Fabrication of semi‐flexible carbon quantum dots‐reinforced polypyrrole ( PPy / CQDs ) composite electrodes by hybrid electrospray deposition for high‐performance energy storage device

Abstract

A carbon quantum dots-reinforced polypyrrole (PPy/CQDs) composite electrodes were prepared via the hybrid electrospray method. PPy/CQDs composite shows superior electrochemical performance with a specific capacity (Qg) of 174.21 C g−1 at 1 A g−1 in 3 M KOH aqueous electrolyte. An all-solid-state asymmetric supercapacitor (ASC) is composed of PPy/CQDs as a positive electrode and rGO as a negative electrode with PVA/KOH gel electrolyte, which exhibited the specific capacity (Qg) of 79.25 C g−1 at the current density of 1.5 A g−1 with an energy and power density of 26.44 Wh kg−1 and 18 090.82 W kg−1, respectively. An assembled PPy/CQDs//rGO device offers cyclic retention of about 76.8% at 15 A g−1 after 10 000 cycles. The above results confirmed that the as-prepared PPy/CQDs composite electrode is more suitable for high-performance-based semi-flexible supercapacitor application.