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

A novel nanostructure of SnO 2 @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 SnO 2 and PPy, the as-obtained SnO 2 @PPy/CC composites show significant improvement of electrochemical performances compared to single components. Specifically, the SnO 2 @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 SnO 2 @PPy/CC electrodes and polyvinyl alcohol-potassium hydroxide gel electrolyte. Remarkably, the SnO 2 @PPy/CC//SnO 2 @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.