SOLID ELECTROLYTE, METHOD FOR PREPARING SAME, AND ALL-SOLID-STATE BATTERY INCLUDING SAME

The present invention relates to a solid polymer electrolyte and a method for preparing the solid polymer electrolyte, more particularly, to a solid polymer electrolyte comprising a multifunctional acrylate-based polymer, a C1 to C10 polyalkylene oxide, a flame-retardant polymer, a lithium salt, and a non-aqueous solvent, wherein the multifunctional acrylate-based polymer is cross-linked with the polyalkylene oxide to form semi-interpenetrating polymer networks (semi-IPN), and the flame-retardant polymer is blended with the semi-interpenetrating polymer networks of the multifunctional acrylate-based polymer and the polyalkylene oxide, which shows high solid content and flame-retardant characteristics, and a method for preparing the same.