Fabrication and Characterizations of LAGP/PEO Composite Electrolytes for All Solid-State Lithium-Ion Batteries" With the rise of electric vehicles and increasing dependence on mobile electronics, the demands for lithium-ion batteries have followed in tandem for their high energy and power densities.However, traditional lithium-ion batteries consisting of liquid electrolytes have limited operating temperatures and are susceptible to ignition and subsequent fires.Recently, battery research has diverged into solid state chemistry to address the aforementioned issues.In this research, we systematically investigate a series of ceramic/polymer lithium-ion conducting composite electrolytes, i.e.Li1.4Al0.4Ge1.6(PO4)3/lithiated polyethylene oxide (LAGP/PEO).Lithiated PEO was prepared with two different lithium salts, LiBF4 and LITFSI.The impacts of the LAGP on the electrical, thermal, and mechanical properties of the two lithiated PEO systems are assessed.When LAGP is homogenously distributed in PEO-LiTFSI films, ionic conductivities and thermal properties remain relatively uninhibited; the elastic modulus and ultimate strength increased up to 450% and 200%, respectively.When LAGP was added to PEO-LiBF4 films, it increased the elastic strength nearly 200% without compromising the ultimate strength and thermal properties, but at the sacrifice of ionic iv conductivity.The ceramic/polymeric electrolytes have potential applications to flexible all solid state lithium-ion batteries.