Insulation pad, battery top cover and power battery

Abstract

The utility model relates to an insulating pad, a battery top cover and a power battery, the battery top cover comprises a top cover sheet, an insulating spacer and a lower plastic part, and corresponding pole penetrating holes are arranged at two ends of the top cover sheet, the insulating spacer and the lower plastic part; the pole columns on the positive / negative lower pole block sequentially penetrate through the top cover sheet, the insulating spacer and the corresponding pole column penetrating holes in the lower plastic part and then are assembled with the positive / negative upper pole block to form a battery top cover; the length of the insulating spacer is consistent with that of the top cover sheet, two ends of the insulating spacer are concave upwards to form an anti-twisting boss on the upper surface and a limiting groove on the lower surface, and the lower end of the positive / negative upper pole block is provided with an anti-twisting groove matched with the anti-twisting boss; the width of the anti-twisting boss is not less than that of the positive / negative upper pole block; limiting protrusions in small clearance fit with the limiting grooves protrude from the two ends of the top cover piece. Assembly is simple and reliable, reliable and anti-twisting are achieved, and the short circuit problem caused by mistaken assembly and confusion is completely avoided.

Description

Technical Field

[0001] This utility model relates to the field of new energy battery technology, specifically to an insulating pad, a battery top cover, and a power battery. Background Technology

[0002] Lithium-ion batteries are widely used in portable electronic devices, power tools, and new energy vehicles. With the diversification of applications, the requirements for battery safety and performance are becoming increasingly stringent.

[0003] As a crucial component of power batteries, the top cover typically includes a top cover sheet, positive terminal, negative terminal, and insulating blocks mounted on the terminals. The main function of the insulating block is to isolate the positive and negative terminals from the top cover sheet, preventing short circuits. It also uses assembly structure designs to limit the positioning of the positive and negative terminals. However, existing insulating block structures generally suffer from the following problems: 1. Insufficient foolproof design: Currently, most top cover positive terminal insulating blocks have a weak conductivity design, with a resistance between 100Ω and 10KΩ, making the battery casing positively charged. The negative terminal insulating block needs to be insulated from the top cover. This design ensures that the aluminum casing has a high potential and does not undergo electrochemical corrosion in the event of a micro-short circuit. However, current insulating blocks usually employ symmetrical or standardized designs, making it easy for positive and negative terminal insulating blocks to be confused during assembly, leading to assembly errors. When the weakly conductive positive terminal insulating block is assembled onto the positive terminal, it can cause short circuits and other safety hazards. However, with the improvement of lithium battery manufacturing capabilities and foreign object control, this weak conductivity design is no longer necessary. 2. Poor torsional resistance: In actual use, batteries may be subjected to external impacts or torsional forces. Existing insulation block designs cannot effectively prevent the top cover and terminal blocks from twisting, affecting the mechanical connection stability of the battery and thus reducing its safety and service life. 3. The positive electrode insulation block, which maintains weak conductivity, suffers from significant resistance fluctuations due to the difficulty in precisely controlling the mixing of conductive fillers. When the resistance is low, insulation failure is likely to occur. 4. The insulation block only covers the positive and negative terminals, providing no protection for other structures on the top cover. Summary of the Invention

[0004] The purpose of this utility model is to overcome the shortcomings of the prior art and provide an insulating pad that adopts an integrated design, is simple and reliable to assemble, is reliable and anti-twisting, and completely avoids short circuit problems caused by incorrect assembly.

[0005] This utility model also provides a battery top cover and a power battery.

[0006] A battery top cover includes a top cover sheet, an insulating gasket, and a lower plastic part. The top cover sheet, the insulating gasket, and the lower plastic part are provided with corresponding electrode post through holes at both ends. The electrodes on the positive / negative lower electrode blocks pass through the corresponding electrode post through holes on the top cover sheet, the insulating gasket, and the lower plastic part in sequence and are assembled together with the positive / negative upper electrode blocks to form a battery top cover.

[0007] The length of the insulating pad is the same as that of the top cover plate. The two ends of the insulating pad are concave upward to form anti-torsion protrusions on the upper surface and limiting grooves on the lower surface. The lower end of the positive / negative upper electrode block has an anti-torsion groove that cooperates with the anti-torsion protrusions. The width of the anti-torsion protrusions is not less than the width of the positive / negative upper electrode blocks.

[0008] The top cover plate has a limit groove at both ends that fits with the limit protrusion.

[0009] The positive / negative lower electrode blocks are fitted with sealing rings on the outer edge of the electrode posts.

[0010] The top cover plate is provided with an explosion-proof valve mounting hole and a liquid injection hole.

[0011] The insulating gasket has a liquid injection clearance hole corresponding to the liquid injection hole on the top cover plate and an explosion-proof valve grille corresponding to the explosion-proof valve mounting hole. The grille spacing of the explosion-proof valve grille is 1mm and the width of the explosion-proof valve grille is 1mm.

[0012] The outer periphery of the electrolyte injection clearance hole has an upward-protruding ring to prevent electrolyte leakage.

