Capacitor with double electric layers and electrolyte for capacitor

Abstract

The invention belongs to the field of electrochemistry, and discloses a capacitor with double electric layers and electrolyte for the capacitor. The electrolyte for the capacitor with the double electric layers comprises fluoro-fatty acid salt ionic liquid and fluoro-alkyl boride, and the molar ratio of the fluoro-fatty acid salt ionic liquid to the fluoro-alkyl boride ranges from 1:0.001 to 1:0.05. The electrolyte for the capacitor with the double electric layers is prepared by mixing the fluoro-fatty acid salt ionic liquid with the fluoro-alkyl boride, complexes can be formed by the fluoro-alkyl boride and fluoro-fatty acid radicals, accordingly, the dissociation degree of the fluoro-fatty acid salt ionic liquid is increased, the conductivity of the fluoro-fatty acid salt ionic liquid is greatly improved, and equivalent internal resistance of the capacitor with the double electric layers is greatly reduced. Besides, the fluoro-alkyl boride is used as an additive, an effect of greatly improving the conductivity can be realized only by utilizing the fluoro-alkyl boride with the dosage lower than 5% of the total mass, while a large amount of organic liquid is required to dissolve low-dissolvability fluoro-fatty acid salt ionic liquid when organic solvents are added to improve conductivity in the prior art, accordingly, the dosage of the electrolyte for the capacitor with the double electric layers is greatly reduced, and the cost of the electrolyte for the capacitor with the double electric layers is greatly saved.

Description

technical field [0001] The invention relates to the field of electrochemistry, in particular to an electrolytic solution for an electric double layer capacitor. The invention also relates to an electric double layer capacitor using the electrolytic solution of the electric double layer capacitor. Background technique [0002] Electric double layer capacitor is a new type of energy storage device, which has the advantages of high power density, high cycle life, and fast charge and discharge performance. It is widely used in military fields, mobile communication devices, computers, and hybrid power supplies for electric vehicles. As an important part of the electric double layer capacitor, the electrolyte has a great influence on the storage performance of the electric double layer capacitor, which determines the working voltage range, storage capacity, working temperature and working environment of the capacitor. [0003] Ionic liquids are organic liquid substances composed ...

AI Technical Summary

Problems solved by technology

Ionic liquids have good development prospects as the electrolyte of electric double-layer capacitors. However, the capacitance of pure ionic liquids at room temperature is not high, resulting in the equivalent internal resistance of electric double-layer capacitors using pure ionic liquids as electrolytes. Big

Fluorinated fatty acid salt ionic liquid is currently one of the most commonly used ionic liquid electrolytes because of its easy synthesis and low cost. However, its high resistance limits its application as an electrolyte for electric double layer capacitors. Adding a large amount of organic The method of solvent (acetonitrile, propylene carbonate, 1-butyrolactone) can achieve the purpose of greatly reducing the equivalent internal resistance of the electric double layer capacitor, but it greatly increases the amount of electrolyte in the electric double layer capacitor, thereby increasing the cost

Images