| abstract |
In order to improve safety during overcharging, a current interrupter valve must be actuated during the initial period of the overcharging. Further, a technique for suppressing overcharging is needed that can achieve battery performance at the same time. This lithium ion secondary battery is provided with a positive electrode capable of occluding and releasing lithium ions, a negative electrode capable of occluding and releasing lithium ions, a separator arranged between the positive electrode and the negative electrode, an electrolyte, and a current interrupter mechanism which operates in response to rises in battery internal pressure, wherein the electrolyte has an aromatic compound, the separator has a carbon dioxide generating agent, and said carbon dioxide generating agent is represented by the general formula A X CO 3 or A y HCO 3 . Thereby, this lithium ion secondary battery has increased responsiveness to overcharging. |