Non-gravity-dependent two-phase electrolyte, preparation method and application thereof, and aqueous zinc-iodine battery

Abstract

The invention provides a non-gravity-dependent two-phase electrolyte, a preparation method and application thereof, and an aqueous zinc-iodine battery, and belongs to the technical field of batteries. According to the invention, ethyl acetate and water are respectively used as solvents to construct a two-phase electrolyte system, when the two-phase electrolyte system is used for a zinc-iodine battery, an organic phase electrolyte is arranged on the positive electrode side, and the ethyl acetate is used for efficiently extracting iodine and polyiodide, so that the polyiodide and iodine can be fixed on the positive electrode side, the amount of the polyiodide entering the aqueous electrolyte is reduced, and the production cost is reduced. The shuttle effect of the polyiodide is effectively limited; meanwhile, a stable non-gravity-dependent biphase zinc-iodine battery device is constructed by using the PAM-CMC hydrogel and the active carbon positive electrode, so that the stable biphase interface can be maintained without depending on gravity, the corrosion of the negative electrode caused by the contact between the organic phase electrolyte and the negative electrode is avoided, and the cycle performance of the zinc-iodine battery is improved.

Description

Technical Field

[0001] The invention belongs to the technical field of batteries, and in particular relates to a non-gravity-dependent biphasic electrolyte, a preparation method and application thereof, and an aqueous zinc-iodine battery. Background Art

[0002] With the rapid development of the economy, fossil energy is becoming increasingly depleted and the global greenhouse effect is intensifying. In order to adapt to the needs of development, the new energy industry is playing an increasingly important role in the national economy. For example, wind energy, solar energy, and tidal energy are gradually entering every corner of daily life and industrial production.

[0003] Zinc-iodine battery is an energy storage device composed of metallic zinc as the negative electrode and iodine and its compounds as the positive electrode. It is an extremely promising large-scale energy storage technology. During the charging process of zinc-iodine battery, iodine undergoes oxidation reaction to produce I 3- and I 5- The polyiodide intermediates represented by are highly soluble and will dissolve in aqueous electrolytes. The color of the solution is generally yellow or dark brown. During the charging process, the polyiodide produced by the positive electrode will gradually diffuse and cross the diaphragm under the action of the concentration gradient, and react with the metal zinc at the negative electrode to generate I - and Zn 2+ , which causes the negative electrode to corrode and produce a loose structure. This phenomenon is called the shuttle effect. The shuttle effect of polyiodide seriously reduces the performance of the battery, causing significant degradation in cycle stability, discharge capacity, coulombic efficiency and self-discharge performance.

[0004] Constructing electrolyte / electrode interface via iodine chemical adsorption (e.g., HI, NI, and OI bonds) is an effective strategy to immobilize polyiodides; however, the irreversible adsorption behavior leads to the gradual loss of active iodine after multiple charge / discharge cycles. Summary of the invention

[0005] The purpose of the present invention is to provide a gravity-independent biphasic electrolyte, a preparation method and application thereof, and an aqueous zinc-iodine battery. The gravity-independent biphasic electrolyte provided by the present invention can absorb polyiodides, inhibit the shuttle effect of polyiodides, and will not form irreversible compounds, thereby avoiding the consumption of active iodine.

[0006] In order to achieve the above-mentioned object of the invention, the present invention provides the following technical solutions:

[0007] The present invention provides a gravity-independent biphasic electrolyte, comprising an organic phase electrolyte and a hydrogel electrolyte arranged adjacent to each other; the organic phase electrolyte is zinc bis(trifluoromethanesulfonyl)imide (Zn(TFSI) 2) in an ethyl acetate (EA) solution; the hydrogel electrolyte comprises a carboxymethyl cellulose-polyacrylamide copolymer (PAM-CMC) and an aqueous electrolyte adsorbed in the PAM-CMC, wherein the aqueous electrolyte is an aqueous solution of zinc sulfate and iodide.

