High-performance Li3YCl3Br3 halide solid electrolyte synthesized using wet-chemistry route for all-solid-state battery

A dual-halide solid electrolyte, Li 3 YCl 3 Br 3 , was synthesized using a wet-chemistry route instead of the conventional mechanical ball-milling route. Li 3 YCl 3 B r3 exhibits an ion conductivity of 2.08 mS/cm and an electro- chemical stability window of 3.8 V. Additionally, an all-solid-state lithium-ion battery using Li 3 YCl 3 Br 3 and LiNi 0.83 Co 0.11 Mn 0.06 O 2 (NCM811) as the cathode material achieves a capacity retention of 93% after 200 cycles at 0.3 C and maintains a specific capacity of 115 mA·h/g during 2 C cycling. This exceptional performance is attributed to the high oxidative stability of Li 3 YCl 3 Br 3 and the in-situ formation of Y 2 O 3 inert protective layer on the NCM811 surface under high voltage. Consequently, the study demonstrates the feasibility of a simple, cost-effective wet-chemistry route for synthesizing multi-component halides, highlighting its potential for large-scale production of halide solid electrolytes for practical applications.