TY - JOUR
T1 - Unravelling Ultraslow Lithium-Ion Diffusion in γ-LiAlO2
T2 - Experiments with Tracers, Neutrons, and Charge Carriers
AU - Wiedemann, Dennis
AU - Nakhal, Suliman
AU - Rahn, Johanna
AU - Witt, Elena
AU - Islam, Mazharul M.
AU - Zander, Stefan
AU - Heitjans, Paul
AU - Schmidt, Harald
AU - Bredow, Thomas
AU - Wilkening, Martin
AU - Lerch, Martin
PY - 2016/2/9
Y1 - 2016/2/9
N2 - Lithium aluminum oxide (γ-LiAlO2) has been discussed and used for various applications, e.g., as electrode coating, membrane, or tritium breeder material. Although lithium-ion diffusion in this solid is essential for these purposes, it is still not sufficiently understood on the microscopic scale. Herein, we not only summarize and assess the available studies on diffusion in different crystalline forms of γ-LiAlO2, but also complement them with tracer-diffusion experiments on (001)- and conductivity spectroscopy on (100)-oriented single crystals, yielding activation energies of 1.20(5) and 1.12(1) eV, respectively. Scrutinous crystal-chemical considerations, Voronoi-Dirichlet partitioning, and Hirshfeld surface analysis are employed to identify possible diffusion pathways. The one-particle potential, as derived from high-temperature powder neutron diffraction data presented as well, reveals the major path to be strongly curved and to run between adjacent lithium positions with a migration barrier of 0.72(5) eV. This finding is substantiated by comparison with recently published computational results. For the first time, a complete model for lithium-ion diffusion in γ-LiAlO2, consistent with all available data, is presented.
AB - Lithium aluminum oxide (γ-LiAlO2) has been discussed and used for various applications, e.g., as electrode coating, membrane, or tritium breeder material. Although lithium-ion diffusion in this solid is essential for these purposes, it is still not sufficiently understood on the microscopic scale. Herein, we not only summarize and assess the available studies on diffusion in different crystalline forms of γ-LiAlO2, but also complement them with tracer-diffusion experiments on (001)- and conductivity spectroscopy on (100)-oriented single crystals, yielding activation energies of 1.20(5) and 1.12(1) eV, respectively. Scrutinous crystal-chemical considerations, Voronoi-Dirichlet partitioning, and Hirshfeld surface analysis are employed to identify possible diffusion pathways. The one-particle potential, as derived from high-temperature powder neutron diffraction data presented as well, reveals the major path to be strongly curved and to run between adjacent lithium positions with a migration barrier of 0.72(5) eV. This finding is substantiated by comparison with recently published computational results. For the first time, a complete model for lithium-ion diffusion in γ-LiAlO2, consistent with all available data, is presented.
UR - http://www.scopus.com/inward/record.url?scp=84957990857&partnerID=8YFLogxK
U2 - 10.1021/acs.chemmater.5b04608
DO - 10.1021/acs.chemmater.5b04608
M3 - Article
AN - SCOPUS:84957990857
SN - 0897-4756
VL - 28
SP - 915
EP - 924
JO - Chemistry of Materials
JF - Chemistry of Materials
IS - 3
ER -