Electrochemical reaction of lithium with nanostructured thin film of antimony trioxide

In order to investigate whether the reversible formation and decomposition of Li2O could be driven by other metal such as metal antimony, crystalline Sb2O3 thin films were firstly fabricated by using pulsed laser deposition. The physical, electrochemical and spectroelectrochemical properties of the as-deposited thin film have been investigated by scanning electron microscopy (SEM), X-ray diffraction (XRD), transmission electron microscopy (TEM), and selected area electron diffraction (SAED), galvanostatic cycling, cyclic voltammetry (CV) and in situ transmission spectra measurements. Nanostructured thin film electrode of Sb2O3 exhibited a high reversible capacity of 8.6 Li per Sb2O3 with good cycling performance. A new couple of reduction and oxidation peaks at 1.41 and 1.48 V were observed firstly. Our results demonstrated that the electrochemical properties of Sb2O3 thin film with Li were utterly different from those of Sb2O3 in bulk (powder electrode), indicating a new electrochemical reaction mechanism of nanostructured thin film of Sb2O3. Both alloying/dealloying processes and oxidation/reduction processes of Sb were revealed during the lithium electrochemical reaction of Sb2O3 thin film electrode instead of the classical alloying of Sb2O3 in bulk with Li.