阅读说明：本技术 二次电池以及用于二次电池的组件 (Secondary battery and assembly for secondary battery ) 是由 王佳军 来佑磊 郑于炼 王鹏 夏天军 于 2016-12-02 设计创作，主要内容包括：本申请公开了一种二次电池以及用于二次电池的组件。本申请实施例的用于二次电池的组件包括：第一连接片,包括第一极柱连接部、第一极耳连接部以及第一熔断部,第一熔断部的两端分别与第一极柱连接部和第一极耳连接部固定连接,第一极柱连接部和第一极耳连接部上均设有贯通的固定孔；绝缘保持块,包括第一保持部,第一保持部包括设置于第一连接片沿厚度方向的一侧的第一部分以及与第一部分相连的固定柱,固定柱与固定孔对应,固定柱穿入固定孔并固定连接于第一极柱连接部和第一极耳连接部,当第一熔断部熔断后,第一保持部能够保持第一极柱连接部和第一极耳连接部的相对位置固定。(Disclosed are a secondary battery and an assembly for the secondary battery. The assembly for a secondary battery of the embodiment of the present application includes: the first connecting sheet comprises a first pole connecting part, a first tab connecting part and a first fusing part, two ends of the first fusing part are respectively and fixedly connected with the first pole connecting part and the first tab connecting part, and the first pole connecting part and the first tab connecting part are both provided with through fixing holes; the insulating holding block comprises a first holding portion, the first holding portion comprises a first portion and a fixing column, the first portion is arranged on one side of the first connecting piece in the thickness direction, the fixing column is connected with the first portion, the fixing column corresponds to the fixing hole, the fixing column penetrates into the fixing hole and is fixedly connected to the first pole connecting portion and the first pole lug connecting portion, and after the first fusing portion is fused, the first holding portion can keep the relative position of the first pole connecting portion and the first pole lug connecting portion fixed.)

1. An assembly for a secondary battery, comprising:

the first connecting sheet comprises a first pole connecting part, a first tab connecting part and a first fusing part, wherein two ends of the first fusing part are respectively and fixedly connected with the first pole connecting part and the first tab connecting part, and the first pole connecting part and the first tab connecting part are both provided with through fixing holes;

the insulating holding block comprises a first holding portion, the first holding portion comprises a first portion and a fixing column, the first portion is arranged on one side, in the thickness direction, of the first connecting sheet, the fixing column is connected with the first portion, the fixing column corresponds to the fixing hole, the fixing column penetrates through the fixing hole and is fixedly connected to the first pole connecting portion and the first pole lug connecting portion, and after the first fusing portion is fused, the first holding portion can keep the relative positions of the first pole connecting portion and the first pole lug connecting portion fixed.

2. The assembly for a secondary battery according to claim 1, wherein the fixing post is fixedly coupled with the first tab connection part by heat fusion, interference fit, riveting or bonding.

3. The assembly for a secondary battery according to claim 1, wherein the fixing hole is a waist hole or a round hole, and the fixing post has a shape corresponding to the shape of the fixing hole.

4. The assembly for a secondary battery according to claim 1,

the first connecting piece is provided with an opening, and the first fusing part comprises sub fusing parts positioned on two sides of the opening in the width direction; or

The first fusing part is provided with notches along two sides of the width direction.

5. The assembly for a secondary battery according to claim 1,

the first tab connecting part includes: two first tab connecting portions extending in a length direction; the first tab collecting part extends along the width direction, and two ends of the first tab collecting part are respectively connected with the two first tab connecting parts;

the first pole post connecting part is positioned between the two first pole lug connecting parts and extends along the length direction;

the first fusing part extends along the length direction and is connected with the first tab collecting part and the first pole connecting part.

6. The assembly for a secondary battery as defined in claim 5, further comprising: and the insulating patch is pasted on the surface of the first connecting sheet and at least covers the edges of the first pole connecting part along the two sides of the width direction.

