 adhered to itself via the first adhesive particles, and the hardness of the support body is greater than that of the diaphragm.

[0005] In the battery cell provided in the embodiments of the present application, the electrode assembly can be formed by disposing a support body having an annular structure and first adhesive particles on the inner surface of the support body at the innermost ring, and by fixing the separator to the outer surface of the support body. The positive electrode sheet, separator, and negative electrode sheet are stacked and wound around the outer periphery of the support body. During the compaction process, the inner surface of the support body can adhere to itself via the first adhesive particles, so that the support body can form a flat structure without an opening, and the support body can support the inner ring of the separator, thereby preventing the separator in the inner ring (especially the innermost ring) from rebounding or shrinking inward. Based on this, the interlayer gap between the positive and negative electrode sheets in the inner ring (especially the innermost ring) can be prevented from increasing, and the separator in the innermost ring can be closely attached to the outer surface of the support body. This can ensure that the electrode assembly is closely attached to each other with a smaller interlayer gap, and the electrode assembly can be fully compacted. This can reduce the risk of pre-pressing openings in the electrode assembly due to insufficient compaction, reduce OH (Outgassing & Hooping, i.e., expansion / contraction) dislocation caused by pre-pressing openings, improve the structural stability of the electrode assembly and the uniformity of the electrochemical reaction, and provide sufficient restraint on the electrode sheets to prevent the ends of the electrode sheets from moving due to external forces. This can reduce the risk of the positive electrode sheet extending beyond the negative electrode sheet due to movement of the electrode sheet ends, thereby causing metal deposition and short circuits. It can also reduce the risk of excessive interlayer gaps between the positive and negative electrode sheets affecting active ion transport performance and causing metal deposition during battery cell use. It can also reduce the risk of foreign particles falling into the electrode assembly along the interlayer gaps and affecting product yield, and the risk of foreign metal particles falling into the electrode assembly along the interlayer gaps and causing short circuits. This can improve the performance, reliability, and service life of the battery cells.

[0006] By adopting the above scheme, by making the hardness of the support body greater than the hardness of the diaphragm, the support body can be made to have a higher hardness than the diaphragm. Based on this, during the needle withdrawal of the winding needle and the clamping needle, the support body with high hardness has a stronger self-deformation resistance than the diaphragm. When the winding needle / clamping needle is pulled out, it is not easy to be twisted or depressed due to external force, and can maintain an annular shape with high morphological stability, thereby reducing the contact deformation and friction resistance between the support body and the winding needle / clamping needle, improving the smoothness of the needle withdrawal operation, reducing the risk of the support body and the diaphragm being pulled out, thereby causing the positive electrode and the negative electrode to overlap and short-circuit, reducing the risk of defects such as wrinkles and folds on the support body and the diaphragm, reducing the risk of structural damage during the needle withdrawal process, and reducing the problem of poor needle withdrawal. Moreover, since the support body has a higher hardness than the diaphragm, the flat support body formed by compaction can form a stable "inner ring skeleton" by virtue of its higher hardness, can form a hard support for the inner ring of the diaphragm, can continuously resist the rebound stress of the diaphragm, and can reliably prevent the diaphragm from rebounding and shrinking inward, thereby promoting the electrode assembly to be fully compacted, tightly attached circle by circle, and reduce the gap between layers, which can improve the structural stability and structural reliability of the electrode assembly.

[0007] In some embodiments, the first adhesive particles are pressure-sensitive adhesive particles, heat-sensitive adhesive particles, or heat-pressure-cooperative adhesive particles.

[0008] By adopting the above scheme, by making the first adhesive particles pressure-sensitive adhesive particles, heat-sensitive adhesive particles or hot-pressing cooperative adhesive particles, the first adhesive particles can be in a low-viscosity state or basically non-viscosity before the compaction process (including the winding process, the blanking process and the material transfer process), so that the inner annular surface of the support body will not be tightly bonded to the winding needle and the clamping needle through the first adhesive particles, thereby reducing the risk of the support body and the diaphragm being pulled apart due to excessive bonding force, thereby causing a short circuit between the positive and negative pole pieces, and reducing the risk of defects such as wrinkles and folds on the support body and the diaphragm due to excessive bonding force, thereby improving the qualified rate of the winding process and the smoothness of the needle pulling operation, and reducing the problem of poor needle pulling. During the compaction process, the first adhesive particles can activate their viscosity based on temperature and pressure, so that the inner annular surface of the support body can be adhered to itself through the first adhesive particles, so that the support body can form a flat structure without openings, which can enhance the stability and reliability of the structure and shape of the support body after compaction.

[0009] In some embodiments, the surface roughness of the inner annular surface of the support body is less than the surface roughness of the diaphragm.

[0010] By adopting the above scheme, by making the surface roughness of the inner ring surface of the support body smaller than the surface roughness of the diaphragm, the inner ring surface of the support body can be made smoother than the surface of the diaphragm. Based on this, during the needle removal of the winding needle and the clamping needle, the contact interface between the inner ring surface of the support body and the winding needle and the clamping needle has fewer microscopic bumps and smaller friction with the winding needle / clamping needle, and it is not easy to generate static electricity due to friction, nor is it easy for the inner ring surface of the support body to adhere to the winding needle / clamping needle due to electrostatic adsorption, thereby improving the smoothness of the needle removal operation, reducing the followability of the support body during needle removal, reducing the risk of the support body and the diaphragm being pulled away, thereby causing the positive electrode and the negative electrode to overlap and short-circuit, reducing the risk of defects such as wrinkles and folds on the support body and the diaphragm, reducing the risk of structural damage during the needle removal process, reducing needle removal defects, and improving the yield rate of the electrode assembly.

[0011] In some embodiments, the thickness of the support body from its outer annular surface to its inner annular surface is 50 μm (micrometers) to 500 μm.

[0012] By adopting the above solution, by ensuring the thickness of the support body from its outer annular surface to its inner annular surface is 50μm to 500μm, the support body can be made sufficiently thick and strong. This improves the support body's own deformation resistance and reduces the risk of deformation or wrinkling due to external forces during the winding and compaction processes. It also improves the basic support capacity of the compacted flat support body, enabling the compacted flat support body to provide reliable support for the inner ring of the separator, providing sufficient reaction force to reliably resist the rebound stress of the separator and reliably prevent the separator from rebounding and shrinking inward. This promotes full compaction of the electrode assembly, ensuring close contact between each ring, and reducing interlayer gaps, thereby improving the structural stability and reliability of the electrode assembly. Furthermore, it reduces the risk of the support body occupying too much space due to excessive thickness, reduces the volume share of the support body in the electrode assembly, and reduces the support body's impact on the energy margin of the battery cell, thereby maintaining and improving the energy density and group margin of the battery cell. In addition, it can also reduce the risk of the support body excessively occupying the normal expansion space of the electrode assembly due to its excessive thickness, reduce the risk of the overly thick support body restricting the expansion buffering of the inner circle area, reduce the risk of excessive accumulation of expansion force in the later stage of the battery cell cycle, and reduce the risk of shell deformation, seal leakage, shell rupture, short circuit, thermal runaway and other phenomena caused by excessive expansion force, thereby maintaining and improving the reliability and service life of the battery cell.

[0013] In some embodiments, the diameter of the first bonding particles is 5 μm to 30 μm.

[0014] By adopting the above scheme and setting the diameter of the first adhesive particles to 5 μm to 30 μm, the risk of agglomeration of the first adhesive particles due to overly small particles, overly large specific surface area, and overly high surface energy can be reduced, the first adhesive particles can have better particle dispersion and are less likely to agglomerate, and the uniformity of the distribution of the bonding points on the inner annular surface of the support body can be improved. The risk of a reduction in the number of bonding points due to overly large particles, limited contact area, and increased gaps between particles can also be reduced, and a sufficient number of bonding points can be formed per unit area of ​​the inner annular surface of the support body, and a single first adhesive particle can have a moderate contact area and adhesion area. As a result, the adhesion strength of the first adhesive particles can be optimized, the inner annular surface of the support body can be effectively self-adhered via the first adhesive particles during the compaction process, and the support body can be formed into a stable flat structure without openings. Moreover, it can also reduce the effect of the first adhesive particles on the increasing thickness of the electrode assembly after compaction, and reduce the risk of increased thickness of the electrode assembly after compaction due to excessively large particles, thereby reducing the occupation of the support body and its first adhesive particles on the energy margin of the battery cell, and can maintain and improve the energy density and group margin of the battery cell.

[0015] In some embodiments, the outer annular surface of the support body is provided with at least one groove, and the groove depth of the groove is smaller than the thickness of the support body from the outer annular surface to the inner annular surface.

[0016] By adopting the above solution, by providing grooves on the outer annular surface of the support body, when the electrode assembly is fully compacted, the grooves provide electrolyte infiltration channels within the inner ring of the electrode assembly (particularly between the tightly fitted support body and separator), allowing the electrolyte to diffuse smoothly and fully penetrate the inner ring of the electrode assembly. This can alleviate the problems of slow electrolyte filling and poor localized infiltration of the inner ring caused by the tight fit of the inner ring, thereby maintaining and improving the electrochemical performance of the battery cell. Furthermore, the grooves can reserve electrolyte storage space for pre-storage electrolyte. Later in the battery cell cycle, the electrolyte stored in the grooves is released through expansion and compression, thereby replenishing the supply of electrolyte, compensating for consumption, and maintaining and improving the battery cell's liquid retention capacity, cycle performance, and service life. Moreover, since the groove depth is smaller than the thickness of the support body from its outer ring surface to its inner ring surface, the groove can be only partially recessed on the outer ring surface of the support body without destroying the overall continuity of the support body, thereby maintaining the structural strength of the annular support body and the basic supporting capacity of the compacted flat support body, enabling the compacted flat support body to form reliable support for the inner ring of the diaphragm, resist the rebound stress of the diaphragm, and prevent the diaphragm from rebounding and shrinking inward.

[0017] In some embodiments, at least one groove is a linear groove.

[0018] By adopting the above solution, the grooves are linear, resulting in a simple, bend-free path. This reduces electrolyte flow resistance within the grooves and promotes directional electrolyte transport and diffusion along their extension direction, thereby improving the directional transport and efficiency of the electrolyte along the grooves, increasing electrolyte filling speed and improving the wetting of the inner ring of the electrode assembly. Furthermore, the linear nature of the linear grooves promotes more stable electrolyte flow and storage within the grooves, reducing localized accumulation of electrolyte or dead spots caused by bends, thereby improving electrolyte wetting uniformity and storage compensation reliability. Furthermore, the regular edges of linear grooves reduce stress concentration effects compared to curved grooves, reducing the risk of localized fracture of the support body caused by the linear grooves during compaction or circulation. Furthermore, the machining process for linear grooves is simplified and less complex, improving processing feasibility, convenience, and consistency.

[0019] In some embodiments, at least one groove is an annular groove.

[0020] By adopting the above solution, by making the groove an annular groove, a circumferential electrolyte channel can be formed on the outer annular surface of the support body through the annular groove. This allows the electrolyte to diffuse evenly along the annular path, covering a large area of ​​the outer annular surface of the support body, thereby reducing local blind spots and improving the uniformity and consistency of electrolyte infiltration. Furthermore, the annular groove forms a circumferential storage space, ensuring uniform distribution and stable storage of electrolyte within the annular groove. During the later stages of the battery cell cycle, under the expansion and compression of the electrode assembly, the electrolyte within the annular groove can be evenly released along the annular path, replenishing the inner and adjacent areas of the annular groove, thereby optimizing the cycle life and electrolyte retention capacity of the battery cell. Furthermore, the closed contour of the annular groove ensures a more symmetrical stress distribution at the edge, and the stress of the annular groove (especially the circular shape) is evenly distributed along the annular direction. This reduces the risk of local fracture of the support body caused by the annular groove during compaction or long-term cycling, thereby maintaining the overall structural strength of the support body.

[0021] In some embodiments, at least one groove is an arc-shaped groove.

[0022] By adopting this approach, the arcuate grooves, whose extension range is between the unidirectionality of linear grooves and the full-circumference coverage of annular grooves, provide broad coverage within a specific arc. Furthermore, their directional arcuate extension directs electrolyte to areas of the inner ring prone to insufficient electrolyte penetration (such as near corners of the flat support body), thereby specifically improving localized blind spots and balancing the directionality and coverage of electrolyte penetration. Furthermore, the curved shape of the arcuate grooves creates an "arc-shaped storage space" on the outer annular surface of the support body. During the later stages of a battery cell cycle, the electrolyte stored in the arcuate grooves can diffuse along the arcuate path toward the periphery under the pressure of electrode assembly expansion and compression, thereby optimizing the cycle life and electrolyte retention of the battery cell. Furthermore, the arcuate grooves have smooth curved edges, minimizing stress concentration, reducing the risk of cracking of the support body due to edge stress concentration during compaction or long-term cycling.

[0023] In some embodiments, at least one groove is a dot-shaped groove.

[0024] By adopting the above solution, based on the "point distribution" characteristics of the point grooves, point grooves can be set in a targeted manner in local areas of the inner ring of the electrode assembly where insufficient wetting is likely to occur. That is, the point grooves can be discretely arranged 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 spots, and improving the flexibility, accuracy and targeting of electrolyte wetting. In addition, multiple discretely distributed point grooves can form a decentralized electrolyte storage space, so that the electrolyte is reserved at different positions on the outer ring surface of the support body. Based on this, in the later stage of the battery cell cycle, as the electrode assembly expands and squeezes, the electrolyte in each point groove can be released to the surrounding area respectively, which can reduce the problem of concentrated or insufficient electrolyte release caused by local uneven squeezing of a single long groove, thereby improving the balance of electrolyte replenishment, making it easy to reliably compensate for electrolyte consumption during the cycle, and helping to maintain the long-term cycle performance of the battery cell. Furthermore, the dot-shaped grooves have a minimal and dispersed impact on the overall strength of the support body. The stress concentration at the edges of individual dot-shaped grooves is limited, reducing the risk of localized fracture of the support body during compaction or long-term circulation. Furthermore, the dot-shaped grooves can be fabricated using simple processes such as stamping and punching. Their location, number, and size can be flexibly adjusted, providing high process feasibility and adaptability.

[0025] In some embodiments, the groove width is 50 μm-500 μm, and the groove depth is 50 μm-500 μm.

[0026] By adopting the above solution, by making the groove width of the groove 50μm~500μm and the groove depth of the groove 50μm~500μm, the groove can be formed into a capillary structure, which can promote the adsorption of the electrolyte by the groove with a capillary structure, that is, the adsorption capacity of the groove for the electrolyte can be optimized. In addition, the capillary phenomenon (driven by the surface tension of the liquid and the adhesion of the groove wall) can be mainly relied on to promote the climbing of the electrolyte, that is, to promote the flow of the electrolyte in the groove, which can reduce the risk of capillary blockage due to too small a 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 a size, thereby causing the electrolyte to sink to the bottom and accumulate, hindering the diffusion and infiltration of the electrolyte, thereby balancing and optimizing the infiltration effect and infiltration speed of the electrolyte. In addition, based on the configuration of this embodiment, the volume of the groove is moderate, which can store sufficient electrolyte for compensation in the later stage of the cycle without weakening the support strength and compressive resistance of the support body.

[0027] In some embodiments, the battery cell includes a shell having a first end wall and a second end wall opposite to each other, and a side wall connected between the first end wall and the second end wall; the electrode assembly is disposed in the shell, the electrode assembly includes a main body, and a pole ear extending toward the first end wall and outside the main body, the pole ear is electrically isolated from the side wall, and the electrode assembly is electrically isolated from the second end wall.

[0028] By adopting the above solution, while the outer shell houses and protects the electrode assembly, the tabs of the electrode assembly can be electrically isolated from the sidewalls, and the electrode assembly can be electrically isolated from the second end wall, thereby reducing the risk of short circuits caused by direct contact between the tabs and the sidewalls, and between the electrode assembly and the second end wall. This maintains the stable operation of the battery cells and improves their reliability and service life.

[0029] 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; In each electrode assembly, the 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 component and has a first extension portion extending toward the first end wall to the outside of the main body. The electrode ear of each electrode assembly is located between the two first extension portions and is electrically isolated from the side wall by the two first extension portions.

[0030] By adopting the above solution, when multiple electrode assemblies are arranged side by side along the first direction, the insulating support bodies of the two first electrode assemblies can be extended toward the first end wall to form a first extension portion, so that a unified isolation space is formed by the two first extension portions, and the tabs of all electrode assemblies are constrained between the two first extension portions. Based on this, an "enclosed" insulating protective wall can be formed by the two first extension portions, which physically prevents the tabs from deviating toward the side walls due to vibration, deformation, etc., thereby reliably preventing the tabs from directly contacting the side walls to form a conductive path, reducing the risk of short circuits caused by direct contact between the tabs and the side walls, improving insulation reliability, and improving the reliability and service life of the battery cell. Moreover, based on the arrangement of this embodiment, there is no need to design an insulation structure separately for each tab, thereby simplifying the insulation solution in the multi-tab scenario, reducing independent insulating components, and simplifying and optimizing the structure of the battery cell. In addition, the support body itself assumes the winding support function of the electrode assembly, and the first extension formed by its extension additionally assumes the tab isolation function, realizing "one material for multiple uses" and "functional reuse". Based on this functional integration, the space reserved for isolating the tabs can be reduced (such as reserving a separate insulating space between the side wall and the tab), which helps to compress the internal redundancy of the battery cell and help to improve the space utilization and energy density of the battery cell.

[0031] In some embodiments, the battery cell includes an insulating shell disposed within the outer shell, the insulating shell covering the electrode assembly, and the electrode assembly is electrically isolated from the side wall and the second end wall by the insulating shell.

[0032] By adopting the above solution, an insulating shell covering the electrode assembly can be added to the outer shell to construct an integrated, comprehensive insulation barrier to uniformly achieve electrical isolation between the electrode assembly and the sidewall (especially between the tab and the sidewall) and between the electrode assembly and the second end wall, thereby reducing the risk of short circuits caused by direct contact between the electrode assembly and the sidewall (especially between the tab and the sidewall) and between the electrode assembly and the second end wall, and reducing the risk of multi-path short circuits, thereby improving insulation reliability and improving the reliability and service life of the battery cell. In addition, this embodiment is compatible with different numbers of electrode assemblies, and there is no need to adjust the insulation solution based on the number of electrode assemblies, nor is there a need to design separate insulation structures for each electrode assembly, each tab, or multiple sides of the electrode assembly. This improves the versatility of the insulation design, simplifies the insulation solution, reduces independent insulation components, and simplifies and optimizes the structure of the battery cell.

[0033] In some embodiments, the battery cell includes a bottom support plate disposed in the housing, the bottom support plate being disposed between the electrode assembly and the second end wall, and the electrode assembly is electrically isolated from the second end wall by the bottom support plate.

[0034] By adopting the above solution, by adding a bottom support plate between the electrode assembly and the second end wall, the bottom support plate can provide reliable support for the electrode assembly, and the bottom support 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, thereby achieving electrical isolation between the electrode assembly and the second end wall, reducing the risk of short circuit due to direct contact between the electrode assembly and the second end wall; and, the bottom support plate can cover the bottom of the electrode assembly with its own flat support surface, dispersing pressure and reducing the risk of insulation damage; thereby, improving insulation reliability, and improving the reliability and service life of the battery cell. In addition, this embodiment is compatible with different numbers of electrode assemblies, and there is no need to adjust the insulation solution according to the number of electrode assemblies, and there is no need to design an insulation structure separately for each electrode assembly, thereby improving the versatility of the insulation design, simplifying the insulation solution, reducing independent insulation components, and simplifying and optimizing the structure of the battery cell.

[0035] In some embodiments, the battery cell includes an insulating support member disposed in the shell, the insulating support member abuts against the side of the electrode assembly facing the second end wall, the support body of the electrode assembly has a second extension portion extending outside the main body, and the second extension portion is connected to the insulating support member.

[0036] By adopting the above solution, while the insulating support member abuts and supports the electrode assembly, achieving electrical isolation between the electrode assembly and the second end wall, the electrode assembly support body can be extended to form a second extension portion, which is connected and fixed to the insulating support member via the second extension portion, thereby forming a fixed point between the electrode assembly and the insulating support member. This helps to fix the electrode assembly relative to the insulating support member, stabilizes the position and state of the electrode assembly relative to the insulating support member, and prevents the electrode assembly from moving relative to the insulating support member, thereby improving the structural stability and reliability of the battery cell. Furthermore, during the use of the battery cell, due to the improved positional stability of the electrode assembly and the reduced risk of movement, the risk of contact short circuit between the electrode assembly and the second end wall due to relative displacement between the electrode assembly and the insulating support member can be reduced. The risk of contact short circuit between the electrode tab and the side wall due to positional deviation of the electrode tab can also be reduced, thereby reducing the risk of short circuit and improving the reliability and service life of the battery cell.

[0037] In some embodiments, the second extension portion is bent and disposed between the main body portion and the insulating support member.

[0038] By adopting the above solution, by bending the second extension portion between the main body and the insulating support, the contact area and connection area between the second extension portion and the insulating support are increased, thereby enhancing the connection strength, stability, and reliability between the second extension portion and the insulating support. This improves the connection stability and reliability between the electrode assembly and the insulating support, consolidates the position and position of the electrode assembly relative to the insulating support, reduces the risk of short circuits, and improves the structural stability, reliability, operational reliability, and service life of the battery cell. Furthermore, the bent shape imparts a certain degree of elastic deformation capability to the second extension portion. When the battery cell 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 portion absorbs some of the energy through its own deformation, acting as a buffer. This reduces the direct transmission of stress to the main body or the insulating support, reduces the risk of structural damage to the electrode assembly due to rigid stress, and reduces the stress load on the insulating support, thereby extending the service life of the insulating support. Moreover, the bending setting enables the second extension portion to be reasonably arranged within the limited space between the main body portion and the insulating support member. The bent second extension portion can be compressed by "folding" to occupy the space between the main body portion and the insulating support member, which can adapt to the compact layout requirements inside the shell and is conducive to improving the energy density of the battery cell.

