Electrode assembly, manufacturing method and equipment thereof, battery and electric device

Abstract

The embodiment of the invention provides an electrode assembly and a manufacturing method and equipment thereof, a battery and a power utilization device, the electrode assembly is used for a battery monomer (100) and comprises a first pole piece (1) and a second pole piece (2) which are opposite in polarity, and each of the first pole piece (1) and the second pole piece (2) comprises a main body part (11) and a tab (12) protruding out of the main body part (11), the first pole piece (1) and the second pole piece (2) are wound around a winding axis (K), so that respective main body parts (11) form a winding main body (S); the end part of the winding main body (S) comprises at least one conductive region (121) and at least one liquid guide region (111), the tab (12) is led out from the conductive region (121), is wound for at least one circle and is used for being electrically connected with a terminal (1022) of a battery monomer (100), and the liquid guide region (111) and the conductive region (121) are arranged adjacently along the radial direction of the winding main body (S) and are used for guiding electrolyte to flow into the winding main body (S).

Description

[0001] This application is a divisional application of the invention patent application with the application date of September 29, 2021, the application number of 202180084755.2, and the name of "Battery cell and manufacturing method and equipment thereof, battery, and electric device". TECHNICAL FIELD

[0002] The present application relates to the technical field of batteries, in particular to an electrode assembly and a manufacturing method and equipment thereof, a battery, and an electric device. BACKGROUND

[0003] With the advantages of high energy density, high power density, multiple cycle times, and long storage time, lithium-ion batteries and other batteries have been widely used in electric vehicles.

[0004] However, improving the working performance of the battery of the electric vehicle has always been a difficult problem in the industry. SUMMARY

[0005] The purpose of the present application is to improve the performance of the battery.

[0006] According to a first aspect of the present application, an electrode assembly for a battery cell is provided, the electrode assembly comprising: a first pole piece and a second pole piece with opposite polarities, the first pole piece and the second pole piece each comprising a main body portion and a tab protruding from the main body portion, the first pole piece and the second pole piece being wound around a winding axis to form a winding main body for each of the main body portions. The end portion of the winding main body comprises at least one conductive area and at least one liquid guiding area, the tab is led out at the conductive area and wound at least one turn, and is used for electrical connection with a terminal of the battery cell, the liquid guiding area is arranged adjacent to the conductive area along the radial direction of the winding main body, and is used for guiding the electrolyte to flow into the inside of the winding main body.

[0007] The embodiment of the present application has the conductive area and the liquid guiding area at the end portion of the winding main body, since the liquid guiding area is not provided with the tab, and the tab of the conductive area is flattened, the electrolyte in the battery cell also easily flows into the inside of the winding main body through the gap between the first pole piece and the second pole piece at the liquid guiding area, the wettability of the electrode assembly is ensured, so that the electrolyte fully reacts with the active material on the first pole piece and the second pole piece in the process of charging and discharging of the battery, thereby optimizing the performance of the battery cell.

[0008] Moreover, since the tab continuously extends at least one turn around the conductive area, the tab root has good self-supporting effect due to good connection strength with the main body in the circumferential direction, so that the tab is prevented from being wrinkled during the rubbing process of applying circumferential force to the tab, the shape of the rubbed area is stable, the effect of welding the tab and the terminal is optimized, the electrode assembly reliably transmits electric energy outward, and the overcurrent capacity is improved. In addition, the particles generated during welding of the tab are not easy to fall between the first and second pole pieces of the liquid guide area in the circumferential direction, which can improve the reliability of the electrode assembly in operation and prevent short circuit or pole piece scratching.

[0009] In addition, by providing the continuous tab on part of the winding length of the main body, the overcurrent capacity of the tab can be met, and discrete tabs do not need to be provided on the entire winding length of the main body, so that the die cutting process of the pole piece can be simplified, and at the same time, when the first and second pole pieces are wound to form the winding main body, tab alignment is not required, so that the process can be simplified and the production efficiency of the electrode assembly is improved.

[0010] In some embodiments, the tab is wound multiple turns around the conductive area.

[0011] This embodiment of the present application further strengthens the support effect on the tab by winding the tab multiple turns around the conductive area and overlapping the bending portions of adjacent tabs after rubbing, so that the tab is prevented from being wrinkled during rubbing, the shape of the bending portion is stable, the effect of welding the tab and the terminal is optimized, and the welding area between the tab and the terminal after rubbing can be increased, so that the welding of the tab and the terminal is more firm, the electrode assembly reliably transmits electric energy outward, and the overcurrent capacity is improved.

[0012] In some embodiments, the number of conductive areas and liquid guide areas is greater than or equal to three, and the conductive areas and liquid guide areas are alternately arranged in the radial direction of the winding main body.

[0013] This embodiment of the present application alternately arranges at least three conductive areas and liquid guide areas in the radial direction of the winding main body, so that the electrolyte entering the inside of the winding main body from the liquid guide area can more easily reach the conductive area, which is beneficial to rapid infiltration of the electrolyte; moreover, this structure can shorten the transmission distance of electrons from the liquid guide area to the conductive area, ensure timely and effective transmission of electrons, improve the uniformity of current distribution, and prevent polarization of the electrode assembly.

[0014] In some embodiments, the conductive area is located in the middle region in the radial direction of the end portion of the winding main body, and one liquid guide area is arranged on each side of the conductive area in the radial direction.

[0015] The embodiment of the present application is provided with one liquid guiding area on each side of the conductive area along the radial direction, and the electrolyte can enter the winding main body through the two liquid guiding areas at the same time, and permeate to the part of the first and second pole pieces located in the conductive area, which can further improve the electrolyte infiltration performance of the electrode assembly. Moreover, the transmission distance of the electrons from the inner and outer liquid guiding areas to the conductive area is shortened, which can improve the current distribution uniformity and prevent polarization problems. In addition, the conductive area is provided with one, which is also convenient for the electrical connection of the tab and the terminal. The above advantages can improve the battery performance.

[0016] In some embodiments, at least one of the first and second pole pieces is provided with a plurality of tabs spaced along the winding direction to form a plurality of conductive areas spaced along the radial direction at the end of the winding main body.

[0017] The embodiment of the present application can make the electrolyte entering the winding main body through the liquid guiding area permeate to the two sides of the conductive area at the same time, so that the electrolyte smoothly reaches the part of the first and second pole pieces located in the conductive area, and improves the electrolyte infiltration performance of the electrode assembly. Moreover, the electrons can reach the conductive area from the liquid guiding area along the radial inside and outside at the same time, which can greatly shorten the electron transmission distance, improve the current distribution uniformity, and prevent polarization problems; when the first and second pole pieces are unfolded and relatively long, the design of the segmented tab can better avoid the polarization problem caused by the long local electron transmission distance. In addition, the plurality of conductive areas can prolong the overall length of the tab arranged in the radial direction, facilitate the welding of the tab and the adapter, and electrically connect the tab and the terminal through the adapter. The above advantages can improve the battery performance.

[0018] In some embodiments, the conductive area is provided with two and located at the inside and outside of the winding main body along the radial direction, and the liquid guiding area is located between the two conductive areas.

[0019] The embodiment of the present application provides two conductive areas in the non-infiltration bottleneck area, such as the inner and outer circles of the electrode assembly, which can optimize the infiltration effect and also prevent polarization problems.

[0020] In some embodiments, the conductive area and the liquid guiding area are provided with one respectively, and the conductive area is located on the radial inside of the liquid guiding area.

[0021] The embodiment of the present application provides the conductive area inside the liquid guiding area, which can prevent the tab from contacting the inner wall of the shell after the bending part is formed by kneading, or prevent particles from falling to the inner wall of the shell when the tab is welded with the terminal, so as to avoid short circuit and improve the working safety of the battery monomer.

[0022] In some embodiments, the liquid guiding areas at both ends of the winding main body have the same radial size, and the conductive areas at both ends of the winding main body have the same radial size.

[0023] The structure of the two ends of the winding main body in this embodiment of the present application is symmetrical, the first pole piece and the second pole piece can be processed into the same structure, the processing difficulty of the electrode assembly can be reduced, and the production efficiency of the electrode assembly can be improved.

[0024] In some embodiments, the liquid guiding area at one end of the winding main body has the same radial size as the electrically conductive area at the other end.

[0025] In this embodiment of the present application, the electrically conductive area and the liquid guiding area at the two ends of the winding main body are arranged radially offset, that is, the electrically conductive area at one end of the winding main body corresponds to the liquid guiding area at the other end, so that the winding main body has a liquid guiding area at any position along the radial direction, which can make the electrolyte enter the inside of the winding main body more quickly and fully, make the electrolyte in the inside of the electrode assembly more evenly distributed, and make the electrolyte and the active material on the first pole piece and the second pole piece react uniformly in the process of charging and discharging of the battery, thereby optimizing the performance of the battery monomer.

[0026] In some embodiments, the electrode assembly further comprises a separator, the separator is used to isolate the first pole piece and the second pole piece, and the separator, the main body part of the first pole piece and the main body part of the second pole piece are wound to form a winding main body. In the extension direction of the winding axis, the part of the separator located in the liquid guiding area exceeds the side edges of the main body part of the first pole piece and the main body part of the second pole piece.

[0027] In this embodiment of the present application, the separator is designed in a stepped shape and widened in the liquid guiding area, which can make the side edges of the separator extend outward between the first pole piece and the second pole piece in the liquid guiding area and be soaked in the electrolyte, thereby making the separator more easily absorb the electrolyte under capillary action, improving the wetting performance of the electrode assembly, and further improving the performance of the battery monomer.

[0028] In some embodiments, the electrode assembly further comprises a separator, the separator is used to isolate the first pole piece and the second pole piece, and the main body part of at least one of the first pole piece and the second pole piece comprises an active material area and a flow guiding area arranged side by side along the extension direction of the winding axis, the flow guiding area is located outside the active material area, and the gap between the surface of the main body part located in the flow guiding area and the separator is greater than the gap between the surface of the main body part located in the active material area and the separator.

