Current collector, electrode plate, battery cell assembly and cylindrical battery

Abstract

The embodiment of the invention provides a current collector, an electrode plate, a battery core assembly and a cylindrical battery, and relates to the technical field of batteries, the current collector comprises a current collector body and a tab group, the current collector body is provided with a first surface, the first surface is provided with a coating area and a blank area, and the coating area is at least used for coating an active material layer. The tab group at least comprises a first tab and a second tab, the first tab and the second tab are arranged at an interval along the winding direction of the current collector body and are respectively connected to the partial blank area, and the first tab and the second tab extend towards the direction deviating from the coating area. Wherein the first tabs and the second tabs are different in shape or area, and when the current collector body is wound into a winding core and the first tabs and the second tabs are both flattened towards the center of the winding core, the area of the part of the second tabs shielding the close first tabs is smaller than or equal to a first preset area. According to the current collector provided by the embodiment of the invention, the welding strength and the overflowing area of the inner-layer tab can be improved.

Description

Technical Field

[0001] The present application relates to the field of battery technology, and in particular to a current collector, an electrode sheet, a battery cell assembly and a cylindrical battery. Background Art

[0002] Batteries, as a power source for transportation vehicles, are widely used in new energy vehicles and other electrical equipment. Batteries can be categorized by packaging method and shape into soft-pack, prismatic, and cylindrical batteries. The cells within cylindrical batteries are typically manufactured using a winding process.

[0003] In related technologies, the battery cell inside a cylindrical battery is made by stacking the positive electrode sheet, the negative electrode sheet and the separator and then winding them. Then, each electrode tab needs to be flattened toward the center of the battery cell so that it can be welded to the current collecting plate.

[0004] However, due to the large overlap between the outer and inner tabs in the battery cell, the effective contact area between the inner tab and the current collecting plate or busbar is insufficient, thereby affecting the welding strength and flow area. Summary of the Invention

[0005] Based on this, the present application provides a current collector, an electrode sheet, a battery cell assembly and a cylindrical battery to solve the problem that in existing cylindrical batteries, there is a large overlap area between the outer electrode tabs and the inner electrode tabs, resulting in insufficient effective contact area between the inner electrode tabs and the current collecting plate, thereby affecting the welding strength and flow area.

[0006] In a first aspect, the present application provides a current collector, comprising:

[0007] A current collector body having a first surface, a coating area and a blank area on the first surface, wherein the coating area is at least used for coating an active material layer;

[0008] A tab group, comprising at least a first tab and a second tab, wherein the first tab and the second tab are spaced apart along the winding direction of the current collector body and are respectively connected to a portion of the blank area, and the first tab and the second tab extend in a direction away from the coating area;

[0009] Among them, the first pole ear and the second pole ear have different shapes or areas, and are wound into a core on the current collector body. When the first pole ear and the second pole ear are flattened toward the center of the core, the area of ​​the first pole ear partially blocked by the second pole ear is less than or equal to the first preset area.

[0010] In one possible implementation, the first electrode tab has at least a first side, a second side, and a third side connected in sequence, and the side of the current collector body facing away from the coating area has a reference side parallel to the winding direction;

[0011] The first side and the third side are parallel and intersect with the reference side respectively, and the second side is parallel to the reference side and faces away from the coating area.

[0012] In a possible implementation manner, the first side or the third side forms a first angle with the reference side, and the first angle is an acute angle.

[0013] In a possible implementation, the second electrode tab has at least a fourth side, a fifth side, and a sixth side connected in sequence, the fourth side and the sixth side are opposite and intersect with the reference side respectively, and the fifth side is parallel to the reference side and faces away from the coating area.

[0014] In a possible implementation, the fourth side or the sixth side forms a second angle with the reference side, and the second angle is an acute angle.

[0015] In a possible implementation, the distance between the second side and the reference side is greater than or equal to the distance between the fifth side and the reference side.

[0016] In a possible implementation, the distance between the adjacent first side and the third side is smaller than the distance between the adjacent fourth side and the sixth side.

[0017] In a possible implementation, the tab group further includes a third tab, and the first tab, the second tab, and the third tab are spaced apart along the winding direction and are respectively connected to a portion of the blank area and extend in a direction away from the coating area.

[0018] Among them, the third pole ear has a different shape or area from the second pole ear, and is wound into a core on the current collector body. When the first pole ear, the second pole ear and the third pole ear are flattened toward the center of the core, the area of ​​the second pole ear partially blocked by the third pole ear is less than or equal to the second preset area.

[0019] In a possible implementation, the third electrode tab has at least a seventh side, an eighth side, and a ninth side connected in sequence, the seventh side and the ninth side are opposite and intersect with the reference side respectively, and the eighth side is parallel to the reference side and faces away from the coating area.

[0020] In a possible implementation, the seventh side or the ninth side forms a third angle with the reference side, and the third angle is an acute angle.

[0021] In a possible implementation, the distance between the eighth side and the reference side is smaller than the distance between the fifth side and the reference side.

[0022] In a possible implementation, the distance between the adjacent fourth side and the adjacent sixth side is less than or equal to the distance between the adjacent seventh side and the adjacent ninth side.

