A method for manufacturing a lithium battery roll core, a lithium battery roll core, and a lithium battery

Abstract

The present invention discloses a method for manufacturing a lithium battery roll core, a lithium battery roll core and a lithium battery, comprising the steps of: coating an electrode slurry on a current collector to form a plurality of spaced film regions, wherein the width of the film regions is an even multiple of the width of a pole piece required for a single roll core; when the multiple of the width of the film region and the width of the pole piece required for a single lithium battery roll core is greater than 2, cutting each film region so that the width of each film region after cutting is twice the width of the pole piece required for a single roll core; first winding the current collector and then cutting and separating adjacent film regions or first cutting and separating adjacent film regions and then winding the current collector to obtain a rolled-up pre-roll core, wherein the pre-roll core comprises a film region and a spacing region between adjacent film regions; and cutting the pre-roll core to obtain two roll cores.

Description

Technical Field

[0001] The present invention relates to the technical field of lithium battery processing, and in particular to a method for manufacturing a lithium battery roll core, a lithium battery roll core and a lithium battery. Background Art

[0002] Lithium batteries are widely used in 3C digital products, electric vehicles, start-stop power supplies, model aircraft, energy storage and other fields due to their many advantages such as high voltage, high capacity, long cycle life, low self-discharge efficiency and good safety performance.

[0003] When manufacturing the winding core body, one of the components of lithium batteries, the winding core body is cut into the width of a single battery through a slitting process, and then the positive electrode sheet, negative electrode sheet and separator to be wound are wound one by one through a winding machine. In this way, only one battery can be wound in a single winding, which is inefficient. Summary of the invention

[0004] The purpose of the present invention is to provide a lithium battery core manufacturing method, a lithium battery core and a lithium battery, which can complete the winding of two batteries in a single winding with high efficiency.

[0005] The present invention discloses a method for manufacturing a lithium battery roll core, comprising the steps of:

[0006] The electrode slurry is coated on the current collector to form a plurality of spaced film regions, wherein the width of the film region is an even multiple of the width of the electrode sheet required for a single winding core;

[0007] When the multiple of the width of the film area and the width of the pole piece required for a single roll of the lithium battery is greater than 2, cut each film area so that the width of each film area after cutting is twice the width of the pole piece required for a single roll;

[0008] Firstly winding the current collector and then cutting and separating the adjacent film regions or firstly cutting and separating the adjacent film regions and then winding the current collector to obtain a rolled-up pre-rolled core, wherein the pre-rolled core includes a film region and a spacing region between adjacent film regions;

[0009] The pre-rolled core is cut to obtain two roll cores.

[0010] Optionally, before the step of first winding the current collector and then cutting and separating the adjacent film regions or first cutting and separating the adjacent film regions and then winding the current collector, the method further includes the following steps:

[0011] Paste the adhesive tape, and the adhesive tape is located at the center line or non-center line position of the current collector.

[0012] Optionally, before the step of first winding the current collector and then cutting and separating the adjacent film regions or first cutting and separating the adjacent film regions and then winding the current collector, the method further includes the following steps:

[0013] The upper pole ears are fixedly connected on both sides of the spacing area.

[0014] Optionally, the winding core comprises a positive electrode current collector, a negative electrode current collector and a separator, and the electrode slurry comprises a positive electrode slurry and a negative electrode slurry; and the manufacturing method is specifically as follows:

[0015] The positive electrode slurry is coated on the positive electrode collector, and the negative electrode slurry is coated on the negative electrode collector, and a plurality of film regions arranged in intervals are formed on the positive electrode collector and the negative electrode collector respectively, and the width of the film region is an even multiple of the width of the pole piece required for a single winding core body;

[0016] stacking a positive electrode current collector, a separator and a negative electrode current collector in sequence;

[0017] When the multiple of the width of the film area and the width of the pole piece required for a single roll of lithium battery is greater than 2, cut each film area so that the width of each film area after cutting is twice the width of the pole piece required for a single roll; when the width of the film area is twice the width of the pole piece required for a single roll, each film area is not cut and the next step is directly executed;

[0018] Winding the positive electrode current collector, the separator and the negative electrode current collector, and cutting and separating the adjacent film regions to obtain a rolled-up pre-rolled core, wherein the positive electrode current collector and the negative electrode current collector of the pre-rolled core both include a film region and a spacer region between adjacent film regions;

[0019] The pre-rolled core is cut to obtain two roll cores.

