title: Stabilization of oxygen-deficient structure for conducting Li4Ti5O12-δ by molybdenum doping in a reducing atmosphere.
abstract: Li4Ti5O12 (LTO) is recognized as being one of the most promising anode materials for high power Li ion batteries; however, its insulating nature is a major drawback. In recent years, a simple thermal treatment carried out in a reducing atmosphere has been shown to generate oxygen vacancies (VO) for increasing the electronic conductivity of this material. Such structural defects, however, lead to re-oxidization over time, causing serious deterioration in anode performance. Herein, we report a unique approach to increasing the electronic conductivity with simultaneous improvement in structural stability. Doping of LTO with Mo in a reducing atmosphere resulted in extra charges at Ti sites caused by charge compensation by the homogeneously distributed Mo(6+) ions, being delocalized over the entire lattice, with fewer oxygen vacancies (VO) generated. Using this simple method, a marked increase in electronic conductivity was achieved, in addition to an extremely high rate capability, with no performance deterioration over time.
authors.affiliation: Department of Energy System, Pusan National University, Busan 609-735, Republic of Korea.
authors.forename: Hannah
authors.initials: H
authors.lastname: Song
authors.affiliation: Department of Energy System, Pusan National University, Busan 609-735, Republic of Korea.
authors.forename: Tae-Gyung
authors.initials: TG
authors.lastname: Jeong
authors.affiliation: Department of Energy System, Pusan National University, Busan 609-735, Republic of Korea.
authors.forename: Young Hoon
authors.initials: YH
authors.lastname: Moon
authors.affiliation: Global Core Research Center for Ships and Offshore Plants (GCRC-SOP), Pusan National University, Busan 609-735, Republic of Korea.
authors.forename: Ho-Hwan
authors.initials: HH
authors.lastname: Chun
authors.affiliation: Center for Energy Conversion, Korea Institute of Science and Technology, Seoul 130-650, Korea.
authors.forename: Kyung Yoon
authors.initials: KY
authors.lastname: Chung
authors.affiliation: Center for Energy Conversion, Korea Institute of Science and Technology, Seoul 130-650, Korea.
authors.forename: Hyung Sun
authors.initials: HS
authors.lastname: Kim
authors.affiliation: Center for Energy Conversion, Korea Institute of Science and Technology, Seoul 130-650, Korea.
authors.forename: Byung Won
authors.initials: BW
authors.lastname: Cho
authors.affiliation: Department of Energy System, Pusan National University, Busan 609-735, Republic of Korea.
authors.forename: Yong-Tae
authors.initials: YT
authors.lastname: Kim