CN113346200A

CN113346200A - Connection piece, battery cell and battery package

Info

Publication number: CN113346200A
Application number: CN202110719426.2A
Authority: CN
Inventors: 吴玉源; 周龙; 郭敏
Original assignee: Xiamen Haichen New Energy Technology Co Ltd
Current assignee: Xiamen Haichen New Energy Technology Co Ltd
Priority date: 2021-06-28
Filing date: 2021-06-28
Publication date: 2021-09-03

Abstract

The application provides a connection piece, battery cell and battery package relates to lithium ion battery technical field. The connection piece includes interconnect's the utmost point post district that is used for being connected with utmost point post and is used for the first utmost point ear district of being connected with multilayer utmost point ear, and first utmost point ear district has the first end of being connected with utmost point post district and keeps away from utmost point post district's second end to the size of the direction of the first end of perpendicular to second end is the width, and along the direction of first end to second end, the width in first utmost point ear district reduces gradually. Can weld the multilayer utmost point ear on the connection piece through the mode of limit welding or side welding, and the width in first utmost point ear district reduces from the direction of first end to second end gradually, can enough reduce the material of switching piece, can satisfy the ability of overflowing of switching piece again, can also guarantee the effective welding of multilayer utmost point ear.

Description

Connection piece, battery cell and battery package

Technical Field

The application relates to the technical field of lithium ion batteries, in particular to a connecting sheet, a single battery and a battery pack.

Background

Generally, a lithium ion battery cell includes a case, a cap assembly, and two cell assemblies, each having a multi-layered positive electrode tab and a multi-layered negative electrode tab. In order to lead out the current generated by the battery core, the multilayer positive electrode tabs of the two battery core assemblies are welded at two ends of the positive electrode soft connecting sheet, and the positive electrode soft connecting sheet is welded with the positive electrode pole of the top cover assembly; and welding the multilayer negative electrode tabs of the two electrode assembly components at two ends of the negative electrode flexible connecting sheet, welding the negative electrode flexible connecting sheet with the negative electrode pole of the top cover assembly, and then leading out the current through the positive electrode pole and the negative electrode pole on the top cover assembly.

Fig. 1 is a schematic structural diagram of a flexible connecting sheet in the prior art. Referring to fig. 1, taking an anode flexible connecting sheet as an example, the flexible connecting sheet includes a terminal connecting region 10, a first terminal tab connecting region 21 and a second terminal tab connecting region 22, the first terminal tab connecting region 21 and the second terminal tab connecting region 22 are both connected to the terminal connecting region 10, and the first terminal tab connecting region 21 and the second terminal tab connecting region 22 are both square and spaced apart from each other by a distance. In order to weld the first tab connection area 21 to the multi-layer tab of one electrode assembly, the second tab connection area 22 is welded to the multi-layer tab of another electrode assembly, the multi-layer tab is overlapped on the tab connection area, then a metal sheet is placed above the multi-layer tab, and the multi-layer tab and the tab connection area are welded by means of ultrasonic welding, so that a square ultrasonic welding area 23 shown in fig. 1 is formed, and the ultrasonic welding area 23 is basically located in the middle of the square tab connection area.

Disclosure of Invention

The inventor researches and discovers that the welding mode of the multilayer tab can be realized by a cold welding machine in addition to the mode of welding the multilayer tab by using ultrasonic welding, edge welding, side welding and the like, and the welding area can be obviously reduced by welding the end part of the multilayer tab to the side surface or the edge of the tab connecting area in a melting way during welding.

Based on above-mentioned welding mode, this application provides connection piece, battery cell and battery package, can reduce the material of connection piece to make its overcurrent capacity and the welding of multilayer utmost point ear obtain satisfying.

