Preparation method of organic co-crystal gel electrolyte, zinc metal battery

Abstract

The application provides a preparation method of an organic co-crystal gel electrolyte and a zinc metal battery, and belongs to the technical field of gel electrolytes. The preparation method utilizes a new type of gel electrolyte formed by in-situ compounding of organic co-crystals and gels through ultraviolet light. The organic co-crystal gel electrolyte can form a more stable crystal structure in different environments through non-covalent bond interactions such as hydrogen bonds and van der Waals forces between components, effectively avoiding the problems of instability and poor solubility of organic small molecules in electrolytes. The co-crystals can also combine different functional organic small molecule components to achieve functional complementation and synergistic enhancement, thereby achieving balanced optimization of stability and specific capacity, and solving the problems that existing gel electrolytes cannot simultaneously solve the problems of dendrite growth, corrosion and hydrogen evolution of zinc negative electrodes, and the limited regulation ability of the solvation structure at the zinc interface and the electrode / electrolyte interface.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of gel electrolyte, and particularly relates to a preparation method of an organic co-crystal gel electrolyte and a zinc metal battery. BACKGROUND

[0002] As a strong contender for the next generation of energy storage technology, aqueous zinc metal batteries have attracted widespread attention due to their high safety, low cost and environmental friendliness. As a core component of the battery, the performance of the electrolyte directly determines the overall performance of the battery. Traditional liquid electrolytes have high ionic conductivity, but their inherent problems are also very prominent: the narrow electrochemical window of water limits the operating voltage of the battery; the side reactions between water molecules and the zinc negative electrode, such as hydrogen evolution and corrosion, can lead to poor cycle stability of the battery, and there is also a risk of liquid leakage.

[0003] In order to overcome the above-mentioned defects, researchers have developed gel polymer electrolytes, which fix water and zinc salts through a polymer network to form a quasi-solid-state electrolyte with good mechanical properties and ionic conduction ability. This type of electrolyte not only inhibits the growth of zinc dendrites, but also improves the flexibility and safety of the battery. However, existing gel electrolyte technology still faces many challenges. In order to improve performance, researchers often use inorganic fillers such as silica or zinc oxide to enhance mechanical strength; or add organic small molecules such as ethylene glycol or glycerol to reduce water activity and inhibit side reactions. However, these methods can only solve a single problem, and even bring new drawbacks, such as inorganic particles that easily agglomerate, affecting the uniformity of ion transport; or organic small molecules that may precipitate during the cycle process, leading to performance degradation. More fundamentally, existing strategies lack synergistic effects and cannot simultaneously solve the multiple problems of zinc negative electrode, such as dendrite growth, corrosion and hydrogen evolution. On the other hand, existing additives have limited ability to regulate the solvation structure at the zinc interface and the electrode / electrolyte interface, making it difficult to fundamentally improve the uniformity of zinc deposition and the stability of the interface.

[0004] Therefore, developing a new electrolyte system that can simultaneously solve the above-mentioned problems is a key to promoting the commercial application of aqueous zinc ion batteries. SUMMARY

[0005] In view of the problems existing in the background art, the purpose of the present application is to provide a preparation method of an organic co-crystal gel electrolyte and a zinc metal battery. The preparation method uses a new type of gel electrolyte formed by in-situ compounding of organic co-crystals and gels through ultraviolet light, which solves the problems of existing gel electrolytes that cannot simultaneously solve the problems of zinc negative electrode, such as dendrite growth, corrosion and hydrogen evolution, and the limited ability to regulate the solvation structure at the zinc interface and the electrode / electrolyte interface.

[0006] To achieve the above-mentioned purposes, the technical solutions of the present application are as follows:

[0007] A preparation method of an organic co-crystal gel electrolyte, comprising the following steps:

[0008] S1, dissolving an electron acceptor (A) and an electron donor (D) in an organic solvent to obtain a mixed solution, then the mixed solution is heated by ultrasonic, naturally volatilized and cleaned to obtain an organic co-crystal;

[0009] S2, mixing a polymer, a photoinitiator and the organic co-crystal, adding a zinc salt solution to obtain a gel pre-polymer solution;

[0010] S3, the gel pre-polymer solution obtained in S2 is subjected to ultraviolet irradiation, and the reaction obtains an organic co-crystal gel electrolyte.

