METHOD FOR PREPARING POLYMER SOLID ELECTROLYTE AND METHOD FOR PREPARING COMPOSITE SOLID ELECTROLYTE

A method for preparing a polymer solid electrolyte includes (S1) preparing a polymer crosslinked with a polyethylene oxide-based copolymer containing a crosslinkable functional group; and (S2) vapor-depositing a polar solvent onto the polymer prepared in (S1), wherein the vapor deposition step is carried out for a period of time that satisfies a prescribed Equation.