BATTERY SEPARATOR, METHOD FOR MANUFACTURING BATTERY SEPARATOR, CYLINDRICAL BATTERY, AND METHOD FOR MANUFACTURING CYLINDRICAL BATTERY

摘要

PROBLEM TO BE SOLVED: To provide a cylindrical battery including an electrode body comprising a positive electrode plate and a negative electrode plate overlapped with a separator interposed therebetween to be spirally wound, in which a possibility of a short circuit caused due to the penetration of a part of the positive electrode plate through the separator is reduced.SOLUTION: A separator 23 of the present invention includes: a main separator 231 formed of a material having insulation properties; and a first auxiliary separator 232 and a second auxiliary separator 233 which are formed of a material having insulation properties and partially disposed in the main separator 231. A portion where the first auxiliary separator 232 and the second auxiliary separator 233 are disposed in the main separator 231 has a higher density than other portion and the same thickness with the other portion.