Binder-free high-performance Fe_3O_4 fine particles in situ grown onto N-doped porous graphene layers co-embedded into porous substrate as supercapacitor electrode

摘要

It has repeatedly been reported that low conductivity of iron oxide as a major challenge limited its supercapacitive application, where compositing Fe_3O_4 with carbonaceous nanomaterial can be considered as excellent solution strategy. In this paper, we report Fe_3O_4 nanoparticles electrochemically deposited on graphene oxide sheets as high-performance nanocomposite for energy storage applications. Iron oxide nanoparticles (Fe_3O_4) are cathodically decorated on N-doped porous graphene (N-PG) nanosheets. The prepared pristine and nanocomposite materials were characterized by FT-IR, Raman, XRD, BET, TEM, FE-SEM, EDS, as well as TGA/DSC techniques. The electrochemical properties of resulting Fe_3O_4/Ni foam and Fe_3O_4@N-PG/Ni foam electrodes were investigated through CV, GCD, and EIS techniques, and the obtained data showed that the fabricated hybrid electrode (i.e., Fe_3O_4@N-PG/Ni foam) is enable to present specific capacitance values s as high as 822 and 631 F g~(-1) at the 0.5 and 10 A g~(-1), respectively, where the pristine Fe_3O_4/Ni foam electrode showed 279 and 131 F g~(-1) at the 0.5 and 10 A g~(-1). Furthermore, the hybrid Fe_3O_4@N-PG/Ni foam electrode showed excellent cycling ability, good high rate, and higher energy density as compared with the Fe_3O_4/Ni foam electrode. These enhancements were assigned to the synergetic contributions between N-doped porous graphene sheets and iron oxide particles, which mainly results from the rational architecture of N-PG nanosheets and Fe_3O_4 nanoparticles provided by the applied synthetic route.