CN215497006U

CN215497006U - Secondary battery top cap and secondary battery thereof

Info

Publication number: CN215497006U
Application number: CN202121406520.4U
Authority: CN
Inventors: 邓平华; 王雷
Original assignee: Jiangxi Baisili New Energy Technology Co ltd
Current assignee: Jiangxi Baisili New Energy Technology Co ltd
Priority date: 2021-06-23
Filing date: 2021-06-23
Publication date: 2022-01-11
Anticipated expiration: 2031-06-23

Abstract

The utility model provides a secondary battery top cover and a secondary battery thereof, wherein the secondary battery top cover comprises a top cover plate, a positive electrode unit and a negative electrode unit, the positive electrode unit and the negative electrode unit are connected with the top cover plate, the top cover plate is provided with a positive electrode lead-in hole, the positive electrode unit comprises a positive electrode post penetrating through the positive electrode lead-in hole and a positive electrode adapter connected with the positive electrode post, the middle part of the positive electrode adapter is provided with a fusing gap and a first insulating piece, and the first insulating piece is clamped and covered on the fusing gap. The fusing gap is clamped with the first insulating part and covered by the first insulating part, the rubber coating is replaced by clamping, the problem that the welding quality is poor due to pollution caused by the rubber coating can be avoided, and the clamping mode is firm, so that the insulativity in the fusing gap can be effectively guaranteed. In addition, the first insulating part covers the fusing gap, so that the situation that the breaking part of the positive pole adapter contacts the positive pole column to be conducted again under the influence of air pressure or use after the positive pole adapter is broken through the fusing gap can be avoided, and the effectiveness of current cut-off when the secondary battery is abnormal can be guaranteed through the arrangement of the first insulating part.

Description

Secondary battery top cap and secondary battery thereof

Technical Field

The utility model relates to the field of energy storage instruments, in particular to a secondary battery top cover and a secondary battery thereof.

Background

With the development of modern society and the enhancement of environmental awareness of people, more and more driving power supplies of electric tools and new energy vehicles develop towards the directions of high capacity and high safety, which provides a wide space for the application and development of secondary batteries.

The secondary battery generally employs an adaptor to connect the electrode post and the electrode assembly, and the adaptor is generally fixed to the electrode post by laser welding. In order to prevent the danger of explosion caused by abnormal generation of large current in the battery, the industry people set a current cut-off device on the top cover, for example, a turnover piece electrically connected with the top cover piece and the pole is set, more gas is generated in the battery, the turnover piece turns over to break the electrical connection between the top cover piece and the pole after the internal pressure exceeds a set value, or a fusing gap is set on the adapter, namely, the local overcurrent capacity is weakened, so that the current can be cut off by breaking at the gap when large current is generated, but the breaking part can be contacted with air pressure or used to be conducted again after the adapter breaks, so that an insulating part needs to be set at the fusing gap to prevent the fusing part from being electrically connected again, and the fusing gap is generally encapsulated or a plastic sheet is adhered to one side facing the top cover piece at present. The encapsulation is easy to produce pollution to affect the welding between the adaptor and the pole, and the adhered plastic sheet has poor firmness and is easy to fall off, so the above way can affect the use of the top cover.

SUMMERY OF THE UTILITY MODEL

In order to ensure the welding firmness between the pole and the connecting piece and the use safety of the secondary battery, the utility model provides a secondary battery top cover on one aspect, which comprises: the utility model discloses a fuse-breaking device, including top cap piece, connection the anodal unit and the negative pole unit of top cap piece, the top cap piece is equipped with the positive pole and introduces the hole, the anodal unit is including wearing to establish the anodal post that the hole was introduced to the positive pole is introduced with the connection the anodal adaptor of anodal post, the middle part of anodal adaptor is equipped with fusing breach and first insulation piece, first insulation piece joint and cover in the fusing breach.

Compared with the prior art, the fusing gap of the anode adapter of the secondary battery top cover is clamped with the first insulating part and covered by the first insulating part, the clamping mode is used for replacing the rubber coating mode, the problem that the welding quality is poor due to pollution caused by rubber coating can be avoided, the clamping mode is firm, and the insulativity in the fusing gap can be effectively guaranteed. More importantly, first insulating part covers the fusing breach, can avoid anodal adaptor after the fusing breach fracture, thereby its fracture portion receives the atmospheric pressure, or the influence of using and contact positive post switches on once more, so can guarantee the validity of cutting off the electric current when secondary battery is unusual through the setting of first insulating part to guarantee secondary battery's safety in utilization.

