Electrode sheet, battery cell and battery

Abstract

The present application relates to the technical field of batteries. Provided are an electrode sheet, a battery cell and a battery. The electrode sheet comprises a current collector, and an active layer and an insulating layer which are located on the current collector, wherein the active layer comprises a first body area and an edge area connected to each other; the insulating layer comprises a second body area, and a first side area close to the active layer, the thickness of the first side area of the insulating layer being less than that of the second body area of the insulating layer. The ratio of the minimum thickness of the edge area to the thickness of the first body area is 0.95-1.05. The electrode sheet provided in the embodiments of the present application can effectively reduce the overall thickness difference of the active layer, such that the active layer on the current collector has a more uniform thickness. In this way, after the electrode sheet is wound or stacked, the accumulation of thickness differences can be effectively reduced, and the thickness difference between a middle body portion and the edge of a battery cell can be effectively reduced. The content of the active layer can be effectively increased, thereby effectively increasing the energy density of the battery cell.

Description

Pole piece, battery cell and battery TECHNICAL FIELD

[0001] The present application relates to the technical field of battery, in particular to a pole piece, a battery cell and a battery. BACKGROUND

[0002] Battery is a kind of component that converts chemical energy into electrical energy, which has very wide application in daily life and work. For example, lithium ion battery is often used in mobile phones, cameras, notebooks and tablets and other electronic devices, providing power supply for electronic devices, and occupying a very important position in people's life and work.

[0003] Lithium ion battery includes a pole piece, which includes a current collector and an active layer and an insulating layer coated on the current collector. Generally, in the process of coating the active layer on the current collector, the part of the active layer close to the edge has a thinning area. The thickness of the thinning area is usually thinner, and the thickness of the thinning area is usually several microns different from the thickness of the main body area of the active layer. Thus, after being wound or stacked for many times, the thickness difference will accumulate, making the difference between the thickness of the edge of the pole piece and the thickness of the main body area reach several millimeters, greatly reducing the energy density of the battery cell. SUMMARY

[0004] The present application provides a pole piece, a battery cell and a battery, which can effectively improve the energy density of the edge of the battery cell.

[0005] One aspect of the present application provides a pole piece, comprising a current collector and an active layer and an insulating layer on the current collector.

[0006] The active layer comprises a first main body area and an edge area connected, and the insulating layer is arranged adjacent to the edge area of the active layer, and the insulating layer comprises a second main body area and a first side area close to the active layer, and the thickness of the first side area of the insulating layer is less than the thickness of the second main body area of the insulating layer.

[0007] The ratio of the minimum thickness of the edge area to the thickness of the first main body area is 0.95-1.05.

[0008] The present application makes the ratio of the minimum thickness of the edge area of the active layer to the thickness of the first main body area 0.95-1.05, which can effectively reduce the thickness difference of the whole active layer, make the thickness of the active layer on the current collector more uniform, effectively reduce the thickness difference between the middle main body part and the edge of the pole piece, and make the thickness of the whole pole piece more uniform. After winding or stacking the pole piece, the accumulation of thickness difference can be effectively reduced, and the thickness difference between the middle main body part and the edge of the battery cell can be effectively reduced. The content of the active layer can be effectively improved, thereby effectively improving the energy density of the battery cell.

[0009] In a possible implementation, the thickness of the edge region gradually decreases from one end of the edge region close to the first body region to the other end of the edge region away from the first body region.

[0010] In a possible implementation, the ratio of the thickness of the highest point of the second body region to the thickness of the highest point of the first body region is 1:1-1:4.

[0011] In a possible implementation, the current collector comprises a tab region and a lug region connected to each other.

[0012] The active layer is located on the tab region, and the second body region of the insulating layer is located on the lug region.

[0013] In a possible implementation, the distance from the highest point of the second body region to the edge region is a, and the distance from the highest point of the second body region to the end of the insulating layer away from the edge region is b, and the value of a is less than or equal to the value of b.

