Battery cell and battery pack

Abstract

The utility model provides a battery cell and a battery pack, the battery cell comprises a shell, a core bag and a connecting piece, a pole is arranged on the shell, the core bag is arranged in the shell, and a plurality of tabs are arranged on the core bag. The connecting piece comprises a pole connecting part and a plurality of tab connecting parts connected to the pole connecting part, the pole connecting part is electrically connected with the pole, and the same tab is electrically connected with at least two tab connecting parts. According to the battery cell provided by the utility model, the technical problem that the over-current capability of the battery cell is relatively weak can be solved.

Description

Technical Field

[0001] The utility model relates to the technical field of batteries, in particular to a battery core and a battery pack. Background Art

[0002] A battery pack is usually composed of multiple cells. There are multiple core packs in the cell. Each core pack is provided with a pole ear. The pole ears of multiple core packs are welded through connecting pieces, and the connecting pieces are welded to the poles. In this way, the current transmission between the core packs and the poles can be realized, and then the charging and discharging of the battery cell can be realized. And when the battery cell is charging and discharging, the current is mainly transmitted through the welding position between the pole ear, the connecting piece and the pole, so the size of the welding area determines the current carrying capacity of the battery cell. However, in the related art, the welding area between the connecting piece and the pole ear of the core pack is small, resulting in a large internal resistance of the battery cell and a weak current carrying capacity, which cannot meet the use requirements. Utility Model Content

[0003] The embodiments of the utility model provide a battery cell, a battery pack and an electrical device, which can improve the technical problem of weak current carrying capacity of the battery cell.

[0004] In a first aspect, an embodiment of the utility model provides a battery cell, the battery cell comprising a shell, a core pack and a connecting piece, the shell having a pole installed thereon, the core pack being installed in the shell, and the core pack being provided with a plurality of pole tabs. The connecting piece comprises a pole connecting portion and a plurality of pole tab connecting portions connected to the pole connecting portion, the pole connecting portion being electrically connected to the pole, and the same pole tab being electrically connected to at least two pole tab connecting portions.

[0005] Optionally, in one embodiment, the plurality of electrode tabs include a plurality of positive electrode tabs and a plurality of negative electrode tabs, and a plurality of connecting sheets are provided; at least one connecting sheet is electrically connected to at least two of the positive electrode tabs, and each of the positive electrode tabs is electrically connected to the plurality of electrode tab connecting portions on the same connecting sheet; at least one connecting sheet is electrically connected to at least two of the negative electrode tabs, and each of the negative electrode tabs is electrically connected to the plurality of electrode tab connecting portions on the same connecting sheet.

[0006] Optionally, in one embodiment, a plurality of positive electrode ears are provided on the same core package, and the connecting piece is connected between the plurality of positive electrode ears on the same core package; and / or a plurality of negative electrode ears are provided on the same core package, and the connecting piece is connected between the plurality of negative electrode ears on the same core package.

[0007] Optionally, in one embodiment, at least two of the pole lug connecting portions connected to the same pole lug are respectively located on both sides of the pole column connecting portion in the length direction.

[0008] Optionally, in one embodiment, the core package includes a first core package, and a first pole lug is provided on the first core package; the multiple pole lug connection parts on the connecting sheet include a first left connection part and a first right connection part, and the first left connection part and the first right connection part are respectively located on both sides of the pole connection part along the length direction of the connecting sheet, and the first left connection part and the first right connection part are respectively electrically connected to the first pole lug.

[0009] Optionally, in one embodiment, the core package further includes a second core package, a second pole lug is provided on the second core package, and the first pole lug and the second pole lug are spaced opposite to each other along the width direction of the connecting sheet; the multiple pole lug connecting portions on the connecting sheet further include a second left connecting portion and a second right connecting portion, the second left connecting portion and the second right connecting portion are respectively located on both sides of the pole connecting portion along the length of the connecting sheet, and the second left connecting portion and the second right connecting portion are respectively electrically connected to the second pole lug.

[0010] Optionally, in one embodiment, the first left connecting portion and the first right connecting portion are respectively welded to the first pole tab to form a welding area, and the second left connecting portion and the second right connecting portion are also respectively welded to the second pole tab to form a welding area;

[0011] The two welding areas on the first pole lug are arranged opposite to each other along the length direction of the connecting piece, and the two welding areas on the first pole lug are arranged symmetrically about the pole connecting portion;

[0012] And / or, the two welding areas on the second pole lug are arranged opposite to each other along the length direction of the connecting piece, and the two welding areas on the second pole lug are arranged symmetrically about the pole connecting portion.

