Spray-Printed Flexible Li₂S Cathode with Inorganic Ion-Conductive Binder Nano-Li₃PS₄

Flexible solid-state batteries fabricated by printing techniques are promising integrated power supplies for miniaturized and customized electronic devices. While typically these batteries use polymer solid electrolytes, a flexible Li2S cathode with sulfide solid electrolyte is spray-printed in this work, by using solvated Li3PS4 nanoparticles as inorganic ion-conductive binder. This benefits from a novel low-temperature-sintering property of these nanoparticles, which can be pressure-free densified, along with the desolvation process, and thus bind the cathode at 250 degrees C. The battery can be stably charged and discharged for 300 cycles with no stacking pressure, and the capacity maintains at 840 mA h g(Li2 S)(-1). We believe this low-temperature-sintering phenomenon of solid electrolyte nanoparticles will open a new path toward the application of sulfide solid electrolytes in printed solid-state batteries.