Hydrothermally Synthesized SnS₂ Anode Materials with Selectively Tuned Crystallinity

Area of Science:

• Materials Science
• Electrochemistry
• Energy Storage

Background:

• Tin disulfide (SnS2) is a promising anode material for lithium-ion batteries.
• Controlling the crystallinity of SnS2 is crucial for optimizing its electrochemical performance.

Purpose of the Study:

• To synthesize SnS2 anode materials with varying crystallinity using a hydrothermal method.
• To investigate the effect of precursor ratios on SnS2 crystallization and electrochemical properties.
• To understand the lithium-ion diffusion kinetics and conversion reaction mechanisms.

Main Methods:

• Hydrothermal synthesis with varying tin chloride to thioacetamide ratios.
• In situ electrochemical impedance spectroscopy (EIS).
• Galvanostatic intermittent titration technique (GITT).
• Transmission electron microscopy (TEM).

Main Results:

• The 1:4 tin chloride to thioacetamide ratio produced SnS2 with the highest specific reversible capacity (598 mAh g-1 after 100 cycles) and rate performance (605 mAh g-1).
• EIS and GITT revealed insights into lithium-ion diffusion kinetics and conversion reactions up to x ≈ 2.08.
• TEM confirmed the presence of amorphous/crystalline domains and additional Sn2S3 layers in some samples.

Conclusions:

• The hydrothermal method allows for tuning SnS2 crystallinity for enhanced lithium-ion battery anodes.
• The 1:4 precursor ratio is optimal for achieving superior electrochemical performance in SnS2 anodes.
• Understanding reaction mechanisms and kinetics is key to further material development.