Experimental Study of the Electrochemical Performance of Low-temperature Proton-exchange Membrane Fuel Cells

Low-temperature proton exchange membrane fuel cells (LT-PEMFCs) expect the potential for use in broad contemporary electrochemical energy conversion. This experimental study was to investigate the dependencies of the electrochemical performance of LT-PEMFC (with Nafion-112 as the polymer electrolytic membranes) upon the cell temperature (80 and 90°C), temperature of reactants (hydrogen and air at 30 and 80°C), and reactant gas flow rates. Detailed voltage-current (V-I) polarization diagrams and power and current density diagrams were obtained at varying operating temperature, backpressure, and reactant gas flow rates. The measured highest open circuit voltage (OCV) is up to 0.93 V, max current density up to 1.6 A/cm2, and max power density up to 400 mW/cm2. Experimental observation showed that dehydration significantly influenced the proton conduction of the Nafion membrane with highest proton conductivity of 127.7×10^(-4) Scm-1 at 100% relative humidity (RH) and cell temperature of 80°C while the proton conductivity decreases to 78.54×10^(-4) Scm-1 at RH of 67.29% at the cell temperature of 90°C. FTIR was used to examine the acid effect in Nafion membrane. The study shows the crucial insights in enhancing the cell performance of LT-PEMFCs suitable for the green energy technologies.