Quasi-solid-state zinc symmetric battery and zinc ion battery based on in-situ cross-linked dual-network hydrogel electrolyte and preparation method of quasi-solid-state zinc symmetric battery and zinc ion battery

Abstract

The invention discloses a quasi-solid-state zinc symmetric battery and a zinc ion battery based on in-situ cross-linked dual-network hydrogel electrolyte and a preparation method thereof, xanthan gum, acrylamide and the like are used as raw materials, a simple one-pot method is adopted, the quasi-solid-state zinc symmetric battery and the zinc ion battery are integrated through one-step in-situ cross-linking, the preparation method is simple and convenient, the consumed time is short, and the cost is low. The method is environment-friendly; the gel electrolyte is of a double-network interlaced structure, and in-situ crosslinking and device integration effectively improve the interface contact of electrode-electrolyte and reduce the interface impedance; the quasi-solid-state zinc symmetric battery and the zinc ion battery based on the in-situ dual-network hydrogel electrolyte have long cycle life, good interface compatibility and interface stability, and a feasible scheme is provided for a quasi-solid-state device and a flexible bendable device.

Description

Technical Field

[0001] The present invention relates to the technical field of energy storage, in particular to a quasi-solid-state zinc symmetric battery and a zinc ion battery based on an in-situ cross-linked double-network hydrogel electrolyte and a preparation method thereof. Background Art

[0003] Due to its high safety, low cost and environmental friendliness, the aqueous zinc ion battery has shown broad application prospects in large-scale energy storage systems. The aqueous zinc ion battery generally consists of a metallic zinc negative electrode, an organic or inorganic transition metal compound positive electrode, a glass fiber separator and an aqueous electrolyte containing zinc ions. However, since the metallic zinc negative electrode faces many challenges such as zinc dendrite growth, hydrogen evolution reaction, by-products, etc. in aqueous solution, it severely restricts the service life of the aqueous zinc ion battery.

[0004] In recent years, hydrogel electrolytes have received extensive attention from researchers at home and abroad due to their unique physical and chemical properties, and can replace the aqueous electrolyte and separator in traditional aqueous zinc ion batteries. The hydrogel electrolyte combines the safety of solid electrolytes and the high ionic conductivity of liquid electrolytes, and can not only effectively inhibit the growth of zinc dendrites, but also inhibit the occurrence of side reactions.

[0005] In the prior art, the preparation of hydrogel electrolytes usually involves first preparing a hydrogel matrix with almost no ionic conductivity, and then soaking it in a certain electrolyte. Through the swelling process and ion diffusion behavior of the hydrogel, a certain amount of electrolyte is retained inside the hydrogel, thereby endowing the hydrogel with ionic conductive properties. However, this method has many drawbacks. For example, the water absorption process of the hydrogel after soaking in the aqueous electrolyte will destroy the original cross-linked structure, resulting in significant volume swelling of the hydrogel electrolyte and a sharp decline in mechanical properties. Moreover, the hydrogel needs to be soaked in the corresponding electrolyte for a long time and the fresh electrolyte needs to be replaced frequently, with complex operations and long time consumption, which is not conducive to practical applications. Most importantly, the water content of this kind of hydrogel electrolyte is generally high, and it is still easy to cause problems such as hydrogen evolution and zinc dendrite growth. Hu et al. prepared a hydrogel electrolyte for aqueous zinc ion batteries using polyvinyl alcohol and agar. The preparation process requires an electrolyte activation process of 2 - 3 days, and the life in the Zn symmetric battery is only 200 hours, and the rate performance is also not ideal.

[0006] It can be seen that developing a hydrogel electrolyte with a simple preparation process, one-pot in-situ cross-linking, and one-step integration with the electrode, as well as a quasi-solid-state zinc symmetric battery and an aqueous zinc ion battery based on it, is the key to solving the above problems and improving the cycle stability, rate performance, Coulomb efficiency, etc. of the device. Summary of the Invention

[0007] The object of the present invention is to solve the problems existing in the prior art, and to provide a quasi-solid-state zinc symmetric battery and an aqueous zinc ion battery based on an in-situ double-network hydrogel electrolyte and a preparation method thereof. By adopting a strategy of in-situ cross-linking and integration of the hydrogel electrolyte and the electrode, through a simple one-pot method, the interfacial conditions between the electrode and the electrolyte are effectively improved, the growth of zinc dendrites is inhibited, the cycle stability of the quasi-solid-state zinc symmetric battery is enhanced, and at the same time, a feasible solution is provided for the flexible quasi-solid-state aqueous zinc ion battery.

