An electrode sheet, an electrode, an electrode assembly, an electric double layer capacitor, an electric storage device, and a power storage device
By setting grooves in the active material layer of the electrode sheet and adjusting the groove distance and the current collector thickness, the problem of electrolyte difficulty in penetrating large-sized electrode sheets was solved, improving the wetting effect and cycle performance of the battery cell.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- CALB GROUP CO LTD
- Filing Date
- 2025-08-14
- Publication Date
- 2026-07-03
AI Technical Summary
As battery capacity requirements increase and electrode size grows, electrolytes struggle to fully penetrate and wet the central active material layer, leading to black spots appearing on the active material layer during cell use and affecting cell cycle performance.
Multiple grooves are set on the side of the active material layer of the electrode sheet away from the current collector to increase the contact area between the active material layer and the electrolyte. By adjusting the minimum distance between the grooves and the thickness range of the current collector, the total amount of active material is ensured to be appropriate, reducing the difficulty of electrolyte wetting.
This improves the wetting effect of the electrolyte on the active material layer, reduces the probability of black spots appearing on the active material layer during the charging and discharging process of the battery cell, and enhances the cycle performance and mechanical stability of the battery cell.
Smart Images
Figure CN224458102U_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of battery technology, and in particular to an electrode sheet, a battery cell, a battery, a battery pack, and an electrical device. Background Technology
[0002] As the demand for high-capacity batteries continues to increase, the size of individual batteries is also constantly growing. This trend has led to a gradual increase in the size of the electrode plates inside the battery cell, including both length and width.
[0003] Electrode sheets generally consist of a current collector and an active material layer. The active material layer covers one or two surfaces of the current collector. During the cell manufacturing process, electrolyte needs to be injected to fully wet the active material layer.
[0004] Due to the increased size of the electrode sheets and the multiple layers of electrode sheets stacked together, it is difficult for the electrolyte to fully penetrate and wet the electrode sheets in the middle, especially the central area of the electrode sheets in the middle. The unwetted active material layer is prone to black spots during the use of the battery cell, which significantly reduces the cycle performance of the battery cell. Utility Model Content
[0005] This application provides an electrode sheet, a battery cell, a battery, a battery pack, and an electrical device to solve the problem that the electrolyte is difficult to completely wet and penetrate the active material layer of the electrode sheet, which leads to black spots easily appearing on the active material layer during the use of the battery cell.
[0006] In a first aspect, this application provides an electrode sheet, comprising:
[0007] A current collector, the thickness of which is D2;
[0008] An active material layer covers at least one surface of the current collector. The active material layer has multiple grooves on the side away from the current collector. The minimum distance between two adjacent grooves is Q. The thickness of the active material layer is D1.
[0009] Where, 0.67μm≤ ≤75μm.
[0010] Secondly, this application provides a battery cell including the electrode sheet described in the first aspect.
[0011] Thirdly, this application provides a battery including the cell described in the second aspect.
[0012] Fourthly, this application provides a battery pack, including the battery cell described in the second aspect or the battery described in the third aspect.
[0013] Fifthly, this application provides an electrical device, including an electrical appliance and a battery as described in the third aspect or a battery pack as described in the fourth aspect, wherein the battery or the battery pack is used to supply power to the electrical appliance.
[0014] The above technical solution has at least the following beneficial effects: The electrode sheet is provided with a current collector and an active material layer. The active material layer covers at least one surface of the current collector. Multiple grooves are provided on the side of the active material layer facing away from the current collector. These grooves increase the contact area between the active material layer and the electrolyte, enhance capillary action, and facilitate electrolyte wetting of the active material layer. Simultaneously, the minimum distance between two adjacent grooves is Q, and the thicknesses D1 and D2 of the active material layer satisfy 0.67 μm ≤ Q. Within the range of ≤75μm, the total amount of active material in the active material layer can be kept within an appropriate range to ensure the capacity of the cell. At the same time, it can reduce the difficulty of electrolyte wetting the active material layer, allowing the electrolyte to better wet the active material layer, thereby reducing the probability of black spots appearing in the active material layer during the charging and discharging process of the cell and improving the cycle performance of the cell. Attached Figure Description
[0015] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this application and, together with the description, serve to explain the principles of this application.
[0016] Figure 1 This is a schematic diagram of the structure of a first embodiment of the electrode sheet provided in this application.
[0017] Figure 2 This is a schematic diagram of a second embodiment of the electrode sheet provided in this application.
