A power battery top cover and a secondary battery

Abstract

This invention discloses a power battery top cover, comprising a top cover sheet, an explosion-proof valve structure, a liquid injection hole structure, and a lower plastic component, a positive terminal assembly electrically connected to the top cover sheet, and a negative terminal assembly insulated from the top cover sheet. The invention is characterized by further including a terminal through-hole, an annular boss on the upper surface of the top cover sheet, and a groove on the lower surface of the top cover sheet. The terminal through-hole penetrates the center of the groove, and its upper edge has a corner structure. The negative terminal assembly includes a negative terminal penetrating the terminal through-hole, a sealing ring fitted onto the negative terminal, and an insulating substrate. The top of the negative terminal has an inverted portion. The negative terminal sequentially penetrates the lower insulating component, the top cover sheet, and the insulating substrate, and is then fixedly connected by potting compound. This power battery top cover with the above-described structure reduces the number of structural components, thins the top cover, thereby reducing the height of the battery cell, enhancing the terminal strength, and improving connection reliability.

Description

Technical Field

[0001] This invention relates to the field of power battery energy storage technology, and in particular to a power battery top cover and a secondary battery. Background Technology

[0002] Traditional power battery top covers mostly consist of positive and negative terminals penetrating the top cover sheet, which is then fixed to conductive or insulating components via riveting blocks or ceramic spring clips. Existing battery top covers suffer from at least the following technical defects:

[0003] 1) The top cover structure is complex.

[0004] 2) Most top cover plates have a groove on the lower surface and an upward convex shape on the upper surface, and are then riveted together with rivet blocks. Obviously, the overall thickness of the top cover plate with this structure is relatively thick, and the utilization rate of the height space is relatively low.

[0005] 3) The rivet block also includes anti-twist ceramic particles to prevent the positive and negative electrodes from rotating. As we all know, ceramics are brittle and easily broken during the manufacturing process, which leads to material waste. At the same time, the assembly process is cumbersome, which affects efficiency and indirectly increases costs.

[0006] Based on the above technical problems, the present invention provides a relatively thin and light power battery top cover, which mainly optimizes the structure and assembly method of the positive and negative terminals. It not only optimizes the structure of the top cover sheet, but also reduces the number of parts. Moreover, it reduces the overall height of the battery cell without affecting the internal height of the battery cell, which is conducive to improving the energy density of the battery cell. Summary of the Invention

[0007] This invention provides a power battery top cover, including a top cover sheet, an explosion-proof valve structure mounted on the top cover sheet, a liquid injection hole structure and a lower plastic part, a positive terminal assembly electrically connected to the top cover sheet and a negative terminal assembly insulated from the top cover sheet, characterized in that it further includes a terminal through hole, an upwardly protruding annular boss disposed around the periphery of the terminal through hole, and a groove disposed on the lower surface of the top cover sheet, the negative terminal assembly including a negative terminal through the terminal through hole, a sealing ring sleeved on the negative terminal, and an insulating substrate;

[0008] Furthermore, the through hole of the pole post is smaller than the contour of the groove;

[0009] Furthermore, the upper edge of the through hole of the pole post is also provided with a chamfered structure;

[0010] Furthermore, the negative electrode post includes a base, a through portion, and an inverted portion. The base is distributed at the bottom of the negative electrode post and is precisely embedded in the groove. The bottom end of the through portion is connected to the base, and the top end is connected to the inverted portion. The inverted portion is inverted and fastened to the edge of the insulating substrate.

[0011] Furthermore, the negative electrode post passes through the lower insulating component, the top cover plate, and the insulating substrate in sequence. The insulating substrate is precisely matched with the annular boss and then fixedly connected by potting glue.