[0008] To achieve the above object, the present invention is implemented according to the following technical solutions: The object of the present invention is to provide a zinc symmetric battery and a zinc ion battery based on an in-situ double-network hydrogel electrolyte and a preparation method thereof, including the following steps: (1) Add a certain mass of xanthan gum to an aqueous zinc sulfate solution, stir at 80 °C until the xanthan gum is completely dissolved, then cool to room temperature, and then add acrylamide, N,N'-methylenebisacrylamide and potassium persulfate in sequence. Stir at room temperature for 1 to 2 hours until fully dissolved, and then ultrasonicate for 20 minutes to remove the bubbles in the mixed solution; (2) Use a pipette to measure a certain amount of the mixed solution after ultrasonication in step (1), and drop it on the surface of a zinc foil with a diameter of 10 to 16 mm; (3) After step (2), immediately cover another zinc foil of the same size on the droplet, and cross-link for a certain time at room temperature to obtain a quasi-solid-state zinc symmetric battery; (4) After step (2), immediately cover another positive electrode of the same size on the droplet, and cross-link for a certain time at room temperature to obtain a quasi-solid-state zinc ion battery.

[0009] Further, the amount of xanthan gum added in step (1) is 0.005 to 0.1 g.

[0010] Further, the concentration of the aqueous zinc sulfate solution in step (1) is 1 to 2 mol / L, and the volume is 5 to 20 mL.

[0011] Further, the mass of acrylamide added in step (1) is 50 to 200 times the amount of xanthan gum added, the amount of N,N'-methylenebisacrylamide added is 5% to 30% of the amount of xanthan gum added, and the amount of potassium persulfate added is 15% to 80% of the amount of xanthan gum added.

[0012] Further, the volume of the mixed solution measured by the pipette in step (2) is 100 to 200 μL.

[0013] Further, the cross-linking time in step (3) is 30 minutes to 1 hour.

[0014] Further, the positive electrode in step (4) can be selected from materials suitable for use as the positive electrode of a zinc ion battery, such as manganese-based and vanadium-based materials.

[0015] Further, the positive electrode in step (4) needs to be treated in a salt solution of a halogen, and the treatment time is 5 minutes to 1 hour.

[0016] Further, the positive electrode in step (4) is prepared by a coating method, and the current collector can be selected from stainless steel mesh, titanium mesh, titanium foil, stainless steel foil, etc.

[0017] Further, the crosslinking time in step (4) is 30 minutes to 2 hours.

[0018] Compared with the prior art, the present invention has the following beneficial effects: (1) A hydrogel electrolyte is obtained by in-situ crosslinking an electrolyte containing zinc ions with xanthan gum / acrylamide through a one-pot method. The preparation method is simple, time-consuming, and environmentally friendly. (2) The in-situ crosslinked double-network hydrogel undergoes a chemical redox reaction with the surface of the zinc foil, effectively improving the interface contact between the electrode and the electrolyte and reducing the interface impedance. (3) The in-situ crosslinked double-network hydrogel promotes the preferential deposition of zinc ions along the (002) crystal plane during charge and discharge, effectively avoiding the growth of zinc dendrites and improving the cycle stability of the device and the reversibility of Zn deposition / dissolution during charge and discharge. (4) The zinc symmetric battery based on the in-situ double-network hydrogel electrolyte can maintain an ultra-long cycle life of 1550 hours under the conditions of 1 mA / cm 2 and 1 mAh / cm 2 ; (5) The in-situ crosslinked double-network hydrogel electrolyte provides a feasible solution for quasi-solid-state aqueous zinc ion batteries and flexible and bendable devices due to its good interface compatibility and interface stability.

[0019] Therefore, the present invention has important practical significance and application value for ultra-long cycle life quasi-solid-state zinc-based energy storage devices and their applications in flexible and wearable electronic devices. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 is a schematic diagram of the cross-sectional electron microscope scanning structure of the in-situ crosslinked double-network hydrogel in the present invention; Figure 2 is a schematic diagram of the cycle life of the zinc symmetric battery based on the in-situ crosslinked double-network hydrogel electrolyte in the present invention; Figure 3 is a schematic diagram of the rate performance of the zinc symmetric battery based on the in-situ crosslinked double-network hydrogel electrolyte in the present invention; Figure 4Schematic diagram of charge-discharge cycle stability and Coulomb efficiency of a zinc-ion battery based on an in-situ crosslinked double-network hydrogel electrolyte in the present invention. Detailed implementation manners

[0021] To make the objectives, technical solutions and advantages of the present invention clearer and more understandable, the present invention will be further described in detail below in conjunction with embodiments. The specific embodiments described herein are only used to explain the present invention and are not used to limit the invention. Embodiment 1

