An electrode assembly and a stacked battery

Abstract

This invention provides an electrode assembly and a stacked battery, comprising: a positive electrode, a negative electrode, and a separator separating the positive and negative electrodes. Multiple positive electrodes, multiple negative electrodes, and multiple separators are stacked and hot-pressed to form a stacked body. At least one separator includes a main region and an edge region located on at least one side of the main region. The edge region extends at least partially to the outside of the positive and negative electrodes and is configured to contract and bend towards the adjacent positive or negative electrode side during hot pressing, so as to at least partially tighten at the end of the adjacent positive or negative electrode. The electrode assembly and stacked battery of this invention can improve the technical problem of the separator at the edge of the stacked body easily folding, causing the stacked body to expose black residue.

Description

Technical Field

[0001] This utility model relates to the field of battery technology, and in particular to an electrode assembly and a stacked battery. Background Technology

[0002] With the rapid development of the new energy industry, lithium-ion batteries, such as stacked batteries, have become a research hotspot. The electrode assembly is a crucial component of stacked batteries, serving as the core site of electrochemical reactions. The electrode assembly is housed within the battery casing and typically includes a positive electrode, a negative electrode, and a separator separating the positive and negative electrodes. These three components are stacked and hot-pressed to form the stack. However, in actual production, it has been found that the separator at the edges of the stack is prone to folding, causing the stack to expose black spots, and in severe cases, resulting in a short circuit between the positive and negative electrodes. Utility Model Content

[0003] In view of the shortcomings of the prior art, the present invention provides an electrode assembly and a stacked battery to improve the technical problem that the separator at the edge of the stacked body is easily folded, causing the stacked body to expose black.

[0004] This utility model provides an electrode assembly, including: a positive electrode, a negative electrode and a separator separating the positive electrode and the negative electrode, wherein multiple positive electrode, multiple negative electrode and multiple separator are stacked and hot-pressed to form a stacked body;

[0005] The membrane includes a main body region and an edge region located on at least one side of the main body region. The edge region extends at least partially to the outside of the positive and negative electrode plates and is configured to be able to contract and bend toward the adjacent positive or negative electrode plate side during hot pressing to at least partially tighten onto the end of the adjacent positive or negative electrode plate.

[0006] In one embodiment of the present invention, the separator includes a base film extending from the main body region to the edge region. The surface of the base film in the edge region is provided with a heat-shrinkable coating. The glass transition temperature of the heat-shrinkable coating is lower than the hot pressing temperature, so that the heat-shrinkable coating can drive the base film in the edge region to shrink and bend towards the adjacent positive electrode side or negative electrode side during the hot pressing process.

[0007] In one embodiment of this utility model, the glass transition temperature of the base film is higher than the hot pressing temperature;

[0008] And / or, the hot melt temperature of the heat-shrinkable coating is higher than the hot pressing temperature.

[0009] In one embodiment of this utility model, the hot-pressing temperature is 90℃~100℃, wherein:

[0010] The glass transition temperature of the base film is above 100℃;

[0011] And / or, the glass transition temperature of the heat-shrinkable coating is 60℃~80℃.

[0012] In one embodiment of this utility model, the base film is made of polyethylene or polypropylene.

[0013] And / or, the heat-shrinkable coating is made of polyester or polyurethane.

[0014] In one embodiment of the present invention, the base film in the edge region of multiple separators is provided with a heat-shrinkable coating on the same side surface facing the positive electrode side or the negative electrode side.

[0015] And / or, the thickness of the heat-shrinkable coating is 2µm to 3µm.

[0016] In one embodiment of this utility model, the positive electrode and the negative electrode extend out of the diaphragm to form an electrode tab, and the main body area has an edge area on the side near the electrode tab.

[0017] In one embodiment of the present invention, a first intersection line is formed between the edge area and the main body area, and a second intersection line is formed between the electrode tab and the electrode sheet. The distance L between the first intersection line and the second intersection line is 5 to 20 mm.

[0018] In one embodiment of the present invention, the electrode tabs include positive electrode tabs and negative electrode tabs disposed opposite to each other on both sides of the stacked body, and the main body area is provided with edge areas on the side near the positive electrode tab and the side near the negative electrode tab.

[0019] And / or, a thinning area is provided on the side of the negative electrode sheet near the negative electrode tab, and the edge area covers the thinning area.

