Preparation and application of carboxylated cellulose-based flexible zinc dendrite-resistant hydrogel electrolyte

Abstract

The present invention discloses the preparation and application of a carboxylated cellulose-based flexible zinc dendrite-resistant hydrogel electrolyte, comprising the following steps: (1) dissolving cellulose and a high molecular weight polymer in an organic base / CO2 / organic solvent system to obtain product A; (2) first adding a monoanhydride functional group compound to product A for a derivatization reaction to obtain product B; (3) cooling product B and adding a polyanhydride functional group compound, mixing and stirring uniformly, and pouring into a mold to obtain product C; (4) displacing product C with pure water to neutrality to obtain a carboxylated cellulose-based hydrogel; (5) soaking the carboxylated cellulose-based hydrogel in a zinc-containing electrolyte salt solution to obtain a carboxylated cellulose-based flexible zinc dendrite-resistant hydrogel electrolyte. The present invention utilizes the organic base / organic solvent / CO2 system to design a hydrogel electrolyte that solves the serious zinc dendrite problem of aqueous ZIHCs and improves the mechanical strength of the gel electrolyte.

Description

Technical Field

[0001] The present invention belongs to the technical field of zinc ion hybrid capacitors, and more specifically, relates to a preparation method and application of a carboxylated cellulose-based flexible zinc dendrite-resistant hydrogel electrolyte. Background Art

[0002] Aqueous zinc-ion hybrid capacitors (ZIHCs) combine the advantages of safety and low investment costs, promising applications in large-scale grid energy storage, wearable electronics, and other fields, making them one of the most promising energy storage systems. Aqueous ZIHCs, as hybrid supercapacitors, are typically composed of a battery-type Zn metal anode, a capacitive cathode (porous carbon materials are the most widely studied), and an aqueous electrolyte. Unlike Zn-ion battery cathodes, porous carbon cathodes primarily store charge through electric double-layer capacitance (EDLC) and surface pseudocapacitance. The highly reversible charge storage mechanism of the porous carbon cathodes gives ZIHCs an exceptionally long life. The Zn anode stores charge through zinc plating and stripping, endowing ZIHCs with high capacity. Furthermore, the low redox potential of the Zn anode combined with the carbon cathode allows aqueous ZIHCs to offer a higher voltage window (≈1.6-1.8 V) than symmetric C||C supercapacitors (≈1 V). Due to this hybrid configuration, ZIHCs can bridge the energy density gap between supercapacitors and batteries.

[0003] However, metal batteries and capacitors are inevitably affected by the dendrite problem. This is due to the uneven diffusion and deposition of ions on the metal anode, which causes metal batteries and capacitors to suffer from severe dendrite problems for a long time, making it difficult to achieve satisfactory safety and service life. This problem greatly limits the commercial application of ZIHCs. In order to solve these problems, some researchers have proposed a new type of ZIHCs gel electrolyte, which is a quasi-solid electrolyte sandwiched between the positive and negative electrodes, and can overcome the above problems to a certain extent. Although various ZIHCs gel electrolytes have been widely studied and applied to ZIHCs, the current ZIHCs gel electrolytes still have defects such as poor flexibility, low mechanical strength, low ionic conductivity and poor electrochemical stability, which are also the main problems of aqueous ZIHCs at this stage.

[0004] In recent years, researchers have used industrial carboxymethyl cellulose to construct a three-dimensional gel electrolyte network for aqueous ZIHCs. For example, Qiu et al. added a small amount of industrial carboxymethyl cellulose (4 wt%) to polyvinyl alcohol to construct a gel electrolyte for ZIHCs, using the charged functional group (carboxyl) to induce Zn 2+The carboxymethyl cellulose gel electrolyte prepared by uniform electroplating and deposition during the charge and discharge process has excellent anti-zinc dendrite performance and electrochemical properties, which can solve the above problems to a certain extent. However, its gel electrolyte uses a large amount of non-renewable petroleum-based raw materials (polyvinyl alcohol) and industrial products (carboxymethyl cellulose), which cannot fundamentally solve the dilemma of the depletion of fossil energy.

[0005] The conventional method for preparing carboxymethyl cellulose raw material involves adding 30%-40% NaOH to an alkaline etherification reactor, adding 10ml of anhydrous ethanol and a small amount of urea, stirring thoroughly, adding 5g of chopped cotton, and heating in a constant-temperature water bath at 30-35°C for 1-2 hours. A certain amount of chloroacetic acid in ethanol is then added dropwise, and the reaction is continued at 40-45°C for 0.5 hours. The temperature is then raised to 70°C for 1-2 hours. The crude carboxymethyl cellulose is then removed, neutralized with hydrochloric acid to a pH of 7, and washed three times with 80% ethanol solution at a bath ratio of 1:4 in a constant-temperature water bath at 40-45°C for 10 minutes with continuous stirring. The washed product is then centrifuged for dealcoholization and then dried in a 105°C oven for 2 hours. Odorless, odorless, fibrous carboxymethyl cellulose particles are obtained after drying. This demonstrates the complex process for preparing industrial carboxymethyl cellulose, requiring the use of large amounts of strong acids, strong bases, and toxic organic solvents. These organic solvents are expensive, and the investment in organic solvent recovery equipment is substantial.

[0006] Therefore, based on the shortcomings of traditional carboxymethyl cellulose electrolytes, the present invention directly uses cellulose as a raw material, achieving gelation during the carboxylation process, thereby constructing a three-dimensional network of ion channels. The ingenious introduction of a second polymer to participate in the gelation process, through covalent and non-covalent bonds, participates in the construction of a three-dimensional network of ion channels, improving the electrical properties of the gel electrolyte while enhancing its mechanical properties. This can effectively address the shortcomings of traditional electrolytes and is very important for the promotion and popularization of rechargeable aqueous ZIHCs. Summary of the Invention

[0007] The present invention addresses the current challenges in the development of ZIHCs. By designing and modifying aqueous electrolytes, a carboxylated cellulose-based flexible, zinc dendrite-resistant hydrogel electrolyte was developed using an organic base / organic solvent / CO₂ system. This solution addresses the severe zinc dendrite problem in aqueous ZIHCs and further improves their lifespan. Furthermore, the mechanical strength of the gel electrolyte is improved through covalent and non-covalent crosslinking.

