Single cell stack for battery cells

Abstract

The invention relates to a single cell stack for battery cells, comprising a plurality of single cells (M) stacked one after the other in a stacking direction, each of the single cells (M) being formed by alternately joining an electrode sheet (K), a separator sheet (S1), a corresponding electrode sheet (A) and a further separator sheet (S2) in the stacking direction. According to the invention, the two separator sheets (S1, S2) are constituent parts of a double-sheet layer (D) which is folded over along a folding edge (11) around the electrode sheet (K) to form a U-shaped folded structure. A counter electrode sheet (A) is arranged on the outside of one of the separator sheets (S1, S2).

Description

[0001] The invention relates to a single-cell stack for battery cells according to the preamble of claim 1 and to a method or a process device for producing such a single-cell stack according to claim 10 .

[0002] Electrode / separator stacks for battery cells can be manufactured, for example, as a Z-folded structure, in which a continuous separator web is folded around electrode sheets arranged one above the other to form a Z-folded structure. Alternatively, the electrode / separator stack can also be manufactured as a single-cell stack of the type described in the present invention. The single-cell stack has single cells stacked one after the other in a stacking direction. Each single cell is alternately joined together into a one-piece structural unit, for example in a laminating station, from electrode sheets, separator sheets, corresponding electrode sheets and other separator sheets in a stacking direction. Compared to electrode / separator stacks manufactured in a Z-folded structure, the mass production of such single-cell stacks has a significantly higher process speed.

[0003] An electrode device is known from patent document US 2019 / 0189976 A1. A rechargeable battery is known from patent document EP 3 246 979 A1. An electrode device and a method for producing such an electrode device are known from patent document WO 2020 / 121044 A1. An electrode / separator stack for a battery cell is known from patent document US 2010 / 0190081 A1. Another electrode device for a battery cell is known from patent document EP 3 242 346 A1.

[0004] The technical problem to be solved by the present invention is to provide a single-cell stack for battery cells, which can be mass-produced and has a greater process speed and / or lower manufacturing cost compared to the prior art.

[0005] This object is achieved by the features of claim 1 or claim 10. Preferred developments of the invention are disclosed in the dependent claims.

[0006] The present invention is based on a single-cell stack for battery cells, which has a plurality of single cells stacked in sequence along a stacking direction. Each single cell is formed by alternately joining electrode sheets, separator sheets, corresponding electrode sheets and other separator sheets along the stacking direction. According to the characteristic part of claim 1, the two separator sheets are components of a double sheet layer. The double sheet layer is folded around the electrode sheet along the folding edge in a U-shaped folding structure. The corresponding electrode sheet is arranged on the outside of the separator sheet.

[0007] The process device for producing such a single-cell stack has the following process steps: First, the electrode sheet, the corresponding electrode sheet and the double sheet layer are cut out from the continuous web in a cutting device. Then, the electrode sheet is placed on the double sheet layer in a first placing device. In the subsequent process, the double sheet layer is folded around the electrode sheet along the folded edge with the help of a folding device. Then, the corresponding electrode sheet is arranged on the outside of one of the separator sheets with the help of a second placing device. Then, the still loose sheet structure is input into a laminating device, in which the electrode sheet and the separator sheet are laminated into a single cell. The manufactured single cell is transferred to a stacking device, in which the single cells are stacked into a single-cell stack.

[0008] In a preferred variant design, the single cell stack can be terminated at its two stack ends along the stacking direction with a corresponding electrode sheet, respectively. The corresponding electrode sheet can preferably be implemented as an anode sheet, and the electrode sheet can be implemented as a cathode sheet.

[0009] According to a first variant design, single cells can be stacked in a single battery stack in an identically repeated sequence of electrode-separator sheets along the stacking direction, i.e., stacking from the first stack end to the second stack end. Single cells with end sides of corresponding electrode sheets (preferably anode sheets) located outside can be arranged at the first stack end. And single cells with end sides of separator sheets located outside can be arranged at the second stack end. A single corresponding electrode sheet (i.e., especially an anode sheet) can preferably be stacked on the separator sheet located outside at the second stack end. The single counter electrode sheet is manufactured as a separate construction unit, i.e., independent of the single cell, in a preceding process step.

