In order to define the mechanisms that control the corrosion of current collector materials in molten carbonate fuel cells, the corrosion of iron with
Li2CO3‐K2CO3
melts at 650°C was investigated. Thermochemical calculations were used to identify equilibrium corrosion products and establish phase stability diagrams for the Fe‐Li‐K‐C‐O system. The corrosion of iron with a 2.0 mg/cm2 carbonate deposit of
false(Li0.62K0.38)2CO3
under
20%O2‐false(0.01–50false)%CO2‐normalAr
proceeded according to a parabolic rate law, where the corrosion rate was controlled by the diffusion of iron cations through
normalFeO
and
Fe3O4
inner layers. The corrosion of iron with the carbonate deposit under
Po2<102
Pa followed a linear rate, where the controlling step was the dissolution of oxygen from the gas phase into the carbonate. With the aid of the phase stability diagrams, the corrosion kinetics and scale morphologies were examined.
The reaction of chromium with
Li2CO3‐K2CO3
melts was investigated from a thermodynamic point of view. Thermochemical calculations with the SOLGASMIX‐PV computer program were used to establish equilibrium phase relationships for the Cr‐Li‐K‐C‐O system at 650°C. The calculated phase relationships were checked experimentally by thermogravimetric analysis (TGA) and differential thermal analysis (DTA). The results of TGA and DTA were self‐consistent with respect to the reaction products predicted from the calculated phase stability diagrams. Finally, the phase stability diagrams of the Cr‐Li‐K‐C‐O system were used as an aid in understanding the corrosion processes of chromium in molten carbonate salt under both fuel gas and oxidizing gas used in molten carbonate fuel cells.
Porous Ni/ZrO2-Y203 cermets are electronically con~ ducting at Ni contents greater than 30 v/o of total solids. Below this level, the conductivity falls to that of the ionically conducting zirconia matrix. The 30 v/o value was found to be independent of the zirconia particle size for the two sizes studied. Nevertheless, considerable improvement in the electronic conduction of the cermet (Ni content > 30 v/o) was made by increasing the zirconia particle size. This improvement probably results from better Ni particle-to-particle contact.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.