Battery cell and battery pack

Abstract

The present application provides a battery cell and a battery pack. The battery cell comprises a casing, a cell pack, and connecting pieces; a pole is mounted on the casing; the cell pack is mounted in the casing; and a plurality of tabs are arranged on the cell pack. Each 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 to the pole, and the same tab is electrically connected to at least two tab connecting parts.

Description

Battery cell and battery pack

[0001] This application claims priority to Chinese patent application No. 202420820269.3 filed on April 18, 2024 and No. 202421243598.2 filed on May 31, 2024, the contents of which are incorporated herein by reference in their entirety. TECHNICAL FIELD

[0002] The present application relates to the technical field of battery, in particular to a battery cell and a battery pack. BACKGROUND

[0003] A soft battery pack is usually composed of a plurality of battery cells, each of which is provided with a plurality of cell packs. Each cell pack is provided with a tab. The tabs of the plurality of cell packs are welded by a connecting sheet. The connecting sheet is welded with a pole. In this way, current transmission between the cell pack and the pole can be achieved, and in turn, charging and discharging of the battery cell can be achieved. When the battery cell is charging and discharging, the current is mainly transmitted through the welding position between the tab, the connecting sheet and the pole. Therefore, the size of the welding area determines the overcurrent capacity of the battery cell. SUMMARY

[0004] However, in the related art, the welding area between the connecting sheet and the tab of the cell pack is small, resulting in large internal resistance and weak overcurrent capacity of the battery cell, which cannot meet the use requirements.

[0005] In a first aspect, embodiments of the present application provide a battery cell, which comprises a shell, a cell pack and a connecting sheet. The shell is provided with a pole. The cell pack is installed in the shell and is provided with a plurality of tabs. The connecting sheet comprises a pole connecting portion and a plurality of tab connecting portions connected to the pole connecting portion. The pole connecting portion is electrically connected to the pole. The same tab on the cell pack is electrically connected to at least two tab connecting portions on the connecting sheet.

[0006] In a second aspect, embodiments of the present application provide a battery pack, which comprises the battery cell according to any one of the above embodiments. ADVANTAGEOUS EFFECTS

[0007] In the embodiments of the present application, a plurality of tab connecting portions are arranged on the connecting sheet, and the same tab on the cell pack is electrically connected to at least two tab connecting portions on the connecting sheet. In this way, the overcurrent area between the tab and the connecting sheet can be increased, the internal resistance of the battery cell can be reduced, and the overcurrent capacity of the battery cell can be improved. BRIEF DESCRIPTION OF DRAWINGS

[0008] Fig. 1 is a structural sectional view of an embodiment of the battery cell of the present application;

[0009] Fig. 2 is a structural schematic view of an embodiment of the connecting sheet in the battery cell of the present application;

[0010] Fig. 3 is a structural schematic diagram of an embodiment of the cell pack in the battery cell of the present application;

[0011] Fig. 4 is a structural schematic diagram of an embodiment of the connecting plate and the cell pack in the battery cell of the present application;

[0012] Fig. 5 is a structural schematic diagram of another embodiment of the connecting plate and the cell pack in the battery cell of the present application;

[0013] Fig. 6 is a plan schematic diagram of an embodiment of the cover plate assembly provided by the embodiment of the present application;

[0014] Fig. 7 is a plan schematic diagram of another embodiment of the cover plate assembly provided by the embodiment of the present application;

[0015] Fig. 8 is a plan schematic diagram of a further embodiment of the cover plate assembly provided by the embodiment of the present application;

[0016] Fig. 9 is a plan schematic diagram of a still further embodiment of the cover plate assembly provided by the embodiment of the present application;

[0017] Fig. 10 is a plan schematic diagram of a still further embodiment of the cover plate assembly provided by the embodiment of the present application;

[0018] Fig. 11 is a plan schematic diagram of a still further embodiment of the cover plate assembly provided by the embodiment of the present application;

[0019] Fig. 12 is a plan schematic diagram of a still further embodiment of the cover plate assembly provided by the embodiment of the present application;

[0020] Fig. 13 is a plan schematic diagram of a still further embodiment of the cover plate assembly provided by the embodiment of the present application;

[0021] Fig. 14 is a plan schematic diagram of a still further embodiment of the cover plate assembly provided by the embodiment of the present application;

[0022] Fig. 15 is a plan schematic diagram of a still further embodiment of the cover plate assembly provided by the embodiment of the present application;

[0023] Fig. 16 is a plan schematic diagram of a still further embodiment of the cover plate assembly provided by the embodiment of the present application;

[0024] Fig. 17 is a plan schematic diagram of a still further embodiment of the cover plate assembly provided by the embodiment of the present application;

[0025] Fig. 18 is a plan schematic diagram of a still further embodiment of the cover plate assembly provided by the embodiment of the present application;

[0026] Fig. 19 is a plan schematic diagram of a still further embodiment of the cover plate assembly provided by the embodiment of the present application;

[0027] Fig. 20 is a plan schematic diagram of a still further embodiment of the cover plate assembly provided by the embodiment of the present application;

[0028] Fig. 21 is a plan view of an embodiment sixteen of the cover assembly according to the present application;

[0029] Fig. 22 is a plan view of an embodiment seventeen of the cover assembly according to the present application;

[0030] Fig. 23 is a plan view of an embodiment eighteen of the cover assembly according to the present application;

[0031] Fig. 24 is a plan view of an embodiment nineteen of the cover assembly according to the present application;

