Large-scale manufacturing sulfide superionic conductor for advancing all-solid-state batteries

Lithium argyrodites with high ionic conductivities are favorable solid electrolytes (SEs) for all-solid-state batteries (ASSBs). However, their low preparation efficiency and poor cycling performance hinder their large-scale applications. In this work, we demonstrate successful large-scale production (over 1 kg per batch for the first time) of Li_5.5PS_4.5Cl_0.75Br_0.75 (LPSCB) by fast dry mixing followed by annealing, which presents high room temperature ionic conductivities of 13 mS cm⁻¹ for cold-pressed and 25 mS cm⁻¹ for sintered pellets. Combining neutron powder diffraction and ⁶Li → ⁷Li tracer-exchange nuclear magnetic resonance (NMR) spectroscopy measurements, we show that intercage jumps frequently occur through the 48h-16e-48h pathway in LPSCB, promoting the overall lithium conduction. The assembled ASSBs using LPSCB and a LiNi_0.83Co_0.11Mn_0.06O₂ electrode can be cycled for over 2,500 cycles at a 0.5 C rate and 1,800 cycles at a 2 C rate without any capacity degradation. Our results will accelerate the commercialization of sulfide SE for ASSBs.