Simple Synthesis of Nanocrystalline Tin Sulfide/N-Doped Reduced Graphene Oxide Composites as Lithium Ion Battery Anodes.

Composites of nitrogen-doped reduced graphene oxide (NRGO) and nanocrystalline tin sulfides were synthesized, and their performance as lithium ion battery anodes was evaluated. Following the first cycle the composite consisted of LiS/LiSn/NRGO. The conductive NRGO cushions the stress associated with the expansion of lithiation of Sn, and the noncycling LiS increases the residual Coulombic capacity of the cycled anode because (a) Sn domains in the composite formed of unsupported SnS expand only by 63% while those in the composite formed of unsupported SnS expand by 91% and (b) Li percolates rapidly at the boundary between the LiS and LiSn nanodomains. The best cycling SnS/NRGO-derived composite retained a specific capacity of 562 mAh g at the 200th cycle at 0.2 A g rate.