(30c) Novel Crosslinked Ion Exchange Membranes with Phenyl Acrylate for Direct Urea Fuel Cell and Nonaqueous Flow Battery Applications

Ion exchange membranes (IEMs) are crucial for various energy devices, including direct urea fuel cells (DUFCs) and flow batteries. A major role of IEMs in such devices is to permit counterion and suppress co-ion transport. While commercially available IEMs (Fumasep® and Nafion®) exhibit decent power and energy densities in these devices, they often experience swelling over time (leading to a reduction in device performance because of crossover). Therefore, the design of IEMs that can suppress crossover is important for device performance. Here, we report a new class of stand-alone crosslinked ion exchange membranes with favorable mechanical toughness. These materials are based on a hydrophobic monomer (phenyl acrylate, PA) and a charged monomer (methacroylcholine chloride, MACC, or 2-acrylamido-2-methyl-1-propanesulfonic acid, AMPS). These membranes (PA/MACC and PA/AMPS) were evaluated in DUFC and flow battery devices. We observed competitive device performance relative to measurements made using Fumasep® and Nafion® IEMs. Transport properties (permeability and sorption coefficient) were measured to understand the solute (e.g., urea and redox shuttle) crossover and to further analyze device performance.