Battery cell connecting piece, battery cell and battery

Abstract

The utility model relates to the technical field of energy storage equipment, in particular to a battery cell connecting piece, a battery cell and a battery. The battery cell connecting piece is formed by stacking and fixing multiple layers of flexible connecting pieces, the battery cell connecting piece is provided with a to-be-bent area, a pre-pressing groove is formed in the first face of the to-be-bent area, after the battery cell connecting piece is bent and formed, the to-be-bent area forms a curved surface area, and the groove bottom of the pre-pressing groove forms the inner side wall face of the curved surface area. The battery cell comprises a battery cell shell, an output piece, a pole group and the battery cell connecting piece. The battery comprises a battery shell and the battery cell, wherein the battery cell is arranged in the battery shell. The battery cell connecting piece, the battery cell and the battery can improve the yield, reduce the cost and improve the production efficiency.

Description

Technical Field

[0001] The utility model relates to the technical field of energy storage equipment, and in particular to a battery core connecting piece, a battery core and a battery. Background Art

[0002] The battery cell is provided with a connecting piece, which is used to connect the tab of the electrode group with the output part of the battery cell. The performance of the connecting piece has a relatively critical impact on the power conduction and safety of the battery cell. There are currently three types of connecting pieces: hard connecting pieces, soft connecting single-layer connecting pieces, and soft connecting multi-layer connecting pieces. Among them, the hard connecting piece is generally a metal piece, which has good structural strength and is not easily deformed under stress. However, in order to ensure that the battery cell has a certain flow capacity, the hard connecting piece is required to have a sufficiently large width and a sufficiently large cross-sectional area. However, a hard connecting piece with sufficient width is not easy to bend and process into shape. The curvature of the transition curved surface section of the hard connecting piece after bending is small, resulting in a large space occupation, which is not conducive to improving the energy density of the battery cell. The soft connecting single-layer connecting piece is easy to bend, and the transition curved surface section can have a large curvature, reducing the space occupied by the connecting piece, but its structural strength is insufficient and it is easily deformed under stress. Auxiliary parts need to be added to prevent excessive deformation from affecting the quality of the battery cell. In addition, the thickness is too low and the flow capacity is insufficient. The flexible connection multi-layer connecting piece is made of multiple layers of flexible connecting pieces, and has better performance than the previous two in terms of structural strength, current capacity and bendability.

[0003] However, when processing and manufacturing a soft-connect multi-layer connecting piece with a laterally open U-shaped structure, the bending angle must be within the range of 180°±15°. If the bending angle is greater than 195°, there is a risk that the tab will be tightened and then broken. If the bending angle is less than 165°, that is, the bending is not in place, there is a risk that the space occupied by the connecting piece will increase, the bending space of the tab will decrease, the tab will be compressed toward the pole group, and there is a risk that the tab will be inserted into the pole group upside down, which may eventually cause the insulation of the battery cell to fail. The existing technology is to directly use bending equipment to bend the flat-plate connecting piece. The connecting pieces with bending angles that meet the above requirements only account for 81.2%. The high defective rate will directly lead to high processing costs and low production efficiency. Utility Model Content

[0004] One purpose of the utility model is to provide a battery core connecting piece that can improve yield, reduce costs, and improve production efficiency.

[0005] To achieve this purpose, the present invention adopts the following technical solutions:

[0006] A battery cell connecting sheet is provided, wherein the battery cell connecting sheet is formed by stacking and fixing multiple layers of soft connecting sheets. The battery cell connecting sheet has a to-be-bent area, and a pre-pressing groove is provided on a first surface of the to-be-bent area. After the battery cell connecting sheet is bent and formed, the to-be-bent area forms a curved area, and the bottom of the pre-pressing groove forms the inner wall surface of the curved area.

[0007] Optionally, the curved surface area is arranged to penetrate along a first direction, and the pre-pressing groove is arranged to penetrate along the first direction.

[0008] Optionally, the thickness of the battery cell connecting piece ranges from 0.5 mm to 1.5 mm;

[0009] And / or, the ratio of the maximum depth of the pre-pressing groove to the thickness of the battery cell connecting piece is in the range of 20%-50%;

[0010] And / or, the ratio of the width of the pre-pressing groove to the thickness of the battery cell connecting piece is in the range of 4-8.