7. The assembly for a secondary battery as claimed in claim 5, wherein the first connection tab is entirely planar.

8. The assembly for a secondary battery according to claim 1, wherein the first holding portion is made of plastic.

9. A secondary battery, characterized by comprising:

a first pole column;

the battery cell is provided with a first tab;

the assembly of any one of claims 1-8, said first pole tab connection being in fixed electrical connection with said first pole tab.

10. The secondary battery according to claim 9,

the first tab is provided with a connecting section fixedly connected with the first tab connecting part;

the secondary battery further comprises a welding protection plate, and the welding protection plate, the connecting section and the first tab connecting part are fixedly connected through ultrasonic welding.

Technical Field

The present application relates to the field of batteries, and more particularly, to a secondary battery and a module for a secondary battery.

Background

Referring to fig. 1 to 3, in the prior art, a first connection plate 3 is generally used to realize fixed electrical connection between a first tab 21 of a battery core 2 and a first terminal 11 of a top cover 1, and a first fusing part 33 is arranged on the first connection plate 3, so that when a large current flows through the first connection plate 3, the first fusing part 33 can be fused in time to rapidly cut off the electrical connection between the first tab 21 and the first terminal 11, thereby preventing thermal runaway of a secondary battery; however, after the first fusing part 33 is fused, the first pole connecting part 31 and the first tab connecting part 32 of the first connecting plate 3 become two mutually independent parts, when the electric core 2 is vibrated by external impact, the first tab connecting part 32 is driven to move up and down through the first tab 21, the first tab connecting part 31 is easily overlapped with the first pole connecting part, the circuit is switched on again, the thermal runaway is caused, and the explosion is caused, so that the first fusing part 33 cannot play a role in safety protection.

Disclosure of Invention

In view of the problems in the background art, it is an object of the present application to provide a secondary battery and an assembly for the secondary battery, which can prevent thermal runaway of the secondary battery and improve the safety of the battery.

In a first aspect, the present application provides an assembly for a secondary battery, comprising: the first connecting sheet comprises a first pole connecting part, a first tab connecting part and a first fusing part, two ends of the first fusing part are respectively and fixedly connected with the first pole connecting part and the first tab connecting part, and the first pole connecting part and the first tab connecting part are both provided with through fixing holes; the insulating holding block comprises a first holding portion, the first holding portion comprises a first portion and a fixing column, the first portion is arranged on one side of the first connecting piece in the thickness direction, the fixing column is connected with the first portion, the fixing column corresponds to the fixing hole, the fixing column penetrates into the fixing hole and is fixedly connected to the first pole connecting portion and the first pole lug connecting portion, and after the first fusing portion is fused, the first holding portion can keep the relative position of the first pole connecting portion and the first pole lug connecting portion fixed.

In some embodiments, the fixing post is fixedly connected to the first tab connecting portion by heat fusion, interference fit, riveting or bonding.

In some embodiments, the fixing hole is a waist hole or a round hole, and the shape of the fixing column corresponds to the shape of the fixing hole.

In some embodiments, the first connecting piece has an opening formed therein, and the first fusing part includes sub fusing parts located at both sides of the opening in the width direction; or, notches are arranged on two sides of the first fusing part along the width direction.

In some embodiments, the first tab connection part includes: two first tab connecting portions extending in a length direction; and the first tab collecting part extends along the width direction, and two ends of the first tab collecting part are respectively connected with the two first tab connecting parts. The first pole connecting portion is located between the two first pole tab connecting portions and extends in the length direction. The first fusing part extends along the length direction and is connected with the first tab collecting part and the first pole connecting part.

In some embodiments, the assembly for a secondary battery further comprises: and the insulating patches are pasted on the surface of the first connecting sheet and at least cover the edges of the two sides of the first pole connecting part in the width direction.

In some embodiments, the first connecting piece is entirely planar.

In some embodiments, the first retaining portion is made of plastic.

In a second aspect, the present application also provides a secondary battery including: a first pole column; the battery cell is provided with a first tab; in the assembly of any embodiment of the first aspect, the first pole tab connection portion is fixedly and electrically connected to the first pole, and the first pole tab connection portion is fixedly and electrically connected to the first pole tab.