[0018] Figure 3 This is a schematic diagram of a third embodiment of the electrode sheet provided in this application.
[0019] Figure 4 A schematic diagram of the battery cell structure provided in the embodiments of this application. Figure 1 ;
[0020] Figure 5 A schematic diagram of the battery cell structure provided in the embodiments of this application. Figure 2 ;
[0021] Figure 6 This is a schematic diagram of the battery structure provided in an embodiment of this application.
[0022] Explanation of reference numerals in the attached figures:
[0023] 100-Electrode sheet, 110-Current collector, 120-Active material layer, 121-Groove, 130-Taper, 140-Insulating adhesive layer, 200-Cell, 210-Separator, 300-Battery, 310-Casing, 320-Terminal post.
[0024] The accompanying drawings illustrate specific embodiments of this application, which will be described in more detail below. These drawings and descriptions are not intended to limit the scope of the concept in any way, but rather to illustrate the concept of this application to those skilled in the art through reference to particular embodiments. Detailed Implementation
[0025] Exemplary embodiments will now be described in detail, examples of which are illustrated in the accompanying drawings. When the following description relates to the drawings, unless otherwise indicated, the same numbers in different drawings denote the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with this application. Rather, they are merely examples of apparatuses and methods consistent with some aspects of this application as detailed in the appended claims.
[0026] As described in the background section, whether it is a wound cell or a stacked cell, multiple positive and negative electrodes are usually arranged alternately in sequence, and the positive and negative electrodes are separated by a separator to avoid direct contact between them.
[0027] Both positive and negative electrode plates are made of electrode plates. The difference between the two is that the current collector of the positive electrode plate is coated with a positive active material layer, while the current collector of the negative electrode plate is coated with a negative active material layer. After multiple layers of positive and negative electrode plates are alternately arranged, the active material layer of the middle electrode plate can only be penetrated by electrolyte at the edge. At this time, it is more difficult for electrolyte to penetrate, and the closer to the middle of the active material layer of the electrode plate, the more difficult it is to wet.
[0028] In addition, with the increasing demand for high-capacity batteries, the length and width of the electrode sheets are increasing. Moreover, in order to better ensure the energy density of the battery, the current collector is becoming thinner and thinner, while the thickness of the active material layer coated on the current collector is becoming thicker and thicker, which further increases the difficulty of electrolyte wetting.
[0029] If the active material layer cannot be completely soaked by the electrolyte, it will have a significant impact on the battery performance. Taking lithium-ion batteries as an example, an electrochemical reaction occurs during the charging and discharging process. Lithium ions migrate between the positive and negative active material layers, thereby generating current. If there are areas in the active material layer that are not wetted by the electrode liquid, these unwetted areas cannot participate in the electrochemical reaction, leading to a decrease in local electrochemical performance and the formation of black spots. Black spots not only affect the appearance of the battery but may also lead to a decrease in battery performance, such as capacity loss and shortened cycle life.
[0030] To address this, this application provides an electrode sheet in which multiple grooves are provided on the side of the active material layer facing away from the current collector. These grooves increase the contact area between the active material layer and the electrolyte, facilitating electrolyte wetting of the active material layer. Simultaneously, the minimum distance between two adjacent grooves is Q, and the thicknesses D1 and D2 of the active material layer satisfy a relationship of 0.67 μm ≤ Q. Within the range of ≤75μm, the total amount of active material in the active material layer can be kept within an appropriate range to ensure the capacity of the cell. At the same time, it can reduce the difficulty of electrolyte wetting the active material layer, allowing the electrolyte to better wet the active material layer, thereby reducing the probability of black spots appearing in the active material layer during the charging and discharging process of the cell and improving the cycle performance of the cell.
[0031] The technical solution of this application and how the technical solution of this application solves the above-mentioned technical problems are described in detail below with specific embodiments. These specific embodiments can be combined with each other, and the same or similar concepts or processes may not be described again in some embodiments. The embodiments of this application will now be described with reference to the accompanying drawings.
[0032] This application provides an electrode sheet 100; please refer to [link / reference]. Figure 1 , Figure 2 , Figure 3 , Figure 4 and Figure 5 As shown, it includes a current collector 110 and an active material layer 120.
[0033] The current collector 110 is a sheet-like structure made of common conductive materials such as copper, aluminum, and nickel. It has two large surfaces, and the active material layer 120 is coated on at least one of the large surfaces of the current collector 110.
[0034] The type of activity selected for the active material layer 120 can be determined according to the application of the active electrode sheet 100.
