Towards Reliable High-Temperature Electrochemical Devices: Proton Conducting Ceramic Cells in Metal Supported Architecture

Kurzfassung

Electrochemical energy conversion from renewable resources offers promising routes to alternative energy resources, as well as to significant reduction of CO2 emission. For their functionality at high temperatures and high stability of the components, solid oxide cells (SOC) demonstrate many potential applications, e.g. fuel cells and Power-to-X (P2X) technologies, of high efficiency and durability for long term operation. P2X technologies cover various processes converting electric energy into heat, hydrogen or synthetic fuels, while reducing CO2 emission and providing huge capacity of energy storage. Proton conducting ceramic cells (PCC) were developed and their potentials for fuel cells and P2X applications were reported decades ago. The PCC geometry allows to supply and to produce pure hydrogen in fuel cell and steam electrolysis operations, respectively, which prevents fuel dilution and maintains PH2O low in Ni-based fuel electrode, in contrast to conventional SOCs. PCCs are also promising in the application of hydrogen extraction, pumping and compression as well as direct synthesis of hydrocarbons. However, the refractory character of the PCC electrolytes restricts upscaling of cell size and the manufacturing yield, and reliable air electrode materials are not yet well identified to realize highly efficient and reliable PCCs. In contrast to ceramic supported cells, metal supported (MS) architecture offers intrinsically superior mechanical strength, tolerance under thermal/re-dox cycles and cost reduction by replacing expensive ceramic based supporting materials with cheap metal alloys. One of the specific challenges is to find a process for the manufacturing of gas-tight electrolyte layers below 1000 °C that MS can withstand. Transferring the know-how and technologies developed on MS-SOCs with thin film electrolyte [1], here we report our development of MS-PCC in the project DAICHI (EIG CONCERT-Japan): Thin and dense electrolyte coatings of BaZrCeO3-based perovskites were successfully fabricated by pulsed laser deposition (PLD) technique implementing macro-/mesoporous electrode layers laminated onto ITM supports - commercial porous metallic substrate - having pore size of a few tens of micro m [2]. Latest status of the MS-PCC development will be presented and prospects and challenges will be discussed towards the manufacturing of robust, durable, efficient and cost-effective MS-PCCs.