fig6

Figure 6. (A) Polarization and power density curves with low Pt loading (0.30 mg_Pt cm^-2 in the cathode) at 160 °C (H₂/air) without back-pressure. (B) CV of the MEAs at 160 °C (H₂/N₂). (C) Polarization and power density curves and (D) EIS analysis at 0.6 V (inset: equivalent circuit) with ultra-low Pt loading (0.10 mg_Pt cm^-2 in the cathode) at 160 °C (H₂/air) without back-pressure. (E) Fitted values of various impedances from (D). (F) Performance comparison of the H₂-air HT-PEMFCs with the low-Pt-loadings below 0.50 mg_Pt cm^-2 in the cathode CLs^{[18,24,54-63]}. (G) Durability test of STG-PtCo/EC with an ultra-low-Pt-loading of 0.10 mg_Pt cm^-2 at 200 mA cm^-2 and 160 °C under H₂/air without back-pressure. (H) Contact angle tests for PA on the cathode CLs of (H1) PtCo/EC with 5 wt% PTFE and (H2) STG-PtCo/EC with 5 wt% PTFE. (I) PA distribution diagram in the different cathode CLs of MEAs in HT-PEMFCs: (I1) PtCo/EC with 20 wt% PTFE, (I2) PtCo/EC with 5 wt% PTFE and (I3) STG-PtCo/EC with 5 wt% PTFE.