A neutral zinc-air fiber battery and its preparation method

Abstract

The present invention discloses a neutral zinc-air fiber battery and a preparation method thereof, belonging to the technical field of batteries. Aiming at the problem in the prior art that due to too large bending stiffness, bending causes poor charge and discharge effects, the present invention provides a neutral zinc-air fiber battery and a preparation method thereof, which are assembled in a coaxial structure by a carbon nanotube / zinc powder composite fiber negative electrode, a double-layer gel electrolyte, and a platinum / ruthenium oxide modified carbon nanotube film positive electrode. The method steps are as follows: preparing a carbon nanotube / zinc powder composite fiber; preparing an organic gel electrolyte; preparing a hydrogel electrolyte precursor, and in-situ gelating the hydrogel electrolyte precursor on the composite fiber after curing with the organic gel electrolyte to obtain a fiber negative electrode wrapped with a double-layer gel; winding the platinum / ruthenium oxide nanoparticle modified carbon nanotube film positive electrode around the fiber negative electrode wrapped with the double-layer gel. It has a small bending stiffness and has a good charge and discharge curve for different degrees of bending.

Description

Technical Field

[0001] The present invention relates to the technical field of batteries, and more specifically, to a neutral zinc-air fiber battery and a preparation method thereof. Background Art

[0002] With the need of people for a more convenient and comfortable life, wearable electronic devices have obtained great development opportunities and have broad development prospects. At the same time, in order to meet the daily energy supply requirements of various wearable electronic devices, new wearable energy devices have increasingly attracted people's attention. The existing battery types have started to be diversified.

[0003] There are already related technologies of zinc-air fiber batteries in the prior art. For example, Chinese Patent Application No. 202110991586.2, with a publication date of November 23, 2021, discloses a novel cable-type flexible zinc-air battery. A strong alkaline electrolyte is dissolved in deionized water to prepare an alkaline electrolyte solution with a concentration of 6 mol / L; a hollow composite fiber is completely infiltrated in the electrolyte solution and used as the electrolyte material of the zinc-air battery. A flexible zinc rod is inserted through the center of the fiber electrolyte, and an air electrode is wrapped on the outer layer to assemble a cable-type structure. This invention innovatively uses a fiber electrolyte, which not only avoids the complex process of preparing traditional gel electrolytes but also realizes the transformation from a water-based battery to a flexible battery. Thanks to the good water absorption and flexibility of the fiber electrolyte, the assembled cable-type zinc-air battery shows all-round flexibility, and when the battery shows performance decline or failure during operation, the performance of the battery can be restored after adding alkaline solution. This novel cable-type flexible zinc-air battery is simple to prepare, low in cost, and highly operable, and has great prospects in wearable electronic products. However, its charge and discharge effect is not good, and bending will cause deterioration of charge and discharge. Summary of the Invention

[0004] 1. Technical Problems to be Solved

[0005] Aiming at the problems in the prior art that due to too large bending stiffness, it cannot be bent, bending will cause poor charge and discharge effects, and bending causes poor charge and discharge effects, the present invention provides a neutral zinc-air fiber battery and a preparation method thereof, which has a small bending stiffness. The smaller the bending stiffness, the softer it is, and it has good charge and discharge curves for different degrees of bending.

[0006] 2. Technical Solutions

[0007] The object of the present invention is achieved through the following technical solutions.

[0008] The present invention aims to provide a preparation method of a neutral zinc-air fiber battery to meet the requirements of wearable energy devices in terms of safety, flexibility, and electrochemical performance.

[0009] The neutral zinc-air fiber battery provided by the present invention is assembled in a coaxial structure from a carbon nanotube / zinc powder composite fiber negative electrode, a double-layer gel electrolyte, and a platinum / ruthenium oxide modified carbon nanotube film positive electrode.

