Battery cell and battery

Abstract

The application provides a battery monomer structure, which belongs to the technical field of batteries and specifically relates to a battery monomer, which comprises an electrode assembly with a first tab, a first cover plate assembly comprising a first cover plate body and a first electrode terminal, the first cover plate body being provided with a recess, and the first electrode terminal being arranged in the recess; and a fixing frame arranged at the outer periphery of the electrode assembly, the fixing frame comprising a top plate, the top plate being provided with a through slot, the first tab of the electrode assembly passing through the through slot and being connected with the first electrode terminal, and the width of the first tab being smaller than the width of the through slot. The battery monomer effectively prevents the probability of collision damage in the process by arranging the first electrode terminal in the recess of the first cover plate assembly; the fixing frame at the outer periphery of the electrode assembly can improve the support strength of the electrode assembly; and the first tab passes through the through slot in the middle of the top plate of the fixing frame and is connected with the first electrode terminal, thereby improving the insulation protection. The application also provides a battery comprising the battery monomer.

Description

Technical Field

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

[0002] Currently, all battery cell covers are flat, with rivet blocks protruding from the aluminum plate. This occupies external space during module assembly, affecting the pack assembly rate. Furthermore, the rivet blocks and the protruding plastic on the outer surface of the cover (as shown in the diagram) offer poor protection, frequently resulting in damage during transportation and assembly, leading to performance, safety, and aesthetic issues in the battery cells and overall battery. Explosion-proof valves are typically located on both end covers, resulting in long venting paths, which is detrimental to battery cell thermal runaway. The electrode assembly ends are all planar, making it difficult to adapt to the battery cell shape, impacting cell capacity and assembly ratio. Conventional electrode assembly welding to the cover, using connecting plates (due to limitations in electrode assembly technology, the gap between the electrode assembly and the cover plate terminals is relatively large; to prevent excessively long tabs from tearing or short-circuiting, connecting plates are typically used for transition), increases the number of structural components and cost. Both the electrode assembly and the cover are flat structures with surface contact assembly. The cover plate does not provide good positioning for the electrode assembly along its length. If the gap is unreasonable, the electrode assembly may move around inside the housing, resulting in tearing of the tabs and damage to the electrode sheets. The design of the electrode assembly and the support surface of the cover plate is unreasonable, which can easily cause damage to the electrode sheets and excessive movement when pushing the negative electrode assembly into the housing and fixing it. Summary of the Invention

[0003] In view of this, this application provides a battery cell and a battery, which effectively protects against the probability of impact damage during the manufacturing process by setting the first electrode terminal in the recess of the first cover plate assembly; the fixing frame on the outer periphery of the electrode assembly can improve the support strength of the electrode assembly; the first tab passes through the through groove in the middle of the top plate of the fixing frame and connects to the first electrode terminal, thereby improving insulation protection.

[0004] To achieve the above objectives, this application provides the following technical solution: A single battery cell, comprising: Electrode assembly, having a first electrode tab; The first cover plate assembly includes a first cover plate body and a first electrode terminal. The first cover plate body is provided with a recess, and the first electrode terminal is disposed in the recess. A fixing frame is disposed on the outer periphery of the electrode assembly. The fixing frame includes a top plate with a through groove. The first electrode tab of the electrode assembly passes through the through groove and is connected to the first electrode terminal. The width of the first electrode tab is smaller than the width of the through groove.

[0005] Optionally, the electrode assembly has a recess at one end corresponding to the first cover plate assembly and protrusions on both sides of the recess. The top plate includes a raised section and a recessed section between two adjacent raised sections, and the through groove is disposed in the recessed section.

[0006] Optionally, the relationship between the length L2 of the through groove and the width L1 of the first electrode lug satisfies: 2.5mm≤(L2-L1) / 2≤6mm.

[0007] Optionally, the relationship between the length L2 of the through groove and the length L3 of the recessed section satisfies: 0.75≤L2 / L3≤0.87.

[0008] Optional, also includes: The second cover plate assembly is located at the other end of the electrode assembly away from the first cover plate assembly. The fixing frame also includes two side plates, which are integrally connected to the top plate. The ends of the side plates away from the top plate are connected to the second cover plate assembly.

