The High Temperature Fuel Cells group works on aspects related with solid oxides and molten carbonates electrolytes fuel cells (SOFC and MCFC). The group is composed of three PhD researchers, and a variable number of personnel in formation (predoctoral, graduate students, and visitors). Activities comprise fundamental research on the development of electrodes, fabrication of electrolyte supported cells, fuel cell evaluation and the development and evaluation of cathodes for molten carbonate fuel cells. A brief explanation is given below. For more information (contact).

 

Development of electrodes

The Group is working on the development of new electrodes for Intermediate Temperature Solid Oxide Fuel Cells. Several synthesis methods have been explored such as conventional (solid state reaction) and soft chemical (nitrate citrate route, microemulsion and freeze-drying) in order to optimize and control the electrode microstructure. An optimal microstructure can favorably affect electrical properties and increase the electrocatalytic reaction zone, so fuel cells will reach higher efficiency. Their structure, morphology, catalytic and transport properties, thermal and chemical stability as well as the electrochemical characterization of interface electrode/electrolyte are studied. Some special cell measurement equipments as conductivity cell, electrochemical cell and catalytic reactor have been built.

              

With regards to anode materials, mixed oxides of ceria doped with metallic components combined with Ni and/or Cu such as Mo, W, Co, Ag or Rh and double pervoskistes of Nb or Cr- doped Sr₂MgMoO_6-d have been studied as anode for methane direct oxidation. These materials present thermal, electrochemical and catalytic properties that are appropriated by SOFC anode as well as have high carbon deposition resistance and high sulfur tolerance. 

            

In cathode materials, our work has been focused on developing new mixed-conducting cathodic materials based on La₂NiO_4+d with K₂NiF₄-type structure. Three systems, La₂Ni_1-xCu_xO_4+d (0 < x < 1), La₂Ni_1-xCoxO_4+d (0 <  x <  1) and La₂-ySr_yNiO_4+d (0 <  y <  1) have been exhaustively studied. These compounds have shown to exhibit the capability to store a wide range of hyperstoichiometric oxygen at the interstitial positions of the last layer. The results obtained suggested that both La₂NiO_4+d and La₂Ni_0.6Cu_0.4O_4+d compounds could be promising cathode materials to be used in IT-SOFC.   

            

 

Preparation of electrolyte supported cells

Layers of commercial electrolytes (YSZ, ScSZ, LSGM and SDC) with a thickness ~ 100 µm have been prepared by tape casting. The selection of the suspension compounds, drying and calcined conditions have been investigated for each electrolyte material. An automatic system of tape casting with velocity control has been built.  The optimization of electrode inks has been carefully studied in order to identify the experimental conditions as well as to find the most appropriate solvent, dispersant agent, binder and plasticizer. The optimized inks are deposited by screen printing on electrolyte layer. The final conditions of calcination are defined in based on thermogravimetric studies. 

 

Cell evaluation in several atmospheres

Two test benches have been mounted with possibilities for cell operation under controlled gas flow rates, compositions, humidification and temperature.  The electrochemical behavior of the cells can be studied in pure H₂ or CH₄ and several simulated gas mixtures (CO₂, CH₄, N₂ and H₂).

       

In addition, the influence of the presence of NH₃, CO and H₂S, in the fuel can be also investigated. The performance characterization of cell is evaluated by I-V curves, impedance spectroscopy and long term tests. Cell post mortem analyses are carried out using different techniques.

        

 

REFERENCES

Ni-Ce-ZrO₂ system as anode material for direct internal reforming biogas solid oxide fuel cells, Escudero M.J., Valero C., Cauqui M.A., Goma D., Yeste M.P.Fuel 322 (2022) 124247. DOI: 10.1016/j.fuel.2022.124247.

Impedance analysis of electrolyte-supported solid oxide fuel cell with nickel-tungsten -cerium anode fed with CH₄-CO₂ mixtures and siloxanes, Escudero M.J., Maffiotte C.A., Serrano J.L. Electrochimica Acta 427 (2022) 140852. DOI:10.1016/j.electacta.2022.140852.