[0039] In a second aspect, a method for manufacturing an electrode assembly is provided, comprising the following steps: The support body is sleeved on the outer periphery of the winding needle, so that the winding needle is stretched and pressed against the support body, wherein the support body is an annular structure, and the inner annular surface of the support body is provided with first adhesive particles; The rolled end of the diaphragm is fixedly connected to the outer annular surface of the support body; After the separator is wound around the outer periphery of the support body for a predetermined number of turns, the negative electrode sheet is then wound in. When the wound length of the negative electrode sheet exceeds the predetermined length, the positive electrode sheet is then wound in, so that the positive electrode sheet, separator, and negative electrode sheet are wound around the outer periphery of the support body; First cut the positive electrode sheet, then cut the negative electrode sheet, then cut the separator, and then wind and finish to form a winding structure; Unload the coiled structure from the coiling needle; The wound structure is compacted so that the inner annular surface of the support body is adhered to itself via the first adhesive particles, thereby forming a flat electrode assembly.

[0040] By adopting the above scheme and the method for manufacturing an electrode assembly provided in the embodiments of the present application, the positive electrode sheet, separator, and negative electrode sheet can be first wound around the periphery of the support body, so that the support body, separator, negative electrode sheet, and positive electrode sheet together form a wound structure; the wound structure is then compacted until the inner annular surface of the support body is adhered to itself via the first adhesive particles, so that the support body forms a flat structure without an opening, thereby obtaining a flat electrode assembly. Based on this, the electrode assembly provided in the embodiments of the present application with a support body and fully compacted can be conveniently and quickly manufactured, which can improve the manufacturability, production convenience, production efficiency, production consistency, and production yield of the electrode assembly.

[0041] In some embodiments, the first adhesive particles are pressure-sensitive adhesive particles, heat-sensitive adhesive particles, or heat-pressure synergistic adhesive particles; During the steps of sleeve-arranging the support body around the outer periphery of the winding needle so that the winding needle is stretched and pressed against the support body and the step of unloading the wound structure from the winding needle, the first adhesive particles are not activated; In the step of compacting the wound structure, the first adhesive particles activate adhesiveness, so that the inner annular surface of the support body is adhered to itself via the first adhesive particles.

[0042] By adopting the above scheme, by making the first adhesive particles pressure-sensitive adhesive particles, heat-sensitive adhesive particles or hot-pressing cooperative adhesive particles, the first adhesive particles can be made inactive and in a low-viscosity state or basically non-viscous in the step of "sleeving the support body on the periphery of the winding needle, so that the winding needle is stretched and presses the support body" to the step of "unloading the winding structure from the winding needle", so that the inner annular surface of the support body will not be tightly bonded to the outer peripheral surface of the winding needle and the clamping needle through the first adhesive particles, thereby reducing the risk of the support body and the diaphragm being pulled out due to excessive adhesive force during the removal of the winding needle and the insertion and removal of the clamping needle in the step of "unloading the winding structure from the winding needle", and reducing the risk of defects such as wrinkles and folds on the support body and the diaphragm due to excessive adhesive force. This can improve the qualified rate of the winding process and the smoothness of the needle removal operation, and reduce the problem of poor needle removal. Furthermore, during the step of compacting the wound structure, the first adhesive particles can activate their adhesive properties based on temperature and pressure, allowing the inner annular surface of the support body to adhere to itself via the first adhesive particles, resulting in a flat structure without openings. This improves the pass rate of the compaction process and enhances the stability and reliability of the structure and morphology of the support body after compaction. This improves the manufacturability, production convenience, production efficiency, production consistency, and production yield of the electrode assembly.

[0043] In some embodiments, in the step of fixedly connecting the rolled-in end of the diaphragm to the outer annular surface of the support body, the rolled-in end of the diaphragm is fixedly connected to the outer annular surface of the support body by heat melting or ultrasonic welding.

[0044] By adopting the above solution, in the step of "fixedly connecting the wound end of the diaphragm to the outer annular surface of the support body," a hot melt connection or ultrasonic welding method can be used to conveniently and quickly achieve a fixed connection between the wound end of the diaphragm and the outer annular surface of the support body. Based on this, the convenience, strength, stability, and reliability of the connection between the wound 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. Furthermore, because hot melt connection or ultrasonic welding methods do not require additional consumables (such as solder, adhesive, etc.), the impact of residual additional consumables on the structure and performance of the electrode assembly can be reduced, which can improve the molding quality of the electrode assembly; the impact of residual additional consumables on the electrolyte can be reduced, and the performance of the battery cells can be optimized; and costs can be reduced.

[0045] In some embodiments, the fixed connection area between the rolled end of the diaphragm and the outer annular surface of the support body is the 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 (millimeter) and less than or equal to the size of the support body.

[0046] By adopting the above solution, sufficient axial connection length and area can be achieved between the winding end of the diaphragm and the outer annular surface of the support body based on the first connection area. This improves the connection strength, stability, and reliability between the winding end of the diaphragm and the outer annular surface of the support body, reduces the risk of the diaphragm falling off the support body during the initial winding process, improves the pass rate of the step of "fixedly connecting the winding end of the diaphragm to the outer annular surface of the support body," and improves the production convenience, production efficiency, and production yield of the electrode assembly. Furthermore, the first connection area does not extend beyond the axial boundary of the support body, which reduces the damage caused by the formation of the first connection area to the winding needle, protects the winding needle from damage, maintains the reliability and service life of the winding needle, and reduces equipment maintenance costs and the risk of downtime.

[0047] In some embodiments, the fixed connection area between the rolled end of the diaphragm and the outer annular surface of the support body is the first connection area; along the circumference 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.

[0048] By adopting the above scheme, based on the first connection area, the winding end of the diaphragm and the outer annular surface of the support body can have sufficient circumferential connection length and connection area, thereby improving the connection strength, connection stability and connection reliability between the winding end of the diaphragm and the outer annular surface of the support body, reducing the risk of the diaphragm falling off the support body in the early stage of winding, improving the pass rate of the step of "fixedly connecting the winding end of the diaphragm to the outer annular surface of the support body", and improving the production convenience, production efficiency and production yield of the electrode assembly.

[0049] In some embodiments, the preset number of turns is 0.5 turns to 1 turn.

[0050] By adopting the above solution, after the step of "fixing the wound end of the diaphragm to the outer annular surface of the support body", the diaphragm can be first wound around the outer circumference of the support body by 0.5 to 1 turn. Based on this, the pre-wound 0.5 to 1 turn of the diaphragm can be made to cover at least half of the outer annular surface of the support body, forming a "half-wrapped" inner ring insulation barrier to insulate and isolate the support body and the electrode sheets, and between the positive and negative electrode sheets, thereby reducing the risk of short circuits. In particular, it can reduce the risk of the end of the electrode sheet moving, causing the electrode sheet to exceed the insulation isolation range of the diaphragm, resulting in a short circuit between the positive and negative electrode sheets, thereby improving the molding quality and production yield of the electrode assembly. Moreover, the initial winding number of the diaphragm is 0.5 to 1 turn, which is relatively small, and the volume of the "starting core" (i.e., the support body and the initial diaphragm) of the winding structure can be smaller and more compact. Based on this, in the subsequent compaction process, the compact starting core can evenly transfer the pressure to the entire winding structure, which can reduce the problem of insufficient local compaction caused by too many initial winding turns of the diaphragm and too thick starting core, thereby improving the compaction density and compaction efficiency, and improving the overall volume energy density of the electrode assembly.

[0051] In some embodiments, the predetermined length is 2 mm.

[0052] By adopting the above solution, the positive electrode sheet can be rolled in before the negative electrode sheet is rolled in, even if the rolled-in length of the negative electrode sheet exceeds 2 mm. Based on this, the negative electrode sheet can be rolled in before the positive electrode sheet, the rolled-in length of the negative electrode sheet can be made to exceed the positive electrode sheet by 2 mm, and the rolled-in end of the positive electrode sheet can be reliably covered by the negative electrode sheet. This can follow the design principle of "negative electrode sheet covering positive electrode sheet", fundamentally reduce the probability of metal precipitation and short circuit, and improve the molding quality and production yield of the electrode assembly.

[0053] In some embodiments, the number of the winding needle is one, and the winding needle maintains a preset position during the winding process.

[0054] By adopting this solution, equipment with a single winding needle that maintains a preset position during the winding process can be used to perform the steps from "sleeving a support body around the outer periphery of the winding needle, causing the winding needle to expand and press against the support body" to "unloading the wound structure from the winding needle." This simplifies the equipment structure, reduces equipment complexity and failure rate, and indirectly improves production continuity. Furthermore, because the winding needle maintains its preset position, eliminating the need for station switching, the stability and consistency of the winding process are enhanced, thereby improving the molding quality and production yield of the electrode assembly.

[0055] In some embodiments, there are two winding needles, and the two winding needles are capable of rotating around a preset axis so that the two winding needles alternate between the first station and the second station; wherein, in each step of the method for manufacturing the electrode assembly: The steps of sleeve-arranging the support body around the outer periphery of the winding needle, making the winding needle open and press against the support body, winding and finishing to form a winding structure, and unloading the winding structure from the winding needle are performed at the first station; The steps of fixing the rolled end of the separator to the outer annular surface of the support body and first cutting the positive electrode sheet and then cutting the negative electrode sheet are performed at the second station; The step of cutting the membrane is performed between the second station and the first station.

[0056] By adopting the above solution, two winding needles can be used to work alternately at the first and second stations. The various steps of the electrode assembly winding process can be split into different stations to achieve alternating operations. This allows the two winding needles to operate in parallel, shortening waiting time and production cycle time. This eliminates the window period of "completing one product before starting the next" in the single-needle winding mode, reducing equipment idle time, creating a "seamless connection", and increasing production capacity per unit time (theoretically, one operation cycle can basically complete the winding process of two electrode assemblies, which is nearly twice the efficiency of a single winding needle), thereby improving production efficiency. Furthermore, after splitting the steps into fixed stations, the operations at each station can be specialized and optimized. Each station can perform the corresponding operations with high precision, stability, and accuracy. The operating parameters of each step can be easily standardized, thereby optimizing process stability and improving the consistency and yield rate of batch production.

[0057] In some embodiments, when two winding needles complete the workstation switching, the diaphragm is overlapped from the first workstation to the outer annular surface of the support body located at the second workstation, and the step of fixing the winding end of the diaphragm to the outer annular surface of the support body is first performed at the second workstation, and then the step of cutting the diaphragm is performed between the second workstation and the first workstation, and then the step of winding and finishing to form a winding structure is performed at the first workstation.

[0058] By adopting the above scheme, on the basis of two alternating winding needle stations, through the process design of "overlapping the diaphragm from the first station to the support body of the second station - fixing the winding end of the diaphragm at the second station - cutting the diaphragm between the first station and the second station - winding and finishing at the first station", the diaphragm can be seamlessly overlapped, the continuous utilization of the diaphragm can be optimized, the diaphragm does not need to be re-rolled at each switch, the redundant waste of diaphragm caused by each separate winding can be reduced, the material utilization rate can be improved, and the operation of "fixing the winding end of the diaphragm at the second station" can be simplified based on the continuous overlap of the diaphragm, the process continuity can be improved, and the coordination of the double-station operation can be enhanced. In addition, the sequential connection of overlapping, fixing, cutting and finishing of the diaphragm enables the second station to start winding after fixing the diaphragm, and enables the first station to use the cut diaphragm for finishing almost at the same time, so that the first station and the second station share a section of diaphragm in time-sharing utilization, so that the "finishing" of the previous product and the "initial winding" of the next product can be carried out in parallel, which can reduce the waiting time of the station caused by the conflict of diaphragm allocation (such as the stagnation of "the previous finishing is not completed and the next winding cannot take the diaphragm"), thereby compressing the production rhythm and improving production efficiency.

[0059] In some embodiments, there are three winding needles, which are capable of rotating about a preset axis so that the three winding needles alternately cycle between the first station, the second station, and the third station, and the three winding needles are located in a one-to-one correspondence between the first station, the second station, and the third station; wherein, in each step of the electrode assembly manufacturing method: The step of sleeve-arranging the support body on the outer periphery of the winding needle so that the winding needle is stretched and pressed against the support body is performed at the first station; The steps of fixing the rolled end of the separator to the outer annular surface of the support body and first cutting the positive electrode sheet and then cutting the negative electrode sheet are performed at the second station; The step of cutting the diaphragm is performed between the second station and the third station; The steps of finishing the winding to form a winding structure and unloading the winding structure from the winding needle are performed at the third station.

[0060] By adopting the above solution, three winding needles can be used to cycle and work alternately at the first, second, and third stations in sequence. This allows the various steps of the electrode assembly winding process to be split into three stations for alternating operation. This allows the three winding needles to operate in parallel, compressing waiting time and production cycle time, eliminating the window period of "completing one product before starting the next" in the single-needle winding mode, reducing equipment idle time, creating a "seamless connection," and increasing production capacity per unit time (theoretically, one operation cycle can basically complete the winding process of three electrode assemblies, which is nearly three times the efficiency of a single winding needle), thereby improving production efficiency. Furthermore, after splitting the steps 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. The operating parameters of each step can be easily standardized, thereby optimizing process stability and improving the consistency and yield rate of batch production.

[0061] In some embodiments, there are four winding needles, which are capable of rotating about a preset axis so that the four winding needles alternately cycle through the first station, the second station, the third station, and the fourth station, and the four winding needles are located in a one-to-one correspondence with 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 sleeve-arranging the support body on the outer periphery of the winding needle so that the winding needle is stretched and pressed against the support body is performed at the first station; The steps of fixing the rolled end of the separator to the outer annular surface of the support body and first cutting the positive electrode sheet and then cutting the negative electrode sheet are performed at the second station; The step of cutting the diaphragm is performed between the second station and the third station; The step of winding and finishing to form a winding structure is carried out at the third station; The step of unloading the wound structure from the winding needle is carried out at the fourth station.

[0062] By adopting the above solution, four winding needles can be used to cycle and work alternately at the first, second, third, and fourth stations, splitting the various steps of the electrode assembly winding process into four stations for alternating operation. This allows the four winding needles to operate in parallel, shortening waiting time and production cycle time, eliminating the window period of "completing one product before starting the next" in the single-needle winding mode, reducing equipment idle time, creating a "seamless connection," and increasing production capacity per unit time (theoretically, one operation cycle can basically complete the winding process of four electrode assemblies, which is nearly four times the efficiency of a single winding needle), thereby improving production efficiency. Furthermore, after splitting the steps 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. The operating parameters of each step can be easily standardized, thereby optimizing process stability and improving the consistency and yield rate of batch production.

[0063] In a third aspect, a battery device is provided, which includes the battery cell provided in the embodiment of the present application.

[0064] By adopting the above solution, the battery device can improve the performance, reliability and service life by applying the battery cells provided in the embodiments of the present application.

[0065] In a fourth aspect, an electrical device is provided, which includes the battery device provided in an embodiment of the present application, or the battery cell provided in an embodiment of the present application.

[0066] By adopting the above solution, the electrical device can improve the performance, reliability and service life by applying the battery device or battery cell provided by the embodiment of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0067] In order to clearly illustrate the technical solutions in the embodiments of the present application, the following briefly introduces the drawings required for use in the embodiments of the present application or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0068] Figure 1 A schematic structural diagram of a vehicle provided in some embodiments of the present application; Figure 2 An exploded schematic diagram of a battery device provided in some embodiments of the present application; Figure 3 An exploded schematic diagram of a battery cell provided in some embodiments of the present application; Figure 4 An exploded schematic diagram of a battery cell provided in some embodiments of the present application, wherein the electrode assembly includes a support body; Figure 5 A schematic perspective view of an electrode assembly provided in some embodiments of the present application; Figure 6 A cross-sectional view of an electrode assembly provided in some embodiments of the present application; Figure 7 for Figure 6 Magnified image of region A is provided; Figure 8 A front view of a support body in a compacted state provided in some embodiments of the present application; Figure 9 for Figure 8 A front view of the support body in an uncompacted state is provided; Figure 10A front view of a support body in an uncompacted state provided in some other embodiments of the present application, wherein the outer annular surface of the support body is provided with a groove; Figure 11 for Figure 10 A front view of the support body in a compacted state is provided; Figure 12 for Figure 11 A top view of the support body is provided; Figure 13 A top view of a support body provided in some other embodiments of the present application, wherein the groove is a linear groove; Figure 14 A top view of a support body provided in some other embodiments of the present application, wherein the groove is an annular groove; Figure 15 A top view of a support body provided in some other embodiments of the present application, wherein a portion of the grooves are linear grooves and a portion of the grooves are arc-shaped grooves; Figure 16 A top view of a support body provided in some other embodiments of the present application, wherein the groove is a dot-shaped groove; Figure 17 A schematic structural diagram of a battery cell provided in some embodiments of the present application, wherein the battery cell is provided with an insulating shell but without a bottom support plate, and the support body is provided with a first extension portion and a second extension portion; Figure 18 Schematic diagram of the structure of a battery cell provided in some other embodiments of the present application, wherein the battery cell is provided with a bottom support plate but not an insulating shell, and the support body is provided with a first extension portion and a second extension portion; Figure 19 Schematic diagram of the structure of a battery cell provided in some other embodiments of the present application, wherein the battery cell is provided with an insulating shell and a bottom support plate, and the support body is not provided with the first extension portion and the second extension portion; Figure 20 A flowchart of a method for manufacturing an electrode assembly provided in some embodiments of the present application; Figure 21 A schematic structural diagram corresponding to the step of "sleeving the support body around the outer periphery of the winding needle so that the winding needle is stretched and pressed against the support body" provided in some embodiments of the present application; Figure 22 A schematic structural diagram corresponding to the step of “fixing the rolled-in end of the diaphragm to the outer annular surface of the support body” provided in some embodiments of the present application; Figure 23 A schematic structural diagram corresponding to the step of “winding the diaphragm around the outer periphery of the support body for a predetermined number of turns” provided in some embodiments of the present application; Figure 24A schematic diagram of the structure corresponding to the step of "winding the separator a predetermined number of times around the periphery of the support body, then rolling the negative electrode sheet, and when the rolled-up length of the negative electrode sheet exceeds a predetermined length, then rolling the positive electrode sheet, thereby winding the positive electrode sheet, separator, and negative electrode sheet around the periphery of the support body" provided in some embodiments of the present application; Figure 25 Schematic diagram of the structure corresponding to the step of "fixedly connecting the rolled-in end of the diaphragm to the outer annular surface of the support body" provided in other embodiments of the present application, wherein the connecting mark of the first connecting area is linear, and the extending direction of the connecting mark is substantially parallel to the axial direction of the support body; Figure 26 Schematic diagram of the structure corresponding to the step of "fixedly connecting the rolled-in end of the diaphragm to the outer annular surface of the support body" provided in other embodiments of the present application, wherein the connecting mark of the first connecting area is linear, and the extending direction of the connecting mark is substantially perpendicular to the axial direction of the support body; Figure 27 A schematic structural diagram corresponding to the step of "fixedly connecting the rolled-in end of the diaphragm to the outer annular surface of the support body" provided in other embodiments of the present application, wherein the connection mark of the first connection area is curved; Figure 28 A schematic structural diagram corresponding to the step of "fixedly connecting the rolled-in end of the diaphragm to the outer annular surface of the support body" provided in some other embodiments of the present application, wherein the connection mark of the first connection area is in the shape of a dot; Figure 29 A schematic diagram of the structure of a turret and two winding needles provided in some embodiments of the present application; Figure 30 A schematic diagram of the structure of a turret and three winding needles provided in some embodiments of the present application; Figure 31 Schematic diagram of the structure of the turret and four winding needles provided in some embodiments of the present application.

[0069] Among them, the reference numerals in the figures are: 1-battery device, 2-controller, 3-motor; 100-battery unit, 200-housing, 201-first part, 202-second part; 10-battery cell, 11-housing, 111-first end wall, 112-second end wall, 113-side wall; 12-electrode assembly, 12a-first electrode assembly, 121-main body, 122-ear, 122a-positive electrode ear, 122b-negative electrode ear, 123-electrode sheet, 123a-positive electrode sheet, 123b-negative electrode sheet, 124-diaphragm, 125-support, 1251-first adhesive particle, 1252-groove, 1252a-straight groove, 1252b-annular groove, 1252c-arc groove, 1252d- Point-shaped groove, 1253-first extension part, 1254-second extension part, 1255-first connection area, 12551-connection print; 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 part; 14-electrode terminal, 14a-positive electrode terminal, 14b-negative electrode terminal; 15-adapter, 15a-positive electrode adaptor, 15b-negative electrode adaptor; 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

[0070] In order to make the technical problems, technical solutions and beneficial effects to be solved by this application clear and understandable, the application is described in detail below in conjunction with the accompanying drawings and examples. It should be understood that the specific embodiments described herein are merely used to explain this application and are not intended to limit this application. Unless otherwise specified, all embodiments and optional embodiments of this application can be combined with each other to form new technical solutions. Unless otherwise specified, all technical features and optional technical features of this application can be combined with each other to form new technical solutions.

