Embodiments of an electrochemical flow cell stack are disclosed. A plurality of frame layers may each have a peripheral gasket channel configured to receive a gasket material. The gasket channel may surround a recessed area having a size and a structure configured to receive an insert layer. Each of the plurality of frame layers may include at least one void area defining a first half-cell chamber of a flow cell. A plurality of insert layers may each be nested within a corresponding frame layers. Each insert layer may include at least one void area defining a second half-cell chamber of the flow cell. A flow cell may be formed by one of the plurality of frame layers and one of the plurality of insert layers.
STATEMENT OF FEDERALLY FUNDED RESEARCH
 Inventions included in this patent application were made with Government support under DE-OE0000225 "Recovery Act--Flow Battery Solution for Smart Grid Renewable Energy Applications" awarded by the US Department of Energy (DOE). The Government has certain rights in these inventions.