阅读说明：本技术 一种二次电池 (Secondary battery ) 是由 陈圣立 姜斌 邹武元 张瑞朋 于 2021-08-13 设计创作，主要内容包括：本发明属于电池生产制造的技术领域,具体涉及一种二次电池,包括极耳连接件和汇流件,所述极耳连接件与所述汇流件固定连接；所述极耳连接件包括本体部和连接部,所述本体部位于所述电芯的本体件沿横向X的一侧并沿高度方向Z延伸,所述连接部从所述本体部沿纵向Y的两侧延伸并向所述本体部回折,所述连接部在高度方向Z上错位设置并用于与所述极耳连接；所述汇流件包括用于与所述极柱连接的极柱连接部。本发明省去了激光焊接,有助于降低焊渣造成内短路的风险。(The invention belongs to the technical field of battery production and manufacture, and particularly relates to a secondary battery which comprises a tab connecting piece and a bus piece, wherein the tab connecting piece is fixedly connected with the bus piece; the tab connecting piece comprises a body part and a connecting part, the body part is positioned on one side of the body part of the battery cell along the transverse direction X and extends along the height direction Z, the connecting part extends from the body part along the two sides of the body part along the longitudinal direction Y and is folded back towards the body part, and the connecting part is arranged in a staggered mode in the height direction Z and is used for being connected with a tab; the confluence piece comprises a pole connecting part used for being connected with the pole. The invention omits laser welding and is beneficial to reducing the risk of internal short circuit caused by welding slag.)

1. A secondary battery comprising:

a housing provided with an opening;

a top cover sheet (5) for closing the opening and provided with a pole (51);

a plurality of cells (6) within the housing, the cells (6) comprising a body member and tabs (61) extending from the body member in a transverse direction (X);

the novel pole ear collector is characterized by comprising a pole ear connecting piece (10) and a bus piece (4), wherein the pole ear connecting piece (10) is fixedly connected with the bus piece (4);

the tab connecting piece (10) comprises a body part (1) and a connecting part (2), wherein the body part (1) is positioned on one side of the battery cell (6) in the transverse direction (X) and extends in the height direction (Z), the connecting part (2) extends from the body part (1) in the longitudinal direction (Y) and is folded back towards the body part (1), and the connecting part (2) is arranged in a staggered mode in the height direction (Z) and is used for being connected with a tab (61);

the bus bar (4) comprises a pole connection (41) for connection with the pole (51).

2. A secondary battery as claimed in claim 1, wherein: the connecting parts (2) do not overlap.

3. A secondary battery as claimed in claim 1, wherein: the tab (61) is connected along the outer surface of the connecting part (2) in a bending way.

4. A secondary battery as claimed in claim 3, wherein: the tab connection piece (10) further comprises a first electric switching part (3) extending from the body part (1) to one side of the longitudinal direction (Y) and turning back to the body part (1), and the bus bar piece (4) further comprises a second electric switching part (42) embedded into the first electric switching part (3) and the body part (1).

5. A secondary battery as claimed in claim 4, wherein: the second electric adapter part (42) is connected along the inner surface of the first electric adapter part (3) in a bending mode.

6. A secondary battery as claimed in claim 5, wherein: the pole connecting part (41) extends along the transverse direction (X), and the pole connecting part (41) and the second electric transfer part (42) are integrally formed.

7. A secondary battery as claimed in claim 5, wherein: the pole connecting part (41) extends along the transverse direction (X) and is bent towards the height direction (Z), and the pole connecting part (41) and the second electric switching part (42) are integrally formed.

8. A secondary battery as claimed in claim 7, wherein: the pole connecting part (41) is bent towards the height direction (Z) and the orthographic projection of the connecting part (2) on a plane formed by the height direction (Z) and the longitudinal direction (Y) is not overlapped.

9. A secondary battery as claimed in any one of claims 1 to 8, wherein: the number of the pole ear connecting pieces (10) is at least 2.

