A cell structure, a battery, and an electrical device

Abstract

This application relates to a battery cell structure, a battery, and an electrical device, specifically in the field of power battery technology. The battery cell structure includes a positive electrode, a negative electrode, and a separator. The positive electrode includes a positive electrode foil with positive active layers coated on both sides. The negative electrode includes a negative electrode foil with negative active layers coated on both sides. The separator is disposed between the positive and negative electrode sheets. Thinning regions are formed at the edges of both the positive and negative active layers, while thickening regions are formed at the edges of the separator, with the thickening regions interlocking with the thinning regions on both sides. The battery cell structure provided by this application can improve problems such as insufficient compaction pressure during hot pressing of the thinned electrode edges, which affects battery life and safety.

Description

Technical Field

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

[0002] In the production of lithium-ion battery electrodes, a thinning zone with a gradual change in thickness is usually formed at the edge of the foil during coating. This thinning zone reduces the thick edges formed by the diffusion of the coating paste at the edges. By reducing the formation of thick edges, problems such as overpressure or alignment deviations at the electrode edges are reduced in subsequent processing.

[0003] After the slurry coating is completed, subsequent steps such as hot pressing are required. During hot pressing, the electrode edges become thinner due to the presence of a thinning zone, resulting in a decrease in pressure at the edges. This leads to insufficient effective compaction pressure in this area, resulting in poor adhesion between the separator and the electrode. 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 a cell structure, battery, and electrical device that can improve the problems caused by 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 a battery cell structure comprising a positive electrode, a negative electrode, and a separator. The positive electrode includes a positive foil with positive active layers coated on both sides. The negative electrode includes a negative foil with negative active layers coated on both sides. The separator is disposed between the positive and negative electrode. Thinning regions are formed at the edges of both the positive and negative active layers, and thickening regions are formed at the edges of the separator, the thickening regions being interlocked with the thinning regions on both sides.

[0007] Based on the above embodiments of this application, compared with the existing cell structure, this application improves the structure of the separator between the positive and negative electrode sheets by setting a thickened area at the edge of the separator. This thickened area interlocks with the corresponding thinned area, and the increased thickness of the thickened area compensates for the reduced thickness of the thinned areas on both sides. Ultimately, the overall thickness of the cell structure composed of the positive electrode sheet, separator, and negative electrode sheet is made more consistent, meaning the thickness of the central region and the edge of the stacked cell structure is more consistent. Therefore, during hot pressing, the pressure in the central region and the edge remains consistent under the same pressure, ensuring good compaction in both areas. This allows the separator and the electrode edge to maintain a good fit, reducing lithium-ion deposition caused by gaps between the electrode and the separator, thereby reducing the impact of lithium-ion deposition on the safety and lifespan of the lithium battery.

[0008] In some embodiments, the diaphragm includes a base membrane, with a thickened region formed by protrusions at the edge of the base membrane.

[0009] Based on the above embodiments of this application, a method for forming a separator is provided. The separator is integrally formed, with a base film as the main body, and a thickened area is formed by adding material at the edge of the base film. In this case, the integrally formed separator has higher overall mechanical strength, which can better cope with various stresses during the cell stacking or winding process, and better cope with the volume changes of the electrodes during charge and discharge cycles, reducing the possibility of the separator tearing itself and causing short circuits.

[0010] In some embodiments, the diaphragm includes a base membrane and a thickening coating, the thickening coating being protruding from the edge of the base membrane to form a thickened area.

[0011] Based on the embodiments described above, another method for forming the separator is provided. In this method, a base film is used as the main material, and a thickened area is formed at the edge of the base film by a thickening coating. In this case, the thickness of the base film can remain constant during actual production and processing; by changing the thickness of the thickening coating, different sizes of thinning areas can be accommodated. Furthermore, by selecting a thickening coating made of a specific material, the thermal stability and other related properties of the separator can be enhanced, thereby improving the overall safety of the battery.

[0012] In some embodiments, the thickness of the thickened region is D, where 2μm≤D≤20μm.

