Preparation method of quasi-solid electrolyte for zinc ion battery with dual functions of load-carrying and ion-conducting

Abstract

The present invention discloses a preparation method of a quasi-solid electrolyte for a zinc ion battery with a dual function of carrying ion conduction, the method comprising the following steps: step one: zinc salt is completely dissolved in an ionic liquid to obtain a mixed solution, epoxy resin and a curing agent are added to the mixed solution to obtain a solidification precursor solution; step two: using ultrathin glass fiber as a substrate, the solidification precursor solution configured in step one is completely impregnated; step three: pre-curing after vacuum degassing of the glass fiber prepreg; step four: the glass fiber prepreg after pre-curing is first kept warm at 60 to 80 ° C for 2 to 4 hours, then kept warm at 90 to 120 ° C for 1 to 3 hours, and then overnight at 60 to 80 ° C to obtain a quasi-solid electrolyte for a zinc ion battery. The quasi-solid electrolyte prepared by the present invention is specifically suitable for structural energy storage zinc ion batteries, and the preparation method is simple, efficient and reliable, does not need to use a sophisticated instrument with complex operation, and is easy to apply on a large scale.

Description

Technical Field

[0001] The present invention belongs to the technical field of structural energy storage, and relates to a method for preparing a quasi-solid-state electrolyte, and specifically to a method for preparing a quasi-solid-state polymer electrolyte with dual functions of load-bearing and ion conductivity based on a zinc ion battery system. Background Art

[0002] Electrification is an inevitable trend in the iteration of small spacecraft. However, the existing power batteries are not enough to meet the high mileage requirements of drones, and increasing the number of energy storage devices will reduce their mass energy density. In order to solve this problem, achieving energy storage and structural integrity at the same time is an effective solution to improve system efficiency. Solid electrolytes are key components for realizing multifunctional energy storage devices. However, there is a common correlation: as the mechanical properties of the electrolyte increase, the ionic conductivity decreases. The homogeneous electrolyte systems currently being studied, such as liquid electrolytes, gel electrolytes, and solid polymer electrolytes, the former two have high ionic conductivity but basically do not provide any mechanical properties. The latter exhibits better mechanical properties, but the low ionic conductivity is not enough to support practical applications. Therefore, designing a quasi-solid electrolyte with the dual functions of load-bearing and ion conductivity is an important way to realize structural energy storage zinc-ion batteries. Summary of the Invention

[0003] This invention addresses the issues of uneven mechanical loading and ionic conductivity of solid-state electrolytes, as well as the poor environmental tolerance of conventional solid-state electrolytes, by providing a method for preparing a quasi-solid-state electrolyte for zinc-ion batteries that possesses both load-bearing and ion-conducting properties. The quasi-solid-state electrolyte prepared in this invention is specifically suitable for structural energy storage zinc-ion batteries. The preparation method is simple, efficient, and reliable, requiring no complex precision instruments, making it easy to scale up and apply.

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

[0005] A method for preparing a quasi-solid electrolyte for zinc ion batteries having dual functions of load-carrying and ion-conducting properties comprises the following steps:

[0006] Step 1: 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, wherein:

[0007] In the mixed solution, the mass ratio of the ionic liquid to the zinc salt is 1.016:0.2-0.5;

[0008] The mass ratio of the mixed liquid to the epoxy resin is 5-8:2-5;

[0009] The mass ratio of the epoxy resin to the curing agent is 4:1;

[0010] The epoxy resin is at least one of bisphenol F epoxy resin and bisphenol A epoxy resin;

[0011] The resin curing agent is an amine curing agent;

[0012] 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);

[0013] The zinc salt is zinc bis(trifluoromethylsulfonyl)imide (Zn(TFSI)2), and the content of Zn(TFSI)2 is regulated according to actual conditions;

[0014] The solidification precursor liquid needs to be fully stirred at a stirring rate of 200 to 300 rmin -1 ;

[0015] Step 2: Using ultra-thin glass fiber as the substrate, completely soak it in the curing precursor solution prepared in step 1;

[0016] Step 3: vacuum degassing the glass fiber prepreg and pre-curing it, wherein:

[0017] The pre-curing temperature is 50-70°C and the time is 5-10 minutes to prevent the curing precursor from leaking in the subsequent process;

[0018] Step 4: thermally curing the pre-cured glass fiber prepreg to obtain a quasi-solid electrolyte for zinc ion batteries, wherein:

[0019] The thermal curing mechanism is as follows: first keep the temperature at 60-80℃ for 2-4h, then keep the temperature at 90-120℃ for 1-3h, and then keep the temperature at 60-80℃ overnight, with the temperature change rate controlled at 2-4℃min -1 .

