Method for preparing zinc negative electrode in-situ coupled with hydrogel electrolyte and application of the zinc negative electrode in zinc battery

Abstract

This invention discloses a method for preparing a zinc anode with in-situ coupled hydrogel electrolyte and its application in zinc batteries, comprising the following steps: 1) placing the zinc anode in a coupling agent solution and immersing it at 30-50°C for 0.5-5 hours to form a chelate layer linked by coordination bonds on the surface of the zinc anode; 2) reacting the chelated zinc anode from step 1) in a hydrogel precursor solution to obtain a zinc anode with in-situ coupled hydrogel electrolyte via covalent bonds. This invention employs a coupling agent possessing both polar functional groups (chelated with metallic zinc via coordination bonds) and active functional groups (covalently coupled with the hydrogel electrolyte). Through rational formulation design, a rich hydrogen bond network is constructed within the hydrogel electrolyte, forming a synergistic structure of "coordination bond-covalent bond-hydrogen bond," thereby reducing the interfacial resistance between the zinc anode and the electrolyte.

Description

Technical Field

[0001] This invention belongs to the field of battery technology, specifically relating to the preparation method of a zinc anode with in-situ coupled hydrogel electrolyte and its application in zinc batteries. Background Technology

[0002] Driven by the strategic need for the new energy system to evolve towards higher safety, higher reliability, and higher sustainability, there is an urgent need to overcome the bottlenecks of existing energy storage technologies in terms of resource constraints, safety risks, and environmental impact. Lithium resources suffer from high dependence on imports and significant thermal runaway risks, making it difficult to meet the urgent needs of large-scale renewable energy grid integration, long-term grid-side energy storage, and distributed energy systems for intrinsically safe energy storage equipment. Against this backdrop, aqueous zinc batteries, with their advantages of abundant zinc resources, low cost, and no risk of combustion or explosion, have been listed as a key development direction for new energy storage technologies in China. However, traditional aqueous liquid electrolyte systems suffer from key problems such as uncontrollable zinc dendrite formation, severe hydrogen evolution corrosion, and short cycle life, seriously hindering their progress towards ampere-hour-level engineering applications.

[0003] Hydrogel electrolytes, as quasi-solid-state ionic conductors, effectively confine free water molecules through their three-dimensional cross-linked network structure, significantly suppressing side reactions; they can also directionally regulate Zn. 2+ Solvation structure to achieve dense, dendrite-free Zn 2+ Deposition significantly improves battery cycle stability. However, in existing technologies, the hydrogel electrolyte and zinc anode are often simply physically stacked, resulting in high interfacial impedance, making it impossible to obtain a stable zinc battery interface state, and making it difficult to balance the contradiction between the internal ionic conductivity and mechanical properties of the hydrogel electrolyte. Summary of the Invention

[0004] To address the aforementioned problems, the present invention aims to provide a method for preparing a zinc anode with in-situ coupled hydrogel electrolyte, and another objective of the present invention is to provide an application of the zinc anode prepared by this method in zinc batteries.

[0005] To achieve the above objectives, the present invention adopts the following technical solution:

[0006] A method for preparing a zinc anode of an in-situ coupled hydrogel electrolyte includes the following steps:

[0007] 1) Place the zinc anode in a coupling agent solution and soak it at 30~50℃ for 0.5~5 h. Remove it and dry it at 40~60℃ for 4~8 h to form a chelate layer linked by coordination bonds on the surface of the zinc anode. The coupling agent solution is made of a coupling agent with both polar and active functional groups and a solvent for dissolving the coupling agent. The polar functional group of the coupling agent is amino, hydroxyl or thiol, and the active functional group of the coupling agent is olefin, alkyne, thiol or epoxy group.

[0008] 2) The zinc anode modified by chelation in step 1) is placed in the hydrogel precursor solution for reaction to obtain a zinc anode with hydrogel electrolyte covalently coupled in situ on the surface.

[0009] The coupling agent is 4-ethynylaniline, hydroxyethyl methacrylate, N-(2-hydroxyethyl)acrylamide, 3-butyn-1-ol, glycidyl, propylene mercaptan, pentaerythritol tetrakis(3-mercaptopropionic acid), 3,6-dioxa-1,8-octanedithiol, or bis(mercaptoacetic acid) glycol ester. The molar ratio of the coupling agent to the solvent for dissolving the coupling agent is 1:(1~10). The hydrogel precursor solution consists of the following components: monomer solution, zinc salt, and initiator. The monomer solution is prepared by hydrogel monomer, main solvent for dissolving the monomer, and co-solvent for dissolving the monomer in a molar ratio of 1:(5~20):(0.5~2). The molar concentration of zinc salt in the monomer solution is 0.4~4 mol•L. –1 .

