Data-Driven First-Principles Methods for the Study and Design of Alkali Superionic Conductors

We
present a detailed exposition of how first-principles methods
can be used to guide alkali superionic conductor (ASIC) study and
design. Using the argyrodite Li6PS5Cl as a case
study, we demonstrate how modern information technology (IT) infrastructure
and software tools can facilitate the assessment of alkali superionic
conductors in terms of various critical properties of interest such
as phase and electrochemical stability and ionic conductivity. The
emphasis is on well-documented, reproducible analysis code that can
be readily generalized to other material systems and design problems.
For our chosen Li6PS5Cl case study material,
we show that Li excess is crucial to enhancing its conductivity by
increasing the occupancy of interstitial sites that promote long-range
Li+ diffusion between cage-like frameworks. The predicted
room-temperature conductivities and activation barriers are in reasonably
good agreement with experimental values.