Nanostructured Bi2Te3 and Sb2Te3 films prepared via MOCVD for Li-ion battery anodes

Vapor deposition techniques are particularly attractive for lithium-ion battery materials, for both powder coatings as well as thin-film electrodes. To increase capacity, alloying anodes represent a new class of materials for energy-dense films. Herein, we use metal organic chemical vapor deposition to prepare bismuth telluride (Bi2Te3) and antimony telluride (Sb2Te3) thin-film electrodes, materials which have not been studied extensively for lithium-ion batteries, and assess their lithium storage performance. A deposition process was developed to yield continuous thin films with thicknesses ranging from 0.5 to 1.4 mu m on electrically conductive substrates. By varying the growth time of the deposition process, capacities up to similar to 0.3 mA h cm(-2) were obtained with a growth time of 60 min. The Sb2Te3 thin-film electrode outperforms Bi2Te3 for similar deposition conditions, which is primarily attributed to the high performance of native Sb that exhibits high capacity and stable cycling. Although the final phase of these thin-film electrodes separates into a biphasic domain, it is evident that the starting compound Sb2Te3 is stable up to 50 cycles. Yet, since cracks are still observed from post-cycling scanning electron microscopy, it is evident that a proper balance between film thickness and cycling must be remediated. (C) 2020 Elsevier B.V. All rights reserved.