Solid-state synthesis and electrochemical performance of Ce-doped Li4Ti5O12 anode materials for lithium-ion batteries

Ce-doped Li4Ti5O12 anode materials are prepared via a solid state reaction. The Ce is designed to replace of Ti (Li4Ti5-xCexO12) or take the place of octahedral interstice (Li4Ti5CexO12). The structure and morphology of these materials are characterized and their electrochemical performance is investigated. The structure analysis results show that it is difficult for Ce to dope into the lattice of Li4Ti5O12, only few Ce can dope in the lattice of Li4Ti5O12 and CeO2 impurity is inevitable in Ce-doped Li4Ti5O12 materials. As we designed, Li4Ti5Ce0.1O12 with Ce interstitial doping has the bigger lattice volume than Li4Ti4.9Ce0.1O12 with Ce substitution doping and pristine Li4Ti5O12. As for the electrochemical performance, Li4Ti5Ce0.1O12 delivers the highest capacity at 0.2 C (over 170 mAh g(-1)) and best rate performance among the pristine and Ce-doped Li4Ti5O12 materials. Ac impedance results show that the impedance of Li4Ti5Ce0.1O12 is much less than the other samples, which is the main reason for the best electrochemical performance. (C) 2015 Elsevier Ltd. All rights reserved.