Positive electrode assembly and battery
By forming a staggered structure at the tail end of the positive electrode component and adding a hot melt adhesive layer, the flatness problem of the single and double material junction area at the tail end of the lithium battery positive electrode is solved, thereby improving the stability and lifespan of the battery.
Patent Information
- Application Number
- CN202423184106.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-23
- Publication Date
- 2025-12-12
- Estimated Expiration
- 2034-12-23
AI Technical Summary
The junction area of the single and double materials at the tail of the positive electrode of a lithium battery falls on the tab, resulting in poor battery flatness. Consequently, the battery is prone to breakage during charge and discharge cycles, affecting battery performance and lifespan.
A staggered structure of single and double-sided coating areas is formed at the tail end of the positive electrode component, and a hot melt adhesive layer of a specific thickness is added to this structure to adjust the thickness of the flat area of the battery and enhance the stability of the positive electrode component.
It improves the flatness of lithium batteries, reduces the risk of positive electrode component breakage during charge and discharge cycles, and enhances battery stability and lifespan.
Smart Images
Figure CN223665463U_ABST
Abstract
Description
Technical Field
[0001] This disclosure relates to the field of lithium battery manufacturing technology, and in particular to a positive electrode component and a battery. Background Technology
[0002] With the rapid development of lithium battery technology, battery flatness has become one of the key indicators for measuring the quality of battery components, and has a profound impact on battery performance and stability. In particular, for wound pouch batteries with a large thickness-to-width ratio, the curved part of its edge is large while the flat area is small. This leads to the risk that the single and double fabric junction area at the positive electrode tail may fall onto the tab, thus significantly reducing the flatness of the battery.
[0003] However, poor battery flatness can cause uneven stress in different areas during formation, especially at the interface between the single and double sides of the positive electrode, where stress increases, making the battery more prone to breakage during subsequent charge-discharge cycles. Breakage inside the battery not only reduces its capacity but also significantly shortens its service life, threatening its safety and reliability. Utility Model Content
[0004] The purpose of this disclosure is to overcome the shortcomings of the prior art and provide a structure and lithium battery that improves battery flatness, enhances the rigidity of the positive electrode tail, and prevents lithium battery electrode breakage.
[0005] The purpose of this disclosure is achieved through the following technical solution:
[0006] A positive electrode assembly for winding with a separator and a negative electrode assembly to form a battery core, the positive electrode assembly including a positive current collector, a first active coating, a second active coating, a positive electrode tab, and an adhesive layer.
[0007] The positive current collector has a first surface and a second surface, the first active coating is coated on the first surface, and the second active coating is coated on the second surface.
[0008] The first end of the first active coating and the first end of the second active coating are aligned at the first end of the positive electrode assembly, and the second end of the first active coating and the second end of the second active coating are misaligned at the second end of the positive electrode assembly; the first end of the positive electrode assembly serves as its winding start end, and the second end serves as its winding end.
[0009] The positive electrode tab is connected to the positive current collector and is located between the first and second ends of the positive electrode assembly.
[0010] The adhesive layer includes a first hot melt adhesive layer and a second hot melt adhesive layer. The first hot melt adhesive layer is located on the first surface of the positive electrode current collector, and one end of the first hot melt adhesive layer overlaps with the second end of the first active coating. The second hot melt adhesive layer is located on the second surface of the positive electrode current collector, and one end of the second hot melt adhesive layer overlaps with the second end of the second active coating.
[0011] In one embodiment, the first active coating has a first dressing area and a second dressing area, and the second active coating has a third dressing area and a fourth dressing area; the end of the second dressing area away from the first dressing area and the end of the fourth dressing area away from the third dressing area are aligned at the first end of the positive electrode assembly; the end of the first dressing area away from the second dressing area and the end of the third dressing area away from the fourth dressing area are offset at the second end of the positive electrode assembly.
