DMFC Performance of Cross-linked Sulfoethylcellulose/Poly(vinyl alcohol) Blend Electrolyte Membranes

摘要

Membrane electrode assembly (MEA) was fabricated using cross-linked sulfoethylcellulose/poly(vinyl alcohol) blend membrane (CL-SEC/PVA), and its performance was evaluated in details in the direct methanol fuel cell (DMFC) operated with various concentrations of methanol fuel. The highest power density of 23.4 mW cm~(-2) at 50 °C with 1M of methanol solution was achieved for the CL-SEC/PVA. Although the CL-SEC/PVA had a lower proton conductivity than Nafion NRE-212, its maximum power density and the open circuit voltage were higher than those of the latter when the concentration of methanol solution was over 10 M due to its extremely low methanol permeability. Continuous operation test at a constant current density of 80 raA cm~2 showed that DMFC performance reduced about 20 % after 48 h operation. Based on FT-IR spectroscopy and IEC measurement, sulfonic groups in the membrane were found to be eliminated during the continuous operation of DMFC.