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

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

Electrochemical analysis of nano-electro fuels based on multi-walled carbon nanotubes and graphene nanoplatelets for vanadium redox flow batteries

The limited energy performance of vanadium redox flow batteries (VRFBs) prevents their commercialization on a large scale. Active research is conducted aiming enhancement of electrochemical properties of VRFBs, nanotechnology is constantly penetrating the energy sector with its superior electrochemical properties. Multi-walled carbon nanotubes (MWCNTs) and graphene nanoplatelets (GNPs) are the two highly sought out nanomaterials in VRFBs performance enhancement research due to their exceptional chemical stability in acid environments. In the current research, electrochemical performance analysis of commercially available MWCNTs and GNPs are performed by their dispersion in base vanadium electrolyte of VRFBs, forming nano-electro fuels. It is concluded from electrochemical characterizations that nano-electro fuels based on MWCNTs and GNPs perform better when compared to conventional electrolytes