CN210110854U - Secondary battery top cover - Google Patents

Abstract

The utility model provides a secondary battery top cover, which comprises a top cover plate, and an anode column member and a cathode column member which are arranged on the top cover plate, wherein the top cover plate is provided with a cathode mounting hole and a turnover piece accommodating hole, the cathode column member is arranged in the cathode mounting hole in an insulating way, the anode column member is electrically connected with the top cover plate, the cathode column member is provided with an upper terminal part and a lower terminal part which is connected with the upper terminal part, the lower terminal part is arranged and fixed in the cathode mounting hole, the top cover plate is also provided with a connecting piece, the negative pole column piece is provided with a lower terminal part, a connecting piece is arranged in a lower terminal part of the negative pole column piece, the lower terminal part is arranged in a lower terminal part of the negative pole column piece, the connecting piece is fixedly arranged in a negative pole mounting hole and is isolated from the lower terminal part, the connecting piece is connected with the injection molding piece in an embedded mode, the turnover piece is contained in a turnover piece containing hole and is arranged below the upper terminal part, a first groove is formed in the position, facing one side of the turnover piece, of the upper terminal part and at least. The connecting piece and the negative pole column piece are embedded with the injection molding piece, so that the injection molding piece can be prevented from falling off or warping due to uneven stress.

Description

Secondary battery top cover

Technical Field

The utility model relates to an energy storage apparatus field especially relates to a secondary battery top cap.

Background

In modern society, driving power sources for more and more electric tools and new energy vehicles are developed in a direction of high capacity and high safety, and batteries are widely used in electric tools and new energy vehicles due to their excellent characteristics such as high capacity. These batteries should have good safety in addition to high capacity to meet the standards of use and to meet the needs of people.

General secondary battery, the negative pole end needs to satisfy with the electrical insulation of top cap and casing, therefore can set up numerous insulating assemblies, if go up plastic part with negative pole post and top cap insulation, arrange the sealing member that carries out electrical insulation and sealed in the negative pole mounting hole in, and carry out electrical insulation's lower plastic part with negative pole connection piece and top cap, these subassemblies are when carrying out the installation of top cap piece negative pole end, in order to control its gas tightness strictly, the required precision of its installation is very high, both carry out the pre-compaction to the sealing member, clearance between each part of will strictly controlling again, therefore with high costs and yields are low. Meanwhile, in order to guarantee the safety of the secondary battery, the turnover piece is installed at the negative end of the top cover of some batteries in the prior art, and the top cover piece is electrically connected with the positive end, so that when the internal air pressure of the secondary battery rises due to accidents such as overcharge or electrolyte reaction of the battery, the turnover piece overturns and forms external current between the positive electrode and the negative electrode, overcharge is stopped, the internal energy of the secondary battery is released through slow overcurrent heat dissipation of the resistor at the positive end, dangers such as overcharge, fire, explosion and the like can not occur, and the safety performance of the secondary battery is improved. Because the negative pole end needs to be provided with the turnover piece and enough space is reserved for the turnover piece to turn over, the injection molding part and the connecting piece can not be completely matched, the combination of the injection molding part and the connecting piece at the end where the turnover piece is arranged is not firm relative to other parts, and when the secondary battery top cover and the shell are installed or assembled into a secondary battery pack, the problems that the injection molding part drops and warps at the end where the turnover piece is arranged can occur, so that the sealing performance of the secondary battery top cover is influenced, and potential safety hazards are generated.

Therefore, it is urgently needed to provide a new top cover structure to solve the problem that the injection molding member and the connecting member are not firmly combined in the existing secondary battery top cover provided with the turnover piece.

SUMMERY OF THE UTILITY MODEL

An object of the utility model is to provide a secondary battery top cap to prior art's not enough, it can effectively solve the problem that injection molding piece and connecting piece combine not firmly in the secondary battery top cap that has the upset piece structure.