[0011] Further, the electron acceptor is one or more of 1,2,4,5-tetracyano benzene (TCNB), 7,7,8,8-tetracyanoquinodimethane (TCNQ) and 4,8-bis(dicyanomethylene)-4,8-dihydrobenzo[1,2-b:4,5-b’]-dithiophene (DTTCNQ).

[0012] Further, the electron donor is one or more of naphthobenzofuran (BNF), 1,4,8,11-tetramethyl-6,13-triethylsilacetylene pentacene (TM) and indolo[2,3-B]carbazole (5,7-ICN).

[0013] Further, in S1, the organic solvent is one or more of dichloroethane or tetrahydrofuran; and the cleaning uses petroleum ether.

[0014] Further, in S1, the molar ratio of the electron acceptor to the electron donor is 2:(1-4); and the total concentration of the electron acceptor and the electron donor in the mixed solution is 1-5 mg / mL.

[0015] Further, in S2, the mass ratio of the polymer, the photoinitiator and the organic co-crystal is (5-20):1:(1-3).

[0016] Further, the polymer is one or more of acrylamide, N,N'-methylenebisacrylamide, polyvinyl alcohol, polyethylene glycol or sodium carboxymethyl cellulose.

[0017] Further, the photoinitiator is one or more of 2,4,6-(trimethylbenzoyl)-diphenyl phosphine oxide, 1-hydroxycyclohexyl phenyl ketone or 2-hydroxy-2-methyl-1-phenyl-1-propanone.

[0018] Further, the zinc salt solution is one or more of ZnSO4, Zn(OTF)2, ZnCl2 or Zn(NO3)2; the concentration of the zinc salt solution is 0.5-3 mol / L.

[0019] Further, in S3, the ultraviolet wavelength is 254-365 nm.

[0020] A zinc metal battery comprises a positive electrode, an organic co-crystal gel electrolyte and a negative electrode.

[0021] The negative electrode is a zinc electrode, and the positive electrode is one or more of VO2, V2O5 or NaVO3.

[0022] Further, the thickness of the zinc electrode is 30-100 μm, and the thickness of the organic co-crystal gel electrolyte is 0.8-1.2 mm.

[0023] The mechanism of the present application is as follows:

[0024] The organic co-crystal gel electrolyte provided by the present application is a new quasi-solid electrolyte system formed by in-situ compounding of organic co-crystal and gel polymer network using ultraviolet light. This system is different from traditional deep eutectic solvents or simple gel systems. The organic co-crystal, as a functional crystal unit, can exist in a stable and uniform dispersed form in the gel network. The co-crystal is self-assembled from two or more components in a specific stoichiometric ratio. The components are connected by non-covalent interactions such as hydrogen bonds, halogen bonds, π-π stacking and charge transfer interactions, to construct a highly ordered supramolecular crystal structure. In the compounding process induced by ultraviolet light, these co-crystal molecules and gel polymer segments are tightly combined through non-covalent interactions, so that the co-crystal microcrystal region and the flexible gel network are mutually penetrating and stable, thereby constructing an electrolyte framework with both rigid support and flexible adjustment, and embedding or crosslinking in the three-dimensional network of the gel. Benefiting from this molecular-level interaction, the organic co-crystal does not precipitate or agglomerate in the gel, but forms a stable and uniformly distributed crystal microregion, realizing the coordination and unity of crystalline order and flexible gel network.

[0025] In this composite system, the solid-state packing structure of organic co-crystals and the polymer network of gels complement each other to jointly build continuous ion conduction channels and stable interface environments. On the one hand, the ordered lattice of co-crystals and the polar functional groups (such as cyano, ethynyl, thiophene ring, etc.) inside can effectively regulate the electronic structure and the solvation environment of zinc ions. The electron-attracting effect of cyano can improve the electrical conductivity and ion transport capacity of the material; the conjugated electronic structure of the thiophene ring helps to promote the reversible deposition and stripping of zinc ions; the high electron density of the ethynyl group enhances the electron transfer rate; the presence of the benzene ring skeleton further improves the structural stability of the system, reducing the volume change during charging and discharging. The synergistic effect of these molecular functional groups makes the deposition of zinc ions more uniform, fundamentally inhibiting the formation and growth of dendrites.

