Three-Dimensional Bi-Continuous Nanoporous Gold/Nickel Foam Supported MnO2 for High Performance Supercapacitors

摘要

A three-dimensional bi-continuous nanoporous gold (NPG)ickel foam is developed though the electrodeposition of a gold–tin alloy on Ni foam and subsequent chemical dealloying of tin. The newly-designed 3D metal structure is used to anchor MnO2 nanosheets for high-performance supercapacitors. The formed ternary composite electrodes exhibit significantly-enhanced capacitance performance, rate capability, and excellent cycling stability. A specific capacitance of 442 Fg⁻¹ is achieved at a scan rate of 5 mV s⁻¹ and a relatively high mass loading of 865 μg cm⁻². After 2500 cycles, only a 1% decay is found at a scan rate of 50 mV s⁻¹. A high power density of 3513 W kg⁻¹ and an energy density of 25.73 Wh kg⁻¹ are realized for potential energy storage devices. The results demonstrate that the NPGickel foam hybrid structure significantly improves the dispersibility of MnO2 and makes it promising for practical energy storage applications.