[0023] In a possible implementation, the blank area is provided with at least a first tab-free connection section and a multi-tab connection section along the winding direction, and the tab group is located in the multi-tab connection section.

[0024] In a possible implementation, the blank area is further provided with a second tab-free connecting section along the winding direction, and the first tab-free connecting section, the multi-tab connecting section and the second tab-free connecting section are arranged in sequence.

[0025] In a second aspect, the present application further provides an electrode sheet comprising an active material layer and any one of the current collectors provided in the first aspect, wherein the active material layer is coated on the coating area.

[0026] In a possible implementation, a protective material layer is further included, which is also coated on the coating area and located between the active material layer and the blank area.

[0027] In a third aspect, the present application further provides a battery cell assembly, comprising a battery cell body and a current collecting plate, wherein the battery cell body comprises a diaphragm and at least one electrode sheet of any one of the types provided in the second aspect, and the battery cell body is formed by winding the electrode sheet and the diaphragm;

[0028] The current collecting disk is located at the end of the battery cell body and is connected to at least a portion of the first pole tab and a portion of the second pole tab on the current collector in the electrode sheet.

[0029] In a possible implementation, a plurality of welding areas are provided on the current collecting disk, and the welding areas are spaced apart and distributed around the center of the current collecting disk;

[0030] The welding area includes a first welding area and a second welding area, and the first welding area and the second welding area are both used for welding a portion of the first tab and a portion of the second tab;

[0031] The first welding area extends along a first direction, the second welding area extends along the first direction, and the first direction is perpendicular to or intersects with the second direction.

[0032] In a possible implementation, a plurality of liquid seepage areas are further provided on the current collecting tray, and the liquid seepage areas are distributed at intervals around the center of the current collecting tray.

[0033] In a fourth aspect, the present application further provides a cylindrical battery comprising a shell and any one of the battery cell assemblies provided in the third aspect arranged in the shell.

[0034] The present application provides a current collector, an electrode sheet, a cell assembly, and a cylindrical battery. The current collector includes a current collector body and a tab group. The current collector body has a first surface. A coating area and a blank area are provided on the first surface, and an active material layer is coated on the coating area. The tab group includes at least a first tab and a second tab. The first tab and the second tab are spaced apart along the winding direction of the current collector body and are respectively connected to a portion of the blank area. The first tab and the second tab are arranged to extend in a direction away from the coating area. The first tab and the second tab have different shapes or areas, and the current collector body is wound into a core. When the first tab and the second tab are flattened toward the center of the core, the area of ​​the adjacent first tab blocked by the second tab is less than or equal to the first preset area, thereby reducing the area of ​​the inner tab blocked. As a result, the current collector provided by the present application can increase the effective contact area between the inner tab and the current collector plate, thereby ensuring welding strength and flow area, and improving battery performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the following is a brief introduction to the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative labor.

[0036] Figure 1 A schematic diagram of the structure of the current collector provided in an embodiment of the present application;

[0037] Figure 2 for Figure 1 A partial enlarged view of point A in the middle;

[0038] Figure 3 for Figure 1 A partial enlarged view of point B in the middle;

[0039] Figure 4 for Figure 1 A partial enlarged view of point C in the middle;

[0040] Figure 5 A schematic diagram of the structure of the battery cell body provided in an embodiment of the present application;

[0041] Figure 6 for Figure 5 A schematic diagram of the positional relationship between a first electrode tab and a second electrode tab;

[0042] Figure 7 for Figure 5 A schematic diagram of the positional relationship between a second tab and a third tab;

[0043] Figure 8This is a schematic structural diagram of the current collecting disk in the battery cell assembly provided in an embodiment of the present application.

[0044] Reference numerals:

[0045] 10: active material layer; 20: protective material layer; 30: current collecting plate; 31: welding area; 32: liquid seepage area;

[0046] 100: current collector body; 110: coating area; 120: blank area; 121: first tab-free connecting section; 122: multi-tab connecting section; 1221: first tab connecting section; 1222: second tab connecting section; 1223: third tab connecting section; 123: second tab-free connecting section;

[0047] 200: Tab group; 210: First tab; 211: First side; 212: Second side; 213: Third side; 220: Second tab; 221: Fourth side; 222: Fifth side; 223: Sixth side; 230: Third tab; 231: Seventh side; 232: Eighth side; 233: Ninth side. DETAILED DESCRIPTION

[0048] Exemplary embodiments will be described in detail herein, with examples illustrated in the accompanying drawings. In the following description, when referring to the drawings, identical numerals in different figures represent identical or similar elements, unless otherwise indicated. The embodiments described in the following exemplary embodiments are not intended to represent all embodiments consistent with the present application. Rather, they are merely examples of methods and apparatus consistent with certain aspects of the present application, as detailed in the appended claims.

[0049] The terms "first," "second," "third," "fourth," etc. (if any) in the specification and claims of the present application and in the above-mentioned drawings are used to distinguish similar objects and are not necessarily used to describe a specific order or sequential sequence. It should be understood that the numbers used in this way are interchangeable where appropriate, so that the embodiments of the present application described herein can, for example, be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having," and any variations thereof, are intended to cover non-exclusive inclusions, for example, a process, method, system, product, or apparatus comprising a series of steps or units is not necessarily limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products, or apparatus.

