Cell stacking method

Abstract

The present invention relates to a cell stacking method including the steps of setting a virtual reference line at the center of a cell and stacking a plurality of cells with the reference line set thereon, wherein the stacked cells are stacked in a state where the reference lines are aligned.

Description

[[Technical Field]]

[0001] The present invention relates to a cell stacking method, which is characterized in that a virtual reference line is set on each cell, and the cells are aligned so that the reference lines coincide with each other.

[0002] This application claims the benefit of priority based on Korean Patent Application No. 10-2023-0005584 filed on January 13, 2023, and all contents disclosed in the document of the Korean Patent Application are incorporated as a part of the present specification. [[Background Art]]

[0003] Secondary batteries, which have high applicability depending on product groups and have electrical characteristics such as high energy density, are widely applied not only to portable devices, but also to electric vehicles or hybrid vehicles driven by electric drive sources, power storage devices, and the like. Such secondary batteries are attracting attention as a new energy source for improving energy efficiency, because they are environmentally friendly in that they not only have the primary advantage of being able to drastically reduce the use of fossil fuels, but also produce no by-products from energy use.

[0004] While one, or two to four, battery cells per device are used in small mobile devices, high output and large capacity are required for medium and large devices such as automobiles. Therefore, medium and large battery modules in which a large number of battery cells are electrically connected are used.

[0005] Since medium and large battery modules are preferably manufactured with as small a size and weight as possible, they can be stacked with a high degree of integration, and prismatic batteries, pouch-type batteries, etc., which are light in weight relative to their capacity, are mainly used as battery cells for medium and large battery modules.

[0006] Generally, in order to protect the cell stack from external impact, heat or vibration, a battery module may include a frame member having an open front surface and an open rear surface to accommodate the cell stack in an internal space.

[0007] On the other hand, in a cell stack structure in which multiple battery cells are stacked, the alignment of each battery cell is one of the important issues that affects the performance of the secondary battery.

[0008] Before stacking the battery cells C, the position of each battery cell C is corrected as shown in Figure 1, and then the battery cells C are stacked. However, at this time, slight positional imbalances may occur due to structural limitations of the battery cells C.

[0009] Figure 2 shows a cell stack Cs included in a battery module, and it can be seen that battery cells C, whose positive electrode lead L1 and negative electrode lead L2 are in opposite positions to each other, are misaligned vertically on the diagram.

[0010] When the positions of each battery cell C contained within the cell stack Cs shift slightly in this way, a contact error may occur between the electrode lead Le and the busbar B to which the electrode lead Le is electrically connected. [Prior art documents] [Patent Documents]

[0011] [Patent Document 1] Korean Published Patent No. 10-2021-0049471 [Overview of the Initiative] [Problems that the invention aims to solve]

[0012] Therefore, the present invention was devised to solve the above-mentioned problems, and aims to provide a cell stacking method that can improve the alignment of each cell in cell stacking.

[0013] Other objects and advantages of the present invention can be understood from the following description and will be more clearly seen from the embodiments of the present invention. Furthermore, it will be readily apparent that the objects and advantages of the present invention can be realized by the means and combinations set forth in the claims. [Means for solving the problem]

[0014] The present invention provides a cell stacking method comprising the steps of setting a virtual reference line in the center of a cell and stacking a plurality of cells on which the reference line is set, wherein the stacked cells are aligned and stacked so that the reference lines coincide.

[0015] The above cell contains an electrode assembly in which multiple electrodes are stacked, and electrode leads electrically connected to the electrode assembly can be led out from both sides.

[0016] A reference line can be set at a position corresponding to the center of the electrode included in the uppermost part of the electrode assembly described above.

[0017] The above cell may consist of a housing portion in which the electrode assembly is located and an outlet portion in which the electrode leads are located.

[0018] A step is formed between the housing section and the outlet section, and the central part may correspond to the central position starting from the position where the step begins on both sides of the housing section.

[0019] The center of the above cell may correspond to the central position starting from the edges of both ends of the above housing section.

[0020] The center of the above cell may correspond to a position that is halfway between the edges of the housing at both ends.

[0021] The above reference line may be formed across the center of the cell such that electrode leads are positioned on both sides.

[0022] The above reference line may correspond to the center position, starting from both ends of the electrode included in the uppermost part of the electrode assembly.

