Method and unit for manufacturing battery cells

Abstract

The present invention relates to a method for manufacturing cells for secondary batteries, and this method is - The first operation involves rewinding the separator film (3), - A second operation involves depositing the first electrode (1) onto the separator film (3), -A third operation in which the first horizontal edge (4) and the first vertical edge (6) of the first electrode (1) are held on the separator film (3) using the first holding element (8), and the second horizontal edge (5) on the opposite side of the first horizontal edge (4) and the first vertical edge (6) of the first electrode (1) is also held using the second holding element (10), - A fourth operation involves unwinding the separator film (3) to cover the first electrode (1), Includes.

Description

Technical Field

[0001] The present invention relates to the field of rechargeable batteries for electric motors. Specifically, the present invention relates to the manufacture of electric cells used in batteries. More specifically, the present invention relates to a method and unit for manufacturing a "pouch" type lithium-ion electrochemical cell.

Background Art

[0002] Electric cells, called pouch cells for rechargeable batteries, can be manufactured in various ways.

[0003] One way to manufacture these cells is to cut electrodes of opposite polarities, separate them by an insulating separator film, and stack them on top of each other.

[0004] The separator film is unwound when the electrode is deposited on the separator film. Therefore, the separator film is first unwound. The first electrode is deposited. The separator film is unwound again to cover the first electrode. The second electrode of opposite polarity to the first electrode is deposited on the separator film. Next, the separator film is unwound again to cover the second electrode. These operations are repeated several times according to the capacity and required power.

[0005] After the operation of depositing the electrode and before unwinding the separator film to cover the deposited electrode, the method generally includes the operation of holding the electrode with a holding element. At least two holding elements press against the electrode in contact with the separator film and then spread over the electrode so that the separator film covers the pressed electrode. When the separator film is unwound, the holding element is removed to attach other electrodes.

[0006] The holding element tightens the electrode at the lateral ends and ensures that the mechanically tensioned separator does not damage or come off the electrode during unwinding because the electrode is thin and deformable.

[0007] While this method is partially satisfactory, there is still room for improvement. The separator film, under mechanical tension, is in contact with the retaining element because the film is folded around it. When the retaining element is removed, it can cause frictional damage to the separator film. Subsequently, the separator film may become scratched or even torn.

[0008] Damaged separator film can cause serious accidents such as fires or explosions if the defect is not detected early.

[0009] The present invention aims to overcome this drawback. [Overview of the project]

[0010] For this purpose, a method for manufacturing cells for secondary batteries was first proposed, and this method is - The first operation involves rewinding the separator film, - A second operation involves depositing the first electrode onto the separator film, - A third operation in which the first horizontal edge and the first vertical edge of the first electrode are held on the separator film using a first holding element, and the second horizontal edge on the opposite side of the first horizontal edge and the first vertical edge of the first electrode are also held using a second holding element. - A fourth operation involves unwinding the separator film to cover the first electrode, - A fifth operation, wherein a second electrode of opposite polarity to a first electrode is deposited on a separator film, the second electrode being positioned substantially opposite to the first electrode. - A sixth operation in which the third horizontal and third vertical edges of the second electrode are held on the separator film using a third holding element, and the fourth horizontal and third vertical edges of the second electrode are also held using a fourth holding element. -The seventh operation involves unwinding the separator film to cover the second electrode, - An eighth operation to remove the first retaining element and the second retaining element, - A ninth operation to remove the third and fourth retaining elements, Includes, This method allows the operation to be repeated multiple times, and the eighth operation by this method involves continuous removal and includes a first lateral movement in which the first retaining element and the second retaining element move along the first axis parallel to the first and second lateral edges, and a first detachment movement in which the first retaining element and the second retaining element move away from the first electrode. or The eighth operation includes a first lateral movement in which the first retaining element and the second retaining element move along a first axis parallel to the first and second lateral edges, and a first detachment movement in which the first retaining element and the second retaining element move away from the first electrode.

[0011] The eighth removal operation involves lateral movement along the first axis and, advantageously, does not damage the separator film. In fact, the first and second retaining elements are tightly secured by the separator film after the fourth operation. The first and second retaining elements can be engaged with and disengaged from the separator film by the first lateral movement along the first axis without damaging the separator film.

