Advanced Manufacturing of Solid Oxide Electrodes Using ALD

The degradation in high steam environments of the fuel electrode in solid oxide electrolysis cells (SOECs) limits their commercial viability. Nickel migration in the fuel electrode due to long term operation at high overpotential reduces the amount of triple phase boundaries (TPBs), resulting in irreversible loss of electrochemical performance. This is the key degradation issue to solve to allow for wide-spread adoption of the unrivaled conversion efficiency (~90%) SOECs. RMD Inc. will address this challenge with the Atomic Layer Deposition (ALD) to grow an aluminum titanate (ALT) chemical anchor to prevent nickel migration without reducing the density of active TPBs, enhancing the lifetime of the SOECs. Within the regular processing temperature range, ALT to decomposes into TiO2 and Al2O3, which then react individually with the YSZ scaffold and Ni particles respectively to form the anchor. An ALD method is uniquely capable of forming thin layers of two oxides epitaxially to act as the anchor while being porous to maintain access by steam to the TPB for electrolysis of occur. RMD Inc. demonstrated the technical feasibility of applying a thin ALT coating to porous YSZ button cells. The resulting ALT anchor coating with proper activation, significantly improved the thermal stability of the nickel in button cells, improving the electrochemical performance as measured with IV polarization curves and EIS, and reducing the migration and agglomeration of nickel as shown in the SEM cross-sections. RMD Inc. plans to in Year 1 optimize the ALD growth parameters and activation of the ALT anchor. In Year 2 RMD plans to collaborate with OxEon Energy, LLC to integrate the ALD process in their SOEC manufacturing. Currently, two methods are envisioned 1) ALD infiltration into a YSZ scaffold cells and 2) a novel particle ALD (p-ALD) on the raw YSZ materials used to manufacture cells. Thus, developing processes to introduce ALD-ALT within SOEC manufacturing processes that can be integrated with various SOEC manufacturing techniques. The proposed development of the chemical anchor for the fuel electrode in SOECs will improve the long-term stability of SOECs, providing an efficient method of storing the excess energy from various low-cost and renewable electricity sources as hydrogen fuel, as well as the reverse in fuel cell mode to produce energy from chemical fuels. Additionally, SOECs can be utilized to generate oxygen for life support in the US manned space-flight programs and to generate oxygen from Mars’ atmosphere.