NEUTRON-DIFFRACTION STUDY OF LINI0.8MN0.2O2

Structure of the layered oxide, LiNi0.8Mn0.2O2, was determined by TOF neutron powder diffraction using space group R (3) over bar m. Its ion ic distribution was determined to be [Li-0.956 Ni-0.044](3a)-(Ni0.791M n0.209)(3b)O-2. Slightly higher temperature of the synthesis caused th e disordered arrangement of the Ni ions in the Li 3a sites. Neverthele ss, the manganese ions introduced into the lattice were situated only at the Ni sites. The structural changes caused by the manganese substi tution are clarified, and the relationship between the ionic distribut ion and the cathodic properties of the lithium cells is discussed. (C) 1997 Academic Press.