[0032] Fig. 25 is a plan view of an embodiment twenty of the cover assembly according to the present application;

[0033] Fig. 26 is a plan view of a first connecting member according to the present application;

[0034] Fig. 27 is a plan view of a second connecting member according to the present application. Embodiments of the present application

[0035] In the description of the present application, unless otherwise clearly specified and limited, the terms "connection", "connecting", and "fixed" should be understood broadly, for example, can be fixed connection, can also be detachable connection, or integral; can be mechanical connection, can also be electrical connection; can be directly connected, can also be indirectly connected through an intermediate medium, can be internal communication of two elements or interaction relationship between two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0036] In the present application, unless otherwise clearly specified and limited, the first feature "on" or "under" the second feature can include that the first and second features are in direct contact, or that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, the first feature "on", "above" and "over" the second feature includes that the first feature is directly above and obliquely above the second feature, and the horizontal height of the first feature is higher than that of the second feature. The first feature "under", "below" and "under" the second feature includes that the first feature is directly below and obliquely below the second feature, and the horizontal height of the first feature is lower than that of the second feature.

[0037] In the description of the present embodiment, the terms "upper", "lower", "left", "right", "front", "back", and the like, orientation or positional relationship are based on the orientation or positional relationship shown in the drawings, and are for the convenience of description and simplification of operation, and do not indicate or imply that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the present application. In addition, the terms "first" and "second" are used to distinguish the description and have no special meaning.

[0038] In some embodiments, the first aspect, the embodiments of the present application provide an electric core 100, as shown in FIG. 1, the electric core 100 includes a shell 10, a core package 20 and a connecting sheet 30. Wherein, the shell 10 is provided with a pole 11, the core package 20 is installed in the shell 10, and the core package 20 is provided with a plurality of tabs 21. 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 communicated with the installation cavity 121, and the core package 20 is installed into the installation cavity 121 through the cavity opening 122. The core package 20 is a component for generating electrochemical reaction to enable the electric core 100 to charge and discharge, and the core package 20 is usually wound by a positive plate, a negative plate and a separator between the positive plate and the negative plate. The specific winding mode, working principle and the like of the positive plate, the negative plate and the separator can be referred to the related art, and will not be described in detail here.

[0039] In order to realize the inflow and outflow of current, the core package 20 is also provided with a plurality of tabs 21. Generally, one core package 20 includes at least one positive tab 213 and one negative tab 214, the positive tab 213 is electrically connected with the positive plate in the core package 20, and the negative tab 214 is electrically connected with the negative plate in the core package 20. In use, the core package 20 realizes the inflow and outflow of current through the positive tab 213 and the negative tab 214.

[0040] As shown in FIG. 1, 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 with the positive tab 213 of the core package 20 through the connecting sheet 30, and the negative pole 112 is electrically connected with the negative tab 214 through the connecting sheet 30. In this way, the entire electric core 100 can realize the inflow and outflow of current through the positive pole 111 and the negative pole 112.

[0041] As shown in FIG. 1, the cover plate 13 covers the cavity opening 122 of the mounting cavity 121 to seal the mounting cavity 121 and protect the core package 20. The cover plate 13 is provided with the pole 11. Generally, the pole 11 includes the positive pole 111 and the negative pole 112. The positive pole 111 is electrically connected to the positive tab 213 of the core package 20 through the connecting sheet 30. The negative pole 112 is electrically connected to the negative tab 214 through the connecting sheet 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.

[0042] In the related art, because 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 overcurrent capacity is weak, which cannot meet the use requirements.

[0043] Therefore, in the embodiment, as shown in FIG. 2, the connecting sheet 30 includes the pole connecting part 31 and the plurality of tab connecting parts 32 connected to the pole connecting part 31. The pole connecting part 31 is electrically connected to the pole 11. The same tab 21 is electrically connected to at least two tab connecting parts 32.

[0044] 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, etc. As shown in FIG. 1, in one battery cell 100, generally two connecting sheets 30 are provided. One connecting sheet 30 is connected between the positive tab 213 and the positive pole 111. The other connecting sheet 30 is connected between the negative tab 214 and the negative pole 112.

[0045] In the embodiment, each connecting sheet 30 is electrically connected to the pole 11 through the pole connecting part 31. Specifically, the connecting sheet 30 can be fixed to the corresponding pole 11 through welding, sleeving or clamping, as long as the connecting sheet 30 and the corresponding pole 11 can be in contact to realize conduction. For example, as shown in FIG. 1 and FIG. 2, the pole connecting part 31 is provided with a convex bump 313. The pole 11 is provided with a groove corresponding to the position of the convex bump 313. The convex bump 313 is clamped into the groove and welded and fixed to the pole 11. In this way, the welding between the connecting sheet 30 and the pole 11 can be realized, and the quick positioning between the connecting sheet 30 and the pole 11 is facilitated.

[0046] In the present embodiment, as shown in FIGS. 2, 3 and 4, each of the connecting pieces 30 is further provided with a plurality of tab connecting portions 32, and in assembly, the same tab 21 on the core pack 20 is simultaneously electrically connected with at least two tab connecting portions 32, and stable conductive contact between each of the tab connecting portions 32 and the corresponding tab 21 can be achieved by welding, clamping, clamping and the like. For example, in the structural scheme shown in FIG. 4, the connecting piece 30 is provided with four tab connecting portions 32, of which two tab connecting portions 32 are electrically connected with the same tab 21, and the other two tab connecting portions 32 are electrically connected with another tab 21. Of course, in other embodiments, one tab 21 can also be simultaneously connected with three, four, five or more tab connecting portions 32.