[0013] Optionally, in one embodiment, the first left connecting portion and the second left connecting portion are spaced apart and opposite to each other along the width direction of the connecting piece, and a first spacing area is formed between the first left connecting portion and the second left connecting portion; the welding area on the first left connecting portion and the welding area on the second left connecting portion are arranged opposite to each other along the width direction of the connecting piece, and the welding area on the first left connecting portion and the welding area on the second left connecting portion are arranged symmetrically with respect to the first spacing area;

[0014] And / or, the first right connecting part and the second right connecting part are spaced apart from each other along the width direction of the connecting piece, and a second spacing area is formed between the first right connecting part and the second right connecting part; the welding area on the first right connecting part and the welding area on the second right connecting part are arranged opposite to each other along the width direction of the connecting piece, and the welding area on the first right connecting part and the welding area on the second right connecting part are arranged symmetrically about the second spacing area.

[0015] Optionally, in one embodiment, in the length direction of the connecting piece, the length of the welding zone is greater than or equal to one quarter of the length of the connecting piece, and less than or equal to one third of the length of the connection; and / or, in the width direction of the connecting piece, the width of the welding zone is greater than or equal to one quarter of the width of the pole lug connection portion, and less than or equal to four fifths of the width of the pole lug connection portion.

[0016] Optionally, in one embodiment, the length direction of the pole lug is parallel to the length direction of the connecting piece, and the length of the pole lug is greater than or equal to the length of the connecting piece, and the difference between the length of the pole lug and the length of the connecting piece is less than or equal to 20 mm.

[0017] Optionally, in one embodiment, a bulge is further provided on the pole connection portion, the bulge is fixedly connected to the pole, and the bulge is centrally arranged on the pole connection portion, or the bulge is centrally arranged relative to the plurality of pole lug connection portions on the same connecting sheet.

[0018] Optionally, in one embodiment, the tab is also in conductive contact with the side wall of the convex hump.

[0019] In a second aspect, an embodiment of the present invention provides a battery pack, which includes the battery cell described in any one of the above embodiments.

[0020] Beneficial effects of the embodiments of the utility model:

[0021] In an embodiment of the utility model, a plurality of pole lug connecting portions are provided on the connecting sheet, and the same pole lug on the core package is electrically connected to at least two pole lug connecting portions on the connecting sheet. In this way, the flow area between the pole lug and the connecting sheet can be increased, the internal resistance of the battery cell can be reduced, and the flow capacity of the battery cell can be improved, thereby improving the technical problem of the weak flow capacity of the battery cell. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative work.

[0023] Figure 1 This is a structural cross-sectional view of an embodiment of a battery cell of the utility model;

[0024] Figure 2 It is a structural schematic diagram of an embodiment of a connecting piece in a battery cell of the utility model;

[0025] Figure 3 It is a structural schematic diagram of an embodiment of a core pack in a battery cell of the utility model;

[0026] Figure 4 It is a structural schematic diagram of an embodiment of a connecting piece and a core package in a battery cell of the utility model;

[0027] Figure 5 It is a structural schematic diagram of another embodiment of the connecting piece and the core package in the battery core of the utility model. DETAILED DESCRIPTION

[0028] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, rather than all of the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the utility model. In addition, it should be understood that the specific implementation methods described herein are only used to illustrate and explain the utility model, and are not used to limit the utility model. In the utility model, unless otherwise stated, the directional words used, such as "upper" and "lower", generally refer to the upper and lower parts of the device in actual use or working state, specifically the drawing direction in the accompanying drawings; while "inside" and "outside" refer to the outline of the device.

[0029] In a first aspect, an embodiment of the present utility model provides a battery cell 100, such as Figure 1 As shown, the battery cell 100 includes a housing 10 , a core package 20 and a connecting sheet 30 .

[0030] The shell 10 is provided with a pole 11, the core package 20 is installed in the shell 10, and a plurality of pole ears 21 are provided on the core package 20. Specifically, the shell 10 mainly includes a bottom shell 12 and a cover plate 13, the bottom shell 12 is provided with an installation cavity 121, the top of the bottom shell 12 is provided with a cavity opening 122 communicating with the installation cavity 121, and the core package 20 is installed in the installation cavity 121 through the cavity opening 122.