The utility model provides a secondary battery top cap, including the top cap piece with set up in the positive pole post spare and the negative pole post spare of top cap piece, the top cap piece is equipped with negative pole mounting hole and upset piece accommodation hole, negative pole post spare insulation install in the negative pole mounting hole, positive pole post spare with the top cap piece electricity is connected, negative pole post spare have last terminal part and with the lower terminal part that last terminal part links to each other, lower terminal part wears to establish and is fixed in the negative pole mounting hole, still be equipped with connecting piece, upset piece on the top cap piece and enclose and locate the injection molding of negative pole post spare, the connecting piece is fixed in negative pole mounting hole and with lower terminal part keeps apart, the connecting piece with the injection molding gomphosis is connected, the upset piece holding in upset piece accommodation hole is placed in the below of last terminal part, last terminal part towards one side of upset piece just at least in be equipped with first concave between lower terminal part and the upset piece accommodation hole The injection molding piece is provided with an upper bulge, and the upper bulge is embedded into the first groove.

The utility model discloses a connecting piece and the injection molding gomphosis of secondary battery top cap negative pole end are connected, and the last terminal part of negative pole post is equipped with first recess towards one side of upset piece and at least between terminal part and upset piece accommodation hole down, the last arch and the first recess gomphosis of injection molding, therefore the injection molding is not only with the connecting piece gomphosis, still carry out the gomphosis with negative pole post to being less than near upset piece department simultaneously, therefore can avoid the secondary battery top cap to weld, the installation, during the equipment, the injection molding takes place to drop or warpage scheduling problem because of the atress inequality in being close to upset piece department (between lower terminal part and the upset piece accommodation hole).

Furthermore, the connecting piece is provided with a second groove, the injection molding piece is also provided with a lower bulge, the lower bulge is embedded into the second groove, and the connecting piece and the injection molding piece can be embedded and connected in the groove in a protruding and embedded mode.

Furthermore, in order to facilitate the processing of the parts and the uniform stress, the upper bulge and the lower bulge are preferably in a symmetrical structure.

Furthermore, the size of the outer caliber of the notch of the first groove and the second groove is smaller than that of the inner caliber, so that the injection molding piece is more firmly embedded in the first groove and the second groove, and the cross section of the first groove and the cross section of the second groove can be isosceles trapezoid or T-shaped.

Further, the first groove and the second groove are annular grooves, that is, the first groove on the upper terminal portion is not only provided between the lower terminal portion and the flap accommodating hole, but is provided around the lower terminal portion.

Furthermore, the connecting piece is provided with a body part and an embedding part connected with the body part, the body part is fixedly connected with the top cover plate, the embedding part is embedded into the injection molding part, the second groove is formed in one end, close to the turnover piece, of the body part, the connecting piece is not only in embedded connection with the injection molding part through the embedding part, but also provided with the second groove for embedding the injection molding part, and the double-layer embedding enables the embedding between the connecting piece and the injection molding part to be firmer.

Furthermore, a longitudinal groove parallel to the second groove is formed in one side, facing the turnover piece, of the upper end portion, and a plurality of criss-cross grooves are formed in one side, facing the turnover piece, of the upper end portion, at least one groove is formed between the lower end portion and the turnover piece accommodating hole, and the upper end portion and the injection molding part can be firmly embedded through the grooves.

Furthermore, the upper end part faces one side of the turnover sheet and is provided with a plurality of positioning holes above the turnover sheet, so that the negative pole column piece can be accurately installed on the turnover sheet of the top cover plate.

Furthermore, the outer wall of the upper end sub-portion is provided with a continuous chamfer, and the injection molding piece wraps the chamfer. The outer wall of the upper end portion is provided with a continuous chamfer wrapped by the injection molding part, after the chamfer is arranged, stress concentration formed at the encapsulation part of the upper end portion can be relieved, and the encapsulated terminal can bear larger thrust (more than 1500N) to increase the strength of the encapsulated terminal, so that the situation that the injection molding part cracks in the ordinary thrust test process to influence subsequent use of the injection molding part is avoided.

