High Energy Density Asymmetric Supercapacitors From Mesoporous NiCo2S4 Nanosheets

High-purity NiCo2S4 mesoporous nanosheets prepared through utilizing CS2 as novel sulfur source were fabricated as advanced electrode for electrochemical supercapacitors. Well-defined X-ray diffraction pattern, high specific surface areas and suitable pore size distribution (2 similar to 6 nm) were observed for the asobtained NiCO2S4 sample, demonstrating remarkable electrochemical performances resulting from the porous feature of NiCO2S4 nanosheets that increase the amount of electroactive sites and facilitate the electrolyte penetration. The as-assembled asymmetric supercapacitor (ASC) exhibits a high energy density of 25.5 Wh kg-1 at a power density of 334W kg(-1) and still remains an impressive energy density of 10.8 Wh kg(-1) at a high power density of 8 kW kg. The outstanding performance of this ASC device will undoubtedly make the mesoporous NiCO2S4 nanosheets attractive for high-performance electrode materials. (C) 2015 Elsevier Ltd. All rights reserved.