Characterization of Sulfonated Poly(Ether Ether Ketone)/Polytetrafluoroethylene Composite Membranes for Fuel Cell Applications

Abstract

The sulfonated poly(ether ether ketone) (SPEEK) / polytetrafluoroethylene (PTFE) composite membranes were produced to aid the swelling properties. The PTFE porous films were used as reinforcing material for the SPEEK/PTFE composite membranes. Scanning electron micrographs showed that SPEEK resin was distributed uniformly in the composite membrane and completely plugged the micropores; there is a continuous thin SPEEK film present on the PTFE surface. The dimensional stability and mechanical strength of the composite membranes were apparently improved. The composite membrane had a smaller oxygen permeability than the Nafion® membrane despite it being larger than that of the SPEEK homogenous membrane. The performance and stability of the PEMFC with SPEEK/PTFE composite membranes were also tested. Results showed that the fuel cell had a larger resistance than the SPEEK homogenous membrane or the Nafion® membrane, but these disadvantages are compensated for with the thinner composite membrane, because of its low gas permeability and high mechanical strength. Stability testing showed that the cell performance could be kept steady for more than 150 hours. The structure of the composite membrane didn't undergo any change and a tight bond remained between the composite membrane and the catalyst layers of electrode after more than 300 hours of intermittent operation.

Crosslinked SPEEK membranes: Mechanical, thermal, and hydrothermal properties

“…Different strategies have been developed to solve this problem. First, reinforced materials, such as polytetrafluorethylene, 13,14 inorganic carbon fibers, 15 ceramic oxides, 16 or silanol moieties, 17 were introduced into the polymer matrix to improve its mechanical, thermal, and structural stability. The stabilization effect can be owed to the reinforcement by additives and intermolecular interactions between the polymer and other components.…”

Understanding methods of preparation and characterization of pore-filling polymer composites for proton exchange membranes: a beginner’s guide

“…It is unclear, though, how the ePTFE matrix influenced the membrane properties, as no comparison with bulk SPS film was made. In another study, SPEEK/PTFE membranes (pore size, 0.3-0.5 μm; porosity, 85%) prepared from SPEEK solutions in N-methyl pyrrolidone (NMP) (Xing et al 2005) and N,Ndimethylacetamide (DMAC) (Wei et al 2012) demonstrated lower σ and water uptake and higher oxygen permeability, as compared with recast SPEEK films. The PEMFC performance was below that of both recast SPEEK and Nafion.…”

Polymer and Hybrid Materials: Electrochemistry and Applications

“…The reinforcement materials used have included PTFE porous films, woven PEEKs, and fiber-glasses. The composite membranes have demonstrated improved properties, such as mechanical strength and dimensional stability [105]. Despite the lower EW of these composites, due to the addition of insulating reinforcement materials, a low resistance can be achieved by using thin membranes [106].…”