Vanadium based flow battery stack

A flow cell battery comprising:

• a stack comprising a plurality of vanadium flow battery electrochemical cells connected tandemly, each of the plurality of vanadium flow battery electrochemical cells comprising:
• an ion exchange membrane;
• an anode having a thickness of 2.30 mm to 2.67 mm;
• a first bipolar plate to separate the plurality of vanadium flow battery electrochemical cells on an anode side;
• a first flow frame disposed between the anode and the first bipolar plate, the first flow frame defining a plurality of first flow channels;
• a cathode having a thickness from 2.30 mm to 2.67 mm;
• a second bipolar plate to separate the plurality of vanadium flow battery electrochemical cells on a cathode side;
• and
• a second flow frame disposed between the cathode and the second bipolar plate;
• an anode current collector electrically connected to an anode side of the stack;
• a first end plate comprising an epoxy resin, in contact with the anode current collector;
• a cathode current collector electrically connected to a cathode side of the stack;
• a second end plate comprising an epoxy resin, in contact with the cathode current collector;
• a first tank comprising an anolyte, the anolyte comprising V4+ and V5+;
• a first pump configured to flow the anolyte from the first tank to each of the plurality of vanadium flow battery electrochemical cells, into each of the plurality of first flow channels;
• a second tank comprising a catholyte, the catholyte comprising V2+ and V3+;
• and
• a second pump configured to flow the catholyte from the second tank to each of the plurality of vanadium flow battery electrochemical cells, into each of the plurality of second flow channels.

A flow cell battery comprising:

• an electrochemical cell, the electrochemical cell comprising:
• an ion exchange membrane;
• an anode;
• an anode current collector electrically connected to the anode;
• a first bipolar plate disposed between the anode and the anode current collector;
• a first flow frame disposed between the ion exchange membrane and the first bipolar plate, the first flow frame defining a plurality of first flow channels, each of the plurality of first flow channels having a width of 3 mm and being separated from each other by a rib having a width of 6 mm;
• a first end plate comprising an epoxy resin, in contact with the anode current collector;
• a first tank comprising an anolyte, the anolyte comprising V4+ and V5+;
• a first pump configured to flow the anolyte from the first tank into the plurality of first flow channels;
• a cathode;
• a cathode current collector electrically connected to the cathode;
• a second bipolar plate disposed between the cathode and the cathode current collector;
• a second flow frame disposed between the ion exchange membrane and the second bipolar plate, the second flow frame defining a plurality of second flow channels, each of the plurality of second flow channels having a width of 3 mm and being separated from each other by a rib having a width of 6 mm;
• a second end plate comprising the epoxy resin, in contact with the cathode current collector;
• a second tank comprising a catholyte, the catholyte comprising V2+ and V3+;
• and
• a second pump configured to flow the catholyte from the second tank into the plurality of second flow channels.