[0008] Preferably, the Zn(TFSI) 2 The concentration of zinc ions in the EA solution is 0.2-3 mol / L.

[0009] Preferably, the mass ratio of the PAM-CMC to the volume of the aqueous electrolyte is 0.9 g: (1-20) mL.

[0010] Preferably, the concentration of zinc sulfate in the aqueous electrolyte is 0.5 to 2 mol / L.

[0011] Preferably, the iodide comprises KI, NaI or LiI.

[0012] Preferably, the concentration of iodide in the aqueous electrolyte is 0.1-1 mol / L.

[0013] Preferably, the mass ratio of the organic phase electrolyte to the hydrogel electrolyte is 1:(0.5-2).

[0014] The present invention also provides a method for preparing the non-gravity-dependent biphasic electrolyte described in the above technical solution, comprising:

[0015] The PAM-CMC is immersed in an aqueous electrolyte for adsorption to obtain a hydrogel electrolyte;

[0016] Zn(TFSI) 2 Mixed with EA to obtain Zn(TFSI) 2 of EA solution.

[0017] The present invention also provides the use of the non-gravity-dependent biphasic electrolyte described in the above technical solution in an aqueous zinc-iodine battery.

[0018] The present invention also provides an aqueous zinc-iodine battery, comprising an activated carbon positive electrode, a zinc metal negative electrode, and a non-gravity-dependent biphasic electrolyte arranged between the activated carbon positive electrode and the zinc metal negative electrode; the non-gravity-dependent biphasic electrolyte is the non-gravity-dependent biphasic electrolyte described in the above technical solution; the hydrogel electrolyte of the non-gravity-dependent biphasic electrolyte is arranged on the zinc metal negative electrode side, and the organic phase electrolyte of the non-gravity-dependent biphasic electrolyte is arranged on the activated carbon positive electrode side.

[0019] The present invention provides a gravity-independent two-phase electrolyte, comprising an organic phase electrolyte and a hydrogel electrolyte arranged adjacent to each other; the organic phase electrolyte is Zn(TFSI) 2EA solution; the hydrogel electrolyte includes PAM-CMC and an aqueous electrolyte adsorbed in the PAM-CMC, and the aqueous electrolyte is an aqueous solution of zinc sulfate and iodide. The present invention uses EA and water as solvents to construct a biphasic (BP) electrolyte system. When used in a zinc-iodine battery, the organic phase electrolyte is arranged on the positive electrode side. The efficient extraction of iodine and polyiodides by EA can fix polyiodides and iodine on the positive electrode side, reduce the amount of polyiodides entering the aqueous electrolyte, and effectively limit the shuttling effect of polyiodides; at the same time, a stable non-gravity-dependent BP zinc-iodine battery device is constructed using PAM-CMC hydrogel and activated carbon positive electrode, so that it can maintain a stable BP interface without relying on gravity, avoid the corrosion of the negative electrode caused by the contact between the organic phase electrolyte and the negative electrode, and improve the cycle performance of the zinc-iodine battery. The results of the embodiment show that when the non-gravity-dependent biphasic electrolyte provided by the present invention is used in an aqueous zinc-iodine battery, at 5mA·cm -2 At a current density of , after 2500 cycles, the capacity retention rate is 100% and the coulombic efficiency is 100%. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 The dissolution of different Zn salts in EA in Comparative Example 1 of the present invention, wherein (a) is 1 mol / L Zn(TFSI) 2 ; (b) 1 mol / L Zn(OTf) 2 ; (c) 1 mol / L Zn(ClO 4 ) 2 ; (d) 1 mol / L ZnSO 4 ;

[0021] Figure 2 The stratification of different Zn salt / KI aqueous solutions after mixing with 1 mol / L ZnTFSI / EA solution in Comparative Example 2 of the present invention, where (a) is 1 mol / L Zn(TFSI) 2 +0.5mol / L KI; (b) 1molL Zn(OTf) 2 +0.5mol / L KI; (c) 1molL Zn(ClO 4 ) 2 +0.5mol / L KI; (d) 1molL ZnSO 4 +0.5mol / LKI;

