Electronic structure and stability of Li1+xMn2-xO4 spinels

Trends in the electronic structure of the spinel-type manganese oxide Li1 xMn2 - xO4, 0 less than or equal to x less than or equal to 1/4, are studi ed using the LMTO-ASA method. The stability of the system is discussed in t erms of composition (x) and the position of lithium in the structure; the i nfluence of the latter on the total valence energy and the density-of-state s (DOS) is also probed systematically. The "extra" lithium atoms are shown to prefer the octahedral 16d position for x < 2/16, and the octahedral 16c position for higher degrees of substitution. The open-circuit voltage reach es a maximum for x = 1/16.