[0010] The coupling agent is 4-ethynylaniline (CAS14235-81-5, click reaction type with monomer is thiol-alkynyl), hydroxyethyl methacrylate (CAS868-77-9, click reaction type with monomer is thiol-ene), N-(2-hydroxyethyl)acrylamide (CAS7646-67-5, click reaction type with monomer is thiol-ene), 3-butyn-1-ol (CAS927-74-2, click reaction type with monomer is thiol-alkynyl), glycidyl (CAS556-52-5, click reaction type with monomer is thiol-epoxy) or propylene thiol (CAS870-23-5, click reaction type with monomer is thiol-epoxy). When the coupling agent is of the type thiol-ene, the active functional group of the coupling agent is a non-thiol group, and the hydrogel monomer is a mixture of thiol monomers and alkene monomers, wherein the molar ratio between thiol monomers and alkene monomers is (2~5):1; when the coupling agent is pentaerythritol tetrakis(3-mercaptopropionic acid) ester (CAS7575-23-7), 3,6-dioxa-1,8-octanedithiol (CAS14970-87-7) or bis(mercaptoacetic acid) ethylene glycol ester (CAS123-81-9), the thiol group of the coupling agent is both a polar functional group and an active functional group, and the hydrogel monomer is an alkene monomer, an alkyne monomer or an epoxy monomer, and the click reaction type between the coupling agent and the monomer is thiol-alkene, thiol-alkyne, thiol-epoxy.

[0011] The thiol monomers are trimethylolpropane tris(3-mercaptopropionic acid) ester (CAS 33007-83-9), 3,6-dioxa-1,8-octanedithiol (CAS 14970-87-7), 4,4'-bis(mercaptomethyl)biphenyl (CAS 43012-19-7), or bis(mercaptoacetic acid) glycol ester (CAS 123-81-9); the olefin monomers are polyethylene glycol diacrylate (CAS 26570-48-9), 1,6-divinylperfluorohexane (CAS 1800-91-5), N,N'-methylenebisacrylamide (CAS 110-26-9), or pentaerythritol triacrylate (CAS 3524-68-3); the alkynyl monomers are diynyl polyethylene glycol (commercial compound) or 1,7-octadiyne (CAS 3524-68-3). 871-84-1); the epoxy monomer is polyethylene glycol diglycidyl ether (CAS 72207-80-8) or bisphenol A diglycidyl ether (CAS 1675-54-3).

[0012] The zinc salt is one of ZnSO4, ZnCl2, Zn(OTf)2, Zn(ClO4)2, and Zn(BF4)2; the solvent for dissolving the coupling agent is one of acetonitrile, acetone, ethanol, and N,N-dimethylformamide; the main solvent for dissolving the monomer is water, and the co-solvent for dissolving the monomer is one of ethanol and acetone; when the hydrogel monomer is a thiol monomer, alkene monomer, or alkyne monomer, the initiator is a thermal initiator or a photoinitiator, and the molar ratio of the initiator to the monomer is (0.1~2):100; when the hydrogel monomer is an epoxy monomer, the initiator is an alkaline catalyst, and the molar ratio of the alkaline catalyst to the epoxy monomer is (0.5~5):100.

[0013] The thermal initiator is azobisisobutyronitrile, benzoyl peroxide, or tert-butyl peroxide; the photoinitiator is phenylacetone, 1-hydroxycyclohexyl phenyl ketone, 2-hydroxy-2-methylphenylacetone, or isooctyl p-dimethylaminobenzoate; the base catalyst is 1-methylimidazole, trialkylamine, or diazabicyclo[4.3.0]non-5-ene.

[0014] In step 2), the initiator in the hydrogel precursor solution is a thermal initiator, and the reaction conditions are: temperature 40~70℃, time 0.5~8 h; the initiator in the hydrogel precursor solution is a photoinitiator, and the reaction conditions are: time 5 min~2 h; when the hydrogel monomer in the hydrogel precursor solution is an epoxy monomer, the reaction is driven by an alkaline catalyst, and the reaction conditions are: temperature 40~70℃, time 0.5~8 h.

