Method for making solid electrolyte

A method for making a solid electrolyte, comprising:

• providing a first monomer, a second monomer, an initiator, and a lithium salt;
• wherein the first monomer is R1—OCH2—Ch2—OnR2, the second monomer is R3—OCH2—CH2—OnR4, each “R1”, “R2” and “R3” comprises —C═C— group or —C≡C— group, “R4” is an alkyl group or a hydrogen (H), “m” and “n” respectively represents an integer number, and a molecular weight of the first monomer or a molecular weight of the second monomer is greater than or equal to 100, and less than or equal to 800;
• mixing the first monomer, the second monomer, the initiator, and the lithium salt to form a mixture;
• wherein the first monomer is less than or equal to 50% of the second monomer by weight;
• and
• polymerizing the first monomer with the second monomer to form an interpenetrating polymer network, and transforming the lithium salt into a solid solution and dispersing in the interpenetrating polymer network, thereby forming the solid electrolyte.