Electrochemical Hydrogen Storage Within a Modified Reversible PEM Fuel Cell and Its Performance Analysis with Interdigitated and Spiral Micro Flow Channels

Abstract

A conventional fuel cell-based power generation eco-system includes a separate electrolyser, gas storage and a fuel cell. The presence of a significantly large number of components lead to drop in round-the-trip efficiency of the system. An attempt has been made to integrate the three individual sub-systems i.e. electrolyser, storage and fuel cell into a single system known as a modified reversible proton exchange membrane fuel cell. The fabrication of an experimental unit is presented that could run both as electrolyser to split water and fuel cell to give out electricity. It possesses an integrated activated carbon electrode to store the produced hydrogen electrochemically thereby, eliminating the need of a separate storage. The performance of the system is gauged with two separate orientations of micro flow channels i.e., interdigitated and spiral that are inherent part of the end plates of the fabricated cell. Comparative result analyses for the tested micro flow channel orientations are presented. It was found that the spiral orientation favors the electrochemical hydrogen storage better than the interdigitated design. With the interdigitated channel design, the cell stored 1.47 wt% of hydrogen in ionic form and gave out 1.14 wt%. On the other hand, with spiral orientation it stored 1.67 wt% and gave out 1.21 wt%. The obtained results clearly showed the better distribution of reactants and current across the cell with the spiral micro flow channel orientation than its counterpart which surely is a step forward toward making the hydrogen storage technology commercially viable.