High-performance all-solid-state supercapacitor derived from PPy coated carbonized silk fabric

Abstract

Polypyrrole (PPy) has attracted renewed interest as a promising electrode material for supercapacitors. However, excellent gravimetric capacitance with the low areal capacitance of PPy composite electrodes is ascribed to the small mass loading, limiting the practical application for high energy systems. Herein, based on advantages of carbonized silk fabric (CSF) with large accessible area and hierarchically porous interconnected structure, a composite electrode with high PPy mass loading of 16.02 mg cm−2 (CSF/PPy) was prepared by electro-depositing PPy on the framework of CSF. The CSF/PPy composite electrode displays an outstanding areal capacitance of 4040 mF cm−2 at 2 mA cm−2 and a good cycling stability (88.6% capacitance retention after 1500 cycles). In addition, the prepared CSF/PPy were used as electrodes to fabricate the all-solid symmetric supercapacitor, achieving excellent areal specific capacitances of 666.78 mF cm−2 and volumetric capacitance of 15.29 F cm−3 at the current density of 2 mA cm−2. Moreover, the all-solid supercapacitor exhibits higher energy density of 6.88 mWh cm−3 at a power density of 0.04 W cm−3, which is higher than most of PPy-coated supercapacitors. Importantly, the carbonized fabrics have a promising application to be treated as porous carbon substrates to enhance active material mass loading for improvement of energy storage performance.