[0020] This utility model also provides a stacked battery, including a housing, and the above-mentioned electrode assembly is disposed inside the housing.

[0021] The beneficial effects of this utility model are as follows: The electrode assembly proposed in this utility model includes at least one separator comprising a main body region and an edge region located on at least one side of the main body region. The edge region extends at least partially to the outside of the positive and negative electrode sheets and is configured to shrink and bend towards the adjacent positive or negative electrode sheet during hot pressing, so as to at least partially tighten at the end of the adjacent positive or negative electrode sheet. That is, the edge region of the separator has self-shrinking properties after hot pressing and can shrink and bend to one side during hot pressing. In this way, during the process of stacking the positive electrode sheet, negative electrode sheet and separator and hot pressing to form a stack, the edge region of the separator will automatically shrink and bend towards the adjacent positive or negative electrode sheet, thereby tightening the edge region of the separator at the end of the positive or negative electrode sheet. Therefore, it can play a certain protective role for the stack. Moreover, the edge region after hot shrinkage can effectively improve the technical problem of the separator folding at the edge of the stack, thereby improving the production efficiency and safety of the battery. Attached Figure Description

[0022] 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. It is obvious that the drawings described below are merely some embodiments of this application, and those skilled in the art can obtain other drawings based on these drawings without any inventive effort.

[0023] In the attached diagram:

[0024] Figure 1 A schematic diagram of the principle structure of an electrode assembly provided in an embodiment of this utility model;

[0025] Figure 2 Provided for an embodiment of this utility model Figure 1 A schematic diagram of the edge area of ​​the septum before shrinkage and bending;

[0026] Figure 3 Provided for an embodiment of this utility model Figure 1 A schematic diagram of the edge area of ​​the diaphragm after shrinkage and bending.

[0027] The attached figures are labeled as follows:

[0028] 1. Electrode assembly; 11. Positive electrode plate; 111. Positive electrode tab; 12. Negative electrode plate; 121. Negative electrode tab; 1211. Second junction line; 122. Thinning region; 13. Separator; 1311. Main body region; 1312. Edge region; 1313. First junction line. Detailed Implementation

[0029] The following specific examples illustrate the implementation of this utility model. Those skilled in the art can easily understand other advantages and effects of this utility model from the content disclosed in this specification. This utility model can also be implemented or applied through other different specific embodiments. Various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of this utility model. In the absence of conflict, the following embodiments and features in the embodiments can be combined with each other.

[0030] It should be noted that the illustrations provided in the following embodiments are only schematic representations of the basic concept of the present invention. The drawings only show the components related to the present invention and are not drawn according to the actual number, shape and size of the components. In actual implementation, the form, quantity and proportion of each component can be arbitrarily changed, and the layout of the components may also be more complex.

[0031] In the following description, numerous details are explored to provide a more thorough explanation of embodiments of the present invention. However, it will be apparent to those skilled in the art that embodiments of the present invention may be practiced without these specific details. In other embodiments, well-known structures and devices are shown in block diagram form rather than in detail to avoid obscuring embodiments of the present invention.

[0032] In actual production, it was found that after the laminated body is formed, the separator is prone to folding on the surface due to its own tension, causing the laminate to expose black spots and creating a risk of internal short circuits. Furthermore, although hot pressing can bond the positive electrode, negative electrode, and separator together, the antistatic capability of the hot press plate gradually weakens with increasing usage time, making it easy to lift the separators from the upper and lower layers of the laminated body. This can further cause the electrode to form openings, and may even cause the separator to fold into the interior of the laminated body, resulting in a short circuit between the positive and negative electrode, leading to electrode assembly failure. To solve this problem, this utility model adopts the following solution:

[0033] Please see Figures 1-3 This invention provides an electrode assembly 1, comprising: a positive electrode 11, a negative electrode 12, and a separator 13 separating the positive electrode 11 and the negative electrode 12. Multiple positive electrode 11s, multiple negative electrode 12s, and multiple separators 13 are stacked and hot-pressed to form a stacked body. The separator 13 plays a crucial role in preventing the positive and negative electrodes from conducting. The separator 13 typically includes a base film, and additionally, specific material layers, such as a PVDF coating and / or a ceramic layer, can be applied to the base film as needed. In one embodiment of this invention, the separator includes a base film and a PVDF coating disposed on the base film. This design not only provides good chemical stability but also allows the PVDF coating to melt during hot pressing, tightly bonding the electrode and the separator 13, resulting in a flat and rigid stacked body, facilitating subsequent processing. Specifically, the PVDF coating is a porous film made from polyvinylidene fluoride (PVDF) resin, coated onto the surface of a substrate using an aqueous or solvent-based process, and firmly bonded to the positive and negative electrode during the hot pressing process. However, it should be noted that if the base film itself has good hot-pressing adhesion properties, a PVDF coating may not be necessary.