[0010] The preparation method of the neutral zinc-air fiber battery provided by the present invention comprises the following specific steps:

[0011] (1) Prepare a carbon nanotube / zinc powder composite fiber electrode;

[0012] (2) Prepare an organic gel electrolyte solution, immerse the fiber electrode prepared in step (1) in the organic gel electrolyte solution for 1 min - 5 min, then take it out and air-dry it in the air for 5 min - 15 min to solidify the organic gel electrolyte;

[0013] (3) Prepare a hydrogel electrolyte precursor;

[0014] (4) The hydrogel electrolyte precursor is in-situ gelled on the fiber negative electrode treated in step (2);

[0015] (5) Wind the platinum / ruthenium oxide nanoparticle modified carbon nanotube film positive electrode around the fiber negative electrode treated in step (3).

[0016] In the present invention, the preparation steps of the carbon nanotube / zinc powder composite fiber electrode are as follows: (1) Add 75 mg - 125 mg of zinc powder into 4 mL - 8 mL of absolute ethanol, and perform ultrasonic treatment on it to form a relatively uniform dispersion A; (2) Pull out a carbon nanotube film with a length of 3 cm - 5 cm and a width of 0.5 cm - 1.5 cm from a super-aligned carbon nanotube array, suck 20 μL - 60 μL of dispersion A, and uniformly drop it on the carbon nanotube film, and let it stand for 1 min - 5 min to air-dry it; (3) On the film prepared in step (2), repeat step (2) several times, such as 2 - 4 times of step (2), to obtain a carbon nanotube / zinc powder composite film; from the two steps of pulling out and dropping, repeat them to form a structure similar to a sandwich layer by layer to form a composite film; (4) Roll up the film prepared in step (3) along the length direction and twist it into a fiber to obtain a carbon nanotube / zinc powder composite fiber negative electrode. The super-aligned carbon nanotube array in this solution is existing content and can be prepared by the following method of the existing technology: continuously spinnable carbon nanotube filaments, Fan Shoushan, etc., "Nature", 2002, volume number 419, page number 801. No more elaboration will be made here.

[0017] In the present invention, the preparation steps of the organic gel electrolyte are as follows: (1) mixing dichloromethane and acetone in a mass ratio of (20-30):1 to obtain solution A; (2) mixing 0.8g-1.4g of polyethylene oxide and 1g-2g of zinc bistrifluoromethanesulfonyl imide with 5-10mL of solution A, and stirring well to obtain the organic gel electrolyte.

[0018] In the present invention, the preparation steps of the hydrogel electrolyte precursor are as follows: (1) measuring 8mL-12mL ultrapure water; (2) adding 1g-1.5g acrylamide, 2.5g-3.5g zinc acetate and 1g-2g potassium chloride to the ultrapure water in step (1), stirring and dissolving at room temperature to form a uniform solution A; (3) adding 0.06g-0.12g ammonium persulfate, 0.006g-0.012g N,N′-methylenebisacrylamide and 0.01g-0.04g dipotassium ethylenediaminetetraacetate to solution A, stirring and dissolving at room temperature to form a uniform solution and continuing stirring.

[0019] In the present invention, the process of in-situ gelation of the hydrogel electrolyte on the fiber electrode is as follows: (1) a mixed solution of a hydrogel electrolyte precursor and tetramethylethylenediamine is poured into a tubular mold with an inner diameter of 300 μm-500 μm at a volume ratio of (20-40):1; (2) the fiber electrode is placed in the mold, and wait for 5 min-15 min to allow the precursor electrolyte to gel in situ on the fiber electrode.

