2003 Volume 71 Issue 12 Pages 1142-1144
We investigated the crystal structure change during the charge-discharge process of LiMn1.5Ni0.5O4 as a 5 V class cathode active material, which was prepared by the sol-gel method. The lithium content of Li1−xMn1.5Ni0.5O4 (x = 0.5, 0.7, 1.0) was controlled by electrochemical lithium extraction. The crystal structure was determined by Rietveld analysis using powder neutron diffraction. As a result, all samples consisted of three phases (space group: P4332) of different lattice constant and Ni valences. The each phase showed a different distortion of the Mn,Ni (12d)-O octahedral site and the Madelung energy.