Battery cell, preparation method thereof and battery

Abstract

The present invention discloses a battery cell, a preparation method thereof and a battery. The battery cell of the present invention comprises at least one stacked battery cell unit; the stacked battery cell unit comprises a first electrode sheet, a second electrode sheet and a diaphragm; wherein the first electrode sheet and the second electrode sheet are both U-shaped or V-shaped folding structures; one end of the first electrode sheet is inserted into the U-shaped or V-shaped gap of the second electrode sheet, and one end of the second electrode sheet is inserted into the U-shaped or V-shaped gap of the first electrode sheet; and the diaphragm is attached between the first electrode sheet and the second electrode sheet to isolate the first electrode sheet from the second electrode sheet. The battery contains the battery cell of the present invention. The battery cell has low ohmic resistance and high safety performance.

Description

Technical Field

[0001] The invention belongs to the field of batteries, and in particular relates to a battery cell and a preparation method thereof, and a battery. Background Art

[0002] As an energy storage device, the battery mainly consists of the following parts: positive electrode, negative electrode, separator, and electrolyte. Among them, the positive electrode, separator, and negative electrode are stacked in sequence to form a sandwich structure to form a battery cell. In addition to the materials and properties of the positive electrode, negative electrode, separator, and electrolyte, which play a vital role in the electrochemical performance and safety of the battery cycle, the structure of the battery cell itself also plays a vital role in the electrochemical performance and safety.

[0003] Conventional batteries such as secondary batteries generally contain cells of laminated structure. For example, before assembling lithium-sulfur batteries, the positive and negative electrode sheets must be cut into the required shape, and then the positive / diaphragm / negative electrode sheets are laminated to form a cell. In this way, the current collectors of each positive electrode sheet and each negative electrode sheet are only connected by welding at the tabs, resulting in a large ohmic resistance of the entire positive electrode system or negative electrode system. During the battery charging and discharging process, the tab connection is prone to heat and temperature rise, which affects the battery performance and poses a safety hazard. Summary of the invention

[0004] The purpose of the present invention is to overcome the above-mentioned deficiencies of the prior art and to provide a battery cell and a method for preparing the same, so as to solve the technical problem that the existing laminated battery cells are connected by welding the tabs, resulting in high resistance and safety hazards.

[0005] Another object of the present invention is to provide a battery to solve the technical problem that the existing battery has unsatisfactory electrochemical performance and safety due to the existing laminated battery core contained therein.

[0006] In order to achieve the above-mentioned purpose, one aspect of the present invention provides a battery cell. The battery cell of the present invention comprises at least one stacked battery cell unit; the stacked battery cell unit comprises a first electrode sheet, a second electrode sheet and a separator; wherein the first electrode sheet and the second electrode sheet are both U-shaped or V-shaped folding structures;

[0007] One end of the first electrode sheet is inserted into the U-shaped or V-shaped gap of the second electrode sheet, and one end of the second electrode sheet is inserted into the U-shaped or V-shaped gap of the first electrode sheet;

[0008] The diaphragm is attached between the first electrode sheet and the second electrode sheet to isolate the first electrode sheet from the second electrode sheet.

[0009] Another aspect of the present invention provides a method for preparing the battery cell of the present invention. The battery cell of the present invention comprises the following steps:

[0010] Obtaining a first electrode sheet body, wherein the first electrode sheet body comprises at least one electrode sheet, and folding the electrode sheet into a U-shape or a V-shape to form a first electrode sheet having at least one U-shaped or V-shaped folding structure;

[0011] Obtaining a second electrode sheet body, wherein the second electrode sheet body comprises at least one electrode sheet, and folding the electrode sheet into a U-shape or a V-shape to form a second electrode sheet having at least one U-shaped or V-shaped folding structure;

[0012] A separator is attached to at least the surfaces of both ends of each of the first electrode sheet and the second electrode sheet;

[0013] According to the first electrode sheet and the second electrode sheet as a group, one end of the first electrode sheet of each group is inserted into the U-shaped or V-shaped gap of the second electrode sheet, and one end of the second electrode sheet is inserted into the U-shaped or V-shaped gap of the first electrode sheet, so as to assemble at least one battery stack cell unit;

[0014] Assemble at least one battery stack cell unit into a battery cell.

[0015] In another aspect of the present invention, a battery is provided. The battery of the present invention comprises a battery cell, wherein the battery cell is the battery cell of the present invention or a battery cell prepared by the method for preparing the battery cell of the present invention.

