Nanostructured Ternary Chalcogenide Electrode Materials for Electrochemical Energy Storage
From portable electronics and transportation systems to backup systems that complement renewable sources such as solar and wind, the demand for energy storage is expected to grow substantially well into the foreseeable future. Electrochemical capacitors (ECs) or supercapacitors are energy-storage devices which possess higher energy density (0.5–10 Wh/kg) than conventional dielectric capacitors and higher power density (1–10 kW/kg) than batteries. ECs find applications in electric vehicles, uninterruptible power supplies, DC power systems, and mobile devices. A supercapacitor stores energy using either ion adsorption (electrical double layer capacitors, EDLCs) or fast and reversible Faradic reactions (pseudocapacitors). These two mechanisms can function simultaneously, depending on the nature of the electrode material. While EDLCs, the most common supercapacitors at present, use carbon-based active materials with high surface area as the electrode materials, pseudocapacitors use transition metal oxides or transition metal sulfides or electrically conducting polymers as active materials. Because of the highly versatile electronic structure and high surface area, the transition metal sulfide, Molybdenum disulfide (MoS2) can be considered as an excellent electrode material for electrochemical energy storage applications. The capacitive performance of MoS2 can be further improved by the doping of the material with either Fe2+ or Co3+ or Ni3+ ions.
Keywords or phrases: Supercpacitor, Hydrothermal, CoMoS2