Ni-soc-MOF derived carbon hollow sphere encapsulated Ni3Se4 nanocrystals for high-rate supercapacitors

Abstract

Carbon hollow sphere encapsulated Ni₃Se₄ (Ni₃Se₄@CHS) nanocrystals are prepared using the Ni-soc-MOF by pyrolysis and further selenization. Ni₃Se₄@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 Ni₃Se₄@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.