Preparation and characterization of cathode catalysts for molten carbonate fuel cells

G Prabhu, S Dheenadayalan, Arul Raj, R Chandrasekaran, & Pattabiraman
2001 Indian Journal of Chemical Technology   unpublished
Three different meth ods were ad opted to prepare the lithiated nickel oxide cathodes for Molten Carbo nate Fuel Cell (MCFC). In the first method Ni electrodes with desired porosity were prepared and oxidized and Iithiated inside the cell (in-situ method). Loose po wder sintering. slurry casting and tape casting methods were followed to prepare the electrodes. In the seco nd method, out of cell ox idation and lithiatio n o f ni ckel powder was carried o ut by mi xing ni ckel powder with lithium
more » ... powder with lithium carbo nate followed by oxidation in air at 650° C (ex-situ method) and then formed into the electrodes. In the third method, the pre-lithiated nickel catalyst was form ed into an electrode by tape casting technique and th e electrodes were subj ec ted to in cell or o ut of ce ll oxidatio n and sintering. The physico-che mical characteri zati o n o f the catalyst and the elec trodes were o btained by XRD and mercury porosimetry respectively. The performance o f the e lectrodes was evaluated in single cell MCFC with 45 cm 2 area electrodes at 650°C. The molten carbonate fuel cell (MCFC) represents an efficient device for the conversion of chemical energy into electrical energy 1.2_ A typical fuel cell assembly consi sts of a porous nickel anode and porous lithium doped nickel oxide cathode. They are separated by an electrolyte structure (62 mol % Li 2 C0 3 and 38 mol % K 2 C0 3) contained within a porous ceramic lithium aluminate matrix. The cell is operated at 650° C. Efficient fu el cell operation requires that the electrodes must contain sufficient electrolyte to maintain the electrode/electrolyte/reactant gas necessary for the electrochemical reaction. This requires careful control of the overall porosity and pore size distribution 3-7. Ideally, the electrodes with high surface area and porosity of 70-80% with mean pore diameter in the range 10-15).!m were reported to be suitable. The life expectancy of the cathode structures is also aimed towards 40000 h for successful commer-cialisation of MCFC 8 .