Boosted electrochemical performance of CuS anchored on carbon cloth as an integrated electrode for quasi-solid-state flexible supercapacitor

As a typical flexible electrode substrate, carbon cloth (CC) has high flexibility but compromised capacitance performance. In this work, CuS nanoflake arrays with enhanced pseudocapacitance property are loaded on the surface of CC via a one-step solvothermal method. CuS nanoflakes provide the electroactive sites required for faradaic redox reaction, while the channels between the nanoflake arrays play a vital role to improve the efficiency of charges transportation. Benefit from the favorable microstructure, CuS/CC-4 demonstrates the specific capacity of 213.8 C g(-1) at 0.49 A g(-1) (436.5 mF cm(-2) at 1 mA cm(-2)), and maintains 75.1% of initial capacitance after 5000 cycles. Furthermore, a quasi-solid-state asymmetric flexible supercapacitor (AFSC) is assembled with the voltage window of 1.6 V, which delivers the energy density of 0.027 mWh cm(-2) and exhibits outstanding cycle stability of 86.4% after 5000 cycles at a high current density of 5 mA cm(-2). This work provides insights into the integrated electrode containing the merits of flexibility, lightweight and satisfying electrochemical performance, and revealing its promising application prospects in flexible energy storage devices.

Automated summary

The study successfully improved the capacitance performance by loading CuS nanoflake arrays on the surface of carbon cloth, showing that CuS/CC-4 has good specific capacity and cycle stability under favorable microstructure; in addition, the assembled asymmetric flexible supercapacitor has high energy density and outstanding cycle stability.