Improved high-temperature battery structure and production process

Abstract

The invention relates to an improved high-temperature battery structure and a production process, the improved high-temperature battery structure comprises a battery shell with an opening at one end, a battery core body, a support body, an electrolyte and a battery cover, the battery shell and the battery cover form an accommodating cavity, the battery core body is a roll body, and the support body is arranged in the accommodating cavity. The battery core is formed by sequentially overlapping and winding a negative electrode assembly, first isolation insulation paper, a positive electrode assembly and second isolation insulation paper, a supporting cavity is formed in the middle of the battery core, the supporting body is inserted into the supporting cavity, the positive electrode assembly is of a multi-layer sheet structure comprising a negative electrode film, and the second isolation insulation paper is of a multi-layer sheet structure comprising a negative electrode film. And the negative electrode assembly is of a multi-layer sheet body structure comprising a lithium sheet. Through the design of the three-layer positive electrode structure, the three-layer negative electrode structure and the supporting body, the effects of increasing the effective reaction area of the lithium sheet, increasing the conductive area, preventing the pole sheet from falling off and the like can be achieved, and the purposes of stable capacity / current, large-current discharge, high temperature resistance and safety are achieved.

Description

Technical Field

[0001] The present invention relates to the technical field of high temperature batteries, and in particular to an improved high temperature battery structure and production process. Background Art

[0002] A high-temperature battery, such as a lithium thionyl chloride battery, is often used in high-temperature drilling environments. It is a primary inorganic non-aqueous electrolyte battery with a stable voltage platform, a wide operating temperature, a long storage life, and does not contain any heavy metal elements. The existing lithium thionyl chloride battery core includes a positive electrode sheet, a diaphragm, and a metal lithium sheet. However, the existing single-layer positive electrode sheet structure is prone to limited conductive area and low discharge power; and the single-layer negative electrode structure is prone to incomplete reaction, which causes the battery to fail to reach the rated capacity and causes the battery capacity / current to be unstable. Therefore, technical personnel in this field need to read these technical documents. At the same time, it is necessary to further improve the battery power and capacity of lithium thionyl chloride batteries, as well as reduce material costs. Summary of the invention

[0003] To achieve the above-mentioned purpose, the present invention provides the following technical solutions: an improved high-temperature battery structure, comprising a battery shell with an opening at one end, a battery core, a support body, an electrolyte and a battery cover, wherein the battery shell and the battery cover form a containing cavity, the battery core is a coil, which is formed by stacking and winding a negative electrode assembly, a first isolation insulating paper, a positive electrode assembly and a second isolation insulating paper in sequence, a support cavity is provided in the middle of the battery core, and the support body is inserted in the support cavity, the positive electrode assembly is a sheet body, which is a multi-layer structure including a cathode film, the negative electrode assembly is a sheet body, which is a multi-layer structure including a lithium sheet, the negative electrode assembly includes a lithium sheet lower layer, a negative electrode nickel mesh interlayer and a lithium sheet upper layer stacked in sequence, the lithium sheet upper layer and the lithium sheet lower layer are respectively arranged on the upper surface and the lower surface of the negative electrode nickel mesh interlayer, the lengths of the lithium sheet lower layer and the lithium sheet upper layer are respectively greater than half of the negative electrode nickel mesh interlayer, and one end of the lithium sheet lower layer and the lithium sheet upper layer are respectively flush with the corresponding end of the negative electrode nickel mesh interlayer.

[0004] Preferably, it also includes anti-damage insulating paper, which is square in shape, and the first isolation insulating paper and the second isolation insulating paper are folded isolation insulating paper of an integral structure, which is folded when in use, with the second isolation insulating paper located at the top and the first isolation insulating paper located at the bottom, and the anti-damage insulating paper is arranged on the first isolation insulating paper and close to the folded crease, one end of the positive electrode assembly abuts against the other end of the anti-damage insulating paper, and the positive electrode assembly is sandwiched between the second isolation insulating paper and the first isolation insulating paper.

[0005] Preferably, the first isolation insulating paper, the second isolation insulating paper and the damage-proof insulating paper are all made of glass fiber.

[0006] Preferably, the support body is formed by bending a metal spring sheet along a wide side, wherein the four corners of the metal spring sheet are rounded, and the metal spring sheet is provided with a plurality of through holes.