[0008] The technical solution of the present invention is a method for preparing a carboxylated cellulose-based flexible zinc dendrite-resistant hydrogel electrolyte, comprising the following steps:

[0009] (1) dissolving cellulose in an organic base / CO2 / organic solvent system; wherein the mass concentration of the organic base in the system is 0.1-50%, the mass concentration of the dissolved cellulose is 0.1-30%, the pressure of the injected CO2 is 0.1-15 MPa, the dissolution temperature is 50-150°C, and the dissolution time is 1-24 hours; then adding a high molecular weight polymer, and continuing to stir and dissolve at 20-50°C to obtain product A;

[0010] (2) First, add a compound containing a monoanhydride functional group to product A and stir at 20-100°C for 1-24 hours to carry out a derivatization reaction to obtain product B;

[0011] (3) Cool product B to -20-20°C, then add the compound containing a polyanhydride functional group, mix and stir evenly, pour into a mold, and react at 20-100°C for 1-24 hours to obtain product C;

[0012] (4) displacing product C with pure water 1-10 times until neutral, to obtain a carboxylated cellulose-based hydrogel;

[0013] (5) Taking a carboxylated cellulose-based hydrogel, soaking it in a 0.1-10 mol / L zinc-containing electrolyte salt solution for 1-48 hours to obtain a carboxylated cellulose-based flexible zinc dendrite-resistant hydrogel electrolyte.

[0014] Preferably, in the preparation method of the aforementioned carboxylated cellulose-based flexible zinc dendrite-resistant hydrogel electrolyte, the cellulose is one or any combination of microcrystalline cellulose, α-cellulose, or plant cellulose separated from cotton, wood pulp, bamboo pulp, and agricultural and forestry lignocellulose waste.

[0015] Preferably, in the preparation method of the aforementioned carboxylated cellulose-based flexible anti-zinc dendrite hydrogel electrolyte, the organic solvent is one or any combination of dimethyl sulfoxide, N-methylpyrrolidone, tetramethyl urea, tetraethyl urea, N,N-dimethylimidazolidinone, N,N-dimethylformamide, N,N-diethylacetamide, pyrrolidone, 2-nitrohexyl ketone, N,N-dimethylpropylene urea or cyclopentane sulfone.

[0016] Preferably, in the aforementioned method for preparing the carboxylated cellulose-based flexible zinc dendrite-resistant hydrogel electrolyte, the acid-base dissociation constant of the organic base is greater than 20, and the organic base has the following structural characteristics:

[0017]

[0018] Wherein, n=1 or 2; R is independently hydrogen or an alkyl group having 1 to 6 carbon atoms; R1, R2, R3, R4 and R5 are independently methyl or ethyl.

[0019] Preferably, in the preparation method of the aforementioned carboxylated cellulose-based flexible zinc dendrite-resistant hydrogel electrolyte, the molar ratio of the monoanhydride functional group-containing compound to the glucose unit in the product A in step (2) is 0.1:1-10:1; the monoanhydride functional group-containing compound comprises the following structural formula:

[0020]

[0021] Preferably, in the preparation method of the aforementioned carboxylated cellulose-based flexible anti-zinc dendrite hydrogel electrolyte, the mass ratio of the high molecular weight polymer to the cellulose in product A in step (1) is 0.1:1-10:1; the high molecular weight polymer is any combination of one or more of polyvinyl alcohol, polyethylene glycol, polyacrylamide, polymethyl methacrylate, polyethyl methacrylate, polyhydroxyethyl methacrylate or polyacrylonitrile.

[0022] Preferably, in the method for preparing the aforementioned carboxylated cellulose-based flexible zinc dendrite-resistant hydrogel electrolyte, the molar ratio of the polyanhydride functional group-containing compound in step (3) to the glucose unit in the product A is 0.1:1-10:1; the polyanhydride functional group-containing compound comprises the following structural formula:

[0023]

[0024] Preferably, in the preparation method of the aforementioned carboxylated cellulose-based flexible anti-zinc dendrite hydrogel electrolyte, the zinc-containing electrolyte salt includes one or a combination of any multiple of zinc chloride, zinc sulfate, zinc acetate, zinc nitrate, zinc tetrafluoroborate, zinc trifluoromethanesulfonate, bistrifluoromethanesulfonyl imide zinc or bisfluorosulfonyl imide zinc.

[0025] A hydrogel electrolyte prepared by the aforementioned method.

[0026] Application of the hydrogel electrolyte prepared by the aforementioned method in zinc ion hybrid capacitors.

[0027] It should be noted that when using the electrolyte of the present invention, the negative electrode in aqueous ZIHCs directly utilizes zinc foil, which is relatively stable to water. This differs from the choice of negative electrode material for conventional lithium-ion or sodium-ion hybrid capacitors. This is because lithium metal or sodium metal is highly reactive and reacts violently with water, posing safety risks and cannot be directly used as the negative electrode material for aqueous lithium-ion or sodium-ion hybrid capacitors. Furthermore, the aqueous ZIHC gel electrolyte designed by the present invention is specifically designed for aqueous ZIHCs and is not suitable for conventional aqueous lithium-ion or sodium-ion hybrid capacitors.

[0028] Beneficial effects of the present invention

[0029] The aqueous ZIHCs provided by the present invention adopts an organic base / organic solvent / CO2 system to dissolve cellulose, and directly uses cellulose as a raw material to prepare a gel electrolyte with good electrochemical and mechanical properties. During the material preparation process, the organic base not only constitutes a part of the cellulose dissolution system, plays a role in activating and dissolving cellulose, but also acts as a catalyst when the monoanhydride compound reacts with the hydroxyl group on the cellulose, greatly improving the reaction efficiency. On this basis, the present invention constructs a carboxyl-rich cellulose-based hydrogel network by adding a polyanhydride compound for chemical crosslinking, solvent replacement and soaking of zinc salt electrolytes, and chemical crosslinking, physical crosslinking and ionic crosslinking. On the one hand, the addition of polymers improves the mechanical properties and electrochemical properties of the gel electrolyte, providing possibilities for flexible ZIHCs devices; on the other hand, the carboxyl-rich carboxylated cellulose-based gel electrolyte can be used in the presence of Zn 2+ The uniform electric field during the deposition and stripping process suppresses zinc dendrites, thereby improving the cycling stability of aqueous ZIHCs devices. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 The following is a flow chart of the synthesis of carboxylated cellulose-based hydrogels of the present invention.

[0031] Figure 2 The optical pictures of the hydrogels prepared in Examples 1 and 2 of the present invention show that after being immersed in a 2M zinc sulfate aqueous solution, Example 2 shrinks significantly compared to before being immersed, proving that Zn 2+ Ionic cross-linking occurs in the gel.

[0032] Figure 3 The following graphs show the mechanical tensile properties of the hydrogels of Examples 1 and 2 of the present invention. As can be seen from the graphs, the hydrogel of Example 1, which was not immersed in a 2M zinc sulfate solution, has a tensile strength of 20 kPa and an elongation at break of 706%. The hydrogel of Example 2, which was immersed in a 2M zinc sulfate solution, has a tensile strength of 220 kPa and an elongation at break of 908%. This indicates that the incorporation of zinc sulfate electrolytes into the carboxylated cellulose-based hydrogel designed in this invention ionically crosslinks, significantly improving the gel's strength and toughness, fully satisfying the requirements for subsequent assembly of ZIHCs and their flexible applications.

