Three-Dimensional Hierarchically Mesoporous ZnCo2O4Nanowires Grown on Graphene/Sponge Foam for High-Performance, Flexible, All-Solid-State Supercapacitors.
To achieve high energy storage on three-dimensional (3D) structures at low cost, materials with high power and long cycle life characteristics have to be developed. We synthesized ZnCo2O4/reduced graphene oxide (rGO) binary composites in commercial sponges. ZnCo2O4nanosheets were grown on the surface of GO/sponge through a hydrothermal reaction. The resulting flexible, free-standing ZnCo2O4/rGO/sponge electrodes were used as the electrodes in a symmetric supercapacitor. ZnCo2O4/rGO/sponge electrodes have a large specific capacitance of 1116.6 F g-1at a scan rate of 2 mV s-1in aqueous electrolyte. The all-solid-state flexible supercapacitor is assembled based on ZnCo2O4/rGO/sponge electrodes, which show excellent electrochemical performances with a specific capacitance of 143 F g-1at a current density of 1 A g-1. The as-fabricated supercapacitor also exhibits excellent cycling stability (93.4 % capacitance retention after 5000 cycles) and exceptional mechanical flexibility. These results demonstrate the potential of ZnCo2O4/rGO/sponge as an electrode in flexible, high-performance supercapacitors.
Yonsei Institute of Convergence Technology, Yonsei University, Yeonsu-gu, Incheon, 406-840, Republic of Korea.
In Kyu
IK
Moon
Yonsei Institute of Convergence Technology, Yonsei University, Yeonsu-gu, Incheon, 406-840, Republic of Korea.|School of Integrated Technology and, Yonsei Institute of Convergence Technology, Yonsei University, Yeonsu-gu, Incheon, 406-840, Republic of Korea.
Seonno
S
Yoon
Yonsei Institute of Convergence Technology, Yonsei University, Yeonsu-gu, Incheon, 406-840, Republic of Korea.|School of Integrated Technology and, Yonsei Institute of Convergence Technology, Yonsei University, Yeonsu-gu, Incheon, 406-840, Republic of Korea.
Jungwoo
J
Oh
graphene; mesoporous materials; solid-state structures; supercapacitors; transition metals