SYNTHESIS AND ELECTROCHEMICAL STUDIES OF SPINEL LI1.03MN2O4 CATHODE MATERIALS PREPARED BY A SOL-GEL METHOD FOR LITHIUM SECONDARY BATTERIES

The spinel Li1.03Mn2O4 powders having submicron, narrow particle-size distribution, and excellent phase-pure particles have been synthesized at low temperatures from aqueous solution of metal acetate containing glycolic acid as a chelating agent by a sol-gel method. The dependenc e of the physicochemical properties of the spinel Li1.03Mn2O4 powders on the various calcination temperatures and glycolic acid quantity hav e been extensively studied. It was found that the physicochemical prop erties of the Li1.03Mn2O4 powders could be controlled by simply varyin g the pyrolysis processing and chelating agent quantity. The glycolic acid-assisted Li1.03Mn2O4 powders have shown excellent rechargeability and delivered discharge capacity of 134 mAh/g for more than 90 cycles in Li/polymer electrolyte/Li1.03Mn2O4 cells cycled between 3.0 and 4. 3 V. The Li1.03Mn2O4 powders in Li/1 M LiBF4-EC/DEC electrolyte/Li1.03 Mn2O4 cells cycled between 3.6 and 4.3 V retained 94% of its initial c apacity over the 100th cycle.