The Solid Oxide Electrolysis (SOE) team at TNO has made an important step towards the application of the technology in an industrial environment by realizing the fabrication and testing of solid oxide cells with a cell size 4 to 5 times larger than the current industry standards.
An important requirement for the integration of green hydrogen in the industrial environment is its large scale availability. The solid oxide electrolysis technology holds great promise for the production of hydrogen on an industrial scale. However, one of the critical steps in realizing the application potential of the SOE technology is increasing the solid oxide cell (and therefore, the stack) size. This will contribute to reducing the complexity of a SOE system, thereby allowing for a potential decrease in the system costs.
Increased cell size
TNO manufactures solid oxide cells with very thin electrolyte layers (3-5 microns), supported by a thicker electrode (300-500 microns). This guarantees high mechanical integrity. These cells are made by using a manufacturing process in which heat treatment at very high temperatures (>1300oC) is required. This heat treatment can lead to cell breakage and therefore a low manufacturing yield when the cell size is increased. TNO has optimized the cell production method by working on the heat treatment process, allowing the production of solid oxide cells with dimensions of 30 cm x 30 cm . This results in an increase in cell size by a factor of 4-5.
Images: The solid oxide cells with dimensions of 30 x 30 cm2 developed by TNO.
Another challenge is the testing of solid oxide cells with these dimensions, for which TNO has developed and constructed a special stack test platform. The first hydrogen production tests with the new 30×30 cm2 cells were very successful.
Image: The special stack platform developed by TNO.e
The demonstrated increase in cell dimensions and stack test platform are an important step in the realization of the application of the SOE technology for hydrogen production on an industrial scale.