Conductive film for zinc secondary battery, method for manufacturing the same, composite separator for zinc secondary battery, and zinc secondary battery

Abstract

This application relates to the technical field of batteries, specifically to a conductive film for a zinc secondary battery, a method for manufacturing the same, a composite separator for a zinc secondary battery, and a zinc secondary battery. The conductive film for a zinc secondary battery according to this application includes a porous polymer film, and the pores of the porous polymer film are filled with a conductive composition. The conductive composition contains, by weight, 1 to 10 parts of a conductive agent and 0.1 to 1 part of an additive. The conductive agent is at least one of graphite, conductive carbon black, acetylene black, graphene, carbon nanotubes, and copper powder, and the additive is at least one of tin powder, tin dioxide powder, bismuth powder, bismuth oxide powder, indium powder, indium oxide powder, lead powder, lead oxide powder, cadmium powder, and cadmium oxide powder. The composite separator for a zinc secondary battery according to this application is covered on the outer periphery of the cell and can solve the problem that the conventional conductive tin-plated copper foil and the battery separator cannot be welded.

Description

Technical Field

[0001] The present application relates to the technical field of batteries, and specifically relates to a conductive film for a zinc secondary battery, a method for manufacturing the same, a composite separator for a zinc secondary battery, and a zinc secondary battery.

Background Art

[0002] Zinc is an excellent battery material, and many types of batteries centered on zinc, such as zinc nickel secondary batteries, zinc manganese secondary batteries, zinc ion secondary batteries, etc., have been developed. In these zinc secondary batteries, in any case, there is a problem that zinc constituting the negative electrode generates dendrites during charging, and the dendrites penetrate through the separator or react with the metal of the battery case.

[0003] In addition, when the negative electrode and the metal case in the cell are in direct contact, a reaction may occur, resulting in the generation of a large amount of gas or corrosion of the metal case. In order to avoid the reaction between the negative electrode and the metal case, in the prior art, a means of covering the outside of the cell with a layer of metal is used, which can not only play a role in conduction but also prevent the reaction between the negative electrode and the case. For example, in the Chinese utility model registration application with the authorization publication number CN214477788U, a composite separator for a wound battery including a separator is disclosed. At one end of the separator, an adhesive tape is adhered, and the adhesive tape includes a separator adhesion part, a separation part, and a conductive adhesion part sequentially installed along the length direction of the adhesive tape. The separator adhesion part is adhered to one side of the corresponding end of the separator, and a conductive foil material, which is a metal foil material, a graphite film, or a graphene film, is adhered to the conductive adhesion part. The separation part is used to adhere to the surface of the corresponding electrode sheet. However, the separator is generally a polymer film, and the conductive foil material on the composite separator has low compatibility with the separator and a poor connection effect.

Summary of the Invention

Means for Solving the Problems

[0004] In order to improve the connection effect between the conductor outside the cell and the polymer film, the present application provides a conductive film for a zinc secondary battery, a method for manufacturing the same, a composite separator for a zinc secondary battery, and a zinc secondary battery.

[0005] The conductive film for a zinc secondary battery includes a porous polymer film, and the pores of the porous polymer film are filled with a conductive composition. The conductive composition contains, by weight, 1 to 10 parts of a conductive agent and 0.1 to 1 part of an additive. The conductive agent is at least one of graphite, conductive carbon black, acetylene black, graphene, and carbon nanotubes, and the additive is at least one of tin powder, tin dioxide powder, bismuth powder, bismuth oxide powder, indium powder, indium oxide powder, lead powder, lead oxide powder, cadmium powder, and cadmium oxide powder.

[0006] The porous polymer film is any one of a PVC film, a PE film, a PP film, a PTFE film, an SBR film, and a cellulose acetate film.

[0007] The particle size of the additive is 10 to 500 nm. The particle size of the first additive is 10 to 100 nm, and the particle size of the second additive is 20 to 500 nm.

[0008] The pore size of the porous polymer film is 100 to 800 nm, and more preferably 500 to 800 nm.

[0009] The mass ratio of the porous polymer film to the conductive composition is 1:0.02 to 0.2.

[0010] The thickness range of the conductive film is 0.02 to 3.0 mm. When the thickness is close to 3.0 mm, the conductive film actually becomes a conductive plate. Preferably, it is 0.05 to 2.0 mm.

