ZnS nanoparticles as the electrode materials for high-performance supercapacitors

Abstract

ZnS nanoparticles electrode has been synthesized via a simple hydrothermal technique and anion exchange reaction for supercapacitor application. The as-prepared ZnS powder possesses high crystallinity and phase purity, which possesses uniform nanoparticles with an average grain size of 30–40 nm and homogeneous dispersion. The shape of cyclic voltammetry curves with different scanning rates indicates a reduced polarization effect of the ZnS nanoparticles electrode. The ZnS electrode manifests drastically superior electrochemical performance covering a supreme reversible specific capacitance of 824 F g−1 at 1 A g−1, outstanding rate capability of 57.7% capacitance retention even if the current density increases by 20 times, and prominent ultralong-life at large current densities of 5.0 and 10.0 A g−1. The initial specific capacitance of ZnS nanoparticle is 557 F g−1 at 10 A g−1, and it also delivers 518.4 F g−1 after 10,000 cycles with a high capacitance retention of 93.1%. These above results shed light on new avenues for promising electrode materials in supercapacitors.