[0012] The positive electrode tab is located between the first dressing area and the second dressing area, and between the third dressing area and the fourth dressing area;
[0013] The first hot melt adhesive layer is located at the end of the first dressing area away from the second dressing area, and the second hot melt adhesive layer is located at the end of the third dressing area away from the fourth dressing area.
[0014] In one embodiment, the distance between the second end of the first active coating and the second end of the second active coating along the length of the positive electrode assembly is between 75 and 90 mm.
[0015] In one embodiment, the length of the first active coating ranges from 1388 to 1393 mm.
[0016] In one embodiment, the length of the second active coating ranges from 1312 to 1317 mm.
[0017] In one embodiment, in the longitudinal direction of the electrode assembly, the overlap length between the first hot melt adhesive layer and the first active coating is between 1 and 2 mm, and the overlap length between the second hot melt adhesive layer and the second active coating is between 1 and 2 mm.
[0018] In one embodiment, the thickness of the first active coating and / or the second active coating is between 40 and 50 μm.
[0019] In one embodiment, the thickness of the first hot melt adhesive layer is between 50 and 60 μm;
[0020] The thickness of the second hot melt adhesive layer is between 50 and 60 μm.
[0021] In one embodiment, at least one of the first hot melt adhesive layer and the second hot melt adhesive layer is a polyurethane adhesive layer.
[0022] A battery includes a negative electrode assembly, a separator, and a positive electrode assembly as described in any one of the above; the positive electrode assembly, the separator, and the negative electrode assembly are wound together to form a core.
[0023] Compared with the prior art, this disclosure has at least the following advantages:
[0024] 1. In the above-mentioned positive electrode component, the first active coating and the second active coating form a misaligned structure in the single and double-sided coating area at the second end of the positive electrode component, that is, at the tail end of the positive electrode component, and a hot melt adhesive layer of a specific thickness is added to the misaligned structure to adjust the thickness of the flat area of the battery, thereby improving the flatness of the lithium battery after the winding process is completed.
[0025] 2. Due to the good adhesion and flexibility of the hot melt adhesive layer, it helps the tail end of the positive electrode component to withstand greater pressure during charge and discharge cycles, thereby enhancing the stability of the misaligned structure at the junction of the single and double-sided coating areas at the second end of the positive electrode component, and effectively reducing the risk of breakage at the second end of the positive electrode component due to uneven stress during lithium battery charge and discharge cycles. Attached Figure Description
[0026] To more clearly illustrate the technical solutions of the embodiments of this disclosure, the accompanying drawings used in the embodiments will be briefly described below. It should be understood that the following drawings only show some embodiments of this disclosure and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.
[0027] Figure 1 This is a structural diagram of a positive electrode assembly for preventing lithium battery electrode breakage according to an embodiment;
[0028] Figure 2 This is a structural diagram of a negative electrode assembly for preventing lithium battery electrode breakage according to an embodiment;
[0029] Figure 3 This is a line graph showing the thickness of the positive and negative tabs of a conventional core structure according to one embodiment;
[0030] Figure 4 Line graphs showing the thickness of the positive and negative tabs in a structure for preventing lithium battery electrode breakage according to one embodiment. Detailed Implementation
[0031] To facilitate understanding of this disclosure, a more complete description will be given below with reference to the accompanying drawings, which illustrate preferred embodiments of the present disclosure. However, this disclosure can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided to provide a more thorough and complete understanding of the disclosure.
[0032] It should be noted that when an element is referred to as being "fixed to" another element, it can be directly attached to the other element or there may be an intervening element. When an element is referred to as being "connected to" another element, it can be directly connected to the other element or there may be an intervening element. The terms "vertical," "horizontal," "left," "right," and similar expressions used herein are for illustrative purposes only and do not represent the only possible implementation.
[0033] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure belongs. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of this disclosure. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.
[0034] To better understand the technical solutions and beneficial effects of this disclosure, the following detailed description is provided in conjunction with specific embodiments:
[0035] like Figures 1 to 4 As shown, a positive electrode assembly 10 of this disclosure is used to be wound with a separator and a negative electrode assembly to form a core of a battery. The positive electrode assembly 10 includes a positive electrode current collector 100, a first active coating 200, a second active coating 300, a positive electrode tab 400, and an adhesive layer 500.
