Pole piece structure, battery cell and electric device

Abstract

The application relates to a pole piece structure, a battery cell and an electric device, and relates to the technical field of power batteries. The pole piece structure comprises a foil and an active layer. A thickening area is formed at the edge position of the foil, and the thickness of the thickening area gradually increases from the position close to the central area of the foil to the edge position of the foil. The active layer is coated on the foil, and a thinning area is formed at the edge position of the active layer, and the thickness of the thinning area gradually decreases from the position close to the central area of the foil to the edge position of the foil. The thickening area and the thinning area are embedded to keep the thickness of the pole piece structure consistent. The pole piece structure provided by the application can improve the problem that the insufficient compaction pressure during the hot pressing of the pole piece edge thinning area affects the service life and safety of the battery.

Description

Technical Field

[0001] This application relates to the field of power battery technology, specifically to an electrode structure, a battery cell, and an electrical device. Background Technology

[0002] In the production and processing of lithium-ion batteries, during electrode processing, aluminum foil or copper foil is typically used as the substrate and coated with a slurry to form the electrode structure. However, during the coating process, it is usually necessary to form a thinning zone with a gradual change in thickness at the edge of the foil. This thinning zone is designed to prevent the formation of thick edges at the electrode edges, thereby avoiding problems such as overpressure or alignment deviations at the electrode edges during subsequent processing.

[0003] However, during the subsequent hot pressing process, the electrode edges become thinner due to the presence of a thinning zone. This results in a decrease in pressure at the edges during hot pressing, leading to insufficient effective compaction pressure in that area. Consequently, the adhesion between the separator and the electrode is poor. This makes it easier for gaps to form between the separator and the electrode, causing lithium-ion deposition, which not only affects the battery's lifespan but also its safety.

[0004] Therefore, there is an urgent need to provide a lithium-ion battery structure that can improve the problem of insufficient compaction pressure during hot pressing of the thinned area at the edge of the electrode, which affects the battery's service life and safety. Utility Model Content

[0005] The purpose of this application is to provide an electrode structure, a battery cell, and an electrical device that can improve the problem of insufficient compaction pressure during hot pressing of the thinned area at the edge of the electrode, which affects the battery's service life and safety.

[0006] To achieve the above objectives, in a first aspect, this application provides an electrode structure comprising a foil and an active layer. A thickened region is formed at the edge of the foil, the thickness of which gradually increases from near the center of the foil towards the edge. An active layer is coated on the foil, and a thinned region is formed at the edge of the active layer, the thickness of which gradually decreases from near the center of the foil towards the edge. The thickened region and the thinned region are interlocked to ensure a consistent thickness throughout the electrode structure.

[0007] Based on the embodiments described above, by increasing the thickness at the edge of the foil, the increased thickness at the edge compensates for the reduced thickness in the thinning zone. At this point, the overall thickness of the electrode sheet formed by the foil and active layer becomes more consistent, and the thickness difference between the electrode sheet edge and the central region caused by the thinning zone is compensated. Therefore, through the relevant settings of this application, the existence of the thinning zone at the edge of the active layer can be ensured, preventing the formation of a thick edge. Furthermore, the thickness of each part of the electrode sheet is made consistent, thereby ensuring consistent pressure in each part of the electrode sheet during subsequent hot pressing. This avoids problems such as overpressure in the central region or air pressure at the edges, thus ensuring the hot pressing effect and the production quality of the electrode sheet and the battery cell.

[0008] In some embodiments, the thickness of the central region of the foil is D, the thickness of the thickened region is D1, D1=D+D2, and 0.5μm≤D2≤5μm.

[0009] Based on the embodiments described above, the thickened region is formed by thickening the edge of the foil on the basis of its original structure. The thickness of the central region of the foil remains the same as its original thickness, while the thickness D2 is the increase in thickness of the thickened region relative to the original thickness of the foil. By limiting the increased thickness of the thickened region, it is possible for the thickened region to better fit and cooperate with the thinned region.

[0010] In some embodiments, the thickness of the thickened region increases uniformly from a position near the center of the foil towards the edge of the foil.

