Assembly of cells of energy storage element and method for assembling such assembly
The reversible fastening system with folded electrical connections and continuous stacks allows for efficient and damage-free disassembly of battery cells, addressing inefficiencies in existing connection methods.
Patent Information
- Application Number
- CN202380084340.4
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Priority Date
- 2022-12-07
- Filing Date
- 2023-11-27
- Publication Date
- 2025-07-15
AI Technical Summary
The prior art is difficult to disassemble the connection of multiple cells without damaging the cell, and the commonly used fastening methods increase the floor area of the assembly or require additional gaps, which cannot meet the electrical performance and mechanical strength requirements of the cell.
The conductive wiring tab and a reversible fastening device of the folded part extend along the longitudinal axial adjacent cell through the folded part, and the conductive strip and support are tightened together by using a screw connection to achieve a reversible connection of the cell.
The efficient electrical connection of the battery cell is achieved, the battery cell can be disassembled separately during maintenance operations without affecting the mechanical integrity of other batteries, and the impact on the total quality of the battery cell assembly is reduced.
Smart Images
Figure CN120322906A_ABST
Abstract
Description
Field of the Invention
[0001] The present invention relates to the field of electrical energy storage devices such as batteries.
[0002] More specifically, the present invention relates to the electrical connection of cells (especially so-called pouch cells) within a battery to form a component of the cells. Prior Art
[0003] Electrical energy storage devices include electrochemical elements or so-called pouch cells.
[0004] Figure 1 Component 1 of cells 1a to 1h is shown; there are eight cells here. Each of the plurality of cells includes two electrical connection tabs 2a, 3a to 2h, 3h having positive and negative polarities respectively.
[0005] In order to connect a plurality of cells together, it is known to use laser welding to connect the tabs of these cells. However, laser welding is not applicable to all metal materials, especially when combining copper components with aluminum components. In addition, this type of fastening does not allow the separation of multiple cells of the same sub-component without damaging the cells.
[0006] Another solution for connecting a plurality of cells involves assembling these cells by stamping or by riveting with an added U-shaped cross-section part. However, this solution greatly increases the footprint of the component and requires sufficient clearance for the tools for stamping the parts. In addition, this type of fastening does not allow the separation of multiple cells of the same sub-component without damaging the cells.
[0007] It is also known that ultrasonic welding can be used to connect a plurality of cells together. Although this solution provides mechanical strength, the tools for welding require sufficient clearance. In addition, this type of fastening does not allow the separation of multiple cells of the same sub-component without damaging the cells and generates internal mechanical stress on the cells.
[0008] There is a need to optimize the electrical connection of cells within a battery. Summary of the Invention
[0009] Accordingly, an object of the present invention is to overcome the above-mentioned drawbacks.
[0010] An object of the present invention is to improve the electrical connection of cells in a battery cell component so that an individual cell can be disassembled while minimizing the impact on the total mass of the cell component and ensuring the electrical performance of the cells.
[0011] The object of the present invention is a component of a cell of an energy storage element (e.g., a battery), the component comprising at least a first cell and an adjacent second cell, the first cell and the adjacent second cell each comprising two electrically connecting tabs having respectively a positive polarity and a negative polarity.
[0012] Each tab of the first cell comprises a folded portion extending from the first cell to the second cell, and each tab of the second cell comprises a folded portion extending from the second cell to the first cell.
[0013] The component comprises a continuous stack comprising at least one support, a first conductive bar, a folded portion of one of the tabs of the first cell, a second conductive bar, a folded portion of one of the tabs of the second cell, and a third conductive bar.
[0014] The component of the cells comprises a reversible fastening means for the stack, the reversible fastening means being configured to apply a clamping force to the stack.
[0015] Thus, the electrical connection of the cells in the battery cell component is efficient and it is possible to remove a single battery, for example during a maintenance operation, without affecting the mechanical integrity of the other cells.
[0016] For example, it may be provided that the component of the cells comprises a number of cells greater than or equal to three arranged in parallel or in series.
[0017] Advantageously, each electrically connecting tab comprises a first portion extending from an end of the main portion of the corresponding cell and a folded portion extending from an end of the first portion perpendicular to the first portion.