Preferably, the positive adapter is inserted and fixed with the second insulating part, and the insertion and matching of the second insulating part and the positive adapter can ensure that the positive adapter is more firm in insulation.

Preferably, the first insulating part includes consecutive overlap joint portion, stretches into portion and joint portion, overlap joint portion is located the top of fusing breach and overlap joint in the fusing breach, stretch into the portion fill in the fusing breach, joint portion joint is fixed in the lower part border of fusing breach. Preferably, the second insulating part corresponds to the clamping part and is provided with an avoiding groove for accommodating the clamping part.

Preferably, the positive pole adaptor includes contact site, branching portion and is located the contact site with the transition portion between the branching portion, the contact site with positive post welded fastening, set up in the transition portion fusing breach and both ends are to keeping away from the direction of contact site extends and forms branching portion, branching portion is used for connecting secondary battery's positive plate. The positive pole adaptor is of a plate-shaped structure and is consistent in size along the vertical direction. The transition portion with the branching portion encloses and establishes the opening and keeps away from contact portion and the tank bottom is curved hollow groove.

Preferably, the second insulating member includes a body portion, and a first protrusion portion and a second protrusion portion that extend upward from edges of two opposite sides of the body portion, the first protrusion portion and the second protrusion portion are provided with a first long groove and a second long groove that are opposite to each other along a length direction of the body portion, and the positive pole adapter is inserted into the first long groove and the second long groove along the length direction of the body portion.

Preferably, the contact portion extends outwards from two sides of the adaptor in the length direction to form a first insertion portion and a second insertion portion, and the first insertion portion and the second insertion portion are respectively inserted into the first elongated groove and the second elongated groove.

Preferably, the end of the body part is provided with a first limiting part and a second limiting part which limit the insertion stroke of the positive adapter, and the first limiting part and the second limiting part are clamped with the contact part.

Preferably, the positive pole unit further comprises a sealing element and an upper insulating piece arranged around the positive pole, the sealing element is arranged between the top cover plate and the positive pole, the upper insulating piece is clamped to the top cover plate and the positive pole, and the double-layer clamping of the top cover insulating piece can enable the connection firmness of all the parts in the top cover to be stronger. Preferably, the top cover plate is provided with an upper boss around the positive electrode lead-in hole, and the upper insulating part is clamped and fixed with the upper boss. The positive post includes cylindricality portion and is located the platform portion of cylindricality portion below, the periphery wall of cylindricality portion is inwards sunken to form the ring channel, go up the insulating part joint in the ring channel. The bottom surface of the annular groove comprises a curved surface and a plane which is connected with the two ends of the curved surface and faces the negative pole column.

The utility model also provides a secondary battery, which comprises a battery core, a shell for accommodating the battery core and a top cover for sealing the shell, wherein the top cover is the secondary battery top cover. The first insulating part and the adaptor in the secondary battery are good in connection firmness, the positive adaptor and the positive pole can be effectively prevented from being conducted again, and therefore current can be effectively cut off when the battery is abnormal, and the use safety of the secondary battery is guaranteed.

Drawings

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

Fig. 2 is a cross-sectional view taken along a-a of fig. 1.

Fig. 3 is an exploded view of the top cap of the secondary battery according to the present invention in one direction.

Fig. 4 is an exploded view of the secondary battery top cover of the present invention in another direction.

Fig. 5 is an enlarged view of the positive electrode adaptor in one direction.

Fig. 6 is an enlarged view of the positive electrode adaptor in another direction.

Fig. 7 is an enlarged view of the positive adapter of fig. 5.

Fig. 8 is an enlarged view of the positive adapter of fig. 6.

Fig. 9 is an enlarged view of the circled area in fig. 2.