[0013] Based on the above embodiments of this application, by limiting the thickness of the thickened area, the actual thickness of the thickened area can be adaptively set according to the thickness of the thinned area, so that the thickened area can better fit with the thinned area, thereby making the overall thickness dimension consistency of the positive electrode sheet, separator and negative electrode sheet after being stacked together better, so that the pressure of each part is consistent during hot pressing, and ensuring that each area achieves a better hot pressing effect.

[0014] In some embodiments, the thickness of the thickened region increases uniformly, and the thickness of the thickened region gradually increases from the middle of the diaphragm toward the edge of the diaphragm.

[0015] Based on the embodiments described above, by setting a gradient in the thickened area, it adapts to the structure of the thinned area, allowing for better coordination between the two. Furthermore, it avoids stress concentration, reducing the possibility of diaphragm damage due to stress concentration during subsequent lamination or winding processes, thereby minimizing the impact on cell safety.

[0016] In some embodiments, thickened regions are provided on both sides of the diaphragm facing the positive electrode and facing the negative electrode, and the two thickened regions are symmetrically arranged.

[0017] Based on the embodiments described above, since both the positive and negative electrode sheets are generally coated on both sides during processing, when the separator is stacked between the positive and negative electrode sheets, thinning areas exist on both sides of the separator. Therefore, the thickening areas provided separately can respectively cooperate with the thinning areas on both sides to fill the dimensional gaps caused by the thinning areas. At the same time, by symmetrically arranging the thickening areas on both sides, the stress on both sides is more balanced during hot pressing, reducing the possibility of damage to the separator and other structures due to stress concentration.

[0018] In some embodiments, the cell structure includes at least two negative electrode plates and at least one positive electrode plate, with the positive and negative electrode plates arranged alternately in sequence. A separator is disposed between any adjacent negative electrode plate and positive electrode plate.

[0019] Based on the embodiments described above, in practical use, the cell structure is typically configured as a multi-layer structure with alternating positive and negative electrode plates, and a separator is provided between adjacent positive and negative electrode plates. This separator also cooperates with the thinned areas on the positive and negative electrode plates on both sides. 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 cell.

[0020] According to a second aspect of this application, a battery is provided, the battery including a housing and the aforementioned cell structure, the cell structure being disposed within the housing.

[0021] Based on the above embodiments of this application, the battery provided by this application includes the above-described cell structure. Through the above arrangement, the cell structure is subjected to more balanced pressure from the center area to both sides during hot pressing, and the pressure of each part tends to be consistent. This ensures that the electrode and separator of each part maintain a better adhesion effect after hot pressing, reducing the possibility of lithium plating and other problems caused by gaps between the separator and the electrode, thereby extending the battery's service life and improving the battery's safety.

[0022] In some embodiments, the cell structure is configured as a laminated cell structure, or the 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. The device body has an internal power supply cavity, and the battery is disposed within the power supply cavity.

[0025] 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.

[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 battery cell structure provided in the embodiments of this application.

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

[0030] Figure 3 This is a schematic diagram of the separator structure in the battery cell structure provided in the embodiments of this application.

[0031] Figure 4 This is another schematic diagram of the battery cell structure provided in the embodiments of this application.

[0032] Explanation of reference numerals in the attached figures

[0033] 1. Positive electrode sheet; 11. Positive electrode foil; 12. Positive electrode active layer; 2. Negative electrode sheet; 21. Negative electrode foil; 22. Negative electrode active layer; 3. Thinning region; 4. Separator; 41. Base film; 42. Thickening region. Detailed Implementation

[0034] 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.

[0035] 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.

[0036] 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.

[0037] 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.

[0038] 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.

[0039] 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.

[0040] In the production of lithium-ion battery electrodes, a thinning zone with a gradual thickness change typically forms at the edge of the foil during coating. This thinning zone reduces the formation of thick edges due to the diffusion of the coating paste at the edges. Thick edges can lead to overpressure during subsequent rolling and can cause alignment deviations during winding or stacking, thus affecting battery yield. Furthermore, thick edges can cause stress concentration during winding or stacking, potentially leading to burrs piercing the cell and causing a short circuit. The thinning zone effectively prevents the formation of thick edges, thus solving these problems.

