An active electrode material for electrochemical devices such as lithium ion batteries includes a lithium transition metal oxide which is free of sodium and sulfur contaminants. The lithium transition metal oxide is prepared by calcining a mixture of a lithium precursor and a transition metal oxalate. Electrochemical devices use such active electrodes.
The United States Government has rights in this invention pursuant to Contract No. DE-AC02-06CH11357 between the United States Department of Energy and the UChicago Argonne, LLC representing Argonne National Laboratory.