[0034] Please see Figures 1-3At least one diaphragm 13 includes a main body region 1311 and an edge region 1312 located on at least one side of the main body region 1311. The edge region 1312 extends at least partially to the outside of the positive electrode 11 and the negative electrode 12, and is configured to shrink and bend towards the adjacent positive electrode 11 or negative electrode 12 during hot pressing, so as to at least partially tighten at the end of the adjacent positive electrode 11 or negative electrode 12. That is, the edge region 1312 of the diaphragm 13 has self-shrinking properties after hot pressing and can shrink and bend to one side during hot pressing. In this way, during the process of stacking and hot-pressing the positive electrode 11, negative electrode 12, and separator 13 to form a stack, the edge region 1312 of the separator 13 will automatically shrink and bend towards the adjacent positive electrode 11 or negative electrode 12, thereby tightening the edge region 1312 of the separator 13 onto the end of the positive electrode 11 or negative electrode 12. Therefore, it can provide a certain degree of protection for the stack, and the heat-shrinked edge region 1312 can effectively improve the technical problem of separator folding at the edge of the stack, thereby improving the production efficiency and safety of the battery. In this embodiment, only the edge region 1312 shrinking and bending towards the adjacent negative electrode 12 is shown. In other embodiments, the edge region 1312 may also shrink and bend towards the positive electrode 11.

[0035] To achieve the shrinkage and bending of the edge region 1312 of the separator 13 towards the adjacent positive electrode 11 or negative electrode 12 during hot pressing, various implementation methods readily conceived by those skilled in the art can be employed. For example, the main body region 1311 and the edge region 1312 of the separator 13 can be made of different materials. The material used for the edge region 1312 of the separator 13 has a glass transition temperature lower than the hot pressing temperature, allowing the edge region 1312 to shrink and bend to one side during hot pressing. However, for better results, this embodiment preferably adopts the following method:

[0036] Please see Figures 1-3 In one embodiment of the present invention, the separator 13 may include a base film extending from the main body region 1311 to the edge region 1312. The surface of the base film in the edge region 1312 is provided with a heat-shrinkable coating. The glass transition temperature of the heat-shrinkable coating is lower than the hot pressing temperature, so that the heat-shrinkable coating can drive the base film in the edge region 1312 to shrink and bend towards the adjacent positive electrode 11 or negative electrode 12 during the hot pressing process. That is, this embodiment adopts the method of providing a heat-shrinkable coating on the surface of the base film in the edge region 1312. Compared with the method of using different materials for the main body region 1311 and the edge region 1312 of the separator 13, it is more convenient for actual implementation, not only saving costs and improving production efficiency, but also being more suitable for large-scale production.

[0037] In one embodiment of this utility model, the glass transition temperature of the base film can be higher than the hot pressing temperature. This can prevent the base film in the main body region 1311 from shrinking and deforming under the hot pressing temperature, and prevent the base film in the main body region 1311 from forming local depressions or bulges under the hot pressing temperature. During the process of stacking and hot pressing the positive electrode 11, negative electrode 12 and separator 13 to form a stack, only the base film with heat shrinkable coating in the edge region 1312 will shrink and bend towards the adjacent positive electrode 11 or negative electrode 12 during the hot pressing process. The base film in the main body region 1311 will not shrink and deform during the hot pressing process, thereby better protecting the stack and more effectively improving the technical problem of edge separator folding of the stack.

[0038] In one embodiment of the present invention, the melting temperature of the heat-shrinkable coating is higher than the hot-pressing temperature. This can prevent the heat-shrinkable coating from melting at the hot-pressing temperature. During the process of stacking and hot-pressing the positive electrode 11, negative electrode 12 and separator 13 to form a stack, the heat-shrinkable coating can be prevented from melting and sticking together, thus preventing unnecessary safety hazards.