[0050] As mentioned in the background technology section, the multiple tabs on the current collector in the cylindrical battery of the related technology have the same shape and size. When the tabs are flattened after winding, the outer tabs block the inner tabs more, that is, there are more overlapping areas of the tabs, which makes the effective contact area between the inner tabs and the current collector insufficient, thereby affecting the welding strength and the flow area, and further affecting the internal resistance, discharge rate and other aspects of the battery cell.

[0051] In response to the above-mentioned problems existing in the prior art, the present application provides a current collector, an electrode sheet, a cell assembly, and a cylindrical battery. The current collector provided in the present application includes a current collector body and a tab group, the current collector body having a first surface, a coating area and a blank area being provided on the first surface, and an active material layer being coated on the coating area, the tab group including at least a first tab and a second tab, the first tab and the second tab being spaced apart along the winding direction of the current collector body and respectively connected to a portion of the blank area, the first tab and the second tab being arranged to extend in a direction away from the coating area, wherein the first tab and the second tab are provided with different shapes or areas, and when the current collector body is wound into a core, and the first tab and the second tab are flattened toward the center of the core, the area of ​​the adjacent first tab obscured by the second tab is less than or equal to the first preset area, thereby reducing the area obscured by the inner tab, thereby increasing the effective contact area between the inner tab and the current collector plate, thereby ensuring welding strength and flow area, and improving battery performance.

[0052] The following specific embodiments are used to describe the technical solution of the present application in detail. The following specific embodiments can be combined with each other, and the same or similar concepts or processes may not be described in detail in some embodiments.

[0053] First, please refer to Figure 1-Figure 7 As shown, an embodiment of the present application provides a current collector, including a current collector body 100 and a tab group 200 .

[0054] The current collector body 100 has a first surface having a coating area 110 and a blank area 120 . The coating area 110 is at least used for coating the active material layer 10 .

[0055] The tab group 200 includes at least a first tab 210 and a second tab 220 . The first tab 210 and the second tab 220 are spaced apart along the winding direction of the current collector body 100 and are respectively connected to part of the blank area 120 . The first tab 210 and the second tab 220 extend in a direction away from the coating area 110 .

[0056] Among them, the first pole tab 210 and the second pole tab 220 have different shapes or areas, and are wound into a core on the current collector body 100. When the first pole tab 210 and the second pole tab 220 are flattened toward the center of the core, the area of ​​the first pole tab 210 that is partially blocked by the second pole tab 220 is less than or equal to the first preset area.

[0057] The current collector in this embodiment can be used as a positive electrode or a negative electrode in a sodium ion cylindrical battery, wherein the current collector body 100 is used to collect and transmit electrons in the active material layer 10 to form a larger current output. It can be a rectangular sheet structure, and in sodium ion batteries it is mainly metal foil, such as aluminum foil.

[0058] Specifically, the current collector body 100 has a first surface, which can be one of the two large surfaces on the current collector body 100, that is, the front or back of the current collector body 100. The first surface is divided into a coating area 110 and a blank area 120 side by side. The coating area 110 is used to coat the active material layer 10, etc., and the blank area 120 is used to connect the tabs, etc. Figure 1 In the middle Y-axis direction, the large area at the bottom is the coating area 110 , and the small area at the top is the blank area 120 .

[0059] For example, for the positive electrode, the active material layer 10 thereon may be: layered transition metal oxides, Prussian compounds, polyanionic compounds, etc. For the negative electrode, the active material layer 10 thereon may be carbon-based materials, titanium-based compounds, alloy materials, metal compounds, organic compounds, etc.

[0060] It should be noted that the active material layer 10 may be coated on one surface of the current collector body 100 , or may be coated on both surfaces.

[0061] The tab assembly 200 in this embodiment includes at least two tabs, a first tab 210 and a second tab 220, of different shapes or areas. The first tab 210 and the second tab 220 can be integrally formed with the current collector body 100 and formed by die-cutting. The first tab 210 and the second tab 220 can also be connected to the current collector body 100 by bonding or other methods.

[0062] The first pole tab 210 and the second pole tab 220 are sequentially arranged along the winding direction of the current collector body 100. Figure 1 As shown in the positive direction of the X-axis, a plurality of first electrode tabs 210 are spaced apart along the winding direction of the current collector body 100, and a plurality of second electrode tabs 220 are also spaced apart along the winding direction of the current collector body 100. The first electrode tab 210 and the second electrode tab 220 are both connected to a portion of the blank area 120 and extend in a direction away from the coating area 110.

[0063] Specifically, in one example, the first pole tab 210 and the second pole tab 220 have different shapes, so that when the current collector body 100 is wound into a core, and the first pole tab 210 and the second pole tab 220 are flattened toward the center of the core, as shown in FIG. Figure 5 As shown, the first tab 210 and the second tab 220 are misaligned. Figure 6 As shown, the first electrode tab 210 is exposed to a larger area. In another example, the first electrode tab 210 and the second electrode tab 220 have different areas, and the area of ​​the second electrode tab 220 is smaller than that of the first electrode tab 210. This allows the current collector body 100 to be wound into a core and the first and second electrode tabs 210, 220 to be flattened toward the center of the core. The second electrode tab 220 can minimize the obstruction of the first electrode tab 210, thereby also allowing the first electrode tab 210 to be exposed to a larger area.

