A Novel solid oxide fuel cell anode substrate : performance and lifetime studies

Abstract

The competition in the fuel cell market today is driving improved performance and among the fuel cells types the Solid Oxide fuel cell (SOFC) has a top rank because of its high efficiency in combined heat and power applications. The RoxSolid cell (2-R cell) is a newly invented robust construction developed by Fiaxell – a leading company in SOFC developments and is yet another step to further increasing the performance of current SOFCs. Before introducing the 2-R cell to the market its performance characteristics need to determined and documented. In particular it is necessary to show that the claims that the 2-R cell is robust are backed up by laboratory tests. The ability of the cell to withstand the effects of redox cycling is essential and therefore redox cycling is one of the main test techniques used in this work. The performance and life time properties of the received 2-R cells were determined by measuring the I-V characteristics during and after redox cycling. In addition, the electrical resistance of the anode substrate material was studied separately under repeated redox cycling. The test results of the I-V and Power characteristics confirm that the performance of the best 2-R cell is approximately seven times higher than the reference sample (a conventional anode supported SOFC cell). Through the results of resistance value variation of the new anode substrate samples, it was shown that there was an increase of conductivity with the time, converse to the conventional results. The calculated anode conductivity values were approximately 20 % higher than the theoretical data obtained from the percolation theory. The optical microscopy images taken after redox cycle testing confirmed the higher robustness of the cells compared to the reference SOFC, and also showed a better ability of the 2-R cell to withstand redox cyclings. The results of the conducted experiments confirmed that overall performance and lifetime properties of the Fiaxcell “2-R cell” are considerably better than the conventional SOFCs.