[0033] Figure 4 The CV curves of the gel electrolyte of the present invention at different scan rates (5, 10, 20, 50, 100 and 200 mVs -1 ).from Figure 4 It can be seen that within the operating voltage range of 0.2-1.8 V, the CV curve shows symmetrical cyclic ampere-volt-ampere characteristics and has good stability. However, as the scan rate increases, the diffusion-controlled transport of ions in the gel electrolyte of the present invention changes, and the CV curve gradually deviates from the rectangle.

[0034] Figure 5 The gel electrolyte of the present invention is in the operating voltage range of 0.2-1.8V, when the charge and discharge current density is 0.25-20.0Ag -1 The GCD curve of the gel electrolyte of the present invention is an approximately symmetrical triangle, showing good capacitance characteristics and high charging efficiency, which is a typical double-layer behavior. -1 The current densities were 284.0, 253.4, 227.9, 200.8, 155.0, 116.9, 89.1 and 63.8 Fg, respectively. -1 .

[0035] Figure 6 The gel electrolyte of the present invention is tested for zinc at different current densities. When the current density increases from 0.1 to 2.0 mA cm -2 The polarization voltage remains below 150 mV, confirming the stable zinc deposition behavior.

[0036] Figure 7 The gel electrolyte of the present invention is subjected to a current density of 1.0 mA cm -2 In the case of the present invention, a Zn||Zn symmetric battery test was used, with each cycle lasting 2 hours, revealing the cycling stability of the metal zinc foil in the gel electrolyte of the present invention. In the electrolyte of Example 3, the Zn||Zn battery quickly short-circuited after 172 hours of cycling. In the electrolyte of Example 4, the Zn||Zn battery quickly short-circuited after 67 hours of cycling. It is worth noting that the Zn||Zn battery of the hydrogel electrolyte of the present invention remained stable after more than 2000 hours of cycling without short-circuiting or voltage polarization, which shows that the hydrogel electrolyte of the present invention has great prospects in ZHSCs.

[0037] Figure 8 The soft-pack ZIHCs were assembled for the gel electrolyte of the present invention, and the -1 Under current density, the capacity at different bending angles is obtained by bending at 0°, 90°, 180° and recovery. The illustration is an optical image of the soft-pack ZIHCs bending. The capacity during the entire process still maintains 88% of the initial capacity, proving that the gel electrolyte of the present invention has good anti-bending ability.

[0038] Figure 9 The soft-pack ZIHCs assembled with the gel electrolyte of the present invention can maintain about 1.27V (initial voltage 1.8V) after 260 hours of self-discharge, and the self-discharge rate is 2.03mVh -1 The gel electrolyte of the present invention has excellent anti-self-discharge capability and can effectively suppress inherent parasitic reactions.

[0039] Figure 10 The gel electrolyte of the present invention is assembled into a soft-pack ZIHCs to light up an LED lamp, which has good practical application prospects.

[0040] Figure 11 Soft-pack ZIHCs were assembled for the gel electrolyte of the present invention. The rated voltage of one ZIHC was 1.6V. Two soft-pack ZIHCs were connected in series to power a 3V timer, which could provide continuous power for more than 15 hours. This further proves that the gel electrolyte of the present invention has great practical application prospects.

[0041] Figure 12 The gel electrolyte of the present invention is used to assemble button-type ZIHCs, and the -1 After 41,000 cycles of current density cycling, the device still maintained 99.13% capacity and 99.45% coulombic efficiency. The inset shows the GCD of the first 10 cycles and the GCD of the last 10 cycles. The gel electrolysis of the present invention exhibits ultra-long cycling stability. DETAILED DESCRIPTION

[0042] The present invention will be further described below with reference to the examples, but they are not intended to limit the present invention.

[0043] Embodiments of the present invention

[0044] Embodiment 1 of the present invention

[0045] (1) 1.0 g of cotton pulp cellulose, 2.31 g of tetramethylguanidine (the ratio of the molar number of tetramethylguanidine to the molar number of hydroxyl groups in cotton pulp cellulose is 1:1), and 29.39 g of DMSO were added to a reactor filled with 1.0 MPaCO2 and reacted in a 50°C oil bath for 3 h with magnetic stirring to prepare a 3 wt% cotton pulp cellulose solution.

[0046] (2) Take 20 g of the above-mentioned 3 wt% cotton pulp cellulose solution in a two-necked bottle, add succinic anhydride (the molar ratio with the glucose unit of cotton pulp cellulose is 1:1), stir and react at 80 ° C for 3 h, then add polyvinyl alcohol (the mass ratio of polyvinyl alcohol to cotton pulp cellulose is 1:1) and stir to completely dissolve it, then cool it to 0 ° C in an ice bath, add pyromellitic anhydride (the molar ratio with the glucose unit of cotton pulp cellulose is 1:1), and then pour it into a mold and react at 80 ° C for 5 h to obtain a gel, thereby obtaining a cotton pulp cellulose proton type ionic liquid / polyvinyl alcohol organogel.

[0047] (3) The cotton pulp cellulose proton type ionic liquid / polyvinyl alcohol organogel is replaced with pure water to neutrality, thereby obtaining a carboxylated cotton pulp cellulose / polyvinyl alcohol hydrogel.

[0048] Embodiment 2 of the present invention

[0049] (1) 1.0 g of cotton pulp cellulose, 2.31 g of tetramethylguanidine (the ratio of the molar number of tetramethylguanidine to the molar number of hydroxyl groups in cotton pulp cellulose is 1:1), and 29.39 g of DMSO were added to a reactor filled with 1.0 MPaCO2 and reacted in a 50°C oil bath for 3 h with magnetic stirring to prepare a 3 wt% cotton pulp cellulose solution.

[0050] (2) Take 20 g of the above-mentioned 3 wt% cotton pulp cellulose solution in a two-necked bottle, add succinic anhydride (the molar ratio with the glucose unit of cotton pulp cellulose is 1:1), stir and react at 80 ° C for 3 h, then add polyvinyl alcohol (the mass ratio of polyvinyl alcohol to cotton pulp cellulose is 1:1) and stir to completely dissolve it, then cool it to 0 ° C in an ice bath, add pyromellitic anhydride (the molar ratio with the glucose unit of cotton pulp cellulose is 1:1), and then pour it into a mold and react at 80 ° C for 5 h to obtain a gel, thereby obtaining a cotton pulp cellulose proton type ionic liquid / polyvinyl alcohol organogel.

[0051] (3) The cotton pulp cellulose proton type ionic liquid / polyvinyl alcohol organogel is replaced with pure water to neutrality, thereby obtaining a carboxylated cotton pulp cellulose / polyvinyl alcohol hydrogel.

[0052] (4) Soaking the carboxylated cotton pulp cellulose / polyvinyl alcohol hydrogel in a 2M zinc sulfate aqueous solution for 24 hours to obtain a carboxylated cotton pulp cellulose / polyvinyl alcohol hydrogel electrolyte.

