Investigation of gas-liquid two-phase flow on the power-generation process of air-breathing microfluidic fuel cell

Air-breathing microfluidic fuel cells (AMFCs) are considered promising micro power sources due to their competitive cell performance, easy integration, and wide range of applications. However, the gas-liquid two-phase flow mechanism in AMFCs remains unclear. In this work, we propose a novel AMFC that enables high-resolution in-situ observation of the dynamic behavior of gas-liquid two-phase flow within the microchannel. A comprehensive analysis is conducted using mechanical models to investigate the cell performance and two-phase flow behaviors under various conditions, including wettability, flow rates, slant angles and the catalyst loading. Additionally, the influence mechanism of anodic pore size on bubble escape behavior is analyzed. We optimize cell power generation, discharge stability and two-phase flow under conditions of a hydrophilic channel, high flow rate and a 90° slant angle. For the porous anode, increasing the catalyst loading reduces the pore size of the anode surface, which is beneficial to promoting the detachment of small bubbles, thereby enhancing fuel transport, power generation and cell stability. This work provides the new insight into understanding the effects of gas-liquid two-phase flow on cell performance to improve the stability of power generation.