[0020] Compared with the prior art, the present invention has the following advantages:

[0021] 1. Currently, most structural energy storage devices are limited to structural capacitors and structural supercapacitors. The quasi-solid electrolyte prepared by the present invention is used in structural batteries, which can provide higher energy density.

[0022] 2. The present invention uses an environmentally tolerant zinc ion battery system to cope with the complex environmental conditions in practical applications of small and medium-sized drones.

[0023] 3. The quasi-solid electrolyte prepared by the present invention exhibits a dual-continuous phase microstructure, which is a key part in achieving the dual functions of load-bearing and ion conductivity. For its formation, 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 is divided into two phases and finally 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 is present in the through-pores to provide an ion transport phase, and on the other hand, the rigid structure formed after the resin is cured determines the structural strength of the electrolyte. This microstructure is adjustable to obtain the optimal solution to the structure-energy storage game. Therefore, this quasi-solid electrolyte for zinc-ion batteries can exhibit excellent ionic conductivity and excellent mechanical load-bearing capacity at room temperature.

[0024] 4. The bifunctional solid electrolyte prepared by the present invention can be used in zinc ion structure energy storage batteries and provide considerable energy density. The preparation method is simple, efficient and reliable, and does not require the use of complex precision instruments. The improvement effect is beneficial and suitable for large-scale promotion and application. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 These are the impedance diagrams of the SS||SS symmetric batteries assembled with the quasi-solid electrolytes of the zinc-ion batteries in Examples 1, 2, and 3, where SS is the abbreviation of stainless steel sheet.

[0026] Figure 2 The figures are for comparison of the ionic conductivity values ​​of the quasi-solid electrolytes of zinc ion batteries in the comparative example and examples 1, 2 and 3.

[0027] Figure 3 The figures a and b are scanning electron microscope images of the quasi-solid electrolyte of zinc ion batteries, respectively, and are used to illustrate the microscopic morphology of the electrolyte under different examples.

[0028] Figure 4 ] is the tensile stress and tensile deformation correlation curve of the quasi-solid electrolyte in Example 1, wherein EP is the abbreviation of epoxyresin, meaning epoxy resin.

[0029] Figure 5 This is a demonstration of the quasi-solid electrolyte bending experiment for a zinc ion battery assembled with the quasi-solid electrolyte in Example 1. DETAILED DESCRIPTION

[0030] 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.

[0031] Example 1

[0032] This embodiment provides a method for preparing a quasi-solid electrolyte for a zinc ion battery, the method comprising the following steps:

[0033] Step 1: Stir 0.3 g Zn(TFSI)2 in 1.016 g EMIM-TFSI for 6 h to obtain a homogeneous, clear solution.

[0034] Step 2: Add 0.564 g of bisphenol F epoxy resin and 0.141 g of polyetheramine to the clear solution obtained in step 1, and stir thoroughly for 15 minutes to obtain a curing precursor solution.

[0035] Step 3: After the ultra-thin glass fiber is fully soaked in the curing precursor liquid, vacuum degassing is performed and the temperature is kept at 70°C for 5 minutes.

[0036] Step 4: Heat the glass fiber prepreg at 70℃ for 3h, then at 100℃ for 2h, and then at 70℃ overnight, with a temperature change rate of 3℃min -1 , a zinc ion quasi-solid electrolyte was obtained. The dimensions of the zinc ion battery quasi-solid electrolyte are as follows: length 55 mm, width 55 mm, and thickness 2.5 mm.

[0037] Example 2

[0038] This embodiment provides a method for preparing a quasi-solid electrolyte for a zinc ion battery, the method comprising the following steps:

[0039] Step 1: Stir 0.3 g Zn(TFSI)2 in 1.016 g EMIM-TFSI for 6 h to obtain a homogeneous, clear solution.

[0040] Step 2: Add 0.709 g of bisphenol F epoxy resin and 0.177 g of polyetheramine to the clarified liquid obtained in step 1, and stir thoroughly for 15 minutes to obtain a curing precursor solution.

[0041] Step 3: After the ultra-thin glass fiber is fully soaked in the curing precursor liquid, vacuum degassing is performed and the temperature is kept at 70°C for 5 minutes.

[0042] Step 4: Heat the glass fiber prepreg at 70℃ for 3h, then at 100℃ for 2h, and then at 70℃ overnight, with a temperature change rate of 3℃min -1, a zinc ion quasi-solid electrolyte was obtained. The dimensions of the zinc ion battery quasi-solid electrolyte are as follows: length 55 mm, width 55 mm, and thickness 2.5 mm.

