Large Areal Mass and High Scalable and Flexible Cobalt Oxide/Graphene/Bacterial Cellulose Electrode for Supercapacitors

Flexible energy storage devices require a simple, scalable and general strategy for fabricating high electrochemical performance and mechanically tough flexible electrodes. Herein, sustainable and biological bacterial cellulose (BC) is developed as substrate for Co₃O₄/graphene (GN), which permits high flexibility (suitable for bending angle of 180°), excellent tensile strength of 63 MPa, good wettability, and especially large mass loading of 9.61 mg cm^-2 for a flexible and free-standing supercapacitor electrode. The Co₃O₄/GN/BC hybrid electrode exhibits both appreciable areal capacitance of 12.25 F cm^-2 and gravimetric capacitance of 1274.2 F g^-1. Moreover, the remarkable cycling stability with 96.4% capacitance retention after 20000 can be achieved. This study provides a facile procedure to improve the electrochemical performance and mechanical property of flexible supercapacitor electrodes, which are promising candidates for the application of a flexible power source. (Graph Presented).