In a first aspect, the embodiment of the application provides a connection piece, including interconnect's the utmost point post district that is used for being connected with utmost point post and is used for the first utmost point ear district of being connected with multilayer utmost point ear, first utmost point ear district has the first end of being connected with utmost point post district and keeps away from the second end in utmost point post district to the size of the direction of perpendicular to first end to second end is the width, and along the direction of first end to second end, the width in first utmost point ear district reduces gradually.

Because the mode of selecting side welding or edge welding to weld, its weld mark region is rectangular shape structure, compare in the mode of ultrasonic welding, the width in weld mark region obviously reduces (weld mark region narrows down), so the width in the first utmost point ear district of connection piece of this application reduces from the direction of first end to second end gradually, on the one hand, has reduced the width of the one end of keeping away from utmost point post district in first utmost point ear district, has saved the material of connection piece, and has increased the energy density of battery, and can satisfy the demand of modes such as side welding or edge welding. On the other hand, the position width of the connection pole column area of the first pole ear area is large, and the overcurrent capacity of the connection sheet can be guaranteed (the more the single battery is close to the pole column in the operation process, the larger the current is, the larger the area width of the first pole ear area close to the pole column is, and the overcurrent capacity of the connection sheet can be met).

In a possible implementation manner, the connecting sheet further includes a second polar ear region connected to the polar ear region, the extending direction of the first polar ear region away from the polar ear region is consistent with the extending direction of the second polar ear region away from the polar ear region, and the width of the second polar ear region is also gradually reduced along the direction from the first end to the second end.

Through the setting in first utmost point ear district and second utmost point ear district, can connect the multilayer utmost point ear of carrying out two electric core subassemblies and connect, can increase the energy density of battery. The width of the second polar ear area is gradually reduced, the material consumption of the second polar ear area can be reduced, and the multi-layer polar ear welding and overcurrent of the two electric core components are met.

In a possible implementation manner, an opening is arranged between the first polar ear region and the second polar ear region, and the width of the opening gradually increases along the direction from the first end to the second end.

First utmost point ear district and second utmost point ear district are keeping away from the one end in utmost point post district and are partd, can conveniently be in one side that deviates from the second utmost point ear district in first utmost point ear district to and one side that deviates from first utmost point ear district in second utmost point ear district carries out the edge welding or the side welding to the multilayer utmost point ear.

In one possible implementation, a side of the first pole ear region facing away from the second pole ear region and a side of the second pole ear region facing away from the first pole ear region are parallel.

Because the both sides edge in first utmost point ear district and second utmost point ear district is parallel, when installing with the cooperation of electric core subassembly, the both sides profile of electric core subassembly and the both sides profile of connection piece are parallel basically, with multilayer utmost point ear in the welded time, except buckling and welding, can not produce and twist reverse, can avoid the middle part of utmost point ear to bear the torsional forces to a certain extent, the welding effect of utmost point ear is better.

In one possible implementation, the first pole ear region and the second pole ear region are arranged symmetrically.

The structure in first utmost point ear district and second utmost point ear district is unanimous, and the outline in first utmost point ear district and second utmost point ear district is parallel, then first utmost point ear district and second utmost point ear district are right trapezoid or right triangle structure basically, and the structure of connection piece is comparatively reasonable, and first utmost point ear district and second utmost point ear district atress are unanimous basically, and the welding effect of multilayer utmost point ear is better.

In a possible implementation manner, the wall surface of the opening has a first side surface, a connecting surface and a second side surface which are connected in sequence, and the first side surface and the second side surface are planes.

On one hand, the connecting sheet has a simpler structure and is easy to prepare; on the other hand, the structural defects of the connecting sheet can be reduced, so that the strength of the connecting sheet is relatively high, and the welding requirement is met.

In a possible realization mode, the end surface of the second end is a plane, the width of the second end is 1-5mm, and the thickness of the connecting piece is 0.5-1.5 mm.

The width and the thickness can meet the requirement of edge welding or side welding of a plurality of layers of tabs and connecting sheets.

