A method for preparing structural energy storage materials based on zinc ion batteries

Abstract

The present invention discloses a method for preparing a structural energy storage material based on a zinc ion battery, the method comprising the following steps: 1. preparing a carbon fiber / ammonium vanadate electrode; 2. preparing a carbon fiber / zinc electrode; 3. completely dissolving a zinc salt in an ionic liquid to obtain a mixed solution, adding an epoxy resin and a curing agent to the mixed solution to obtain a curing precursor solution, and fully infiltrating a glass fiber with the curing precursor solution; 4. laminating the carbon fiber / ammonium vanadate electrode, the carbon fiber / zinc electrode, and the infiltrated glass fiber from bottom to top to obtain a quasi-solid-state zinc ion structural energy storage material; 5. thermally curing the quasi-solid-state zinc ion structural energy storage material to obtain a structural energy storage material based on a zinc ion battery. The structural energy storage material prepared by the present invention has a higher energy density, and the preparation method is simple, efficient, and reliable, does not require the use of complex precision instruments, has excellent improvement effects, and is suitable for large-scale promotion and application.

Description

Technical Field

[0001] The present invention relates to a method for preparing a structural energy storage material, and in particular to a method for preparing a high-energy-density structural energy storage material based on a zinc ion battery. Background Art

[0002] The electrification of aircraft is a key future development direction. However, the energy density of current power batteries cannot meet the long-range range requirements of drones. Increasing the number of battery packs increases weight, limiting flight range and maneuverability. Coupling structural materials with energy storage devices to achieve "structure-energy storage integration" is an effective solution. Currently, there are two mainstream design approaches: flexible soft-pack batteries wrapped in carbon fiber structural materials; and structural energy storage materials that imbue carbon fiber sheets with energy storage properties. The former can be easily achieved through mechanical coupling methods such as embedding, but the separation of the structural material and energy storage battery components does not fundamentally address the battery's weight. The latter requires the innovation of a completely new battery structure and addresses new challenges. Therefore, designing structural energy storage materials that integrate aircraft structural components with chemical power sources, thereby endowing the structural components with energy storage capabilities, is an ideal approach to addressing this issue. Summary of the Invention

[0003] This invention addresses the structural and energy storage separation issues caused by flexible batteries encased in external structural materials, as well as the low specific energy problem associated with traditional structural energy storage that still utilizes carbon fiber surface capacitance. This method provides a method for preparing structural energy storage materials based on zinc-ion batteries. The structural energy storage materials prepared by this method exhibit excellent energy storage capacity and structural load-bearing properties.

[0004] The purpose of the present invention is achieved through the following technical solutions:

[0005] A method for preparing a structural energy storage material based on a zinc ion battery comprises the following steps:

[0006] Step 1: Preparation of carbon fiber / ammonium vanadate electrode (CF@NH4V4O 10 ):

[0007] Step 11: placing the carbon fiber in a solvent for activation pretreatment, wherein the solvent is at least one of nitric acid and sulfuric acid;

[0008] Step 1 and 2: Using the carbon fiber pre-treated in step 1 as a substrate, a carbon fiber / ammonium vanadate electrode (CF@NH4V4O 10), the specific steps are as follows: dissolving ammonium metavanadate in deionized water, then adding β-cyclodextrin, dropping oxalic acid under stirring, and fully stirring to obtain a mixed solution, wherein the mass ratio of ammonium metavanadate, β-cyclodextrin, and oxalic acid is controlled to be 1:1.2-1.5:0.8-1; transferring the activated pretreated carbon fiber and the mixed solution to an autoclave, and keeping the temperature at 120-140°C for 12-48h to obtain a carbon fiber / ammonium vanadate electrode (CF@NH4V4O 10 ), the insulation time can be adjusted according to actual conditions;

[0009] Step 2: Preparation of carbon fiber / zinc electrode (CF@Zn):

[0010] Step 21: Place the carbon fiber in ammonia water with a concentration of 25-28%, keep it at 120-180° C. for 24 hours, wash it thoroughly, and then dry it to obtain the pretreated carbon fiber;

[0011] Step 2: Zinc is plated on the surface of the carbon fiber by electrodeposition to obtain a carbon fiber / zinc electrode (CF@Zn). The specific steps are as follows: zinc sulfate, sodium sulfate and boric acid are dissolved in deionized water as electrolyte, and the mass ratio of zinc sulfate, sodium sulfate and boric acid is controlled to be 1:1:0.2-0.5 in a three-electrode electrolytic cell at 20-40 mA cm -1 Electrodeposition is performed on the carbon fiber surface at a constant current density, where the current density determines the electrodeposition rate, to obtain a carbon fiber / zinc electrode (CF@Zn).