[0013] A sealant is applied between the lower end face of the insulating gasket and the top cover plate, with the sealant located on the outer periphery of the injection clearance hole.

[0014] The anti-torsion boss has a height of 0.9mm and a width of 2mm.

[0015] An insulating pad includes a sheet-shaped insulating pad with both ends recessed upwards to form an anti-torsion protrusion on the upper surface and a limiting groove on the lower surface. The lower end of the positive / negative upper electrode block has an anti-torsion groove that mates with the anti-torsion protrusion. The length of the anti-torsion protrusion is not less than the diameter of the electrode post on the positive / negative lower electrode block.

[0016] The insulating gasket has a liquid injection clearance hole corresponding to the liquid injection hole on the top cover plate and an explosion-proof valve grille corresponding to the explosion-proof valve mounting hole. The grille spacing of the explosion-proof valve grille is 1mm and the width of the explosion-proof valve grille is 1mm. A ring protrudes upward from the outer periphery of the liquid injection clearance hole to prevent electrolyte from flowing out.

[0017] A power battery includes a cell, a battery case, and a battery top cover as described above, wherein the cell is located within an accommodating space formed by the battery top cover and the battery case.

[0018] Compared with the prior art, the advantages of this utility model are:

[0019] 1. The integrated insulation pad design makes assembly simple and reliable.

[0020] 2. Limiting protrusions are provided at the positive and negative poles of the insulating pad. The width of the limiting protrusions is not less than the width of the positive / negative upper pole blocks. Compared with the existing solutions, it has the largest contact surface and anti-torsional torque. When combined with the top cover substrate and the positive and negative pole blocks, it has excellent anti-torsional effect.

[0021] 3. An insulating pad is installed on the upper surface of the injection hole and a sealant is applied to the lower surface. After assembly, during the electrolyte injection and negative pressure formation of the battery cell, the electrolyte overflowing from the injection hole can be confined to the insulating pad enclosure and will not cause contamination to other surfaces of the battery cell.

[0022] 4. An insulating pad is installed at the explosion-proof valve with a protective grille to ensure that the fragile top cover explosion-proof valve is not damaged by external forces;

[0023] 5. The insulating pad covers the entire upper surface of the top cover, which can ensure that the positive and negative poles and terminals will not come into contact and short-circuit when the battery cells are assembled into modules.

[0024] 6. This utility model directly adopts a fully insulated design, without using conductive fillers to control the resistance value, and will not fail to maintain insulation. Attached Figure Description

[0025] Figure 1 This is a perspective view of the battery top cover of this utility model;

[0026] Figure 2 This is an exploded view of the battery top cover of this utility model;

[0027] Figure 3 This is a top view of the battery top cover of this utility model;

[0028] Figure 4 for Figure 3 Sectional view along axis AA;

[0029] Figure 5 This is a structural diagram of the utility model insulating pad;

[0030] Figure 6 This is a bottom view of the insulating pad of this utility model;

[0031] Figure 7 This is a top view of the insulating pad of this utility model;

[0032] Figure 8 This is a front view of the insulating pad of this utility model;

[0033] Figure 9 for Figure 7 Sectional view along axis AA;

[0034] Figure 10 for Figure 9 Enlarged view of point I;

[0035] Figure 11 for Figure 9 Enlarged view of section II. Detailed Implementation

[0036] like Figure 1-4 As shown, the battery top cover includes a top cover plate 3, an insulating gasket 2, and a lower plastic part 6. The top cover plate 3, the insulating gasket 2, and the lower plastic part 6 are provided with corresponding terminal post through holes 15 at both ends. The terminals on the positive lower electrode block 5 and the negative lower electrode block 7 pass through the corresponding terminal post through holes on the top cover plate 3, the insulating gasket 2, and the lower plastic part 6 in sequence, and are then assembled with the corresponding positive upper electrode block 1 and negative upper electrode block 9 to form the battery top cover. The terminals on the positive lower electrode block 5 and the negative lower electrode block 7 are fitted with sealing rings 4. The top cover plate 3 is provided with an explosion-proof valve mounting hole and a liquid injection hole.

[0037] like Figure 5-8 As shown in Figure 10, the insulating pad 2 has a sheet-like structure with a thickness of 0.5 mm, and is made of high-density polyethylene and polypropylene.

[0038] The insulating gasket 2 has the same length as the top cover plate 3. Both ends of the insulating gasket 2 are recessed upwards, forming anti-torsion protrusions 11 on the upper surface and limiting grooves 17 on the lower surface. The anti-torsion protrusions 11 are 0.9mm high, 2mm wide, and have a thickness equal to the main body thickness of the insulating gasket 2. The anti-torsion protrusions 11 have a rounded transition on their outer edges. The lower ends of the positive upper electrode block 1 and the negative upper electrode block 9 have anti-torsion grooves that mate with the anti-torsion protrusions 11, with a clearance controlled at 0.1mm. The width of the anti-torsion protrusions 11 is not less than the width of the positive / negative upper electrode blocks 1 and 9. Both ends of the top cover plate 3 protrude with limiting protrusions 16 that have a small clearance to mate with the limiting grooves 17. The design of the anti-torsion protrusions 11 on the insulating gasket allows it to form a mechanical interlocking structure with the top cover plate and upper electrode blocks after assembly. When subjected to external torsion, this effectively prevents relative displacement or rotation between the top cover and the terminal blocks, improving the overall torsional strength. The insulating gasket 2 has a liquid injection clearance hole corresponding to the liquid injection hole on the top cover plate 3 and an explosion-proof valve grille 12 corresponding to the explosion-proof valve mounting hole. The grille is 1mm wide and the grille spacing is 1mm, which can protect the fragile explosion-proof valve structure and prevent it from being damaged under external force.