[0020] In the present invention, the steps for preparing the carbon nanotube film positive electrode modified with platinum / ruthenium oxide nanoparticles are as follows: (1) pulling out a layer of carbon nanotube film with a length of 3 cm to 5 cm and a width of 0.5 cm to 1 cm from a super ordered carbon nanotube array, repeatedly pulling out several times, such as 4 to 8 times, overlapping several layers of pulled films, and then dripping anhydrous ethanol on the overlapped films and waiting for them to dry; first, anhydrous ethanol is dripped onto the carbon nanotube film and penetrates into the entire film, and then the anhydrous ethanol evaporates, and the surface tension causes the carbon nanotubes to be spaced apart. The distance between the two electrodes is reduced, and the van der Waals force is enhanced, so that the carbon nanotube film pulled multiple times forms a whole; (2) 0.3 mg-0.6 mg of platinum particles are electrodeposited on the film prepared in step (1) by any constant potential method; (3) 25 mg-50 mg of ruthenium oxide powder is mixed with 10 mL-15 mL of anhydrous ethanol and ultrasonically treated to form a uniform dispersion A; (4) 40 μL-80 μL of dispersion A is dripped on the film treated in step (2), and after it is dried, a carbon nanotube film positive electrode modified with platinum / ruthenium oxide nanoparticles is obtained.

[0021] The maximum charge-discharge current of the high-rate and high-energy-efficiency neutral zinc-air fiber battery proposed by the present invention is 160 mA / g, and the highest energy efficiency is 68%. It reaches an advanced level in the field of neutral zinc-air batteries. Moreover, the fiber battery as a whole has an extremely low bending stiffness and can still work normally under complex deformation conditions, showing application potential in the field of wearable new energy.

[0022] 3. Beneficial Effects

[0023] Compared with the prior art, the advantages of the present invention are as follows:

[0024] The present invention uses a carbon nanotube / zinc powder composite fiber as the negative electrode, replacing the traditional zinc wire or zinc foil negative electrode. Therefore, the entire battery has better flexibility. In addition, the ultra-high specific surface area of zinc powder brings a larger reaction contact area with the electrolyte, improving the problem of poor reaction activity of zinc metal in neutral electrolyte and enhancing the rate performance and energy efficiency of the battery. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 It is a schematic structural diagram of the neutral zinc-air fiber battery of the present invention;

[0026] Figure 2 It is a comparison diagram of the bending stiffness curves of a zinc-air battery with an example and a traditional zinc wire negative electrode;

[0027] Figure 3 It is the charge-discharge curves of an example under three bending states;

[0028] Figure 4 It is a performance comparison diagram of an example and the previously reported neutral zinc-air batteries. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0029] The present invention will be described in detail below with reference to the accompanying drawings of the specification and specific embodiments.

[0030] Example 1

[0031] The following is an example for illustrative purposes and to help further understand the present invention in combination with specific implementation cases. However, the specific details of the implementation cases are only for explaining the present invention and do not represent all the technical solutions under the concept of the present invention. Therefore, it should not be construed as a limitation to the overall technical solution of the present invention. Some non-substantive additions and modifications that do not deviate from the concept of the present invention in the view of those skilled in the art, such as simply replacing or substituting technical features with the same or similar technical effects, all fall within the protection scope of the present invention.

[0032] As Figure 1 , the steps of this example are as follows:

[0033] Prepare a carbon nanotube / zinc powder composite fiber electrode. Add 75 mg of zinc powder to 4 mL of absolute ethanol and perform ultrasonic treatment on it to form a relatively uniform dispersion A; pull out a carbon nanotube film with a length of 3 cm and a width of 0.5 cm from the super-aligned carbon nanotube array, suck 20 μL of dispersion A, and uniformly drop it on the carbon nanotube film, and let it stand for 1 min to dry. Repeat the above steps 2 times to obtain a carbon nanotube / zinc powder composite film; roll up the film along the length direction and twist it into a fiber to obtain a carbon nanotube / zinc powder composite fiber negative electrode.

[0034] Prepare an organic gel electrolyte. Mix dichloromethane and acetone in a mass ratio of 20:1 to obtain solution A; mix 0.8 g of polyethylene oxide and 1.0 g of zinc bis(trifluoromethanesulfonyl)imide with 5 mL of solution A and stir well to obtain an organic gel electrolyte.