[0029] In this embodiment of the present application, the gap between the surface of the main body part located in the flow guiding area and the separator is greater than the gap between the surface of the main body part located in the active material area and the separator, which can form a larger capillary gap between the flow guiding area and the separator, after the electrolyte is absorbed by the end part of the separator, the electrolyte can quickly enter the end part of the winding main body and further enter the active material area to react with the active material. This structure makes the gap between the main body part and the separator gradually decrease from the outside to the inside, which facilitates the electrolyte to enter quickly.

[0030] In some embodiments, the flow guiding area of at least one of the first and second electrode tabs comprises a wicking area adjacent to the active material area, and the gap between the surface of the wicking area of the main body and the separator gradually increases from inside to outside along the extension direction of the winding axis.

[0031] This embodiment of the present application can introduce electrolyte into the active material area through the wicking area after the electrolyte is absorbed by the end of the separator, so as to facilitate the electrolyte to quickly enter the inside of the winding main body to react.

[0032] In some embodiments, the flow guiding area of at least one of the first and second electrode tabs comprises a wicking area adjacent to the active material area, and the main body of at least one of the first and second electrode tabs comprises a current collector, an active material layer and a wicking layer, the active material layer is arranged on the surface of the current collector and located in the active material area, and the wicking layer is arranged on the surface of the current collector and located in the wicking area, and the liquid absorption capacity of the wicking layer is higher than that of the active material layer.

[0033] This embodiment of the present application can improve the ability of the winding main body to absorb electrolyte at the end by coating the wicking layer with a higher liquid absorption capacity on the area close to the outside of the main body, so as to quickly absorb the electrolyte into the inside of the winding main body.

[0034] In some embodiments, the wicking layer comprises an inorganic ceramic coating, a high polymer and an adhesive.

[0035] In some embodiments, the flow guiding area of at least one of the first and second electrode tabs further comprises a guiding area, and the area of the current collector beyond the wicking layer along the extension direction of the winding axis forms the guiding area.

[0036] In this embodiment of the present application, no coating layer is arranged in the guiding area, so that the gap between the current collector and the separator in the guiding area is larger than the gap between the surface of the wicking layer and the separator, a multi-stage channel for absorbing electrolyte can be formed at the end of the winding main body located in the flow guiding area, and the distance between the first or second electrode tab and the separator gradually decreases from the guiding area, the wicking area to the active material area, which can significantly improve the liquid absorption efficiency, improve the wicking properties of the electrode assembly, and thus improve the performance of the battery cell.

[0037] In some embodiments, the first electrode tab is a positive electrode tab and sequentially comprises the active material area, the wicking area and the guiding area from inside to outside along the extension direction of the winding axis, and the second electrode tab is a negative electrode tab and sequentially comprises the active material area and the guiding area from inside to outside along the extension direction of the winding axis.

[0038] The embodiment of the present application considers that the compaction density of the positive electrode tab is large, and the electrolyte enters the positive electrode tab at a slow speed. By adding a wettability area to the positive electrode tab, the speed of the electrolyte penetrating into the positive active material can be accelerated. The speed of the electrolyte entering the negative electrode tab is relatively fast compared with the positive electrode tab. By guiding the electrolyte into the negative electrode tab only through the guide area, the manufacturing process of the negative electrode tab can be simplified. The embodiment can not only make the speed of the electrolyte entering the positive electrode tab and the negative electrode tab close, but also reduce the production difficulty of the electrode assembly.

[0039] In some embodiments, the separator is located at the side of the liquid guide area of at least one of the first electrode tab and the second electrode tab, between the outer side of the liquid guide area and the outer side of the tab.

[0040] The embodiment of the present application makes the side of the separator beyond the outer side of the liquid guide area, so that the protruding part of the separator can be soaked in the electrolyte to absorb the electrolyte by capillary action. Moreover, the side of the separator does not exceed the outer side of the tab, which can prevent the separator from protruding too long in the conductive area to affect the tab flattening, and ensure the conductive effect of the tab.

[0041] In some embodiments, the extension length of the liquid guide area around the winding body is consistent with the active material area.

[0042] The embodiment of the present application can reduce the manufacturing difficulty of the electrode tab with the liquid guide area, and the extension length of the liquid guide area is consistent with the active material area, which can guide the electrolyte to reach the active material area in the entire coating length of the active material area, so that the electrolyte is uniformly distributed in the entire winding length of the electrode tab, thereby improving the performance of the battery cell.

[0043] According to a second aspect of the present application, a battery cell is provided, comprising: a shell having an opening; an end cover assembly for closing the opening, the end cover assembly comprising an end cover body and a terminal provided on the end cover body; and the electrode assembly of the above embodiments, provided in the shell, the tab of the first electrode tab or the tab of the second electrode tab being electrically connected with the terminal.

[0044] In the battery cell of the embodiment of the present application, since the electrode assembly has good wettability characteristics, and the tab and the terminal have high electrical connection reliability, the performance of the battery cell can be improved.

[0045] According to a third aspect of the present application, a battery is provided, comprising: the battery cell of the above embodiments; and a box body for accommodating the battery cell.

[0046] According to a fourth aspect of the present application, a power utilization device is provided, comprising the battery of the above embodiments, the battery being used to provide electric energy for the power utilization device.

[0047] According to a fifth aspect of the present application, a manufacturing method of an electrode assembly is provided, comprising: The first and second polar pieces are provided, and each of the first and second polar pieces includes a main body portion and a tab protruding from the main body portion; The first and second polar pieces are wound around a winding axis to form a winding main body with the respective main body portions, and an end portion of the winding main body includes at least one conductive region and at least one liquid guiding region; The tab is led out at the conductive region and wound at least one turn, and is used to be electrically connected with a terminal of a battery cell. The liquid guiding region is arranged adjacent to the conductive region along a radial direction of the winding main body, and is used to guide electrolyte to flow into an inside of the winding main body.

[0048] According to a sixth aspect of the present application, a manufacturing device of a battery is provided, including: A polar piece providing device configured to provide first and second polar pieces with opposite polarities, and each of the first and second polar pieces includes a main body portion and a tab protruding from the main body portion; and A polar piece winding device configured to wind the first and second polar pieces around a winding axis to form a winding main body with the respective main body portions, and an end portion of the winding main body includes at least one conductive region and at least one liquid guiding region; The tab is led out at the conductive region and wound at least one turn, and is used to be electrically connected with a terminal of a battery cell. The liquid guiding region is arranged adjacent to the conductive region along a radial direction of the winding main body, and is used to guide electrolyte to flow into an inside of the winding main body. BRIEF DESCRIPTION OF DRAWINGS

[0049] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following will briefly introduce the drawings needed to be used in the embodiments of the present application. Obviously, the drawings described below are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without any creative effort on the basis of the drawings.

[0050] Figure 1 The structure diagram of some embodiments of the present application in which the battery is installed in a vehicle.

[0051] Figure 2 The exploded view of some embodiments of the battery of the present application.

[0052] Figure 3 The structure diagram of some embodiments of the battery cell in the battery of the present application.

[0053] Figure 4 The first exploded view of some embodiments of the battery cell in the battery of the present application.

[0054] Figure 5 The second exploded view of some embodiments of the battery cell in the battery of the present application.

[0055] Figure 6FIG. 1 is a cross-sectional view of a first embodiment of a battery of the present application.

[0056] Figure 7 FIG. 2 is a cross-sectional view of a second embodiment of a battery of the present application. Figure 6 FIG. 3 is a schematic view of the end face of the electrode assembly in the battery of FIG. 2.

[0057] Figure 8 FIG. 4 is a cross-sectional view of a third embodiment of a battery of the present application.

[0058] Figure 9 FIG. 5 is a schematic view of the end face of the electrode assembly in the battery of FIG. 4. Figure 8

[0059] FIG. 6 is a cross-sectional view of a fourth embodiment of a battery of the present application. Figure 10

[0060] FIG. 7 is a schematic view of the end face of the electrode assembly in the battery of FIG. 6. Figure 11 Figure 10 FIG. 8 is a schematic view of the end face of the electrode assembly in the battery of FIG. 7.

[0061] Figure 12A Figure 12B FIG. 9 is a schematic view of the end face of the electrode assembly in the battery of FIG. 8. Figure 12C

[0062] FIG. 10 is a schematic view of the end face of the electrode assembly in the battery of FIG. 9. Figure 13A Figure 13B Figure 13C FIG. 11 is a schematic view of the end face of the electrode assembly in the battery of FIG. 10.

[0063] Figure 14A FIG. 12 is a schematic view of the end face of the electrode assembly in the battery of FIG. 11. Figure 14B Figure 14C FIG. 13 is a schematic view of the end face of the electrode assembly in the battery of FIG. 12.

[0064] Figure 15 Figure 6 FIG. 14 is a schematic view of the end face of the electrode assembly in the battery of FIG. 13.

[0065] Figure 16 FIG. 15 is a schematic view of the end face of the electrode assembly in the battery of FIG. 14. Figure 8

[0066] FIG. 16 is a schematic view of the end face of the electrode assembly in the battery of FIG. 15. Figure 17

[0067] FIG. 17 is a schematic view of the end face of the electrode assembly in the battery of FIG. 16. Figure 18

[0068] FIG. 18 is a schematic view of the end face of the electrode assembly in the battery of FIG. 17. Figure 19 FIG. 19 is a schematic view of the end face of the electrode assembly in the battery of FIG. 18.​​​​​​

[0069] Figure 20 Flowchart of some embodiments of the electrode assembly manufacturing method of the present application.

[0070] Figure 21 Block diagram of some embodiments of the electrode assembly manufacturing device of the present application.

[0071] In the drawings, the drawings are not drawn according to the actual scale.