Preparation of LSGM electrolyte via fast combustion method and analysis of electrical properties for ReSOC, Sepulveda E., Mangalaraja R.V., Escudero Berzal M., Jiménez J., Salvo C., Camurri C.P. Journal of Electroceramics 49 (2022) 85-93. DOI:10.1007/s10832-022-00294-7.

Long-term operation of a solid oxide fuel cell with MoNi-CeO2 as anode directly fed by biogas containing simultaneously sulphur and siloxane, Escudero M.J., Maffiotte C.A., Serrano J.L Journal of Power Sources 482 (2021) 229048. DOI: 10.1016/ j.jpowsour.2020.229048.

Double perovskite La_1.8Sr_0.2CoFeO_5+δ as a cathode material for intermediate temperature solid oxide fuel cells, Costilla-Aguilar S.U., Escudero M.J., Cienfuegos-Pelaes R.F., Aguilar-Martínez J. A.Journal of Alloys and Compounds 862 (2021) 158025. DOI: 10.1016/j.jallcom.2020.158025.

Gadolinium doped ceria nanostructured oxide for intermediate temperature solid oxide fuel cells, Costilla-Aguilar S.U., Pech-Canul M.I., Escudero M.J., Cienfuegos-Pelaes R.F., Aguilar-Martínez J.A., Journal of Alloys and Compounds 878 (2021) 160444. DOI:10.1016/j.jallcom.2021.160444.

Performance of a direct methane solid oxide fuel cell using nickel-ceria-yttria stabilized zirconia as the anode, Escudero M.J., Yeste M.P., Cauqui M.A., Muñoz M.A., Materials (MDPI) 13(3) 599 (2020). DOI:10.3390/ma13030599.

Individual impact of several impurities on the performance of direct internal reforming biogas solid oxide fuel cell using W-Ni-CeO2 as anode, Escudero M.J., Serrano J.L. International Journal of Hydrogen Energy 44 (2019) 20616-20636. DOI: 10.1016/j.ijhydene.2019.06.028.

Praseodymium and samarium co-doped ceria as an anode catalyst for DIR-SOFCs fueled by biogas. B. Bochentyn, P. Błaszczak, M. Gazda, A. Fuerte, S.-F. Wang, P. Jasiński. International Journal of Hydrogen Energy 45 (2019) 29131-29142. DOI: 10.1016/j.ijhydene.2020.07.146

Role of Dopants on Ceria-based Anodes for IT-SOFCs Powered by Hydrocarbon Fuels. A. Fuerte, R.X. Valenzuela, M.J. Escudero. Universal Journal of Electrical and Electronic Engineering 5 (2017) 45-55. DOI: 10.13189/ujeee.2017.050301

Performance of Ceria-Electrolyte Solid Oxide Fuel Cell Using Simulated Biogas Mixtures as Fuel. M.J. Escudero, A. Fuerte. Advance in Energy and Power 5 (2017) 20-26. DOI. 10.13189/aep.2017.050202

Electrochemical analysis of a system based on W and Ni combined with CeO2 as potential sulphur-tolerant SOFC anode. M.J. Escudero, A. Fuerte. Fuel Cells 16 (2016) 340-348. DOI: 10.1002/fuce.201500076

Electrochemical impedance study of Ag/Cu-Ca0.2Ce0.8O2+d anode for SOFCs operating with simulated biogas. A. Fuerte, M.J. Escudero. ECS Transactions 68 (2015) 2805-2810. DOI: 10.1149/06801.2805ecst

Impedance spectroscopy studies of the behavior of MoNi-CeO2 anode in SOFC using H2S-containing hydrogen as fuel.  M.J. Escudero, I. Gómez de Parada, A. Fuerte. ECS Transactions 68 (2015) 2723-2733. DOI: 10.1149/06801.2723ecst

Performance evaluation of WNi-CeO2 anode in a Solid Oxide Fuel Cell fed by simulated biogas mixtures.M. J. Escudero, I. Gómez de Parada, A. Fuerte. Int. J. Hydrogen Energy, 40 (2015) 11303-11314. DOI: 10.1016/j.ijhydene.2015.03.110

