A method for manufacturing a battery cell

Abstract

This invention provides a cell manufacturing method, belonging to the field of lithium battery manufacturing technology, comprising: fabricating a negative electrode sheet, the negative electrode sheet including two connected negative electrode units, with a spacer foil area between the two negative electrode units; fabricating a positive electrode unit; thermally bonding and stacking the negative electrode sheet, positive electrode units, and separator to form a composite unit; stacking several composite units to form a cell package, wherein the two negative electrode units of one negative electrode sheet are respectively arranged corresponding to two positive electrode units; and cutting the cell package corresponding to the spacer foil area to form two cell units. The cell manufacturing method provided by this invention thermally bonds and stacks a negative electrode sheet containing two negative electrode units with two corresponding positive electrode units, and then cuts the formed cell package into two cell units. Therefore, two cell units can be formed in one stacking process, improving the cell production efficiency.

Description

Technical Field

[0001] This invention relates to the field of lithium battery manufacturing technology, and more specifically to a method for manufacturing battery cells. Background Technology

[0002] In thermal lamination, a diaphragm is needed to separate the polarity-differentiated electrodes, and the electrodes and diaphragm are laminated together using hot pressing. The laminated strips are then stacked together using a Z-type lamination technique. In existing technology, when laminating polarity electrodes onto the diaphragm, only one individual electrode unit is placed at a time. Therefore, in a single production process, the lamination device can only produce one cell, resulting in low production efficiency. Summary of the Invention

[0003] Therefore, the technical problem to be solved by the present invention is to overcome the low efficiency of the existing technology in the production of battery cells by lamination, thereby providing a battery cell manufacturing method.

[0004] To address the aforementioned problems, this invention provides a battery cell manufacturing method, comprising: fabricating a negative electrode sheet, the negative electrode sheet including two connected negative electrode units, with a spacer foil area between the two negative electrode units; fabricating a positive electrode unit; thermally bonding the negative electrode sheet, the positive electrode unit, and a separator to form a composite unit, and stacking several composite units to form a battery cell package, wherein the two negative electrode units of one negative electrode sheet are respectively disposed corresponding to two positive electrode units; and cutting the battery cell package corresponding to the spacer foil area to form two battery cell units.

[0005] Optionally, during the manufacturing of the battery cell pack, the negative electrode sheet and the positive electrode sheet unit are thermally bonded onto the separator strip to form a composite strip, and the composite strip is Z-stacked to form the battery cell pack.

[0006] Optionally, the fabrication of the negative electrode sheet includes: fabricating a negative electrode strip, coating negative electrode material at intervals along the width direction of the foil material strip to form two negative electrode coating areas, each negative electrode coating area extending along the travel direction of the foil material strip, and forming the spaced empty foil area between the two negative electrode coating areas; cutting the negative electrode strip, cutting the negative electrode strip along the width direction of the negative electrode strip to form the negative electrode sheet.

[0007] Optionally, in the fabrication of the negative electrode strip, a negative electrode tab empty foil area is formed on the side of each negative electrode coating area away from the spacer empty foil area.

[0008] Optionally, after the negative electrode strip is manufactured, the tabs are made by laser cutting or metal die cutting of the negative electrode tab empty foil area, and then the negative electrode strip is cut by laser cutting to form the negative electrode sheet.

[0009] Optionally, after the negative electrode strip is manufactured, a die-cutting roller is used to roll-cut the negative electrode strip, and the tabs and the negative electrode strip are cut simultaneously during the roll-cutting process.

[0010] Optionally, the fabrication of the positive electrode unit includes: fabricating a positive electrode strip, coating a positive electrode material on the foil strip to form a positive electrode coating area, the positive electrode coating area extending along the travel direction of the foil strip; cutting the positive electrode strip, cutting the positive electrode strip along the width direction to form a positive electrode sheet; and slitting the positive electrode sheet, slitting the positive electrode sheet along the travel direction of the positive electrode strip, each positive electrode sheet being slit to form two positive electrode units.

