Cube Fe3O4 nanoparticles embedded in three-dimensional net porous carbon from silicon oxycarbide for high performance supercapacitor

Abstract

Transition metal oxide and porous carbon both with unique structure are hopeful for employing high-performance energy storage devices. In our work, a simple and inexpensive chemical precipitation method was utilized to obtain the ferroferric oxide/carbide-derived carbon (Fe3O4/CDC) composite electrode of supercapacitor. The Fe3O4 nanoparticles with cube shape were embedded in three-dimensional net porous CDC material. Owing to the superior synergistic effect between CDC with high specific surface area and Fe3O4 nanoparticles with high redox activity, the optimal Fe3O4/CDC composite electrode shows good capacitive performances. In the three-electrode system, the Fe3O4/CDC composite electrode exhibits high specific capacitance in neutral Na2SO4 (293.7 F g−1) and alkaline KOH electrolytes (346.5 F g−1) at 1 A g−1. Especially, the Fe3O4/CDC composite shows better electrochemical stability in Na2SO4 electrolyte. The symmetrical supercapacitor was produced by using Na2SO4 as electrolyte and Fe3O4/CDC composite as electrode. The as-produced device offers an excellent energy density of 14.3 Wh kg−1 at 4093 W kg−1. After 4000 cycles, 92.3% of the initial specific capacitance can be retained, proving the remarkable cycle stability. Thus, the effective and facile combination of three-dimensional net porous CDC and Fe3O4 nanoparticles to obtaining electrode material is a promising strategy for efficient energy-storage application.