ELECTROLYTE FOR AN ELECTROCHEMICAL DEVICE, METHOD FOR MANUFACTURING SAME, AND ELECTROCHEMICAL DEVICE INCLUDING SAME

Disclosed is a solid electrolyte for an electrochemical device. The solid electrolyte includes a composite of a plastic crystal matrix electrolyte doped with an ionic salt and a crosslinked polymer structure having a linear polymer as a side chain chemically bonded thereto. The linear polymer has a weight average molecular weight of 100 to 5,000 and one functional group. The electrolyte has high ionic conductivity comparable to that of a liquid electrolyte due to the use of the plastic crystal, and high mechanical strength comparable to that of a solid electrolyte due to the introduction of the crosslinked polymer structure. Further disclosed is method for preparing the solid electrolyte. The method does not essentially require the use of a solvent, eliminating the need for drying. Therefore, the electrolyte can be prepared in a simple manner. The electrolyte is suitable for use in a cable-type battery whose shape is easy to change due to its high ionic conductivity and high mechanical strength comparable to that of a solid electrolyte.