[0031] The core pack 20 is a component for generating an electrochemical reaction so that the battery cell 100 can be charged and discharged. The core pack 20 is usually wound by a positive electrode sheet, a negative electrode sheet and a separator separating the positive electrode sheet and the negative electrode sheet. For the specific winding method, working principle, etc. of the positive electrode sheet, the negative electrode sheet and the separator, please refer to the relevant prior art and will not be described in detail here.

[0032] In order to realize the inflow and outflow of current, a plurality of pole ears 21 are further provided on the core pack 20. Generally, a core pack 20 includes at least one positive pole ear 213 and one negative pole ear 214. The positive pole ear 213 is electrically connected to the positive electrode sheet in the core pack 20, and the negative pole ear 214 is electrically connected to the negative electrode sheet in the core pack 20. When in use, the core pack 20 realizes the inflow and outflow of current through the positive pole ear 213 and the negative pole ear 214.

[0033] like Figure 1 As shown, the cover plate 13 covers the cavity opening 122 of the installation cavity 121 to seal the installation cavity 121 and protect the core package 20. The cover plate 13 is provided with a pole 11. Generally, the pole 11 includes a positive pole 111 and a negative pole 112. The positive pole 111 is electrically connected to the positive pole ear 213 of the core package 20 through the connecting piece 30, and the negative pole 112 is electrically connected to the negative pole ear 214 through the connecting piece 30. In this way, the entire battery cell 100 can realize the inflow and outflow of current through the positive pole 111 and the negative pole 112.

[0034] In the related art, since the welding area between the connecting sheet 30 and the tab 21 of the core package 20 is small, the internal resistance of the battery cell 100 is large and the current carrying capacity is weak, which cannot meet the use requirements.

[0035] Therefore, in order to solve the above technical problems, in this embodiment, Figure 2 As shown, the connecting piece 30 includes a pole connecting portion 31 and a plurality of pole lug connecting portions 32 connected to the pole connecting portion 31 . The pole connecting portion 31 is electrically connected to the pole 11 , and the same pole lug 21 is electrically connected to at least two pole lug connecting portions 32 .

[0036] Specifically, the connecting sheet 30 is a metal sheet structure, for example, the connecting sheet 30 can be a copper sheet, an aluminum sheet, or a copper-aluminum alloy. Figure 1 In a battery cell 100 , two connecting sheets 30 are generally provided, wherein one connecting sheet 30 is connected between the positive electrode ear 213 and the positive electrode column 111 , and the other connecting sheet 30 is connected between the negative electrode ear 214 and the negative electrode column 112 .

[0037] In this embodiment, each connecting piece 30 is electrically connected to the pole 11 through the pole connecting portion 31. Specifically, the connecting piece 30 can be fixed to the corresponding pole 11 by welding, sleeve connection or clamping, as long as the connecting piece 30 and the corresponding pole 11 can contact and achieve electrical conduction. Figure 1 and Figure 2 A convex bump 313 is provided on the pole connecting portion 31, and a groove is provided at the position of the pole 11 corresponding to the convex bump 313. The convex bump 313 is inserted into the groove and welded to the pole 11, so that welding between the connecting piece 30 and the pole 11 can be realized, and quick positioning between the connecting piece 30 and the pole 11 is facilitated.

[0038] The key point is that in this embodiment, please combine Figure 2 , Figure 3 and Figure 4 Each connecting sheet 30 is also provided with a plurality of tab connecting portions 32, and during assembly, the same tab 21 on the core package 20 is electrically connected to at least two tab connecting portions 32 at the same time, and each tab connecting portion 32 can achieve stable conductive contact with the corresponding tab 21 by welding, clamping, or the like. Figure 4 In the structural scheme shown, four tab connecting portions 32 are provided on the connecting sheet 30, two of which are electrically connected to the same tab 21, and the other two tab connecting portions 32 are electrically connected to another tab 21. Of course, in other embodiments, three, four, five, or more tab connecting portions 32 may be simultaneously connected to one tab 21.

[0039] It can be understood that the battery cell 100 of the present invention provides multiple pole lug connecting parts 32 on the connecting sheet 30, and electrically connects the same pole lug 21 on the core package 20 to at least two pole lug connecting parts 32 on the connecting sheet 30. In this way, the flow area between the pole lug 21 and the connecting sheet 30 can be increased, the internal resistance of the battery cell 100 can be reduced, and the flow capacity of the battery cell 100 can be improved, thereby improving the technical problem of weak flow capacity of the battery cell 100.

