INFLUENCE OF THE SUBSTITUTION OF FE FOR MN ON THE ELECTROCHEMICAL PROPERTIES OF LIMN2O4

The first discharge capacities of LiFeyMn2-yO4 (y = 0.0, 0.1, 0.25, 0. 38 and 0.5) in a voltage range 3.5 V-4.3 V decrease as the value y inc reases, but the cycling performance improves. LiFe0.25Mn1.75O4 has the largest discharge capacity after 30 cycles and the best cycling perfo rmance. In the cyclic voltammograms the peaks for oxidation and reduct ion processes shift to the higher voltage side as the amount of substi tution y increases. The samples with higher first discharge capacity i na voltage range 3.5 V-4.3 V have lower first discharge capacity in a voltage range 4.3 V-5.2 V. These two results show that the voltage ran ge for intercalation and deintercalation shifts to the higher voltage side as the amount of substitution y increases. (C) 1998 Elsevier Scie nce B.V. All rights reserved.