[0072] Label explanation: 10, electrode assembly; 1, first tab; 11, main body; 111, liquid guiding area; 112, active material layer; 113, impregnated layer; 114, current collector; 12, tab; 121, conductive area; 122, transition part; 2, second tab; 3, separator; 100, battery cell; 101, shell; 1011, opening; 102, end cap assembly; 1021, end cap body; 1022, terminal; 1023, pressure relief component; 1024, insulating piece; 1024', protruding part; 1025, adapter; 1025A, first connecting piece; 1025B, second connecting piece; 200, battery; 201, box body; 201A, containing part; 201B, first cover body; 201C, second cover body; 300, vehicle; 301, axle; 302, wheel; 303, motor; 304, controller; 400, manufacturing equipment; 410, tab providing device; 420, tab winding device; S, winding main body; K, winding axis; A, active material area; B, flow guiding area; B1, impregnated area; B2, guiding area. DETAILED DESCRIPTION

[0073] The embodiments of the present application will be further described in detail below with reference to the drawings and examples. The detailed description of the following examples and drawings are used to exemplarily illustrate the principles of the present application, but cannot be used to limit the scope of the present application, i.e., the present application is not limited to the described examples.

[0074] In the description of the present application, it should be noted that, unless otherwise specified, the meaning of "a plurality of" is more than two; the orientations or positional relationships indicated by the terms "upper", "lower", "left", "right", "inner", "outer" and the like only serve to facilitate the description of the present application and simplify the description, and do not indicate or imply that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the present application.

[0075] In addition, the terms "first", "second", "third", and the like are used only for descriptive purposes and do not denote or imply relative importance. "Vertical" is not strictly vertical, but within the range of error. "Parallel" is not strictly parallel, but within the range of error. The orientation words appearing in the following description are the directions shown in the drawings, and are not limited to the specific structure of the present application.

[0076] In the description of the present application, it should also be noted that unless otherwise explicitly specified and limited, the terms "mounting", "connecting", "connection" should be understood broadly, for example, it can be fixed connection, or detachable connection, or integrally connected; it can be directly connected, or indirectly connected through an intermediate medium. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0077] Reference herein to "an embodiment" means that a particular feature, structure, or characteristic described in connection with the embodiment can be included in at least one embodiment of the application. The appearances of the phrase in various places in the specification are not necessarily all referring to the same embodiment, nor are they necessarily mutually exclusive or alternative embodiments. It will be explicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0078] In the description of the embodiments of the present application, the term "a plurality of" refers to more than two (including two), and similarly, "a plurality of groups" refers to more than two groups (including two groups), and "a plurality of pieces" refers to more than two pieces (including two pieces).

[0079] The present application uses the description of the orientation or position relationship indicated by "upper", "lower", "top", "bottom", "front", "rear", "inner" and "outer" and the like. This is only for the convenience of describing the present application, and is not intended to indicate or imply that the device must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the scope of protection of the present application.

[0080] The battery cell can include a lithium ion secondary battery, a lithium ion primary battery, a lithium-sulfur battery, a sodium lithium ion battery, a sodium ion battery, or a magnesium ion battery, etc. The embodiments of the present application are not limited thereto. The battery cell can be in the shape of a cylinder, a flat body, a cuboid, or other shapes, etc. The embodiments of the present application are also not limited thereto. The battery cell is generally divided into three types according to the packaging method: cylindrical battery cell, square battery cell, and soft package battery cell, and the embodiments of the present application are also not limited thereto.

[0081] The current battery cell generally comprises a shell and an electrode assembly contained in the shell, and is filled with an electrolyte in the shell. The electrode assembly is mainly formed by laminating or winding a first pole piece and a second pole piece with opposite polarities, and generally a separator is arranged between the first pole piece and the second pole piece. The part of the first pole piece and the second pole piece coated with active material constitutes a main body part of the electrode assembly, and the part of the first pole piece and the second pole piece not coated with active material respectively constitutes a first pole tab and a second pole tab. In a lithium ion battery, the first pole piece can be a positive pole piece, comprising a positive pole current collector and positive pole active material layers arranged on both sides of the positive pole current collector, the material of the positive pole current collector can be, for example, aluminum, and the positive pole active material can be, for example, lithium cobaltate, lithium iron phosphate, ternary lithium or lithium manganate, etc.; the second pole piece can be a negative pole piece, comprising a negative pole current collector and negative pole active material layers arranged on both sides of the negative pole current collector, the material of the negative pole current collector can be, for example, copper, and the negative pole active material can be, for example, graphite or silicon, etc. The first pole tab and the second pole tab can be located at one end of the main body part together or at two ends of the main body part respectively. In the charging and discharging process of the battery cell, the positive pole active material and the negative pole active material react with the electrolyte, and the pole tabs are connected to the terminals to form a current loop.

[0082] In the processing and assembly procedure of the electrode assembly, if the pole pieces are welded after being wound, the gap between the adjacent pole tabs is large, the whole is relatively fluffy, and false welding will occur during laser welding, resulting in the phenomenon of burst points, so it is often necessary to perform rubbing treatment on the pole tabs to make the pole tabs bend and deform and the adjacent pole tabs more compact, so as to facilitate the connection of the pole tabs with the terminals and the assembly of the battery cell. In order to facilitate the application of external force to the pole tabs along the circumferential direction of the electrode assembly for rubbing, the pole tabs are generally designed to continuously extend along the entire winding length of the pole pieces.

[0083] The inventors of the present application have found in practice that the rubbing treatment of the pole tabs causes the end portions of the two adjacent pole tab layers in the laminated structure to abut together and form a closed structure, which to some extent hinders the passage of the electrolyte from the outside space of the pole tabs into the main body part, adversely affects the wetting effect of the electrolyte on the active material in the electrode assembly, causes the positive or negative active material to not fully participate in the reaction, and may affect the efficiency of the electrode assembly, thereby affecting the performance of the battery.

[0084] Therefore, the wetting effect of the electrolyte on the active material in the electrode assembly is an important factor to ensure the high performance of the battery. The inventors want to improve the wetting effect by changing the material or the hierarchical structure of the separator, but this will increase the cost of the electrode assembly and make the preparation process more complex.

[0085] Another idea is to die-cut the continuous tab to form a plurality of discrete tabs, which are wound to form a stack of tabs. After the tabs are flattened, there are tab areas and non-tab areas in the circumferential direction of the electrode assembly. The non-tab areas are convenient for infiltrating electrolyte, and the tab areas are used for connecting terminals. However, after the tab is die-cut and then flattened, there is a wrinkling phenomenon. Moreover, because the tab material is relatively soft, a self-supporting effect cannot be formed at the root of the tab when a circumferential force is applied during tab flattening, so that the flattened area cannot be flattened well, which affects the subsequent welding effect. Moreover, particles generated during tab welding can easily fall between the tab-free areas of the tab.

[0086] Based on the discovery of the above problems, the inventors of the present application have improved the structural design of the electrode assembly to improve the infiltration effect of the electrolyte on the active material in the electrode assembly and improve the performance of the battery. Various embodiments of the present application will be further described below with reference to the accompanying drawings. The electric device includes a battery for providing electric energy for the device, and the device can be a mobile phone, a portable device, a notebook computer, an electric vehicle, an electric vehicle, a ship, a spacecraft, an electric toy and an electric tool, etc. For example, the spacecraft includes an airplane, a rocket, a space shuttle and a spacecraft, etc. The electric toy includes a fixed or mobile electric toy, for example, a game console, an electric car toy, an electric ship toy and an electric plane toy, etc. The electric tool includes a metal cutting electric tool, a grinding electric tool, an assembly electric tool and a railway electric tool, for example, a power drill, a power grinder, a power wrench, a power screwdriver, an electric hammer, an impact drill, a concrete vibrator and an electric planer.

[0087] As shown in Figure 1 The electric device can be a vehicle 300, for example, a new energy vehicle, which can be a pure electric vehicle, a hybrid electric vehicle or an extended range vehicle, etc. Alternatively, the electric device can be a drone or a ship, etc. Specifically, the vehicle 300 can include an axle 301, a wheel 302 connected to the axle 301, a motor 303, a controller 304 and a battery 200. The motor 303 is used to drive the axle 301 to rotate, the controller 304 is used to control the operation of the motor 303, and the battery 200 can be arranged at the bottom, head or tail of the vehicle 300, and is used to provide electric energy for the operation of the motor 303 and other components in the vehicle.

[0088] As shown in Figure 2As shown, battery 200 includes a housing 201 and battery cells 100. Battery 200 can contain one or more battery cells 100. If there are multiple battery cells 100, they can be connected in series, parallel, or a combination thereof. A combination connection means that multiple battery cells 100 can be connected in both series and parallel configurations. This can be achieved by first connecting multiple battery cells 100 in series, parallel, or a combination thereof to form a battery module, and then connecting multiple battery modules in series, parallel, or a combination thereof to form a whole, which is then housed within the housing 201. Alternatively, all battery cells 100 can be directly connected in series, parallel, or a combination thereof, and then the whole formed by all battery cells 100 is housed within the housing 201.

[0089] The housing 201 is hollow inside, used to accommodate one or more battery cells 100. Depending on the shape, number, arrangement, and other requirements of the battery cells 100 accommodated, the housing 201 may also have different shapes and sizes. For example, the housing 201 may include: a receiving portion 201A, a first cover 201B, and a second cover 201C. The receiving portion 201A has openings at both opposite ends, and the first cover 201B and the second cover 201C are respectively used to close the openings at both ends of the receiving portion 201A. Figure 2 According to the arrangement of multiple battery cells 100, the receiving part 201A has a rectangular cylindrical structure.

[0090] like Figure 3 As shown, the battery cell 100 includes a housing 101, an end cap assembly 102, and an electrode assembly 10. The battery cell 100 can be, for example, a lithium-ion secondary battery, a lithium-ion primary battery, a lithium-sulfur battery, a sodium-lithium-ion battery, or a magnesium-ion battery.

[0091] The housing 101 is a hollow structure used to accommodate the electrode assembly 10, and the housing 101 has an opening 1011; the end cap assembly 102 is used to close the opening 1011, the end cap assembly 102 includes an end cap body 1021 and a terminal 1022 provided on the end cap body 1021, and the end cap body 1021 is also provided with a pressure relief component 1023 for depressurizing when the internal pressure of the battery cell 100 exceeds a preset pressure.

