Design and synthesis of tremella-like Ni–Co–S flakes on co-coated cotton textile as high-performance electrode for flexible supercapacitor

Abstract

All-solid-state and flexible supercapacitors have attracted tremendous attention due to the rapid development of modern smart and wearable electronics. In this study, copper and nickel co-coated cotton textile was developed as the substrate, on which tremella-like Ni–Co–S nanoflakes were electrochemically deposited. The obtained electrode exhibits high specific capacity with good rate capability, flexibility and bendability. An asymmetric supercapacitor cell containing Ni–Co–S as cathode, active carbon as anode and PVA/KOH as the solid-state electrolyte, demonstrate superior electrochemical properties for wearable energy storage applications. The obtained supercapacitor cell delivers a high energy density of 48.9 Wh kg−1 at 390 W kg−1. When four cells were connected in series, the connected cells can be safely operated at a wide voltage window of 0.0–6.4 V due to the good electrochemical stability and consistency of the assembled cells. These results demonstrated the flexible textile electrode developed by this work hold great potential for practical application in wearable energy storage devices.