[0036] The positive current collector 100 has a first surface 110 and a second surface 120, a first active coating 200 is coated on the first surface 110, and a second active coating 300 is coated on the second surface 120.
[0037] The first end of the first active coating 200 and the first end of the second active coating 300 are aligned at the first end A of the positive electrode assembly 10, and the second end of the first active coating 200 and the second end of the second active coating 300 are misaligned at the second end B of the positive electrode assembly 10; the first end A of the positive electrode assembly 10 is used as its winding start end, and the second end B is used as its winding end end.
[0038] The positive electrode tab 400 is connected to the positive electrode current collector 100 and is located between the first end A and the second end B of the positive electrode assembly 10.
[0039] The adhesive layer 500 includes a first hot melt adhesive layer 510 and a second hot melt adhesive layer 520. The first hot melt adhesive layer 510 is located on the first surface 110 of the positive electrode current collector 100, and one end of the first hot melt adhesive layer 510 overlaps with the second end of the first active coating 200. The second hot melt adhesive layer 520 is located on the second surface 120 of the positive electrode current collector 100, and one end of the second hot melt adhesive layer 520 overlaps with the second end of the second active coating 300.
[0040] In this embodiment, during the winding operation of the lithium battery, the positive electrode assembly 10, the negative electrode assembly 20, and the insulating separator need to be wound simultaneously to form the core structure of the lithium battery. During this process, the first end of the first active coating 200 and the first end of the second active coating 300 are aligned at the first end A of the positive electrode assembly 10, and the first end A of the positive electrode assembly 10 is the starting end of the winding process. The second ends of the first active coating 200 and the second active coating 300 are misaligned at the second end B of the positive electrode assembly, resulting in a misaligned structure of single and double-sided coating areas at the second end B of the positive electrode assembly 10. On the other hand, since the first hot melt adhesive layer 510 and the second hot melt adhesive layer 520 have good adhesion and flexibility, and one end of the first hot melt adhesive layer 510 overlaps with the second end of the first active coating 200, and one end of the second hot melt adhesive layer 520 overlaps with the second end of the second active coating 300, the first hot melt adhesive layer 510 and the second hot melt adhesive layer 520 play a buffering and bonding role in the misaligned structure of the single and double-sided coating area at the second end B of the positive electrode component 10, and enhance the stability of the misaligned structure of the single and double-sided coating area at the second end B of the positive electrode component 10. This helps to resist the stress and tension generated by the lithium battery during charge and discharge cycles, thereby reducing the risk of breakage at the junction of the single and double-sided coating areas at the second end B of the positive electrode component 10. In addition, by adding the first hot melt adhesive layer 510 and the second hot melt adhesive layer 520 with specific thicknesses, the thickness of the flat area formed after the lithium battery is wound can be adjusted, making the overall thickness distribution of the battery more uniform. This helps to reduce the flatness problem caused by uneven stress during the formation and charge and discharge cycles of the lithium battery.
[0041] Specifically, Figure 3 This is a line graph showing the thickness of the region (Al-tab region) where the positive electrode component 10 is located and the region (Ni-tab region) where the negative electrode component 20 is located in a conventional wound core structure. Figure 3 According to the data, the Al-tab region is the thickest, with a thickness difference of 181 μm between it and the right edge region of the negative electrode tab (the right edge region of the Ni-tab), and a thickness difference of 132 μm between it and the Ni-tab region. This makes it easy for the single and double-sided coating areas at the tail of the positive electrode sheet to break during actual charge and discharge cycles, resulting in a one-time capacity decay.
