Fast Lithium‐Ion Conducting Thin‐Film Electrolytes Integrated Directly on Flexible Substrates for High‐Power Solid‐State Batteries

Abstract
By utilizing an equilibrium processing strategy that enables co-firing of oxides and base metals, a means to integrate the lithium-stable fast lithium-ion conductor lanthanum lithium tantalate directly with a thin copper foil current collector appropriate for a solid-state battery is presented. This resulting thin-film electrolyte possesses a room temperature lithium-ion conductivity of 1.5 × 10−5 S cm−1, which has the potential to increase the power of a solid-state battery over current state of the art.