Expediting solid electrolyte synthesis: Microwave-assisted wet synthesis of halogen-rich Li-argyrodite

Abstract

Li-argyrodites are promising solid electrolytes (SEs) for solid-state Li-ion batteries (SSLBs), but their large-scale industrial application remains a challenge. Conventional synthesis methods for SEs suffer from long reaction times and high energy consumption. In this study, we present a wet process for the synthesis of halogen-rich argyrodite Li6-aPS5-aCl1+a precursors (LPSCl1+a-P, a = 0-0.7) via an energy- saving microwave-assisted process. Utilizing vibrational heating, we accelerate the formation of Liargyrodite precursor, even at excessive Cl-ion concentration, which significantly shortens the reaction time compared to traditional methods. After crystallization, we successfully synthesize the Liargyrodite, Li5.5PS4.5Cl1.5, which exhibits the superior ionic conductivity (7.8 mS cm-1) and low activation energy (0.23 eV) along with extremely low electric conductivity. The Li5.5PS4.5Cl1.5 exhibits superior Li compatibility owing to its high reversible striping/plating ability (over 5000 h) and high current density acceptability (1.3 mA cm-2). It also exhibits excellent cycle reversibility and rate capability with NCM622 cathode (148.3 mA h g-1 at 1 C for 100 cycles with capacity retention of 85.6%). This finding suggests a potentially simpler and more scalable synthetic route to produce high-performance SEs. (c) 2025 Science Press and Dalian Institute of Chemical Physics, Chinese Academy of Sciences. Published by Elsevier B.V. and Science Press. All rights are reserved, including those for text and data mining, AI training, and similar technologies.