The direct methanol fuel cell (DMFC) has the potential to replace lithium-ion rechargeable batteries in portable electronic devices, but currently experiences significant power density and efficiency losses due to high methanol crossover through polymer electrolyte membranes (PEMs). Numerous publications document the synthesis and characterization of new PEMs for the DMFC. This article reviews this research, transport phenomena in PEMs, and experimental techniques used to evaluate new PEMs for the DMFC. Although many PEMs do not show significant improvements over Nafion®, the benchmark PEM in DMFCs, experimental results show that several new PEMs exhibit lower methanol crossover at similar proton conductivities and/or higher DMFC power densities. These results and recommendations for future research are discussed. © 2006 Wiley Periodicals, Inc. J Polym Sci Parts B: Polym Phys 44: 2201–2225, 2006

Polymer electrolyte membranes for the direct methanol fuel cell: A review

Composite membranes consisting primarily of a polymer and an inorganic proton conducting particle or a proton conducting polymer containing inorganic particles for use as proton exchange membranes in low and intermediate temperature fuel cells are reviewed. The chemistry of major inorganic additives that have been used is described in terms of their structure and intrinsic ability to conduct protons. Composites are classified in terms of four main classes: inorganic proton conductors suspended in inert polymers; inorganic particles added to extend polymeric ionomers; inorganic proton conductors blended with polymeric ionomers; and polymer acid complexes between basic polymers and acidic inorganic particles.

Young-Bun Myoung

Papers

A performance evaluation of direct methanol fuel cell using impregnated tetraethyl-orthosilicate in cross-linked polymer membrane