[0053] Embodiment 3 of the present invention

[0054] (1) Dissolve 3 g of polyvinyl alcohol in 57 mL of pure water, stir and react at 80 °C for 3 h, then pour into a mold and freeze and thaw twice to obtain polyvinyl alcohol hydrogel.

[0055] (2) The polyvinyl alcohol hydrogel was immersed in a 2M zinc sulfate aqueous solution for 24 hours to obtain a polyvinyl alcohol hydrogel electrolyte.

[0056] Embodiment 4 of the present invention

[0057] (1) Directly soak the commercial glass fiber membrane in 2M zinc sulfate to obtain the glass fiber membrane electrolyte.

[0058] Embodiment 5 of the present invention

[0059] (1) 1.0 g of cotton pulp cellulose, 2.31 g of tetramethylguanidine (the ratio of the molar number of tetramethylguanidine to the molar number of hydroxyl groups in cotton pulp cellulose is 1:1), and 29.39 g of DMSO were added to a reactor filled with 1.0 MPaCO2 and reacted in a 50°C oil bath for 3 h with magnetic stirring to prepare a 3 wt% cotton pulp cellulose solution.

[0060] (2) Take 20 g of the above-mentioned 3 wt% cotton pulp cellulose solution in a two-necked bottle, add succinic anhydride (the molar ratio with the glucose unit of cotton pulp cellulose is 1:1), stir and react at 80 ° C for 3 h, then add polyvinyl alcohol (the mass ratio of polyvinyl alcohol to cotton pulp cellulose is 1:1) and stir to completely dissolve it, then cool it to 0 ° C in an ice bath, add pyromellitic anhydride (the molar ratio with the glucose unit of cotton pulp cellulose is 1:1), and then pour it into a mold and react at 80 ° C for 5 h to obtain a gel, thereby obtaining a cotton pulp cellulose proton type ionic liquid / polyvinyl alcohol organogel.

[0061] (3) The cotton pulp cellulose proton type ionic liquid / polyvinyl alcohol organogel is replaced with pure water to neutrality, thereby obtaining a carboxylated cotton pulp cellulose / polyvinyl alcohol hydrogel.

[0062] (4) Soaking the carboxylated cotton pulp cellulose / polyvinyl alcohol hydrogel in a 1 M zinc sulfate aqueous solution for 24 hours to obtain a carboxylated cotton pulp cellulose / polyvinyl alcohol hydrogel electrolyte.

[0063] Embodiment 6 of the present invention

[0064] (1) 1.0 g of cotton pulp cellulose, 2.31 g of tetramethylguanidine (the ratio of the molar number of tetramethylguanidine to the molar number of hydroxyl groups in cotton pulp cellulose is 1:1), and 29.39 g of DMSO were added to a reactor filled with 1.0 MPaCO2 and reacted in a 50°C oil bath for 3 h with magnetic stirring to prepare a 3 wt% cotton pulp cellulose solution.

[0065] (2) Take 20 g of the above-mentioned 3 wt% cotton pulp cellulose solution in a two-necked bottle, add succinic anhydride (the molar ratio with the glucose unit of cotton pulp cellulose is 1:1), stir and react at 80 ° C for 3 h, then add polyvinyl alcohol (the mass ratio of polyvinyl alcohol to cotton pulp cellulose is 1:1) and stir to completely dissolve it, then cool it to 0 ° C in an ice bath, add pyromellitic anhydride (the molar ratio with the glucose unit of cotton pulp cellulose is 1:1), and then pour it into a mold and react at 80 ° C for 5 h to obtain a gel, thereby obtaining a cotton pulp cellulose proton type ionic liquid / polyvinyl alcohol organogel.

[0066] (3) The cotton pulp cellulose proton type ionic liquid / polyvinyl alcohol organogel is replaced with pure water to neutrality, thereby obtaining a carboxylated cotton pulp cellulose / polyvinyl alcohol hydrogel.

[0067] (4) Soaking the carboxylated cotton pulp cellulose / polyvinyl alcohol hydrogel in a 1.5 M zinc sulfate aqueous solution for 24 hours to obtain a carboxylated cotton pulp cellulose / polyvinyl alcohol hydrogel electrolyte.

[0068] Embodiment 7 of the present invention

[0069] (1) 1.0 g of cotton pulp cellulose, 2.31 g of tetramethylguanidine (the ratio of the molar number of tetramethylguanidine to the molar number of hydroxyl groups in cotton pulp cellulose is 1:1), and 29.39 g of DMSO were added to a reactor filled with 1.0 MPaCO2 and reacted in a 50°C oil bath for 3 h with magnetic stirring to prepare a 3 wt% cotton pulp cellulose solution.

[0070] (2) Take 20 g of the above-mentioned 3 wt% cotton pulp cellulose solution in a two-necked bottle, add succinic anhydride (the molar ratio with the glucose unit of cotton pulp cellulose is 1:1), stir and react at 80 ° C for 3 h, then add polyvinyl alcohol (the mass ratio of polyvinyl alcohol to cotton pulp cellulose is 1:1) and stir to completely dissolve it, then cool it to 0 ° C in an ice bath, add pyromellitic anhydride (the molar ratio with the glucose unit of cotton pulp cellulose is 1:1), and then pour it into a mold and react at 80 ° C for 5 h to obtain a gel, thereby obtaining a cotton pulp cellulose proton type ionic liquid / polyvinyl alcohol organogel.

[0071] (3) The cotton pulp cellulose proton type ionic liquid / polyvinyl alcohol organogel is replaced with pure water to neutrality, thereby obtaining a carboxylated cotton pulp cellulose / polyvinyl alcohol hydrogel.

[0072] (4) Soaking the carboxylated cotton pulp cellulose / polyvinyl alcohol hydrogel in a 2.5 M zinc sulfate aqueous solution for 24 hours to obtain a carboxylated cotton pulp cellulose / polyvinyl alcohol hydrogel electrolyte.

[0073] Embodiment 8 of the present invention

[0074] (1) 1.0 g of cotton pulp cellulose, 2.31 g of tetramethylguanidine (the ratio of the molar number of tetramethylguanidine to the molar number of hydroxyl groups in cotton pulp cellulose is 1:1), and 29.39 g of DMSO were added to a reactor filled with 1.0 MPaCO2 and reacted in a 50°C oil bath for 3 h with magnetic stirring to prepare a 3 wt% cotton pulp cellulose solution.

[0075] (2) Take 20 g of the above-mentioned 3 wt% cotton pulp cellulose solution in a two-necked bottle, add succinic anhydride (the molar ratio with the glucose unit of cotton pulp cellulose is 1:1), stir and react at 80 ° C for 3 h, then add polyvinyl alcohol (the mass ratio of polyvinyl alcohol to cotton pulp cellulose is 1:1) and stir to completely dissolve it, then cool it to 0 ° C in an ice bath, add pyromellitic anhydride (the molar ratio with the glucose unit of cotton pulp cellulose is 1:1), and then pour it into a mold and react at 80 ° C for 5 h to obtain a gel, thereby obtaining a cotton pulp cellulose proton type ionic liquid / polyvinyl alcohol organogel.

