Synthesis, structure and electrochemistry of LiMn2-yAlyO4 prepared by a wet-chemistry method

The LiMn2-yAlyO4 spinel phases have been synthesised by wet-chemistry techn iques using a methanolic solution of the metal acetates and dicarboxylic ac id as a complexing agent. The formation temperature of LiMn2-yAlyO4 powders has been found to be as low as 350 degreesC using the succinic acid method . The physical properties of the synthesised products have been investigate d by X-ray diffraction, Raman spectroscopy, thermal analyses, and electrica l conductivity. To improve the rechargeable capacity of Li//LiMn2O4 cells, the electrochemical performances of LiMn2-yAlyO4 compounds as positive elec trodes have been evaluated. The structural properties of the materials are very similar to LiMn2O4, the electrochemical performances show that the cap acity is maintained at 95% of the initial value at the 50th cycle, this bei ng explained by the change of the Mn3+/Mn4+ ratio in doped phases.