[0011] Optionally, in the production of the positive electrode strip, positive electrode tab empty foil areas are formed on both sides of the positive electrode coating area, and each positive electrode tab empty foil area extends along the running direction of the positive electrode strip.

[0012] Optionally, after the positive electrode strip is made, the positive electrode tab is made by laser cutting or metal die cutting of the empty foil area, and then the positive electrode strip is cut by laser cutting to form the positive electrode sheet, and the positive electrode sheet is rolled to form the positive electrode unit.

[0013] Optionally, after the positive electrode strip is manufactured, a die-cutting roller is used to roll-cut the positive electrode strip, and the tabs, positive electrode strip cutting, and positive electrode sheet slitting are completed simultaneously during the rolling process.

[0014] Optionally, when thermally bonding the negative electrode sheet and the positive electrode unit onto the separator strip, the negative electrode sheet is spaced apart along the tape direction of the separator on one side of the separator, and the positive electrode unit is spaced apart along the tape direction of the separator on the other side of the separator, with one negative electrode sheet and two positive electrode units corresponding to each other; or, the negative electrode sheet is spaced apart along the tape direction of the separator between the two separator layers, and the positive electrode units are respectively arranged on the two outer sides of the two separator layers, with each negative electrode sheet having two positive electrode units corresponding to only one side, and the positive electrode units corresponding to two adjacent negative electrode sheets being arranged on the two outer sides of the two separator layers.

[0015] The present invention has the following advantages:

[0016] 1. The present invention provides a battery cell manufacturing method in which a negative electrode body containing two negative electrode units is thermally laminated with two positive electrode units, and the resulting battery cell core package is then cut into two battery cell units. Therefore, two battery cell units can be formed in one lamination process, which improves the production efficiency of the battery cell.

[0017] 2. The present invention provides a battery cell manufacturing method, which uses an intermittent coating method to form a negative electrode coating area, an intermittent empty foil area, and a negative electrode tab empty foil area on a foil material strip, which facilitates the subsequent tab fabrication and the cutting of the battery cell package.

[0018] 3. The present invention provides a cell manufacturing method that uses a die-cutting roller to simultaneously process the tabs and cut the negative electrode strip, which simplifies the processing flow of the negative electrode sheet and improves processing efficiency. Attached Figure Description

[0019] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0020] Figure 1 A schematic diagram of the negative electrode strip provided in an embodiment of the present invention is shown;

[0021] Figure 2 This diagram illustrates the structure of the negative electrode strip processed into an electrode tab according to an embodiment of the present invention.

[0022] Figure 3 A schematic diagram of the negative electrode sheet provided in an embodiment of the present invention is shown;

[0023] Figure 4 A schematic diagram of the structure of the positive electrode strip provided in an embodiment of the present invention is shown;

[0024] Figure 5 This diagram illustrates the structure of forming an electrode tab by processing a positive electrode strip according to an embodiment of the present invention.

[0025] Figure 6 A schematic diagram of the structure of the positive electrode sheet provided in an embodiment of the present invention is shown;

[0026] Figure 7 A schematic diagram of the structure of the positive electrode unit provided in an embodiment of the present invention is shown;

[0027] Figure 8 A schematic diagram of the battery cell package provided in an embodiment of the present invention is shown;

[0028] Figure 9 A schematic diagram of the structure of the battery cell unit provided in an embodiment of the present invention is shown;

[0029] Figure 10 A schematic diagram of the structure of the first composite method provided by an embodiment of the present invention is shown;

[0030] Figure 11 A schematic diagram of the second composite method provided by an embodiment of the present invention is shown.