[0039] In one embodiment of this utility model, the hot-pressing temperature can be any value between 90℃ and 100℃, such as 90℃, 95℃, 100℃, etc., and can be flexibly set according to actual usage needs. The glass transition temperature of the base film can be above 100℃, so that when the hot-pressing temperature is between 90℃ and 100℃, the base film in the main body region 1311 can be prevented from shrinking and deforming under the hot-pressing temperature. At this temperature, the base film includes, but is not limited to, polyethylene or polypropylene. Of course, compared with other materials, polyethylene or polypropylene has balanced mechanical properties, excellent chemical and electrical properties, and strong process adaptability. The glass transition temperature of the heat-shrinkable coating can be any value between 60°C and 80°C, such as 60°C, 70°C, or 80°C. When the hot-pressing temperature is 90°C to 100°C, the heat-shrinkable coating can cause the base film of the edge region 1312 to shrink and bend towards the adjacent positive electrode 11 or negative electrode 12. At this temperature, the heat-shrinkable coating includes, but is not limited to, materials such as polyester and its derivatives or polyurethane and its derivatives. Of course, compared with other materials, polyester or polyurethane materials have better chemical stability, thermal stability, and processability, which can not only meet the safety and stability requirements of lithium batteries, but also provide better protection and stability for the separator 13 in practical applications.

[0040] In this embodiment, the heat-shrinkable coating can be applied to only one side of the base film within the edge region 1312, or to both sides of the base film within the edge region 1312. Regardless of the application method, the heat-shrinkable coating can cause the base film in the edge region 1312 to shrink and bend towards the adjacent positive electrode 11 or negative electrode 12 during hot pressing. However, preferably, please refer to... Figures 1-3In this embodiment, the base film in the edge region 1312 of multiple separators 13 can be provided with a heat-shrinkable coating on the same side surface facing the positive electrode 11 or the negative electrode 12. In this way, during the process of stacking the positive electrode 11, the negative electrode 12 and the separator 13 and hot pressing them to form a stack, it is convenient to control the bending direction of the edge region 1312. During the hot pressing process, the heat-shrinkable coating causes the base film of the edge region 1312 to shrink and bend towards the same side of the adjacent positive electrode 11 or negative electrode 12. This results in the base film of the edge region 1312 being layered on top of each other after shrinkage and bending. This further improves the protection effect when affected by external forces such as crosswinds during transportation.

[0041] In this embodiment, the edge region 1312 can be located on the opposite side of the main body region 1311 and the tab (i.e., Figure 1 It can also be set on the non-opposite side of the main body area 1311 and the electrode ear (i.e., the left and right sides). Figure 1 (both sides); However, during the processing of electrode assembly 1, the electrode sheet needs to first extend the diaphragm 13 to form an electrode tab, and then the positive electrode sheet 11, negative electrode sheet 12 and diaphragm 13 are stacked and hot-pressed to form a stacked body. Compared with other sides, the diaphragm 13 on the electrode sheet extension side is more prone to folding. Therefore, in this embodiment, the main body area 1311 near the electrode tab can be provided with an edge area 1312. In this way, setting the edge area 1312 at the place where the diaphragm 13 is prone to folding can more effectively solve the technical problem of folding of the diaphragm at the edge of the stacked body, which not only saves costs but also improves production efficiency.

[0042] Please see Figure 1 In one embodiment of the present invention, a first intersection line 1313 is formed between the edge area 1312 and the main body area 1311, and a second intersection line 1211 is formed between the tab and the electrode sheet. The distance L between the first intersection line 1313 and the second intersection line 1211 can be any value between 5mm and 20mm, such as 5mm, 10mm, 15mm, 20mm, etc., which can be flexibly set according to actual use needs to ensure that the base film of the edge area 1312 after shrinkage and bending has a better protective effect.

[0043] Please see Figure 1In one embodiment of this utility model, the tabs may include positive tabs 111 and negative tabs 121 disposed opposite to each other on both sides of the stacked body. That is, the positive electrode 11 extends out of the diaphragm 13 to form the positive electrode tab 111, and the negative electrode 12 extends out of the diaphragm 13 to form the negative electrode tab 121. The main body area 1311 is provided with edge areas 1312 on the side near the positive electrode tab 111 and the side near the negative electrode tab 121. In this way, during the process of stacking the positive electrode 11, the negative electrode 12 and the diaphragm 13 and hot pressing them to form the stacked body, the edge areas 1312 on the side near the positive electrode tab 111 and the edge areas 1312 on the side near the negative electrode tab 121 will automatically shrink and bend towards the adjacent positive electrode 11 or negative electrode 12, thereby providing protection for the stacked body on both sides. Compared with single-sided protection, the effect is better.

