Method and system to modify the performance of a redox flow battery

Abstract

According to one embodiment of the present disclosure, a redox flow battery is provided comprising an ionically conductive separator, a working side flowing electrolyte, a working electrode in ionic contact with the working side of the ionically conductive separator and the working side flowing electrolyte, a counter electrode, and an auxiliary electrode peripherally circumscribed by the working electrode in a common layer of the flow battery. The auxiliary electrode is in ionic contact with the working electrode, an electrically insulating peripheral gap separates the auxiliary electrode from the working electrode. A working electrode terminal is conductively coupled to the working electrode, an auxiliary electrode terminal is conductively coupled to the auxiliary electrode, and a counter electrode terminal is conductively coupled to the counter electrode. An auxiliary power source is configured to establish an auxiliary circuit voltage differential between the counter electrode terminal and the auxiliary electrode terminal, control an auxiliary electrode voltage such that the auxiliary electrode voltage is within an electrochemical window of the working side flowing electrolyte, and establish a voltage differential between the working electrode terminal and the auxiliary electrode terminal. A method of operation of the redox flow battery is further provided.