Significant capacitance enhancement induced by cyclic voltammetry in pine needle-like Ni-Co-Cu multicomponent electrode

Abstract

Poor conductivity and rate capability are the obstacles faced by nickel-cobalt composites as electrode materials for supercapacitor application. Herein, simple electrochemical treatment conducted by cyclic voltammetry is applied and the overall performance of the active material is considerably enhanced. We discover that this treatment triggers the formation of Ni-Co-Cu ternary composite and optimizes the crystal structure of the untreated counterpart. The areal capacitance of the treated sample rockets up to 6.13 F cm−2 at 2 mA cm−2, almost 13 times higher than the untreated ones. Besides, the resistance is substantially reduced by cyclic voltammetry treatment. Moreover, the Coulombic efficiency and stability are concurrently elevated. The reasons behind this treatment are mulled over and reasonable hypothesis is suggested. This study provides a cheap and effortless way to reform the structures of as-obtained samples as well as vigorously raise the performance of current available materials.