Uniform growth of Zn-Mn-Co ternary oxide nanoneedles for high-performance energy-storage applications

Abstract

This paper reports the facile synthesis of a novel electrode material for high-performance supercapacitor. The binder-free Zn-Mn-Co ternary oxide nanoneedles with highly exposed active sites to electrolyte were examined by multiple characterizations. Zn-Mn-Co ternary oxide nanoneedle electrode exhibited a high specific capacity of 849Cg−1 at a current density of 1Ag−1 in three electrode measurements. Furthermore, it showed an excellent cycling stability after 8000cycles and a very high coulombic efficiency. Moreover, hybrid supercapacitor device was assembled using Zn-Mn-Co ternary oxide nanoneedles as a positive electrode and activated carbon as a negative electrode. The hybrid supercapacitor device showed a high specific capacity of 158Cg−1 at a current density of 1Ag−1. The device delivered a high energy density of 35.5Whkg−1 and a high power density of 7.5kWkg−1. Interestingly, the hybrid supercapacitor device showed 100% initial capacitance retention over 7000cycles. All these attractive results demonstrate the importance of this electrode material towards practical application.