Facile synthesis of layered reduced graphene oxide-copper sulfide (rGO-CuS) hybrid electrode for all solid-state symmetric supercapacitor

摘要

A straightforward process for synthesis of hybrid porous electrode material composed of reduced graphene oxide (rGO) and copper sulfide (CuS) with layered structure on the stainless steel substrate is developed. As-synthesized hybrid electrode shows hexagonal crystal structure of CuS with 77 m(2) gm(-1)specific surface area and 22 nm average pore size. The specific capacitance obtained with rGO-CuS5 hybrid electrode is 1201 F g(-1)at the sweep rate of 5 mV s(-1)in 1 M LiClO(4)aqueous electrolyte. The majority of charge stored by diffusion-controlled process indicates benefits of layered structures for solid-state energy storage. The rGO-CuS5-based hybrid symmetric supercapacitor delivers a specific capacitance (C-s) as high as 109 F g(-1)at a sweep rate of 5 mV s(-1)with polyvinyl alcohol (PVA)-LiClO(4)gel electrolyte. Also, the specific energy of 44 Wh kg(-1)and specific power of 1.4 kW kg(-1)with 87% stability after 6000 cycles at an applied current of 5 mA are obtained. The simple process of synthesis of layered hybrid electrode material for flexible supercapacitor promises its use in smart textile and wearable electronic devices.