Randy Jalem1 2 Ryosuke Natsume3 Masanobu Nakayama2 3 4

1, Japan Science and Technology Agency (JST), PRESTO, Saitama, , Japan
2, National Institute for Materials Science – Global Research Center for Environment and Energy based on Nanomaterials Science (NIMS-GREEN), Tsukuba, , Japan
3, Nagoya Institute of Technology, Nagoya, , Japan
4, Elements Strategy Initiative for Catalysts and Batteries (ESICB), Kyoto University, Kyoto, , Japan

Driven by the promise of high safety and reliability for all-solid Li ion battery applications, many research efforts have since been performed for developing oxide-type solid electrolytes with a garnet framework. This is made evident by the large number of research works found in the literature, particularly on ionic conductivity optimization by way of doping at the cation sub-lattice of the garnet crystal structure. Some of these doping strategies result to direct blockage of the Li ion conduction pathway and could cause profound impacts on the structure and overall conductivity behavior of the material. To elucidate what these impacts exactly are, we carried out atomistic-level computational modelling on two specific doping or cation incorporation in the Li sub-lattice of the garnet structure: i) Ga doping1 which has been reported to reach 10-3 S/cm order of Li ionic conductivity (among the highest reported so far for garnet compounds2) and ii) proton exchange which occurs upon exposure to air or moisture during synthesis or powder handling.

1. Jalem et al., Chem. Mater. 2015, 27, 2821−2831.
2. Bernuy-Lopez et al., Chem. Mater. 2014, 26, 3610−3617.