[0011] The method for manufacturing a conductive film for a zinc secondary battery is Step 1) of uniformly mixing a conductive composition with at least one solvent selected from water, NMP, ethylene glycol dimethyl ether, diethylene glycol dimethyl ether, a carbonate-based solvent, and carboxylic acid esters to prepare a conductive slurry; Step 2) of applying the conductive slurry obtained in Step 1) onto the surface of a porous polymer film, leveling it, and drying it to obtain a conductive film for a zinc secondary battery, or immersing the porous polymer film in the conductive slurry obtained in Step 1), taking it out, and drying it to obtain a conductive film for a zinc secondary battery.

[0012] In Step 1), the uniform mixing is carried out by stirring at a rotational speed of 800 to 3000 rpm for 5 to 50 minutes. The rotational speed is preferably 1000 to 2000 rpm. The stirring time is preferably 10 to 30 minutes.

[0013] The amount of the solvent used is 10 to 100 mL of the solvent per 1 g of the conductive agent.

[0014] In Step 2), when applying the conductive slurry onto the surface of the porous polymer film and leveling it, first, place the porous polymer film flat on the surface of a penetration-preventing film or a penetration-preventing plate. Next, apply the conductive slurry to the surface of the porous polymer film that is away from the penetration-preventing film or the penetration-preventing plate, and then level the conductive slurry applied to the surface of the porous polymer film for 0.5 to 10 minutes. Preferably, the leveling time is 1 to 3 minutes. When leveling, use a scraper blade or a scraper. Further, after one surface is leveled, invert the porous polymer film, attach the penetration-preventing film or the penetration-preventing plate to the surface where the conductive slurry has been leveled, then apply the conductive slurry to the other surface, and then level the conductive slurry applied to the surface of the porous polymer film for 0.5 to 10 minutes. Preferably, the leveling time is 1 to 3 minutes.

[0015] In Step 2), the immersion time of the porous polymer film is 10 to 300 minutes.

[0016] The manufacturing method of the conductive film for zinc secondary batteries includes the steps of uniformly mixing polymer particles, an antioxidant, a conductive composition, and a pore-forming agent, extruding, casting, casting onto a sheet, stretching in the longitudinal direction, stretching in the transverse direction, removing the pore-forming agent, and washing to obtain a conductive film for zinc secondary batteries. The polymer particles are polyethylene particles or polypropylene particles.

[0017] The molecular weight of the above polyethylene or polypropylene is 1,000,000 or more.

[0018] The above antioxidant is at least one of tert-butylhydroquinone and 4,4-thiobis(6-tert-butyl-m-cresol).

[0019] The above pore-forming agent is any one of white oil, n-heptane, and paraffin.

[0020] The mass ratio of the polymer particles, the antioxidant, the conductive agent, the additive, and the pore-forming agent is 70-95:8-10:5-15:10-20.

[0021] After casting onto the sheet, a thick sheet is obtained, and the thickness of the thick sheet is 400-800 μm.

[0022] The temperature during longitudinal stretching is 100-120 °C.

[0023] The temperature during transverse stretching is 110-125 °C.

[0024] When removing the pore-forming agent, it is extracted with methylene chloride.

[0025] The temperature during extrusion is 180-230 °C.

[0026] The composite separator for zinc secondary batteries includes a base separator and the conductive film for zinc secondary batteries connected to one end of the base separator.

[0027] The conductive film for the zinc secondary battery and the substrate separator are connected by thermal welding or ultrasonic welding. Thermal welding is to weld in a dot shape or a planar shape by thermal melting. Ultrasonic welding is to weld in a dot shape or a planar shape by ultrasonic waves.

[0028] The zinc secondary battery includes a cell and the composite separator for the zinc secondary battery covering the outer periphery of the cell.

[0029] The cell includes a positive electrode sheet, a separator, and a negative electrode sheet, and the composite separator for the zinc secondary battery is installed by being bonded to the negative electrode sheet.

[0030] The zinc secondary battery includes a case and a cell installed in the case, and the composite separator for the zinc secondary battery is installed by being bonded to the inner wall of the case.

[0031] The cell is a cylindrical wound cell or a rectangular laminated cell.

Advantages of the Invention

[0032] The composite separator for the zinc secondary battery according to the present application covers the outer periphery of the cell and can solve the problem that the conventional conductive tin-plated copper foil and the battery separator cannot be welded.

[0033] Since the conductive film in the composite separator for the zinc secondary battery according to the present application contains an organic polymer, a conductive agent, and an additive, the resistance of the conductive film is low and the conductivity is high. The conductive film contains an organic substance and can reduce the amount of heat generated outside the battery during a short circuit.

