Hydrothermally Synthesized SnS₂ Anode Materials with Selectively Tuned Crystallinity

SnS₂ -based anode active materials for lithium-ion battery applications aresynthesized with varying degrees of crystallinity via a hydrothermal method,and their electrochemical performance properties are assessed. Different ratios oftin chloride and thioacetamide precursors are used and studied to control thecrystallization. In situ electrochemical impedance spectroscopy and galvanostaticintermittent titration technique experiments are used to study the lithium-iondiffusion kinetics into the crystal structures and the conversion reactionmechanisms for discharge up to x ≈ 2.08 moles of lithiation per SnS₂ , equivalentto a discharge capacity of 300 mAh g^-1 . Transmission electron microscopyreveals the presence of amorphous and crystalline domains, as well as theexistence of additional Sn₂S₃ layers on one of the samples. The highest specificreversible capacity during cycling and rate performance are 598 mAh g^-1 after100 cycles and 605 mAh g^-1 after rate capability test, which are obtained for the samples prepared with the 1:4 tin chloride to thioacetamide ratio.