CsH₂PO₄/Polyvinylidene Fluoride Composite Electrolytes for Intermediate Temperature Fuel Cells

Abstract

In this study CsH 2 PO 4 /polyvinylidene fluoride (PVDF) composite electrolytes were prepared by a slurry casting method and their application in intermediate temperature fuel cells (ITFCs) was investigated. The composite electrolytes consisted of a physical dispersion of CsH 2 PO 4 particles in the PVDF polymer network and were thin and flexible. The crystalline structure and thermal behavior of CsH 2 PO 4 were not influenced by the PVDF. The composite electrolyte with 70 wt% CsH 2 PO 4 showed a high conductivity of 10 mS cm −1 at 270 • C under 30% H 2 O/Ar atmosphere as well as a tensile strength of 7 MPa at room temperature. In addition, the composite electrolytes had area specific resistances of 0.99 and 0.72 cm 2 , for corresponding thicknesses of 101 and 67 μm, which are low values. The composite electrolyte with 70 wt% CsH 2 PO 4 showed stable conductivity at 259 • C under 30% H 2 O/Ar atmosphere for 48 h. A fuel cell assembled with this electrolyte exhibited an open circuit voltage of 0.92 V and a peak power density of 86 mW cm −2 , making the composite electrolyte a candidate electrolyte for ITFCs.

Facile and scalable synthesis of sub-micrometer electrolyte particles for solid acid fuel cells

“…Independent of the mode of application, polymeric binders like PVDF or epoxi resin can be added to improve the mechanical properties of the layer. [7][8][9] Another promising candidate would be polyamide-imides as these are thermally and mechanically stable, available in soluble form, and can be cured at temperatures around the operating temperature of SAFCs.…”

“…However, the membranes were mechanically unstable and the cells showed a rapid decrease of power output. 4 Composites of CsH 2 PO 4 and inorganic oxides 3,5,6 or polymers [7][8][9] revealed improved mechanical stability and are promising for creating stable, thin electrolyte membranes. In any case, the membrane thickness is limited by the size of the electrolyte particles.…”

More sustainable electricity generation in hot and dry fuel cells with a novel hybrid membrane of Nafion/nano-silica/hydroxyl ionic liquid

“…The other main problems of the low temperature PEMFCs include CO poisoning of the electrode catalysts, and the complexity of water and heat [19,20]. Unfortunately, in addition to undergoing noticeable decomposition and/or redox reactions, solid acids seem to be ill suited for forming membranes in FCs [19][20][21].…”

A Flexible CsH5(PO4)2-Doped Composite Electrolyte Membrane for Intermediate-Temperature Fuel Cells

“…Intermediate-temperature fuel cells (ITFCs), which operate at 200-600°C , are superior to low-and high-temperature fuel cells in many aspects [3][4][5][6][7]. For example, they offer reduced electrode catalyst poisoning by carbon monoxide [7,8], lower Pt electrode material requirements [9], less complicated water management, and more responsive kinetics and diffusion rates [7,10,11]. ITFCs broaden the range of applicable materials and extend material lifespans compared to high-temperature fuel cell.…”