[0076] (3) The cotton pulp cellulose proton type ionic liquid / polyvinyl alcohol organogel is replaced with pure water to neutrality, thereby obtaining a carboxylated cotton pulp cellulose / polyvinyl alcohol hydrogel.

[0077] (4) Soaking the carboxylated cotton pulp cellulose / polyvinyl alcohol hydrogel in a 3M zinc sulfate aqueous solution for 24 hours to obtain a carboxylated cotton pulp cellulose / polyvinyl alcohol hydrogel electrolyte.

[0078] The hydrogel was immersed in zinc sulfate of different concentrations, and the ionic conductivity, mechanical strength and swelling rate of the gel electrolyte were tested. The results are shown in Table 1.

[0079] Table 1

[0080]

[0081] Embodiment 9 of the present invention

[0082] (1) 1.0 g of cotton pulp cellulose, 2.31 g of tetramethylguanidine (the ratio of the molar number of tetramethylguanidine to the molar number of hydroxyl groups in cotton pulp cellulose is 1:1), and 29.39 g of DMSO were added to a reactor filled with 1.0 MPaCO2 and reacted in a 50°C oil bath for 3 h with magnetic stirring to prepare a 3 wt% cotton pulp cellulose solution.

[0083] (2) Take 20 g of the above-mentioned 3 wt% cotton pulp cellulose solution in a two-necked bottle, add succinic anhydride (the molar ratio with the glucose unit of cotton pulp cellulose is 1:1), stir and react at 80 ° C for 3 h, then add polyvinyl alcohol (the mass ratio of polyvinyl alcohol to cotton pulp cellulose is 1:1) and stir to completely dissolve it, then cool it to 0 ° C in an ice bath, add pyromellitic anhydride (the molar ratio with the glucose unit of cotton pulp cellulose is 1:1), and then pour it into a mold and react at 80 ° C for 5 h to obtain a gel, thereby obtaining a cotton pulp cellulose proton type ionic liquid / polyvinyl alcohol organogel.

[0084] (3) The cotton pulp cellulose proton type ionic liquid / polyvinyl alcohol organogel is replaced with pure water to neutrality, thereby obtaining a carboxylated cotton pulp cellulose / polyvinyl alcohol hydrogel.

[0085] (4) Soaking the carboxylated cotton pulp cellulose / polyvinyl alcohol hydrogel in a 2M zinc chloride aqueous solution for 24 hours to obtain a carboxylated cotton pulp cellulose / polyvinyl alcohol hydrogel electrolyte.

[0086] Embodiment 10 of the present invention

[0087] (1) 1.0 g of cotton pulp cellulose, 2.31 g of tetramethylguanidine (the ratio of the molar number of tetramethylguanidine to the molar number of hydroxyl groups in cotton pulp cellulose is 1:1), and 29.39 g of DMSO were added to a reactor filled with 1.0 MPaCO2 and reacted in a 50°C oil bath for 3 h with magnetic stirring to prepare a 3 wt% cotton pulp cellulose solution.

[0088] (2) Take 20 g of the above-mentioned 3 wt% cotton pulp cellulose solution in a two-necked bottle, add succinic anhydride (the molar ratio with the glucose unit of cotton pulp cellulose is 1:1), stir and react at 80 ° C for 3 h, then add polyvinyl alcohol (the mass ratio of polyvinyl alcohol to cotton pulp cellulose is 1:1) and stir to completely dissolve it, then cool it to 0 ° C in an ice bath, add pyromellitic anhydride (the molar ratio with the glucose unit of cotton pulp cellulose is 1:1), and then pour it into a mold and react at 80 ° C for 5 h to obtain a gel, thereby obtaining a cotton pulp cellulose proton type ionic liquid / polyvinyl alcohol organogel.

[0089] (3) The cotton pulp cellulose proton type ionic liquid / polyvinyl alcohol organogel is replaced with pure water to neutrality, thereby obtaining a carboxylated cotton pulp cellulose / polyvinyl alcohol hydrogel.

[0090] (4) Soaking the carboxylated cotton pulp cellulose / polyvinyl alcohol hydrogel in a 2M zinc trifluoromethanesulfonate aqueous solution for 24 hours to obtain a carboxylated cotton pulp cellulose / polyvinyl alcohol hydrogel electrolyte.

[0091] Embodiment 11 of the present invention

[0092] (1) 1.0 g of cotton pulp cellulose, 2.31 g of tetramethylguanidine (the ratio of the molar number of tetramethylguanidine to the molar number of hydroxyl groups in cotton pulp cellulose is 1:1), and 29.39 g of DMSO were added to a reactor filled with 1.0 MPaCO2 and reacted in a 50°C oil bath for 3 h with magnetic stirring to prepare a 3 wt% cotton pulp cellulose solution.

[0093] (2) Take 20 g of the above-mentioned 3 wt% cotton pulp cellulose solution in a two-necked bottle, add succinic anhydride (the molar ratio with the glucose unit of cotton pulp cellulose is 1:1), stir and react at 80 ° C for 3 h, then add polyvinyl alcohol (the mass ratio of polyvinyl alcohol to cotton pulp cellulose is 1:1) and stir to completely dissolve it, then cool it to 0 ° C in an ice bath, add pyromellitic anhydride (the molar ratio with the glucose unit of cotton pulp cellulose is 1:1), and then pour it into a mold and react at 80 ° C for 5 h to obtain a gel, thereby obtaining a cotton pulp cellulose proton type ionic liquid / polyvinyl alcohol organogel.

[0094] (3) The cotton pulp cellulose proton type ionic liquid / polyvinyl alcohol organogel is replaced with pure water to neutrality, thereby obtaining a carboxylated cotton pulp cellulose / polyvinyl alcohol hydrogel.

[0095] (4) Soaking the carboxylated cotton pulp cellulose / polyvinyl alcohol hydrogel in a 2M zinc tetrafluoroborate aqueous solution for 24 hours to obtain a carboxylated cotton pulp cellulose / polyvinyl alcohol hydrogel electrolyte.

[0096] Embodiment 12 of the present invention

[0097] (1) 1.0 g of cotton pulp cellulose, 2.31 g of tetramethylguanidine (the ratio of the molar number of tetramethylguanidine to the molar number of hydroxyl groups in cotton pulp cellulose is 1:1), and 29.39 g of DMSO were added to a reactor filled with 1.0 MPaCO2 and reacted in a 50°C oil bath for 3 h with magnetic stirring to prepare a 3 wt% cotton pulp cellulose solution.