[0014] And / or, 0.2mm≤a≤1.5mm.

[0015] And / or, 1.5mm≤b≤3mm.

[0016] In a possible implementation, the ratio of the distance a from the highest point of the second body region to the edge region to the length of the lug region is 0.1-0.3.

[0017] In a possible implementation, the ratio of the thickness of the highest point of the second body region to the thickness of the end of the edge region close to the insulating layer is 1:1-3:1.

[0018] In a possible implementation, there is a gap between at least the partial insulating layer and the edge region, and the ratio of the gap to the width of the insulating layer is less than 0.3.

[0019] And / or, the width of the gap is less than or equal to 0.5mm.

[0020] In a possible implementation, the gap is located in the tab region or in the lug region.

[0021] The second aspect of the present application provides an electric core, comprising a first tab, a second tab and a separator, wherein the first tab is any of the above-mentioned tabs.

[0022] In a possible implementation, in the direction from the tab region to the lug region of the first tab, the highest point of the insulating layer of the first tab exceeds the edge of the second tab.

[0023] The third aspect of the present application provides a battery comprising the above-mentioned battery cell. BRIEF DESCRIPTION OF DRAWINGS

[0024] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiments or prior art description. Obviously, the drawings in the following description are some embodiments of the present application. Those skilled in the art can also obtain other drawings according to these drawings without any creative effort.

[0025] FIG. 1 is a structural schematic diagram of a pole piece according to an embodiment of the present application.

[0026] FIG. 2 is a sectional view of a pole piece according to an embodiment of the present application.

[0027] FIG. 3 is a physical diagram of a sectional view of a pole piece according to an embodiment of the present application.

[0028] FIG. 4 is a structural schematic diagram of a current collector according to an embodiment of the present application.

[0029] Reference signs: 100-pole piece; 110-current collector; 111-pole piece area; 112-tab area; 120-active layer; 121-first main body area; 122-edge area; 130-insulating layer; 131-second main body area; 132-first side area; 140-gap. DETAILED DESCRIPTION

[0030] In order to make the purpose, technical solutions and advantages of the embodiments of the present application more clear, the following will combine the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are some embodiments of the present application, but not all the embodiments. Based on the embodiments in the present application, all the other embodiments obtained by those skilled in the art without any creative effort are within the protection scope of the present application.

[0031] As the content of the above background art, the lithium ion battery comprises a pole piece, and the pole piece comprises a current collector and an active layer coated on the current collector. Generally, in the process of coating the active layer on the current collector, the part of the active layer close to the edge has a thinning area, and the thickness of the thinning area is usually thinner, and the thickness of the thinning area and the thickness of the main body area of the active layer usually differ by several microns. Thus, after being wound or laminated for many times, the thickness difference will be accumulated, so that the difference between the thickness of the edge of the pole piece and the thickness of the main body area reaches several millimeters. Thus, in the process of hot pressing of the pole piece, the side of the battery cell connected with the tab area will appear concave, so that the edge of the pole piece is less pressed, which reduces the adhesion of the edge of the pole piece, and also reduces the energy density of the edge of the battery cell.

[0032] To solve the above problems, the application provides an electrode sheet, so that the ratio of the minimum thickness of the edge area of the active layer to the thickness of the first main body area is 0.95-1.05. In this way, the thickness difference of the active layer as a whole can be effectively reduced, the thickness of the active layer on the current collector is more uniform, the thickness difference between the middle main body part and the edge of the electrode sheet can be effectively reduced, and the thickness of the electrode sheet as a whole is more uniform. After the electrode sheet is wound or stacked, the accumulation of the thickness difference can be effectively reduced, the thickness difference between the middle main body part and the edge of the battery can be effectively reduced. The content of the active layer can be effectively improved, thereby effectively improving the energy density of the battery.

[0033] The electrode sheet provided by the application is described in detail below with reference to the accompanying drawings.

