First-principles perspective on structural evolution, sequential lithiation and physicochemical properties of tin oxide nanoclusters: Sn3Oz and LixSn3Oz (x = 1-10 and z = 0, 3-7)

Abstract

Metal oxides have been reported as high capacity anode materials in Lithium-ion batteries (LIBs) but lack merit of commercialization due to volume-expansion during operation and poor electronic conductivity. Nanosized metal oxide could be used to circumvent these demerits. In this work, we examined the application of tin oxide nanoclusters (Sn3Oz, z = 0, 3–7) as anode materials in LIB using ab initio density functional theory perspective. Analysis of moderately lithiated tin oxide nanoclusters (LixSn3Oz, x = 1–10) indicates a tremendous reduction in volume-expansion due to high surface area of the nanoclusters by analysis of change in Sn-Li bond length with number of lithiation by process of alloying. Structural analysis also revealed the formation of Li2O by conversion reaction during lithiation. Stability studies by binding energy (B.E.) during lithiation showed decreased stability as lithiation increased. The role of chemical reactivity concept on the lithiation of Sn3Oz nanoclusters were revealed by the physicochemical properties of the nanoclusters. Electrophilicity studies reveals the capability of the nanoclusters to accept electrons from the inserted Li. Sn3 and Sn3O3 nanoclusters were the most suitable anode materials amongst other nanoclusters presented with average intercalation voltage (AIV) of 0.67 and 1.12 V respectively. The adsorption energy (Eads) and dissociation energy (Edis) obtained showed that Li dimer formation can be prevented by these nanoclusters as anode. The calculations substantiate the suitability of tin oxide nanoclusters as anode material in LIBs.