Tin disulfide coordinated with sodium alginate as stable anode materials for high-performance lithium ion batteries

Two-dimensional tin disulfide (SnS₂) has emerged as a promising candidate for high-performance energy storage systems, owing to its exceptional theoretical capacity and favorable electrochemical properties. Nevertheless, the practical application of SnS₂ is severely hindered by structural instability during electrochemical cycling, manifested as substantial volumetric expansion, particle agglomeration, and electrolyte-induced dissolution. To address these challenges, we developed a novel nanocomposite through surface modification of SnS₂ with a Sn⁴⁺-crosslinked sodium alginate (Sn-SA) hydrogel matrix. This rationally designed architecture demonstrates dual functionality: accommodating the volume fluctuations of the active material and mitigating parasitic reactions. Benefiting from this structural optimization, the SnS₂@Sn-SA composite electrode delivers an impressive reversible capacity of 797 mAh g⁻¹ at 0.1C while maintaining exceptional cycle life. This study not only presents a viable strategy for stabilizing conversion-alloy-type electrode materials but also highlights the potential of biopolymers in advanced energy storage technologies.