[0022] Figure 3 A schematic diagram of a battery assembled for an application example of the present invention;

[0023] Figure 4 The cycle performance test diagram of the battery provided for the application examples of the present invention and the comparative application examples;

[0024] Figure 5 The constant current discharge test curves of the batteries in different placement modes provided for the application examples of the present invention. DETAILED DESCRIPTION

[0025] All raw materials of the present invention have no particular limitation on their sources and can be purchased from the market or prepared according to conventional methods known to those skilled in the art.

[0026] There is no particular limitation on the purity of all raw materials in the present invention. The present invention preferably uses high-purity raw materials or raw materials with a purity commonly used in the battery field.

[0027] The present invention provides a gravity-independent two-phase electrolyte, comprising an organic phase electrolyte and a hydrogel electrolyte arranged adjacent to each other; the organic phase electrolyte is Zn(TFSI) 2 EA solution; the hydrogel electrolyte includes PAM-CMC and an aqueous electrolyte adsorbed in the PAM-CMC, wherein the aqueous electrolyte is an aqueous solution of zinc sulfate and iodide.

[0028] The gravity-independent two-phase electrolyte provided by the present invention comprises an organic phase electrolyte.

[0029] In the present invention, the organic phase electrolyte is Zn(TFSI) 2 In the present invention, EA has a high extraction rate for polyiodides in the aqueous phase and can form a distinct phase interface with the aqueous phase. EA is used as a solvent of the organic phase electrolyte to form a BP electrolyte system with the aqueous electrolyte, which can effectively limit the shuttle effect of polyiodides; Zn(TFSI) 2 It can be dissolved in EA to form a uniform transparent organic phase solution, ensuring the ion transport performance of the electrolyte.

[0030] In the present invention, the Zn(TFSI) 2 The concentration of zinc ions in the EA solution is preferably 0.2 to 3 mol / L, more preferably 0.5 to 1.5 mol / L; as an embodiment of the present invention, the Zn(TFSI) 2 The concentration of zinc ions in the EA solution can be 0.3 mol / L, 0.6 mol / L, 0.9 mol / L, 1 mol / L, 1.3 mol / L, 2 mol / L, 2.5 mol / L or 2.8 mol / L. Zn(TFSI) 2 The concentration of zinc ions in the EA solution is within the above range, which is beneficial to further improve the cycle performance of the battery.

[0031] The gravity-independent biphasic electrolyte provided by the present invention also includes a hydrogel electrolyte disposed adjacent to the organic phase electrolyte. The present invention uses an aqueous electrolyte in the form of a hydrogel to form a BP electrolyte system with the organic phase electrolyte. The solubility of polyiodides in EA is much greater than that in water. In the BP electrolyte system, iodine and polyiodides can be extracted in EA to reduce the shuttling effect of polyiodides.

[0032] In the present invention, the hydrogel electrolyte includes PAM-CMC and an aqueous electrolyte adsorbed in the PAM-CMC. The present invention adsorbs the aqueous electrolyte in PAM-CMC to form a hydrogel electrolyte, which can confine the aqueous electrolyte to the negative electrode, and at the same time, together with the activated carbon positive electrode, confine the organic phase electrolyte to the positive electrode, which can avoid the corrosion of the negative electrode by polyiodide and enable the battery to adapt to different application scenarios, and will not affect the electrolyte due to the placement of the battery.

[0033] In the present invention, the mass ratio of the PAM-CMC to the volume of the aqueous electrolyte is preferably 0.9 g: (1-20) mL, more preferably 0.9 g: (10-15) mL; as an embodiment of the present invention, the mass ratio of the PAM-CMC to the volume of the aqueous electrolyte can be 0.9 g: 3 mL, 0.9 g: 6 mL, 0.9 g: 9 mL, 0.9 g: 12 mL, 0.9 g: 16 mL or 0.9 g: 18 mL. The mass ratio of the PAM-CMC to the volume of the aqueous electrolyte within the above range is conducive to further improving the cycle performance of the battery.

