Nitrogen-doped carbon coating inside porous TiO2 using small nitrogen-containing molecules for improving performance of lithium-ion batteries

Abstract

Alternative anode materials with more positive lithium intercalation potential than that of graphite are desirable for lithium ion batteries with high safety particularly required for electric vehicles and sustainable energy sources. Thermally stable, mesoporous anatase TiO2 spheres are successfully synthesized, using ethylene diamine as a precursor, via a facile solution-phase process incorporating a nanoscopic carbon coating doped with a relatively high nitrogen content which formed a conducting network with mesoporous TiO2 upon calcination. The structural characterizations demonstrate the crucial function of ethylene diamine in stabilizing and maintaining the well-confined mesoporous structure for TiO2 during calcination. The porous TiO2 material with a conducting network exhibits a highly reversible capacity of 182mA h g −1 after 60 cycles at the current density of 0.5C and an improved rate capability compared to porous TiO2 without modification, indicating the composite is a promising anode material for Li-ion batteries.