Electrochemistry and structural chemistry of Li[CrTi]O-4 (Fd(3)over-barm) in nonaqueous lithium cells

Li[CrTi]O-4 (Fd (3) over bar m; n = 8.32 Angstrom) having a spinel-framewor k structure was prepared and examined in nonaqueous lithium cells. Li/Li[Cr Ti]O-4 cells showed the flat operating voltages of 1.50 V and rechargeable capacity of 150 mAh/g. The X-ray diffraction examinations in this region in dicated that Li[CrTi]O-4 was reduced to Li-2[CrTi]O-4 in a topotactic manne r. Electrochemical oxidation of Li[CrTi]O-4 was also examined. Redox potent ial of 4.7 V vs. Li was observed while reversibility was pool due to the de struction of crystallite. Differences and similarities between Li[CrTi]O-4 and Li[Li0.33Ti1.67]O-4 were discussed with respect to operating voltage, r eversibility, and insertion scheme. (C) 2000 The Electrochemical Society. S 0013-4651(00)02-069-3. All rights reserved.