Abstract
Was synthesized using LiOH, and two different sources (Tosoh and Chuodenki, Japan). Rietveld analysis revealed that the two and compounds exhibited the same structures, respectively. materials showed similar physicochemical properties, but they presented very different cycle retention rates in the 3 V region after 50 cycles (Tosoh, 36.2%; Chuodenki, 98.6%). The ex situ X-ray powder diffraction measurements also revealed that the two materials showed different X-ray patterns after discharge to 2.2 V after 50 cycles. It was seen that synthesized using Tosoh showed a mixture of distinct cubic and many tetragonal phases, but the other one using Chuodenki maintained an almost perfect cubic phase after cycling. We found that the material might show an entirely different cycle characterization in the 3 V region although it was synthesized using the Mn source of the same crystal structure. © 2001 The Electrochemical Society. All rights reserved.