Synthetic Tailoring of Ionic Conductivity in Multicationic Substituted, High-Entropy Lithium Argyrodite Solid...

Area of Science:

• Materials Science
• Electrochemistry
• Solid-State Batteries

Background:

• Superionic conductors are essential for solid-state batteries (SSBs).
• High-entropy materials offer a wide compositional range for novel solid electrolytes (SEs).
• The impact of synthesis on conductivity in complex SEs remains underexplored.

Purpose of the Study:

• To investigate the effect of cooling rate on ionic conductivity in a high-entropy lithium argyrodite.
• To correlate structural and compositional properties with charge transport.
• To evaluate the performance of the material in solid-state battery applications.

Main Methods:

• Synthesis of Li6.5[P0.25Si0.25Ge0.25Sb0.25]S5I with varying cooling rates.
• Powder diffraction, NMR, and XPS for material characterization.
• Electrochemical testing in pellet-type SSBs.

Main Results:

• A moderate cooling rate achieved a room-temperature ionic conductivity of ~12 mS cm-1.
• This conductivity is superior to fast- and slow-cooled samples.
• Favorable bulk and surface properties for lithium diffusion were observed with moderate cooling.

Conclusions:

• Cooling rate significantly influences ionic conductivity in high-entropy lithium argyrodites.
• Optimized synthesis conditions are key to unlocking the potential of these materials.
• Further research is needed to improve the electrochemical stability for practical SSB applications.