[0018] Thus, the folded portion extends along a longitudinal axis perpendicular to the extension axis of the cell towards the adjacent cell.
[0019] In other words, the folded portion of the electrically connecting tab of the first cell extends along the longitudinal axis towards the adjacent second cell, and the folded portion of the electrically connecting tab of the second cell extends along the longitudinal axis towards the adjacent first cell.
[0020] The thickness of the conductive tab is for example about 0.15 millimeters (mm).
[0021] The conductive tab is for example made of a metallic material, which is for example copper, aluminum or nickel. Thus, the conductive tab can be folded.
[0022] Advantageously, an electrically insulating support is arranged between two adjacent cells, and the first conductive bar is arranged on the support.
[0023] For example, the width of the support is less than the longitudinal distance between two adjacent cells.
[0024] In other words, a longitudinal gap is left between the support member and each of the two battery cells.
[0025] The first conductive bar, the second conductive bar, and the third conductive bar are preferably made of the same material, such as a metallic material, for example aluminum.
[0026] Therefore, the first conductive bar, the second conductive bar, and the third conductive bar have the same resistivity.
[0027] Advantageously, the thickness of the second conductive bar is greater than the thickness of each of the first conductive bar and the third conductive bar.
[0028] In fact, the current provided by the first battery cell is carried by the first conductive bar and the second conductive bar, while the current provided by the second battery cell is carried by the second conductive bar and the third conductive bar. Thus, the second conductive bar carries the current from both the first battery cell and the second battery cell. For example, the thickness of the second conductive bar is equal to twice the thickness of each of the first conductive bar and the third conductive bar.
[0029] Therefore, the temperature of the conductive bar in contact with the battery cell is homogenized, which makes it possible to homogenize the temperature of the battery cell.
[0030] Advantageously, each of the first bar, the second bar, and the third bar includes a hole that mates with a reversible fastening device, and the plurality of holes are coaxial to allow the fastening device to pass through.
[0031] For example, the reversible fastening device includes at least one screwing device that mates with the support member.
[0032] According to one embodiment, the screwing device is a screw that mates with a threaded hole formed in the support member.
[0033] Alternatively, it may be provided that the support member includes a threaded extension that extends into the hole of the conductive bar and mates with a nut, and the threaded extension is, for example, a stud.
[0034] By screwing a screw into a corresponding threaded hole formed in the support member, or by tightening a nut that mates with the stud, the following continuous stack can be fastened together: the support member; the first conductive bar; the folded portion of the connection tab of the first battery cell; the second conductive bar; the folded portion of the connection tab of the second battery cell; and the third conductive bar.
[0035] The pressure applied when tightening the screw or the nut allows the necessary current to flow between the conductive bar and the tab through the deformation of the conductive bar on the tab.
[0036] According to one embodiment, the reversible fastening device includes at least two screwing devices that both mate with the support member.
[0037] According to one embodiment, the assembly further includes spring means, such as spring means in the form of a spring strip, which is mounted between two screwing means and a third conductive strip.
[0038] Thus, the spring strip includes: a first part which is attached to a first screwing means integral with the bearing part of the conductive strip; a second part which is attached to a second screwing means integral with the connecting part of the conductive strip; and a central part which connects the first part and the second part. The central part bears on the third conductive strip.
[0039] According to one embodiment, the folded part of the tab of each cell includes a through-hole which mates with the screwing means.
[0040] The through-hole is coaxial with the holes drilled in the first, second and third strips, and the threaded hole or stud of the support.
[0041] For example, the first, second and third strips have a shape configured to connect one tab of each cell to one tab of an adjacent cell.
[0042] For example, the assembly of cells of the battery includes a number of cells equal to eight.
[0043] For example, the first, second and third strips have an E shape which includes: a plurality of transverse bearing parts, each bearing part bearing on the folded part of the tab of the second cell; and a longitudinal connecting part connecting the plurality of bearing parts.
[0044] Preferably, if the number of cells is even, the number of bearing parts is equal to half of the number of cells. If the number of cells is odd, the number of bearing parts is equal to half of the number of cells plus one bearing part.