[0011] Optionally, the maximum depth of the pre-pressing groove ranges from 0.1 mm to 0.75 mm;

[0012] And / or, the width of the pre-pressing groove ranges from 2 mm to 12 mm.

[0013] Optionally, the area to be bent is provided with a through hole.

[0014] Optionally, the battery cell connecting piece further has a first connection area and a second connection area, the first connection area and the second connection area are respectively located on both sides of the area to be bent, the first connection area is used to electrically connect to the output component, and the second connection area is used to electrically connect to the tab.

[0015] Optionally, the multiple layers of the soft connection sheets in the fixing area of ​​the first connection area are fixed by ultrasonic welding, and the output member is laser welded to the fixing area;

[0016] And / or, some of the multiple layers of the soft connecting sheets in the second connecting area are connected to form a first layer group, and the remaining layers are connected to form a second layer group, and the tab is sandwiched between the first layer group and the second layer group.

[0017] Another object of the present invention is to provide a battery cell with a higher yield, lower costs and improved production efficiency.

[0018] To achieve this purpose, the present invention adopts the following technical solutions:

[0019] A battery cell is provided, comprising a battery cell housing, an output component, an electrode group, and the above-mentioned battery cell connecting piece, wherein the battery cell connecting piece and the electrode group are both arranged in the battery cell housing, the output component is inserted into the battery cell housing, and the battery cell connecting piece is electrically connected to the output component and the electrode tabs of the electrode group.

[0020] Another object of the present invention is to provide a battery with a higher yield, lower costs and improved production efficiency.

[0021] To achieve this purpose, the present invention adopts the following technical solutions:

[0022] A battery is provided, comprising a battery casing and the above-mentioned battery core, wherein the battery core is arranged in the battery casing.

[0023] Beneficial effects of the utility model:

[0024] The utility model provides a battery cell connector. The battery cell connector is formed by stacking and fixing multiple layers of flexible connectors. The battery cell connector has a bending area. The first surface of the bending area is provided with a pre-pressing groove. After the battery cell connector is bent, the bending area forms a curved area, and the bottom of the pre-pressing groove forms the inner wall of the curved area. By providing the pre-pressing groove, the bending position can be determined, the stability of subsequent bending is improved, and the bending angle meets the requirements, thereby improving the yield of the battery cell connector, reducing costs, and improving production efficiency.

[0025] The utility model also provides a battery cell comprising a battery cell housing, an output member, an electrode group, and the aforementioned battery cell connecting piece. The battery cell connecting piece and the electrode group are both disposed within the battery cell housing. The output member is inserted into the battery cell housing. The battery cell connecting piece is electrically connected to the output member and the electrode tabs of the electrode group. This battery cell has a higher yield, can reduce costs, and improve production efficiency.

[0026] The utility model also provides a battery, comprising a battery housing and the above-mentioned battery cell, wherein the battery cell is arranged in the battery housing. The battery cell of the battery has a higher yield rate, can reduce costs and improve production efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 This is a schematic structural diagram of a battery cell connecting piece provided by an embodiment of the present utility model;

[0028] Figure 2 This is a schematic diagram of the structure of the battery cell connecting piece provided in an embodiment of the present utility model after being bent;

[0029] Figure 3 This is a front view of the battery cell connecting piece provided by an embodiment of the present utility model;

[0030] Figure 4 This is a side view of the battery cell connecting piece provided by an embodiment of the present utility model;

[0031] Figure 5 yes Figure 4 Enlarged view of point A in the middle;

[0032] Figure 6 yes Figure 4 Enlarged view of point B in the middle;

[0033] Figure 7This is a schematic structural diagram of a battery cell provided by an embodiment of the present utility model from a first perspective;

[0034] Figure 8 This is an exploded view of the battery cell provided by an embodiment of the present utility model;

[0035] Figure 9 This is a schematic structural diagram of a battery cell provided by an embodiment of the present utility model from a second perspective;

[0036] Figure 10 yes Figure 9 Middle CC section view;

[0037] Figure 11 yes Figure 10 Enlarged view of point D in the middle;

[0038] Figure 12 yes Figure 10 Enlarged view of point E in the middle.