[0022] (1) Add 0.02 g of xanthan gum to 5 mL of 2 mol / L zinc sulfate aqueous solution, stir at 80 °C until the xanthan gum is completely dissolved, then cool to room temperature. Then, add 2 g of acrylamide, 1.5 mg of N,N'-methylenebisacrylamide and 10 mg of potassium persulfate in sequence. Stir at room temperature for 1 hour until completely dissolved, and then ultrasonicate for 20 min to remove the bubbles in the mixed solution; (2) Use a pipette to measure 130 μL of the mixed solution after ultrasonication in step (1), and drop it on the surface of a zinc foil with a diameter of 12 mm; (3) After step (2), immediately cover another zinc foil of the same size on the droplet, and crosslink at room temperature for 30 minutes to obtain a quasi-solid-state zinc symmetric battery; (4) After step (2), immediately cover another positive electrode of the same size on the droplet. The positive electrode is made of a manganese-based material. The positive electrode is prepared by a coating method. The current collector is a stainless steel mesh. The coated positive electrode is treated with potassium iodide solution for 10 minutes and crosslinked at room temperature for 1 hour to obtain a quasi-solid-state zinc-ion battery.

[0023] The schematic diagram of the cross-sectional electron microscopy scanning structure of the in-situ crosslinked double-network hydrogel prepared in this example is as Figure 1 shown. It can be seen that the cross-section of the in-situ crosslinked double-network hydrogel prepared in this example has a three-dimensional porous structure and shows a double-network intertwined morphology. Embodiment 2

[0024] (1) Add 0.02 g of xanthan gum to 5 mL of 2 mol / L zinc sulfate aqueous solution, stir at 80 °C until the xanthan gum is completely dissolved, then cool to room temperature. Then, add 2 g of acrylamide, 1.5 mg of N,N'-methylenebisacrylamide and 10 mg of potassium persulfate in sequence. Stir at room temperature for 1 hour until completely dissolved, and then ultrasonicate for 20 minutes to remove the bubbles in the mixed solution; (2) Use a pipette to measure 150 μL of the mixed solution after ultrasonication in step (1), and drop it on the surface of a zinc foil with a diameter of 16 mm; (3) After step (2), immediately cover another zinc foil of the same size on the droplet, and crosslink at room temperature for 30 minutes to obtain a quasi-solid-state zinc symmetric battery; (4) After step (2), immediately cover the droplet with another positive electrode of the same size. The positive electrode is made of a manganese-based material, and the positive electrode is prepared by a coating method. The current collector is a stainless steel mesh. The coated positive electrode is treated with potassium iodide solution for 10 minutes and crosslinked at room temperature for 1 hour to obtain a quasi-solid-state zinc-ion battery.

[0025] The schematic diagram of the cycle life of the zinc symmetric battery with the in-situ crosslinked double-network hydrogel electrolyte prepared in this example is as Figure 2 shown. It can be seen that the zinc symmetric battery with the in-situ crosslinked double-network hydrogel electrolyte prepared in this example has a cycle stability of 1150 hours under the conditions of 2 mA / cm 2 and 1 mAh / cm 2 . Example 3

[0026] (1) Add 0.02 g of xanthan gum to 5 mL of 2 mol / L zinc sulfate aqueous solution, stir at 80 °C until the xanthan gum is completely dissolved, then cool to room temperature. Then add 2 g of acrylamide, 1.5 mg of N,N'-methylenebisacrylamide and 10 mg of potassium persulfate in sequence. Stir at room temperature for 1 hour until completely dissolved, and then ultrasonicate for 20 minutes to remove the bubbles in the mixed solution; (2) Use a pipette to measure 150 μL of the mixed solution after sonication in step (1) and drop it onto the surface of a zinc foil with a diameter of 16 mm; (3) After step (2), immediately cover the droplet with another zinc foil of the same size and crosslink at room temperature for 30 minutes to obtain a quasi-solid-state zinc symmetric battery; (4) After step (2), immediately cover the droplet with another positive electrode of the same size. The positive electrode is made of a manganese-based material, and the positive electrode is prepared by a coating method. The current collector is a stainless steel mesh. The coated positive electrode is treated with potassium iodide solution for 10 minutes and crosslinked at room temperature for 1 hour to obtain a quasi-solid-state zinc-ion battery.

[0027] The schematic diagram of the rate performance of the zinc symmetric battery with the in-situ crosslinked double-network hydrogel electrolyte prepared in this example is as Figure 3 shown. It can be seen that the zinc symmetric battery with the in-situ crosslinked double-network hydrogel electrolyte prepared in this example has good rate performance. Example 4

[0028] (1) Add 0.02 g of xanthan gum to 5 mL of 2 mol / L zinc sulfate aqueous solution, stir at 80 °C until the xanthan gum is completely dissolved, then cool to room temperature. Then add 2 g of acrylamide, 1.5 mg of N,N'-methylenebisacrylamide and 10 mg of potassium persulfate in sequence. Stir at room temperature for 1 hour until completely dissolved, and then ultrasonicate for 20 minutes to remove the bubbles in the mixed solution; (2) Use a pipette to measure 150 μL of the mixed solution after ultrasonication in step (1), and drop it onto the surface of a zinc foil with a diameter of 16 mm. (3) Immediately after step (2), cover the droplet with another zinc foil of the same size. After crosslinking at room temperature for 30 minutes, a quasi-solid-state zinc symmetric battery is obtained. (4) Immediately after step (2), cover the droplet with another positive electrode of the same size. The positive electrode is made of a manganese-based material. The positive electrode is prepared by a coating method. The current collector is a stainless steel mesh. The coated positive electrode is treated with potassium iodide solution for 15 minutes. After crosslinking at room temperature for 45 minutes, a quasi-solid-state zinc-ion battery is obtained.