[0023] The electrode assembly includes a positive electrode, a separation membrane and a negative electrode, the electrode lead includes a positive electrode lead electrically connected to the positive electrode of the electrode assembly, and a negative electrode lead electrically connected to the negative electrode of the electrode assembly, and the pair of adjacent cells may be alternately stacked such that the positions of the positive electrode lead and the negative electrode lead are reversed.

[0024] Each of the cells can be moved in the horizontal direction to adjust the position such that the reference lines of the cells are aligned.

Effects of the Invention

[0025] According to the present invention, in stacking cells, the alignment degree of each cell can be improved, thereby improving the stability of a secondary battery.

Brief Description of Drawings

[0026] [Figure 1] It shows a formation process of a conventional cell stack. [Figure 2] It shows a cell stack included in a conventional battery module. [Figure 3] It shows a flowchart of the cell stacking method of the present invention. [Figure 4] It shows a cell and a visual sensor used in the cell stacking method according to the first embodiment of the present invention. [Figure 5] It shows the cell and the visual sensor of FIG. 4 from a side view. [Figure 6] It shows a boundary point between an accommodation portion and a lead-out portion of a cell. [Figure 7] It shows a process of stacking a plurality of cells. [Figure 8] It shows a cell and a visual sensor used in the cell stacking method according to the second embodiment of the present invention. [Figure 9] It shows the cell and the visual sensor of FIG. 8 from a side view.

Mode for Carrying Out the Invention

[0027] Preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings. Before that, however, the terms and words used herein and in the claims should not be interpreted to be limited to their ordinary or dictionary meanings, but rather to be interpreted as meanings and concepts consistent with the technical idea of ​​the present invention, based on the principle that an inventor may appropriately define the concepts of terms in order to best describe his own invention.

[0028] Therefore, the embodiments described herein and the configurations shown in the drawings represent only one of the most preferred embodiments of the present invention and do not represent the entire technical concept of the present invention; there are various equivalents and modifications that can substitute for them at the time of filing.

[0029] Furthermore, in describing the present invention, if it is determined that a specific description of a related known configuration or function would likely obscure the gist of the invention, such detailed description will be omitted.

[0030] Since embodiments of the present invention are provided to more fully explain the invention to an ordinary person, the shapes and sizes of components in the drawings may be exaggerated, omitted, or shown schematically for the sake of clarity. Accordingly, the sizes and proportions of each component do not fully reflect the actual sizes and proportions.

[0031] The present invention relates to a cell stacking method, characterized in that a virtual reference line is set on each cell, and the cells are aligned and stacked so that the reference lines coincide.

[0032] Multiple cells are stacked in a certain quantity to form a single cell stack. This cell stack is then coupled with busbars electrically connected to each cell and a frame surrounding the outside to protect the cell stack, thereby forming a battery module.

[0033] Figure 3 shows a flowchart of the cell stacking method of the present invention. The cell stacking method of the present invention will now be described step by step with reference to the flowchart above.

[0034] (First Embodiment) Reference line BL setting step (S1)

[0035] This step involves setting a virtual reference line BL in the center of cell C.

[0036] The center of cell C can be located by using the visual sensor S to identify the edges Co on both sides of cell C.

[0037] Figure 4 shows a cell C used in the cell C stacking method according to the first embodiment of the present invention and a visual sensor S used to locate the center of the cell C, and Figure 5 shows the cell C and visual sensor S of Figure 4 from the side.

[0038] The cell C described above houses an electrode assembly (not shown) in which multiple electrodes are stacked, and electrode leads Le, electrically connected to the electrode assembly, are led out on both sides, as shown in Figures 4 and 5.

[0039] The electrode assembly described above includes a positive electrode, a separator membrane, and a negative electrode, and these components are arranged in alternating layers.

[0040] The electrode lead Le includes a positive electrode lead L1 that is electrically connected to the positive electrode of the electrode assembly, and a negative electrode lead L2 that is electrically connected to the negative electrode of the electrode assembly.

[0041] Adjacent pairs of cells C may be stacked alternately such that the positions of the positive lead L1 and the negative lead L2 are opposite, or they may be stacked in pairs such that the positive lead L1 and the negative lead L2 are in the same position.

