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

Ammonia-borane reduction of tin (II) chloride was utilizedto preparecustomized and interconnected Sn@SnO2 core-shellnanoparticles. Remarkably, the Sn@SnO2-based electrodedelivered a reversible capacity of 722 mAh g(-1) at0.5 C after 200 cycles with a Coulombic efficiency of similar to 99%.Also, this electrode exhibited a high rate capability (564 mAh g(-1) at 1.0 C), low charge transfer resistance (44.7 omega),and reasonable electrode polarization (146 mV vs Li/Li+), which led to a high capacity retention (similar to 94%). Additionally,the kinetics of Li-ion storage of the sample revealed that the capacitance contribution plays a main roleat fast C-rates. This new nanoarchitecture is promising for stablelithium-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.