[0012] Furthermore, the groove can be square, circular, polygonal, or other irregular shapes;

[0013] Furthermore, the longitudinal depth of the groove is 0.2~5mm;

[0014] Furthermore, the positive electrode assembly includes a positive electrode post, a sealing ring, a conductive substrate, and a riveting block. The sealing ring is sleeved on the positive electrode post, then passes through the lower plastic part, the top cover plate, and the conductive substrate in sequence, and is then riveted or welded to the riveting block plate for fixation.

[0015] Furthermore, the positive electrode assembly includes an upward or downward protruding bulge integrally formed with the top cover plate, a positive electrode groove corresponding to the bulge, and a conductive substrate. The conductive substrate includes a body portion and a downwardly extending extension portion, which is precisely embedded in the groove and then fixed by welding or riveting processes, or fixed and connected by conductive adhesive.

[0016] Furthermore, at least one positioning hole is provided in the groove of the positive electrode post or on one side, and an embedding angle is provided on the conductive substrate to correspond to it;

[0017] Furthermore, the positive terminal assembly can also adopt a structure similar to the negative terminal assembly described above. Correspondingly, the structure of the top cover is also the same as the above structure, except that the insulating substrate is a conductive substrate.

[0018] The present invention also provides a secondary battery, comprising a battery casing, bare cells housed within the battery casing, electrolyte injected into the battery casing, and a power battery top cover sealed and installed on the upper end of the casing, characterized in that the battery top cover includes the features described above.

[0019] Beneficial effects

[0020] The power battery top cover provided by this invention has the following advantages:

[0021] 1. The top cover plate is provided with a groove and annular protrusion, and the entire negative terminal assembly only includes the negative terminal, sealing ring and insulating substrate, which is fixed by potting glue. Compared with the prior art, the protrusion structure is omitted, the use of rivet blocks and anti-torsion pillars is reduced, thereby reducing the number of accessories, reducing the thickness of the battery top cover, optimizing the structure, and thus reducing the height of the battery to a certain extent.

[0022] 2. The electrode through hole is also provided with a chamfer structure, which plays a certain role in shear resistance and can enhance the sealing performance, thus more effectively preventing electrolyte leakage;

[0023] 3. The base fits perfectly into the groove, the annular protrusion interlocks with the insulating substrate, and the top of the pole is provided with an inverted part that is inverted on the edge of the insulating substrate, which not only strengthens the connection structure but also has a good anti-torsion effect. Attached Figure Description

[0024] Figure 1 This is a schematic diagram of the negative electrode post of the present invention.

[0025] Figure 2 This is an enlarged view of the negative electrode post through hole of the present invention.

[0026] Figure 3 This is a schematic diagram of the structure of the first embodiment of the present invention.

[0027] Figure 4 This is a cross-sectional view of the negative electrode post according to the first embodiment of the present invention.

[0028] Figure 5 This is a schematic diagram of the structure of the second embodiment of the present invention.

[0029] Figure 6 This is a cross-sectional view of the negative electrode post structure according to the second embodiment of the present invention.

[0030] Figure 7 This is a cross-sectional view of the positive electrode post structure according to the second embodiment of the present invention.

[0031] The meanings of the markings in the figure are as follows: 1 Top cover plate, 11 Positive electrode groove, 11a Protrusion, 11b Positioning hole, 12 Electrode through hole, 121 Chamfered structure, 13 Annular boss, 14 Lower groove, 131 Groove edge, 2 Negative electrode, 21 Base, 22 Through part, 23 Inverted part, 3 Conductive substrate, 31 Extension part, 32 Embedded part, 4 Explosion-proof valve structure, 5 Liquid injection hole structure, 6 Sealing ring, 7 Insulating substrate, 8 Lower insulating part, 9 Positive electrode. Detailed Implementation

[0032] The embodiments of the present invention will be further described in detail below with reference to the accompanying drawings and examples. The following detailed description of the embodiments and the accompanying drawings are used to illustrate the principles of the present invention by way of example, but should not be used to limit the scope of the present invention, that is, the present invention is not limited to the described embodiments.