10. A secondary battery as claimed in any one of claims 1 to 8, wherein: the pole (51) and the confluence piece (4) are of an integrally formed structure.

Technical Field

The invention belongs to the technical field of battery production and manufacturing, and particularly relates to a secondary battery.

Background

Nowadays, green, high-efficiency secondary batteries are vigorously developed in various countries. The lithium ion battery as a novel secondary battery has the advantages of large energy density and power density, high working voltage, light weight, small volume, long cycle life, good safety, environmental protection and the like, and has wide application prospect in the aspects of portable electric appliances, electric tools, large-scale energy storage, electric traffic power supplies and the like. In the long battery cell in the industry at present, in order to improve the energy density, a winding structure of a tab at the top end is generally changed into a winding structure of a tab at the side edge; the new winding structure requires the connection of the top cover to the bare cell to be changed.

According to the existing scheme, a bare cell lug and a protection plate are subjected to ultrasonic welding leveling and then are subjected to laser welding with a pin, and welding slag generated by laser welding in the scheme is difficult to avoid falling into a bare cell; and the pins are adopted for ultrasonic welding directly with the lugs of the naked electric core, and then the pins are bent to reduce the space occupied longitudinally.

Disclosure of Invention

The invention aims to: aiming at the defects of the prior art, the secondary battery is provided, the laser welding is omitted, and the risk of internal short circuit caused by welding slag is favorably reduced.

In order to achieve the purpose, the invention adopts the following technical scheme:

a secondary battery includes a case provided with an opening; the top cover plate is used for sealing the opening and is provided with a pole; a plurality of cells positioned within the housing, the cells including a body member and tabs extending laterally X from the body member; the device also comprises a tab connecting piece and a confluence piece, wherein the tab connecting piece is fixedly connected with the confluence piece; the tab connecting piece comprises a body part and a connecting part, the body part is positioned on one side of the body part of the battery cell along the transverse direction X and extends along the height direction Z, the connecting part extends from the body part along the two sides of the body part along the longitudinal direction Y and is folded back towards the body part, and the connecting part is arranged in a staggered mode in the height direction Z and is used for being connected with a tab; the confluence piece comprises a pole connecting part used for being connected with the pole.

Preferably, the connecting portions do not overlap.

Preferably, the tabs are connected along the outer surface of the connecting portion in a bending manner.

Preferably, the tab connector further includes a first electrical adaptor portion extending from the body portion to one side in the longitudinal direction Y and folded back toward the body portion, and the bus bar further includes a second electrical adaptor portion embedded in the first electrical adaptor portion and the body portion.

Preferably, the second electrical connector is bent along an inner surface of the first electrical connector.

Preferably, the post connecting portion extends along a transverse direction X, and the post connecting portion and the second electrical transfer portion are integrally formed.

Preferably, the post connecting portion extends along the transverse direction X and bends toward the height direction Z, and the post connecting portion and the second electrical transfer portion are integrally formed.

Preferably, the pole connecting portion is bent in the height direction Z, and the connecting portion does not overlap with an orthogonal projection on a plane formed by the height direction Z and the longitudinal direction Y.

Preferably, the pole and the confluence piece are of an integrally formed structure.

Preferably, the number of the tab connectors is at least 2.