[0042] Furthermore, Figure 4After optimization of the positive electrode component 10, the thickness line diagrams of the regions where the positive electrode component 10 is located (Al-tab region) and the regions where the negative electrode component 20 is located (Ni-tab region) show that, due to the misalignment structure formed at the second end B of the positive electrode component 10 in the single- and double-sided coating areas, and the addition of a hot melt adhesive layer of a specific thickness within this misalignment structure, the thickness in the flat areas of the battery is leveled. Figure 4 The data shows that the thickest point after optimization is located in the region where the negative tab is located (Ni-tab region), and the thickness difference between it and the region where the positive tab 120 is located (Al-tab region) is 5μm, thereby improving the flatness of the flat area of the battery.
[0043] In the aforementioned positive electrode component 10, the first active coating 200 and the second active coating 300 form a misaligned structure at the second end B of the positive electrode component 10, i.e., the tail end of the positive electrode component 10, in the single- and double-sided coating area. A hot melt adhesive layer of a specific thickness is added to this misaligned structure to adjust the thickness of the flat area of the battery, thereby improving the flatness of the lithium battery after the winding process. Furthermore, since the hot melt adhesive layer has good adhesion and flexibility, it helps the tail end of the positive electrode component 10 to withstand greater pressure during charge-discharge cycles, thereby enhancing the stability of the misaligned structure at the junction of the single- and double-sided coating areas at the second end B of the positive electrode component 10, and effectively reducing the risk of breakage at the second end B of the positive electrode component 10 due to uneven stress during the charge-discharge cycle of the lithium battery.
[0044] like Figure 1As shown, in one embodiment, the first active coating 200 has a first dressing region 210 and a second dressing region 220, and the second active coating 300 has a third dressing region 310 and a fourth dressing region 320; the end of the second dressing region 220 away from the first dressing region 210 and the end of the fourth dressing region 320 away from the third dressing region 310 are aligned at the first end of the positive electrode assembly 10; the end of the first dressing region 210 away from the second dressing region 220 and the end of the third dressing region 310 away from the fourth dressing region 320 are offset at the second end of the positive electrode assembly 10. The positive electrode tab 400 is located between the first dressing region 210 and the second dressing region 220, and between the third dressing region 310 and the fourth dressing region 320; the first hot melt adhesive layer 510 is located at the end of the first dressing region 210 away from the second dressing region 220, and the second hot melt adhesive layer 520 is located at the end of the third dressing region 310 away from the fourth dressing region 320. In this embodiment, when the positive electrode assembly 10, the negative electrode assembly 20, and the insulating separator are simultaneously wound to form the core of a lithium battery, the first coating area 210 and the third coating area 310 are misaligned at the second end B of the positive electrode assembly 10, allowing a misaligned structure of the single and double-sided coating areas to be formed at the tail of the positive electrode assembly 10 during the winding process. This misaligned structure effectively disperses the stress and tension generated during the winding process, preventing electrode breakage caused by stress concentration. Simultaneously, the first hot melt adhesive layer 510 is located at the end of the first coating area 210 away from the second coating area 220, and the second hot melt adhesive layer 520 is located at the end of the third coating area 310 away from the fourth coating area 320. Furthermore, the first hot melt adhesive layer 510 and the second hot melt adhesive layer 520 form a strong bond after heating, enhancing the rigidity at the junction of the single and double-sided coating areas at the tail of the positive electrode assembly 10 and further improving the stability of the battery during charging and discharging. The adhesion and flexibility of hot melt adhesive enable the battery to better withstand mechanical stress during charge and discharge cycles, thereby reducing the risk of breakage at the second end B of the positive electrode component 10 and thus avoiding the problem of battery capacity decay caused by electrode breakage.
[0045] like Figure 1As shown, in one embodiment, the distance between the second end of the first active coating 200 and the second end of the second active coating 300 along the length of the positive electrode assembly 100 is between 75-90 mm. In this embodiment, when the distance between the end of the second coating area 220 away from the first coating area 210 and the end of the third coating area 310 away from the fourth coating area 320 is within the range of 75-90 mm, due to the misalignment structure of the single and double-sided coating areas of the second end B of the positive electrode assembly 10, the adhesive layer 500 can properly cover the misalignment structure. Therefore, after the adhesive layer 500 is added to the misalignment structure, it acts as a buffer and adhesive layer, further enhancing the stability of the positive electrode assembly 10. Secondly, this length difference range allows the thickness of the flat area of the lithium battery after the addition of the adhesive layer 500 to be appropriately adjusted, thereby improving the flatness of the positive electrode assembly 10.