[0039] In the picture:

[0040] 1. Bend area; 11. Pre-pressed groove; 12. Through hole; 2. First connection area; 21. First fixing area; 22. Second fixing area; 3. Second connection area; 31. First layer group; 32. Second layer group; 4. Curved surface area;

[0041] 100, battery cell connecting piece; 101, flexible connecting piece; 200, battery cell casing; 201, top cover; 202, battery cell casing; 300, output component; 400, pole group; 401, pole ear; 500, insulating film; 600, patch; 700, end plate; 800, insulating sheet. DETAILED DESCRIPTION

[0042] The technical solution of the present invention is further described below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely for the purpose of explaining the present invention, and are not intended to limit the present invention. It should also be noted that, for ease of description, the accompanying drawings only illustrate portions relevant to the present invention, not all of it.

[0043] In the description of this utility model, it should be noted that, unless otherwise expressly specified or limited, the terms "mounted," "connected," and "connected" should be understood in a broad sense. For example, they can refer to fixed or detachable connections; mechanical or electrical connections; direct or indirect connections through an intermediate medium; and internal communication between two components. Those skilled in the art will understand the specific meanings of the above terms in this utility model based on the specific circumstances.

[0044] In the present invention, unless otherwise expressly specified or limited, a first feature being "above" or "below" a second feature may include the first and second features being in direct contact, or may include the first and second features being in contact not directly but through another feature between them. Moreover, a first feature being "above," "above," and "above" a second feature may include the first feature being directly above or obliquely above the second feature, or may simply mean that the first feature is higher in level than the second feature. A first feature being "below," "below," and "below" a second feature may include the first feature being directly below or obliquely below the second feature, or may simply mean that the first feature is lower in level than the second feature.

[0045] The battery cell is provided with a connecting piece, which is used to connect the tab of the electrode group with the output part of the battery cell. The performance of the connecting piece has a relatively critical impact on the power conduction and safety of the battery cell. There are currently three types of connecting pieces: hard connecting pieces, soft connecting single-layer connecting pieces, and soft connecting multi-layer connecting pieces. Among them, the hard connecting piece is generally a metal piece, which has good structural strength and is not easily deformed under stress. However, in order to ensure that the battery cell has a certain flow capacity, the hard connecting piece is required to have a sufficiently large width and a sufficiently large cross-sectional area. However, a hard connecting piece with sufficient width is not easy to bend and process into shape. The curvature of the transition curved surface section of the hard connecting piece after bending is small, resulting in a large space occupation, which is not conducive to improving the energy density of the battery cell. The soft connecting single-layer connecting piece is easy to bend, and the transition curved surface section can have a large curvature, reducing the space occupied by the connecting piece, but its structural strength is insufficient and it is easily deformed under stress. Auxiliary parts need to be added to prevent excessive deformation from affecting the quality of the battery cell. In addition, the thickness is too low and the flow capacity is insufficient. The flexible connection multi-layer connecting piece is made of multiple layers of flexible connecting pieces, and has better performance than the previous two in terms of structural strength, current capacity and bendability.

[0046] However, when processing and manufacturing a soft-connect multi-layer connecting piece with a laterally open U-shaped structure, the bending angle must be within the range of 180°±15°. If the bending angle is greater than 195°, there is a risk that the tab will be tightened and then broken. If the bending angle is less than 165°, that is, the bending is not in place, there is a risk that the space occupied by the connecting piece will increase, the bending space of the tab will decrease, the tab will be compressed toward the pole group, and there is a risk that the tab will be inserted into the pole group upside down, which may eventually cause the insulation of the battery cell to fail. The existing technology is to directly use bending equipment to bend the flat-plate connecting piece. The connecting pieces with bending angles that meet the above requirements only account for 81.2%. The high defective rate will directly lead to high processing costs and low production efficiency.

[0047] Therefore, this embodiment provides a cell connecting sheet 100 to improve yield, reduce costs, and improve production efficiency. Figures 1-6As shown, the cell connection sheet 100 of this embodiment is formed by stacking multiple layers of soft connection sheets 101. The cell connection sheet 100 has a bending area 1. The first surface of the bending area 1 is provided with a pre-pressing groove 11. After the cell connection sheet 100 is bent and formed, it is as shown in FIG. Figure 2 As shown, the area to be bent 1 forms a curved area 4 , and the bottom of the pre-pressing groove 11 forms the inner wall of the curved area 4 .