[0040] In addition, it can be understood that because the same pole ear 21 is electrically connected to at least two pole ear connecting portions 32, when the current on the pole ear 21 flows to the connecting plate 30, at least two pole ear connecting portions 32 can also realize the current diversion on the connecting plate 30. In this way, the current flowing through each pole ear connecting portion 32 can be reduced while the total current remains unchanged, thereby reducing the heat generated by the connecting plate 30 and avoiding the situation where the temperature of the battery cell 100 is too high during use.

[0041] Optionally, in one embodiment, please combine Figure 2 , Figure 3 and Figure 4 At least two tab connection portions 32 connected to the same tab 21 are located on both sides of the length direction of the pole connection portion 31. Specifically, in this embodiment, Figure 2 As shown, the pole connection part 31 has a square shape, and the two dotted lines in the figure represent the left and right edges of the pole connection part 31. The connecting piece 30 is provided with four pole lug connection parts 32. The present application names the four pole lug connection parts 32 as the first left connection part 321, the first right connection part 322, the second left connection part 323 and the second right connection part 324 respectively.

[0042] Among them, Figure 4As shown, the first left connection portion 321 and the first right connection portion 322 are connected to the same pole lug 21, and the first left connection portion 321 and the first right connection portion 322 are respectively located on the left and right sides of the pole connection portion 31. Similarly, the second left connection portion 323 and the second right connection portion 324 are connected to the same pole lug 21, and the second left connection portion 323 and the second right connection portion 324 are respectively located on the left and right sides of the pole connection portion 31.

[0043] It can be understood that in this embodiment, by locating at least two pole lug connecting portions 32 connected to the same pole lug 21 on opposite sides of the pole connecting portion 31, the force on the connecting piece 30 can be more balanced and uniform, thereby preventing the connecting piece 30 from shaking due to unbalanced force and thus preventing the connection between the connecting piece 30 and the pole lug 21 from loosening.

[0044] It should be noted that the "left" and "right" in the names of the first left connection part 321 and the first right connection part 322 are only used to indicate the relative position between the first left connection part 321 and the first right connection part 322, that is, the first left connection part 321 and the first right connection part 322 are in a left-right position relationship relative to each other, and do not indicate the absolute position of the first left connection part 321 and the first right connection part 322 on the connecting piece 30. The second left connection part 323 and the second right connection part 324 are similar, and will not be described in detail here.

[0045] It should also be noted that the two pole ears 21 connected by the connecting piece 30 can be two pole ears 21 on the same core package 20. For example, some core packages 20 are provided with two positive pole ears 213 and two negative pole ears 214. In this case, the connecting piece 30 can be connected between the two positive pole ears 213 or the two negative pole ears 214 on the same core package 20.

[0046] Or, optionally, in one embodiment, as Figure 3 As shown, the core package 20 includes a first core package 22 and a second core package 23. The first core package 22 is provided with a first pole ear 211, and the second core package 23 is provided with a second pole ear 212. The first pole ear 211 and the second pole ear 212 are spaced opposite to each other along the width direction of the connecting sheet 30, and the first pole ear 211 and the second pole ear 212 can both be positive pole ears 213, and can also both be negative pole ears 214.

[0047] like Figure 4As shown, the first left connection portion 321 and the first right connection portion 322 are respectively located on both sides of the pole connection portion 31 along the length direction of the connection sheet 30, and the first left connection portion 321 and the first right connection portion 322 are respectively electrically connected to the first pole lug 211. The second left connection portion 323 and the second right connection portion 324 are respectively located on both sides of the pole connection portion 31 along the length of the connection sheet 30, and the second left connection portion 323 and the second right connection portion 324 are respectively electrically connected to the second pole lug 212.

[0048] That is, in this embodiment, the pole tabs 21 on each core package 20 are electrically connected to the connecting piece 30 through two pole tab connecting parts 32. This can increase the flow area between the connecting piece 30 and the pole tabs 21, thereby reducing the internal resistance of the battery cell 100 and improving the flow capacity of the battery cell 100, and also make the connection between the connecting piece 30 and the pole tabs 21 simple and convenient enough to ensure the assembly efficiency of the battery cell 100.

[0049] Optionally, in one embodiment, as Figure 4 As shown, the first left connecting portion 321 and the first right connecting portion 322 are respectively welded with the first pole tab 211 to form two welding areas 40, and the second left connecting portion 323 and the second right connecting portion 324 are also respectively welded with the second pole tab 212 to form two welding areas 40. Among them, the two welding areas 40 on the first pole tab 211 are arranged oppositely along the length direction of the connecting piece 30, and the two welding areas 40 on the first pole tab 211 are arranged symmetrically about the pole connecting portion 31. The two welding areas 40 on the second pole tab 212 are arranged oppositely along the length direction of the connecting piece 30, and the two welding areas 40 on the second pole tab 212 are arranged symmetrically about the pole connecting portion 31.

