An alkaline direct methanol fuel cell with a polymer fiber membrane and MnO2-catalyzed cathode

Abstract

Direct methanol fuel cells (DMFCs) confront with the problems of the high costs of both polymer electrolyte membrane (PEM) and noble metal catalysts. Especially, the PEM has a shortcoming of methanol crossover through it, which lowers the power density of cells and makes cathode catalysts poisoned. In this paper, a new structured alkaline DMFC is presented, which makes a great progress in solving the problems. In this DMFC, PEM is replaced by a polymer fiber membrane (PFM) which shows very low resistance to ions motion in electrolyte and is very inexpensive. MnO2 and PtRu/C have been used as cathode and anode catalysts respectively. The peak power densities of 27.3mWcm−2 and 108.4mWcm−2 have been achieved at 20°C and 68°C respectively, which are around 2–10 times higher than that of published similar researches. The experimental results demonstrate that MnO2 shows not only good electro-catalytic activity and stability for oxygen reduction reaction in alkaline solutions, but also an excellent tolerance to methanol.