Battery cell pole group, battery cell and battery pack

Abstract

The utility model relates to a technical field of electric core, disclose a kind of electric core pole group, electric core and battery pack. Among them, electric core pole group includes: pole group body, a pair of tab and insulating coating, a pair of tab is respectively arranged in the both ends of pole group body along the length direction of electric core pole group;Insulating coating is coated in the outer surface of pole group body and the end portion outer periphery of tab and pole group body connection. The utility model is coated with insulating coating in the outer surface of pole group body and the end portion outer periphery of tab, to replace the conventional bare electric core insulating sheet, can effectively avoid the problem that bare electric core insulating sheet appears wrinkle, breakage due to friction in assembly process, improve the structural stability and insulation reliability of electric core.

Description

Technical Field

[0001] This utility model relates to the field of battery technology, specifically to a cell electrode assembly, a cell, and a battery pack. Background Technology

[0002] A battery cell generally includes a cover plate, a housing, electrode assemblies, electrode assembly end plates, bare cell insulating sheets, an insulating film, and a cover plate top cover. The cover plate is welded to the housing and forms a sealed space protecting the electrode assemblies. The bare cell insulating sheets cover the electrode assemblies to protect them and prevent short circuits within the cell caused by contact with the housing. The electrode assembly end plates secure the tabs and provide space for their protection. The insulating film mainly covers the outside of the housing, providing external insulation.

[0003] However, during the process of inserting the electrode assembly into the casing, the friction between the bare cell insulation sheet on the outer surface of the electrode assembly and the casing will gradually increase. Therefore, the bare cell insulation sheet is prone to wrinkles, damage, and other problems, which affects the pass rate of the cell. Utility Model Content

[0004] In view of this, the present invention provides a cell electrode assembly, a cell, and a battery pack to solve the problem that the bare cell insulation sheet on the surface of the electrode assembly is prone to wrinkling and damage under the influence of friction during the cell assembly process.

[0005] In a first aspect, the present invention provides a battery cell electrode assembly, comprising: an electrode assembly body, a pair of tabs, and an insulating coating, wherein the pair of tabs are respectively disposed at both ends of the electrode assembly body along the length direction of the battery cell electrode assembly; the insulating coating is coated on the outer surface of the electrode assembly body and the outer periphery of the ends where the tabs are connected to the electrode assembly body.

[0006] Beneficial Effects: This invention, by coating the outer surface of the electrode assembly and the outer periphery of the tab connection end with an insulating coating, replaces the conventional bare cell insulation sheet. This effectively avoids the problems of wrinkles and damage to the bare cell insulation sheet caused by friction during assembly, improving the structural stability and insulation reliability of the cell. Specifically, the insulating coating can directly adhere to the outer surface of the electrode assembly and the outer periphery of the end connecting the tab and the electrode assembly body, forming a continuous and stable insulating protective layer. Unlike conventional bare cell insulation sheets, it will not experience positional displacement or physical damage due to friction and compression during assembly, effectively ensuring the integrity of the insulation structure. In addition, the insulating coating not only isolates the electrode assembly body from the cell shell, reducing the risk of short circuits, but also provides insulation protection for a portion of the tab area, preventing direct physical contact between that area and the cell shell.

[0007] In one optional embodiment, the thickness difference of the insulating coating on the electrode assembly body is ±10 μm; and / or, the thickness difference of the insulating coating on the electrode tab is ±10 μm.

[0008] Beneficial effects: This utility model controls the thickness difference of the insulating coating within ±10μm, which can ensure the uniformity of the insulating coating formation and ensure that each area can achieve the preset insulation effect.

[0009] In one alternative embodiment, the thickness of the insulating coating is 0.1 mm to 0.15 mm.

[0010] Beneficial effects: This invention sets the thickness of the insulating coating to 0.1mm to 0.15mm, which not only forms a sufficiently dense insulating barrier to effectively block the electrical connection between the electrode assembly and the cell housing, but also avoids the increase in the overall volume and weight of the electrode assembly due to excessive coating thickness. This prevents additional space occupation or increased cell load, ensuring that the cell's energy density is not significantly affected. Simultaneously, the suitable thickness makes it easier for the coating to form a uniform and stable film during adhesion, reducing potential localized insulation weaknesses caused by uneven thickness and further improving the reliability of insulation protection.

