Prussian blue analogue derived NiCoSe_(4) coupling with nitrogen-doped carbon nanofibers for pseudocapacitive electrodes

The design of pseudocapacitive materials by coupling transition metal compounds with a conductive carbon matrix is important for the high performance of supercapacitors.Herein,we construct the Prussian blue analogue derived nickel-cobalt selenides coupling with nitrogen-doped carbon nanofibers(NiCoSe_(4)-NCNFs)by carbonization and selenization of polyacrylonitrile nanofibers.The effect of selenization and element N doping on the morphological structure and surface chemistry of NiCoSe_(4)-NCNFs are evaluated.Due to the accelerated electrolyte ion diffusion,enlarged active surface area and the modified surface chemistry by the strong interaction at NiCoSe_(4)/NCNFs interfaces,NiCoSe_(4)-NCNFs show excellent capacitive behaviors in 1 mol/L KOH,and the specific capacitance is 1257 F/g at 1 A/g with a rate capability of 78%and cyclic stability of 82.9%.The Gibbs free energy of adsorption OH−is calculated by density functional theory to investigate the charge storage mechanism.This work offers a new strategy to construct the transition metal selenides/carbon nanofibers hybrids for high-performance supercapacitor devices.