[0048] The cell connecting piece 100 of this embodiment is provided with a pre-pressing groove 11. During subsequent bending, the pre-pressing groove 11 is helpful in determining the bending position, improving the stability of the bending, and ensuring that the bending angle of the cell connecting piece 100 meets the requirements after bending, thereby improving the yield of the cell connecting piece 100, reducing costs, and improving production efficiency.

[0049] In actual production, only 81.2% of existing connecting sheets without pre-pressing grooves 11 met the bending angle requirements after bending, resulting in a yield rate of only 81.2%. However, the cell connecting sheet 100 of this embodiment, which has the same specifications as the existing connecting sheet but includes pre-pressing grooves 11, met the bending angle requirements after bending, resulting in a yield rate of 96.8%, a 15.6% increase compared to the existing connecting sheet. The cell connecting sheet 100 of this embodiment significantly improves yield, significantly reducing costs and improving production efficiency.

[0050] Optionally, the curved area 4 is provided through the first direction, and the pre-pressing groove 11 is provided through the first direction. Figure 3 In the ab direction, in this embodiment, the pre-compression groove 11 is not a closed groove, but a groove that is open on both sides. Whether the pre-compression groove 11 is open depends on the bending shape of the battery cell connecting piece 100. In this embodiment, the battery cell connecting piece 100 is bent into a U-shaped structure, that is, the curved surface area 4 is also open at both ends, and the corresponding pre-compression groove 11 is also set to be open at both ends. Of course, in other embodiments, the pre-compression groove 11 can also be a groove with one end closed and the other end open, or a groove with both ends closed, which can be adjusted according to the bending shape of the battery cell connecting piece 100.

[0051] Optionally, the thickness H of the cell connecting piece 100 is in the range of 0.5 mm to 1.5 mm. Figure 5-Figure 6 As shown, the cell connection sheet 100 is composed of eight layers of flexible connection sheets 101 stacked together. Of course, in other embodiments, the flexible connection sheet 101 can also be arranged with two, three, four, five, six, seven, nine, or more layers. In this embodiment, the flexible connection sheet 101 is an aluminum foil substrate or a copper foil substrate. The thickness of the substrate, i.e., the thickness of a single layer, can be 0.1mm, 0.2mm, or 0.3mm. The aluminum foil substrate or copper foil substrate is formed into multiple layers through a process such as winding.

[0052] Optionally, the ratio of the maximum depth h of the pre-pressing groove 11 to the thickness H of the cell connecting piece 100 is in the range of 20%-50%. Optionally, the maximum depth h of the pre-pressing groove 11 is in the range of 0.1mm-0.75mm. Preferably, the maximum depth h of the pre-pressing groove 11 is 0.2mm.

[0053] Optionally, the ratio of the width W of the pre-pressing groove 11 to the thickness H of the cell connecting piece 100 is in the range of 4 to 8. Optionally, the width W of the pre-pressing groove 11 is in the range of 2 mm to 12 mm.

[0054] Table 1

[0055]

[0056] Table 1 above lists twelve examples of cell connector sheets 100. To accommodate cell sizes of varying sizes, the thickness H of the cell connector sheet 100 is selected from 0.5mm, 0.8mm, 1.2mm, and 1.5mm within the range of 0.5mm-1.5mm. The compression depth ratio of the cell connector sheet 100, i.e., the ratio of the maximum depth h of the pre-pressed groove 11 to the thickness H of the cell connector sheet 100, is within the range of 20%-50%. For the three examples with the same thickness H, the compression depth ratio range is wide, with the two end nodes, 20% and 50%, taken as close as possible to characterize the effect of the compression depth ratio within this range on the bending angle. Based on this compression depth ratio, the maximum depth h of the pre-pressed groove 11 is within the range of 0.1mm-0.75mm.

