One-Step Solid-State Synthesis of Sandwich-like, Porous C-SnS2 Matrix Composites as Anode Materials for Rechargeable Lithium Ion Batteries.

Abstract

SnS₂ (tin disulfide) is a promising anode active material for lithium-ion batteries (LIBs) due to its high theoretical capacity and low material cost. Conventional synthesis methods, such as solvothermal, hydrothermal, and solid-state, require long synthesis times, the use of solvents and surfactants, and several separation steps. However, the preparation of coated SnS₂ composites using liquid media is even more complex, requiring suitable precursors, compatible solvents, and potentially several steps. In the present work, a one-step solid-state method is developed to synthesize SnS₂ particles sandwiched in a porous polyacrylonitrile (PAN)-based matrix phase (C-SnS₂) for use as anode active materials for LIBs. The as-synthesized materials exhibit a reversible capacity of 720 mAh g^-1 after 100 cycles when tested versus Li/Li⁺. The performance of this SnS₂-based anode active material is compared to that prepared by the solid-state heat treatment of SnS₂, both with and without PAN. The structure, morphology, chemistry, and electrochemical properties of these compounds are established and comprehensively compared to each other. The observed superior cycling stability and rate capability of the sandwich-like C-SnS₂ are attributed to its phase purity and its incorporation in a porous, conductive, carbonized PAN matrix.