Description of the elements

100-secondary battery top cover; 1-top cover sheet; 11-positive electrode introduction holes; 13-negative electrode lead-in hole; 15-explosion-proof valve mounting holes; 17-an upper boss; 2-a positive electrode unit; 21-positive pole column; 211-a cylindrical portion; 213-platform part; 2111-annular groove; 2111 a-curved surface; 2111 b-plane; 23-a positive adapter; 231-a contact portion; 2311 a-a first mating portion; 2311 b-a second mating portion; 2313-clamping groove; 233-a transition section; 2331-fusing the notch; 235-a bifurcation; 2351-hollow channel; 25-positive seal; 27-positive pole upper insulator; 291-first insulator; 2911-lap joint; 2913-an insertion part; 2915-a clamping part; 293-a second insulator; 2931-body section; 2933 a-first boss; 2933b — a second boss; 2935 a-first elongated slot; 2935 b-a second elongated slot; 2937-snap-fit holes; 2939 a-first stop; 2939b — a second stop; 3-a negative electrode unit; 31-negative pole column; 33-a negative adaptor; 35-negative seal; 37-negative upper insulator; 4-an explosion-proof valve assembly; 41-explosion-proof valve; 43-explosion-proof valve protection plate; 5-liquid injection hole; 6-lower insulation; 61-clamping part

Detailed Description

To facilitate an understanding of the utility model, the utility model will now be described more fully with reference to the accompanying drawings. Preferred embodiments of the present invention are shown in the drawings. This 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, which extends out and is connected with the outside, is an upper side, i.e., a top direction, and the other side is a lower side, i.e., a bottom direction.

The secondary battery top cap and the secondary battery according to the present invention will be described with reference to the accompanying drawings.

Referring to fig. 1 to 5, the secondary battery includes a battery cell, a case for accommodating the battery cell, and a secondary battery top cover 100 for sealing the case, wherein the secondary battery top cover 100 is welded to the case to be sealed, and a secondary battery electrolyte for infiltrating the battery cell is injected into the case. The secondary battery top cover 100 includes a top cover sheet 1, and a positive electrode unit 2, a negative electrode unit 3, a liquid injection hole 5, and an explosion-proof valve assembly 4 provided on the top cover sheet 1. The top cover plate 1 is provided with a positive electrode introducing hole 11, a negative electrode introducing hole 13 and an explosion-proof valve mounting hole 15, the positive electrode introducing hole 11 is connected with the positive electrode unit 2, and the negative electrode introducing hole 13 is connected with the negative electrode unit 3. The explosion-proof valve assembly 4 comprises an explosion-proof valve 41 and an explosion-proof valve protecting piece 43, the explosion-proof valve 41 is arranged in the explosion-proof valve mounting hole 15, and the explosion-proof valve protecting piece 43 is arranged above the explosion-proof valve 41. A lower insulator 6 is provided below the top cover plate 1 to electrically insulate the top cover plate 1 from the cells in the housing.

As shown in fig. 1 to 4 and 9, the positive electrode unit 2 includes a positive electrode post 21 having a positive electrode lead-in hole 11 formed therein, a positive electrode adaptor 23, a sealing member 25, and an upper insulating member 27 surrounding the positive electrode post 21. Anodal post 21 is connected to one side of anodal adaptor 23, and the positive plate of electric core is connected to the opposite side, and sealing member 25 is between top cap piece 1 and anodal post 21, goes up insulating part 27 joint in top cap piece 1 and anodal post 21 simultaneously, and this double-deck joint can make the firm nature of connection of each part stronger in the top cap. The positive post 21 includes a cylindrical portion 211 and a terrace portion 213 located below the cylindrical portion 211, the outer peripheral wall of the cylindrical portion 211 is recessed inward to form an annular groove 2111, and the upper insulator 27 is engaged with the annular groove 2111. And the bottom surface of the annular groove 2111 includes a curved surface 2111a and a flat surface 2111b connecting both ends of the curved surface 2111a and facing the negative pole 31, the arrangement of the annular groove 2111 can make the connectivity stronger. Meanwhile, the top cover plate 1 is provided with an upper boss 17 around the positive electrode lead-in hole 11, and the upper boss 17 is fixed by clamping an upper insulating piece 27. The upper insulator 27 may be injection molded during installation or may be extruded before installation, and has a certain elastic modulus and a certain deformation.

