Polysilsesquioxane polyalkylene glycol polymer having urethane bonds, solid polymer electrolyte composition comprising the same and method of preparing the same

A solid polymer electrolyte, comprising:

• a matrix comprising polyalkylene glycol polymer gel prepared by subjecting a polyalkylene glycol (PAG) polymer having urethane bonds by Structural Formula 1 below to a sol-gel reaction;
• and
• a lithium salt dispersed in the matrix:
• in Structural Formula 1,
• R1 is independently a C1 to C20 alkylene group,
• R2 is independently a C1 to C20 alkylene group,
• R3 to R5 are the same as or different from each other, and are each independently a C1 to C20 alkyl group, and
• n is any one integer of 1 to 150.

A method of preparing a solid polymer electrolyte, comprising:

• (a) preparing a polyalkylene glycol polymer having urethane bonds represented by Structural Formula 1 below by subjecting a polyalkylene glycol represented by Structural Formula 2 below and an isocyanate-based silane represented by Structural Formula 3 below to a condensation reaction;
• (b) preparing a mixture by mixing the polyalkylene glycol polymer and a lithium salt;
• and
• (c) preparing a solid polymer electrolyte by subjecting the polyalkylene glycol polymer of the mixture to a sol-gel reaction:
• in Structural Formula 2,
• R1 is a C1 to C20 alkylene group, and
• n is any one integer of 1 to 150,
• in Structural Formula 3,
• R2 is a C1 to C20 alkylene group, and
• R3 to R5 are the same as or different from each other, and are each independently a C1 to C20 alkyl group, and
• in Structural Formula 1,
• R1 is independently a C1 to C20 alkylene group,
• R2 is independently a C1 to C20 alkylene group,
• R3 to R5 are the same as or different from each other, and are each independently a C1 to C20 alkyl group, and
• n is any one integer of 1 to 150.