The second aspect, the application provides a single cell, including top cap subassembly, electric core subassembly and above-mentioned connection piece, the electric core subassembly includes the multilayer utmost point ear, and the top cap subassembly includes utmost point post, and the multilayer utmost point ear welds in first utmost point ear district through the mode of limit welding or side welding, and utmost point post welds in utmost point post district.

In the single battery, because the multi-layer tabs are welded in the tab area of the connecting sheet in a side welding or side welding mode, the multi-layer tabs can be firmly welded. Meanwhile, the area of the connecting sheet is reduced, the material of the connecting sheet can be saved, and the energy density of the battery is increased.

In a possible implementation manner, the connecting sheet further includes a second polar ear region connected to the polar ear region, the extending direction of the first polar ear region away from the polar ear region is consistent with the extending direction of the second polar ear region away from the polar ear region, and the width of the second polar ear region is also gradually reduced along the direction from the first end to the second end. The multilayer pole ear of one electrode assembly is welded on one side of the first electrode ear area far away from the second electrode ear area in a side welding or edge welding mode, and the multilayer pole ear of the other electrode assembly is welded on one side of the second electrode ear area far away from the first electrode ear area in a side welding or edge welding mode.

Through the setting in first utmost point ear district and second utmost point ear district, can carry out the multilayer utmost point ear of two core subassemblies through the mode of edge welding or side welding and connect, can increase the energy density of battery. And the material consumption can also be reduced, and the multi-layer tab welding and overcurrent of the two core assemblies are met.

In a third aspect, the present application provides a battery pack, which includes a battery box and a plurality of the above single batteries, wherein the single batteries are disposed in the battery box.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings that are required to be used in the embodiments will be briefly described below, it should be understood that the following drawings only illustrate some embodiments of the present application and therefore should not be considered as limiting the scope, and for those skilled in the art, other related drawings can be obtained from the drawings without inventive effort.

FIG. 1 is a schematic structural diagram of a flexible connecting sheet provided in the prior art;

fig. 2 is a schematic view of a first internal structure of a single battery provided in an embodiment of the present application;

fig. 3 is a schematic diagram of a second internal structure of a single battery provided in an embodiment of the present application;

fig. 4 is a schematic diagram of a third internal structure of a single battery provided in an embodiment of the present application;

FIG. 5 is an enlarged view taken at V in FIG. 3;

FIG. 6 is an enlarged view taken at VI in FIG. 4;

FIG. 7 is a first structural schematic view of a connecting piece provided in an embodiment of the present application;

FIG. 8 is a second structural diagram of a connecting piece provided in the embodiments of the present application;

fig. 9 is a third structural diagram of a connecting sheet provided in the embodiment of the present application.

Icon: a 10-pole connection region; 21-a first tab connection area; 22-a second pole ear connection region; 23-ultrasonic welding zone; 110-a first electrical core assembly; 120-a second electrical core assembly; 130-positive connecting piece; 140-negative pole connecting piece; 111-a multi-layer first positive tab; 112-a multi-layer first negative tab; 121-a multilayer second positive electrode tab; 122-a multilayer second negative tab; 141-positive pole post; 142-negative electrode post; 151-pole region; 152-a first polar ear region; 153-second polar ear region; 1521-first end; 1522-second end; 154-a solder print area; 155-opening; 1551-first side; 1552-connecting surface; 1553-second side.

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application.

The application provides a battery pack of an electric device, and the electric device can be a new energy automobile, an electric vehicle and the like. The battery pack comprises a battery box body and a plurality of single batteries, wherein the single batteries are arranged in the battery box body.