[0045] Each of the plurality of bearing parts of the third conductive strip may include a through-hole which mates with a screw.
[0046] Similarly, each of the plurality of bearing parts of the first and second conductive strips may include through-holes, and only two of the holes mate with screws. The holes formed in the first, second and third strips are coaxial.
[0047] For example, the connecting part of the third strip further includes a series of second holes which lead to a threaded hole formed in the support.
[0048] According to a second aspect, the invention relates to a method for assembling an assembly of cells (for example, a battery) of energy storage elements, the assembly including at least a first cell and an adjacent second cell, the first cell and the adjacent second cell each including two electrically connecting tabs having positive and negative polarities respectively.
[0049] According to the assembling method:
[0050] - Position the first conductive bar on the support;
[0051] - Fold one of the two connection tabs of the first battery cell onto the first conductive bar until the folded portion of the tab contacts the first
[0052] conductive bar;
[0053] - Position the second conductive bar on the folded portion of the connection tab of the first battery cell;
[0054] - Fold one of the two connection tabs of the second battery cell onto the second conductive bar until the folded portion of the tab contacts the second
[0055] conductive bar;
[0056] - Position the third conductive bar on the folded portion of the connection tab of the second battery cell; and
[0057] - Fasten the following continuous stack by means of a reversible fastening device: the support; the first conductive bar; the folded portion of the connection tab of the first battery cell; the second conductive bar; the folded portion of the connection tab of the second battery cell; and the third conductive bar.
[0058] The reversible fastening device is configured to apply a clamping force to the stack.
[0059] At the end of the stacking step, a continuous stack of the following is thus obtained: the support; the first conductive bar; the folded portion of the connection tab of the first battery cell; the second conductive bar; the folded portion of the connection tab of the second battery cell; and the third conductive bar. Description of the Drawings
[0060] Further objects, features and advantages of the present invention will become apparent upon reading the following description, which is given by way of non-limiting example only and with reference to the accompanying drawings, in which:
[0061] Figure 1 is a perspective view of a battery cell assembly according to the prior art;
[0062] Figure 2 is a cross-sectional view of an assembly of battery cells according to an embodiment of the present invention;
[0063] Figure 3 is a partial perspective view of the steps of assembling an assembly of battery cells according to Figure 2 ;
[0064] Figure 4 is according to Figure 2 Stereogram of the components of the battery cell;
[0065] Figure 5 is a cross-sectional view of the components of the battery cell according to another embodiment of the present invention;
[0066] Figure 6 is a cross-sectional view of the components of the battery cell according to another embodiment of the present invention; and
[0067] Figure 7 shows a flowchart of a method of assembling the components of the battery cell shown Figure 2 . DETAILED DESCRIPTION
[0068] In the remainder of this description, a standard orthogonal coordinate system X, Y, Z is defined, where:
[0069] - The X-axis represents the longitudinal axis defining the stacking axis of each battery cell of the components of the battery cell;
[0070] - The Y-axis represents the transverse axis, extending through the width of the battery cell; and
[0071] - The Z-axis represents the vertical axis perpendicular to the longitudinal axis X and the transverse axis Y.
[0072] Referring to the example shown Figures 2 to 4 , the components 10 of the battery cells of the battery are arranged parallel to the longitudinal axis X.
[0073] As Figure 2 shown, the components 10 include, in a non-limiting manner, two battery cells 11, 12. Alternatively, it may be provided that the components 10 include a number of battery cells greater than or equal to three arranged in parallel.
[0074] Each battery cell 11, 12 includes a main portion 11a, 12a extending along a vertical axis and two electrical connection tabs 13, 14 having positive and negative polarities respectively, Figure 2 only one of which is shown in
[0075] Each electrical connection tab 13, 14 includes a first portion 13a, 14a extending from the end of the main portion 11a, 12a of the corresponding battery cell 11, 12 and a folded portion 13b, 14b extending perpendicularly to the first portion 13a, 14a from the end of the first portion 13a, 14a. Thus, the folded portions 13b, 14b of each connection tab extend along the longitudinal axis X towards the adjacent battery cells 11, 12.