Brief Description of the Drawings

[0034]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Mode for Carrying Out the Invention

[0035] The technical means of the present application will be described in detail with reference to specific embodiments below. In the following embodiments, unless otherwise specified, all raw materials used are commercially available products.

[0036] (Example 1) The conductive film for a zinc secondary battery according to this example includes a porous polymer film which is a porous polypropylene film. The pores of the porous polymer film are filled with a conductive composition. The conductive composition contains, by weight, 2 g of a conductive agent and 0.1 g of an additive. The conductive agent is conductive carbon black, the additive is tin powder, the particle size of the conductive carbon black is 25 nm, and the particle size of the tin powder is 20 nm. The mass ratio of the porous polymer film to the conductive composition is 5:1.

[0037] The manufacturing method of the conductive film for a zinc secondary battery according to this example is Step 1) of mixing a conductive agent, an additive, and a solvent and uniformly stirring at a rotation speed of 1500 rpm to obtain a conductive slurry. The amount of the solvent used is 20 mL of the solvent per 2 g of the conductive agent. The solvent in this example is deionized water. Step 1), and Bond one side of the porous polypropylene film to the first glass plate, leave the side of the porous polypropylene film that does not contact the first glass plate facing upward, apply the conductive slurry to the upper surface of the porous polypropylene film, and evenly level it back and forth for 1 min using a scraper blade. Subsequently, a second glass plate is bonded to the upper surface of the porous polypropylene film, and the porous polypropylene film is inverted so that the side to which the first glass plate is bonded faces upward. Then, the first glass plate is peeled off. After that, a conductive slurry is applied to the surface of the porous polypropylene film, and a scraper blade is used to evenly spread it back and forth for 1 min in step 2), and In step 2), after the slurry is applied and evenly spread on both sides, the porous polypropylene film is placed in a vacuum drying box together with the second glass plate, dried at 60°C for 2 h, cooled, and taken out in step 3). It includes these steps.

[0038] As shown in FIG. 1, the composite separator of this embodiment includes a base separator 1. The base separator is a cellulose acetate film. One end of the base separator is connected to the conductive film 2 for zinc secondary batteries. One end of the conductive film for zinc secondary batteries and one end of the base separator are laminated and fusion-welded to form a welded portion 3. The length of the base separator is 120 mm, the length of the conductive film for zinc secondary batteries is 30 mm, both the base separator and the conductive film for zinc secondary batteries have a width of 42 mm, and the length of the laminated portion of the base separator and the conductive film for zinc secondary batteries is 5 mm.

[0039] The zinc secondary battery according to this embodiment is a zinc-nickel battery including a positive electrode sheet, a negative electrode sheet, a separator, and an electrolyte. The positive electrode sheet is a foamed nickel electrode. The negative electrode sheet includes a copper tape that functions as a negative electrode current collector and a negative electrode material layer provided on the negative electrode current collector. The negative electrode material layer includes a negative electrode active material, a conductive agent, and an adhesive. The negative electrode active material is a mixture composed of zinc oxide, calcium zincate, and zinc powder with a mass ratio of 60:10:22. The conductive agent is acetylene black, and the adhesive is composed of CMC, polyvinyl alcohol, and PTFE with a mass ratio of 2.5:2:30. The mass ratio of zinc oxide, calcium zincate, zinc powder, acetylene black, CMC, polyvinyl alcohol, and PTFE is 60:10:22:6:0.025:0.02:0.3. The electrolyte is obtained by mixing a KOH solution with a ZnO saturation mass concentration of 30% and a LiOH solution with a mass concentration of 2%. The separator is a separator dedicated to zinc-nickel batteries.

[0040] (Example 2) The conductive film for a zinc secondary battery according to this embodiment includes a porous polymer film which is a porous polypropylene film. The pores of the porous polymer film are filled with a conductive composition. The conductive composition contains, by weight, 5 g of a conductive agent and 0.2 g of an additive. The conductive agent is conductive carbon black, and the additive is tin powder. The particle size of the conductive carbon black is 25 nm, and the particle size of the tin powder is 50 nm. The mass ratio of the porous polymer film to the conductive composition is 5:1.

