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CORDIS - Resultados de investigaciones de la UE

Innovative SOFC Architecture based on Triode Operation

Final Report Summary - T-CELL (Innovative SOFC Architecture based on Triode Operation)

Executive Summary:
The development of Solid Oxide Fuel Cells (SOFCs) operating on hydrocarbon fuels (natural gas, biofuel, LPG) is the key to their short to medium term broad commercialization. The development of direct HC SOFCs still meets lot of challenges and problems arising from the fact that the anode materials operate under severe conditions leading to low activity towards reforming and oxidation reactions, fast deactivation due to carbon formation and instability due to the presence of sulphur compounds. Although research on these issues is intensive, no major technological breakthroughs have been realized so far with respect to robust operation, sufficient lifetime and competitive cost.
T-CELL proposes a novel electrochemical approach aiming at tackling these problems by a comprehensive effort to define, understand, develop and realize a radically new approach in SOFC technology together with a novel, triode architecture for cell and stack design. This advance was accomplished by means of a combined effort based on the development of tolerant materials and on the deployment of an innovative cell design that permits the effective in-situ control of electrocatalytic activity under steam or dry reforming conditions. The novelty of the project lies in the effort to apply modified Ni-based materials of proven advanced tolerance, as anodic electrodes in SOFCs and in the exploitation of the novel triode SOFC concept which introduces a new controllable variable into fuel cell operation. In order to provide a proof-of-concept of the stackability of triode cells, a of prototype triode SOFC short-stack, consisting of 5 repeating units, was developed and its performance was evaluated under methane and steam co-feed.

Project Context and Objectives:
In accordance with the FCH JU Annual Implementation Plan for 2011 T-CELL project objectives aimed at opening new scientific and engineering prospects, which may allow easier penetration of the SOFC system in the energy market. The work represents a holistic approach for understanding anode performance operating in poisoning conditions under controllable potential values imposed by the triode operation, thus mapping out guidelines for the development of new SOFC materials and systems.
The key objective of T-CELL project was the investigation of the synergetic effect of Ni-based cermet anodes modified via doping with a second and/or a third metal in conjunction with triode cell design and operation, in order to control the rate of carbon deposition and sulfur poisoning. A detailed mathematical model was developed to describe the triode mechanism thus enabling prediction of the behaviour of triode SOFCs as a function of cell design and operational parameters. Finally, proof of the triode concept was provided through the development and performance evaluation of a prototype triode stack, consisting of 5 repeating units.
The T-CELL project fits the objectives of the topic SP1-JTI-FCH.2011.3.1: Next generation cell and stack designs, aiming at “Break-through oriented research on novel architectures for cell and/or stack design to provide step change improvements over existing technology in terms of performance, endurance, robustness, tolerance to contaminants and cost targets for relevant applications”. Furthermore, T-CELL project also meets the scope of topic SP1-JTI-FCH.2011.3.4: Proof-of-concept fuel cell systems, which supports “the development and construction of proof-of-concept fuel cell systems for any stationary application, potential feature and technology”.
I this sense, the project endorses some of the core requirements of the MAIP 2008-2013 and AIP 2011 which are: (i) New architectures, adaptation of cell and/or stack designs to specific applications, (ii) New materials and/or strategies to improve tolerance to contaminants, (iii) Improved tolerance to contaminants with respect to state of art FCs.

Project Results:
T-CELL project addressed a number of critical scientific and technological challenges. The major achievements of the project are as follows:
• Establishment of knowledge concerning the effectiveness of triode design and operation in controlling the rate of carbon deposition under steam or dry reforming conditions
• Assessment of the effect of triode operation on cell performance and carbon deposition rate. Triode design & operation results in 40-50% lower carbon deposition rate on standard Ni/GDC anodes.
• Development and complete physicochemical characterization of advanced Ni-based cermet anodes modified via doping with a second or a third metal. Incorporating Au and Mo nanoparticles into the Ni/GDC anodes results in higher stability in 10 ppm H2S under CH4 ISR conditions.
• Delivery of complete triode cells utilizing standard and (Au, Mo nanoparticles) modified anodes using standard and magnetron sputtering methods
• Development and verification of a detailed mathematical model, accounting for all electrochemical processes taking place within a triode cell
• Identification of the key design parameters including electrode structure, associated geometry, (size and position) and configuration, overall cell architecture and that of individual components
• Proof of the triode concept through the development and performance evaluation of a prototype triode 5-cell SOFC stack operating under methane and steam co-feed

The detailed description of the main S & T results/foregrounds is provided as attachment (T-CELL_298000_FINAL REPORT.pdf)

Potential Impact:
The expected impacts by the completion of the project can be classified in two general groups, which comprise (A) the direct techno-economic benefits to the product`s properties, compared to that of SoA technology, and (B) the socio-economic and environmental impacts. These can be summarized as follows:
A1. Verification of the innovative triode concept in stack level advancing the TRL from 3 to 4 (technology validated in the Lab).
A2. Production of SOFC cells with improved (tolerant) anode functional layers (Au and Mo modified Ni-based cermet anodes)
A3. Reduction in the degradation rate of SOFC units that operate with H/C-based fuels. Triode operation results in 40-50% lower carbon deposition rate
A4. Reduction in the degradation rate of SOFC units that operate with H/C-based fuels in the presence of H2S impurities. The Au and Mo modified Ni-based cermet anodes exhibit enhanced tolerance against 10 ppm of H2S under both high and low S/C ratios.
A5. Improvement in the cells` operational lifetime. Triode cells performed 40-50% lower carbon deposition rate, which could provision a two-fold extension of lifetime.
A6. Enhancement of the SOFCs power output and overall electrical efficiency. Tests in button cells revealed electrical efficiency exceeding 55%, while remarkable performance enhancement (~20 % increase in power output) has been realized by triode operation

Furthermore, some of the socio-economic and environmental expected impacts include:
B1. Commercial exploitation of innovative research, thus fulfilling the major requirement of the specific topic/call
B2. Contribution to significant improvement of the efficiency and durability of Ni-based SOFCs and hence to their rapid penetration into market.
B3. Exploitation of the existing natural gas and liquid petroleum gas (LPG) network and easier introduction of SOFCs into households and public buildings
B4. Contribution for a European economy less dependent on imported oil, which is a significant instability factor for industrialized economies.
B5. Significant enhancement of the energy security for EC countries and worldwide
B6. Reduction of GHG emissions and qualitative improvement of the environment and public health in Europe and in the long term globally
B7. Energy savings that will subsequently result in capital investment towards other socioeconomic activities in Europe (e.g. boosting of employment)
B8. Generation of highly-skilled scientists and technologists in innovative SOFCs, able to provide Europe with expertise in advanced technologies
B9. Economic development of isolated regions like in Greece. Specifically, the established cooperation between research and high technology industry will stimulate technology transfer and promote high level scientific career opportunities.
B10. Creation of new jobs in Greece and possibly in other European countries for highly educated and specialized personnel.

The detailed description of the expolitation plan for project results, as well as the potential socio-economic impact and the wider societal implications of the project are reported in the attached Technological Implementation Plan (T-CELL_298000_TIP.pdf).

List of Websites:

Project Coordinator: Prof. Dimitrios Tsiplakides (