3D architecture of a graphene/CoMoO4 composite for asymmetric supercapacitors usable at various temperatures

Designing and optimizing the electrode materials and studying the electrochemical performance or cycle life of the supercapacitor under different working conditions are crucial to its practical application. Herein, we proposed a rational design of 3D-graphene/CoMoO4 nanoplates by a facile two-step hydrothermal method. Owing to the high electron transfer rate of graphene and the high activity of the CoMoO4 nanoplates, the three-dimensional electrode architectures achieved remarkable electrochemical performances with high areal specific capacitance (1255.24 F/g at 1 A/g) and superior cycling stability (91.3% of the original specific capacitance after 3000 cycles at 1 A/g). The all-solid-state asymmetric supercapacitor composed of 3D-graphene/CoMoO4 and activated carbon (AC) exhibited a specific capacitance of 109 F/g at 0.2 A/g and an excellent cycling stability with only 12.1% of the initial specific capacitance off after 3000 cycles at 2 A/g. The effects of temperature and charge-discharge current densities on the charge storage capacity of the supercapacitor were also investigated in detail for practical applications. (C) 2017 Elsevier Inc. All rights reserved.