In some embodiments, the first tab has a connection section fixedly connected to the first tab connection portion. The secondary battery further comprises a welding protection sheet, and the welding protection sheet, the connection section and the first tab connection part are fixedly connected through ultrasonic welding.

In the application, the first fusing part is connected in series between the first pole connecting part and the first tab connecting part, so when the first connecting piece passes large current due to overcharge or abnormal phenomena of the secondary battery, the first fusing part can be timely fused to rapidly cut off the electric connection between the first pole connecting part and the first tab connecting part, and the thermal runaway of the secondary battery is prevented; and after first fusing portion fuses, the relative position that insulating holding block can keep first utmost point post connecting portion and first utmost point ear connecting portion is fixed, prevents that first connection piece from separating into independent two parts at first fusing portion fusing department, first utmost point ear connecting portion and first utmost point post connecting portion contact when avoiding secondary battery to receive external impact, prevent that the circuit from communicateing once more, improve the security performance of battery.

Drawings

Fig. 1 is a schematic view of a prior art secondary battery;

fig. 2 is a sectional view of a prior art secondary battery;

fig. 3 is an exploded view of a prior art secondary battery;

fig. 4 is a schematic view of a secondary battery according to the present application;

fig. 5 is an exploded view of a secondary battery according to the present application;

fig. 6 is a sectional view of a secondary battery according to the present application;

fig. 7 is a schematic view of a first tab of a secondary battery according to the present application;

fig. 8 is another schematic view of a first tab of a secondary battery according to the present application;

fig. 9 is a schematic view of a first connection tab, an insulation holding block, and an insulation patch of a secondary battery according to the present application;

FIG. 10 is an exploded view of FIG. 9;

fig. 11 is a schematic view of a first connection tab of a secondary battery according to the present application;

fig. 12 is a perspective view of an insulation holding block of a secondary battery according to the present application;

FIG. 13 is a top view of FIG. 12;

fig. 14 is a cross-sectional view taken along line a-a of fig. 13.

Wherein the reference numerals are as follows:

1 Top cover 41 second pole connecting part

11 first pole 42 second pole ear connection part

12 second pole 421 second pole ear connection part

2 electric core 422 second pole ear assembly part

21 first pole ear 5 insulation holding block

211 connecting segment 51 first retaining portion

212 bending section 511 fixing column

22 second lug 52 second holding part

23 main body 6 insulating strip

3 first connecting plate 7 insulating patch

31 welding protection sheet for first pole connecting part 8

32 first utmost point ear connecting portion H fixed orifices

321 first tab connecting part G notch

322 first pole ear collecting part S insulating glue

33 first fusing part L in the longitudinal direction

331 width direction of opening W

332 sub-fusing part T thickness direction

4 second connecting sheet

Detailed Description

The secondary battery of the present application is described in detail below with reference to the accompanying drawings.

Referring to fig. 4 to 14, a secondary battery according to the present application includes: the top cover 1 is provided with a first pole post 11 and a second pole post 12 with opposite polarities; the battery cell 2 is provided with a first tab 21 and a second tab 22 with opposite polarities; a first connection tab 3 connected in series between the first tab 21 and the first pole 11; the second pole ear 22 is electrically connected to the second pole post 12. The first connecting piece 3 has: a first pole connecting portion 31 electrically and fixedly connected to the first pole 11; a first tab connection part 32 fixedly and electrically connected to the first tab 21; and a first fuse portion 33 connected in series between the first pole connecting portion 31 and the first tab connecting portion 32. The secondary battery further includes: an insulating holding block 5, both ends of which are fixedly connected to the first pole connecting portion 31 and the first tab connecting portion 32, respectively; when the first fusing part 33 is fused, the insulating holding block 5 can keep the relative positions of the first pole connecting part 31 and the first tab connecting part 32 fixed.

