Controlled Synthesis of Sn Nanoparticle Embedded Nanoporous Carbon Composites for Lithium-Ion Battery Anodes

Sn nanoparticles embedded in porous carbon were synthesized via hydrogen thermal reduction of subnanometer sized SnO2 particles loaded in porous carbon. The synthesis temperature for Sn nanoparticles could be reduced to 300–350 °C by using subnanosized SnO2 as a precursor, and the nanopores of porous carbon suppressed the aggregation of Sn particles. The obtained Sn/porous carbon composite featured highly dispersed Sn particles with sizes of 10–50 nm within the carbon pores. The composite exhibited a high specific capacity of 855 mAh/g based on the Sn content, which is equivalent to 86% of the theoretical capacity of the Sn electrode and maintained 99% of its initial capacity after 30 cycles. The results demonstrate that utilizing pore space as a buffer for the volumetric expansion of Sn electrodes can lead to high-performance secondary batteries, including sodium-ion and all-solid-state batteries.