Further, the top cover sheet is further provided with a sealing element, the connecting element is isolated from the lower terminal part through the sealing element, or a gap exists between the connecting element and the lower terminal part in the horizontal direction, and part of the injection molding element is accommodated in the gap to isolate the connecting element from the lower terminal part.

Drawings

Fig. 1 is a perspective view of an embodiment of a secondary battery top cap according to the present invention.

Fig. 2 is a partial exploded view of the secondary battery top cover according to the present invention in a first direction.

Fig. 3 is a partial exploded view of the secondary battery top cover of the present invention in a second direction.

Fig. 4 is a cross-sectional view taken along a-a of fig. 1.

Fig. 5 is a variation of fig. 2.

Fig. 6 is a variation of fig. 3.

Fig. 7 is a variation of fig. 4.

Fig. 8 is an enlarged view of a portion a in fig. 4.

Fig. 9 is an enlarged view of a portion a in fig. 7.

Fig. 10 is a variation of fig. 8.

Fig. 11 is a variation of fig. 9.

Fig. 12 is an enlarged view of a portion B in fig. 4.

Fig. 13 is an enlarged view of an upper terminal portion in fig. 2.

Fig. 14 is an enlarged view of an upper terminal portion in fig. 3.

Fig. 15 is an enlarged view of an upper terminal portion in fig. 5.

Fig. 16 is an enlarged view of an upper terminal portion in fig. 6.

Fig. 17 is a variation of fig. 15.

Fig. 18 is a plan view of the upper terminal portion of fig. 17.

Description of the element reference numerals

100-secondary battery top cover; 1-top cover sheet; 11-a negative mounting hole; 13-a flip sheet receiving hole; 2-positive terminal; 21-positive pole column piece; 211-positive electrode upper terminal portion; 213-positive electrode lower terminal portion; 22-positive connection; 221-positive electrode body portion; 223-positive electrode insertion portion; 23-positive injection molding; 24-positive seal; 241-the positive electrode body; 243-positive electrode extension part; 3-a negative terminal; 31-negative pole column; 311-upper terminal portion; 3111-a first recess; 3113-positioning the holes; 3115-chamfering; 3117-first step; 3119-a second step; 313-lower terminal portion; 32-a connector; 321-a second groove; 323-body section; 325 — an insert; 3251-transverse through hole; 33-turning over the sheet; 34-injection molding; 341-lower projection; 343-upper bulge; 345-a via; 35-a seal; 351-body; 353-an extension; 4-an explosion-proof valve; and 5-liquid injection hole.

Detailed Description

In order to facilitate understanding of the present invention, the present invention will be described more fully hereinafter with reference to the accompanying drawings. The preferred embodiments of the present invention are shown in the drawings. The invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete. It should be noted that, in general, the secondary battery is placed vertically, one side of the secondary battery top cover, where the pole extends out and is connected with the outside, is an upper side, and the other side is a lower side.

The utility model discloses a secondary battery top cap can be used to the sealed casing and prepares secondary battery, and the secondary battery top cap can weld with the casing and seal. Referring to fig. 1 to 7, a secondary battery top cover 100 has a top cover sheet 1, and a positive electrode column 21 at a positive electrode terminal 2 and a negative electrode column 31 at a negative electrode terminal 3 provided on the top cover sheet 1, the top cover sheet 1 being provided with an explosion-proof valve 4 and an injection hole 5. The top cover plate 1 is provided with a negative electrode mounting hole 11 and a turnover piece accommodating hole 13, the negative electrode column piece 31 is mounted in the negative electrode mounting hole 11 in an insulated manner and is electrically insulated from the top cover plate 1, and the positive electrode column piece 21 is electrically connected with the top cover plate 1. The turning sheet 33 is accommodated in the turning sheet accommodating hole 33, and when the air pressure in the secondary battery exceeds a preset value, the turning sheet 33 turns and is electrically connected with the negative pole column member 31, so that the positive pole and the negative pole are short-circuited to form an external current, thereby improving the safety performance of the secondary battery.

