2533
Lanthanum Nickelate Cathode Materials for Intermediate Temperature-Solid Oxide Fuel Cells

Tuesday, 15 May 2018
Ballroom 6ABC (Washington State Convention Center)
J. I. Lee, K. Y. Park, and J. Y. Park (Sejong University)
Solid oxide fuel cells (SOFCs) have been considered as the next-generation energy conversion electrochemical devices that can transform chemical energy of fuel to electrical energy. In particular, various advantages of SOFCs, such as high energy conversion efficiency, negligible pollutant emission, and the multi-fuel capability, make them indispensable for the renewable society [1].

The rate determining step of energy conversion in state-of-art SOFCs at intermediate temperature (IT) is the sluggish kinetics of oxygen reduction reaction (ORR) in the cathode, and thus the cathode material significantly affects performances of IT-SOFCs. Up to now, cobalt-based perovskite oxides have received great attentions for the cathode material because of the low overpotential for ORR. [2]. However, cobalt-based materials have significantly high thermal expansion coefficient (TEC) values ( ), compared to those of typical electrolytes (yttria-stabilized zirconia and rare-earth-doped ceria, ). This big discrepancy gives rise to mechanical stress to the cell, which affects the long-term stability of cells [3]. Furthermore, cobalt-based materials are expensive and have a low stability under reducing atmospheres. In contrast, the TEC of lanthanum nickelates (Lan+1NinO3n+1) is , which is nearly analogous to the TEC of electrolyte materials [4]. In addition, lanthanum nickelates have high electrical conductivity with the great stability at IT. In this work, the performance and durability of lanthanum nickelates are investigated in the anode-supported cell design and analyzed by using various tools such as TEM, XPS, and DFT calculations [5].

References

[1] K.T. Lee, E.D. Wachsman, Science 334 (2011) 935.

[2] W. Zhou, Z. Shao, J. Power Sources 192 (2009) 231

[3] S. Pang, X. Xi, J. Power Sources 326 (2016) 176.

[4] R.K. Sharma, E. Djurado, J. Power Sources 325 (2016) 337.

[5] T.H Lee, J.-Y. Park. J. Power Sources 331 (2016) 495

Keywords: Solid oxide fuel cells; Lanthanum nickelate; Thermal Expansion Coefficient; Conductivity, Stability