Co(OH)2 nanoflakes grown on 3D graphene foam as a binder-free hybrid electrode for high-performance supercapacitors
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Using a simple hydrothermal method, porous Co(OH)2 nanoflakes were successfully deposited on 3D graphene foam grown by chemical vapor deposition. And the Co(OH)2/3D graphene hybrids were then employed as the binder-free electrode for supercapacitors. Structure and morphology of the hybrid materials were investigated and effect of hydrothermal temperature on electrochemical performance was optimized. The 90 °C-synthesized sample exhibits the highest specific capacitance of 1636 F/g at 0.5 A/g in the KOH electrolyte. Even as the current density increases 120 times to 60 A/g, the specific capacitance of 1180 F/g is still maintained, representing the excellent rate capability. The hybrid electrode also shows good cycling stability with capacity retention of 75% after 1000 cycles. The excellent electrochemical performance of the hybrid electrode is attributed to synergistic effect of the highly conductive graphene and the nano-porous Co(OH)2.
KeywordsFoam Specific Capacitance Electrochemical Performance Cyclic Voltammetry Curve High Specific Capacitance
This work was supported by the National Natural Science Foundation of China (51605293) and Natural Science Foundation of Shanghai (16ZR1423500). The authors also acknowledge financial supported from The Program for Associate Professor of Special Appointment (Young Eastern Scholar) at Shanghai Institutions of Higher Learning (QD2016013).
- 7.J. Yan, Q. Wang, T. Wei, Z. Fan, Adv. Energy Mater. 4(1–43), 1300816 (2014)Google Scholar