[0046] like Figure 1 As shown, in one embodiment, the length of the first active coating 200 ranges from 1388 to 1393 mm. In this embodiment, within this length range, the length of the first active coating 200 is coordinated with the size and proportion of the positive electrode assembly 10, enabling the battery to form a compact, uniform, and stable core structure after winding. This improves the energy density and power density of the battery, which is beneficial for improving the thermal management performance of the battery. Consequently, while ensuring that the lithium battery has sufficient electrochemical active area, the overall size and weight of the positive electrode assembly 10 are also optimized.
[0047] like Figure 1 As shown, in one embodiment, the length of the second active coating 300 ranges from 1312 to 1317 mm. In this embodiment, since the length of the second active coating 300 is less than the length of the first active coating 200, when the positive electrode assembly 10, the negative electrode assembly, and the insulating separator are wound together to form the core of the lithium battery, the second active coating 300 will end the winding process earlier, while the first active coating 200 will continue to extend for a distance, thereby forming a misaligned structure of the single and double-sided coating area at the second end B of the positive electrode assembly. At this time, adding a hot melt adhesive layer of a specific thickness to the misaligned structure can effectively improve the flatness of the battery after winding. At the same time, it is beneficial to enhance the rigidity of the misaligned structure of the single and double-sided coating area at the second end of the positive electrode assembly 10, thereby reducing the risk of breakage at the second end B of the positive electrode assembly 10 due to uneven stress.
[0048] like Figure 1As shown, in one embodiment, the overlap length between the first hot melt adhesive layer and the first active coating layer is between 1-2 mm along the length of the electrode assembly, and the overlap length between the second hot melt adhesive layer and the second active coating layer is also between 1-2 mm. In this embodiment, the overlap width ensures that the hot melt adhesive layer can accurately cover the critical parts of the dressing area, providing additional adhesion and support for the second end B of the positive electrode assembly. During the winding operation of the lithium battery, the precise overlap allows the hot melt adhesive layer to effectively fill the tiny gaps between the dressing areas, preventing misalignment or displacement between layers, thereby ensuring the tightness and consistency of the core structure. Furthermore, due to the good flexibility and adhesion of the hot melt adhesive layer, it can effectively resist the stress and tension generated by lithium ion insertion and extraction during the charge and discharge cycles of the lithium battery, thereby enhancing the rigidity at the junction of the single and double-sided dressing areas of the second end B of the positive electrode assembly, and thus reducing the risk of breakage of the second end B of the positive electrode assembly.
[0049] like Figure 1 As shown, in one embodiment, the thickness of the first active coating 200 and / or the second active coating 300 is between 40-50 μm. In this embodiment, when the thickness of the first active coating 200 and / or the second active coating 300 is within the range of 40-50 μm, good contact between the first active coating 200 and the second active coating 300 and the positive electrode component 10 is ensured, which is beneficial for electron transport and lithium ion migration, thereby improving the electrochemical reaction efficiency and rate of the battery. At the same time, the moderate thickness of the first active coating 200 and the second active coating 300 can maintain their structural strength without excessively increasing the weight and volume of the battery, thus helping to improve the energy density of the lithium battery. Secondly, this thickness range is conducive to forming a uniform current distribution, reducing the risk of local overheating and short circuits, thereby improving the safety and cycle stability of the positive electrode component 10.
