Rational design and synthesis of multi-shelled NiCo2S4 hollow microspheres for high performance supercapacitors

Nickel cobalt sulfide hollow micro-/nanostructures have received extensive attention as potential electrode materials for electrochemical energy storage due to its attractive structure, reach chemistry and excellent conductivity. Compare to ordinary hollow materials, multi-shelled hollow structures apparently have more advantages in specific surface area, energy density and structure stability. Herein, we successfully prepared multi-shelled NiCo2S4 hollow microspheres and pioneered its application in supercapacitors. The multi-shelled NiCo2S4 hollow microspheres show high specific capacity of 1521.3 F g−1 at a current density of 0.5 A g−1. The asymmetric supercapacitor with a positive electrode of multi-shelled NiCo2S4 hollow microspheres and a negative electrode of active carbon reveals excellent energy density of 58.18 Wh kg−1 at the power density of 400.03 W kg−1, and only 14.51% energy density fade after 5000 cycles. Such striking electrochemical performances make the multi-shelled NiCo2S4 hollow microspheres promising for high performance supercapacitors.