Facile growth of hierarchical SnO2@PPy composites on carbon cloth as all-solid-state flexible supercapacitors

Abstract

A novel nanostructure of SnO2 @polypyrrole (PPy) is grown on carbon cloth (CC) by a facile solvothermal method and subsequent chemical oxidative polymerization process in this work. Benefiting from the combination of SnO2 and PPy, the as-obtained SnO2 @PPy/CC composites show significant improvement of electrochemical performances compared to single components. Specifically, the SnO2 @PPy/CC electrode achieves a high areal capacitance of 493.8 mF cm−2 at 1.0 mA cm−2, and good rate capability. Furthermore, all solid state flexible supercapacitors (FSCs) are constructed using SnO2 @PPy/CC electrodes and polyvinyl alcohol-potassium hydroxide gel electrolyte. Remarkably, the SnO2 @PPy/CC//SnO2 @PPy/CC FSCs show a high energy density of 0.7 mWh cm−3 at a power density of 4.74 mW cm−3, superior stability (90.5% capacitance retention after 10,000 cycles at 1.0 mA cm−2) and good mechanical flexibility. This work is expected to bring up inspirations for the development of high-performance FSCs.