MOFs derived (Ni0.75Co0.25)Se2 nanoparticles embedded in N-doped nanocarbon for hybrid supercapacitors

Abstract

Bimetallic selenides have aroused great interest as the electroactive materials for energy storage because of their high conductivity, robust electrochemical activity, and the synergistic effect. Herein, (Ni0.75Co0.25)Se2 nanoparticles embedded in N-doped nanocarbon ((Ni0.75Co0.25)Se2@NC) hybrids were derived from nickel and cobalt bimetal-organic frameworks (NiCo-MOFs), which were synthesized by ethylene glycol solvothermal method. Due to the synergistic contributions and unique architecture, (Ni0.75Co0.25)Se2@NC hybrids electrode presents a considerable specific capacity of 536.6 C g−1 at a discharge current density of 1 A g−1. In addition, an as-assembled (Ni0.75Co0.25)Se2@NC//activated carbon (AC) hybrid supercapacitor (HSC) ((Ni0.75Co0.25)Se2@NC//AC HSC) shows large specific capacitance (73.6 F g−1 at 0.5 A g−1), outstanding energy density (26.2 Wh kg−1 at 400 W kg−1) with superior cyclic performance (88.7% of capacity retention after 5000 cycles). Furthermore, a (Ni0.75Co0.25)Se2@NC//AC device could drive a mini-fan running for 67 s. Thus, (Ni0.75Co0.25)Se2@NC is an outstanding active material for electrochemical energy storage.