[0011] Based on the embodiments described above, since the shape of the thinning zone is naturally formed during the coating process at the edge of the foil, the thickness of the thinning zone is generally reduced uniformly. In this case, by uniformly increasing the thickness of the thickening zone, it adapts to the structure of the thinning zone, allowing for better coordination between the two. Furthermore, it reduces the possibility of stress concentration due to sudden thickness changes, thereby reducing the likelihood of diaphragm damage caused by stress concentration during subsequent lamination or winding processes, and ultimately minimizing the impact on cell safety.

[0012] In some embodiments, the extension dimension of the thickened area from the position near the center of the foil to the edge of the foil is L1, where 1mm≤L1≤5mm.

[0013] Based on the embodiments described above, the increase in thickness of the thickened area relative to the original thickness of the foil is limited. Given a fixed increase in thickness, a larger extension dimension of the thickened area results in a gentler bulge, while a smaller extension dimension results in a steeper bulge. Therefore, by limiting the extension dimension of the thickened area, the problem of ineffective coordination with the thinning area due to an excessively gentle or steep bulge is avoided to some extent.

[0014] In some embodiments, the starting position of the thickening region coincides with the starting position of the thinning region, extending from the center of the foil towards the edge. The extension dimension of the thinning region is L2, where L2 ≤ L1.

[0015] Based on the embodiments described above, by setting the starting position of the thickening area to coincide with the starting position of the thinning area, the thickening area and the thinning area can be better fitted together. Furthermore, by setting the extension dimension of the thickening area to be greater than or equal to the extension dimension of the thinning area, the thickening area can completely cover the thinning area, thereby enabling the thickening area to completely compensate for the thickness deficiency caused by the thinning area and ensuring that the thickness of each part of the electrode is consistent.

[0016] In some embodiments, active layers are coated on both surfaces of the foil in the thickness direction, the active layers on both sides are symmetrically arranged and each has a thinning region, and the thickening region is symmetrically arranged along the thickness direction of the foil to fit the thinning regions on both sides.

[0017] Based on the embodiments described above, in actual use of the electrode sheet, double-layer coating on both sides of the foil can improve the utilization rate of the electrode sheet area, thereby increasing the energy density of the battery cell to a certain extent. Furthermore, the coating process is identical on both sides, resulting in thinning zones in the active layer on both sides. The thickened zones are symmetrically arranged along the thickness direction, allowing them to simultaneously engage with the thinning zones on both sides, and also ensuring more balanced pressure on both sides, preventing damage to the electrode sheet during subsequent processing due to uneven stress.

[0018] According to a second aspect of this application, a battery cell is provided, the battery cell including a separator and at least two of the aforementioned electrode structures. The separator is disposed between any two adjacent electrode structures, and in any two adjacent electrode structures, one is configured as a positive electrode and the other as a negative electrode.

[0019] Based on the above embodiments of this application, the battery cell provided by this application includes the above-mentioned electrode structure. By improving the electrode structure, the thickness loss caused by the thinning area at the edge is compensated by the thickening area on the foil, thereby making the thickness of the center area and the edge area of ​​the electrode more consistent. This makes the overall thickness of the battery cell structure formed by the electrode and the separator more consistent, so that the edge area of ​​the electrode and the separator can maintain a good compaction effect during the subsequent hot pressing process, avoiding gaps between them, thereby improving the overall production and processing quality of the battery cell, and improving the overall safety and service life of the battery cell.

[0020] In some embodiments, the battery cell includes at least two negative electrode plates and at least one positive electrode plate, with the positive and negative electrode plates arranged alternately, and a separator is provided between any adjacent negative and positive electrode plates.

[0021] Based on the embodiments described above, in practical use, the battery cell is typically configured with a multi-layer structure, with positive and negative electrode plates alternately arranged, and a separator is provided between adjacent positive and negative electrode plates. Through the improvements described above, the thickness of each part of both the negative and positive electrode plates is consistent, thus ensuring that the thickness of each part after the electrode plates and separator are stacked remains consistent, avoiding problems such as air pressure during subsequent hot pressing. The specific number of layers of negative and positive electrode plates can be set according to factors such as the actual capacity requirements of the battery cell.