[0039] like Figure 9 , 11 As shown, the outer periphery of the electrolyte injection clearance hole has an upward-protruding ring 10 to prevent electrolyte leakage.

[0040] like Figure 6 As shown, sealant is adhered between the lower end face of the insulating gasket 2 and the top cover plate 3, with the sealant located on the outer periphery of the electrolyte injection clearance hole. Double-sided sealant bonds the insulating gasket 2 to the top cover plate 3, sealing the surrounding gaps. A barrier is installed around the front electrolyte injection hole to prevent electrolyte overflow and ensure that other parts are not contaminated by electrolyte.

[0041] The integrated insulating pad covers the entire upper surface of the top cover, ensuring complete insulation between the terminals formed after the upper and lower electrode blocks are assembled and the top cover, providing excellent insulation protection. The insulating pad has a barrier and sealant at the injection hole to prevent electrolyte leakage and contamination of the battery cell. The integrated insulating pad forms an explosion-proof valve protection grid, eliminating the need for explosion-proof valve protection patches, resulting in a simple structure and good protection. The recesses that mate with the protrusions of the insulating pad penetrate the positive and negative electrode blocks, simplifying processing.

Claims

1. A battery top cover characterized by: The top cover sheet (3), the insulating pad (2) and the lower plastic part (6) are provided with corresponding pole penetrating holes (15) at both ends, and the poles on the positive / negative lower pole block pass through the corresponding pole penetrating holes on the top cover sheet (3), the insulating pad (2) and the lower plastic part (6) in sequence and are assembled with the positive / negative upper pole block to form a battery top cover; The length of the insulating pad (2) is consistent with the length of the top cover sheet (3), the insulating pad (2) is concave upward at both ends to form an anti-twist boss (11) on the upper surface and a limiting groove (17) on the lower surface, the lower end of the positive / negative upper pole block is provided with an anti-twist groove matched with the anti-twist boss (11); the width of the anti-twist boss (11) is not less than the width of the positive / negative upper pole block. The top cover sheet (3) is provided with a limiting protrusion (16) matched with a limiting groove (17) with a small gap at both ends.

2. The battery top cover of claim 1, wherein: The pole sleeve on the positive / negative lower pole block is provided with a sealing ring (4).

3. The battery cover of claim 1, wherein: The top cover sheet (3) is provided with an explosion-proof valve mounting hole and a liquid injection hole.

4. The battery cover of claim 1 or 3, wherein: The insulating pad (2) is provided with a liquid injection gap corresponding to the liquid injection hole on the top cover sheet (3) and an explosion-proof valve grid (12) corresponding to the explosion-proof valve mounting hole, the grid spacing of the explosion-proof valve grid (12) is 1mm, and the width of the explosion-proof valve grid (12) is 1mm.

5. A battery top cover according to claim 4, characterized in that: The outer periphery of the liquid injection gap is upwardly protruded with a ring of surrounding barriers (10) for preventing the outflow of electrolyte.

6. A battery top cover according to claim 5, characterized in that: The lower end surface of the insulating pad (2) is pasted with sealing glue between the top cover sheet (3), and the sealing glue is located on the outer periphery of the liquid injection gap.

7. The battery terminal of claim 1, wherein: The height of the anti-twist boss (11) is 0.9mm, and the width is 2mm.

8. An insulating mat, characterized by: The insulating pad (2) is provided with an anti-twist boss (11) formed by concave upward at both ends to form an anti-twist boss (11) on the upper surface and a limiting groove (17) on the lower surface, and the lower end of the positive / negative upper pole block is provided with an anti-twist groove matched with the anti-twist boss (11); the length of the anti-twist boss (11) is not less than the diameter of the pole on the positive / negative lower pole block.

9. An insulating mat according to claim 8, wherein: The insulating pad (2) is provided with a liquid injection gap corresponding to the liquid injection hole on the top cover sheet (3) and an explosion-proof valve grid (12) corresponding to the explosion-proof valve mounting hole, the grid spacing of the explosion-proof valve grid (12) is 1mm, the width of the explosion-proof valve grid (12) is 1mm, and the outer periphery of the liquid injection gap is upwardly protruded with a ring of surrounding barriers (10) for preventing the outflow of electrolyte.

10. A power cell, characterized by: The battery top cover comprises a battery cell, a battery tank and a battery top cover as claimed in any one of claims 1-7, and the battery cell is located in a containing space enclosed by the battery top cover and the battery tank.

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