[0016] Compared with the prior art, the present invention has the following technical effects:

[0017] The battery cell of the present invention sets the first electrode sheet and the second electrode sheet in the battery cell unit contained in the battery cell as a folding structure, and each folding structure electrode sheet is integrally connected through a current collector, thereby greatly reducing the ohmic resistance of the two electrode sheets and improving the safety performance. By setting the first electrode sheet and the second electrode sheet structure contained in each battery cell unit, the two electrode sheets play a synergistic role, effectively reducing the ohmic resistance of the battery cell, giving the battery cell of the present invention high safety performance, effectively overcoming the high resistance defect of the existing stacked battery cell, and making the battery cell of the present invention suitable for large-capacity batteries.

[0018] The battery cell preparation method of the present invention directly folds the first electrode sheet body and the second electrode sheet body according to the battery cell structure of the present invention to respectively form a first electrode sheet and a second electrode sheet with a U-shaped or V-shaped folding structure, which are arranged as a battery stack battery cell unit, thereby giving the prepared battery cell the characteristics of low ohmic resistance and high safety. In addition, the battery cell preparation method of the present invention has easy controllable process, and the quality and performance of the prepared battery cell are stable and efficient.

[0019] The battery cell of the present invention is the battery cell of the present invention. Therefore, the battery of the present invention has a small internal resistance, excellent rate performance, high safety, and can also be a large-capacity battery. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the specific implementation methods of the present invention or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0021] Figure 1 It is a schematic diagram of the structure of a battery stack cell unit contained in a battery cell according to an embodiment of the present invention;

[0022] Figure 2 For two or more Figure 1 The schematic diagram of the battery cell structure is shown as a stack of battery cell units;

[0023] Figure 3 Schematic diagram of a first electrode sheet body and a U-shaped or V-shaped folding structure formed by a U-shaped or V-shaped folding process; wherein, Figure a is a schematic diagram of the structure of the first electrode sheet body before the U-shaped or V-shaped folding process, and Figure b is a schematic diagram of the structure of the first electrode sheet with a folding structure;

[0024] Figure 4 The schematic diagram of the structure of the battery of the embodiment of the present invention is a lithium-sulfur soft-pack battery.

[0025] Description of the component numbers in the accompanying drawings:

[0026] 1'-a section of the first electrode sheet body; 1-the first electrode sheet; 11-a folding portion of the first electrode sheet; 12-another folding portion of the first electrode sheet; 13-a bending portion of the first electrode sheet; 14-a pole ear of the first electrode sheet 1; 15-a bending line of the electrode sheet 1' for U-shaped or V-shaped folding;

[0027] 2-a second electrode sheet; 21-a folding portion of the second electrode sheet; 22-another folding portion of the second electrode sheet; 23-a bending portion of the second electrode sheet;

[0028] 3- Diaphragm. DETAILED DESCRIPTION

[0029] In order to make the purpose, technical scheme and technical effect of the embodiments of the present invention clearer, the technical scheme in the embodiments of the present invention is clearly and completely described. The embodiments described below are part of the embodiments of the present invention, rather than all of the embodiments. In conjunction with the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention. If the specific conditions are not specified in the embodiments, they are carried out according to conventional conditions or the conditions recommended by the manufacturer; if the manufacturer of the reagents or instruments is not specified, they are all conventional products that can be purchased commercially.

[0030] In the description of the present invention, the term "and / or" describes the association relationship of associated objects, indicating that three relationships may exist. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. A and B can be singular or plural. The character " / " generally indicates that the associated objects before and after are in an "or" relationship.

[0031] In the description of the present invention, "at least one" means one or more, and "plurality" means two or more. "At least one of the following" or similar expressions refers to any combination of these items, including any combination of single items or plural items. For example, "at least one of a, b, or c", or "at least one of a, b, and c" can all mean: a, b, c, ab (i.e., a and b), ac, bc, or abc, where a, b, c can be single or multiple, respectively.

[0032] In addition, unless the context clearly uses otherwise, the expression of the singular form of a word should be understood to include the plural form of the word. The term "includes" or "having" is intended to specify the existence of a feature, quantity, step, operation, element, part or combination thereof, but is not used to exclude the existence or possible addition of one or more other features, quantities, steps, operations, elements, parts or combinations thereof.