[0015] Application of the zinc anode prepared by the above method in zinc batteries.

[0016] Zinc batteries consist of a positive electrode and a zinc negative electrode with an in-situ coupled hydrogel electrolyte. By assembling and encapsulating the zinc negative electrode with the in-situ coupled hydrogel electrolyte and the positive electrode, a zinc battery integrating the module, interface and device is obtained without the need for a separator and electrolyte.

[0017] Compared with the prior art, the present invention has the following beneficial effects:

[0018] 1) This invention relies on the chelation coupling principle between polar groups and metallic zinc to assemble hydrogel electrolytes in situ at the zinc anode interface. It uses a coupling agent that has both polar functional groups (chelated with metallic zinc through coordination bonds) and active functional groups (covalently coupled with hydrogel electrolytes). The polar functional group at one end coordinates with the zinc anode, causing the coupling agent to chelate and modify the zinc anode surface. The active functional group at the other end undergoes a click reaction with alkenes, alkynes, thiols, or epoxides, promoting the in-situ covalent coupling of the hydrogel electrolyte to the zinc anode. This constructs a rich hydrogen bond network inside the hydrogel electrolyte, forming a synergistic structure of "coordination bond-covalent bond-hydrogen bond", which reduces the interfacial resistance between the zinc anode and the electrolyte.

[0019] 2) The hydrogel electrolyte used in this invention homogenizes Zn. 2+ The interface distribution state inhibits zinc dendrite growth and side reactions. On the one hand, the hydrogel electrolyte alleviates the corrosion and passivation of the zinc anode by H2O molecules; on the other hand, the polar functional groups chelate the zinc anode, forming polar dynamic channels on the zinc anode surface and inducing Zn... 2+ Uniform deposition prevents zinc dendrite formation, thus providing the first barrier against zinc dendrites. Even if weak dendrite growth occurs, the robust polymer network constructed through the click reaction can prevent it from connecting to the positive electrode of the battery, preventing short circuits within the battery, thus providing the second barrier against zinc dendrites. Thirdly, the use of polar precursors in the click reaction not only significantly enhances the intrinsic polarity of the hydrogel matrix but also induces the formation of multiple hydrogen bond structures that penetrate the network, thereby improving the Zn... 2+ The improved transport environment enhances the mechanical properties of the hydrogel and improves the cycle stability of the zinc battery; at the same time, it ensures good compatibility between the components in the zinc battery and ensures long-term stable cycling of the integrated zinc battery.

[0020] 3) This invention uses click reaction, which is simple, efficient, highly selective in terms of region and strong in terms of stereoselectivity. Attached Figure Description

[0021] Figure 1 This is a graph showing the ionic conductivity of the hydrogel electrolyte prepared in Example 1 of the present invention as a function of temperature.

[0022] Figure 2The coulombic efficiency diagram is shown for a Cu / Zn battery assembled using the zinc anode of the in-situ coupled hydrogel electrolyte prepared in Example 1 of this invention.

[0023] Figure 3 To test the cycling stability of Zn / Zn batteries assembled using the zinc anode of the in-situ coupled hydrogel electrolyte prepared in Example 1 of this invention under extreme test environments with variable rate;

[0024] Figure 4 To test the charge specific capacity cycling performance of the positive electrode / Zn battery assembled using the zinc negative electrode with the in-situ coupled hydrogel electrolyte prepared in Example 1 of this invention;

[0025] Figure 5 This is a schematic diagram of the zinc negative electrode of the in-situ coupled hydrogel electrolyte involved in this invention. Detailed Implementation

[0026] The present invention will be further described below with reference to specific embodiments and accompanying drawings.

[0027] Example 1

[0028] The coupling agent solution is prepared by mixing pentaerythritol tetrakis(3-mercaptopropionic acid) with thiol (polar functional group and active functional group) and acetonitrile in a molar ratio of 1:10.

[0029] The hydrogel precursor solution consists of the following components: monomer solution, zinc salt, and thermal initiator. The monomer solution is prepared by mixing 1,6-divinylperfluorohexane, water, and acetone in a molar ratio of 1:20:2. The zinc salt is ZnSO4, and the molar concentration of ZnSO4 in the monomer solution is 2 mol•L. –1 The thermal initiator is azobisisobutyronitrile, and the molar ratio of the thermal initiator to the hydrogel monomer is 0.5:100.

