Periodic Reporting for period 1 - Pressuriz3D (3D printing fabrication of tailored interfaces for pressurized Protonic Ceramic Electrolysis Cells)
Reporting period: 2023-07-01 to 2025-06-30
The MSCA fellowship project Pressuriz3D, launched on 1 July 2023, addresses a critical challenge in the deployment of protonic ceramic electrochemical cells (PCECs)—enabling high-efficiency, pressurised operation without the need for large and costly external containment vessels. PCECs have the potential to produce clean, dry, and compressed hydrogen directly from renewable sources at a lower temperature (300-650 °C) and with high efficiency (conversion rates of ≈80 %) compared to conventional solid oxide electrolysers. However, their industrial uptake has been limited by the difficulty of ensuring long-term material stability, reliable sealing, and cost-effective manufacturing for pressurised systems. In particular sealing for normal or pressurized operation is a critical issue due to chemical expansion in during hydration of the cells.
Pressuriz3D combines advanced materials science with additive manufacturing to deliver a new generation of PCEC designs tailored for robust pressurised operation. The project aligns with EU strategic priorities in the European Green Deal, the EU Hydrogen Strategy, and REPowerEU, contributing to the scale-up of clean hydrogen production technologies essential for decarbonisation and energy resilience.
In line with the Grant Agreement, the research is structured around three core objectives:
1. RO1 – Compatibility study
Identify and validate ceramic electrolyte and electrode materials for PCEC construction, focusing on their chemical and mechanical compatibility with advanced glass-based sealants under high-temperature, humidified, and pressurised conditions.
2. RO2 – 3D printing of PCEC components
Develop and optimise high-resolution additive manufacturing routes, including digital light process (DLP) and robocasting, to fabricate dense electrolytes, porous electrodes, and integrated glass-ceramic seals in complex geometries.
3. RO3 – Pressurised single repeating unit (SRU) demonstration
Integrate the developed components into a PCEC SRU and evaluate electrochemical performance under pressurised gas conditions, including microstructural and durability analysis, to validate suitability for high-efficiency hydrogen production.
By delivering novel sealing solutions and cost-efficient 3D printing methods for high-performance, pressurised PCECs, Pressuriz3D is expected to remove critical technological barriers, reduce system cost, and accelerate market readiness. The expected impact extends beyond the hydrogen sector, with potential application in fuel cells, solid-state reactors, and high-temperature gas separation technologies, thereby strengthening Europe’s position in clean energy innovation and advanced manufacturing.
Pressuriz3D combines advanced materials science with additive manufacturing to deliver a new generation of PCEC designs tailored for robust pressurised operation. The project aligns with EU strategic priorities in the European Green Deal, the EU Hydrogen Strategy, and REPowerEU, contributing to the scale-up of clean hydrogen production technologies essential for decarbonisation and energy resilience.
In line with the Grant Agreement, the research is structured around three core objectives:
1. RO1 – Compatibility study
Identify and validate ceramic electrolyte and electrode materials for PCEC construction, focusing on their chemical and mechanical compatibility with advanced glass-based sealants under high-temperature, humidified, and pressurised conditions.
2. RO2 – 3D printing of PCEC components
Develop and optimise high-resolution additive manufacturing routes, including digital light process (DLP) and robocasting, to fabricate dense electrolytes, porous electrodes, and integrated glass-ceramic seals in complex geometries.
3. RO3 – Pressurised single repeating unit (SRU) demonstration
Integrate the developed components into a PCEC SRU and evaluate electrochemical performance under pressurised gas conditions, including microstructural and durability analysis, to validate suitability for high-efficiency hydrogen production.
By delivering novel sealing solutions and cost-efficient 3D printing methods for high-performance, pressurised PCECs, Pressuriz3D is expected to remove critical technological barriers, reduce system cost, and accelerate market readiness. The expected impact extends beyond the hydrogen sector, with potential application in fuel cells, solid-state reactors, and high-temperature gas separation technologies, thereby strengthening Europe’s position in clean energy innovation and advanced manufacturing.
Within the Pressuriz3D project, significant progress was achieved in the development, evaluation, and integration of advanced materials and manufacturing routes for pressurized protonic ceramic electrochemical devices.