[0034] FIG. 1 is a structural schematic diagram of an electrode sheet provided by the application, FIG. 2 is a sectional view of an electrode sheet provided by the application, and FIG. 3 is a sectional view of an electrode sheet provided by the application.

[0035] The application provides an electrode sheet 100, which can be a positive electrode sheet. The positive electrode sheet can be stacked with a negative electrode sheet to form a battery. Referring to FIG. 1 and FIG. 2, the electrode sheet 100 can include a current collector 110, an active layer 120 on the current collector 110, and an insulating layer 130, which can be arranged adjacent to the active layer 120.

[0036] Referring to FIG. 2 and FIG. 3, the active layer 120 can include a first main body area 121 and an edge area 122 connected thereto. The insulating layer can be arranged adjacent to the edge area 122 of the active layer 120, i.e., the edge area 122 is located between the first main body area 121 and the insulating layer 130. The insulating layer 130 can include a second main body area 131 and a first side area 132 adjacent to the active layer 120, i.e., the first side area 132 is located between the edge area 122 and the second main body area 131. The thickness of the first side area 132 of the insulating layer 130 is less than the thickness of the second main body area 131 of the insulating layer 130.

[0037] The dividing point between the first main body area 121 and the first edge area 122 can be determined as follows: from the edge area 122 of the active layer 120 to the first main body area 121 of the active layer 120, every 50 μm is taken as a test point, and the position where the thickness increase rate of adjacent two test points is less than 1% is the dividing point between the first main body area 121 and the first edge area 122.

[0038] Correspondingly, the dividing point between the second main body area 131 and the first side area 132 in the insulating layer 130 can also be determined by referring to the determination method of the dividing point between the first main body area 121 and the first edge area 122.

[0039] The ratio of the minimum thickness d2 of the edge region 122 to the thickness d1 of the first main body region 121 can be 0.95-1.05.

[0040] This can effectively reduce the thickness difference between the first main body region 121 and the edge region 122 of the active layer 120, and make the thickness of the active layer 120 more uniform.

[0041] For example, the active layer 120 can be disposed on the current collector 110 by coating. For example, before coating the active layer 120 on the current collector 110, two rows of adhesive tape can be pasted on the current collector 110, and the two rows of adhesive tape have a gap therebetween. The coating of the active layer 120 is performed between the two rows of adhesive tape, so that the active layer 120 fills the gap between the two rows of adhesive tape. During the coating of the active layer 120, the active layer 120 can be coated more uniformly between the two rows of adhesive tape, so that the thinned region of the active layer 120 is located on the adhesive tape.

[0042] After the coating and drying of the active layer 120 are completed, the adhesive tape can be torn off, and only the active layer 120 between the two rows of adhesive tape remains on the current collector 110. During the tearing off of the adhesive tape, the thinned region of the active layer 120 on the adhesive tape is removed from the current collector 110 together with the adhesive tape, and only the first main body region 121 and the edge region 122 of the active layer 120 remain, and the thickness difference between the edge region 122 and the first main body region 121 is small, which can effectively improve the uniformity of the thickness of the active layer 120 as a whole, and reduce the thickness difference between the middle main body region and the edge region of the pole piece, and make the thickness of the pole piece more uniform.

[0043] Compared with the related art, the ratio of the minimum thickness of the edge region 122 of the active layer 120 to the thickness of the first main body region 121 is 0.95-1.05, which can effectively reduce the thickness difference of the active layer 120 as a whole, make the thickness of the active layer 120 on the current collector 110 more uniform, effectively reduce the thickness difference between the middle main body region and the edge region of the pole piece, and make the thickness of the pole piece more uniform. This can effectively reduce the accumulation of the thickness difference after the pole piece is wound or stacked, effectively reduce the thickness difference between the middle main body region and the edge region of the pole piece, effectively improve the content of the active layer 120, and effectively improve the energy density of the battery cell.