[0076] In other words, the folded portion 13b of each electrical connection tab 13 of the first battery cell 11 extends along the longitudinal axis X towards the adjacent second battery cell 12, and the folded portion 14b of each electrical connection tab 14 of the second battery cell 12 extends along the longitudinal axis X towards the adjacent first battery cell 11.
[0077] As Figure 2 shown, the assembly 10 further includes an electrically insulating support member 15 disposed between two adjacent battery cells 11 and 12. Here, the longitudinal dimension or width of the support member 15 along the longitudinal axis X is smaller than the longitudinal distance between the two adjacent battery cells 11 and 12. In other words, a longitudinal gap is left between the support member 15 and each of the battery cells 11, 12.
[0078] As Figure 2 shown, the assembly 10 further includes a first conductive bar 16 disposed on the support member 15, and a folded portion 13b of the connection tab 13 of the first battery cell 11 is supported on the first conductive bar 16.
[0079] The assembly 10 further includes a second conductive bar 17 and a third conductive bar 18. The second conductive bar 17 is disposed on the folded portion 13b of the connection tab 13 of the first battery cell 11, and the folded portion 14b of the connection tab 14 of the second battery cell 12 is supported on the second conductive bar 17. The third conductive bar 18 is disposed on the folded portion 14b of the connection tab 14 of the second battery cell 12.
[0080] Thus, the assembly 10 includes, in sequence along the vertical axis Z: the support member 15, the first conductive bar 16, the folded portion 13b of the connection tab 13 of the first battery cell 11, the second conductive bar 17, the folded portion 14b of the connection tab 14 of the second battery cell 12, and the third conductive bar 18.
[0081] The current provided by the first battery cell 11 is carried by the first conductive bar 16 and the second conductive bar 17, and the current provided by the second battery cell 12 is carried by the second conductive bar 17 and the third conductive bar 18.
[0082] The first conductive bar 16, the second conductive bar 17, and the third conductive bar 18 are preferably made of the same material, which is, for example, a metallic material such as aluminum. Thus, the first conductive bar 16, the second conductive bar 17, and the third conductive bar 18 have the same resistivity.
[0083] The second conductive bar 17 carries the current from both the first battery cell 11 and the second battery cell 12. The thickness of the second conductive bar 17 is preferably greater than the thickness of each of the first conductive bar 16 and the third conductive bar 18. For example, the thickness of the second conductive bar 17 is equal to twice the thickness of each of the first conductive bar 16 and the third conductive bar 18.
[0084] Thus, the temperatures of the conductive bars 16, 17, 18 in contact with the battery cells 11, 12 are equalized, which makes it possible to equalize the temperatures of the battery cells 11, 12.
[0085] The first strip 16, the second strip 17, and the third strip 18 have a shape configured to connect one of the two tabs of one cell to one of the two tabs of an adjacent cell.
[0086] From Figure 3 and Figure 4 it can be seen that Figure 3 and Figure 4 an exemplary assembly 10 including a number of cells equal to eight is shown.
[0087] As Figure 3 shown, and without limitation in any way, the first strip 16, the second strip 17, and the third strip 18 have an X shape, equivalent to the juxtaposition of an E shape and an inverted E shape.
[0088] The shape will be described with reference to the third strip 18, it being understood that the first strip 16 and the second strip 17 have the same shape as the shape of the third strip 18.
[0089] The third conductive strip 18 includes: four transverse bearing portions 18a, 18b, 18c, 18d, each transverse bearing portion being supported on a folded portion 14b of a tab 14 of the second cell 12; and a longitudinal connecting portion 18a that connects the bearing portions 18a, 18b, 18c, 18d.
[0090] Alternatively, a different number of bearing portions may be provided. The number of bearing portions is equal to half the number of cells.
[0091] Each of the bearing portions 18a, 18b, 18c, 18d of the third conductive strip 18 includes through-holes 20a, 20b, 20c, 20d that cooperate with screws 19, thereby forming a reversible fastening means.