[0041] The manufacturing method of the conductive film for a zinc secondary battery according to this embodiment is Step 1) of mixing a conductive agent, an additive, and a solvent and uniformly stirring at a rotation speed of 1500 rpm to obtain a conductive slurry. The amount of the solvent used is 50 mL of the solvent per 5 g of the conductive agent. The solvent in this embodiment is deionized water. Step 1) and Bond one side of the porous polypropylene film to the first glass plate, leave the side of the porous polypropylene film that does not contact the first glass plate facing upward, apply the conductive slurry to the upper surface of the porous polypropylene film, and use a scraper blade to level it by reciprocating for 1 minute. Then, bond the second glass plate to the upper surface of the porous polypropylene film, invert the porous polypropylene film, turn the side to which the first glass plate is bonded upward, peel off the first glass plate, and then apply the conductive slurry to the surface of the porous polypropylene film and use a scraper blade to level it by reciprocating for 1 minute in step 2). Step 3): After the slurry is applied and leveled on both sides in step 2), put the porous polypropylene film together with the second glass plate into a vacuum drying box, dry it at 60°C for 2 hours, cool it, and take it out.

[0042] The others are the same as in Example 1.

[0043] (Example 3) The conductive film for zinc secondary battery according to this example includes a porous polymer film which is a porous polypropylene film. The pores of the porous polymer film are filled with a conductive composition. The conductive composition contains, by weight, 10 g of a conductive agent and 0.5 g of an additive. The conductive agent is conductive carbon black, the additive is tin powder, the particle size of the conductive carbon black is 25 nm, the particle size of the tin powder is 50 nm. The mass ratio of the porous polymer film to the conductive composition is 5:1.

[0044] The manufacturing method of the conductive film for zinc secondary battery according to this example is Step 1): Mix a conductive agent, an additive, and a solvent, and stir uniformly at a rotation speed of 1500 rpm to obtain a conductive slurry. The amount of the solvent used is 90 mL of the solvent per 10 g of the conductive agent. The solvent in this example is deionized water. Step 1) One side of the porous polypropylene film was bonded to the first glass plate, the side of the porous polypropylene film that did not contact the first glass plate was left facing upward, the conductive slurry was applied to the upper surface of the porous polypropylene film, and a scraper blade was used to level it by reciprocating for 1 min. After that, a second glass plate was bonded to the upper surface of the porous polypropylene film, and the porous polypropylene film was inverted so that the side to which the first glass plate was bonded faced upward, the first glass plate was peeled off, and then the conductive slurry was applied to the surface of the porous polypropylene film, and a scraper blade was used to level it by reciprocating for 1 min in step 2). Step 3) includes putting the porous polypropylene film with the slurry applied and leveled on both sides in step 2) into a vacuum drying box together with the second glass plate, drying it at 60 °C for 2 h, cooling it, and taking it out.

[0045] The others are the same as in Example 1.

[0046] (Example 4) The conductive film for a zinc secondary battery according to this example includes a porous polymer film which is a porous cellulose film. The pores of the porous polymer film are filled with a conductive composition. The conductive composition contains, by weight, 5 g of a conductive agent, 0.2 g of an additive, and 0.1 g of an adhesive. The conductive agent is conductive carbon black, the additive is tin powder, the particle size of the conductive carbon black is 25 nm, and the particle size of the tin powder is 50 nm. The adhesive is PVDF. The mass ratio of the porous cellulose film to the conductive composition is 5:1.

[0047] The manufacturing method of the conductive film for a zinc secondary battery according to this example is Step 1) Mix an adhesive and a solvent, and stir uniformly at a rotational speed of 1500 rpm to obtain an adhesive solution. Then, add a conductive agent and an additive, and stir uniformly at a rotational speed of 1500 rpm to obtain a conductive slurry. The amount of the solvent used is 50 mL of the solvent per 5 g of the conductive agent, and the solvent in this example is N-methylpyrrolidone. Step 1) and It includes the same Step 2) and Step 3) as in Example 2.

[0048] The rest is the same as in Example 2.

[0049] (Example 5) The conductive film for zinc secondary battery according to this example includes a porous polymer film which is a porous cellulose film. The pores of the porous polymer film are filled with a conductive composition. The conductive composition contains, by weight parts, 5 g of a conductive agent, 0.2 g of an additive, and 0.1 g of an adhesive. The conductive agent is conductive carbon black, the additive is a mixture of tin powder and tin dioxide, the mass ratio of tin powder to tin dioxide is 1:1, the particle size of the conductive carbon black is 25 nm, the particle size of the tin powder is 50 nm, and the particle size of the tin dioxide is 20 nm. The adhesive is obtained by mixing PVDF and CMC in a mass ratio of 2:1. The mass ratio of the porous cellulose film to the conductive composition is 5:1.