Study of a SOFC with a bimetallic Cu-Co-ceria anode directly fuelled with simulated biogas mixtures, A.  Fuerte, R.X. Valenzuela, M.J. Escudero, L. Daza,  Int. J. Hydrogen Energy, 39 (2014) 4060-4066. DOI: 10.1016/j.ijhydene.2013.06.142

Analysis of the electrochemical performance of MoNi-CeO2 cermet as anode material for solid oxide fuel cell. Part I. H2, CH4 and H2/CH4 mixtures as fuels. M.J. Escudero, I. Gómez de Parada, A. Fuerte, J.L. Serrano, J. Power Sources, 253 (2014) 64-73. DOI: 10.1016/j.jpowsour.2013.12.027.

Electrochemical performance of SOFC with an anode based on Cu-Ni/CeO2 for methane direct.  A.  Hornés, M.J. Escudero, L. Daza, A. Martínez-Arias, J. Power Sources, 249 (2014) 520-526. DOI: 10.1016/j.jpowsour.2013.05.159

Study of Sr2Mg(Mo0.8Nb0.2)O6-d as anode material for SOFC using hydrocarbons as fuel. M. J. Escudero, I. Gómez de Parada, A. Fuerte, L. Daza, J. Power Sources 243 (2013) 654-660. DOI: 10.1016/j.jpowsour.2013.05.198

La2NiO4+d potential cathode material on La0.9Sr0.1Ga0.8Mg0.2O2.85 electrolyte for Intermediate Temperature Solid Oxide Fuel Cell. M.J. Escudero, A. Fuerte, L. Daza, J. Power Sources 196 (2011) 7245-7250. DOI: 10.1016/j.jpowsour.2010.11.068

Effect of cobalt incorporation in copper-ceria based anodes for hydrocarbon utilization in IT-SOFCs. A. Fuerte, R.X. Valenzuela, M.J. Escudero, L. Daza, J. Power Sources 196 (2011) 4324-4331. DOI: 10.1016/j.jpowsour.2010.12.053

Structural, catalytic/redox and electrical characterization of systems combining Cu-Fe with CeO2 or Ce1-xMxO2-d (M = Gd or Tb) for direct methane oxidation. A. Hornés, G. Munuera ,  A. Fuerte,  M. J. Escudero, L. Daza, A. Martínez-Arias, J. Power Sources 196 (2011) 4218-4225. DOI: 10.1016/j.jpowsour.2010.10.042

Electrochemical behavior of La2Ni0.6Cu0.4O4+d  oxide on SDC electrolyte as cathode for IT-SOFC.  D. Pérez-Coll, A. Aguadero, M.J. Escudero, L. Daza, ECS Transactions, 25 (2) (2009) 2589-2596. DOI: 10.1149/1.3205816

Study of CuFe-Ce0.9Gd0.1O2-d as IT-SOFC anode: catalytic activity, thermal expansion, morphology, electrical conductivity and chemical compatibility. A. Fuerte, A. Hornés , P. Bera, A. Martínez-Arias,  M. J. Escudero, L. Daza,  ECS Transactions, 25 (2) (2009) 2183-2192. DOI: 10.1149/1.3205768

Performance of a new Cu-ceria based anode for SOFCs running on different fuels.  A. Fuerte, R.X. Valenzuela, M.J. Escudero, L. Daza, ECS Transactions, 25 (2) (2009) 2173-2182. DOI: 10.1149/1.3205767

Ammonia as efficient fuel for SOFC. A. Fuerte, R.X. Valenzuela, M.J. Escudero, L. Daza,  J. Power Sources 192 (2009) 170-174. DOI: 10.1016/j.jpowsour.2008.11.037

SrCo1-xSbxO3-d perovskite oxides as cathode materials in SOFC. A. Aguadero, D.  Pérez-Coll, C. de la Calle, J.A Alonso, M.J. Escudero, L. Daza, J. Power Sources 192 (2009) 132-137. DOI: 10.1016/j.jpowsour.2008.12.138

