Synergistic multi-physics catalysis enabled by lotus-root-inspired flow fields in proton exchange membrane fuel cells

Abstract

Proton exchange membrane fuel cells (PEMFCs) suffer from performance degradation under complex operating conditions due to the non-uniform transport of gases, water, heat, protons, and electrons. As a critical structural element, the cathode flow field (FF) plays a central role in governing multiphase transport and directly impacts catalytic activity and device stability. Here, we present a bio-inspired lotus root FF design that integrates wave-shaped main channels with sub-channels to facilitate enhanced under-rib transport through lateral inter-rib pathways. This architecture significantly improves the spatial uniformity of multi-physics distributions, yielding a 12% enhancement in field uniformity and a 10.45% increase in peak power density relative to conventional parallel FFs. A comprehensive multi-indicator evaluation further reveals the lotus root FF's capability to regulate coupled transport phenomena and reduce electrochemical overpotentials. These findings demonstrate a robust strategy for promoting synergistic multi-physics catalysis and achieving high-performance, stable PEMFC operation.