[0031] Explanation of reference numerals in the attached figures:

[0032] 100, Negative electrode strip; 110, Negative electrode sheet; 111, Negative electrode sheet unit; 120, Spacing foil area; 130, Negative electrode coating area; 140, Negative electrode tab spacing foil area; 200, Positive electrode strip; 210, Positive electrode sheet; 211, Positive electrode sheet unit; 220, Positive electrode coating area; 230, Positive electrode tab spacing foil area; 400, Separator. Detailed Implementation

[0033] The technical solution of the present invention will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0034] In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0035] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0036] Furthermore, the technical features involved in the different embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0037] like Figures 1 to 11 One specific embodiment of the battery cell manufacturing method shown includes:

[0038] Fabrication of negative electrode plate 110, such as Figure 3 As shown, the negative electrode body 110 includes two negative electrode units 111 connected together, and the two negative electrode units 111 are separated by a spacer foil area 120.

[0039] Fabrication of positive electrode unit 211;

[0040] The negative electrode sheet 110 and the positive electrode unit 211 are thermally bonded onto the separator strip to form a composite strip. The composite strip is then Z-stacked to form a battery cell package. For example... Figure 8 As shown, two negative electrode units 111 of a negative electrode body 110 are respectively arranged corresponding to two positive electrode units 211;

[0041] like Figure 9 As shown, the battery cell core package is cut into two battery cell units by corresponding spacing foil area 120.

[0042] It is worth noting that the two negative electrode units 111 are connected by foil corresponding to the spacer foil area 120 to form a negative electrode body 110.

[0043] A negative electrode body 110 containing two negative electrode units 111 is thermally laminated with two positive electrode units 211, and then the resulting battery cell core is cut into two battery cell units. Therefore, two battery cell units can be formed in one lamination process, which improves the production efficiency of the battery cell.

[0044] In this embodiment, the composite strip formed by thermally bonding the negative electrode sheet 110 and the positive electrode unit 211 onto the separator strip includes several continuously arranged composite units. Of course, when manufacturing the battery cell pack, the negative electrode sheet 110, the positive electrode unit 211, and the separator 400 can be thermally bonded together to form individual composite units, and then several individual composite units can be stacked together to form the battery cell pack.

[0045] It is worth noting that, according to the requirements of the cell lamination process, the area of ​​the positive electrode unit 211 is smaller than that of the negative electrode unit 111. The positive electrode body 210 is completely separated to form the positive electrode unit 211, and then it is laminated with the negative electrode body 110 to ensure the alignment between the negative electrode unit 111 and the positive electrode unit 211.

[0046] It should be further explained that by first laminating the negative electrode sheet 110 with the separator 400, and then cutting the negative electrode sheet 110 and the separator 400, not only is the electrode sheet manufacturing efficiency and lamination efficiency improved, but also the negative electrode sheet unit 111 formed by the cutting is flush with the separator 400, which ensures the quality of the battery cell production.

[0047] like Figures 1 to 3 As shown, the fabrication of the negative electrode sheet 110 includes:

[0048] A negative electrode strip 100 is fabricated, and negative electrode material is coated at intervals along the width direction of the foil material strip to form two negative electrode coating areas 130. Each negative electrode coating area 130 extends along the walking direction of the foil material strip, and a spacer foil area 120 is formed between the two negative electrode coating areas 130. A negative electrode tab spacer foil area 140 is formed on the side of each negative electrode coating area 130 away from the spacer foil area 120.

[0049] The electrode tab is formed by processing the empty foil area 140 of the negative electrode tab.

[0050] Cut the negative electrode strip 100 along its width to form a negative electrode sheet 110.

[0051] An intermittent coating method is used to form a negative electrode coating area 130, an intermittent empty foil area 120, and a negative electrode tab empty foil area 140 on the foil material strip, which facilitates the subsequent fabrication of the tabs and the cutting of the battery cell package.

[0052] It is worth noting that, please refer to Figure 1 and Figure 2 The width direction of the foil material strip and the width direction of the negative electrode material strip 100 are respectively... Figure 1 and Figure 2 The vertical direction; the direction of the foil material strip's travel, that is... Figure 1 and Figure 2 The left and right directions in the middle.

