A Reverse-Current Decay Mechanism for Fuel Cells

TLDR

The paper presents a mechanism that may cause accelerated performance decay of fuel cells. The mechanism, modeled by a one‑dimensional potential profile and validated in two experimental setups, reproduces the carbon‑corrosion phenomenon that accelerates fuel‑cell decay. Analysis shows that partial exposure of the anode to hydrogen and oxygen causes the electrolyte potential to drop, driving reverse current at the oxygen‑exposed region, raising the cathode interfacial potential to 1.44 V, and inducing carbon corrosion that reduces performance.

Abstract

A mechanism that may cause accelerated performance decay of fuel cells is presented. The mechanism is explained using a one-dimensional model of the potential profile. The analysis indicates that the electrolyte potential drops from 0 to (vs. RHE) when the anode is partially exposed to hydrogen and partially exposed to oxygen. This causes flow of current opposite to normal fuel cell mode at the oxygen-exposed region and raises the cathode interfacial potential difference to 1.44 V, causing carbon corrosion, which decreases performance. The decay mechanism was validated using two different experimental setups which reproduced the carbon-corrosion phenomenon.