Synthesis of CoO-Decorated Graphene Hollow Nanoballs for High-Performance Flexible Supercapacitors

• DOI: 10.1021/acsami.0c12898
• Publication Date: 2020-08-13T16:40:59Z
• Authors: Chi-Ang Tseng; Prasanta Kumar Sahoo; Chuan-Pei Lee; Yu-Ting Lin; Jing-Han Xu; Yit-Tsong Chen
• Keywords: 02 engineering and technology; 0210 nano-technology; 7. Clean energy

The formation of thin and uniform capacitive layers for fully interacting with an electrolyte in a supercapacitor is key challenge to achieve optimal capacitance. Here, we demonstrate binder-free flexible the electrode made cobalt oxide nanoparticle (CoO NP)-wrapped graphene hollow nanoballs (GHBs). growth process Co(OH)2 NPs, which could subsequently be thermally annealed CoO was monitored by situ electrochemical liquid transmission electron microscopy (TEM). In dynamic NPs on film GHBs, lateral fan-shaped clusters spread over surface GHBs observed TEM. This CoO-GHBs/CC exhibits high specific capacitance (2238 F g–1 at 1 A g–1) good rate capability (1170 15 g–1). outstanding performance were achieved synergistic combination highly pseudocapacitive electrically conductive large areas. solid-state symmetric (SSC), CoO-GHBs/CCs used both positive negative electrodes, power density (6000 W kg–1 8.2 Wh kg–1), energy (16 800 cycling stability (∼100% retention after 5000 cycles), excellent mechanical flexibility various bending positions. Finally, serial connection four SSC devices can efficiently red light-emitting diode being charged 20 s, demonstrating practical application this CoO-GHBs/CC-based device efficient storage.