[0041] However, the thinning zone can also lead to other problems in subsequent processing. After the slurry coating is completed, subsequent steps such as hot pressing are required. During hot pressing, the electrode edges are thinner due to the presence of the thinning zone, resulting in a decrease in pressure at the edges. This leads to insufficient effective compaction pressure in this area, resulting in poor adhesion between the separator and the electrode. 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.

[0042] 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 breakage. Conversely, simply increasing the hot-pressing pressure can lead to over-compaction in areas other than the edges, affecting ion transport rates.

[0043] 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.

[0044] To address the aforementioned problems in the prior art, this application provides a battery cell structure, with reference to... Figures 1 to 3 As shown, the battery cell structure includes a positive electrode 1, a negative electrode 2, and a separator 4. The positive electrode 1 includes a positive electrode foil 11, with positive active layers 12 coated on both sides of the positive electrode foil 11. The negative electrode 2 includes a negative electrode foil 21, with negative active layers 22 coated on both sides of the negative electrode foil 21. The separator 4 is disposed between the positive electrode 1 and the negative electrode 2. Thinning regions 3 are formed at the edges of both the positive and negative active layers 12 and 22, and thickening regions 42 are formed at the edges of the separator 4, with the thickening regions 42 interlocking with the thinning regions 3 on both sides.

[0045] Based on the above embodiments of this application, compared with the existing cell structure, this application improves the structure of the separator 4 between the positive electrode 1 and the negative electrode 2 by setting a thickening region 42 at the edge of the separator 4. The thickening region 42 is fitted with the corresponding thinning region 3. The increased thickness of the thickening region 42 compensates for the reduced thickness of the thinning regions 3 on both sides. Finally, the overall thickness of the cell structure composed of the positive electrode 1, the separator 4 and the negative electrode 2 tends to be consistent, that is, the thickness of the central region and the edge of the cell structure composed of the stacked layers tends to be consistent.

[0046] During hot pressing, the pressure in the central and edge areas remains consistent under the same pressure, ensuring good compaction in both areas and preventing over-pressure in the central area while leaving the edges under pressure. This allows for better adhesion between the separator 4 and the electrode edges, reducing lithium-ion deposition caused by gaps between the electrode and separator 4, thereby mitigating the impact of lithium-ion deposition on lithium battery safety and lifespan.

[0047] With the above settings, the thickness of the central region and edge positions of the battery cell structure, which is composed of the positive electrode 1, the separator 4, and the negative electrode 2, tends to be consistent. At this point, appropriate hot-pressing parameters can be set based on this thickness, specifically including parameters such as the spacing between the pressure rollers and the hot-pressing temperature. By selecting suitable hot-pressing parameters based on this thickness, a good hot-pressing effect can be achieved. Furthermore, under these hot-pressing parameters, the pressure in each part of the battery cell structure with consistent thickness also tends to be consistent, thus maintaining good adhesion between the separator 4 and the electrode in each part of the battery cell.

[0048] Furthermore, the thickness of the cell structure mentioned above in this application refers to the thickness dimension of the cell structure along the stacking direction of each layer. Unless otherwise specified, the descriptions of the thickness of the electrode sheet and separator 4 in the following text also refer to the dimensions of the electrode sheet or separator 4 along the stacking direction. Additionally, the vertical direction mentioned later also refers to the stacking direction of each layer.

[0049] In the battery cell structure, the separator 4 is positioned between the positive electrode 1 and the negative electrode 2 to prevent direct contact between them. Simultaneously, the porous structure of the separator 4 allows lithium ions to pass through during charging and discharging. However, in existing technologies, the presence of the thinning region 3 leads to a lithium ion shortage at the electrode edge, meaning insufficient lithium ion intercalation occurs at the location of the thinning region 3. By incorporating the thickening region 42 in this application, the amount of lithium ions passing through and stored at the edge of the separator 4 can be increased, thereby compensating for the lithium ion shortage in the thinning region 3, reducing the concentration difference between the electrode edge and the central region, and improving the edge polarization effect.