[0071] In the description of this application, it should be understood that the terms "length", "width", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on this application.

[0072] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features being referred to. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of such features. Throughout the description of this application, "plurality" means two or more, unless otherwise specifically defined.

[0073] In this application, unless otherwise expressly specified or limited, terms such as "mounted," "connected," "connect," and "fixed" should be understood in a broad sense. For example, they may refer to fixed connections, detachable connections, or integration; mechanical connections or electrical connections; direct connections or indirect connections through an intermediate medium; and internal connections between two components or interactions between two components. Those skilled in the art will understand the specific meanings of these terms in this application based on specific circumstances.

[0074] A battery cell is the smallest unit for storing and outputting electrical energy. A battery cell typically contains at least one electrode assembly. The electrode assembly is essential for the electrochemical reactions within the battery cell. The electrode assembly includes a positive electrode sheet, a negative electrode sheet, and a separator that separates the positive and negative electrode sheets. The positive electrode sheet, separator, and negative electrode sheet are wound together and undergo post-processing, such as compaction, to form a flat, rolled electrode assembly with a main body and a bend zone located at the end of the main body.

[0075] However, due to the thinness (approximately 10 microns) and elasticity of the separator, the corners of the separator at the bend area experience significant rebound force during the compaction process. This can cause the inner (especially innermost) separator to cause the inner electrode sheets to rebound and retract inward, widening the interlayer gap between the positive and negative electrode sheets. This can make compaction of the electrode assembly difficult (i.e., undercompacting), leading to pre-compression gapping in the undercompacted electrode assembly. In some cases, design requirements necessitate increasing the thickness of the electrode sheets to enhance product competitiveness. However, the greater the designed thickness of the electrode sheets, the greater the probability of pre-compression gapping, and the larger the gap. "Pre-compression gapping" refers to the phenomenon in which, after compaction, the interlayer structure of the electrode assembly (primarily between the positive electrode sheet, separator, and negative electrode sheet) that should be tightly fitted exhibits partial or complete enlargement of gaps, delamination, or even warping, similar to an "open" state.

[0076] If the interlayer gap between the positive electrode sheet and the negative electrode sheet is too large, during the use of the battery cell, especially in the later stages of the cycle when the battery cell undergoes multiple charge and discharge cycles (i.e., long-term use), it will affect the active ion transmission performance and induce metal precipitation (for example, if the active ions are lithium ions, the metal precipitation phenomenon is lithium precipitation), thereby affecting the performance, reliability and service life of the battery cell.

[0077] If the electrode assembly is pre-stressed and opened, during the subsequent charge and discharge process, the electrode assembly will cause inter-layer dislocation (dislocation) 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 performance, reliability, and service life of the battery cell. In addition, in the initial design of the electrode assembly, the negative electrode plate will extend beyond the positive electrode plate (i.e., "negative electrode over-design" or "negative electrode covering the positive electrode") to reduce the risk of metal precipitation and short circuit. However, the pre-stressed opening will cause the plate to lack sufficient restraint, causing the end of the plate to easily move due to external forces such as vibration. If the end of the plate moves, causing the positive electrode plate to extend beyond the negative electrode plate, it will increase the risk of metal precipitation and short circuit, affecting the performance, reliability, and service life of the battery cell.

[0078] If the electrode assembly is not fully compacted and the gaps between layers are large, foreign particles, such as particles from the environment and those generated during processing and assembly, can easily fall through the gaps between the layers into the electrode assembly, affecting the yield rate of the electrode assembly. If the foreign particles that fall into the electrode assembly are metallic particles, they can easily cause short circuits, affecting the performance, reliability, and service life of the battery cells.

[0079] Thus, some embodiments of the present application provide a battery cell, wherein the electrode assembly of the battery cell can be configured by disposing a support body having an annular structure and first adhesive particles on the inner surface of the support body at the innermost ring, and by fixing a separator to the outer surface of the support body. Furthermore, the positive electrode sheet, separator, and negative electrode sheet are stacked and wound around the outer periphery of the support body. During the compaction process, the inner surface of the support body can adhere to itself via the first adhesive particles, allowing the support body to form a flat structure without an opening. The support body can support the inner ring of the separator, thereby preventing the separator in the inner ring (particularly the innermost ring) from rebounding or retracting inward. This prevents the interlayer gap between the positive and negative electrode sheets in the inner ring (particularly the innermost ring) from increasing, promotes close contact between the separator in the innermost ring and the outer surface of the support body, promotes close contact between the electrode assembly with smaller interlayer gaps, and promotes sufficient compaction of the electrode assembly. This can reduce the risk of pre-pressing and opening the electrode assembly due to insufficient compaction, reduce OH dislocation caused by pre-pressing and opening, improve the structural stability of the electrode assembly and the uniformity of the electrochemical reaction, form sufficient restraint on the electrode piece to prevent the end of the electrode piece from moving due to external forces, and reduce the risk of the positive electrode piece extending beyond the negative electrode piece due to the movement of the electrode piece end, thereby causing metal precipitation and short circuit. It can also reduce the risk of excessive interlayer gaps between the positive and negative electrode pieces affecting the active ion transmission performance and causing metal precipitation during the use of the battery cell. It can also reduce the risk of foreign particles falling into the electrode assembly along the interlayer gaps and affecting the yield rate, and the risk of foreign metal particles falling into the electrode assembly along the interlayer gaps and causing short circuits. As a result, the performance, reliability, and service life of the battery cell can be improved.

[0080] The battery cells disclosed in the embodiments of the present application can be used independently or in combination with other battery cells to form modular battery devices that can provide higher voltage and capacity, such as battery modules, battery modules, or battery packs. The battery cells and battery devices disclosed in the embodiments of the present application can be used in electrical devices that use the battery cells and battery devices as power sources, or in various energy storage systems that use the battery cells and battery devices as energy storage elements. The electrical devices may be, but are not limited to, vehicles, mobile phones, portable devices, laptops, ships, spacecraft, electric toys, and power tools, etc. Vehicles may be fuel vehicles, gas vehicles, or new energy vehicles. New energy vehicles may be pure electric vehicles, hybrid vehicles, or extended-range vehicles, etc. Spacecraft include aircraft, rockets, space shuttles, and spacecraft, etc. Electric toys include fixed or mobile electric toys, such as game consoles, electric car toys, electric ship toys, and electric airplane toys, etc. Power tools include metal cutting power tools, grinding power tools, assembly power tools, and railway power tools, such as electric drills, electric grinders, electric wrenches, electric screwdrivers, electric hammers, impact drills, concrete vibrators, and electric planers, etc.

[0081] In order to illustrate the technical solution provided by the present application, the following is a detailed description with reference to specific drawings and embodiments, taking "the electrical device being a vehicle" as an example.

[0082] See also Figure 1 , Figure 1 Schematic diagram of the structure of a vehicle provided for some embodiments of the present application. The vehicle can be a fuel vehicle, a gas vehicle or a new energy vehicle. The new energy vehicle can be a pure electric vehicle, a hybrid vehicle or an extended-range vehicle, etc. A battery device 1 is provided inside the vehicle, and the battery device 1 can be provided at the bottom, head or tail of the vehicle. The battery device 1 is used to power the vehicle. For example, the battery device 1 can serve as an operating power source for the vehicle. The vehicle may also include a controller 2 and a motor 3. The controller 2 is used to control the battery device 1 to power the motor 3, for example, for starting, navigating and operating power requirements of the vehicle during driving.

[0083] In some embodiments of the present application, the battery device 1 can serve not only as an operating power source for the vehicle, but also as a driving power source for the vehicle, replacing or partially replacing fuel or natural gas to provide driving power for the vehicle.

[0084] See also Figure 2 , Figure 2 This is an exploded schematic diagram of a battery device 1 provided in some embodiments of the present application. The battery device 1 includes a battery unit 100 and a housing 200 , wherein the battery unit 100 is accommodated in the housing 200 .

[0085] The box 200 is used to provide a storage space for components such as the battery cell 100. The box 200 can protect the battery cell 100 and other components contained therein from dust and water, thereby reducing the impact of external liquids or other foreign matter on the effectiveness and performance of the battery cell 100 and other components, and effectively extending the service life of the battery device 1.

[0086] The housing 200 can adopt a variety of structures. In some embodiments, the housing 200 can include a first portion 201 and a second portion 202, which cover each other and together define a storage space for accommodating the battery cell 100. The second portion 202 can be a hollow structure with one end open, and the first portion 201 can be a plate-like structure, with the first portion 201 covering the open side of the second portion 202, so that the first portion 201 and the second portion 202 jointly define the storage space. The first portion 201 and the second portion 202 can also be hollow structures with one end open, with the open side of the first portion 201 covering the open side of the second portion 202.

[0087] The box body 200 may be in various shapes, such as a cylinder, a cuboid, etc.

[0088] The box body 200 can be made of a variety of materials, such as copper, iron, aluminum, stainless steel, aluminum alloy, plastic, etc.

[0089] Battery cells 100 are energy storage units that convert chemical energy into electrical energy. In battery device 1, one or at least two battery cells 100 may be provided. When at least two battery cells 100 are provided, the at least two battery cells 100 may be connected in series, in parallel, or in a hybrid configuration. A hybrid configuration refers to a combination of series and parallel configurations for the at least two battery cells 100.

[0090] The battery unit 100 may include at least two battery cells. The at least two battery cells may be directly connected in series, in parallel, or in a mixed manner, and the whole formed by the at least two battery cells may be housed in the casing 200. The battery cells may be lithium-ion secondary battery cells, lithium-sulfur battery cells, sodium-lithium-ion battery cells, sodium-ion battery cells, magnesium-ion battery cells, and the like. The battery cells may be cylindrical, flat, rectangular, or in other shapes. The battery cells may be packaged in different ways to form cylindrical battery cells, square battery cells, or soft-pack battery cells, and the like.

[0091] Alternatively, the battery unit 100 may be a battery module or battery pack. That is, at least two battery cells may be connected in series, parallel, or in series to form a modular structure (i.e., a battery module or battery pack); at least two battery modules or battery packs may then be connected in series, parallel, or in series to form a whole structure, which is then housed in the housing 200.

[0092] Of course, the battery device 1 may also include other structures. For example, the battery device 1 may also include a busbar component (not shown) for achieving electrical connection between at least two battery cells 100. For another example, the battery device 1 may also include a power distribution device (not shown) for serving as a control unit for distributing energy in the battery device 1 and distributing high voltage to the battery device 1.

[0093] Of course, in some embodiments, the battery device 1 may not include the box body 200, but instead electrically connects at least two battery cells and forms a whole through necessary fixing structures (such as end plates, side plates, straps, etc.) and then assembles it into an electrical device.

[0094] See also Figure 3 , Figure 3 This is an exploded schematic diagram of a battery cell 10 provided in some embodiments of the present application. A battery cell 10 is the smallest unit for storing and outputting electrical energy. It includes a housing 11, an electrode assembly 12, an insulator 13, electrode terminals 14, an adapter 15, a pressure relief mechanism 16, and an electrolyte (not shown).

[0095] The outer shell 11 is a component that isolates the internal environment of the battery cell 10 from the external environment. The internal environment enclosed by the outer shell 11 can be used to accommodate components such as the electrode assembly 12 and the electrolyte. The outer shell 11 may include a first end wall 111, a second end wall, and a side wall 113. The side wall 113 may be cylindrical, such as a circular cylinder, a rectangular cylinder, a polygonal cylinder, etc. The first end wall 111 and the second end wall respectively cover the 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 connection surface before other components are installed in the shell. When the shell 11 needs to be encapsulated, the first end wall 111 can cover 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 cover an opening at one end of the side wall 113, and the first end wall 111 and the side wall 113 are fixedly connected. Similarly, in some embodiments, the second end wall and the side wall 113 can be independent components. The second end wall can cover an opening at one end of the side wall 113, and the second end wall and the side wall 113 are fixedly connected. 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 connection surface before other components are installed in the shell. When the shell 11 needs to be encapsulated, the second end wall can cover 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 a certain hardness and strength, so that the outer shell 11 is not easily deformed when squeezed or collided, so that the battery cell 10 can have a higher structural strength and structural reliability. Among them, the materials of the first end wall 111, the second end wall, and the side wall 113 can be set to the same or different. The materials 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, etc. as needed.

[0096] The electrode assembly 12 is a component in the battery cell 10 where electrochemical reactions occur. The housing 11 may include one or at least two electrode assemblies 12. 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 electrodes with opposite polarities, and the separator separates the positive electrode sheet from the negative electrode sheet. The positive electrode sheet, the separator and the negative electrode sheet can be processed by winding to form the electrode assembly 12. In the electrode assembly 12, the portions of the two electrode sheets with active materials constitute the main body 121 of the electrode assembly 12, and the portions of the two electrode sheets without active materials each constitute a pole ear 122. The pole ear 122 is the current transmission end of the electrode assembly 12, which is used to transmit current. The tab 122 of the positive electrode sheet is the positive electrode tab 122 a , and the tab 122 of the negative electrode sheet is the negative electrode tab 122 b . The positive electrode tab 122 a and the negative electrode tab 122 b can be located together at one end of the main body 121 or respectively at both ends of the main body 121 .

[0097] The electrolyte is the liquid that soaks the electrode assembly 12. The battery cell 10 mainly relies on the movement of active ions between the positive electrode plate and the negative electrode plate to work. When the battery cell 10 is charged, the positive electrode plate will generate active ions. The active ions provided by the positive electrode plate can penetrate the pores of the diaphragm, move to the negative electrode plate through the electrolyte, and embed into the negative active material of the negative electrode plate. Conversely, when the battery cell 10 is discharged, the active ions embedded in the negative active material of the negative electrode plate are released. The active ions released from the negative electrode plate can penetrate the pores of the diaphragm, move to the positive electrode plate through the electrolyte, and embed into the positive active material of the positive electrode plate. Among them, the active ions can be lithium ions, sodium ions, etc.

[0098] The electrode terminal 14 is a component that is electrically connected to the electrode assembly 12 and is used to output or input electrical 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 on the housing 11 and stabilize the mounting position and mounting state relative to the housing 11. In some embodiments, the electrode terminal 14 can be mounted on the housing 11 by flanging and riveting.

[0099] The adapter 15 is a current collecting component electrically connected between the tab 122 of the electrode assembly 12 and the corresponding electrode terminal 14. The adapter 15 can also be called a adapter connector, a current collecting plate, or an adapter plate. The adapter 15 has conductive properties and is made of a conductive material. The material of the adapter 15 may include aluminum, aluminum alloy, copper, copper alloy, copper-aluminum alloy, etc. The adapter 15 includes a positive electrode adapter 15a and a negative electrode adapter 15b. The positive electrode tab 122a of the electrode assembly 12 can be electrically connected to the positive electrode terminal 14a through the positive electrode adapter 15a, and the negative electrode tab 122b of the electrode assembly 12 can be electrically connected to the negative electrode terminal 14b through the negative electrode adapter 15b to form a current loop. In some embodiments, the adapter 15 can be connected to the tab 122 of the electrode assembly 12 by welding, abutting, etc. The adapter 15 can be connected to the electrode terminal 14 by welding, abutting, etc. The shape of the adapter 15 can be various, such as square, round, special-shaped, etc.

[0100] The insulating member 13 is a component with insulating properties. The insulating member 13 is disposed within the outer shell 11, particularly between the electrode assembly 12 and the wall portion of the outer shell 11 having the electrode terminal 14 (e.g., the first end wall 111). On the basis that the tabs 122 of the electrode assembly 12 and the corresponding electrode terminals 14 can be electrically connected, the insulating member 13 can be used to insulate and isolate the electrode assembly 12 from the wall portion of the outer shell 11 having the electrode terminal 14, thereby reducing the risk of short circuits, current leakage, and the like. Furthermore, the insulating member 13 can also be fixed to the wall portion of the outer shell 11 having the electrode terminal 14 and abut against the electrode assembly 12 to fill the gap between the electrode assembly 12 and the wall portion of the outer shell 11, thereby tightly fixing the electrode assembly 12. This prevents the electrode assembly 12 from relative movement or shaking during use of the battery cell 10, thereby maintaining the structural integrity of the battery cell 10 and reducing the risk of loosening or deformation of the electrode assembly 12.

[0101] The pressure relief mechanism 16 is disposed on the outer casing 11 and is used to release internal pressure when the internal pressure (or temperature) of the battery cell 10 reaches a threshold. In some cases, the pressure relief mechanism 16 may also be referred to as an explosion-proof valve. In some embodiments, the pressure relief mechanism 16 may be integrally formed with the wall portion of the outer casing 11 (e.g., the first end wall 111) where the pressure relief mechanism 16 is disposed (i.e., a one-piece structure). For example, the pressure relief mechanism 16 may be a notch disposed in the corresponding wall portion of the outer casing 11. In other embodiments, the pressure relief mechanism 16 may be separately formed and connected to the corresponding wall portion of the outer casing 11 (e.g., the first end wall 111) (i.e., a split structure).

[0102] See also 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 sheet 123a, a negative electrode sheet 123b, a separator 124, and a support 125. The positive electrode sheet 123a, the separator 124, and the negative electrode sheet 123b are wound around the periphery of the support 125. The support 125 is an annular structure, and the outer annular surface of the support 125 is fixedly connected to the separator 124. Please refer to Figure 8 、 Figure 9 The inner ring surface of the support body 125 is provided with first adhesive particles 1251 , and the inner ring surface of the support body 125 is adhered to itself via the first adhesive particles 1251 .

[0103] It should be noted that the electrode assembly 12 is a component where electrochemical reactions occur in the battery cell 10. One or more electrode assemblies 12 may be disposed inside the battery cell 10.

[0104] The electrode assembly 12 includes a positive electrode sheet 123a, a negative electrode sheet 123b, a separator 124, and a support 125. The positive electrode sheet 123a and the negative electrode sheet 123b are two electrodes 123 with opposite polarity. The separator 124 is an insulating film that separates the positive electrode sheet 123a and the negative electrode sheet 123b of opposite polarity to prevent direct contact between the positive electrode sheet 123a and the negative electrode sheet 123b, which could cause a short circuit. The separator 124 has a number of pores that allow active ions to pass freely. The separator 124 can be made of materials such as PP (polypropylene) or PE (polyethylene).

[0105] The support body 125 is a ring structure. Figure 6 、 Figure 8 、 Figure 9 As shown, in some embodiments, support body 125 is a closed ring structure. Of course, in other embodiments, support body 125 may be an open ring structure. Support body 125 may be an insulating component, such as a plastic component, a thermosetting structural component, a porous structure made of an insulating material, etc.; support body 125 may also be a conductive component, such as a metal component, an aluminum-plastic film, etc. For example, in some embodiments, support body 125 may be made of polyester film (polyethylene terephthalate, PET).

[0106] During the winding process, the support body 125 is in an uncompacted state and has a circular ring structure. 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 to the outer ring surface of the support body 125, and the fixed connection method can be hot melt connection, ultrasonic welding or bonding. Two diaphragms 124 can be provided, one of which is provided between the positive electrode sheet 123a and the negative electrode sheet 123b, and the other diaphragm 124 is provided on the side of the negative electrode sheet 123b away from the positive electrode sheet 123a. side, or is arranged on the side of the positive electrode sheet 123a away from the negative electrode sheet 123b, so as to realize the stacking of the positive electrode sheet 123a, the separator 124 and the negative electrode sheet 123b, and promote the separator 124 to reliably separate 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; the positive electrode sheet 123a, the separator 124 and the negative electrode sheet 123b are stacked and wound on the outer periphery of the support body 125, so that the support body 125 is located at the innermost circle of the electrode assembly 12.

[0107] During the compaction process, the inner ring surface of the support body 125 is adhered to itself through the first adhesive particles 1251, so that the inner ring of the support body 125 has no opening, so that the support body 125 forms a flat structure; the flat support body 125 can be supported on the inner ring of the diaphragm 124, which can prevent the diaphragm 124 of the inner ring (especially the innermost ring) from rebounding and shrinking inward, and can prevent the interlayer gap between the positive electrode plate 123a and the negative electrode plate 123b of the inner ring (especially the innermost ring) from becoming larger, and can promote the innermost ring of the diaphragm 124 to be tightly attached to the outer ring surface of the support body 125, and can promote the electrode assembly 12 to be tightly attached circle by circle with a smaller interlayer gap, and can promote the electrode assembly 12 to be fully compacted.

[0108] The outer annular surface of the support body 125 may or may not be provided with second adhesive particles (not shown). If the outer annular surface of the support body 125 is provided with second adhesive particles, during the compaction process, the innermost diaphragm 124 and the outer annular surface of the support body 125 can be adhered to each other via the second adhesive particles, thereby improving the fit and reducing the interlayer gap.

[0109] The surface of the separator 124 may or may not have third adhesive particles (not shown). If the separator 124 has third adhesive particles, during the compaction process, the innermost separator 124 can be bonded to the outer surface of the support body 125 via the third adhesive particles. Each ring of separator 124 can also be bonded to the adjacent electrode sheet 123 via the third adhesive particles. This can improve the tightness of the electrode assembly 12 from ring to ring, reduce the interlayer gaps between the layers of the electrode assembly 12, and promote tight compaction of the electrode assembly 12. It should be noted that, when the electrode assembly 12 is not provided with a support body 125 and the surface of the diaphragm 124 has third adhesive particles, during the compaction process, since the diaphragm 124 is thin, elastic and has a large corner rebound force, the inner circle diaphragm 124 (especially the loose end of the innermost circle diaphragm 124) will rebound and shrink inward, resulting in the innermost circle diaphragm 124 being unable to adhere to itself through the third adhesive particles like the support body 125. That is, in this case, the problem of "the electrode assembly 12 is difficult to be fully compacted, the interlayer gap between the inner circle positive electrode sheet 123a and the negative electrode sheet 123b is large, and pre-compression opening and other phenomena occur" will still exist.