First, referring to fig. 2 to 9, describing the structure of the negative terminal 3, the negative column 31 has an upper terminal portion 311 and a lower terminal portion 313 connected to the upper terminal portion 311, the lower terminal portion 313 penetrates and is fixed to the negative mounting hole 11, the top cover plate 1 is further provided with a connecting member 32, a sealing member 35, and an injection molded part 34 surrounding the negative column 31, the connecting member 32 is fixed to the negative mounting hole 11 and is isolated from the lower terminal portion 313 by the sealing member 35, the connecting member 32 is connected to the injection molded part 34 in an embedded manner, the flip sheet 33 is disposed below the upper terminal portion 311, the upper terminal portion 311 faces one side of the flip sheet 33 and is at least provided with a first groove 3111 between the lower terminal portion 313 and the flip sheet receiving hole 13, and the injection molded part 34 has an upper protrusion 343, and the upper protrusion 343 is. When the pressure inside the secondary battery exceeds a preset value, the turning piece 33 turns upwards to contact with the upper terminal part 311 of the negative pole column 31, and the positive pole column 21 is electrically connected with the top cover plate 1, so that the negative pole column 31, the positive pole column 21 and the top cover plate 1 are electrically conducted to form an external short circuit to ensure the safety of the secondary battery.

As shown in fig. 2 to 3 and 8, the connecting member 32 is provided with a second groove 321, the outer diameter of the notch of the first groove 3111 and the second groove 321 is smaller than the inner diameter, and the cross-sectional shape of the first groove 3111 and the second groove 321 may be T "shaped, so that the injection molded part 34 is more firmly fitted in the first groove 3111 and the second groove 321. As shown in fig. 2 to 3 and 13 to 14, the first groove 3111 and the second groove 321 are annular grooves, which means that the first groove 3111 on the upper terminal portion 311 is not only disposed between the lower terminal portion 313 and the flap accommodating hole 13, but is disposed around the lower terminal portion 313. The injection-molded part 34 further has a lower protrusion 341, the lower protrusion 341 is inserted into the second groove 321, and the connection member 32 and the injection-molded part 34 can be connected by fitting the protrusion into the groove. In order to facilitate the processing of the components and the uniform stress, the upper protrusion 343 and the lower protrusion 341 are preferably symmetrical.

Alternatively, as shown in fig. 5 to 6 and fig. 9, the connecting member 32 has a main body 323 and an embedded portion 325 connected to the main body 323, the embedded portion 315 has a transverse through hole 3251, the main body 323 is fixedly connected to the top cover plate 1, the embedded portion 325 is embedded in the injection-molded part 34, and a part of the injection-molded part 34 can be embedded in the transverse through hole 3251, thereby increasing the reliability of the engagement between the injection-molded part 34 and the embedded portion 315. The body 323 is provided with a second groove 321 at one end close to the turning sheet 33, the injection molding part 34 is provided with a lower protrusion 341, the lower protrusion 341 is embedded into the second groove 321, the connecting piece 32 is embedded and connected with the injection molding part 34 through the embedded part 325, the second groove 321 is also provided for embedding the injection molding part 34, and the double-layer embedding can ensure that the embedding between the connecting piece 32 and the injection molding part 34 is firmer. The outer diameter of the notch of the first groove 3111 and the second groove 321 is smaller than the inner diameter, and the cross-sectional shape of the first groove 3111 and the second groove 321 may be isosceles trapezoid, so that the injection molded part 34 is more firmly fitted in the first groove 3111 and the second groove 321. In order to facilitate the processing of the components and the uniform stress, the upper protrusion 343 and the lower protrusion 341 are preferably symmetrical. As shown in fig. 15 to 16, the upper terminal portion 311 faces the flip sheet 33, and a vertical groove parallel to the second concave groove 321 is formed between the lower terminal portion 313 and the flip sheet accommodating hole 13, and constitutes a first concave groove 3111. As another mode, as shown in fig. 17 to 18, a plurality of criss-cross grooves are formed on a side of the upper terminal portion 311 facing the flip sheet 33, and at least one groove is located between the lower terminal portion 313 and the flip sheet accommodating hole 13, which is a first groove 3111, so that the upper terminal portion 311 and the injection molded part 34 can be more firmly embedded through the plurality of grooves.

