In the case of a safety device for an accumulator cell, which has an electrode assembly disposed in an elastic cell sheath and at least one electrical connector, a blocking element is provided which blocks at least a first electrical contact associated with the electrical connector with at least a second electrical contact in a releasable electrical connection, the blocking element being configured for the purpose of releasing the releasable electrical connection when the cell sheath expands as a result of a change in volume of the accumulator cell during operation. A separation of the second contact from the first contact is thereby made possible.