Pressure Drop through Platinized Titanium Porous Electrodes for Cerium-Based Redox Flow Batteries

The pressure drop, Delta P, across a redox flow battery is linked to pumping costs and energy efficiency, making fluid properties of the electrolyte important in scale-up operations. The Delta P at diverse platinized titanium electrodes in Ce-based redox flow batteries is reported as a function of mean linear electrolyte velocity measured in a rectangular channel flow cell. Darcy's friction factor and permeability vs. Reynolds number are calculated. Average permeability values are: 7.10 x 10(-4) cm(2) for Pt/Ti mesh, 4.45 x 10(-40) cm(2) for Pt/Ti plate + turbulence promoters, 1.67 x 10(-5) cm(2) for Pt/Ti micromesh, and 1.31 x 10(-6) cm(2) for Pt/Ti felt. The electrochemical volumetric mass transport coefficient, k(m)A(e), is provided as a function of Delta P. In the flow-by configuration, Pt/Ti felt combines high k(m)A(e) values with a relatively high Delta P, followed by Pt/Ti micromesh. Pt/Ti mesh and Pt/Ti plate gave a lower Delta P but poorer electrochemical performance. Implications for cell design are discussed. (c) 2017 American Institute of Chemical Engineers