[0110] Among them, in the electrode assembly 12, the parts of the two pole pieces 123 with active materials constitute the main body 121 of the electrode assembly 12, and the parts of the two pole pieces 123 without active materials each constitute a pole ear 122. The pole ear 122 is the current transmission end of the electrode assembly 12 and is used to transmit current. The pole ear 122 of the positive pole piece 123a is the positive pole ear 122a, and the pole ear 122 of the negative pole piece 123b is the negative pole ear 122b. The positive pole ear 122a and the negative pole ear 122b can be located on the same side of the support body 125 (such as Figure 5 As shown), they may also be located on both sides of the support body 125.

[0111] In summary, in the battery cell 10 provided in the embodiment of the present application, the electrode assembly 12 can be achieved by providing a support body 125 with a ring-shaped structure and an inner ring surface with first adhesive particles 1251 in the innermost circle, and fixing the diaphragm 124 to the outer ring surface of the support body 125, and stacking the positive electrode sheet 123a, the diaphragm 124 and the negative electrode sheet 123b and winding them around the outer periphery of the support body 125, so that during the compaction process, the inner ring surface of the support body 125 can be adhered to itself through the first adhesive particles 1251, so that the support body 125 can form a flat structure without an opening, so that the support body 125 can be supported on the inner circle of the diaphragm 124 and prevent the diaphragm 124 of the inner circle (especially the innermost circle) from rebounding and shrinking inward. Based on this, the interlayer gap between the positive electrode plate 123a and the negative electrode plate 123b in the inner circle (especially the innermost circle) can be prevented from becoming larger, the innermost circle diaphragm 124 can be urged to be tightly attached to the outer ring surface of the support body 125, the electrode assembly 12 can be urged to be tightly attached circle by circle with a smaller interlayer gap, and the electrode assembly 12 can be fully compacted. As a result, the risk of pre-stressing and opening the electrode assembly 12 due to insufficient compaction can be reduced, the OH dislocation caused by pre-stressing and 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 piece 123 to prevent the end of the electrode piece 123 from moving due to external forces, and the risk of the positive electrode piece 123a exceeding the negative electrode piece 123b due to the movement of the end of the electrode piece 123, thereby causing metal precipitation and short circuiting can be reduced; the risk of the active ion transmission performance being affected by the excessive interlayer gap between the positive electrode piece 123a and the negative electrode piece 123b, and the risk of metal precipitation during the use of the battery cell 10 can be reduced, the risk of foreign particles falling into the electrode assembly 12 along the interlayer gap and affecting the yield can be reduced, and the risk of foreign metal particles falling into the electrode assembly 12 along the interlayer gap and causing short circuiting can be reduced. As a result, the performance, reliability and service life of the battery cell 10 can be improved.

[0112] See also 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-pressure synergistic adhesive particles.

[0113] It should be noted that pressure-sensitive adhesive particles are adhesive particles that are triggered to adhere by pressure. At room temperature, they exhibit low or essentially no adhesion. When pressure is applied, the particles deform, diffuse, and adhere tightly to the contact surface, achieving adhesion through intermolecular forces (such as van der Waals forces). If the first adhesive particles 1251 are pressure-sensitive, they can be low or essentially non-adhesive during the winding process, preventing the inner annular surface of the support body 125 from tightly adhering to the winding and clamping pins via the first adhesive particles 1251. Furthermore, during the compaction process, the pressure applied to the first adhesive particles 1251 activates their adhesive properties, allowing the inner annular surface of the support body 125 to adhere to itself via the first adhesive particles 1251, resulting in a flat structure without openings. For example, the pressure-sensitive adhesive particles may be PCS (Pressure Sensitive Coating / Adhesive) adhesive particles (e.g., acrylic pressure-sensitive adhesive particles), butyl rubber particles, etc. The winding needle is used to assist in the winding and forming of the electrode assembly 12, and the clamping needle is used to clamp, transfer, and perform other actions on the preformed electrode assembly 12.

[0114] Thermosensitive adhesive particles are adhesive particles that trigger adhesion through temperature changes. At room temperature, they are non-adhesive or low-adhesive. When the temperature rises to a specific threshold (softening point or melting point), they soften, melt, and activate their adhesive properties. After cooling and solidifying, they form a stable bond. If the first adhesive particles 1251 are thermosensitive, they can be non-adhesive or low-adhesive during the winding process, preventing the inner annular surface of the support body 125 from tightly bonding to the winding and clamping pins via the first adhesive particles 1251. Furthermore, during the compaction process, the first adhesive particles 1251 activate their adhesive properties due to the rising temperature, allowing the inner annular surface of the support body 125 to adhere to itself via the first adhesive particles 1251, resulting in a flat structure without openings. For example, the heat-sensitive adhesive particles may be hot melt adhesive particles (such as ethylene vinyl acetate (EVA) particles, etc.), wax composite particles, etc.

[0115] Hot-press synergistic adhesive particles require both temperature and pressure to trigger adhesion. Heat or pressure alone produce weak adhesion. However, with the combined effects of temperature and pressure, these particles soften, flow, and fully wet the contact surface, forming a high-strength bond upon cooling. If the first adhesive particles 1251 are hot-press synergistic, they can exhibit low or essentially no adhesion during the winding process, preventing the inner annular surface of the support 125 from tightly bonding to the winding and clamping pins via the first adhesive particles 1251. Furthermore, during the compaction process, the pressure and temperature of the first adhesive particles 1251 activate their adhesive properties, allowing the inner annular surface of the support 125 to adhere to itself via the first adhesive particles 1251, resulting in a flat structure without openings. For example, the heat-pressure synergistic adhesive particles may be polyurethane hot-melt pressure-sensitive adhesive particles, epoxy-phenolic composite particles, and the like.

[0116] By adopting the above-mentioned scheme, by making the first adhesive particles 1251 pressure-sensitive adhesive particles, heat-sensitive adhesive particles or hot-pressing cooperative adhesive particles, the first adhesive particles 1251 can be in a low-viscosity state or basically non-viscosity before the compaction process (including the winding process, the blanking process and the material transfer process), so that the inner annular surface of the support body 125 will not be tightly bonded to the winding needle and the clamping needle through the first adhesive particles 1251, thereby reducing the risk of the support body 125 and the diaphragm 124 being pulled away due to excessive bonding force, thereby causing the positive electrode 123a and the negative electrode 123b to overlap and short-circuit during the needle withdrawal of the winding needle and the clamping needle, and reducing the risk of defects such as wrinkles and folds in the support body 125 and the diaphragm 124 due to excessive bonding force. The qualified rate of the winding process and the smoothness of the needle withdrawal operation can be improved, and the problem of poor needle withdrawal can be reduced. During the compaction process, the first adhesive particles 1251 can activate viscosity based on temperature and pressure, so that the inner annular surface of the support body 125 can be adhered to itself through the first adhesive particles 1251, so that the support body 125 can form a flat structure without openings, which can enhance the stability and reliability of the structure and shape of the support body 125 after compaction.

[0117] See also 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 diaphragm 124 .

[0118] It should be noted that the hardness of the support body 125 is greater than that of the diaphragm 124, meaning that the support body 125 is harder than the diaphragm 124 and is made of a harder material. The hardness of the support body 125 refers to the hardness of the support body 125 as a whole, primarily the annular portion of the support body 125, and does not refer solely to the hardness of the first adhesive particles 1251. The hardness of the support body 125 and the diaphragm 124 can be measured using nanoindentation. Specifically, the diamond indenter of a nanoindenter is pressed into the surface of the support body 125 (or diaphragm 124) with an extremely small load (in the μN range), the load-displacement curve is recorded, and the hardness value is calculated (hardness value = maximum load / projected indentation area). This method can accurately measure the local hardness of the support body 125 (or diaphragm 124) and reduces the "penetration effect" of macroscopic methods.

[0119] By adopting 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 a higher hardness than the diaphragm 124. Based on this, during the needle withdrawal of the winding needle and the clamping needle, the high-hardness support body 125 has a stronger self-deformation resistance than the diaphragm 124, and is not easily twisted or concave due to external pulling when the winding needle / clamping needle is withdrawn. It can maintain an annular shape and has high morphological 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 withdrawal operation, reducing the risk of the support body 125 and the diaphragm 124 being pulled out, thereby causing the positive electrode 123a and the negative electrode 123b to overlap and short-circuit, reducing the risk of defects such as wrinkles and folds on the support body 125 and the diaphragm 124, reducing the risk of structural damage during the needle withdrawal process, and reducing the problem of poor needle withdrawal. Moreover, since the support body 125 has a higher hardness than the diaphragm 124, the flat support body 125 formed by compaction can form a stable "inner ring skeleton" by virtue of its higher hardness, can form a hard support for the inner ring of the diaphragm 124, can continuously resist the rebound stress of the diaphragm 124, and can reliably prevent the diaphragm 124 from rebounding and shrinking inward, thereby prompting the electrode assembly 12 to be fully compacted, tightly attached circle by circle, and reduce the interlayer gap, which can improve the structural stability and structural reliability of the electrode assembly 12.

[0120] See also 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 smaller than the surface roughness of the diaphragm 124 .

[0121] It should be noted that because the surface of diaphragm 124 contains many particles (such as ceramic powder, etc.), the surface roughness of diaphragm 124 is relatively large. Furthermore, because the inner annular surface of support body 125 is provided with first adhesive particles 1251 (substantially free of other particles), and because the inner annular surface of support body 125 is the primary contact interface with the winding and clamping needles, the surface roughness of the inner annular surface of support body 125 can be designed to be less than that of diaphragm 124. This allows the inner annular surface of support body 125, while not completely smooth, to be smoother than the surface of diaphragm 124. Surface roughness can be measured using a laser scanning method (non-contact measurement). This method utilizes the principle of laser interferometry, illuminating the measured surface (i.e., the inner annular surface of support body 125 and the surface of diaphragm 124) with a laser beam, receiving the interference signal of the reflected light, and converting it into surface profile data, thereby rapidly acquiring roughness information for large-area surfaces.

[0122] By adopting the above solution, by making the surface roughness of the inner ring surface of the support body 125 smaller than the surface roughness of the diaphragm 124, the inner ring surface of the support body 125 can be made smoother than the surface of the diaphragm 124. Based on this, during the needle pulling and winding needle pulling, the inner ring surface of the support body 125 has fewer microscopic bumps and concavities on the contact interface with the needle and the clamping needle, and the friction force with the needle and the clamping needle is smaller, and it is not easy to generate static electricity due to friction, nor is it easy to cause the support body 125 to be adsorbed by static electricity. The inner ring surface of 25 is adhered to the winding needle / clamping needle, thereby improving the smoothness of the needle pulling operation, reducing the followability of the support body 125 when pulling out the needle, reducing the risk of the support body 125 and the diaphragm 124 being pulled out, thereby causing the positive electrode plate 123a and the negative electrode plate 123b to overlap and short-circuit, reducing the risk of defects such as wrinkles and folds on the support body 125 and the diaphragm 124, reducing the risk of structural damage during the needle pulling process, reducing the problem of poor needle pulling, and improving the yield of the electrode assembly 12.

[0123] See also 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.

[0124] It should be noted that the thickness d1 of the support body from its outer annular surface to its inner annular surface is in the range of 50 μm to 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, and can be, for example, 50 μm, 100 μm, 150 μm, 200 μm, 250 μm, 300 μm, 350 μm, 400 μm, 450 μm, 500 μm, etc. The thickness d1 of the support body from its outer annular surface to its inner annular surface can be measured using image analysis. For example, a cross-sectional image of the support body 125 can be captured using a scanning electron microscope (SEM). After calibrating the scale using image analysis software (e.g., Image-Pro Plus), the perpendicular distance between the outer annular surface and the inner annular surface in the radial direction can be directly measured to obtain the thickness d1 of the support body from its outer annular surface to its inner annular surface.

[0125] By adopting the above scheme, by making the thickness d1 of the support body from its outer ring surface to its inner ring surface 50μm~500μm, the support body 125 can have sufficient thickness and sufficient strength. Based on this, the deformation resistance of the support body 125 itself can be improved, and the risk of the support body 125 being deformed or wrinkled due to external force during the winding and compaction process can be reduced; the basic supporting capacity of the compacted flat support body 125 can also be improved, and the compacted flat support body 125 can be enabled to form a reliable support for the inner circle of the diaphragm 124, and can provide sufficient reaction force to reliably resist the rebound stress of the diaphragm 124, and can reliably prevent the diaphragm 124 from rebounding and shrinking inward; thereby, the electrode assembly 12 can be fully compacted, tightly attached circle by circle, and the interlayer gap can be reduced, which can improve the structural stability and structural reliability of the electrode assembly 12. Furthermore, the risk of the support body 125 occupying too much space due to excessive thickness can be reduced, the volume share of the support body 125 in the electrode assembly 12 can be reduced, and the encroachment of the support body 125 on the energy margin of the battery cell 10 can be reduced, thereby maintaining and improving the energy density and group margin of the battery cell 10. Furthermore, the risk of the support body 125 occupying too much of the normal expansion space of the electrode assembly 12 due to excessive thickness can be reduced, the risk of an overly thick support body 125 restricting the expansion buffer of the inner ring area can be reduced, the risk of excessive accumulation of expansion force in the late stages of the battery cell 10 cycle can be reduced, and the risk of deformation of the outer shell 11, seal leakage, rupture of the outer shell 11, short circuit, thermal runaway, and other phenomena caused by excessive expansion force can be reduced, thereby maintaining and improving the reliability and service life of the battery cell 10.

[0126] See also Figure 4 、 Figure 6 、 Figure 9 In some embodiments of the present application, the diameter of the first adhesive particles 1251 is 5 μm to 30 μm.

[0127] It should be noted that the diameter of the first adhesive particles 1251 (i.e., particle diameter) is between 5 μm and 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, and can be, for example, 5 μm, 10 μm, 15 μm, 20 μm, 25 μm, 30 μm, etc. The diameter of the first adhesive particles 1251 can be measured using a scanning electron microscope (SEM). The steps are 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 (e.g., a carbon-coated glass slide); if the particles are prone to agglomeration, ultrasonic dispersion can be used to assist in dispersion; a clear image of the particles is obtained using the SEM, and the diameters of several particles are counted using the device's built-in size measurement tool (e.g., direct measurement after a calibrated scale ruler). The average or distribution range is then calculated to determine the diameter of the first adhesive particles 1251.

[0128] By adopting the above scheme, by making the diameter of the first adhesive particles 1251 5μm~30μm, 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 dispersion of the first adhesive particles 1251 can be better and not easy to agglomerate, and the uniformity of the distribution of the bonding points on the inner ring surface of the support body 125 can be improved; the risk of a reduction in the number of bonding points due to too large particles, limited contact area, and increased gaps between particles can be reduced, and a sufficient number of bonding points can be formed within a unit area of ​​the inner ring surface of the support body 125, and a single first adhesive particle 1251 can have a moderate contact area and adhesion area; thereby, the adhesion strength of the first adhesive particle 1251 can be optimized, the inner ring surface of the support body 125 can be effectively self-adhered through the first adhesive particles 1251 during the compaction process, and the support body 125 can be formed into a stable flat structure without openings. Moreover, the effect of the first adhesive particles 1251 on the thickness increase of the electrode assembly 12 after compaction can be reduced, and the risk of the thickness of the electrode assembly 12 after compaction increasing due to excessively large particles can be reduced, thereby reducing the support body 125 and its first adhesive particles 1251 from crowding out the energy margin of the battery cell 10, and maintaining and improving the energy density and group margin of the battery cell 10.

[0129] See also Figure 10 、 Figure 11 、 Figure 12 In some embodiments of the present application, the outer annular surface of the support body 125 is provided with at least one groove 1252 , and the groove depth d2 of the groove is smaller than the thickness d1 of the support body from its outer annular surface to its inner annular surface.

[0130] It should be noted that the outer ring surface of the support body 125 is provided with at least one groove 1252, and the groove 1252 can be a straight groove 1252a (such as Figure 13As shown), broken line grooves, curved grooves (such as annular grooves 1252b (such as Figure 14 As shown), arc groove 1252c (as Figure 15 As shown), wavy grooves, etc.), dot grooves 1252d (as shown Figure 16 If multiple grooves 1252 are provided, they can be flexibly arranged on the outer surface of the support body 125, such as in a horizontal and vertical cross pattern, a matrix array, an evenly spaced arrangement, or an unevenly spaced arrangement. The shapes and sizes of the 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 to its inner surface. That is, the groove 1252 does not penetrate the support body 125 along its depth.

[0131] By adopting the above solution, by providing the groove 1252 on the outer ring surface of the support body 125, when the electrode assembly 12 is fully compacted, the inner ring of the electrode assembly 12 (especially between the support body 125 and the diaphragm 124 that fit closely together, such as Figure 6 、 Figure 7 As shown in FIG, the electrolyte infiltration channel is provided, and the electrolyte is allowed to diffuse smoothly and fully penetrate into the inner ring of the electrode assembly 12, thereby improving the problem of slow electrolyte filling speed and poor local infiltration of the inner ring caused by the close fit of the inner ring, and maintaining and improving the battery cell 10 (as shown in FIG. Figure 4 (as shown). Furthermore, groove 1252 can reserve electrolyte storage space to pre-store electrolyte. Later in the cycle of the battery cell 10, the electrolyte stored in groove 1252 is released through expansion and compression, thereby replenishing the electrolyte and compensating for electrolyte consumption, thereby maintaining and improving the battery cell 10's liquid retention capacity, cycle performance, and service life. Furthermore, because the groove depth d2 is less than the thickness d1 of the support body from its outer annular surface to its inner annular surface, groove 1252 is only partially recessed in the outer annular 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 and the basic supporting capacity of the compacted, flattened support body 125. This allows the compacted, flattened support body 125 to reliably support the inner ring of the diaphragm 124, resisting the rebound stress of the diaphragm 124 and preventing the diaphragm 124 from rebounding or retracting inward.

[0132] Of course, if Figure 8 、 Figure 9 As shown, in other embodiments, the outer annular surface of the support body 125 may not be provided with the groove 1252 .

[0133] See also Figure 6 、 Figure 12 、 Figure 13 、 Figure 15In some embodiments of the present application, at least one groove 1252 is a linear groove 1252a.

[0134] It should be noted that at least one groove 1252 is extended linearly to form a linear groove 1252a. The extension direction of the linear groove 1252a can be parallel to the axial direction of the support body 125, can be parallel to the circumferential direction of the support body 125, or can intersect the axial direction 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 circumferential direction of the outer annular surface of the support body 125.

[0135] For example, Figure 12 As shown, in some embodiments, the outer annular surface of the support body 125 is provided with a plurality of linear grooves 1252a, wherein the extension direction of a portion of the linear grooves 1252a is parallel to the axial direction of the support body 125, and the extension direction of another portion of the linear grooves 1252a is parallel to the circumferential direction of the support body 125, and together form a horizontal and vertical cross layout, wherein the plurality of linear grooves 1252a arranged parallel to each other can be arranged at equal intervals or at unequal intervals.

[0136] For example, Figure 13 As shown, in some embodiments, the outer ring surface of the support body 125 is provided with a plurality of linear grooves 1252a, and the extension direction of each linear groove 1252a is parallel to the axial direction of the support body 125. The linear grooves 1252a can be arranged at equal intervals or at unequal intervals.

[0137] By adopting the above solution, by configuring the grooves 1252 as straight grooves 1252a, the extension path of the grooves 1252 is simplified and free of unnecessary bends. This reduces the flow resistance of the electrolyte within the grooves 1252 and promotes directional transmission and diffusion of the electrolyte along the extension direction of the grooves 1252. This improves the directional transmission and efficiency of the electrolyte along the grooves 1252, increases the electrolyte filling speed, and improves the wetting effect on the inner ring of the electrode assembly 12. Furthermore, the "straight line" of the straight grooves 1252a promotes more stable electrolyte flow and storage within the grooves, reducing localized liquid accumulation or dead spots caused by bends, thereby improving the uniformity of electrolyte wetting and the reliability of storage compensation. Furthermore, the straight grooves 1252a have regular edges, resulting in less stress concentration than curved grooves, reducing the risk of localized fracture of the support body 125 caused by the straight grooves 1252a during compaction or circulation. In addition, the processing technology of the linear groove 1252a is simplified and the processing difficulty is low, which can improve the processing feasibility, processing convenience and processing consistency.

[0138] See also Figure 4 、 Figure 6 、 Figure 14In some embodiments of the present application, at least one groove 1252 is an annular groove 1252b.

[0139] It should be noted that at least one groove 1252 is an annular groove 1252b. In particular, the groove 1252 may be annular, such as a circular ring, a polygonal ring, etc., when looking down at the outer surface of the support body 125; or it may be annular along the circumference of the support body 125. For example, Figure 14 As shown, in some embodiments, when looking down at the outer annular surface of the support body 125, the plurality of annular grooves 1252b are arranged in a matrix array.