[0007] Preferably, the positive electrode assembly comprises a cathode film upper layer, a positive electrode nickel mesh interlayer, and a cathode film lower layer stacked in sequence, wherein the cathode film upper layer, the positive electrode nickel mesh interlayer, and the cathode film lower layer are all in a square shape, and the positive electrode nickel mesh interlayer is provided with a lead wire.

[0008] Preferably, the lead is parallel to the width direction, and one end of the lead extends out of the cathode film, and the length of the lead is greater than the width of the positive electrode nickel mesh interlayer.

[0009] The present invention also provides a production process for an improved high-temperature battery: the production process is used for producing the above-mentioned improved high-temperature battery structure, and the production process comprises the following steps:

[0010] Step 1: assembling a positive electrode assembly, wherein step 1 completes the assembly of a positive electrode assembly having a cathode film as a lower layer, a nickel mesh as a middle layer, and a cathode film as an upper layer;

[0011] Step 2: Assembling the negative electrode assembly; Step 2 completes the assembly of the negative electrode assembly with a lower layer of lithium sheet, a middle layer of nickel mesh, and an upper layer of lithium sheet, wherein the upper lithium sheet as the upper layer of the lithium sheet and the lower lithium sheet as the lower layer of the lithium sheet are respectively arranged on the upper surface and the lower surface of the negative electrode nickel mesh interlayer, and one end of the lower layer of the lithium sheet and the upper layer of the lithium sheet are respectively flush with the corresponding end of the negative electrode nickel mesh interlayer;

[0012] Step 3: Assembling the battery core; in the step 3, the positive electrode assembly is first sandwiched in the folded isolation insulating paper, and the anti-damage insulating paper is arranged between the fold of the folded isolation insulating paper and the positive electrode assembly, and then the combination of the positive electrode assembly and the folded isolation insulating paper is superimposed on the negative electrode assembly and then wound to form a roll with a support cavity in the middle;

[0013] Step 4: Assembling the support body, wherein the step 4 completes inserting the support body into the support cavity of the roll body in step 3;

[0014] Step 5: The battery core is welded and fixed to the inner wall of the battery shell.

[0015] Step 6: Cover and fix the battery housing;

[0016] Step 7: electrolyte perfusion;

[0017] Step 8: Dry.

[0018] Preferably, step 2 includes the following sub-steps:

[0019] Sub-step 21: Take a double-layer lithium sheet, separate the double-layer lithium sheet, and lay it flat on the work surface in the vertical direction, take another nickel mesh as a negative electrode nickel mesh interlayer, and place the negative electrode nickel mesh interlayer under the lower lithium sheet;

[0020] Sub-step 22: Take the lower lithium sheet as the lower layer of the lithium sheet, align the wide side of its left side with the wide side of the left side of the negative electrode nickel mesh interlayer, overlap the lower layer of the lithium sheet on the upper surface of the negative electrode nickel mesh interlayer, and compact the lower layer of the lithium sheet and the negative electrode nickel mesh interlayer with a compacting hammer;

[0021] Sub-step 23: flipping the assembly of the negative electrode nickel mesh interlayer and the lithium sheet lower layer 180 degrees horizontally, where the lithium sheet lower layer is located on the right lower bottom surface of the negative electrode nickel mesh interlayer;

[0022] Sub-step 24: Take the upper lithium sheet and use it as the upper layer of the lithium sheet. Align the left wide edge of the upper layer of the lithium sheet with the left wide edge of the negative electrode nickel mesh interlayer, then overlap them, and compact the upper layer of the lithium sheet and the negative electrode nickel mesh interlayer with a compacting hammer.

[0023] The present invention has the following beneficial effects:

[0024] The negative electrode assembly provided by the present invention comprises a lithium sheet lower layer, a negative electrode nickel mesh interlayer and a lithium sheet upper layer stacked in sequence, the lengths of the lithium sheet lower layer and the lithium sheet upper layer are respectively greater than half of the negative electrode nickel mesh interlayer, and one end of the lithium sheet lower layer and the lithium sheet upper layer are respectively flush with the corresponding end of the negative electrode nickel mesh interlayer. The negative electrode nickel mesh interlayer is mesh nickel, which greatly increases the conductive contact area between the lithium sheet and the nickel wire, increases the reaction amount and reaction speed of the lithium sheet, and thus improves the battery power and capacity of the lithium thionyl chloride battery. In addition, the lower layer of the lithium sheet, the negative electrode nickel mesh interlayer and the upper layer of the lithium sheet are overlapped, and the lengths of the lower layer of the lithium sheet and the upper layer of the lithium sheet are respectively greater than half of the negative electrode nickel mesh interlayer, so that the upper and lower bottom surfaces of the middle part of the negative electrode nickel mesh interlayer are evenly in contact with the lithium sheet, thereby greatly increasing the contact area between the negative electrode nickel mesh interlayer and the middle part of the lithium sheet. After the negative electrode assembly is wound, its inner side surface is in contact with the support body, and its outer side is in contact with the inner wall of the battery shell, therefore, not so many lithium sheets are needed to participate in the reaction, thereby saving the amount of lithium sheets. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 : Structural schematic diagram of the present invention

