IMPROVEMENT OF MOLTEN-CARBONATE FUEL-CELL (MCFC) LIFETIME

At the Netherlands Energy Research Foundation, ECN, two approaches to the molten-carbonate fuel cell (MCFC) cathode lifetime problem have been investigated. In the first approach, efforts have been made to reduce the dissolution rate of the state-of-the-art NiO material by means of electrolyte additives. Thus far, it has been possible to obtain a reduction of c. 50% using alkaline-earth oxides or carbonates. The second approach is the development of alternative materials with good performance and very low dissolution rate, suitable to replace NiO. In this respect LiCoO2 is a promising candidate. In addition to a good in-cell behaviour, this material has a dissolution rate which is almost an order of magnitude lower than that of NiO, and its solubility shows favourable gas pressure dependences. In order to explain the significant differences in NiO, LiCoO2 and LiFeO2 performance, porous electrode modelling has been started. Preliminary results indicate that intrinsic materials properties, i.e., catalytic activity and electrical conductivity, play a crucial role in the observed polarization behaviour.