[0026] On the other hand, the gel network provides a stable dispersion carrier for organic co-crystals, and its flexible three-dimensional structure not only ensures the mechanical integrity of the electrolyte, but also inhibits the free movement of active water molecules through confinement effects, thereby reducing the probability of water reduction side reactions. The interaction between co-crystal molecules and gel segments can also regulate the solvation structure of the system, reduce the content of active water, and increase the Gibbs free energy of the system, inhibiting the kinetics of water decomposition reactions and significantly reducing hydrogen evolution. Compared to traditional liquid electrolytes or physically mixed small molecule additive systems, this in-situ composite organic co-crystal gel structure has higher stability and longer cycle life, and does not cause small molecule precipitation or performance degradation due to high pressure or long-term operation.

[0027] In summary, due to the adoption of the above technical solutions, the application has the following beneficial effects:

[0028] The electron donor-electron acceptor organic co-crystal gel electrolyte provided by the application can realize multiple regulation and optimization of electrochemical performance through the synergistic effect of the co-crystal system and the gel network. The supramolecular crystal structure of the organic co-crystal in the electrolyte not only gives the co-crystal stable crystalline properties and intermolecular interaction networks, but also enables it to exist in the form of uniform dispersion and firm combination in the gel polymer.

[0029] In this system, the electron donor and the electron acceptor each assume different but complementary functions. The electron donor molecule has excellent electron transport capacity and chemical stability, and can preferentially adsorb on the surface of the zinc electrode to form a dense and uniform interface protection layer. This protection layer can effectively inhibit local electric field concentration and the disordered growth of dendrites, thereby improving the deposition uniformity and cycle stability of the zinc negative electrode. At the same time, the electron acceptor molecule, with its strong electrochemical activity and coordination ability, can form a stable coordination complex with Zn 2+The stable coordination structure is formed, the original solvation environment is changed, the ion migration path is optimized, and thus the transmission kinetics is improved and the polarization is reduced. The charge transfer interaction between the donor and the acceptor not only enhances the electronic coupling effect of the system, but also provides a more continuous transmission channel for the conductivity of the electrolyte and the interface electrochemical reaction.

[0030] Compared with the traditional single small molecule added electrolyte system, the electron donor-electron acceptor organic co-crystal gel electrolyte constructed by the application can maintain a high stability of the crystal structure under different electrochemical environments due to the multiple non-covalent interactions between the components, avoiding the problems such as dissolution, precipitation and decomposition commonly seen in the small molecule system. The synergistic combination of different functional components in the co-crystal enables the system to have dual channels for electron and ion transmission, realizing functional complementation and performance synergy. Meanwhile, the gel matrix provides a three-dimensional confined space and flexible network support on this basis, not only preventing the aggregation of co-crystal microcrystals, but also reducing the participation of active water through the confinement effect, further inhibiting the occurrence of hydrogen evolution reaction.

[0031] The synergistic mechanism of the co-crystal-gel enables the electrochemical stability window of the electrolyte to be significantly widened, the water decomposition side reaction to be effectively inhibited, and the battery assembled by the electrolyte to exhibit higher initial specific capacity and capacity retention rate, the dendrite generation in the cycle process to be effectively inhibited, the interface reaction to be more controllable, and the dissolution problem of the vanadium-based positive electrode to be obviously alleviated. Thus, the organic co-crystal gel electrolyte of the application realizes high energy density and long cycle life, and provides a new material solution for the safety and reliability of the aqueous zinc battery. BRIEF DESCRIPTION OF DRAWINGS

[0032] Figure 1 The figure is a crystal packing structure of the organic co-crystal.

[0033] Figure 2 The figure is an XRD spectrum of the organic co-crystal.

[0034] Figure 3 The figure is an FT-IR spectrum of the organic co-crystal.

[0035] Figure 4 The figure is an optical photo of different gel electrolytes.

[0036] Figure 5 The figure is a picture of different gel electrolytes under ultraviolet irradiation.

[0037] Figure 6 The figure is a charge-discharge test graph of the symmetrical battery composed of different gel electrolytes.

