Strontium Stannate as an Alternative Anode Material for Li-Ion Batteries

Abstract

Although strontium stannate (SrSnO3) has been considered as an anode for Li-ion batteries, a deep understanding of its Li-ion transport properties remains lacking. In this work, the structural, electronic, mechanical, and transport properties of SrSnO3 are explored using density functional theory and force-field-based simulations. Our results show that the norm-conserving approximation is particularly accurate for reproducing the lattice parameters and electronic structure of SrSnO3. SrSnO3 exhibits an indirect energy gap of ∼3.0 eV, in agreement with the experiment. SrSnO3 is a mechanically stable and a quasi-brittle material that is also more isotropic with respect to the volume change than the shape change. Defect energy simulations reveal a low energetic cost for the Li-ion incorporation mechanism proposed, which is beneficial for its potential application as an electrode material. A comparison of the Li-ion transport properties of Li-doped mono- and nanocrystalline SrSnO3 samples reveals that the nanocrystalline material exhibits a lower diffusion activation energy of ∼0.28 eV and higher diffusivity at operative temperature. The understanding and properties illustrated in this work open an avenue for the consideration of SrSnO3 as a potential candidate to be used as an anode for Li-ion batteries.