[0057] In the above embodiment, the width-to-thickness ratio of the pre-pressing groove 11 of the cell connecting piece 100, that is, the ratio of the width W of the pre-pressing groove 11 to the thickness H of the cell connecting piece 100, is in the range of 4-8. Accordingly, the width W of the pre-pressing groove 11 is in the range of 2 mm-12 mm.

[0058] The above-mentioned embodiments of the battery cell connecting sheet 100 all meet the preferred pressing-depth ratio and width-to-thickness ratio of the pre-pressing groove 11. The bending angles of the finished products obtained after bending are all within the range of 169°-192°, which fully meets the yield requirement of 180°±15°. This can avoid the risk of the tab 401 being stretched and broken, as well as the risk of the tab 401 being invertedly inserted into the electrode group 400, thereby ensuring the stability of the battery cell quality.

[0059] In addition, the bending angles of the finished products after directly bending the connecting pieces of the same specifications as in the embodiment without setting the pre-pressing groove 11 were compared. The thicknesses of the connecting pieces were 0.5mm, 0.8mm, 1.2mm, and 1.5mm, respectively. The bending angles of the finished products after bending were 138°, 141°, 140°, and 135°, respectively. All of them are cases of incomplete bending. It can be seen that setting the pre-pressing groove 11 significantly improves the bending angle of the finished product after bending.

[0060] Table 2

[0061]

[0062] Table 2 above lists sixteen comparative examples to illustrate the effect of the compression ratio on the bending angle. The thickness of the cell connector 100 remains within the range of 0.5mm-1.5mm, and the width-to-thickness ratio of the pre-pressed groove 11 also conforms to the more optimal range of 4-8. The compression ratios of the first eight comparative examples are all less than 20%, and the bending angles are all less than 165°, indicating that the bending is not in place. There is a risk that the cell connector 100 occupies a large space, the tab 401 has little bending space, and the tab 401 is compressed toward the electrode assembly 400 and inserted upside down into the electrode assembly 400, which may ultimately lead to cell insulation failure. The compression ratios of the last eight comparative examples are all greater than 50%, and the bending angles are all greater than 200°, indicating that the bending is excessive, and there is a risk that the tab 401 is tightened and then broken.

[0063] It can be seen from this that a value of the pressure depth ratio in the range of 20%-50% can best ensure that the bending angle is around 180°. If the pressure depth ratio is too small, the effect of the pre-compression groove 11 is too small, and the bending will not be in place. When the pressure depth ratio is too large, the pre-compression groove 11 is too deep, and the bending will be excessive. Not only is there a risk of the tab 401 breaking, but it will also affect the structural strength of the battery cell connecting piece 100 in the curved area 4, reducing the quality stability of the battery cell.

[0064] Table 3

[0065]

[0066] Table 3 above lists sixteen other comparative examples to illustrate the effect of the width-to-thickness ratio of the pre-pressed groove 11 on the bending angle. The thickness of the cell connector 100 remains within the range of 0.5mm-1.5mm, and the pressing-to-depth ratio also conforms to the more optimal range of 20%-50%. The width-to-thickness ratios of the pre-pressed grooves 11 in the first eight comparative examples are all less than 4, and the bending angles are all less than 165°, meaning they are not bent properly. This creates a risk of the cell connector 100 occupying a large space, leaving the tab 401 with little room to bend, and the tab 401 being compressed toward the electrode assembly 400 and inserted upside down, ultimately leading to cell insulation failure. The width-to-thickness ratios of the pre-pressed grooves 11 in the last eight comparative examples are all greater than 8, and the bending angles are all greater than 195°, meaning they are excessively bent, creating a risk of the tab 401 being stretched and subsequently broken.

[0067] It can be seen from this that the value of the width-to-thickness ratio of the pre-compression groove 11 in the range of 4-8 can best ensure that the bending angle is around 180°. If the width-to-thickness ratio of the pre-compression groove 11 is too small, the effect of the pre-compression groove 11 is too small, and the bending area 1 on both sides of the pre-compression groove 11 will still affect the bending effect, and the bending is not in place. When the width-to-thickness ratio of the pre-compression groove 11 is too large, the pre-compression groove 11 is too wide and will bend excessively. Not only is there a risk of the tab 401 breaking, but it will also affect the structural strength of the battery cell connecting piece 100 in the curved area 4, reduce the quality stability of the battery cell, and affect the conduction capacity of the battery cell connecting piece 100.

