Formation of needle-like porous CoNi2S4-MnOOH for high performance hybrid supercapacitors with high energy density

Abstract

Seeking for suitable electrode materials and designing rational porous structures are great challenges for developing high performance supercapacitors. Herein, needle-like porous CoNi2S4-MnOOH (denoted as NCS-MO) were prepared via a simple two steps solvothermal method and used as battery-type electrode of supercapacitor for the first time. Owing to the multiple oxidation states of needle-like porous NCS-MO and the inherent porous structure, the electrode delivers outstanding electrochemical capacitive properties with a high gravimetric specific capacitance of 1267.7 F g−1 at the scan rate of 1 mV s−1. To further assess the practical electrochemical performances, we assembled a hybrid supercapacitor using the as-synthesized porous NCS-MO as cathode and active carbon as anode. The device exhibits excellent performance with a high energy density of 47.1 Wh kg−1 at the power density of 998 W kg−1 in an extended voltage range of 1.6 V and outstanding cycling stability. These results demonstrate that the needle-like porous NCS-MO could be promising potential electrode material for high performance supercapacitor.