Stability and conductivity study of NH4PO3–PTFE composites at intermediate temperatures

A stable NH4PO3-glass proton conductor for intermediate temperature fuel cells

“…Although the melting effect was investigated through the SEM picture after the conductivity measurements, the conductivity of NH 4 PO 3 -SiO 2 -P 2 O 5 composite is stable during the measured over 100 h. The melting contents of NH 4 PO 3 have been retained in the composite matrix which is the source of high conductivity. It is believed that the yielded acid from decomposition of NH 4 PO 3 retains in the glass phase, similar to what we previously observed in NH 4 PO 3 -PTFE composites [18].…”

“…The stability of conductivity is very important in commercial applications, which will determine the stability of long-term performance of electrochemical devices. In a previous paper, we reported the conductivity change of NH 4 PO 3 -PTFE composite in air at 250°C [18]. Here we focus on the conductivity stability in wet 5% H 2 /Ar to observe the effects of water.…”

“…After long-term measurements of conductivity at high temperature, the particles distributed on the surface changed to needle and/or rod type. All the particles have been united together due to the melting effect or decomposition of NH 4 PO 3 to form conductive acid [18]. Although the melting effect was investigated through the SEM picture after the conductivity measurements, the conductivity of NH 4 PO 3 -SiO 2 -P 2 O 5 composite is stable during the measured over 100 h. The melting contents of NH 4 PO 3 have been retained in the composite matrix which is the source of high conductivity.…”

“…It was found that the conductivity of the composites is generally below 10 −2 S/cm therefore cannot be used as an efficient electrolyte for fuel cells [18]. In the paper, a NH 4 PO 3 -SiO 2 -P 2 O 5 composite material was prepared by a sol-gel process.…”

CsH2PO4/Polyvinylidene Fluoride Composite Electrolytes for Intermediate Temperature Fuel Cells

“…27,28 Polymers are considered as promising matrix materials to prepare flexible and thin composite electrolytes. [29][30][31][32][33] The group of Hibino [29][30][31][32] used polystyrene-b-poly(ethylene/butylene)-b-polystyrene, 29 sulfonated polystyrene-b-poly(ethylene/butylene)-b-polystyrene 29 and polystyrene-b-poly(ethylene/propylene)-b-polystyrene 30 as supporting matrices and Sn 0.95 Al 0.05 P 2 O 7 as the proton conductor to prepare thin composite electrolytes with thicknesses less than 100 μm. The composite electrolytes had conductivity of up to 10 mS cm −1 .…”