The invention has the beneficial effects that the invention comprises a shell which is provided with an opening; the top cover plate is used for sealing the opening and is provided with a pole; a plurality of cells positioned within the housing, the cells including a body member and tabs extending laterally X from the body member; the device also comprises a tab connecting piece and a confluence piece, wherein the tab connecting piece is fixedly connected with the confluence piece; the tab connecting piece comprises a body part and a connecting part, the body part is positioned on one side of the body part of the battery cell along the transverse direction X and extends along the height direction Z, the connecting part extends from the body part along the two sides of the body part along the longitudinal direction Y and is folded back towards the body part, and the connecting part is arranged in a staggered mode in the height direction Z and is used for being connected with a tab; the confluence piece comprises a pole connecting part used for being connected with the pole. Because the lug of the bare cell and the protection plate are subjected to ultrasonic welding leveling and then are subjected to laser welding with the pin in the conventional scheme, welding slag generated by the laser welding in the scheme is difficult to avoid falling into the bare cell; the scheme also adopts the ultrasonic welding of the pins directly and the lugs of the naked electric core, and then the pins are bent to reduce the space occupied longitudinally, the thickness of the naked electric core is required to be large enough, so that a welding head or a welding seat for the ultrasonic welding can extend between the two pins, therefore, a connecting part bent relative to the body part is arranged on the body part, when the lug connecting piece is connected with the electric core and the lug connecting piece is positioned relative to the lug, the lug can be fixedly connected with the lug under the state that the surface of the connecting part and the surface of the body part form a preset angle, namely, the lug is ultrasonically welded with the upright connecting part, because the lug is not stacked at the moment, the welding plane of the connecting part and the lug is vertical to the end surface of the electric core, the ultrasonic welding head and the welding seat are not influenced by the distance between the lugs of the stacked electric cores, and after the ultrasonic welding, the lug and the upright connecting part are bent by the preset angle, so that the lug is flush with the end surface of the electric core, the space occupied at the two ends of the battery core is reduced, the tab can be folded, so that the size of the secondary battery is reduced, the difficulty of the battery in a bending connection structure process is improved, in addition, the tab connecting piece can separate the tab from the end surface of the battery core, the probability of short circuit is reduced, wherein the tab does not participate in fixing and positioning the battery core, and the tab can be effectively protected from being damaged; the connecting part is formed by extending from the body part and is bent relative to the body part, so that a rotating device is omitted, the size of the battery is reduced, laser welding is omitted, and the problem of short circuit in the battery caused by welding slag is solved; after the lug connecting piece is installed, the pole connecting part on the confluence piece is used for connecting the poles of the battery, so that the electric connection between the poles of the battery and the lugs is realized, and the confluence piece can be connected with a plurality of electric cores, thereby being beneficial to improving the overall energy density of the battery. The invention omits laser welding and is beneficial to reducing the risk of internal short circuit caused by welding slag.

Drawings

Features, advantages and technical effects of exemplary embodiments of the present invention will be described below with reference to the accompanying drawings.

Fig. 1 is a schematic structural view of a tab connector according to the present invention.

Fig. 2 is a schematic structural view of a tab connector of the present invention before welding.

Fig. 3 is a schematic structural view of a tab connector of the present invention after welding.

Fig. 4 is a schematic structural view of the bus bar of the present invention.

Fig. 5 is a schematic structural view of the present invention before the bus bar is not mounted.

Fig. 6 is a schematic structural view of a bus bar of the present invention before welding.

Fig. 7 is a schematic structural view of the bus bar of the present invention after welding.

Fig. 8 is a schematic structural diagram of a battery having four battery cells according to the present invention.

Fig. 9 is a schematic structural diagram of a battery having six cells according to the present invention.

Fig. 10 is a schematic view of the connection of a bus bar and a top cover sheet according to one embodiment of the present invention.

Fig. 11 is a schematic view showing the connection of a bus bar and a top cover sheet according to another embodiment of the present invention.

Wherein the reference numerals are as follows:

1-a body portion; 10-tab connection;

2-a connecting part;

3-a first electrical transfer section;

4-a junction piece; 41-pole connecting part; 42-a second electrical junction; 421-notch;

5-top cover sheet; a 51-pole; 511-a recessed structure;

6-electric core; 61-a tab;

z-height direction; y-longitudinal direction; x-transverse direction.

Detailed Description

As used in the specification and in the claims, certain terms are used to refer to particular components. As one skilled in the art will appreciate, manufacturers may refer to a component by different names. This specification and claims do not intend to distinguish between components that differ in name but not function. In the following description and in the claims, the terms "include" and "comprise" are used in an open-ended fashion, and thus should be interpreted to mean "include, but not limited to. "substantially" means within an acceptable error range, and a person skilled in the art can solve the technical problem within a certain error range to substantially achieve the technical effect.

