A thin free-standing composite solid electrolyte film for solid-state lithium metal batteries

Abstract

A thin free-standing composite solid electrolyte film (CSE, ∼15 μm) is prepared by a tape casting and solution infusion method, which owns a high ionic conductivity (2.76 × 10⁻⁴ S cm⁻¹ at 25 °C) and a wide electrochemical stability window (4.8 V vs. Li⁺/Li). The CSE-based solid-state lithium metal batteries with the LiCoO₂ cathode present good cycling stability and capacity retention with a 4.5 V cut-off voltage.