Rational design of the composition and electrochemically favorable structural configuration of electrode materials are highly required to develop high-performance supercapacitors. Here, we report our findings on the design of interconnected NiGa2O4 nanosheets as advanced cathode electrodes for supercapacitors. Rietveld refinement analysis demonstrates that the incorporation of Ga into NiO leads to a larger cubic lattice parameter that promotes faster charge-transfer kinetics, enabling significantly improved electrochemical performance. The NiGa2O4 electrode delivers a specific capacitance of 1508 F g-1 at a current density of 1 A g-1 with a capacitance retention of 63.7% at 20 A g-1, together with excellent cycling stability after 10000 charge-discharge cycles (capacitance retention of 102.4%). An asymmetric supercapacitor device was assembled by using NiGa2O4 and Fe2O3 as cathode and anode electrodes, respectively. The ASC delivers a high energy density of 45.2 W h kg-1 at a power density of 1600 W kg-1 with exceptional cycling stability (94.3% cell capacitance retention after 10000 cycles). These results suggest that NiGa2O4 can serve as a new class cathode material for advanced electrochemical energy storage applications.
Bibliographical noteFunding Information:
This work was supported by the Science and Technology Development Fund from Macau SAR (FDCT-098/2015/A3), the Start-up Research Grant (SRG2015-00057-FST) from the Research & Development Office at the University of Macau, the UEA funding, and the Korean Government (MSIP) (No. 2015R1A5A1037668) through the National Research Foundation of Korea (NRF) funded by the Ministry of Education, Science, and Technology (MEST). H.-F. Li acknowledges the nancial support from the Science and Technology Development Fund from Macau SAR (FDCT-064/2016/A2).
© 2017 The Royal Society of Chemistry.
All Science Journal Classification (ASJC) codes
- Renewable Energy, Sustainability and the Environment
- Materials Science(all)