[0038] Figure 7 The figure is a cycle performance curve of the full battery composed of different gel electrolytes.

[0039] Figure 8A graph for capacity retention performance of a full cell with different gel electrolyte compositions. DETAILED DESCRIPTION

[0040] In order to make the objectives, technical solutions and advantages of the present application clearer, the present application will be further described in detail below with reference to the embodiments and drawings.

[0041] Embodiment 1

[0042] A preparation method of an organic co-crystal gel electrolyte comprises:

[0043] S1, dissolving an electron acceptor and an electron donor in an organic solvent to obtain a mixed solution, the mixed solution is subjected to ultrasonic heating and natural volatilization after standing, and then is washed with petroleum ether to obtain an organic co-crystal;

[0044] The electron acceptor is 1,2,4,5-tetracyano benzene; the electron donor is naphthobenzofuran; and the organic solvent is dichloroethane;

[0045] The molar ratio of the electron acceptor to the electron donor is 2:1; and the concentration of the mixed solution is 1 mg / mL;

[0046] S2, mixing a polymer, a photoinitiator and the organic co-crystal, and then adding a zinc salt solution to obtain a gel pre-polymer solution;

[0047] The mass ratio of the polymer, the photoinitiator and the organic co-crystal is 5:1:1;

[0048] The polymer is polyvinyl alcohol; the photoinitiator is 2,4,6-(trimethylbenzoyl)-diphenyl phosphine oxide; and the zinc salt solution is a ZnSO4 solution, and the concentration of the zinc salt solution is 0.5 mol / L;

[0049] S3, placing the gel pre-polymer solution on the surface of a zinc electrode, and reacting in situ on the surface of the zinc electrode under ultraviolet irradiation to obtain the organic co-crystal gel electrolyte; the ultraviolet wavelength is 254 nm; and the thickness of the zinc electrode is 30 μm.

[0050] Embodiment 2

[0051] A preparation method of an organic co-crystal gel electrolyte comprises:

[0052] S1, dissolving an electron acceptor and an electron donor in an organic solvent to obtain a mixed solution, the mixed solution is subjected to ultrasonic heating and natural volatilization after standing, and then is washed with petroleum ether to obtain an organic co-crystal;

[0053] The electron acceptor is 7,7,8,8-tetracyano-p-quinodimethane; the electron donor is 1,4,8,11-tetramethyl-6,13-triethylsilacetylene pentacene; and the organic solvent is tetrahydrofuran;

[0054] The molar ratio of the electron acceptor to the electron donor is 2:4; the concentration of the mixed solution is 5 mg / mL;

[0055] S2, after mixing the polymer, the photoinitiator and the organic co-crystal, the zinc salt solution is added to obtain a gel pre-polymer solution;

[0056] The mass ratio of the polymer, the photoinitiator and the organic co-crystal is 20:1:3;

[0057] The polymer is polyethylene glycol; the photoinitiator is 1-hydroxycyclohexyl phenyl ketone; the zinc salt solution is Zn(OTF)2 solution; the concentration of the zinc salt solution is 3 mol / L;

[0058] S3, the gel pre-polymer solution is reacted on the surface of a zinc electrode under ultraviolet irradiation to obtain an organic co-crystal gel electrolyte; the ultraviolet wavelength is 365 nm; the thickness of the zinc electrode is 100 μm.

[0059] Embodiment 3

[0060] A preparation method of an organic co-crystal gel electrolyte, comprising:

[0061] S1, dissolving an electron acceptor and an electron donor in an organic solvent to obtain a mixed solution, the mixed solution is washed by petroleum ether after ultrasonic heating and natural standing to obtain an organic co-crystal;

[0062] The electron acceptor is 7,7,8,8-tetracyanoquinodimethane and 4,8-bis(dicyanomethylene)-4,8-dihydrobenzo[1,2-b:4,5-b’]-dithiophene with a mass ratio of 1:1; the electron donor is 1,4,8,11-tetramethyl-6,13-triethylsilacetylene pentacene and indolino[2,3-B]carbazole with a mass ratio of 1:1; the organic solvent is dichloroethane and tetrahydrofuran with a volume ratio of 1:1;

[0063] The molar ratio of the electron acceptor to the electron donor is 2:3; the concentration of the mixed solution is 3 mg / mL;

