Porous Fe_3O_4/carbon composite electrode material prepared from metal-organic framework template and effect of temperature on its capacitance

摘要

In this paper, we report a porous Fe_3O_4/carbon composite supercapacitor electrode material possessing great temperature variation-resistive long-term cycle stability. The material is prepared via a facile one-step calcination of an iron-based metal organic framework (Fe-MOF) template and composed of porous Fe_3O_4 nanoparticles and carbon as a result of a well-controlled incomplete annealing process of the MOF template. With this material as an electrode, a specific capacitance of 139 F g~(-1) at a discharging current density of 0.5 A g~(-1) can be achieved. More attractively, the specific capacitance is significantly increased when the working temperature is elevated from 0 to 60 °C. Furthermore, even after 4000 cycles of charge-discharge at varied temperatures, 83.3% of the capacitance of the electrode materialis retained, showing excellent temperature variation-resistive long-term cycle stability of the prepared composite electrode material.