[0012] Step 3: Completely dissolve the zinc salt in the ionic liquid to obtain a mixed solution, add epoxy resin and curing agent to the mixed solution to obtain a curing precursor solution, use glass fiber as a substrate, fully infiltrate the glass fiber with the curing precursor solution, and then vacuum degas, wherein:

[0013] In the mixed solution, the mass ratio of the ionic liquid to the zinc salt is 1.016:0.2-0.5;

[0014] The mass ratio of the mixed liquid to the epoxy resin is 5-8:2-5;

[0015] The mass ratio of the epoxy resin to the curing agent is 4:1;

[0016] The epoxy resin is at least one of bisphenol F epoxy resin or bisphenol A epoxy resin;

[0017] The curing agent is an amine curing agent;

[0018] The ionic liquid is selected from at least one of 1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide (BMIM-TFSI) and 1-ethyl-3-methylimidazoline bis(trifluoromethylsulfonyl)imide (EMIM-TFSI);

[0019] The zinc salt is zinc bis(trifluoromethylsulfonyl)imide (Zn(TFSI)2), and the content of Zn(TFSI)2 is regulated according to actual conditions;

[0020] Step 4: stacking the carbon fiber / ammonium vanadate electrode in step 1, the carbon fiber / zinc electrode in step 2, and the glass fiber soaked in step 3 from bottom to top to obtain a quasi-solid-state zinc ion structure energy storage material;

[0021] Step 5: thermally curing the quasi-solid zinc ion structured energy storage material obtained in step 4 to obtain a structured energy storage material based on a zinc ion battery. After curing, the electrolyte exhibits a bicontinuous phase microstructure, wherein:

[0022] The thermal curing mechanism is as follows: keeping the temperature at 60-80°C for 2-4 hours, then keeping the temperature at 90-120°C for 1-3 hours, and then keeping the temperature at 60-80°C overnight, with the temperature ramp rate controlled at 2-4°C / min;

[0023] The specific energy density of the structural energy storage material is based on the positive electrode NH4V4O 10 Calculation shows that the mass of the positive electrode per unit area is 1.0-1.5 mg / cm 2 ;

[0024] The structural energy storage material can be applied in structural zinc ion batteries.

[0025] Compared with the prior art, the present invention has the following advantages:

[0026] 1. Currently, structural energy storage still relies on carbon fiber surface adsorption for energy storage. Embedded battery behavior can provide higher energy density.

[0027] 2. Use environmentally tolerant zinc-ion battery systems to cope with practical applications in complex situations.

[0028] 3. The electrolyte with a bicontinuous phase microstructure is a key component in providing both mechanical load-bearing and ion conduction. Its formation is driven by the fact that within a similar temperature window, the solubility of the polymer in the solvent decreases, causing the solution to separate into two phases. When the system separates into two phases and eventually reaches phase equilibrium, the diffusion of each component between the two phases reaches a dynamic equilibrium, and the phase separation behavior can be described by the Cahn-Hilliard equation. On the one hand, the ionic liquid exists in the through-pores to facilitate zinc ion transport, while on the other hand, the resin curing behavior affects the structural strength of the electrolyte. This microstructure can be adjusted to achieve the optimal solution to the structure-energy storage game. Therefore, zinc-ion batteries with this structure can exhibit stable long-cycle performance and excellent mechanical load-bearing capacity at room temperature.

[0029] 4. The structural energy storage material prepared by the present invention has a higher energy density, and the preparation method is simple, efficient and reliable, does not require the use of complex precision instruments, has excellent improvement effects, and is suitable for large-scale promotion and application. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 The figures are for comparison of the ionic conductivity values of the zinc ion structure electrolytes in the comparative example and Examples 1, 2, and 3.

[0031] Figure 2 are scanning electron microscope photos of the zinc ion structure electrolyte, and a to d are scanning electron microscope photos of the zinc ion structure electrolyte in the comparative example, embodiment 3, embodiment 2, and embodiment 1, respectively.