[0068] Optionally, the bending area 1 is provided with a through hole 12 to further reduce the bending force required and ensure the stability of the bending effect. Optionally, the bending area 1 is provided with multiple through holes 12 spaced apart along the first direction so that the bending force required at each location along the first direction is substantially the same.

[0069] Optionally, the cell connecting sheet 100 further comprises a first connecting region 2 and a second connecting region 3, wherein the first connecting region 2 and the second connecting region 3 are respectively located on both sides of the to-be-bent region 1. Figure 11 and Figure 12 As shown, the first connection area 2 is used to electrically connect to the output component 300, and the second connection area 3 is used to electrically connect to the tab 401. After the battery cell connection sheet 100 is bent, one of the two parallel plates of the U-shaped structure is connected to the output component 300, that is, the pole, and the other is connected to the tab 401. In this embodiment, the first connection area 2, the bending area 1 and the second connection area 3 are arranged in sequence along the second direction. The second direction is Figure 3 cd direction in .

[0070] In order to prevent the multi-layer soft connecting sheets 101 from being misaligned with each other and leaving gaps, which causes the conductive resistance to increase, it is necessary to fix the multi-layer soft connecting sheets 101. Optionally, the multi-layer soft connecting sheets 101 in the fixed area of ​​the first connection area 2 are fixed by ultrasonic welding, and the output part 300 is laser welded to the fixed area. That is, by ultrasonic welding a part of the first connection area 2, the multi-layer soft connecting sheet 101 can be fixed to prevent misalignment. After ultrasonic welding, the tensile strength of the first connection area 2 is greater than 50N, which can ensure the structural strength. After the ultrasonic welding is completed, there will be weld marks on the welding surface. When laser welding is performed between the first connection area 2 and the pole, the pits on the weld mark surface can absorb the laser to avoid reflection problems.

[0071] like Figure 1As shown, in this embodiment, the fixing area includes a first fixing area 21 and a second fixing area 22, that is, the first fixing area 21 and the second fixing area 22 are both ultrasonic welding fixing areas. Among them, the first fixing area 21 is located near the middle and has the largest area, and is used for laser welding the pole. Multiple second fixing areas 22 are dispersed on both sides of the first fixing area 21. The multiple second fixing areas 22 are all long strips and extend along the length direction of the first connection area 2. The multiple second fixing areas 22 are arranged in parallel at intervals. Of course, in other embodiments, the shape, position, number, etc. of the first fixing areas 21 and the second fixing areas 22 can be arranged according to the shape of the first connection area 2.

[0072] like Figure 4 and Figure 6 As shown, optionally, some of the multiple layers of flexible connecting sheets 101 in the second connection area 3 are connected to form a first layer group 31, and the remaining layers are connected to form a second layer group 32. In this embodiment, four layers of flexible connecting sheets 101 on one side form the first layer group 31, and four layers of flexible connecting sheets 101 on the other side form the second layer group 32. Of course, in other embodiments, the first layer group 31 may also include two, three, five, six, or more layers of flexible connecting sheets 101, and the second layer group 32 may also include two, three, five, six, or more layers of flexible connecting sheets 101, without limitation herein.

[0073] like Figure 6 As shown, the base material is wound to obtain the cell connecting sheet 100, which can achieve that the ends of the two central layers of the soft connecting sheet 101 of the first layer group 31 are originally connected, and the ends of the two outer layers of the soft connecting sheet 101 are also connected, forming a form of connection from the inside to the outside, and the same is true for the second layer group 32. Optionally, the innermost layer misalignment is less than 1mm. Optionally, the tab 401 can be sandwiched between the first layer group 31 and the second layer group 32, and because the end connection of the first layer group 31 is closed and the end connection of the second layer group 32 is closed, when the tab 401 is sandwiched between the two, the gap between the first layer group 31 and the second layer group 32 can be quickly found, thereby improving processing efficiency. Optionally, the tab 401 is fixed to the second connection area 3 by laser welding to ensure welding accuracy.