As shown in fig. 3 to 8, a fusing gap 2331 and a first insulating member 291 are disposed in the middle of the positive electrode adaptor 23, the first insulating member 291 is clamped and covers the fusing gap 2331, a second insulating member 293 is disposed at the lower portion of the positive electrode adaptor 23, and the second insulating member 293 is inserted and matched with the positive electrode adaptor 23. The fusing gap 2331 of the positive adapter 23 is clamped with the first insulating member 291 and covered by the first insulating member 291, and the clamping method is used for replacing the encapsulation method, so that the problem of poor welding quality caused by pollution caused by encapsulation can be solved, and the clamping method is firm and can effectively ensure the insulativity in the fusing gap 2331. Meanwhile, the first insulating member 291 covers the fuse 2331, so that it is ensured that the broken portion of the positive electrode adaptor 23 contacts the positive electrode post 21 to be conducted again under the influence of air pressure or use after the fuse 2331 is broken, and the effectiveness of current cut-off when the secondary battery is abnormal can be ensured by the arrangement of the first insulating member 291, thereby ensuring the safety of the secondary battery. The second insulating member 293 and the positive adapter 23 are inserted into each other to ensure that the positive adapter 23 is more firmly insulated.

The first insulating member 291 includes a bridging portion 2911, an extending portion 2913 and a clamping portion 2915, which are sequentially connected, the bridging portion 2911 is located above the fuse gap 2331 and is bridged over the fuse gap 2331, the extending portion 2913 is filled in the fuse gap 2331, and the clamping portion 2915 is clamped and fixed to a lower edge of the fuse gap 2331.

The second insulating member 293 includes a main body 2931, and a first protrusion 2933a and a second protrusion 2933b extending upward from two opposite side edges of the main body 2931, the first protrusion 2933a and the second protrusion 2933b are provided with a first elongated groove 2935a and a second elongated groove 2935b opposite to each other along the length direction of the main body 2931, and the positive electrode adaptor 23 is inserted into the first elongated groove 2935a and the second elongated groove 2935b along the length direction of the main body 2931. The end of the main body 2931 is provided with a first position-limiting part 2939a and a second position-limiting part 2929b which limit the insertion stroke of the positive adapter 23, and the first position-limiting part 2939a and the second position-limiting part 2939b are both clamped in the contact part 231. The main body 2931 is provided with a relief groove 2937 for accommodating the snap portion 2915 in correspondence with the snap portion 2915.

The positive electrode adaptor 23 includes a contact portion 231, a branch portion 235 and a transition portion 233 between the contact portion 231 and the branch portion 235, the contact portion 231 is welded to the positive electrode post 31, the transition portion 233 is provided with a fusing gap 2331, two ends of the transition portion extend in a direction away from the contact portion 231 to form the branch portion 235, and the branch portion 235 is used for connecting a positive electrode tab of the secondary battery. The contact portion 231 extends outwards from two sides of the adaptor 23 in the length direction to form a first insertion part 2311a and a second insertion part 2311b, and the first insertion part 2311a and the second insertion part 2311b are inserted into the first elongated groove 2935a and the second elongated groove 2935b respectively. The end of the contact portion 231 is provided with a clamping groove 2313 for clamping the first and second position-limiting

portions

2939a and 2939b of the second insulating member 293. The positive electrode adaptor 23 is preferably of a plate-like structure and uniform in size in the vertical direction. Form two parts 235 and be favorable to electric core to be a plurality of times, the anodal ear of electric core and anodal adaptor 23 be connected, more accurate, be convenient for separate with the anodal ear of a plurality of electric cores carry out laser or ultrasonic bonding on the part 235 that divides to divide with the difference. Transition portion 233 and bifurcated portion 235 enclose and establish the opening and keep away from contact portion 2351 and the tank bottom is curved hollow groove 2351, forms hollow groove structure and is favorable to the utmost point ear of a plurality of electric cores and bifurcated portion 235 to carry out laser or ultrasonic welding operation.