[0047] It can be understood that the battery cell 100 of the present application can increase the flow area between the tab 21 and the connecting piece 30, reduce the internal resistance of the battery cell 100, and improve the flow capacity of the battery cell 100 by providing a plurality of tab connecting portions 32 on the connecting piece 30 and electrically connecting the same tab 21 on the core pack 20 with at least two tab connecting portions 32 on the connecting piece 30.

[0048] In addition, it can also be understood that because the same tab 21 is electrically connected with at least two tab connecting portions 32, when the current on the tab 21 flows to the connecting piece 30, at least two tab connecting portions 32 can also achieve current shunt on the connecting piece 30, so that the current flowing through each tab connecting portion 32 can be reduced under the condition that the total current remains unchanged, and the heat generation of the connecting piece 30 can be reduced to avoid the case that the temperature of the battery cell 100 is too high during use.

[0049] In some embodiments, as shown in FIGS. 2, 3 and 4, the at least two tab connecting portions 32 connected to the same tab 21 are respectively located on both sides of the length direction of the pole connecting portion 31. Specifically, in the present embodiment, as shown in FIG. 2, the pole connecting portion 31 has a square shape, and the two dashed lines in the figure represent the left and right edges of the pole connecting portion 31. The connecting piece 30 is provided with four tab connecting portions 32, and the four tab connecting portions 32 are respectively named as the first left connecting portion 321, the first right connecting portion 322, the second left connecting portion 323 and the second right connecting portion 324.

[0050] As shown in FIG. 4, the first left connecting portion 321 and the first right connecting portion 322 are connected to the same tab 21, and the first left connecting portion 321 and the first right connecting portion 322 are respectively located on the left and right sides of the pole connecting portion 31. Similarly, the second left connecting portion 323 and the second right connecting portion 324 are connected to the same tab 21, and the second left connecting portion 323 and the second right connecting portion 324 are respectively located on the left and right sides of the pole connecting portion 31.

[0051] It can be understood that, by arranging the at least two lug connecting portions 32 connected to the same lug 21 on opposite sides of the pole connecting portion 31, the force on the connecting piece 30 is more balanced and uniform, and the connecting piece 30 is prevented from shaking and loosening from the lug 21 due to unbalanced force.

[0052] It should be noted that the "left" and "right" in the names of the first left connecting portion 321 and the first right connecting portion 322 are only used to represent the relative positions between the first left connecting portion 321 and the first right connecting portion 322, i.e., the relative position relationship between the first left connecting portion 321 and the first right connecting portion 322 is left-right, and do not represent the absolute positions of the first left connecting portion 321 and the first right connecting portion 322 on the connecting piece 30. The same applies to the second left connecting portion 323 and the second right connecting portion 324, which will not be described here.

[0053] It should also be noted that the two lugs 21 connected by the connecting piece 30 can be two lugs 21 on the same core pack 20. For example, some core packs 20 are provided with two positive lugs 213 and two negative lugs 214, and the connecting piece 30 can be connected between the two positive lugs 213 or the two negative lugs 214 on the same core pack 20.

[0054] In some embodiments, as shown in FIG. 3, the core pack 20 includes a first core pack 22 and a second core pack 23, the first core pack 22 is provided with a first lug 211, and the second core pack 23 is provided with a second lug 212. The first lug 211 and the second lug 212 are spaced apart in the width direction of the connecting piece 30, and the first lug 211 and the second lug 212 can both be positive lugs 213 or both be negative lugs 214.

[0055] As shown in FIG. 4, the first left connecting portion 321 and the first right connecting portion 322 are respectively located on the two sides of the pole connecting portion 31 in the length direction of the connecting piece 30, and the first left connecting portion 321 and the first right connecting portion 322 are respectively electrically connected to the first lug 211. The second left connecting portion 323 and the second right connecting portion 324 are respectively located on the two sides of the pole connecting portion 31 in the length direction of the connecting piece 30, and the second left connecting portion 323 and the second right connecting portion 324 are respectively electrically connected to the second lug 212.

[0056] That is, in the embodiment, the tab 21 on each core pack 20 is electrically connected with the connecting piece 30 through two tab connecting portions 32, which can not only increase the flow area between the connecting piece 30 and the tab 21, reduce the internal resistance of the battery cell 100, and improve the flow capacity of the battery cell 100, but also make the connection between the connecting piece 30 and the tab 21 simple and convenient enough to ensure the assembly efficiency of the battery cell 100.

[0057] In some embodiments, as shown in FIG. 4, the first left connecting portion 321 and the first right connecting portion 322 are respectively welded with the first tab 211 to form two welding areas 40, and the second left connecting portion 323 and the second right connecting portion 324 are respectively welded with the second tab 212 to form two welding areas 40. Among them, the two welding areas 40 on the first tab 211 are oppositely arranged along the length direction of the connecting piece 30, and the two welding areas 40 on the first tab 211 are symmetrically arranged about the pole connecting portion 31. The two welding areas 40 on the second tab 212 are oppositely arranged along the length direction of the connecting piece 30, and the two welding areas 40 on the second tab 212 are symmetrically arranged about the pole connecting portion 31.

