TY  - JOUR
AU  - Hartel, Johannes
AU  - Banik, Ananya
AU  - Gerdes, Josef Maximilian
AU  - Wankmiller, Björn
AU  - Helm, Bianca
AU  - Li, Cheng
AU  - Kraft, Marvin A.
AU  - Hansen, Michael Ryan
AU  - Zeier, Wolfgang G.
TI  - Understanding Lithium-Ion Transport in Selenophosphate-Based Lithium Argyrodites and Their Limitations in Solid-State Batteries
JO  - Chemistry of materials
VL  - 35
IS  - 12
SN  - 0897-4756
CY  - Washington, DC
PB  - American Chemical Society
M1  - FZJ-2023-02508
SP  - 4798 - 4809
PY  - 2023
AB  - To develop solid-state batteries with high power and energy densities, solid electrolytes with fast Li+ transport are required. Superionic lithium argyrodites have proven to be a versatile system, in which superior ionic conductivities can be achieved by elemental substitutions. Herein, we report the novel selenophosphate-based lithium argyrodites Li6–xPSe5–xBr1+x (0 ≤ x ≤ 0.2) exhibiting ionic conductivities up to 8.5 mS·cm–1 and uncover the origin of their fast Li+ transport. Rietveld refinement of neutron powder diffraction data reveals a better interconnection of the Li+ cages compared to the thiophosphate analogue Li6PS5Br, by the occupation of two additional Li+ sites, facilitating fast Li+ transport. Additionally, a larger unit cell volume, lattice softening, and higher structural disorder between halide and chalcogenide are unveiled. The application of Li5.85PSe4.85Br1.15 as the catholyte in In/LiIn|Li6PS5Br|LiNi0.83Co0.11Mn0.06O2:Li5.85PSe4.85Br1.15 solid-state batteries leads to severe degradation upon charging of the cell, revealing that selenophosphate-based lithium argyrodites are not suitable for applications in lithium nickel cobalt manganese oxide-based solid-state batteries from a performance perspective. This work further expands on the understanding of the structure–transport relationship in Li+ conducting argyrodites and re-emphasizes the necessity to consider chemical and electrochemical stability of solid electrolytes against the active materials when developing fast Li+ conductors.
LB  - PUB:(DE-HGF)16
UR  - <Go to ISI:>//WOS:001006225800001
DO  - DOI:10.1021/acs.chemmater.3c00658
UR  - https://juser.fz-juelich.de/record/1008848
ER  -