[0029] The schematic diagrams of the cycle stability and Coulomb efficiency of the zinc-ion battery with the in-situ crosslinked double-network hydrogel electrolyte prepared in this example are as Figure 4 shown. It can be seen that after cycling 65 times at a current density of 1 A / g, the capacity retention rate of the zinc-ion battery with the in-situ crosslinked double-network hydrogel electrolyte prepared in this example is as high as 97.6%, and the Coulomb efficiency is 100%. Example 5

[0030] (1) Add 0.02 g of xanthan gum to 5 mL of 2 mol / L zinc sulfate aqueous solution. Stir at 80 °C until the xanthan gum is completely dissolved, and then cool to room temperature. Then add 2 g of acrylamide, 1.5 mg of N-N methylene bisacrylamide, and 10 mg of potassium persulfate in sequence. Stir at room temperature for 1 hour until fully dissolved, and then ultrasonicate for 20 minutes to remove the bubbles in the mixed solution. (2) Use a pipette to measure 130 μL of the mixed solution after ultrasonication in step (1), and drop it onto the surface of a zinc foil with a diameter of 12 mm. (3) Immediately after step (2), cover the droplet with another zinc foil of the same size. After crosslinking at room temperature for 30 minutes, a quasi-solid-state zinc symmetric battery is obtained. (4) Immediately after step (2), cover the droplet with another positive electrode of the same size. The positive electrode is made of a manganese-based material. The positive electrode is prepared by a coating method. The current collector is a stainless steel mesh. The coated positive electrode is treated with potassium iodide solution for 10 minutes. After crosslinking at room temperature for 1 hour, a quasi-solid-state zinc-ion battery is obtained.

[0031] The technical solutions of the present invention are not limited to the limitations of the above specific embodiments. Any technical deformation made according to the technical solutions of the present invention falls within the protection scope of the present invention.

Claims

1. A quasi-solid-state zinc symmetric battery and zinc ion battery based on in-situ cross-linked double network hydrogel electrolyte and a preparation method thereof, characterized in that: The following steps are involved: (1) Add a certain amount of xanthan gum to a zinc sulfate aqueous solution, stir at 80 °C until the xanthan gum is completely dissolved, then cool to room temperature, then add acrylamide, NN methylene bisacrylamide and potassium persulfate in turn, stir at room temperature for 1-2 hours until the xanthan gum is fully dissolved, and then ultrasonicate for 20 minutes to remove bubbles in the mixed solution; (2) Using a pipette, measure a certain amount of the mixed solution after ultrasonic treatment in step (1) and drop it onto the surface of a zinc foil with a diameter of 10 to 16 mm; (3) After step (2), another zinc foil of the same size is immediately covered on the droplet, and after cross-linking for a certain period of time at room temperature, a quasi-solid-state zinc symmetric battery is obtained; (4) After step (2), another positive electrode of the same size is immediately covered on the droplet, and after cross-linking for a certain period of time at room temperature, a quasi-solid-state zinc ion battery is obtained; Furthermore, in step (1), the amount of xanthan gum added is 0.005-0.1 g; Furthermore, in step (1), the concentration of the zinc sulfate aqueous solution is 1 to 2 mol / L, and the volume is 5 to 20 ml; Furthermore, the mass of acrylamide added in step (1) is 50 to 200 times the amount of xanthan gum added, the amount of NN methylenebisacrylamide added is 5% to 30% of the amount of xanthan gum added, and the amount of potassium persulfate added is 15% to 80% of the amount of xanthan gum added; Furthermore, the volume of the mixed solution measured by the pipette in step (2) is 100 to 200 μl; Furthermore, the cross-linking time in step (3) is 30 minutes to 1 hour; Furthermore, the positive electrode in step (4) can be made of manganese-based, vanadium-based or other materials suitable for the positive electrode of zinc ion batteries; Furthermore, the positive electrode in step (4) needs to be treated in a halogen salt solution for 5 minutes to 1 hour; Furthermore, the positive electrode in step (4) is prepared by a coating method, and the current collector can be selected from stainless steel mesh, titanium mesh, titanium foil, stainless steel foil, etc.; Furthermore, the cross-linking time in step (4) is 30 minutes to 2 hours.

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