[0098] (2) Take 20 g of the above-mentioned 3 wt% cotton pulp cellulose solution in a two-necked bottle, add succinic anhydride (the molar ratio with the glucose unit of cotton pulp cellulose is 1:1), stir and react at 80 ° C for 3 h, then add polyvinyl alcohol (the mass ratio of polyvinyl alcohol to cotton pulp cellulose is 1:1) and stir to completely dissolve it, then cool it to 0 ° C in an ice bath, add pyromellitic anhydride (the molar ratio with the glucose unit of cotton pulp cellulose is 1:1), and then pour it into a mold and react at 80 ° C for 5 h to obtain a gel, thereby obtaining a cotton pulp cellulose proton type ionic liquid / polyvinyl alcohol organogel.

[0099] (3) The cotton pulp cellulose proton type ionic liquid / polyvinyl alcohol organogel is replaced with pure water to neutrality, thereby obtaining a carboxylated cotton pulp cellulose / polyvinyl alcohol hydrogel.

[0100] (4) Soaking the carboxylated cotton pulp cellulose / polyvinyl alcohol hydrogel in a 2M zinc nitrate aqueous solution for 24 hours to obtain a carboxylated cotton pulp cellulose / polyvinyl alcohol hydrogel electrolyte.

[0101] Embodiment 13 of the present invention

[0102] (1) 1.0 g of cotton pulp cellulose, 2.31 g of tetramethylguanidine (the ratio of the molar number of tetramethylguanidine to the molar number of hydroxyl groups in cotton pulp cellulose is 1:1), and 29.39 g of DMSO were added to a reactor filled with 1.0 MPaCO2 and reacted in a 50°C oil bath for 3 h with magnetic stirring to prepare a 3 wt% cotton pulp cellulose solution.

[0103] (2) Take 20 g of the above-mentioned 3 wt% cotton pulp cellulose solution in a two-necked bottle, add succinic anhydride (the molar ratio with the glucose unit of cotton pulp cellulose is 1:1), stir and react at 80 ° C for 3 h, then add polyvinyl alcohol (the mass ratio of polyvinyl alcohol to cotton pulp cellulose is 1:1) and stir to completely dissolve it, then cool it to 0 ° C in an ice bath, add pyromellitic anhydride (the molar ratio with the glucose unit of cotton pulp cellulose is 1:1), and then pour it into a mold and react at 80 ° C for 5 h to obtain a gel, thereby obtaining a cotton pulp cellulose proton type ionic liquid / polyvinyl alcohol organogel.

[0104] (3) The cotton pulp cellulose proton type ionic liquid / polyvinyl alcohol organogel is replaced with pure water to neutrality, thereby obtaining a carboxylated cotton pulp cellulose / polyvinyl alcohol hydrogel.

[0105] (4) Soaking the carboxylated cotton pulp cellulose / polyvinyl alcohol hydrogel in a 2M zinc acetate aqueous solution for 24 hours to obtain a carboxylated cotton pulp cellulose / polyvinyl alcohol hydrogel electrolyte.

[0106] The hydrogel was immersed in 2M different types of zinc salts, and the ionic conductivity, mechanical strength and swelling rate of the gel electrolyte were tested. The results are shown in Table 2.

[0107] Table 2

[0108]

[0109] Embodiment 14 of the present invention

[0110] (1) 1.0 g of microcrystalline cellulose, 2.31 g of tetramethylguanidine (the ratio of the molar number of tetramethylguanidine to the molar number of hydroxyl groups in microcrystalline cellulose is 1:1), and 29.39 g of DMSO were added to a reactor filled with 1.0 MPa of CO2 and reacted in an oil bath at 50°C for 3 h with magnetic stirring to prepare a 3 wt% microcrystalline cellulose solution.

[0111] (2) Take 20 g of the above-mentioned 3 wt% microcrystalline cellulose solution in a two-necked bottle, add succinic anhydride (the molar ratio with the microcrystalline cellulose glucose unit is 1:1), stir and react at 80 ° C for 3 h, then add polyvinyl alcohol (the mass ratio of polyvinyl alcohol to microcrystalline cellulose is 1:1) and stir to completely dissolve it, then cool it to 0 ° C in an ice bath, add pyromellitic anhydride (the molar ratio with the microcrystalline cellulose glucose unit is 1:1) dropwise, and then pour it into a mold and react at 80 ° C for 5 h to obtain a gel, thereby obtaining a microcrystalline cellulose proton type ionic liquid / polyvinyl alcohol organogel.

[0112] (3) The proton-type ionic liquid microcrystalline cellulose / polyvinyl alcohol organogel is replaced with pure water to neutrality, thereby obtaining a carboxylated microcrystalline cellulose / polyvinyl alcohol hydrogel.

[0113] (4) Soaking the carboxylated microcrystalline cellulose / polyvinyl alcohol hydrogel in a 2M zinc sulfate aqueous solution for 24 hours to obtain a carboxylated microcrystalline cellulose / polyvinyl alcohol hydrogel electrolyte.

[0114] Embodiment 15 of the present invention

[0115] (1) 1.0 g of α-cellulose, 2.31 g of tetramethylguanidine (the ratio of the molar number of tetramethylguanidine to the molar number of hydroxyl groups in α-cellulose is 1:1), and 29.39 g of DMSO were added to a reactor filled with 1.0 MPaCO2 and reacted in a 50°C oil bath for 3 h with magnetic stirring to prepare a 3 wt% α-cellulose solution.

[0116] (2) Take 20 g of the above-mentioned 3 wt% α-cellulose solution in a two-necked bottle, add succinic anhydride (the molar ratio with α-cellulose glucose unit is 1:1), stir and react at 80 ° C for 3 h, then add polyvinyl alcohol (the mass ratio of polyvinyl alcohol to α-cellulose is 1:1) and stir to completely dissolve it, then cool it to 0 ° C in an ice bath, add pyromellitic anhydride (the molar ratio with α-cellulose glucose unit is 1:1) dropwise, and then pour it into a mold and react at 80 ° C for 5 h to obtain a gel, thereby obtaining an α-cellulose proton type ionic liquid / polyvinyl alcohol organic gel.

[0117] (3) The α-cellulose proton type ionic liquid / polyvinyl alcohol organogel is replaced with pure water to neutrality, thereby obtaining a carboxylated α-cellulose / polyvinyl alcohol hydrogel.

[0118] (4) Soaking the carboxylated α-cellulose / polyvinyl alcohol hydrogel in a 2M zinc sulfate aqueous solution for 24 hours to obtain a carboxylated α-cellulose / polyvinyl alcohol hydrogel electrolyte.

[0119] Embodiment 16 of the present invention

[0120] (1) 1.0 g of bamboo pulp cellulose, 2.31 g of tetramethylguanidine (the ratio of the molar number of tetramethylguanidine to the molar number of hydroxyl groups in bamboo pulp cellulose is 1:1), and 29.39 g of DMSO were added to a reactor filled with 1.0 MPaCO2 and reacted in an oil bath at 50°C for 3 h with magnetic stirring to prepare a 3 wt% bamboo pulp cellulose solution.

