Controllable synthesis of spherical S@CoMn2O4 battery-type electrode material for hybrid supercapacitors

Abstract

A novel spherical Co-Mn composite -CoMn2O4 was synthesized via a one-step solvothermal method, and S doping CoMn2O4 (S@CoMn2O4) battery-type electrode material was further obtained via a hydrothermal vulcanization. This ion exchange technique is mainly carried out on the surface of the material and will not destroy the morphology of the original oxide-MOF, so the obtained materials generally have a core-shell structure. The S@CoMn2O4 not only remains a spherical character, but also possesses a coarser surface and porous structure, which considerably increases the specific surface areas (SSA) and electrochemical active sites (EAS) for electrode materials, thus facilitating the charge transfer kinetics for ions and electrons. When the current density (CD) is 1 A g-1, the specific capacity (Cs) of S@CoMn2O4 is 812 C g-1. Moreover, S@CoMn2O4 has excellent electrochemical cycling performance, and the retention rate of Cs for the S@CoMn2O4 reach 92.91% after 5000 cycles at 10 A g-1. When the specific power (Ps) is 775 W kg-1, the specific energy (Es) for S@CoMn2O4//AC device reaches 44.36 Wh kg-1.