[0092] Figure 3 The illustration shows an embodiment with only one electrode assembly 10. Those skilled in the art should understand that in other embodiments, the battery cell 100 may also include multiple electrode assemblies 10, and the terminal 1022 may also be designed according to the number and arrangement of the electrode assemblies 10. Furthermore, depending on the shape and placement of the electrode assemblies 10, and the combination of multiple electrode assemblies 10, the housing 101 may be cylindrical, flat, cuboid, or other shapes. like Figure 4As shown, the electrode assembly 10 is disposed within the housing 101. Both the first and second electrode plates, with opposite polarities, have tabs 12. The tabs 12 of either the first or second electrode plate are electrically connected to the terminal 1022. The end cap assembly 102 may further include an adapter 1025, which is disposed between the end cap body 1021 and the electrode assembly 10, for realizing the electrical connection between the tabs 12 and the terminal 1022. Figure 5 As shown, in order to achieve insulation between the end cap body 1021 and the adapter 1025, the end cap assembly 102 may also include an insulating member 1024 disposed between the end cap body 1021 and the adapter 1025.

[0093] exist Figure 4 and Figure 5 In the illustrated embodiment, the housing 101 of the battery cell 100 is a hollow cylinder with openings 1011 at both ends, both openings 1011 being closed by end cap assemblies 102. The electrode assembly 10 can be inserted into the housing 101 through the openings 1011. The first electrode and the second electrode are wound to form a cylindrical electrode assembly 10. The tabs 12 of the first electrode and the second electrode are respectively led out from both ends of the electrode assembly 10 along the axial direction, and are electrically connected to the terminals 1022 of the corresponding ends through adapters 1025.

[0094] In other alternative embodiments, the housing 101 of the battery cell 100 is a hollow cylinder, closed at one end and with an opening 1011 at the other end, which is closed by the end cap assembly 102. The first electrode and the second electrode are wound to form a cylindrical electrode assembly 10. The tabs 12 of the first electrode and the second electrode are respectively led out from both ends of the electrode assembly 10 along the axial direction. The tab 12 of the first electrode, such as the negative electrode, is electrically connected to the terminal 1022 through the adapter 1025. The tab 12 of the second electrode, such as the positive electrode, is directly electrically connected to the end wall of the housing 101.

[0095] The structure of the electrode assembly 10 will be described in detail below.

[0096] In some embodiments, such as Figures 6 to 11 As shown, the electrode assembly 10 is used for the battery cell 100. The electrode assembly 10 includes a first electrode 1 and a second electrode 2 with opposite polarities. Both the first electrode 1 and the second electrode 2 include a main body portion 11 and an electrode tab 12 protruding from the main body portion 11. The first electrode 1 and the second electrode 2 are wound around the winding axis K so that their respective main body portions 11 form a wound body S.

[0097] The end of the winding body S comprises at least one conductive area 121 and at least one liquid guiding area 111, the tab 12 is led out from the conductive area 121 and wound at least one turn, and is used for electrically connecting with the terminal 1022 of the battery monomer 100, the liquid guiding area 111 is arranged adjacent to the conductive area 121 along the radial direction of the winding body S, and is used for guiding the electrolyte to flow into the inside of the winding body S.

[0098] The first and second pole pieces 1 and 2 have substantially the same shape, which can be a long strip-shaped structure, the first and second pole pieces 1 and 2 are arranged in a stacking manner along the direction perpendicular to the winding axis K, and the formed winding body S can be a cylinder, a flat body, a cuboid or other shapes. For example, the first pole piece 1 is a positive pole piece, and the second pole piece 2 is a negative pole piece; or the first pole piece 1 is a negative pole piece, and the second pole piece 2 is a positive pole piece. The electrode assembly 10 further comprises a diaphragm 3, which is used for isolating the first and second pole pieces 1 and 2, and the diaphragm 3, the main body part 11 of the first pole piece 1 and the main body part of the second pole piece 2 are wound to form the winding body S.

[0099] Optionally, one end of the winding body S comprises at least one conductive area 121 and at least one liquid guiding area 111, the tab 12 is led out from the conductive area 121 and wound at least one turn, so that the conductive area 121 and the liquid guiding area 111 form a ring-shaped structure, the tab 12 is flattened to form a bending part, and is electrically connected with the terminal 1022 of the battery monomer 100 through the bending part, for example, by welding. In the unfolded state of the first or second pole piece 1 or 2, the tab 12 can be arranged in the middle region, the end region or other regions of the pole piece.

[0100] The liquid guiding area 111 is not provided with the tab 12, and the gap between the first or second pole piece 1 or 2 and the diaphragm 3 is in communication with the outside of the electrode assembly 10, so that the electrolyte is more easily allowed to flow into the inside of the winding body S from the gap between the first or second pole piece 1 or 2 and the diaphragm 3, and the diaphragm 3 can fully play a liquid absorption role to allow the electrolyte to fully react with the active material on the first and second pole pieces 1 and 2 in the process of charging and discharging of the battery.

[0101] Optionally, both ends of the winding body S comprise at least one conductive area 121 and at least one liquid guiding area 111, and the electrolyte can be infiltrated from the liquid guiding areas 111 at both ends of the winding body S to the inside, so that the infiltration path of the electrolyte can be shortened, and the liquid absorption effect can be improved.

[0102] In this embodiment of the application, the end of the winding body S has both a conductive region 121 and a liquid guiding region 111. Since the liquid guiding region 111 is not provided with tabs 12, after the tabs 12 of the conductive region 121 are flattened, the electrolyte in the battery cell 100 can also easily flow into the interior of the winding body S through the gap between the first electrode 1 and the second electrode 2 in the liquid guiding region 111, ensuring the wetting performance of the electrode assembly 10, so that the electrolyte can fully react with the active materials on the first electrode 1 and the second electrode 2 during the charging and discharging process of the battery, thereby optimizing the performance of the battery cell 100.

[0103] Furthermore, since the tab 12 extends continuously and wraps around the conductive area 121 at least once, it has good connection strength with the main body 11 in the circumferential direction, giving the root of the tab 12 a good self-supporting effect. During the process of applying circumferential force to flatten the tab 12, wrinkling of the tab 12 is prevented, the shape of the flattened area is stabilized, the welding effect of the tab 12 and the terminal 1022 is optimized, ensuring that the electrode assembly 10 reliably transmits electrical energy and improves the current carrying capacity. In addition, particles generated during the welding of the tab 12 are less likely to fall circumferentially between the first electrode 1 and the second electrode 2 in the liquid guiding area 111, which can improve the reliability of the electrode assembly 10 and prevent short circuits or electrode scratches.

[0104] Furthermore, by providing continuous tabs 12 along a portion of the winding length of the main body 11, the current carrying capacity of the tabs 12 can be met, eliminating the need to provide discrete tabs 12 along the entire winding length of the main body 11. This simplifies the die-cutting electrode sheet process. Additionally, when the first electrode sheet 1 and the second electrode sheet are wound to form the winding body S, there is no need to address the tab 12 alignment issue, which simplifies the process and improves the production efficiency of the electrode assembly 10.

[0105] In some embodiments, such as Figures 6 to 11 As shown, the tab 12 is wound multiple times in the conductive region 121. The tab 12 can be wound at least two times, for example, to achieve a better self-supporting effect, the number of turns is at least five. The number of turns can be designed according to the current carrying capacity and polarization of the electrode assembly 10.

[0106] This embodiment of the application further strengthens the support of the tabs 12 by winding the tabs 12 multiple times in the conductive area 121 and flattening them so that the bent portions of adjacent tabs 12 overlap each other. This prevents the tabs 12 from wrinkling and flattening, stabilizes the shape of the bent portions, and optimizes the welding effect between the tabs 12 and the terminal 1022. Moreover, it can also increase the welding area between the flattened tabs 12 and the terminal 1022, making the welding between the tabs 12 and the terminal 1022 more secure, ensuring that the electrode assembly 10 reliably transmits electrical energy to the outside, and improving the overcurrent capacity.

[0107] In some embodiments, the number of the conductive regions 121 and the liquid conducting regions 111 is greater than or equal to three, and they are arranged alternately along the radial direction of the winding body S. For example, as shown in Figs. 1 and 2, one conductive region 121 and two liquid conducting regions 111 are arranged alternately along the radial direction of the winding body S; as shown in Figs. 3 and 4, two conductive regions 121 and one liquid conducting region 111 are arranged alternately along the radial direction of the winding body S. Figure 6 and Figure 7 For example, as shown in Figs. 1 and 2, one conductive region 121 and two liquid conducting regions 111 are arranged alternately along the radial direction of the winding body S; as shown in Figs. 3 and 4, two conductive regions 121 and one liquid conducting region 111 are arranged alternately along the radial direction of the winding body S. Figure 8 and Figure 9 For example, as shown in Figs. 1 and 2, one conductive region 121 and two liquid conducting regions 111 are arranged alternately along the radial direction of the winding body S; as shown in Figs. 3 and 4, two conductive regions 121 and one liquid conducting region 111 are arranged alternately along the radial direction of the winding body S.

[0108] In some embodiments, the number of the conductive regions 121 and the liquid conducting regions 111 is greater than or equal to three, and they are arranged alternately along the radial direction of the winding body S. For example, as shown in Figs. 1 and 2, one conductive region 121 and two liquid conducting regions 111 are arranged alternately along the radial direction of the winding body S; as shown in Figs. 3 and 4, two conductive regions 121 and one liquid conducting region 111 are arranged alternately along the radial direction of the winding body S.

[0109] In some embodiments, the number of the conductive regions 121 and the liquid conducting regions 111 is greater than or equal to three, and they are arranged alternately along the radial direction of the winding body S. For example, as shown in Figs. 1 and 2, one conductive region 121 and two liquid conducting regions 111 are arranged alternately along the radial direction of the winding body S; as shown in Figs. 3 and 4, two conductive regions 121 and one liquid conducting region 111 are arranged alternately along the radial direction of the winding body S. Figure 6 and Figure 7 For example, as shown in Figs. 1 and 2, one conductive region 121 and two liquid conducting regions 111 are arranged alternately along the radial direction of the winding body S; as shown in Figs. 3 and 4, two conductive regions 121 and one liquid conducting region 111 are arranged alternately along the radial direction of the winding body S.

[0110] For example, as shown in Figs. 1 and 2, one conductive region 121 and two liquid conducting regions 111 are arranged alternately along the radial direction of the winding body S; as shown in Figs. 3 and 4, two conductive regions 121 and one liquid conducting region 111 are arranged alternately along the radial direction of the winding body S.