[0033] Explanation of the relevant names below:

[0034] Battery cell unit: refers to Figure 1 The first electrode sheet 1, the second electrode sheet 2 and the diaphragm 3 are stacked in a stacking manner of first electrode sheet 1 / diaphragm 3 / second electrode sheet 2 to form a combined structure.

[0035] Battery cell: refers to a battery composed of multiple Figure 1 The structure formed by stacking battery cell units.

[0036] U-shaped or V-shaped folding structure: refers to Figure 3 A section of the electrode sheet shown in Figure a is folded into a U-shape or a V-shape to form Figure 3The U-shaped or V-shaped structure shown in Figure b.

[0037] Hinge section: refers to the two end areas of a U-shaped or V-shaped folding structure.

[0038] Bending section: refers to the bending area connecting two adjacent folding sections.

[0039] On the one hand, an embodiment of the present invention provides a battery cell. The structure of the battery cell of the embodiment of the present invention is as follows Figures 1 to 3 As shown, it includes at least one stack cell unit 01 arranged in layers, and the stack cell unit 01 includes a first electrode sheet 1, a second electrode sheet 2 and a separator 3; wherein,

[0040] The structure of the first electrode sheet 1 is as follows Figure 1 and Figure 3 As shown, it is a U-shaped or V-shaped folding structure. The U-shaped or V-shaped folding structure is as shown in FIG. Figure 1 , Figure 2 and Figure 3 As shown in FIG. b, it includes a folding portion 11 and a folding portion 12 at both ends and a U-shaped or V-shaped bending portion 13 connecting the folding portion 11 and the folding portion 12. The folding portion 11 and the folding portion 12 respectively include two folding pages arranged opposite to each other, and the bending portion 13 includes a convex surface and a concave surface arranged opposite to each other. Setting the first electrode sheet 1 as a folding structure is equivalent to directly forming the two electrodes contained in the traditional disc-type battery cell into a whole, which effectively reduces the ohmic resistance of the first electrode sheet.

[0041] In an embodiment of the present invention, the gap between the bending portion 13 of the first electrode sheet 1 and the two folding portions 11 and the folding portion 12 is required to clamp one of the bending portions of the second electrode sheet 2. Therefore, in order to make the bending portion 13 better clamp one of the bending portions of the second electrode sheet 2, it is preferred that the bending portion 13 has a U-shape as opposed to a V-shape.

[0042] The structure of the second electrode sheet 2 is as follows Figure 1 and Figure 2 As shown, the structure and morphology of the first electrode sheet 1 are similar, and the structure is a U-shaped or V-shaped folding structure. Figure 1 , Figure 2 As shown, it includes a folding portion 21 and a folding portion 22 at both ends and a U-shaped or V-shaped bending portion 23 connecting the folding portion 21 and the folding portion 22. The folding portion 21 and the folding portion 22 respectively include two folding pages arranged opposite to each other, and the bending portion 23 includes a convex surface and a concave surface arranged opposite to each other. The second electrode sheet 2 is set as a folding structure, which is equivalent to directly forming the two electrodes contained in the traditional disc-type battery cell into a whole, which effectively reduces the ohmic resistance of the second electrode sheet.

[0043] In an embodiment of the present invention, the gap enclosed by the bending portion 23 of the second electrode sheet 2 and the two folding portions 21 and the folding portion 22 is required to clamp one of the bending portions of the first electrode sheet 1. Therefore, in order to make the bending portion 23 better clamp one of the bending portions of the first electrode sheet 1, it is preferred that the bending portion 23 has a U-shape as opposed to a V-shape.

[0044] Based on the structure of the first electrode sheet 1 and the second electrode sheet 2, as Figure 1 and Figure 2 As shown, one end of the first electrode sheet 1, i.e., the folding portion 12, is inserted into the U-shaped or V-shaped gap enclosed by the bending portion 23 of the second electrode sheet 2 and the two folding portions 21 and the folding portion 22. One end of the second electrode sheet 2 is inserted into the U-shaped or V-shaped gap of the first electrode sheet. Moreover, the first electrode sheet 1 and the second electrode sheet 2 are isolated by a diaphragm 3, thereby forming a battery stack cell unit 01.