[0050] like Figure 1As shown, in one embodiment, the thickness of the first hot melt adhesive layer 510 is between 50-60 μm; the thickness of the second hot melt adhesive layer 520 is also between 50-60 μm. In this embodiment, the first hot melt adhesive layer 510 and the second hot melt adhesive layer 520, with a thickness range of 50-60 μm, can ensure a sufficiently strong bond after heating and adhere tightly to the first surface 110 and the second surface 120 of the positive electrode current collector 100. They can also form effective overlapping adhesion with the second ends of the first active coating 200 and the second active coating 300, respectively, thereby enhancing the structural rigidity at the junction of the single and double-sided coating areas at the second end B of the positive electrode component 10, thus ensuring the stability of the lithium battery core structure. Furthermore, the first hot melt adhesive layer 510 and the second hot melt adhesive layer 520 have sufficient flexibility and elasticity, effectively dispersing and mitigating the resulting stress and tension during the charge-discharge cycle of the lithium battery, thereby reducing the risk of breakage at the second end B of the positive electrode component 10.
[0051] like Figure 1 As shown, in one embodiment, at least one of the first and second hot melt adhesive layers is a polyurethane adhesive layer. In this embodiment, when the lithium battery is wound, the polyurethane adhesive layer softens rapidly upon heating and exhibits a certain degree of fluidity. This allows it to fill the interface in the misaligned structure of the single / double-sided coating area at the second end B of the positive electrode component, ensuring a tight fit between the layers without offset or misalignment. As the temperature decreases, the polyurethane adhesive layer gradually solidifies, forming a strong bond, thereby improving the structural stability of the lithium battery during charge and discharge. The flexibility of the polyurethane adhesive layer allows it to adapt to the minute deformations caused by lithium ion insertion and extraction during the charge and discharge cycles of the lithium battery, effectively alleviating stress concentration within the battery.
[0052] A battery includes a negative electrode assembly, a separator, and a positive electrode assembly of any one of the above. The positive electrode assembly, separator, and negative electrode assembly are wound together to form a core. In this embodiment, during the winding operation of the lithium battery, the positive electrode assembly 10, the negative electrode assembly 20, and the insulating separator are wound simultaneously to form a core structure of the lithium battery. During this process, the first end of the first active coating 200 and the first end of the second active coating 300 are aligned at the first end A of the positive electrode assembly 10, and the first end A of the positive electrode assembly 10 is the starting end of the winding process. The second end of the first active coating 200 and the second end of the second active coating 300 are misaligned at the second end B of the positive electrode assembly, so that the second end B of the positive electrode assembly 10 forms a misaligned structure of single and double-sided coating areas. On the other hand, since the first hot melt adhesive layer 510 and the second hot melt adhesive layer 520 have good adhesion and flexibility, and the first hot melt adhesive layer 510 has a... One end of the first hot melt adhesive layer 510 overlaps with the second end of the first active coating 200, and one end of the second hot melt adhesive layer 520 overlaps with the second end of the second active coating 300. This allows the first hot melt adhesive layer 510 and the second hot melt adhesive layer 520 to act as buffers and adhesives in the misaligned structure of the single- and double-sided coating area at the second end B of the positive electrode assembly 10, enhancing the stability of the misaligned structure. This helps resist the stress and tension generated during the charge-discharge cycle of the lithium battery, reducing the risk of breakage at the junction of the single- and double-sided coating areas at the second end B of the positive electrode assembly 10. Furthermore, by adding the first hot melt adhesive layer 510 and the second hot melt adhesive layer 520 with specific thicknesses, the thickness of the flat area formed after the lithium battery is wound can be adjusted, resulting in a more uniform overall thickness distribution of the battery. This helps reduce flatness problems caused by uneven stress during the formation and charge-discharge cycle of the lithium battery.
[0053] Compared with the prior art, this disclosure has at least the following advantages:
[0054] 1. In the above-mentioned positive electrode component 10, the first active coating 200 and the second active coating 300 form a misaligned structure in the single and double-sided coating area at the second end B of the positive electrode component 10, that is, the tail end of the positive electrode component 10, and a hot melt adhesive layer of a specific thickness is added to the misaligned structure to adjust the thickness of the flat area of the battery, thereby improving the flatness of the lithium battery after the winding process is completed.