[0012] Various additional features can be offered individually or in combination. - The first detachment movement is performed along a second axis perpendicular to the first axis, the second axis being parallel to the first and second longitudinal edges of the first electrode, and the longitudinal edges being substantially perpendicular to the first and second transverse edges. -The first retaining element and the second retaining element each contact the first electrode and the separator film, and as a result, parts of the first and second elements contact the first electrode, and other parts of the first and second retaining elements contact the separator film located below the first electrode, and by this method, the separator film is folded around the first and second retaining elements, defining a first fold extending along the second axis, -During the first lateral movement, the first and second holding elements move along the first axis from the first fold toward the second vertical edge. -The ninth operation involves a series of removals, including a second lateral movement in which the third and fourth retaining elements move along the first axis, and a second detachment movement in which the third and fourth retaining elements move away from the second electrode. or The ninth operation simultaneously includes a second lateral movement in which the third and fourth retaining elements move along the first axis, and a second detachment movement in which the third and fourth retaining elements move away from the second electrode. - The second detachment movement is performed along a second axis perpendicular to the first axis, the second axis being parallel to the first and second longitudinal edges of the second electrode, and the third and fourth longitudinal edges being substantially perpendicular to the third and fourth transverse edges. -The third and fourth retaining elements contact the third and fourth transverse edges, respectively, and as a result, parts of the third and fourth retaining elements contact the second electrode, and other parts of the third and fourth retaining elements contact the separator film located below the second electrode, and by this method, the separator film is folded around the third and fourth retaining elements, defining a second fold extending along the second axis. -During the second lateral movement, the first and second holding elements move along the first axis from the second fold toward the fourth vertical edge. -The rewind operation and the operation of depositing the first electrode are performed simultaneously. -This method includes an initial operation to rewind the separator film before the rewinding operation and the operation to deposit the first electrode. - The initial operation is performed only once during the assembly of electrodes to form the cell.

[0013] Next, a manufacturing unit is proposed that includes the following: -Means for rewinding the separator film, -Means for depositing electrodes onto a separator film, - A first retaining element, a second retaining element, a third retaining element, and a fourth retaining element, - A control unit including a computer program capable of executing the method disclosed above, is provided.

[0014] Various additional features can be provided alone or in combination, - The manufacturing unit includes a movable carriage equipped with a first holding element and a second holding element, and the holding elements are gripping means for simultaneously gripping the separator film and the first electrode, - The third holding element and the fourth holding element are different from the means for rewinding the separator film and the means for depositing the second electrode.

[0015] Further features and advantages of the present invention will become apparent from the following detailed description, with reference to the accompanying drawings for the sake of understanding.

Brief Description of the Drawings

[0016] [Figure 1] It is a schematic diagram of the first stage of a secondary battery cell. [Figure 2] It is a schematic diagram of the second stage of the secondary battery cell of FIG. 1. [Figure 3] It is a schematic diagram of the method according to the present invention. [Figure 4] It is a schematic diagram of the method according to an embodiment of the present invention.

Modes for Carrying Out the Invention

[0017] FIG. 1 and FIG. 2 show the first electrode 1 and the second electrode 2 respectively. The second electrode 2 has the opposite polarity to the first electrode 1 and is pressed against the separator film 3.

[0018] In the remaining disclosure, but not limited to, independent of the earth's gravity, longitudinal, lateral, and vertical orientations are defined according to the X, Y, Z three-axis coordinate system shown in the figures. - The first axis X corresponds to a first axis oriented laterally with respect to the electrodes 1, 2, - The second axis Y is perpendicular to axis X and corresponds to a second axis oriented longitudinally with respect to electrodes 1 and 2. - The third axis Z is perpendicular to axes X and Y.

[0019] The three-axis coordinate system XYZ defines the planes XY, XZ, and YZ.

[0020] Below, we disclose a method 25 for manufacturing cells for secondary batteries, i.e., rechargeable batteries.

