Single-step, in-situ fabrication of flower-like NiCuMn hybrid oxyhydroxide electrodes for enhanced supercapacitor performance

Abstract

The rational design of highly active and low-cost electrode material is very promising for energy storage applications. The development of supercapacitors with high energy/power density is an imperative and challenging research objective. Herein, we report a highly facile synthesis approach for developing unique nano-porous hybrid NiCuMn oxyhydroxide architecture with remarkable electrochemical energy storage characteristics. The process involves dealloying of Ni15Cu15Mn70 alloy in an oxygen rich environment, resulting in a uniform 3-dimensional flower like morphology. The dealloyed electrode demonstrates ultra-high specific capacitance of 4110 F cm−3 at a high current density of 20 mA cm−2. A symmetric device exhibits a high volumetric capacitance of 365 F cm−3 at a current density of 10 mA cm−2 with a large potential window of 1.7 V. Even at very high-power density of 850 W l−1, the device exhibits a high energy density of 146 Wh l−1 along with remarkable cyclic stability of 95.4% after 10 000 cycles. The superior performance of nano-porous hybrid NiCuMn oxyhydroxide architecture was attributed to its unique microstructure that provides high surface area, and marginal internal resistance ensuring rapid charge transport.