In the secondary battery according to the present application, the first fusing part 33 is connected in series between the first tab connecting part 32 and the first post connecting part 31, so when a large current is passed through the first connecting tab 3 due to overcharge or an abnormal phenomenon, the first fusing part 33 can be fused in time to rapidly cut off the electrical connection of the first tab 21 with the first post 11, preventing the thermal runaway of the secondary battery; and after first fusing portion 33 melts, insulating holding block 5 can keep the relative position of first utmost point post connecting portion 31 and first utmost point ear connecting portion 32 fixed, prevent that first connection piece 3 from separating into independent two parts (first utmost point post connecting portion 31 and first utmost point ear connecting portion 32 promptly) in first fusing portion 33 melting department, first utmost point ear connecting portion 32 and first utmost point post connecting portion 31 contact when avoiding secondary battery to receive external impact (secondary battery receives when assaulting, electric core 2 takes place vibrations, thereby drive first utmost point ear connecting portion 32 through first utmost point ear 21 and remove, probably cause first utmost point ear connecting portion 32 and first utmost point ear connecting portion 31 overlap joint together), prevent that the circuit from communicateing once more, improve the security performance of battery.

In the secondary battery according to the present application, referring to fig. 9 to 14, the first pole connecting portion 31 and the first tab connecting portion 32 are each provided with a through fixing hole H; correspondingly, the insulating holding block 5 includes: a first holding portion 51 provided on one side of the first connecting piece 3 in the thickness direction T and having a fixing column 511 corresponding to the fixing hole H, the fixing column 511 extending to the other side of the first connecting piece 3 in the thickness direction T through the corresponding fixing hole H; and a second holding portion 52 provided on the other side of the first connecting piece 3 in the thickness direction T and fixedly connected to a fixing column 511 of the first holding portion 51 passing through the corresponding fixing hole H. The first holding portion 51 and the second holding portion 52 may be made of plastic.

In the secondary battery according to the present application, the insulating holding block 5 is fixedly connected to the first pole connecting portion 31 and the first tab connecting portion 32 by the engagement of the first holding portion 51 and the second holding portion 52. The second holding portion 52 can be fixedly connected to the fixing post 511 of the first holding portion 51 by heat fusion, interference fit, caulking, snap connection, adhesion, insertion, or the like, but is not limited to the above connection, as long as the fixing post 511 of the first holding portion 51 and the second holding portion 52 can be fixedly connected.

In the secondary battery according to the present application, the first pole connecting portion 31 and the first tab connecting portion 32 are each provided with a through fixing hole H; the insulating holding block 5 includes: the first holding portion 51 is disposed on one side of the first connecting piece 3 in the thickness direction T, and has a fixing column 511 corresponding to the fixing hole H, and the fixing column 511 penetrates through the corresponding fixing hole H and is fixedly connected to the first connecting piece 3. The first holding portion 51 may be made of plastic.

In the secondary battery according to the present application, the fixing posts 511 may be directly fixedly coupled to the first tab connecting portion 32 by means of heat fusion, interference fit, riveting, bonding, or the like, but are not limited to the above coupling manner.

In the secondary battery according to the present application, the fixing hole H is a waist hole. The fixing post 511 has a shape corresponding to the fixing hole H.

In the secondary battery according to the present application, referring to fig. 9 to 11, the fixing holes H are circular holes, and at least two fixing holes H are formed in the first pole tab connecting portion 31 and at least two fixing holes H are formed in the first pole tab connecting portion 32. The fixing post 511 has a shape corresponding to the fixing hole H. With the embodiment in which the fixed connection of the first pole tab connecting portion 31 and the first pole tab connecting portion 32 is achieved by the cooperation of the first holding portion 51 and the second holding portion 52, if there is only one fixing hole H in the first pole tab connecting portion 32 (or the first pole tab connecting portion 31) (that is, there is only one fixing post 511 passing through the first pole tab connecting portion 32), then when the first fusing portion 33 is fused, the secondary battery is subjected to an external impact, which may cause the first pole tab connecting portion 32 to rotate about the fixing post 511, thereby causing the first pole tab connecting portion 32 and the first pole tab connecting portion 31 to come into contact. In the embodiment in which the first tab 3 is directly fixed to the fixing post 511 of the first holding portion 51, one fixing hole H may be formed in the first pole connecting portion 31 and one fixing hole H may be formed in the first tab connecting portion 32.

