A Highly Integrated Component with Tri‐Part Significantly Enhances Fuel Cell Power Density by Reducing Mass Transfer Resistance and Excellent Humidity Tolerance

Abstract Traditional flow fields and gas diffusion layers (GDL) suffer from water flooding at the rib contact surface, resulting in mass transfer obstruction. Herein, an integrated component (i‐component) with tri‐part of the flow field, gas diffusion backing, and the microporous layer is prepared using the filter molding method to prevent flooding at the rib. The i‐component with micro‐tunnels is more compact than traditional fuel cells and has no distinct interface, significantly enhancing fuel cell performance, reducing mass transfer resistance, and improving water management. Remarkably, the mass transfer resistance of the i‐components is reduced by six times, accompanied by a 50% increase in power density (1.63 W cm −2 ) and a 146% surge in volume‐specific power (24 500 W L −1 ). Additionally, it exhibits excellent humidity tolerance in the relative humidity range of 30–100%. This method achieves large‐area i‐component (388 cm 2 ) preparation in 0.5 h at 350 °C, which reduces time by dozens and energy consumption by over 100 times compared to the traditional method for preparing commercial GDL. The i‐component significantly enhances the mass transfer and water management capabilities of fuel cells. Hence, the i‐component provides new strategies for next‐generation fuel cells, water electrolysis, flow battery, carbon dioxide reduction, etc.