Intimate Interfacial Contact Between the Electrode and Sulfide-based Solid Electrolytes by Hot-Pressing for High-Performance All-Solid-State Batteries

Argyrodite-type Li 6 PS 5 Cl (LPSCl) has emerged as a promising electrolyte candidate for all-solid-state batteries (ASSBs) due to its high ionic conductivity and favorable mechanical properties. However, poor densification and insufficient interface contacts between the LPSCl and electrodes by general cold-pressing severely limit their energy storage capability. In this study, we demonstrate a hot-pressing approach to enhance both the bulk density of LPSCl and its interfacial contact with electrodes. The hot-pressed LPSCl at 100 °C exhibited high relative density (93%), enhanced Li-ion conductivity (1.61 mS cm −1 ), reduced interfacial resistance with Li metal (44.8 Ω cm 2 ), and superior critical current density (1.6 mA cm −2 ). In addition, these improvements translated into enhanced electrochemical performance in full-cell ASSBs pressed at 100 °C with LiNi 0.6 Mn 0.3 Co 0.1 O 2 cathodes, demonstrating a reversible capacity of 150.4 mAh g −1 at C/10, excellent rate capability with capacity retention of 94%, and cycling stability of 79% over 100 cycles at C/3.