Novel layered Li-Cr-Ti-O cathode materials for lithium rechargeable batteries

New cathode materials of Li-Cr-Ti-O compounds were synthesized using conventional solid-state reaction at different conditions in air. XRD patterns for these materials indicated that they are isostructure with Li2MnO3 or Li2TiO3, which have a layered structure with a monoclinic symmetry (space group C2/m). The sample with the best electrochemical properties can deliver initial discharge capacities of 152 and 202 mAh/g for cycling between 2.0 and 4.8 V at a constant current density of 0.44 mA/cm(2) (32 mA/g) at room temperature (about 30 degreesC) and 60 degreesC, respectively. The excellent cycling performance was also observed, even at the elevated temperature. These materials demonstrated that Cr3+/Cr6+ could reversibly cycle with a considerably high capacity in a Li2TiO3-like framework after a significant irreversible capacity loss during the initial cycle. (C) 2002 Elsevier Science B.V. All rights reserved.