[0010] In another variant design, a single electrode sheet (preferably a single anode sheet) can be stacked on the corresponding electrode sheet located outside at the first stack end with a separator sheet arranged in the middle. Before the stacking process, the single electrode sheet and the separator sheet can be joined to form a layered composite structure. The layered composite structure can be stacked onto the corresponding electrode sheet located outside during the stacking process.

[0011] In another variant design, the stack of single cells can be divided into at least two sub-stacks along the stacking direction. In the first sub-stack, the single cells can be stacked in an identically repeated sequence of electrodes and separator sheets along the stacking direction. The second sub-stack can be folded 180° relative to the first sub-stack. In this case, the single cells are stacked in the second sub-stack in an opposite sequence of electrodes and separator sheets that is identically repeated along the stacking direction.

[0012] The two sub-stacks are opposed in the stacking direction by means of a separator sheet of a double sheet layer, with a single corresponding electrode sheet (especially an anode) placed in between.

[0013] The electrode sheets and / or the counter-electrode sheets can each consist of a current conductor foil with a double-sided electrode coating in a conventional manner. In addition, the electrode sheets and / or the counter-electrode sheets can each be extended with a laterally protruding conductor flange. In a first embodiment, the folded edges of the double sheet layers in the single cell stack can be arranged alternately on opposite single cell stack sides when viewed along the stacking direction. Alternatively, the folded edges of the double sheet layers in the single cell stack can also be arranged on the same single cell stack side.

[0014] The conductor flange of the electrode sheet and / or the conductor flange of the counter-electrode sheet can be oriented, for example, parallel to the folded edge. Alternatively, the conductor flange of the electrode sheet can protrude on the side opposite to the folded edge.

[0015] The embodiments of the present invention are described below with reference to the accompanying drawings. In the accompanying drawings:

[0016] Figures 1 to 3 A single cell stack according to a first embodiment is shown;

[0017] Figures 4 to 6 The drawings are respectively used to illustrate the process sequence of manufacturing a single cell stack;

[0018] Figures 7 to 11 Other variant designs of single-cell stacks are shown.

[0019] Figure 1 A single-cell stack for a battery cell is shown, which consists of a plurality of single cells 1 stacked one behind the other in a stacking direction. Figure 3 One of the single cells M is shown separately. Accordingly, the single cell 1 is composed (from top to bottom) of a cathode sheet K, a separator sheet S1, an anode sheet A and a further separator sheet S2 joined in a lamination process. The cathode sheet K and the anode sheet A are each composed in a known manner of a current conductor foil 3, which is coated on both sides with an electrode coating 5. The current conductor foil 3 is respectively provided with a conductor flange 7 ( Figures 8 to 11 ) or the conductor flange 9 on the anode side ( Figures 8 to 11 )extend.

[0020] Depend on Figure 2 or Figure 3 It can be seen that the two separator sheets S1 and S2 are components of the double sheet layer D. The double sheet layer D is folded along the folding edge 11 around the cathode sheet K to form a U-shaped folded structure. Figure 3 On the lower separator sheet S2.

[0021] according to Figure 1 or Figure 2 The single cell stack is terminated with anode sheets A at both ends of the stack along the stacking direction. Figure 1 and Figure 2The stack of single cells in the stack is divided into two sub-stacks 13 and 15 along the stacking direction. In the upper first sub-stack 13, the single cells M are stacked in an electrode-separator sheet sequence that is identically repeated along the stacking direction, namely, from bottom to top, the first separator sheet S1, the cathode sheet K, the second separator sheet S2 and the anode sheet A. The single cells M are also stacked in the lower second sub-stack 15 in the same manner in an electrode-separator sheet sequence that is identically repeated along the stacking direction, namely, from top to bottom, the first separator sheet S1, the cathode sheet K, the second separator sheet S2 and the anode sheet A. With respect to the sheet sequence in the second sub-stack 15, the anode sheet A of each single cell M is positioned at the bottom, followed by the second separator sheet, the cathode sheet K and the first separator sheet S1. Therefore, according to Figure 2 The exploded view of the two sub-stacks 13 and 15 is opposite to each other along the stacking direction with the first separator sheet S1 of the corresponding double sheet layer, and a single anode sheet A is arranged in the middle. E The anode sheet is not a component of the single cell M, but is manufactured independently of the single cell.