[0050] Furthermore, the aforementioned improvement to the structure of the separator 4 in this application compensates for the size of the thinned region 3, thereby addressing the air pressure problem that occurs in the thinned region 3 during subsequent hot pressing. The specific material selection and coating process for the positive electrode foil 11, negative electrode foil 21, positive electrode active layer 12, and negative electrode active layer 22 can be chosen arbitrarily based on existing technologies. For example, the positive electrode foil 11 can be aluminum foil, while the negative electrode foil 21 can be copper foil. Simultaneously, the positive electrode active layer 12 can be made primarily of lithium iron phosphate, while the negative electrode active layer 22 can be made primarily of graphite-based materials. The specific selection can be made according to the actual process conditions, and this application does not impose specific restrictions in this regard.

[0051] In this application, the diaphragm 4 can be configured with any suitable structure and the thickened region 42 can be formed in any suitable manner.

[0052] In one exemplary embodiment provided in this application, the diaphragm 4 includes a base membrane 41, and a thickened region 42 is formed by protrusions at the edge of the base membrane 41.

[0053] Based on the above embodiments of this application, a method for forming the separator 4 is provided. The separator 4 is integrally formed, with the base film 41 as the main body, and a thickened area 42 is formed by adding material at the edge of the base film 41. In this case, the integrally formed separator 4 has higher overall mechanical strength, which can better cope with various stresses during the cell stacking or winding process, and better cope with the pressure changes of the separator 4 caused by the volume changes of the electrodes during charge and discharge cycles, reducing the possibility of the separator 4 tearing and causing short circuits.

[0054] In practical applications, the base film 41 can be made of 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.

[0055] Alternatively, in another embodiment of this application, the diaphragm 4 may include a base film 41 and a thickening coating, the thickening coating being protruding from the edge of the base film 41 to form a thickening region 42.

[0056] Based on the embodiments described above, another method for forming the diaphragm 4 is provided. In this method, a base film 41 is used as the main material, and a thickened region 42 is formed at the edge of the base film 41 by a thickening coating. In this case, the thickness of the base film 41 can remain constant during actual production and processing. Therefore, there is no need to separately adjust the processing technology of the base film 41 or the mold, avoiding increased processing costs due to process adjustments. For thinned regions 3 of different sizes and structures, the thickness and shape of the thickening coating can be changed to accommodate them.

[0057] Meanwhile, by selecting a specific material for the thickened coating, the thermal stability and other related properties of the separator 4 can be enhanced, thereby improving the overall safety of the battery. In practical applications, the base membrane 41 can still be a microporous polyolefin film, while the thickened coating can be made of materials such as ceramic coatings. The excellent thermal stability and high mechanical strength of the ceramic coating itself can be used to improve the overall performance of the separator 4.

[0058] The above discloses two different structures and formation methods of the diaphragm 4 and the thickened region 42. Based on this, in order to ensure that the thickened region 42 can better cooperate with the thinned region 3, the specific structure and size of the thickened region 42 can be further restricted.

[0059] In some embodiments of this application, reference is made to Figure 3 As shown, the thickness of the thickened region 42 is D, and the specific size range of the thickness D of the thickened region 42 can be set to 2μm≤D≤20μm.

[0060] Based on the above embodiments of this application, by limiting the thickness of the thickened region 42, the actual thickness of the thickened region 42 can be adaptively set according to the thickness of the thinned region 3, so that the thickened region 42 can be better fitted with the thinned region 3, thereby making the overall thickness dimension consistency of the positive electrode 1, the separator 4 and the negative electrode 2 after being stacked together better, so that the pressure of each part is consistent during hot pressing, and ensuring that each region achieves a better hot pressing effect.

[0061] In specific settings, the thickness of the thickened region 42 can be further restricted, for example, by limiting it to 5μm-10μm. This narrows the thickness range of the thickened region 42, preventing it from protruding excessively and reducing the possibility of stress concentration.