[0044] Continuing to participate in the edge area 122 shown in Figure 2, from the edge area 122 close to one end of the first main body area 121 to the edge area 122 away from one end of the first main body area 121, the thickness of the edge area 122 gradually decreases. That is, the lowest thickness of the edge area 122 is the thickness of the edge area 122 away from one end of the first main body area 121. Therefore, it can be understood that the ratio of the lowest thickness of the edge area 122 to the thickness of the first main body area 121 is the ratio of the thickness of the edge area 122 away from one end of the first main body area 121 to the thickness of the first main body area 121.

[0045] The thickness of the edge area 122 away from one end of the first main body area 121 is the thinnest part of the entire active layer 120, and the thickness of the first main body area 121 is the thickest part of the active layer 120, that is, the ratio between the thinnest part of the active layer 120 and the thickest part of the active layer 120 is 0.95-1.05. In this way, the overall thickness difference of the active layer 120 can be effectively reduced, the overall thickness uniformity of the active layer 120 can be effectively improved, the overall thickness uniformity of the pole piece 100 can be effectively improved, and the content of the active layer 120 can be effectively improved, thereby effectively improving the energy density of the battery cell.

[0046] The ratio of the thickness of the highest point of the second main body area 131 of the insulating layer 130 to the thickness of the highest point of the first main body area 121 of the active layer 120 is 1:1-1:4. The thickness of the insulating layer 130 is relatively small compared to the thickness of the active layer 120, and the difference between the thickness of the insulating layer 130 and the thickness of the active layer 120 is also relatively small, which can make the thickness of the material layer on the current collector more uniform. During the hot pressing formation process of the pole piece, the depression at the connection tab area of the battery cell can be reduced, and the overall stress of the battery cell can be more uniform, thereby effectively improving the adhesion of the edge of the pole piece and improving the overall structural stability of the battery cell.

[0047] Figure 4 is a structural schematic diagram of a current collector provided by an embodiment of the present application.

[0048] Referring to Figure 4, the current collector 110 can include a pole piece area 111 and a tab area 112 connected thereto, for example, the tab area 112 can be cut on the current collector 110 by cutting or the like. For example, after the insulating layer 130 is point-set on the current collector 110, the pole piece 100 can be cut or trimmed to form the tab area 112.

[0049] The active layer 120 can be located on the tab area 111, and the second main body area 131 of the insulating layer 130 can be located on the tab ear area 112. The insulating layer 130 can be dropped on the current collector 110 by means of glue-dropping, and after the insulating layer 130 is dropped on the current collector 110, the insulating layer 130 can extend outward, and as the insulating layer 130 extends outward, the thickness of the insulating layer 130 gradually thins, and the thickest part of the insulating layer 130 is the second main body area 131 of the insulating layer 130.

[0050] When the insulating layer 130 is arranged by means of glue-dropping, the insulating layer 130 can be dropped on the tab ear area 112, so that the second main body area 131 of the insulating layer 130 falls on the tab ear area. In this way, the amount of the insulating layer 130 arranged on the tab ear area 112 can be ensured, so that the insulating layer 130 can effectively cover burrs at the cutting edge of the tab ear area 112, thereby effectively preventing the burrs from piercing the diaphragm and causing problems such as short circuit of the battery, and the safety of the battery can be effectively improved.

[0051] Moreover, the second main body area 131 of the insulating layer 130 is the thickest part of the insulating layer 130, and the second main body area 131 is located on the tab ear area 112 and has a relatively large thickness, which can increase the thickness of the edge area of the tab 100. The difference between the thickness of the edge area 122 of the tab 100 and the thickness of the middle of the tab 100 is small, which can effectively improve the uniformity of the overall thickness of the tab 100. In this way, after the tab 100 is wound or stacked, the accumulation of the thickness difference can be effectively reduced, and the thickness difference between the middle main body part and the edge of the battery cell can be effectively reduced. During the hot-pressing formation process of the tab 100, the depression at the tab ear area 112 of the battery cell can be reduced, so that the stress on the battery cell as a whole is more uniform, thereby effectively improving the adhesion of the edge of the tab 100 and improving the structural stability of the battery cell as a whole.

