Conversion of MOF into carbon-coated NiSe2 yolk-shell microspheres as advanced battery-type electrodes

Abstract

Construction and design of electrode materials with complex hollow structure are of great significance and challenging. Herein, uniform carbon modified NiSe2 yolk-shell spheres were constructed by a facile and effective strategy using Ni-based metal-organic framework as self-sacrificing template. In particular, the carbon shells pyrolysis from organic ligands can improve electron conductivity and mechanical stability. Therefore, the as-obtained NiSe2@C nanocomposites exhibit a high specific capacity of 730 C/g at 2 A/g and remarkable cycling stability of 94% capacity retention after 10,000 cycles. In addition, the faradic behavior also has been carefully studied, and the low conduct resistance between carbon and NiSe2 nanoparticles can promote electron transfer efficiency, and ideal porosity structure can effectively facilitate ion diffusion, contributing to the outstanding electrochemical performance. Moreover, the assembled hybrid supercapacitor can deliver high energy density of 48.6 Wh/kg at 1023 W/kg and excellent cycling performance of 90% capacity retention after 8000 cycles, demonstrating its promising potential in practical application.