Compound semiconducting SnSb alloy anodes for Li ion batteries: effect of elemental composition of Sn–Sb

Abstract

Compound semiconducting alloy SnSb anodes have been prepared in three different compositions, SnxSby (x = 2–4; y = 3–5) by regular and microwave assisted co-precipitation techniques. Preliminary structural analysis reveals that all the Sn–Sb alloy systems fall into the hexagonal symmetry which is confirmed by the Rietveld refined XRD patterns, SAED pattern and Raman analyses. Increasing the Sn to Sb ratio provides better stoichiometry in SnxSby alloy system which is ensured with EDX analysis. This is further superior in the case of microwave treated SnxSby nanoparticles. Cyclic voltammetry analysis provides augmented redox reactions when increasing the Sn–Sb composition. On the whole, highly crystalline Sn4Sb5 sample treated in microwave radiation exhibit better electrochemical and electrical properties. The diffusion co-efficient of SnxSby nanoparticles lies the range of 10–11–10–12 cm2 s−1. Among all, specific capacity of the Sn4Sb5 treated in microwave radiation is highly stable and provides the highest value in the range ∼153 mAh g−1 for 50 cycles in the aqueous based electrochemical system. Similarly, this sample delivers the highest electrical conductivity in the range of 4.54 × 10–4 S cm−1. Such a behavior is expected to possess better rate capability and reversibility thereby fulfilling the requirements of a successful anodic component in both aqueous/non-aqueous Li-on batteries.