Direct Synthesis of Non-Stoichometric Nanocrystalline Metal Oxides and Their Composites: Improving the Reversibility and Current Capability of Lithium-Ion Batteries

Abstract

As the demand for large scale batteries grows, considerations such as earth abundance, cost, and toxicity gain increased significance. Metal oxides are worthy of evaluation as active materials for electrochemical energy storage, particularly those utilizing earth abundant, low cost, environmentally benign metal centers. However, to facilitate broader implementation of metal oxides in batteries, improvements to current capability and reversibility are needed. Some metal oxides adopt close-packed coordination environments, which optimize ion density. However, ion and electron transfer are challenges which may or may not be exacerbated as a result of high ion density. An emerging paradigm for the implementation of close-packed materials in higher current applications is the tuning of the materials crystallite dimensions, where the reduction of crystallite size should minimize the path length for ion transport upon discharge, resulting in a reduction of both internal cell resistance and the resultant structural strain associated with lithium insertion. Significant improvements in current capability of metal oxides and their composites via direct crystallite size control and other strategies will be described. The synthetic approaches described in this presentation will provide new strategies which may be applicable toward development of other new classes of materials and composites with energy or energy storage applications.