[0121] (2) Take 20g of the above-mentioned 3wt% bamboo pulp cellulose solution in a two-necked bottle, add succinic anhydride (the molar ratio of bamboo pulp cellulose glucose unit is 1:1), stir and react at 80℃ for 3h, then add polyvinyl alcohol (the mass ratio of polyvinyl alcohol to bamboo pulp cellulose is 1:1) and stir to completely dissolve it, then cool it to 0℃ in an ice bath, add pyromellitic anhydride (the molar ratio of bamboo pulp cellulose glucose unit is 1:1), then pour it into a mold and react at 80℃ for 5h to obtain a gel, thereby obtaining a bamboo pulp cellulose proton type ionic liquid / polyvinyl alcohol organogel.

[0122] (3) The bamboo pulp cellulose proton type ionic liquid / polyvinyl alcohol organogel is replaced with pure water to neutrality, thereby obtaining carboxylated bamboo pulp cellulose / polyvinyl alcohol hydrogel.

[0123] (4) Soaking the carboxylated bamboo pulp cellulose / polyvinyl alcohol hydrogel in a 2M zinc sulfate aqueous solution for 24 hours to obtain a carboxylated bamboo pulp cellulose / polyvinyl alcohol hydrogel electrolyte.

[0124] Embodiment 17 of the present invention

[0125] (1) 1.0 g of wood pulp cellulose, 2.31 g of tetramethylguanidine (the ratio of the molar number of tetramethylguanidine to the molar number of hydroxyl groups in the wood pulp cellulose is 1:1), and 29.39 g of DMSO were added to a reactor and charged with 1.0 MPaCO2. The mixture was heated in an oil bath at 50°C for 3 h with magnetic stirring to prepare a 3 wt% wood pulp cellulose solution.

[0126] (2) Take 20g of the above-mentioned 3wt% wood pulp cellulose solution in a two-necked bottle, add succinic anhydride (the molar ratio with the glucose unit of wood pulp cellulose is 1:1), stir and react at 80℃ for 3h, then add polyvinyl alcohol (the mass ratio of polyvinyl alcohol to wood pulp cellulose is 1:1) and stir to completely dissolve it, then cool it to 0℃ in an ice bath and add pyromellitic anhydride (the molar ratio with the glucose unit of wood pulp cellulose is 1:1), then pour it into a mold and react at 80℃ for 5h to obtain a gel, thereby obtaining a wood pulp cellulose proton type ionic liquid / polyvinyl alcohol organogel.

[0127] (3) The wood pulp cellulose proton type ionic liquid / polyvinyl alcohol organogel is replaced with pure water to neutrality, thereby obtaining a carboxylated wood pulp cellulose / polyvinyl alcohol hydrogel.

[0128] (4) Soaking the carboxylated wood pulp cellulose / polyvinyl alcohol hydrogel in a 2M zinc sulfate aqueous solution for 24 hours to obtain a carboxylated wood pulp cellulose / polyvinyl alcohol hydrogel electrolyte.

[0129] Embodiment 18 of the present invention

[0130] (1) 1.0 g of cellulose, 2.31 g of tetramethylguanidine (the ratio of the molar number of tetramethylguanidine to the molar number of hydroxyl groups in cellulose is 1:1), and 29.39 g of DMSO were placed in a reactor filled with 1.0 MPaCO2 and reacted in a 50°C oil bath for 3 h with magnetic stirring to prepare a 3 wt% cellulose solution.

[0131] (2) Take 20 g of the above-mentioned 3 wt% lignocellulose solution in a two-necked bottle, add succinic anhydride (with a molar ratio of 1:1 to the glucose unit of lignocellulose), stir and react at 80 ° C for 3 h, then add polyvinyl alcohol (the mass ratio of polyvinyl alcohol to lignocellulose is 1:1) and stir to completely dissolve it, then cool it to 0 ° C in an ice bath and add pyromellitic anhydride (with a molar ratio of 1:1 to the glucose unit of lignocellulose) dropwise, then pour it into a mold and react at 80 ° C for 5 h to obtain a gel, thereby obtaining a lignocellulose proton ionic liquid / polyvinyl alcohol organic gel.

[0132] (3) The lignocellulose proton ionic liquid / polyvinyl alcohol organogel is replaced with pure water to neutralize the lignocellulose proton ionic liquid / polyvinyl alcohol organogel, thereby obtaining a carboxylated lignocellulose / polyvinyl alcohol hydrogel.

[0133] (4) Soaking the carboxylated lignocellulose / polyvinyl alcohol hydrogel in a 2M zinc sulfate aqueous solution for 24 hours to obtain a carboxylated lignocellulose / polyvinyl alcohol hydrogel electrolyte.

[0134] Different types of cellulose hydrogels were prepared by soaking in 2M zinc sulfate. The ionic conductivity, mechanical strength and swelling rate of the gel electrolyte were tested. The results are shown in Table 3.

[0135] Table 3

[0136]

[0137] Embodiment 19 of the present invention

[0138] (1) 2.0 g of microcrystalline cellulose, 4.6 g of 1,5-diazabicyclo[4.3.0]non-5-ene, and 31.77 g of N-methylpyrrolidone were placed in a reaction vessel, filled with 0.1 MPa CO2, and reacted in an oil bath at 100°C for 12 h with magnetic stirring to prepare a microcrystalline cellulose solution.

[0139] (2) Take 20 g of the above-mentioned microcrystalline cellulose solution in a two-necked bottle, add maleic anhydride (the molar ratio of maleic anhydride to microcrystalline cellulose glucose unit is 0.1:1), stir and react at 20°C for 24 hours, then add polyethylene glycol (the mass ratio of polyethylene glycol to microcrystalline cellulose is 0.1:1) and stir to completely dissolve it, then cool it to 0°C in an ice bath, add pyromellitic anhydride (the molar ratio of maleic anhydride to microcrystalline cellulose glucose unit is 0.1:1), then pour it into a mold and react at 20°C for 24 hours to obtain a gel, thereby obtaining a microcrystalline cellulose proton type ionic liquid / polyethylene glycol organogel.

[0140] (3) The microcrystalline cellulose proton ionic liquid / polyethylene glycol organogel was replaced with pure water twice and finally immersed in a 0.1 M zinc chloride aqueous solution for 48 h to obtain a carboxylated microcrystalline cellulose / polyethylene glycol hydrogel electrolyte.

[0141] Embodiment 20 of the present invention

[0142] (1) 2.0 g of α-cellulose, 5.64 g of 1,8-diazabicycloundec-7-ene, and 15.73 g of N,N-dimethylformamide were placed in a reactor and charged with 15 MPa of CO2. The mixture was heated in an oil bath at 50°C for 24 h with magnetic stirring to prepare an α-cellulose solution.