[0058] Specifically, as shown in FIG. 2, the pole connecting portion 31 has a square shape, and the pole connecting portion 31 has a first median line 311 extending along the width direction of the connecting piece 30, and the first median line 311 divides the pole connecting portion 31 into two halves. Please understand in combination with FIG. 2 and FIG. 4 that the two welding areas 40 on the first tab 211 are symmetrically arranged about the first median line 311, and the two welding areas 40 on the second tab 212 are also symmetrically arranged about the first median line 311. It can be understood that this can make the stress of the connecting piece 30 more balanced and uniform, improve the stability of the connecting piece 30 and the core pack 20 in the shell 10, and improve the reliability of the battery cell 100.

[0059] It should be noted that when the two welding areas 40 on the first tab 211 are symmetrically arranged about the pole connecting portion 31, the two welding areas 40 on the first tab 211 can be symmetrically arranged about the first median line 311 of the pole connecting portion 31 as mentioned above. It can also be understood that the pole connecting 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 tab 211 are symmetrically arranged about the relatively thick "straight line". The same logic applies to the symmetric arrangement of the two welding areas 40 on the second tab 212 about the pole connecting portion 31, which will not be described here.

[0060] As shown in FIG. 2, the first left connecting part 321 and the second left connecting part 323 are opposite to each other along the width direction of the connecting sheet 30, and a first interval area 33 is formed between the first left connecting part 321 and the second left connecting part 323. As shown in FIG. 2 and FIG. 4, the welding area 40 on the first left connecting part 321 and the welding area 40 on the second left connecting part 323 are opposite to each other along the width direction of the connecting sheet 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 about the first interval area 33.

[0061] Specifically, as shown in FIG. 2, the pole connecting part 31 further has a second median line 312 extending along the length direction of the connecting sheet 30, and the second median line 312 can divide the first interval area 33 into two halves. As shown in FIG. 2 and FIG. 4, 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 about the second median line 312. It can be understood that in this way, the stress on the connecting sheet 30 is more balanced and uniform, the stability of the connecting sheet 30 and the core pack 20 in the shell 10 is improved, and the reliability of the battery cell 100 is improved.

[0062] Similarly, as shown in FIG. 2, the first right connecting part 322 and the second right connecting part 324 are opposite to each other along the width direction of the connecting sheet 30, and a second interval area 34 is formed between the first right connecting part 322 and the second right connecting part 324. As shown in FIG. 2 and FIG. 4, the welding area 40 on the first right connecting part 322 and the welding area 40 on the second right connecting part 324 are opposite to each other along the width direction of the connecting sheet 30, and the welding area 40 on the first right connecting part 322 and the welding area 40 on the second right connecting part 324 are symmetrically arranged about the second interval area 34.

[0063] 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 median line 312. It can be understood that in this way, the stress on the connecting sheet 30 is more balanced and uniform, the stability of the connecting sheet 30 and the core pack 20 in the shell 10 is improved, and the reliability of the battery cell 100 is improved.

[0064] It also needs to be explained 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 about the first interval area 33, the first interval area 33 can also be understood as a relatively thick "dashed line" extending along the length direction of the connecting sheet 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 about the relatively thick "dashed line". The same logic applies to the symmetric 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 about the second interval area 34, which will not be described here.

[0065] In some embodiments, in the length direction of the connecting tab 30, the length of the welding area 40 is greater than or equal to one fourth of the length of the connecting tab 30 and less than or equal to one third of the length of the connecting tab 30.

[0066] Specifically, as shown in FIG. 5, L1 represents the length of the welding area 40, and L2 represents the length of the connecting tab 30. L1 is greater than or equal to one fourth of L2 and less than or equal to one third of L2. Specifically, L1 can be one fourth of L2 (i.e., forty-tenths of ten), thirty-nine-tenths of ten, thirty-eight-tenths of ten, thirty-eight-tenths of ten, thirty-seven-tenths of ten, thirty-six-tenths of ten, thirty-five-tenths of ten, thirty-four-tenths of ten, thirty-three-tenths of ten, thirty-two-tenths of ten, thirty-one-tenths of ten, one third of L2 (i.e., thirty-tenths of ten), and the like.

[0067] It can be understood that if the length of the welding area 40 is less than one fourth of the length of the connecting tab 30, the area of the welding area 40 will be relatively small, and the flow area between the connecting tab 30 and the tab 21 cannot be effectively increased, and the flow capacity of the battery cell 100 cannot be effectively improved. If the length of the welding area 40 is greater than one third of the length of the connecting tab 30, the welding area 40 will extend to one side of the convex 313, and the welding head will interfere with the convex 313 during welding, increasing the welding difficulty and reducing the assembly efficiency of the battery cell 100.

[0068] Therefore, by making the length of the welding area 40 greater than or equal to one fourth of the length of the connecting tab 30 and less than or equal to one third of the length of the connecting tab 30, the flow area between the connecting tab 30 and the tab 21 can be ensured to be sufficient, thereby effectively improving the flow capacity of the battery cell 100, and the welding difficulty between the connecting tab 30 and the tab 21 is avoided to be increased, and the assembly efficiency of the battery cell 100 is ensured.

[0069] In some embodiments, in the width direction of the connecting tab 30, the width of the welding area 40 is greater than or equal to one fourth of the width of the tab connecting portion 32 and less than or equal to five fourths of the width of the tab connecting portion 32.

