Regulation mechanisms of In, Bi, and Sb doping on the structural, electronic, and lithiation performances of layered SnS 2 anodes: a first-principles study

Abstract As a layered sulfide anode material, SnS 2 offers high lithium storage potential through interlayer van der Waals gaps for Li + transport. However, its wide bandgap and lithiation-induced interlayer collapse hinder practical use. This study employed DFT calculations to construct 2D/3D models of In, Bi, and Sb doped SnS 2 , investigating doping effects on structural stability, electronic structure, lithiation kinetics, and elastic properties. Results reveal that performance differences arise from the synergy of atomic radius and orbital characteristics. In doping causes significant lattice distortion (10.08%), enhancing Li + adsorption but sacrificing cycling stability. Bi doping induces compressive strain, increasing the Li + diffusion barrier to 1.36 eV and limiting electronic delocalization. Sb doping, with a minimal 0.82% distortion, narrows the bandgap to 0.10 eV via strong Sb-5s/5p and S-3p orbital hybridization, reducing the diffusion barrier to 0.88 eV. It also exhibits good toughness, achieving a theoretical capacity of 729.20 mAh g −1 .