[0020] Optionally, before the step of winding the positive electrode current collector, the separator and the negative electrode current collector, the method further comprises the following steps:

[0021] Adhesive tape is respectively pasted on the positive electrode current collector and the negative electrode current collector, and the adhesive tape is located at the midline or non-midline position of the positive electrode current collector and the negative electrode current collector.

[0022] Optionally, the electrode tabs include positive electrode tabs and negative electrode tabs; before the step of winding the positive electrode current collector, the separator and the negative electrode current collector, the step further includes:

[0023] The positive electrode tabs are fixedly connected to both sides of the spacer on the positive electrode current collector, and the negative electrode tabs are fixedly connected to both sides of the spacer on the negative electrode current collector.

[0024] Optionally, the length of the film area on the negative electrode sheet is greater than the length of the film area on the positive electrode sheet.

[0025] Optionally, the relationship between the width of the film area and the width of the winding core is:

[0026] Film area width = core height × 2 × N (N ≥ 0)

[0027] Wherein, N is the number of roll cores required to be produced for each film area.

[0028] The present invention also discloses a lithium battery roll core body, which is manufactured by the above-mentioned manufacturing method.

[0029] The present invention also discloses a lithium battery, comprising the battery roll core body as described above.

[0030] In the lithium battery core production method of the present invention, multiple film areas are coated on the current collector, and the width of the film area is an even multiple of the width of the pole piece required for a single core. Before winding, the current collector coated with the film area is cut into twice the width of the pole piece required for a single core, and then the cut current collector with a width twice the width of the pole piece required for a single core is wound. After winding, the pre-rolled core is cut again, and finally two cores can be obtained. In other words, the lithium battery core production method of the present invention can achieve two cores by winding once, reducing the number of windings by half, doubling the winding efficiency, and having high efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] The included drawings are used to provide a further understanding of the embodiments of the present invention, which constitute a part of the specification, are used to illustrate the implementation of the present invention, and together with the text description, explain the principles of the present invention. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work. In the drawings:

[0032] Figure 1 is a schematic diagram of a method for manufacturing a lithium battery roll core according to an embodiment of the present invention;

[0033] Figure 2 is a schematic diagram of current collector coating according to an embodiment of the present invention;

[0034] Figure 3 is a schematic diagram of current collector cutting according to an embodiment of the present invention;

[0035] Figure 4 Schematic diagram of a current collector welded to a tab without adhesive tape attached in an embodiment of the present invention;

[0036] Figure 5 yes Figure 4 A schematic diagram of a pre-wound core formed after the current collector is wound;

[0037] Figure 6 yes Figure 5 Schematic diagram of a pre-rolled core body cut to obtain a rolled core body;

[0038] Figure 7 Schematic diagram of welding the current collector to the electrode tab and pasting the adhesive tape according to an embodiment of the present invention;

[0039] Figure 8 yes Figure 7A schematic diagram of a pre-wound core formed after the current collector is wound;

[0040] Fig. 9 yes Figure 8 Schematic diagram of cutting a pre-rolled core to obtain a rolled core.

[0041] Among them, 1. current collector; 11. membrane area; 12. spacer area; 13. positive electrode current collector; 14. negative electrode current collector; 2. adhesive tape; 3. tab; 31. positive electrode tab; 32. negative electrode tab; 4. pre-rolled core; 5. rolled core. DETAILED DESCRIPTION

[0042] It should be understood that the terms used herein, the specific structures and functional details disclosed are only for describing specific embodiments and are representative, but the present invention can be implemented in many alternative forms and should not be construed as being limited to only the embodiments described herein.