[0021] Referring to Figures 3 and 4, the analog steps are given the same reference numbers, and Method 25 includes a first operation O1 of unwinding the separator film 3. This first operation O1 is performed by a rewinding device (not shown in the drawings). The separator film 3 is initially wound onto a reel, and the rewinding device unwinds the reel as electrodes 1 and 2 are sequentially stacked. The rewinding device takes the form of a carriage that moves back and forth along a first axis X.

[0022] Method 25 includes a second operation O2 in which the first electrode 1 is deposited onto the separator film 3. In the drawing shown in Figure 1, the first electrode 1 has a substantially rectangular non-limiting shape.

[0023] The first electrode 1 is -A first horizontal edge 4 parallel to the first axis X, - A second horizontal edge 5 is located on the opposite side of the first horizontal edge 4 and is parallel to the first axis X, and is the same length as the first horizontal edge 4, -A first vertical edge 6 that is parallel to the second axis Y and longer than the first horizontal edge 4 and the second horizontal edge 5, - A second vertical edge 7 is located on the opposite side of the first vertical edge 6 and is parallel to the second axis Y, and is the same length as the first vertical edge 6, It is equipped with.

[0024] Method 25 includes a third operation O3 that holds both the first horizontal edge 4 and the first vertical edge 6 of the first electrode 1, and the second horizontal edge 5 and the first vertical edge 6 of the first electrode 1, on the separator film 3. The third holding operation O3 is performed using the first holding element 8 and the second holding element 10.

[0025] Method 25 includes a fourth operation O4 in which the separator film 3 is unwound. During the execution of the fourth operation O4, the separator film 3 is unwound to cover the first electrode 1.

[0026] Method 25 includes a fifth operation O5 in which a second electrode 2 is deposited on a separator film 3. The second electrode 2 is positioned substantially opposite the first electrode 1.

[0027] The second electrode 2 is -A third horizontal edge 18 parallel to the first axis X, - A fourth horizontal edge 19 is located on the opposite side of the third horizontal edge 18, is parallel to the first axis X, and is the same length as the third horizontal edge 18, -A third vertical edge 20 that is parallel to the second axis Y and longer than the third horizontal edge 18 and the fourth horizontal edge 19, - A fourth vertical edge 21 is located opposite the third vertical edge 20 and parallel to the second axis Y, and is the same length as the first vertical edge 6. It is equipped with.

[0028] Method 25 includes a sixth operation O6 that holds both the third transverse edge 18 and the third vertical edge 20 of the second electrode 2, and the fourth transverse edge 19 and the third vertical edge 20 of the second electrode 2, on the separator film 3. The sixth holding operation O6 is performed using the third holding element 11 and the fourth holding element 12.

[0029] Method 25 includes a seventh operation O7 in which the separator film 3 is unwound to cover the second electrode 2.

[0030] Method 25 includes an eighth operation O8 for removing the first retaining element 8 and the second retaining element 10.

[0031] Method 25 includes a ninth operation O9 for removing the third retaining element 11 and the fourth retaining element 12.

[0032] The first, second, third, fourth, fifth, sixth, seventh, eighth, and ninth operations (O1-O9) are repeated several times. As a result, the stack of electrodes 1 and 2 is separated by the separator film 3. It should be noted that the operations should not necessarily be performed in the order described above. In fact, technical adaptations of the above-described method 25 can modify the order of operations without affecting the present invention.

[0033] The eighth operation O8 involves a series of detachments and includes a first lateral movement 13 and a first detachment movement 14.

[0034] During the first lateral movement 13, both retaining element 8 and retaining element 10 move along the first axis X. During the first detachment movement 14, retaining element 8 and retaining element 10 move away from the first electrode 1 along the second axis Y.

[0035] Alternatively, the eighth operation O8 simultaneously performs a detachment and includes a first lateral movement 13 and a first detachment movement 14.

[0036] During the first lateral movement 13, both retaining element 8 and retaining element 10 move along the first axis X. During the first detachment movement 14, retaining element 8 and retaining element 10 move away from the first electrode 1 along the second axis Y. In this alternative, the first retaining element 8 and the second retaining element 10 each perform the first curved movement 15.

