Yao Tinghui, Guo Xin, Qin Shengchun, Xia Fangyuan, Li Qun, Li Yali, Chen Qiang, Li Junshuai, He Deyan
1Key Laboratory of Special Function Materials and Structure Design of the Ministry of Education, Key Laboratory for Magnetism and Magnetic Materials of the Ministry of Education, and School of Physical Science and Technology, Lanzhou University, 222 South Tianshui Road, Lanzhou, 730000 People's Republic of China.
2Institute of Electromagnetics and Acoustics, Department of Electronic Science, and Fujian Provincial Key Laboratory of Plasma and Magnetic Resonance, Xiamen University, Xiamen, 361005 People's Republic of China.
Nanomicro Lett. 2017;9(4):38. doi: 10.1007/s40820-017-0141-9. Epub 2017 Mar 17.
In this study, the effect of reduced graphene oxide (rGO) on interconnected CoO nanosheets and the improved supercapacitive behaviors is reported. By optimizing the experimental parameters, we achieved a specific capacitance of 1016.4 F g for the CoO/rGO/NF (nickel foam) system at a current density of 1 A g. However, the CoO/NF structure without rGO only delivers a specific capacitance of ~520.0 F g at the same current density. The stability test demonstrates that CoO/rGO/NF retains ~95.5% of the initial capacitance value even after 3000 charge-discharge cycles at a high current density of 7 A g. Further investigation reveals that capacitance improvement for the CoO/rGO/NF structure is mainly because of a higher specific surface area (87.8 m g) and a more optimal mesoporous size (4-15 nm) compared to the corresponding values of 67.1 m g and 6-25 nm, respectively, for the CoO/NF structure. rGO and the thinner CoO nanosheets benefit from the strain relaxation during the charge and discharge processes, improving the cycling stability of CoO/rGO/NF.
本研究报道了还原氧化石墨烯（rGO）对相互连接的CoO纳米片的影响以及由此改善的超级电容性能。通过优化实验参数，我们在1 A g的电流密度下，CoO/rGO/NF（泡沫镍）体系实现了约1016.4 F g的比电容。然而，不含rGO的CoO/NF结构在相同电流密度下仅提供约520.0 F g的比电容。稳定性测试表明，即使在7 A g的高电流密度下进行3000次充放电循环后，CoO/rGO/NF仍保留约95.5%的初始电容值。进一步研究表明，CoO/rGO/NF结构的电容提高主要归因于其具有更高的比表面积（约87.8 m g）和更优化的介孔尺寸（4 - 15 nm），相比之下，CoO/NF结构的相应值分别为67.1 m g和6 - 25 nm。rGO和更薄的CoO纳米片得益于充放电过程中的应变弛豫，提高了CoO/rGO/NF的循环稳定性。