[0035] Prepare a hydrogel electrolyte precursor. Measure 8 mL of ultrapure water; add 1 g of acrylamide, 2.5 g of zinc acetate, and 1 g of potassium chloride to the ultrapure water and stir and dissolve at room temperature to form a uniform solution A; add 0.05 g of ammonium persulfate, 0.005 g of N,N′-methylenebisacrylamide, and 0.01 g of dipotassium ethylenediaminetetraacetate to solution A, stir and dissolve at room temperature to form a uniform solution and continue stirring.

[0036] Prepare a platinum / ruthenium oxide nanoparticle-modified carbon nanotube film positive electrode. Pull out a carbon nanotube film with a length of 3 cm and a width of 0.5 cm from the super-aligned carbon nanotube array and continuously repeat the pulling 4 times to make several layers of films coincide into a whole film, then drop absolute ethanol on it and wait for it to dry; electro-deposit 0.3 mg of platinum particles on the carbon nanotube film by any potentiostatic method; mix 25 mg of ruthenium oxide powder with 10 mL of absolute ethanol and perform ultrasonic treatment to form a uniform dispersion A; drop 40 μL of dispersion A on the carbon nanotube film deposited with platinum nanoparticles and wait for it to dry to obtain a platinum / ruthenium oxide nanoparticle-modified carbon nanotube film positive electrode.

[0037] Assemble a neutral zinc-air battery. Immerse the carbon nanotube / zinc powder composite fiber negative electrode in the organic gel electrolyte for 1 min, then take it out and air-dry it for 5 min to solidify the organic gel electrolyte. Pour a mixed solution of the hydrogel electrolyte precursor and tetramethylethylenediamine into a tubular mold with an inner diameter of 300 μm at a volume ratio of 20:1; put the fiber electrode coated with the organic gel electrolyte into the mold and wait for 5 min for the precursor electrolyte to in-situ gel on the fiber electrode; demold and take out the fiber negative electrode wrapped with the hydrogel. Wind the platinum / ruthenium oxide nanoparticle-modified carbon nanotube film positive electrode around the double-layer gel-wrapped carbon nanotube / zinc powder composite fiber negative electrode.

[0038] The present invention uses a carbon nanotube / zinc powder composite fiber as the negative electrode, replacing the traditional zinc wire or zinc foil negative electrode. Therefore, the entire battery has better flexibility. In addition, the ultra-high specific surface area of the zinc powder brings a larger reaction contact area with the electrolyte, improving the problem of poor reaction activity of zinc metal in neutral electrolytes and enhancing the rate performance and energy efficiency of the battery. The fiber battery can perform charge and discharge reactions in air with an energy efficiency of up to 68%, and the maximum charge and discharge current is 160 mA / g, reaching an advanced level in the field of neutral zinc-air batteries. Moreover, the fiber battery as a whole has an extremely low bending stiffness and can still work normally under complex deformation conditions, showing application potential in the field of wearable new energy. Through Figure 2 、 3 As can be seen from 4, when the carbon nanotube / zinc powder composite fiber prepared by this solution is bent, the stress generated is much smaller than that of the zinc wire, showing excellent flexibility. The neutral zinc-air battery maintains good charge and discharge performance in different deformation states and has advantages in terms of current density and energy efficiency.

[0039] Example 2

[0040] Prepare a carbon nanotube / zinc powder composite fiber electrode. Add 100 mg of zinc powder to 6 mL of absolute ethanol and perform ultrasonic treatment on it to form a relatively uniform dispersion A. Pull out a carbon nanotube film with a length of 4 cm and a width of 0.8 cm from the super-aligned carbon nanotube array, suck 40 μL of dispersion A, and uniformly drop it on the carbon nanotube film. Let it stand for 2 min to dry, and repeat the above steps 3 times to obtain a carbon nanotube / zinc powder composite film. Roll up the film along the length direction and twist it into a fiber to obtain a carbon nanotube / zinc powder composite fiber.