[0064] S2, after mixing the polymer, the photoinitiator and the organic co-crystal, the zinc salt solution is added to obtain a gel pre-polymer solution;

[0065] The mass ratio of the polymer, the photoinitiator and the organic co-crystal is 10:1:2;

[0066] The polymer is carboxymethyl cellulose sodium; the photoinitiator is 2,4,6-(trimethylbenzoyl)-diphenyl phosphine oxide and 2-hydroxy-2-methyl-1-phenyl-1-propanone with a mass ratio of 1:1; the zinc salt solution is ZnCl2 and ZnNO3 solution with a mass ratio of 1:1; the concentration of the zinc salt solution is 2 mol / L;

[0067] S3, the gel prepolymer solution is reacted on the surface of the zinc electrode under ultraviolet irradiation to obtain an organic co-crystal gel electrolyte; the ultraviolet wavelength is 302 nm; the thickness of the zinc electrode is 80 pm.

[0068] Example 4

[0069] A preparation method of an organic co-crystal gel electrolyte comprises:

[0070] S1, dissolving an electron acceptor and an electron donor in an organic solvent to obtain a mixed solution, the mixed solution is obtained after ultrasonic heating and natural standing and evaporation, and is washed by petroleum ether to obtain an organic co-crystal;

[0071] The electron acceptor is 4,8-bis(dicyanomethylene)-4,8-dihydrobenzo[1,2-b:4,5-b’]-dithiophene; the electron donor is 1,4,8,11-tetramethyl-6,13-triethylsilacetylene pentacene; the organic solvent is dichloroethane and tetrahydrofuran in a volume ratio of 1:1;

[0072] The molar ratio of the electron acceptor to the electron donor is 1:1; the concentration of the mixed solution is 1 mg / mL;

[0073] S2, mixing a polymer, a photoinitiator and an organic co-crystal, and adding a zinc salt solution to obtain a gel prepolymer solution;

[0074] The mass ratio of the polymer, the photoinitiator and the organic co-crystal is (5-20):1:(1-3);

[0075] The polymer is acrylamide and N,N’-methylene bisacrylamide in a mass ratio of 50:1; the photoinitiator is 2,4,6-(trimethylbenzoyl)-diphenyl phosphine oxide; the zinc salt solution comprises: Zn(OTF)2 solution; the concentration of the zinc salt solution is 3 mol / L;

[0076] S3, the gel prepolymer solution is reacted on the surface of the zinc electrode under ultraviolet irradiation to obtain an organic co-crystal gel electrolyte; the ultraviolet wavelength is 365 nm; the thickness of the zinc electrode is 80 pm.

[0077] Comparative Example 1

[0078] The gel electrolyte is prepared according to the steps of Example 4, S1 is not performed, and the organic co-crystal in S2 is removed, and the other steps remain unchanged.

[0079] Comparative Example 2

[0080] The gel electrolyte is prepared according to the steps of Example 4, and only the electron donor is not added in S1, and the other steps remain unchanged.

[0081] Comparative Example 3

[0082] The gel electrolyte was prepared according to the procedure of Example 4, except that no electron acceptor was added in S1, and other steps were unchanged.

[0083] Comparative Example 4

[0084] The gel electrolyte was prepared according to the procedure of Example 4, except that S1 was not performed, and the organic co-crystal in S2 was replaced by an electron donor and an electron acceptor, and other steps were unchanged.

[0085] The crystal packing structure of the organic co-crystal prepared in Example 4 is shown in Figure 1 . The donor and acceptor molecules co-crystallize in a 1:1 molar ratio and are arranged in a mixed packing manner. The organic co-crystal grows preferentially along the a-axis direction, and the distance between the D-A molecules is 3.52 Å, indicating strong π-π interaction. Along the direction of the donor-acceptor molecular packing, there is a S…C short contact interaction between the donor and acceptor molecules, with a distance of 3.496 Å, in addition to a C-H…N hydrogen bond interaction with a distance of 2.697 Å, and the acceptor molecules are fixed by four donor molecules through the above-mentioned weak interaction forces, effectively stabilizing the supramolecular framework and eliminating the disorder of the acceptor molecules.

