Report

Teaser, summary, work performed and final results

Periodic Reporting for period 2 - SElySOs (Development of new electrode materials and understanding of degradation mechanisms on Solid Oxide High Temperature Electrolysis Cells.)

Teaser

The high temperature Solid Oxide Electrolysis (SOEC) technology has a huge potential for future mass production of hydrogen (and synthesis gas) and shows great dynamics to become commercially competitive against other electrolysis technologies (AEL, PEMEL), which are better...

Summary

The high temperature Solid Oxide Electrolysis (SOEC) technology has a huge potential for future mass production of hydrogen (and synthesis gas) and shows great dynamics to become commercially competitive against other electrolysis technologies (AEL, PEMEL), which are better established but more expensive and less efficient. However, SOECs are less mature and performance plus durability are currently the most important issues that need to be tackled. Currently, the investigation on degradation mechanisms for SOECs is on primary stage and in general the reported data are not based on standardized testing conditions. Indicatively, various experimental parameters like the operation temperature and mode (galvanostatic or potentiostatic), the current density and the absolute humidity, vary among the reported publications. Last but not least, there are important diversifications in the published data, which are attributed to the different kind of measurements for example between single cell and stack systems, as well as between the examined cell configurations (e.g. planar or tubular, electrolyte-, anode- or metal-supported).

In this respect, the consortium of SElySOs is taking advantage of the opportunity for a 4-years duration project and focuses on understanding of the degradation and lifetime fundamentals on both of the SOEC electrodes, for minimization of their degradation and improvement of their performance and stability mainly under H2O electrolysis and in a certain extent under H2O/CO2 co-electrolysis conditions. The successful development of efficient electrodes of stable structure for long-life functioning under SOEC operating conditions is solely depended on applied research and deeper understanding of the parameters affecting the electrocatalytic properties and the stability of electrodes’ microstructure under operating conditions. These prerequisites are perfectly aligned with the planned Technology Readiness Level of the launched topic, starting from 3 and aiming to reach 5 by the end of the project.

In brief, the prime objective of SELySOs is to improve or develop new more efficient electrodes and understand the reaction mechanisms and processes that cause degradation on both SOEC electrodes, by combining experiments with theoretical modeling over an extended range of operating conditions. This is accomplished by using a targeted number of modified SoA Ni-based and perovskite-type electrocatalysts both for the H2O and O2 electrodes. Moreover, the technical goal of the project is to identify the key design parameters and acquire the necessary knowledge to guide the development of new SOECs less prone to degradation with improved performance and stability.

Work performed

The 1st Period Progress report describes the project objectives, work progress and achievements, as well as project management during the 1st Reporting Period of the SElySOs project. This concise overview of the objectives and the progress of work is given in reference with the structure of Description of Work (DoW) of the Grant Agreement. The so far performed work comprises:

Development of efficient, durable fuel (cathode) electrodes, through the preparation of two type of materials (a) Ni-based: Au – Mo – BaO – modified NiO/GDC by using commercially available NiO/GDC powder and (b) Ni-free perovskite materials of the type La0.75Sr0.25Cr0.9M0.1O3 (M=Mn, Fe, Co and Ni)

Development of SOEC air (anode) electrodes from new materials and more specifically nickelates.

Advanced thorough physicochemical characterization of the developed materials

Single SOEC measurements aiming to study the effect of the cathode electrode development on: (i) the performance mainly under H2O electrolysis conditions and in a certain extent for the H2O/CO2 co-electrolysis.

Single SOEC measurements aiming to study degradation on (i) SoA anodes and (ii) the effect of the new developed anode air electrodes.

Development of a detailed mathematical model accounting for all reactions taking place in a SOEC for the H2O electrolysis and H2O/CO2 co-electrolysis processes

Fabrication of single cells (electrolyte or electrode-supported) by applying SoA fabrication techniques and Thermal Spraying.

Elaboration of manufacture approaches for the construction of a 1st short SOEC stack

Dissemination and project management activities

Final results

The SElySOs project promises to deliver efficient and tolerant to degradation cathodes (comprising modified Ni-based or perovskite anodes) and anodes (perovskites), modeling (for understanding degradation), novel cells’ fabrication methods (thermal spraying), production design and techniques (scaled-up of manufacturing processes), and prototype SOEC stacks both for water electrolysis and CO2/H2O co-electrolysis. It also addresses the need to connect research science and commercialization. Within the course of SElySOs project the R&D activities are mainly focused on the development of the novel materials, components and their combinations, while in parallel the selected materials will undergo scaling up processes in order to arrive at feasible choices in sight of their application. Validation of their performance will last until the end of the project and will give input to a design model that will project the actual application of the SElySOs concepts for a hydrogen filling station of MW scale. Given the lack of an established market and the imperative need for advanced materials, on the one side, and the step change improvements anticipated through the SElySOs, on the other side, a high innovation potential is recognized. The project introduces a differentiated market offering, which is re-positioned towards similar products (e.g. the well-defined global market of SOFCs) and it is considered as capable of expanding products portfolio and render a distinguished share in the electrolytic hydrogen production market.

Electrolytic hydrogen production represents 4% of the global hydrogen production (65 million tons), a market which is today dominated by conventional alkaline electrolysis, accounting for practically the entire installed capacity worldwide. Solid oxide electrolysis is the least advanced technology, which holds though great promise for (a) cost reduction as operation at high temperature can produce hydrogen with much lower electricity inputs than conventional electrolyzers offering higher electrical system efficiency (a significant share of the energy input can be provided in the form of heat, preferably low-cost waste heat) and (b) syngas, and thus hydrocarbons (such as liquid fuels), production when operated as co-electrolyzer of both steam and CO2 (CO2 utilization and upgrade). The driving force for the hoped-for development in SOECs is strongly economic, namely cost reduction.

With respect to this development momentum, SElySOs project addresses cost effective electrolytic hydrogen production in SOE offering substantial development and step change improvements regarding efficiency and lifetime of a high-potential final product that aims to encompass research innovation with market orientation, leveraging the current Technology Readiness Level from 3 to 5.
In total, it is believed that the final outcome of SElySOs will be a useful contribution to the scientific and industrial sector.

Website & more info

More info: http://selysos.iceht.forth.gr/.