[0034] In the present invention, the aqueous electrolyte is an aqueous solution of zinc sulfate and iodide. The aqueous solution of zinc sulfate and iodide can form a BP electrolyte system with the organic phase electrolyte, extract iodine and polyiodide in the organic phase electrolyte, and reduce the shuttle effect of polyiodide.

[0035] In the present invention, the concentration of zinc sulfate in the aqueous electrolyte is preferably 0.5-2 mol / L, more preferably 1-1.5 mol / L; as an embodiment of the present invention, the concentration of zinc sulfate in the aqueous electrolyte may be 0.6 mol / L, 0.8 mol / L, 0.9 mol / L, 1.2 mol / L, 1.4 mol / L or 1.6 mol / L. The concentration of zinc sulfate in the aqueous electrolyte within the above range is conducive to further improving the cycle performance of the battery.

[0036] In the present invention, the iodide preferably includes KI, NaI or LiI. The use of the above iodide in the aqueous electrolyte is beneficial to further improve the cycle performance of the battery.

[0037] In the present invention, the concentration of iodide in the aqueous electrolyte is preferably 0.1-1 mol / L, more preferably 0.5-0.8 mol / L; as an embodiment of the present invention, the concentration of iodide in the aqueous electrolyte can be 0.2 mol / L, 0.3 mol / L, 0.4 mol / L, 0.6 mol / L, 0.7 mol / L or 0.9 mol / L. The concentration of iodide in the aqueous electrolyte within the above range is conducive to further improving the cycle performance of the battery.

[0038] In the present invention, the mass ratio of the organic phase electrolyte to the hydrogel electrolyte is preferably 1:(0.5-2), more preferably 1:1; as an embodiment of the present invention, the mass ratio of the organic phase electrolyte to the hydrogel electrolyte may be 1:0.6, 1:0.8, 1:1.2, 1:1.4, 1:1.6 or 1:1.8. The mass ratio of the organic phase electrolyte to the hydrogel electrolyte within the above range is conducive to further improving the cycle performance of the battery.

[0039] The present invention uses EA and water as solvents to construct a BP electrolyte system. When used in a zinc-iodine battery, an organic phase electrolyte is arranged on the positive electrode side. The EA is used to efficiently extract iodine and polyiodides, so that polyiodides and iodine can be fixed on the positive electrode side, thereby reducing the amount of polyiodides entering the aqueous electrolyte and effectively limiting the shuttling effect of polyiodides. At the same time, a stable non-gravity-dependent BP zinc-iodine battery device is constructed using a PAM-CMC hydrogel and an activated carbon positive electrode, so that the device can maintain a stable BP interface without relying on gravity, thereby avoiding corrosion of the negative electrode caused by contact between the organic phase electrolyte and the negative electrode, and improving the cycle performance of the zinc-iodine battery.

[0040] The present invention also provides a method for preparing the non-gravity-dependent biphasic electrolyte described in the above technical solution, comprising:

[0041] The PAM-CMC is immersed in an aqueous electrolyte for adsorption to obtain a hydrogel electrolyte;

[0042] Zn(TFSI) 2 Mixed with EA to obtain Zn(TFSI) 2 of EA solution.

[0043] The present invention soaks PAM-CMC in an aqueous electrolyte for adsorption to obtain a hydrogel electrolyte.

[0044] The present invention has no particular limitation on the source of the PAM-CMC, and the PAM-CMC can be prepared by a method known to those skilled in the art or a commercially available product. In an embodiment of the present invention, the PAM-CMC is prepared by oneself.