[0064] It can be understood that, relative to the uniform shape and size of the pole ears, the application of the current collector in the embodiment of the present application can increase the effective contact area between the inner pole ears and the current collecting plate by reducing the obstruction of the inner pole ears by the outer pole ears, thereby ensuring the welding strength and flow area, improving the welding tension between the current collecting plate and the pole ears, and improving the performance of the battery.

[0065] It should be noted that the first preset area can be determined according to actual needs and is not specifically limited in this embodiment.

[0066] Thus, the current collector provided in the embodiment of the present application includes a current collector body 100 and a tab group 200. The current collector body 100 has a first surface. A coating area 110 and a blank area 120 are provided on the first surface, and an active material layer 10 is coated on the coating area 110. The tab group 200 includes at least a first tab 210 and a second tab 220. The first tab 210 and the second tab 220 are spaced apart along the winding direction of the current collector body 100 and are respectively connected to part of the blank area 120. The first tab 210 and the second tab 220 are provided. 220 extends in a direction away from the coating area 110, wherein the first pole ear 210 and the second pole ear 220 are arranged to have different shapes or areas, and are wound into a core on the current collector body 100, and the first pole ear 210 and the second pole ear 220 are flattened toward the center of the core, the area of ​​the first pole ear 210 blocked by part of the second pole ear 220 is less than or equal to the first preset area, so that the area of ​​the inner pole ear blocked is reduced, and the effective contact area between the inner pole ear and the current collecting disk can be increased, thereby ensuring the welding strength and the flow area, and improving the performance of the battery.

[0067] In one possible design, the first electrode tab 210 has at least a first side 211 , a second side 212 , and a third side 213 connected in sequence, and the side of the current collector body 100 facing away from the coating area 110 has a reference side a parallel to the winding direction.

[0068] The first side 211 and the third side 213 are parallel and intersect with the reference side respectively. The second side 212 is parallel to the reference side and faces away from the coating area 110 .

[0069] Specifically, if Figure 1 、 Figure 2 As shown, the current collector body 100 has a reference side a on the side away from the coating area 110, and the reference side a is parallel to the winding direction. The extension direction of the reference side a is as shown in FIG. Figure 1 In the X-axis direction.

[0070] The first electrode tab 210 is substantially in the shape of a parallelogram, wherein the first side 211 and the third side 213 are parallel to each other, one end of the first side and the third side 213 are connected to the reference side a, and the other end of the first side and the third side are connected to the second side 212 .

[0071] Of course, the intersections of the first side 211 and the third side 213 with the second side 212 may be rounded, and the intersections of the first side 211 and the third side 213 with the reference side a may be rounded to avoid stress concentration.

[0072] Furthermore, in this embodiment, the first side 211 or the third side 213 forms a first angle θ1 with the reference side, and the first angle θ1 is an acute angle.

[0073] Specifically, if Figure 2 As shown, the first angle θ1 can be 75°~85°, and the specific size can be determined according to actual needs, and is not too limited in this embodiment.

[0074] In some embodiments, the second electrode tab 220 has at least a fourth side 221 , a fifth side 222 and a sixth side 223 connected in sequence, the fourth side 221 and the sixth side 223 are opposite and intersect with the reference side respectively, and the fifth side 222 is parallel to the reference side and away from the coating area 110 .

[0075] Specifically, if Figure 1 、 Figure 3 As shown, the second electrode tab 220 is roughly in the shape of an isosceles trapezoid, with the fourth side 221 and the sixth side 223 arranged opposite to each other, one end of the same side of the two being connected to the reference side a, and the other end of the same side of the two being connected to the fifth side 222, and the fourth side 221 and the sixth side 223 being of equal length and larger than the fifth side 222.

[0076] Of course, the intersections of the fourth side 221 and the sixth side 223 with the fifth side 222 can also be rounded, and the intersections of the fourth side 221 and the sixth side 223 with the reference side a can also be rounded to avoid stress concentration.

[0077] Furthermore, in this embodiment, the fourth side 221 or the sixth side 223 forms a second angle θ2 with the reference side a, and the second angle θ2 is an acute angle.

[0078] Specifically, if Figure 3 As shown, the second angle θ2 can also be 75°~85°, and the specific size can be determined according to actual needs, and is not too limited in this embodiment.

[0079] Furthermore, in this embodiment, the distance H1 between the second side 212 and the reference side a is greater than or equal to the distance H2 between the fifth side 222 and the reference side a.

[0080] Specifically, if Figure 2 、 Figure 3 As shown, H1 can be 4.5mm~5.0mm, and H2 can also be 4.5mm~5.0mm, but H1 is not smaller than H2. The specific size can be determined according to actual needs and is not excessively restricted in this embodiment.

[0081] Furthermore, in this embodiment, the spacing S1 between the adjacent first side 211 and the third side 213 is smaller than the spacing S2 between the adjacent fourth side 221 and the sixth side 223 .

[0082] Specifically, if Figure 2 、 Figure 3 As shown, S1 and S2 can be an average spacing, a minimum spacing or a maximum spacing. S1 can be 1.0 mm to 1.5 mm, and S2 can be 1.5 mm to 2.0 mm. The specific size can be determined according to actual needs and is not excessively restricted in this embodiment.