[0022] In some embodiments, the battery cell is configured as a laminated battery cell structure, or the battery cell is configured as a wound core structure.

[0023] Based on the embodiments described above, the aforementioned cell structure configurations can be applied to both stacked cell structures and wound cell structures. These improvements to the cell structure maintain a relatively good compaction effect and enhance the adhesion between the layers, reducing the possibility of gaps between them. Therefore, whether applied to stacked cell structures or wound cell structures, these improvements can extend battery life and improve battery safety to a certain extent.

[0024] According to a third aspect of this application, an electrical device is provided, comprising a device body and the aforementioned battery cell. A power supply cavity is provided inside the device body, and the battery cell is disposed within the power supply cavity.

[0025] Based on the above embodiments of this application, the electrical equipment provided by this application includes the above-mentioned battery cell, and therefore also has the above-mentioned beneficial effects. To avoid repetition, it will not be described again here.

[0026] Other features and advantages of this application will be described in detail in the following detailed description section. Attached Figure Description

[0027] The accompanying drawings are provided to further illustrate the present application and form part of the specification. They are used together with the following detailed description to explain the present application, but do not constitute a limitation thereof. In the drawings:

[0028] Figure 1 This is a schematic diagram of the electrode structure provided in the embodiments of this application.

[0029] Figure 2 This is a schematic diagram of the battery cell structure provided in the embodiments of this application.

[0030] Explanation of reference numerals in the attached figures

[0031] 1. Foil material; 11. Thickened area; 2. Active layer; 21. Thinned area; 3. Positive electrode sheet; 4. Negative electrode sheet; 5. Separator. Detailed Implementation

[0032] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this application.

[0033] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. The components of the embodiments of this application described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0034] Therefore, the following detailed description of the embodiments of this application provided in the accompanying drawings is not intended to limit the scope of the claimed application, but merely to illustrate selected embodiments of the application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without inventive effort are within the scope of protection of this application.

[0035] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0036] In the description of this application, it should be noted that, unless otherwise stated, the terms "inner," "outer," etc., indicating the orientation or positional relationship are based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship commonly used when the product is in use. They are used only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation on this application. In addition, the terms "first," "second," etc., are used only to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0037] In the description of this application, it should also be noted that, unless otherwise expressly specified and limited, the terms "setup" and "connection" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0038] In the manufacturing process of lithium-ion batteries, aluminum or copper foil is typically used as the substrate and coated with a slurry to form the electrode structure. However, during the coating process, a thinning zone with a gradual thickness change is usually formed at the edge of the foil. This thinning zone is designed to prevent the formation of thick edges on the electrode. Thick edges can lead to overpressure during subsequent rolling and can cause alignment deviations during winding or stacking, thus affecting the battery production yield. Furthermore, stress concentration during winding or stacking can cause edge burrs to puncture the cell, leading to internal short circuits. The thinning zone effectively prevents the formation of thick edges, thus solving these problems.

[0039] However, during the subsequent hot pressing process, the electrode edges become thinner due to the presence of a thinning zone. This results in a decrease in pressure at the edges during hot pressing, leading to insufficient effective compaction pressure in that area. Consequently, the adhesion between the separator and the electrode is poor. This makes it easier for gaps to form between the separator and the electrode, causing lithium-ion deposition, which not only affects the battery's lifespan but also its safety.

[0040] In existing technologies, to address the issue of insufficient compaction pressure at the edges, methods such as adjusting hot-pressing parameters, like increasing the hot-pressing pressure or temperature, are typically employed. However, during actual processing, increasing the hot-pressing temperature not only increases energy costs but may also damage the substrate, increasing the risk of substrate failure. Conversely, simply increasing the hot-pressing pressure can lead to over-compaction in areas other than the edges, affecting ion transport rates.

[0041] Therefore, there is an urgent need to provide a lithium-ion battery structure that can improve the problem of insufficient compaction pressure during hot pressing of the thinned area at the edge of the electrode, which affects the battery's lifespan and safety, while avoiding the aforementioned problems caused by adjusting the hot pressing parameters.

