LITHIUM ION SECONDARY BATTERY

摘要

Disclosed is a lithium ion secondary battery, in which a vinyl alcohol polymer or a derivative thereof is arranged inside the battery in an amount of 0.3 mg or more per 1 mAh of battery capacity in terms of a vinyl alcohol unit moiety content. The lithium ion secondary battery can decrease the battery voltage under high-temperature conditions, and cannot be recharged after being exposed to high-temperature conditions.