Atomically Engineered Encapsulation of SnS₂ Nanoribbons by Single-Walled Carbon Nanotubes for High-Efficiency Lithium Storage

Rechargeable lithium-ion batteries are integral to contemporary energy storage, yet current anode material systems struggle to meet the increasing demand for extended range capabilities. This work introduces a novel composite anode material composed of one-dimensional 2H-phase tin disulfide (SnS₂) nanoribbons enclosed within cavities of single-walled carbon nanotubes (SnS₂@SWCNTs), achieved through precise atomic engineering. Employing aberration-corrected transmission electron microscopy, we precisely elucidated the crystal structure of SnS₂ within the confines of the SWCNTs. This deliberate design effectively addresses the inherent limitations of SnS₂ as a lithium-ion anode material, including its low electrical conductivity, considerable volume expansion effects, and unstable solid electrolyte interface membrane. Testing confirmed that SnS₂ transforms into the Li₅Sn₂ alloy phase after full lithiation and back to SnS₂ after delithiation, showing excellent reversibility. The composite also benefits from edge effects, improving lithium storage through stronger binding and lower migration barriers, which were supported by calculations. This pioneering work advances high-performance anode materials for applications.