[0042] To address the aforementioned problems in the prior art, this application provides an electrode structure, referring to... Figure 1 As shown, the electrode structure includes a foil 1 and an active layer 2. A thickened region 11 is formed at the edge of the foil 1, and the thickness of the thickened region 11 gradually increases from near the center of the foil 1 towards the edge. The active layer 2 is coated on the foil 1, and a thinned region 21 is formed at the edge of the active layer 2, and the thickness of the thinned region 21 gradually decreases from near the center of the foil 1 towards the edge. The thickened region 11 and the thinned region 21 are interlocked to ensure a consistent thickness throughout the electrode structure.

[0043] Based on the embodiments described above, by increasing the thickness at the edge of the foil 1, the increased thickness at the edge of the foil 1 compensates for the reduced thickness in the thinning region 21. At this time, the overall thickness of the electrode sheet formed by the foil 1 and the active layer 2 tends to be consistent, and the thickness difference between the electrode sheet edge and the central region caused by the presence of the thinning region 21 is compensated.

[0044] Therefore, the relevant settings in this application can ensure the existence of the thinned edge region 21 of the active layer 2, avoiding the formation of a thick edge. It also ensures that the thickness of each part of the electrode is consistent, thereby ensuring consistent pressure in each part of the electrode during subsequent hot pressing. This avoids problems such as overpressure in the central area or air pressure at the edges, thus guaranteeing the hot pressing effect and ensuring the production and processing quality of the electrode and the battery cell.

[0045] Through the above improvements, the thickness of the electrode's central region and edge positions tends to be consistent. Subsequently, during hot pressing, whether it's a single electrode or multiple electrodes stacked together, the thickness of the electrode's central region and edge remains uniform. This consistency allows for the adjustment of various hot pressing parameters, such as the roller spacing and hot pressing temperature. With the pressure on the electrode's central region and edge positions being consistent, when the hot pressing parameters are adjusted appropriately, both the central region and edge positions can achieve good compaction, avoiding the problem of over-compactment in some areas and air compression in others.

[0046] In some embodiments of this application, reference is made to Figure 1 As shown, the thickness of the central region of foil 1 is D, the thickness of the thickened region 11 is D1, D1=D+D2, and 0.5μm≤D2≤5μm.

[0047] It should be noted that the thickness of the central region of the foil 1 and the thickness of the thickened region 11 mentioned above in this application refer to the dimensions along the lamination direction of the foil 1 and the active layer 2. Unless otherwise stated, the thickness of the thickened region 11 and the thickness of the thinned region 21 mentioned below also refer to the dimensions along the lamination direction of the foil 1 and the active layer 2.

[0048] Based on the above embodiments of this application, the thickened region 11 is formed by thickening the edge of the foil 1 on the basis of the original structure of the foil 1. At this time, the thickness of the central region of the foil 1 remains the original thickness of the foil 1, while the thickness D2 is the increase in thickness of the thickened region 11 relative to the original thickness of the foil 1. By limiting the thickness increase of the thickened region 11, the thickened region 11 can better fit and cooperate with the thinned region 21.

[0049] In practical applications, the specific value of the thickness D2 can be further limited based on the actual usage conditions. For example, the thickness D2 can be further limited to between 1 μm and 2 μm. Specific factors such as the flowability of the active layer 2 slurry can be considered, but this application does not impose specific limitations in this regard.

[0050] Meanwhile, to ensure consistent thickness across all parts of the electrode formed after the foil 1 and active layer 2 are stacked, the thickness of the thickened region 11 needs to be compatible with the thickness of the thinned region 21. For example, if the total electrode thickness is 20 μm and the original thickness of the foil 1 is 10 μm, then the thickness of the active layer 2, excluding the thinned region 21, is also 10 μm. In this case, if the thickness D1 at a certain location of the thickened region 11 is 12 μm (i.e., the thickness D2 is 2 μm), then the corresponding thickness of the thinned region 21 is 8 μm. Conversely, if the thickness D1 at another location of the thickened region 11 is 14 μm, then the corresponding thickness of the thinned region 21 is 6 μm.