[0062] In some embodiments of this application, the thickness of the thickened region 42 increases uniformly, and the thickness of the thickened region 42 gradually increases from the middle of the diaphragm 4 toward the edge of the diaphragm 4.

[0063] In practical applications, the shape of the thickened area 42 can be adapted to the shape of the thinned area 3, allowing the thickened area 42 to better match the thinned area 3 and compensate for the thickness gap at the location of the thinned area 3. Since the shape of the thinned area 3 is naturally formed during coating, its thickness is typically reduced uniformly. The uniformly thickened area 42 can adapt to the structure of the thinned area 3, resulting in a better fit between them. Furthermore, by setting the thickness of the thickened area 42 to be uniformly increased, stress concentration can be avoided, reducing the possibility of diaphragm 4 breaking due to stress concentration during subsequent lamination or winding processes, thereby reducing the impact on cell safety.

[0064] Specifically, the thickness range of the thickened region 42 defined above in this application refers to the overall thickness range of the thickened region 42. The thickness of the thickened region 42 gradually increases. The above limitation on the thickness of the thickened region 42 means that the thickness at both ends of the thickened region 42 is limited to this thickness range. That is, the thickness of the end of the thickened region 42 closest to the center region of the diaphragm 4 is at least 2 μm, and the thickness of the end of the thickened region 42 furthest from the center region of the diaphragm 4 is at most 20 μm.

[0065] The specific structure of the thickened region 42 on the separator 4 has been disclosed above. By restricting the structure and size of the thickened region 42, it is possible to compensate for the dimensional gaps in the thinned region 3. In the actual assembly of the battery cell structure, positive electrode 1 and negative electrode 2 are stacked on both sides of the separator 4, and both positive electrode 1 and negative electrode 2 are usually coated on both sides during production. Therefore, thinned regions 3 exist on both the upper and lower sides of the separator 4.

[0066] refer to Figure 4 As shown in some embodiments of this application, the diaphragm 4 has thickened regions 42 on both sides facing the positive electrode 1 and the negative electrode 2, and the two thickened regions 42 are symmetrically arranged.

[0067] Based on the embodiments described above, since the positive electrode 1 and the negative electrode 2 are generally coated on both sides during processing, when the separator 4 is stacked between the positive electrode 1 and the negative electrode 2, there are thinning areas 3 on both sides of the separator 4. Therefore, the thickening areas 42 provided separately can respectively cooperate with the thinning areas 3 on both sides to fill the dimensional gaps caused by the thinning areas 3. At the same time, by symmetrically arranging the thickening areas 42 on both sides, the stress on both sides is more balanced during hot pressing, reducing the possibility of damage to the separator 4 and other structures due to stress concentration.

[0068] In some embodiments of this application, reference is made to Figure 4As shown, the cell structure includes at least two negative electrode plates 2 and at least one positive electrode plate 1, with the positive electrode plate 1 and the negative electrode plate 2 arranged alternately in sequence. A separator 4 is provided between any adjacent negative electrode plate 2 and positive electrode plate 1.

[0069] Based on the embodiments described above, in practical use, the battery cell structure is typically configured as a multi-layer structure, with positive electrode plates 1 and negative electrode plates 2 alternately arranged, and a separator 4 is provided between adjacent positive electrode plates 1 and negative electrode plates 2. In this case, the separator 4 also cooperates with the thinned areas 3 on the positive electrode plates 1 and negative electrode plates 2 on both sides. The specific number of layers of negative electrode plates 2 and positive electrode plates 1 can be set according to factors such as the actual capacity requirements of the battery cell.

[0070] When positive electrode 1 and negative electrode 2 are stacked within a battery cell, the outermost layer is usually set as negative electrode 2. Therefore, the number of negative electrode 2 is usually one more than the number of positive electrode 1. The specific number can be set according to factors such as the cell capacity. For example, two negative electrode 2 and one positive electrode 1 can be set, with the positive electrode 1 stacked between the two negative electrode 2, and a separator 4 is set between the positive electrode 1 and the negative electrode 2. Alternatively, three negative electrode 2 and two positive electrode 1 can be set, with the positive electrode 1 and negative electrode 2 arranged alternately, and the two outermost layers both set with negative electrode 2, with a separator 4 set between the positive electrode 1 and the negative electrode 2.

