Facile fabrication of a spindle-like CuO anchored on Graphene nanocomposite with relative high-rate performance and cycle stability for flexible supercapacitor

It is a great challenge to find the electrode of supercapacitor with a high rate and long cycle life. Based on the excellent electrical conductivity of graphene, spindle-like CuO-graphene nanocomposites were prepared by one-step hydrolysis process and then a self-supporting flexible electrodes were prepared by ultrasonic dispersion combined with filtration technology. Among them, graphene with layered structure not only builds a solid framework but also ensures a fast electron transport path. Ion transport is also facilitated by the linked macroporous structure. In addition, small CuO nanoparticles have short transmission paths and fast pseudo-capacitance storage capacity. Therefore, the CuO-graphene self-supporting electrode has 93.1% capacitor retention after 4000 cycles at 4 A g⁻¹ with ultra-long cycle life, a high mass specific capacity of 170 F g⁻¹ at 0.5 A g⁻¹, and relative high-rate performance of 153 F g⁻¹ at 5 A g⁻¹, which show its good prospects for future applications.