| The development of modernization is inseparable from the supply of energy and the effective use of the current development situation of our country, the energy problem is still grim. Lithium ion batteries and supercapacitors are widely concerned and applied because of their unique energy storage mechanism and advantages. It is of great practical value and theoretical significance to develop high capacity electrode materials.In order to improve the electrochemical performance of carbon based materials as lithium ion batteries and supercapacitors, this paper adopts two kinds of methods of the preparation of optimization and adjustment of structure of graphite nanocages, improve their electrochemical performance.N-doped nanocages with thin-walled graphitic shells ??1.2 nm? were synthesized by removing ferrous cores of Fe@C nanoparticles. The Fe@C nanopores were prepared by floating catalytic pyrolysis with N atoms being in situ doped in their graphitic shells. Due to thin-walled graphitic shells of nanocages, the fast distribution of the electrolyte and ions were achieved and the prepared nanocage-based anode of lithium-ion batteries showed excellent performance: a high reversible specific capacity (760 mA h g-1 at 0.5 A g-1) and a remarkable rate capability (250 mA h g-1 at 10 A g-1).Thin-walled graphitic nanocages made up from highly nanoporous shells have been successfully synthesized by removing N-doping template. N-doped template is carboxyl groups and nitro-groups, which forms from oxidation of N-doped structure of GNCs by acid-treatment. After partially removal of N-doping template by annealing in vacuum,nanopores forms in the shells of the thin-walled GNCs. Thus, their specific surface area (1100 vs.700 m2 g-1) and specific capacitances (370 vs. 300 F g-1 at a current density of 0.1 A g-1)are sharply raised. With current density increasing to 1 A g-1, the capacitance of the GNCs is still high (230 F g-1), indicating such GNCs is a superb electrode material of supercapacitor. |
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