[0032] Figure 3 Schematic diagram of the zinc ion structure energy storage material demonstration and its mechanical bearing capacity in Example 1.

[0033] Figure 4 This is a long cycle performance diagram of the zinc ion structure energy storage material in Example 1.

[0034] Figure 5 This is the charge and discharge curve of the zinc ion structure energy storage material in Example 1. DETAILED DESCRIPTION

[0035] The technical solution of the present invention is further described below with reference to the embodiments, but is not limited thereto. Any modification or equivalent replacement of the technical solution of the present invention that does not depart from the spirit and scope of the technical solution of the present invention should be included in the scope of protection of the present invention.

[0036] Example 1

[0037] This embodiment provides a method for preparing a structural energy storage material based on a zinc ion battery, the method comprising the following steps:

[0038] Step 1: Place the cleaned carbon cloth (5×5cm) in a 1M sulfuric acid solution and ultrasonicate for 1h before washing. Weigh 283.5mg of ammonium metavanadate and stir to dissolve it in 30mL of deionized water. Then add 341mg of β-cyclodextrin and stir the mixture for 30min. While stirring, add 235mg of oxalic acid dropwise into the mixture and stir thoroughly for 90min. Transfer the pretreated carbon fiber and the mixture to an autoclave, keep it at 120℃ for 12h, and cool it naturally to obtain CF@NH4V4O 10 .

[0039] Step 2: Place the cleaned carbon cloth (5×5 cm) in 60 mL of 25-28% ammonia water and keep it at 150°C for 24 hours to wash it thoroughly. Prepare 20 g of zinc sulfate, 20 g of sodium sulfate and 6.6 g of boric acid dissolved in 150 mL of deionized water as electrolyte and place it in a three-electrode electrolytic cell at 40 mA cm -1 CF@Zn was obtained by electrodeposition on the carbon fiber surface at a constant current density.

[0040] Step 3: Completely dissolve 0.3 g Zn(TFSI)2 in 1.016 g EMIM-TFSI to obtain a mixed solution, prepare the mixed solution and bisphenol F epoxy resin in a mass ratio of 7:3, add polyetheramine (mass ratio to epoxy resin 1:4) and stir thoroughly to obtain a curing precursor solution, fully infiltrate the glass fiber (5.2×5.2 cm) with the curing precursor solution, and vacuum degas for 15 minutes.

[0041] Step 4: Assemble the carbon fiber composite material obtained in steps 1 and 2 and the glass fiber soaked in step 3 by stacking from bottom to top to obtain a quasi-solid-state zinc ion structure energy storage material.

[0042] Step 5: Transfer the quasi-solid zinc ion structure energy storage material to an oven, keep it at 70°C for 3 hours, then keep it at 100°C for 2 hours, and then keep it at 70°C overnight, with a temperature change rate of 3°C min -1 , a zinc ion structure energy storage material is obtained, and the dimensions of the structure energy storage material are as follows: length 50 mm, width 50 mm, and thickness 2.5 mm.

[0043] Example 2

[0044] This embodiment provides a method for preparing a structural energy storage material based on a zinc ion battery, the method comprising the following steps:

[0045] Step 1: Place the cleaned carbon cloth (5×5cm) in a 1M sulfuric acid solution and ultrasonicate for 1h before washing. Weigh 283.5mg of ammonium metavanadate and stir to dissolve it in 30mL of deionized water. Then add 341mg of β-cyclodextrin and stir the mixture for 30min. While stirring, add 235mg of oxalic acid dropwise into the mixture and stir thoroughly for 90min. Transfer the pretreated carbon fiber and the mixture to an autoclave, keep it at 120℃ for 12h, and cool it naturally to obtain CF@NH4V4O 10 .

[0046] Step 2: Place the cleaned carbon cloth (5×5 cm) in 60 mL of 25-28% ammonia water and keep it at 180°C for 24 hours to wash it thoroughly. Prepare 20 g of zinc sulfate, 20 g of sodium sulfate and 6.6 g of boric acid dissolved in 150 mL of deionized water as electrolyte and place it in a three-electrode electrolytic cell at 40 mA cm -1CF@Zn was obtained by electrodeposition on the carbon fiber surface at a constant current density.

