Hydrothermal Synthesis of CuCo2S4 Nano-structure and N-Doped Graphene for High-Performance Aqueous Asymmetric Supercapacitors

Hong Dong

Yuanyuan Li

Hui Chai Email

Yali Cao

Xin Chen

Key laboratory of Energy Materials Chemistry, Ministry of Education, Key Laboratory of Advanced Functional Materials, Institute of Applied Chemistry, Xinjiang University, Urumqi 830046, Xinjiang, China

Abstract

Recently, transition metal sulfides have drawn a lot of attention due to their potential application in energy and environmental fields. In this paper, we present a simple and facile method for preparing CuCo2S4 nanoparticles as high performance supercapacitor electrode materials. Electrochemical measurements exhibit that the CuCo2S4 nanoparticles electrode has a high specific capacitance of (190 C g-1 at 1A g-1), relatively high rate capability (46 % capacitance retention at 10A g-1) and good cycling stability (77 % of the initial specific capacitance can be maintained after 3000 cycles at 4A g-1). When fabricated as aqueous asymmetric supercapacitor by using CuCo2S4 nanoparticles and N-doped graphene (NG) composites as the positive electrode and the negative electrode, respectively. The assembled device exhibits a high energy density of 32.7 Wh kg-1 at a power density of 794 W kg-1. And it still operates at a high power density of 6.4 kW kg-1 with an energy density of 19.5 Wh kg-1. Moreover, after 6000 consecutive GCD cycles at a current density of 4 A g-1, 78.0 % of the initial capacitance value can be maintained. These attractive results manifest that CuCo2S4 //NG hold a great potential for practical applications in the field of energy storage system.

Hydrothermal Synthesis of CuCo2S4 Nano-structure and N-Doped Graphene for High-Performance Aqueous Asymmetric Supercapacitors