A novel self-humidifying membrane electrode assembly with water transfer region for proton exchange membrane fuel cells

摘要

A novel self-humidifying membrane electrode assembly (MEA) with the active electrode region surrounded by a unactive "water transfer region (WTR)" was proposed to achieve effective water management and high performance for proton exchange membrane fuel cells (PEMFCs). By this configuration, excess water in the cathode was transferred to anode through Nafion membrane to humidify hydrogen. Polarization curves and power curves of conventional and the self-humidifying MEAs were compared. The self-humidifying MEA showed power density of 85 mW cm~(-2) at 0.5 V, which is two times higher than that of a conventional MEA with cathode open. The effects of anode hydrogen flow rates on the performance of the self-humidifying MEA were investigated and its best performance was obtained at a flow rate of 40 ml min~(-1). Its performance was the best when the environmental temperature was 40℃. The performance of the self-humidifying MEA was slightly affected by environmental humidity. The area of WTR was optimized, and feasible area ratio of the self-humidifying MEA was 28%.