[0045] The diaphragm 3 is attached between the first electrode sheet 1 and the second electrode sheet 2 to isolate the first electrode sheet 1 from the second electrode sheet 2. Therefore, the diaphragm 3 is at least attached to the two opposite folded pages of the folding portion 11 of the first electrode sheet 1 and the two opposite folded pages of the folding portion 12, and at least attached to the two opposite folded pages of the folding portion 21 of the second electrode sheet 2 and the two opposite folded pages of the folding portion 22. Of course, it can also be further attached to the convex surface and the concave surface of the bending portion 13 of the first electrode sheet 1, and can also be further attached to the convex surface and the concave surface of the bending portion 23 of the second electrode sheet 2. In the embodiment of the present invention, it is ideal that the diaphragm 3 is simultaneously adhered to the two opposite folding pages of the folding portion 11 of the first electrode sheet 1 and the two opposite folding pages of the folding portion 12, and at least adhered to the two opposite folding pages of the folding portion 21 of the second electrode sheet 2 and the two opposite folding pages of the folding portion 22, and is also adhered to the convex surface and concave surface of the bending portion 13 of the first electrode sheet 1 and the convex surface and concave surface of the bending portion 23 of the second electrode sheet 2, so as to improve the safety and electrochemical stability of the battery stack cell unit 01.

[0046] In a specific embodiment, the diaphragm 3 is a whole diaphragm and is attached to the two opposite surfaces of the first electrode sheet 1 and the second electrode sheet 2. Figure 1 As shown in the figure, the separator 3 is attached between the folding part 11 of the first electrode sheet 1 and the folding part 21 of the second electrode sheet 2, the separator 3 is attached between the folding part 12 of the first electrode sheet 1 and the folding part 22 of the second electrode sheet 2, and is also attached to the convex surface and concave surface of the bending part 13 of the first electrode sheet 1 and the convex surface and concave surface of the bending part 23 of the second electrode sheet 2. This effectively improves the safety of the battery cell.

[0047] In the battery cell of the embodiment of the present invention, the battery cell may contain only one battery stack cell unit 01 described above, and of course may contain more than two battery stack cell units 01 described above. In the embodiment, the battery cell may contain 1-200 battery stack cell units 01 described above, further 1-100, and further 1-50. In the embodiment, when the battery cell contains more than two battery stack cell units 01 described above, the diaphragm 3 is also attached between adjacent battery stack cell units 01 to isolate the adjacent battery stack cell units 01. In another embodiment, when more than two battery stack cell units 01 are used to assemble the battery cell, each battery stack cell unit 01 is stacked in sequence along an extension direction. In a specific embodiment, the number of battery stack cell units 01 of the assembled battery cell can be controlled according to specific needs.

[0048] Thus, in the battery cell unit 01, the first electrode sheet 1 and the second electrode sheet 2 are configured as a folding structure, and the two are inserted and stacked, and each folding structure electrode sheet is integrally connected through a current collector, thereby greatly reducing the ohmic resistance of the two electrode sheets and improving safety performance. By configuring the structure of the first electrode sheet 1 and the second electrode sheet 2 contained in each battery cell unit 01, the two electrode sheets play a synergistic role, effectively reducing the ohmic resistance of the cell, giving the cell high safety performance, and effectively overcoming the high resistance defect of the existing stacked cell, making the cell suitable for large-capacity batteries.

[0049] Based on the structure of the battery cell unit 01 in the above embodiments, as an embodiment of the present invention, one of the first electrode sheet 1 and the second electrode sheet 2 is a positive electrode sheet, and the other electrode sheet is a negative electrode sheet. For example, in a specific embodiment, the first electrode sheet 1 is a positive electrode sheet, and the second electrode sheet 2 is a negative electrode sheet.

[0050] In the embodiment, when one of the electrode sheets in the battery cell unit 01, such as the first electrode sheet 1, is a positive electrode sheet, in a specific embodiment, the positive electrode sheet is a positive electrode sheet of a lithium-sulfur battery, and the specific positive electrode sheet of the lithium-sulfur battery includes a current collector and a positive electrode material layer containing active sulfur material and conductive material formed on the surface of the current collector. When another electrode sheet in the battery cell unit 01, such as the second electrode sheet 2, is a negative electrode sheet, in a specific embodiment, the negative electrode sheet is a lithium metal sheet. Among them, the lithium metal sheet includes lithium metal foil or lithium metal alloy foil. At this time, the battery cell unit of the battery cell is a lithium-sulfur battery cell unit, and the cell constitutes a lithium-sulfur battery cell.