[0047] Step 3: Completely dissolve 0.3 g Zn(TFSI)2 in 1.016 g EMIM-TFSI to obtain a mixed solution, prepare the mixed solution and bisphenol F epoxy resin in a mass ratio of 6.5:3.5, add polyetheramine (mass ratio to epoxy resin 1:4) and stir thoroughly to obtain a curing precursor solution, fully soak the glass fiber (5.2×5.2 cm) in the precursor solution, and vacuum degas for 15 minutes.

[0048] Step 4: Assemble the carbon fiber composite material obtained in steps 1 and 2 and the glass fiber soaked in step 3 by stacking from bottom to top to obtain a quasi-solid-state zinc ion structure energy storage material.

[0049] Step 5: Transfer the quasi-solid zinc ion structure energy storage material to an oven, keep it at 70°C for 3 hours, then keep it at 100°C for 2 hours, and then keep it at 70°C overnight, with a temperature change rate of 3°C min -1 , a zinc ion structure energy storage material is obtained, and the dimensions of the structure energy storage material are as follows: length 50 mm, width 50 mm, and thickness 2.5 mm.

[0050] Example 3

[0051] This embodiment provides a method for preparing a structural energy storage material based on a zinc ion battery, the method comprising the following steps:

[0052] Step 1: Place the cleaned carbon cloth (5×5cm) in a 1M sulfuric acid solution and ultrasonicate for 1h before washing. Weigh 283.5mg of ammonium metavanadate and stir to dissolve it in 30mL of deionized water. Then add 341mg of β-cyclodextrin and stir the mixture for 30min. While stirring, add 235mg of oxalic acid dropwise into the mixture and stir thoroughly for 90min. Transfer the pretreated carbon fiber and the mixture to an autoclave, keep it at 120℃ for 12h, and cool it naturally to obtain CF@NH4V4O 10 .

[0053] Step 2: Place the cleaned carbon cloth (5×5 cm) in 60 mL of 25-28% ammonia water and keep it at 120°C for 24 hours to wash it thoroughly. Prepare 20 g of zinc sulfate, 20 g of sodium sulfate and 6.6 g of boric acid dissolved in 150 mL of deionized water as electrolyte and place it in a three-electrode electrolytic cell at 40 mA cm -1 CF@Zn was obtained by electrodeposition on the carbon fiber surface at a constant current density.

[0054] Step 3: Completely dissolve 0.3 g Zn(TFSI)2 in 1.016 g EMIM-TFSI to obtain a mixed solution, prepare the mixed solution and bisphenol F epoxy resin in a mass ratio of 6:4, add polyetheramine (mass ratio to epoxy resin 1:4) and stir thoroughly to obtain a curing precursor solution, fully infiltrate the glass fiber (5.2×5.2 cm) with the curing precursor solution, and vacuum degas for 15 minutes.

[0055] Step 4: Assemble the carbon fiber composite material obtained in steps 1 and 2 and the glass fiber soaked in step 3 by stacking from bottom to top to obtain a quasi-solid-state zinc ion structure energy storage material.

[0056] Step 5: Transfer the quasi-solid zinc ion structure energy storage material to an oven, keep it at 70°C for 3 hours, then keep it at 100°C for 2 hours, and then keep it at 70°C overnight, with a temperature change rate of 3°C min -1 , a zinc ion structure energy storage material is obtained, and the dimensions of the structure energy storage material are as follows: length 50 mm, width 50 mm, and thickness 2.5 mm.

[0057] Comparative Example

[0058] The difference between this comparative example and Example 1 is that in the curing precursor solution, the mass proportion of bisphenol F epoxy resin is 50% or more, and the electrolyte cannot form a bicontinuous phase structure after curing and basically has no energy storage capacity.

[0059] Figure 1 The comparison shows that the ohmic impedance and ionic conductivity of the embodiment are much higher than those of the comparative example. Reasonable regulation of the structural electrolyte components can greatly improve the ion conduction performance. Figure 2 The microstructure of the structural electrolyte, combined with Figure 1 It is observed that the abundance rate of through-pore structures in structured electrolytes is positively correlated with the ionic conductivity of the structured electrolytes. Figure 3 This shows that this material has excellent mechanical stress and can meet the structural bearing requirements. Figure 4 This shows that the energy storage mode of structural energy storage materials is battery behavior. Figure 5 This shows that this structural energy storage material has excellent long-cycle performance and has potential application value.

