fig7

Figure 7. (A) Optical microscope images of GDL_{3D print}; (B) Adhesive force measurement of the O₂ bubbles on GDL_{3D print}; (C) Electrochemical impedance spectra of various porous transport layers recorded under AEMWE at 0.2 A cm^-2, with the matched equivalent circuit model displayed in the inset panel; (D) Comparison of split polarization components for pure-water-fed AEMWE operated at 500 mA cm^-2 and 1,000 mA cm^-2. (A-D) Reprinted in part with permission from^[173]. Copyright 2023, Elsevier; (E) SEM image of perforated GDL; (F) NIST neutron imaging setup and fuel cell hardware; (G) Neutron radiographs of water breakthrough in the baseline GDL (upper image) and the laser-perforated GDL (lower image). (E-G) Reprinted in part with permission from^[174]. Copyright 2013, Electrochemical Society Inc; (H and I) SEM images of the patterned MPL: top-view morphology (H) and cross-sectional profiles (I); (J) Sequential snapshots tracking water condensation processes on patterned MPL surfaces at different reaction phases. (H-J) Reprinted in part with permission from^[175]. Copyright 2024, Tsinghua University Press; (K and L) Structural sketches: standard MEA configuration (K); Janus ordered dual-functional interlayer with outstanding gas-water transfer capacity (L); (M) In-situ EIS data recorded on single cells pre- and post-ADT aging cycles; (N) ECSA retention curve after multiple accelerated test cycles. (K-N) Reprinted in part with permission from^[123]. Copyright 2021, Wiley. GDL: Gas diffusion layer; NF: nickel foam; VACNT: vertically aligned carbon nanotube; MPL: microporous layer; PEM: proton exchange membrane; SEM: scanning electron microscopy; MEA: membrane electrode assembly; EIS: electrochemical impedance spectroscopy; ADT: accelerated degradation test; ECSA: electrochemical active surface area.