SnO2 nanoparticles uniformly encapsulated in polyaniline-derived nitrogen-doped carbon as anode materials for lithium-ion batteries.

SnO 2 nanoparticles encapsulated in polyaniline (PANI)-derived nitrogen-doped carbon composite powders (SnO 2 /NC) are successfully synthesized by in-situ polymerization and carbonization processes under an inert atmosphere. The results indicate that SnO 2 nanoparticles of the targeted powders (SnO 2 /NC-3) are uniformly dispersed in the N-doped carbon matrix when the added amount of SnCl 4 ·5H 2 O is precisely controlled at 3 mmol, in which PANI suppresses the aggregation of SnO 2 nanoparticles and is converted into N-doped carbon during the calcination process. The cell assembled with the SnO 2 /NC-3 electrode displays high initial discharge specific capacity of 1116.3 mAh g−1 and reversible discharge specific capacity of 567.2 mAh g−1 after 100 cycles at 100 mA g−1. Moreover, the SnO 2 /NC-3 electrode also exhibits relatively high Li+ ions diffusion coefficient of about 1.22 × 10−12 cm2 s−1. The improved electrochemical performance can be partly ascribed to the fact that the proper amount of SnO 2 nanoparticles contributes to the enhancement of lithium storage capacity, and partly to that the N-doped carbon effectively relieves the volume expansion of SnO 2 nanoparticles. Therefore, the proposed method of using PANI as N-doped carbon source may provide a feasible strategy to fabricate anode materials for high-performance lithium-ion batteries. • SnO 2 @NC composite powders are prepared by in-situ polymerization and carbonization. • SnO 2 nanoparticles are well dispersed in polyaniline-derived nitrogen-doped carbon. • The SnO 2 @NC-3 electrode presents superior capacity and cycle performance. [ABSTRACT FROM AUTHOR]