A supercapacitor based on antifreeze hydrogel electrolyte and its preparation method

Abstract

The invention relates to the field of energy storage devices, in particular to a super capacitor based on an anti-freezing hydrogel electrolyte and a preparation method thereof. The super capacitor comprises an anti-freezing hydrogel electrolyte and an electrode material tightly attached to the two sides of the anti-freezing hydrogel electrolyte. The electrode material comprises carbon nanotube paper and a conductive polymer. The anti-freezing hydrogel comprises water, nanofibers, a cross-linked polymer and a lithium salt. The super capacitor adopts anti-freezing hydrogel of a pure water system as an electrolyte and needs no diaphragm, the ionic conductivity of the used anti-freezing hydrogel reaches 0.023S / cm, and the anti-freezing hydrogel has good anti-freezing performance and mechanical performance, so that the capacitor obtained has high specific capacitance, excellent bending resistance and charge-discharge cycle stability, the specific capacitance of the capacitor at 25 DEG C reaches 32.7-110.2 mF / cm<2>, the specific capacitance at -20 DEG C reaches 36.9 mF / cm<2>, and the specific capacitance of the capacitor exceeds that of a hydrogel-based solid super capacitor reported atpresent. The preparation method is simple in process, mild in condition and suitable for large-scale production.

Description

technical field [0001] The invention relates to the field of energy storage devices, in particular to a supercapacitor based on an antifreeze hydrogel electrolyte and a preparation method thereof. Background technique [0002] In recent years, with the vigorous development of wearable electronic devices, higher requirements have been put forward for energy storage and supply methods, and new technical challenges have also been brought. As a new type of electrochemical energy storage device, flexible all-solid-state supercapacitors have broader application prospects in the field of flexible wearable electronics due to their unique mechanical flexibility. Generally speaking, a flexible all-solid-state supercapacitor is a sandwich sandwich structure assembled with two flexible electrodes and a solid-state electrolyte. The choice of solid electrolyte is one of the key factors determining the structure and performance of supercapacitors. Polymer hydrogel electrolyte has a speci...

AI Technical Summary

Problems solved by technology

However, conventional polymer hydrogels usually contain a large amount of water and are prone to freezing at subzero temperatures, impeding ion transport and decreasing mechanical flexibility, which further limit the application of flexible solid-state supercapacitors in low-temperature climates and high-altitude regions.

At present, it has been reported that most low-temperature resistant polymer hydrogel electrolytes use water / organic solvent systems, but the participation of organic solvents often causes environmental pollution, which is not conducive to the construction of green supercapacitors.

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