Abstract
The preparation and characterization of spinel 
having small average particle sizes (<4.0 μm) and narrow particle size distribution are reported. They were obtained by heating a 1:4 
mixture at 650 to 850°C in oxygen. Particle size control of the product was achieved by controlling the particle sizes of the precursor materials and the heating conditions. Heating the 
mixture results in the formation of 
initially, which then reacts with 
to form spinel 
according to: 
. The 
cathodes have shown excellent rechargeability as well as superior rate capability in Li/polymer electrolyte/
cells cycled between 3.0 and 4.3 V. Specific capacities between 0.75 and 0.83 Li per 
were obtained for more than fifty cycles. The 
cathodes can be reversibly cycled between 2.4 and 3.5 V but with declining capacity. For the 
prepared at 650°C, cycling in the 3 V region has little effect on its subsequent performance in the 4 V region, while for the 
prepared at higher temperatures, such cycling causes the 4 V capacity to decline.