Improved manufacture of solid oxide fuel cells
Summary of technology
Solid oxide fuel cells (SOFCs) are a mature technology for the direct conversion of a gas fuel, often natural gas or hydrogen, to electricity without the need for combustion or a turbine. SOFCs are gaining an increasing share of the market for large-scale backup power, stand-alone generation and facility-wide or residential combined heat and power (CHP).
In order to further grow market share in today’s energy mix, there is a need to increase the financial viability of SOFCs: by reducing their cost of manufacture, or increasing efficiency. Curtin University researchers have developed two key technologies to address these issues.
In-situ sinter-free cathode
Conventional manufacture of SOFCs uses a process of layered deposition – the electrolyte material is coated onto a supporting anode, followed by screen-printing of a cathode material. After the cathode material is printed the assembly is sintered at high temperature (approximately 1,000 °C). To prevent reaction between the cathode and electrolyte during sintering, they are separated by a cerium oxide separation layer.
Our researchers have developed a unique process to remove the need for both the separation layer and the final sintering step, which reduces the time, capital cost and energy use of manufacture.
Anchored catalysts for increased efficiency
Our research team have also developed an improved cathode formulation, by including a small percentage of palladium in the ceramic mixture. By applying an electrical field to the cathode after deposition, palladium has been shown to be ‘exsolved’ from the ceramic material, forming surface nanoparticles. The particles act to catalyse the breakdown of oxygen on the cathode surface. As the palladium has migrated from the material, the nanoparticles are anchored within the structure, and consequently have the stability required for action through the high ranges of temperature cycling of an SOFC.
The action of the surface catalysts has been measured to increase peak power density from 0.58 W/cm2 to 1.40 W/cm2.
- Lower capital cost of manufacturing plant
- Lower energy requirement and greater throughput of fabrication leading to lower unit costs
- Greater power efficiency
The inventions have been made by Professor San Ping Jiang and Dr Kongfa Chen, both based at Curtin’s Fuels and Energy Technology Institute (FETI). Prof Jiang received his B.Eng. from South China University of Technology in 1982 and PhD from The City University, London in 1988. He has published over 200 papers encompassing fuel cells and water electrolysis, solid state ionics, electrocatalysis, and nanostructured functional materials. Dr Chen has held research positions at Curtin since 2010, focusing largely on solid oxide fuel cells.
Stage of development
The technologies have been proven on a small-scale laboratory set-up, with approximately 1 cm2 solid oxide stacks. Tests have shown significantly increased peak power density resulting from both innovations, across a range of material types.
Provisional patents have been filed in Australia to protect both the in-situ sinter-free manufacturing, and the anchored catalyst fabrication.
Curtin University is seeking commercial partners to assist with development and commercialisation of these discoveries. Ideal partner companies will have the facilities to test larger-scale prototypes of our inventions and will be able to bring a product to market.