Scaling up Studies on PEMFC Using a Modified Serpentine Flow Field Incorporating Porous Sponge Inserts to Observe Water Molecules

Abstract

Flooding of the cathode flow channel is a major hindrance in achieving maximum performance from Proton Exchange Membrane Fuel Cells (PEMFC) during the scaling up process. Water accumulated between the interface region of Gas Diffusion Layer (GDL) and rib of the cathode flow field can be removed by the use of Porous Sponge Inserts (PSI) on the ribs. In the present work, the experimental investigations are carried out on PEMFC for the various reaction areas, namely 25, 50 and 100 cm2. Stoichiometry value of 2 is maintained for all experiments to avoid variations in power density obtained due to differences in fuel utilization. The experiments include two flow fields, namely Serpentine Flow Field (SFF) and Modified Serpentine with Staggered provisions of 4 mm PSI (4 mm × 2 mm × 2 mm) Flow Field (MSSFF). The peak power densities obtained on MSSFF are 0.420 W/cm2, 0.298 W/cm2 and 0.232 W/cm2 compared to SFF which yields 0.242 W/cm2, 0.213 W/cm2 and 0.171 W/cm2 for reaction areas of 25, 50 and 100 cm2 respectively. Further, the reliability of experimental results is verified for SFF and MSSFF on 25 cm2 PEMFC by using Electrochemical Impedance Spectroscopy (EIS). The use of 4 mm PSI is found to improve the performance of PEMFC through the better water management.

Local durability optimization of a large-scale direct methanol fuel cell: catalyst layer tuning for homogeneous operation and in-operando detection of localized hydrogen evolution

“…Beneath the mentioned issues, cathode degradation is regulated by a complex interplay of different physical phenomena which are strongly affected by locally varying operating conditions, which effect is a heterogeneous CCL degradation. Moreover, the issue can be exacerbated in the upscale process of the membrane-electrode assembly (MEA) from lab-scale to commercially meaningful sizes, which is known to be a non-trivial, complex development task, usually leading to considerably lower cell performance [6,7]. Hence, research effort on DMFC degradation is recently evolving towards locally-resolved analyses and larger scales MEAs or stacks [5,[8][9][10][11].…”