Since the new energy automobile is a large-scale electric device and needs a large voltage, two electric core assemblies can be arranged in each single battery to increase the energy density of the battery. Fig. 2 is a schematic view of a first internal structure of a single battery provided in an embodiment of the present application; fig. 3 is a schematic diagram of a second internal structure of a single battery provided in an embodiment of the present application; fig. 4 is a schematic diagram of a third internal structure of a single battery provided in an embodiment of the present application. Referring to fig. 2 to 4, in the present application, a unit cell includes a cell case, a cap assembly (not shown in fig. 2), a first cell assembly 110, a second cell assembly 120, a positive electrode connection tab 130, and a negative electrode connection tab 140. The first cell assembly 110 and the second cell assembly 120 are arranged in the battery shell, and the positive connecting sheet 130 and the negative connecting sheet 140 are respectively connected with the top cover assembly and the first cell assembly 110 and the second cell assembly 120 so as to lead out the current generated by the cell assemblies.

The positive connection piece 130 and the negative connection piece 140 have the same structure, and may be made of different materials. For example: the positive connecting piece 130 is an aluminum sheet, and the negative connecting piece 140 is a copper sheet. Optionally, the positive connection piece 130 and the negative connection piece 140 are each 0.5-1.5mm thick. Because of its thin thickness, it can deform to some extent, which may also be called a soft tab. Illustratively, the connecting tab may have a thickness of 0.5mm, 0.6mm, 0.7mm, 0.8mm, 0.9mm, 1mm, 1.1mm, 1.2mm, 1.3mm, 1.4mm, or 1.5 mm.

In the present application, the first core assembly 110 includes a plurality of layers of first positive electrode tabs 111 and a plurality of layers of first negative electrode tabs 112; second electrode subassembly 120 includes anodal utmost point ear 121 of multilayer second and multilayer second negative pole utmost point ear 122, the top cap subassembly includes anodal utmost point post 141 and negative pole utmost point post 142, the welding of the anodal utmost point ear 111 of multilayer first anodal utmost point ear 111 and multilayer second anodal utmost point ear 121 is on anodal connection piece 130, anodal connection piece 130 welding is on anodal utmost point post 141, the welding of the first negative pole utmost point ear 112 of multilayer and multilayer second negative pole utmost point ear 122 is on negative pole connection piece 140, negative pole connection piece 140 welding is on negative pole utmost point post 142, the anodal utmost point post 141 and the negative pole utmost point post 142 through the top cap subassembly are drawn forth the electric current.

Wherein, anodal connection piece 130 includes interconnect's anodal ear district and anodal utmost point post 141 district, negative pole connection piece 140 includes interconnect's anodal ear district and anodal utmost point post 142 district, anodal ear district and the welding of the anodal utmost point ear 121 of the first anodal utmost point ear 111 of multilayer and multilayer second, anodal utmost point post 141 district and anodal utmost point post 141 welding, anodal ear district and the welding of the first utmost point ear 112 of multilayer and multilayer second utmost point ear 122 of negative pole, utmost point post 142 district and the welding of negative pole post 142, thereby realize the electric connection of electrode core subassembly and negative pole post.

Because the structures of the anode adapter plate and the cathode adapter plate are basically consistent, the structure of the connecting plate is directly described in detail subsequently, and the structure is suitable for both the anode adapter plate and the cathode adapter plate.

In the prior art, a plurality of layers of tabs are overlapped on a tab connection area, then a metal sheet is placed above the tabs, and the tabs and the tab connection area are welded in an ultrasonic welding mode to form a square ultrasonic welding area 23 (as shown in fig. 1) shown in fig. 1, wherein the ultrasonic welding area 23 is basically positioned in the middle of the square tab connection area, the length of the ultrasonic welding area 23 is about 5-50mm, and the width of the ultrasonic welding area is about 3-25 mm.

