| abstract |
And a heat-resistant porous layer disposed on at least one side of the substrate and comprising a phosphonate-based copolymer, wherein the phosphonate-based copolymer has a repeating unit represented by the following formula (1) and a repeating unit represented by the following formula A separator for a lithium secondary battery comprising the same, and a lithium secondary battery comprising the separator. [Chemical Formula 1] (2) Wherein X 1 , X 2 , R 1 , R 2 , n and m are as defined in the specification. |