NONAQUEOUS ELECTROLYTE SECONDARY BATTERY

摘要

PROBLEM TO BE SOLVED: To provide a nonaqueous electrolyte secondary battery which generates only a small magnetic field with a current flow when used, and hardly causes internal short circuit even when a small number of protection tapes are used.SOLUTION: A flat wound electrode body 10A of a nonaqueous electrolyte secondary battery includes: a first protection tape 32 which is bonded, starting from, on a cathode active material mixture layer 22 at an outer peripheral surface side of a positive electrode plate 20, via a boundary between the cathode active material mixture layer 22 and a positive electrode core exposed portion 21a, to the positive electrode core exposed portion 21a at a start-of-winding side; a second protection tape 33 which is bonded, starting from, on the cathode active material mixture layer 22 at an inner peripheral surface side of the positive electrode plate 20, via a boundary between the cathode active material mixture layer 22 and the positive electrode core exposed portion 21a, on the positive electrode core exposed portion 21a at a start-of-winding side of the first protection tape 32; and a negative electrode core exposed portion 25a which is formed at an end of a start-of-winding side of a negative electrode plate 24 so as to have both surfaces in the same length. An end 25s of a start-of-winding side of the negative electrode core exposed portion 25a and a negative electrode tab 13 are arranged so as to face the first protection tape 32 and the second protection tape 33 via separators 30 and 31.