[0055] 2. Due to the good adhesion and flexibility of the hot melt adhesive layer, it helps the tail end of the positive electrode component 10 to withstand greater pressure during the charge and discharge cycle, thereby enhancing the stability of the misaligned structure at the junction of the single and double-sided coating areas of the second end B of the positive electrode component 10, and effectively reducing the risk of breakage of the second end B of the positive electrode component 10 due to uneven stress during the charge and discharge cycle of the lithium battery.
[0056] The embodiments described above are merely illustrative of several implementations of this disclosure, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of the disclosed patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this disclosure, and these all fall within the protection scope of this disclosure. Therefore, the protection scope of this patent should be determined by the appended claims.
Claims
1. A positive electrode assembly for winding with a separator and a negative electrode assembly to form a core of a battery, characterized in that, The positive electrode assembly includes a positive electrode current collector, a first active coating, a second active coating, a positive electrode tab, and an adhesive layer; The positive current collector has a first surface and a second surface, the first active coating is coated on the first surface, and the second active coating is coated on the second surface; The first end of the first active coating and the first end of the second active coating are aligned at the first end of the positive electrode assembly, and the second end of the first active coating and the second end of the second active coating are misaligned at the second end of the positive electrode assembly; the first end of the positive electrode assembly is used as its winding start end, and the second end is used as its winding end end. The positive electrode tab is connected to the positive electrode current collector and is located between the first and second ends of the positive electrode assembly; The adhesive layer includes a first hot melt adhesive layer and a second hot melt adhesive layer. The first hot melt adhesive layer is located on the first surface of the positive electrode current collector, and one end of the first hot melt adhesive layer overlaps with the second end of the first active coating. The second hot melt adhesive layer is located on the second surface of the positive electrode current collector, and one end of the second hot melt adhesive layer overlaps with the second end of the second active coating.
2. The positive electrode component according to claim 1, characterized in that, The first active coating has a first dressing area and a second dressing area, and the second active coating has a third dressing area and a fourth dressing area; the end of the second dressing area away from the first dressing area and the end of the fourth dressing area away from the third dressing area are aligned at the first end of the positive electrode assembly; the end of the first dressing area away from the second dressing area and the end of the third dressing area away from the fourth dressing area are offset at the second end of the positive electrode assembly. The positive electrode tab is located between the first dressing area and the second dressing area, and between the third dressing area and the fourth dressing area; The first hot melt adhesive layer is located at the end of the first dressing area away from the second dressing area, and the second hot melt adhesive layer is located at the end of the third dressing area away from the fourth dressing area.
3. The positive electrode component according to claim 1, characterized in that, The distance between the second end of the first active coating and the second end of the second active coating along the length of the positive electrode assembly is between 75 and 90 mm.
4. The positive electrode assembly according to claim 1, characterized in that, The length of the first active coating ranges from 1388 to 1393 mm.
5. The positive electrode assembly according to claim 4, characterized in that, The length of the second active coating ranges from 1312 to 1317 mm.
6. The positive electrode assembly according to claim 1, characterized in that, Along the length of the electrode assembly, the overlap length between the first hot melt adhesive layer and the first active coating is between 1 and 2 mm, and the overlap length between the second hot melt adhesive layer and the second active coating is between 1 and 2 mm.
7. The positive electrode assembly according to claim 3, characterized in that, The thickness of the first active coating and / or the second active coating is between 40 and 50 μm.
8. The positive electrode assembly according to claim 1, characterized in that, The thickness of the first hot melt adhesive layer is between 50-60 μm; The thickness of the second hot melt adhesive layer is between 50 and 60 μm.
9. The positive electrode assembly according to claim 1, characterized in that, At least one of the first hot melt adhesive layer and the second hot melt adhesive layer is a polyurethane adhesive layer.
10. A battery, characterized in that, It includes a negative electrode assembly, a separator, and a positive electrode assembly as described in any one of claims 1 to 9; the positive electrode assembly, the separator, and the negative electrode assembly are wound together to form a core.