[0009] Optionally, the relationship between the thickness T2 of the top plate and the thickness T1 of the side plate satisfies: T2 > T1.

[0010] Optionally, the thickness T2 of the top plate satisfies: 0.8mm≤T2≤3mm.

[0011] Optional, also includes: The housing is located outside the fixed frame. A first exhaust groove is provided on the side plate, and an explosion-proof valve hole is provided on the surface of the housing corresponding to the first exhaust groove.

[0012] Optionally, a second venting groove is provided on the protrusion.

[0013] The battery cell provided in this application effectively protects against the probability of impact damage during the manufacturing process by setting the first electrode terminal in the recess of the first cover plate assembly; the fixing frame on the outer periphery of the electrode assembly can improve the supporting strength of the electrode assembly; the first tab passes through the through groove in the middle of the top plate of the fixing frame and connects to the first electrode terminal, thereby improving insulation protection.

[0014] This application also provides a battery, including the aforementioned battery cell, which can improve the overall safety of the battery. Attached Figure Description

[0015] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of this application. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0016] Figure 1 This is a schematic diagram of a single battery cell according to this application.

[0017] Figure 2 This is a side view of a single battery cell of this application.

[0018] Figure 3 for Figure 2 Sectional view at point AA.

[0019] Figure 4 This is a schematic diagram of the cover plate.

[0020] Figure 5 This is a top view of the cover plate.

[0021] Figure 6 for Figure 5 Sectional view at point BB.

[0022] Figure 7 This is a schematic diagram of the electrode assembly.

[0023] Figure 8 This is a side view of the electrode assembly.

[0024] Figure 9 This is a schematic diagram of the negative terminal of the electrode assembly of this application.

[0025] Figure 10 A diagram of a fixed frame Figure 1 .

[0026] Figure 11 This is a schematic diagram of the top slab.

[0027] Figure 12 This is a schematic diagram of the side panel.

[0028] Figure 13 A diagram of a fixed frame Figure 2 .

[0029] Figure 14 A diagram of a fixed frame Figure 3 .

[0030] Figure 15 This is a diagram showing the assembly of the cover plate and the fixing frame. Figure 1 .

[0031] Figure 16 This is a diagram showing the assembly of the cover plate and the fixing frame. Figure 2 .

[0032] Figure 17 This is a schematic diagram showing the assembly of the cover plate, the fixing frame, and the electrode assembly.

[0033] Figure 18 for Figure 17Enlarged view of the area within the Chinese box.

[0034] Figure 19 This is a schematic diagram of the casing.

[0035] Figure 20 This is a schematic diagram of the inner insulating film.

[0036] exist Figures 1-20 middle: 1. First cover plate assembly; 11. Base plate; 111. Protrusion; 112. Inclined connecting part; 113. Recess; 12. Riveting block; 13. Upper plastic; 14. Lower plastic; 15. Electrode post base plate; 2. Electrode assembly; 21. Protrusion; 211. Second vent groove; 22. Recess; 3. Fixing frame; 31. Top plate; 311. Protrusion section; 312. Transition section; 313. Recessed section; 3131. Through groove; 32. Side plate; 321. First vent groove; 4. First electrode ear; 5. Housing; 51. Explosion-proof valve hole; 52. Notch; 6. Inner insulating film. Detailed Implementation

[0037] This application provides a battery cell and a battery. By setting the first electrode terminal in the recess of the first cover assembly, the probability of impact damage during the manufacturing process is effectively protected. The fixing frame on the outer periphery of the electrode assembly can improve the support strength of the electrode assembly. The first tab passes through the through groove in the middle of the top plate of the fixing frame and connects to the first electrode terminal, thereby improving insulation protection and improving the overall safety of the battery.

