Prussian blue analogue derived NiCoSe4 coupling with nitrogen-doped carbon nanofibers for pseudocapacitive electrodes

The design of pseudocapacitive materials by coupling transition metal compounds with a conductive car-bon 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 (NiCoSe4 -NCNFs) by carbonization and selenization of polyacrylonitrile nanofibers. The effect of selenization and el-ement N doping on the morphological structure and surface chemistry of NiCoSe4-NCNFs are evaluated. Due to the accelerated electrolyte ion diffusion, enlarged active surface area and the modified surface chemistry by the strong interaction at NiCoSe4/NCNFs interfaces, NiCoSe4-NCNFs show excellent capaci-tive 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 func-tional 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.& COPY; 2023 Published by Elsevier B.V. on behalf of Chinese Chemical Society and Institute of Materia Medica, Chinese Academy of Medical Sciences.

Automated summary

The design of pseudocapacitive materials by coupling transition metal compounds with a conductive carbon matrix is crucial for enhancing the performance of supercapacitors. In this study, NiCoSe4-NCNFs were synthesized by carbonizing and selenizing polyacrylonitrile nanofibers, which exhibited excellent capacitive behaviors in 1 mol/L KOH electrolyte due to accelerated ion diffusion, enlarged active surface area, and modified surface chemistry at NiCoSe4/NCNFs interfaces. This work provides a novel strategy for constructing high-performance supercapacitors using transition metal selenides/carbon nanofibers hybrids.