[0050] Specifically, Figure 2 As shown, the pole connection part 31 has a square shape, and the pole connection part 31 has a first midpoint perpendicular line 311, which extends along the width direction of the connecting piece 30 and divides the pole connection part 31 into two halves. Figure 2 and Figure 4 It is understood that the two welding areas 40 on the first pole tab 211 are symmetrically arranged about the first perpendicular midline 311, and the two welding areas 40 on the second pole tab 212 are also symmetrically arranged about the first perpendicular midline 311. It is understood that this can further make the force on the connecting piece 30 more balanced and uniform, thereby improving the stability of the connecting piece 30 and the core package 20 in the housing 10, and improving the reliability of the battery cell 100.

[0051] It should be noted that when the two welding areas 40 on the first pole tab 211 are symmetrically arranged about the pole connection portion 31, as described above, the two welding areas 40 on the first pole tab 211 are symmetrically arranged about the first perpendicular midline 311 of the pole connection portion 31. It can also be understood that the pole connection portion 31 is a relatively thick "straight line" extending along the width direction of the connecting piece 30, and the two welding areas 40 on the first pole tab 211 are symmetrically arranged about the relatively thick "straight line". The same logic applies to the symmetrical arrangement of the two welding areas 40 on the second pole tab 212 about the pole connection portion 31, which will not be repeated here.

[0052] Further, such as Figure 2 As shown, the first left connecting portion 321 and the second left connecting portion 323 are spaced apart from each other along the width direction of the connecting piece 30, and a first spacing area 33 is formed between the first left connecting portion 321 and the second left connecting portion 323. Figure 2 and Figure 4 The welding area 40 on the first left connecting portion 321 and the welding area 40 on the second left connecting portion 323 are arranged opposite to each other along the width direction of the connecting piece 30, and the welding area 40 on the first left connecting portion 321 and the welding area 40 on the second left connecting portion 323 are arranged symmetrically about the first spacing area 33.

[0053] Specifically, Figure 2 As shown, the pole connecting portion 31 also has a second midpoint perpendicular line 312, which extends along the length direction of the connecting piece 30, and the second midpoint perpendicular line 312 can divide the first spacing area 33 into two halves. Figure 2 and Figure 4 It is understood that the welding area 40 on the first left connecting portion 321 and the welding area 40 on the second left connecting portion 323 are symmetrically arranged about the second perpendicular midline 312. It is understood that this can further make the force on the connecting piece 30 more balanced and uniform, thereby improving the stability of the connecting piece 30 and the core package 20 in the housing 10 and improving the reliability of the battery cell 100.

[0054] Similarly, if Figure 2 As shown, the first right connecting portion 322 and the second right connecting portion 324 are spaced apart from each other along the width direction of the connecting piece 30, and a second spacing area 34 is formed between the first right connecting portion 322 and the second right connecting portion 324. Figure 2 and Figure 4 The welding area 40 on the first right connecting portion 322 and the welding area 40 on the second right connecting portion 324 are arranged opposite to each other along the width direction of the connecting piece 30 , and the welding area 40 on the first right connecting portion 322 and the welding area 40 on the second right connecting portion 324 are arranged symmetrically about the second spacing area 34 .

[0055] Specifically, the welding area 40 on the first left connecting part 321 and the welding area 40 on the second left connecting part 323 are also symmetrically arranged about the second perpendicular midline 312. It can be understood that this can further make the force on the connecting piece 30 more balanced and uniform, thereby improving the stability of the connecting piece 30 and the core package 20 in the shell 10, and improving the reliability of the battery cell 100.

[0056] It should also be noted that when the welding area 40 on the first left connecting part 321 and the welding area 40 on the second left connecting part 323 are symmetrically arranged with respect to the first spacing area 33, it can also be understood that the first spacing area 33 is a thicker "dummy line" extending along the length direction of the connecting piece 30, and the welding area 40 on the first left connecting part 321 and the welding area 40 on the second left connecting part 323 are symmetrically arranged with respect to the thicker "dummy line". The same logic applies to the symmetrical arrangement of the welding area 40 on the first right connecting part 322 and the welding area 40 on the second right connecting part 324 with respect to the second spacing area 34, which will not be repeated here.

