Electrode Materials of Cobaltous Fluoride for Supercapacitor and Electrocatalysis Applications

Herein, CoF₂ was synthesized by a solvothermal method. The characterization results of the phase and morphology of the sample show that it was successfully synthesized and its morphology is composed of micron particles with uneven size and shape. The electrochemical test results of SCs in different electrolytes show that CoF₂ has electrochemical activity only in alkaline electrolytes. Notably, the electrochemical behavior of CoF₂ in LiOH solution is different from that in other alkaline solutions in that charge-discharge curve has a quasi-isosceles triangle shape and the CV curve has no obvious redox peak. That is, it has pseudocapacitance behavior in LiOH. Furthermore, CoF₂ as catalyst for HER requires an overpotential of only 168 mV to obtain current density of 10 mA cm^-2 and a Tafel slope of 116 mV dec^-1 in 1 M KOH solution. This research provides a novel way to explore excellent performance electrode materials for SC and HER.