NiCo-S nanosheets grown on Ti3C2Tx-wrapped carbon cloth for high-performance flexible supercapacitor

Abstract

In this study, Ti3C2Tx was directly deposited on carbon cloth (CC) to obtain a flexible substrate for NiCo-S. Then, 3D self-supported flexible NiCo-S/Ti3C2Tx/CC composite electrode was prepared by a two-step hydrothermal method. Compared with the NiCo-S/CC electrode, the specific capacity of the NiCo-S/Ti3C2Tx/CC electrode increases from 908 to 1690 C g−1 at 2 A g−1. The rate capability (2–20 A g−1) increases from 42% to 66%, and the cyclic performance (5000 charge-discharge cycles at a current density of 10 A g−1) increases from 50% to 82%. The enhanced electrochemical performance may be attributed to the introduction of Ti3C2Tx, which reduces the resistance of composite and facilitates the electron/ion transport, while the presence of Ti2+ in Ti3C2Tx provides more sites for redox reactions. The assembled flexible all-solid supercapacitor (NiCo-S/Ti3C2Tx/CC//AC) manifests a high energy density of 62 Wh kg−1 at 800 W kg−1 and an excellent cyclic stability with 89% capacity retention after 5000 cycles at 10 A g−1. In addition, the device demonstrates no obvious capacity change at different states and bending angles, showing broad application prospects in high-performance wearable energy-storage devices.