[0057] Optionally, in one embodiment, in the length direction of the connecting piece 30 , the length of the welding area 40 is greater than or equal to one quarter of the length of the connecting piece 30 , and less than or equal to one third of the length of the connection.

[0058] Specifically, if Figure 5 As shown, L1 represents the length of the welding area 40, and L2 represents the length of the connecting piece 30. L1 is greater than or equal to one quarter of L2 and less than or equal to one third of L2. Specifically, L1 can be one quarter of L2 (i.e., 10 / 40s), 10 / 39, 10 / 38, 10 / 37, 10 / 36, 10 / 35, 10 / 34, 10 / 33, 10 / 32, 10 / 31, 1 / 3 (i.e., 10 / 30s), and so on.

[0059] It is understandable that if the length of the welding area 40 is less than one-fourth of the length of the connecting piece 30, the area of ​​the welding area 40 will be relatively small, and thus the flow area between the connecting piece 30 and the tab 21 cannot be effectively increased, and thus the flow capacity of the battery cell 100 cannot be effectively increased. If the length of the welding area 40 is greater than one-third of the length of the connecting piece 30, the welding area 40 will extend to one side of the convex bump 313, which will cause interference between the welding head and the convex bump 313 during welding, increasing the difficulty of welding and reducing the assembly efficiency of the battery cell 100.

[0060] Therefore, in this embodiment, by making the length of the welding area 40 greater than or equal to one-fourth of the length of the connecting piece 30 and less than or equal to one-third of the length of the connection, it can ensure that there is sufficient flow area between the connecting piece 30 and the pole lug 21, thereby effectively improving the flow capacity of the battery cell 100, and avoid increasing the difficulty of welding between the connecting piece 30 and the pole lug 21, thereby ensuring the assembly efficiency of the battery cell 100.

[0061] Furthermore, in the width direction of the connecting sheet 30 , the width of the welding area 40 is greater than or equal to one quarter of the width of the tab connecting portion 32 , and less than or equal to four fifths of the width of the tab connecting portion 32 .

[0062] Specifically, if Figure 5 As shown, W1 represents the width of the welding area 40, and W2 represents the width of each pole ear connecting portion 32. W1 is greater than or equal to one-fourth of W2 and less than or equal to four-fifths of W2. Specifically, W1 can be one-fourth of W2 (i.e., five-twentieths), six-twentieths, seven-twentieths, six-twentieths, eight-twentieths, nine-twentieths, ten-twentieths, eleven-twentieths, twelve-twentieths, thirteen-twentieths, fourteen-twentieths, fifteen-twenty, four-fifths (i.e., sixteen-twenty), and so on.

[0063] It can be understood that if the width of the welding area 40 is less than one-fourth of the width of the tab connection portion 32, the area of ​​the welding area 40 will be relatively small, and thus the flow area between the connecting piece 30 and the tab 21 cannot be effectively increased, and thus the flow capacity of the battery cell 100 cannot be effectively increased. If the width of the welding area 40 is greater than four-fifths of the width of the connecting piece 30, then the welding head needs to move multiple times along the width direction of the connecting piece 30 for each welding of a welding area 40, and the welding actions are numerous, and thus the assembly efficiency is low.

[0064] Therefore, in this embodiment, by making the width of the welding area 40 greater than or equal to one-fourth of the width of the pole tab connection portion 32 and less than or equal to four-fifths of the width of the pole tab connection portion 32, it can ensure that there is sufficient flow area between the connecting plate 30 and the pole tab 21, thereby effectively improving the flow capacity of the battery cell 100, and avoiding redundant welding, thereby ensuring the assembly efficiency of the battery cell 100.

[0065] Optionally, in one embodiment, the length direction of the pole lug 21 is parallel to the length direction of the connecting piece 30, and the length of the pole lug 21 is greater than or equal to the length of the connecting piece 30, and the difference between the length of the pole lug 21 and the connecting piece 30 is less than or equal to 20 mm.

[0066] Specifically, if Figure 5As shown, L2 represents the length of the connecting plate 30, L3 represents the length of the pole ear 21, L3 is greater than or equal to L2, and the difference in length between L3 and L2 is less than or equal to 20 mm. Specifically, the difference in length between L3 and L2 can be 20 mm, 19 mm, 18 mm, 17 mm, 16 mm, 15 mm, 14 mm, 13 mm, 12 mm, 11 mm, 10 mm, 9 mm, 8 mm, 7 mm, 6 mm, 5 mm, 4 mm, 3 mm, 2 mm, 1 mm, etc.