[0022] exist Figure 1 or Figure 2 In the embodiment shown in FIG. 1 , all folded edges 11 of the first partial stack 13 are positioned on the side surfaces of the single cells, while the folded edges 11 of the second partial stack 15 are positioned on the side surfaces of the opposite single cell stack.

[0023] according to Figures 4 to 6 Describes the process used to make Figure 1 The process sequence of single cell stacking is shown as follows: Figure 4 As shown, the cathode sheet K, the anode sheet A and the double sheet layer D are cut into single sheets from the continuous web in the cutting device. Figure 4 ) is placed on the double sheet layer D. The double sheet layer D is folded along the folding edge 11 around the cathode sheet K into a U-shaped folded structure ( Figure 5 ). In another process step ( Figure 6 ), the anode sheet A is positioned on the outside of the separator S2. Then, a lamination (not shown) is performed, during which the individual sheets of the still loose single cell sheet structure are joined in a lamination device. The single cells M are then stacked into a single cell stack in a stacking device.

[0024] Figures 7 to 11 Other embodiments of single cell stacks are shown. Figure 7 The single cell stack shown is Figure 1 The illustrated single cell stacks are constructed essentially identically. Figure 1 or Figure 2 The difference is that in Figure 7 In the embodiment shown in FIG. 1 , all fold edges 11 are positioned on a common side of the single-cell stack.

[0025] Figure 8 The single cell stack shown corresponds essentially to Figure 7 The single cell stack shown. Figure 7 The difference is that in Figure 8 In the embodiment, the conductor flanges 7, 9 protrude outward at right angles to the folded edge 11. Therefore, the cathode-side conductor flange 7 is extended toward the left side of the single cell stack, while the anode-side conductor flange 9 is extended toward the right side of the single cell stack.

[0026] Fig. 9 Another single-cell stack is shown, which is not composed of two stacks 13, 15 and a central anode A arranged in the middle. E composition. Fig. 9 In the embodiment, the single cells M are stacked in an electrode-separator sheet sequence that is repeated identically along the stacking direction S from the upper first stack end to the lower second stack end. At the first stack end, an end-side single cell M is arranged, which has an anode sheet A located on the outside. At the lower second stack end, an end-side single cell M is arranged, which has a separator sheet S1 located on the outside. A single anode sheet A is additionally stacked on the separator sheet S1 located on the outside of the lower second stack end. E .

[0027] Compared with the previous figure, Fig.10 The single cells M in the embodiment are constructed differently: in the corresponding single cells M, the double sheet layer D is no longer folded around the cathode sheet K, but around the anode sheet A. The cathode sheet K is arranged on the outer side on the separator sheet S2. Fig. 9 Similarly, the single cells M are also stacked into a single cell stack from the first upper stack end to the second lower stack end in an identically repeated sequence of electrode-separator sheets along the stacking direction. The single cell M with the end side of the first separator sheet S1 located on the outside is arranged at the first upper stack end of the stack. The single cell M with the end side of the cathode sheet K located on the outside is arranged at the second lower stack end. The layered composite structure 17 is stacked on the cathode sheet K located on the outside at the first lower stack end, and the cathode sheet on the outside is composed of a single anode sheet A. E The separator double sheet layer is folded around the single anode sheet. E It is arranged on the cathode sheet K at the bottom, with a separator S in the middle.

[0028] Fig.11 A single-cell stack according to another embodiment is shown. Fig.11 The single cell stack shown is Fig.10 The illustrated single cell stacks are constructed essentially identically. Fig.10 The difference is that in Fig.11In the embodiment, the anode-side and cathode-side conductor flanges 7, 9 protrude at right angles to the folded edge 11. The anode-side conductor flange 9 protrudes from the left-hand side of the single cell stack, while the cathode-side conductor flange 7 protrudes from the right-hand side of the single cell stack.