[0052] In the embodiments of the present application, the forming material of the insulating layer 130 can be any one of bormite, aluminum oxide or polyimide. The above-mentioned materials all have good insulation, which can effectively improve the insulation performance of the insulating layer 130, and can effectively reduce or avoid short circuit of the battery, thereby effectively improving the safety of the battery.

[0053] Continuing to refer to FIG. 2, the distance from the highest point of the second main body area 131 to the edge area 122 can be a, and 0.2mm≤a≤1.5mm, in other words, it can be understood that the distance between the dropping position of the insulating layer 130 and the size of the edge area 122 of the active layer 120 is the above-mentioned value.

[0054] By controlling the distance between the dropping point of the insulation layer 130 and the edge area 122 of the active layer 120, the insulation layer 130 can be reasonably contacted with the edge of the active layer 120 during the spreading of the insulation layer 130. The gap between the insulation layer 130 and the active layer 120 can be effectively reduced, and the mutual fusion between the insulation layer 130 and the active layer 120 can be reduced or avoided.

[0055] In this way, the gap between the insulation layer 130 and the active layer 120 can be prevented from being too large to cause the negative pole piece to contact the current collector and short circuit. The contact and fusion between the insulation layer 130 and the active layer 120 can also be avoided to prevent the thickness of the fused part from being too high to cause the thickness of the pole piece to be uneven.

[0056] Referring back to FIG. 2, the distance from the highest point of the second main body area 131 to the end of the insulation layer 130 away from the edge area 122 can be b, and 1.5 mm≤b≤3 mm. That is, the distance from the highest point of the insulation layer 130 to the end of the insulation layer 130 away from the edge area 122 is small, which can reduce the proportion of the insulation layer 130 on the current collector, thereby increasing the proportion of the active layer 120 on the current collector and effectively improving the energy density of the battery.

[0057] In the formula, the value of a can be less than the value of b. After the insulation layer 130 drops on the tab area 112, the insulation layer 130 flows in the direction away from the active layer 120 by a distance of b, and the insulation layer 130 flows in the direction close to the active layer 120 by a distance of a. By making the value of a less than the value of b, that is, the insulation layer 130 stops flowing after contacting the active layer 120 by a distance, while the insulation layer 130 continues to flow in the direction away from the active layer 120.

[0058] In the formula, the insulation layer 130 stops flowing after encountering the block of the active layer 120, and the thickness of the end of the insulation layer 130 close to the active layer 120 gradually increases as the insulation layer 130 continues to flow. In this way, the thickness difference between the insulation layer 130 and the active layer 120 can be effectively reduced, thereby effectively improving the uniformity and consistency of the overall thickness of the battery cell.

[0059] Referring back to FIG. 2, the ratio of the distance a from the highest point of the insulation layer 130 to the edge area 122 to the length of the tab area 112 can be 0.1-0.3. In this way, the coverage size of the insulation layer 130 on the tab area 112 can be increased. When the battery is at high temperature and the isolation film shrinks, the negative pole piece can contact the insulation layer 130, which can avoid the negative pole piece from contacting the tab area 112 and causing short circuit, thereby helping to improve the safety of the battery.

[0060] Continuing to refer to FIG. 2, the thickness of the highest point of the insulation layer 130 can be d3, the thickness of the edge area 122 close to one end of the insulation layer 130 can be d2, and the ratio between the value of d3 and the value of d2 can be 1:1-3:1. In this way, the thickness difference between the insulation layer 130 and the active layer 120 can be reduced, the flatness of the overall thickness of the battery cell can be effectively improved, the adhesion of the edge of the battery cell can be improved, and the stability of the battery cell can be effectively improved.