[0067] It is understandable that if the length of the pole ear 21 is less than the length of the connecting piece 30, the length of the welding area 40 will be relatively small, which will lead to a smaller flow area between the connecting piece 30 and the pole ear 21, and a weaker flow capacity of the battery cell 100. If the length of the pole ear 21 is greater than the length of the connecting piece 30, and the difference between the length of the pole ear 21 and the length of the connecting piece 30 is greater than 20 mm, the pole ear 21 will be dry with the cover plate 13, thereby affecting the installation of the cover plate 13 on the bottom shell 12.

[0068] Therefore, in this embodiment, by making the length of the pole ear 21 greater than or equal to the length of the connecting piece 30, and the difference in length between the pole ear 21 and the connecting piece 30 less than or equal to 20 mm, it is possible to avoid the problem that the length of the welding area 40 is relatively small, thereby avoiding the problem that the flow area between the connecting piece 30 and the pole ear 21 is small and the flow capacity of the battery cell 100 is weak, and it is also possible to avoid the problem that the pole ear 21 interferes with the cover plate 13, thereby affecting the installation of the cover plate 13 on the bottom shell 12.

[0069] Optionally, in one embodiment, as Figure 4 As shown, a convex bump 313 is also provided on the pole connecting portion 31 . The convex bump 313 is formed by bending and protruding a part of the surface of the connecting piece 30 relative to other surfaces. The convex bump 313 is fixedly connected to the pole 11 , and the convex bump 313 is centrally arranged on the pole connecting portion 31 .

[0070] For details, please refer to Figure 4 If a line is drawn between the welding area 40 on the first left connection part 321 and the welding area 40 on the second right connection part 324, and a line is drawn between the welding area 40 on the first right connection part 322 and the welding area 40 on the second left connection part 323, then the intersection of the two lines is the position of the convex bulge 313. That is, the spacing between the convex bulge 313 and each welding area 40 is the same, which can further make the force on the connecting piece 30 more balanced and uniform, thereby improving the stability of the connecting piece 30 and the core package 20 in the housing 10 and improving the reliability of the battery cell 100.

[0071] Furthermore, in one embodiment, if Figure 4As shown, the pole ear 21 is also in conductive contact with the side wall of the bulge 313. Specifically, as shown in the figure, in the width direction of the connecting piece 30, the first pole ear 211 and the second pole ear 212 are also extended to one side of the bulge 313 respectively, and are in conductive contact with the bulge 313. This can increase the contact area between the connecting piece 30 and the pole ear 21, thereby improving the current carrying capacity of the battery cell 100.

[0072] On the second aspect, an embodiment of the utility model provides a battery pack (not shown), the battery pack comprising a battery cell 100 of any one of the above embodiments. Since the battery pack of the utility model adopts all the technical solutions of all the above embodiments, it has at least all the beneficial effects brought by the technical solutions of the above embodiments, which will not be described one by one here.

[0073] In the third aspect, the embodiment of the utility model provides an electric device (not shown), which includes the above battery pack. Since the electric device of the utility model adopts all the technical solutions of all the above embodiments, it at least has all the beneficial effects brought by the technical solutions of the above embodiments, which will not be described one by one here. Specifically, the electric device can be an electric car, or other electrical equipment that needs a battery as a power source.

[0074] The above is a detailed introduction to the embodiments of the present invention. Specific examples are used in this article to illustrate the principles and implementation methods of the present invention. The description of the above embodiments is only used to help understand the method and core idea of ​​the present invention. At the same time, for technicians in this field, according to the idea of ​​the present invention, there will be changes in the specific implementation method and application scope. In summary, the content of this specification should not be understood as a limitation on the present invention.

Claims

1. A battery cell, characterized in that: include: A shell, on which a pole is mounted; A core package, the core package is installed in the shell, and a plurality of tabs are provided on the core package; and A connecting piece, the connecting piece includes a pole connecting portion and a plurality of pole lug connecting portions connected to the pole connecting portion, the pole connecting portion is electrically connected to the pole, and the same pole lug is electrically connected to at least two pole lug connecting portions.