[0044] During the research process, the inventors discovered that in order to reserve expansion space at the edge of the electrode and prevent the edge of the electrode from bulging and squeezing the diaphragm 13, causing a short circuit, a thinning area 122 is usually provided on the side of the negative electrode 12 near the negative electrode tab 121. Due to the presence of the thinning area 122, the diaphragm 13 is not easy to compact after hot pressing at this point, and it is loose. As a result, it is easy to bend when affected by external forces such as crosswinds during transportation, which will lead to a short circuit between the positive and negative electrodes and cause unnecessary risks. To address this issue, in this embodiment, the edge region 1312 can cover the thinned region 122. Since the surface of the base film within the edge region 1312 is coated with a heat-shrinkable coating, which is thicker and has stronger heat-shrinkability compared to other areas, it enhances the adaptability to the thinned region 122 during hot pressing. This ensures effective compaction after hot pressing, reducing loosening and thus minimizing the risk of diaphragm 13 folding. Furthermore, after shrinking and bending, the edge region 1312 protects the stacked sheet at the thinned region 122, effectively resisting external forces and reducing the risk of diaphragm 13 folding during transport. The thickness of the heat-shrinkable coating can be any value between 2µm and 3µm, such as 2µm, 2.3µm, 2.5µm, 3µm, etc., and can be flexibly set according to actual usage needs to simultaneously consider the thickness and heat-shrinkability of the coating.

[0045] This utility model also provides a stacked battery, including a housing, and the electrode assembly 1 described above is disposed inside the housing. The specific structure of the electrode assembly 1 is the same as above, and will not be described again here.

[0046] In summary, the electrode assembly and stacked battery of this invention, during the process of stacking and hot-pressing the positive electrode, negative electrode, and separator to form a stacked body, exhibits a feature where the edge area of ​​the separator automatically contracts and bends towards the adjacent positive or negative electrode, thus providing a certain degree of protection for the stacked body. This effectively improves the technical problem of separator folding at the edge of the stacked body, thereby enhancing battery production efficiency and safety. The electrode assembly and stacked battery of this invention can effectively prevent separator folding, thereby preventing blackening of the stacked body. This solves the battery failure problem caused by exposed active materials due to tension and electrostatic effects during stacking and hot-pressing processes, significantly improving safety.

[0047] This embodiment provides an electrode assembly and a stacked battery, the specific implementation of which is as follows:

[0048] Electrode assembly 1 structure:

[0049] Multiple positive electrode sheets 11, negative electrode sheets 12, and separators 13 are stacked and hot-pressed to form a laminate. The positive electrode sheet 11 is an aluminum foil coated with a ternary material, and the negative electrode sheet 12 is a copper foil coated with a graphite material. The separator 13 includes a polyethylene base film (glass transition temperature of 105°C), and a PVDF coating is applied to the surface of the base film to enhance adhesion.

[0050] Diaphragm 13 edge region 1312 design:

[0051] Edge regions 1312 are provided on both sides of the main body region 1311 of the diaphragm 13. The width of the edge region 1312 is 15mm (that is, the distance between the first intersection line 1313 and the second intersection line 1211 between the tab and the electrode is 15mm). The base film surface in the edge region 1312 is coated with a polyurethane heat-shrinkable coating with a coating thickness of 3μm and a glass transition temperature of 70℃.

[0052] Hot pressing process:

[0053] The stacked positive electrode 11, negative electrode 12, and separator 13 are hot-pressed at 95°C. During the hot-pressing process, the heat-shrinkable coating of the edge region 1312 shrinks due to heat, causing the base film to bend towards the adjacent negative electrode 12. The bent edge region 1312 partially blocks the end of the negative electrode 12.

[0054] Effect:

[0055] After hot pressing, the edge region 1312 shrinks and bends uniformly, forming a layered protective structure that effectively prevents the separator 13 from folding over. There is no blackening at the edge of the stacked body, and the electrode ends are fully shielded, reducing the risk of internal short circuits. Simultaneously, the edge region 1312 covers the thinned area of ​​the negative electrode 12, enhancing the compaction of this area and preventing the separator from loosening due to external forces during transport. Furthermore, an experiment was conducted using 1000 cells, showing a folding rate of 0%, achieving highly efficient fabrication with zero defects.