[0011] In one alternative embodiment, the insulation resistance of the insulating coating is greater than 1 GΩ under a DC voltage of 500 volts.

[0012] Beneficial effects: The insulation resistance is greater than 1 GΩ at 500 volt DC voltage, ensuring that the insulating coating has good insulation performance, thereby effectively blocking current leakage and reducing the risk of short circuit.

[0013] In one optional embodiment, the insulating coating is made of urethane acrylate.

[0014] Beneficial effects: Polyurethane acrylate exhibits excellent adhesion properties, allowing it to adhere tightly to the electrode assembly body and tab connection ends after coating. Simultaneously, its good flexibility resists external forces such as friction and vibration during assembly and use, preventing coating peeling and cracking, ensuring the integrity of the insulation structure, and solving the problem of easy damage to conventional bare cell insulation sheets. Furthermore, this material possesses strong chemical corrosion resistance and temperature resistance, adapting to the complex internal environment of the cell, resisting electrolyte erosion and temperature fluctuations, extending the service life of the insulation coating, and thus improving the overall stability and durability of the cell electrode assembly.

[0015] In one optional embodiment, the end of the tab away from the electrode assembly body is provided with a welding area for welding to the electrode post corresponding to the battery cell, and a gap L is left between the edge of the insulating coating on the tab and the edge of the welding area on the tab along the length direction of the battery cell electrode assembly.

[0016] Beneficial effects: The gap prevents the insulating coating from covering the welding area, ensuring that the welding operation between the tab and the cell terminal is not interfered with by the coating, guaranteeing exposed metal at the welding point, facilitating the formation of a stable and robust weld connection, improving welding quality and efficiency, and providing reliable protection for the cell's conductivity. Secondly, the insulating coating provides effective insulation protection for the end connecting the tab to the electrode assembly body and the area near that end. Combined with the excellent properties of urethane acrylate material, it prevents unnecessary electrical connections between the tab and the outside in non-welding areas, reducing the risk of short circuits. Simultaneously, the gap L reduces the impact of high temperatures during welding on the insulating coating, preventing melting or deterioration due to welding heat, ensuring the integrity and insulation performance of the insulating coating in non-welding areas, thus achieving a balance between the tab's insulation protection and welding function, improving the overall reliability and practicality of the cell electrode assembly.

[0017] In one optional embodiment, the gap L along the length of the cell electrode assembly ranges from 3mm ≤ L ≤ 5mm.

[0018] Beneficial effects: This invention sets the gap L to a range of 3mm ≤ L ≤ 5mm. This avoids the insulating coating from obstructing the welding area, providing sufficient space for the welding operation between the tab and the post, ensuring a smooth welding process and improving the stability of welding quality. At the same time, the gap is not too large, preventing the insulating coating from reducing its coverage on the tab, maintaining good insulation performance, and reducing the risk of short circuits in non-welded areas. Furthermore, the 3mm to 5mm distance effectively blocks the high temperature generated during welding from being transmitted to the insulating coating, preventing damage due to overheating and ensuring the durability of its insulation effect. It also avoids excessive exposure of the tab due to an excessively large gap, thus preventing additional safety hazards and enhancing the rationality and reliability of the cell electrode assembly structure.

[0019] Secondly, this utility model also provides a battery cell, comprising: The aforementioned cell electrode assembly; The battery cell housing has openings at both ends along the length of the battery cell electrode assembly, which communicate with the interior of the openings. The battery cell electrode assembly is assembled into the battery cell housing through one of the openings. A pair of cover plates are provided and cover the corresponding openings, and the cover plates are provided with pole posts, which are welded to the corresponding pole tabs.