[0053] It should be noted that the negative electrode coating area 130 refers to the area on the foil material strip where the negative electrode material is coated only, while the empty foil area 120 and the empty foil area 140 of the negative electrode tab are non-coated areas.

[0054] In this embodiment, the tabs and negative electrode strip 100 can be made by laser cutting, metal die cutting and roll cutting.

[0055] Alternatively, a die-cutting roller can be used to roll-cut the negative electrode strip 100, simultaneously completing the tab forming and the cutting of the negative electrode strip 100 during the roll-cutting process. Simultaneously processing the tabs and cutting the negative electrode strip 100 simplifies the processing flow of the negative electrode sheet 110 and improves processing efficiency.

[0056] like Figures 4 to 7 As shown, the fabrication of the positive electrode unit 211 includes:

[0057] A positive electrode strip 200 is fabricated, and a positive electrode material is coated on the foil material strip to form a positive electrode coating area 220. The positive electrode coating area 220 extends along the travel direction of the foil material strip, and positive electrode tab empty foil areas 230 are formed on both sides of the positive electrode coating area 220. Each positive electrode tab empty foil area 230 extends along the travel direction of the foil material strip.

[0058] The electrode tab is formed by processing the empty foil region 230 of the positive electrode tab.

[0059] Cut the positive electrode strip 200 along the width direction to form the positive electrode sheet 210;

[0060] The positive electrode sheet 210 is cut along the carrying direction of the positive electrode strip 200, and each positive electrode sheet 210 is cut to form two positive electrode units 211.

[0061] It is worth noting that when cutting the positive electrode sheet 210, it is preferable to cut along the center line of the positive electrode sheet 210 to form two identical positive electrode sheet units 211, thereby ensuring the alignment of the positive electrode sheet unit 211 and the negative electrode sheet unit 111 and the consistency of the two battery cell units produced.

[0062] An intermittent coating method is used to form a positive electrode coating area 220 and a positive electrode tab empty foil area 230 on the foil material strip, which facilitates the subsequent tab fabrication.

[0063] It is worth noting that, please refer to Figure 4 and Figure 5 The direction of travel of the foil material strip and the direction of travel of the positive electrode material strip 200 are, respectively, the direction of travel of the foil material strip and the direction of travel of the positive electrode material strip 200. Figure 4 and Figure 5 The left and right directions; the width direction of the positive electrode strip 200, that is... Figure 4 and Figure 5 The up and down directions.

[0064] It should be noted that the positive electrode coating area 220 refers to the area on the foil material strip where the positive electrode material is coated only, while the positive electrode tab empty foil area 230 is an uncoated area.

[0065] Further explanation is needed; please refer to [link / reference]. Figure 4 The positive electrode coating area 220 is located in the middle region of the positive electrode strip 200 in the width direction, and two positive electrode tab empty foil areas 230 are formed on the upper and lower sides of this area.

[0066] In this embodiment, the electrode tabs, positive electrode strips 200, and positive electrode sheets 210 can be formed by laser cutting, metal die cutting, and roll cutting.

[0067] Alternatively, a die-cutting roller can be used to roll-cut the positive electrode strip 200, simultaneously completing the tab forming, the cutting of the positive electrode strip 200, and the slitting of the positive electrode sheet 210. By processing the tabs, cutting the positive electrode strip 200, and slitting the positive electrode sheet 210 simultaneously, the processing flow of the positive electrode unit 211 is simplified, and processing efficiency is improved.

[0068] It is worth noting that, please refer to Figure 3 The negative electrode strip 100 only needs to be cut to form two connected negative electrode units 111 with opposite tab orientations; please refer to Figure 6 and Figure 7 The positive electrode strip 200 needs to be cut and split to form two separate positive electrode units 211 with opposite tab orientations.

