| 摘要 |
PROBLEM TO BE SOLVED: To provide a power storage device including a gas drainage valve which allows the gas permeation amount to increase, achieves long life, and maintains excellent power storage characteristics while preventing moisture, such as an electrolyte, from adhering to a gas permeation part of the gas drainage valve and hindering the gas permeation function and also preventing size change of the gas drainage valve.SOLUTION: A power storage device includes: a power storage element; a cup shaped outer case housing the power storage element; and a sealing plate which seals an opening of the outer case. A gas drainage valve having gas permeability is provided at a through hole of the sealing plate. The gas drainage valve includes: a cylindrical outer cylinder; an inner cylinder part; a first closing part which closes the inner cylinder; and a second closing part which closes a space between the outer cylinder and the inner cylinder. The first closing part is located closer to the power storage element side than the second closing part. A recessed part, which opens to the power storage element side, is formed in the space between the outer cylinder and the inner cylinder. |