[0086] The grown organic co-crystal was characterized by X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FT-IR), and the characterization results are shown in Figure 2 and Figure 3 . The XRD spectrum of Figure 2 shows that the diffraction peaks of the organic co-crystal powder have obvious differences compared with the D / A single component, meaning that the donor and acceptor molecules form a highly ordered organic co-crystal structure through solution self-assembly. The FT-IR results show that the C≡N stretching vibration peaks of the acceptor molecule and the co-crystal are located at 2214 cm⁻ 1 and 2212 cm⁻ 1 , respectively. The slight shift of the characteristic peak proves the existence of charge transfer interaction between the DA molecules.

[0087] The optical photographs of the blank gel of Comparative Example 1, the gel of Comparative Example 2 only doped with D, the gel of Comparative Example 3 only doped with A, the physical addition gel of Comparative Example 4, and the organic co-crystal gel of Example 4 are shown in Figure 4As shown in the figure. The results show that Comparative Example 3, with only A added, did not polymerize, while Comparative Example 4, although its viscosity increased, still did not polymerize; Comparative Examples 1, 2, and 4 successfully polymerized, forming quasi-solid gel electrolytes. This is because A may consume free radicals from the photoinitiator, thus causing the polymer crosslinking to fail; at the same time, physically added D+A exhibits partial molecular recognition in solution, resulting in increased viscosity. The successful synthesis of the organic eutectic gel indicates that it forms a stable crystal structure through non-covalent bond forces, preventing A from consuming free radicals. This marks a fundamental difference between organic eutectic gels and those with physically added D+A.

[0088] Figure 5 Images of different gel electrolytes under UV irradiation. The physically added gel in Comparative Example 4 exhibits fluorescence under UV light, while the organic eutectic in Example 4 does not, further proving the aforementioned point.

[0089] Since the gels of Comparative Example 3 (with only A added) and Comparative Example 4 (with physical addition of D+A) did not polymerize, the positive and negative electrodes of the battery would come into direct contact and short-circuit. Therefore, these two electrolytes cannot be used to assemble batteries.

[0090] Therefore, the blank gel of Comparative Example 1, the gel of Comparative Example 2 with only added D, and the organic eutectic gel of Example 4 were used to assemble button cells, and charge-discharge tests were performed on a Blue Battery testing system. The button cell assembly process was as follows: the negative electrode shell, spring, gasket, zinc negative electrode, gel electrolyte, vanadium positive electrode, and positive electrode shell were sequentially packaged to obtain a zinc metal battery; VO2 was used as the vanadium positive electrode. The results of the symmetrical cells are as follows... Figure 6 As shown, at 0.5 mA•cm -2 and 0.5mAh•cm -2 Under the specified conditions, the blank gel, the gel with only added D, and the organic eutectic gel were run for 155, 862, and 1562 hours, respectively. The gel with only added D showed a significant growth compared to the blank gel, but it was still insufficient compared to the organic eutectic gel of Example 4. This indicates that the organic eutectic gel electrolyte can be synergistically optimized by D and A, inducing uniform electroplating / stripping of zinc ions at the interface and forming a uniform protective layer, thereby better suppressing the growth of zinc dendrites and ensuring the cycle stability of the battery during long-term operation.

[0091] Full cell results as follows Figure 7 and Figure 8 As shown, the initial capacity of the gel with added organic eutectic (186.6 mAh•g) -1 The capacity retention after 5000 cycles (57.2%) was significantly higher than that of the gel with only added D (184.7 mAh•g). -1 (and 40.4%) and blank gel (165 mAh•g)-1 and 28.4%)greatly improved. By the effect of full-cell cycling, it is speculated that the organic co-crystal gel changes the solvation environment of Zn 2+ , improves the transmission kinetics, and better inhibits the dissolution of the vanadium positive electrode, avoiding excessive capacity reduction and loss.

[0092] The combination of D and A in the organic co-crystal grows, compared with a single organic small molecule, the co-crystal can better realize functional complementation and synergistic enhancement, and then realize the balance optimization of the cycle stability and specific capacity in the symmetric battery and full battery. The combination of the organic co-crystal and the gel electrolyte can more effectively solve the current liquid electrolyte leakage, dendrite growth, serious hydrogen evolution, inorganic additive easy polymerization, single organic small molecule instability, zinc interface electroplating / peeling uneven, vanadium positive electrode easy to dissolve and ordinary gel poor cycle stability and other limitations, and further possibility is brought for realizing long cycle and high performance zinc metal battery.