[0038] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0039] like Figures 1-6 As shown, the battery cell provided in this application includes: Electrode assembly 2 has a first electrode tab 4; The first cover plate assembly 1 includes a first cover plate body and a first electrode terminal. The first cover plate body is provided with a recess, and the first electrode terminal is disposed in the recess. The first cover plate body includes a substrate 11 and a lower plastic 14 disposed below the substrate 11. In this embodiment, the substrate 11 is a smooth aluminum plate. Specifically, the substrate 11 includes protrusions 111 at both ends and a recess 113 in the middle. The protrusions 111 and the recess 113 are connected by an inclined connecting part 112. The protrusions 111, the inclined connecting part 112 and the recess 113 together form the aforementioned pit. Similarly, the shape of the lower plastic 14 is basically matched, including protrusions at both ends and a recess in the middle. The protrusions and the recess are connected by an inclined connecting part. The upper surface of the lower plastic 14 is completely attached to the lower surface of the substrate 11. The first electrode terminal includes a riveting block 12, an integral electrode post and an electrode post base plate 15. The electrode post passes through the substrate 11 and the lower plastic 14. The electrode post base plate 15 is located below the lower plastic 14 and connected to the lower end of the electrode post. The riveting block 12 is located above the substrate 11 and is located in the recess 113. The upper end of the electrode post passes through the riveting block 12 and is welded and fixed to the riveting block 12. A fixing frame 3 is disposed on the outer periphery of the electrode assembly 2 to improve the supporting strength of the electrode assembly 2. The fixing frame 3 includes a top plate 31, which is disposed between the end of the electrode assembly 2 with the first electrode tab 4 and the first cover plate assembly 1. A through groove 3131 is provided on the top plate 31, through which the first electrode tab 4 of the electrode assembly 2 passes and is connected to the electrode post base plate 15 of the first electrode terminal. The width of the first electrode tab 4 is smaller than the width of the through groove 3131, wherein the width of the first electrode tab 4 and the width of the through groove 3131 are... Figure 3 The dimension in the Y direction.

[0040] In this application, the first electrode terminal is disposed in the recess 113 of the first cover plate assembly 1, which effectively protects against the probability of bumps and knocks during the process; at the same time, a fixing frame 3 is used on the outer periphery of the electrode assembly 2 to improve the support strength of the electrode assembly 2. The top plate 31 of the fixing frame 3 has a through groove 3131 in the middle, through which the first electrode tab 4 passes and is connected to the first electrode terminal, thereby improving the insulation protection.

[0041] In a preferred embodiment, such as Figures 7-9 As shown, the electrode assembly 2 is provided with a recess 22 at one end corresponding to the first cover plate assembly 1 and a protrusion 21 on both sides of the recess 22. The top plate 31 includes a protruding section 311 and a recessed section 313 between two adjacent protruding sections 311. An inclined transition section 312 is also provided between the protruding section 311 and the recessed section 313. A through groove 3131 is provided on the recessed section 313.

[0042] To match the shape of the first cover plate assembly 1, the end of the electrode assembly 2 with the first tab 4 adopts a concave-convex structure corresponding to the first cover plate assembly 1. Thus, the upper end surface formed by the concave portion 22 and the convex portion 21 can effectively fit the lower end surface of the first cover plate assembly 1. Furthermore, to effectively support the electrode assembly 2, the shape of the top plate 31 also matches the shape of the end of the first tab 4 of the electrode assembly 2. Specifically, as shown... Figure 18 As shown, the lower end face of the top plate 31 is attached to the upper end face formed by the recess 22 and the protrusion 21 of the electrode assembly 2, while the lower end face of the inclined connecting portion of the lower plastic 14 of the first cover plate assembly 1 is attached to the upper end face of the transition section 312 of the top plate 31, effectively in the direction perpendicular to the first cover plate assembly 1 ( Figure 3 The electrode assembly 2 is positioned in the X direction, thereby reducing the risk of the electrode assembly 2 moving inside the cell and causing adverse effects such as damage to the electrode assembly 2 and tearing of the first tab 4.

[0043] In a preferred embodiment, such as Figure 14 , Figure 17 , Figure 18 As shown, the relationship between the length L2 of the through groove 3131 and the width L1 of the first pole lug 4 satisfies: 2.5mm≤(L2-L1) / 2≤6mm.

