Poly(ionic liquid)-derived nitrogen-doped hollow carbon spheres: synthesis and loading with Fe2O3 for high-performance lithium ion batteries

Abstract

Porous nitrogen-doped hollow carbon spheres (NHCSs) with tailored particle size, nitrogen content and wall thickness were prepared by grafting a thin layer of poly(ionic liquid) as carbon precursor onto silica particle surface followed by carbonization and template removal. In the next step, Fe₂O₃ nanoparticles were anchored onto the NHCSs via an impregnation-thermal decomposition route using Fe(NO₃)₃ as iron source. The as-synthesized Fe₂O₃–NHCS composite was utilized as the anode material for a lithium-ion battery, which exhibited a high reversible capacity of 1120 mAh g⁻¹ at a rate of 100 mA g⁻¹, and a coulombic efficiency of ∼98% at a rate of 500 mA g⁻¹ after 65 cycles.