[0026] Figure 2 : Schematic diagram of the structure of the battery core,

[0027] Figure 3 : Schematic diagram and structural decomposition diagram of the negative electrode assembly,

[0028] Figure 4 : Schematic diagram and structural decomposition diagram of the positive electrode assembly,

[0029] Figure 5 : Schematic diagram of the structure of the support body,

[0030] Figure 6 : Schematic diagram of the assembly process of the positive electrode component and the insulator.

[0031] Description of the numbers in the figure:

[0032] Battery shell 1, battery cover 11, battery core 2, support cavity 20, support body 3, cavity 20, negative electrode assembly 21, lithium sheet lower layer 213, negative electrode nickel mesh interlayer 212, lithium sheet upper layer 211, positive electrode assembly 22, cathode film upper layer 221, positive electrode nickel mesh interlayer 222, cathode film lower layer 223, first isolation insulating paper 231, second isolation insulating paper 232, anti-damage insulating paper 24. DETAILED DESCRIPTION

[0033] The technical solution in one embodiment of the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present invention.

[0034] See also Figure 1-6 :

[0035] An improved high-temperature battery structure includes a battery case 1 with an opening at one end, a battery core 2, a support body 3, an electrolyte and a battery cover 11, wherein the battery case 1 and the battery cover 11 form a receiving cavity 20, the battery core 2 is a roll, which is formed by stacking and winding a negative electrode assembly 21, a first isolation insulating paper 231, a positive electrode assembly 22 and a second isolation insulating paper 232 in sequence, and a support cavity 20 is provided in the middle of the battery core 2, the support body 3 is inserted in the support cavity 20, and the positive electrode assembly 21 is provided in the support cavity 20. Component 22 is a sheet body, which is a multi-layer structure including a cathode film. The negative electrode assembly 21 is a sheet body, which is a multi-layer structure including a lithium sheet. The negative electrode assembly 21 includes a lithium sheet lower layer 213, a negative electrode nickel mesh interlayer 212 and a lithium sheet upper layer 211 stacked in sequence. The lengths of the lithium sheet lower layer 213 and the lithium sheet upper layer 211 are respectively greater than half of the negative electrode nickel mesh interlayer 212, and one end of the lithium sheet lower layer 213 and the lithium sheet upper layer 211 are respectively flush with the corresponding end of the negative electrode nickel mesh interlayer 212. The negative electrode nickel mesh interlayer 212 is mesh nickel, which greatly increases the conductive contact area between the lithium sheet and the nickel wire, increases the reaction amount and reaction speed of the lithium sheet, and thus improves the battery power and capacity of the lithium thionyl chloride battery. In addition, the lithium sheet lower layer 213, the negative electrode nickel mesh interlayer 212 and the lithium sheet upper layer 211 are overlapped up and down, and the lengths of the lithium sheet lower layer 213 and the lithium sheet upper layer 211 are respectively greater than half of the negative electrode nickel mesh interlayer 212, so that the upper and lower bottom surfaces of the middle part of the negative electrode nickel mesh interlayer 212 are evenly in contact with the lithium sheet, thereby greatly increasing the contact area between the negative electrode nickel mesh interlayer 212 and the middle part of the lithium sheet. After the negative electrode assembly 21 is wound, its inner side surface is in contact with the support body 3, and its outer side is in contact with the inner wall of the battery shell 1. Therefore, not so many lithium sheets are needed to participate in the reaction, thereby saving the amount of lithium sheets.