[0074] Optionally, the tab 401 may also be welded to the outer surface of the second connection area 3, as shown in FIG. Figure 11 and Figure 12 As shown, the tab 401 is connected to the side of the second connection area 3 facing the first connection area 2, that is, the tab 401 is located in the space between the first connection area 2 and the second connection area 3, which can save space in the battery cell. In this case, the second connection area 3 can be configured as a first layer group 31 and a second layer group 32, or multiple layers can be omitted.

[0075] Optionally, in this embodiment, the battery cell connecting sheet 100 is made of O-state 1060 aluminum foil, the thickness of a single layer of the aluminum foil substrate is 0.1 mm, and there are 8 layers in total, with a total thickness of 0.8 mm.

[0076] like Figure 7-12 As shown, this embodiment further provides a battery cell, including a battery cell housing 200, an output member 300, an electrode group 400 and the above-mentioned battery cell connecting piece 100. The battery cell has a higher yield, can reduce costs and improve production efficiency.

[0077] The cell connection piece 100 and the electrode group 400 are both arranged in the cell housing 200, and the output piece 300 is inserted into the cell housing 200. The cell connection piece 100 is electrically connected to the output piece 300 and the pole lug 401 of the pole group 400. Optionally, the cell housing 200 includes a cell shell 202 and a top cover 201 arranged at both ends. The cell shell 202 and the top cover 201 are laser welded to form a sealed space for accommodating the pole lug 401. The output piece 300 is arranged on the top cover 201, wherein the positive pole output piece 300 is arranged on one side of the top cover 201, and the negative pole output piece 300 is arranged on the other side of the top cover 201. The cell connection piece 100 is first welded to the pole lug 401 and then welded to the top cover 201 to achieve electrical energy conduction.

[0078] To prevent short circuits between cells through the cell housing 200, an insulating film 500 is optionally provided on the cell housing 202, and a patch 600 is attached to the outside of the top cover 201. To prevent short circuits between the electrode assembly 400 and the cell housing 202, an insulating sheet 800 is also provided on the electrode assembly 400, sandwiched between the assembly and the cell housing 202. Insulating sheet 800 is made of a plastic material such as PP or PC to ensure internal insulation.

[0079] Optionally, the battery cell may be provided with an end plate 700, specifically located between the top cover 201 and the electrode group 400, to support the battery cell connecting piece 100 and provide space for the battery cell connecting piece 100 to prevent the stress-bearing curved surface area 4 of the battery cell connecting piece 100 from breaking. Figure 8 and Figure 12 As shown, the end plate 700 supports and limits the portion of the cell connection piece 100 not connected to the output member 300, preventing deformation or contact with the top cover 201. End plates 700 may be provided on the top covers 201 at both ends, or one end may be provided while the other is not, or neither end may be provided. The selection can be based on the specifications and shape of the cell.

[0080] This embodiment also provides a battery comprising a battery housing and the aforementioned battery cell, wherein the battery cell is disposed within the battery housing, and multiple battery cells can be grouped in series or parallel and then loaded into the battery housing. The battery cell of this battery has a higher yield, can reduce costs, and improve production efficiency.

[0081] The manufacturing method of the battery cell connecting sheet 100 includes multiple steps, which are specifically as follows.

[0082] Winding and fixing stage: The foil is wound into a multi-layer structure, and then the multi-layer structure of the first connection area 2 is fixed by ultrasonic welding. The battery cell connecting sheet 100 is flattened using a flattening device.

[0083] Optionally, an intermediate product with four layers of soft connecting sheets 101 is formed by winding, wherein the two inner layers are the same sheet and the two outer layers are the same sheet. Then, two intermediate products with four layers of soft connecting sheets 101 are taken, and after being stacked and aligned, the unwound end is used as the first connection area 2, and ultrasonic welding is performed at the position of the first connection area 2 to obtain an intermediate product with eight layers of soft connecting sheets 101, and then flattened. The intermediate product with eight layers of soft connecting sheets 101 can be directly formed as follows in the second connection area 3. Figure 6 In the structure shown, the first layer group 31 and the second layer group 32 are easy to separate.

[0084] Optionally, an intermediate product of a three-layer, five-layer, six-layer or more-layer soft connecting sheet 101 can be directly formed by winding, and then ultrasonic welding is performed directly in the first connecting area 2, and then flattened, and then the tab 401 is directly welded to one side of the second connecting area 3.

