Doping-template approach of porous-walled graphitic nanocages for superior performance anodes of lithium ion batteries

Abstract

In a template approach to porous-walled graphitic nanocages (PWGNC) with N-doping structure, nanopores have been equably and efficiently created in the shells of GNCs by partially removing N-doped templates, which replace some C atoms in the graphitic layers of the GNCs by in situ doping during thermal pyrolytic preparation of GNCs. Such created nanopores offer many efficient diffusion channels for fast distribution of the electrolyte and Li⁺ (specific surface area and mesopore volume sharply rose 1100 vs. 700 m² g⁻¹; 1.9 vs. 1 cm³ g⁻¹), leading to their hollow inner structure available even at elevated charge/discharge rates, which sharply enhances the performance of the PWGNC-based anode with charge–discharge rate increases (31% increase: 1200 vs. 917 mA h g⁻¹ at current density of 0.2 A g⁻¹; 52% increase: 510 vs. 335 mA h g⁻¹ at 5 A g⁻¹).