[0070] Specifically, as shown in FIG. 5, W1 represents the width of the welding area 40, and W2 represents the width of each tab connecting portion 32. W1 is greater than or equal to one fourth of W2 and less than or equal to five fourths of W2. Specifically, W1 can be one fourth of W2 (i.e., twenty-fifths of ten), twenty-sixths of ten, twenty-sevenths of ten, twenty-sixths of ten, twenty-eighths of ten, twenty-ninths of ten, twenty-tenths of ten, twenty-one-tenths of ten, twenty-two-tenths of ten, twenty-three-tenths of ten, twenty-four-tenths of ten, twenty-five-tenths of ten (i.e., twenty-sixths of ten), and the like.

[0071] It can be understood that if the width of the welding area 40 is less than one fourth of the width of the tab connecting portion 32, the area of the welding area 40 will be relatively small, and the flow area between the connecting tab 30 and the tab 21 cannot be effectively increased, and the flow capacity of the battery cell 100 cannot be effectively improved. If the width of the welding area 40 is greater than four fifths of the width of the connecting tab 30, the welding head needs to move multiple times along the width direction of the connecting tab 30 for each welding of the welding area 40, and the welding operation is complicated, and the assembly efficiency is low.

[0072] Therefore, in the embodiment, the width of the welding area 40 is greater than or equal to one fourth 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. In this way, the flow area between the connecting tab 30 and the tab 21 can be ensured to be sufficient, so as to effectively improve the flow capacity of the battery cell 100, and the welding operation is avoided to be complicated, and the assembly efficiency of the battery cell 100 is ensured.

[0073] In some embodiments, the length direction of the tab 21 is parallel to the length direction of the connecting tab 30, the length of the tab 21 is greater than or equal to the length of the connecting tab 30, and the difference between the length of the tab 21 and the length of the connecting tab 30 is less than or equal to 20 mm.

[0074] Specifically, as shown in FIG. 5, L2 represents the length of the connecting tab 30, and L3 represents the length of the tab 21. L3 is greater than or equal to L2, and the difference between L3 and L2 is less than or equal to 20 mm. Specifically, the difference 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.

[0075] It can be understood that if the length of the tab 21 is less than the length of the connecting tab 30, the length of the welding area 40 will be relatively small, the flow area between the connecting tab 30 and the tab 21 will be small, and the flow capacity of the battery cell 100 will be weak. If the length of the tab 21 is greater than the length of the connecting tab 30, and the difference between the length of the tab 21 and the length of the connecting tab 30 is greater than 20 mm, the tab 21 will interfere with the cover plate 13, affecting the installation of the cover plate 13 on the bottom shell 12.

[0076] Therefore, by making the length of the tab 21 greater than or equal to the length of the connecting piece 30, and the difference between the length of the tab 21 and the length of the connecting piece 30 less than or equal to 20 mm, the length of the welding area 40 can be avoided to be relatively small, the flow area between the connecting piece 30 and the tab 21 can be avoided to be small, the overcurrent capacity of the battery cell 100 can be improved, and the tab 21 can be avoided to interfere with the cover plate 13, affecting the installation of the cover plate 13 on the bottom shell 12.

[0077] In some embodiments, as shown in FIG. 4, the tab 21 is further provided with a convex 313 on the pole connecting part 31. The convex 313 is formed by bending the part of the surface of the connecting piece 30 relative to the other surface. The convex 313 is fixedly connected with the pole 11, and the convex 313 is centrally arranged on the pole connecting part 31.

[0078] Specifically, as shown in FIG. 4, if the line between the welding area 40 on the first left connecting part 321 and the welding area 40 on the second right connecting part 324, and the line between the welding area 40 on the first right connecting part 322 and the welding area 40 on the second left connecting part 323, then the intersection position of the two lines is the position of the convex 313. That is, the distance between the convex 313 and each welding area 40 is the same, which can make the stress of the connecting piece 30 more balanced and uniform, improve the stability of the connecting piece 30 and the core package 20 in the shell 10, and improve the reliability of the battery cell 100.

[0079] In some embodiments, as shown in FIG. 4, the tab 21 is also in conductive contact with the side wall of the convex 313. Specifically, as shown in the figure, in the width direction of the connecting piece 30, the first tab 211 and the second tab 212 also extend to one side of the convex 313 respectively and are in conductive contact with the convex 313. This can increase the contact area between the connecting piece 30 and the tab 21, and improve the overcurrent capacity of the battery cell 100.

[0080] As shown in FIGS. 6-27, the shell further comprises a cover plate, the cover plate assembly comprises a cover plate 13, the cover plate 13 has a first end face and a second end face 110 oppositely arranged along a first direction; the pole column 11 comprises a plurality of first pole columns 2111 and a plurality of second pole columns 2222, the plurality of first pole columns 2111 and the plurality of second pole columns 2222 are arranged on the cover plate 13; a plurality of first connecting pieces 3111 and a plurality of second connecting pieces 3222 are arranged on the second end face 110, the first connecting piece 3111 is connected with the first pole column 2111 one by one, the second connecting piece 3222 is connected with the second pole column 2222 one by one, and there is a gap between any first connecting piece 3111 and any second connecting piece 3222; wherein, at least the first connecting piece 3111 and the adjacent second connecting piece 3222 are provided with an insulation structure 401, and the insulation structure 401 is arranged on the side of the first connecting piece 3111 and the second connecting piece 3222 away from the cover plate 13.

