Advanced Processes Enabling Low cost and High Performing Large Scale Solid Oxide Electrolyser Production

Project Information

PilotSOEL

Grant agreement ID: 101112026

DOI

10.3030/101112026

EC signature date 3 May 2023

Start date 1 June 2023

End date 31 August 2026

Funded under

• Climate, Energy and Mobility

Total cost

€ 2 000 000,00

EU contribution

€ 2 000 000,00

Coordinated by

DANMARKS TEKNISKE UNIVERSITET
Denmark

Periodic Reporting for period 1 - PilotSOEL (Advanced Processes Enabling Low cost and High Performing Large Scale Solid Oxide Electrolyser Production)

Reporting period: 2023-06-01 to 2024-11-30

Summary of the context and overall objectives of the project

The EU hydrogen strategy has set an ambitious target to reach 80 GW of electrolysis by 2030. Meeting this target requires the EU to significantly upscale its manufacturing capacities for electrolysers from the current capacity of ca. 1.75 GW per year to 17.5 GW per year . Solid oxide electrolysis (SOEL) is a key enabling technology for highly efficient hydrogen production from the renewable electricity. For SOEL to be cost competitive to other technologies, mass production of all components including cells, interconnector (IC) plates, coatings and balance-of-plant (BoP) components is required. The manufacturing processes must be up-scaled and modified to reduce costs and thereby further bring down the hydrogen production price. A particular focus must be on increasing current density under operation and reducing the degradation rate of solid oxide cells and stacks, to meet the market expectations.
Taking into account the very ambitious target on installed electrolyser capacity, there is a need to secure the supply chain for materials that are not mined within the European Union. Designing and developing advanced production processes together with decreasing the amount of production wastes via recycling is needed to reduce the use of critical raw materials (CRM) and to enable reaching GW-level mass-manufacture.

The aim of PilotSOEL is to advance cheap green hydrogen production by developing large-scale and low-cost manufacturing of electrolyser system core components. PilotSOEL will develop and demonstrate solid oxide cells and stacks for high-current electrolysis operation, applying advanced scalable manufacturing processes to enable solid oxide electrolyser production at much lower cost than for today’s state-of-the-art (SoA) products. To achieve these goals, the PilotSOEL project will design and optimize the SOEL stack production chain for larger scale production and bring the “manufacturing readiness level” of the key components from MRL 4 to at least MRL 5.

Work performed from the beginning of the project to the end of the period covered by the report and main results achieved so far

In the first period of the project, significant progresses have been made on developing novel processes for solid oxide electrolysis stack manufacture, including cell manufacture and optimisation, inter-diffusion barrier deposition, interconnector coating deposition, optical inspection system for stack assembly and preliminary lifecycle analysis of the developed processes. More specifically:

A environmentally friendly water-based tape casting process has been developed and successfully manufactured half-cells with 12*12 cm2.
Two different inter-diffusion barrier layer deposition processes, PVD and ALD processes have been successfully developed for applying a <500 nm thin and dense layer. This can not only improve the cell performance but significantly reduce the raw material and CRM usage.
The most promising coating material, Cu-doped MnCO oxide, has been selected based on a comprehensive literature review. The substitution of Cu with Co will further reduce the CRM usage. A PVD coating process has been developed for deposition layers below 100 nm thickness.
Applying PVD coating on interconnectors can not only reduce the material usage, but also give very good corrosion protection properties. Recent test results showed an ASR <5 mohm*cm2 after more than 3000 hours operation.
Two generations of optical inspection systems have been designed and constructed. They will provide assistance in stack assembly and quality assurance.
Electrochemical test results show that cells with PVD interdiffusion barrier layer exhibit ca. 10-20% of performance improvement. And the second batch of optimized cells showed an excellent stability with <1%/1000 h degradation in the more than 2500 hours of operation.
A stack test station has been upgraded and a multichannel electrochemical work station has been constructed for stack test which is also capable of testing the final 20 kW demonstration stack.
The LCA model has been established with the preliminary input of the developed processes from partners.

Progress beyond the state of the art and expected potential impact (including the socio-economic impact and the wider societal implications of the project so far)

A co-casting procedure for water-based tape casting is under development, which will simplify the cell manufacture process, thus potentially reduce the cell production cost.
Further optimization of the cells to eliminate the degradation due to Ni migration is needed for further extending the cell's lifetime.
Optimization the PVD and ALD deposition process is required to reduce the total thickness variation (TTV) to below 15% thus ensure uniformity of the layer thickness.
Life cycle analysis and techno-economic assessment is ongoing to evaluate the novel processes developed in the PilotSOEL project with the SoA conventional processes.

PilotSOEL project overall concept

Corrosion test results of the coatings manufactured by PVD process

Microstructure of interconnector coating deposited by PVD process

Durability test result of the optimised cell