[0056] This comparative example also provides an electrode assembly and a stacked battery, which adopts the same hot pressing process and the same positive electrode 11, negative electrode 12 and separator 13 as the above embodiment. The only difference from the above embodiment is that the edge area 1312 of the separator 13 is not provided with a heat shrinkable coating.

[0057] Effect:

[0058] During hot pressing, the edge region 1312 has no shrinkage characteristics and relies solely on the tension of the base film to maintain its shape. After hot pressing, the edge region 1312 of the separator 13 is prone to folding due to tension, resulting in blackening at the edges of the stack and exposure of the electrode ends. Furthermore, during subsequent transport, under the influence of static electricity or external forces, the separator 13 may fold further into the stack, posing a risk of short circuit between the positive and negative electrodes. Especially in the negative electrode thinning area 122, the separator 13 is not sufficiently compacted, exhibiting significant looseness and poor protective effect. Similarly, through testing with 1000 cells, the folding rate was 5%, far higher than the 0% in the above embodiment, indicating that the heat-shrinkable coating on the edge region 1312 of the separator 13 in the above embodiment can effectively prevent the separator 13 from folding.

[0059] The above embodiments are merely illustrative of the principles and effects of this utility model and are not intended to limit the scope of this utility model. Any person skilled in the art can modify or alter the above embodiments without departing from the spirit and scope of this utility model. Therefore, all equivalent modifications or alterations made by those skilled in the art without departing from the spirit and technical concept disclosed in this utility model should still be covered by the claims of this utility model.

Claims

1. An electrode assembly, characterized in that, include: A positive electrode, a negative electrode, and a separator separating the positive and negative electrode sheets are stacked and hot-pressed to form a stacked body; The diaphragm includes a main body region and an edge region located on at least one side of the main body region. The edge region extends at least partially to the outside of the positive electrode and the negative electrode and is configured to bend and contract toward the adjacent positive electrode or the negative electrode during hot pressing to at least partially tighten at the end of the adjacent positive electrode or the negative electrode.

2. The electrode assembly according to claim 1, characterized in that, The separator includes a base film extending from the main body region to the edge region. The surface of the base film in the edge region is provided with a heat-shrinkable coating. The glass transition temperature of the heat-shrinkable coating is lower than the hot-pressing temperature, so that the heat-shrinkable coating can drive the base film in the edge region to shrink and bend towards the adjacent positive electrode side or negative electrode side during the hot-pressing process.

3. The electrode assembly according to claim 2, characterized in that, The glass transition temperature of the base film is higher than the hot pressing temperature; And / or, the hot melt temperature of the heat-shrinkable coating is higher than the hot pressing temperature.

4. The electrode assembly according to claim 2, characterized in that, The hot pressing temperature is 90℃~100℃, wherein: The glass transition temperature of the base film is above 100°C; And / or, the glass transition temperature of the heat-shrinkable coating is 60°C to 80°C.

5. The electrode assembly according to claim 4, characterized in that, The base film is made of polyethylene or polypropylene. And / or, the heat-shrinkable coating is made of polyester or polyurethane.

6. The electrode assembly according to claim 2, characterized in that, The heat-shrinkable coating is provided on the same side surface of the base film in the edge region of the multiple separators facing the positive electrode side or the negative electrode side; And / or, the thickness of the heat-shrinkable coating is 2µm to 3µm.

7. The electrode assembly according to any one of claims 1 to 6, characterized in that, The positive and negative electrode plates extend out of the diaphragm to form tabs, and the main body region has an edge region on the side near the tabs.

8. The electrode assembly according to claim 7, characterized in that, A first intersection line is formed between the edge area and the main body area, and a second intersection line is formed between the tab and the electrode sheet. The distance L between the first intersection line and the second intersection line is 5 to 20 mm.

9. The electrode assembly according to claim 7, characterized in that, The electrode tabs include positive electrode tabs and negative electrode tabs disposed opposite to each other on both sides of the stacked body, and the edge area is provided on both the side of the main body near the positive electrode tab and the side near the negative electrode tab; And / or, the negative electrode sheet has a thinning area on the side near the negative electrode tab, and the edge area covers the thinning area.

10. A stacked battery, characterized in that, It includes a housing, wherein the housing contains an electrode assembly as described in any one of claims 1 to 9.

Images