[0033] In the description of this invention, it should be noted that, unless otherwise stated, "a plurality of" means two or more; the terms "upper", "lower", "left", "right", "inner", "outer", etc., indicating manner or positional relationship are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this invention.

[0034] In the description of this invention, it should also be noted that, unless explicitly specified and limited in the art, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, "connection" can be a fixed connection, a detachable connection, or an integral connection; it can be a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0035] To better understand this invention, the following is combined with... Figures 1 to 6 The battery top cover of an embodiment of the present invention will be described in detail.

[0036] Example 1

[0037] like Figure 3 and Figure 4 The power battery top cover shown includes a top cover plate 1, an explosion-proof valve structure 4 mounted on the top cover plate 1, a liquid injection hole structure 5 and a lower plastic part 8, and also includes a positive terminal assembly electrically connected to the top cover plate 1 and a negative terminal assembly insulated from the top cover plate 1.

[0038] like Figure 2 and Figure 4 As shown, the top cover plate also includes an electrode through hole 12, an annular boss 13 on the upper surface of the top cover plate, and a groove 14 on the lower surface of the top cover plate 1. The electrode through hole 12 penetrates the center of the groove 14. The annular boss is an upwardly protruding boss structure that is provided around the periphery of the electrode through hole 12. The outline of the electrode through hole 12 is smaller than that of the groove 14.

[0039] like Figure 2 As shown, the upper edge of the through hole 12 of the pole post is also provided with a chamfered structure 121;

[0040] Furthermore, the negative electrode assembly includes a negative electrode 2 that penetrates the top cover plate, a sealing ring 6 sleeved on the negative electrode 2, and an insulating substrate 7.

[0041] like Figure 1As shown, the negative electrode post 2 includes a base 21, a through portion 22, and an inverted portion 23. The base 21 is located at the bottom of the negative electrode post 2 and is precisely embedded in the groove 14. The bottom end of the through portion 22 is connected to the base 21, and the top end is connected to the inverted portion 23. The inverted portion 23 is inverted and fastened to the edge of the insulating substrate 7 to enhance the reliability of the electrode post connection. After the negative electrode post passes through the lower insulating member 8, the top cover plate 1, and the insulating substrate 7 in sequence, the insulating substrate 7 and the annular boss 13 interlock. The inverted portion 23 of the electrode post is inverted and fastened to the edge of the insulating substrate 7. The connection is then fixed by potting glue. This structural form can enhance the reliability and sealing of the connection.

[0042] In this embodiment 1, the positive electrode assembly adopts a structure similar to that of the negative electrode assembly. Correspondingly, the structure of the top cover plate 1 is also the same as the above structure. The difference is that the insulating substrate 7 is a conductive substrate 3. That is to say, the structure of the positive electrode 9 is the same as that of the negative electrode 2. The position on the top cover plate 1 where the positive electrode 9 is installed is also provided with a corresponding annular boss, groove and through hole structure. During assembly, after the positive electrode 9 is fitted with the sealing ring 6, it passes through the lower insulating member 8, the top cover plate 1 and the conductive substrate 3 in sequence. The inverted part 23 of the electrode is exactly inverted on the edge of the conductive substrate 3, and then fixed and connected by potting glue.

[0043] Furthermore, the lower groove 14 can be square, circular, polygonal or other irregular shapes, preferably square;

[0044] Furthermore, the longitudinal depth of the annular boss 13 and the lower groove 14 is 0.2~5mm. In this embodiment, the longitudinal depths of the annular boss 13 and the lower groove 14 are 2mm and 3mm, respectively.

[0045] Furthermore, the insulating substrate is made of polymer insulating materials such as PPS, PA, PP, and PTFA. In this embodiment, PPS is preferred because it has higher strength, better electrolysis resistance, and stronger weather resistance compared to other materials.