[0020] Beneficial effects: The openings at both ends of the cell casing along the length of the cell electrode assembly provide a convenient passage for assembly. Simultaneously, by employing this type of cell electrode assembly, the problems of wrinkling and damage to the insulating sheets of conventional bare cells due to friction during assembly can be avoided, ensuring the stability of the electrode assembly's insulation performance and reducing safety hazards such as short circuits caused by insulation failure. Furthermore, the corresponding sealing of a pair of cover plates and a pair of openings not only ensures the internal sealing of the cell, preventing electrolyte leakage, but also allows for effective current conduction through the welding of the electrode posts and tabs on the cover plates.

[0021] In one optional embodiment, a solder mark is formed at the welding point between the electrode post and the electrode tab, and the insulating coating on the electrode tab and the solder mark on the electrode tab are spaced apart along the length direction of the cell electrode assembly.

[0022] Beneficial effects: The spacing between the insulating coating on the electrode tab and the solder mark on the electrode tab can prevent the insulating coating from contaminating the forming area of ​​the solder mark during the forming process, thus ensuring the quality of subsequent welding. On the other hand, it can prevent the high temperature generated during the welding process from damaging the insulating coating, ensuring that the insulating performance of the coating on the electrode tab is not affected.

[0023] Thirdly, this utility model also provides a battery pack, including the aforementioned battery cell.

[0024] Beneficial effects: The battery pack of this utility model includes the battery cell as described above and has all the beneficial technical effects of the battery cell, which will not be repeated here. Attached Figure Description

[0025] To more clearly illustrate the specific embodiments of this utility model or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this utility model. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0026] Figure 1 This is a schematic diagram of the structure of a pole group according to an embodiment of the present utility model; Figure 2 This is a schematic diagram of the structure of a battery cell according to an embodiment of the present utility model; Figure 3 for Figure 2 A magnified view of part A in the diagram.

[0027] Explanation of reference numerals in the attached figures: 1. Electrode assembly body; 2. Electrode tab; 201. Welding area; 3. Insulating coating; 4. Cell housing; 5. Cover plate. Detailed Implementation

[0028] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this utility model, not all embodiments. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of this utility model.

[0029] To address the problem that the bare cell insulation sheets on the electrode assembly surface are prone to wrinkling and damage under the influence of friction during the cell assembly process, this utility model provides a cell electrode assembly, a cell, and a battery pack.

[0030] The following is combined Figures 1 to 3 The following describes embodiments of the present invention.

[0031] According to embodiments of the present invention, on the one hand, such as Figure 1 As shown, a battery cell electrode assembly is provided, including: an electrode assembly body 1, a pair of tabs 2, and an insulating coating 3. The pair of tabs 2 are respectively disposed at both ends of the electrode assembly body 1 along the length direction of the battery cell electrode assembly. The insulating coating 3 is coated on the outer surface of the electrode assembly body 1 and the outer periphery of the ends where the tabs 2 are connected to the electrode assembly body 1.

[0032] This invention, by coating the outer surface of the electrode assembly body 1 and the outer periphery of the connecting end of the tab 2 with an insulating coating 3, replaces the conventional bare cell insulation sheet. This effectively avoids the problems of wrinkles and damage to the bare cell insulation sheet caused by friction during assembly, improving the structural stability and insulation reliability of the cell. Specifically, the insulating coating 3 can be directly attached to the outer surface of the electrode assembly body 1 and the outer periphery of the end where the tab 2 connects to the electrode assembly body 1, forming a continuous and stable insulating protective layer. Unlike conventional bare cell insulation sheets, it will not experience positional displacement or physical damage due to friction and compression during assembly, effectively ensuring the integrity of the insulation structure. In addition, the insulating coating 3 not only isolates the electrode assembly body 1 from the cell housing 4, reducing the risk of short circuits, but also provides insulation protection for a portion of the tab 2, preventing direct physical contact between this area and the cell housing 4.

[0033] Furthermore, conventional bare cell insulation sheets are generally composed of multiple stacked layered structures. While this multi-layered structure can improve insulation performance to some extent, relative displacement between layers can occur due to friction and compression during assembly, leading to a loose overall structure. This not only increases the probability of wrinkles and damage but may also increase the volume of the cell electrode assembly. In contrast, this embodiment uses an insulating coating 3 to replace the conventional bare cell insulation sheet, structurally avoiding the drawbacks of multi-layer stacking. The specific reason is as follows: the insulating coating 3 in this embodiment is continuously coated onto the electrode assembly surface using an ultraviolet curing spraying process (UV spraying process), eliminating interlayer displacement issues and maintaining a consistently stable insulation and protective effect.