[0069] It should be further clarified that the above-mentioned cutting refers to the division along the width direction of the material strip, while the above-mentioned splitting refers to the division along the conveyor belt direction.

[0070] like Figure 10 As shown, when the negative electrode sheet 110 and the positive electrode unit 211 are thermally bonded to the separator 400, the negative electrode sheet 110 is spaced apart along the tape direction of the separator 400 on one side, and the positive electrode unit 211 is spaced apart along the tape direction of the separator 400 on the other side. One negative electrode sheet 110 and two positive electrode units 211 are correspondingly arranged. Therefore, one negative electrode sheet 110, two positive electrode units 211, and the separator 400 located between them are bonded to form a composite unit. Figure 10 As shown, the composite strip is Z-stacked, and the separator 400 between two adjacent composite units is laid between the negative electrode sheet 110 and the positive electrode sheet 211 of the two adjacent composite units. Therefore, a stacked structure of negative electrode sheet 110- separator 400-positive electrode sheet 211 (two)- separator 400-negative electrode sheet 110... can be formed.

[0071] In other alternative implementations, such as Figure 11 As shown, negative electrode plates 110 are spaced apart between two layers of separators 400 along the belt direction of the separators 400, and positive electrode units 211 are respectively arranged on the two outer sides of the two layers of separators 400. Each negative electrode plate 110 has two positive electrode units 211 arranged on only one side, and the positive electrode units 211 corresponding to two adjacent negative electrode plates 110 are respectively arranged on the two outer sides of the two layers of separators 400.

[0072] It is worth noting that, please refer to Figure 11 The two outer sides of the two 400-layer diaphragms are... Figure 11 The two layers of separator 400 are located on the left and right sides. Each negative electrode plate 110 has two positive electrode units 211 arranged on its left or right side. If two positive electrode units 211 are arranged on the left side of a negative electrode plate 110, then two positive electrode units 211 are arranged on the right side of the adjacent negative electrode plate 110. Similarly, if two positive electrode units 211 are arranged on the right side of a negative electrode plate 110, then two positive electrode units 211 are arranged on the left side of the adjacent negative electrode plate 110.

[0073] Therefore, as Figure 11 As shown, a composite unit is formed by two layers of separators 400, a negative electrode sheet 110 between the two layers of separators 400, and two positive electrode sheet units 211 on one side of the two layers of separators 400. Figure 11 As shown, the composite strip is Z-folded, and a fold is formed between two adjacent composite units. Therefore, a stacked structure of negative electrode sheet 110-diaphragm 400-positive electrode sheet unit 211 (two)-diaphragm 400-negative electrode sheet 110... can be formed.

[0074] Of course, the composite of negative electrode body 110, positive electrode unit 211 (two) and separator 400 can also adopt other composite forms, as long as the composite strip formed by the composite can form a stacked structure of negative electrode body 110- separator 400-positive electrode unit 211 (two)- separator 400-negative electrode body 110... after Z-stack.

[0075] Based on the above description, this patent application has the following advantages:

[0076] 1. The negative electrode material strip is cut into negative electrode sheets, which are then directly used for composite stacking. During the sheet making process, there is no need to cut the negative electrode sheets one by one, which improves the sheet making efficiency of negative electrode sheets.

[0077] 2. A composite lamination of one negative electrode body and two positive electrode units is adopted, and then the lamination is cut after completion to improve the cell production efficiency.

[0078] Obviously, the above embodiments are merely illustrative examples for clear explanation and are not intended to limit the implementation. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. However, obvious variations or modifications derived therefrom are still within the scope of protection of this invention.