[0030] A method for preparing a zinc anode of an in-situ coupled hydrogel electrolyte includes the following steps:

[0031] 1) Place a 10 cm × 10 cm zinc anode (zinc foil) in a coupling agent solution (3 mL), soak it at 40 °C for 2 h, take it out, and dry it at 40 °C for 8 h to form a chelating layer linked by zinc-thiol coordination bonds on the surface of the zinc anode.

[0032] 2) The chelated zinc anode from step 1) was placed in a hydrogel precursor solution (3 mL) and reacted at 60℃ for 4 h to obtain a hydrogel electrolyte. The hydrogel electrolyte and the zinc anode were linked by a covalent bond constructed through a thiol-enothermal-initiated click reaction, resulting in a zinc anode with in-situ chelated coupling of the hydrogel electrolyte on its surface. Figure 5 As shown.

[0033] The zinc anode prepared by the above method is used in zinc batteries. The zinc battery includes a positive electrode and a zinc anode with in-situ coupled hydrogel electrolyte. The zinc anode with in-situ coupled hydrogel electrolyte is assembled with the positive electrode without the need for a separator and electrolyte. After encapsulation, an integrated zinc battery of "component-interface-device" is obtained.

[0034] Example 2

[0035] The coupling agent solution is prepared by hydroxyethyl methacrylate and acetone, which simultaneously contain hydroxyl groups (polar functional groups) and olefins (active functional groups), in a molar ratio of 1:5.

[0036] The hydrogel precursor solution consists of the following components: monomer solution, zinc salt, and photoinitiator. The monomer solution is prepared by hydrogel monomer, water, and ethanol in a molar ratio of 1:10:1. The hydrogel monomer is composed of 3,6-dioxa-1,8-octanedithiol and polyethylene glycol diacrylate in a molar ratio of 5:1. The zinc salt is Zn(OTf)₂, and the molar concentration of Zn(OTf)₂ in the monomer solution is 4 mol•L⁻¹. –1 The photoinitiator is phenylacetone, and the molar ratio of the photoinitiator to the hydrogel monomer is 1:100.

[0037] A method for preparing a zinc anode of an in-situ coupled hydrogel electrolyte includes the following steps:

[0038] 1) Place a 10 cm × 10 cm zinc anode (zinc foil) in a coupling agent solution (3 mL), soak it at 50 °C for 0.5 h, take it out, and dry it at 40 °C for 8 h to form a chelate layer linked by zinc-hydroxy coordination bonds on the surface of the zinc anode.

[0039] 2) The chelated zinc anode from step 1) was placed in a hydrogel precursor solution (3 mL) and irradiated with ultraviolet light for 2 h to prepare a hydrogel electrolyte. The hydrogel electrolyte and the zinc anode were linked by a covalent bond constructed through a thiol-ene photo-initiated click reaction, resulting in a zinc anode with in-situ chelated coupling of the hydrogel electrolyte on its surface. Figure 5 As shown.

[0040] The zinc anode prepared by the above method is used in zinc batteries. The zinc battery includes a positive electrode and a zinc anode with in-situ coupled hydrogel electrolyte. The zinc anode with in-situ coupled hydrogel electrolyte is assembled with the positive electrode without the need for a separator and electrolyte. After encapsulation, an integrated zinc battery of "component-interface-device" is obtained.

[0041] Example 3

[0042] The coupling agent solution is prepared by mixing 4-ethynylaniline, which contains both amino (polar functional group) and alkyne (active functional group) and N,N-dimethylformamide in a molar ratio of 1:1.

[0043] The hydrogel precursor solution consists of the following components: monomer solution, zinc salt, and thermal initiator. The monomer solution is prepared by hydrogel monomer, water, and acetone in a molar ratio of 1:5:0.5. The hydrogel monomer is composed of 3,6-dioxa-1,8-octanedithiol and N,N'-methylenebisacrylamide in a molar ratio of 2:1. The zinc salt is Zn(BF4)2, and the molar concentration of Zn(BF4)2 in the monomer solution is 0.4 mol•L. –1 The thermal initiator is benzoyl peroxide, and the molar ratio of the thermal initiator to the hydrogel monomer is 2:100.