[0111] In some embodiments, the number of the conductive regions 121 and the liquid conducting regions 111 is greater than or equal to three, and they are arranged alternately along the radial direction of the winding body S. For example, as shown in Figs. 1 and 2, one conductive region 121 and two liquid conducting regions 111 are arranged alternately along the radial direction of the winding body S; as shown in Figs. 3 and 4, two conductive regions 121 and one liquid conducting region 111 are arranged alternately along the radial direction of the winding body S.

[0112] In some embodiments, the number of the conductive regions 121 and the liquid conducting regions 111 is greater than or equal to three, and they are arranged alternately along the radial direction of the winding body S. For example, as shown in Figs. 1 and 2, one conductive region 121 and two liquid conducting regions 111 are arranged alternately along the radial direction of the winding body S; as shown in Figs. 3 and 4, two conductive regions 121 and one liquid conducting region 111 are arranged alternately along the radial direction of the winding body S. Figure 8 and Figure 9 For example, as shown in Figs. 1 and 2, one conductive region 121 and two liquid conducting regions 111 are arranged alternately along the radial direction of the winding body S; as shown in Figs. 3 and 4, two conductive regions 121 and one liquid conducting region 111 are arranged alternately along the radial direction of the winding body S.

[0113] In the extension direction of the winding axis K, two or more tabs 12 are arranged on one side of the main body 11 of at least one of the first and second pole pieces 1 and 2, and each tab 12 forms a conductive area 121 at the end of the winding body S. For example, the number of segments of the tab 12 can be no more than 10 segments, depending on the length of the pole piece. This embodiment of the application can make the electrolyte entering the inside of the winding body S through the liquid guide area 111 permeate to the two side conductive areas 121 at the same time, so that the electrolyte smoothly reaches the part of the first and second pole pieces 1 and 2 located in the conductive area 121, and improves the electrolyte infiltration performance of the electrode assembly 10. Moreover, the electrons from the liquid guide area 111 can reach the conductive area 121 along the radial inside and the radial outside at the same time, which can greatly shorten the electron transmission distance, improve the current distribution uniformity, and prevent polarization problems; when the first and second pole pieces 1 and 2 are unfolded and relatively long, the design of the segmented tab 12 can better avoid the polarization problem caused by the long local electron transmission distance. In addition, the arrangement of multiple conductive areas 121 can prolong the overall length of the tab 12 arranged in the radial direction, facilitate the welding of the tab 12 and the adapter 1025, and electrically connect the tab 12 and the terminal 1022 through the adapter 1025. The above advantages can improve the performance of the battery.

[0114] In some embodiments, as Figure 8 and Figure 9 , the conductive area 121 is provided with two and is located on the inner side and the outer side of the radial direction of the end of the winding body S, and the liquid guide area 111 is located between the two conductive areas 121.

[0115] Because the infiltration speed of the electrode assembly 10 at different positions is different, for example, the electrolyte infiltration of the part of the electrode assembly 10 closest to the inner circle and the part closest to the outer circle is relatively easy, the electrolyte of the inner circle has a center tube for flow guide, and the electrolyte of the outer circle has a gap between the shell 101 and the electrode assembly 10 for contact, therefore, the inner and outer circles of the electrode assembly 10 are more easily immersed in the electrolyte than the middle region.

[0116] This embodiment of the application provides two conductive areas 121 in the non-infiltration bottleneck region, for example, the inner circle and the outer circle of the electrode assembly 10, which can optimize the infiltration effect and also prevent polarization problems.

[0117] In some embodiments, as Figure 10 and Figure 11 , the conductive area 121 and the liquid guide area 111 are provided with one respectively, and the conductive area 121 is located on the radial inner side of the liquid guide area 111. For example, the radial width of the conductive area 121 can be greater than that of the liquid guide area 111, so as to improve the flow capacity of the electrode assembly 10.

[0118] The embodiment of the present application sets the conductive area 121 inside the liquid guiding area 111, which can prevent the tab 12 from contacting the inner wall of the shell 101 after the bending part is formed by rubbing, or prevent particles from falling to the inner wall of the shell 101 when the tab 12 is welded with the terminal 1022, so as to avoid short circuit and improve the working safety of the battery monomer 100, on the basis of ensuring the soaking characteristics of the electrode assembly 10 by the liquid guiding area 111.

[0119] In some embodiments, the liquid guiding area 111 at both ends of the winding body S has the same radial size, and the conductive area 121 at both ends of the winding body S has the same radial size. Wherein, the tabs 12 of the first and second pole pieces 1 and 2 are drawn from both ends of the winding body S, and the winding body S is provided with the conductive area 121 and the liquid guiding area 111 at both ends, and the "radial size" includes the radial position and the radial size.

[0120] The structure of the winding body S at both ends in the embodiment of the present application is symmetrical, the first and second pole pieces 1 and 2 can be processed into the same structure, which can reduce the processing difficulty of the electrode assembly 10 and improve the production efficiency of the electrode assembly 10.

[0121] In other embodiments, the liquid guiding area 111 at one end of the winding body S has the same radial size as the conductive area 121 at the other end. Wherein, the tabs 12 of the first and second pole pieces 1 and 2 are drawn from both ends of the winding body S, and the winding body S is provided with the conductive area 121 and the liquid guiding area 111 at both ends, and the "radial size" includes the radial position and the radial size.

[0122] In the embodiment of the present application, the conductive area 121 and the liquid guiding area 111 at both ends of the winding body S are arranged in a radial position, that is, the conductive area 121 at one end of the winding body S corresponds to the liquid guiding area 111 at the other end, so that the winding body S has the liquid guiding area 111 at any position in the radial direction, which can make the electrolyte enter the inside of the winding body S more quickly and fully, and make the electrolyte in the electrode assembly 10 more evenly distributed, so that the electrolyte and the active material on the first and second pole pieces 1 and 2 react uniformly in the process of battery charging and discharging, thereby optimizing the performance of the battery monomer 100.

[0123] In some embodiments, as Figure 6 , Figure 8 and Figure 10 , the electrode assembly 10 further comprises a diaphragm 3, the diaphragm 3 is used to isolate the first and second pole pieces 1 and 2, and the diaphragm 3, the main body part 11 of the first pole piece 1 and the main body part of the second pole piece 2 are wound to form the winding body S; in the extension direction of the winding axis K, at least one side of the diaphragm 3 is located in the part of the liquid guiding area 111 which exceeds the side of the main body part 11 of the first pole piece 1 and the side of the main body part 11 of the second pole piece 2.

[0124] The diaphragm 3 can be in a strip shape in an unfolded state, and the diaphragm 3 can be made of PP (polypropylene) or PE (polyethylene) material, and has micropores of micron or nanometer level inside, for allowing metal ions to pass through in the charging and discharging process of the battery.

[0125] Optionally, in the extension direction of the winding axis K, one side of the diaphragm 3 is located at the part of the liquid guide area 111 beyond the side edge of the main body part 11 of the first pole piece 1 and the side edge of the main body part 11 of the second pole piece 2; or as shown in Figure 13A both sides of the diaphragm 3 are located at the part of the liquid guide area 111 beyond the side edge of the main body part 11 of the first pole piece 1 and the side edge of the main body part 11 of the second pole piece 2.

[0126] The diaphragm 3 is designed in a stepped shape in this embodiment of the application, and is widened at the liquid guide area 111, so that the side edge of the diaphragm 3 can extend outward between the first pole piece 1 and the second pole piece 2 at the liquid guide area 111 and be soaked in the electrolyte, so that the diaphragm 3 can more easily absorb the electrolyte under capillary action, improve the wettability of the electrode assembly 10, and further improve the performance of the battery monomer 100. Optionally, as shown in Figure 12A the diaphragm 3 can also be designed in a strip shape with equal width.

[0127] In some embodiments, as shown in Figure 13A the electrode assembly 10 further includes a diaphragm 3 for separating the first pole piece 1 and the second pole piece 2, and the main body part 11 of at least one of the first pole piece 1 and the second pole piece 2 includes an active material area A and a liquid guide area B arranged side by side in the extension direction of the winding axis K, and the liquid guide area B is located outside the active material area A and is used to guide the electrolyte into the inside of the winding main body S; as shown in Figure 17 and Figure 18 the gap between the surface of the main body part 11 at the liquid guide area B and the diaphragm 3 is greater than the gap between the surface of the main body part 11 at the active material area A and the diaphragm 3.

[0128] For example, the first pole piece 1 is a positive pole piece, and the active material area A is coated with a positive active material, for example, the positive active material can be a ternary material, lithium manganate or lithium iron phosphate; and the second pole piece 2 is a negative active material, and the negative active material can be graphite or silicon.

[0129] This embodiment of the application makes the gap between the surface of the main body part 11 at the liquid guide area B and the diaphragm 3 greater than the gap between the surface of the main body part 11 at the active material area A and the diaphragm 3, so that a larger capillary gap can be formed between the liquid guide area B and the diaphragm 3, and after the electrolyte is absorbed at the end of the diaphragm 3, the electrolyte can quickly enter the end of the winding main body S and further enter the active material area A to react with the active material. This structure makes the gap between the main body part 11 and the diaphragm 3 gradually decrease from outside to inside, so that the electrolyte can quickly enter.

[0130] In some embodiments, as shown in Figure 12A the flow guide area B of at least one of the first and second electrode sheets 1 and 2 comprises an infiltration area B1 adjacent to the active material area A, and the gap between the surface of the infiltration area B1 and the separator 3 gradually increases from inside to outside along the extension direction of the winding axis K.

[0131] In some embodiments, the infiltration area B1 can be a long strip-shaped structure extending along the entire winding direction of the body portion 11 for introducing electrolyte, and the width of the infiltration area B1 along the extension direction of the winding axis K is smaller than the width of the active material area A. As shown in Figure 17 and Figure 18 the surface of the infiltration area B1 along the extension direction of the winding axis K can be a slope, or can also be designed as an arc, a step, etc., as long as the gap between the surface of the infiltration area B1 and the separator 3 gradually increases from inside to outside is within the protection scope of the present application.