[0093] The above is only a specific embodiment of the present application, any feature disclosed in the specification can be replaced by other equivalent or similar purpose alternative features unless specifically described; all features disclosed, or steps in all methods or processes, except for mutually exclusive features and / or steps, can be combined in any way.

Claims

1. A method for producing an organic co-crystal gel electrolyte, characterized by, The method comprises the following steps: S1, dissolving an electron acceptor and an electron donor in an organic solvent to obtain a mixed solution, then the mixed solution is heated by ultrasonic, naturally volatilized by standing, and washed to obtain an organic co-crystal; the electron acceptor is one or more of 1,2,4,5-tetracyano benzene, 7,7,8,8-tetracyano p-phenylenediamine and 4,8-bis(dicyanomethylene)-4,8-dihydrobenzo[1,2-b:4,5-b']-dithiophene; the electron donor is one or more of naphthobenzofuran, 1,4,8,11-tetramethyl-6,13-triethylsilacetylene pentacene and indolino[2,3-B] carbazole; S2, mixing a polymer, a photoinitiator and the organic co-crystal, adding a zinc salt solution to obtain a gel pre-polymer solution; the polymer is one or more of acrylamide, N,N'-methylene bisacrylamide, polyvinyl alcohol, polyethylene glycol or sodium carboxymethyl cellulose; the photoinitiator is one or more of 2,4,6-(trimethylbenzoyl)-diphenyl phosphine oxide, 1-hydroxycyclohexyl phenyl ketone or 2-hydroxy-2-methyl-1-phenyl-1-propanone; S3, the gel pre-polymer solution obtained in S2 is subjected to ultraviolet irradiation, and an organic co-crystal gel electrolyte is obtained by reaction.

2. The method for preparing an organic co-crystal gel electrolyte according to claim 1, wherein In S1, the molar ratio of the electron acceptor to the electron donor is 2:(1-4); the total concentration of the electron acceptor and the electron donor in the mixed solution is 1-5 mg / mL. 3.The method of claim 1, wherein the organic co-crystal gel electrolyte is prepared by the steps of: (a) dissolving the organic co-crystal in a solvent; (b) adding the electrolyte salt to the organic co-crystal solution; and (c) stirring the mixture. In S1, the organic solvent is one or more of dichloroethane or tetrahydrofuran; petroleum ether is used for washing.

4. The method of claim 1, wherein the organic co-crystal gel electrolyte is prepared by the steps of: (a) dissolving the organic co-crystal in a solvent; (b) adding the electrolyte salt to the organic co-crystal solution; and (c) stirring the mixture. In S2, the mass ratio of the polymer, the photoinitiator and the organic co-crystal is (5-20):1:(1-3).

5. The method of claim 1, wherein the organic co-crystal gel electrolyte is prepared by the steps of: (a) dissolving the organic co-crystal in a solvent; (b) adding the electrolyte salt to the organic co-crystal solution; and (c) stirring the mixture. The zinc salt solution is one or more of ZnSO4, Zn(OTF)2, ZnCl2 or Zn(NO3)2; the concentration of the zinc salt solution is 0.5-3 mol / L.

6. The method of claim 1, wherein the organic co-crystal gel electrolyte is prepared by the steps of: (a) dissolving the organic co-crystal in a solvent; (b) adding the electrolyte salt to the organic co-crystal solution; and (c) stirring the mixture. In S3, the wavelength of the ultraviolet light in the ultraviolet irradiation is 254-365 nm.

7. A zinc metal battery, characterized by, The method comprises a positive electrode, an organic co-crystal gel electrolyte prepared by the preparation method of any one of claims 1-6, and a negative electrode; The negative electrode is a zinc electrode, and the positive electrode is one or more of VO2, V2O5 or NaVO3.

8. The zinc metal battery of claim 7, wherein, The thickness of the zinc electrode is 30-100 μm, and the thickness of the organic co-crystal gel electrolyte is 0.8-1.2 mm.

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