[0044] A method for preparing a zinc anode of an in-situ coupled hydrogel electrolyte includes the following steps:

[0045] 1) Place a 10 cm × 10 cm zinc anode (zinc foil) in a coupling agent solution (3 mL), soak it at 30 °C for 5 h, take it out, and dry it at 45 °C for 6 h to form a chelating layer linked by zinc-amino coordination bonds on the surface of the zinc anode.

[0046] 2) The chelated zinc anode from step 1) was placed in a hydrogel precursor solution (3 mL) and reacted at 70℃ for 8 h to obtain a hydrogel electrolyte. The hydrogel electrolyte and the zinc anode were linked by a covalent bond constructed through a thiol-acetylenic thermally initiated click reaction, resulting in a zinc anode with in-situ chelated coupling of the hydrogel electrolyte to its surface. Figure 5 As shown.

[0047] The zinc anode prepared by the above method is used in zinc batteries. The zinc battery includes a positive electrode and a zinc anode with in-situ coupled hydrogel electrolyte. The zinc anode with in-situ coupled hydrogel electrolyte is assembled with the positive electrode without the need for a separator and electrolyte. After encapsulation, an integrated zinc battery of "component-interface-device" is obtained.

[0048] Example 4

[0049] The coupling agent solution is prepared by glycidyl ether and ethanol, which simultaneously contain hydroxyl groups (polar functional groups) and epoxy groups (active functional groups), in a molar ratio of 1:5.

[0050] The hydrogel precursor solution consists of the following components: monomer solution, zinc salt, and alkaline catalyst. The monomer solution is prepared by hydrogel monomer, water, and acetone in a molar ratio of 1:10:1. The hydrogel monomer is composed of ethylene glycol bis(thioglycolic acid) and pentaerythritol triacrylate in a molar ratio of 3:1. The zinc salt is ZnCl2, and the molar concentration of ZnCl2 in the monomer solution is 2 mol·L⁻¹. –1 The alkaline catalyst is diazabicyclo[4.3.0]non-5-ene, and the molar ratio of the alkaline catalyst to the hydrogel monomer is 0.1:100.

[0051] A method for preparing a zinc anode of an in-situ coupled hydrogel electrolyte includes the following steps:

[0052] 1) Place a 10 cm × 10 cm zinc anode (zinc foil) in a coupling agent solution (3 mL), soak it at 40 °C for 3 h, take it out, and dry it at 40 °C for 8 h to form a chelating layer linked by zinc-hydroxy coordination bonds on the surface of the zinc anode.

[0053] 2) The chelated zinc anode from step 1) was placed in a hydrogel precursor solution (3 mL) and reacted at 60℃ for 6 h to obtain a hydrogel electrolyte. The hydrogel electrolyte and the zinc anode were linked by a covalent bond constructed through a thiol-epoxy thermally initiated click reaction, resulting in a zinc anode with in-situ chelated coupling of the hydrogel electrolyte on its surface. Figure 5 As shown.

[0054] The zinc anode prepared by the above method is used in zinc batteries. The zinc battery includes a positive electrode and a zinc anode with in-situ coupled hydrogel electrolyte. The zinc anode with in-situ coupled hydrogel electrolyte is assembled with the positive electrode without the need for a separator and electrolyte. After encapsulation, an integrated zinc battery of "component-interface-device" is obtained.

[0055] Example 5 Performance Testing

[0056] The ionic conductivity of the hydrogel electrolyte prepared in Example 1 as a function of temperature was tested.

[0057] The hydrogel precursor solution from Example 1 was placed in a container and irradiated with ultraviolet light for 2 hours to prepare the hydrogel electrolyte. A stainless steel|hydrogel electrolyte|stainless steel battery was assembled, and the ionic conductivity of the hydrogel electrolyte was determined by AC impedance spectroscopy.

[0058] Test conditions: Test frequency 1M–100 Hz, sinusoidal amplitude 10 mV, test temperature 30–70℃, temperature interval 10℃. The conductivity calculation formula is as follows:

[0059] σ = L / (S×R)

[0060] Where: σ is the ionic conductivity; L is the thickness of the hydrogel electrolyte; S is the actual conductive area in the test; and R is the resistance value of the hydrogel electrolyte obtained in the experiment.