[0092] Similarly, each of the plurality of bearing portions of the first conductive strip 16 and the second conductive strip 17 includes through-holes that cooperate with screws 19, Figure 3 only two of these through-holes 17a, 17b being shown therein. The holes in the first strip 16, the second strip 17, and the third strip 18 are coaxial.
[0093] The connecting portion 18a of the third strip 18 further includes a series of second holes 21 that lead to threaded holes (not shown in the figure) formed in the support 15.
[0094] Alternatively, it may be provided that the support 15 includes threaded extensions, such as studs, that extend into the holes of the conductive strips 16, 17, 18 and cooperate with nuts.
[0095] The following continuous stack is fastened by screwing a screw 19 into a corresponding threaded hole formed in a support member 15: the support member 15; a first conductive bar 16; a folded portion 13b of a connection tab 13 of a first battery cell 11; a second conductive bar 17; a folded portion 14b of a connection tab 14 of a second battery cell 12; and a third conductive bar 18.
[0096] The pressure applied when tightening the screw 19 allows the necessary current to flow between the conductive bars 16, 17, 18 and the tabs 13, 14 through the deformation of the tabs 13, 14 by the conductive bars 16, 17, 18.
[0097] Thus, if one battery cell of the battery cell assembly 10 is replaced, when replacing the first battery cell 11, it is sufficient to remove the third conductive bar 18 and then the second conductive bar 17. The folded portions 13b, 14b of the tabs 13, 14 of the battery cell to be replaced are unfolded.
[0098] The ability to individually disassemble each battery cell reduces maintenance costs.
[0099] The tongue is very thin, for example 0.15 mm, which generates electrical stress. This makes it easier to fold and unfold the folded portions of the tabs.
[0100] Figure 5 Another embodiment is shown, in which the same elements have the same reference numerals, and which differs from the embodiment shown in Figures 2 to 4 only in that the assembly 10 includes spring means 22 in the form of a leaf spring.
[0101] The leaf spring 22 is mounted between two screwed devices 19 (screws or nuts) and the third conductive bar 18.
[0102] Thus, the leaf spring 22 includes: a first portion 22a, which is attached to a first screwed device 19 integral with a bearing portion of the conductive bars 16, 17, 18; a second portion 22b, which is attached to a second screwed device 19 integral with a connecting portion of the conductive bars 16, 17, 18; and a central portion 22c, which connects the first portion 22a and the second portion 22b. The central portion 22c bears on the third conductive bar 18.
[0103] Figure 6 Another embodiment is shown, in which the same elements have the same reference numerals, and which differs from the embodiment shown in Figures 2 to 4 only in that the folded portions 13b, 14b of the tabs 13, 14 of the battery cells 11, 12 of the assembly 10 each include through holes (not shown) that cooperate with the screwed devices 19. The through holes are coaxial with the holes drilled in the first bar 16, the second bar 17 and the third bar 18, and the threaded holes or studs of the support member 15.
[0104] Figure 7 shows a method 30 for assembling a component 10 of an electric cell as shown, wherein, in step 31, a first conductive strip 16 is positioned on a support 15, and then, in step 32, a tab 13 of a first electric cell 11 is folded onto the first conductive strip 16 until a folded portion 13b contacts the first conductive strip 16. Figure 2
[0105] Then, in step 33, a second conductive strip 17 is positioned on the folded portion 13b of the tab 13 of the first electric cell 11, and in step 34, a tab 14 of a second electric cell 12 adjacent to the first electric cell 11 is folded onto the second conductive strip 17 until a folded portion 14b bears on the second conductive strip 17.
[0106] Then, in step 35, a third conductive strip 18 is positioned on the folded portion 14b of the tab 14 of the second electric cell 12.
[0107] At the end of step 35, a continuous stack is obtained of: a support 15; a first conductive strip 16; a folded portion 13b of a connection tab 13 of a first electric cell 11; a second conductive strip 17; a folded portion 14b of a connection tab 14 of a second electric cell 12; and a third conductive strip
[0108] Then, in step 36, the stack is fastened by a reversible fastening means (for example, a screwing device 19 configured to apply a clamping force to the stack).
