Device for storing electrical energy and method for operating the device

The invention relates to a device for storing electrical energy, comprising at least one electrochemical cell (1) having an anode chamber (5) and a cathode chamber (11), which are separated by a solid electrolyte (3), and comprising a first store (7) for anode material which is connected to the anode chamber (5), and a second store (23) for cathode material which is connected to the cathode chamber (11), characterised in that the cathode chamber (11) is also connected to a third store (25), the second store (23) and the third store (25) are connected to one another via a gas line (33), wherein the gas line (33) enters in the upper region of the second store (23) and the third store (25) and a conveying device (35) for gas having a reversible conveying direction is accommodated in the gas line (33), and wherein (i) the second store (23) has a withdrawal point (27) in the lower region of the store (23), which is connected to a line (17) that enters in the upper region of the cathode chamber (11), and the third store (25) has a withdrawal point (29) at the surface (31) of the fluid contained in the third store (25), which is connected to a line (19) that enters in the lower region of the cathode chamber (11), or (ii) the second store (23) and the third store (25) each have a withdrawal point (41) in the lower region of the store, which are connected to a line (19) that enters in the lower region of the cathode chamber (11), and each have a withdrawal point (43) at the surface (31) of the fluid contained in the store (23, 25), which are connected to a line (17) that enters in the upper region of the cathode chamber (11). The invention also relates to a method for operating the device.