Capillary-Engineered Self-Breathing Anode for Enhanced Mass Transport and Power Generation in Direct Liquid Fuel Cells

Direct liquid fuel cells (DLFCs) are a promising technology for clean energy conversion because they directly convert small-molecule liquid fuels into electricity. However, under high current densities, gas bubbles generated at the anode tend to accumulate on active sites, thereby impeding fuel transport and deteriorating cell performance. To mitigate this limitation, a capillary-engineered porous self-breathing anode (SBA) with a stable Janus interface was developed to facilitate in situ bubble release. By combining visualization experiments, mechanical analysis, and finite-element simulations, this study clarifies how the wettability and pore size of the hydrophobic porous transport layer influence bubble emission behavior and antiflooding performance. The results show that the SBA promotes rapid bubble release, improves the gas–liquid−solid interfacial environment, and enhances anode mass transport. As a result, DLFCs equipped with the SBA exhibit improved cell performance and operational stability compared with conventional anodes. This work provides mechanistic insight and practical guidance for the design and optimization of gas-evolving anodes in DLFCs.