[0081] By applying the technical scheme of the present application, a plurality of first pole columns 2111 and a plurality of second pole columns 2222 are arranged on the first end face of the cover plate 13, a plurality of first connecting pieces 3111 and a plurality of second connecting pieces 3222 are arranged on the second end face 110 of the cover plate 13, and the plurality of first pole columns 2111 and the plurality of second pole columns 2222 are arranged on the first end face. The first connecting piece 3111 is connected with the first pole column 2111 one by one, the second connecting piece 3222 is connected with the second pole column 2222 one by one, and there is a gap between any first connecting piece 3111 and any second connecting piece 3222. This can prevent the risk of short circuit caused by the overlap of the first connecting piece 3111 and the adjacent second connecting piece 3222, and at least the first connecting piece 3111 and the adjacent second connecting piece 3222 are provided with an insulation structure 401. This can prevent the risk of internal short circuit caused by the overlap of the first connecting piece and the adjacent second connecting piece, thereby improving the safety of the battery and facilitating the user's use.

[0082] It can be understood that the polarity of the first pole column 2111 and the second pole column 2222 is opposite, and the polarity of the first connecting piece 3111 and the second connecting piece 3222 is also opposite. When the first pole column 2111 is positive, the first connecting piece 3111 is also positive, then the second pole column 2222 is negative, and the second connecting piece 3222 is also negative. Conversely, when the first pole column 2111 is negative, the first connecting piece 3111 is also negative, then the second pole column 2222 is positive, and the second connecting piece 3222 is also positive. Herein, no specific limitation is made.

[0083] In the embodiments of the present application, when the number of the first pole column 2111 and the second pole column 2222 is both 2, they can be arranged and combined in the following ways: positive-positive-negative-negative, positive-negative-negative-positive, positive-negative-positive-negative, and so on, as long as the use requirements of the device can be met; when the number of the first pole column 2111 and the second pole column 2222 is both 3, they can be arranged and combined in the following ways: positive-positive-positive-negative-negative, positive-positive-negative-positive-negative, positive-positive-negative-positive-negative, positive-positive-negative-negative-positive, positive-negative-positive-positive-negative, and so on, so as to improve the applicability and application range of the battery cell as much as possible.

[0084] In the application, X is the second direction, which is the length direction of the cover plate 13, and the first direction is the thickness direction of the cover plate 13.

[0085] As shown in FIGS. 6-10, the above pictures are the case when the first pole column 2111 and the second pole column 2222 are both provided with two, taking the first pole column 2111 as a positive pole column, the first connecting piece 3111 as a positive polarity, the second pole column 2222 as a negative pole column, and the second connecting piece 3222 as a negative polarity as an example, the above pictures are the case of positive-negative-positive-negative (positive and negative poles staggered).

[0086] As shown in FIGS. 10-13, the above pictures are the case when the first pole column 2111 and the second pole column 2222 are both provided with two, taking the first pole column 2111 as a positive pole column, the first connecting piece 3111 as a positive polarity, the second pole column 2222 as a negative pole column, and the second connecting piece 3222 as a negative polarity as an example, the above pictures are the case of positive-positive-negative-negative (positive and negative poles on the same side).

[0087] As shown in FIGS. 14-17, the above pictures are the case when the first pole column 2111 and the second pole column 2222 are both provided with two, taking the first pole column 2111 as a positive pole column, the first connecting piece 3111 as a positive polarity, the second pole column 2222 as a negative pole column, and the second connecting piece 3222 as a negative polarity as an example, the above pictures are the case of positive-negative-negative-positive.

[0088] As shown in FIGS. 18-21, the above pictures are the case when the first pole column 2111 and the second pole column 2222 are both provided with two, taking the first pole column 2111 as a positive pole column, the first connecting piece 3111 as a positive polarity, the second pole column 2222 as a negative pole column, and the second connecting piece 3222 as a negative polarity as an example, the above pictures are the case of negative-positive-positive-negative.

[0089] As shown in FIGS. 22-23, the above pictures are the case when the first pole column 2111 and the second pole column 2222 are both provided with three, taking the first pole column 2111 as a positive pole column, the first connecting piece 3111 as a positive polarity, the second pole column 2222 as a negative pole column, and the second connecting piece 3222 as a negative polarity as an example, the above pictures are the case of positive-negative poles staggered.

[0090] As shown in FIGS. 24-25, the above pictures are the case when the first pole 2111 and the second pole 2222 are both provided as three, taking the first pole 2111 as the positive pole, the first connecting piece 3111 as the positive polarity, the second pole 2222 as the negative pole, and the second connecting piece 3222 as the negative polarity as an example, the above pictures are the case of positive-positive-positive-negative-negative (positive and negative poles on the same side).

[0091] In the present application, when at least one first pole 2111 and at least one second pole 2222 are arranged adjacent to each other in the first direction, the remaining plurality of first poles 2111 and the remaining plurality of second poles 2222 can be arranged in parallel in the second direction.

[0092] The plurality of first connecting pieces 3111 and the plurality of second connecting pieces 3222 are arranged in the second direction, and the second direction is perpendicular to the first direction. In this way, the overall appearance of the cover plate 13 assembly is more beautiful and neat, and it is also convenient to connect with external components. The plurality of first poles 2111 and the plurality of second poles 2222 can also be arranged in other directions as long as the use requirements of the device can be met. In the present application, the spaced arrangement specifically refers to that the plurality of first poles 2111 and the plurality of second poles 2222 are located on the same straight line, and the polarity of the adjacent two poles is not limited here. The specific arrangement should be selected according to the use environment of the device.

[0093] Specifically, the plurality of first connecting pieces 3111 and the plurality of second connecting pieces 3222 are arranged alternately in the second direction. In this way, the first poles 2111 and the second poles 2222 are evenly distributed on the cover plate 13, which can make the current density more uniform when the battery is charging and discharging, thereby reducing the heating of the battery to maintain the stable operation of the battery.

