Tin Disulfide Nanoflowers versus Nanosheets as Anodes in Lithium-ion Batteries: How the Nanostructure Controls Performance

A scalable one-pot solvothermal route is presented for preparing tin disulfide (SnS2) nanosheets and nanoflowers. Urea, mercapto propionic acid as an organic additive, steers the growth of SnS2 nanosheets and thiourea (TU) orchestrates the formation hierarchical SnS2 nanoflowers. A time dependent experiment reveals the following growth mechanism: from SnO2 with a tetragonal rutile structure (1 h), to SnS2 nanosheets and nanoflowers with a hexagonal crystal structure (12 h). When SnS2 nanosheets and nanoflowers are incorporated into Li-ion battery half cells, both nanostructures exhibit excellent capacity retention and rate capability. SnS2 nanoflowers and nanosheets retained a capacity of 466 and 196 mAh g−1 even at very high current density of 3000 mA g−1 after 65 cycles. The outstanding reversible Li-ion storage responses and the visible blue-green photoluminescence shown by SnS2 nanosheets and nanoflowers are prime indicators of the potential these nanostructures have for not just energy storage and but also for energy harvesting applications.