Abstract
While post-synthesis processing steps are frequently applied in the preparation of cathode composites for solid-state batteries to ensure homogeneous mixing and good contact with the cathode active material, little is known about the processes that occur during milling and how they influence structure and transport of solid electrolytes. Here, an extensive set of experimental methods and simulations are used to study the effects of post-synthesis milling by a frequency and planetary ball mill on the highly conducting chloride-rich argyrodite Li5.5PS4.5Cl1.5. Structural analyses show that processing can reduce the coherence length and increase the disorder. The reduced crystallite size correlates with a decrease in ionic conductivity in the post-processed solid electrolytes. Simulating the ball milling processes by the discrete element method provides fundamental understanding and reveals the correlation of the loss in coherence with the specific energy input and the numbers of stressing events during the milling process. An observed decrease in particle size in ball milled samples leads to lower tortuosity in the cathode composites. As the loss in coherence and decrease in particle size have opposite effects on the performance, optimizing these processing conditions will play a significant role on the road to highly performing solid-state batteries.
Original language | English |
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Journal | Advanced Energy Materials |
DOIs | |
State | Accepted/In press - 2024 |
Funding
The research was supported by the International Graduate School for Battery Chemistry, Characterization, Analysis, Recycling and Application (BACCARA), which is funded by the Ministry for Culture and Science of North Rhine Westphalia, Germany. The authors acknowledge financial support within the cluster of competence FESTBATT funded by the Bundesministerium f\u00FCr Bildung und Forschung (BMBF; projects 03XP0430A, 03XP0430F, 03XP0430C). The authors further acknowledge funding from the Deutsche Forschungsgemeinschaft under project number 459785385. HMRW thanks the FFG (Austrian Research Promotion Agency) for financial support within the project safeLIB. This research used resources at the Spallation Neutron Source, a DOE Office of Science User Facility operated by the Oak Ridge National Laboratory.
Keywords
- argyrodite
- mechanical milling
- processing
- solid electrolytes
- solid state batteries