[0041] Prepare an organic gel electrolyte. Mix dichloromethane and acetone in a mass ratio of 25:1 to obtain solution A. Mix 1.2 g of polyethylene oxide, 1.5 g of zinc bis(trifluoromethanesulfonyl)imide with 7.5 mL of solution A and stir well to obtain an organic gel electrolyte.

[0042] Prepare a hydrogel electrolyte precursor. Measure 10 mL of ultrapure water. Add 1.2 g of acrylamide, 3 g of zinc acetate and 1.2 g of potassium chloride to the ultrapure water and stir and dissolve at room temperature to form a uniform solution A. Add 0.08 g of ammonium persulfate, 0.008 g of N,N′-methylenebisacrylamide and 0.04 g of potassium ethylenediaminetetraacetate to solution A, stir and dissolve at room temperature to form a uniform solution and continue stirring.

[0043] Prepare a positive electrode of platinum / ruthenium oxide nanoparticle-modified carbon nanotube film. Pull out a carbon nanotube film with a length of 4 cm and a width of 0.6 cm from a super-aligned carbon nanotube array, and continuously repeat the pulling 5 times to overlap these several layers of films into a whole film. Then, drop anhydrous ethanol on it and wait for it to dry. Electro-deposit 0.4 mg of platinum particles on the carbon nanotube film by any potentiostatic method. Mix 40 mg of ruthenium oxide powder with 12 mL of anhydrous ethanol and ultrasonically treat it to form a uniform dispersion A. Drop 60 μL of dispersion A on the carbon nanotube film deposited with platinum nanoparticles, and wait for it to dry to obtain a positive electrode of platinum / ruthenium oxide nanoparticle-modified carbon nanotube film.

[0044] Assemble a neutral zinc-air battery. Immerse the carbon nanotube / zinc powder composite fiber negative electrode in the organic gel electrolyte for 2 min, then take it out and dry it in the air for 8 min to solidify the organic gel electrolyte. Pour a mixed solution of a hydrogel electrolyte precursor and tetramethylethylenediamine into a tubular mold with an inner diameter of 350 μm at a volume ratio of 25:1. Put the fiber electrode coated with the organic gel electrolyte into the mold and wait for 8 min for the precursor electrolyte to in-situ gel on the fiber electrode. Demold and take out the composite fiber wrapped with the hydrogel. The composite fiber serves as the negative electrode. Wind the positive electrode of platinum / ruthenium oxide nanoparticle-modified carbon nanotube film around the negative electrode of the carbon nanotube / zinc powder composite fiber wrapped with a double-layer gel.

[0045] Example 3

[0046] Prepare a carbon nanotube / zinc powder composite fiber electrode. Add 125 mg of zinc powder to 8 mL of anhydrous ethanol and ultrasonically treat it to form a relatively uniform dispersion A. Pull out a carbon nanotube film with a length of 5 cm and a width of 1.5 cm from a super-aligned carbon nanotube array, suck 60 μL of dispersion A, uniformly drop it on the carbon nanotube film, let it stand for 5 min to dry, and repeat the above steps 4 times to obtain a carbon nanotube / zinc powder composite film. Roll up the film along the length direction and twist it into a fiber to obtain a carbon nanotube / zinc powder composite fiber negative electrode.

[0047] Prepare an organic gel electrolyte. Mix dichloromethane and acetone in a mass ratio of 30:1 to obtain solution A. Mix 1.4 g of polyethylene oxide and 2 g of zinc bis(trifluoromethanesulfonyl)imide with 10 mL of solution A and stir well to obtain the organic gel electrolyte.

[0048] Prepare a hydrogel electrolyte precursor. Measure 12 mL of ultrapure water; add 1.5 g of acrylamide, 3.5 g of zinc acetate, and 2 g of potassium chloride to the ultrapure water, and stir to dissolve at room temperature to form a homogeneous solution A; add 0.12 g of ammonium persulfate, 0.012 g of N,N′-methylenebisacrylamide, and 0.03 g of dipotassium ethylenediaminetetraacetate to solution A, stir to dissolve at room temperature to form a homogeneous solution, and continue stirring.