[0046] Furthermore, the through portion 22 of the pole post can be cylindrical, oval cylindrical, elliptical cylindrical, three-dimensional cylindrical or other structural forms, and in this embodiment, a cylindrical structure is preferred;

[0047] Furthermore, the sealing ring 6 is an elastic sealing ring with a compression amount of 5% to 70% in the thickness direction. In order for the sealing ring 6 to achieve the best sealing effect, the compression amount in the thickness direction is preferably 15% to 45%, and in this embodiment 1, it is preferably 40%.

[0048] Example 2

[0049] like Figure 5 and Figure 6 The power battery top cover shown includes a top cover plate 1, an explosion-proof valve structure 4 mounted on the top cover plate 1, a liquid injection hole structure 5 and a lower plastic part 8, and also includes a positive terminal assembly electrically connected to the top cover plate 1 and a negative terminal assembly insulated from the top cover plate 1.

[0050] like Figure 2 and Figure 6 As shown, the top cover plate also includes an electrode through hole 12, an annular boss 13 on the upper surface of the top cover plate, and a groove 14 on the lower surface of the top cover plate 1. The electrode through hole 12 penetrates the center of the groove 14. The annular boss is an upwardly protruding boss structure that is provided around the periphery of the electrode through hole 12. The outline of the electrode through hole 12 is smaller than that of the groove 14.

[0051] like Figure 2 As shown, the upper edge of the through hole 12 of the pole post is also provided with a chamfered structure 121;

[0052] Furthermore, the negative electrode assembly includes a negative electrode 2 that penetrates the top cover plate, a sealing ring 6 sleeved on the negative electrode 2, and an insulating substrate 7.

[0053] like Figure 1 As shown, the negative electrode post 2 includes a base 21, a through portion 22, and an inverted portion 23. The base 21 is located at the bottom of the negative electrode post 2 and is precisely embedded in the groove 14. The bottom end of the through portion 22 is connected to the base 21, and the top end is connected to the inverted portion 23. The inverted portion 23 is inverted and fastened to the edge of the insulating substrate 7 to enhance the reliability of the electrode post connection. After the negative electrode post passes through the lower insulating member 8, the top cover plate 1, and the insulating substrate 7 in sequence, the insulating substrate 7 and the annular boss 13 interlock. The inverted portion 23 of the electrode post is inverted and fastened to the edge of the insulating substrate 7. The connection is then fixed by potting glue. This structural form can enhance the reliability and sealing of the connection.

[0054] In this embodiment 2, as Figure 7As shown, the positive electrode assembly includes a downwardly protruding convex 11a integrally formed with the top cover plate 1, a positive electrode groove 11 corresponding to the convex 1a, and a conductive substrate 3. The conductive substrate 3 is embedded in the groove 11 and then fixed by welding or riveting. The positive electrode groove 11 is also provided with two positioning holes 11b. The positive electrode plate 3 is provided with a downwardly extending portion 31 and two embedding angles 32. During assembly, it is precisely embedded in the positive electrode groove 11 and the embedding angles 32. The extending portion is embedded in the positive electrode groove 11 to enhance the reliability of the connection. The embedding angles 32 are embedded in the positioning holes 11b, which not only enhance the reliability of the connection but also have a certain anti-torsion effect. Moreover, the presence of the positive electrode groove 11 can also accommodate the protrusion welded between the conductive substrate 3 and the top cover plate 1.

[0055] Furthermore, the positioning hole 11b can be one or more, and the positioning hole 11b can also be disposed on the outside of the positive electrode post groove 11;

[0056] Furthermore, the groove 14 can be square, circular, polygonal or other irregular shapes, preferably square;

[0057] Furthermore, the longitudinal depth of the groove 14 and the positive electrode post groove 11 is 0.2~5mm. In this embodiment, the longitudinal depths of the groove 14 and the positive electrode post groove 11 are 2mm and 2mm, respectively.