WP1 – Compatibility of electrolyte, glass sealant, and interconnect materials
A systematic compatibility study was performed between six Ba-based perovskite electrolyte compositions (with and without 1 wt% ZnO sintering aid), a commercial B/Ba-based glass sealant, and AISI 441 ferritic stainless-steel interconnects. Pellets were joined to metal interconnects at 700 °C for 30 min, subjected to six thermal cycles (50% air / 50% steam, up to 700 °C), and thermally aged at 600 °C for 500 h (50% air / 50% steam).
All joints remained mechanically intact after thermal exposure. The glass formed continuous, defect-free interfaces with both ceramic and metallic components. Localized crystallization occurred after ageing near the ceramic interface, involving Ca-, Ba-, and Al-rich phases, but without detrimental effects on adhesion or sealing integrity. ZnO-containing ceramics exhibited improved densification and fewer crystalline inclusions. No significant interdiffusion was observed at the ceramic/glass or metal/glass boundaries. Overall, the match between the B/Ba-based glass and the Ba-based perovskites demonstrated excellent chemical and mechanical stability, confirming their suitability for long-term, high-temperature, and humidified operation in pressurized solid oxide and protonic ceramic electrochemical devices.
WP2 – Additive manufacturing of dense ceramic membranes
Two complementary 3D printing approaches, Digital Light Processing (DLP) and robocasting, were explored for shaping dense BZY and BZCY electrolytes.
For DLP, BZY was selected over BZCY due to superior UV-curing behaviour. Thermal analysis guided a controlled three-step debinding cycle, followed by sintering at 1500 °C. Printed BZY membranes exhibited promising microstructural development, demonstrating the feasibility of DLP for electrolyte shaping.
In parallel, robocasting of BZCY using thermocurable yielded membranes with 99.5% theoretical density (6.15 g/cm³) after sintering at 1550 °C. SEM analysis confirmed crack-free, continuous structures. The inherent surface waviness from layer-by-layer deposition was retained and could be advantageous for electrode adhesion. As a first integration step, a porous BZCY–BLC composite electrode was applied and sintered at 1100 °C, achieving excellent adhesion and a favourable porous architecture.
WP3 – Electrode integration and electrochemical characterisation
A porous BZCY–BLC composite electrode was applied and sintered at 1100 °C on dense robocast BZCY membranes, achieving excellent adhesion and a favourable porous architecture. SEM revealed a defect-free, continuous electrode–electrolyte interface and a highly porous electrode structure conducive to gas transport.
Electrochemical testing with Ag, Au, and BLC electrodes under wet and dry air demonstrated clear proton conduction behaviour. The highest conductivity (~10⁻³ S·cm⁻¹ at 700 °C) was achieved with Ag electrodes in wet air (activation energy 1.1 eV). Conductivity decreased by one order of magnitude under dry air, with higher activation energies (1.3 eV), confirming hydration-dependent proton transport.
These results validate the use of thermocurable robocasting for producing high-quality, dense BZCY membranes and confirm their compatibility with porous electrodes for integration into protonic ceramic electrolysis and fuel cell devices.
WP1 – Compatibility of electrolyte, glass sealant, and interconnect materials
A systematic compatibility study was performed between six Ba-based perovskite electrolyte compositions (with and without 1 wt% ZnO sintering aid), a commercial B/Ba-based glass sealant, and AISI 441 ferritic stainless-steel interconnects. Pellets were joined to metal interconnects at 700 °C for 30 min, subjected to six thermal cycles (50% air / 50% steam, up to 700 °C), and thermally aged at 600 °C for 500 h (50% air / 50% steam).
All joints remained mechanically intact after thermal exposure. The glass formed continuous, defect-free interfaces with both ceramic and metallic components. Localized crystallization occurred after ageing near the ceramic interface, involving Ca-, Ba-, and Al-rich phases, but without detrimental effects on adhesion or sealing integrity. ZnO-containing ceramics exhibited improved densification and fewer crystalline inclusions. No significant interdiffusion was observed at the ceramic/glass or metal/glass boundaries. Overall, the match between the B/Ba-based glass and the Ba-based perovskites demonstrated excellent chemical and mechanical stability, confirming their suitability for long-term, high-temperature, and humidified operation in pressurized solid oxide and protonic ceramic electrochemical devices.