[0035] For example, in the lithium-ion battery 300, when the electrode sheet 100 is used as a negative electrode, the active material used in the active material layer 120 can be lithium cobalt oxide (…). Lithium iron phosphate () ), lithium manganese oxide ( Nickel cobalt manganese oxide (NCM or NMC) or nickel cobalt aluminum oxide (NCA); when the electrode sheet 100 is used as a positive electrode sheet, the active material used in the active material layer 120 can be graphite, silicon-based material or hard carbon or soft carbon.
[0036] For example, in the lead-acid battery 300, when the electrode sheet 100 is used as a negative electrode, the active material used in the active material layer 120 can be lead dioxide (lead oxide). When the electrode sheet 100 is used as a positive electrode sheet, the active material used in the active material layer 120 can be spongy lead.
[0037] For example, in the nickel-metal hydride battery 300, when the electrode sheet 100 is used as a negative electrode, the active material used in the active material layer 120 can be nickel hydroxide (NiMH). When the electrode sheet 100 is used as a positive electrode sheet, the active material used in the active material layer 120 can be a metal hydride.
[0038] It should be noted that the selection of active materials for the active material layer 120 mentioned above is only an example and not a limitation. The specific selection can be adjusted according to the actual situation.
[0039] Multiple grooves 121 are provided on the side of the active material layer 120 away from the current collector 110. The depth direction of the grooves 121 is the same as the thickness direction of the active material layer 120. The minimum distance between two adjacent grooves 121 is Q, and the thickness of the active material layer 120 is D1.
[0040] At the same time, make 0.67μm≤ The thickness of the active material layer 120 is ≤75μm. The structure of the electrode sheet 100 is adjusted by combining the thickness of the active material layer 120, the thickness of the current collector 110, and the minimum distance between two adjacent grooves 121. On the one hand, the distance between the grooves 121 is made appropriate by considering the proportion of the active material layer 120 in the electrode sheet 100, so as not to occupy too much space by the grooves 121, so that the total amount of active material in the active material layer 120 is within an appropriate range, ensuring the capacity of the cell 200. On the other hand, the appropriate distance between the grooves 121 can effectively increase the contact surface area between the active material layer 120 and the electrolyte, enhance capillary action, and guide the electrolyte to penetrate into the active material layer 120, effectively reducing the difficulty of the electrolyte wetting the active material layer 120, thereby reducing the probability of black spots appearing in the active material layer 120 during the charging and discharging process of the cell 200 and improving the cycle performance of the cell 200.
[0041] In addition, the groove 121 can alleviate the volume change caused by electrolyte wetting, which helps to enhance the mechanical stability and durability of the active material layer.
[0042] After the groove 121 is set, the groove 121 will occupy part of the space of the active material layer 120, which will reduce the total amount of active material in the active material layer 120. >75μm, the groove 121 occupies less space in the active material layer 120. Although it has a small impact on the capacity of the cell 200, it also increases the contact area between the active material layer 120 and the electrolyte, resulting in a relatively poor effect on the electrolyte wetting of the active material layer 120 and making it difficult for the electrode liquid to completely wet the active material layer 120. If If the groove is less than 0.67μm, it means that the groove 121 occupies more space of the active material of the active substance. In this case, it can effectively increase the surface area of the active material layer 120 that is in contact with the electrolyte, and can guide the electrolyte to penetrate into the active material layer 120. It can better assist the electrolyte to thoroughly wet the active material layer 120. However, this results in the groove 121 occupying more space of the active material of the active material layer 120, resulting in less active material and a smaller capacity of the cell 200.
[0043] In some embodiments of this application, the depth of the groove 121 is less than the thickness of the active material layer 120. That is, the maximum distance between the bottom of the groove 121 and the surface of the active material layer 120 facing away from the current collector 110 is less than the thickness of the active material layer 120. The groove 121 will not penetrate the active material layer 120. It can also be understood that there is always an active material separating the groove 121 and the current collector 110.
[0044] Specifically, the groove 121 is mainly formed by extruding the active material layer 120 during the processing. For example, the active material is first coated on the current collector 110, and then the active material layer 120 is rolled and fixed on the current collector 110 by a pressure roller. During the rolling process, corresponding protrusions can be added to the pressure roller so that after the pressure roller extrudes the active material layer 120, the protrusions can extrude the groove 121 on the surface of the active material layer 120. The shape and size of the groove 121 can be determined by the protrusions. This means that the processing of the electrode sheet 100 does not require additional steps compared to the traditional electrode sheet 100, thereby avoiding additional time and cost.
