Fabrication and performance evaluation for a novel small planar passive direct methanol fuel cell stack

In this paper, several practical operating performances were evaluated with a novel small passive direct methanol fuel cell (DMFC) stack in different potential application conditions. Combined with a DC–DC convertor, the fuel cell can realize a much more stable constant voltage output; combined with super capacitors, it can provide a large current pulse discharge. After a reproducible operation of approximately 300 h at 60 mA with five times of refueling fuel, the Faradic efficiency and energy efficiency were a little decreased and the maximum performance degradation was approximately 8%. As increasing the operating time, the methanol crossover and produced water at the cathode could cause the fuel cell performance degradation. Before realizing the portable application of passive DMFC, the stability of the cell for a long-term operation as well as the increase of the energy conversion efficiency is an important problem to be solved.