[0051] Furthermore, in some embodiments of this application, the thickness of the thickened region 11 increases uniformly from a position near the center of the foil 1 towards the edge of the foil 1.

[0052] Based on the embodiments described above, since the shape of the thinning region 21 is naturally formed during the coating process at the edge of the foil 1, the thickness of the thinning region 21 is generally reduced uniformly. In this case, by uniformly increasing the thickness of the thickening region 11, it adapts to the structure of the thinning region 21, allowing for better cooperation between the two. Furthermore, it reduces the possibility of stress concentration due to sudden thickness changes, thereby reducing the likelihood of diaphragm 5 damage caused by stress concentration during subsequent lamination or winding processes, and ultimately minimizing the impact on cell safety.

[0053] Specifically, when the thickness of the thickened region 11 increases uniformly, the aforementioned specific limitation on the thickness of the thickened region 11 means that the thickness at each location of the thickened region 11 should be within the aforementioned range. That is, the thickness D2 of the thickened region 11 at the end closest to the center region of the foil 1 should be greater than or equal to 0.5 μm, while the thickness D2 of the thickened region 11 at the end furthest from the center region of the foil 1 should be less than or equal to 5 μm.

[0054] refer to Figure 1 As shown in some embodiments of this application, the extension dimension of the thickened area 11 from the position near the center region of the foil 1 to the edge position of the foil 1 is L1, where 1mm≤L1≤5mm.

[0055] Based on the embodiments described above, the increase in thickness of the thickened region 11 relative to the original thickness of the foil 1 is limited. Given a fixed increase in thickness of the thickened region 11, a larger extension dimension of the thickened region 11 results in a gentler bulge, while a smaller extension dimension results in a steeper bulge. Therefore, by limiting the extension dimension of the thickened region 11, the problem of ineffective cooperation with the thinning region 21 due to an excessively gentle or steep bulge is avoided to some extent.

[0056] In practical use, the extension dimension of the thickened area 11 can be specifically set to multiple values ​​such as 1mm, 2mm, 3mm, 4mm and 5mm, and this application does not impose specific restrictions on it.

[0057] In some embodiments of this application, the starting position of the thickening region 11 coincides with the starting position of the thinning region 21 from a position near the center of the foil 1 towards the edge of the foil 1. The extension dimension of the thinning region 21 is L2, where L2 ≤ L1.

[0058] Based on the embodiments described above, by setting the starting position of the thickened region 11 to coincide with the starting position of the thinned region 21, the thickened region 11 and the thinned region 21 can be better fitted together. Furthermore, by setting the extension dimension of the thickened region 11 to be greater than or equal to the extension dimension of the thinned region 21, the thickened region 11 can completely cover the thinned region 21, thereby ensuring that the thickened region 11 can completely compensate for the thickness deficiency caused by the thinned region 21, guaranteeing consistent thickness across all parts of the electrode sheet.

[0059] It should be noted that the starting position of the thickened region 11 mentioned above in this application refers to the position where the thickness of the foil 1 begins to increase compared to its original thickness. Similarly, the starting position of the thinning region 21 refers to the position where the thickness of the active layer 2 begins to decrease compared to its original thickness.

[0060] refer to Figure 1 As shown, in some embodiments, active layers 2 are coated on both surfaces of the foil 1 in the thickness direction. The active layers 2 on both sides are symmetrically arranged and each has a thinning region 21. Thickening regions 11 are symmetrically arranged along the thickness direction of the foil 1 to fit the thinning regions 21 on both sides.

[0061] Based on the embodiments described above, in actual use of the electrode, the double-layer coating on both sides of the foil 1 can improve the utilization rate of the electrode area, thereby increasing the energy density of the battery cell to a certain extent. Furthermore, the coating process is identical on both sides, resulting in thinning regions 21 formed on both sides of the active layer 2. The thickening regions 11 are symmetrically arranged along the thickness direction, allowing them to simultaneously engage with the thinning regions 21 on both sides, and also ensuring more balanced pressure on both sides, preventing damage to the electrode during subsequent processing due to uneven stress.