[0044] If the difference between L2 and L1 is too large, it will easily affect the capacity of the battery cell and the energy density of the battery. If the difference between L2 and L1 is too small, it will cause difficulties in the assembly process and easily damage the first tab 4. Therefore, it is preferable to set the difference between L2 and L1 between 2.5mm and 6mm.

[0045] In a preferred embodiment, such as Figures 13-14 As shown, the relationship between the length L2 of the through groove 3131 and the length L3 of the recessed section 313 satisfies: 0.75≤L2 / L3≤0.87.

[0046] If the ratio of L2 to L3 is too large, it can easily affect the capacity of the battery cells and the energy density of the battery. If the ratio of L2 to L3 is too small, it can easily reduce the strength of the top plate 31 and cause tearing damage to the top plate 31. Therefore, it is preferable to set the ratio of L2 to L3 between 0.75 and 0.87.

[0047] In a preferred embodiment, such as Figures 10-16 As shown, it also includes: The second cover plate assembly is located at the other end of the electrode assembly 2 away from the first cover plate assembly 1. The second cover plate assembly has a different structure from the first cover plate assembly 1, with a flat bottom. Correspondingly, the end of the electrode assembly 2 near the second cover plate assembly is also flat. The fixing frame 3 also includes two side plates 32, the length direction of which is along... Figure 3Extending in the X direction, one end of the side plate 32 is connected to the end of the protruding section 311 of the top plate 31, and the side plate 32 and the top plate 31 are integrally connected to form a roughly U-shaped structure, such as... Figures 16-17 As shown, two side plates 32 are disposed on the narrow surface of the electrode assembly 2 located between the first cover plate assembly 1 and the second cover plate assembly, and the ends of the side plates 32 away from the top plate 31 are connected to the second cover plate assembly.

[0048] In this embodiment, the battery cell adopts an integrated U-shaped fixing frame 3. The closed end of the U-shaped structure corresponds to the first cover plate assembly 1 with a concave-convex structure on the lower end surface, and the open end of the U-shaped structure corresponds to the second cover plate assembly with a flat lower end surface. This can reduce the number of parts, simplify the process flow, better protect the electrode assembly 2, and make the electrode assembly 2 more balanced.

[0049] Of course, in other preferred embodiments, the second cover plate assembly can also have the same structure as the first cover plate assembly 1. Correspondingly, the fixing frame 3 can be set as a closed frame structure, that is, based on the U-shaped structure, a top plate 31 is also set at the position corresponding to the second cover plate assembly and connected to it, so that the electrode can protect the electrode assembly 2 and make the electrode assembly 2 more balanced. At the same time, a through groove 3131 is provided on the top plate 31, and the electrode assembly 2 is provided with a second electrode tab on one side of the second cover plate assembly. The second electrode tab passes through the through groove 3131 and is connected to the second electrode terminal on the second cover plate assembly, thereby improving the insulation performance.

[0050] In this embodiment, the electrode assembly 2 is the negative terminal at one end of the first cover plate assembly 1 and the positive terminal at one end of the second cover plate assembly. Of course, depending on specific requirements, both the positive and negative terminals can be set at the same end.

[0051] In a preferred embodiment, such as Figure 13 As shown, the relationship between the thickness T2 of the top plate 31 and the thickness T1 of the side plate 32 satisfies: T2 > T1.

[0052] The fixed frame 3 is an integral structure, and the force of the first cover plate assembly 1 is transmitted to the electrode assembly 2 through its top plate 31. Therefore, the top plate 31 needs to be thicker to ensure its strength and avoid tearing. Therefore, the thickness T2 here is set to be greater than the thickness of the side plate 32.

[0053] Furthermore, such as Figure 13 As shown, the thickness T2 of the top plate 31 satisfies: 0.8mm≤T2≤3mm.

[0054] Preferably, in order to support the electrode assembly 2, the thickness T2 of the protruding section 311 of the top plate 31 is greater than or equal to 0.8 mm to meet its strength requirements, but it cannot be too thick, otherwise it will easily increase costs and waste, and also increase the overall weight of the battery. Therefore, the thickness should be set within 3 mm.

