Li/Na atoms' substitution effects on the structural, electronic, and mechanical properties of the CaSnO3 perovskite for battery applications

Abstract

Calcium stannate perovskite CaSnO3 (CSO) is an interesting material for lithium- and sodium-ion batteries (LIBs and SIBs), due to their high hardness and mechanical resistance. In this work, we systematically investigate the effects of substituting lithium/sodium (Li/Na) atoms on the structural, electronic, and mechanical properties of LixCa1-xSnO3 and NaxCa1-xSnO3 perovskite compounds with concentrations × = 0.00, 0.25 and 0.50 using DFT-based in the generalized gradient approximation (GGA) and norm-conserving pseudopotential. This allows describing which substitution generates optimal conditions for structural, mechanical stability, and electronic properties for the CSO perovskite.Lattice parameters behavior as a function of the concentration shows a gradual decrease (increase) in a and c as Li (Na) amount increases. The Na configurations show a small volumetric expansion, on the other hand, the Li configurations have contractions. According to the cohesive energy analysis, it is demonstrated that Li concentrations are more stable than Na ones. The electronic band structure shows that all the Li and Na configurations have a metallic behavior. Finally, the mechanical properties indicate that Na degrades in a less proportion than the Li-substituted compounds; these results demonstrate that SIBs are more favorable than LIBs.