[0042] As shown in Figure 5, cell C consists of a housing section Pr and an outlet section Pe.

[0043] An electrode assembly may be located in the housing portion Pr, and an electrode lead Le may be located in the lead-out portion Pe.

[0044] A step is formed between the housing portion Pr and the outlet portion Pe. In this case, the height of the step may vary depending on the thickness of the electrode assembly contained in the housing portion Pr.

[0045] The present invention's cell C stacking method is characterized by setting a virtual reference line BL for each cell C to be stacked, and stacking the cells C in such a way that the reference lines BL coincide with each other.

[0046] The above reference line BL corresponds to the center of cell C, and the center of each cell C is found by using the positions of both ends of the housing Pr of that cell C as a reference.

[0047] In other words, the center of the housing Pr is the point that is halfway between the positions of both ends of the housing Pr.

[0048] The center of cell C corresponds to the center of the electrode assembly, and the reference line BL is formed to pass through the center of cell C. More specifically, the reference line BL is formed to cross the center of cell C such that the electrode leads Le of cell C are located on both sides.

[0049] The above reference line BL is set at a position corresponding to the center of the uppermost electrode in the electrode assembly contained in the housing Pr. That is, the reference line BL is formed at the center position, starting from both ends of the uppermost electrode in the electrode assembly.

[0050] The ends of the electrode included in the uppermost part of the electrode assembly described above correspond to the boundary point between the housing portion Pr and the lead-out portion Pe, or to the position where the step begins on both sides of the housing portion Pr.

[0051] Figure 6 shows the boundary points between the housing section Pr and the output section Pe of cell C.

[0052] The point where the step begins at either end of the uppermost electrode in the electrode assembly, or at the boundary between the housing portion Pr and the lead-out portion Pe, corresponds to the end of the uppermost electrode, as shown in Figure 6.

[0053] As shown in Figure 6, multiple stacked electrodes may have slight differences in the position of their ends. In this invention, in order to quickly locate the center of cell C and set a reference line BL, both ends of the electrode located at the top of the electrode assembly are identified, and the center of the electrode is located based on the identified positions of both ends of the electrode to form a virtual reference line BL.

[0054] The edges at both ends of the above-mentioned housing Pr can be identified by the visual sensor S, as shown in Figures 4 and 5.

[0055] The above-mentioned visual sensor S is located at the top of both sides of cell C to identify the end positions of the target cell C, and sets a virtual reference line BL passing through the center of cell C based on the identified end positions. At this time, the center of cell C corresponds to a position that is half the length of the edge positions of both ends of the housing Pr.

[0056] In this manner, each cell C is assigned its own reference line BL.

[0057] Cell C stacking step (S2)

[0058] This step involves stacking multiple cells C, each with a reference line BL set.

[0059] Figure 7 shows the process of stacking multiple cells C.

[0060] As described above, each stacked cell C is characterized by being aligned so that the reference line BL coincides with each other.

[0061] Before stacking each cell C, the positional differences between cells C may be large, as shown in Figure 7. Each cell C is then repositioned so that its respective reference line BL coincides with the others. At this time, each cell C is moved in the longitudinal direction to adjust its position so that the reference line BL coincides.

[0062] As described above, when the positions are corrected and the reference lines BL set for multiple cells C all coincide, the cells C will be stacked to form a single cell stack Cs.

[0063] (Second Embodiment) The cell C stacking method of the present invention is applicable not only to cell C in which electrode leads Le are led out at both ends, but also to cell C in which a pair of electrode leads Le are led out on one side.

[0064] Figure 8 shows a cell C used in the cell C stacking method according to the second embodiment of the present invention and a visual sensor S used to locate the center of the cell C, and Figure 9 shows the cell C and visual sensor S of Figure 8 from a side view.

[0065] The cell C described above houses an electrode assembly (not shown) in which multiple electrodes are stacked, and as shown in Figures 8 and 9, electrode leads Le, which are electrically connected to the electrode assembly, are led out to one side.

[0066] The cell C stacking method of the second embodiment is also characterized in that, similar to the cell C stacking method of the first embodiment, a virtual reference line BL is set for each cell C to be stacked, and the cells C are stacked in an aligned manner so that the reference lines BL coincide with each other.

