KAGAKU KOGAKU RONBUNSHU, Vol.29, No.2, 170-173, 2003
Modification effect of proton-exchange membrane on performance of a direct methanol fuel cell
Cell performance and electrochemical properties of a DMFC system were investigated using as received Nafion 117 (DuPont) and Nafion membrane modified with a counter-ion. The short circuit current of 392 mA/cm(2) and the open circuit voltage of 0.658 V were obtained at 363 K with Nafion 117 membrane. For the modified Nafion membrane with the counter ion of (CH3)(4)N+, the cell performance decreased in comparison with as-received Nafion 117 membrane. The short circuit current density was 156 mA/cm(2) for the modified membrane at 353 K because of low proton conductivity of the membrane. However, the open circuit voltage was improved to 0.635 V and 0.732 V at 343 K and 383 K, respectively. Since the reduction of the methanol permeate flux raised the open circuit voltage, it was confirmed that the methanol crossover was suppressed by using the modified Nafion membrane.