| 摘要 |
PROBLEM TO BE SOLVED: To relieve the swelling of a battery container caused by expansion of a power generation element, without reducing the charge/discharge capacity of the battery.SOLUTION: An air gap 40S is formed between each circular arc portion 34 provided on both sides in the width direction (X direction) of an axis core 30 and an axis core portion 40A of a power generation element 40. A tip portion in the width direction of each circular arc portion 34 of the axis core 30 is stopped at a position more inside than a boundary face 40Z between a circular arc portion 40U and a flat portion 40Q in the axis core portion 40A. In other words, the air gap 40S extends over the regions of the circular arc portion 40U and the flat portion 40Q abutting on both sides of the boundary face 40Z. When the power generation element 40 expands in the thickness direction due to charge/discharge, the air gap 40S creates an escape use space for the expansion of the power generation element 40. |
