Low Temperature Synthesis of Insertion Oxides for Lithium Batteries

The increasing demand for portable electronic devices has created significant activity in the development of compact lightweight batteries of high-energy density, and lithium batteries have become attractive in this regard. The commercial lithium cells use lithium cobalt oxide cathodes and the high cost and toxicity of cobalt has prompted the design and synthesis of alternate insertion hosts. Several low-temperature synthesis routes have been pursued during the past few years both to improve the properties of known oxide hosts as well as to access new insertion oxides, particularly metastable phases. This review, after providing a brief background to lithium batteries, lithium insertion compounds, and lithium ion batteries, presents the low-temperature synthesis and electrochemical properties of manganese, cobalt, nickel, iron, vanadium, chromium, titanium, molybdenum, and tin oxides. The use of soft chemistry methods such as sol−gel processing, ion-exchange reactions, hydrothermal reactions, and oxidation−reduction reactions in solutions to obtain oxide hosts are presented.