[0045] By making the depth of the groove 121 less than the thickness of the active material layer 120, it is possible to avoid the protruding part from making direct hard contact with the current collector 110, thereby avoiding damage to the current collector 110.
[0046] Meanwhile, the depth of the groove 121 is less than the thickness of the active material layer 120. This can increase the contact area between the active material layer 120 and the electrolyte while reducing the space occupied by the active material in the active material layer 120 occupied by the groove 121, and guide the electrolyte to better penetrate into the active material layer 120.
[0047] Furthermore, the depth h of the groove 121 is 5μm-8μm. The depth h of the groove 121 is kept within this range, which can be adapted to current collectors 110 and active material layers 120 of most thicknesses.
[0048] In practical applications, if the thickness D1 of the active material layer 120 is large, the value of h can be appropriately increased. The larger h is, the better the effect of guiding the electrolyte flow, and thus the better the wetting effect of the electrolyte.
[0049] When h is large, 75μm ≤ At this point, the density of the groove 121 can be appropriately reduced to effectively increase the capacity of the cell 200 while ensuring the electrolyte wetting effect.
[0050] In addition, during electrolyte impregnation, the electrolyte mainly moves from the edge of the active material layer 120 toward the center of the active material layer 120, gradually impregnating it. The more difficult area to impregnate is the center of the active material layer 120. The closer to the center of the active material layer 120, the more difficult the electrolyte impregnation becomes.
[0051] To address this, the minimum distance between the groove 121 and the edge of the active material layer 120 can be 10μm-150μm. That is, the groove 121 can be omitted in the edge region of the active material layer 120, where electrolyte wetting is easier. The groove 121 is only placed in the region of the active material layer 120 where electrolyte wetting is more difficult. This can improve the wetting effect of the electrolyte and reduce the impact of the groove 121 on the capacity of the cell 200.
[0052] Furthermore, the area of the groove 121 projected onto the surface of the current collector 110 gradually decreases along the direction toward the edge of the active material layer 120; that is, the area of the groove 121 is larger the closer it is to the center region of the active material layer 120.
[0053] The closer to the center of the active material layer 120, the more difficult it is for the electrolyte to wet the active material layer 120. However, the larger the area of the groove 121 is, the better it is for the groove 121 to guide the electrolyte to wet the active material layer 120, thereby effectively improving the wetting effect of the electrolyte on the central region of the active material layer 120.
[0054] Furthermore, along the direction from the edge of the active material layer 120 to the geometric center of the active material layer 120, the density of the grooves 121 gradually increases. That is, the closer to the central region of the active material layer 120, the more grooves 121 there are, and the smaller the gap between adjacent grooves 121. This ensures the capacity of the battery cell 200 while maximizing the wetting effect of the electrolyte on the active material layer 120.
[0055] In some embodiments of this application, the size of the groove 121 gradually decreases from the side of the active material layer 120 away from the current collector 110 to the current collector 110, that is, the size of the groove 121 away from the current collector 110 is larger than the size of the groove 121 facing the current collector 110.
[0056] This makes it easier for the electrolyte to enter the groove 121. After the groove 121 contains part of the electrolyte, it can better guide the electrolyte to penetrate into the active material layer 120, thereby improving the wetting effect of the electrolyte.
[0057] At the same time, this groove 121 structure, which has a large opening and a small bottom, is relatively easy to process.
[0058] Furthermore, the groove 121 is a curved groove, meaning that the groove 121 does not have any sharp edges or corners, and the whole is smoothly transitioned through a curved surface.
[0059] During processing, the raised parts on the pressure roller are rounded, which can further reduce the probability of the pressure roller scratching the current collector 110 and provide better protection for the electrode sheet 100.
[0060] For a common battery cell 200, the thickness D1 of the active material layer 120 is usually 30μm-90μm, and the thickness of the current collector 110 can usually be determined according to the application of the current collector 110. For example, when the electrode plate 100 is a positive electrode plate, the thickness of the current collector 110 is 6μm-15μm, and when the electrode plate 100 is a negative electrode plate, the thickness of the current collector 110 is 3μm-10μm.
[0061] Generally speaking, the size of the cell 200 is limited. Within this limited space, the total thickness of each electrode sheet 100 is also fixed. At this time, the ratio of D1 / D2 can be adjusted to control the capacity of the cell 200 and the difficulty of electrolyte wetting.