[0061] The ionic conductivity of hydrogel electrolytes as a function of temperature is shown in the following curve. Figure 1 As shown, the hydrogel electrolyte prepared in Example 1 has an ionic conductivity of 7.52 × 10⁻⁶ at 30 °C. –4 S•cm –1 .

[0062] The coulombic efficiency of the Cu / Zn battery assembled with the zinc anode of the in-situ coupled hydrogel electrolyte prepared in Example 1 was tested as follows:

[0063] A copper / zinc battery assembled using the zinc anode with in-situ coupled hydrogel electrolyte prepared in Example 1, with a current of 1 mA·cm⁻¹ –2 The current density was used to charge and discharge the battery at constant current, and the results were as follows: Figure 2 As shown.

[0064] Depend on Figure 2 It can be seen that during the 1000-cycle test, the coulombic efficiency of the battery remained at approximately 99%, indicating that the internal interface stability of the battery system is good, and Zn 2+ Smooth conduction across interfaces within the battery.

[0065] The Zn / Zn battery assembled with an in-situ coupled hydrogel electrolyte zinc anode prepared in Example 1 of this invention was tested for cycle stability under extreme testing environments with varying rates.

[0066] Zn|Zn batteries assembled using the zinc anode with in-situ coupled hydrogel electrolyte prepared in Example 1 were tested at speeds of 0.5, 1, 2, 5, 10, and 20 mA•cm. –2 The current density affects the battery's rate of charge and discharge, and then recovers to 0.5 mA•cm. –2 The battery was subjected to constant rate charge and discharge at a constant current density for an extended period to investigate the cycle stability of the hydrogel electrolyte under extreme test conditions with varying rates.

[0067] Among them, in the initial 0.5 mA•cm –2 Current density was cycled 10 times, followed by cycles at 1, 2, 5, 10, and 20 mA •cm². –2 The current density was cycled 5 times, and recovered to 0.5 mA•cm. –2 The current density was then further increased, and the cycle continued for over 3000 times. The results were as follows: Figure 3 As shown.

[0068] Depend on Figure 3 It is known that the initial value is 0.5 mA•cm. –2 During current density cycling, the polarization voltage was 53 mV. As the current density used in the test increased, the polarization voltage also increased. When the current density recovered to 0.5 mA•cm... –2 During current density cycling, the polarization voltage stabilizes at around 61mV, with little change from the initial state. The system maintains a low polarization potential during long-term cycling, and the battery cycle state is stable, indicating that the hydrogel electrolyte has excellent cycle stability.

[0069] The charge specific capacity and cycle performance of the positive electrode / Zn battery assembled with the in-situ coupled hydrogel electrolyte prepared in Example 1 of this invention were tested:

[0070] Assemble a positive electrode | hydrogel electrolyte | zinc battery, using 1A•g –1 The current density was used to test the battery's charge-to-capacity cycle performance. The results are as follows: Figure 4 As shown.

[0071] Depend on Figure 4 It can be seen that initially, the battery's specific capacity reached 115.8 mAh•g. –1 After 2000 cycles, the battery's specific capacity still reaches 79.5 mAh•g. –1 This indicates that the zinc anode of the hydrogel electrolyte assembled by in-situ chelation coupling on the surface of the present invention still maintains a high specific capacity during long-term cycling, which can ensure good compatibility between the components in the zinc battery, ensure long-term stable cycling of the integrated zinc battery, and show good prospects for battery application.