[0143] (2) Take 20 g of the above cellulose solution in a two-necked bottle, add phthalic anhydride (the molar ratio of phthalic anhydride to α-cellulose glucose unit is 5:1), stir and react at 60 ° C for 12 h, then add polyacrylamide (the mass ratio of polyacrylamide to α-cellulose is 5:1) and stir to completely dissolve it, then cool it to -15 ° C in an ice bath, add pyromellitic anhydride (the molar ratio of phthalic anhydride to α-cellulose glucose unit is 5:1) dropwise, and then pour it into a mold and react at 60 ° C for 12 h to obtain a gel, thereby obtaining an α-cellulose proton type ionic liquid / polyacrylamide organogel.

[0144] (3) The α-cellulose proton type ionic liquid / polyacrylamide organogel was replaced with pure water five times and finally immersed in a 5M zinc trifluoromethanesulfonate aqueous solution for 24 h to obtain a carboxylated α-cellulose / polyacrylamide hydrogel electrolyte.

[0145] Embodiment 21 of the present invention

[0146] (1) 1.0 g of bamboo pulp cellulose, 2.577 g of 1,5,7-triazabicyclo[4.4.0]dec-5-ene, and 28.941 g of 2-nitrohexyl cyclopentane were placed in a reactor and charged with 1.0 MPa of CO2. The mixture was heated in an oil bath at 150°C for 1 h with magnetic stirring to prepare a bamboo pulp cellulose solution.

[0147] (2) 20 g of the above bamboo pulp cellulose solution was placed in a two-necked flask, and itaconic anhydride (the molar ratio of itaconic anhydride to the glucose unit of bamboo pulp cellulose was 10:1) was added. The mixture was stirred and reacted at 100°C for 1 hour. Polymethyl methacrylate (the mass ratio of polymethyl methacrylate to bamboo pulp cellulose was 10:1) was then added and stirred to completely dissolve. The mixture was then cooled to 5°C in an ice bath, and pyromellitic anhydride (the molar ratio of itaconic anhydride to the glucose unit of bamboo pulp cellulose was 10:1) was added dropwise. The mixture was then poured into a mold and reacted at 100°C for 1 hour to obtain a gel. A bamboo pulp cellulose proton type ionic liquid / polymethyl methacrylate organogel was obtained.

[0148] (3) The bamboo pulp cellulose proton-type ionic liquid / polymethyl methacrylate organogel was replaced with pure water 10 times and finally immersed in a 10 M zinc tetrafluoroborate aqueous solution for 1 h to obtain a carboxylated bamboo pulp cellulose / polymethyl methacrylate hydrogel electrolyte.

[0149] The above description is only a preferred specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any technician familiar with the technical field, within the technical scope disclosed by the present invention, can make equivalent replacements or changes based on the technical solutions and inventive concepts of the present invention, which should be covered by the scope of protection of the present invention.

Claims

1. A method for preparing a carboxylated cellulose-based flexible zinc dendrite-resistant hydrogel electrolyte, characterized in that: The steps include: (1) dissolving cellulose in an organic base / CO2 / organic solvent system; wherein the mass concentration of the organic base in the system is 0.1-50%, the mass concentration of the dissolved cellulose is 0.1-30%, the pressure of the injected CO2 is 0.1-15 MPa, the dissolution temperature is 50-150°C, and the dissolution time is 1-24 hours; then adding a high molecular weight polymer and continuing to stir it to dissolve it to obtain product A; wherein the organic solvent is one or more of dimethyl sulfoxide, N-methylpyrrolidone, tetramethylurea, tetraethylurea, N,N-dimethylimidazolidinone, N,N-dimethylformamide, N,N-diethylacetamide, pyrrolidone, 2-nitrohexyl ketone, N,N-dimethylpropylene urea or cyclopentane sulfone; the acid-base dissociation constant of the organic base is greater than 20, and the organic base has the following structural characteristics: wherein n=1 or 2; R is independently hydrogen or an alkyl group having 1 to 6 carbon atoms; R1, R2, R3, R4 and R5 are independently methyl or ethyl; The high molecular polymer is any combination of one or more of polyvinyl alcohol, polyethylene glycol, polyacrylamide, polymethyl methacrylate, polyethyl methacrylate, polyhydroxyethyl methacrylate or polyacrylonitrile; (2) First, add a compound containing a monoanhydride functional group to product A, and stir at 20-100° C. for a derivatization reaction for 1-24 hours to obtain product B; wherein the compound containing a monoanhydride functional group comprises the following structural formula: (3) Cooling product B to -20-20°C, then adding a compound containing a polyanhydride functional group, mixing and stirring evenly, pouring into a mold, and reacting at 20-100°C for 1-24 hours to obtain product C; wherein the compound containing a polyanhydride functional group comprises the following structural formula: (4) displacing product C with pure water 1-10 times until neutral, to obtain a carboxylated cellulose-based hydrogel; (5) Taking a carboxylated cellulose-based hydrogel, soaking it in a 0.1-10 mol / L zinc-containing electrolyte salt solution for 1-48 hours to obtain a carboxylated cellulose-based flexible zinc dendrite-resistant hydrogel electrolyte.

2. The method for preparing the carboxylated cellulose-based flexible zinc dendrite-resistant hydrogel electrolyte according to claim 1, characterized in that: The cellulose is one or any combination of microcrystalline cellulose, α-cellulose or plant cellulose separated from cotton, wood pulp, bamboo pulp and agricultural and forestry wood cellulose waste.

3. The method for preparing the carboxylated cellulose-based flexible zinc dendrite-resistant hydrogel electrolyte according to claim 1, characterized in that: The molar ratio of the monoanhydride functional group-containing compound in step (2) to the glucose unit in product A is 0.1:1-10:

1.

4. The method for preparing the carboxylated cellulose-based flexible zinc dendrite-resistant hydrogel electrolyte according to claim 1, wherein: The mass ratio of the high molecular weight polymer in step (1) to the cellulose in product A is 0.1:1-10:

1.

5. The method for preparing the carboxylated cellulose-based flexible zinc dendrite-resistant hydrogel electrolyte according to claim 1, wherein: The molar ratio of the polyanhydride functional group-containing compound in step (3) to the glucose unit in product A is 0.1:1-10:

1.

6. The method for preparing the carboxylated cellulose-based flexible zinc dendrite-resistant hydrogel electrolyte according to claim 1, characterized in that: The zinc-containing electrolyte salt includes one or a combination of any two or more of zinc chloride, zinc sulfate, zinc acetate, zinc nitrate, zinc tetrafluoroborate, zinc trifluoromethanesulfonate, zinc bistrifluoromethanesulfonyl imide or zinc bisfluorosulfonyl imide.

7. A hydrogel electrolyte prepared according to the method according to any one of claims 1 to 6.

8. Use of a hydrogel electrolyte prepared according to the method according to any one of claims 1 to 6 in a zinc ion hybrid capacitor.

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