Application of multi-layer graphene (MLG) in the anion exchange membrane fuel cells

Abstract

Anion exchange membrane fuel cells (AEMFCs) employing multilayer graphene (MLG) are investigated to improve water management and electrode stability at low operating temperatures. MLG sheets are produced via ultrasound exfoliation of thermally expanded graphite and are fabricated into disk electrodes (MLGD) or incorporated directly into catalyst inks (G-ink). Membrane‐electrode assemblies are tested over a range of anode/cathode dew‐point temperatures under H2/O2 feeds. MLGD‐based cells achieve a peak power density (PPD) of 320 mW cm−2 at 60 °C, but suffer from high ohmic resistance and flooding due to graphene's hydrophobicity. Incorporating 10 wt% MLG into the anode and cathode inks (G-ink) increases the PPD to 1.15 W cm−2 and delivers enhanced mass‐transport control, showing a degradation rate of 7.2 10−4 V h−1 over an 85 h durability test. Further, G-ink deployed only at the anode exhibits a PPD of 1.17 W cm−2, outstanding long‐term stability (>300 h, degradation rate 1.3 10−4 V h−1). These results demonstrate that MLG enables steered water management, offers a facile, possibly low-cost hydrophobic alternative to traditional materials, and promises performance enhancements for low‐temperature AEMFCs.