Performance Analysis of an Air‐Breathing Micro‐Direct Methanol Fuel Cell with an Extended Anode Region

Abstract A design approach of extending the anode zone for miniaturization of the fuel cells was investigated in an air‐breathing micro‐direct methanol fuel cell (µDMFC) with an extended anode catalyst region on the walls of the fuel flow channel. This non‐conventional design is demonstrated to be a feasible approach to enhance the volumetric power density of a micro‐direct methanol fuel cell by increasing the total anode catalyst amount without affecting the cell dimensions. The fuel cell with extra anode catalyst on the fuel channel walls improves the maximum power density of a micro‐fuel cell by at least 20% compared to the conventional design with only a catalyst coated membrane (CCM). The effects of key operating conditions on the overall cell and individual electrode performances are examined. The mass transport of methanol to the catalyst active sites is more efficient in the fuel cell with anode catalyst on both the membrane and channel walls than the conventional fuel cell design with anode catalyst only on the membrane.