[0037] The eighth operation O8 involves detachment and includes a first lateral movement 13 along the first axis X, which is advantageous as it does not damage the separator film 3. In fact, the first retaining element 8 and the second retaining element 10 are tightly fastened by the separator film 3 after the fourth operation O4. The first lateral movement 13 along axis X allows the first retaining element 8 and the second retaining element 10 to engage with and disengage from the separator film 3 without damage.

[0038] Advantageously, the first detachment movement 14 is performed along the second axis Y. This detachment movement allows for the rapid release of the first retaining element 8 and the second retaining element 10, thereby increasing the production rate.

[0039] As can be seen from Figure 1, the first retaining element 8 is in close contact with both the first electrode 1 and the separator film 3. Therefore, a portion of the first retaining element 8 is located on the first electrode 1, while another portion of the first retaining element 8 is located on the separator film 3. The separator film 3 is folded around the first retaining element 8 and the second retaining element 10, defining a first fold 16 that extends along the second axis Y.

[0040] The first retaining element 8 and the second retaining element 10 together prevent the first electrode 1 from being damaged by the stretched separator film 3.

[0041] Advantageously, during the execution of the first lateral movement 13, the first retaining element 8 and the second retaining element 10 move along the first axis X toward the opposite side from the first fold 16, that is, away from the first fold 16 and toward the second vertical edge 7 which does not face the first fold 16.

[0042] This advantageously allows the first retaining element 8 and the second retaining element 10 to extract themselves from the elongated narrow zone located close to the first fold 16 before initiating the final removal. This significantly reduces the risk of damaging the separator film 3 near the first fold 16.

[0043] Advantageously, the ninth operation O9 simultaneously includes a second lateral movement 23 in which the third retaining element 11 and the fourth retaining element 12 move along the first axis X, and a second detachment movement 24 in which the third retaining element 11 and the fourth retaining element 12 move away from the second electrode 2.

[0044] Alternatively, the ninth operation O9 may simultaneously detach and include a second lateral movement 23 in which the third retaining element 11 and the fourth retaining element 12 move along the first axis X, and a second detachment movement 24 in which the third retaining element 11 and the fourth retaining element 12 move away from the second electrode 2. In this alternative, the third retaining element 11 and the fourth retaining element 12 each perform a second curved movement 22.

[0045] The ninth operation O9 involves detachment and includes a second lateral movement 23 along axis X, which is advantageous as it does not damage the separator film 3. In fact, the third retaining element 11 and the fourth retaining element 12 are tightened by the separator film 3 after the sixth operation O6. The second lateral movement 23 along axis X allows the third retaining element 11 and the fourth retaining element 12 to engage with and disengage from the separator film 3 without damage.

[0046] Advantageously, the second detachment movement 24 is performed along the second axis Y. This detachment movement allows for the rapid release of the first retaining element 11 and the second retaining element 12, thereby increasing the production rate.

[0047] As can be seen in Figure 2, the third retaining element 11 is in close contact with both the second electrode 2 and the separator film 3. Therefore, a portion of the third retaining element 11 is located above the second electrode 2, while another portion of the third retaining element 11 is located above the separator film 3. The separator film 3 is folded around the first retaining element 11 and the second retaining element 12, defining a first fold 17 that extends along the second axis Y.

[0048] The third retaining element 11 and the fourth retaining element 12 together prevent the second electrode 2 from being damaged by the stretched separator film 3.

[0049] Advantageously, during the execution of the second lateral movement 23, the third retaining element 11 and the fourth retaining element 12 move along the first axis X toward the opposite side from the second fold 17, that is, away from the second fold 17 and toward the fourth vertical edge 21 which does not face the second fold 17.

[0050] This advantageously allows the third retaining element 11 and the fourth retaining element 12 to extract themselves from the elongated narrow zone located close to the second fold 17 before initiating the final removal. This significantly reduces the risk of damaging the separator film 3 near the second fold 17.

[0051] Advantageously, in one embodiment, the unwinding operation O1 and the electrode deposition operation O2 are performed simultaneously. In other words, the carriage described above is used to perform both unwinding the separator and depositing the first electrode.