[0050] The manufacturing method of the conductive film for zinc secondary battery according to this example is Step 1) Mix an adhesive and a solvent, and stir uniformly at a rotational speed of 1500 rpm to obtain an adhesive solution. Then, add a conductive agent and an additive, and stir uniformly at a rotational speed of 2000 rpm to obtain a conductive slurry. The amount of the solvent used is 50 mL of the solvent per 5 g of the conductive agent, and the solvent in this example is N-methylpyrrolidone. Step 1) and It includes the same Step 2) and Step 3) as in Example 2.

[0051] The rest is the same as in Example 2.

[0052] (Example 6) The conductive film for a zinc secondary battery according to this example includes a porous polymer film which is a porous cellulose film. The pores of the porous polymer film are filled with a conductive composition. The conductive composition contains, by parts by weight, 5 g of a conductive agent, 0.38 g of an additive, and 0.1 g of an adhesive. The conductive agent is conductive carbon black. The additive is formed by mixing tin powder, tin dioxide, bismuth powder, and indium powder in a mass ratio of 1.5:1.5:0.5:0.3. The particle size of the conductive carbon black is 25 nm, the particle size of the tin powder is 50 nm, the particle size of the tin dioxide is 20 nm, the particle size of the bismuth powder is 50 nm, and the particle size of the indium powder is 60 nm. The adhesive is obtained by mixing PVDF and CMC in a mass ratio of 2:1. The mass ratio of the porous cellulose film to the conductive composition is 5:1.

[0053] Others are the same as in Example 5.

[0054] (Example 7) The difference between this example and Example 6 is that the additive is formed by mixing tin powder, tin oxide, bismuth oxide powder, indium powder, lead oxide, and cadmium oxide in a mass ratio of 1.5:1.2:0.5:0.3:0.2:0.1. The particle size of the tin powder is 50 nm, the particle size of the tin dioxide is 20 nm, the particle size of the bismuth oxide powder is 50 nm, the particle size of the indium powder is 60 nm, the particle size of the lead oxide is 100 nm, and the particle size of the cadmium oxide is 150 nm.

[0055] Others are the same as in Example 6.

[0056] (Example 8) The conductive film for a zinc secondary battery according to this embodiment includes a porous polymer film which is a porous polyethylene film. The pores of the porous polymer film are filled with a conductive composition. The conductive composition contains, by weight, 5 g of a conductive agent and 0.38 g of an additive. The conductive agent is conductive carbon black, and the additive is a mixture of tin powder, tin oxide, bismuth oxide powder, indium powder, lead oxide, and cadmium oxide in a mass ratio of 1.5:1.2:0.5:0.3:0.2:0.1. The particle size of the conductive carbon black is 25 nm, and the particle size of the tin powder is 50 nm.

[0057] The manufacturing method of the conductive film for a zinc secondary battery according to this embodiment includes the steps of uniformly mixing polymer polyethylene particles (molecular weight 1 million), 4,4 - thiobis(6 - tert - butyl - m - cresol), the conductive composition, and white oil in a mass ratio of 80:8:15:20, adding them to an extruder, heating and melting, extruding at 225 °C, casting by rolling, and casting onto a sheet to obtain a thick sheet with a thickness of 500 μm. Then, stretching longitudinally at 110 °C, stretching laterally at 115 °C, extracting with methylene chloride to remove the white oil, and washing to obtain the conductive film for a zinc secondary battery.

[0058] In other embodiments, the adhesive may be replaced by at least one of PVA, PAAS, CMC, PEO, PVDF, PAN, HPMC, and SBR.

[0059] As shown in FIGS. 2 and 3, in other embodiments, the negative electrode sheet includes an electrode sheet 11. One end of the negative electrode sheet is connected to the conductive film 22 for a zinc secondary battery. One end of the conductive film for a zinc secondary battery and one end of the negative electrode sheet are laminated and melt - welded or adhered to form a welded portion 33. The negative electrode sheet is installed on the outermost side of the cell, and the length of the conductive film for a zinc secondary battery is set such that the wound conductive film for a zinc secondary battery completely covers the cell.

[0060] As shown in FIGS. 4 to 7, in other embodiments, the zinc secondary battery includes a metal case 00 and a cell installed in the metal case. The metal case is a cylindrical case, and the conductive film 01 for the zinc secondary battery is installed on the inner wall. (Experimental Example) (1) Tensile test

[0061] A tensile test is performed using the composite separators for zinc secondary batteries obtained in Examples 1 to 4. The test results are shown in the following table.