Claims

1. A method for manufacturing a battery cell, characterized in that, include: A negative electrode sheet (110) is fabricated. The negative electrode sheet (110) includes two connected negative electrode sheet units (111). There is a spacer foil area (120) between the two negative electrode sheet units (111). A negative electrode tab foil area (140) is formed on the side of each negative electrode sheet unit (111) away from the spacer foil area (120). Fabricate the positive electrode unit (211); A composite unit is formed by combining a negative electrode sheet (110), a positive electrode unit (211), and a separator (400). The method includes arranging negative electrode plates (110) at intervals along the belt direction of the separator (400) on one side of the separator (400), and arranging positive electrode units (211) at intervals along the belt direction of the separator (400) on the other side of the separator (400). One negative electrode plate (110) and two positive electrode units (211) are arranged correspondingly on both sides of the separator (400). Alternatively, negative electrode plates (110) are spaced apart between the two separators (400) along the direction of the separator (400), and positive electrode units (211) are respectively arranged on the two outer sides of the two separators (400). Each negative electrode plate (110) has two positive electrode units (211) arranged on only one side, and the positive electrode units (211) corresponding to two adjacent negative electrode plates (110) are respectively arranged on the two outer sides of the two separators (400). Several composite units are stacked in a Z-shape to form a battery cell package; The battery cell core package is cut into the corresponding spaced foil area (120) to form two battery cell units. The negative electrode unit (111) and the separator (400) formed by the cutting are flush at the cutting position.

2. The cell manufacturing method according to claim 1, characterized in that, Fabrication of the negative electrode sheet (110) includes: A negative electrode strip (100) is fabricated, and negative electrode material is coated at intervals along the width direction of the foil material strip to form two negative electrode coating areas (130). Each negative electrode coating area (130) extends along the carrying direction of the foil material strip, and the spaced empty foil area (120) is formed between the two negative electrode coating areas (130). Cut the negative electrode strip (100) along the width direction of the negative electrode strip (100) to form a negative electrode sheet (110).

3. The cell manufacturing method according to claim 2, characterized in that, In the fabrication of the negative electrode strip (100), a negative electrode tab empty foil area (140) is formed on the side of each negative electrode coating area (130) away from the spacer empty foil area (120).

4. The cell manufacturing method according to claim 3, characterized in that, After the negative electrode strip (100) is made, the tab is made by laser cutting or metal die cutting of the negative electrode tab empty foil area (140), and then the negative electrode strip (100) is cut by laser to form the negative electrode sheet (110).

5. The cell manufacturing method according to claim 3, characterized in that, After the negative electrode strip (100) is made, the negative electrode strip (100) is cut by a die-cutting roller. During the cutting process, the electrode tab and the negative electrode strip (100) are cut simultaneously.

6. The cell manufacturing method according to claim 1, characterized in that, Fabricating the positive electrode unit (211) includes: A positive electrode strip (200) is fabricated, and a positive electrode material is coated on the foil material strip to form a positive electrode coating area (220). The positive electrode coating area (220) extends along the carrying direction of the foil material strip. Cut the positive electrode strip (200) along the width direction of the positive electrode strip (200) to form a positive electrode sheet (210). The positive electrode sheet (210) is cut along the direction of the positive electrode strip (200), and each positive electrode sheet (210) is cut to form two positive electrode units (211).

7. The cell manufacturing method according to claim 6, characterized in that, In the fabrication of the positive electrode strip (200), positive electrode tab empty foil regions (230) are formed on both sides of the positive electrode coating area (220), and each positive electrode tab empty foil region (230) extends along the running direction of the positive electrode strip (200).

8. The cell manufacturing method according to claim 7, characterized in that, After the positive electrode strip (200) is made, the positive electrode tab is made by laser cutting or metal die cutting of the empty foil area (230). Then, the positive electrode strip (200) is cut by laser to form the positive electrode sheet (210). The positive electrode sheet (210) is then rolled to form the positive electrode unit (211).

9. The cell manufacturing method according to claim 7, characterized in that, After the positive electrode strip (200) is made, the positive electrode strip (200) is cut by a die-cutting roller. During the cutting process, the tabs, the cutting of the positive electrode strip (200) and the cutting of the positive electrode sheet (210) are completed simultaneously.

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