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.
