Enhanced electrochemical performance of 3‐D microporous nickel/nickel oxide nanoflakes for application in supercapacitors

Abstract

Increasing energy demands, depletion of fossil fuels, and environmental issues have impelled society to choose the pathways of renewable and clean energy, which motivated scientists and engineers to develop sustainable, renewable, and clean energy resources. However, the major challenge is the implementation of low‐cost, flexible approaches and materials to fulfill the requirements of energy storage and conversion technologies, specifically those involving batteries and supercapacitors. In this context, herein, we demonstrate an integrated approach to realize three‐dimensional (3‐D) mesoporous nickel(Ni)/nickel oxide (NiO) nanostructures with enhanced performance for supercapacitor applications. Conformal deposition of NiO nanoflakes on 3‐D mesoporous Ni onto inexpensive Cu substrates with large active surface area, providing easy ion accessibility through mesoporous channels and improving electron transport through interconnected nickel network. The 3‐D mesoporous Ni/NiO nanoflakes exhibit excellent electrochemical performance, namely, areal capacitance of 720 mFcm −2 , energy density of 4 μWhcm −2 and power density of 2.5 mWcm −2 and a reasonable capacity retention for 5000 cycles. We believe that these results may provide a roadmap to further tune the conditions so as to engineer oxide architectures to derive enhanced energy performance of supercapacitor devices for practical applications.