[0036] In this embodiment, as a preference, it also includes anti-damage insulating paper 24, which is square, and the first isolation insulating paper 231 and the second isolation insulating paper 232 are folded isolation insulating papers of an integral structure, which are folded when in use, the second isolation insulating paper 232 is located at the top, and the first isolation insulating paper 231 is located at the bottom. The anti-damage insulating paper 24 is arranged on the first isolation insulating paper and close to the folded crease, and one end of the positive electrode assembly 22 is against the other end of the anti-damage insulating paper 24, and the positive electrode assembly 22 is sandwiched between the second isolation insulating paper 232 and the first isolation insulating paper 231. In order to prevent the positive electrode assembly 22 from being overstressed during the installation with the folded isolation insulating paper, the nickel mesh side of the positive electrode assembly 22 scratches or pierces the fold of the folded isolation insulating paper, directly contacts the battery housing 1 and causes an internal short circuit, therefore, a piece of anti-damage insulating paper 24 is arranged at the fold of the folded isolation insulating paper.

[0037] In this embodiment, preferably, the first isolation insulating paper 231 , the second isolation insulating paper 232 and the anti-damage insulating paper 24 are all made of glass fiber.

[0038] In the present embodiment, as a preference, the support body 3 is formed by bending a metal spring sheet along a wide side, wherein the four corners of the metal spring sheet are rounded, and the metal spring sheet is provided with a plurality of through holes. The metal spring sheet is provided with a plurality of through holes to facilitate rapid filling of the cavity 20 when pouring the electrolyte, and also to facilitate free circulation of the electrolyte, so as to completely contact and react with the lithium sheet; moreover, it can also reduce the overall mass of the battery and improve the energy density.

[0039] In this embodiment, as a preference, the positive electrode assembly 22 includes a cathode film upper layer 221, a nickel mesh interlayer, and a cathode film lower layer 223 stacked in sequence. The cathode film upper layer 221, the positive electrode nickel mesh interlayer 222, and the cathode film lower layer 223 are all in a square shape. The positive electrode nickel mesh interlayer 222 is provided with a lead.

[0040] In this embodiment, preferably, the lead is parallel to the width direction, and one end of the lead extends out of the cathode film, and the length of the lead is greater than the width of the positive electrode nickel mesh interlayer 222.

[0041] The present invention also provides a production process for an improved high-temperature battery: the production process is used for producing the above-mentioned improved high-temperature battery structure, and the production process includes the following steps:

[0042] Step 1: assembling the positive electrode assembly 22, wherein step 1 completes the assembly of the positive electrode assembly 22 with the lower layer being the cathode film, the middle layer being the nickel mesh, and the upper layer being the cathode film;

[0043] Step 2: Assembling the negative electrode assembly 21; wherein, step 2 completes the assembly of the negative electrode assembly 21 with a lower layer of lithium sheet, a middle layer of nickel mesh, and an upper layer of lithium sheet, wherein the upper lithium sheet as the upper layer of the lithium sheet and the lower lithium sheet as the lower layer of the lithium sheet are respectively arranged on the upper surface and the lower surface of the negative electrode nickel mesh interlayer, and one end of the lithium sheet lower layer and the lithium sheet upper layer are respectively flush with the corresponding end of the negative electrode nickel mesh interlayer;

[0044] Step 3: Assembling the battery core 2; wherein, in step 3, the positive electrode assembly 22 is first sandwiched in the folded isolation insulating paper, and the anti-damage insulating paper 24 is arranged between the fold of the folded isolation insulating paper and the positive electrode assembly 22, and then, the combination of the positive electrode assembly 22 and the folded isolation insulating paper is superimposed on the negative electrode assembly 21 and then wound to form a roll with a support cavity 20 in the middle;

[0045] Step 4: assembling the support body 3, wherein step 4 completes inserting the support body 3 into the support cavity 20 of the roll body in step 3;

[0046] Step 5: The battery core 2 is welded and fixed to the inner wall of the battery shell 1.

[0047] Step 6: Cover and fix the battery housing 1;

[0048] Step 7: electrolyte perfusion;

[0049] Step 8: Dry.

[0050] The specific steps of step 1, step 2 and step 3 are as follows:

[0051] Step 1: Assembling the positive electrode assembly 22: Take a cathode film as the cathode film lower layer 223 and place it on the first work surface, take a nickel mesh as the positive electrode nickel mesh interlayer 222 and place it on the second work surface, dip a brush into the adhesive container to dip the adhesive, and then use the brush to brush the surface of the positive electrode nickel mesh interlayer 222. After brushing, turn the positive electrode nickel mesh interlayer 222 over and overlap it on the cathode film, then dip the brush into the adhesive container to dip the adhesive, and then use the brush to brush the surface of the positive electrode nickel mesh interlayer 222. Finally, take another cathode film as the cathode film upper layer 221 and overlap it on the upper surface of the positive electrode nickel mesh interlayer 222 to complete the assembly of the positive electrode assembly 22.

