Colloidal processing of Li₂S–P₂S₅ films fabricated via electrophoretic deposition methods and their characterization as a solid electrolyte for all solid state lithium ion batteries

Abstract

Li₂S–P₂S₅ (LPS) film was prepared using colloidal process by employing electrophoretic deposition (EPD) technique followed by warm pressing for advanced processing of all-solid-state lithium ion battery. LPS precursor film with positive surface charge was obtained from its suspension that was synthesized by liquid-phase shaking method. The homogeneous film with thickness of 10–100 µm was controllably prepared. Resulted LPS film exhibited high conductivity (1.98 × 10⁻⁴ S cm⁻¹) at ambient temperature and significantly low activation energy (16.6 kJ mol⁻¹) compared with conventional LPS materials. Thus, good solid–solid interfacial contact can be obtained in the sulfide-based ionic conductor by employing EPD process followed by warm pressing.