LiMnPO[sub 4] as an Advanced Cathode Material for Rechargeable Lithium Batteries

nanoparticles synthesized by the polyol method were examined as a cathode material for advanced Li-ion batteries. The structure, surface morphology, and performance were characterized by X-ray diffraction, high resolution scanning electron microscopy, high resolution transmission electron microscopy, Raman, Fourier transform IR, and photoelectron spectroscopies, and standard electrochemical techniques. A stable reversible capacity up to could be measured at discharge potentials vs , with a reasonable capacity retention during prolonged charge/discharge cycling. The rate capability of the electrodes studied herein was higher than that of and (NCA) in similar experiments and measurements. The active mass studied herein seems to be the least surface reactive in alkyl solutions. We attribute the low surface activity of this material, compared to the lithiated transition-metal oxides that are examined and used as cathode materials for Li-ion batteries, to the relatively low basicity and nucleophilicity of the oxygen atoms in the olivine compounds. The thermal stability of the material in solutions (measured by differential scanning calorimetry) is much higher compared to that of transition-metal oxide cathodes. This is demonstrated herein by a comparison with NCA electrodes.