[0140] By adopting the above solution, by making the groove 1252 into an annular groove 1252b, a surrounding electrolyte channel can be formed on the outer annular surface of the support body 125 through the annular groove 1252b, allowing the electrolyte to spread evenly along the annular path and cover a larger area of ​​the outer annular surface of the support body 125, thereby reducing local infiltration blind spots and improving the uniformity and consistency of electrolyte infiltration. In addition, a surrounding storage space can be formed through the annular groove 1252b, so that the electrolyte is evenly distributed and stably stored within the annular groove 1252b. In the later stages of the battery cell 10 cycle, under the expansion and compression of the electrode assembly 12, the electrolyte in the annular groove 1252b can be evenly released along the annular path, replenishing the electrolyte within the annular groove 1252b and the surrounding area, thereby optimizing the cycle life and liquid retention capacity of the battery cell 10. Moreover, the closed profile of the annular groove 1252b can make the stress distribution at the edge more symmetrical, and the stress of the annular groove 1252b (especially the circular ring shape) can be evenly dispersed along the annular direction, thereby reducing the risk of local fracture of the support body 125 caused by the annular groove 1252b during the compaction process or long-term circulation, and maintaining the overall structural strength of the support body 125.

[0141] See also Figure 4 、 Figure 6 、 Figure 15 In some embodiments of the present application, at least one groove 1252 is an arc-shaped groove 1252c.

[0142] It should be noted that at least one groove 1252 is an arc-shaped groove 1252c, that is, when looking down at the outer annular surface of the support body 125, the groove 1252 is arc-shaped, for example, a semicircular arc shape.

[0143] By adopting the above solution, since the arcuate groove 1252c extends between the unidirectional nature of the linear groove 1252a and the fully circumferential nature of the annular groove 1252b, it not only provides wide coverage within a specific arc, but also, through its directional arcuate extension, directs electrolyte to areas of the inner circle prone to insufficient wetting (such as areas near corners of the flat support body 125). This can specifically improve localized blind spots and balance the directionality and coverage of electrolyte wetting. Furthermore, the curved shape of the arcuate groove 1252c creates an "arc-shaped storage space" on the outer surface of the support body 125. During the later stages of the battery cell 10 cycle, the electrolyte stored in the arcuate groove 1252c can diffuse along the arcuate path toward the periphery due to the expansion and compression of the electrode assembly 12, thereby optimizing the cycle life and electrolyte retention of the battery cell 10. Furthermore, the edge of the arc-shaped groove 1252 c is a smooth curve transition, and the stress concentration effect is relatively weak, which can reduce the risk of cracking of the support body 125 due to edge stress concentration during the compaction process or long-term circulation.

[0144] See also Figure 4 、 Figure 6 、 Figure 16 In some embodiments of the present application, at least one groove 1252 is a dot-shaped groove 1252d.

[0145] It should be noted that at least one groove 1252 is a dot-shaped groove 1252d, that is, when looking down at the outer annular surface of the support body 125, the groove 1252 is dot-shaped, such as a circular dot, a polygonal dot, etc., similar to a hole structure. Figure 16 As shown, in some embodiments, when looking down at the outer annular surface of the support body 125, the plurality of dot-shaped grooves 1252d are arranged in a matrix array.

[0146] By adopting the above scheme, based on the "point distribution" characteristics of the point grooves 1252d, the point grooves 1252d can be set in the local areas of the inner circle of the electrode assembly 12 where insufficient wetting is likely to occur. That is, the point grooves 1252d can be discretely arranged according to the wetting requirements of the inner circle to adapt to the improvement of local wetting shortcomings, thereby achieving accurate supplementation of specific wetting blind spots and improving the flexibility, accuracy and targeting of electrolyte wetting. Furthermore, the multiple, discretely distributed dot-shaped grooves 1252d form a distributed electrolyte storage space, allowing electrolyte to be stored at various locations on the outer surface of the support body 125. Consequently, during the later stages of the battery cell 10 cycle, as the electrode assembly 12 expands and squeezes, the electrolyte within each dot-shaped groove 1252d can be released to the surrounding area. This reduces the concentrated or insufficient electrolyte release that can occur in a single long groove due to uneven local squeezing. This improves the balance of electrolyte replenishment, facilitates reliable compensation for electrolyte consumption during cycling, and helps maintain the long-term cycling performance of the battery cell 10. Furthermore, the dot-shaped grooves 1252d exert minimal and dispersed weakening on the overall strength of the support body 125. The stress concentration at the edges of individual dot-shaped grooves 1252d is limited, reducing the risk of local fracture of the support body 125 caused by the dot-shaped grooves 1252d during the compaction process or long-term cycling. In addition, the processing of the dot-shaped grooves 1252d can be achieved through simple processes such as stamping and punching. The position, number and size of the dot-shaped grooves 1252d can be flexibly adjusted, and the processing feasibility and adaptability are high.

[0147] It should be noted that, when the outer ring surface of the support body 125 is provided with a plurality of grooves 1252, the linear grooves 1252a, annular grooves 1252b, arc grooves 1252c, and dot grooves 1252d can be provided selectively or in any combination. Figure 15 As shown, in some embodiments, half of the outer annular surface of the support body 125 is provided with four straight grooves 1252a and four arcuate grooves 1252c, and the extension direction of the straight grooves 1252a intersects with the axial direction of the support body 125 and the circumferential direction of the support body 125, and the four straight grooves 1252a are combined in pairs, and the two straight grooves 1252a combined in pairs cross each other in an "X" shape, and the two groups of straight grooves 1252a are arranged adjacent to each other and connected to each other; the four arcuate grooves 1252c are combined in pairs, one group of arcuate grooves 1252c is provided on one side of the four straight grooves 1252a, and the other group of arcuate grooves 1252c is provided on the other side of the four straight grooves 1252a, and the arcuate grooves 1252c combined in pairs are connected in sequence in an "m" shape and are connected between the two straight grooves 1252a.

[0148] Of course, in other embodiments, the groove 1252 may be in other shapes, such as a broken line groove, a curved groove such as a wavy groove, and so on.

[0149] See also Figure 10In some embodiments of the present application, the groove width d3 of the groove is 50 μm~500 μm, and the groove depth d2 of the groove is 50 μm~500 μm.

[0150] It should be noted that the groove width d3 is 50 μm to 500 μm, that is, the groove width d3 is greater than or equal to 50 μm and less than or equal to 500 μm, and can be, for example, 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 can be measured using a scanning electron microscope (SEM). That is, the edge of the groove 1252 can be clearly displayed through electronic imaging, and the groove width value can be directly read using the ruler function of the SEM.

[0151] The groove depth d2 is 50 μm to 500 μm, that is, the groove width d3 is greater than or equal to 50 μm and less than or equal to 500 μm, and can be, for example, 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 and the groove depth d2 are within the same range, but the specific values ​​can be set to the same or different. The groove depth d2 of the groove can be determined using a laser confocal microscope. That is, the surface of the groove 1252 can be scanned by laser to generate a three-dimensional topography image, and the vertical height difference between the bottom of the groove 1252 and the outer annular surface can be directly read to obtain the groove depth d2 of the groove.

[0152] By adopting the above solution, by setting the groove width d3 to 50μm-500μm and the groove depth d2 to 50μm-500μm, groove 1252 can form a capillary structure, which can promote adsorption of electrolyte by the capillary structure groove 1252, that is, optimize the adsorption capacity of groove 1252 for electrolyte. Furthermore, the capillary phenomenon (driven by the combined forces of liquid surface tension and adhesion to the walls of groove 1252) can be relied upon to promote electrolyte creep, that is, promote the flow of electrolyte within groove 1252. This can reduce the risk of capillary blockage and thus electrolyte flow obstruction due to undersized grooves, and the risk of electrolyte sedimentation and accumulation due to oversized grooves, where the gravity of the electrolyte exceeds the capillary force, thereby hindering electrolyte diffusion and infiltration. This can thus achieve a balanced and optimized electrolyte infiltration effect and infiltration speed. Moreover, based on the configuration of this embodiment, the volume of the groove 1252 is moderate, which can store a sufficient amount of electrolyte for compensation in the later stage of the cycle without weakening the supporting strength and compressive resistance of the support body 125.

[0153] See also Figure 4 、 Figure 17 、 Figure 18 、 Figure 19In some embodiments of the present application, a battery cell 10 includes a housing 11 having a first end wall 111 and a second end wall 112 that are opposite to each other, and a side wall 113 connected between the first end wall 111 and the second end wall 112. An electrode assembly 12 is disposed within the housing 11. The electrode assembly 12 includes a main body 121 and a tab 122 that extends toward the first end wall 111 and out of the main body 121. The tab 122 is electrically isolated from the side wall 113, and the electrode assembly 12 is electrically isolated from the second end wall 112.

[0154] It should be noted that the outer shell 11 is a component that isolates the internal environment of the battery cell 10 from the external environment. The internal environment enclosed by the outer shell 11 can be used to accommodate components such as the electrode assembly 12 and the electrolyte. The outer shell 11 may include a side wall 113, a first end wall 111, and a second end wall 112. The side wall 113 may be cylindrical, such as a circular cylinder, a rectangular cylinder, a polygonal cylinder, and the like. The first end wall 111 and the second end wall 112 respectively cover the 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 outer shell 11 and its side walls 113, the first end wall 111, and the second end wall 112 can be found in the previous text and will not be repeated here.

[0155] The electrode assembly 12 is disposed within the housing 11 and includes a main body 121 and a tab 122. The tab 122 extends outside the main body 121 toward the first end wall 111. The tab 122 serves as the current transmission end of the electrode assembly 12 and is used to transmit current. For further description of the electrode assembly 12 and its main body 121 and tab 122, please refer to the previous text and will not be repeated here.

[0156] The tabs 122 are electrically isolated from the sidewalls 113 to reduce the risk of short circuits caused by direct contact between the tabs 122 and the sidewalls 113. The tabs 122 can be electrically isolated from the sidewalls 113 by, but are not limited to, insulating components such as the insulating member 13, the support 125, and the insulating shell 17.

[0157] 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, insulating components such as the insulating shell 17 and the bottom support plate 18.

[0158] By adopting the above solution, while the outer shell 11 accommodates and protects the electrode assembly 12, the tabs 122 of the electrode assembly 12 are electrically isolated from the sidewalls 113, and the electrode assembly 12 is electrically isolated from the second end wall 112. This reduces the risk of short circuits caused by direct contact between the tabs 122 and the sidewalls 113, and between the electrode assembly 12 and the second end wall 112. This maintains the stable operation of the battery cell 10 and improves the reliability and service life of the battery cell 10.

[0159] See also Figure 4 、 Figure 17 、 Figure 18 In some embodiments of the present application, multiple electrode assemblies 12 are provided, and the multiple electrode assemblies 12 are arranged side by side along the first direction x. Among each electrode assembly 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 component and has a first extension portion 1253 extending toward the first end wall 111 and outside the main body 121. The electrode tab 122 of each electrode assembly 12 is located between the two first extension portions 1253 and is electrically isolated from the sidewall 113 by the two first extension portions 1253.

[0160] It should be noted that this embodiment is applicable to the case where “a plurality of electrode assemblies 12 are provided.” Within the housing 11 , the plurality of electrode assemblies 12 may be arranged side by side along a first direction x, which may correspond to the thickness direction of the electrode assembly 12 .

[0161] Among the electrode assemblies 12, the two electrode assemblies 12 located at both ends along the first direction x are first electrode assemblies 12a. Figure 17As shown, if there are only two electrode assemblies 12, the two electrode assemblies 12 are first electrode assemblies 12a. For another example, if there are three electrode assemblies 12, the two electrode assemblies 12 at the ends along the first direction x are first electrode assemblies 12a, and the electrode assembly 12 in the middle is not a first electrode assembly 12a; and so on. The support body 125 of the first electrode assembly 12a is an insulating component with insulating properties. For example, the material of the support body 125 of the first electrode assembly 12a can be polyester film (polyethylene terephthalate, PET). The support body 125 of the first electrode assembly 12a has a first extension portion 1253. The first extension portion 1253 extends toward the first end wall 111 and outside the main body 121. The first extension portion 1253 and the first end wall 111 can be arranged in contact or spaced apart. Since there are two first electrode assemblies 12a, two first extension portions 1253 are also provided. The electrode tab 122 of each electrode assembly 12 may be located between the two first extension portions 1253 , so that the electrode tab 122 of each electrode assembly 12 may be electrically isolated from the sidewall 113 by the two first extension portions 1253 .

[0162] By adopting the above solution, when multiple electrode assemblies 12 are arranged side by side along the first direction x, the insulating supports 125 of the two first electrode assemblies 12a can be extended toward the first end wall 111 to form a first extension portion 1253. The two first extension portions 1253 enclose a unified isolation space, and the tabs 122 of all electrode assemblies 12 are constrained between the two first extension portions 1253. Based on this, a "closed-loop" insulating protective wall can be formed by the two first extension portions 1253, which physically prevents the tabs 122 from deviating toward the sidewalls 113 due to vibration, deformation, etc., thereby reliably preventing the tabs 122 from directly contacting the sidewalls 113 to form a conductive path. This can reduce the risk of short circuits caused by direct contact between the tabs 122 and the sidewalls 113, improve insulation reliability, and increase the reliability and service life of the battery cell 10. Furthermore, based on the configuration of this embodiment, there is no need to design a separate insulation structure for each tab 122, thereby simplifying the insulation solution in scenarios with multiple tabs 122, reducing independent insulation components, and simplifying and optimizing the structure of the battery cell 10. Furthermore, the support body 125 itself serves as the winding support for the electrode assembly 12, while the first extension 1253 formed by its extension serves the additional function of isolating the tabs 122, achieving "multiple uses" and "functional reuse" of a single material. Based on this functional integration, the space reserved for isolating the tabs 122 (such as reserving a separate insulation space between the sidewall 113 and the tab 122) can be reduced, thereby helping to reduce internal redundancy in the battery cell 10 and improving the space utilization and energy density of the battery cell 10.

[0163] See also Figure 4 、 Figure 17 、 Figure 19 In some embodiments of the present application, the battery cell 10 includes an insulating shell 17 disposed in the outer shell 11, the insulating shell 17 is covered on the outside of the electrode assembly 12, and the electrode assembly 12 is electrically isolated from the side wall 113 and the second end wall 112 by the insulating shell 17.

[0164] It should be noted that this embodiment is applicable to the case where "there is one electrode assembly 12" and also to the case where "there are multiple electrode assemblies 12".

[0165] The insulating shell 17 is disposed within the outer shell 11. This is an insulating, shell-like structure with an open top. The electrode assembly 12 is housed within the insulating shell 17, covering the exterior of the electrode assembly 12, particularly covering all portions of the electrode assembly 12 except the top (i.e., the circumferential sides and bottom of the electrode assembly 12). The insulating shell 17 is made of an insulating material and has insulating properties. It serves to insulate and isolate the electrode assembly 12 from the sidewalls 113 and the second end wall 112, thereby achieving electrical isolation between the electrode assembly 12 and the sidewalls 113 (particularly between the tabs 122 and the sidewalls 113) and between the electrode assembly 12 and the second end wall 112. This reduces the risk of direct contact and short circuits between the electrode assembly 12 and the sidewalls 113 (particularly between the tabs 122 and the sidewalls 113) and between the electrode assembly 12 and the second end wall 112. The insulating shell 17 can be made of an inorganic insulating material, such as silicon oxide, silicon nitride, aluminum oxide, or aluminum nitride. The insulating shell 17 may also be made of organic insulating materials, such as polyimide, polyethylene, polyvinylidene fluoride, polytetrafluoroethylene, etc.

[0166] By adopting the above solution, an insulating shell 17 enclosing the electrode assembly 12 can be added to the outer shell 11 to form an integrated, comprehensive insulation barrier, thereby uniformly achieving electrical isolation between the electrode assembly 12 and the sidewall 113 (especially between the tab 122 and the sidewall 113), and between the electrode assembly 12 and the second end wall 112. This reduces the risk of short circuits caused by direct contact between the electrode assembly 12 and the sidewall 113 (especially between the tab 122 and the sidewall 113), and between the electrode assembly 12 and the second end wall 112, and reduces the risk of multi-path short circuits, thereby improving insulation reliability and increasing the reliability and service life of the battery cell 10. Furthermore, this embodiment is compatible with different numbers of electrode assemblies 12, eliminating the need to adjust the insulation solution based on the number of electrode assemblies 12, nor to design separate insulation structures for each electrode assembly 12, each tab 122, or multiple sides of the electrode assembly 12. This improves the versatility of the insulation design, simplifies the insulation solution, reduces the number of independent insulation components, and simplifies and optimizes the structure of the battery cell 10.

[0167] It should be noted that this embodiment and the previous embodiment can be set selectively or in combination to achieve electrical isolation between the tab 122 and the side wall 113. Figure 17 As shown, in some embodiments, the electrical isolation between the tab 122 and the side wall 113 can be achieved through the insulating shell 17 and the two first extensions 1253. This configuration can improve the insulation reliability between the tab 122 and the side wall 113, and can improve the reliability and service life of the battery cell 10. Figure 18 As shown, in other embodiments, the electrical isolation between the tab 122 and the side wall 113 can be achieved only by the two first extensions 1253. 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 outside of the electrode assembly 12 can be omitted. Such a configuration can save the space occupied by the insulating shell 17, improve the space utilization of the battery cell 10 in the first direction x and the second direction, and thus improve the volume energy density of the battery cell 10, wherein the second direction is perpendicular to both the first direction x and the thickness direction of the first end wall 111. Figure 19 As shown, in other embodiments, the electrical isolation between the pole ear 122 and the side wall 113 can be achieved only by the insulating shell 17, and the two first extension portions 1253 can be omitted. In this way, the space occupied by the two first extension portions 1253 can be saved, and the vacant space can be used to store electrolyte, thereby improving the ion conduction efficiency, and optimizing the rate performance, cycle life, and long-term stability of the battery cell 10. Moreover, this situation has a wider scope of application, and is applicable to the situation of "one electrode assembly 12" or "multiple electrode assemblies 12", and is applicable to the situation of "the pole ear 122 is flexibly arranged on any side of the support body 125".

[0168] See also Figure 18 、 Figure 19 In some embodiments of the present application, the battery cell 10 includes a bottom support plate 18 disposed in the housing 11 , the bottom support plate 18 is disposed 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 by the bottom support plate 18 .

[0169] It should be noted that this embodiment is applicable to the case where "there is one electrode assembly 12" and also to the case where "there are multiple electrode assemblies 12".

[0170] The bottom support plate 18 is disposed within the housing 11 and between the electrode assembly 12 and the second end wall 112. The bottom support plate 18 is made of an insulating material and has insulating properties. The bottom support plate 18 provides reliable support for the electrode assembly 12 and provides insulation between the electrode assembly 12 and the second end wall 112.

[0171] By adopting the above solution, by adding a bottom support plate 18 between the electrode assembly 12 and the second end wall 112, the bottom support plate 18 can provide reliable support for the electrode assembly 12, and the bottom support plate 18 can serve 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, thereby achieving electrical isolation between the electrode assembly 12 and the second end wall 112, reducing the risk of short circuit caused by direct contact between the electrode assembly 12 and the second end wall 112; furthermore, the bottom support plate 18 can cover the bottom of the electrode assembly 12 with its own flat support surface, dispersing pressure and reducing the risk of insulation damage; thereby, the insulation reliability can be improved, and the reliability and service life of the battery cell 10 can be improved. Furthermore, this embodiment is compatible with different numbers of electrode assemblies 12, and there is no need to adjust the insulation solution according to the number of electrode assemblies 12, nor is there a need to design a separate insulation structure for each electrode assembly 12, thereby improving the versatility of the insulation design, simplifying the insulation solution, reducing independent insulation components, and simplifying and optimizing the structure of the battery cell 10.

[0172] It should be noted that this embodiment and the previous embodiment can be set selectively or in combination to achieve electrical isolation between the electrode assembly 12 and the second end wall 112. Figure 17 As shown, in some embodiments, the electrical isolation between the electrode assembly 12 and the second end wall 112 can be achieved only by the insulating shell 17, and the bottom support plate 18 can be omitted. This configuration can save the space occupied by the bottom support plate 18, improve the space utilization of the battery cell 10 in the thickness direction of the first end wall 111, and improve the energy density of the battery cell 10. Figure 18 As shown, in other embodiments, the electrical isolation between the electrode assembly 12 and the second end wall 112 can be achieved only by the bottom support plate 18, and the insulating shell 17 can be omitted. Such a configuration can save the space occupied by the insulating shell 17, and can improve the space utilization of the battery cell 10 in the first direction x and the second direction, thereby improving the volume energy density of the battery cell 10, wherein the second direction is a direction perpendicular to both the first direction x and the thickness direction of the first end wall 111. Figure 19 As shown, in other embodiments, the insulating shell 17 and the bottom support plate 18 can be used to jointly achieve electrical isolation between the electrode assembly 12 and the second end wall 112. Such a setting can improve the insulation reliability between the electrode assembly 12 and the second end wall 112, and can improve the reliability and service life of the battery cell 10.