FIG. 5 is an enlarged view taken at V in FIG. 3; FIG. 6 is an enlarged view taken at VI in FIG. 4; fig. 7 is a first structural diagram of a connecting sheet provided in an embodiment of the present application. Referring to fig. 3-7, in the present application, the welding is performed by a cold welding machine in a side welding manner (as fig. 6) or an edge welding manner (as fig. 5), and since the welding manner is fusion welding, the positions where the end portions of the multi-layer tab contact with the tab region can be directly welded together to form a welding mark region in a strip-shaped structure, wherein the welding mark region 154 during side welding is as shown in fig. 7, the length of the welding mark region 154 is 5-50mm, the width of the welding mark region 154 is 0.5-2.5mm, and the width of the welding mark region 154 is significantly reduced (the welding mark region 154 is narrowed); the weld area in the edge weld is located on the side of the pole ear region (not shown in fig. 7).

Referring to fig. 7, in the present application, the connecting sheet includes a terminal area 151, a first terminal area 152 and a second terminal area 153, the first terminal area 152 and the second terminal area 153 are connected to the terminal area 151, and ends of the first terminal area 152 and the second terminal area 153 far away from the terminal area 151 extend toward the same side direction. As shown in fig. 7, the vertical dashed line 1 in fig. 7 may divide the connecting tab into a pole region 151 and a pole ear region, and the lateral dashed line 2 in fig. 7 divides the pole ear region into a first pole ear region 152 and a second pole ear region 153. The division is not a standard division, but is merely a division for convenience of the following description, and the division does not limit the scope of the present application.

The first pole ear region 152 has a first end 1521 connected to the pole region 151 and a second end 1522 far away from the pole region 151, and the dimension perpendicular to the direction from the first end 1521 to the second end 1522 is taken as the width, and along the direction from the first end 1521 to the second end 1522, the width of the first pole ear region 152 is gradually reduced, and the width of the second pole ear region 153 is also gradually reduced. The utmost point post is welded with the utmost point post district 151 of connection piece, and first multilayer utmost point ear is connected through the mode of side welding or edge welding with first utmost point ear district 152, and the second multilayer utmost point ear is connected through the mode of side welding or edge welding with second utmost point ear district 153.

The width of the tab region (the first tab region 152 or/and the second tab region 153) of the connecting piece provided by the application is gradually reduced from the first end 1521 to the second end 1522, so that the width of the second end 1522 of the tab region is reduced (the width of the ends, far away from the terminal region 151, of the first tab region 152 and the second tab region 153) is reduced, on one hand, the material of the connecting piece is saved, the energy density of the battery is increased, and the requirements of side welding or edge welding and other modes can be met; on the other hand, the position width of the connection pole column region 151 in the pole ear region is large, so that the overcurrent capacity of the connection sheet can be ensured (the more the single battery is close to the pole column in the operation process, the larger the current is, the larger the area width of the pole column close to the pole column in the pole ear region is, and the overcurrent capacity of the connection sheet can be met).

Optionally, the end surface of the second end 1522 is a plane, the width of the second end 1522 is 2-3mm, the width of the second end 1522 of the first pole ear region 152 is 1-5mm, and the width of the second end of the second pole ear region 153 is also 1-5 mm. The width can meet the requirement of edge welding or side welding of a plurality of layers of tabs and connecting sheets. Illustratively, the width of the second end 1522 is 1mm, 2mm, 3mm, 4mm, or 5 mm.

Referring to fig. 7, an opening 155 is disposed between the first pole ear region 152 and the second pole ear region 153, and the width of the opening 155 gradually increases along a direction from the first end 1521 to the second end 1522. The first pole ear region 152 and the second pole ear region 153 are separated at an end away from the pole region 151, which facilitates edge welding or side welding of the multi-layer pole ear at a side of the first pole ear region 152 facing away from the second pole ear region 153 and at a side of the second pole ear region 153 facing away from the first pole ear region 152.

Optionally, a side of the first polar ear region 152 facing away from the second polar ear region 153 is parallel to a side of the second polar ear region 153 facing away from said first polar ear region 152. Because the both sides edge of first utmost point ear district 152 and second utmost point ear district 153 is parallel, when installing with the cooperation of electric core subassembly, the both sides profile of electric core subassembly and the both sides profile of connection piece are parallel basically, when with multilayer utmost point ear in the welded, except buckling and welding, can not produce and twist reverse, can avoid the middle part of utmost point ear to bear the torsional forces to a certain extent, and the welding effect of utmost point ear is better.