[0034] Furthermore, compared to conventional bare cell insulation sheets, the insulation coating 3 is not limited by pre-formed specifications. The thickness can be flexibly adjusted according to the specific insulation performance requirements of different areas of the cell housing 4 by precisely controlling the electrostatic spraying parameters (such as spraying time, amount of spraying material, etc.). The thickness can be appropriately increased for areas requiring higher insulation levels, while the coating can be thinned for areas with relatively lower insulation requirements.

[0035] Furthermore, compared to conventional bare cell insulating sheets that require additional adhesive tape to fix them to the electrode assembly, the insulating coating 3 of this embodiment can be directly adhered to the surface of the electrode assembly body 1 and the tab 2 through a coating process, forming a tight bond with the electrode assembly. Therefore, replacing the conventional bare cell insulating sheet with the insulating coating 3 reduces the number of internal structural components, simplifies the cell assembly process, and improves assembly efficiency and yield. It also allows for more internal space within the cell, facilitating an increase in energy density.

[0036] Furthermore, it is understood that, in order to ensure that the insulation withstand voltage performance and flame retardant performance of the battery cell do not decrease after the insulation coating 3 replaces the bare battery cell insulation sheet, the insulation withstand voltage performance and flame retardant performance of the insulation coating 3 in this embodiment cannot be lower than the insulation withstand voltage performance and flame retardant performance of the bare battery cell insulation sheet.

[0037] According to one embodiment of the present invention, the thickness difference of the insulating coating 3 on the electrode assembly body 1 is ±10μm; and / or, the thickness difference of the insulating coating 3 on the electrode tab 2 is ±10μm. By controlling the thickness difference of the insulating coating 3 within ±10μm, this embodiment of the present invention ensures the uniformity of the insulating coating 3 formation and guarantees that each area achieves the preset insulation effect.

[0038] According to one embodiment of the present invention, the thickness of the insulating coating 3 is 0.1 mm to 0.15 mm. This embodiment sets the thickness of the insulating coating 3 to 0.1 mm to 0.15 mm, which not only forms a sufficiently dense insulating barrier to effectively block the electrical connection between the electrode assembly body 1 and the cell housing 4, but also avoids an increase in the overall volume and weight of the electrode assembly due to excessive coating thickness. This prevents additional space occupation or increased cell load, ensuring that the energy density of the cell is not significantly affected. Simultaneously, the suitable thickness makes it easier for the coating to form a uniform and stable film during adhesion, reducing potential localized insulation weaknesses caused by uneven thickness and further improving the reliability of insulation protection.

[0039] It is understood that the thickness of the insulating coating 3 in this embodiment can be, but is not limited to, 0.1mm, 0.11mm, 0.12mm, 0.13mm, 0.14mm, 0.15mm or any value range between the two.

[0040] According to one embodiment of this invention, under a DC voltage of 500 volts, the insulation resistance of the insulating coating 3 is greater than 1 GΩ. This ensures that the insulating coating 3 has good insulation properties, thereby effectively blocking current leakage and reducing the risk of short circuits.

[0041] Specifically, the test process for the insulation withstand voltage performance of the insulation coating 3 is as follows: Under the test conditions of DC voltage of volts and 2 seconds, check whether the leakage current can be controlled within 1mA.

[0042] According to one embodiment of this utility model, the insulating coating 3 can be made of urethane acrylate. Urethane acrylate has excellent adhesion properties, allowing it to adhere tightly to the electrode assembly body 1 and the connecting ends of the tabs 2 after coating. Simultaneously, its good flexibility helps resist external forces such as friction and vibration during assembly and use, preventing coating peeling and cracking, ensuring the integrity of the insulation structure, and solving the problem of easy damage to conventional bare battery cell insulation sheets. Furthermore, this material also possesses strong chemical corrosion resistance and temperature resistance, adapting to the complex environment inside the battery cell, resisting electrolyte erosion and temperature fluctuations, extending the service life of the insulating coating 3, and thus improving the overall stability and durability of the battery cell electrode assembly.