[0052] Step 2: Assembling the negative electrode assembly 21, take a double-layer lithium sheet, separate the double-layer lithium sheet, and lay it flat on the third work surface in the vertical direction, and take another nickel mesh as the negative electrode nickel mesh interlayer 212, and place the negative electrode nickel mesh interlayer 212 under the lower lithium sheet. This placement method can improve production efficiency; then, take the lower lithium sheet as the lithium sheet lower layer 213, align its left wide side with the left wide side of the negative electrode nickel mesh interlayer 212,

[0053] Then, the lithium sheet lower layer 213 is overlapped on the upper surface of the negative electrode nickel mesh interlayer 212, and then the combination of the negative electrode nickel mesh interlayer 212 and the lithium sheet lower layer 213 is flipped 180 degrees in the horizontal direction. At this time, the lithium sheet lower layer 213 is located on the right lower bottom surface of the negative electrode nickel mesh interlayer 212. Then, the upper lithium sheet is taken and used as the lithium sheet upper layer 211. The left wide side of the lithium sheet upper layer 211 is aligned with the left wide side of the negative electrode nickel mesh interlayer 212, and then overlapped. Finally, the lithium sheet upper layer 211 and the negative electrode nickel mesh interlayer 212 are compacted with a compacting hammer. In this way, the lithium sheet upper layer 211 and the lithium sheet lower layer 213 are respectively located at the upper and lower ends of the negative electrode nickel mesh interlayer 212, and the assembly of the negative electrode assembly 21 is completed. The assembly steps of the negative electrode assembly can improve production efficiency.

[0054] Step 3: Assembly of battery core 2,

[0055] Take a temporary winding rod and place it on one end of the negative electrode assembly 21, and use the temporary winding rod to wind the negative electrode assembly 21 one to two turns.

[0056] Then take a piece of isolation fiber paper and fold it into two layers, with the lower layer serving as the first isolation insulating paper 231 and the upper layer serving as the second isolation insulating paper 232. Then, place one end of the anti-damage insulating paper 24 against the fold of the folded isolation insulating paper, and place one end of the positive electrode assembly 22 against the other end of the anti-damage insulating paper 24. Then, overlap the second isolation insulating paper 232 on the positive electrode assembly 22 to form the positive electrode assembly 22 separator. Then, overlap the positive electrode assembly 22 separator on the surface of the negative electrode assembly 21, and place the outer folded end of the positive electrode assembly 22 separator close to the winding end of the negative electrode assembly 21. Then, use a temporary rolling rod to roll the cathode assembly separator and the anode assembly into a battery core 2. Finally, take out the temporary rolling rod so that a support cavity 20 exists in the middle of the battery core 2.

[0057] The above descriptions are merely embodiments of the present invention and are not intended to limit the patent scope of the present invention. Any equivalent structure or equivalent process transformation made using the contents of the present invention specification and drawings, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present invention.

Claims

1. An improved high temperature battery structure, characterized in that: The invention comprises a battery shell with an opening at one end, a battery core, a support body, an electrolyte and a battery cover, wherein the battery shell and the battery cover form a containing cavity, the battery core is a coil, which is formed by stacking and winding a negative electrode assembly, a first isolation insulating paper, a positive electrode assembly and a second isolation insulating paper in sequence, a support cavity is provided in the middle of the battery core, and the support body is inserted in the support cavity, the positive electrode assembly is a sheet body, which is a multi-layer structure including a cathode film, the negative electrode assembly is a sheet body, which is a multi-layer structure including a lithium sheet, the negative electrode assembly comprises a lithium sheet lower layer, a negative electrode nickel mesh interlayer and a lithium sheet upper layer stacked in sequence, the lithium sheet upper layer and the lithium sheet lower layer are respectively arranged on the upper surface and the lower surface of the negative electrode nickel mesh interlayer, the lengths of the lithium sheet lower layer and the lithium sheet upper layer are respectively greater than half of the negative electrode nickel mesh interlayer, and one end of the lithium sheet lower layer and the lithium sheet upper layer are respectively flush with the corresponding end of the negative electrode nickel mesh interlayer.

