Rongji Chen, M. Whittingham
Apr 1, 1997
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0
Influential Citations
69
Citations
Journal
Journal of The Electrochemical Society
Abstract
Extensive research is currently underway to find promising candidates for cathode materials in lithium secondary batteries, and a manganese oxide that behaved like the layered LiCoCO{sub 2} would be a prime candidate for this application because of its high free-energy of reaction with lithium and relatively low cost. The reaction of potassium, sodium, and lithium permanganate in water at 170 C leads directly to potassium, sodium, and lithium manganese dioxides, A{sub y}MnO {center_dot} nH{sub 2}O, with a R{bar 3}m rhombohedral structure. These crystalline layered structures after dehydration readily and reversibly react with lithium through an intercalation mechanism. The capacity for lithium is a function of the alkali ion present, and the larger potassium ion maintains the capacity best. For lithium there is a tendency to convert to the spinel structure which leads to loss of capacity.