In the secondary battery according to the present application, referring to fig. 10, the first fusing part 33 is formed by opening an opening 331 in the first connecting tab 3, and the opening 331 has sub fusing parts 332 at both sides in the width direction W, respectively. The first holding portion 51 may further have fixing posts 511 passing through the opening 331.

In the secondary battery according to the present application, referring to fig. 11, first fusing part 33 is provided with notches G on both sides in width direction W.

In the secondary battery according to the present application, the overcurrent sectional area of the first fusing part 33 is smaller than the first pole terminal connecting part 31 and the first tab connecting part 32 (by providing the opening 331 or the notch G), and therefore, when the first connecting tab 3 passes a large current, the first fusing part 33 can be fused in time to rapidly cut off the electrical connection of the first tab 21 and the first pole terminal 11, preventing the thermal runaway of the secondary battery.

In the secondary battery according to the present application, the number of the battery cells 2 is plural; correspondingly, referring to fig. 9 to 11, the first tab connection part 32 includes: two first tab connecting portions 321 extending along the length direction L, and each first tab connecting portion 321 is electrically connected to the first tab 21 of the corresponding battery cell 2; and a first tab collecting part 322 extending in the width direction W and having both ends connected to the two first tab connecting parts 321, respectively. The first pole connecting portion 31 is located between the two first tab connecting portions 321 and extends in the length direction L. The first fusing portion 33 extends in the longitudinal direction L and connects the first tab collecting portion 322 and the first pole connecting portion 31. The first connecting piece 3 is entirely planar.

In the secondary battery according to the present application, the extending direction and the arrangement manner of the two first tab connection portions 321 (the same as the extending direction of the first pole connection portion 31, and located on both sides of the first pole connection portion 31) can increase the contact area between the first tab 21 of the battery cell 2 and the corresponding first tab connection portion 321, thereby increasing the flow area.

In a secondary battery according to the present application, referring to fig. 4, the secondary battery further includes: two insulation strips 6 are respectively disposed in the gaps between the first pole connecting portion 31 and the corresponding first tab connecting portion 321, and each insulation strip 6 is not lower than the surface of the first connecting tab 3 connected to the first tab 21 (i.e., the surface of the first pole connecting portion 31 opposite to the main body 23 of the battery cell 2) in the thickness direction T. When the first tab 21 is excessively long, it may exceed the above gap in the width direction W and extend to the first pole connecting portion 31, thereby causing the first tab 21 to directly contact the first pole connecting portion 31, resulting in a failure of the first fusing portion 33; and through setting up the insulating strip 6 in above-mentioned clearance, and each insulating strip 6 is not lower than the surface of being connected with first utmost point ear 21 of first connection piece 3 in thickness direction T, so insulating strip 6 can play the effect of cutting off, prevents that first utmost point ear 21 from being connected with first utmost point post connecting portion 31 electricity (if each insulating strip 6 is on thickness direction T and the surface of being connected with first utmost point ear 21 of first connection piece 3 are flush, then insulating strip 6 can avoid first utmost point ear 21 to constitute the lateral wall electricity of clearance with first utmost point post connecting portion 31 and be connected, and if each insulating strip 6 exceeds the surface of being connected with first utmost point ear 21 of first connection piece 3 in thickness direction T, can further avoid the surface contact of first utmost point ear 21 and first utmost point post connecting portion 31 relative with main part 23 of electric core 2). It is also supplemented that the above-mentioned "not lower" and "exceeding" are directed to the thickness direction T shown in fig. 4, in other words, each of the insulating strips 6 is flush with or protrudes toward the battery cell 2 with respect to the first connecting piece 3 after the secondary battery is actually molded.