[0061] Continuing to refer to FIG. 2, the insulation layer 130 and the edge area 122 have a gap 140 therebetween, and the width of the gap 140 is less than or equal to 0.5 mm. The size of the gap 140 is small, which can reduce or avoid the negative tab area from contacting the current collector 110 to cause internal short circuit of the battery, and helps to improve the safety of the battery.

[0062] And / or, the ratio between the width of the gap 140 and the width of the insulation layer 130 (i.e., a+b) can be less than 0.3. By controlling the ratio between the width of the gap 140 and the width of the insulation layer 130, the size of the gap 140 can be controlled, and the size of the gap 140 can be effectively reduced. In this way, the negative tab area can be prevented from contacting the current collector 110 to cause internal short circuit of the battery, and the safety of the battery can be improved.

[0063] The gap 140 can be located in the tab area 111 or in the tab area 112. Since the length of the tab 100 is relatively long, during the coating of the active layer 120 on the current collector 110, the edge of the active layer 120 will be offset to some extent, so that part of the edge of the active layer 120 is located on the tab area 111 and part of the edge of the active layer 120 is located on the tab area 112. Therefore, the gap 140 is located in the tab area 111 or in the tab area 112.

[0064] The embodiments of the present application can also provide a battery cell, which can include a first tab, a second tab, and a separator. The first tab can be the tab 100 in any of the above scenarios. For example, the tab 100 can be a positive tab, and the second tab can be a negative tab. By including the tab 100 described above, the recessed position in the battery cell can be effectively reduced, the uniformity of the overall thickness of the battery cell can be effectively improved, the adhesion of the overall battery cell can be improved, and the structural stability of the battery cell can be effectively improved. Moreover, the energy density of the battery cell can also be effectively improved.

[0065] In the direction from the tab area 111 to the tab area 112 of the first tab, the highest point of the insulation layer 130 exceeds the edge of the second tab, in other words, the highest point of the insulation layer 130 is located outside the negative tab. In this way, the edge of the negative tab can be close to the edge of the positive tab under the premise of meeting the wrapping effect of the positive tab, the size difference between the negative tab and the positive tab can be effectively reduced, and the overall energy density of the battery cell can be improved.

[0066] The embodiment of the present application can also provide a battery, which can include the above-mentioned battery cell. By making the battery include the above-mentioned battery cell, the battery cell has good flatness and structural stability, which can effectively improve the flatness and structural stability of the battery as a whole, and help to improve the service life of the battery. Moreover, the battery can also have a high energy density, which can improve the endurance time of the battery.

[0067] In the description of the present application, it should be understood that the orientations or positional relationships indicated by the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer" and the like are based on the orientations or positional relationships shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and therefore cannot be understood as indicating or implying 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.

[0068] In the description of the present application, it should be understood that the terms "include" and "have" and any variations thereof used herein are intended to cover non-exclusive inclusion, for example, a process, method, system, product or device including a series of steps or units need not be limited to those clearly listed steps or units, but can include other steps or units not clearly listed or inherent to these processes, methods, products or devices.

[0069] Unless otherwise explicitly specified and limited, the terms "mount", "connect", "connect", "fix", and the like should be understood in a broad sense, for example, it can be fixedly connected, or it can be detachably connected, or it can be integrated; it can be directly connected, or it can be indirectly connected through an intermediate medium; it can be connected internally between two elements or interactively between two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances. In addition, the terms "first", "second", etc. are only for the purpose of description, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the technical features indicated.

[0070] Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the present application, and not to limit them; although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that they can still modify the technical solutions recorded in the foregoing embodiments, or make equivalent replacement for part or all of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present application.

Claims

1. An electrode sheet, characterized in that, Includes a current collector, an active layer on the current collector, and an insulating layer; The active layer includes a first main region and an edge region connected together. The insulating layer is disposed adjacent to the edge region of the active layer. The insulating layer includes a second main region and a first side region near the active layer. The thickness of the first side region of the insulating layer is less than the thickness of the second main region of the insulating layer. The ratio of the minimum thickness of the edge region to the thickness of the first main body region is 0.95 to 1.