[0083] In some embodiments, the tab group 200 further includes a third tab 230 . The first tab 210 , the second tab 220 , and the third tab 230 are spaced apart along the winding direction and are respectively connected to a portion of the blank area 120 , and extend in a direction away from the coating area 110 .

[0084] Among them, the third pole tab 230 has a different shape or area from the second pole tab 220, and is wound into a core on the current collector body 100. When the first pole tab 210, the second pole tab 220 and the third pole tab 230 are all flattened toward the center of the core, the area of ​​the second pole tab 220 that is partially blocked by the third pole tab 230 is less than or equal to the second preset area.

[0085] That is to say, if Figure 1 、 Figure 4As shown, a third electrode tab 230 is provided on top of the first electrode tab 210 and the second electrode tab 220 to form a three-stage current collector. The third electrode tab 230 can be integrally formed with the current collector body 100 and formed by die-cutting. The third electrode tab 230 can also be connected to the current collector body 100 by bonding or other means. The first electrode tab 210, the second electrode tab 220, and the third electrode tab 230 are arranged sequentially along the winding direction of the current collector body 100. Multiple third electrode tabs 230 are arranged at intervals along the winding direction of the current collector body 100, connected to a portion of the blank area 120, and extending away from the coating area 110.

[0086] Specifically, in one example, the area of ​​the third pole tab 230 is different from that of the second pole tab 220, and the area of ​​the third pole tab 230 is smaller than that of the second pole tab 220, so that when the current collector body 100 is wound into a core, and the first pole tab 210 and the second pole tab 220 are flattened toward the center of the core, as shown in FIG. Figure 5 As shown, the shielding of the second tab 220 is minimized as much as possible. Figure 7 As shown, the second electrode tab 220 can also be exposed to a larger area. In another example, the third electrode tab 230 and the second electrode tab 220 have different shapes. When the current collector body 100 is wound into a core and the first electrode tab 210 and the second electrode tab 220 are flattened toward the center of the core, the third electrode tab 230 and the second electrode tab 220 are misaligned, thereby allowing the second electrode tab 220 to be exposed to a larger area.

[0087] In this way, by reducing the obstruction of the inner tab by the outer tab, the effective contact area between the inner tab and the current collecting plate can be increased, thereby ensuring the welding strength and flow area, and improving the performance of the battery.

[0088] It should be noted that the second preset area can be determined according to actual needs and is not specifically limited in this embodiment.

[0089] Furthermore, in this embodiment, the third electrode tab 230 has at least a seventh side 231, an eighth side 232 and a ninth side 233 connected in sequence, the seventh side 231 and the ninth side 233 are opposite and intersect with the reference side a respectively, and the eighth side 232 is parallel to the reference side a and away from the coating area 110.

[0090] Specifically, if Figure 1 、 Figure 4 As shown, the third electrode ear 230 is roughly in the shape of an isosceles trapezoid, with the seventh side 231 and the ninth side 233 arranged opposite to each other, one end of the same side of the two being connected to the reference side a, and the other end of the same side of the two being connected to the eighth side 232, and the seventh side 231 and the ninth side 233 being of equal length and larger than the eighth side 232.

[0091] Of course, the intersections of the seventh side 231 and the ninth side 233 with the eighth side 232 can also be rounded, and the intersections of the seventh side 231 and the ninth side 233 with the reference side a can also be rounded to avoid stress concentration.

[0092] Furthermore, in this embodiment, the seventh side 231 or the ninth side 233 forms a third angle θ3 with the reference side, and the third angle θ3 is an acute angle.

[0093] Specifically, if Figure 4 As shown, the second angle θ3 may also be 75° to 85°, and the specific size may be determined according to actual needs, and is not excessively limited in this embodiment.

[0094] Furthermore, in this embodiment, the distance H3 between the eighth side 232 and the reference side a is smaller than the distance H2 between the fifth side 222 and the reference side a.

[0095] Specifically, if Figure 3 、 Figure 4 As shown, H3 can be 4.0mm~4.5mm, and H2 can also be 4.5mm~5.0mm, but H3 is not larger than H2. The specific size can be determined according to actual needs and is not excessively restricted in this embodiment.

[0096] Furthermore, in this embodiment, the spacing S2 between the adjacent fourth side 221 and the adjacent sixth side 223 is less than or equal to the spacing S3 between the adjacent seventh side 231 and the adjacent ninth side 233 .

[0097] Specifically, if Figure 3 、 Figure 4 As shown, S2 and S3 can be an average spacing, a minimum spacing or a maximum spacing. S2 can be 1.5mm~2.0mm, and S3 can also be 1.5mm~2.0mm. The specific size can be determined according to actual needs and is not excessively restricted in this embodiment.

[0098] In some embodiments, the blank area 120 is provided with at least a first tab-free connecting section 121 and a multi-tab connecting section 122 along the winding direction, and the tab group 200 is located in the multi-tab connecting section 122 .