Claims

1. A method for preparing a structural energy storage material based on a zinc ion battery, characterized in that The method comprises the following steps: Step 1: Preparation of carbon fiber / ammonium vanadate electrode: Step 11: placing the carbon fiber in a solvent for activation pretreatment; Step 12: Using the carbon fiber pre-treated by activation in step 1 as a substrate, a carbon fiber / ammonium vanadate electrode is prepared by a hydrothermal method; Step 2: Preparation of carbon fiber / zinc electrode: Step 21: Place the carbon fiber in ammonia water, keep it at 120-180°C for 24 hours, wash it thoroughly, and then dry it to obtain the pretreated carbon fiber; Step 22: zinc is plated on the surface of the carbon fiber by electrodeposition to obtain a carbon fiber / zinc electrode; Step 3: completely dissolving the zinc salt in the ionic liquid to obtain a mixed solution, adding an epoxy resin and a curing agent to the mixed solution to obtain a curing precursor solution, using glass fiber as a substrate, fully infiltrating the glass fiber with the curing precursor solution, and then vacuum degassing, wherein: in the mixed solution, the mass ratio of the ionic liquid to the zinc salt is 1.016:0.2-0.5; the mass ratio of the mixed solution to the epoxy resin is 5-8:2-5; and the mass ratio of the epoxy resin to the curing agent is 4:1; Step 4: stacking the carbon fiber / ammonium vanadate electrode in step 1, the carbon fiber / zinc electrode in step 2, and the glass fiber soaked in step 3 from bottom to top to obtain a quasi-solid-state zinc ion structure energy storage material; Step 5: thermally solidify the quasi-solid zinc ion structure energy storage material obtained in step 4 to obtain a structure energy storage material based on a zinc ion battery.

2. The method for preparing a structural energy storage material based on a zinc ion battery according to claim 1, wherein In the step 11, the solvent is at least one of nitric acid and sulfuric acid.

3. The method for preparing a structural energy storage material based on a zinc ion battery according to claim 1, wherein The specific steps of steps one and two are as follows: dissolving ammonium metavanadate in deionized water, then adding β-cyclodextrin, adding oxalic acid dropwise while stirring, and obtaining a mixed solution after sufficient stirring, wherein the mass ratio of ammonium metavanadate, β-cyclodextrin, and oxalic acid is controlled to be 1:1.2-1.5:0.8-1; transferring the activated pretreated carbon fiber and the mixed solution to an autoclave, and keeping the mixture at 120-140°C for 12-48 hours to obtain a carbon fiber / ammonium vanadate electrode.

4. The method for preparing a structural energy storage material based on a zinc ion battery according to claim 1, wherein The specific steps of step 22 are as follows: dissolving zinc sulfate, sodium sulfate and boric acid in deionized water as electrolyte, controlling the mass ratio of zinc sulfate, sodium sulfate and boric acid to be 1:1:0.2-0.5, and conducting the electrolysis in a three-electrode electrolytic cell at 20-40 mA cm -1 Electrodeposition was performed on the carbon fiber surface at a constant current density to obtain a carbon fiber / zinc electrode.

5. The method for preparing a structural energy storage material based on a zinc ion battery according to claim 1, wherein In the step 3, the epoxy resin is at least one of bisphenol F epoxy resin and bisphenol A epoxy resin, and the curing agent is an amine curing agent.

6. The method for preparing a structural energy storage material based on a zinc ion battery according to claim 1, wherein The ionic liquid is selected from at least one of 1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide (BMIM-TFSI) and 1-ethyl-3-methylimidazoline bis(trifluoromethylsulfonyl)imide (EMIM-TFSI), and the zinc salt is zinc bis(trifluoromethylsulfonyl)imide (Zn(TFSI)2).

7. The method for preparing a structural energy storage material based on a zinc ion battery according to claim 1, wherein In step five, the thermal curing mechanism is as follows: keeping the temperature at 60-80°C for 2-4 hours, then keeping the temperature at 90-120°C for 1-3 hours, and then keeping the temperature at 60-80°C overnight, with the temperature change rate controlled at 2-4°C / min.

8. The method for preparing a structural energy storage material based on a zinc ion battery according to claim 1, wherein In step 5, the mass of the positive electrode per unit area is 1.0-1.5 mg / cm 2 .

9. A structural energy storage material based on a zinc ion battery prepared by the method according to any one of claims 1 to 8.

10. Use of a structural energy storage material based on a zinc ion battery prepared by the method according to any one of claims 1 to 8 in a structural zinc ion battery.

Images