Synthesis of Co3O4/reduced graphene oxide by one step-hydrothermal and calcination method for high-performance supercapacitors

• Published in: Ionics 2021, Vol.27 (1), p.339-349
• Main Authors: Yue, Xiao-Ming, Liu, Zi-Jing, Xiao, Cui-Cui, Ye, Mei, Ge, Zan-Peng, Peng, Cheng, Gu, Zi-Yi, Zhu, Jun-Sheng, Zhang, Shuang-Quan
• Format: Article
• Language: English
• Subjects: Chemistry; Chemistry and Materials Science; Condensed Matter Physics; Electrochemistry; Energy Storage; Optical and Electronic Materials; Original Paper; Renewable and Green Energy
• ISSN: 0947-7047; 1862-0760
• DOI: 10.1007/s11581-020-03797-x

In this work, a simple and environmental one step-hydrothermal and calcination method was used to prepare Co 3 O 4 /reduced graphene oxide (rGO) composite. The result shows that tiny Co 3 O 4 nanoparticles are dispersed on rGO sheets to form a three-dimensional structure, which provides more active sites than Co 3 O 4 nanowires structure. When acting as an electrochemical supercapacitor, structure optimized Co 3 O 4 /rGO-120-12 electrode exhibits high specific capacitance of 1152 F/g at 1 A/g in 6 M KOH electrolyte. As an assemble device, Co 3 O 4 /rGO reveals higher specific capacitance (about 85 F/g) than Co 3 O 4 (about 36 F/g) at current density of 1 A/g and excellent stability with 89.1% after 5000 cycles. The device exhibits a relatively high energy density of 57.26 Wh/kg at a power density of 2240.68 W/kg. Hence, the superior pseudocapacitive performance of Co 3 O 4 /rGO can be ascribed to the synergy between rGO and Co 3 O 4 as well as the excellent three-dimensional structure obtained by changing the hydrothermal conditions.