[0132] This embodiment of the present application can introduce electrolyte into the active material area A through the infiltration area B1 after the electrolyte is absorbed at the end of the separator 3, so as to facilitate the electrolyte to quickly enter the inside of the winding body S to react.

[0133] In some embodiments, as shown in Figure 17 and Figure 18 the flow guide area B of at least one of the first and second electrode sheets 1 and 2 comprises an infiltration area B1 adjacent to the active material area A, the body portion 11 of at least one of the first and second electrode sheets 1 and 2 comprises a current collector 114, an active material layer 112 and an infiltration layer 113, the active material layer 112 is arranged on the surface of the current collector 114 and located in the active material area A, the infiltration layer 113 is arranged on the surface of the current collector 114 and located in the infiltration area B1, and the liquid absorption capacity of the infiltration layer 113 is higher than that of the active material layer 112.

[0134] In some embodiments, the "liquid absorption capacity" refers to the capacity of a unit area of a coating layer to absorb electrolyte in a unit of time. For example, the first electrode sheet 1 is a positive electrode sheet, and an aluminum foil can be used as the current collector 114, and the second electrode sheet 2 is a negative electrode sheet, and a copper foil can be used as the current collector 114. For example, the infiltration layer 113 comprises an inorganic ceramic coating, a polymer and an adhesive. As shown in Figure 17 the side edge of the infiltration layer 113 is flush with the side edge of the current collector 114, and the side edge of the separator 3 adjacent to the first electrode sheet 1 exceeds the side edges of the infiltration layer 113 and the current collector 114.

[0135] The embodiment of the present application can improve the ability of the end portion of the winding body S to absorb electrolyte by coating the wicking layer 113 with higher liquid absorption capacity than the active material layer 112 on the region of the main body 11 close to the outer side, so as to quickly absorb electrolyte into the inside of the winding body S.

[0136] Further, the gap between the main body 11 and the separator 3 in the wicking region B1 gradually increases from the inside to the outside, that is, the thickness of the wicking layer 113 is smaller than the thickness of the active material layer 112, and a gap gradually expanding from the inside to the outside is formed between the wicking layer 113 and the separator 3, which also facilitates the absorption of electrolyte. Through the dual improvement of structural design and material properties, the wicking properties of the electrode assembly 10 can be better improved.

[0137] In some embodiments, as shown in Figure 13A , 14A , 14B and 18, the current-carrying region B of at least one of the first and second pole pieces 1 and 2 further comprises a guiding region B2, and the region where the current collector 114 extends beyond the wicking layer 113 along the extension direction of the winding axis K forms the guiding region B2.

[0138] The guiding region B2 is the region where the current collector 114 extends beyond the wicking layer 113 along the extension direction of the winding axis K, and the region is not provided with a coating layer, and the part of the current collector 114 located in the guiding region B2 is connected integrally with the tab 12. The side edge of the separator 3 adjacent to the first pole piece 1 extends beyond the side edge of the current collector 114, so that the electrolyte is first absorbed through the separator 3, and then enters the active material region A through the guiding region B2 and the wicking region B1 in sequence.

[0139] In the embodiment of the present application, the guiding region B2 is not provided with a coating layer, so that the gap between the current collector 114 and the separator 3 in the guiding region B2 is larger than the gap between the surface of the wicking layer 113 and the separator 3. A multi-stage electrolyte absorption channel can be formed at the end portion of the winding body S located in the guiding region B2, and the distance between the first or second pole piece 1 and the separator 3 gradually decreases from the guiding region B2, the wicking region B1 to the active material region A, which can significantly improve the absorption efficiency and the wicking properties of the electrode assembly 10, thereby improving the performance of the battery monomer 100.

[0140] In some embodiments, as shown in Figure 13A , the first pole piece 1 is a positive pole piece and is sequentially provided with the active material region A, the wicking region B1 and the guiding region B2 along the extension direction of the winding axis K; as shown in Figure 13B , the second pole piece 2 is a negative pole piece and is sequentially provided with the active material region A and the guiding region B2 along the extension direction of the winding axis K.

[0141] The embodiment of the present application considers that the compaction density of the positive electrode tab is large, and the speed of electrolyte entering the positive electrode tab is slow. By adding the infiltration area B1 to the positive electrode tab, the speed of electrolyte penetrating into the positive active material can be accelerated. The speed of electrolyte entering the negative electrode tab is relatively fast compared with the positive electrode tab. By guiding electrolyte into the negative electrode tab through the guide area B2, the manufacturing process of the negative electrode tab can be simplified. The embodiment can not only make the speed of electrolyte entering the positive electrode tab and the negative electrode tab close, but also reduce the production difficulty of the electrode assembly 10. Alternatively, the first electrode tab 1 and the second electrode tab 2 can also be set to the same structure, for example, both are provided with the infiltration area B1, or neither is provided with the infiltration area B1.

[0142] In some embodiments, the diaphragm 3 is located at the side of the liquid guide area 111 of at least one of the first electrode tab 1 and the second electrode tab 2, between the outer side of the guide flow area B and the outer side of the tab 12.

[0143] The embodiment of the present application makes the side of the diaphragm 3 beyond the outer side of the guide flow area B, so that the protruding part of the diaphragm 3 can be soaked in the electrolyte to absorb the electrolyte by capillary action. Moreover, the side of the diaphragm 3 does not exceed the outer side of the tab 12, which can prevent the diaphragm 3 from protruding too long in the conductive area 121 to affect the tab 12, and ensure the conductive effect of the tab 12.

[0144] In some embodiments, as Figures 12A to 16 , the extension length of the guide flow area B around the winding main body S is consistent with the active material area A.

[0145] The embodiment of the present application can reduce the manufacturing difficulty of the electrode tab provided with the guide flow area B, and the extension length of the guide flow area is consistent with the active material area A, which can guide the electrolyte to reach the active material area A in the entire coating length of the active material area A, so that the electrolyte is uniformly distributed in the entire winding length of the electrode tab, thereby improving the performance of the battery monomer 100.

[0146] In the above-mentioned partial embodiments, the specific structure of the electrode tab is introduced by taking the first electrode tab 1 as an example. The second electrode tab 2 can also adopt the same or similar structure.

[0147] Some specific embodiments will be given below to illustrate the structure of the electrode assembly 10.

[0148] In the first embodiment, as Figure 6 and Figure 7 shown, Figure 6Only one end of the battery cell 100 is shown, and the other end can be symmetrical to the one shown in the figure. The shell 101 is provided with the electrode assembly 10, and the end of the shell 101 is provided with an opening 1011 and is closed by an end cover assembly 102, which includes an end cover body 1021, a terminal 1022, an insulating piece 1024, and an adapter piece 1025. The insulating piece 1024 is arranged on the side of the end cover body 1021 close to the electrode assembly 10, and the adapter piece 1025 is arranged on the side of the insulating piece 1024 close to the electrode assembly 10.

[0149] The electrode assembly 10 includes the first tab 1, the second tab 2, and the separator 3. The first tab 1 and the second tab 2 are arranged in a stack, and the separator 3 is used to separate the first tab 1 and the second tab 2. The first tab 1, the second tab 2, and the separator 3 are wound together, so that the main body part 11 of each of the first tab 1 and the second tab 2 forms a winding main body S. The end of the winding main body S is concentrically provided with one conductive area 121 and two liquid-conducting areas 111, and the conductive area 121 is located between the two liquid-conducting areas 111. The tab 12 is led out at the conductive area 121 and wound for multiple turns, for example, 6 turns. After being flattened, the tab 12 forms a bending part, and is electrically connected to the terminal 1022 at the same end through the adapter piece 1025. The tab 12 can be bent radially inward, so as to prevent the bending part from touching the inner wall of the shell 101, and facilitate reducing the radial dimension of the adapter piece 1025.

[0150] In the conductive area 121, the first tab 1 has the longest extension, the second is the separator 3, and the second tab 2 extends to the horizontal dashed line. In the liquid-conducting area 111, the separator 3 has the longest extension, and the first tab 1 and the second tab 2 extend to the horizontal dashed line, and the first tab 1 and the second tab 2 are arranged alternately.

[0151] As shown in Figure 6 , the outer ring of the insulating piece 1024 is provided with a protruding part 1024', which is used to separate the tab 12 and the shell 101, so as to improve the insulation performance. For example, the adapter piece 1025 can include a first connecting sheet 1025A and a second connecting sheet 1025B connected to each other, the first connecting sheet 1025A is welded with the tab 12, and the second connecting sheet 1025B is connected with the terminal 1022.

[0152] In the second embodiment, as shown in Figure 8 and Figure 9 , the difference from the first embodiment is that the end of the winding main body S is concentrically provided with two conductive areas 121 and one liquid-conducting area 111, and the liquid-conducting area 111 is located between the two conductive areas 121. The tab 12 of each conductive area 121 is continuously wound for multiple turns, for example, 5 turns.

[0153] In the third embodiment, as shown in Figure 10 and Figure 11As shown, the difference from the first embodiment is that a conductive region 121 and a liquid-conducting region 111 are concentrically provided at the end of the winding body S, with the liquid-conducting region 111 located radially outside the conductive region 121. For example, the radial width of the conductive region 121 is greater than the radial width of the liquid-conducting region 111.

[0154] The following specific embodiments will be given to illustrate the structure of the first electrode 1, the second electrode 2, and the diaphragm 3 after unfolding.

[0155] In the first embodiment, as Figure 12A As shown, the first electrode 1 is a positive electrode. The main body 11 of the first electrode 1 includes an active material region A and a wetting region B1 arranged side by side along the extension direction of the winding axis K. The wetting region B1 is located outside the active material region A. Figure 17 As shown, the current collector 114 can be coated with an active material layer 112 in the active material region A and a wetting layer 113 in the wetting region B1. The liquid absorption performance of the wetting layer 113 is higher than that of the active material layer 112, and the gap between the surface of the wetting layer 113 and the diaphragm 3 gradually decreases from the outside to the inside, and is greater than the gap between the active material layer 112 and the diaphragm 3. The side of the diaphragm 3 can extend beyond the side of the first electrode 1 by a width of W9.