[0052] Therefore, for example, the carriage is advantageously equipped with a separator gripping means that enables gripping of the separator and the first electrode. Thus, as the carriage moves, the separator is unwound and the first electrode moves and is deposited.

[0053] Advantageously, in the embodiment shown by Figure 4, method 25 includes an initial operation O0 for unwinding the separator film 3. The initial operation O0 precedes operations O1 and O2.

[0054] Advantageously, the initial operation O0 is performed only once during the assembly of electrodes to form the cell.

[0055] This initial operation O0 allows the separator film to be unwound even without the first electrode on the stacking table. Therefore, during operations O1 and O2, the first electrode is deposited on the unwound separator film during the initial operation O0.

[0056] The first electrode is transported, for example, together with a separator film 3 on a surface. After the carriage's gripping means grips the separator film and the first electrode, they are moved together along axis X, resulting in the separator film 3 being folded around the gripping means.

[0057] The present invention also relates to a manufacturing unit, wherein the manufacturing unit is -Means for rewinding the separator film 3, -Means for depositing electrodes onto the separator film 3, - The first retaining element 8, the second retaining element 10, the third retaining element 11, and the fourth retaining element 12, - A control unit including a computer program capable of performing the method 25 disclosed above, It is equipped with.

[0058] Specifically, this manufacturing unit includes a control unit equipped with a computer program for implementing the method 25 described above, which advantageously reduces the risk of damage to the separator film 3, thereby improving the reliability of the manufactured cells and user safety.

[0059] Advantageously, in one embodiment, the manufacturing unit comprises a movable carriage. The first retaining element 8 and the second retaining element 9 of the first electrode are mounted on the movable carriage. The first retaining element 8 and the second retaining element 9 take the form of gripping means for simultaneously gripping the separator film 3 and the first electrode.

[0060] Next, the carriage moves to rewind the separator film, allowing the first electrode to move simultaneously.

[0061] This will shorten production time and, consequently, optimize production time.

[0062] Advantageously, in one embodiment, the third retaining element 11 and the fourth retaining element 12 are different from means for unwinding the separator film and means for depositing the second electrode. The third retaining element 11 and the fourth retaining element 12 are in the form of plates.

Claims

1. A method for manufacturing cells for secondary batteries (25), the method is - The first operation (O1) involves rewinding the separator film (3), - A second operation (O2) to deposit the first electrode (1) onto the separator film (3), - A third operation (O3) is performed in which the first horizontal edge (4) and the first vertical edge (6) of the first electrode (1) are held on the separator film (3) using the first holding element (8), and the second horizontal edge (5) on the opposite side of the first horizontal edge (4) and the first vertical edge (6) of the first electrode (1) is also held using the second holding element (10), - A fourth operation (O4) to unwind the separator film (3) in order to cover the first electrode (1), - A fifth operation (O5) is to deposit a second electrode (2) having opposite polarity to the first electrode (1) on the separator film (3), wherein the second electrode (2) is positioned substantially opposite to the first electrode (1), - A sixth operation (O6) is performed, in which the third horizontal edge (18) and the third vertical edge (20) of the second electrode (2) are held on the separator film (3) using the third holding element (11), and the fourth horizontal edge (19) and the third vertical edge (20) of the second electrode (2) are also held using the fourth holding element (12), - A seventh operation (O7) to unwind the separator film (3) in order to cover the second electrode (2), - An eighth operation (O8) to remove the first retaining element (8) and the second retaining element (10), - A ninth operation (O9) to remove the third retaining element (11) and the fourth retaining element (12), The above method allows the above operation to be repeated multiple times. According to the method described above, the eighth operation (O8) includes a first lateral movement (13) in which the first retaining element (8) and the second retaining element (10) move along the first axis (X) parallel to the first lateral edge (4) and the second lateral edge (5), and a first detachment movement (14) in which the first retaining element (8) and the second retaining element (10) move away from the first electrode (1), or The eighth operation (O8) is a method (25) which includes simultaneously removing the first retaining element (8) and the second retaining element (10) moving along a first axis (X) parallel to the first lateral edge (4) and the second lateral edge (5), and moving the first retaining element (8) and the second retaining element (10) away from the first electrode (1).

