cm9b03852_si_001.pdf (2.81 MB)
Rapid Crystallization and Kinetic Freezing of Site-Disorder in the Lithium Superionic Argyrodite Li6PS5Br
journal contribution
posted on 2019-12-03, 15:11 authored by Ajay Gautam, Marcel Sadowski, Nils Prinz, Henrik Eickhoff, Nicolò Minafra, Michael Ghidiu, Sean P. Culver, Karsten Albe, Thomas F. Fässler, Mirijam Zobel, Wolfgang G. ZeierLithium argyrodite superionic conductors are currently
being investigated
as solid electrolytes for all-solid-state batteries. Recently, in
the lithium argyrodite Li6PS5X (X = Cl, Br,
and I), a site-disorder between the anions S2– and
X– has been observed, which strongly affects the
ionic transport and appears to be a function of the halide present.
In this work, we show how such a disorder in Li6PS5Br can be engineered via the synthesis method. By comparing
fast cooling (i.e., quenching) to more slowly cooled samples, we find
that the anion site-disorder is higher at elevated temperatures, and
that fast cooling can be used to kinetically trap the desired disorder,
leading to higher ionic conductivities as shown by impedance spectroscopy
in combination with ab initio molecular dynamics. Furthermore, we
observe that after milling, a crystalline lithium argyrodite can be
obtained within 1 min of heat treatment. This rapid crystallization
highlights the reactive nature of mechanical milling and shows that
long reaction times with high energy consumption are not needed in
this class of materials. The fact that site-disorder induced via quenching
is beneficial for ionic transport provides an additional approach
for the optimization and design of lithium superionic conductors.
History
Usage metrics
Categories
Keywords
energy consumptionsynthesis methodlithium superionic conductorsheat treatmentLithium Superionic Argyrodite Li 6 PS 5 Br Lithium argyrodite superionic conductorsmilling1 minreactive naturelithium argyrodite Li 6 PS 5 Ximpedance spectroscopyquenchingkinetically trapcoolinglithium argyroditeRapid Crystallizationall-solid-state batteriesanion site-disorderreaction timesKinetic Freezingab initioLi 6 PS 5 Br