The stability of orthorhombic and monoclinic-layered LiMnO2

LiMnO2 is one of only a few ternary oxides which are known to form in the orthorhombic Pmmn structure. The layered alpha-NaFeO2 structure, favored for application as a Li-insertion electrode, is found in many other alkali transition metal oxides. We find that the the strong antiferromagnetic interactions between Mn+3 ions contribute to the stabilization of the orthorhombic structure. Using first-principles pseudopotential calculations, we find that doping with Al, Co, Cr, V, Ti, Mo, Mg, Nb, Zn, and Pd helps stabilize the layered structure over the orthorhombic structure. (C) 1999 The Electrochemical Society. S1099-0062(99)06-081-2. All rights reserved.