Synthesis and electrochemical studies of spinel phase LiMn2O4 cathode materials prepared by the Pechini process

LiMn2O4-based spinels are of great interest as positive electrode materials for lithium-ion batteries. We describe here what is believed to be the first synthesis of these materials using the Pechini process, a low temperature synthetic method that often yields inorganic oxides of excellent phase purity and well-controlled stoichiometry. Using this process, it has been possible to synthesize phase-pure crystalline spinel LiMn2O4 by calcining the appropriate polymeric precursors in air at 250 degrees C for several hours. The influence of different firing temperatures and the effect of substituting a small amount of Mn with Ni have also been explored. Electrochemical studies show that the Pechini-synthesized materials appear to offer not only high quality performance but also significant analytical advantages which allow us to understand the structural mechanism of Li intercalation.