In addition, with reference to fig. 8 to 9, the upper terminal portion 311 of the negative pole member 31 is usually made of aluminum for connection with the outside, and the lower terminal portion 313 is made of copper. The upper terminal portion 311 is provided with a first step 3117 and a second step 3119 along the vertical direction, the injection molded part 34 wraps the second step 3119, and the upper surface of the injection molded part 34 is flush with the platform of the first step 3117, so that the injection molded part 34 and the negative pole piece 31 can be firmly embedded. The upper terminal portion 311 faces the side of the flip sheet 33 and is provided with a plurality of positioning holes 3113 above the flip sheet 33 so that the negative column 31 can be accurately mounted on the flip sheet 33 of the top cover sheet 1. The outer edge of the upper end portion 311 is provided with a continuous chamfer 3115, and the injection molding 34 covers the chamfer 3115. The chamfer 3115 may be a straight chamfer having an angle of 10 ° to 80 ° and a dimension of 0.1 to 1.0, or the chamfer 3115 may be a circular chamfer of R0.1 to R1.0. After the chamfer is arranged, the stress concentration formed at the encapsulation part of the terminal can be relieved, and the encapsulated terminal can bear larger thrust (more than 1500N) to increase the strength, so that the situation that the injection molding part cracks in the ordinary thrust test process to influence the subsequent use of the injection molding part is avoided. The sealing member 35 has a body 351 and an extension portion 353 extending downward from the body 351, the body 351 is interposed between the injection molded member 34 and the negative pole column member 31, and the extension portion 353 surrounds the side surface of the negative pole column member 31. The extension part 353 is arranged around the side surface of the negative pole column 31, so that the negative pole column 31 can be prevented from contacting the connecting piece 32 due to shaking during injection molding, and the negative pole column 31 is further ensured to be arranged on the connecting piece 32 in an insulating manner before injection molding. The injection molding part 34 is provided with a through hole which is coaxial with the turnover sheet accommodating hole 13 and has a radius larger than or equal to that of the turnover sheet accommodating hole 13 at the turnover sheet accommodating hole 13, and the through hole 13 can be used for the turnover of the turnover sheet 13.

Of course, the isolation between the connecting member 32 and the lower terminal portion 313 may be implemented by other structures besides the sealing member 35, as shown in fig. 10 to 11, in the horizontal direction, a gap exists between the connecting member 32 and the lower terminal portion 313, and a part of the injection molded part 34 is accommodated in the gap to isolate the connecting member 32 from the lower terminal portion 313, that is, the sealing member 35 is directly replaced by the part of the injection molded part 34, and after the sealing member 35 is omitted, the isolation and the electrical insulation between the connecting member 32 and the lower terminal portion 313 can be implemented at the same position.

Next, the structure of the positive terminal 2 will be described with reference to the drawings, which may be the structure shown in fig. 4 and 12, the top cover plate 1 is provided with a positive mounting hole (not shown), a positive column 21, a positive connector 22, a positive sealing member 24, and a positive injection molded part 23 surrounding the positive column 21, the positive column 21 has a positive upper terminal portion 211 and a positive lower terminal portion 213 connected to the positive upper terminal portion 211, the positive upper terminal portion 211 and the positive lower terminal portion 213 may be an integral structure and both made of aluminum, and the positive column 21 is inserted into and fixed to the positive mounting hole. The positive electrode connector 22 has a positive electrode main body 221 and a positive electrode insertion portion 223 connected to the positive electrode main body 221, the positive electrode main body 221 is fixedly connected to the top cover plate 1, the positive electrode insertion portion 223 is inserted into the positive electrode injection molded part 23, the positive electrode connector 22 is fixed to the positive electrode mounting hole and is isolated from the positive electrode lower terminal portion 213 by the positive electrode sealing member 24, and of course, isolation may be achieved by replacing the positive electrode sealing member 24 with a part of the positive electrode injection molded part 23 (omitting the positive electrode sealing member 24). However, in order to satisfy the electrical connection between the top cover plate 1 and the positive pole column member 21, the positive pole injection molded part 23 is configured as a conductive injection molded part, and conductive particles, such as conductive carbon or conductive metal, may be added to the injection molded material, so that the positive pole column member 21 and the top cover plate 1 are electrically connected through conductive plastic. Of course, the positive terminal 2 may have other structures besides the above-mentioned structure, such as directly welding the positive post 21 to the top cover sheet 1 or integrally forming the positive terminal 2 directly from the top cover sheet 1, and the structure of the positive terminal 2 includes but is not limited to the above-mentioned structure, and other structures that can achieve the electrical conduction between the positive terminal 2 and the top cover sheet 1 are also feasible.