[0043] The present invention is described in detail below with reference to the accompanying drawings and optional embodiments.

[0044] like Figures 2 to 6 As shown, as an embodiment of the present invention, a method for manufacturing a lithium battery roll core is disclosed, comprising the steps of:

[0045] S100: coating the electrode slurry on the current collector to form a plurality of spaced-apart film regions, wherein the width of the film region is an even multiple of the width of the electrode sheet required for a single winding core;

[0046] S200: When the multiple of the width of the film area and the width of the pole piece required for a single roll of the lithium battery is greater than 2, cut each film area so that the width of each film area after cutting is twice the width of the pole piece required for a single roll; when the width of the film area is twice the width of the pole piece required for a single roll, each film area is not cut and the next step is directly executed;

[0047] S300: first winding the current collector and then cutting and separating the adjacent film regions, or first cutting and separating the adjacent film regions and then winding the current collector, to obtain a rolled-up pre-rolled core, wherein the pre-rolled core includes a film region and a spacing region between adjacent film regions;

[0048] S400: Cutting the pre-rolled core to obtain two roll cores.

[0049] like Figure 1 As shown, when the lithium battery core body 5 is currently manufactured, the current collector 1 coated with the film area 11 is generally cut and each cut current collector 1 is wound separately to form the lithium battery core body 5. In this way, each lithium battery core body 5 needs to be wound separately. Figure 1After the current collector 1 coated with the film area 11 is divided into 6 equal parts, the 6 parts of the single film area 11 before cutting need to be wound 6 times to obtain 6 lithium battery winding core bodies 5 ( Figure 1 The cut current collector shown in the figure will be cut into three parts, and finally 18 times of winding will be performed to obtain 18 lithium battery roll core bodies 5). In the production process of the lithium battery roll core body 5, the coating, cutting and other processes are not time-consuming and efficient, but the winding process is the most time-consuming and the least efficient process. The number of winding actions has a great impact on the production efficiency of the lithium battery roll core body 5.

[0050] In the method for making a lithium battery roll core body of the present invention, a plurality of film regions 11 are coated on the current collector 1, and the width of the film region 11 is an even multiple of the width of the roll core body 5. Before winding, the current collector 1 coated with the film region 11 is cut into twice the width of the roll core body 5, and then the cut current collector 1 having a width twice the width of the roll core body 5 is wound. After winding, the pre-rolled core body 4 is cut, and finally two roll core bodies 5 can be obtained. In other words, the method for making a lithium battery roll core body 5 of the present invention can achieve two roll core bodies 5 by winding once, reducing the number of winding times by half, doubling the winding efficiency, and having high efficiency.

[0051] Specifically, after the electrode slurry is coated on the current collector 1 to form the film area 11, it becomes a pole piece after drying, rolling and compacting. Therefore, after step S100, the steps of drying, rolling and compacting the membrane area are also included. The electrode slurry includes positive electrode slurry and negative electrode slurry, and the current collector 1 includes positive electrode collector 13 and negative electrode collector 14. The positive electrode slurry is coated on the positive electrode collector 13 and becomes a positive electrode sheet after drying, rolling and compacting, and the negative electrode slurry is coated on the negative electrode collector 14 and becomes a negative electrode sheet after drying, rolling and compacting. The positive electrode sheet, the separator and the negative electrode sheet are stacked in sequence and then wound to form a lithium battery roll body 5. In the method for making a lithium battery roll body of the present invention, since the width of the current collector 1 and the membrane area 11 before winding is doubled, the width is increased, the pole piece is wide during winding, the pole piece rigidity is improved, and the winding stability is improved. At the same time, the alignment tolerance between the two becomes larger, and the positive and negative electrodes are easier to align, which can improve the alignment between the positive and negative electrodes during winding, avoid the misalignment between the positive and negative electrodes beyond the required range, and thus reduce the defective rate of the winding core 5 caused by poor coating. Therefore, the cutting position does not need to be designed with excessive width to ensure coating, which can further improve the energy density of lithium-ion batteries.

