| 摘要 |
PROBLEM TO BE SOLVED: To prevent an active layer from cracking or falling and eliminate electric short between positive and negative electrode sheets, by winding a both-electrode sheet which includes a positive sheet and a negative sheet having lack part of active material to provide a flat wound assembly, and positioning the lack part of active material at a turn end of the most inside of the winding. SOLUTION: The assembling sheet A consists of a positive electrode sheet 1 which includes a positive electrode collector 11 and positive electrode active materials 12, 12' placed respectively on its both surfaces, a negative electrode sheet 2 which includes a negative electrode collector 21 and negative electrode active materials 22, 22' placed respectively on its both surfaces, and separators 3, 3', and is wound such that the separator is inside. The positive electrode active materials 12, 12' and the negative electrode active materials 22, 22' in part of the assembly sheet A which is positioned at the turn end B of the most inside of the winding are lacked so that the positive electrode collector 11 and the negative electrode collector 21 are unwrapped. Because no active material layer exists at the turn end B even when the flat wound assembly is compressed to remove a space S, problem of electric short does not occur. |
