Plasma polymerized electrolyte membranes and electrodes for miniaturized fuel cells

Solid polymer electrolyte membranes for fuel cell applications—a review

“…An improvement in the reaction kinetics accompanied by high conductivity up to 200 • C and lower methanol crossover were observed. A reduction in methanol crossover by coating a thin layer of plasma polymerized tetrafluoroethylene (with vinyl phosphoric acid) on Nafion ® membrane was attempted by Mex and Muller [57]. Finsterwalder and Hambitzer investigated a similar method of depositing a PTFE source with chlorosulfonic acid on Nafion ® in order to obtain a low methanol crossover [58].…”

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

“…However, most of thesePEMs possess similar transport properties to Nafion® 61. Other PEMs developed in the literature for the DMFC constitute a variety of designapproaches, such as the synthesis of newionic (sulfonic acid) random and block copolymers,21, 23, 24, 26, 28, 30, 31, 36, 43–46, 48, 51, 57, 63–72 graft copolymerization of ionic polymers unto hydrophobic membranes,15, 16, 34, 52, 73 blending ionic and nonionic polymers,13, 20, 17, 49, 53, 54, 57, 58, 74–88 the synthesis of interpenetrating networks of ionic and nonionic polymers,42, 50, 89–99 incorporating a variety of fillers (e.g., silica, montmorillonite) into ionic polymer membranes,12, 14, 18, 19, 22, 25, 27, 29, 33, 37–39, 41, 47, 92, 100–118 and coating ionic polymer membranes with thin barrier coatings 12, 32, 35, 40, 80, 119–126. The subsections below highlight findings from these investigations.…”

Optimization and synthesis of plasma polymerized proton exchange membranes for direct methanol fuel cells

“…Among various types of PEMs, the membranes synthesized by a plasma polymerization are particularly attractive due to their potential ability to provide better solutions to the aforementioned shortcomings associated with Nafion, especially in terms of reduction in methanol permeability [14][15][16][17][18]. Plasma polymerization is a dry membrane synthesis method, which allows for a high degree control over the thickness of membranes and a better compatibility of membranes with the other active layers (such as gas diffusion layers and catalytic layers) of the fuel cell [19][20][21].…”

“…It is demonstrated that plasma polymerized membranes usually have highly cross-linked structures, which improves their thermal and chemical stabilities, thereby increases their lifetime and broadens their operating conditions when used in fuel cells. Their high degree of cross-linking can also decrease the crossover of methanol through the membranes, a process which could cause the reduction of fuel utilization and cathode performance and therefore is a particularly pronounced limiting factor needing to be addressed in DMFCs [5,6,[14][15][16][17][18][19][20][21]. The thin and controllable structures of plasma-polymerized membranes are their additional significant advantages, which can reduce the membrane resistance and the path length of proton diffusion and thus increase their efficiency and dynamic response.…”

“…In combination with other thin film processes (e.g., sputter deposition of the catalyst material), a membrane electrode assembly (MEA) of miniaturized DMFCs can be realized in successive deposition steps which have the potential to improve the three-phase boundary (membrane, electrode, and catalyst) and improve the performance of DMFCs. In addition, this technique allows large scale fabrications of membrane electrode assemblies at low cost [14][15][16][17][18]22,23].…”