In a secondary battery according to the present application, referring to fig. 4, 9 and 10, the secondary battery further includes: and an insulating patch 7 that is attached to a surface of the first connection tab 3 that faces the battery cell 2 (main body 23), and covers at least edges of both sides of the first pole connection portion 31 in the width direction W. When the first tab 21 is too long, it may exceed the above gap in the width direction W and extend to the corresponding edge of the first pole connecting portion 31 in the width direction W, thereby causing the first tab 21 to directly contact the first pole connecting portion 31, resulting in failure of the first fusing portion 33; the insulating patches 7 cover at least both side edges of the first pole connecting portion 31 in the width direction W, so that the first tab 21 and the first pole connecting portion 31 can be separated from each other, and the first tab 21 and the first pole connecting portion 31 can be prevented from being electrically connected.

In the secondary battery according to the present application, referring to fig. 7 and 8, the first tab 21 has: a connection section 211, the outer side of which is fixedly connected to the first tab connection part 32; and a bending section 212 which is bent and connected with the main body 23 of the battery cell 2 and the connecting section 211, wherein an included angle formed by the connecting section 211 and the bending section 212 is less than 120 °.

In the secondary battery according to the present application, referring to fig. 8, the connection section 211 and the bent section 212 form an angle of 85 ° to 95 °. At this time, the bent section 212 extends approximately in the thickness direction T, and short circuit caused by the pressing of the bent section 212 can be prevented.

In the secondary battery according to the present application, referring to fig. 7, the connection section 211 and the bent section 212 form an angle of 0 ° to 45 °. At this time, the bending section 212 is approximately folded back to the connection section 211, so that the space occupied by the first tab 21 is effectively reduced, and the space utilization rate inside the secondary battery is improved.

In the secondary battery according to the present application, referring to fig. 7 and 8, an insulating paste S is pasted at least on a portion of the inside of the connection segment 211 directly opposite to the main body 23 of the battery cell 2. When the top cover 1 is assembled with a casing (not shown) for accommodating the battery cell 2, the first tab 21 is pressed, so that the connection section 211 of the first tab 21 (especially the part of the connection section 211 directly opposite to the main body 23 of the battery cell 2) is easily caused to directly contact with the main body 23 of the battery cell 2 (the pole piece with the opposite polarity to the first tab 21), thereby causing a short circuit; and through setting up insulating cement S, can avoid electric core 2 short circuit, improve secondary battery' S security performance.

In the secondary battery according to the present application, referring to fig. 7 and 8, it is preferable that the insulating paste S is entirely pasted inside the connection section 211 and inside the bending section 212.

In the secondary battery according to the present application, referring to fig. 7 and 8, an insulating paste S is pasted to the outer side of the bent section 212. When the top cover 1 is assembled with a casing (not shown) accommodating the battery cell 2, the first tab 21 is pressed to be bent, and the outer side of the bent section 212 is easily contacted with the casing, so that a short circuit is caused; and the insulating glue S is pasted on the outer side of the bending section 212, so that the short circuit of the battery core 2 can be avoided, and the safety performance of the secondary battery is improved.

In a secondary battery according to the present application, referring to fig. 4 to 8, the secondary battery further includes: a welding protection sheet 8 disposed on the first tab 21; the weld protective sheet 8, the connection segment 211 of the first tab 21, and the first tab connection portion 32 are fixedly connected together by ultrasonic welding. The weld protector sheet 8 can improve the connection strength between the connection segment 211 of the first tab 21 and the first tab connection portion 32. The welding seal formed by ultrasonic welding can be adhered with insulating gummed paper. Insulating gummed paper can fix the metal fillings that produce among the welding process, prevents to get into inside the metal fillings gets into electric core 2, simultaneously, can also play insulating effect, prevents electric core 2 internal short circuit.

In a secondary battery according to the present application, referring to fig. 4 and 5, the secondary battery further includes: and a second connecting piece 4 connected in series between the second pole lug 22 and the second pole column 12.

In the secondary battery according to the present application, referring to fig. 4 and 5, the second connection piece 4 has: a second pole connecting portion 41 electrically and fixedly connected to the second pole 12; and a second tab connection portion 42 electrically and fixedly connected to the second tab 22 of the cell 2.