[0045] As an embodiment of the present invention, the preparation method of the PAM-CMC can be: dissolving carboxymethyl cellulose and acrylamide powder in water, and then adding an initiator, a crosslinking agent, and a crosslinking accelerator to carry out a crosslinking reaction to obtain PAM-CMC.

[0046] In an embodiment of the present invention, the mass of the carboxymethyl cellulose can be 0.1-0.5g, or 0.2g; the mass of the acrylamide powder can be 0.6g-2.5g, or 1.6g; the water can be deionized water, and the volume of the deionized water can be 8mL; the initiator can be ammonium persulfate, and the mass of the initiator can be 0.001-0.01g, or 0.0038g; the crosslinking agent can be N,N'-methylenebisacrylamide, and the mass of the crosslinking agent can be 0.001-0.01g, or 0.0019g; the crosslinking accelerator can be N,N,N',N'-tetramethylethylenediamine, the mass of the cross-linking accelerator can be 0.001-0.01g, or 0.0038g; the cross-linking reaction can be carried out under stirring conditions, and the cross-linking reaction time can be 0.5-10min, or 2min; after the cross-linking reaction, the reaction solution can also be introduced into a glass culture dish, sealed and allowed to stand, the standing temperature can be 30-100°C, or 60°C, the standing time can be 0.5-12h, or 6h, and the standing can be carried out in an oven; when used, the sealing film is uncovered and dried at room temperature to obtain PAM-CMC.

[0047] The present invention has no special requirements for the adsorption time, as long as the aqueous electrolyte can be adsorbed into the PAM-CMC. As an embodiment of the present invention, the adsorption time can be 0.5 to 12 hours, or 6 hours.

[0048] The present invention converts Zn(TFSI) 2 Mixed with EA to obtain Zn(TFSI) 2 of EA solution.

[0049] The present invention has no particular limitation on the specific manner of mixing, and any mixing manner well known to those skilled in the art may be used.

[0050] The present invention also provides the use of the non-gravity-dependent biphasic electrolyte described in the above technical solution in an aqueous zinc-iodine battery.

[0051] As an embodiment of the present invention, in the application, the hydrogel electrolyte in the non-gravity-dependent two-phase electrolyte is arranged on the negative electrode side, and the organic phase electrolyte is arranged on the positive electrode side.

[0052] The present invention also provides an aqueous zinc-iodine battery, comprising an activated carbon positive electrode, a zinc metal negative electrode, and a non-gravity-dependent biphasic electrolyte arranged between the activated carbon positive electrode and the zinc metal negative electrode; the non-gravity-dependent biphasic electrolyte is the non-gravity-dependent biphasic electrolyte described in the above technical solution; the hydrogel electrolyte of the non-gravity-dependent biphasic electrolyte is arranged on the zinc metal negative electrode side, and the organic phase electrolyte of the non-gravity-dependent biphasic electrolyte is arranged on the activated carbon positive electrode side.

[0053] The present invention has no particular limitation on the raw materials and assembly method of the aqueous zinc-iodine battery, and conventional raw materials and assembly methods in the art may be used.

[0054] The aqueous zinc-iodine battery provided by the present invention has excellent cycle performance, and different placement methods will not affect the performance of the battery, thereby overcoming the gravity dependence of the existing BP electrolyte and expanding the applicability of the battery.

[0055] The technical solutions in the present invention will be described clearly and completely below in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0056] Example 1

[0057] A gravity-independent biphasic electrolyte, comprising an organic phase electrolyte and a hydrogel electrolyte (PAM-CMC hydrogel electrolyte) arranged adjacent to each other; wherein the organic phase electrolyte is 1 mol / L Zn(TFSI) 2 EA solution (ZnTFSI / EA electrolyte), the hydrogel electrolyte is 0.9g PAM-CMC and 15mL aqueous electrolyte adsorbed on PAM-CMC, the aqueous electrolyte is an aqueous solution of zinc sulfate and potassium iodide, wherein the concentration of zinc sulfate is 1mol / L, and the concentration of potassium iodide is 0.5mol / L.