[0156] The tab 12 protrudes from the side of the main body 11 along the winding axis K. The tab 12 can be located near one end of the main body 11 along the winding length. After winding, the conductive area 121 can be located in the inner ring or the outer ring. The wetting layer 113 extends along the entire winding length of the first electrode 1. The outer edge of the wetting layer 113 located in the conductive area 121 may have a small portion of its width on the tab 12. A transition portion 122, such as a rounded corner or chamfer, can be provided at the root position where the tab 12 connects to the main body 11 to reduce the stress on the root of the tab 12 when it is rolled up, and to prevent the tab 12 from cracking or being stretched. Optionally, a transition portion 122 can also be provided at the corner position of the outer edge of the tab 12. For example, the rounded corner value of the outer edge corner position of the tab 12 is in the range of R3-R12, preferably R8; the rounded corner value at the connection with the main body 11 is in the range of R1-R8, preferably R5.

[0157] like Figure 12B As shown, the second electrode 2 is a negative electrode. The main body 11 of the second electrode 2 only includes the active material region A, and the tab 12 can be provided at one end of the main body 11 along the winding length.

[0158] like Figure 12C As shown, the diaphragm 3 is rectangular and has a uniform width structure.

[0159] During winding, the tabs 12 of the first pole piece 1 and the second pole piece 2 are located on opposite sides in the direction of extension of the winding axis K.

[0160] In a second embodiment, as shown in Figure 13A the first tab 1 is a positive electrode tab, the main body 11 of the first tab 1 includes the active material region A, the wicking region B1 and the guide region B2 arranged side by side along the extension direction of the winding axis K, and the wicking region B1 is located between the active material region A and the guide region B2. The wicking region B1 and the guide region B2 extend along the entire winding length of the first tab 1.

[0161] As shown in Figure 18 the current collector 114 can be coated with the active material layer 112 in the active material region A, and can be coated with the wicking layer 113 in the wicking region B1, the wicking performance of the wicking layer 113 can be higher than that of the active material layer 112, and the gap between the surface of the wicking layer 113 and the separator 3 gradually decreases from the outside to the inside, and is greater than the gap between the active material layer 112 and the separator 3. The width of the side edge of the separator 3 can exceed the width W9' of the side edge of the guide region B2.

[0162] The tab 12 protrudes from the side of the main body 11 along the extension direction of the winding axis K, and the tab 12 can be arranged at one end of the main body 11. After winding, the conductive region 121 can be located in the inner ring or the outer ring.

[0163] As shown in Figure 13B the second tab 2 is a negative electrode tab, the main body 11 of the second tab 2 includes the active material region A and the guide region B2, and the tab 12 can be arranged at a position close to one end along the winding length of the main body 11. The current collector 114 can be coated with the active material layer 112 in the active material region A, and the part of the current collector 114 beyond the side edge of the active material region A forms the guide region B2.

[0164] As shown in Figure 13C the width of the separator 3 in the conductive region 121 is W0, and the two side edges of the separator 3 are widened by W1 in the liquid guiding region 111, so that the side edges of the separator 3 in the liquid guiding region 111 exceed the side edges of the main body 11, facilitating liquid absorption.

[0165] During winding, the tabs 12 of the first tab 1 and the second tab 2 are located at different sides in the extension direction of the winding axis K.

[0166] In a third embodiment, as shown in Figure 14A the first tab 1 is a positive electrode tab, and the structure is the same as Figure 13A In the extension direction of the winding axis K, the width of the active material region A is W4, the width of the wicking region B1 is W3, the width of the guide region B2 is W2, and the width of the tab 12 is W5.

[0167] As shown in Figure 14BAs shown, the second tab 2 is a negative electrode tab, and the structure is the same as 14A. In the extension direction of the winding axis K, the width of the active material area A is W8, the width of the infiltration area B1 is W7, the width of the guide area B2 is W6, and the width of the tab 12 is W9.

[0168] As shown, the width of the conductive area 121 of the separator 3 is W0, and the two side edges of the separator 3 are widened by W1 in the liquid guide area 111, so that the side edges of the separator 3 in the liquid guide area 111 exceed the side edges of the main body 11, facilitating liquid absorption. Alternatively, the separator 3 can also adopt an equal-width structure. Figure 14C As shown, the width of the conductive area 121 of the separator 3 is W0, and the two side edges of the separator 3 are widened by W1 in the liquid guide area 111, so that the side edges of the separator 3 in the liquid guide area 111 exceed the side edges of the main body 11, facilitating liquid absorption. Alternatively, the separator 3 can also adopt an equal-width structure. Figure 12C As shown, the width of the conductive area 121 of the separator 3 is W0, and the two side edges of the separator 3 are widened by W1 in the liquid guide area 111, so that the side edges of the separator 3 in the liquid guide area 111 exceed the side edges of the main body 11, facilitating liquid absorption. Alternatively, the separator 3 can also adopt an equal-width structure.

[0169] In other embodiments, as shown, the first tab 1 can be a positive electrode tab or a negative electrode tab, and the main body 11 of the first tab 1 includes active material areas A and infiltration areas B1 arranged side by side in the extension direction of the winding axis K, and the infiltration areas B1 are located outside the active material areas A. The tab 12 can be located in the middle region of the main body 11 along the winding length, and after winding, the conductive area 121 is located in the middle region of the winding main body S in the radial direction. Figure 15 In other embodiments, as shown, the first tab 1 can be a positive electrode tab or a negative electrode tab, and the main body 11 of the first tab 1 includes active material areas A and infiltration areas B1 arranged side by side in the extension direction of the winding axis K, and the infiltration areas B1 are located outside the active material areas A. The tab 12 can be located in the middle region of the main body 11 along the winding length, and after winding, the conductive area 121 is located in the middle region of the winding main body S in the radial direction.

[0170] Figure 16 In other embodiments, as shown, the first tab 1 can be a positive electrode tab or a negative electrode tab, and the main body 11 of the first tab 1 includes active material areas A and infiltration areas B1 arranged side by side in the extension direction of the winding axis K, and the infiltration areas B1 are located outside the active material areas A. The tab 12 can be located in the middle region of the main body 11 along the winding length, and after winding, the conductive area 121 is located in the middle region of the winding main body S in the radial direction. Figure 15

[0171] Figure 19 Structure diagram of some embodiments of the first tab 1, the second tab 2 and the separator 3 before winding. For example, the first tab 1 can be a negative electrode tab, and the second tab 2 is a positive electrode tab accordingly, the first tab 1 is longer than the second tab 2, and the separator 3 is longer than the first tab 1. The tabs 12 of the first tab 1 and the second tab 2 are opposite in the lead-out direction of the winding axis K, and are both located in the position close to the first end of the main body 11 along the winding direction, and the first end is the left end, and the tab 12 continuously extends in part of the winding length direction of the main body 11.

[0172] ​​The main body part 11 of the first tab 1 only includes the active material coating area A, and the main body part 11 of the second tab 2 includes the active material area A and the infiltration area B1 arranged side by side along the extension direction of the winding axis K, and the infiltration area B1 is located outside the active material area A. In the extension direction of the winding axis K, the width edges on both sides of the active material coating area A of the first tab 1 both exceed the width edges on the corresponding sides of the active material coating area A of the second tab 2. The separator 3 adopts an equal-width structure, and the two side edges of the separator 3 both exceed the side edges on the same side of the main body part 11 of the first tab 1 and the second tab 2 and do not exceed the outside edges of the tab 12.

[0173] The above specific embodiments only schematically show the structure and combination of the first tab 1, the second tab 2 and the separator 3, and different first tabs 1, second tabs 2 and separators 3 can be combined as needed in actual arrangement.

[0174] Secondly, the application provides a manufacturing method of the electrode assembly 10, as shown in some embodiments, the manufacturing method comprises: Figure 20 S110, providing a first tab 1 and a second tab 2 with opposite polarities, and the first tab 1 and the second tab 2 both include a main body part 11 and a tab 12 protruding from the main body part 11; S120, winding the first tab 1 and the second tab 2 around a winding axis K to form a winding main body S of the respective main body parts 11, and the end part of the winding main body S includes at least one conductive area 121 and at least one liquid guide area 111; Wherein, the tab 12 is led out from the conductive area 121 and wound at least one turn, and is used for electrically connecting with the terminal 1022 of the battery monomer 100, and the liquid guide area 111 is arranged adjacent to the conductive area 121 along the radial direction of the winding main body S, and is used for guiding the electrolyte to flow into the inside of the winding main body S.

[0175] After winding through S120, the tab 12 at the end part of the winding main body S is rubbed flat to form a bending part of the tab 12, which is convenient for electrically connecting with the terminal 1022.

[0176] In this embodiment of the application, the end part of the winding main body S simultaneously has the conductive area 121 and the liquid guide area 111, since the liquid guide area 111 is not provided with the tab 12, after the tab 12 of the conductive area 121 is rubbed flat, the electrolyte in the battery monomer 100 also easily flows into the inside of the winding main body S through the gap between the first tab 1 and the second tab 2 at the liquid guide area 111, which guarantees the infiltration performance of the electrode assembly 10, so that the electrolyte fully reacts with the active material on the first tab 1 and the second tab 2 in the process of charging and discharging of the battery, thereby optimizing the performance of the battery monomer 100.

[0177] ​Furthermore, since the tab 12 extends continuously and wraps around the conductive area 121 at least once, it has good connection strength with the main body 11 in the circumferential direction, giving the root of the tab 12 a good self-supporting effect. During the process of applying circumferential force to flatten the tab 12, wrinkling of the tab 12 is prevented, the shape of the flattened area is stabilized, the welding effect of the tab 12 and the terminal 1022 is optimized, ensuring that the electrode assembly 10 reliably transmits electrical energy and improves the current carrying capacity. In addition, particles generated during the welding of the tab 12 are less likely to fall circumferentially between the first electrode 1 and the second electrode 2 in the liquid guiding area 111, which can improve the reliability of the electrode assembly 10.