In the secondary battery according to the present application, referring to fig. 4 and 5, the battery cell 2 is plural. Correspondingly, the second tab connecting portion 42 includes: two second tab connecting portions 421 extending along the length direction L, wherein each second tab connecting portion 421 is electrically connected to a corresponding second tab 22 of the electrical core 2; and a second tab collecting portion 422 extending in the width direction W and having two ends connected to the two second tab connecting portions 421, respectively. The second pole connecting portion 41 is located between the two second pole ear connecting portions 421, and extends to the second pole ear collecting portion 422 along the length direction L.

In the secondary battery according to the present application, the extending direction and arrangement of the two second pole ear connection parts 421 (which are located on both sides of the second pole leg connection part 41 in the same direction as the second pole leg connection part 41 extends) can increase the contact area between the second pole ear 22 of the battery cell 2 and the corresponding second pole ear connection part 421, thereby increasing the flow area.

In the secondary battery according to the present application, the secondary battery further includes: a welding protection sheet 8 arranged on the second tab 22; the weld protective sheet 8, the second tab 22, and the second tab connecting portion 421 are fixedly joined together by ultrasonic welding. The welding seal formed by ultrasonic welding can be adhered with insulating gummed paper. Insulating adhesive tape can fix the metal fillings that produce among the welding process, prevents to get into the bits and gets into inside electric core 2, simultaneously, can also play insulating effect, prevents electric core 2 internal short circuit.

In the secondary battery according to the present application, the first pole connecting portion 31 and the first pole 11 are fixedly connected together by laser welding, and the second pole connecting portion 41 and the second pole 12 are fixedly connected together by laser welding. The welding seal formed by laser welding can be adhered with insulating gummed paper. Insulating adhesive tape can fix the metal fillings that produce among the welding process, prevents to get into the bits and gets into inside electric core 2, simultaneously, can also play insulating effect, prevents electric core 2 internal short circuit.

The present application also provides an assembly for a secondary battery including a first connection tab and an insulating retention block. The first connecting sheet is provided with a first pole connecting part, a first tab connecting part and a first fusing part connected in series between the first pole connecting part and the first tab connecting part, and two ends of the first fusing part are fixedly connected with the first pole connecting part and the first tab connecting part respectively. Two ends of the insulating holding block are respectively fixedly connected with the first pole connecting part and the first pole lug connecting part. After the first fusing part fuses, the insulating holding block can keep the relative position of the first pole connecting part and the first pole lug connecting part fixed. All be equipped with the fixed orifices that link up on first utmost point post connecting portion and the first utmost point ear connecting portion.

The insulation holding block includes: the first holding part is arranged on one side of the first connecting sheet in the thickness direction and is provided with a fixing column corresponding to the fixing hole, and the fixing column penetrates through the corresponding fixing hole and extends to the other side of the first connecting sheet in the thickness direction; and the second holding part is arranged on the other side of the first connecting sheet in the thickness direction and is fixedly connected with the fixing column of the first holding part, which penetrates through the corresponding fixing hole.

In some embodiments, the second retaining portion is fixedly connected to the fixing post of the first retaining portion by heat fusion, interference fit, riveting, snap connection, bonding, or plugging.

In some embodiments, the fixation holes are kidney holes.

In some embodiments, the fixing holes are circular holes, and at least two fixing holes are formed in the first pole connecting portion and at least two fixing holes are formed in the first pole tab connecting portion.

In some embodiments, the first fusing part is formed by opening an opening on the first connection tab, and the opening has sub fusing parts at both sides in the width direction, respectively.

In some embodiments, the first fusing part is provided with notches at both sides in the width direction.

In some embodiments, the first tab connection part has: two first tab connecting portions extending in a length direction; and the first tab collecting part extends along the width direction, and two ends of the first tab collecting part are respectively connected with the two first tab connecting parts. The first pole connecting portion is located between the two first pole tab connecting portions and extends in the length direction. The first fusing part extends along the length direction and is connected with the first tab collecting part and the first pole connecting part.

In some embodiments, the assembly for a secondary battery further includes: and the insulating patches are pasted on the surface of the first connecting sheet and at least cover the edges of the two sides of the first pole connecting part in the width direction.

In some embodiments, the first connecting piece is entirely planar.