High-Performance Nickel Cobalt Hydroxide Nanosheets/Graphene/Ni foam Composite Electrode for Supercapacitor Applications

Abstract Nickel Cobalt Hydroxide (NCH) has attracted increasing interests due to its pseudo-capacitive performance. However, its low conductivity and poor cycling performance have still restricted its practical application. Herein, we report a NCH nanosheets (NSs)/graphene/nickel foam (NCH NSs/G/NF) composite electrode prepared by chemical vapor deposition (CVD) followed by a facile hydrothermal process. No alkali, organic solvent and chemical binders were used in the preparation process. The as-prepared NCH NSs/G/NF composite electrode exhibits a significantly enhanced specific capacitance of 2854.9 F g−1 at 1 A g−1 and a rate performance of 2023.5F g−1 at 10 A g−1 with a retained ~81.3% initial capacitance after 3000 charging/discharging cycles at 30 A g−1. The high capacitive performance is mainly attributed to the high specific area and the significantly improved electrical conductive property by the well conductive three-dimensional network and the NCH NSs structure. The results have provided a new way for improving the capacitive performance of NCH electrode and promoting its supercapacitor applications.