[0178] Finally, this application provides a manufacturing apparatus 400 for the electrode assembly 10, such as... Figure 21 As shown, in some embodiments, the manufacturing apparatus 400 includes an electrode supply device 410 and an electrode winding device 420. The electrode supply device 410 is configured to provide a first electrode 1 and a second electrode 2 with opposite polarities. Both the first electrode 1 and the second electrode 2 include a body portion 11 and an electrode tab 12 protruding from the body portion 11. The electrode winding device 420 is configured to wind the first electrode 1 and the second electrode 2 around a winding axis K such that their respective body portions 11 form a winding body S. The end of the winding body S includes at least one conductive region 121 and at least one liquid-conducting region 111. The electrode tab 12 extends out of the conductive region 121 and is wound at least one turn, and is used for electrical connection with the terminal 1022 of the battery cell 100. The liquid-conducting region 111 is arranged radially adjacent to the conductive region 121 and is used to guide electrolyte into the interior of the winding body S.

[0179] The manufacturing equipment 400 and manufacturing method of this embodiment have the same technical effects.

[0180] Although this application has been described with reference to preferred embodiments, various modifications can be made thereto and components can be replaced with equivalents without departing from the scope of this application. In particular, the technical features mentioned in the various embodiments can be combined in any manner, provided there is no structural conflict. This application is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

Claims

1. An electrode assembly (10) for a battery cell (100), characterized in that, The electrode assembly (10) includes a first electrode (1) and a second electrode (2) with opposite polarities. The first electrode (1) and the second electrode (2) each include a main body (11) and an electrode tab (12) protruding from the main body (11). The first electrode (1) and the second electrode (2) are wound around a winding axis (K) so that their respective main bodies (11) form a wound body (S). The end of the winding body (S) includes at least one conductive region (121) and at least one liquid guiding region (111). The tab (12) is led out from the conductive region (121) and wound around at least one turn, and is used to electrically connect with the terminal (1022) of the battery cell (100). The liquid guiding region (111) and the conductive region (121) are arranged adjacent to each other in the radial direction of the winding body (S), and are used to guide the electrolyte into the interior of the winding body (S).

2. The electrode assembly (10) according to claim 1, characterized in that The tab (12) is wound multiple times in the conductive area (121).

3. The electrode assembly (10) according to claim 1, characterized in that The sum of the number of the conductive area (121) and the liquid guiding area (111) is greater than or equal to three, and they are arranged alternately along the radial direction of the winding body (S).

4. The electrode assembly (10) according to claim 3, characterized in that The conductive area (121) is located in the middle region of the radial direction at the end of the winding body (S), and a liquid guiding area (111) is provided on each side of the conductive area (121) in the radial direction.

5. The electrode assembly (10) of claim 1, wherein, At least one of the first electrode (1) and the second electrode (2) is provided with a plurality of said tabs (12) spaced apart along the winding direction to form a plurality of said conductive regions (121) spaced apart along the radial direction at the end of the winding body (S).

6. The electrode assembly (10) according to claim 5, characterized in that The conductive area (121) is provided in two and is located on the inner and outer sides of the end of the winding body (S) along the radial direction, respectively, and the liquid guiding area (111) is located between the two conductive areas (121).

7. The electrode assembly (10) of claim 1, wherein, One conductive region (121) and one liquid-conducting region (111) are respectively provided, and the conductive region (121) is located on the radial inner side of the liquid-conducting region (111).

8. The electrode assembly (10) according to any one of claims 1 to 7, characterized in that, The liquid-conducting regions (111) at both ends of the winding body (S) have the same radial dimension, and the conductive regions (121) at both ends of the winding body (S) have the same radial dimension; or The liquid-conducting region (111) at one end of the winding body (S) and the conductive region (121) at the other end have the same radial dimension.

9. The electrode assembly (10) according to any one of claims 1 to 7, characterized in that It also includes a diaphragm (3), which is used to isolate the first electrode (1) and the second electrode (2). The diaphragm (3), the main body (11) of the first electrode (1) and the main body of the second electrode (2) are wound together to form the wound body (S). In the extension direction of the winding axis (K), the portion of the diaphragm (3) located in the liquid guiding area (111) extends beyond the side of the main body portion (11) of the first electrode (1) and the side of the main body portion (11) of the second electrode (2).

10. The electrode assembly (10) according to any one of claims 1 to 7, characterized in that The separator (3) is arranged between the surface of the main body portion (11) of the first and second electrode plates (1, 2) in the current conducting region (B) and the surface of the main body portion (11) of the first and second electrode plates (1, 2) in the active material region (A).

11. The electrode assembly (10) according to claim 10, characterized in that The current conducting region (B) of at least one of the first and second electrode plates (1, 2) comprises a wetting region (B1) adjacent to the active material region (A), and the gap between the surface of the main body portion (11) in the wetting region (B1) and the separator (3) gradually increases from inside to outside along the extension direction of the winding axis (K).

12. The electrode assembly (10) of claim 10, characterized by The current conducting region (B) of at least one of the first and second electrode plates (1, 2) comprises a wetting region (B1) adjacent to the active material region (A), and the main body portion (11) of at least one of the first and second electrode plates (1, 2) comprises a current collector (114), an active material layer (112) and a wetting layer (113), the active material layer (112) is arranged on the surface of the current collector (114) and located in the active material region (A), and the wetting layer (113) is arranged on the surface of the current collector (114) and located in the wetting region (B1), the liquid absorption capacity of the wetting layer (113) is higher than that of the active material layer (112).

13. The electrode assembly (10) according to claim 12, characterized in that The wetting layer (113) comprises an inorganic ceramic coating, a high molecular polymer and an adhesive.

14. The electrode assembly (10) of claim 12, characterized by The current conducting region (B) of at least one of the first and second electrode plates (1, 2) further comprises a guide region (B2), and the current collector (114) forms the guide region (B2) by extending beyond the area of the wetting layer (113) along the extension direction of the winding axis (K).

15. The electrode assembly (10) according to claim 14, characterized in that The first electrode plate (1) is a positive electrode plate and sequentially comprises the active material region (A), the wetting region (B1) and the guide region (B2) from inside to outside along the extension direction of the winding axis (K), and the second electrode plate (2) is a negative electrode plate and sequentially comprises the active material region (A) and the guide region (B2) from inside to outside along the winding axis (K).

16. The electrode assembly (10) of claim 10, wherein, The separator (3) is arranged at the side of the liquid conducting region (111) of at least one of the first and second electrode plates (1, 2) and between the outer side of the current conducting region (B) and the outer side of the tab (12).

17. The electrode assembly (10) of claim 10, wherein, The extension length of the current conducting region (B) around the winding body (S) in the circumferential direction is consistent with that of the active material region (A).

18. The electrode assembly (10) according to any one of claims 1 to 7, characterized in that Further comprising a separator (3) for isolating the first and second pole pieces (1, 2), the separator (3), the main body portion (11) of the first pole piece (1) and the main body portion (11) of the second pole piece (2) being wound to form the wound body (S); In the extension direction of the winding axis (K), the portions of the separator (3) on both sides of the liquid guide region (111) exceed the side edges of the main body portion (11) of the first pole piece (1) and the main body portion (11) of the second pole piece (2).

19. A battery cell (100) characterized by, Comprise: a housing (101) having an opening (1011); an end cover assembly (102) for closing the opening (1011), the end cover assembly (102) comprising an end cover body (1021) and a terminal (1022) provided on the end cover body (1021); and the electrode assembly (10) of any one of claims 1-18 is provided in the housing (101), and the tab (12) of the first pole piece (1) or the tab (12) of the second pole piece (2) is electrically connected to the terminal (1022).

20. The battery cell (100) of claim 19, wherein, The end cover assembly (102) further comprises: an insulating member (1024) and an adapter member (1025), the adapter member (1024) being provided on the side of the end cover body (1021) close to the electrode assembly (10), and the adapter member (1025) being provided on the side of the insulating member (1024) close to the electrode assembly (10).

21. A battery (200) characterized by, Comprise: the battery cell (100) of claim 19; and a box (201) for accommodating the battery cell (100).

22. A power consuming device comprising the battery of claim 21, the battery being configured to provide power for the power consuming device.

23. A method of manufacturing an electrode assembly (10) according to any one of claims 1 to 18, characterized in that The manufacturing method comprises: providing a first pole piece (1) and a second pole piece (2) having opposite polarities, the first pole piece (1) and the second pole piece (2) each comprising a main body portion (11) and a tab (12) protruding from the main body portion (11); winding the first pole piece (1) and the second pole piece (2) around a winding axis (K) to form a wound body (S) with the respective main body portion (11), the end portion of the wound body (S) comprising at least one electrically conductive region (121) and at least one liquid guide region (111); wherein the tab (12) is led out at the electrically conductive region (121) and wound at least one turn, and is configured to be electrically connected to a terminal (1022) of the battery cell (100), and the liquid guide region (111) is arranged adjacent to the electrically conductive region (121) in the radial direction of the wound body (S), and is configured to guide electrolyte to flow into the interior of the wound body (S).

24. A manufacturing apparatus (400) of an electrode assembly (10), the electrode assembly (10) being the electrode assembly (10) according to any one of claims 1 to 18, characterized in that, The manufacturing device (400) comprises: a pole piece providing device (410) configured to provide a first pole piece (1) and a second pole piece (2) having opposite polarities, the first pole piece (1) and the second pole piece (2) each comprising a main body portion (11) and a tab (12) protruding from the main body portion (11); and a winding device (420) configured to wind the first pole piece (1) and the second pole piece (2) around a winding axis (K) to form a wound body (S) with the respective main body portion (11), the end portion of the wound body (S) comprising at least one electrically conductive region (121) and at least one liquid guide region (111). The pole piece winding device (420) is configured to wind the first pole piece (1) and the second pole piece (2) around a winding axis (K) to form a winding body (S) with the respective main body part (11), and the end of the winding body (S) includes at least one conductive area (121) and at least one liquid guide area (111); Wherein, the tab (12) is led out at the conductive area (121) and wound at least one turn, and is used for electrically connecting with the terminal (1022) of the battery monomer (100), and the liquid guide area (111) is arranged adjacent to the conductive area (121) along the radial direction of the winding body (S), and is used for guiding the electrolyte to flow into the inside of the winding body (S).

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