The negative electrode unit 3 has a structure substantially similar to that of the positive electrode unit 2, and includes a negative electrode post 31 provided with a negative electrode introducing hole 13, a negative electrode adaptor 33, a negative electrode sealing member 35, and a negative electrode upper insulating member 37 provided around the negative electrode post 31. Negative pole post 31 is connected to one side of negative pole adaptor 33, and the negative pole piece of electric core is connected to the opposite side, and negative pole sealing member 35 is between top cap piece 1 and negative pole post 31, and insulating part 37 joint in top cap piece 1 and negative pole post 31 simultaneously on the negative pole, and this double-deck joint can make the firm nature of connection of each part stronger in the top cap. Different from the positive electrode unit, the weak region of fusing is not arranged on the negative electrode adaptor 33, so that the first insulating member 291 and the second insulating member 293 in the positive electrode unit 2 are not required to be arranged, and only the lower insulating member 6 is required to be isolated from the battery core.

It should be noted that the above-mentioned embodiments illustrate rather than limit the scope of the utility model, and that those skilled in the art will be able to modify the utility model in its various equivalent forms after reading the present invention and to fall within the scope of the utility model as defined in the appended claims.

Claims

1. A secondary battery top cap (100), comprising: top cap piece (1), connection positive pole unit (2) and negative pole unit (3) of top cap piece (1), top cap piece (1) is equipped with positive pole introduction hole (11), its characterized in that, positive pole unit (2) are including wearing to establish positive post (21) and the connection of positive post (21) the anodal adaptor (23) of positive post (21), the middle part of anodal adaptor (23) is equipped with fusing breach (2331) and first insulator (291), first insulator (291) joint and cover in fusing breach (2331).

2. The secondary battery top cover (100) according to claim 1, wherein the positive electrode adaptor (23) is inserted and fixed to the second insulating member (293).

3. The secondary battery top cap (100) according to claim 2, wherein the first insulating member (291) comprises a bridging portion (2911), an extending portion (2913) and a clamping portion (2915) which are sequentially connected, the bridging portion (2911) is positioned above the fusing gap (2331) and is bridged over the fusing gap (2331), the extending portion (2913) is filled in the fusing gap (2331), and the clamping portion (2915) is clamped and fixed to the lower edge of the fusing gap (2331).

4. The secondary battery top cap (100) according to claim 3, wherein the second insulating member (293) is provided with a relief groove (2937) corresponding to the snap portion (2915) to receive the snap portion (2915).

5. The secondary battery top cap (100) according to claim 2, wherein the positive electrode adaptor (23) comprises a contact portion (231), a branch portion (235) and a transition portion (233) located between the contact portion (231) and the branch portion (235), the contact portion (231) is welded and fixed to the positive electrode pillar (21), the transition portion (233) is provided with the fusing notch (2331) and two ends of the fusing notch extend away from the contact portion (231) to form the branch portion (235).

6. The secondary battery top cover (100) according to claim 5, wherein the second insulating member (293) comprises a body portion (2931) and a first protrusion portion (2933a) and a second protrusion portion (2933b) formed by extending upward from edges of two opposite sides of the body portion (2931), the first protrusion portion (2933a) and the second protrusion portion (2933b) are provided with a first elongated groove (2935a) and a second elongated groove (2935b) opposite to each other along a length direction of the body portion (2931), and the positive electrode adaptor (23) is inserted into the first elongated groove (2935a) and the second elongated groove (2935b) along the length direction of the body portion (2931).

7. The secondary battery top cap (100) according to claim 6, wherein the contact portion (231) extends outwardly at both sides of the adaptor (23) in the longitudinal direction to form a first mating portion (2311a) and a second mating portion (2311b), and the first mating portion (2311a) and the second mating portion (2311b) are mated with the first elongated groove (2935a) and the second elongated groove (2935b), respectively.

8. The secondary battery top cover (100) according to claim 6, wherein the end of the body part (2931) is provided with a first limiting part (2939a) and a second limiting part (2939b) which limit the insertion stroke of the positive electrode adaptor (23), and the first limiting part (2939a) and the second limiting part (2939b) are clamped with the contact part (231).

9. The secondary battery top cover (100) according to claim 1, wherein the positive electrode unit (2) further comprises a sealing member (25) and an upper insulating member (27) surrounding the positive electrode post (21), the sealing member (25) is arranged between the top cover sheet (1) and the positive electrode post (21), and the upper insulating member (27) is clamped on the top cover sheet (1) and the positive electrode post (21) simultaneously.

10. A secondary battery comprising a battery cell, a casing for accommodating the battery cell, and a top cover for sealing the casing, wherein the top cover is the secondary battery top cover (100) according to any one of claims 1 to 9.