Back to search

ENERGIX-Stort program energi

H2 production at IntermediAte temperAture

Alternative title: hydrogenproduksjon ved mellomliggende temperatur

Awarded: NOK 9.6 mill.

In the AH2A project, SINTEF and UiO have, together with international partners, worked to develop a proton conducting electrolyzer cell with operating temperature på 600 °C for efficient use of heat and steam supplied by geothermal, solar, or waste energy from industrial plants. The cell concept utilizes an iron chromium metallic substrate for mechanical support and current collection, combined with cell components fabricated using low temperature methods. Proton conducting oxides have very high sintering temperature, which is not very compatible with the melting point of the metal. In addition, the metal cannot tolerate long time at high temperature in air without oxidizing. The main focus in the project has been to develop low temperature methods like spray coating and pulsed laser deposition (PLD) for fabrication of the thin porous and dense films in the cells. In the project period, our efforts have focused on customizing the component layers to reduce problems with cracking during fabrication and operation of the thin proton conducting electrolyte. Towards achieving the goals of the project, we have developed and integrated a new thin-film electrolyte with a thermal expansion which is more similar to the other cell components, and thus the cracking is reduced. It is important that the film is dense to avoid oxygen leakage through the film. Another challenge which are being addressed, is to improve the structure of the hydrogen electrode, to improve the microstructure of the thin film electrolyte, BSZCY. Additional nanoporous layers have been added to the structure, in collaboration with a German project partner. The nano structure improves the quality of the deposited electrolyte. The gradual decrease in pressure during deposition is applied for decreasing the strain between the electrolyte layer and nanocoating and for obtaining dense electrolyte. The effect of coating parameters such as temperature and film-thickness is investigated. The work described has resulted in a dense 1-2 micron thick electrolyte film. By testing the electrochemical performance of the cell, we found that the thin electrolyte layer exhibits low resistance at 600°C (below 0.4 ohm.cm2) and the total cell resistance of the cell is about 1-2 ohm.cm2 at 600 °C in single atmosphere. Furthermore, a MS-PCEC cell prepared by the international partner DLR, in collaboration with UiO and SINTEF, was successfully tested under electrolysis mode and showed a reasonable cell total resistance at 600 °C (4 ohm.cm2). As far as we know this is the first report on metal supported proton conducting electrolysis cell.

Produced MS by tape casting + coating. Due to low conductivity/too high brittleness, commercial Plansee supports were used LSTN was used as SICL layer. Microstructure of LSTN was optimised. Roughness goals were achieved (< 2 µm). Electrical conductivity for LSTN is good in reducing atmosphere. The mechanical stability of LSTN nanolayer should be improved further Novel cell architecture New electrolyte with better TEC Better crystallinity of PLD layer (comp with METALLICA starting point) Produced button cells Delivered samples to SP3 Not done upscaling BGLC applied by brush painting or PLD has been used in AH2A. Pt paint + Pt net has been used as air electrode GLAD not possible due to technical limitation. Mica and aremco ceramic tested as sealant. Aremco worked best and was used Impedance spectroscopy of single cells gave an ASR of 1 ohm cm2 in humid harmix. A cell from DLR (with electrolyte from UiO) was tested in electrolysis mode. ASR is 4 ohm cm2 at 600 C

AH2A will contribute to develop a technology for sustainable utilization of renewable energy resources in Norway - while preserving the natural environment and ensuring security of H2 supply. Dry pressurized H2 will be produced from renewable energy sources for higher well to tank efficiency utilizing a proton conductor working at intermediate temperature. AH2A will further develop electrolyser cells based on the metal supported (MS) thin film of proton-conducting BaZr0.85Y0.15O3 electrolyte developed at SINTEF/UiO in the METALLICA project using pulsed laser deposition (PLD). AH2A will develop improved smooth intermediate conducting layers (SICL) and novel electrodes which is critical for the electrolyser assemblies working at 600 °C to reach a total resistance less than 1 ohm.cm2 for the cell. In addition air electrode with good electrochemical properties under high water vapor composition compatible with fabrication routes based on wet chemical - and vacuum methods. In collaboration with the international partners, the scalability will be demonstrated through the realization of 6 x 6 cm2 cells with optimized components using a novel PLD at SINTEF. Testing of these cells will be done to prove the target and investigate for possible long-term degradation issues under operation. These robust electrolysis cells with an overall low resistance will, when fully optimized, enable efficient production of H2 from water by renewable energy and waste heat from industry. This pioneering work will open new scientific and technological pathways for sound management of renewable sources and deployment of protonics technology within innovative SMEs. The project is coordinated by Dr. Marit Stange, SINTEF with support from UiO. It trains one post-doc at UiO, has a budget of 10,233 MNOK and lasts 3 years.

Publications from Cristin

No publications found

No publications found

Funding scheme:

ENERGIX-Stort program energi