New electrospinning/electrospraying method delivers high power density fuel cell electrodes with ultra-low platinum loadings
Researchers at Drexel University have developed a new electrospinning/electrospraying (E/E) technique for fuel cell electrodes which produces a unique nanoparticle/nanofiber cathode catalyst layer morphology. The electrodes produced by the method show high power densities with ultra-low platinum loadings.
As reported in a paper in the Journal of Power Sources, the researchers evaluated H2/O2 and H2/air polymer electrolyte membrane fuel cell performance for these E/E MEAs at ultra-low Pt cathode loadings of 0.052 and 0.022 mgPt cm−2. Maximum power densities of 1.090 and 0.936 W cm−2 (H2/O2) and 0.656 and 0.625 W cm−2 (H2/air) were achieved at these two Pt loadings, respectively.
This compares to a conventional control MEA at a 0.42 mgPt cm−2 cathode catalyst loading with maximum power densities of 1.420 and 0.839 W cm−2 for H2/O2 and H2/air, respectively.
These results correspond to a significant reduction in Pt loading (5–12% of control) at only a modest reduction in power density (∼66–78% of control) for the E/E electrodes. Excellent platinum utilization in the cathode of 0.024 gPt kW−1 (∼42 kW gPt−1) was achieved for the E/E electrode at 0.022 mgPt cm−2 cathode loading.
Cyclic voltammetry results show an electrochemical surface area higher in the E/E electrodes compared to the control, which provides a rationale for the excellent platinum utilization results, where the E/E morphology results in more triple phase boundaries with more accessible Pt in the electrode.—Wang et al.
Reducing the amount of precious metal catalyst required could would result in lower cost fuel cells—an important target for commercialization.
Xuhai Wang, Francis W. Richey, Kevin H. Wujcik, Yossef A. Elabd (2014) “Ultra-low platinum loadings in polymer electrolyte membrane fuel cell electrodes fabricated via simultaneous electrospinning/electrospraying method,” Journal of Power Sources, Volume 264, Pages 42-48 doi: 10.1016/j.jpowsour.2014.04.052