Heteroanionic titanium oxide-fluoride compounds: from anionic ordering to defects Damien Dambournet1; 1SORBONNE UNIVERSITY, Paris, France; PAPER: 91/Chemistry/Invited (Oral) SCHEDULED: 15:15/Fri. 25 Oct. 2019/Aphrodite A (100/Gr. F) ABSTRACT: The crystal chemistry of inorganic compounds featuring mixed anionic framework provides a broad richness from the standpoint of the structure and properties.(1-2) The solid-state chemistry of titanium-based oxide-fluoride compounds is a school case to exemplify how anions can arrange in different structural arrangements. In this presentation, we shall exemplify the structural arrangements through two examples showing how anions, particularly fluoride, can be ordered. In a first example, we will describe the structure of a cubic phase TiOF<sub>2</sub> from the average to the local order standpoints. Thereafter, we will describe how monovalent anions such as fluoride and hydroxide can be stabilized in an oxide framework, leading to the stabilization of cationic vacancies (3). Finally, we will present how these defects can unlock the electrochemical activity toward multivalent ions opening new avenues to develop new electrochemical devices (4). References: (1) Kageyama, H.; Hayashi, K.; Maeda, K.; Attfield, J. P.; Hiroi, Z.; Rondinelli, J. M.; Poeppelmeier, K. R. Expanding Frontiers in Materials Chemistry and Physics with Multiple Anions. Nat. Commun. 2018, 9 (1), 772. https://doi.org/10.1038/s41467-018-02838F-4. (2) Harada, J. K.; Charles, N.; Poeppelmeier, K. R.; Rondinelli, J. M. Heteroanionic Materials by Design: Progress Toward Targeted Properties. Adv. Mater. 0 (0), 1805295. https://doi.org/10.1002/adma.201805295. (3) Li, W.; Corradini, D.; Body, M.; Legein, C.; Salanne, M.; Ma, J.; Chapman, K. W.; Chupas, P. J.; Rollet, A.-L.; Julien, C.; et al. High Substitution Rate in TiO2 Anatase Nanoparticles with Cationic Vacancies for Fast Lithium Storage. Chem. Mater. 2015, 27 (14), 5014-5019. https://doi.org/10.1021/acs.chemmater.5b01407. (4) Koketsu, T.; Ma, J.; Morgan, B. J.; Body, M.; Legein, C.; Dachraoui, W.; Giannini, M.; Demortire, A.; Salanne, M.; Dardoize, F.; et al. Reversible Magnesium and Aluminium Ions Insertion in Cation-Deficient Anatase TiO2. Nat. Mater. 2017, 16 (11), 1142. https://doi.org/10.1038/nmat4976. |