Metal-Supported SOEC Cell
LaboratoryLawrence Berkeley National Laboratory (LBNL)
Capability ExpertMike Tucker
Process and Manufacturing Scale-Up
Node Readiness Category1: High-Temperature Electrolysis (HTE)
Lawrence Berkeley National Laboratory (LBNL) has developed unique metal-supported solid oxide electrochemical cells for about two decades, and has a core capability for developing architecture and processing solutions to materials limitations and compatibility issues. LBNL can produce metal-supported cells with the metal support on anode, cathode, or both sides. Advantages of the symmetric cell architecture include: fully symmetric cell structure for reduced strain during thermal excursions; low cost, mechanical ruggedness, and tolerance to rapid thermal transients due to stainless steel mechanical support and thin ceramic layers; extremely high electrode performance; and potential to overcome catalyst delamination due to nano-scale infiltrated catalysts. Catalysts are not present during high-temperature sintering steps that produce the metal and ceramic cell structure, opening up the range of catalysts to those that are not compatible with sintering conditions, and allowing high-throughput screening of catalyst compositions because re-optimization of processing conditions for the standardized electrode backbones are not necessary to test a new catalyst. The catalyst also coats the stainless steel support, which dramatically lowers oxidation rate. LBNL also has experience developing robust braze seals to join the metal support to manifolding and seal the cell.
LBNL's symmetric metal-supported cells with Sc-stabilized zirconia electrolyte developed within this capability show very high performance for steam electrolysis (see Figure 2). Cells with (Ba,Zr,Ce,Y)-oxide proton conducting electrolyte are also being developed, and key issues related to co-processing this material with stainless steel supports in reducing sintering conditions are addressed. Implementing other electrolyte, anode, and cathode materials is within the capability.
LBNL's symmetric metal-supported SOEC (MS-SOEC) cell architecture and the associated infiltrated catalysts with very high active area provide key benefits for HTE SOEC applications:
- Mechanical ruggedness
- High performance: 2.6 A/cm2 at 1.3 V, 50% steam/50% hydrogen, 700°C 
- Tolerance to extreme thermal cycling (room temperature to 700°C in 20 seconds)
- Tolerance to complete oxidation of the hydrogen catalyst
- Low materials cost ($20/kW)
- Very high catalyst active area and 3D structure to reduce delamination at the oxygen electrode.
- Mechanical strength enables independent optimization of gas pressure (i.e., can produce pressurized oxygen).
Catalyst infiltration is a key process within this capability, and can be applied to all types of HTE SOEC cells, including conventional, ceramic, electrode-supported, and electrolyte-supported. A wide variety of compositions can be infiltrated, including anode catalyst, cathode catalyst, ionic conductor, electronic conductor, or protective coating. Infiltration typically consists of flooding the pores of the cell with a precursor solution of metal-nitrates, -acetates, or –chlorides. The cell is then heated to convert the metal salts to nanoparticles of metal or oxide in the desired composition. Additional post-infiltration processing can optimize the microstructure. Dense continuous coatings, isolated islands, and highly porous nano-coatings can be formed via this process. See Figure 3.
See capability "Probing and Mitigating Chemical, Electrochemical and Photochemical Corrosion of Electrochemical and Photoelectrochemical Assemblies" for related assessment and mitigation capabilities for oxidation of metal supports and interconnects/bipolar plates.
Limited to cells approximately 100 cm2 and short stacks five cells or less.
LBNL is the only national lab actively working on metal-supported ceramic devices and has a broad IP portfolio and expertise protecting metal-supported high temperature oxide-conductor electrochemical devices.
No limitations, is available.
The MS-SOEC cell architecture is tolerant of mechanical abuse, high pressure, differential pressure, and rapid thermal cycles. Metal-supported cells can operate intermittently or with rapidly changing operating temperature, enabling use in applications that capture renewable or other intermittent power. Cell materials and processing costs are lower than for ceramic-supported cells. The high-triple phase boundary catalyst architecture leads to low activation overpotential and may overcome delamination issues.
Catalyst infiltration can be used to improve performance, provide functional coatings, and overcome materials compatibility limitations in electrode-supported, electrolyte-supported, and metal-supported cells of all types.
Figure 1. Metal supported solid oxide cell.
Figure 2. Performance of LBNL metal-supported solid oxide cell with ScSZ ceramic layers.
Figure 3. Infiltrated catalyst structures prepared at LBNL.
- R. Wang, C. Byrne, M. C. Tucker, "Assessment of co-sintering as a fabrication approach for metal-supported proton-conducting solid oxide cells," Solid State Ionics 332 (2019): 25-33, doi.org/10.1016/j.ssi.2019.01.004.
- R. Wang, E. Dogdibegovic, G. Y. Lau, and M. C. Tucker, "Metal-Supported Solid Oxide Electrolysis Cell (MS-SOEC) With Significantly Enhanced Catalysis," Energy Technologies (2019): published online, doi.org/10.1002/ente.201801154.
- R. Wang, G. Y. Lau, D. Ding, T. Zhu, M. C. Tucker, "Approaches for Co-Sintering Metal-Supported Proton-Conducting Solid Oxide Cells with Ba(Zr,Ce,Y,Yb)O3-δ Electrolyte," International Journal of Hydrogen Energy 44 (2019): 13768-13776, doi.org/10.1016/j.ijhydene.2019.03.181.
- M. C. Tucker, "Progress in Metal-Supported SOFCs: A Review," Journal of Power Sources 195 (2010): 4570-4582.
- M. C. Tucker, G. Y. Lau, C. P. Jacobson, L. C. DeJonghe, and S. J. Visco, "Stability and Robustness of Metal-Supported SOFCs," Journal of Power Sources 175 (2008): 447-451.
- M. C. Tucker, "Durability of symmetric-structured metal-supported solid oxide fuel cells," Journal of Power Sources 369 (2017): 6-12.
- M. C. Tucker, "Metal-supported solid oxide fuel cell with high power density," Energy Tech. 5 (2017): 2175-2181.
- E. Dogdibegovic, R. Wang, G. Y. Lau, M. C. Tucker, "High performance metal-supported solid oxide fuel cells with inﬁltrated electrodes," Journal of Power Sources 410-411 (2019): 91-98, doi.org/10.1016/j.jpowsour.2018.11.004.
- M. C. Tucker, "Dynamic-Temperature Operation of Metal-Supported Solid Oxide Fuel Cells," Journal of Power Sources 395 (2018): 314-317, doi.org/10.1016/j.jpowsour.2018.05.094.