[0058] Furthermore, the insulating substrate is made of polymer insulating materials such as PPS, PA, PP, and PTFA. In this embodiment, PPS is preferred because it has higher strength, better electrolysis resistance, and stronger weather resistance compared to other materials.

[0059] Furthermore, the through portion 22 of the pole post can be cylindrical, oval cylindrical, elliptical cylindrical, three-dimensional cylindrical or other structural forms, and in this embodiment, a cylindrical structure is preferred;

[0060] Furthermore, the sealing ring 6 is an elastic sealing ring with a compression amount of 5% to 70% in the thickness direction. In order for the sealing ring 6 to achieve the best sealing effect, the compression amount in the thickness direction is preferably 15% to 45%, and in this embodiment, it is preferably 40%.

[0061] The above description, in conjunction with specific preferred embodiments, provides a further detailed explanation of the present invention. It should not be construed that the specific implementation of the present invention is limited to these descriptions. For those skilled in the art, various simple deductions or substitutions can be made without departing from the inventive concept, and all such modifications and substitutions should be considered to fall within the patent protection scope defined by the submitted claims.

Claims

1. A power battery top cover, comprising a top cover sheet, an explosion-proof valve structure mounted on the top cover sheet, a liquid injection hole structure, and a lower plastic part, a positive terminal assembly electrically connected to the top cover sheet, and a negative terminal assembly insulated from the top cover sheet, characterized in that, It also includes a through-hole for the electrode post, an upwardly protruding annular boss around the periphery of the through-hole for the electrode post, and a groove on the lower surface of the top cover plate. The top cover plate is partially thinned to form the groove. The through-hole for the electrode post penetrates the groove. The negative electrode post assembly includes a negative electrode post penetrating the through-hole for the electrode post, a sealing ring fitted onto the negative electrode post, and an insulating substrate. The negative electrode post includes a base and a through part. The bottom end of the through part is connected to the base. The through part passes through the through hole of the electrode post, and the base is precisely embedded in the groove. It also includes a positive electrode assembly, which includes a downwardly protruding convex bulge integrally formed with the top cover sheet and a conductive substrate. The conductive substrate includes a body portion and a downwardly extending extension portion. The top cover sheet includes a positive electrode groove corresponding to the convex bulge. The extension portion is precisely embedded in the positive electrode groove. Along the thickness direction of the top cover sheet, the outer contour of the orthographic projection of the extension portion on the top cover sheet is located within the outer contour of the orthographic projection of the body portion on the top cover sheet. The side of the extension portion facing the convex bulge is completely fitted with the bottom wall of the positive electrode groove. The position of the top cover sheet facing the convex bulge and corresponding to the convex bulge is a plane. The extension portion is welded to the top cover sheet to form a protrusion. The protrusion is located in the positive electrode groove. At least one positioning hole is also provided in or on one side of the positive electrode groove, and at least one embedding angle corresponding to the positioning hole is provided on the conductive substrate.

2. The power battery top cover according to claim 1, characterized in that, The through hole of the pole post is smaller than the contour of the groove, and the upper edge of the through hole of the pole post is also provided with a chamfered structure.

3. The power battery top cover according to claim 1, characterized in that, The negative terminal includes an inverted portion, the top end of the through portion is connected to the inverted portion, and the inverted portion is inverted and fastened to the edge of the insulating substrate.

4. A power battery top cover according to claim 1, characterized in that, The negative electrode post passes through the lower plastic part, the top cover plate and the insulating substrate in sequence. The insulating substrate and the annular boss are interlocked and then fixedly connected by potting glue.

5. A power battery top cover according to claim 1, characterized in that, The longitudinal depth of the groove is 0.2~5mm.

6. A secondary battery, comprising a battery casing, bare battery cells housed within the battery casing, an electrolyte filled within the battery casing, and a power battery top cover sealed and mounted on the upper end of the casing, characterized in that, The battery top cover includes any one of claims 1-5.

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