Furthermore, the terms "first," "second," and the like are used for descriptive purposes only and are not to be construed as indicating or implying relative importance.

In the present invention, unless otherwise expressly specified or limited, the terms "mounted," "connected," "secured," and the like are to be construed broadly and can, for example, be fixedly connected, detachably connected, or integrally connected; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meanings of the above terms in the present invention can be understood by those skilled in the art according to specific situations.

The present invention will be described in further detail with reference to fig. 1 to 11, but the present invention is not limited thereto.

A secondary battery including a case provided with an opening; a top cover 5 for closing the opening and provided with a pole 51; a plurality of cells 6 positioned within the housing, the cells 6 including a body member and tabs 61 extending in a transverse direction X from the body member; the device comprises a tab connecting piece 10 and a bus piece 4, wherein the tab connecting piece 10 is fixedly connected with the bus piece 4; the tab connecting piece 10 comprises a body part 1 and a connecting part 2, wherein the body part 1 is positioned on one side of the cell 6 along the transverse direction X and extends along the height direction Z, the connecting part 2 extends from the body part 1 along the two sides along the longitudinal direction Y and is folded back towards the body part 1, and the connecting part 2 is arranged in a staggered manner in the height direction Z and is used for being connected with a tab 61; the bus bar 4 comprises a pole connection 41 for connection with a pole 51.

Because the lug of the bare cell and the protection plate are subjected to ultrasonic welding leveling and then are subjected to laser welding with the pin in the conventional scheme, welding slag generated by the laser welding in the scheme is difficult to avoid falling into the bare cell; the scheme also adopts the ultrasonic welding of the pins directly and the lugs of the naked electric core, and then the pins are bent to reduce the space occupied longitudinally, the proposal requires that the thickness of the naked electric core is large enough, so that a welding head or a welding seat for the ultrasonic welding can extend between the two pins, therefore, the connecting part 2 bent relative to the body part 1 is arranged on the body part 1, when the lug connecting piece 10 is connected with the electric core 6, and after the position of the lug connecting piece 10 relative to the lug 61 is determined, the lug can be fixedly connected with the lug 61 under the state that the surfaces of the connecting part 2 and the body part 1 form a preset angle, namely, the lug 61 is ultrasonically welded with the upright connecting part 2, because the lug 61 is not stacked at the moment, the welding plane of the connecting part 2 and the lug 61 is vertical to the end surface of the electric core 6, the ultrasonic welding head and the welding seat are not influenced by the distance between the lugs 61 of the stacked electric core 6, and after the ultrasonic welding, the lug 61 and the upright connecting part 2 are bent by the preset angle, the tab 61 is flush with the end surface of the battery cell 6, the space occupied at the two ends of the battery cell 6 is reduced, the tab 61 can be folded back, the size of the secondary battery is reduced, the difficulty of the battery in the bending connection structure process is improved, in addition, the tab connecting piece 10 can separate the tab 61 from the end surface of the battery cell 6, the probability of short circuit is reduced, wherein the tab 61 does not participate in fixing and positioning the battery cell 6, and the tab 61 can be effectively protected from being damaged; the connecting part 2 is formed by extending from the body part 1 and is bent relative to the body part 1, so that a rotating device is omitted, the size of the battery is reduced, laser welding is omitted, and the problem of short circuit in the battery caused by welding slag is solved; after the tab connection member 10 is installed, the pole 51 of the battery is connected through the pole connection portion 41 on the confluence member 4, so that the pole 51 of the battery and the tab 61 are electrically connected, and the confluence member 4 can be connected with a plurality of battery cells 6, thereby being beneficial to improving the energy density of the whole battery.

