Tin(IV) Sulfide (Stannic Sulfide) is a moderately water and acid soluble Tin source for uses compatible with sulfates. It is an inert, brittle, black solid that is easily dispersed in cold liquids or hot solvents, and is also available as a nanopowder.
Transition metal sulfides are potential candidates for next-generation thin-film solar absorber layers. They are formulated from cheap, earth-abundant elements and exhibit the desired mid-range direct band gap required for this type of solar cell. Additionally, they are nontoxic, exhibiting very low vapor pressures and aqueous stability, making them suitable for battery applications.
Currently, cadmium telluride and copper indium gallium sulfide are used as the p-type absorber layer in commercial thin-film solar cells. However, these materials are expensive to fabricate and contain toxic constituents such as tin(II) chloride and mercury (II). Additionally, they have low open-circuit voltages.
The present invention discloses an economic process for the wet-chemical preparation of tin iv sulfide. The process consists of reacting a tin salt with sulfur in the presence of ammonium chloride. Upon reaction, the mixture is calcined to yield a loose, golden-yellow, homogeneous SnS2 powder.
This tin sulfide is then characterized by powder X-ray diffraction and scanning electron microscopy, fabricated into electrodes, and subjected to galvanostatic intermittent titration tests vs. Li+/Li in CR 2016 coin cell formats. The GITT data were correlated with the potentials calculated for equilibrium lithiation using the thermodynamic description of the Li-Sn system at each composition. The results indicate that the tin iv sulfide is metastable with respect to lithium ion intercalation up to x = 1.5.