title: Gallium-Doped Li7La3Zr2O12Garnet-Type Electrolytes with High Lithium-Ion Conductivity.
abstract: Owing to their high conductivity, crystalline Li7-3xGaxLa3Zr2O12garnets are promising electrolytes for all-solid-state lithium-ion batteries. Herein, the influence of Ga doping on the phase, lithium-ion distribution, and conductivity of Li7-3xGaxLa3Zr2O12garnets is investigated, with the determined concentration and mobility of lithium ions shedding light on the origin of the high conductivity of Li7-3xGaxLa3Zr2O12. When the Ga concentration exceeds 0.20 Ga per formula unit, the garnet-type material is found to assume a cubic structure, but lower Ga concentrations result in the coexistence of cubic and tetragonal phases. Most lithium within Li7-3xGaxLa3Zr2O12is found to reside at the octahedral 96h site, away from the central octahedral 48g site, while the remaining lithium resides at the tetrahedral 24d site. Such kind of lithium distribution leads to high lithium-ion mobility, which is the origin of the high conductivity; the highest lithium-ion conductivity of 1.46 mS/cm at 25 °C is found to be achieved for Li7-3xGaxLa3Zr2O12at x = 0.25. Additionally, there are two lithium-ion migration pathways in the Li7-3xGaxLa3Zr2O12garnets: 96h-96h and 24d-96h-24d, but the lithium ions transporting through the 96h-96h pathway determine the overall conductivity.
authors.affiliation: School of Materials Science and Engineering, Huazhong University of Science and Technology , Wuhan 430074, P. R. China.
authors.forename: Jian-Fang
authors.initials: JF
authors.lastname: Wu
authors.affiliation: School of Materials Science and Engineering, Huazhong University of Science and Technology , Wuhan 430074, P. R. China.
authors.forename: En-Yi
authors.initials: EY
authors.lastname: Chen
authors.affiliation: School of Materials Science and Engineering, Huazhong University of Science and Technology , Wuhan 430074, P. R. China.
authors.forename: Yao
authors.initials: Y
authors.lastname: Yu
authors.affiliation: School of Materials Science and Engineering, Huazhong University of Science and Technology , Wuhan 430074, P. R. China.
authors.forename: Lin
authors.initials: L
authors.lastname: Liu
authors.affiliation: School of Materials Science and Engineering, Huazhong University of Science and Technology , Wuhan 430074, P. R. China.|Department of Physics and Astronomy, University of North Carolina , Chapel Hill, North Carolina 27599-3255, United States.
authors.forename: Yue
authors.initials: Y
authors.lastname: Wu
authors.affiliation: Australian Centre for Neutron Scattering, Australian Nuclear Science and Technology Organisation , Locked Bag 2001, Kirrawee DC, New South Wales 2232, Australia.|Institute for Superconducting & Electronic Materials, Faculty of Engineering, University of Wollongong , Wollongong, New South Wales 2522, Australia.
authors.forename: Wei Kong
authors.initials: WK
authors.lastname: Pang
authors.affiliation: Australian Centre for Neutron Scattering, Australian Nuclear Science and Technology Organisation , Locked Bag 2001, Kirrawee DC, New South Wales 2232, Australia.|Institute for Superconducting & Electronic Materials, Faculty of Engineering, University of Wollongong , Wollongong, New South Wales 2522, Australia.
authors.forename: Vanessa K
authors.initials: VK
authors.lastname: Peterson
authors.affiliation: School of Materials Science and Engineering, Huazhong University of Science and Technology , Wuhan 430074, P. R. China.
authors.forename: Xin
authors.identifier: http://orcid.org/0000-0003-1546-8119
authors.initials: X
authors.lastname: Guo
keywords: Li7−3xGaxLa3Zr2O12 garnet; ionic conductivity; lithium ion; lithium vacancy; mobility