Dehydration and Lithium Insertion Studies in Phyllomanganates

Abstract

AbstractLayered oxides AxMnO≈2,yH20 (A = Na, K, NH4, Cs or Mn2+) have been dehydrated and intercalated by lithium. Dehydration is accompanied by a shrinking of the interlayer space height depending on the size of A. The valence of Mn is reduced to +2 by reaction with n-butyllithium. Electrochemical studies of cells AxMnO≈2-graphite | LiClO4-PC|I Li showed two main reaction peaks at ca. 3V and below 2 V. The first reaction is a reversible reduction to a disordered Mn3+ phased. Capacities at the third cycle are ca. 300 Wh/kg. No marked difference was found as a function of A or of the degree of order of the starting compound.