[0058] The preparation method of the non-gravity-dependent two-phase electrolyte is:

[0059] Preparation of ZnTFSI / EA electrolyte: 31.25 g Zn(TFSI) 2 , add it into a 50mL volumetric flask, add EA until the scale line, shake evenly to obtain a transparent clear solution, which is 1mol / L ZnTFSI / EA electrolyte.

[0060] Preparation of PAM-CMC hydrogel electrolyte: 0.2g carboxymethyl cellulose and 1.6g acrylamide powder were dissolved in 8mL deionized water, stirred for 10min, and then 0.0038g ammonium persulfate and 0.0019g N,N'-methylenebisacrylamide were added; after degassing, 0.0038g N,N,N',N'-tetramethylethylenediamine was added; after vigorous stirring for 2min, the solution was introduced into a glass culture dish, sealed with a sealing film, and placed in an oven at 60℃ for 6h; the sealing film was removed, and after drying at room temperature, 0.9g of the solid material was soaked in 1mol / LZnSO 4 / 0.5mol / L KI aqueous solution for 6h to obtain PAM-CMC hydrogel electrolyte.

[0061] Comparative Example 1

[0062] Different zinc salts Zn(ClO 4 ) 2 、ZnSO 4 、Zn(OTf) 2 and Zn(TFSI) 2 Prepare a 1 mol / L aqueous solution and mix it with EA solvent. The mixed state is as follows: Figure 1 As shown, from Figure 1 It can be seen that ZnClO 4 、ZnSO 4 、Zn(OTf) 2 The salt cannot dissolve and forms a solid precipitate, only Zn(TFSI) 2 The salt can be dissolved to form a homogeneous clear solution.

[0063] Comparative Example 2

[0064] Different Zn salts Zn(ClO 4 ) 2 、Zn(TFSI) 2 、ZnSO 4 and Zn(OTf) 2 The aqueous electrolyte was prepared with 0.5 mol / L KI and matched with the organic electrolyte (1 mol / L ZnTFSI / EA) at the same volume. Figure 2 As shown, from Figure 2 It can be seen that only 1 mol / L ZnSO 4 +0.5mol / LKI successfully constructed an immiscible BP system.

[0065] Application Examples

[0066] The non-gravity-dependent biphasic electrolyte in the above embodiment is assembled into an aqueous zinc-iodine battery with an activated carbon positive electrode and a zinc metal negative electrode, and the specific steps are as follows:

[0067] Take 0.8 g of activated carbon (YP-80F), mix activated carbon, SuperP and sodium carboxymethyl cellulose in a mass ratio of 8:1:1, use water as solvent, mix into a uniform slurry, and coat it on graphite paper. The active material loading is 15 mg cm -2 ;

[0068] The zinc metal negative electrode, PAM-CMC hydrogel electrolyte, and activated carbon positive electrode with 30 μL ZnTFSI / EA electrolyte were assembled into a 2032-type button cell at room temperature, denoted as BP cell, with the following structure: Figure 3 As shown, from Figure 3 It can be seen that the battery provided by the present invention is independent of gravity.

[0069] Comparative Application Examples

[0070] Assemble the battery according to the method in the application example, and the electrolyte is 1mol / LZnSO 4 / 0.5mol / LKI aqueous solution, denoted as SP battery.

[0071] Cyclic performance test

[0072] The batteries assembled from the application examples and the comparative application examples were heated at 5 mA cm -2 At a current density of , after 2500 cycles, the cycle performance of the battery is as follows Figure 4 As shown. Figure 4 It can be seen that the coulombic efficiencies of the two batteries are close to 100%, the battery capacity retention rate of the application example is also close to 100%, and the battery capacity retention rate of the comparative application example is only 46%, indicating that the non-gravity-dependent biphasic electrolyte provided by the present invention effectively suppresses the shuttle effect of polyiodides and improves the cycle performance of the battery.