In some embodiments, the bus bar 4 comprises a pole connection portion 41 and a second electrical transition portion 42, the pole connection portion 41 being perpendicular to the second electrical transition portion 42 for connecting the pole 51 of the battery, the second electrical transition portion 42 being provided with an indentation 421 cooperating with the connection portion 2, the end of the pole connection portion 41 and the second electrical transition portion 42 forming a U-shaped or claw-shaped like structure. In this embodiment, the junction member 4 is divided into the pole connecting portion 41 and the second electrical transferring portion 42, the second electrical transferring portion 42 is parallel to the end surface of the battery cell 6, i.e. flush with the plane of the body portion 1, the second electrical transferring portion 42 is fixedly connected with the first electrical transferring portion 3 to realize the fixed connection between the junction member 4 and the tab connection member 10, and meanwhile, the pole connecting portion 41 is perpendicular to the second electrical transferring portion 42 to connect the pole 51 of the battery.

In the present embodiment, the body portion 1 and the connection portions 2 are both plate-shaped structures, and the number of the connection portions 2 is 2, but the present invention is not limited thereto, and the number of the connection portions 2 may be adjusted according to the number of the actual battery cells 6; the tabs 6 at the same end of the battery cell 6 are both positive electrodes, and may also be both negative electrodes.

In the secondary battery according to the present invention, the connection parts 2 do not overlap. Specifically, two adjacent connecting portions 2 stagger in direction of height X and set up, two adjacent connecting portions 2 do not overlap, two adjacent connecting portions 2 are all perpendicular to this somatic part 1 before ultrasonic welding, be convenient for carry out ultrasonic welding with connecting portion 2 and utmost point ear 61, and simultaneously, two connecting portions 2 all can be behind ultrasonic welding, utmost point ear 61 is connected along the surface buckling of connecting portion 2, utmost point ear 61 exposes outside, connecting portion 2 presss from both sides between the terminal surface of utmost point ear 61 and electric core 6, play the effect of interval utmost point ear 61 and electric core 6.

In the secondary battery according to the present invention, the tab connector 10 further includes a first electrical relay portion 3 extending from the body portion 1 to one side in the longitudinal direction Y and folded back toward the body portion 1, and the bus bar 4 further includes a second electrical relay portion 42 embedded in the first electrical relay portion 3 and the body portion 1. The connecting portion 2 is provided with a bendable first electrical switching portion 3 on one side opposite to the longitudinal direction Y, the tab connecting member 10 is conveniently connected with the pole 51 of the battery by adding the first electrical switching portion 3, the area of the first electrical switching portion 3 is large, the welding area of the first electrical switching portion 3 and the pole 51 is increased, and the stability between the first electrical switching portion 3 and the pole 51 is improved. Wherein, first electricity switching part 3 can buckle, can be after first electricity switching part 3 and the piece 4 fixed connection that converges, and partly converge piece 4 and first electricity switching part 3 buckle, and second electricity switching part 42 is connected along the internal surface bending type of first electricity switching part 3 promptly, helps reducing the space that occupies the battery top to improve the energy density of battery.

In some embodiments, the pole connecting portion 41 extends along the transverse direction X, and the pole connecting portion 41 and the second electrical transferring portion 42 are integrally formed, so that the process of welding the pole connecting portion 41 and the second electrical transferring portion 42 is omitted, the mechanical strength of the whole tab connection member 10 can be improved, and the service life of the battery can be prolonged.

In some embodiments, the post connecting portion 41 extends along the transverse direction X and is bent towards the height direction Z, the post connecting portion 41 and the second electrical transfer portion 42 are integrally formed, the second electrical transfer portion 42 is equivalent to a strip-shaped structure extending outwards from the end portion of the post connecting portion 41, and an integrally formed structure is adopted, so that a welding process is omitted, and the assembly efficiency of the battery is improved.

