One-pot synthesis of CoNi2S4 nanoparticle-loaded carbon nanofiber composite with superior electrochemical performance

•CoNi2S4-CNF composite has been prepared via a novel one-pot synthetic strategy.•The introduction of CNF prevents the agglomeration of CoNi2S4 and CNF.•The capacitance retention of the hybrid supercapacitor is 76.6% after 5000 cycles.•The enhanced capacitive performance is ascribed to the unique heterostructure.