Method for operating a redox flow battery and redox flow battery

Abstract

Method for operating a redox flow battery (1), wherein the redox flow battery (1) has at least one cell stack (2) made of redox flow cells (3), wherein during a standstill phase in which no electrolytes are pumped through the cell stack (2): - a voltage (V) is detected at the at least one cell stack (2), - the detected voltage (V) is compared with a predetermined threshold value (Vmin), and - if the predetermined threshold value (Vmin) is undershot, electrolytes contained in the cell stack volume (12) are charged by applying a charging voltage to the cell stack (2), wherein the method steps are repeated at predetermined time intervals, wherein in the case in which the detected voltage (V) does not fall below the predetermined threshold value (Vmin), the predetermined time interval is selected as a function of the detected voltage (V), wherein the predetermined time interval is selected to be shorter,the smaller the difference between the detected voltage (V) and the specified voltage (Vmin).,

Claims

[1] Method for operating a redox flow battery (1), wherein the redox flow battery (1) has at least one cell stack (2) of redox flow cells (3), during a standstill phase in which no electrolytes are pumped through the cell stack (2): - a voltage (V) is detected at at least one cell stack (2), - the detected voltage (V) is compared with a predetermined threshold value (Vmin), and - if the predetermined threshold value (Vmin) is undershot, electrolytes contained in the cell stack volume (12) are charged by applying a charging voltage to the cell stack (2), whereby the process steps are repeated at specified intervals, wherein in the case where the detected voltage (V) does not fall below the predetermined threshold value (Vmin), the predetermined time interval is selected as a function of the detected voltage (V), wherein the predetermined time interval is selected to be shorter the smaller the difference between the detected voltage (V) and the predetermined voltage (Vmin). [2] Method according to claim 1, characterized by that the charging is carried out by means of a power converter (9) which connects the redox flow battery (1) to a house or supply network (20). [3] Method according to claim 1 or 2, characterized by that charging takes place with a specified power for a specified period of time. [4] Method according to one of the preceding claims, characterized by that a voltage (V) is detected at the cell stack (2) during charging, wherein charging is terminated and / or aborted when a predetermined maximum voltage (Vmax) is reached or exceeded. [5] Redox flow battery (1), comprising: at least one cell stack (2) of redox flow cells, a voltage detection device (10) configured to detect a voltage (V) at the at least one cell stack (2), and a control device (11), wherein the control device (11) is designed to during a standstill phase in which no electrolytes are pumped through the cell stack (2), to obtain a voltage (V) detected on the at least one cell stack (2) by means of the voltage detection device (10), to compare the detected voltage (V) with a predetermined threshold value (Vmin), and in the event of the predetermined threshold value (Vmin) being undershot, to initiate charging of electrolytes contained in the cell stack volume by applying a charging voltage to the cell stack (2), wherein the control device (11) is further configured to repeat the method steps at predetermined time intervals, and in the case where the detected voltage (V) does not fall below the predetermined threshold value (Vmin), to select the predetermined time interval as a function of the detected voltage (V), wherein the predetermined time interval is selected to be shorter the smaller the difference between the detected voltage (V) and the predetermined voltage (Vmin). [6] Redox flow battery (1) according to claim 5, characterized by a power converter (9), wherein the power converter (9) is designed to connect the redox flow battery (1) to a house or supply network (20), wherein the control device (11) is designed to initiate charging by means of the power converter (9). [7] Redox flow battery (1) according to claim 5 or 6, characterized by that charging takes place with a specified power for a specified period of time. [8] Redox flow battery (1) according to one of claims 5 to 7, characterized by in that the control device (11) is further configured to receive a voltage (V) detected on the cell stack (2) during charging by means of the voltage detection device (10), and to terminate and / or abort charging when a predetermined maximum voltage (Vmax) is reached or exceeded.

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