Further, the first pole ear region 152 and the second pole ear region 153 are symmetrically disposed. First utmost point ear district 152 is unanimous with the structure of second utmost point ear district 153, and the outline of first utmost point ear district 152 and second utmost point ear district 153 is parallel, utmost point ear district is square structure basically, first utmost point ear district 152 and second utmost point ear district 153 are right trapezoid or right angled triangle structure basically, when welding multilayer utmost point ear, respectively with the multilayer utmost point ear welding of two electric core subassemblies at diameter triangle-shaped or right trapezoid's right angle limit or the position that is close to the right angle limit, multilayer utmost point ear is when the welded this moment, except buckling and welding, can not produce and twist reverse, can avoid the middle part of utmost point ear to bear the torsional forces to a certain extent, the welding effect of utmost point ear is better.

With reference to fig. 7, the wall of the opening 155 has a first side 1551, a connecting surface 1552 and a second side 1553 connected in sequence, and the first side 1551 and the second side 1553 are planar. On one hand, the connecting sheet has a simpler structure and is easy to prepare; on the other hand, the structural defects of the connecting sheet can be reduced, so that the strength of the connecting sheet is relatively high, and the welding requirement is met.

Further, the connection surface 1552 is an arc surface, and the arc surface is concave toward the pole region 151. The opening 155 of the polar ear region (the first polar ear region 152 and the second polar ear region 153) on the side close to the polar column region 151 is an arc surface, so that the polar column region 151 and the part of the polar ear region close to the polar column region 151 jointly form a region (for example, a region with a circular dotted line in fig. 7) for welding a polar column, the firm welding of the polar column can be ensured, the whole area of the connecting sheet is reduced, meanwhile, the flow area of the region of the polar ear region close to the polar column region 151 is larger, and the use of materials can be reduced while the flow is guided.

In this application, the direction from the first end 1521 to the second end 1522 is taken as the length direction, and the distance between the arc surface and the connecting line between the polar ear region and the polar post region 151 is 0.3 to 0.8 times the length of the polar post region 151, that is, the distance a between the arc surface and the dashed line 1 is 0.3 to 0.8 times the distance b between the left edge of the polar post region 151 and the dashed line 1. Utmost point post district 151 and the utmost point ear district that is close to utmost point post district 151 all can weld utmost point post, and the size of connection piece satisfies above-mentioned condition, can make the length of utmost point post district 151 shorter, just can satisfy the welding of utmost point post to reduce the material consumption of connection piece. Illustratively, the distance a is 0.3, 0.4, 0.5, 0.6, 0.7, or 0.8 times the distance b.

Optionally, the pole region 151 has a square structure, the width of the pole region (the distance between the side of the first pole region 152 facing away from the second pole region 153 and the side of the second pole region facing away from the first pole region) is 1.5-3 times the width of the pole region 151, and the pole region 151 is connected to the middle of one side (dashed line 1) of the pole region. When the connection piece is installed, the connection piece is located one side of the electrode assembly close to the top cover assembly, the width of the electrode lug area and the width of the electrode pole area 151 are limited in the range, on one hand, the welding of the electrode pole area 151 and the electrode pole can be facilitated, on the other hand, after the multilayer electrode lugs are bent, the direct welding is carried out on the edge of the electrode lug area (the side welding or the side welding is facilitated), the length of the electrode lugs is reduced to a certain extent, and therefore the energy density of the battery is increased. Illustratively, the width of the tab region is 1.5, 2, 2.5, or 3 times the width of the post region 151.