[0173] Since the two first extensions 1253 and the insulating shell 17 can be used to electrically isolate the tab 122 from the side wall 113, and since the insulating shell 17 and the bottom support plate 18 can be used to electrically isolate the electrode assembly 12 from the second end wall 112, the two first extensions 1253, the insulating shell 17, and the bottom support 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. Figure 17 As shown, in 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 extensions 1253, and the electrical isolation between the electrode assembly 12 and the second end wall 112 can be achieved only by the insulating shell 17, and the bottom support plate 18 is omitted. Such a configuration can improve the insulation reliability, the reliability and service life of the battery cell 10; and can save the space occupied by the bottom support plate 18, improve the space utilization of the battery cell 10 in the thickness direction of the first end wall 111, and improve the energy density of the battery cell 10. Figure 18 As shown, in other embodiments, the electrical isolation between the tab 122 and the side wall 113 can be achieved only by the two first extensions 1253, and the electrical isolation between the electrode assembly 12 and the second end wall 112 can be achieved only by the bottom support plate 18, and the insulating shell 17 is omitted. Such a configuration can save the space occupied by the insulating shell 17, and can improve the space utilization of the battery cell 10 in the first direction x and the second direction, thereby improving the volume energy density of the battery cell 10, wherein the second direction is a direction perpendicular to both the first direction x and the thickness direction of the first end wall 111. Figure 19As shown, in other embodiments, the electrical isolation between the pole ear 122 and the side wall 113 can be achieved only by the insulating shell 17, and the electrical isolation between the electrode assembly 12 and the second end wall 112 can be achieved jointly by the insulating shell 17 and the bottom support plate 18, and the two first extensions 1253 are omitted. In this way, the space occupied by the two first extensions 1253 can be saved, and the vacant space can be used to store electrolyte, thereby improving the ion conduction efficiency and optimizing the rate performance, cycle life, and long-term stability of the battery cell 10; the insulation reliability between the electrode assembly 12 and the second end wall 112 can also be improved through the insulating shell 17 and the bottom support plate 18, thereby improving the reliability and service life of the battery cell 10. In other embodiments, the electrical isolation between the pole tab 122 and the side wall 113 can be achieved by the insulating shell 17 and the two first extensions 1253, and the electrical isolation between the electrode assembly 12 and the second end wall 112 can be achieved by the insulating shell 17 and the bottom support plate 18. Such a setting can improve the insulation reliability between the pole tab 122 and the side wall 113 and between the electrode assembly 12 and the second end wall 112, and can improve the reliability and service life of the battery cell 10. In other embodiments, electrical isolation between the tab 122 and the side wall 113, and electrical isolation between the electrode assembly 12 and the second end wall 112 can be achieved only through the insulating shell 17. Such a configuration can save the space occupied by the two first extensions 1253, and the vacant space can be used to store electrolyte, thereby improving the ion conduction efficiency and optimizing the rate performance, cycle life, and long-term stability of the battery cell 10; it can also save the space occupied by the bottom support plate 18, improve the space utilization of the battery cell 10 in the thickness direction of the first end wall 111, and improve the energy density of the battery cell 10.

[0174] See also Figure 17 、 Figure 18 In some embodiments of the present application, the battery cell 10 includes an insulating support member 19 disposed in the outer shell 11, the insulating support member 19 abuts against the side of the electrode assembly 12 facing the second end wall 112, and the support body 125 of the electrode assembly 12 has a second extension portion 1254 extending outside the main body 121, and the second extension portion 1254 is connected to the insulating support member 19.

[0175] It should be noted that the insulating support 19 is disposed in the housing 11, between the electrode assembly 12 and the second end wall 112, and abuts against 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.

[0176] In the embodiment where 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 where electrical isolation between the electrode assembly 12 and the second end wall 112 is achieved jointly by the insulating shell 17 and the bottom support plate 18, since the portion of the insulating shell 17 located between the electrode assembly 12 and the second end wall 112 is in abutment 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 member 19.

[0177] In the embodiment where electrical isolation between the electrode assembly 12 and the second end wall 112 is achieved only by the bottom supporting plate 18 , since the bottom supporting plate 18 abuts against the side of the electrode assembly 12 facing the second end wall 112 , the bottom supporting plate 18 serves as the insulating support member 19 .

[0178] The support body 125 of the electrode assembly 12 may have a second extension portion 1254, which extends toward the insulating support member 19 and outside the main body 121. The second extension portion 1254 is connected and fixed to the insulating support member 19, so that the electrode assembly 12 is fixed relative to the insulating support member 19, thereby stabilizing the position and state of the electrode assembly 12 relative to the insulating support member 19. The second extension portion 1254 and the insulating support member 19 can be connected by hot melt connection, ultrasonic welding or bonding. This embodiment is applicable to the case where "one electrode assembly 12 is provided", and is also applicable to the case where "multiple electrode assemblies 12 are provided".

[0179] By adopting the above-mentioned scheme, on the basis of supporting the electrode assembly 12 by the insulating support 19 and realizing 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 portion 1254, so as to be connected and fixed to the insulating support 19 via the second extension portion 1254, and a fixed point is formed between the electrode assembly 12 and the insulating support 19, so as to fix the electrode assembly 12 relative to the insulating support 19, stabilize the position and state of the electrode assembly 12 relative to the insulating support 19, and prevent the electrode assembly 12 from moving relative to the insulating support 19, thereby improving the structural stability and structural reliability of the battery cell 10. Moreover, during the use of the battery cell 10, since the position stability of the electrode assembly 12 is improved and the risk of movement is reduced, the risk of relative displacement between the electrode assembly 12 and the insulating support 19, which may cause a contact short circuit between the electrode assembly 12 and the second end wall 112, can be reduced. The risk of position displacement of the pole ear 122 of the electrode assembly 12, which may cause a contact short circuit between the pole ear 122 and the side wall 113, can also be reduced. This can reduce the risk of short circuits and improve the reliability and service life of the battery cell 10.

[0180] Of course, in other embodiments, the support body 125 of the electrode assembly 12 may omit the second extension portion 1254. In this way, the space occupied by the second extension portion 1254 can be saved, and the vacant space can be used to store electrolyte, thereby improving the ion conduction efficiency and optimizing the rate performance, cycle life, and long-term stability of the battery cell 10.

[0181] See also Figure 17 、 Figure 18 In some embodiments of the present application, the second extension portion 1254 is bent and disposed between the main body 121 and the insulating support member 19 .

[0182] It should be noted that the second extension portion 1254 is first bent between the main body 121 and the insulating support member 19 , and then connected and fixed to the insulating support member 19 .

[0183] By adopting the above-mentioned scheme, by bending the second extension portion 1254 and setting it between the main body 121 and the insulating support member 19, the abutment area and connection area between the second extension portion 1254 and the insulating support member 19 can be increased, thereby enhancing the connection strength, connection stability and connection reliability between the second extension portion 1254 and the insulating support member 19, improving the connection stability and connection reliability between the electrode assembly 12 and the insulating support member 19, consolidating the position and state of the electrode assembly 12 relative to the insulating support member 19, reducing the risk of short circuit, and improving the structural stability, structural reliability, use reliability and service life of the battery cell 10. Furthermore, the bent configuration imparts a certain degree of elastic deformation capability to the second extension portion 1254. When the battery cell 10 is subjected to external impact or internal stress (such as the expansion and contraction of the electrode assembly 12 during charging and discharging), the bent second extension portion 1254 can absorb some of the energy through its own deformation, acting as a buffer. This reduces the direct transmission of stress to the main body 121 or the insulating support member 19, thereby reducing the risk of structural damage to the electrode assembly 12 due to rigid stress and alleviating the load on the insulating support member 19, thereby extending its service life. Furthermore, the bent configuration allows the second extension portion 1254 to be rationally arranged within the limited space between the main body 121 and the insulating support member 19. By "folding," the bent second extension portion 1254 compresses the space occupied between the main body 121 and the insulating support member 19, accommodating the compact layout requirements within the housing 11 and facilitating improved energy density of the battery cell 10.

[0184] Of course, in other embodiments, the second extension portion 1254 may not be bent and may be directly connected to the insulating support member 19 .

[0185] See also Figure 4 、 Figure 5 、 Figure 6 、 Figure 7 、 Figure 10 、 Figure 11 、 Figure 12 、 Figure 17 In summary, the present invention provides a specific example of a battery cell 10 based on the above embodiments. The battery cell 10 includes a housing 11 , and an electrode assembly 12 and an insulating shell 17 disposed in the housing 11 .

[0186] The electrode assembly 12 includes a positive electrode sheet 123a, a negative electrode sheet 123b, a separator 124, and a support 125. The support 125 is a closed ring structure. The outer annular surface of the support 125 is fixedly connected to the separator 124. The positive electrode sheet 123a, separator 124, and negative electrode sheet 123b are wound around the outer circumference of the support 125. The inner annular surface of the support 125 is provided with first adhesive particles 1251. These first adhesive particles 1251 are pressure-sensitive, heat-sensitive, or heat-compression-cooperative adhesive particles, with a diameter of 5 to 30 μm. The hardness of the support 125 is greater than that of the separator 124. The surface roughness of the inner annular surface of the support 125 is less than that of the separator 124. The thickness d1 of the support from the outer to inner annular surface is 50 to 500 μm. Based on the above structure, the first adhesive particles 1251 are in a low-viscosity state or basically have no viscosity before the compaction process (including the winding process, the blanking process and the material transfer process), so that the inner ring surface of the support body 125 will not be tightly bonded to the winding needle and the clamping needle through the first adhesive particles 1251, thereby reducing the risk of the support body 125 and the diaphragm 124 being pulled apart due to excessive bonding force, thereby causing the positive electrode sheet 123a and the negative electrode sheet 123b to overlap and short-circuit during the needle withdrawal of the winding needle and the clamping needle, and reducing the risk of defects such as wrinkles and folds on the support body 125 and the diaphragm 124 due to excessive bonding force, thereby improving the qualified rate of the winding process and the smoothness of the needle withdrawal operation, and reducing the problem of poor needle withdrawal.In addition, the first adhesive particles 1251 can activate viscosity based on temperature and pressure during the compaction process, so that the inner ring surface of the support body 125 can be adhered to itself through the first adhesive particles 1251, so that the support body 125 can form a flat structure without openings, so that the support body 125 can be supported on the inner ring of the diaphragm 124 and prevent the diaphragm 124 of the inner ring (especially the innermost ring) from rebounding and shrinking inward. Based on this, the interlayer gap between the positive electrode sheet 123a and the negative electrode sheet 123b of the inner ring (especially the innermost ring) can be prevented from becoming larger, and the diaphragm 124 of the innermost ring can be pressed tightly against the outer ring surface of the support body 125, so that the electrode assembly 12 can be pressed tightly against each other with a smaller interlayer gap, so that the electrode assembly 12 can be fully compacted, thereby reducing the phenomenon of pre-compression opening and the like of the electrode assembly 12 due to insufficient compaction. The risk of OH dislocation caused by pre-stressing and opening can be reduced, the structural stability of the electrode assembly 12 and the uniformity of the electrochemical reaction can be improved, and sufficient restraint can be formed on the electrode 123 to prevent the end of the electrode 123 from moving due to external forces. The risk of the positive electrode 123a exceeding the negative electrode 123b due to the movement of the end of the electrode 123 can be reduced, thereby causing metal precipitation and short circuit. The risk of the active ion transmission performance being affected by the excessive interlayer gap between the positive electrode 123a and the negative electrode 123b, and the risk of metal precipitation during the use of the battery cell 10 can be reduced. The risk of foreign particles falling into the electrode assembly 12 along the interlayer gap and affecting the yield rate can be reduced. The risk of foreign metal particles falling into the electrode assembly 12 along the interlayer gap and causing short circuit can be reduced. As a result, the performance, reliability and service life of the battery cell 10 can be improved.

[0187] The outer surface of the support body 125 is provided with a plurality of grooves 1252. The groove depth d2 is less than the thickness d1 of the support body from its outer surface to its inner surface. The groove width d3 ranges from 50 μm to 500 μm, and the groove depth d2 ranges from 50 μm to 500 μm. Among the grooves 1252, some are linear grooves 1252a extending parallel to the axial direction of the support body 125, while others are linear grooves 1252a extending parallel to the circumference of the support body 125, forming a horizontal and vertical cross-pattern. Based on the above structure, when the electrode assembly 12 is fully compacted, the grooves 1252 provide an electrolyte infiltration channel within the inner ring of the electrode assembly 12 (particularly between the tightly fitted support body 125 and separator 124), allowing the electrolyte to diffuse smoothly and fully penetrate the inner ring of the electrode assembly 12. This alleviates the problems of slow electrolyte filling and poor localized infiltration of the inner ring caused by the tight fit of the inner ring, thereby maintaining and improving the electrochemical performance of the battery cell 10. Furthermore, the grooves 1252 reserve electrolyte storage space for pre-storing electrolyte. At the end of the battery cell 10 cycle, the electrolyte stored in the grooves 1252 is released through expansion and compression, thereby replenishing the electrolyte supply and compensating for consumption, thereby maintaining and improving the battery cell 10's liquid retention capacity, cycle performance, and service life. Moreover, the groove 1252 is only partially recessed in the outer ring surface of the support body 125 without destroying the overall continuity of the support body 125, thereby maintaining the structural strength of the annular support body 125, maintaining the basic supporting capacity of the compacted flat support body 125, and enabling the compacted flat support body 125 to form a reliable support for the inner ring of the diaphragm 124, resist the rebound stress of the diaphragm 124, and prevent the diaphragm 124 from rebounding and shrinking inward.

[0188] The outer shell 11 has a first end wall 111 and a second end wall 112 that are opposite to each other, and a side wall 113 connected between the first end wall 111 and the second end wall 112. The electrode assembly 12 includes a main body 121 and a tab 122 that extends toward the first end wall 111 and out of the main body 121. Two electrode assemblies 12 are provided, and the two electrode assemblies 12 are arranged side by side along the first direction x. Both electrode assemblies 12 are first electrode assemblies 12a. The support body 125 of the first electrode assembly 12a is an insulating component. The support body 125 of the first electrode assembly 12a has a first extension portion 1253 that extends toward the first end wall 111 and out of the main body 121. The tabs 122 of the two electrode assemblies 12 are located between the two first extension portions 1253. The insulating shell 17 covers the exterior of the two electrode assemblies 12. Based on the above structure, the electrical isolation between the pole ear 122 and the side wall 113 can be achieved through the insulating shell 17 and the two first extension parts 1253, and the electrical isolation between the electrode assembly 12 and the second end wall 112 can be achieved through the insulating shell 17. Based on this, the risk of short circuit due to direct contact between the pole ear 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, and the reliability and service life of the battery cell 10 can be improved; and the bottom support plate 18 can be omitted, which can save the space occupied by the bottom support plate 18, improve the space utilization of the battery cell 10 in the thickness direction of the first end wall 111, and improve the energy density of the battery cell 10.

[0189] Since the portion of the insulating shell 17 located between the electrode assembly 12 and the second end wall 112 is in 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. The support body 125 of the electrode assembly 12 has a second extension portion 1254 extending outside the main body 121. The second extension portion 1254 is bent and arranged between the main body 121 and the insulating support 19, and is connected to the insulating support 19. Based on the above structure, the second extension portion 1254 can be connected and fixed to the insulating support 19, and a fixed point can be formed between the electrode assembly 12 and the insulating support 19, so as to fix the electrode assembly 12 relative to the insulating support 19, stabilize the position and state of the electrode assembly 12 relative to the insulating support 19, and prevent the electrode assembly 12 from moving relative to the insulating support 19, thereby improving the structural stability and reliability of the battery cell 10. Moreover, during the use of the battery cell 10, since the position stability of the electrode assembly 12 is improved and the risk of movement is reduced, the risk of relative displacement between the electrode assembly 12 and the insulating support 19, which may cause a contact short circuit between the electrode assembly 12 and the second end wall 112, can be reduced. The risk of position displacement of the pole ear 122 of the electrode assembly 12, which may cause a contact short circuit between the pole ear 122 and the side wall 113, can also be reduced. This can reduce the risk of short circuits and improve the reliability and service life of the battery cell 10.

[0190] See also Figure 20 、 Figure 6 、 Figure 7 、 Figure 9 Some embodiments of the present application provide a method for manufacturing an electrode assembly 12, which is used to manufacture the electrode assembly 12 with a support 125 provided in the embodiments of the present application. Figure 21 、 Figure 22 、 Figure 23 、 Figure 24 The manufacturing method of the electrode assembly 12 includes the following steps: S1. Sleeve the support 125 around the outer periphery of the winding needle 20, so that the winding needle 20 is stretched and pressed against the support 125. The support 125 is an annular structure, and the inner annular surface of the support 125 is provided with first adhesive particles 1251. Figure 21 As shown, since the support body 125 is an annular structure, the support body 125 can be sleeved around the outer periphery of the winding needle 20. At this time, the support body 125 is basically annular; then, the winding needle 20 is stretched outward and pressed against the support body 125, so that the support body 125 can be loaded 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 around the outer periphery of the winding needle 20", the winding needle 20 can be retracted to facilitate the process of "sleeving the support body 125 around the outer periphery of the winding needle 20" behind the turret 30; after the process of "sprung the winding needle 20 and pressed against the support body 125", the winding needle 20 can be reset and extended to facilitate the subsequent steps. The inner annular surface of the support body 125 is provided with first adhesive particles 1251. After the process of "sleeving the support body 125 around the outer periphery of the winding needle 20," the inner annular surface of the support body 125 will contact the outer periphery of the winding needle 20. The inner annular surface of the support body 125 may be slightly bonded to the outer periphery of the winding needle 20 via the first adhesive particles 1251, or substantially not bonded, and this will have little impact on the subsequent step of "unloading the wound structure from the winding needle 20." The winding needle 20 is used to assist in the winding and forming of the electrode assembly 12, and the turret 30 is the component that mounts and supports the winding needle 20.

[0191] S2, the rolled end of the diaphragm 124 is fixedly connected to the outer annular surface of the support body 125. It should be noted that, if Figure 22 As shown, after the support body 125 is loaded, the diaphragm 124 can be rolled in first, and the rolled end of the diaphragm 124 can be fixedly connected to the outer ring surface of the support body 125, thereby providing a stable starting point for subsequent winding, prompting the diaphragm 124 and the support body 125 to move synchronously, and reducing the deviation in the initial stage of winding. Among them, the fixed connection method can be hot melt connection, ultrasonic welding or bonding.

[0192] S3, after the separator 124 is wound around the outer periphery of the support 125 for a preset number of turns, the negative electrode sheet 123b is then rolled in. When the rolled-in length of the negative electrode sheet 123b exceeds the preset length L, the positive electrode sheet 123a is then rolled in, so that the positive electrode sheet 123a, the separator 124 and the negative electrode sheet 123b are wound around the outer periphery of the support 125. It should be noted that, if Figure 23 、 Figure 24As shown, after the rolled end of the diaphragm 124 is fixedly connected to the outer annular surface of the support body 125, the diaphragm 124 can be first wound around the outer periphery of the support body 125 for a preset number of turns, so that the pre-rolled diaphragm 124 can form a longer inner ring insulation barrier, and the insulation isolation between the support body 125 and the electrode 123, and between the positive electrode 123a and the negative electrode 123b, thereby reducing the risk of short circuit, especially reducing the risk of the end of the electrode 123 moving, causing the electrode 123 to exceed the insulation isolation range of the diaphragm 124, resulting in overlapping and short circuiting of the positive electrode 123a and the negative electrode 123b, wherein the preset number of turns can be an integer (for example, 1 turn, 2 turns, etc.) or a decimal (for example, 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 electrode sheet 123b is then rolled in. After the rolled-in length of the negative electrode sheet 123b exceeds the preset length L, the positive electrode sheet 123a is then rolled in. Based on this, the negative electrode sheet 123b can be rolled in before the positive electrode sheet 123a, and the rolled-in end of the positive electrode sheet 123a can be covered by the negative electrode sheet 123b. The design principle of "the negative electrode sheet 123b covers the positive electrode sheet 123a" can be followed, and the probability of metal precipitation and short circuit can be reduced from the root. Among them, the preset length L can be an integer (for example, 1 mm, 2 mm, 3 mm, etc.) or a decimal (for example, 1.5 mm, 2.5 mm, 3.5 mm, etc.). Among them, two diaphragms 124 can be set, one of which is set between the positive electrode sheet 123a and the negative electrode sheet 123b, and the other diaphragm 124 is set on the side of the negative electrode sheet 123b away from the positive electrode sheet 123a, or is set on the side of the positive electrode sheet 123a away from the negative electrode sheet 123b, so as to realize the stacking arrangement of the positive electrode sheet 123a, the diaphragm 124 and the negative electrode sheet 123b, and promote the diaphragm 124 to reliably separate 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. Among them, after the diaphragm 124 is rolled up and before the negative electrode sheet 123b is rolled up, only the diaphragm 124 is wound around the outer periphery of the support body 125; after the negative electrode sheet 123b is rolled up and before the positive electrode sheet 123a is rolled up, the negative electrode sheet 123b and the diaphragm 124 are wound together around the outer periphery of the support body 125; after the positive electrode sheet 123a is rolled up, the positive electrode sheet 123a, the diaphragm 124 and the negative electrode sheet 123b are wound together around the outer periphery of the support body 125; the winding direction y remains unchanged during this period.

[0193] S4. Cut the positive electrode sheet 123a first, then the negative electrode sheet 123b. It should be noted that cutting the positive electrode sheet 123a before the negative electrode sheet 123b ensures that the tail end of the positive electrode sheet 123a is also covered by the negative electrode sheet 123b, making the winding length of the negative electrode sheet 123b longer than the winding length of the positive electrode sheet 123a. This adheres to the design principle of "negative electrode sheet 123b covering positive electrode sheet 123a" and fundamentally reduces the probability of metal precipitation and short circuits. The winding action continues during this process.

[0194] S5. Cut the separator 124 again. It should be noted that cutting the separator 124 after the negative electrode sheet 123b allows the separator 124 to reliably separate the positive electrode sheet 123a and the negative electrode sheet 123b, thereby preventing the positive electrode sheet 123a and the negative electrode sheet 123b from short-circuiting. During this period, the winding operation continues.

