Abstract: A sealed electrochemical cell (1) fitted with a circuit-breaking terminal (3) which ensures electrical connection between an external contact part (7) of the terminal and one (6) of the positive or negative electrodes of the cell, the external contact part (7) of the terminal being electrically connected to a wall (11) which ensures that the terminal is sealed and which is capable of being deformed under the action of an increase in internal pressure, the wall (11) being connected to said electrode (6) by means (13, 14, 16) which ensure electrical continuity, the continuity being interrupted when an internal pressure P is reached which is greater than a determined value P.sub.1, causing the wall to deform and the connection between the wall (11) and a break part (13) to break, the cell being characterized in that said circuit-breaking terminal (3) passes in a sealed manner through a closure lid (2) of the cell, the lid also being fitted separately with a safety capsule (4) which breaks under a pressure P.sub.