[0094] The number of first connecting pieces 3111 is equal to the number of second connecting pieces 3222. In this way, the stability of the battery output can be ensured to maintain the normal operation of the battery.

[0095] Specifically, the first connecting piece 3111 and the second connecting piece 3222 are provided with an insulating structure 401 at both ends in the second direction. In this way, the insulation effect of the first connecting piece 3111 and the second connecting piece 3222 can be improved, which can prevent the first connecting piece and the second connecting piece 3222 from being overlapped to cause the risk of internal short circuit, thereby increasing the safety of the battery.

[0096] The extension length of the insulation structure 401 along the second direction is L, and 2mm≤L≤3mm. When L>3mm, the extension length of the insulation material along the second direction is too large, which increases the use cost of the insulation material, and also reduces the welding area of the first connecting piece 3111 or the second connecting piece 3222 and the tab, which is not conducive to the welding of the two. When L<2mm, the extension length of the insulation material along the second direction is too small, which makes the cross-sectional area of the insulation material small, and easily causes the adjacent first connecting piece 3111 and the second connecting piece 3222 to be overlapped to cause a short circuit risk, which cannot meet the insulation requirement of the first connecting piece 3111 and the second connecting piece 3222. Therefore, 2mm≤L≤3mm is beneficial to reduce the production cost, thereby realizing the batch production of the assembly, and can also ensure the welding area of the first connecting piece 3111 or the second connecting piece 3222 and the tab, which is conducive to the welding of the two, and the cross-sectional area of the insulation material is large, which can avoid the risk of short circuit caused by the overlap of the adjacent first connecting piece 3111 and the second connecting piece 3222, and meet the insulation requirement of the first connecting piece 3111 and the second connecting piece 3222. L can be set to 2mm, 2.5mm or 3mm, etc. The specific setting condition should be selected according to the use environment of the first connecting piece 3111 and the second connecting piece 3222, which is not limited here.

[0097] Specifically, the first connecting piece 3111 and the second connecting piece 3222 have a protruding portion 50 extending along the second direction, and the protruding portion 50 of the first connecting piece 3111 is arranged in the opposite direction to the protruding portion 50 of the adjacent second connecting piece 3222. In this way, the spacing between the adjacent first connecting piece 3111 and the second connecting piece 3222 is as large as possible, thereby avoiding the risk of short circuit caused by the overlap of the first connecting piece 3111 and the adjacent second connecting piece 3222 as much as possible, and being beneficial to maintaining the stability of the battery during operation.

[0098] The insulation structure 401 includes a ceramic silicone rubber layer or a fluorine rubber layer. In other embodiments of the present application, the insulation structure 401 can also be set as a TC composite tape, a mica plate, a mica roll, ceramic, polytetrafluoroethylene, etc., as long as it can meet the insulation requirement of the battery.

[0099] In the present application, the extension length of the insulating structure 401 in the width direction of the cover plate 13 is equal to the extension length of the first connecting piece 3111 in the width direction of the cover plate 13. By setting the above structure, the coverage of the insulating structure 401 to the first connecting piece 3111 can be ensured. Of course, the extension length of the insulating structure 401 in the width direction of the cover plate 13 can also be set to be equal to the extension length of the second connecting piece 3222 in the width direction of the cover plate 13, so as to ensure the coverage effect of the insulating structure 401 to the first connecting piece 3111 and the second connecting piece 3222, thereby preventing the risk of short circuit between the components.

[0100] Specifically, the first connecting piece 3111 comprises an aluminum connecting piece, and the second connecting piece 3222 comprises a copper connecting piece. Since the positive electrode of the battery is realized by oxidation reaction, it means that the entire electrochemical process must be completed by oxidation reaction. In this process, the chemical reaction of the positive electrode will release a large amount of heat, and aluminum can withstand high temperature, so it is selected as the positive electrode material. In addition, aluminum has a lower potential and better conductivity. The negative electrode of the battery is realized by reduction reaction, that is, the entire electrochemical process must be completed by reduction reaction. Unlike the positive electrode, the chemical reaction of the negative electrode will consume a large amount of heat, and copper has good conductivity and can withstand this reaction condition at room temperature, so it is selected as the negative electrode material. In addition, the high potential of copper can also ensure the flow of current, so that the battery can work more stably.

[0101] In the second aspect, the embodiments of the present application provide a battery pack, the battery pack comprising the battery cell 100 of any one of the above embodiments. Since the battery pack of the present application adopts all the technical solutions of the above embodiments, it at least has all the beneficial effects brought by the technical solutions of the above embodiments, which will not be repeated here.

Claims

1. An electric cell, comprising: a housing, on which a pole post is mounted; a cell pack, which is installed in the housing, and on which a plurality of tabs are provided; and a connecting sheet, which comprises a pole post connecting portion and a plurality of tab connecting portions connected to the pole post connecting portion, the pole post connecting portion being electrically connected to the pole post, and the same tab being electrically connected to at least two of the tab connecting portions.

2. The electric cell of claim 1, wherein, The plurality of tabs comprises a plurality of positive tabs and a plurality of negative tabs, and the connecting sheet is provided with a plurality of At least one of the connecting sheets is electrically connected to at least two of the positive tabs, and each of the positive 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 tabs, and each of the negative tabs is electrically connected to a plurality of the tab connecting portions on the same connecting sheet.

