Zn-Co-Mo-rGO Ultra-Thin Nanosheets Arrays-Based Electrode Materials for Asymmetric Supercapacitor

Abstract

The design of electrode materials for supercapacitors (SCs) with high specific capacity and high energy density has always been a research hotspot. In this paper, ternary metal oxides Zn-Co-Mo-rGO (ZCMG) and Zn-Co-Mo (ZCM) based electrode materials were prepared by one-step hydrothermal method. Compared with the ZCM, SEM and TEM results demonstrates the ultra-thin nanosheets grown vertically on the nickel foam for ZCMG. Owing to synergistic effect of the multi-component composites, the as-prepared electrode with ZCMG exhibits the specific capacity of 713 C g−1 (1189 F g−1) at 1 A g−1, which was higher than that of ZCM without rGO (492 F g−1, 295 C g−1). The assembled ZCMG//AC (activated carbon) asymmetric supercapacitor (ASC) delivers the maximum specific capacity of 68 C g−1 (45 F g−1) at 1 A g−1. After 1000 cycles, it still has a high-capacity retention rate of 95%. Furthermore, the ASC exhibited an energy density of 14 Wh kg−1 at 750 W kg−1, and it can retain 5.23 Wh kg−1, even at 7500 W kg−1.