[0051] Of course, the first electrode sheet 1 and the second electrode sheet 2 in the above embodiments are respectively provided with tabs. In a specific embodiment, the tabs included in the first electrode sheet 1 are as follows: Figure 3 The tab 14 in the middle a diagram, the tab included in the second electrode sheet 2 can be Figure 3 The tabs in Figure a are the same or similar.

[0052] Therefore, the battery cells in the above-mentioned embodiments arrange the first electrode sheet 1 and the second motor sheet 2 structure contained in each battery stack cell unit 01 so that the two electrode sheets play a synergistic role, effectively reduce the ohmic resistance of the battery cell, give the battery cell high safety performance, and effectively overcome the high resistance defect of the existing stacked battery cells, making the battery cells suitable for large-capacity batteries.

[0053] Accordingly, an embodiment of the present invention also provides a method for preparing the above battery cell. The method for preparing the battery cell comprises the following steps:

[0054] S01: obtaining a first electrode sheet body, wherein the first electrode sheet body comprises at least one electrode sheet, and folding the electrode sheet into a U-shape or a V-shape to form a first electrode sheet having at least one U-shaped or V-shaped folding structure;

[0055] S02: obtaining a second electrode sheet body, wherein the second electrode sheet body comprises at least one electrode sheet, and folding the electrode sheet into a U-shape or a V-shape to form a second electrode sheet having at least one U-shaped or V-shaped folding structure;

[0056] S03: attaching a separator to at least the surfaces of both ends of each of the first electrode sheet and the second electrode sheet;

[0057] S04: according to the first electrode sheet and the second electrode sheet as a group, one end of the first electrode sheet of each group is inserted into the U-shaped or V-shaped gap of the second electrode sheet, and one end of the second electrode sheet is inserted into the U-shaped or V-shaped gap of the first electrode sheet, so as to assemble at least one battery stack cell unit;

[0058] S05: Assemble at least one battery stack cell unit into a battery cell.

[0059] The first electrode sheet body in step S01 is formed Figure 1 Each electrode sheet is folded in a U-shape or a V-shape. Figure 3 As shown in FIG. a, one of the electrode sheets 1' is folded into a U-shape or a V-shape along the bending line 15 to form a Figure 3 The U-shaped or V-shaped folding structure shown in Figure b. In addition, the first electrode sheet body is the electrode sheet body of the first electrode sheet 1 described in the battery cell above. When the first electrode sheet 1 is a positive electrode sheet, such as a positive electrode sheet of a lithium-sulfur battery, the electrode sheet 1' is a positive electrode sheet of a lithium-sulfur battery; when the first electrode sheet 1 is a negative electrode sheet, such as a lithium metal sheet, the electrode sheet 1' is a lithium metal sheet.

[0060] The U-shaped or V-shaped folding of the second electrode sheet body in step S02 refers to the U-shaped or V-shaped folding of the first electrode sheet body in step S01. The U-shaped or V-shaped folding structure of the second electrode sheet is the same or similar to the U-shaped or V-shaped folding structure of the first electrode sheet.

[0061] In addition, there is no order between step S01 and step S02, and between step S01 and step S03.

[0062] The diaphragm in step S03 is the diaphragm 3 contained in the battery cell unit 01 of the battery cell of the above embodiment of the present invention, wherein the position where the diaphragm is attached to the first electrode sheet and the second electrode sheet is the same as the position where the diaphragm 3 contained in the above battery cell is attached in the battery cell unit 01.

[0063] The method for plugging the first electrode sheet and the second electrode sheet in step S04 is specifically as described above. Figure 1 The first electrode sheet 1 and the second electrode sheet 2 included in the battery stack cell unit 01 are plugged in a plug-in manner to form the above battery stack cell unit 01.

[0064] The battery stack cell units in step S05 can be assembled into battery cells according to conventional methods. In the embodiment, when more than two battery stack cell units 01 are used to assemble battery cells, adjacent battery stack cell units 01 are separated by diaphragms 3. In the embodiment, when more than two battery stack cell units 01 are used to assemble battery cells, each battery stack cell unit 01 is stacked in sequence along an extension direction. In a specific embodiment, the number of battery stack cell units 01 for assembling battery cells can be controlled according to specific needs.