[0085] Punching stage: Punching pre-pressed grooves 11 and punching through holes 12 in the bending area 1 to obtain the battery cell connection sheet 100. In this embodiment, the pre-pressed grooves 11 and punching through holes 12 are punched in the bending area 1 of the intermediate product with eight layers of flexible connection sheets 101.

[0086] Inspection stage: The cell connector 100 is manually cut and then oiled on both sides. Finally, the cell connector 100 is inspected using a CCD full inspection method to check whether the size of the cell connector 100 and the size and position of the pre-pressing groove 11 and the through hole 12 meet the design requirements.

[0087] Bending stage: the battery cell connecting sheet 100 is bent until the bending area 1 is bent to form the curved area 4 .

[0088] The above manufacturing method can improve the yield of the finished product obtained by bending the battery cell connecting piece 100, thereby reducing costs and improving production efficiency.

[0089] Obviously, the above embodiments of the present invention are merely examples for the purpose of clearly illustrating the present invention, and are not intended to limit the implementation methods of the present invention. Those skilled in the art will appreciate that other variations or modifications can be made based on the above description. It is not necessary and impossible to enumerate all implementation methods here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention shall be included within the scope of protection of the claims of the present invention.

Claims

1. A battery cell connecting piece, characterized in that: The cell connection sheet (100) is formed by stacking and fixing multiple layers of soft connection sheets (101). The cell connection sheet (100) has a to-be-bent area (1). A pre-pressing groove (11) is provided on a first surface of the to-be-bent area (1). After the cell connection sheet (100) is bent and formed, the to-be-bent area (1) forms a curved area (4), and the bottom of the pre-pressing groove (11) forms an inner wall surface of the curved area (4).

2. The battery cell connecting sheet according to claim 1, characterized in that: The curved surface area (4) is arranged to penetrate along a first direction, and the pre-pressing groove (11) is arranged to penetrate along the first direction.

3. The battery cell connecting sheet according to claim 1, characterized in that: The thickness of the battery core connecting piece (100) ranges from 0.5 mm to 1.5 mm; And / or, the ratio of the maximum depth of the pre-pressing groove (11) to the thickness of the battery cell connecting piece (100) is in the range of 20%-50%; And / or, the ratio of the width of the pre-pressing groove (11) to the thickness of the battery cell connecting piece (100) is in the range of 4-8.

4. The battery cell connecting piece according to claim 3, characterized in that: The maximum depth of the pre-pressing groove (11) is in the range of 0.1 mm to 0.75 mm; And / or, the width of the pre-pressing groove (11) is in the range of 2 mm to 12 mm.

5. The battery cell connecting sheet according to claim 1, characterized in that: The to-be-bent area (1) is provided with a through hole (12).

6. The battery cell connecting sheet according to claim 1, characterized in that: The battery cell connecting piece (100) further comprises a first connecting area (2) and a second connecting area (3), wherein the first connecting area (2) and the second connecting area (3) are respectively located on both sides of the area to be bent (1), the first connecting area (2) is used for electrically connecting to the output component (300), and the second connecting area (3) is used for electrically connecting to the tab (401).

7. The battery cell connecting sheet according to claim 6, characterized in that: The multiple layers of the soft connection sheets (101) in the fixing area of ​​the first connection area (2) are fixed by ultrasonic welding, and the output member (300) is laser welded to the fixing area; And / or, some of the multiple layers of the soft connecting sheet (101) in the second connecting area (3) are connected to form a first layer group (31), and the remaining layers are connected to form a second layer group (32), and the tab (401) is sandwiched between the first layer group (31) and the second layer group (32).

8. A battery cell, characterized in that: The invention comprises a cell shell (200), an output component (300), a pole group (400) and a cell connecting piece according to any one of claims 1 to 7, wherein the cell connecting piece (100) and the pole group (400) are both arranged in the cell shell (200), the output component (300) is inserted into the cell shell (200), and the cell connecting piece (100) is electrically connected to the output component (300) and the pole ear (401) of the pole group (400).

9. A battery, characterized in that The invention comprises a battery casing and the battery core as claimed in claim 8, wherein the battery core is arranged in the battery casing.

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