2. An improved high temperature battery structure according to claim 1, characterized in that: It also includes anti-damage insulating paper, which is square in shape. The first isolation insulating paper and the second isolation insulating paper are folded isolation insulating paper of an integrated structure, which is folded when in use, with the second isolation insulating paper located at the top and the first isolation insulating paper located at the bottom. The anti-damage insulating paper is arranged on the first isolation insulating paper and close to the folded crease. One end of the positive electrode assembly abuts against the other end of the anti-damage insulating paper, and the positive electrode assembly is sandwiched between the second isolation insulating paper and the first isolation insulating paper.

3. An improved high temperature battery structure according to claim 2, characterized in that: The first isolation insulating paper, the second isolation insulating paper and the damage-proof insulating paper are all made of glass fiber.

4. The improved high temperature battery structure according to claim 1, characterized in that: The support body is formed by bending a metal spring sheet along a wide side, wherein the four corners of the metal spring sheet are rounded, and the metal spring sheet is provided with a plurality of through holes.

5. The improved high temperature battery structure according to claim 1, characterized in that: The positive electrode assembly includes a cathode film upper layer, a positive electrode nickel mesh interlayer, and a cathode film lower layer stacked in sequence. The cathode film upper layer, the positive electrode nickel mesh interlayer, and the cathode film lower layer are all square in shape, and the positive electrode nickel mesh interlayer is provided with a lead.

6. The improved high temperature battery structure according to claim 1, characterized in that: The lead is parallel to the width direction, and one end of the lead extends out of the cathode film. The length of the lead is greater than the width of the positive electrode nickel mesh interlayer.

7. An improved high temperature battery production process: characterized in that: The production process is used for producing an improved high-temperature battery structure according to any one of claims 1 to 6, and the production process comprises the following steps: Step 1: assembling a positive electrode assembly, wherein step 1 completes the assembly of a positive electrode assembly having a cathode film as a lower layer, a nickel mesh as a middle layer, and a cathode film as an upper layer; Step 2: Assembling the negative electrode assembly; wherein, step 2 completes the assembly of the negative electrode assembly with the lower layer being a lithium sheet, the middle layer being a nickel mesh, and the upper layer being a lithium sheet, the upper lithium sheet as the upper layer of the lithium sheet and the lower lithium sheet as the lower layer of the lithium sheet are respectively arranged on the upper surface and the lower surface of the negative electrode nickel mesh interlayer, and one end of the lithium sheet lower layer and the lithium sheet upper layer are respectively flush with the corresponding end of the negative electrode nickel mesh interlayer; Step 3: assembling the battery core; wherein, in step 3, the positive electrode assembly is first sandwiched in the folded isolation insulating paper, and the anti-damage insulating paper is arranged between the fold of the folded isolation insulating paper and the positive electrode assembly, and then, the combination of the positive electrode assembly and the folded isolation insulating paper is superimposed on the negative electrode assembly and then wound to form a roll with a support cavity in the middle; Step 4: Assembling the support body, wherein the step 4 completes inserting the support body into the support cavity of the roll body in step 3; Step 5: The battery core is welded and fixed to the inner wall of the battery shell. Step 6: Cover and fix the battery housing; Step 7: electrolyte perfusion; Step 8: Dry.

8. The production process of an improved high temperature battery according to claim 7, characterized in that: The step 2 includes the following sub-steps: Sub-step 21: Take a double-layer lithium sheet, separate the double-layer lithium sheet, and lay it flat on the work surface in the vertical direction, take another nickel mesh as a negative electrode nickel mesh interlayer, and place the negative electrode nickel mesh interlayer under the lower lithium sheet; Sub-step 22: Take the lower lithium sheet as the lower layer of the lithium sheet, align the wide side of its left side with the wide side of the left side of the negative electrode nickel mesh interlayer, overlap the lower layer of the lithium sheet on the upper surface of the negative electrode nickel mesh interlayer, and compact the lower layer of the lithium sheet and the negative electrode nickel mesh interlayer with a compacting hammer; Sub-step 23: flipping the assembly of the negative electrode nickel mesh interlayer and the lithium sheet lower layer 180 degrees horizontally, where the lithium sheet lower layer is located on the right lower bottom surface of the negative electrode nickel mesh interlayer; Sub-step 24: Take the upper lithium sheet and use it as the upper layer of the lithium sheet. Align the left wide edge of the upper layer of the lithium sheet with the left wide edge of the negative electrode nickel mesh interlayer, then overlap them, and compact the upper layer of the lithium sheet and the negative electrode nickel mesh interlayer with a compacting hammer.

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