Sol-gel processing of transition metal oxide precursors has been used to produce porous materials of high surface area. The technique has permitted the synthesis of solid amorphous vanadium and manganese oxides that are capable of reversibly intercalating large amounts of lithium ions. Therefore, these materials may function as high capacity (500-600 mAh/g), high-energy positive electrodes in lithium batteries. Methods to improve the kinetics and the cycle performance of these positive electrodes are showing promise.