We study the oxo-hexametallate Li7TaO6 with first-principles and classical molecular dynamics simulations, obtaining a low activation barrier for diffusion of ∼0.29 eV and a high ionic conductivity of 5.7×10−4 S cm−1 at room temperature (300 K). We find evidence for a wide electrochemical stability window from both calculations and experiments, suggesting its viable use as a solid-state electrolyte in next-generation solid-state Li-ion batteries. To assess its applicability in an electrochemical energy storage system, we performed electrochemical impedance spectroscopy measurements on multicrystalline pellets, finding substantial ionic conductivity, if below the values predicted from simulation. We further elucidate the relationship between synthesis conditions and the observed ionic conductivity using X-ray diffraction, inductively coupled plasma optical emission spectrometry, and X-ray photoelectron spectroscopy, and study the effects of Zr and Mo doping.
@article{arxiv.1910.11079,
title = {The solid-state Li-ion conductor Li$_7$TaO$_6$: A combined computational and experimental study},
author = {Leonid Kahle and Xi Cheng and Tobias Binninger and Steven David Lacey and Aris Marcolongo and Federico Zipoli and Elisa Gilardi and Claire Villevieille and Mario El Kazzi and Nicola Marzari and Daniele Pergolesi},
journal= {arXiv preprint arXiv:1910.11079},
year = {2021}
}