Extended lithium titanate cycling potential window with near zero capacity loss

Lithium titanate (Li(4)Ti(5)O(12), or LTO) is a promising anode for lithium-ion batteries due to its rate capability and cycling stability. However, its structural instability and solid electrolyte interphase formation at low potential limits its application within a high cut-off voltage above 1 V. which significantly sacrifices the cell voltage and energy density. This work demonstrates how a few atomic layers of Al(2)O(3) deposited on LTO electrode improved its cycling performance (no capacity degradation after 100 cycles) and provided a higher Coulombic efficiency compared with the standard uncoated LTO electrode when they are cycled at low potential down to 1 mV. It has been found that the ultrathin oxide layers served as a passivation film not only stabilized the LTO structure but also surprisingly suppressed some undesirable chemical reactions. (C) 2011 Elsevier B.V. All rights reserved.