It should be noted that the above-mentioned embodiments illustrate rather than limit the scope of the invention, and that modifications of various equivalent forms of the invention, which may occur to those skilled in the art after reading the present application, fall within the scope of the appended claims.

Claims (10)

1. A secondary battery top cover comprises a top cover plate, and an anode column and a cathode column which are arranged on the top cover plate, wherein the top cover plate is provided with a cathode mounting hole and an overturning sheet accommodating hole, the cathode column is mounted in the cathode mounting hole in an insulated manner, the anode column is electrically connected with the top cover plate, the secondary battery top cover is characterized in that the cathode column is provided with an upper terminal part and a lower terminal part connected with the upper terminal part, the lower terminal part penetrates through and is fixed in the cathode mounting hole, the top cover plate is further provided with a connecting piece, an overturning sheet and an injection molding part which is arranged on the cathode column in a surrounding manner, the connecting piece is fixed in the cathode mounting hole and is isolated from the lower terminal part, the connecting piece is connected with the injection molding part in an embedding manner, the overturning sheet is accommodated in the overturning sheet accommodating hole and is arranged below the upper terminal part, the upper terminal part faces one side of the overturning sheet, and at least a first concave part is The injection molding piece is provided with an upper bulge, and the upper bulge is embedded into the first groove.

2. The secondary battery top cap according to claim 1, wherein the connecting member is provided with a second groove, and the injection molded member further has a lower protrusion, and the lower protrusion is fitted into the second groove.

3. The secondary battery top cap according to claim 2, wherein the upper protrusion and the lower protrusion are of a symmetrical structure, and the outer diameter of the notch of the first groove and the second groove is smaller than the inner diameter.

4. The secondary battery top cap according to claim 2, wherein the first groove and the second groove are both annular grooves.

5. The secondary battery top cap according to claim 2, wherein the connecting member has a body portion fixedly connected to the top cap sheet and an insertion portion connected to the body portion, the insertion portion being inserted into the injection molded member, and the body portion is provided with the second groove at an end thereof adjacent to the flip sheet.

6. The secondary battery top cap according to claim 5, wherein the upper terminal portion faces a side of the inversion sheet and a longitudinal groove parallel to the second groove is provided between the lower terminal portion and the inversion sheet accommodation hole.

7. The secondary battery top cap according to claim 2, wherein a plurality of grooves are formed in a crisscross pattern on a side of the upper terminal portion facing the flip sheet, and at least one groove is formed between the lower terminal portion and the flip sheet receiving hole.

8. The secondary battery top cap according to claim 1, wherein the upper terminal portion faces a side of the flip sheet and is provided with a plurality of positioning holes above the flip sheet.

9. The secondary battery top cap according to claim 1, wherein the outer wall of the upper terminal portion is provided with a continuous chamfer, and the injection molded piece wraps around the chamfer.

10. The secondary battery top cap according to claim 1, wherein a sealing member is further provided on the top cap sheet, and the connecting member is isolated from the lower terminal part by the sealing member, or a gap exists between the connecting member and the lower terminal part in a horizontal direction, and a part of the injection-molded member is received in the gap to isolate the connecting member from the lower terminal part.

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