NiCo2S4 nanosheet grafted SiO2@C core-shelled spheres as a novel electrode for high performance supercapacitors

摘要

A high-performance supercapacitor electrode NiCo2S4 (NCS) nanosheet on SiO2@C core-shell nanospheres (SiO2@C-NCS nanocomposite) is prepared via simple an effective solution-based method. Benefiting from compositional and structural advantages, the as-prepared SiO2@C-NCS nanocomposite exhibits a high specific capacitance (625 F g(-1) at 1 mA cm(-2)) and a stable cycling performance. An asymmetric supercapacitor (ASC) assembled with SiO2@C-NCS nanocomposite as a positive electrode and carbon nanotube paper as a negative electrode in aqueous KOH solution demonstrated a high energy density of 16 Wh kg(-1) at an ultra-high specific power of 7200 W kg(-1). These promising results suggest the possible application of mixed transition metal sulfides-based composites as advanced electrode materials for high-performance ASCs.