WP2 – Additive manufacturing of dense ceramic membranes
Two complementary 3D printing approaches, Digital Light Processing (DLP) and robocasting, were explored for shaping dense BZY and BZCY electrolytes.
For DLP, BZY was selected over BZCY due to superior UV-curing behaviour. Thermal analysis guided a controlled three-step debinding cycle, followed by sintering at 1500 °C. Printed BZY membranes exhibited promising microstructural development, demonstrating the feasibility of DLP for electrolyte shaping.
In parallel, robocasting of BZCY using thermocurable yielded membranes with 99.5% theoretical density (6.15 g/cm³) after sintering at 1550 °C. SEM analysis confirmed crack-free, continuous structures. The inherent surface waviness from layer-by-layer deposition was retained and could be advantageous for electrode adhesion. As a first integration step, a porous BZCY–BLC composite electrode was applied and sintered at 1100 °C, achieving excellent adhesion and a favourable porous architecture.
WP3 – Electrode integration and electrochemical characterisation
A porous BZCY–BLC composite electrode was applied and sintered at 1100 °C on dense robocast BZCY membranes, achieving excellent adhesion and a favourable porous architecture. SEM revealed a defect-free, continuous electrode–electrolyte interface and a highly porous electrode structure conducive to gas transport.
Electrochemical testing with Ag, Au, and BLC electrodes under wet and dry air demonstrated clear proton conduction behaviour. The highest conductivity (~10⁻³ S·cm⁻¹ at 700 °C) was achieved with Ag electrodes in wet air (activation energy 1.1 eV). Conductivity decreased by one order of magnitude under dry air, with higher activation energies (1.3 eV), confirming hydration-dependent proton transport.
These results validate the use of thermocurable robocasting for producing high-quality, dense BZCY membranes and confirm their compatibility with porous electrodes for integration into protonic ceramic electrolysis and fuel cell devices.
The project delivered two major advancements with strong potential impact for pressurized PCECs:
1. Novel glass sealant compatibility for PCECs – This is the first comprehensive demonstration of a commercial B/Ba-based glass showing excellent chemical, mechanical, and thermal stability when joined to different Ba-based perovskite electrolytes and ferritic stainless-steel interconnects under high-temperature, humidified, and pressurised conditions. The defect-free, stable interfaces and absence of detrimental interdiffusion address a key materials integration challenge for PCECs, enabling more reliable long-term operation.
2. Thermocurable-paste robocasting for dense protonic membranes – The development of a reproducible robocasting route using thermocurable pastes yielded fully dense, crack-free BZCY electrolytes with excellent electrode adhesion. This approach, scarcely reported in the literature, enables shaping complex, monolithic components with potential to reduce manufacturing costs and facilitate customised designs.
These results open pathways for next-generation PCEC stacks with improved durability and design flexibility. Further work should focus on long-term stack-level demonstrations, optimisation of 3D-printed architectures for performance enhancement, and engagement with industrial stakeholders to accelerate technology transfer and market uptake.
1. Novel glass sealant compatibility for PCECs – This is the first comprehensive demonstration of a commercial B/Ba-based glass showing excellent chemical, mechanical, and thermal stability when joined to different Ba-based perovskite electrolytes and ferritic stainless-steel interconnects under high-temperature, humidified, and pressurised conditions. The defect-free, stable interfaces and absence of detrimental interdiffusion address a key materials integration challenge for PCECs, enabling more reliable long-term operation.
2. Thermocurable-paste robocasting for dense protonic membranes – The development of a reproducible robocasting route using thermocurable pastes yielded fully dense, crack-free BZCY electrolytes with excellent electrode adhesion. This approach, scarcely reported in the literature, enables shaping complex, monolithic components with potential to reduce manufacturing costs and facilitate customised designs.
These results open pathways for next-generation PCEC stacks with improved durability and design flexibility. Further work should focus on long-term stack-level demonstrations, optimisation of 3D-printed architectures for performance enhancement, and engagement with industrial stakeholders to accelerate technology transfer and market uptake.