Synthesis Of Graphite Nanocages With Porous Shells And Their Applications In Supercapacitor

When carbon materials are applied in electrodes of supercapacitor, their high specific surface area will enhance the specific capacitances and their well graphitic structure will improve service life and corrosion-resistance of carbon-based electrodes. Unfortunately, the specific surface area of such materials is usually not high, because a good graphitization usually trades off property of surface area and surface reactivity. For solving this problem, a novel approach of graphitic nanocages was developed. Graphitic nanocages (GNCs) made up from highly nanoporous shells were prepared by removing doping template inserted in the graphitic layers of GNCs. The precursor Fe@C nanoparticles were synthesized from thermal pyrolysis. The doping atoms partially replaced C ones in the graphitic shells to form doping structure, when the shells were prepared by thermal pyrolysis. Then, doped GNCs were prepared by removing the ferrous cores of the precursor. Due to partially removing doping template inserted in the graphitic layers of GNCs, porous-walled GNCs (PWGNCs) were prepared, and therefore the specific surface area (890 vs.620 m2 g-1), mesopore volume (1.91 vs.1.01 cm3 g-1) and the specific capacitances of PWGNCs (355 vs.297 F g-1 at current densities of 0.1 A g-1)were sharply raised, indicating such doping-template approach was effective towards high performance supercapacitor materials.