[0062] Specifically, the larger the ratio of D1 to D2, the greater the proportion of the surface active material layer 120 and the thicker the active material layer 120. At this time, the capacity of the cell 200 is larger. However, when the active material layer 120 is thicker, the difficulty of the electrolyte completely wetting the active material layer 120 also increases accordingly.
[0063] The smaller the ratio of D1 to D2, the thinner the active material layer 120 and the smaller the capacity of the cell 200. In this case, it is relatively easy for the electrolyte to wet the active material layer 120.
[0064] However, both small capacity and excessive difficulty in electrolyte wetting will have an adverse effect on the performance of cell 200. Therefore, D1 / D2 can be set to a value within which the relationship between cell 200 capacity and electrolyte wetting difficulty can be better balanced. On this basis, by reasonably setting the number and area of grooves 121 and the minimum distance Q between adjacent grooves 121, the difficulty of electrolyte wetting can be effectively reduced.
[0065] Furthermore, Q can be 20μm-150μm, within which range it can meet the needs of most D1 / D2 ratio electrode sheets 100.
[0066] In some embodiments of this application, if both large surfaces of the current collector 110 are coated with the active material layer 120, compared to coating only one large surface of the current collector 110 with the active material layer 120, the difficulty of electrolyte wetting will increase. In this case, the thickness of the current collector 110 can be ≤ 0.77μm. ≤75μm. While ensuring the appropriate capacity of cell 200, the minimum distance Q between two adjacent grooves 121 should be appropriately reduced to ensure the wetting effect of the electrolyte.
[0067] In addition, in practical applications, the size of the negative electrode of the cell 200 usually needs to be larger than the size of the positive electrode to ensure the safety of the cell 200. At this time, the size of the active material layer 120 on the negative electrode is also larger than the size of the active material layer 120 on the positive electrode. Therefore, the parameters of the positive and negative electrodes can be adjusted adaptively.
[0068] For example, when electrode 100 is used as a positive electrode, 1.33μm≤ ≤75μm.
[0069] For example, when electrode 100 is used as a negative electrode, 0.67μm≤ ≤50μm.
[0070] In some embodiments of this application, a tab 130 is provided on one side of the current collector 110. When the electrode sheet 100 is used as the negative electrode sheet, an insulating adhesive layer 140 can also be provided between the active material layer 120 and the tab 130. The insulating adhesive layer 140 covers the current collector 110 and can connect the current collector 110 and the separator 210 to prevent the tab 130 from shifting and contacting the opposite electrode, thereby reducing the risk of short circuit. It can also help fix the position of the current collector 110 and the separator 210, which helps to maintain the integrity of the internal structure of the cell 200. Of course, the insulating adhesive layer 140 can also improve the additional sealing ability, prevent the electrolyte from leaking from the tab 130 area, and reduce the safety risk of the battery 300.
[0071] After adding the insulating adhesive layer 140, the insulating adhesive layer 140 will occupy part of the space on the surface of the current collector 110. This will cause the size of the active material layer 120 to be reduced relative to the size of the current collector 110. However, correspondingly, the insulating adhesive layer 140 will also close one side of the active material layer 120, causing the electrolyte to only wet into the active material layer 120 from the area around the active material layer 120 excluding the insulating adhesive layer 140. This will increase the difficulty of the electrolyte wetting the active material layer 120.
[0072] In response, after multiple experiments, it was found that within 0.67μm ≤ When the thickness is ≤75μm, the wetting effect of the electrolyte can be effectively improved while ensuring the cell capacity of 200 mAh as much as possible.
[0073] It should be noted that the insulating adhesive layer 140 can be formed using commonly used insulating adhesives, as long as they can effectively bond the current collector 110 and the diaphragm 210.
[0074] This application also provides a battery cell 200, please refer to [link to relevant documentation]. Figure 4 and Figure 5 As shown, it includes the electrode sheet 100 in the above embodiments.
[0075] The battery cell 200 also includes a separator 210. By changing the type of active material used in the active material layer 120 of the electrode sheet 100, positive and negative electrode sheets are formed respectively. The positive and negative electrode sheets are arranged alternately in sequence, and the separator 210 is located between the positive and negative electrode sheets to separate them. That is, a layer of positive electrode sheet, a layer of separator 210, and a layer of negative electrode sheet are placed in sequence. The separator 210 prevents the positive and negative electrode sheets from directly contacting and short-circuiting. Of course, the outermost positive and negative electrode sheets are also covered with the separator 210.