[0062] Meanwhile, since thickened regions 11 are formed on both surfaces of the foil 1 at this time, and the positions of the two thickened regions 11 coincide in the thickness direction of the foil 1, the thickness of the thickened region 11 at this time is D1 = D + 2D2.

[0063] Based on the above technical solutions, and referring to Figure 2 As shown, this application also provides a battery cell, which includes a separator 5 and at least two of the aforementioned electrode structures. The separator 5 is disposed between any two adjacent electrode structures, and in any two adjacent electrode structures, one is configured as a positive electrode 3 and the other as a negative electrode 4.

[0064] Based on the above embodiments of this application, the battery cell provided by this application includes the above-mentioned electrode structure. By improving the electrode structure, the thickness loss caused by the thinning area 21 at the edge is compensated by the thickening area 11 on the foil 1, thereby making the thickness of the center area and the edge of the electrode more consistent. This makes the overall thickness of the battery cell structure formed by the electrode and the separator 5 more consistent, so that the edge of the electrode and the separator 5 can maintain a good compaction effect during the subsequent hot pressing process, avoiding gaps between them, thereby improving the overall production and processing quality of the battery cell, and improving the overall safety and service life of the battery cell.

[0065] In practical applications, the base film can be any suitable material, typically a microporous polyolefin film, such as polyethylene (PE) film, polypropylene (PP) film, or a polyethylene / polypropylene composite film. The specific choice depends on the process requirements, and this application does not impose any specific limitations.

[0066] In some embodiments, the battery cell includes at least two negative electrode plates 4 and at least one positive electrode plate 3, the positive electrode plates 3 and the negative electrode plates 4 are arranged alternately, and a separator 5 is provided between any adjacent negative electrode plates 4 and positive electrode plates 3.

[0067] Based on the embodiments described above, in practical use, the battery cell is typically configured with a multi-layer structure, with positive electrode plates 3 and negative electrode plates 4 alternately arranged, and a separator 5 is provided between adjacent positive electrode plates 3 and negative electrode plates 4. Through the improvements described above, the thickness of each part of the negative electrode plate 4 and the positive electrode plate 3 is consistent, so the thickness of each part after the electrode plates and separator 5 are stacked can also be consistent, thus avoiding problems such as air pressure during subsequent hot pressing. The specific number of layers of the negative electrode plate 4 and the positive electrode plate 3 can be set according to factors such as the actual capacity requirements of the battery cell.

[0068] When positive electrode plates 3 and negative electrode plates 4 are stacked within a battery cell, the outermost layer is usually set as negative electrode plates 4. Therefore, the number of negative electrode plates 4 is usually one more than the number of positive electrode plates 3. The specific number can be set according to factors such as the cell capacity. For example, two negative electrode plates 4 and one positive electrode plate 3 can be set, with the positive electrode plates 3 stacked between the two negative electrode plates 4, and a separator 5 is set between the positive electrode plates 3 and the negative electrode plates 4. Alternatively, three negative electrode plates 4 and two positive electrode plates 3 can be set, with the positive electrode plates 3 and negative electrode plates 4 arranged alternately, with the two outermost plates both set as negative electrode plates 4, and a separator 5 is set between the positive electrode plates 3 and the negative electrode plates 4.

[0069] In the prior art, since the thinning regions 21 are all formed at the edges of the positive electrode 3 or the negative electrode 4, the areas where the thinning regions 21 are located will also overlap after multiple electrode layers are stacked, further increasing the thickness difference between the center region and the edge region of the cell. In this application, by improving the structure of the foil 1, the thickness of the center region and the edge region of the electrode is made consistent, thus effectively avoiding the problem of further increasing thickness difference caused by the stacking of multiple electrode layers.

[0070] In some embodiments of this application, the battery cell may be configured as a stacked battery cell structure, or the battery cell may be configured as a wound core structure.

[0071] Based on the embodiments described above, the aforementioned cell structure configurations can be applied to both stacked cell structures and wound cell structures. These improvements to the cell structure maintain a relatively good compaction effect and enhance the adhesion between the layers, reducing the possibility of gaps between them. Therefore, whether applied to stacked cell structures or wound cell structures, these improvements can extend battery life and improve battery safety to a certain extent.