[0029] Reference numerals list

[0030] 1 single cell

[0031] 3. Current conductor foil

[0032] 5. Electrode coating

[0033] 7 Conductor flange on cathode side

[0034] 9 Conductor flange on the anode side

[0035] 11 Folding edges

[0036] 13, 15 stacking

[0037] 17Layered composite structure

[0038] M single cell

[0039] Anode

[0040] K cathode

[0041] D double sheet layer

[0042] S, S1, S2 separator sheet

Claims

1. A single cell stack for a battery cell, the single cell stack comprising a plurality of single cells (M) stacked in sequence along a stacking direction, wherein each single cell (M) is formed by alternately joining an electrode sheet (K), a separator sheet (S1), a corresponding electrode sheet (A) and other separator sheets (S2) along the stacking direction, characterized in that: The two separator sheets (S1, S2) are components of a double sheet layer (D), which is folded along a folding edge (11) around an electrode sheet (K) into a U-shaped folded structure, and a corresponding electrode sheet (A) is arranged on the outside of one of the separator sheets (S1, S2).

2. The single cell stack according to claim 1, characterized in that: The stack of single cells ends in the stacking direction at both stack ends with corresponding electrode sheets (A).

3. The single cell stack according to claim 1 or 2, characterized in that: The single cells (M) are stacked in a single cell stack in an electrode-separator sheet sequence that is repeated identically along the stacking direction from a first stack end to a second stack end, and in particular, a single cell (M) having an end side with a corresponding electrode sheet (A) located on the outside is arranged at the first stack end, and a single cell (11) having an end side with a separator sheet (S2) located on the outside is arranged at the second stack end, and in particular, a single corresponding electrode sheet (A) is stacked on the separator sheet (S2) located on the outside at the second stack end. E ).

4. The single cell stack according to claim 3, characterized in that: Single electrode sheet (A E ) are stacked on the outer corresponding electrode sheet (K) at the end of the first stack, with a separator sheet (S) arranged in the middle, and in particular a single electrode sheet (A E ) and the separator sheet (S) are joined to form a layered composite structure (17) before the stacking process, and the layered composite structure is stacked on the corresponding electrode sheet (K) located on the outside.

5. The single cell stack according to claim 1 or 2, characterized in that: A stack of single cells is divided into at least two sub-stacks (13, 15) along a stacking direction, wherein the single cells (M) are stacked in a first sub-stack (13) and a second sub-stack (15) in an electrode-separator sheet sequence that is identically repeated along the stacking direction, and the second sub-stack (15) is folded 180° relative to the first sub-stack (13), so that the single cells (11) are stacked in a second sub-stack (15) in an opposite electrode-separator sheet sequence that is identically repeated along the stacking direction.

6. The single cell stack according to claim 5, characterized in that: The two sub-stacks (13, 15) are respectively arranged opposite to each other with a separator sheet (S1) of a double sheet layer (D) in the stacking direction, and a corresponding electrode sheet (A) is arranged in the middle. E ).

7. The single cell stack according to any one of the preceding claims, characterized in that The electrode sheet (K) and / or the counter-electrode sheet (A) each consist of a current conductor foil (3) with a double-sided electrode coating (5) and / or the electrode sheet (K) and / or the counter-electrode sheet (A) are each extended by a laterally protruding conductor flange (7, 9).

8. Single-layer paper stack according to one of the preceding claims, characterized in that The folded edges (11) of the double pane layer (D) are arranged alternately on opposite sides of the cell stack in the cell stack as viewed in the stacking direction, or on the same side of the cell stack.

9. The single cell stack according to claim 7 or 8, characterized in that: The conductor flanges (7, 9) of the electrode sheet (K) and / or the conductor flanges (7, 9) of the corresponding electrode sheet (A) protrude outwards parallel to the folded edge (11), or the conductor flanges (7, 9) of the electrode sheet (A, K) protrude outwards on the side opposite to the folded edge (11).

10. A process device or method for manufacturing a single-cell stack according to one of the preceding claims, the process device having a cutting device, in which an electrode sheet (K), a corresponding electrode sheet (A) and a double sheet layer (D) are cut from a material web roll, the process device also having a first placing device, in which the electrode sheet (K) is placed on the double sheet layer (D), the process device also having a folding device, in which the double sheet layer (D) is folded along the folding edge around the electrode sheet (K) into a U-shaped folded structure, the process device also having a second placing device, in which the corresponding electrode sheet (A) is arranged on the outside on one of the separator sheets (S1, S2), the process device also having a laminating device, in which the electrode sheet and the separator sheets (S1, K, S2, A) are laminated into a single cell (M), the process device also having a stacking device, in which the single cells (11) are stacked.

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