Influence of reducing agents in nanoparticle synthesis: SnO₂‐ZnO composite anode

Abstract

The present research work is dedicated to understand the effect of synthesis medium on the nanocomposite anode, SnO 2 : ZnO, and their synergistic effects towards Li-ion battery applications. Alkaline and acidic media as reducing agents such as NaOH, LiOH, and NaBH 4 are chosen for the preparation of the composite, and the results are surprisingly varying. Structural analysis by means of X-ray diffraction shows the mixed crystal symmetry inclusive of SnO 2 and ZnO phases for all the three systems with varying ranges of each phases. The average crystallite sizes are around 20-39 nm for all the three samples. Morphological analysis of SnO 2 : ZnO anode by means of transmission electron microscopy indicates mixed shapes of grains for the samples synthesized by NaOH and LiOH, whereas reducing agent, NaBH 4 , falls into the spherical shape predominantly. Raman and selected area electron diffraction analyses validate the mixed crystal symmetry of all the three samples. Electrochemical performance of the samples is promising where NaBH 4 mediated anode delivers reversible capacity around 225 m Ahg À1 exclusively. In the aspect of electrical conductivity, almost all the three samples employed with three different reducing agents fall in the range of $10 À4 S cm À1 at room temperature, validating the choice of the material as anode in Li-ion battery technology.