[0055] In a preferred embodiment, such as Figure 19 As shown, it also includes: The housing 5 is located outside the fixed frame 3. The housing 5 has a notch 52 on one side of the first cover plate assembly, which corresponds to the recess 113 of the first cover plate assembly 1. The side plate 32 is provided with a first exhaust groove 321, which is formed by the recess in the middle of the side plate 32. The housing 5 is provided with an explosion-proof valve hole 51 on the surface corresponding to the first exhaust groove 321.

[0056] In this embodiment, an explosion-proof valve hole 51 is provided on the narrow surface of the housing 5, that is, on the surface corresponding to the exhaust groove of the side plate 32, so that there is no need to provide an explosion-proof valve on the first cover plate assembly 1 or the second cover plate assembly. In this way, gas can reach the explosion-proof valve hole 51 on the narrow surface of the housing 5 from the first cover plate assembly 1 and / or the second cover plate assembly through the exhaust groove and push open the explosion-proof valve, shortening the exhaust path of the battery cell and improving the safety performance of the battery cell.

[0057] In a preferred embodiment, such as Figure 20 As shown, it also includes: An inner insulating film 6 surrounds the circumference of the electrode assembly 2. The inner insulating film 6 has a notch on one side of the first cover plate assembly 1 so that its shape matches the shape of the electrode assembly 2.

[0058] In a preferred embodiment, such as Figure 9 As shown, a second vent groove 211 is provided on the protrusion 21 of the electrode assembly 2. The provision of the second vent groove 211 facilitates the gas discharge of the electrode assembly 2 at one end of the first cover plate assembly 1.

[0059] To verify whether the battery cell structure of the present invention can better complete the assembly, multiple sets of battery cells were assembled into the casing and the assembled battery cells were tested. The assembly status and test results are shown in the table below. Among them, the casing 5 has a wall thickness of 0.35mm; the inner insulating film 6 is made of PP with a wall thickness of 0.1mm; the upper plastic 13 is made of PPS, the lower plastic 14 is made of PP, and the width W1 of the through groove 3131 is 1.5mm.

[0060] Referring to the parameters in the table above, it can be seen that in Examples 1 to 6, the parameters T1, T2, W1, L1, L2, L3, (L2-L1) / 2, and L2 / L3 are all within the defined range, and no abnormalities were found during the assembly process and after testing of the battery cells. However, in Comparative Examples 1 to 5, different cases of battery cell assembly failures occurred, specifically: Comparative Example 1 shows that during the assembly process, defects such as extrusion damage and tearing were found in the first tab 4 due to process fluctuations. This is mainly caused by the small difference between the length L2 of the through groove 3131 and the width L1 of the first tab 4. As can be seen from the table, this phenomenon begins to appear when (L2-L1) / 2=2. Comparative Example 2 shows that the cell temperature rise is too large or the cell capacity is reduced to meet the overcurrent requirement. This is mainly because the difference between the length L2 of the through slot 3131 and the width L1 of the first tab 4 is too large, which makes the width L1 of the first tab 4 too small, affecting the overcurrent capacity of the first tab 4. As can be seen from the table, this phenomenon begins to appear when (L2-L1) / 2=7. Comparative Example 3 shows the interference phenomenon of the first tab 4 caused by the deformation of the top plate 31 during the shell assembly process. This is because the ratio L2 / L3 of the length L2 of the through groove 3131 opened in the recessed section 313 of the top plate 31 is too large, which makes the top plate 31 deform due to insufficient strength at the through groove 3131. As can be seen from the table, this phenomenon begins to appear when L2 / L3=0.89. Comparative Example 4 shows that the cell temperature rise is too large or the cell capacity is reduced to meet the overcurrent requirement. This is because L2 / L3 is too small. In order to ensure that the tab does not interfere when passing through the through slot 3131, the width L1 of the tab is limited. As can be seen from the table, this phenomenon begins to appear when L2 / L3=0.73. Comparative Example 5 shows the interference phenomenon of the first pole lug 4 caused by the deformation of the top plate 31 during the shell assembly process. This is due to the small thickness T2 of the top plate 31 and the insufficient structural strength at the through groove 3131. As can be seen from the table, this phenomenon begins to appear when T2=0.7.