Structure, thermal stability and conductivity of Ca(V0.5Mo0.5)O3 as potential SOFC anode. A. Aguadero, C. de la Calle, J.A Alonso, D.  Pérez-Coll, M.J. Escudero, L. Daza, J. Power Sources 192 (2009) 78-83. DOI: 10.1016/j.jpowsour.2008.12.035

Structural, catalytic/redox and electrical characterization of systems combining Cu-Ni with CeO2 or Ce1-xMxO2-d (M = Gd or Tb) for direct methane oxidation. A. Hornés , D. Gamarra, G. Munuera, A. Fuerte, R. X. Valenzuela, M. J. Escudero, L. Daza,  J.C. Conesa, P. Bera, A. Martínez-Arias, J. Power Sources 192 (2009) 70-77. DOI: 10.1016/j.jpowsour.2008.12.015

Development of anode material based on La-substituted SrTiO3 perovskites doped with manganese and/or gallium for SOFC. M.J. Escudero, J.T.S. Irvine, L. Daza, J. Power Sources 192 (2009) 43-50. DOI: 10.1016/j.jpowsour.2008.11.132

Effect of DC current polarization on the electrochemical behaviour of La2NiO4+d and La3Ni2O7+d-based systems. D. Pérez-Coll, A.  Aguadero, M.J. Escudero, L. Daza, J. Power Sources 192 (2009) 2-13. DOI: 10.1016/j.jpowsour.2008.10.073

Optimization of the interface polarization of the La2NiO4-based cathode working with the Ce1-xSmxO2-d electrolyte system. D. Pérez-Coll, A.  Aguadero, M.J. Escudero, P. Núñez, L. Daza, J. Power Sources 178 (2008) 151-162. DOI: 10.1016/j.jpowsour.2007.12.030

Evaluation of the La2Ni1- xCuxO4+d system as SOFC cathode material with 8YSZ and LSGM as electrolytes. A. Aguadero, J.A. Alonso, M.T. Fernández-Díaz, M.J. Escudero, L. Daza, Solid State Ionics 179 (2008) 393-400. DOI: 10.1016/j.ssi.2008.01.099

Structural and electrical characterization of the novel SrCo0.9Sb0.1O3-d  perovskite: evaluation as SOFC cathode material. A. Aguadero, C. de la Calle,  J.A. Alonso, M.J. Escudero, M.T. Fernández-Díaz, L. Daza, Chem. Mater. 19 (2007) 6437-6444. DOI: 10.1021/cm071837x

A kinetic study of oxygen reduction reaction on La2NiO4 cathodes by means of impedance spectroscopy, M.J. Escudero, A. Aguadero, J.A. Alonso, L. Daza, J. Electroanal. Chem. 611 (2007) 107-116. DOI: 10.1016/j.jelechem.2007.08.006

Preparation and characterisation of SOFC anodic materials based on Ce-Cu, A. Fuerte, R.X. Valenzuela, L. Daza, J. Power Sources 169 (2007) 47-52. DOI: 10.1016/j.jpowsour.2007.03.033

In situ high temperature neutron powder diffraction study of La2Ni0.6Cu0.4O4+d  in air: correlation with the electrical behaviour. A. Aguadero, J.A. Alonso, M.T. Fernández-Díaz, M.J. Escudero, L. Daza, J. Power Sources 169 (2007) 17-24. DOI: 10.1016/j.jpowsour.2007.01.075

Hyperstoichiometric La1.9Sr0.1NiO4+d mixed conductor as novel cathode for intermediate temperature solid oxide fuel cells. A. Aguadero,  M.J. Escudero, M. Pérez,  J.A. Alonso,  L. Daza, J. Fuel Cell Sci. Technol. 4  (2007) 294-298. DOI: 10.1115/1.2743075

Effect of Sr content on the crystal structure and electrical properties of the system La2-xSrxNiO4+d (0<x<1). A. Aguadero,  M.J. Escudero, M. Pérez,  J.A. Alonso, V. Pomjakushim, L. Daza, Dalton Trans. (2006) 4377-4383. DOI: 10.1039/B606316K 