[0062] Table 1 Comparison of test results of composite separators in Examples 1 to 4

Table 1

[0063] The composite separators for zinc secondary batteries obtained in Examples 1 to 4 are covered on the outer peripheral surface of the cell to manufacture a cylindrical zinc nickel battery (AA1000 mAh battery).

[0064] After starting the battery at 0.2C, charging it at 0.2C for 5 hours, leaving the battery to stand for 10 minutes, and then performing a charge-discharge test at 1C, the test is terminated after 500 cycles. The capacity retention rate is calculated.

[0065] Table 2 Comparison of test results of zinc secondary batteries in Examples 1 to 4

Table 2

Claims

1. It includes a porous polymer film, The pores of the porous polymer film are filled with a conductive composition, The conductive composition contains, by weight, 1 to 10 parts of a conductive agent and 0.1 to 1 part of an additive, The conductive agent is at least one of graphite, conductive carbon black, acetylene black, graphene, and carbon nanotubes, The additive is at least one of tin powder, tin dioxide powder, bismuth powder, bismuth oxide powder, indium powder, indium oxide powder, lead powder, lead oxide powder, cadmium powder, and cadmium oxide powder, A conductive film for a zinc secondary battery, characterized in that.

2. The additive is formed by mixing a first additive and a second additive in a mass ratio of 1 to 5:0.2 to 3, The first additive is at least one of tin powder, bismuth powder, indium powder, lead powder, and cadmium powder, The second additive is at least one of tin dioxide powder, bismuth oxide powder, indium oxide powder, lead oxide powder, and cadmium oxide powder, The conductive film for a zinc secondary battery according to claim 1, characterized in that.

3. The mass ratio of the porous polymer film to the conductive composition is 1:0.02 to 0.2, The conductive film for a zinc secondary battery according to claim 1, characterized in that.

4. Step 1) of uniformly mixing the conductive composition with at least one solvent selected from water, NMP, ethylene glycol dimethyl ether, diethylene glycol dimethyl ether, carbonate solvents, and carboxylic acid esters to prepare a conductive slurry; Step 2) of applying the conductive slurry obtained in Step 1) onto the surface of the porous polymer film, leveling it, and drying it to obtain a conductive film for a zinc secondary battery, or immersing the porous polymer film in the conductive slurry obtained in Step 1), taking it out, and drying it to obtain a conductive film for a zinc secondary battery, A method for manufacturing a conductive film for a zinc secondary battery according to claim 1, characterized in that.

5. In Step 1), the uniform mixing is achieved by stirring at a rotation speed of 800 to 3000 rpm for 5 to 50 minutes. The method for manufacturing a conductive film for a zinc secondary battery according to claim 4, characterized in that.

6. In step (2), when applying and leveling the conductive slurry on the surface of the porous polymer film, first, place the porous polymer film flat on the surface of the penetration-preventing film or penetration-preventing plate. Next, apply the conductive slurry to the surface of the porous polymer film that is away from the penetration-preventing film or penetration-preventing plate. Then, level the conductive slurry applied on the surface of the porous polymer film for 0.5 to 10 minutes. The manufacturing method of the conductive film for zinc secondary battery according to claim 4 is characterized by this.

7. It includes steps of uniformly mixing polymer particles, an antioxidant, a conductive composition, and a pore-forming agent, extruding, casting, casting into a sheet, stretching in the longitudinal direction, stretching in the transverse direction, removing the pore-forming agent, and washing to obtain a conductive film for zinc secondary battery. The polymer particles are polyethylene particles or polypropylene particles. The manufacturing method of the conductive film for zinc secondary battery according to claim 1 is characterized by this.

8. The mass ratio of the polymer particles, the antioxidant, the conductive composition, and the pore-forming agent is 70 to 95: 8 to 10: 5 to 15: 10 to 20. The manufacturing method of the conductive film for zinc secondary battery according to claim 7 is characterized by this.

9. A substrate separator, A conductive film for zinc secondary battery according to claim 1 connected to one end of the substrate separator, and it is characterized by this. A composite separator for zinc secondary battery.

10. A cell, A composite separator for zinc secondary battery according to claim 9 covering the outer periphery of the cell, and the zinc secondary battery is characterized by this.

11. The cell includes a positive electrode sheet, a separator, and a negative electrode sheet. The composite separator for zinc secondary battery is installed by being bonded to the negative electrode sheet. The zinc secondary battery according to claim 10 is characterized by this.

12. A case, A cell installed in the case, and On the inner wall of the case, a composite separator for zinc secondary battery according to claim 9 is installed by being bonded. The zinc secondary battery is characterized by this.

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