Abstract: An electrochemical storage device comprises an electrolyte which forms an ignitable gas under certain conditions during use. The electrochemical storage device is constituted by a tank and a lid which is joined in a liquid-tight manner thereto and in which the terminal pillars are brought out at the top. Furthermore, it has a labyrinth-type pressure equalization connection built into the lid to connect to atmosphere the space situated above the electrolyte and enclosed by the housing. A separate, shape-adapted displacement body having an hermetically closed cavity is disposed in the space between the lid and the electrolyte surface so that the housing does not burst in the event of an ignition of the gas.