1. Ultrahigh energy density battery-type asymmetric supercapacitors: NiMoO4 nanorod-decorated graphene and graphene/Fe2O3 quantum dots.
- Author
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Yang, Jiao, Liu, Wei, Niu, Hao, Cheng, Kui, Ye, Ke, Zhu, Kai, Wang, Guiling, Cao, Dianxue, and Yan, Jun
- Abstract
NiMoO
4 has attracted intensive attention as one of the promising ternary metal oxides because of its high specific capacitance and electrical conductivity compared to traditional transition-metal oxides. In this study, NiMoO4 nanorods uniformly decorated on graphene nanosheets (G-NiMoO4 ) are synthesized through a facile hydrothermal method. The prepared G-NiMoO4 composite exhibits a high specific capacitance of 714 C·g−1 at 1 A·g−1 and an excellent rate capability, with a retention ratio of 57.7% even at 100 A·g−1 . An asymmetric supercapacitor (ASC) fabricated with the G-NiMoO4 composite as the positive electrode and Fe2 O3 quantum dot-decorated graphene (G-Fe2 O3 -QDs) as the negative electrode delivers an ultrahigh energy density of 130 Wh·kg−1 , which is comparable to those of previously reported aqueous NiMoO4 -based ASCs. Even when the power density reaches 33.6 kW·kg−1 , an energy density of 56 Wh·kg−1 can be maintained. The ASC device exhibits outstanding cycling stability, with a capacitance retention of 113% after 40,000 cycles. These results indicate that the G-NiMoO4 composite is a promising candidate for ASCs with ultrahigh energy density and excellent cycling stability. Moreover, the present work provides an exciting guideline for the future design of high-performance supercapacitors for industrial and consumer applications via the simultaneous use of various pseudocapacitive materials with suitable potential windows as the positive and negative electrodes.[ABSTRACT FROM AUTHOR]
- Published
- 2018
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