[0195] S6. Winding is then performed to form a wound structure. It should be noted that after the separator 124 is cut, winding is performed to form a wound structure with the support 125, separator 124, negative electrode sheet 123b, and positive electrode sheet 123a. The wound structure is the intermediate form of the electrode assembly 12. The winding operation of a wound structure is completed on a single winding needle 20, without interrupting the winding operation and replacing the winding needle 20.

[0196] S7, unloading the wound structure from the winding needle 20. It should be noted that the wound structure is unloaded from the winding needle 20. In some embodiments, the wound structure can be clamped from the winding needle 20 by a clamping needle and transferred to the pre-pressing device.

[0197] S8. Compact the winding structure so that the inner annular surface of the support body 125 is adhered to itself via the first adhesive particles 1251, thereby forming a flat electrode assembly 12. It should be noted that after the winding structure is cut, the winding structure can be compacted to flatten the winding structure by compaction, until the inner annular surface of the support body 125 is adhered to itself via the first adhesive particles 1251, so that the support body 125 forms a flat structure without an opening. In this way, a flat electrode assembly 12 can be obtained, and the morphological transformation from a "cylindrical winding structure" to a "flat electrode assembly 12" can be achieved. In some embodiments, the winding structure can be compacted by a pre-pressing device, and the winding structure can even be flattened by a clamping needle in combination with the pre-pressing device.

[0198] By adopting the above scheme and the method for manufacturing the electrode assembly 12 provided in the embodiment of the present application, the positive electrode sheet 123a, the separator 124, and the negative electrode sheet 123b can be first wound around the outer periphery of the support body 125, so that the support body 125, the separator 124, the negative electrode sheet 123b, and the positive electrode sheet 123a together form a wound structure; then the wound structure is compacted until the inner annular surface of the support body 125 is adhered to itself via the first adhesive particles 1251, so that the support body 125 forms a flat structure without an opening, thereby obtaining a flat electrode assembly 12. Based on this, the electrode assembly 12 provided in the embodiment of the present application with the support body 125 and fully compacted can be conveniently and quickly manufactured, which can provide the manufacturability, production convenience, production efficiency, production consistency, and production yield of the electrode assembly 12.

[0199] See also 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-pressure-cooperative adhesive particles. From the step of sleeve-mounting the support 125 on the outer periphery of the winding needle 20, so that the winding needle 20 is stretched and pressed against the support 125 (i.e., S1) to the step of unloading 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 wound structure (ie, S8 ), the first adhesive particles 1251 activate the adhesiveness, so that the inner annular surface of the support body 125 is adhered to itself via the first adhesive particles 1251 .

[0200] It should be noted that the relevant descriptions of the pressure-sensitive adhesive particles, the heat-sensitive adhesive particles, and the heat-pressure synergistic adhesive particles can be found in the previous text and will not be repeated here.

[0201] It should also be noted that in each step of the method for manufacturing the electrode assembly 12: In the steps of "sleeving the support body 125 on the outer periphery of the winding needle 20 so that the winding needle 20 is stretched and presses the support body 125" (i.e. S1) to "unloading 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-viscosity state or basically have no viscosity, so that the inner annular surface of the support body 125 will not be tightly bonded to the outer peripheral surface of the winding needle 20 and the clamping needle through the first adhesive particles 1251.

[0202] In the step of compacting the winding structure (ie, S8 ), the first adhesive particles 1251 can activate viscosity based on temperature and pressure, so that the inner annular surface of the support body 125 can be adhered to itself via the first adhesive particles 1251 , so that the support body 125 can form a flat structure without openings.

[0203] By adopting the above solution, by making the first adhesive particles 1251 pressure-sensitive adhesive particles, heat-sensitive adhesive particles or heat-pressure cooperative adhesive particles, in the step of "sleeving the support body 125 on the outer periphery of the winding needle 20, so that the winding needle 20 is stretched and presses the support body 125" (i.e. S1) to the step of "unloading the winding structure from the winding needle 20" (i.e. S7), the first adhesive particles 1251 are not activated and are in a low-viscosity state or basically have no viscosity, so that the inner annular surface of the support body 125 will not be affected by the first adhesive particles 1251. The particles 1251 are tightly bonded to the outer peripheral surface of the winding needle 20 and the clamping needle, thereby reducing the risk of the support body 125 and the diaphragm 124 being pulled out due to excessive bonding force during the step of "unloading the winding structure from the winding needle 20" (i.e., S7), as well as the risk of defects such as wrinkles and folds on the support body 125 and the diaphragm 124 due to excessive bonding force. This improves the qualified rate of the winding process and the smoothness of the needle extraction operation, and reduces the problem of defective needle extraction. Furthermore, during the step of compacting the wound structure (i.e., S8), the first adhesive particles 1251 can activate their adhesive properties based on temperature and pressure, thereby allowing the inner annular surface of the support body 125 to adhere to itself via the first adhesive particles 1251, allowing the support body 125 to form a flat structure without openings. This improves the pass rate of the compaction process and enhances the stability and reliability of the structure and morphology of the support body 125 after compaction. This improves the manufacturability, production convenience, production efficiency, production consistency, and production yield of the electrode assembly 12.

[0204] See also Figure 20 、 Figure 22 、 Figure 4 In some embodiments of the present application, in the step of fixing the rolled-in end of the diaphragm 124 to the outer annular surface of the support body 125 (i.e., S2), hot melt connection or ultrasonic welding is used to fix the rolled-in end of the diaphragm 124 to the outer annular surface of the support body 125.

[0205] By adopting the above solution, in the step of "fixedly connecting the rolled end of the separator 124 to the outer annular surface of the support body 125" (i.e., S2), a hot melt connection or ultrasonic welding method can be used to conveniently and quickly achieve a fixed connection between the rolled end of the separator 124 and the outer annular surface of the support body 125. This improves the convenience, strength, stability, and reliability of the connection between the rolled end of the separator 124 and the outer annular surface of the support body 125, thereby improving the production convenience, production efficiency, and production yield of the electrode assembly 12. Furthermore, because hot melt connection or ultrasonic welding methods do not require additional consumables (such as solder, adhesive, etc.), the impact of residual consumables on the structure and performance of the electrode assembly 12 can be reduced, thereby improving the molding quality of the electrode assembly 12; the impact of residual consumables on the electrolyte can be reduced, the performance of the battery cell 10 can be optimized, and the cost can be reduced.

[0206] Of course, in other embodiments, other methods (such as bonding, etc.) can be used to achieve a fixed connection between the rolled-in end of the diaphragm 124 and the outer annular surface of the support body 125 .

[0207] See also Figure 20 、 Figure 22 、 Figure 6 In some embodiments of the present application, the fixed connection area between the rolled-in end of the diaphragm 124 and the outer annular surface of the support body 125 is a first connection area 1255. Along the axial direction of the support body 125, the dimension of the first connection area 1255 (i.e., d4) is greater than or equal to 10 mm and less than or equal to the dimension of the support body 125 (i.e., d5).

[0208] It should be noted that in the step of "fixedly connecting the rolled-in end of the diaphragm 124 to the outer annular surface of the support body 125" (i.e., S2), the fixed connection area between the rolled-in end of the diaphragm 124 and the outer annular surface of the support body 125 is the first connection area 1255. The shape of the connection mark 12551 of the first connection area 1255 can be flexibly set as needed, for example, it can be in a grid shape (such as Figure 22 As shown), stripes extending along the axial direction of the support body 125 (as shown Figure 25 As shown), stripes extending along the circumference of the support body 125 (as shown Figure 26 As shown), the curved line extension setting (as shown Figure 27 as shown), dot-shaped (as shown Figure 28 shown) and so on.

[0209] Along the axial direction of the support body 125, the size of the first connection area 1255 (i.e., d4) is greater than or equal to 10 mm and less than or equal to the size of the support body 125 (i.e., d5), that is, the size of the first connection area 1255 (i.e., d4) cannot exceed the size of the support body 125 (i.e., d5); if the size of the diaphragm 124 is smaller than the size of the support body 125 (i.e., d5), the size of the first connection area 1255 (i.e., d4) is allowed to exceed the size of the diaphragm 124 but cannot exceed the size of the support body 125 (i.e., d5).

[0210] By adopting the above solution, the first connection region 1255 ensures sufficient axial connection length and area between the winding end of the separator 124 and the outer annular surface of the support body 125. This improves the strength, stability, and reliability of the connection between the winding end of the separator 124 and the outer annular surface of the support body 125, reduces the risk of the separator 124 falling off the support body 125 during the initial winding process, and improves the pass rate of the step of "fixing the winding end of the separator 124 to the outer annular surface of the support body 125" (i.e., S2). This improves the production convenience, efficiency, and yield rate of the electrode assembly 12. Furthermore, the first connection region 1255 does not extend beyond the axial boundary of the support body 125, which reduces the damage caused by the formation of the first connection region 1255 to the winding needle 20, protects the winding needle 20 from damage, maintains the reliability and service life of the winding needle 20, and reduces equipment maintenance costs and the risk of downtime.

[0211] See also Figure 20 、 Figure 22 、 Figure 6 In some embodiments of the present application, the fixed connection area between the rolled-in end of the diaphragm 124 and the outer annular surface of the support body 125 is a first connection area 1255. Along the circumference of the support body 125, the size of the first connection area 1255 (i.e., d6) is greater than or equal to 5 mm and less than or equal to the circumference of the support body 125.

[0212] It should be noted that in the step of "fixedly connecting the rolled-in end of diaphragm 124 to the outer annular surface of support body 125" (i.e., S2), the fixed connection area between the rolled-in end of diaphragm 124 and the outer annular surface of support body 125 is first connection area 1255. Along the circumference of support body 125, the dimension of first connection area 1255 (i.e., d6) is greater than or equal to 5 mm and less than or equal to the circumference of support body 125. In other words, first connection area 1255 is formed around support body 125 at most.

[0213] By adopting the above-mentioned scheme, based on the first connection area 1255, the winding end of the diaphragm 124 and the outer annular surface of the support body 125 can have sufficient circumferential connection length and connection area, thereby improving the connection strength, connection stability and connection reliability between the winding end of the diaphragm 124 and the outer annular surface of the support body 125, reducing the risk of the diaphragm 124 falling off the support body 125 in the early stage of winding, improving the pass rate of the step of "fixing the winding end of the diaphragm 124 to the outer annular surface of the support body 125" (i.e., S2), and improving the production convenience, production efficiency and production yield of the electrode assembly 12.

[0214] See also 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.

[0215] It should be noted that, in the step (i.e., S3) of “after winding the separator 124 around the periphery of the support body 125 for a preset number of turns, the negative electrode sheet 123b is then rolled in, and when the rolled-in length of the negative electrode sheet 123b exceeds the preset length L, the positive electrode sheet 123a is then rolled in, so as to wind the positive electrode sheet 123a, the separator 124, and the negative electrode sheet 123b around the periphery of the support body 125”, the separator 124 is wound around the periphery of the support body 125 for 0.5 to 1 turn.

[0216] By adopting the above solution, after the step of "fixing the wound end of the separator 124 to the outer annular surface of the support body 125" (i.e., S2), the separator 124 can be first wound around the outer circumference of the support body 125 by 0.5 to 1 turn. Based on this, the pre-wound 0.5 to 1 turn of the separator 124 can be ensured to cover at least half of the outer annular surface of the support body 125, forming a "half-wrapped" inner ring insulation barrier to insulate and isolate the support body 125 and the electrode sheet 123, and between the positive electrode sheet 123a and the negative electrode sheet 123b, thereby reducing the risk of short circuits, especially the risk of the end of the electrode sheet 123 moving, causing the electrode sheet 123 to exceed the insulation isolation range of the separator 124, and causing the positive electrode sheet 123a and the negative electrode sheet 123b to overlap and short-circuit, thereby improving the molding quality and production yield of the electrode assembly 12. Moreover, the initial winding number of the separator 124 is 0.5 to 1, which is relatively small, so that the volume of the "starting core" (i.e., the support body 125 and the initial separator 124) of the winding structure is smaller and more compact. Based on this, in the subsequent compaction process, the compact starting core can evenly transmit the pressure to the entire winding structure, which can reduce the problem of insufficient local compaction caused by too many initial winding turns of the separator 124 and too thick starting core, thereby improving the compaction density and compaction efficiency, and improving the electrode assembly 12 (such as Figure 6 The overall volumetric energy density is shown).

[0217] Of course, in other embodiments, the preset number of revolutions may be other integers or decimals.

[0218] See also Figure 20 、 Figure 24 、 Figure 6 In some embodiments of the present application, the preset length L is 2 mm.

[0219] It should be noted that in the step (i.e., S3) of "after winding the separator 124 around the periphery of the support body 125 for a preset number of turns, the negative electrode sheet 123b is then rolled in, and when the rolled-in length of the negative electrode sheet 123b exceeds the preset length L, the positive electrode sheet 123a is then rolled in, so as to wind the positive electrode sheet 123a, the separator 124 and the negative electrode sheet 123b around the periphery of the support body 125", when the rolled-in length of the negative electrode sheet 123b exceeds 2 mm, the positive electrode sheet 123a is then rolled in.

[0220] By adopting the above solution, the positive electrode sheet 123a can be rolled in after the negative electrode sheet 123b has been rolled in for a length exceeding 2 mm. This allows the negative electrode sheet 123b to be rolled in before the positive electrode sheet 123a, allowing the rolled-in length of the negative electrode sheet 123b to exceed the positive electrode sheet 123a by 2 mm. This ensures that the rolled-in end of the positive electrode sheet 123a is reliably covered by the negative electrode sheet 123b, adhering to the design principle of "negative electrode sheet 123b covering positive electrode sheet 123a." This fundamentally reduces the probability of metal precipitation and short circuits, and improves the molding quality and production yield of the electrode assembly 12.

[0221] Of course, in other embodiments, the preset length L may be other integers or decimals.

[0222] See also Figure 20 、 Figure 21 、 Figure 6 In some embodiments of the present application, the number of the winding needle 20 is one, and the winding needle 20 maintains a preset position unchanged during the winding process.

[0223] It should be noted that there is only one winding needle 20. Within one operation cycle, one winding needle 20 can perform the winding process of one electrode assembly 12. The winding process includes the steps of "sleeving the support body 125 on the outer periphery of the winding needle 20, so that the winding needle 20 is stretched and presses the support body 125 tightly" (i.e. S1) to "unloading the winding structure from the winding needle 20" (i.e. S7), and the winding needle 20 maintains the preset position unchanged during the winding process.

[0224] By adopting the above solution, a single winding needle 20 can be used, with the winding needle 20 maintaining a preset position during the winding process, to execute steps from "slipping the support body 125 onto the outer periphery of the winding needle 20, thereby expanding the winding needle 20 and pressing against the support body 125" (i.e., S1) to "unloading the wound structure from the winding needle 20" (i.e., S7). This simplifies the equipment structure, reduces equipment complexity and failure rate, and indirectly improves production continuity. Furthermore, because the winding needle 20 maintains its preset position, eliminating the need for station switching, the stability and consistency of the winding process can be improved, thereby enhancing the molding quality and production yield of the electrode assembly 12.

[0225] See also Figure 20 、 Figure 24 、 Figure 29 、 Figure 6 In some embodiments of the present application, there are two winding needles 20, which are capable of rotating about a predetermined axis, so that the two winding needles 20 alternate between the first station 31 and the second station 32. Among the steps in the method for manufacturing the electrode assembly 12, the steps of "sleeving the support body 125 around the outer periphery of the winding needle 20, so that the winding needle 20 opens and presses against the support body 125" (i.e., S1), "finishing the winding to form a wound structure" (i.e., S6), and "unloading the wound structure from the winding needle 20" (i.e., S7) are performed at the first station 31; the steps of "fixing the winding end of the separator 124 to the outer annular surface of the support body 125" (i.e., S2) to "first cutting the positive electrode sheet 123a and then cutting the negative electrode sheet 123b" (i.e., S4) are performed at the second station 32; and the step of cutting the separator 124 (i.e., S5) is performed between the second station 32 and the first station 31.

[0226] It should be noted that the turret 30 is equipped with two winding needles 20, which are located in a one-to-one correspondence between the first and second workstations 31 and 32. Driven by the turret 30, the two winding needles 20 can rotate about a preset axis, allowing the two winding needles 20 to alternately swap positions, switching between the first and second workstations 31 and 32. That is, the winding needle 20 originally in the first workstation 31 switches to the second workstation 32, and the winding needle 20 originally in the second workstation 32 switches to the first workstation 31. The preset axis corresponds to the central axis of the turret 30.

[0227] Within one operation cycle (i.e., within the cycle in which the winding needle 20 rotates one circle around the preset axis), one winding needle 20 can perform the winding process of one electrode assembly 12, and two winding needles 20 can perform the winding process of two electrode assemblies 12 one-to-one. The winding process includes the steps of "sleeving the support body 125 on the outer periphery of the winding needle 20, so that the winding needle 20 is stretched and presses the support body 125 tightly" (i.e., S1) to "unloading the winding structure from the winding needle 20" (i.e., S7).

[0228] For each winding needle 20, when the winding needle 20 is located at the first station 31, the step of "sleeving the support body 125 on the outer periphery of the winding needle 20 so that the winding needle 20 is stretched and pressed against the support body 125" (i.e., S1) is executed; and when the winding needle 20 is switched from the first station 31 to the second station 32, 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 "first cutting the positive electrode sheet 123a, then cutting the negative electrode sheet 123a" are executed. The step of “cutting the diaphragm 123b” (i.e., S4) is performed; when the winding needle 20 switches from the second station 32 to the first station 31, 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 and finishing to form a winding structure” (i.e., S6) and the step of “unloading the winding structure from the winding needle 20” (i.e., S7) are performed at the first station 31; at this point, the winding needle 20 can complete the winding process of the primary electrode assembly 12.

[0229] For the two winding needles 20, the winding needle 20 located at the first workstation 31 handles the "finishing and unloading" of the previous product and the "loading of the support body 125" of the next product, and the winding needle 20 located at the second workstation 32 handles the "winding of the diaphragm 124 and the pole piece 123". The actions of the two winding needles 20 at the two workstations are carried out in parallel, which can compress the waiting time and eliminate the window period of "finishing one product before starting the next one" in the single winding needle mode.

[0230] By adopting the above solution, two winding needles 20 can be used to alternate between the first and second workstations 31 and 32. This allows the winding steps (i.e., S1-S7) of the electrode assembly 12 to be split into different workstations for alternating operation. This allows the two winding needles 20 to operate in parallel, shortening waiting time and production cycle time. This eliminates the idle period in the single-needle winding mode where one product needs to be completed before the next one is started. This reduces equipment idle time, creates a seamless connection, and improves production capacity per unit time (theoretically, a single cycle can essentially complete the winding process for two electrode assemblies 12, nearly double the efficiency of a single winding needle). Furthermore, by splitting the steps into fixed workstations, the operations at each workstation can be specialized and optimized. Each workstation can perform the corresponding operation with high precision, stability, and accuracy. The operating parameters of each step can be easily standardized, thereby optimizing process stability and improving the consistency and yield rate of batch production.

[0231] See also Figure 20 、 Figure 24 、 Figure 29 、 Figure 6In some embodiments of the present application, when the two winding needles 20 complete the work station switching, the diaphragm 124 is overlapped from the first work station 31 to the outer annular surface of the support body 125 located at the second work station 32, and the step of "fixing the winding end of the diaphragm 124 to the outer annular surface of the support body 125" (i.e., S2) is first performed at the second work station 32, and then the step of cutting the diaphragm 124 is performed between the second work station 32 and the first work station 31 (i.e., S5), and then the step of winding and finishing to form a winding structure is performed at the first work station 31 (i.e., S6).

[0232] It should be noted that, when the two winding needles 20 complete the station switching, that is, when the winding needle 20 originally at the first station 31 switches to the second station 32, and the winding needle 20 originally at the second station 32 switches to the first station 31, the diaphragm 124 will be overlapped from the first station 31 to the outer annular surface of the support body 125 at the second station 32; in this state, the step of "fixing the winding end of the diaphragm 124 to the outer annular surface of the support body 125" can be performed at the second station 32 first (that is, S2, which is different from the later-described steps S5 and S6). The step of cutting the diaphragm 124 between the second station 32 and the first station 31 (i.e., S5, which is a step in the winding process of the same electrode assembly 12) is performed to ensure that the diaphragm 124 is fixedly connected to the support body 125 of the subsequent product; the step of cutting the diaphragm 124 is performed between the second station 32 and the first station 31 (i.e., S6, which is a step in the winding process of the same electrode assembly 12) to cut and separate the diaphragms 124 of the first station 31 and the second station 32; the step of "performing winding and finishing to form a winding structure" (i.e., S6) is performed at the first station 31 to complete the winding of the previous product.

[0233] By adopting the above scheme, on the basis of the alternating stations of the two winding needles 20, 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 winds and finishes", the diaphragm 124 can be seamlessly overlapped, the continuous utilization of the diaphragm 124 can be optimized, the diaphragm 124 does not need to be re-rolled at each switch, the redundant waste of the diaphragm 124 caused by each separate winding can be reduced, the material utilization rate can be improved, and the operation of "fixing the winding end of the diaphragm 124 at the second station 32" can be simplified based on the continuous overlap of the diaphragm 124, the process continuity can be improved, and the coordination of the double-station operation can be enhanced. Moreover, the sequential connection of the overlapping, fixing, cutting and finishing of the diaphragm 124 enables the second workstation 32 to start winding after fixing the diaphragm 124, and enables the first workstation 31 to use the cut diaphragm 124 for finishing at almost the same time, so that the first workstation 31 and the second workstation 32 share a section of the diaphragm 124 for time-sharing utilization, so that the "finishing" of the previous product and the "initial winding" of the next product can be carried out in parallel, which can reduce the waiting time of the workstation caused by the conflict of the allocation of the diaphragm 124 (such as the stagnation of "the previous finishing is not completed and the next winding cannot take the diaphragm 124"), thereby compressing the production rhythm and improving production efficiency.

