Composite polymer electrolyte (CPE) membranes for secondary solid state li-metal cells and process for the production thereof

The present invention relates to a curable composition for preparing a composite polymer electrode, the curable composition containing:A) a Li-ion conducting solid electrolyte whose general composition has the formula:Li7+x−yMIIxMIII3−xMIV2−yO12whereinMII, MIII, MIV, MV are species of valence II to V; where 0≤x<3, preferably 0≤x≤2; and 0≤y<2 preferably 0≤y≤1;(B) a polymer;(C) a lithium salt;(D) an active plasticizer; and(E) a photoinitiator.The invention also relates to a process of preparing the curable composition, cured compositions and films derived from the curable composition, and solid-state lithium batteries whose solid electrolyte layer contains a cured composition or a cured film according to the invention.