In situ high temperature neutron powder diffraction study of oxygen-rich La2NiO4+d in air: correla [Ver]tion with the electrical behaviour. A. Aguadero,  J.A. Alonso, M.J. Martínez-Lope, M.T. Fernández-Díaz, M.J. Escudero, L. Daza, J. Mater. Chem. 16 (2006) 3402-3408. DOI: 10.1039/B605886H

The Group has worked on the development of alternative cathode materials for MCFC, based on nickel impregnated with cerium and lithium nickel mixed oxides modified by lanthanum or cerium impregnation, as well as nickel modified with cobalt using the potentiostatic electrochemical technique. The structure, morphology and electrochemical behavior in a eutectic mixture of Li and K have been investigated. Finally, cells using nickel-cerium and nickel-cobalt as cathode materials were prepared and their performance and endurance evaluated and compared with that for a commercial NiO cathode. The results revealed that the addition of cerium or cobalt can be beneficial to overcome the dissolution of the nickel cathode in the electrolyte, which is considered one of the major limits to the lifetime of a MCFC. 

                     

REFERENCES

Porous nickel MCFC cathode coated by potentiostatically deposited cobalt oxide: III. Electrochemical behavior in molten carbonate. Review. M.J. Escudero, A. Ringuedé, M. Cassir, T. Gonzalez, L. Daza, J. Power Sources 171 (2007) 261-271. DOI: 10.1016/j.jpowsour.2007.06.013

Porous nickel MCFC cathode coated by potentiostatically deposited cobalt oxide: II. Structural and morphological behavior in molten carbonate. M.J. Escudero, T.  Rodrigo, L. Mendoza, M. Cassir, L.Daza, J. Power Sources 160 (2006) 775-781. DOI: 10.1016/j.jpowsour.2006.04.056

Molten carbonate fuel cell cathodes: Improvement of the electrocatalytic activity. M.J. Escudero, T. Rodrigo, L. Daza, Catal. Today 107-108 (2005) 377-387. DOI: 10.1016/j.cattod.2005.07.097

Porous nickel MCFC cathode coated by potentiostatically deposited cobalt oxide: I. A structural and morphological study. M.J. Escudero, T.  Rodrigo, L. Mendoza, M. Cassir, L.Daza, J. Power Sources 140 (2005) 81-87. DOI: 10.1016/j.jpowsour.2004.08.009

Electrochemical behaviour of lithium-nickel oxides in molten carbonate. M.J. Escudero, T. Rodrigo, L. Daza,  J. Power Sources 118 (2003) 23-34. DOI: 10.1016/S0378-7753(03)00057-0

Study of a Li-Ni oxides mixture as a novel cathode for MCFC by electrochemical impedance spectroscopy. M.J. Escudero, X.R. Novoa, T. Rodrigo, L. Daza, J. Appl. Electrochem. 32 (2002) 929-936. DOI. 10.1023/A:1020572308690

Influence of lanthanum oxide as quality promoter on cathodes for MCFC. M.J. Escudero, X.R. Novoa, T. Rodrigo, L. Daza, J. Power Sources 106 (2002) 196-205. DOI: 10.1016/S0378-7753(01)01043-6

Endurance test on single cell of a novel cathode material for MCFC. J. Soler, T. Gónzalez, M.J. Escudero, T. Rodrigo, L. Daza, J. Power Sources 106 (2002) 189-195. DOI: 10.1016/S0378-7753(01)01041-2

 

Collaborations with other groups

• José Antonio Alonso ((Institute of Materials Science, ICMM-CSIC,Madrid- Spain)
• Arturo Martínez-Arias Institute of Catalysis and Petrochemistry, ICP-CSIC, Madrid-Spain)
• Jesús Canales (Institute for Renewable Energy Research, Albacete-Spain)
• Michel Cassir (Ecole Nationale Supérieure de Chimie de Paris, ENSCP-CNRS, Francia)

 

Other activities

• Participation in the International Electrotechnical Commission (IEC) IEC/TC105  (AENOR CTN206/SC105) group for Fuel Cells Normalization as well as Technological Evaluations for KIC InnoEnergy 
• Memberships: Spanish Fuel Cell Association (APPICE)