[0234] See also 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 preset axis so that the three winding needles 20 cyclically alternate in the first workstation 31, the second workstation 32 and the third workstation 33 in turn, and the three winding needles 20 are located at the first workstation 31, the second workstation 32 and the third workstation 33 one by one. Among them, in each step 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, so that the winding needle 20 is stretched and presses the support body 125" (i.e., S1) is performed at the first station 31; the step of "fixing the winding end of the diaphragm 124 to the outer annular surface of the support body 125" (i.e., S2) to the step of "first cutting the positive electrode sheet 123a, and then cutting the negative electrode sheet 123b" (i.e., S4) are performed at the second station 32; the step of cutting the diaphragm 124 (i.e., S5) is performed between the second station 32 and the third station 33; the step of "finishing the winding to form a winding structure" (i.e., S6), and the step of "unloading the winding structure from the winding needle 20" (i.e., S7) are performed at the third station 33.

[0235] It should be noted that the turret 30 is equipped with three winding needles 20, which are correspondingly located at the first workstation 31, the second workstation 32, and the third workstation 33. Driven by the turret 30, the three winding needles 20 can rotate about a preset axis, so that the three winding needles 20 alternate positions sequentially and cyclically, so that each winding needle 20 sequentially and cyclically switches between the first workstation 31, the second workstation 32, and the third workstation 33. That is, the winding needle 20 originally in the first workstation 31 switches to the second workstation 32, the winding needle 20 originally in the second workstation 32 switches to the third workstation 33, and the winding needle 20 originally in the third workstation 33 switches to the first workstation 31. The preset axis corresponds to the central axis of the turret 30.

[0236] Within one operation cycle (i.e., within the cycle in which the winding needle 20 rotates one circle around the preset axis), one winding needle 20 can perform the winding process of one electrode assembly 12, and three winding needles 20 can perform the winding process of three electrode assemblies 12 one-to-one. The winding process includes the steps of "sleeving the support body 125 on the outer periphery of the winding needle 20, so that the winding needle 20 is stretched and presses the support body 125 tightly" (i.e., S1) to "unloading the winding structure from the winding needle 20" (i.e., S7).

[0237] For each winding needle 20, when the winding needle 20 is located at the first station 31, the step of "sleeving the support body 125 on the outer periphery of the winding needle 20 so that the winding needle 20 is stretched and pressed against the support body 125" (i.e., S1) is executed; and when the winding needle 20 is switched from the first station 31 to the second station 32, 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 "first cutting the positive electrode sheet 123a, then cutting the negative electrode sheet 123a" are executed. The step of “cutting the diaphragm 123b” (i.e., S4) is performed; when the winding needle 20 switches from the second station 32 to the third station 33, the step of cutting the diaphragm 124 is performed between the second station 32 and the third station 33 (i.e., S5), and then the step of “winding and finishing to form a winding structure” (i.e., S6) and the step of “unloading the winding structure from the winding needle 20” (i.e., S7) are performed at the third station 33; at this point, the winding needle 20 can complete the winding process of the primary electrode assembly 12.

[0238] For the three winding needles 20, the winding needle 20 located at the first workstation 31 handles the "loading of the support body 125", the winding needle 20 located at the second workstation 32 handles the "winding of the diaphragm 124 and the electrode 123", and the winding needle 20 located at the third workstation 33 handles the "finishing and unloading". The actions of the three winding needles 20 at the three workstations are carried out in parallel, which can compress the waiting time and eliminate the window period of "completing one product before starting the next one" in the single winding needle mode.

[0239] By adopting the above solution, three winding needles 20 can alternately operate in a first, second, and third stations 31, 32, and 33, respectively. This allows the winding process steps (i.e., S1-S7) of the electrode assembly 12 to be split into three stations for alternating operation. This allows the three winding needles 20 to operate in parallel, shortening waiting time and production cycle time. This eliminates the idle period in the single-needle winding mode where one product needs to be completed before the next one is started. This reduces equipment idle time, creates a seamless connection, and improves production capacity per unit time (theoretically, one cycle can essentially complete the winding process of three electrode assemblies 12, nearly three times the efficiency of a single winding needle). Furthermore, by splitting the steps into fixed stations, operations at each station can be specialized and optimized. Each station can perform the corresponding operation with high precision, stability, and accuracy. The operating parameters of each step can be easily standardized, thereby optimizing process stability and improving the consistency and yield rate of batch production.

[0240] See also 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 a preset axis so that the four winding needles 20 cyclically alternate in the first station 31, the second station 32, the third station 33 and the fourth station 34, and the four winding needles 20 are located at the first station 31, the second station 32, the third station 33 and the fourth station 34 one by one. Among them, in each step 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, so that the winding needle 20 is stretched and presses the support body 125" (i.e., S1) is performed at the first station 31; the step of "fixing the winding end of the diaphragm 124 to the outer ring surface of the support body 125" (i.e., S2) to the step of "first cutting the positive electrode sheet 123a, and then cutting the negative electrode sheet 123b" (i.e., S4) are performed at the second station 32; the step of cutting the diaphragm 124 (i.e., S5) is performed between the second station 32 and the third station 33; the step of "winding and finishing to form a winding structure" (i.e., S6) is performed at the third station 33; and the step of "unloading the winding structure from the winding needle 20" (i.e., S7) is performed at the fourth station 34.

[0241] It should be noted that the turret 30 is equipped with four winding needles 20, which are correspondingly located at the first station 31, the second station 32, the third station 33, and the fourth station 34. Driven by the turret 30, the four winding needles 20 can rotate about a preset axis, so that the four winding needles 20 alternate positions sequentially and cyclically, so that each winding needle 20 sequentially and cyclically switches between the first station 31, the second station 32, the third station 33, and the fourth station 34. That is, the winding needle 20 originally in the first station 31 switches to the second station 32, the winding needle 20 originally in the second station 32 switches to the third station 33, the winding needle 20 originally in the third station 33 switches to the fourth station 34, and the winding needle 20 originally in the fourth station 34 switches to the first station 31. The preset axis corresponds to the central axis of the turret 30.

[0242] Within one operation cycle (i.e., within the cycle in which the winding needle 20 rotates one circle around the preset axis), one winding needle 20 can perform the winding process of one electrode assembly 12, and four winding needles 20 can perform the winding process of four electrode assemblies 12 one-to-one. The winding process includes the steps of "sleeving the support body 125 on the outer periphery of the winding needle 20, so that the winding needle 20 is stretched and presses the support body 125 tightly" (i.e., S1) to "unloading the winding structure from the winding needle 20" (i.e., S7).

[0243] For each winding needle 20, when the winding needle 20 is located at the first station 31, the steps of "sleeving the support body 125 on the outer periphery of the winding needle 20 so that the winding needle 20 is stretched and pressed against the support body 125" (i.e., S1) are executed; and when the winding needle 20 is switched from the first station 31 to the second station 32, the steps of "fixing the winding end of the diaphragm 124 to the outer annular surface of the support body 125" (i.e., S2) to "first cutting the positive electrode sheet 123a and then cutting the negative electrode sheet 123b" (i.e., S4) are executed. ); when the winding needle 20 switches from the second station 32 to the third station 33, the step of cutting the diaphragm 124 is performed between the second station 32 and the third station 33 (i.e., S5), and then the step of "winding and finishing to form a winding structure" is performed at the third station 33 (i.e., S6); when the winding needle 20 switches from the third station 33 to the fourth station 34, the step of "unloading the winding structure from the winding needle 20" is performed (i.e., S7); at this point, the winding needle 20 can complete the winding process of the primary electrode assembly 12.

[0244] For the four winding needles 20, the winding needle 20 located at the first workstation 31 handles "loading of the support body 125", the winding needle 20 located at the second workstation 32 handles "winding of the diaphragm 124 and the electrode 123", the winding needle 20 located at the third workstation 33 handles "finishing", and the winding needle 20 located at the fourth workstation 34 handles "unloading". The actions of the four winding needles 20 at the four workstations are carried out in parallel, which can compress the waiting time and eliminate the window period of "completing one product before starting the next one" in the single winding needle mode.

[0245] By adopting the above solution, four winding needles 20 can alternately operate in a cyclic manner at the first, second, third, and fourth stations 31, 32, 33, and 34, respectively. This allows the winding process steps (i.e., S1-S7) of the electrode assembly 12 to be split into four stations for alternating operation. This allows the four winding needles 20 to operate in parallel, shortening waiting time and production cycle time. This eliminates the idle period in the single-needle winding mode where one product needs to be completed before the next one is started. This reduces equipment idle time, creates a seamless connection, and improves production capacity per unit time (theoretically, one cycle can essentially complete the winding process of four electrode assemblies 12, nearly four times the efficiency of a single winding needle). Furthermore, by splitting the steps into fixed stations, operations at each station can be specialized and optimized, allowing each station to perform the corresponding operation with high precision, stability, and accuracy. The operating parameters of each step can be easily standardized, thereby optimizing process stability and improving the consistency and yield rate of batch production.

[0246] See also Figure 20 、 Figure 24 、 Figure 30 、 Figure 31 In some embodiments of the present application, when three (or four) winding needles 20 complete a station switching, the diaphragm 124 is overlapped from the third station 33 to the outer annular surface of the support body 125 located at the second station 32, and the step of "fixing the winding end of the diaphragm 124 to the outer annular surface of the support body 125" (i.e., S2) is first performed at the second station 32, and then the step of cutting the diaphragm 124 is performed between the second station 32 and the third station 33 (i.e., S5), and then the step of "winding and finishing to form a winding structure" (i.e., S6) is performed at the third station 33.

[0247] It should be noted that this embodiment is applicable to the case where “three winding needles 20 are provided” and is also applicable to the case where “four winding needles 20 are provided”.

[0248] When three (or four) winding needles 20 complete one station switching, the diaphragm 124 will be overlapped from the third station 33 to the outer annular surface of the support body 125 located at the second station 32; in this state, the step of "fixing the winding end of the diaphragm 124 to the outer annular surface of the support body 125" (i.e., S2, which is not the same as the steps S5 and S6 described later) can be performed at the second station 32. Figure 6 The step of cutting the diaphragm 124 between the second station 32 and the third station 33 (i.e., S5, which is a step in the winding process of the same electrode assembly 12 as the step S6 described later) is performed to cut and separate the diaphragm 124 at the third station 33 and the second station 32; the step of "finishing the winding to form a winding structure" (i.e., S6) is performed at the third station 33 to complete the winding of the previous product.

[0249] By adopting the above scheme, on the basis of three (or four) alternating stations of winding needles 20, 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 off between the third station 33 and the second station 32 - the third station 33 winds and finishes", the diaphragm 124 can be seamlessly overlapped, the continuous utilization of the diaphragm 124 can be optimized, the diaphragm 124 does not need to be re-rolled at each switch, the redundant waste of the diaphragm 124 caused by each separate winding can be reduced, the material utilization rate can be improved, and the operation of "fixing the winding end of the diaphragm 124 at the second station 32" can be simplified based on the continuous overlap of the diaphragm 124, the process continuity can be improved, and the coordination of the double-station operation can be enhanced. Moreover, the sequential connection of the overlapping, fixing, cutting and finishing of the diaphragm 124 enables the second workstation 32 to start winding after fixing the diaphragm 124, and enables the third workstation 33 to use the cut diaphragm 124 for finishing at almost the same time, so that the third workstation 33 and the second workstation 32 share a section of the diaphragm 124 for time-sharing utilization, so that the "finishing" of the previous product and the "initial winding" of the next product can be carried out in parallel, which can reduce the waiting time of the workstation caused by the conflict of the allocation of the diaphragm 124 (such as the stagnation of "the previous finishing is not completed and the next winding cannot take the diaphragm 124"), thereby compressing the production rhythm and improving production efficiency.

[0250] Of course, in other embodiments, the number of winding needles 20 may be five or more, so as to subdivide and split each step (ie, S1-S7) of the winding process of the electrode assembly 12 into various workstations to achieve alternating operations and parallel operations.

[0251] See also Figure 1 、 Figure 4Some embodiments of the present application provide a battery device 1, which includes a battery cell 10 provided in an embodiment of the present application.

[0252] By adopting the above solution, the battery device 1 can improve the performance, reliability and service life by applying the battery cell 10 provided in the embodiment of the present application.

[0253] See also Figure 1 、 Figure 4 Some embodiments of the present application provide an electrical device, which includes the battery device 1 provided in an embodiment of the present application, or the battery cell 10 provided in an embodiment of the present application.

[0254] By adopting the above solution, the electrical device can improve the performance, reliability and service life by applying the battery device 1 or the battery cell 10 provided in the embodiment of the present application.

[0255] The above are merely optional embodiments of the present application and are not intended to limit the present application. For those skilled in the art, the present application may have various modifications and variations. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present application should be included within the scope of the claims of the present application.

Claims

1. A battery cell, characterized in that: The battery cell 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; The positive electrode sheet, the separator and the negative electrode sheet are wound around the outer periphery of the support body; The support body is an annular structure, the outer ring surface of the support body is fixedly connected to 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 adhered to itself via the first adhesive particles, and the hardness of the support body is greater than that of the diaphragm.

2. The battery cell according to claim 1, wherein The first adhesive particles are pressure-sensitive adhesive particles, heat-sensitive adhesive particles or heat-pressure-cooperative adhesive particles.

3. The battery cell according to claim 1, wherein The surface roughness of the inner annular surface of the support body is smaller than the surface roughness of the diaphragm.

4. The battery cell according to claim 1, wherein: The thickness of the support body from its outer annular surface to its inner annular surface is 50 μm to 500 μm.

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

6. The battery cell according to any one of claims 1 to 5, characterized in that: The outer annular surface of the support body is provided with at least one groove, and the groove depth of the groove is smaller than the thickness of the support body from the outer annular surface to the inner annular surface.

7. The battery cell according to claim 6, wherein: At least one of the grooves is a linear groove; and / or, at least one of the grooves is an annular groove; and / or, at least one of the grooves is an arc-shaped groove; And / or, at least one of the grooves is a dot-shaped groove.

8. The battery cell according to claim 6, 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.

9. The battery cell according to any one of claims 1 to 5, characterized in that: The battery cell includes a shell having a first end wall and a second end wall opposite to each other, and a side wall connected between the first end wall and the second end wall; the electrode assembly is arranged in the shell, and the electrode assembly includes a main body and a tab extending toward the first end wall to the outside of the main body, the tab is electrically isolated from the side wall, and the electrode assembly is electrically isolated from the second end wall.

10. The battery cell according to claim 9, wherein: There are multiple electrode assemblies, and the multiple electrode assemblies are arranged side by side along the first direction; In each of the electrode assemblies, the 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 component, and has a first extension portion extending toward the first end wall to the outside of the main body, and the electrode ear of each of the electrode assemblies is located between the two first extension portions and is electrically isolated from the side wall by the two first extension portions.

11. The battery cell according to claim 9, wherein: The battery cell includes an insulating shell disposed in the outer shell, the insulating shell covering the electrode assembly, and the electrode assembly is electrically isolated from the side wall and the second end wall by the insulating shell.

12. The battery cell according to claim 9, wherein: The battery cell includes a bottom supporting plate disposed in the housing, the bottom supporting plate being disposed between the electrode assembly and the second end wall, and the electrode assembly is electrically isolated from the second end wall by the bottom supporting plate.

13. The battery cell according to claim 9, wherein: The battery cell includes an insulating support member arranged in the shell, the insulating support member abuts against the side of the electrode assembly facing the second end wall, the support body of the electrode assembly has a second extension portion extending outside the main body, and the second extension portion is connected to the insulating support member.

14. The battery cell according to claim 13, wherein: The second extension portion is bent and disposed between the main body portion and the insulating support member.

15. A method for manufacturing an electrode assembly, characterized in that: The following steps are involved: The support body is sleeved on the outer periphery of the winding needle, so that the winding needle is stretched and pressed against the support body, wherein the support body is an annular structure, and the inner annular surface of the support body is provided with first adhesive particles; The rolled end of the diaphragm is fixedly connected to the outer annular surface of the support body; After the separator is wound around the periphery of the support body for a preset number of turns, the negative electrode sheet is then rolled in. When the rolled-in length of the negative electrode sheet exceeds a preset length, the positive electrode sheet is then rolled in, so that the positive electrode sheet, the separator, and the negative electrode sheet are wound around the periphery of the support body; First, the positive electrode sheet is cut, then the negative electrode sheet is cut, then the separator is cut, and then winding is performed to form a winding structure; unloading the coiled structure from the coiling needle; The wound structure is compacted so that the inner annular surface of the support body is adhered to itself via the first adhesive particles, thereby forming the flat electrode assembly.

16. The method for manufacturing an electrode assembly according to claim 15, wherein: The first adhesive particles are pressure-sensitive adhesive particles, heat-sensitive adhesive particles or heat-pressure synergistic adhesive particles; During the steps of sleeve-arranging the support body on the outer periphery of the winding needle so that the winding needle is stretched and pressed against the support body and the step of unloading the winding structure from the winding needle, the first adhesive particles are not activated; In the step of compacting the wound structure, the first adhesive particles activate adhesiveness, so that the inner annular surface of the support body is adhered to itself via the first adhesive particles.

17. The method for manufacturing an electrode assembly according to claim 15, wherein: In the step of fixedly connecting the rolled-in end of the diaphragm to the outer annular surface of the support body, the rolled-in end of the diaphragm is fixedly connected to the outer annular surface of the support body by using hot melt connection or ultrasonic welding.

18. The method for manufacturing an electrode assembly according to claim 15, wherein: The fixed connection area between the rolled-in end of the diaphragm and the outer annular surface of the support body is the 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 circumference 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.

19. The method for manufacturing an electrode assembly according to claim 15, wherein: The preset number of circles is 0.5 to 1 circle.

20. The method for manufacturing an electrode assembly according to claim 15, wherein: The preset length is 2 mm.

21. The method for manufacturing an electrode assembly according to any one of claims 15 to 20, wherein: The number of the winding needle is one, and the winding needle maintains a preset position unchanged during the winding process.

22. The method for manufacturing an electrode assembly according to any one of claims 15 to 20, wherein: There are two winding needles, and the two winding needles can rotate around a preset axis so that the two winding needles can alternately switch between the first station and the second station; wherein, in each step of the manufacturing method of the electrode assembly: The steps of sleeve-arranging the support body on the outer periphery of the winding needle, making the winding needle open and press against the support body, the steps of winding and finishing to form a winding structure, and the step of unloading the winding structure from the winding needle are performed at the first station; The steps of fixing the rolled end of the separator to the outer annular surface of the support body to first cutting the positive electrode sheet and then cutting the negative electrode sheet are performed in the second station; The step of cutting the diaphragm is performed between the second station and the first station.

23. The method for manufacturing an electrode assembly according to claim 22, wherein: When the two winding needles complete the workstation switching, the diaphragm is overlapped from the first workstation to the outer annular surface of the support body located at the second workstation, and the step of fixing the winding end of the diaphragm to the outer annular surface of the support body is first performed at the second workstation, and then the step of cutting the diaphragm is performed between the second workstation and the first workstation, and then the step of winding and finishing to form a winding structure is performed at the first workstation.

24. The method for manufacturing an electrode assembly according to any one of claims 15 to 20, wherein: There are three winding needles, which can rotate around a preset axis so that the three winding needles are cyclically alternated in the first station, the second station, and the third station, and the three winding needles are located in a one-to-one correspondence with the first station, the second station, and the third station; wherein, in each step of the manufacturing method of the electrode assembly: The step of sleeve-arranging the support body on the outer periphery of the winding needle so that the winding needle is stretched and pressed against the support body is performed at the first station; The steps of fixing the rolled end of the separator to the outer annular surface of the support body to first cutting the positive electrode sheet and then cutting the negative electrode sheet are performed in the second station; The step of cutting the diaphragm is performed between the second station and the third station; The steps of finishing the winding to form a winding structure and unloading the winding structure from the winding needle are performed at the third station.

25. The method for manufacturing an electrode assembly according to any one of claims 15 to 20, wherein: There are four winding needles, and the four winding needles can rotate around a preset axis so that the four winding needles are cyclically alternated in the first station, the second station, the third station, and the fourth station, and the four winding needles are located in a one-to-one correspondence with the first station, the second station, the third station, and the fourth station; wherein, in each step of the manufacturing method of the electrode assembly: The step of sleeve-arranging the support body on the outer periphery of the winding needle so that the winding needle is stretched and pressed against the support body is performed at the first station; The steps of fixing the rolled end of the separator to the outer annular surface of the support body to first cutting the positive electrode sheet and then cutting the negative electrode sheet are performed in the second station; The step of cutting the diaphragm is performed between the second station and the third station; The step of winding and finishing to form a winding structure is performed at the third station; The step of unloading the winding structure from the winding needle is performed at the fourth station.

26. A battery device, characterized in that: The battery device includes the battery cell according to any one of claims 1 to 14.

27. An electrical device, characterized in that: The electrical device includes the battery device according to claim 26, or the battery cell according to any one of claims 1 to 14.

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