In-situ growth of flexible 3D hollow tubular Cu2S nanorods on Cu foam for high electrochemical performance supercapacitor

For pursing high-performance supercapacitors, both of the design strategy and structural characteristic of electrode materials are crucial. Herein, we report the in-situ growth of flexible self-assembled 3D hollow tubular Cu2S nanorods on Cu foam substrate (Cu2[email protected]). The Cu substrate is simultaneously acted as a copper source and a collector, which reduces the contact resistance. Moreover, the highly ordered 3D unique structure increases the redox reactive sites and enhances the ion transmission effectively, resulting in greatly improved electrochemical performance. Based on the Cu2[email protected] electrode, the supercapacitor exhibits high areal capacitance of 1000 mF cm−2 at a current density of 2 mA cm−2, and great cycle stability, maintaining 96.9% capacitance after 10,000 cycles. Furthermore, the supercapacitor also shows an excellent flexibility with no significant decrease in the twisting or bending state. The capacity retention rates are 99.8% and 86.1%, respectively, and finally recover to 99.3%, confirming its great potential in practical application for portable electronic devices.