*WINNER* Direct Formic Acid Fuel Cells: Mass Transport Optimization of the Anode Catalyst Layer

Abstract

To meet the ever-rising demand for portable power sources, batteries have become a vital part in mobile electronics such as cell phones and laptops. However, the efficiency of batteries is compromised due to exponential degradation over time, lengthy recharging times, and limited charge capacity. Direct formic acid fuel cells (DFAFC) present an alternative to batteries, due to their near instantaneous re-fueling times, higher efficiency, and 24/7 operation capabilities. However, two-phase flow in conjunction with the small pore size between anode catalyst agglomerates (~20 nm) restricts the cell's efficiency. To improve the mass transport gaseous products (carbon dioxide) and liquid reactants (formic acid), a pore-former is integrated into the anode catalyst layer during fabrication and subsequently removed. The additional templated porosity enhances the two-phase mass transport in and out of the anode catalyst layer. Previous work has been done with the addition of a smaller pore-former, MgO (~50 nm) resulting in an increase in cell performance and electrochemical surface area. [2] The intent of the pore-former is to increase the porosity of the anode catalyst layer while retaining the connectivity of the agglomerates. The present work aims study more variations in the wt% of pore-former (0-60 wt%).
1. Lam, S., Bixby, M.M., and Rice, C.A., Optimization of Mass Transport within Direct Formic Acid Fuel Cell Catalyst Layer via Pore Formers. 2020, 98, 355.