Testing cells decide what your redox flow battery data actually means. A flow cell is not just a fixture — it imposes the flow field, compression, and sealing that determine whether you are measuring intrinsic membrane and electrode performance or fighting bypass leakage and shunt currents. The hardware on this page is built for vanadium, iron-chromium, all-iron, organic (quinone, viologen, TEMPO), zinc-bromine, and emerging aqueous and non-aqueous flow chemistries.
The collection covers three working scales:
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Single-cell test fixtures for benchmarking a new membrane, felt, or catalyst at a fixed active area. Serpentine, interdigitated, and flow-through designs are available so you can isolate kinetic from mass-transport limitations.
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Multi-cell stacks with serpentine flow channels for studying how cells behave in series-electrical / parallel-fluid configurations — bipolar plate contact, manifold pressure drop, and shunt-current losses only appear at stack level.
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Operando and in-situ cells with optical, IR, or X-ray windows for visualizing electrolyte flow distribution, electrode wetting, gas evolution, and crossover during cycling.
Material choices reflect what flow battery electrolytes actually do to hardware. End plates and frames use PTFE, PVDF, or PEEK to resist concentrated sulfuric, hydrochloric, or bromide media. Current collectors are graphite or gold-plated for vanadium service; titanium alloys are offered for less aggressive aqueous organic systems. Carbon felt and carbon paper electrodes (with or without integrated microporous layers) seat against the flow field; ion-exchange membranes — sulfonated PFSA ionomers such as Nafion, hydrocarbon cation-exchange membranes, and anion-exchange membranes — are clamped between gaskets sized for the active area you specify.
For diagnostics beyond polarization curves, pair a testing cell with a reference electrode port to separate anode and cathode overpotentials, or with a transparent window cell to observe bubble formation, felt flooding, and dendrite or precipitate growth in zinc-based and iron-based chemistries.
If you are screening a new membrane or electrode, start with a single-cell fixture in the active-area range that matches your electrolyte volume. If you are evaluating system-level efficiency, shunt currents, or thermal behavior, move to a stack. For mechanism work on crossover, side reactions, or electrode wetting, see the operando and window-equipped cells. For the supporting hardware — felts, membranes, bipolar plates, and electrolytes — see Redox Flow Battery.
