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.

The development of improved solid electrolytes (SEs) plays a crucial role in the advancement of bulk-type solid-state battery (SSB) technologies. In recent years, multicomponent or high-entropy SEs are gaining increased attention for their advantageous charge-transport and (electro)chemical properties. However, a comprehensive understanding of how configurational entropy affects ionic conductivity is largely lacking. Herein we investigate a series of multication-substituted lithium argyrodites with the general formula Li_6+x[M1_aM2_bM3_cM4_d]S₅I, with M being P, Si, Ge, and Sb. Structure-property relationships related to ion mobility are probed using a combination of diffraction techniques, solid-state nuclear magnetic resonance spectroscopy, and charge-transport measurements. We present, to the best of our knowledge, the first experimental evidence of a direct correlation between occupational disorder in the cationic host lattice and lithium transport. By controlling the configurational entropy through compositional design, high bulk ionic conductivities up to 18 mS cm⁻¹ at room temperature are achieved for optimized lithium argyrodites. Our results indicate the possibility of improving ionic conductivity in ceramic ion conductors via entropy engineering, overcoming compositional limitations for the design of advanced electrolytes and opening up new avenues in the field.