[0049] Prepare a platinum / ruthenium oxide nanoparticle-modified carbon nanotube film positive electrode. Pull out a carbon nanotube film with a length of 5 cm and a width of 1 cm from a super-aligned carbon nanotube array, continuously repeat the pulling 8 times to make several layers of the film coincide into a whole film, then drop anhydrous ethanol on it and wait for it to dry; electro-deposit 0.6 mg of platinum particles on the carbon nanotube film by any potentiostatic method; mix 50 mg of ruthenium oxide powder with 15 mL of anhydrous ethanol and ultrasonically treat to form a homogeneous dispersion A; drop 80 μL of dispersion A on the carbon nanotube film deposited with platinum nanoparticles, and wait for it to dry to obtain a platinum / ruthenium oxide nanoparticle-modified carbon nanotube film positive electrode.

[0050] Assemble a neutral zinc-air battery. Immerse the carbon nanotube / zinc powder composite fiber negative electrode in the organic gel electrolyte for 5 min, then take it out and air-dry it for 15 min to solidify the organic gel electrolyte. Pour a mixed solution of the hydrogel electrolyte precursor and tetramethylethylenediamine into a tubular mold with an inner diameter of 500 μm at a volume ratio of 30:1; put the fiber electrode coated with the organic gel electrolyte into the mold and wait for 15 min for the precursor electrolyte to in-situ gel on the fiber electrode; demold and take out the fiber negative electrode wrapped with the hydrogel. Wind the platinum / ruthenium oxide nanoparticle-modified carbon nanotube film positive electrode around the double-layer gel-wrapped carbon nanotube / zinc powder composite fiber negative electrode.

[0051] Example 4

[0052] The battery of this solution is a battery made by the above method. The battery structure consists of a carbon nanotube / zinc powder composite fiber negative electrode, a double-layer gel electrolyte, and a platinum / ruthenium oxide nanoparticle-modified carbon nanotube film positive electrode arranged in a coaxial structure from the inside to the outside.

[0053] The above has schematically described the present invention and its implementation manners. This description is not restrictive. Without departing from the spirit or basic characteristics of the present invention, the present invention can be implemented in other specific forms. What is shown in the drawings is only one of the implementation manners of the present invention, and the actual structure is not limited thereto. Any reference signs in the claims should not limit the claimed claims. Therefore, if those of ordinary skill in the art are inspired by it and, without departing from the purpose of this creation, design similar structural manners and embodiments to this technical solution without creative efforts, they should all fall within the protection scope of this patent. In addition, the term "comprising" does not exclude other elements or steps, and the term "a" before an element does not exclude including "a plurality of" such elements. The plurality of elements stated in the product claims can also be implemented by one element through software or hardware. The terms such as "first" and "second" are used to indicate names and do not indicate any specific order.

