Abstract: Disclosed is a highly heat-resistant film for electrode terminals. The heat-resistant film includes a polymer layer as a central substrate to be sealably interposed between a pouch and electrode terminals. The polymer layer is formed of a mixture of (a) at least one polymer selected from the group consisting of an ethylene-norbornene copolymer and a polymethylpentene with (b) a polypropylene resin. Preferably, the polypropylene resin is highly heat resistant and the mixture has a weight ratio of 1.9 to 5:5. The heat-resistant film simultaneously meets requirements in terms of thermal adhesiveness and high temperature dimensional stability, which are contradictory to each other in conventional films for electrode terminals of secondary batteries. In addition, the heat-resistant film has enhanced electrolyte resistance to improve the durability of a secondary battery.

Abstract: Disclosed is a highly heat-resistant film for electrode terminals. The heat-resistant film includes a polymer layer as a central substrate to be sealably interposed between a pouch and electrode terminals. The polymer layer is formed of a mixture of at least one polymer selected from the group consisting of an ethylene-norbornene copolymer, polymethylpentene, polyalkylene terephthalate and polyphenylene sulfide with highly heat-resistant polypropylene in a weight ratio of 5:5 to 9:1. The heat-resistant film simultaneously meets requirements in terms of thermal adhesiveness and high temperature dimensional stability, which are contradictory to each other in conventional films for electrode terminals of secondary batteries. In addition, the heat-resistant film has enhanced electrolyte resistance to improve the durability of a secondary battery. Further disclosed are a method for producing the heat-resistant film and an electrode terminal structure including the heat-resistant film.