[0076] It should be noted that the separator 210 is usually a microporous polymer membrane that allows ions to pass through while blocking electrons, thereby avoiding direct contact between the positive and negative electrodes.
[0077] This application also provides a battery 300, please refer to... Figure 6 As shown, it includes the battery cell 200 in the above embodiment.
[0078] Of course, the battery 300 usually also includes components such as the housing 310 and the terminal post 320. The battery cell 200 is placed inside the housing 310, and the terminal post 320 is electrically connected to the tab 130 of the battery cell 200.
[0079] This application also provides a battery pack, including the cell 200 or battery 300 in the above embodiments.
[0080] Of course, the battery pack usually also includes components such as a tray and a battery management system. The battery cells 200 or batteries 300 are fixed in the tray, while the battery management system controls the temperature of the battery cells 200 or batteries 300 and monitors various parameters of the battery cells 200 or batteries 300 to ensure the stable operation of the battery pack.
[0081] This application embodiment also provides an electrical device, including an electrical device and the battery 300 or battery pack in the above embodiment, the battery 300 or battery pack being used to supply power to the electrical device.
[0082] It should be noted that electrical equipment includes, but is not limited to, electric vehicles, hybrid vehicles, medical equipment, aerospace equipment, energy storage systems, and home electronic products that require power from batteries or battery packs.
[0083] Other embodiments of this application will readily occur to those skilled in the art upon consideration of the specification and practice of the utility models disclosed herein. This application is intended to cover any variations, uses, or adaptations of this application that follow the general principles of this application and include common knowledge or customary techniques in the art not disclosed herein. The specification and examples are to be considered exemplary only, and the true scope and spirit of this application are indicated by the following claims.
[0084] It should be understood that this application is not limited to the precise structure described above and shown in the accompanying drawings, and various modifications and changes can be made without departing from its scope. The scope of this application is limited only by the appended claims.
Claims
1. An electrode tab (100) characterized in that, include: A current collector (110) having a thickness of D2; An active material layer (120) is provided, which covers at least one surface of the current collector (110). The active material layer (120) has a plurality of grooves (121) on the side away from the current collector (110). The minimum distance between two adjacent grooves (121) is Q. The thickness of the active material layer (120) is D1. wherein 0.67 pm < d < 1.5 pm ≤ 75 pm.
2. The electrode pad (100) according to claim 1, characterized in that The depth of the groove (121) is less than the thickness of the active material layer (120).
3. The electrode pad (100) according to claim 2, characterized in that The depth h of the groove (121) is 5μm-8μm.
4. The electrode pad (100) according to claim 1, characterized in that The minimum distance between the groove (121) and the edge of the active material layer (120) is 10μm-150μm.
5. The electrode pad (100) according to claim 1, characterized in that Along the direction from the edge of the active material layer (120) to the geometric center of the active material layer (120), the area of the groove (121) projected toward the surface of the current collector (110) gradually increases.
6. The electrode pad (100) according to claim 1, characterized in that The density of the grooves (121) gradually increases along the direction from the edge of the active material layer (120) to the geometric center of the active material layer (120).
7. The electrode pad (100) according to claim 1, characterized in that The size of the groove (121) gradually decreases from the side of the active material layer (120) away from the current collector (110) to the current collector (110).
8. The electrode pad (100) according to claim 7, characterized in that The groove (121) is a curved groove.
9. The electrode pad (100) according to claim 1, characterized in that An active material layer (120) is provided on both opposite surfaces of the current collector (110); wherein 0.77 pm < d < 1.23 pm ≤ 75 pm.
10. The electrode pad (100) according to claim 1, characterized in that A tab (130) is provided on one side of the current collector (110), and an insulating adhesive layer (140) is provided between the active material layer (120) and the tab (130), and the insulating adhesive layer (140) covers the current collector (110); Where, 0.67μm≤ ≤50μm.
11. The electrode sheet (100) according to any one of claims 1 to 10, characterized in that Q ranges from 20μm to 150μm.
12. An electric core (200), characterized by, Includes the electrode sheet (100) as described in any one of claims 1-11.
13. A battery (300) characterized by Includes the battery cell (200) as described in claim 12.
14. A battery pack, characterized by Includes the cell (200) of claim 12 or the battery (300) of claim 13.
15. An electrical device, characterized by It includes an electrical device, and the battery (300) of claim 13 or the battery pack of claim 14, the battery (300) or the battery pack being used to supply power to the electrical device.