Interconnected Sn@SnO₂ Nanoparticles as an Anode Material for Lithium-Ion Batteries

Abstract

Ammonia-borane reduction of tin (II) chloride was utilized to prepare customized and interconnected Sn@SnO2 core–shell nanoparticles. Remarkably, the Sn@SnO2-based electrode delivered a reversible capacity of 722 mAh g–1 at 0.5 C after 200 cycles with a Coulombic efficiency of ∼99%. Also, this electrode exhibited a high rate capability (564 mAh g–1 at 1.0 C), low charge transfer resistance (44.7 Ω), and reasonable electrode polarization (146 mV vs Li/Li+), which led to a high capacity retention (∼94%). Additionally, the kinetics of Li-ion storage of the sample revealed that the capacitance contribution plays a main role at fast C-rates. This new nanoarchitecture is promising for stable lithium-ion storage because of the presence of voids and a SnO2 shell in the interconnected Sn@SnO2 nanoparticles, in which the cavities mitigate its volume expansion upon cycling; meanwhile, the SnO2 layer increases its capacity.