2. The method according to claim 1 (25), wherein the first detachment movement (14) is carried out along a second axis (Y) perpendicular to the first axis (X), the second axis (Y) is parallel to the first longitudinal edge (6) and the second longitudinal edge (7) of the first electrode (1), and the longitudinal edges (6, 7) are substantially perpendicular to the first transverse edge (4) and the second transverse edge (5).

3. The method (25) of any of the prior claims, wherein the first retaining element (8) and the second retaining element (10) each contact the first electrode (1) and the separator film (3), so that as a result, parts of the first element (8) and the second element (10) contact the first electrode (1), and other parts of the first retaining element (8) and the second retaining element (10) contact the separator film (3) located below the first electrode (1), so that by the method (25), the separator film (3) is folded around the first retaining element (8) and the second retaining element (10) to define a first fold (16) extending along the second axis (Y).

4. The method according to claim 3 (25), wherein during the first lateral movement (13), the first retaining element (8) and the second retaining element (10) move along the first axis (X) from the first fold (16) toward the second vertical edge (7).

5. The ninth operation (O9) includes a second lateral movement (23) in which the third retaining element (11) and the fourth retaining element (12) move along the first axis (X), and a second detachment movement (24) in which the third retaining element (11) and the fourth retaining element (12) move away from the second electrode (2). or The method according to any of the prior claims (25), wherein the ninth operation (O9) includes a second lateral movement (23) in which the third retaining element (11) and the fourth retaining element (12) move along the first axis (X) and a second detachment movement (24) in which the third retaining element (11) and the fourth retaining element (12) move away from the second electrode (2).

6. The method according to claim 5 (25), wherein the second detachment movement (24) is carried out along a second axis (Y) perpendicular to the first axis (X), the second axis (Y) is parallel to the third longitudinal edge (20) and the fourth longitudinal edge (21) of the second electrode (2), and the third longitudinal edge (20) and the fourth longitudinal edge (21) are substantially perpendicular to the third transverse edge (18) and the fourth transverse edge (19).

7. The method (25) of claim 5 or 6, wherein the third retaining element (11) and the fourth retaining element (12) are in contact with the third transverse edge (18) and the fourth transverse edge (19), respectively, and as a result, portions of the third retaining element (11) and the fourth retaining element (12) are in contact with the second electrode (2), and other portions of the third retaining element (11) and the fourth retaining element (12) are in contact with the separator film (3) located below the second electrode (2), and by the method (25), the separator film (3) is folded around the third retaining element (11) and the fourth retaining element (12) to define a second fold (17) extending along the second axis (Y).

8. The method according to claim 7 (25), wherein during the second lateral movement (23), the first retaining element (11) and the second retaining element (12) move along the first axis (X) from the second fold (17) toward the fourth vertical edge (21).

9. The method according to any of the prior claims (25), wherein the rewinding operation (O1) and the operation of depositing the first electrode (O2) are performed simultaneously.

10. The method according to claim 9 (25), wherein the method includes an initial operation (O0) of unwinding the separator film (3) before the unwinding operation (O1) and the operation of depositing the first electrode (O2).

11. The method according to claim 10 (25), wherein the initial operation (O0) is performed only once during the assembly of the electrodes to form the cell.

12. A manufacturing unit, - A means for rewinding the separator film (3), - Means for depositing electrodes (1, 2) onto the separator film (3), - The first retaining element (8), the second retaining element (10), the third retaining element (11), and the fourth retaining element (12), - A control unit including a computer program capable of performing the method (25) according to any one of claims 1 to 11, A manufacturing unit equipped with the necessary components.

13. The manufacturing unit according to claim 12, wherein the unit comprises a movable carriage on which the first retaining element (8) and the second retaining element (10) are mounted, and the retaining elements (8, 9) are gripping means for simultaneously gripping the separator film (3) and the first electrode (1).

14. The manufacturing unit according to any one of claims 12 and 13, wherein the third retaining element (11) and the fourth retaining element (12) are different from means for unwinding the separator film and means for depositing the second electrode (2).

Images