[0099] Specifically, if Figure 1 As shown, the first tab-free connecting section 121 is not connected to the tabs. It is the starting section of the winding, that is, the center of the battery cell. This arrangement avoids blocking the center hole after winding and affecting the seepage. The length of the first tab-free connecting section 121 can be determined according to actual needs.

[0100] Among them, the multi-tab connecting section 122 can be divided into a first tab connecting section 1221, a second tab connecting section 1222 and a third tab connecting section 1223 along the winding direction, which are respectively connected to the first tab 210, the second tab 220 and the third tab 230. The lengths of the first tab connecting section 1221, the second tab connecting section 1222 and the third tab connecting section 1223 along the winding direction can also be determined according to actual needs.

[0101] Furthermore, in this embodiment, the blank area 120 is further provided with a second tab-free connecting section 123 along the winding direction, and the first tab-free connecting section 121, the multi-tab connecting section 122 and the second tab-free connecting section 123 are arranged in sequence.

[0102] Specifically, continue as Figure 1 As shown, the length of the second tab-free connecting segment 123 is less than the length of the first tab-free connecting segment 121 .

[0103] In a second aspect, an embodiment of the present application further provides an electrode sheet, comprising an active material layer 10 and a current collector provided by any of the above embodiments, wherein the active material layer 10 is coated on a coating area 110 .

[0104] The structure of the current collector has been described in detail in the above embodiments and will not be repeated here.

[0105] Specifically, if Figure 1 As shown, the electrode sheet can be made into a positive electrode sheet or a negative electrode sheet according to the difference of the active material layer 10 .

[0106] The electrode sheet provided in the embodiment of the present application is configured with a current collector, which includes a current collector body 100 and a tab group 200. The current collector body 100 has a first surface, and a coating area 110 and a blank area 120 are provided on the first surface, and an active material layer 10 is coated on the coating area 110. The tab group 200 includes at least a first tab 210 and a second tab 220. The first tab 210 and the second tab 220 are spaced apart along the winding direction of the current collector body 100 and are respectively connected to part of the blank area 120. The first tab 210 and the second tab 220 are provided. The second pole tab 220 extends in a direction away from the coating area 110, wherein the first pole tab 210 and the second pole tab 220 are arranged to have different shapes or areas, and are wound into a core on the current collector body 100, and the first pole tab 210 and the second pole tab 220 are flattened toward the center of the core, the area of ​​the first pole tab 210 that is partially blocked by the second pole tab 220 is less than or equal to the first preset area, so that the area of ​​the inner pole tab blocked is reduced, and the effective contact area between the inner pole tab and the current collecting plate can be increased, thereby ensuring the welding strength and the flow area, and improving the performance of the battery.

[0107] Furthermore, in this embodiment, a protective material layer 20 is further included. The protective material layer 20 is also coated on the coating area 110 and is located between the active material layer 10 and the blank area 120 .

[0108] Specifically, continue as Figure 1 As shown, if it is a positive electrode sheet, a protective material layer 20 can be coated on one side of the blank area 120 close to the coating area 110. The protective material layer 20 can be made of boehmite, alumina and other materials, which can play a role in protection, insulation, etc., and improve the yield rate of the battery cell.

[0109] The protective material layer 20 is along Figure 1 The width in the Y-axis direction may be 2.2 mm to 2.5 mm, and the distance between the reference edge a and the protective material layer 20 may be 2.0 mm to 2.5 mm. The specific distance may be determined according to actual needs and is not excessively limited in this embodiment.

[0110] Thirdly, embodiments of the present application further provide a battery cell assembly, comprising a battery cell body and a current collector 30. The battery cell body comprises a separator and at least one electrode sheet provided in any of the above embodiments, and the battery cell body is formed by winding the electrode sheets and separator. The battery cell body is formed by winding at least one positive electrode sheet and one negative electrode sheet, sandwiching a separator.

[0111] The current collecting plate 30 is located at the end of the battery cell body and is connected to at least a portion of the first electrode tab 210 and a portion of the second electrode tab 220 on the current collector in the electrode sheet, such as by welding or soldering.

[0112] The structure of the electrode sheet has been described in detail in the above embodiments and will not be described again here.

[0113] The battery cell assembly provided by the embodiment of the present application is provided with an electrode sheet, the electrode sheet includes a current collector, the current collector includes a current collector body 100 and a tab group 200, the current collector body 100 has a first surface, by setting a coating area 110 and a blank area 120 on the first surface, and coating the active material layer 10 in the coating area 110, the tab group 200 includes at least a first tab 210 and a second tab 220, by setting the first tab 210 and the second tab 220 to be spaced apart along the winding direction of the current collector body 100 and respectively connected to part of the blank area 120, and setting the first tab 210 and the second tab 220 to be spaced apart along the winding direction of the current collector body 100 and respectively connected to part of the blank area 120, The ear 210 and the second pole ear 220 extend in a direction away from the coating area 110, wherein the first pole ear 210 and the second pole ear 220 are set to have different shapes or areas, and are wound into a core on the current collector body 100, and the first pole ear 210 and the second pole ear 220 are flattened toward the center of the core, the area of ​​the first pole ear 210 blocked by part of the second pole ear 220 is less than or equal to the first preset area, so that the area of ​​the inner pole ear blocked is reduced, and the effective contact area between the inner pole ear and the current collecting plate can be increased, thereby ensuring the welding strength and the flow area, and improving the performance of the battery.