[0052] Specifically, Figure 2 As shown in the figure, the current collector is rectangular, and the film area is coated into a rectangle along the width direction of the current collector. When cutting each film area, Figure 2 The cut is shown along the length of the current collector.

[0053] Specifically, Figure 2As shown, the electrode slurry is coated on the current collector 1 to form a membrane region 11, and the interval between adjacent membrane regions 11 is the interval region 12. The side of the membrane region 11 perpendicular to the length direction of the current collector 1 is the width of the membrane region 11, and the side in the same direction as the length direction of the current collector 1 is the length of the membrane region 11.

[0054] In step S100, if Figure 1 As shown, a plurality of spaced film regions 11 are coated on the current collector 1, and the width of the film region 11 is an even multiple of the width of the roll core 5 to be manufactured, such as two, four, six, eight, etc. The current collector 1 is generally in a roll shape before coating, and is unrolled and coated during coating to achieve continuous coating operation.

[0055] In step S200, if the width of the coated film area 11 is only twice the width of the roll core 5 to be manufactured, it is not necessary to cut each film area 11, and the next step is directly performed. If the multiple of the width of the coated film area 11 and the width of the lithium battery roll core 5 is greater than 2, for example, the width of the film area 11 is four times, six times, eight times, etc., the width of the roll core 5 to be manufactured is Figure 3 As shown, each film area 11 is first cut into a width twice the width of the winding core 5, and then the next step is performed.

[0056] In step S300, the current collector 1 coated with the electrode slurry is wound, and the adjacent film regions 11 are cut and separated to obtain a rolled pre-rolled core 4, such as Figure 5 As shown. Figure 4 As shown, the pre-rolled core 4 includes a film area 11 and a spacer area 12. That is, when the adjacent film areas 11 are cut and separated, one film area 11 and one spacer area 12 are cut as a group, so as to obtain the following Figure 5 The pre-rolled core 4 is shown.

[0057] In step S400, if Figure 5 As shown, the width of the pre-rolled core 4 is twice the width of the roll core 5 to be made. Figure 6 As shown, by cutting the pre-rolled core 4, two roll cores 5 can be obtained, so that two roll cores 5 can be obtained by winding once. In step S400, Figure 6 As shown, the pre-rolled core 4 can be cut into equal parts to obtain roll cores 5 with uniform heights, or the pre-rolled core 4 can be cut into unequal parts to obtain roll cores 5 with different heights.

[0058] Specifically, Figure 7 As shown, before the step of first winding the current collector and then cutting and separating the adjacent membrane regions or first cutting and separating the adjacent membrane regions and then winding the current collector in S300, the step further includes: pasting adhesive tape, the adhesive tape being located at the center line or non-center line position of the current collector. Figure 7As shown, the adhesive tape 2 is pasted on the center line or non-center line position of the current collector 1, that is, the adhesive tape 2 is pasted on the cutting position in step S400. The adhesive tape 2 can reduce the risk of contact between the positive electrode sheet and the negative electrode sheet at the cutting position.

[0059] Specifically, Figure 4 or Figure 7 As shown, before the step of first winding the current collector and then cutting and separating the adjacent membrane regions or first cutting and separating the adjacent membrane regions and then winding the current collector in S300, the step further includes: fixing and connecting the upper tabs on both sides of the spacer region. The tabs 3 can be fixed on both sides of the spacer region 12 by welding. After the pre-rolled core 4 is cut in S400, as shown in FIG. Figure 6 or Figure 8 As shown, each winding core 5 has only one positive electrode tab 31 and one negative electrode tab 32. Since the side of the winding core 5 needs to be welded with the tab 3, the width of the film area 11 can only be cut to twice the width of the winding core 5 in step S200, so that the tabs 3 are welded on both sides of the spacing area 12 before cutting in step S400, and each winding core 5 after cutting can be guaranteed to have one positive electrode tab 31 and one negative electrode tab 32, while ensuring normal cutting in step S400. If the width of the film area 11 is cut to four times the width of the winding core 5 in step S200, four winding cores 5 can be cut in step S400, but the sides of the two middle winding cores 5 cannot be welded with the tabs 3, otherwise it will hinder the cutting of the pre-rolled core 4.