[0043] Example 3

[0044] This embodiment provides a method for preparing a quasi-solid electrolyte for a zinc ion battery, the method comprising the following steps:

[0045] Step 1: Stir 0.3 g Zn(TFSI)2 in 1.016 g EMIM-TFSI for 6 h to obtain a homogeneous, clear solution.

[0046] Step 2: Add 0.877 g of bisphenol F epoxy resin and 0.219 g of polyetheramine to the clarified liquid obtained in step 1, and stir thoroughly for 15 minutes to obtain a curing precursor solution.

[0047] Step 3: After the ultra-thin glass fiber is fully soaked in the curing precursor liquid, vacuum degassing is performed and the temperature is kept at 70°C for 5 minutes.

[0048] Step 4: Heat the glass fiber prepreg at 70℃ for 3h, then at 100℃ for 2h, and then at 70℃ overnight, with a temperature change rate of 3℃min -1 , a zinc ion quasi-solid electrolyte was obtained. The dimensions of the zinc ion battery quasi-solid electrolyte are as follows: length 55 mm, width 55 mm, and thickness 2.5 mm.

[0049] Comparative Example

[0050] The difference between this comparative example and experimental example 1 is that the bisphenol F epoxy resin in the curing precursor solution accounts for 50% or more, and the electrolyte cannot form a bicontinuous phase structure after curing and basically has no ion conductivity.

[0051] Figure 1 and Figure 2 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 quasi-solid electrolyte components can greatly improve the ion conductivity performance. Figure 3 The microstructure of the quasi-solid electrolyte, combined with Figure 1 、 Figure 2 It is observed that the abundance of through-pore structures in quasi-solid electrolytes is positively correlated with the electrolyte ion conductivity. Figure 4 It shows that the embodiments can show better performance when the tensile strength increases. Figure 5 The bending performance test of structural energy storage zinc-ion batteries was demonstrated to meet the structural load-bearing requirements.

Claims

1. A method for preparing a quasi-solid electrolyte for zinc ion batteries having dual functions of load-carrying and ion-conducting properties, characterized in that The method comprises the following steps: Step 1: Completely dissolving the zinc salt in the ionic liquid to obtain a mixed solution, and adding the epoxy resin and the curing agent to the mixed solution to obtain a curing precursor solution, 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 2: Using ultra-thin glass fiber as the substrate, completely soak it in the curing precursor solution prepared in step 1; Step 3: vacuum degassing and pre-curing the glass fiber prepreg; Step 4: thermally curing the pre-cured glass fiber prepreg to obtain a quasi-solid electrolyte for zinc ion batteries.

2. The method for preparing a quasi-solid electrolyte for zinc ion batteries having dual functions of load-carrying and ion-conducting properties according to claim 1, wherein In the step 1, the epoxy resin is at least one of bisphenol F epoxy resin and bisphenol A epoxy resin.

3. The method for preparing a quasi-solid electrolyte for zinc ion batteries having dual functions of load-carrying and ion-conducting properties according to claim 1, wherein In the step 1, the resin curing agent is an amine curing agent.

4. The method for preparing a quasi-solid electrolyte for zinc ion batteries having dual functions of load-carrying and ion-conducting properties according to claim 1, wherein In the step 1, 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).

5. The method for preparing a quasi-solid electrolyte for zinc ion batteries having dual functions of load-carrying and ion-conducting properties according to claim 1, wherein In the step 1, the zinc salt is zinc bis(trifluoromethylsulfonyl)imide (Zn(TFSI)2).

6. The method for preparing a quasi-solid electrolyte for zinc ion batteries having dual functions of load-carrying and ion-conducting properties according to claim 1, wherein In the first step, the solidification precursor solution needs to be fully stirred at a stirring rate of 200 to 300 rmin. -1 .

7. The method for preparing a quasi-solid electrolyte for zinc ion batteries having dual functions of load-carrying and ion-conducting properties according to claim 1, wherein In the step 3, the pre-curing temperature is 50-70° C. and the time is 5-10 minutes.

8. The method for preparing a quasi-solid electrolyte for zinc ion batteries having dual functions of load-carrying and ion-conducting according to claim 1, characterized in that In step 4, the thermal curing mechanism is as follows: first, keep the temperature at 60-80°C for 2-4 hours, then keep the temperature at 90-120°C for 1-3 hours, and then keep the temperature at 60-80°C overnight, with the temperature change rate controlled at 2-4°C min -1 .

9. A quasi-solid electrolyte for zinc ion batteries having dual functions of load-carrying and ion-conducting properties, prepared by the method according to any one of claims 1 to 8.

10. Use of a zinc ion battery quasi-solid electrolyte having dual functions of load-bearing and ion-conducting prepared by the method according to any one of claims 1 to 8 in a structural energy storage zinc ion battery.

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