Manufacturing method of a separator for a lithium secondary battery and an organic electrolyte lithium secondary battery using the same separator

An organic electrolyte lithium secondary battery wherein lithium is an active material. The battery comprises a negative electrode made of metallic lithium or a lithium alloy and a separator made of a microporous polyolefin separator matrix whose pores are filled with an ionic conductive gel electrolyte. The separator is in the form of a sheet with at least one face contacting the negative electrode having a gel electrolyte layer. The gel electrolyte is formed by ultraviolet irradiation of a solution having a major component being a mixture of an oligomer and a monomer added to an organic electrolyte. Using the separator in an organic electrolyte lithium secondary battery internal short circuiting of the battery due to dendridic lithium growing on a negative electrode during the charging cycle can be prevented and a longer cycle life achieved.