[0072] Based on the above technical solution, this application also provides an electrical device, which includes a device body and the aforementioned battery cell. The device body has an internal power supply cavity, and the battery cell is disposed within the power supply cavity.

[0073] Specifically, in this application, the electrical equipment can be, but is not limited to, mobile phones, tablets, laptops, electric toys, power tools, electric vehicles, electric cars, ships, spacecraft, etc. Among them, electric toys can include stationary or mobile electric toys, such as game consoles, electric car toys, electric ship toys, and electric airplane toys, etc., and spacecraft can include airplanes, rockets, space shuttles, and spacecraft, etc.

[0074] Based on the above embodiments of this application, the electrical device provided by this application includes the above-mentioned battery, and therefore also has the above-mentioned beneficial effects. To avoid repetition, it will not be described again here.

[0075] The preferred embodiments of this application have been described in detail above with reference to the accompanying drawings. However, this application is not limited to the specific details of the above embodiments. Within the scope of the technical concept of this application, various simple modifications can be made to the technical solution of this application, and these simple modifications all fall within the protection scope of this application.

[0076] It should also be noted that the various specific technical features described in the above embodiments can be combined in any suitable manner without contradiction. In order to avoid unnecessary repetition, this application will not describe the various possible combinations separately.

[0077] Furthermore, various different implementations of this application can be combined in any way, as long as they do not violate the spirit of this application, they should also be regarded as the content disclosed in this application.

Claims

1. An electrode structure, characterized in that, The electrode structure includes: A foil material, wherein a thickened area is formed at the edge of the foil material, and the thickness of the thickened area gradually increases from a position near the center of the foil material to the edge of the foil material; An active layer is coated on the foil, and a thinning zone is formed at the edge of the active layer, the thickness of which gradually decreases from the center of the foil towards the edge. The thickened area and the thinned area are interlocked to ensure that the thickness of the electrode structure remains consistent throughout.

2. The electrode structure according to claim 1, characterized in that, The thickness of the central region of the foil is D, and the thickness of the thickened region is D1, where D1 = D + D2, and 0.5μm ≤ D2 ≤ 5μm.

3. The electrode structure according to claim 2, characterized in that, The thickness of the thickened area increases uniformly from the position near the center of the foil towards the edge of the foil.

4. The electrode structure according to claim 1, characterized in that, The extension dimension of the thickened area from the position near the center of the foil to the edge of the foil is L1, where 1mm≤L1≤5mm.

5. The electrode structure according to claim 4, characterized in that, From a position near the center of the foil towards the edge of the foil, the starting position of the thickening zone coincides with the starting position of the thinning zone; The extension dimension of the thinning zone is L2, where L2 ≤ L1.

6. The electrode structure according to claim 1, characterized in that, The active layer is coated on both surfaces of the foil in the thickness direction. The active layers on both sides are symmetrically arranged and each has a thinning area. The thickening area is symmetrically arranged along the thickness direction of the foil to fit into the thinning areas on both sides.

7. A battery cell, characterized in that, The battery cell includes: Diaphragm; and, At least two electrode structures as described in any one of claims 1-6, wherein the diaphragm is disposed between any two adjacent electrode structures, and in any two adjacent electrode structures, one is configured as a positive electrode and the other is configured as a negative electrode.

8. The battery cell according to claim 7, characterized in that, The battery cell includes at least two negative electrode plates and at least one positive electrode plate, the positive electrode plates and the negative electrode plates are arranged alternately, and a separator is provided between any adjacent negative electrode plates and the positive electrode plates.

9. The battery cell according to claim 7, characterized in that, The battery cell is configured as a laminated battery cell structure, or the battery cell is configured as a wound core structure.

10. An electrical appliance, characterized in that, The electrical equipment includes: The main body of the equipment has an internal power supply chamber; and, The battery cell as described in any one of claims 7-9, wherein the battery cell is disposed within the power supply cavity.

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