Molten Carbonate Fuel Cell Cathode Materials Study

Abstract

Data are presented on the electronic conductivity and molten alkali carbonate stability (Li:K binary of 62:38 mole ratio) of various materials at 923 K under a 30% CO2/normalair atmosphere. Of the examined materials, only LaNiO3 and LaxSr1−xCoO3 satisfied both criteria sufficiently for acceptable use as molten carbonate fuel cell cathode materials.

Complex Formation during Dissolution of Metal Oxides in Molten Alkali Carbonates

“…After evaporation, the remains were dissolved in 0.1 M nitric acid and analyzed by atomic absorption spectroscopy (Perkin Elmer 2100). Due to its high solubility, PbO was analyzed gravimetrically by precipitation as PbCrO 4 .…”

“…It is, however, unlikely to attain a lifetime more than 40,000 h because of its solubility in the carbonate melt. Several investigations have been carried out to measure the solubility of NiO in individual alkali carbonates, 3 binary mixtures, [4][5][6][7] ternary mixtures, 8,9 and alkali/alkaline earth carbonate mixtures. 10,11 In order to obtain other materials as possible substitutes for the lithiated NiO cathode, extensive research has been conducted.…”

Mixed-potential-type YSZ-based sensor with nano-structured NiO and porous TPB processed with pore-formers using coating technique

“…Baumgartner et al [37,38] and Suzuki et al [39]. In view of the fact that the sensitivity kept increasing as the doping ratio increased from 5% to 10%, even the conductivity of YSZ reduced slightly, the main reason should be attributed to the better porosity can provide larger contact area of as-constructed TPB, supply more active sites for the related electrochemical reactions and then hugely accelerate the reactions to a great extent at same time.…”

Other Fuel Cells

“…As the nickel dissolves into Ni 2+ ion, it migrates under the voltage gradient to the anode and is eventually reduced with dissolved hydrogen, precipitating in the electrolyte [33]. This reduces the cathode activity but also can lead to a nickel metal bridge between the anode and cathode.…”