[0114] Furthermore, in this embodiment, a plurality of welding areas 31 are provided on the current collecting plate 30 , and the welding areas 31 are distributed at intervals around the center of the current collecting plate 30 .

[0115] The welding area 31 includes a first welding area and a second welding area. The first welding area and the second welding area are both used for welding a portion of the first electrode tab 210 and a portion of the second electrode tab 220 .

[0116] The first welding area extends along a first direction, the second welding area extends along the first direction, and the first direction is perpendicular to or intersects with the second direction.

[0117] Specifically, if Figure 8 As shown, the current collecting plate 30 may be a disc-shaped structure matching the end of the battery cell body, and the welding areas 31 may be set to four or other numbers and distributed at intervals around the center of the current collecting plate 30 .

[0118] The welding area 31 includes a first welding area and a second welding area, both of which can be connected to a portion of the first electrode tab 210 or a portion of the second electrode tab 220 or a portion of the third electrode tab 230 by laser welding. Figure 8 As shown, taking the upper left welding area 31 as an example, the first welding area can be Figure 8 The second welding area can extend along the Y-axis direction. Figure 8 The first welding area and the second welding area extend in the X-axis direction, that is, the first welding area and the second welding area both extend in the radial direction parallel to the collecting plate 30. The first welding area and the second welding area can be connected in an L shape. The specific shape and position of the welding area 31 can be determined according to actual needs and are not excessively limited in this embodiment.

[0119] Furthermore, in this embodiment, a plurality of liquid seepage areas 32 are provided on the current collecting tray 30 , and the liquid seepage areas 32 are distributed at intervals around the center of the current collecting tray 30 .

[0120] Specifically, if Figure 8 As shown, the liquid seepage areas 32 can be liquid seepage holes, such as circular holes, waist-shaped holes, or slotted holes. The liquid seepage areas 32 are spaced apart around the center of the current collecting tray 30 and do not overlap with the welding area 31. The specific shape and number of the liquid seepage areas 32 can be determined based on actual needs and are not particularly limited in this embodiment. Furthermore, the center piece of the current collecting tray 30 can also be provided with a welding portion for connection to the cover plate.

[0121] In a fourth aspect, an embodiment of the present application further provides a cylindrical battery, comprising a shell and a cell assembly provided by any of the above embodiments arranged in the shell.

[0122] Specifically, the housing is used to encapsulate the battery cell assembly. Its outer shape can be cylindrical, with an internal cavity for accommodating the battery cell assembly and other components. In addition, other necessary components, such as explosion-proof valves and terminals, may also be provided on the inside or outside of the housing. The specific necessary components and size of the cylindrical battery can be determined according to actual needs and are not excessively limited in this embodiment.

[0123] The structure of the battery cell assembly has been described in detail in the above embodiments and will not be repeated here.

[0124] The cylindrical battery provided in the embodiment of the present application is prepared by preparing the above-mentioned battery cell assembly, which includes at least one of the above-mentioned electrode sheets, the electrode sheets including the above-mentioned current collector, the current collector including a current collector body 100 and a tab group 200, the current collector body 100 having a first surface, by providing a coating area 110 and a blank area 120 on the first surface, and coating the active material layer 10 in the coating area 110, the tab group 200 including at least a first tab 210 and a second tab 220, by providing the first tab 210 and the second tab 220 along the winding direction of the current collector body 100, and respectively connected to a portion of the blank area 120. In the white area 120, a first pole ear 210 and a second pole ear 220 are provided to extend in a direction away from the coating area 110, wherein the first pole ear 210 and the second pole ear 220 are provided with different shapes or areas, and are wound into a core on the current collector body 100, and when the first pole ear 210 and the second pole ear 220 are flattened toward the center of the core, the area of ​​the first pole ear 210 blocked by part of the second pole ear 220 is less than or equal to the first preset area, so that the area of ​​the inner pole ear blocked is reduced, and the effective contact area between the inner pole ear and the current collecting disk can be increased, thereby ensuring the welding strength and the flow area, and improving the performance of the battery.

[0125] Those skilled in the art will readily appreciate other embodiments of the present application after considering the specification and practicing the application disclosed herein. This application is intended to cover any variations, uses, or adaptations of the present application that follow the general principles of the present application and include common knowledge or customary techniques in the art not disclosed herein. The description and examples are to be considered merely as exemplary, and the true scope and spirit of the present application are indicated by the claims.

[0126] It should be understood that the present application is not limited to the precise structure described above and shown in the appended drawings, and that various modifications and changes may be made without departing from the scope thereof. The scope of the present application is limited only by the appended claims.

Claims

1. A current collector, characterized in that: include: A current collector body (100) having a first surface, wherein the first surface has a coating area (110) and a blank area (120), wherein the coating area (110) is at least used for coating an active material layer (10); A tab group (200), comprising at least a first tab (210) and a second tab (220), wherein the first tab (210) and the second tab (220) are spaced apart along the winding direction of the current collector body (100) and are respectively connected to a portion of the blank area (120), and the first tab (210) and the second tab (220) extend in a direction away from the coating area (110); The first pole tab (210) and the second pole tab (220) have different shapes or areas, and are wound into a core on the current collector body (100). When the first pole tab (210) and the second pole tab (220) are flattened toward the center of the core, the area of ​​the first pole tab (210) that is partially blocked by the second pole tab (220) is less than or equal to a first preset area.