With continuing reference to fig. 1 and 7, in the present application, the structure of the connecting sheet in fig. 1 is directly changed to the structure of the connecting sheet in fig. 2, on one hand, the overcurrent capability of the connecting sheet can be ensured; on the other hand, the improvement is carried out on the basis of the original connecting sheet, the improvement is not many, the original square tab connecting area is directly changed into a first tab area 152 and a second tab area 153 which are in right triangle or right trapezoid shapes in the application, and the purpose of saving materials can be achieved without greatly improving the connecting sheet, so that the energy density of the battery is increased, and the improvement is more convenient; in a third aspect, the connection with the pole column and the position of the connection piece in the single battery are basically unchanged because the main structure of the connection piece is basically unchanged, and the connection can be completed in the original battery manufacturing process.

Fig. 8 is a second structural diagram of a connecting piece provided in the embodiment of the present application. Referring to fig. 8, in this embodiment, a welding print area 154 is disposed on the first tab area 152, which can satisfy the requirement of using a battery containing an electrode assembly in a single battery, and can also reduce the material of the interposer to some extent, increase the energy density of the battery, and achieve the purpose of welding multiple layers of tabs in cooperation with side welding or edge welding.

Fig. 9 is a schematic view of a third structure of a connecting sheet according to an embodiment of the present application, please refer to fig. 9, in which the area of the connecting sheet is increased but still smaller than that of the connecting sheet in fig. 1, compared to fig. 7; meanwhile, the connection area between the polar post region 151 and the first polar ear region 152 and the connection area between the polar post region 151 and the second polar ear region 153 are larger, so that the flow area between the polar ear region and the polar post region 151 can be ensured, and the flow effect is better.

In the embodiment of the application, the preparation method of the single battery comprises the following steps: welding the positive pole 141 area of the positive pole connecting piece 130 and the part of the positive pole ear area close to the positive pole 141 area on the positive pole 141 of the top cover component, and welding the negative pole 142 area of the negative pole connecting piece 140 and the part of the negative pole ear area close to the negative pole 142 area on the negative pole 142 of the top cover component; the first electrode assembly 110 and the second electrode assembly 120 are both arranged in the battery shell, multiple layers of positive electrode tabs of the first electrode assembly 110 are welded on a first electrode lug area 152 of the positive electrode connecting piece 130 in a side welding or edge welding mode (the side is welded on the side, away from the second electrode lug area 153, of the first electrode lug area 152 of the positive electrode connecting piece 130, the edge, away from the second electrode lug area 153, of the first electrode lug area 152 of the positive electrode connecting piece 130), multiple layers of positive electrode tabs of the second electrode assembly 120 are welded on a second electrode lug area 153 of the positive electrode connecting piece 130 in a side welding or edge welding mode (the side is welded on the side, away from the first electrode lug area 152, of the second electrode lug area 153 of the positive electrode connecting piece 130, the edge, away from the first electrode lug area 152, of the second electrode assembly 120 is welded on the first electrode lug area 152 of the negative electrode connecting piece 140 in a side welding or edge welding mode (the side is welded on the first electrode connecting piece 140) The side edge of the ear region 152 facing away from the second pole ear region 153 is edge-welded to the edge of the first pole ear region 152 facing away from the second pole ear region 153 of the negative pole connecting plate 140), and the multilayer negative pole tab of the second pole assembly 120 is welded to the second pole ear region 153 of the negative pole connecting plate 140 by means of side welding or edge welding (the side edge of the second pole ear region 153 of the negative pole connecting plate 140 facing away from the first pole ear region 152 is edge-welded to the edge of the second pole ear region 153 of the negative pole connecting plate 140 facing away from the first pole ear region 152); and welding the battery shell and the metal cover plate of the top cover assembly, and then injecting liquid to obtain the single battery.

