Effect of electrolyte cations on the capacitive performance of the hexagonal-MoO3/polypyrrole hybrid

Hexagonal-MoO3/polypyrrole conductive hybrid is facilely prepared by wrapping a homogenous polypyrrole (PPy) layer around hexagonal-MoO3 (h-MoO3) prism via in-situ oxidative polymerization of self-assembled pyrrole monomer. The electrochemical performance of the obtained h-MoO3/PPy hybrid in different electrolytes is investigated. The cyclic voltammogram results at different scan rates show that the rate behaviors of h-MoO3/PPy in the three electrolytes improve in the order of Li2SO4 < Na2SO4 < K2SO4. The EIS measurement indicates that the h-MoO3/PPy hybrid in K2SO4 electrolyte exhibits lower charge-transfer resistance and equivalent series resistance, which attributes to the small hydrated ionic radius and fast transfer rate of K+. Furthermore, the cycling stability of the h-MoO3/PPy hybrid also increase in the sequence of Li2SO4 < Na2SO4 < K2SO4. The above results provide valuable supporting information to explore new hybrid supercapacitor system.