Scalable Preparation of Nanostructured Hybrids of Transition Metal Sulfide/Oxide With Carbon Materials for High-Performance Supercapacitors

Abstract

The ever-growing demands and rapid development of energy storage devices and systems pressed the need for low-cost yet highly performing electrode materials. The transition metal oxide and sulfide-based hybrids holds great promise as the active electrode materials in supercapacitors, due to their large surface area and variable oxidation states. These properties enable significantly high energy storage via electrical double layer and pseudocapacitive charge storage mechanisms. Herein, we discuss a facile, scalable, and environment-friendly preparation process to produce transition metal sulfide and oxides based on resource rich metals such as Mn, Fe, V etc. and their hybrids with carbonaceous materials, such as carbon nanotubes and graphene. This strategy encompasses solvent-less mixing of a metal salt, surfeit yet non-toxic abundant elemental sulfur and carbon precursor under continuous ball milling and thermo-annealing. The resulting nanohybrids were thoroughly investigated by means of several techniques. XRD, HRTEM, SEM, Raman and BET could gather insights on the morphology and the fine material structure, as well as on the spectroscopic properties. Finally, the electrochemical properties as supercapacitor components were investigated in regards with varyingly increasing carbon content. The nanohybrids were tested in both aqueous and organic electrolytes for bettering energy and power performances. Charge storage performances and components stability in both symmetric and asymmetric devices were assessed via CV, GCD, EIS.