In addition, the portion of the pole connection portion 41 bent in the height direction Z does not overlap with the orthographic projection of the connection portion 2 on the plane formed by the height direction Z and the longitudinal direction Y, and the portion of the connection portion 2 bent in the transverse direction X is prevented from colliding with the tab 61.

In the secondary battery according to the present invention, the body part 1 has an L-shaped structure. Specifically, before ultrasonic bonding, body portion 1 and first electricity switching portion 3 constitute similar L type structure, and connecting portion 2 is in the state of standing, and connecting portion 2 perpendicular to body portion 1 promptly, after accomplishing the welding, connecting portion 2 and first electricity switching portion 3 all can be buckled into and level with the terminal surface of electric core 6, reduce the space that occupies at the both ends of electric core 6.

In the secondary battery according to the present invention, the body part 1, the connection part 2, and the first electrical connection part 3 are integrally formed, so that a process of welding the connection part 2 and the first electrical connection part 3 is omitted, and the mechanical strength of the entire tab connection member 10 can be improved, thereby prolonging the service life of the battery.

The bending angle of the connection portion 2 of the present embodiment is 0 ° to 180 °. In this embodiment, the angle of the connecting portion 2 before and after ultrasonic welding can be adjusted according to the actual battery structure, the angle of the connecting portion 2 before welding is preferably 90 °, and the angle of the connecting portion 2 after welding can be satisfied to reduce the occupied space.

In some embodiments, a plurality of battery cells 6 are located in the housing, and the battery cells 6 are provided with tabs 61 at both ends in the transverse direction Z; the connection portion 2 is electrically connected to the tab 61. Specifically, a plurality of electric cores 6 pile up in proper order, and every electric core 6 forms positive pole ear and negative pole ear respectively at horizontal Z's both ends, and connecting portion 2 can be connected with the positive pole ear or the negative pole ear with one side, and utmost point post 51 electricity through converging piece 4 and top plate 5 is connected. In the present embodiment, the number of the battery cells 6 is 4 or more than 4.

In some embodiments, as shown in fig. 10, the pole 51 and the current collecting piece 4 are integrally formed, so as to omit welding the pole 51 and the current collecting piece 4, wherein the pole 51 is a cylindrical structure, and the current collecting piece 4 is a plate structure, in other embodiments, as shown in fig. 11, the current collecting piece 4 is arranged around the bottom of the pole 51, and the bottom of the pole 51 is provided with a concave structure 511, so that the material of the pole 51 can be saved, the production cost can be reduced, the overall weight of the battery can be reduced, and the battery can be lightened.

In some embodiments, referring to fig. 9, the number of the battery cells 6 is six, the six battery cells are stacked in sequence, the bus bar 4 can be replaced to match with the tab 61 on one side of the six battery cells 6, the bus bar 4 has a plurality of second electrical connectors 42, the second electrical connectors 42 form a claw-like structure, one end of the claw-like structure is connected to the post connecting portion 41 to perform the function of bus bar, and the other end of the claw-like structure is fixedly connected to the first electrical connector 3 to achieve the fixed connection between the bus bar 4 and the tab connecting portion 10, that is, to achieve the electrical connection with the tab 61.

In some embodiments, the tab 61 is bent along the outer surface of the connection part 2 and exposed outside the body part 1. Specifically, utmost point ear 61 is buckled along the surface of connecting portion 2 and is connected, the angle of buckling is 90, utmost point ear 61 does not cover, connecting portion 2 presss from both sides between utmost point ear 61 and electric core 6's terminal surface, play the effect of interval utmost point ear 61 and electric core 6, avoid utmost point ear 61 to insert electric core 6 upside down, arouse the condition of the inside short circuit of battery, simultaneously, the arc after the surface bending of connecting portion 2 can be laminated with utmost point ear 61 better, utmost point ear 61 actually buckles the angle less, avoid utmost point ear 61 to receive the damage when buckling.