[0071] In existing technologies, since the thinning regions 3 are all formed at the edges of the positive electrode 1 or the negative electrode 2, the areas where the thinning regions 3 are located will also overlap after multiple electrode layers are stacked, further increasing the thickness difference between the center and edge of the cell. In this application, since the separator 4 can simultaneously compensate for the corresponding thinning regions 3 on the upper and lower positive electrode 1 and negative electrode 2, it can effectively avoid the problem of further increasing the thickness difference between the center and edge of the cell due to the stacking of multiple electrode layers.

[0072] Based on the above technical solutions, this application also provides a battery, which includes a casing and the above-mentioned cell structure, wherein the cell structure is disposed inside the casing.

[0073] Based on the above embodiments of this application, the battery provided by this application includes the above-described cell structure. Through the above arrangement, the cell structure is subjected to more balanced pressure from the center area to both sides during hot pressing, and the pressure of each part tends to be consistent. This ensures that after hot pressing, each part of the electrode sheet and the separator 4 maintain a relatively good adhesion effect, reducing the possibility of lithium plating and other problems caused by gaps between the separator 4 and the electrode sheet, thereby extending the battery's service life and improving the battery's safety.

[0074] In some embodiments, the cell structure is configured as a laminated cell structure, or the cell is configured as a wound core structure.

[0075] 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.

[0076] Meanwhile, this application only improves the edge structure of the separator 4, so it does not have a substantial impact on the cell structure after the separator 4 is stacked with the positive electrode 1 and the negative electrode 2, and therefore will not affect the subsequent winding or stacking process.

[0077] Based on the above technical solution, this application also provides an electrical device, which includes a device body and the aforementioned battery. The device body has an internal power supply cavity, and the battery is disposed within the power supply cavity.

[0078] 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.

[0079] 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.

[0080] 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.

[0081] 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.

[0082] 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 electric cell structure, characterized by, The cell structure includes: A positive electrode sheet, comprising a positive electrode foil, wherein a positive electrode active layer is coated on both sides of the positive electrode foil; A negative electrode sheet, including a negative electrode foil, wherein a negative electrode active layer is coated on both sides of the negative electrode foil; A diaphragm is disposed between the positive electrode and the negative electrode; The positive electrode active layer and the negative electrode active layer are both thinned at their edges, and the membrane is thickened at its edge. The thickened areas are respectively fitted into the thinned areas on both sides.

2. The cell structure of claim 1, wherein, The diaphragm includes a base membrane, and the thickened area is formed by protrusions at the edge of the base membrane.

3. The cell structure of claim 1, wherein, The diaphragm includes a base film and a thickening coating, wherein the thickening coating protrudes from the edge of the base film to form the thickened area.

4. The cell structure according to claim 2 or 3, characterized in that, The thickness of the thickened region is D, where 2μm≤D≤20μm.

5. The cell structure of claim 2 or 3, wherein, The thickness of the thickened area increases uniformly, and the thickness of the thickened area gradually increases from the middle of the diaphragm towards the edge of the diaphragm.

6. The cell structure of claim 1, wherein, The diaphragm has thickened regions on both sides facing the positive electrode and the negative electrode, and the two thickened regions are symmetrically arranged.

7. The cell structure of claim 1, wherein, The cell structure includes at least two negative electrode plates and at least one positive electrode plate, wherein the positive electrode plates and the negative electrode plates are arranged alternately in sequence; A separator is disposed between any two adjacent negative electrode plates and positive electrode plates.

8. A battery, characterized by The battery includes: The shell; and, The cell structure as described in any one of claims 1-7, wherein the cell structure is disposed within the housing.

9. The battery of claim 8, wherein, The cell structure is configured as a laminated cell structure, or the cell is configured as a wound cell structure.

10. An electric device, characterized by The electrical equipment includes: The main body of the equipment has an internal power supply chamber; and, The battery as described in claim 8 or 9, wherein the battery is disposed within the power supply cavity.

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