Carbon-Fuelled Solid Oxide Cells for Military Applications

We are evaluating the suitability of solid oxide cells for efficient power generation from carbons delivered as solids to the anode space in order to satisfy the requirements of military applications such as waste-to-energy and portable power. Ample evidence in the literature testifies to the feasibility of this concept. In order to de-risk a portable battery system based on this concept, consideration is given in this paper to the anode type, gasification rate of carbons, heat and mass transfer within the cell and the control of a complete system. A palladium-based anode is preferred for operation of a cell with carbon adjacent to the anode since the electrical performance is higher and it is more resistant to oxidation under fuel starved conditions than traditional nickel anodes. There is ample experimental evidence that carbon can gasify in CO2 at sufficient rate to support operation of a battery system based on cells bearing these anodes. In fact, cell modelling suggests it is the activity of the anode that is limiting. There are significant heat and mass transfer effects within the components of the cell, but these may not prevent the achievement of sufficient electrical performance to enable a portable system. System modelling suggests such a system at the 150 W scale and equipped with enough carbon for 12 hour operation could be 48% efficient.