Pressure fluctuation prevention tank structure, electrolyte circulation type secondary battery, and redox flow type secondary battery

摘要

A simplified, pressure-variation preventing tank structure capable of preventing pressure variations in a gas phase portion resulting from temperature variations, without bringing stored liquid into contact with air. This pressure-variation preventing structure includes a breather bag arranged in a gas phase portion of a tank and inflating/deflating in communication with outside air, and a manhole to which the breather bag is attached to suspend in a gas phase portion, including a communication hole for the breather bag to communicate with outside air. The breather bag has air-blocking, acid-resistant and expandable characteristics.