Effects of dopant on the electrochemical performance of Li4Ti5O12 as electrode material for lithium ion batteries

The effects of dopant on the electrochemical properties of spinel-type Li3.95M0.15Ti4.9O12 (M = Al, Ga, Co) and Li3.9Mg0.1Al0.15Ti4.85O12 were systematically investigated. Charge-discharge cycling were performed at a constant current density of 0.15 mA cm(-2) between the cut-off voltages of 2.3 and 0.5 V, the experimental results showed that Al3+ dopant greatly improved the reversible capacity and cycling stability over the pristine Li4Ti5O12. The substitution of the Ga3+ slightly increased the capacity of the Li4Ti5O12, but did not essentially alleviate the degradation of cycling stability. Dopants such as Co3+ and Mg2+ to some extent worsened the electrochemical performance of the Li4Ti5O12. (c) 2006 Elsevier B.V. All rights reserved.