[0060] Specifically, the winding core 5 includes a positive electrode current collector 13, a negative electrode current collector 14 and a separator, and the electrode slurry includes a positive electrode slurry and a negative electrode slurry; the manufacturing method is specifically as follows:

[0061] The positive electrode slurry is coated on the positive electrode current collector, and the negative electrode slurry is coated on the negative electrode current collector, and a plurality of spaced film regions are formed on the positive electrode current collector and the negative electrode current collector, respectively, and the width of the film region is an even multiple of the width of the winding core 5;

[0062] stacking a positive electrode current collector, a separator and a negative electrode current collector in sequence;

[0063] When the multiple of the width of the film area and the width of the pole piece required for a single roll of lithium battery is greater than 2, cut each film area so that the width of each film area after cutting is twice the width of the pole piece required for a single roll; when the width of the film area is twice the width of the pole piece required for a single roll, each film area is not cut and the next step is directly executed;

[0064] Winding the positive electrode current collector, the separator and the negative electrode current collector, and cutting and separating the adjacent film regions to obtain a rolled-up pre-rolled core, wherein the positive electrode current collector and the negative electrode current collector of the pre-rolled core both include a film region and a spacer region between adjacent film regions;

[0065] The pre-rolled core is cut to obtain two roll cores.

[0066] After the positive electrode current collector 13 is coated with the positive electrode slurry, it is dried, compacted and finally cut to become a positive electrode sheet. After the negative electrode current collector 14 is coated with the negative electrode slurry, it is dried, compacted and finally cut to become a negative electrode sheet. In this scheme, the positive electrode current collector 13, the separator and the negative electrode current collector 14 are stacked in sequence, and the separator is located between the positive electrode current collector 13 and the negative electrode current collector 1, which can insulate and separate the positive electrode current collector 13 and the negative electrode current collector 14. Finally, the roll core 5 obtained by cutting the pre-rolled core 4 is a complete roll core 5 that can be directly used to prepare a battery cell.

[0067] When the adjacent membrane regions 11 are cut and separated, the cathode current collector 1, the separator and the anode current collector 14 are cut at the same time.

[0068] Specifically, before the step of winding the positive electrode current collector, the separator and the negative electrode current collector, the step of: pasting adhesive tape on the positive electrode current collector and the negative electrode current collector respectively, the adhesive tape is located at the midline or non-midline position of the positive electrode current collector and the negative electrode current collector. The adhesive tape can reduce the risk of contact between the positive electrode sheet and the negative electrode sheet at the cutting position. Specifically, as Figure 7 As shown, adhesive tape 2 is pasted along the length direction of the positive electrode current collector and the negative electrode current collector respectively.

[0069] Specifically, the tabs 3 include a positive tab 31 and a negative tab 32; before the step of winding the positive current collector, the separator and the negative current collector, the step of: fixing the positive tabs on both sides of the spacer on the positive current collector, and fixing the negative tabs on both sides of the spacer on the negative current collector. After the positive tabs 31 and the negative tabs 32 are fixedly connected on both sides of the spacer 12 on the positive current collector 13 and the negative current collector 14, respectively, Figure 7 After cutting, Fig. 9 shown.

[0070] Specifically, the length of the film area 11 on the negative electrode sheet is greater than the length of the film area 11 on the positive electrode sheet.

