NiCo2S4/Co3S4 heterogeneous double-shelled nanocages for high-performance electrochemical energy storage

Zeolitic imidazolate framework-67 (ZIF-67)-derived yolk-shelled ZIF-67/Ni-Co layered double hydroxides were further vulcanized, forming heterogeneous double-shelled cage-in-cage NiCo2S4/Co3S4. As-synthesized double-shelled nanocages were characterized by XRD, SEM and TEM. As active materials for water-based electrochemical energy storage devices, NiCo2S4/Co3S4 showed relatively high discharge capacity and cycling stability, large current adaptability and reversibility. These could be due to the cage-in-cage hollow nanostructure and high electrochemical activity of transition metal sulfide.