Li1+xFe1-3xTi1+2xO4 (0.0 ≤ x ≤ 0.33) based spinels:: Possible negative electrode materials for future Li-ion batteries

Members of the spinel solid solution between LiFeTiO4 and Li4Ti5O12, i.e., Li1+xFe1-3xTi1+2xO4 (0.0 less than or equal to x less than or equal to 0.33) have been investigated as possible negative electrodes for future lithium-ion batteries. Electrochemical behavior and associated structural changes have been investigated over the potential range 0.01-2.6 V vs. Li+/Li. Results are promising with anodic capacities in excess of 200 mAh g(-1) or similar to 700 mAh cm(-3) being obtained over 25 cycles for x = 0.33. Samples containing Fe have reduced reversible capacity, however, the capacity below 1.00 V-Li is greatly increased. A spinel-type structure is retained upon lithiation for all compositions studied, however, the degree of cation disorder increases with Fe content. (C) 1999 The Electrochemical Society. S0013-4651(99)02-071-6. All rights reserved.