headerSearch form

Changing the World through Creative Research

Computational Design and Experimental Synthesis of Air-stable Solid-state Ionic Conductors with High Conductivity

Journal
CHEM MATER
Date
2021.08.16
Abstract

All-solid-state Li-ion batteries are promising next-generation energy storage devices for enhanced safety and energy density compared to presently available lithium ion batteries. The development of such batteries requires solid-state ionic conducting materials with extremely high ionic conductivity. Here we report the design and synthesis of Si-doped lithium tantalum phosphates as solid-state ionic conductors with high ionic conductivities. First-principles computation based on density functional theory predicts high phase stability and ionic conductivity of Li1+xTa2P1-xSixO8. Experimental synthesis of the designed materials confirms a very high ionic conductivity of 1.18 mS/cm (total conductivity) in Li1.4Ta2P0.6Si0.4O8 at room temperature, which rivals the best lithium oxide solid-state electrolytes such as Li-NASICONs, perovskites, and lithium garnets, with the advantage of being stable in ambient conditions. The high ionic conductivity is due to enhanced lithium diffusion by introducing Si into the phosphate groups and activating an isotropic diffusion pathway in the structure, while simultaneously reducing the grain boundary resistance.

Reference
Chem. Mater. 2021, 33, 17, 6909?6917
DOI
http://dx.doi.org/10.1021/acs.chemmater.1c01837