[0071] Specifically, the relationship between the width of the film area and the width of the winding core is:

[0072] Film area width = core height × 2 × N (N ≥ 0)

[0073] Wherein, N is the number of roll cores required to be produced for each film area.

[0074] Specifically, the width of the film area 11 is 6 times the width of the winding core 5, and the step of cutting each film area 11 is specifically: cutting each film area into three equal parts.

[0075] As another embodiment of the present invention, a lithium battery roll core is disclosed, which is manufactured using the above-mentioned manufacturing method.

[0076] As another embodiment of the present invention, a lithium battery is disclosed, including the battery roll core body as described above.

[0077] It should be noted that the limitations on the various steps involved in this scheme, without affecting the implementation of the specific scheme, are not deemed to limit the order of the steps. The steps written in the front can be executed first, or can be executed later, or even simultaneously. As long as this scheme can be implemented, it should be regarded as belonging to the scope of protection of the present invention.

[0078] The above contents are further detailed descriptions of the present invention in combination with specific optional implementation methods, and it cannot be determined that the specific implementation of the present invention is limited to these descriptions. For ordinary technicians in the technical field to which the present invention belongs, several simple deductions or substitutions can be made without departing from the concept of the present invention, which should be regarded as falling within the scope of protection of the present invention.

Claims

1. A method for manufacturing a lithium battery roll core, characterized in that: The winding core body includes a positive electrode current collector, a negative electrode current collector and a separator, and the electrode slurry includes a positive electrode slurry and a negative electrode slurry; the manufacturing method includes the steps of: The positive electrode slurry is coated on the positive electrode collector, and the negative electrode slurry is coated on the negative electrode collector, and a plurality of spaced film regions are formed on the positive electrode collector and the negative electrode collector, respectively, and the width of the film region is an even multiple of the width of the pole piece required for a single winding core body; stacking a positive electrode current collector, a separator and a negative electrode current collector in sequence; When the multiple of the width of the film area and the width of the pole piece required for a single roll of lithium battery is greater than 2, cut each film area so that the width of each film area after cutting is twice the width of the pole piece required for a single roll; when the width of the film area is twice the width of the pole piece required for a single roll, each film area is not cut and the next step is directly executed; Winding the positive electrode current collector, the separator and the negative electrode current collector, and cutting and separating the adjacent film regions to obtain a rolled-up pre-rolled core, wherein the positive electrode current collector and the negative electrode current collector of the pre-rolled core both include a film region and a spacer region between adjacent film regions; The pre-rolled core is cut to obtain two roll cores.

2. The method according to claim 1, characterized in that: Before the step of winding the positive electrode current collector, the separator and the negative electrode current collector, the step further includes: The upper pole ears are fixedly connected on both sides of the spacing area.

3. The method according to claim 1, characterized in that: Before the step of winding the positive electrode current collector, the separator and the negative electrode current collector, the step further includes: Adhesive tape is respectively pasted on the positive electrode current collector and the negative electrode current collector, and the adhesive tape is located at the midline or non-midline position of the positive electrode current collector and the negative electrode current collector.

4. The method according to claim 2, characterized in that: The tabs include a positive tab and a negative tab; before the step of winding the positive current collector, the separator and the negative current collector, the step further includes: The positive electrode tabs are fixedly connected to both sides of the spacer on the positive electrode current collector, and the negative electrode tabs are fixedly connected to both sides of the spacer on the negative electrode current collector.

5. The method according to claim 1, characterized in that: The length of the film area on the negative electrode sheet of the lithium battery is greater than the length of the film area on the positive electrode sheet of the lithium battery.

6. The method according to claim 1, characterized in that: The relationship between the width of the film area and the width of the winding core is: Film area width = core height × 2 × N (N ≥ 0) Wherein, N is the number of roll cores required to be produced for each film area.

7. A lithium battery roll core, characterized in that: The method is adopted as claimed in any one of claims 1 to 6.

8. A lithium battery, characterized in that: Comprising the lithium battery roll core as described in claim 7.

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