[0067] The above reference line BL corresponds to the center of cell C, and the center of each cell C is found by using the positions of both ends of the housing Pr of that cell C as a reference.

[0068] In other words, the center of the housing Pr is the point that is halfway between the positions of both ends of the housing Pr.

[0069] The center of cell C corresponds to the center of the electrode assembly, and the reference line BL is formed to pass through the center of cell C. More specifically, the reference line BL is formed to cross the center of cell C such that the electrode lead Le of cell C is located on one side.

[0070] The above reference line BL is set at a position corresponding to the center of the uppermost electrode in the electrode assembly contained in the housing Pr. That is, the reference line BL is formed at the center position, starting from both ends of the uppermost electrode in the electrode assembly.

[0071] The ends of the electrodes included in the uppermost part of the electrode assembly described above correspond to the positions where the steps begin on both sides of the housing part Pr.

[0072] Multiple stacked electrodes may have slight differences in the position of their ends. In this invention, in order to quickly locate the center of cell C and set a reference line BL, both ends of the electrode located at the top of the electrode assembly are identified, and the center of the electrode is located based on the identified positions of both ends of the electrode, and a virtual reference line BL is formed.

[0073] The edges at both ends of the above-mentioned housing Pr can be identified by the visual sensor S, as shown in Figures 8 and 9.

[0074] The above-mentioned visual sensor S is located at the top of both sides of cell C to identify the end positions of the target cell C, and sets a virtual reference line BL passing through the center of cell C based on the identified end positions. At this time, the center of cell C corresponds to a position that is half the length of the edge positions of both ends of the housing Pr.

[0075] In this manner, each cell C is assigned its own reference line BL.

[0076] The present invention has been described in more detail above through the drawings and embodiments. However, the configurations described in the drawings or embodiments described herein are merely one embodiment of the present invention and do not represent the entire technical concept of the present invention. Therefore, there may be various equivalents and modifications that can substitute for them at the time of filing. [Explanation of Symbols]

[0077] Cs: Cellular laminate C: (Battery) Cell Co:Edge Le: Electrode lead L1: Positive lead L2: Negative lead B: Bus bar S: Visual sensor BL: Reference line Pr: Containment Unit Pe: Derivation part

Claims

1. The steps of identifying the center of a cell by identifying the edges on both sides of the cell with a visual sensor, The steps include setting a virtual reference line in the center of the cell, The step includes stacking a plurality of cells on which the aforementioned reference line is set, A cell stacking method in which the cells to be stacked are stacked in a state in which they are aligned so that the reference lines coincide.

2. The cell stacking method according to claim 1, wherein the cell contains an electrode assembly in which a plurality of electrodes are stacked, and electrode leads electrically connected to the electrode assembly are led out on both sides.

3. The cell stacking method according to claim 2, wherein the reference line is set at a position corresponding to the center of the electrode included in the uppermost part of the electrode assembly.

4. The cell stacking method according to claim 2, wherein the cell comprises a housing portion in which the electrode assembly is located and an outlet portion in which the electrode leads are located.

5. A step is formed between the housing section and the outlet section. The cell stacking method according to claim 4, wherein the central part corresponds to the central position starting from the position where the steps begin on both sides of the housing portion.

6. The cell stacking method according to claim 4, wherein the central part of the cell corresponds to the central position starting from the edges of both ends of the housing portion.

7. The cell stacking method according to claim 4, wherein the center of the cell corresponds to a position that is halfway between the edge positions of both ends of the housing portion.

8. The cell stacking method according to claim 2, wherein the reference line is formed across the center of the cell such that electrode leads are located on both sides.

9. The cell stacking method according to claim 2, wherein the reference line is formed at a central position starting from both ends of the electrode included in the uppermost part of the electrode assembly.

10. The electrode assembly includes a positive electrode, a separator membrane, and a negative electrode. The electrode lead includes a positive electrode lead electrically connected to the positive electrode of the electrode assembly, and a negative electrode lead electrically connected to the negative electrode of the electrode assembly. The cell stacking method according to claim 2, wherein adjacent pairs of cells are stacked alternately such that the positions of the positive electrode lead and the negative electrode lead are opposite.

11. The cell stacking method according to any one of claims 1 to 10, wherein each of the cells is moved in the longitudinal direction of the cell to adjust its position so that the reference line coincides.

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