[0043] Furthermore, it should be noted that in conventional battery cell structures, a bare battery cell insulating sheet is usually wrapped around the tab 2. However, due to the heat generated during the welding process between the tab 2 and the terminal post, the bare battery cell insulating sheet on the tab 2 is prone to melting and shrinkage due to high temperatures, resulting in damage to the structural integrity of the insulating sheet and loss of its original insulating and protective function. This embodiment of the invention effectively solves this problem by replacing the conventional bare battery cell insulating sheet with an insulating coating 3. Specifically, the insulating coating 3 is made of materials with good temperature resistance, such as urethane or acrylate, and possesses a certain degree of high-temperature resistance. Moreover, the insulating coating 3 on the tab 2 is separated from the welding area 201 by a reasonable gap L, which reduces the possibility of welding heat being directly conducted to the coating, thereby ensuring the integrity of the coverage area of ​​the insulating coating 3.

[0044] According to one embodiment of this utility model, the end of the tab 2 furthest from the electrode assembly body 1 is provided with a welding area 201 for welding to the corresponding electrode post of the battery cell. Along the length direction of the battery cell electrode assembly, a gap L is left between the edge of the insulating coating 3 on the tab 2 and the edge of the welding area 201 on the tab 2. The gap prevents the insulating coating 3 from covering the welding area 201, ensuring that the welding operation between the tab 2 and the battery cell electrode post is not interfered with by the coating, ensuring that the metal at the welding part is exposed, facilitating the formation of a stable and firm welding connection, improving welding quality and efficiency, and providing reliable protection for the conductivity of the battery cell. Secondly, the insulating coating 3 can form effective insulation protection for the end of the tab 2 connected to the electrode assembly body 1 and the area near that end. Combined with the excellent properties of urethane acrylate material, it can prevent unnecessary electrical connection between the tab 2 and the outside in the non-welding area 201, reducing the risk of short circuit. Meanwhile, the presence of gap L can reduce the impact of high temperature on the insulating coating 3 during the welding process, avoid problems such as melting and deterioration of the coating due to welding heat, ensure the integrity and insulation performance of the insulating coating 3 in the non-welding area 201, and enable the insulation protection and welding function of the tab 2 to be taken into account, thereby improving the overall reliability and practicality of the cell electrode assembly.

[0045] According to one embodiment of the present invention, such as Figure 3As shown, along the length of the cell electrode assembly, the gap L ranges from 3mm to 5mm. This embodiment of the invention sets the gap L to 3mm to 5mm, which avoids the insulating coating 3 obstructing the welding area 201, providing sufficient space for the welding operation between the tab 2 and the pole, ensuring a smooth welding process and improving the stability of welding quality. Simultaneously, the gap is not too large, preventing the insulating coating 3 from reducing its coverage on the tab 2, maintaining good insulation performance, and reducing the risk of short circuits in the non-welding area 201. Furthermore, the 3mm to 5mm distance effectively blocks the high temperature generated during welding from being transmitted to the insulating coating 3, preventing damage due to overheating and ensuring the durability of its insulation effect. It also avoids excessive exposure of the tab 2 due to an excessively large gap, thus preventing additional safety hazards and enhancing the rationality and reliability of the cell electrode assembly structure.

[0046] It is understood that the value of the gap L in this embodiment can be, but is not limited to, 3mm, 3.2mm, 3.5mm, 3.8mm, 4mm, 4.2mm, 4.5mm, 4.8mm, 5mm or any value range between the two.

[0047] According to an embodiment of the present invention, on the other hand, as... Figure 2 As shown, a battery cell is also provided, including: the aforementioned battery cell electrode group, battery cell housing 4, and a pair of cover plates 5.

[0048] Specifically, along the length of the cell electrode assembly, the two ends of the cell housing 4 are respectively provided with openings that communicate with the interior of the cell. The cell electrode assembly is assembled into the cell housing 4 through one of the openings. A pair of cover plates 5 are provided with a pair of openings and cover the corresponding openings. The cover plates 5 are provided with pole posts, which are welded to the corresponding pole tabs 2.