2. The battery cell according to claim 1, characterized in that: The plurality of pole tabs include a plurality of positive pole tabs and a plurality of negative pole tabs, and the plurality of connecting pieces are provided; At least one of the connecting sheets is electrically connected to at least two of the positive electrode tabs, and each of the positive electrode tabs is electrically connected to a plurality of the tab connecting portions on the same connecting sheet; At least one of the connecting sheets is electrically connected to at least two of the negative electrode tabs, and each of the negative electrode tabs is electrically connected to a plurality of the tab connecting portions on the same connecting sheet.

3. The battery cell according to claim 2, characterized in that: A plurality of positive electrode tabs are arranged on the same core package, and the connecting sheet is connected between the plurality of positive electrode tabs on the same core package; And / or, a plurality of negative electrode tabs are arranged on the same core package, and the connecting sheet is connected between the plurality of negative electrode tabs on the same core package.

4. The battery cell according to claim 1, characterized in that: At least two of the pole lug connection portions connected to the same pole lug are respectively located on both sides of the pole column connection portion in the length direction.

5. The battery cell according to claim 4, characterized in that: The core package comprises a first core package, and the first core package is provided with a first electrode tab; The multiple pole lug connection parts on the connecting sheet include a first left connection part and a first right connection part, the first left connection part and the first right connection part are respectively located on both sides of the pole connection part along the length direction of the connecting sheet, and the first left connection part and the first right connection part are respectively electrically connected to the first pole lug.

6. The battery cell according to claim 5, characterized in that: The core package further includes a second core package, on which a second pole lug is disposed, and the first pole lug and the second pole lug are spaced apart and opposite to each other along a width direction of the connecting sheet; The multiple pole lug connections on the connecting sheet also include a second left connection portion and a second right connection portion, wherein the second left connection portion and the second right connection portion are respectively located on both sides of the pole connection portion along the length of the connecting sheet, and the second left connection portion and the second right connection portion are respectively electrically connected to the second pole lug.

7. The battery cell according to claim 6, characterized in that: The first left connecting portion and the first right connecting portion are respectively welded to the first pole tab to form a welding area, and the second left connecting portion and the second right connecting portion are also respectively welded to the second pole tab to form a welding area; The two welding areas on the first pole lug are arranged opposite to each other along the length direction of the connecting piece, and the two welding areas on the first pole lug are arranged symmetrically about the pole connecting portion; And / or, the two welding areas on the second pole lug are arranged opposite to each other along the length direction of the connecting piece, and the two welding areas on the second pole lug are arranged symmetrically about the pole connecting portion.

8. The battery cell according to claim 7, characterized in that: The first left connecting portion and the second left connecting portion are spaced apart and opposite to each other along the width direction of the connecting piece, and a first spacing area is formed between the first left connecting portion and the second left connecting portion; the welding area on the first left connecting portion and the welding area on the second left connecting portion are arranged opposite to each other along the width direction of the connecting piece, and the welding area on the first left connecting portion and the welding area on the second left connecting portion are arranged symmetrically with respect to the first spacing area; And / or, the first right connecting part and the second right connecting part are spaced apart from each other along the width direction of the connecting piece, and a second spacing area is formed between the first right connecting part and the second right connecting part; the welding area on the first right connecting part and the welding area on the second right connecting part are arranged opposite to each other along the width direction of the connecting piece, and the welding area on the first right connecting part and the welding area on the second right connecting part are arranged symmetrically about the second spacing area.

9. The battery cell according to claim 7, characterized in that: In the length direction of the connecting piece, the length of the welding area is greater than or equal to one quarter of the length of the connecting piece and less than or equal to one third of the length of the connecting piece; And / or, in the width direction of the connecting sheet, the width of the welding area is greater than or equal to one quarter of the width of the pole tab connecting portion, and less than or equal to four fifths of the width of the pole tab connecting portion.

10. The battery cell according to any one of claims 1 to 9, characterized in that: The length direction of the pole lug is parallel to the length direction of the connecting piece, and the length of the pole lug is greater than or equal to the length of the connecting piece, and the difference between the length of the pole lug and the length of the connecting piece is less than or equal to 20 mm.

11. The battery cell according to any one of claims 1 to 9, characterized in that: The pole connecting portion is also provided with a convex bump, and the convex bump is fixedly connected to the pole; The convex bump is centrally arranged on the pole connecting portion, or the convex bump is centrally arranged relative to a plurality of pole lug connecting portions on the same connecting sheet.

12. The battery cell according to claim 11, characterized in that: The tab is also in conductive contact with the sidewall of the convex bump.

13. A battery pack, characterized in that: Comprising the battery cell as described in any one of claims 1 to 12.

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