A nature-inspired solution for water management in flow fields for electrochemical devices

Abstract

A systematic, nature-inspired chemical engineering approach is employed to solve the issue of flooding in electrochemical devices. The mechanism of passive water transport utilized by lizards living in arid environments is leveraged to design flow-fields with a microchannel structure on their surface, through which capillary pressure rapidly removes the water generated in the electrochemical device. This water management strategy is implemented in proton exchange membrane fuel cells (PEMFCs) with a lung-inspired flow-field, which ensures uniform distribution of reactants across the catalyst layer. Jointly, this nature-inspired approach results in flood-free, stable operation at 100% RH and a ∼60% increase in current (∼1.9 A cm⁻²) and peak power density (∼650 mW cm⁻²) compared to current PEMFCs with a flood-prone, serpentine flow-field (∼0.8 A cm⁻² and 280 mW cm⁻², respectively). This significant advance allows for PEMFC operation at fully humidified conditions.