Ni-soc-MOF derived carbon hollow sphere encapsulated Ni 3 Se 4 nanocrystals for high-rate supercapacitors.

Carbon hollow sphere encapsulated Ni 3 Se 4 (Ni 3 Se 4 @CHS) nanocrystals are prepared using the Ni-soc-MOF by pyrolysis and further selenization. Ni 3 Se 4 @CHS exhibits a capacitance of 1720 F g -1 at 1 A g -1 and a capacitance retention of 97% after 6000 cycles at 5 A g -1 . Moreover, the asymmetric supercapacitor of Ni 3 Se 4 @CHS//AC displays a wide potential window of 1.6 V, an energy density of 45.2 W h kg -1 at a power density of 800 W kg -1 , and excellent cycling stability (89% capacitance retention) after 5000 cycles. Overall, this work establishes a significant step to synthesize a new carbon-based material with appreciable capacitance and long cycling durability for potential applications in energy storage and beyond.