Performance of an active direct methanol fuel cell fed with neat methanol

Based on our previous fundamental studies on the mass transport and electrode performance of a passive direct methanol fuel cell (DMFC) with a novel electrode structure using a porous carbon plate (PCP), a single cell of an active DMFC with this structure and having the extended active area of 30 cm(2) was designed and fabricated. The power generation characteristics of the active DMFC using neat methanol (99.8 wt%), including the power density, the rate of methanol crossover and the overall energy conversion efficiency of the single cell, were investigated at different operating conditions. The highest power density was obtained with 100% methanol in the different methanol concentration range of 70 -100 wt% suggesting that the electrode structure with PCP was set for the 100% methanol use under the active conditions. The maximum power density of 62 mW cm(-2) with an overall efficiency of 0.28 was obtained at 65 degrees C. The performance was comparable or relatively higher than those of the other DMFCs using diluted methanol solutions ranging from 3 to 10 wt%. The performance was established in humid air around saturation at the small feed rate less than one-fourth that used for the DMFCs with the diluted methanol solutions. The single cell was continuously operated for 100 h with an almost constant power density. (C) 2012 Elsevier B.V. All rights reserved.