[0065] In this way, the method for preparing a battery cell in an embodiment of the present invention directly folds the first electrode sheet body and the second electrode sheet body according to the battery cell structure of the embodiment of the present invention above to respectively form a first electrode sheet and a second electrode sheet with a U-shaped or V-shaped folding structure, and sets them as battery stack cell units, thereby giving the prepared battery cell the characteristics of low ohmic resistance and high safety. In addition, the battery cell preparation method is easy to control, and the quality and performance of the prepared battery cell are stable, and the efficiency is high.

[0066] On the other hand, based on the above-mentioned battery cell and its preparation method of the embodiment of the present invention, the embodiment of the present invention also provides a battery. The battery includes a battery cell, and of course also includes necessary components of the battery, such as a battery shell for coating the battery cell and an electrolyte that acts on the battery cell. Among them, the battery cell is the battery cell of the embodiment of the present invention above. Since the battery cell contained in the battery is the battery cell of the embodiment of the present invention above, the battery of the embodiment of the present invention has a small internal resistance, excellent rate performance, high safety, and can also be a large-capacity battery.

[0067] In the embodiment, when the first electrode sheet 1 contained in the battery cell is lithium foil, and the second electrode sheet 2 is a positive electrode, specifically a sulfur-containing battery positive electrode, the battery is a lithium-sulfur battery. When the lithium-sulfur battery is a lithium-sulfur soft-pack battery, the battery structure is as follows: Figure 4 Of course, the battery of the embodiment of the present invention may also be other types of batteries, as long as they contain the battery cells of the embodiment of the present invention described above, they are all within the scope disclosed in the embodiment of the present invention.

[0068] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A battery cell, characterized in that: The battery cell comprises more than two battery stack battery cell units, each of which is stacked in sequence in an extending direction; the battery stack battery cell unit comprises a first electrode sheet, a second electrode sheet and a separator; wherein the first electrode sheet and the second electrode sheet are both U-shaped folding structures, the folding structure comprises folding parts at both ends and a U-shaped bending part connecting the two folding parts, and the first electrode sheet and the second electrode sheet are respectively formed by performing U-shaped folding processing on the electrode sheets; A folded portion of the first electrode sheet is inserted into the U-shaped gap of the second electrode sheet, and a folded portion of the second electrode sheet is inserted into the U-shaped gap of the first electrode sheet; The diaphragm is a whole diaphragm, which is attached to two opposite surfaces of the first electrode sheet and the second electrode sheet to isolate the first electrode sheet from the second electrode sheet; The diaphragm is attached between adjacent battery stack cell units to isolate adjacent battery stack cell units.

2. The battery cell according to claim 1, characterized in that: The number of the battery stack cell units is 2-200.

3. The battery cell according to any one of claims 1 to 2, characterized in that: One of the first electrode sheet and the second electrode sheet is a positive electrode sheet, and the other electrode sheet is a negative electrode sheet.

4. The battery cell according to claim 3, characterized in that: The positive electrode sheet is a positive electrode sheet of a lithium-sulfur battery; the negative electrode sheet is a lithium metal sheet.

5. The method for preparing a battery cell according to any one of claims 1 to 4, comprising the following steps: Obtaining a first electrode sheet body, wherein the first electrode sheet body comprises at least one electrode sheet, and performing a U-shaped folding process on the electrode sheet to form a first electrode sheet having at least one U-shaped folding structure; Obtaining a second electrode sheet body, wherein the second electrode sheet body comprises at least one electrode sheet, and performing a U-shaped folding process on the electrode sheet to form a second electrode sheet having at least one U-shaped folding structure; A diaphragm is attached to at least two opposite surfaces of each of the first electrode sheet and the second electrode sheet; According to the first electrode sheet and the second electrode sheet as a group, one of the folded portions of the first electrode sheet of each group is inserted into the U-shaped gap of the second electrode sheet, and at the same time, one of the folded portions of the second electrode sheet is inserted into the U-shaped gap of the first electrode sheet, so as to assemble at least one battery stack cell unit; Two or more of the battery stack cell units are stacked and arranged, and two adjacent battery stack cell units are isolated by a diaphragm to assemble into a battery cell.

6. A battery, comprising a battery cell, characterized in that: The battery cell is the battery cell according to any one of claims 1 to 4 or the battery cell prepared by the preparation method according to claim 5.

7. The battery according to claim 6, characterized in that: The battery is a lithium-sulfur battery.

8. The battery according to claim 7, characterized in that: The lithium-sulfur battery is a lithium-sulfur soft-pack battery.

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