| 摘要 |
PROBLEM TO BE SOLVED: To provide a lithium ion secondary battery which exhibits excellent rate and cycle characteristics owing to adhesive strength and physical properties of a separator in the battery.SOLUTION: In a lithium ion secondary battery comprised of an electrode group consisting of a cathode and an anode and a separator interposed between the cathode and the anode, the separator and the anode are bonded with an adhesive strength of 6 N/m to 15 N/m, both ends incl., and the separator has an air permeability of 180 seconds to 600 seconds, both ends incl. As a result, internal stresses in the electrode group occurring when the anode swells in thickness at charge and discharge time can be restrained, so that excellent rate and cycle characteristics can be had. |
