The spinel phases LiAlyMn2-yO4 (y = 0, 1/12, 1/9, 1/6, 1/3) and Li(Al,M)(1/6)Mn11/6O4 (M = Cr, Co) as the cathode for rechargeable lithium batteries

In order to improve the cycle performance of LiMn2O4, the spinel phases LiA lyMn2-yO4 (y = 0, 1/12, 1/9, 1/6, 1/3) and Li(Al,M)(1/6)Mn11/6O4 (M = Cr, C o) were prepared at 650 degrees C for 24 h in air. By substituting, the cyc le performance was improved at the expense of an initial capacity. For LiAl 1/12Cr1/12Mn11/6O4, the capacity of the cell maintained 90% of the initial capacity at the 200th cycle. By substituting, the chemical diffusion coeffi cient of lithium ion in the cathodes increased by one order of magnitude co mparing with that of parent LiMn2O4. The phase transition due to the Jahn-T eller distortion caused by Mn3+ was suppressed in these partially substitut ed spinels. (C) 1999 Elsevier Science B.V. All rights reserved.