[0073] Constant current charge and discharge test in different placement methods

[0074] The battery of the application example is tested for constant current charging and discharging with the positive electrode facing upward and the negative electrode facing upward, and the GCD curve is obtained, as shown in Figure 5 As shown. Figure 5 It can be seen that the charge and discharge performances of the battery with the positive electrode facing upward and the battery with the negative electrode facing upward are almost completely the same, indicating that the non-gravity-dependent two-phase electrolyte provided by the present invention has an excellent non-gravity-dependent effect, and the placement of the battery has no effect on the battery performance.

[0075] Through the performance tests of the above application examples and comparative application examples, it can be seen that the non-gravity-dependent two-phase electrolyte provided by the present invention has excellent cycle performance after being assembled into a battery, and is not affected by the placement of the battery, and has a wider applicability.

[0076] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A gravity-independent biphasic electrolyte, comprising an organic phase electrolyte and a hydrogel electrolyte disposed adjacent to each other; the organic phase electrolyte is an ethyl acetate solution of zinc bis(trifluoromethanesulfonyl)imide; the hydrogel electrolyte comprises a carboxymethyl cellulose-polyacrylamide copolymer and an aqueous electrolyte adsorbed in the carboxymethyl cellulose-polyacrylamide copolymer, wherein the aqueous electrolyte is an aqueous solution of zinc sulfate and iodide.

2. The gravity-independent biphasic electrolyte according to claim 1, characterized in that: The concentration of zinc ions in the ethyl acetate solution of zinc bis(trifluoromethanesulfonyl)imide is 0.2-3 mol / L.

3. The gravity-independent biphasic electrolyte according to claim 1, characterized in that: The mass ratio of the carboxymethyl cellulose-polyacrylamide copolymer to the volume ratio of the aqueous electrolyte is 0.9 g: (1-20) mL.

4. The gravity-independent biphasic electrolyte according to claim 1 or 3, characterized in that: The concentration of zinc sulfate in the aqueous electrolyte is 0.5-2 mol / L.

5. The gravity-independent biphasic electrolyte according to claim 1, characterized in that: The iodide includes KI, NaI or LiI.

6. The gravity-independent biphasic electrolyte according to claim 1 or 5, characterized in that: The concentration of iodide in the aqueous electrolyte is 0.1-1 mol / L.

7. The gravity-independent biphasic electrolyte according to claim 1, characterized in that: The mass ratio of the organic phase electrolyte to the hydrogel electrolyte is 1:(0.5-2).

8. The method for preparing the gravity-independent biphasic electrolyte according to any one of claims 1 to 7, characterized in that: include: The carboxymethyl cellulose-polyacrylamide copolymer is immersed in an aqueous electrolyte for adsorption to obtain a hydrogel electrolyte; Zinc bis(trifluoromethanesulfonyl)imide is mixed with ethyl acetate to obtain an ethyl acetate solution of zinc bis(trifluoromethanesulfonyl)imide.

9. Use of the gravity-independent biphasic electrolyte according to any one of claims 1 to 7 or the gravity-independent biphasic electrolyte prepared by the preparation method according to claim 8 in an aqueous zinc-iodine battery.

10. An aqueous zinc-iodine battery, characterized in that: It comprises an activated carbon positive electrode, a zinc metal negative electrode and a non-gravity-dependent two-phase electrolyte arranged between the activated carbon positive electrode and the zinc metal negative electrode; the non-gravity-dependent two-phase electrolyte is the non-gravity-dependent two-phase electrolyte described in any one of claims 1 to 7 or the non-gravity-dependent two-phase electrolyte prepared by the preparation method described in claim 8; the hydrogel electrolyte of the non-gravity-dependent two-phase electrolyte is arranged on the zinc metal negative electrode side, and the organic phase electrolyte of the non-gravity-dependent two-phase electrolyte is arranged on the activated carbon positive electrode side.

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