Claims

1. A method for preparing a neutral zinc-air fiber battery, the steps are as follows: Prepare carbon nanotube / zinc powder composite fiber; Prepare an organic gel electrolyte, immerse the fabricated composite fiber electrode in the organic gel electrolyte, then take it out and air-dry it in the air to solidify the organic gel electrolyte; Prepare a hydrogel electrolyte precursor, and in-situ gelate the hydrogel electrolyte precursor on the composite fiber after the organic gel electrolyte is solidified to obtain a fiber negative electrode wrapped with a double-layer gel; Wind the carbon nanotube film positive electrode modified with platinum / ruthenium oxide nanoparticles around the fiber negative electrode wrapped with a double-layer gel; The preparation steps of the carbon nanotube / zinc powder composite fiber are as follows: Add 75 mg - 125 mg of zinc powder to 4 mL - 8 mL of absolute ethanol, and perform ultrasonic treatment on it to form dispersion liquid A; Pull out a carbon nanotube film with a length of 3 cm - 5 cm and a width of 0.5 cm - 1.5 cm from the super-aligned carbon nanotube array, suck 20 μL - 60 μL of dispersion liquid A, uniformly drop dispersion liquid A on the carbon nanotube film, and let it stand for 1 min - 5 min to dry; On the dried film, repeat the steps of pulling out the carbon nanotube film and dropping dispersion liquid A several times to obtain a carbon nanotube / zinc powder composite film; Roll up the carbon nanotube / zinc powder composite film prepared in the previous step along the length direction, twist it into a fiber, and use it as the carbon nanotube / zinc powder composite fiber; The preparation steps of the carbon nanotube film positive electrode modified with platinum / ruthenium oxide nanoparticles are as follows: Pull out a carbon nanotube film with a length of 3 cm - 5 cm and a width of 0.5 cm - 1 cm from the super-aligned carbon nanotube array, continuously repeat the pulling several times, overlap the films pulled several layers, then drop absolute ethanol on the overlapped film, and wait for it to dry; Electrodeposit 0.3 mg - 0.6 mg of platinum particles on the dried film above; Take 25 mg - 50 mg of ruthenium oxide powder and mix it with 10 mL - 15 mL of absolute ethanol, and perform ultrasonic treatment to form a uniform dispersion liquid A; Drop 40 μL - 80 μL of dispersion liquid A on the film after depositing platinum particles in the previous step, and wait for it to dry to obtain the carbon nanotube film positive electrode modified with platinum / ruthenium oxide nanoparticles.

2. The preparation method of the neutral zinc-air fiber battery according to claim 1, characterized in that The preparation steps of the organic gel electrolyte are as follows: Mix dichloromethane and acetone in a mass ratio of (20 - 30):1 to obtain solution A; Mix 0.8 g - 1.4 g of polyethylene oxide and 1 g - 2 g of zinc bis(trifluoromethanesulfonyl)imide with 5 - 10 mL of solution A, and stir well to obtain the organic gel electrolyte.

3. According to the method for preparing a neutral zinc-air fiber battery described in claim 1, wherein, The preparation steps of the hydrogel electrolyte precursor are as follows: Take 8 mL - 12 mL of ultrapure water; Add 1 g - 1.5 g of acrylamide, 2.5 g - 3.5 g of zinc acetate and 1 g - 2 g of potassium chloride to the ultrapure water, and stir and dissolve at room temperature to form a uniform precursor solution A; Add 0.05 g - 0.12 g of ammonium persulfate, 0.005 g - 0.012 g of N,N′-methylenebisacrylamide, and 0.02 g - 0.04 g of dipotassium ethylenediaminetetraacetate to Solution A, and stir and dissolve at room temperature to form a uniform hydrogel electrolyte precursor solution.

4. The preparation method of the neutral zinc-air fiber battery according to claim 1, characterized in that, The specific steps for curing the organic gel electrolyte are as follows: soak the fiber electrode in the organic gel electrolyte for 1 min - 5 min, then take it out and air-dry it for 5 min - 15 min.

5. The preparation method of the neutral zinc-air fiber battery according to claim 1 or 4, characterized in that, The specific steps for in-situ gelation of the hydrogel electrolyte precursor are as follows: Pour a mixed solution of the hydrogel electrolyte precursor and tetramethylethylenediamine into a tubular mold with an inner diameter of 300 μm - 500 μm at a volume ratio of (20 - 40):1; Put the composite fiber electrode coated with the organic gel electrolyte into the mold, and wait for 5 min - 15 min for the precursor electrolyte to gel in-situ on the fiber electrode.

6. The preparation method of the neutral zinc-air fiber battery according to claim 5, characterized in that, Deposit platinum particles by any constant potential method.

7. A neutral zinc-air fiber battery manufactured by the method according to any one of claims 1-6, characterized in that, The battery structure includes a carbon nanotube / zinc powder composite fiber negative electrode, a double-layer gel electrolyte, and a platinum / ruthenium oxide nanoparticle-modified carbon nanotube film positive electrode arranged coaxially from the inside out.

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