05.

2. The electrode sheet according to claim 1, characterized in that, The thickness of the edge region gradually decreases from the end of the edge region closer to the first main body region to the end of the edge region farther away from the first main body region.

3. The electrode sheet according to claim 1 or 2, characterized in that, The ratio of the thickness of the highest point of the second main body area to the thickness of the highest point of the first main body area is 1:1 to 1:

4.

4. The electrode sheet according to any one of claims 1 to 3, characterized in that, The current collector includes a connected electrode region and an electrode tab region; The active layer is located on the electrode region, and the second main body region of the insulating layer is located on the tab region.

5. The electrode sheet according to claim 4, characterized in that, At least a portion of the insulating layer has a gap between itself and the edge region, the ratio of the gap to the width of the insulating layer being less than 0.

3.

6. The electrode sheet according to claim 5, characterized in that, The width of the gap is less than or equal to 0.5 mm.

7. The electrode sheet according to claim 5 or 6, characterized in that, The gap is located in the electrode area or in the tab area.

8. The electrode sheet according to any one of claims 4 to 7, characterized in that, The ratio of the distance 'a' from the highest point of the second main body region to the edge region to the length of the tab region is 0.1 to 0.

3.

9. The electrode sheet according to any one of claims 1 to 8, characterized in that, The distance from the highest point of the second main body region to the edge region is a, and the distance from the highest point of the second main body region to the end of the insulating layer away from the edge region is b, wherein the value of a is less than or equal to the value of b.

10. The electrode sheet according to claim 9, characterized in that, 0.2mm ≤ a ≤ 1.5mm.

11. The electrode according to claim 9 or 10, characterized in that, 1.5mm ≤ b ≤ 3mm.

12. The electrode sheet according to claim 1 or 2, characterized in that, The ratio of the thickness of the highest point of the second main body region to the thickness of the edge region near the end of the insulating layer is 1:1 to 3:

1.

13. The electrode sheet according to claim 1 or 2, characterized in that, The current collector includes a connected electrode region and an electrode tab region; The active layer is located on the electrode region, and the second main body region of the insulating layer is located on the tab region.

14. The electrode sheet according to claim 13, characterized in that, At least a portion of the insulating layer has a gap between itself and the edge region, the ratio of the gap to the width of the insulating layer being less than 0.

3.

15. The electrode sheet according to claim 14, characterized in that, The width of the gap is less than or equal to 0.5 mm.

16. The electrode sheet according to claim 14 or 15, characterized in that, The gap is located in the electrode area or in the tab area.

17. The electrode sheet according to any one of claims 13 to 16, characterized in that, The ratio of the distance 'a' from the highest point of the second main body region to the edge region to the length of the tab region is 0.1 to 0.

3.

18. The electrode according to any one of claims 13 to 17, characterized in that, The distance from the highest point of the second main body region to the edge region is a, and the distance from the highest point of the second main body region to the end of the insulating layer away from the edge region is b, wherein the value of a is less than or equal to the value of b.

19. The electrode according to claim 18, characterized in that, 0.2mm ≤ a ≤ 1.5mm.

20. The electrode sheet according to claim 18 or 19, characterized in that, 1.5mm ≤ b ≤ 3mm.

21. The electrode sheet according to any one of claims 13 to 20, characterized in that, The ratio of the thickness of the highest point of the second main body region to the thickness of the edge region near the end of the insulating layer is 1:1 to 3:

1.

22. A battery cell, characterized in that, It includes a first electrode, a second electrode, and a diaphragm, wherein the first electrode is the electrode described in any one of claims 1 to 21.

23. The battery cell according to claim 22, characterized in that, Along the direction from the electrode region of the first electrode to the tab region, the highest point of the insulating layer of the first electrode extends beyond the edge of the second electrode.

24. A battery, characterized in that, Includes the battery cell described in claim 22 or 23.

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