In the battery according to the present invention, the tabs 61 of two adjacent battery cells 6 are arranged in a staggered manner or symmetrically. In this embodiment, the 4 battery cells 6 are arranged together, the tabs 61 of the two battery cells 6 in the middle are symmetrically arranged and are matched with the notch 421 of the second electrical adapter 42, and the tabs of the battery cells 6 on both sides and the tabs of the battery cell 6 in the middle are arranged in a staggered manner, so that a certain safety distance is kept between the tabs 61, but the present invention is not limited thereto, and the arrangement mode of the tabs 61 of the plurality of battery cells 6 can be adjusted according to the actual battery structure.

The second electrical transfer portion 42 is provided with a notch 421 matched with the connecting portion 2, so that the bus bar 4 is prevented from influencing the connection between the connecting portion 2 and the tab 61, the probability of short circuit inside the battery is reduced, and preferably, the end portion of the terminal connecting portion 41 and the second electrical transfer portion 42 form a similar U-shaped structure or a claw-shaped structure.

The number of the tab connecting pieces 10 is at least 2.

The working principle of the invention is as follows:

the connecting part 2 which is bent relative to the body part 1 is arranged on the body part 1, when the tab connecting part 10 is connected with the battery cell 6, and after the position of the tab connecting part 10 relative to the tab 61 is determined, the connecting part 2 and the surface of the body part 1 form a preset angle, the tab 61 can be fixedly connected with the tab 61, namely, the tab 61 and the upright connecting part 2 can be welded in an ultrasonic mode, because the tab 61 is not stacked at the moment, the welding plane of the connecting part 2 and the tab 61 is perpendicular to the end surface of the battery cell 6, the ultrasonic welding head and the welding seat are not influenced by the distance between the tabs 61 of the stacked battery cells 6, and after the ultrasonic welding, the tab 61 and the upright connecting part 2 are bent by the preset angle, so that the tab 61 is flush with the end surface of the battery cell 6, the space occupied by the two ends of the battery cell 6 is reduced, because the tab 61 can be folded back, the size of the secondary battery is reduced, and the difficulty of the battery in the bending connection structure process is improved, in addition, the tab connecting piece 10 can separate the tab 61 from the end surface of the battery cell 6, so as to reduce the probability of short circuit, wherein the tab 61 does not participate in fixing and positioning the battery cell 6, so that the tab 61 can be effectively protected from being damaged; the connecting part 2 is formed by extending from the body part 1 and is bent relative to the body part 1, so that a rotating device is omitted, the size of the battery is reduced, laser welding is omitted, and the problem of short circuit in the battery caused by welding slag is solved.

Referring to fig. 1 to 7, the specific installation steps are as follows:

1) after the battery cell 6 and the tab connecting piece 10 are positioned after being wound, the tab 61 and the connecting part 2 erected by the tab connecting piece 10 are ultrasonically welded; at the moment, because the lugs 61 are not stacked, the ultrasonic welding head and the welding seat are not influenced by the distance between the lugs 61 of the stacked electric core 6;

2) after ultrasonic welding, the connecting part 2 between the tab 61 and the tab connecting piece 10 is bent for 90 degrees;

3) another battery cell 6 of mirror symmetry is stacked together.

4) After the stacked battery cell and the first electrical switching part 3 are positioned, the first electrical switching part 3 and the second electrical switching part 42 are subjected to ultrasonic welding, and the welding position transversely protrudes out of the entity of the battery cell 6 at the moment, so that the interference of a welding head, a welding seat and the battery cell 6 does not exist;

5) the first electrical transition 3 and the second electrical transition 42 after welding are bent 180 °.

Variations and modifications to the above-described embodiments may also occur to those skilled in the art, which fall within the scope of the invention as disclosed and taught herein. Therefore, the present invention is not limited to the above-mentioned embodiments, and any obvious improvement, replacement or modification made by those skilled in the art based on the present invention is within the protection scope of the present invention. Furthermore, although specific terms are employed herein, they are used in a generic and descriptive sense only and not for purposes of limitation.