Electrophoretic Deposition of Tin Sulfide Nanocubes as High-Performance Lithium-Ion Battery Anodes

We report the use of assemblies of SnS nanocubes as lithium-ion battery anodes. The particles are deposited in dense, conductive thin films with high gravimetric capacity using electrophoretic deposition, negating the requirement for binders or conductive additives. Although SnS nanocube ensembles display both alloying and conversion modes, a significant benefit to capacity retention during long-term cycling was observed by limiting the upper cutoff voltage to 1 V. In this alloying-only regime that is more realistic for practical use, a discharge capacity of 552 mAh g⁻¹ was delivered with a loss of only 0.08 % per cycle observed over the 400 charge/discharge cycles. We further show that the Li₂S formation that occurs in the first lithiation acts as a buffer to the expansion and contraction, though crucially this effect is optimized if this species is not cycled further (>1 V). The SnS nanocube electrodes are tested in both half-cell (HC) and full-cell (FC) configurations and are analyzed by using ex situ SEM and EIS analysis. Finally, the electrophoretic deposition of SnS nanocubes onto a 3D textured current collector is demonstrated to increase the mass loadings.