3. The electric cell of claim 2, wherein, The same cell pack is provided with a plurality of positive tabs, and the connecting sheet is connected between a plurality of the positive tabs on the same cell pack. And / or, the same cell pack is provided with a plurality of negative tabs, and the connecting sheet is connected between a plurality of the negative tabs on the same cell pack.

4. The electric cell of claim 1, wherein, The at least two of the tab connecting portions connected to the same tab are respectively located on both sides of the pole post connecting portion in the length direction of the pole post connecting portion.

5. The electric cell of claim 4, wherein, The cell pack comprises a first cell pack, on which a first tab is provided. The plurality of tab connecting portions on the connecting sheet comprises a first left connecting portion and a first right connecting portion, which are respectively located on both sides of the pole post connecting portion in the length direction of the connecting sheet, and the first left connecting portion and the first right connecting portion are respectively electrically connected to the first tab.

6. The electric cell of claim 5, wherein, The cell pack further comprises a second cell pack, The second cell pack is provided with a second tab, and the first tab and the second tab are spaced apart in the width direction of the connecting sheet. The plurality of tab connecting portions on the connecting sheet further comprises a second left connecting portion and a second right connecting portion, which are respectively located on both sides of the pole post connecting portion in the length direction of the connecting sheet, and the second left connecting portion and the second right connecting portion are respectively electrically connected to the second tab.

7. The electric cell of claim 6, wherein, The first left connecting portion and the first right connecting portion are respectively welded to the first 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 tab to form a welding area. The two welding areas on the first tab are oppositely arranged in the length direction of the connecting sheet, and the two welding areas on the first tab are symmetrically arranged about the pole post connecting portion. And / or, the two welding areas on the second tab are oppositely arranged in the length direction of the connecting sheet, and the two welding areas on the second tab are symmetrically arranged about the pole post connecting portion.

8. The electric cell of claim 7, wherein, The first left connecting part and the second left connecting part are opposite to each other along the width direction of the connecting sheet, and a first interval region is formed between the first left connecting part and the second left connecting part; the welding region on the first left connecting part and the welding region on the second left connecting part are arranged opposite to each other along the width direction of the connecting sheet, and the welding region on the first left connecting part and the welding region on the second left connecting part are symmetrically arranged about the first interval region; And / or, the first right connecting part and the second right connecting part are opposite to each other along the width direction of the connecting sheet, and a second interval region is formed between the first right connecting part and the second right connecting part; the welding region on the first right connecting part and the welding region on the second right connecting part are arranged opposite to each other along the width direction of the connecting sheet, and the welding region on the first right connecting part and the welding region on the second right connecting part are symmetrically arranged about the second interval region.

9. The electric cell of claim 7, wherein, In the length direction of the connecting sheet, the length of the welding region is greater than or equal to one fourth of the length of the connecting sheet, and less than or equal to one third of the length of the connecting sheet; And / or, in the width direction of the connecting sheet, the width of the welding region is greater than or equal to one fourth of the width of the tab connecting part, and less than or equal to five fourths of the width of the tab connecting part.

10. The battery cell according to any one of claims 1-9, wherein the length direction of the tab is parallel to the length direction of the connecting sheet, and the length of the tab is greater than or equal to the length of the connecting sheet, and the difference between the length of the tab and the length of the connecting sheet is less than or equal to 20 mm.

11. The battery cell according to any one of claims 1-9, wherein a convex bump is further provided on the tab connecting part, and the convex bump is fixedly connected with the tab connecting part; The convex bump is centrally arranged on the tab connecting part, or the convex bump is centrally arranged with respect to a plurality of tab connecting parts on the same connecting sheet. The tab is further in conductive contact with the side wall of the convex bump.

12. The electric cell of claim 11, wherein, 13. The battery cell according to claim 1, wherein: The shell comprises a cover plate assembly, and the cover plate assembly comprises a cover plate having a first end face and a second end face arranged opposite to each other along a first direction; The tab comprises a plurality of first tabs and a plurality of second tabs, and the plurality of first tabs and the plurality of second tabs are arranged on the cover plate in a spaced manner; A plurality of first connecting members and a plurality of second connecting members are arranged on the second end face, the first connecting members are connected with the first tabs one by one, the second connecting members are connected with the second tabs one by one, and there is a spacing between any first connecting member and any second connecting member; At least the mutually close parts of the first connecting member and the adjacent second connecting member are provided with an insulating structure, and the insulating structure is arranged on the side of the first connecting member and the second connecting member away from the cover plate. wherein, The plurality of first connecting members and the plurality of second connecting members are arranged in a spaced manner along a second direction, and the second direction is perpendicular to the first direction.

14. The electric cell of claim 13, wherein, ​ 15. The electric cell of claim 14, wherein, The first connecting members and the second connecting members are arranged alternately in the second direction.

16. The electric cell of any of claims 14-15, wherein, The first connecting members and the second connecting members are arranged alternately in the second direction.

17. The cell of any of claims 14-15, wherein, The insulation structure has an extension length L in the second direction, and 2mm≤L≤3mm.

18. The electric cell of claim 14, wherein, The first connecting members and the second connecting members each have a protruding portion extending in the second direction, and the protruding portion of the first connecting member is arranged opposite to the protruding portion of the second connecting member.

19. The electrically core of claim 16, wherein, The insulation structure has an extension length in the width direction of the cover plate, which is equal to the extension length of the first connecting member in the width direction of the cover plate.

20. A battery pack comprising: The battery cell of any one of claims 1-19.

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