[0061] This application also provides a battery including the aforementioned battery cell, which can improve the overall safety of the battery.

[0062] The basic principles of this application have been described above with reference to specific embodiments. However, it should be noted that the advantages, benefits, and effects mentioned in this application are merely examples and not limitations, and should not be considered as essential features of each embodiment of this application. Furthermore, the specific details disclosed above are for illustrative and facilitative purposes only, and are not limitations. These details do not limit the application to the necessity of employing the aforementioned specific details for implementation.

[0063] The block diagrams of devices, apparatuses, devices, and systems involved in this application are merely illustrative examples and are not intended to require or imply that they must be connected, arranged, or configured in the manner shown in the block diagrams. As those skilled in the art will recognize, these devices, apparatuses, devices, and systems can be connected, arranged, and configured in any manner. Words such as “comprising,” “including,” “having,” etc., are open-ended terms meaning “including but not limited to,” and are used interchangeably with them. The terms “or” and “and” as used herein refer to the word “or” and are used interchangeably with them unless the context clearly indicates otherwise. The term “such as” as used herein refers to the phrase “such as but not limited to,” and is used interchangeably with it.

[0064] It should also be noted that in the apparatus, equipment, and methods of this application, the components or steps can be disassembled or recombined. These disassemblies or recombinations should be considered as equivalent solutions of this application.

[0065] The above description of the disclosed aspects is provided to enable any person skilled in the art to make or use this application. Various modifications to these aspects will be readily apparent to those skilled in the art, and the general principles defined herein can be applied to other aspects without departing from the scope of this application. Therefore, this application is not intended to be limited to the aspects shown herein, but rather to be accorded the widest scope consistent with the principles and novel features disclosed herein.

[0066] It should be understood that the qualifiers “first,” “second,” “third,” “fourth,” “fifth,” and “sixth” used in the description of the embodiments of this application are only used to more clearly illustrate the technical solutions and are not intended to limit the scope of protection of this application.

[0067] The above description has been given for purposes of illustration and description. Furthermore, this description is not intended to limit the embodiments of this application to the forms disclosed herein. Although numerous exemplary aspects and embodiments have been discussed above, those skilled in the art will recognize certain variations, modifications, alterations, additions, and sub-combinations thereof.

Claims

1. A battery cell, characterized in that, include: Electrode assembly, having a first electrode tab; The first cover plate assembly includes a first cover plate body and a first electrode terminal. The first cover plate body is provided with a recess, and the first electrode terminal is disposed in the recess. A fixing frame is disposed on the outer periphery of the electrode assembly. The fixing frame includes a top plate and two side plates. A through groove is provided on the top plate. The first electrode tab of the electrode assembly passes through the through groove and is connected to the first electrode terminal. The width of the first electrode tab is smaller than the width of the through groove. A housing is located outside the fixed frame, and a first vent groove is provided on the side plate. An explosion-proof valve hole is provided on the surface of the housing corresponding to the first vent groove. The electrode assembly has a recess at one end corresponding to the first cover plate assembly and protrusions on both sides of the recess. The top plate includes a raised section and a recessed section between two adjacent raised sections. The through groove is provided in the recessed section. A second venting groove is provided on the protrusion. The relationship between the length L2 of the through groove and the width L1 of the first electrode lug satisfies: 2.5mm≤(L2-L1) / 2≤6mm; The relationship between the length L2 of the through groove and the length L3 of the recessed section satisfies: 0.75≤L2 / L3≤0.87; The relationship between the thickness T2 of the top plate and the thickness T1 of the side plate satisfies: T2 > T1; The thickness T2 of the top plate satisfies: 0.8mm≤T2≤3mm.

2. The battery cell according to claim 1, characterized in that, Also includes: The second cover plate assembly is located at the other end of the electrode assembly away from the first cover plate assembly, and the side plate is integrally connected to the top plate; the end of the side plate away from the top plate is connected to the second cover plate assembly.

3. A battery, characterized in that, Includes the battery cell as described in any one of claims 1-2.

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