[0049] The openings at both ends of the cell housing 4 along the length of the cell electrode assembly provide a convenient passage for assembly. Simultaneously, by employing the aforementioned cell electrode assembly, the problems of wrinkling and damage to the insulating sheets of conventional bare cells due to friction during assembly can be avoided, ensuring the stability of the electrode assembly's insulation performance and reducing safety hazards such as short circuits caused by insulation failure. Furthermore, a pair of cover plates 5 corresponding to a pair of openings not only ensure the internal sealing of the cell, preventing electrolyte leakage, but also allow for effective current conduction through the welding of the electrode posts and tabs 2 on the cover plates 5.

[0050] According to one embodiment of the present invention, such as Figure 3As shown, a solder mark is formed at the welding point between the electrode post and the tab 2. Along the length of the cell electrode assembly, the insulating coating 3 on the tab 2 and the solder mark on the tab 2 are spaced apart. This arrangement serves two purposes: firstly, it prevents the insulating coating 3 from contaminating the forming area of ​​the solder mark during the forming process, ensuring the quality of subsequent welding; secondly, it prevents the high temperature generated during welding from damaging the insulating coating 3, ensuring that the insulating performance of the coating on the tab 2 is not affected.

[0051] According to an embodiment of the present invention, in another aspect, a battery pack is also provided, comprising the aforementioned battery cell. The battery pack of this embodiment includes the battery cell as described above, and possesses all the beneficial technical effects of that battery cell, which will not be repeated here.

[0052] Although embodiments of the present invention have been described in conjunction with the accompanying drawings, those skilled in the art can make various modifications and variations without departing from the spirit and scope of the present invention, and such modifications and variations all fall within the scope defined by the appended claims.

Claims

1. A cell electrode assembly, characterized in that, include: The electrode assembly includes a body, a pair of tabs, and an insulating coating. The pair of tabs are respectively located at both ends of the electrode assembly along the length of the electrode assembly. The insulating coating is applied to the outer surface of the electrode assembly and the outer periphery of the ends where the tabs connect to the electrode assembly.

2. The cell electrode assembly according to claim 1, characterized in that, The thickness difference of the insulating coating on the electrode assembly body is ±10 μm; and / or, the thickness difference of the insulating coating on the electrode tab is ±10 μm.

3. The cell electrode assembly according to claim 1, characterized in that, The thickness of the insulating coating is 0.1 mm to 0.15 mm.

4. The cell electrode assembly according to claim 1, characterized in that, Under a DC voltage of 500 volts, the insulation resistance of the insulating coating is greater than 1 GΩ.

5. The cell electrode assembly according to claim 1, characterized in that, The insulating coating is made of urethane acrylate.

6. The cell electrode assembly according to claim 1, characterized in that, The end of the tab away from the electrode assembly body is provided with a welding area (201) for welding the electrode post corresponding to the battery cell. Along the length direction of the battery cell electrode assembly, there is a gap L between the edge of the insulating coating on the tab and the edge of the welding area (201) on the tab.

7. The cell electrode assembly according to claim 6, characterized in that, Along the length of the cell electrode assembly, the gap L ranges from 3mm ≤ L ≤ 5mm.

8. A battery cell, characterized in that, include: The cell electrode assembly according to any one of claims 1 to 7; The battery cell housing has openings at both ends along the length of the battery cell electrode assembly, which are connected to the interior of the battery cell housing. The battery cell electrode assembly is assembled into the battery cell housing through one of the openings. A pair of cover plates are provided and cover the corresponding openings, and the cover plates are provided with pole posts, which are welded to the corresponding pole tabs.

9. The battery cell according to claim 8, characterized in that, A solder mark is formed at the welding point between the electrode post and the electrode tab. Along the length direction of the cell electrode assembly, the insulating coating on the electrode tab and the solder mark on the electrode tab are spaced apart.

10. A battery pack, characterized in that, include: The battery cell according to any one of claims 8 or 9.

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