[0109] The connection of the electric cells is described here with reference to the parallel connection of the electric cells and the connection of the negative electrode on the one hand and the positive electrode on the other hand. Alternatively, a connection can be provided: a series connection in which the negative electrode of an electric cell is connected to the positive electrode of an adjacent electric cell.
[0110] Thanks to the present invention, it is easy to replace the electric cell of the component of the electric cell without damaging the rest of the component.
Claims
1. A component (10) of an energy storage element cell (11, 12), said component (10) comprising at least: A first electric cell (11) and an adjacent second electric cell (12), each of the first electric cell (11) and the adjacent second electric cell (11, 12) comprising two electrically connecting tabs (13, 14) having respectively a positive polarity and a negative polarity, characterized in that each tab (13) of the first electric cell comprises a folded portion (13b) extending from the first electric cell (11) to the second electric cell (12), and each tab (14) of the second electric cell comprises a folded portion (14b) extending from the second electric cell (12) to the first electric cell (11), and the assembly (10) comprises a continuous stack, the stack comprising: a support (15), a first conductive bar (16), a folded portion (13b) of one of the tabs (13) of the first electric cell (11), a second conductive bar (17), a folded portion (14b) of one of the tabs (14) of the second electric cell (12), and a third conductive bar (18), the assembly (10) comprising reversible fastening means (19, 22) for the stack, the reversible fastening means being configured to apply a clamping force to the stack.
2. The component (10) according to claim 1, wherein, The electrically insulating support (15) is arranged between two adjacent electric cells (11, 12), and wherein the first conductive bar (16) is arranged on the support (15).
3. The component (10) according to claim 1, wherein, The width of the support (15) is less than the longitudinal distance between two adjacent electric cells (11, 12).
4. The component (10) according to claim 1 or 2, wherein The first conductive bar (16), the second conductive bar (17) and the third conductive bar (18) are made of the same material.
5. The component (10) according to any one of the preceding claims, wherein, The thickness of the second conductive bar (17) is greater than the thickness of each of the first conductive bar (16) and the third conductive bar (18).
6. The component (10) according to any one of the preceding claims, wherein, Each of the first bar (16), the second bar (17) and the third bar (18) comprises a hole for cooperating with the fastening means (19), and a plurality of the holes are coaxial.
7. The component (10) according to any one of the preceding claims, wherein, The reversible fastening means comprises at least one screwing means (19) for cooperating with the support (15).
8. The component (10) according to claim 7, wherein, The reversible fastening means comprises at least two screwing means (19) both for cooperating with the support (15).
9. The assembly (10) according to claim 8, comprising spring means (22) mounted between the two screwing means (19) and the third conductive bar (18).
10. The assembly (10) according to any one of the preceding claims, wherein, The folded portions (13b, 14b) of the tabs (13, 14) of the electric cells (11, 12) each comprise a through hole for cooperating with the screwing means (19).
11. A method of assembling an assembly (10) of electric cells (11, 12) of an energy storage element, the assembly (10) at least comprising a first electric cell (11) and an adjacent second electric cell (12), each of the first electric cell (11) and the adjacent second electric cell (12) comprising two electrically connecting tabs (13, 14) having respectively a positive polarity and a negative polarity, wherein: - Positioning a first conductive bar (16) on a support (15); - Fold one of the connection tabs (13) of the first battery cell (11) onto the first conductive strip (16) until the folded portion (13b) of the connection tab (13) contacts the first conductive strip (16); - Position the second conductive strip (17) on the folded portion (13b) of the connection tab (13) of the first battery cell (11); - Fold one of the connection tabs (14) of the second battery cell (12) onto the second conductive strip (17) until the folded portion (14b) of the connection tab (14) contacts the second conductive strip (17); - Position the third conductive strip (18) on the folded portion (14b) of the connection tab (14) of the second battery cell (12); And - Fasten the successive stackings of: the support (15); the first conductive strip (16); the folded portion (13b) of the connection tab (13) of the first battery cell (11); the second conductive strip (17); the folded portion (14b) of the connection tab (14) of the second battery cell (12); And the third conductive strip (18) by means of reversible fastening means (19, 22), the reversible fastening means being configured to apply a clamping force to the stack.