METPROCELL

The METPROCELL Project has been a collaborative European (SEVENTH FRAMEWORK PROGRAMME THEME SP1-JTI-FCH.2010.3.1) project funded by the Fuel Cell and Hydrogen Joint Undertaking (FCH JU) where 8 partners worked together to develop a new generation of intermediate temperature fuel cells based on the Proton Conducting Fuel Cell (PCFC) technology. PCFC is one of the most promising technologies to reach the requirements related to cogeneration application, especially for small power systems (1-5 kWel). The investigation in the concept of advanced thin-film ceramic fuel cell technology at operating intermediate temperature between 400 and 700 °C  aims at improving the characteristics (thermal cycling, heat transfer, current collection,.) as well as lowering drastically the costs of the system.

The aim of METPROCELL was to develop innovative Proton Conducting Fuel Cells (PCFCs) by using new electrolytes and electrode materials and implementing conventional as well as new alternative fabrication routes. Following a complementary approach, the cell architecture shall be optimised on both metal and anode type supports, with the aim of improving the performance, durability and cost effectiveness of the cells. Moreover, METPROCELL aimed to bring the proof of concept of these novel PCFCs by the set-up and validation of prototype like stacks in relevant industrial conditions.

Specific objectives:

• Development of novel electrolyte (e.g. BTi02, BCY10/BCY10) and electrode materials (e.g. NiO-BIT02 and NiO-BCY10/BCY10 anodes) with enhanced properties for improved proton conducting fuel cells dedicated to 500-600°C.
• Development of alternative manufacturing routes using cost effective thermal spray technologies such detonation spraying (electrolytes and protective coatings on interconnects) and plasma spraying (anode).
• Development of innovative proton conducting fuel cell configurations to be constructed on the basis of both metal supported and anode supported cell designs.
• To up-scale the manufacturing procedures based on both conventional wet chemical methods and thermal spraying for the production of flat Stack Cells with a footprint of 12 x 12 cm.
• Bring the proof of concept of these novel PCFCs by the set-up and validation of prototype like stacks in relevant industrial systems.

Main results collected in METPROCELL:

1. Novel electrode and electrolyte materials more tolerant to CO₂ and dedicated to 500-600°C:
   • BSCF/BCZY cathodes with ASR down to 0.44 ohm.cm²; SmBSCF-BCZY / cathodes with higher chemical stability and electrochemical performance. 
   • BCZY-NiO anodes with ASR down to  0.07ohm.cm² and σ_e >1000 S.cm^-1
   • BCZYYb-ZnO electrolytes with σ_H+ of 14 mS.cm^-1. 
2. Anode supported button cells (Conf. Ni-BCZY / BCZY-ZnO / SmBSCF-BCZYYb / SmBSCF) with very high max. power densities of 513, 630 and 762 mW.cm^-2 at 600, 650 and 700°C, respectively.
3. Low cost ferritic stainless steels porous supports with CTE close to that of the electrolytes (10•10^-6 K^-1) and improved corrosion resistance under humid H₂ at 600°C (oxide thickness below 1 µm after 1000h of operation) thanks to Ce or Y based coating (porosities around 44%).
4. Up-scaled anode supports with metallic behaviour and good percolation of the nickel phase, s_e- = 1280 S.cm^-1 at 600°C, crack-free 600 µm thick. Selected cell configurations up-scaled to 70 x 70 mm² and tested under relevant service conditions at lab-scale. Durability & Micro-cogeneration profile tests:  Durability: dV/V= +3.6%/1000h; micro-cogeneration (dynamic) profile: dV/V= -1.5%/1000h. SSC and SmBSCF materials as air electrode components seem to be more efficient than BSCF one, as very high power densities have been measured (> 500 mW.cm^-2 at 600°C). METPROCELL’ results are among the best results published in the literature.
5. For the first time, the PCFC technology has been assessed at lab scale level in electrolysis mode (900 mA.cm^-2 at 1.3 V and 700°C - Stability: 7%/kh). Lower ASR in EC mode compared to FC mode.