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The change in porosity of the Ni-3.5YSZ (ZrO stabilized with 3.5 mol.% YO) composite, when produced, and the effect of porosity on the strength and electrical conductivity is studied. The porosity was provided by adding granular starch to the mixture of NiO and 3.5YSZ powders. The content of 18 vol.% pore-forming agent in the Ni-3.5YSZ cermet provides open porosity 47.1%, while its strength and electrical conductivity are 74.3 MPa and 0.93 · 10 S/m, respectively. [ABSTRACT FROM AUTHOR]

This paper describes briefly the use of Ni-YSZ (yttrium oxide doped with 8 % in mol of zirconium oxide) for methanol oxidation in 1.0 mol L KOH solution. The Ni-YSZ has a great performance for methanol oxidation reaching a current density around 160 mA cm. This value is at least four times greater than in platinum electrode. The high performance of Ni-YSZ compared with Pt electrode can also be viewed in measures electrochemical impedance spectroscopy. The Ni-YSZ shows the charge transfer resistance around 1.80 Ohm cm. Thus, in our material, the effect of NiO(OH) barrier is drastically reduced. The chronoamperograms for methanol oxidation at potential equal to 1.0 V shows that the charge density for Ni-YSZ electrode is about four times larger than in Pt electrode. [ABSTRACT FROM AUTHOR]

The most important requirements to electrodes for solid oxide fuel cells and similar devices are listed, and it is explained how the requirements usually lead to a composite electrode. Three examples of composite electrodes are described in some details, namely the ceria based hydrogen electrode, the Ni-YSZ cermet anode and the LSM-YSZ. Here YSZ means yttria stabilized zirconia, and LSM is lanthanum strontium manganate. [ABSTRACT FROM AUTHOR]