Developments in the soluble lead-acid flow battery

The history of soluble lead flow batteries is concisely reviewed and recent developments are highlighted. The development of a practical, undivided cell is considered. An in-house, monopolar unit cell (geometrical electrode area 100 cm(2)) and an FM01-LC bipolar (2 x 64 cm(2)) flow cell are used. Porous, three-dimensional, reticulated vitreous carbon (RVC) and planar, carbon-HDPE composite electrodes have been used in laboratory flow cells. The performance of such cells under constant current density (10-160 mA cm(-2)) cycling is examined using a controlled flow rate (mean linear flow velocity < 14 cm s(-1)) at a temperature of approximately 298 K. Voltage versus time and voltage versus current density relationships are considered. High charge (< 90%), voltage (< 80%) and energy (< 70%) efficiencies are possible. Possible failure modes encountered during early scale-up from a small, laboratory flow cell to larger, pilot-scale cells are discussed.