Tape Calandering of Solid oxide fuel cell

Solid oxide fuel cell
A solid oxide fuel cell (SOFC) produces electricity directly from oxidizing a fuel and has a solid oxide or ceramic, electrolyte. Advantages of solid oxide fuel cells include high efficiency, long-term stability, fuel flexibility, low emissions, and relatively low cost. The largest disadvantage is the high operating temperature which results in longer start-up times and mechanical and chemical compatibility issues.
Methods of fabrication
Currently, all R&D efforts are focused on fabrication methods of ceramic SOFC components.
SOFC components manufacturing processes.
Stiff structural ceramic parts can be manufactured by:
Extrusion
Dry pressing
Tape casting and
Calandering
Functional ceramic parts can be manufactured by:
Screen printing
Slurry coating
EVD, PVD and
Plasma and flame spraying
Tape Calandering
In Tape Calandering , a continuous thin sheet or tape of controlled thickness is produced. A high intensity mixer is used to mix the ceramic powder, binder and plasticiser. The mixing results in heating-up the batch and softening the binder to form a plastic mass. Then, the mass is rolled to form a thin, flat tape using a two-roll mill, and adjusting the spacing between the two mills controls the tape thickness.
This technique is used to fabricate monolithic FCs via a co-sintering process, where the individual tapes are laminated in a second rolling operation, and FCs with very thin electrolyte layer, which enables to operate at low temperatures (600 ºC) is produced.
The fabrication details of typical 2 cm2 area fuel cell components which includes preparation of anode, electrolyte, cathode cermet pastes, nickel net (60 mesh and grip on anode side) are given below.
• Anode: NiO,
• Cathode: perovskite Ca0,9La0,1MnO3 (CLM),
• Electrolyte (SDCm-1)
Cermet proportions
• Anode: Electrolyte cermet, at: 1:1, % by volume
• Cathode/electrolyte cermet, at 1:1 % by volume
• Binder : 3% Teflon by mass to every component
• Nickel net dimensions: Anode: 22x22 mm,
• Anode/Cathode thickness: 0.5 mm each, including nickel net
• Electrolyte thickness: 0.5 mm
• Sintering of samples: 600 °C, 2 h under nitrogen atmosphere