A kind of silk nanofiber membrane and its preparation method and application in supercapacitor

Abstract

The invention discloses a silk nanofiber film, a preparation method thereof and an application in a supercapacitor. The method prepares the silk nanofiber diaphragm through the four-step process of deep eutectic solvent pretreatment, ultrasonic, centrifugation, and suction filtration. The contact angle between the silk nanofiber supercapacitor diaphragm prepared by the present invention and the electrolyte is 20°-60° , the size does not shrink at 150°C, and the tensile strength is 30-80MPa; the silk nanofiber separator provided by the present invention has good electrolyte affinity, excellent thermal stability and mechanical properties, which greatly improves the performance of supercapacitors. Rate performance, cycle life and safety performance. At the same time, the preparation method of the silk nanofiber membrane provided by the present invention is environmentally friendly, low in cost, simple and easy to operate, and easy for large-scale production.

Description

technical field [0001] The invention belongs to the field of materials, and relates to a silk nanofiber film, a preparation method thereof and an application in a supercapacitor. Background technique [0002] Supercapacitor is a new type of energy storage device between electrolytic capacitors and batteries. It has the characteristics of high current charge and discharge, long cycle life, etc. It has a wide application market. increasingly widespread attention. Supercapacitors are mainly composed of positive and negative electrode materials, electrolyte and separator. The diaphragm is located between the positive and negative materials of the supercapacitor and is one of the important components of the supercapacitor. The diaphragm plays an important role in isolating the positive and negative electrodes and preventing the internal short circuit of the battery. With the continuous development of supercapacitors, the requirements for diaphragm performance are getting highe...

AI Technical Summary

Problems solved by technology

At present, the commonly used separator materials for supercapacitors are mainly polyolefin microporous polymer films. Although they already have good electrochemical stability and suitable mechanical strength, they also have many shortcomings: (1) poor wettability of electrolyte; ( 2) Poor thermal dimensional stability, significant dimensional shrinkage occurs when the temperature is higher than 120°C, and short circuit occurs inside the battery

At present, the development and utilization of silk is first to dissolve the silk with a solvent to obtain a silk fibroin solution. Usually, the solvents that can dissolve silk include strong acids, strong alkalis, organic solvents or salt solutions. High concentrations of strong acids and strong alkalis can significantly reduce the molecular weight of silk proteins. It is reprocessed, so it is not widely used; after dissolving silk with a high-concentration neutral salt solution, it is necessary to place the silk fibroin protein salt solution in a dialysis bag for long-term dialysis (generally more than 3 days), and then obtain regeneration. Silk fibroin aqueous solution, the process is relatively complicated and the cycle is long, and the mechanical properties of the regenerated silk fibroin product are poor, especially in the brittleness and low strength of the processed material, which greatly limits the regeneration and preparation of silk fibroin Industrialized production and its wide application

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