2. The current collector according to claim 1, characterized in that The first electrode tab (210) has at least a first side (211), a second side (212), and a third side (213) connected in sequence, and the side of the current collector body (100) facing away from the coating area (110) has a reference side parallel to the winding direction; The first side (211) and the third side (213) are parallel and intersect with the reference side respectively, and the second side (212) is parallel to the reference side and faces away from the coating area (110).

3. The current collector according to claim 2, characterized in that The first side (211) or the third side (213) forms a first angle with the reference side, and the first angle is an acute angle.

4. The current collector according to claim 2, characterized in that The second electrode tab (220) has at least a fourth side (221), a fifth side (222), and a sixth side (223) connected in sequence, the fourth side (221) and the sixth side (223) are opposite to each other and intersect with the reference side respectively, and the fifth side (222) is parallel to the reference side and faces away from the coating area (110).

5. The current collector according to claim 4, characterized in that The fourth side (221) or the sixth side (223) forms a second angle with the reference side, and the second angle is an acute angle.

6. The current collector according to claim 4, characterized in that The distance between the second side (212) and the reference side is greater than or equal to the distance between the fifth side (222) and the reference side.

7. The current collector according to claim 4, characterized in that The distance between the adjacent first side (211) and the third side (213) is smaller than the distance between the adjacent fourth side (221) and the sixth side (223).

8. The current collector according to claim 4, characterized in that The electrode tab group (200) further includes a third electrode tab (230), wherein the first electrode tab (210), the second electrode tab (220), and the third electrode tab (230) are spaced apart along the winding direction and are respectively connected to a portion of the blank area (120), and respectively extend in a direction away from the coating area (110); The third pole tab (230) is different from the second pole tab (220) in shape or area, and is wound into the core on the current collector body (100). When the first pole tab (210), the second pole tab (220) and the third pole tab (230) are flattened toward the center of the core, the area of ​​the second pole tab (220) blocked by part of the third pole tab (230) is less than or equal to the second preset area.

9. The current collector according to claim 8, characterized in that The third electrode tab (230) has at least a seventh side (231), an eighth side (232), and a ninth side (233) connected in sequence, the seventh side (231) and the ninth side (233) are opposite to each other and intersect with the reference side respectively, and the eighth side (232) is parallel to the reference side and faces away from the coating area (110).

10. The current collector according to claim 9, characterized in that The seventh side (231) or the ninth side (233) forms a third angle with the reference side, and the third angle is an acute angle.

11. The current collector according to claim 9, characterized in that The distance between the eighth side (232) and the reference side is smaller than the distance between the fifth side (222) and the reference side.

12. The current collector according to claim 9, characterized in that The distance between the adjacent fourth side (221) and the sixth side (223) is less than or equal to the distance between the adjacent seventh side (231) and the ninth side (233).

13. The current collector according to any one of claims 1 to 12, characterized in that: The blank area (120) is provided with at least a first tab-free connecting section (121) and a multi-tab connecting section (122) along the winding direction, and the tab group (200) is located in the multi-tab connecting section (122).

14. The current collector according to claim 13, characterized in that The blank area (120) is further provided with a second tab-free connecting section (123) along the winding direction, and the first tab-free connecting section (121), the multi-tab connecting section (122), and the second tab-free connecting section (123) are arranged in sequence.

15. An electrode sheet, characterized in that: The invention comprises an active material layer (10) and a current collector according to any one of claims 1 to 14, wherein the active material layer (10) is coated on the coating area (110).

16. The electrode sheet according to claim 15, characterized in that It also includes a protective material layer (20), which is also coated on the coating area (110) and located between the active material layer (10) and the blank area (120).

17. A battery cell assembly, characterized in that: Comprising a battery cell body and a current collecting plate (30), the battery cell body comprising a diaphragm and at least one electrode sheet according to any one of claims 15 to 16, the battery cell body being formed by winding the electrode sheet and the diaphragm; The current collecting plate (30) is located at the end of the battery cell body and is connected to at least a portion of the first pole tab (210) and a portion of the second pole tab (220) on the current collector in the electrode sheet.

18. The battery cell assembly according to claim 17, characterized in that: The current collecting disk (30) is provided with a plurality of welding areas (31), and the welding areas (31) are spaced apart and distributed around the center of the current collecting disk (30); The welding area (31) comprises a first welding area and a second welding area, wherein the first welding area and the second welding area are both used for welding a portion of the first electrode tab (210) and a portion of the second electrode tab (220); The first welding area extends along a first direction, the second welding area extends along the first direction, and the first direction is perpendicular to or intersects with the second direction.

19. The battery core assembly according to claim 18, characterized in that: The collecting tray (30) is further provided with a plurality of liquid seepage areas (32), and the liquid seepage areas (32) are distributed at intervals around the center of the collecting tray (30).

20. A cylindrical battery, characterized in that: The invention comprises a shell and a battery cell assembly according to any one of claims 17 to 19 arranged in the shell.

Images