Proton conductivity measurements of PEM performed in EasyTest Cell

作者：Radev I^*; Georgiev G; Sinigersky V; Slaucheva E

来源：International Journal of Hydrogen Energy, 2008, 33(18): 4849-4855.

DOI：10.1016/j.ijhydene.2008.06.056

• EasyTest Cell
• PEM
• Proton conductivity
• Hydrogen electrodes
• Graft-copolymers

The paper presents dc measurements of proton exchange membranes (PEMs) as an integral part of a membrane electrode assembly (MEA) performed in a novel EasyTest Cell testing device. Depending on their operating temperature PEMs are divided in two groups. The commercial Nafion membranes (Alfa Aesar) as well as the self-prepared interpenetrating network of poly(acrylamidepropylsulfonic acid) and poly(acrylamide) (PAMPS-PAM), and Nafion 117 with grafted PAMPS chains (Nafion graft-PAMPS) are tested in the low temperature range (upto 80 degrees C). The PEMs from the second group (prepared in the frame of EU project AUTOBRANE, FP 6) - phosphoric acid doped polybenzimidazole (PBI/PA) and PBI, containing cross-linked poly(vinylphosphonic acid) (CR-PVPhA) - are investigated for high temperature applications (120-200 degrees C). The EasyTest Cell is a three electrode electrochemical test that offers the possibility to obtain steady state polarization curves at strict self-regulated constant hydrogen and water vapor partial pressures. The initial slope of the polarization curves, corrected by the electronic resistance of the electrodes under study is used as a criterion for the proton conductivity of the investigated PEMs. The results obtained for the commercially available Nafion are in a good agreement with the available literature data. The PAMPS grafting from Nafion 117 results in 1.5 fold higher proton conductivity compared to the non-grafted one. The proton conductivity of the PBI/PA membrane is almost independent on the relative humidity (RH) in the range of 15-40% (0.110-0.117 S cm(-1) at 180 degrees C) which makes the water management redundant, this way facilitating the fuel cell management. The proton conductivity of the PBI/CR-PVPhA membrane is in the range of 7 x 10(-3) S cm(-1) (170 degrees C, 20% RH). The EasyTest Cell working principle and single chamber design allows precise control of vital working parameters (temperature and RH) for the proton conductivity of PEM.

• 出版日期2008-9