Claims

1. A method for preparing a zinc negative electrode of an in-situ coupled hydrogel electrolyte, characterized in that, Includes the following steps: 1) Place the zinc anode in a coupling agent solution and soak it at 30~50℃ for 0.5~5 h. Remove and dry it to form a chelate layer connected by coordination bonds on the surface of the zinc anode. The coupling agent solution is made of a coupling agent with both polar and active functional groups and a solvent for dissolving the coupling agent. The polar functional group of the coupling agent is amino, hydroxyl or thiol, and the active functional group of the coupling agent is olefin, alkyne, thiol or epoxy group. 2) The zinc anode modified by chelation in step 1) is placed in the hydrogel precursor solution for reaction to obtain a zinc anode with hydrogel electrolyte covalently coupled in situ on the surface. The coupling agent is 4-ethynylaniline, hydroxyethyl methacrylate, N-(2-hydroxyethyl)acrylamide, 3-butyn-1-ol, glycidyl, propylene mercaptan, pentaerythritol tetrakis(3-mercaptopropionic acid), 3,6-dioxa-1,8-octanedithiol, or bis(mercaptoacetic acid) glycol ester. The molar ratio of the coupling agent to the solvent for dissolving the coupling agent is 1:(1~10). The hydrogel precursor solution consists of the following components: monomer solution, zinc salt, and initiator. The monomer solution is prepared by hydrogel monomer, main solvent for dissolving the monomer, and co-solvent for dissolving the monomer in a molar ratio of 1:(5~20):(0.5~2). The molar concentration of zinc salt in the monomer solution is 0.4~4 mol•L. –1 ; When the coupling agent is 4-ethynylaniline, hydroxyethyl methacrylate, N-(2-hydroxyethyl)acrylamide, 3-butyn-1-ol, glycidyl ether, or propylene mercaptan, the hydrogel monomer is a mixture of thiol monomers and olefin monomers, with a molar ratio of thiol monomers to olefin monomers of (2~5):1; when the coupling agent is pentaerythritol tetrakis(3-mercaptopropionic acid), 3,6-dioxa-1,8-octanedithiol, or bis(mercaptoacetic acid) ethylene glycol ester, the hydrogel monomer is an olefin monomer, an alkyne monomer, or an epoxy monomer. In step 2), the initiator in the hydrogel precursor solution is a thermal initiator, and the reaction conditions are: temperature 40~70℃, time 0.5~8 h; the initiator in the hydrogel precursor solution is a photoinitiator, and the reaction conditions are: time 5 min~2 h; when the hydrogel monomer in the hydrogel precursor solution is an epoxy monomer, the reaction is driven by an alkaline catalyst, and the reaction conditions are: temperature 40~70℃, time 0.5~8 h.

2. The method for preparing the zinc negative electrode of the in-situ coupled hydrogel electrolyte as described in claim 1, characterized in that, The thiol monomers are trimethylolpropane tris(3-mercaptopropionic acid), 3,6-dioxa-1,8-octanedithiol, 4,4'-bis(mercaptomethyl)biphenyl, or bis(mercaptoacetic acid) glycol ester; the olefin monomers are polyethylene glycol diacrylate, 1,6-divinylperfluorohexane, N,N'-methylenebisacrylamide, or pentaerythritol triacrylate; the alkynyl monomers are diynyl polyethylene glycol or 1,7-octadiyne; and the epoxy monomers are polyethylene glycol diglycidyl ether or bisphenol A diglycidyl ether.

3. The method for preparing the zinc negative electrode of the in-situ coupled hydrogel electrolyte as described in claim 2, characterized in that, The zinc salt is one of ZnSO4, ZnCl2, Zn(OTf)2, Zn(ClO4)2, and Zn(BF4)2; the solvent for dissolving the coupling agent is one of acetonitrile, acetone, ethanol, and N,N-dimethylformamide; the main solvent for dissolving the monomer is water, and the co-solvent for dissolving the monomer is one of ethanol and acetone; when the hydrogel monomer is a thiol monomer, alkene monomer, or alkyne monomer, the initiator is a thermal initiator or a photoinitiator, and the molar ratio of the initiator to the hydrogel monomer is (0.1~2):100; when the hydrogel monomer is an epoxy monomer, the initiator is an alkaline catalyst, and the molar ratio of the alkaline catalyst to the epoxy monomer is (0.5~5):

100.

4. The method for preparing the zinc negative electrode of the in-situ coupled hydrogel electrolyte as described in claim 3, characterized in that, The thermal initiator is azobisisobutyronitrile, benzoyl peroxide, or tert-butyl peroxide; the photoinitiator is phenylacetone, 1-hydroxycyclohexyl phenyl ketone, 2-hydroxy-2-methylphenylacetone, or isooctyl p-dimethylaminobenzoate; the base catalyst is 1-methylimidazole, trialkylamine, or diazabicyclo[4.3.0]non-5-ene.

5. The application of the zinc anode prepared by any one of claims 1-4 in zinc batteries.

6. The application as described in claim 5, characterized in that, A zinc battery consists of a positive electrode and a zinc negative electrode with an in-situ coupled hydrogel electrolyte. The zinc negative electrode with the in-situ coupled hydrogel electrolyte is assembled and packaged with the positive electrode to obtain an integrated zinc battery with components, interfaces and devices.

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