Regensburg 2019 – wissenschaftliches Programm

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MM: Fachverband Metall- und Materialphysik

MM 3: Materials for Energy Storage and Conversion

MM 3.2: Vortrag

Montag, 1. April 2019, 10:30–10:45, H44

Controlling oxygen defects in Li₄Ti₅O₁₂ (LTO) — •C. Grosu^1,2, P. Jakes¹, T. Gigl², C. Hugenschmidt², D. Haering², J. Granwehr¹, R.A. Eichel¹, K. Reuter², and C. Scheurer² — ¹IEK-9, FZ Jülich — ²TU München

Spinel Li₄Ti₅O₁₂ (LTO) is an interesting anode material for next-generation all solid state Li-ion batteries (ASSB). Its "zero strain" charge/discharge behavior promises high safety and long cycling lifetimes. Yet, pristine, white LTO possesses poor ionic and electronic conductivity. The latter can be increased by tailoring the sintering protocol to produce oxygen vacancies, resulting in a performing, blue LTO material. Hitherto, the detailed structure and distribution of the vacancies is not known. Producing a controlled gradient of vacancies will help understanding, first what the fundamental impact on the conductivity is and later optimizing the design of the material itself. We will discuss a controlled procedure to introduce oxygen vacancies, creating a gradient of defects from the surface to bulk. In a combined experimental and theoretical approach, the resulting disordered, defect-rich LTO structures are analyzed and theoretical defect models compared to the results of depth-resolved positron coincidence Doppler broadening spectroscopy (CDBS) measured at the Garching positron source NEPOMUC.