Performance Durability of Direct Methanol Fuel Cells

Abstract

This paper addresses various routes for performance losses in single direct methanol fuel cells and DMFC stacks. The study identifies recoverable (reversible) and unrecoverable (irreversible) sources of DMFC performance degradation during single-cell operation for up to 3000 hours and short stack operation for up to 850 hours. Single-cell test data focus on two otherwise identical MEAs, of which one was prepared by a standard low-temperature approach (Standard MEA) whereas the other was made by high-temperature method to improve anode durability (Novel MEA). Thanks to the approach taken in the preparation of the Novel MEA, the unrecoverable DMFC performance loss was reduced to 10 mV over 3000 hours, relative to a 60-mV loss incurred by the Standard MEA over the same period of time. Both single-cell MEAs exhibited much lower performance loss than individual cells in a six-cell stack, which lost 40-80 mV per cell during only 850 hours of stack testing.