The connection piece, battery cell, battery package and electric installation that this application embodiment provided get beneficial effect and include:

(1) because the multilayer tabs are welded on the adapter plate in a side welding or edge welding manner, the width of the welding area 154 is obviously reduced, the width of the tab area (the first tab area 152 or/and the second tab area 153) in the arranged adapter plate is gradually reduced from the first end 1521 to the second end 1522, that is, the position width of the tab area connecting the tab area 151 is larger, the position width far away from the tab area 151 is smaller, and the area with smaller width can meet the requirement of side welding; and the material of the connecting sheet can be saved, and the energy density of the battery is increased.

(2) When welding multilayer utmost point ear, weld the multilayer utmost point ear of two core subassemblies respectively on diameter triangle-shaped or right angle trapezoidal right angle limit (side welding) or be close to the position on right angle limit (side welding), multilayer utmost point ear this moment is in the welded time, except buckling and welding, can not produce and twist reverse, can avoid the middle part of utmost point ear to bear the torsional forces to a certain extent, and the welding effect of utmost point ear is better.

(3) The original square tab connection area is directly changed into a first tab area 152 and a second tab area 153 which are in right triangle or right trapezoid shapes in the application, and the purpose of saving materials can be achieved without greatly improving connection sheets, so that the energy density of the battery is increased, and the improvement is more convenient; the main structure of the connecting piece is basically not changed, the connecting piece is connected with the pole column, and the position of the connecting piece in the single battery is basically not changed, so that the method can be completed in the original battery manufacturing process.

The above description is only a preferred embodiment of the present application and is not intended to limit the present application, and various modifications and changes may be made by those skilled in the art. Any modification, equivalent replacement, improvement and the like made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. The utility model provides a connection piece, its characterized in that, including interconnect be used for with utmost point post district be connected with utmost point post and be used for with multilayer utmost point ear district that utmost point is connected, first utmost point ear district have with the first end that utmost point post district is connected with keep away from the second end in utmost point post district, with the perpendicular to first end extremely the size of the direction of second end is the width, follows first end extremely the direction of second end, the width in first utmost point ear district reduces gradually.

2. The tab of claim 1, further comprising a second tab region connected to the tab terminal region, wherein an extending direction of the first tab region away from the tab terminal region is identical to an extending direction of the second tab region away from the tab terminal region, and a width of the second tab region is gradually reduced along a direction from the first end to the second end.

3. The tab of claim 2, wherein an opening is disposed between the first tab region and the second tab region, the opening having a width that gradually increases in a direction from the first end to the second end.

4. A tab according to claim 3, wherein the side of the first tab region facing away from the second tab region and the side of the second tab region facing away from the first tab region are parallel.

5. The tab of claim 4 wherein the first and second tab regions are symmetrically disposed.

6. A web according to claim 3, wherein the wall of the opening has a first side, a connecting surface and a second side, which are connected in series, the first side and the second side being planar.

7. A web according to any of claims 1-6, wherein the end surface of the second end is plane, the width of the second end is 1-5mm and the thickness of the web is 0.5-1.5 mm.

8. A single battery, which comprises a top cover component, an electric core component and the connecting sheet of any one of claims 1 to 7, wherein the electric core component comprises a plurality of layers of tabs, the top cover component comprises a terminal, and the plurality of layers of tabs are welded to the first terminal area by means of edge welding or side welding; the pole is welded in the pole area.

9. The single battery according to claim 8, wherein the connecting sheet further comprises a second polar ear region connected to the polar ear region, the extending direction of the first polar ear region away from the polar ear region is consistent with the extending direction of the second polar ear region away from the polar ear region, and the width of the second polar ear region is gradually reduced along the direction from the first end to the second end;

one the multilayer utmost point ear of electricity core subassembly welds through the mode of side welding or side welding in keeping away from in first utmost point ear district one side in second utmost point ear district, another the multilayer utmost point ear of electricity core subassembly welds through the mode of side welding or side welding in keeping away from in second utmost point ear district one side in first utmost point ear district.

10. A battery pack, comprising a battery box and a plurality of single batteries according to claim 8 or 9, wherein the single batteries are arranged in the battery box.