%0 Journal Article %A Jakes, Peter %A Granwehr, Josef %A Kungl, Hans %A Eichel, Rüdiger-A. %T Mixed Ionic–Electronic Conducting Li4Ti5O12 as Anode Material for Lithium Ion Batteries with Enhanced Rate Capability – Impact of Oxygen Non-Stoichiometry and Aliovalent Mg2+-Doping Studied by Electron Paramagnetic Resonance %J Zeitschrift für physikalische Chemie %V 229 %N 9 %@ 2196-7156 %C Berlin %I De @Gruyter %M FZJ-2015-06219 %P 1439-1450 %D 2015 %X Spinel-type Li4Ti5O12 is an attractive anode material for lithium-ion battery applications owing to its high specific energy and almost vanishing mechanical strain upon Li-(de)intercalation. The impact of oxygen non-stoichiometry and aliovalent Mg-doping on the defect chemistry of Li4Ti5O12 has been characterized by quantitative electron paramagnetic resonance (EPR) spectroscopy. The results obtained demonstrate that the Mg2+-ions are amphoterically incorporated at the here studied concentrations on both lithium (MgLi•) and titanium (Mg′′Ti) sites. Mg2+-doping thus simultaneously results in the formation of donor (MgLi•) and acceptor (Mg′′Ti) centers. Furthermore, upon both oxygen deficiency and Mg2+-doping, the concentration of `polaronic'-type Ti3+-states is increased, accounting for the enhanced electronic conductivity. %F PUB:(DE-HGF)16 %9 Journal Article %U <Go to ISI:>//WOS:000363494500014 %R 10.1515/zpch-2015-0618 %U https://juser.fz-juelich.de/record/256252