Periodic Reporting for period 1 - NEWELY (Next Generation Alkaline Membrane Water Electrolysers with Improved Components and Materials)
Période du rapport: 2020-01-01 au 2021-06-30
A major global challenge for the 21st century is the sustainable provision of the increasing energy demanded by human activity. Green hydrogen, or hydrogen produced from renewable energy resources, is an important contender in the race, making electrolysers a key area of investment for many countries and economies. Electrolysers split water into hydrogen and oxygen, using electricity to do so. Of the three main low temperature water electrolysis technologies on the market, anion exchange membrane water electrolysis (AEMWE) combines the benefits of the other two (polymer electrolyte membrane water electrolysis and alkaline water electrolysis), but it is not yet competitive commercially, in terms of performance.
Objectives: NEWELY project aims to redefine AEMWE, surpassing the current state of AWE and bringing it one step closer to PEMWE in terms of efficiency but at lower cost. The three main technical challenges of AEMWE: membrane, electrodes and stack are addressed by 3 small-medium-enterprises (SME) with their successful markets related to each of these topics. They are supported by a group of 7 renowned R&D centers. In this period, the NEWELY consortium will develop a prototypic 5-cell stack with elevated hydrogen output pressure. It will contain highly conductive and stable anionic membranes as well as efficient and durable low-cost electrodes. It will reach twice the performance of the state of the art of AEMWE. The targeted performance of the NEWELY prototype will be validated in a 2,000 hours endurance test. The new AEMWE stack will lead to a significant cost reduction of water electrolysis boosting the competitiveness of green hydrogen.
Objectives: NEWELY project aims to redefine AEMWE, surpassing the current state of AWE and bringing it one step closer to PEMWE in terms of efficiency but at lower cost. The three main technical challenges of AEMWE: membrane, electrodes and stack are addressed by 3 small-medium-enterprises (SME) with their successful markets related to each of these topics. They are supported by a group of 7 renowned R&D centers. In this period, the NEWELY consortium will develop a prototypic 5-cell stack with elevated hydrogen output pressure. It will contain highly conductive and stable anionic membranes as well as efficient and durable low-cost electrodes. It will reach twice the performance of the state of the art of AEMWE. The targeted performance of the NEWELY prototype will be validated in a 2,000 hours endurance test. The new AEMWE stack will lead to a significant cost reduction of water electrolysis boosting the competitiveness of green hydrogen.
The project started with setting up the components' requirements and overview of the materials available.
IMC has developed novel 60 µm thin non-reinforced block copolymer anion exchange membrane with good mechanical properties, high conductivity (˃ 50 mS cm-1) and low area specific resistance, ASR (< 0.07 Ω cm2), at room temperature. Highly conductive binder, based on the same chemistry, was also developed and its binding capability for used catalyst, as well as high ionic conductivity, was proved. Preliminary stability tests showed high hydroxide stability.
KIST developed a method to measure the true hydroxide conductivity of AEM in water, and set up a tensile testing system, which allows to measure mechanical properties of membranes inside of water. KIST also developed a new membrane system, in which 1) polybenzimidazole nanofiber mats prepared by electrospinning are pore filled with the halogenated AEM precursor polymer (mTPBr or polymer from IMC), 2) the halomethylated polymer reacts with PBI amine groups, 3) the remaining halomethylated groups are quaternized by reaction with an amine. The thus engineered support/matrix interface is expected to mitigate formation of voids during electrolyser operation, which would increase gas crossover.
Ion exchange capacity measurement was acquired and optimized based on the UCTP procedure by the detection of the nitrate ions by UV-VIS spectroscopy. UCTP implemented the method of the true hydroxide conductivity of AEM measurement.
Membrasenz works on membrane upscaling with material and processes which hold potential to be rapid, cost effective and suitable for production of large material quantities.
CENmat upscaled the synthesis of the oxygen evolution reaction (OER) and hydrogen evolution reaction (HER) catalyst free of any critical raw materials and performed multiple tests to determine the catalyst performance in various AEM electrolyser cell configurations in different KOH concentrations. Furthermore, CENmat designed and synthesized various other OER and HER catalysts free of CRM.
The potential of the CENmat non-noble metal catalyst was demonstrated in CENmat test cell using commercial AEM, ionomer and PTL. In 0.1 M KOH 1.85 V @ 2 A/cm2 was achieved.
For a porous transport layer with optimized gas and liquid transport properties and reduced electrical contact resistance plasma-spray coated Nickel microporous layer (MPL) on stainless steel mesh was prepared at DLR. Due to the MPL a reduction of cell voltage was demonstrated. The developments were supported by many characterization methods to determine physical properties.
The methods of direct deposition of the catalyst layers on the surface of the AEM using sonicated dispersion deposition, automatic spray coating, doctor-blade coating and decal method were successfully modified to allow the catalyst coated membrane electrode assembly preparation. The processes were optimized in terms of catalyst layer composition.
Testing at single cell and stack level processes was agreed with the other two consortia involved in AEM WE technology. It is the ambition of the NEWELY project to reach the target performance in pure water or very diluted KOH with non-noble metal catalyst. Applying MEA preparation processes to project materials MEAs with PSEBS membrane from UCTP and catalyst from CENmat were tested in single cell. A sensitivity study with interesting results to the components that constitute the MEA was carried out. Full NEWELY components MEA (UCTP membrane and ionomer and CENmat catalyst) have achieved at the present state of the project 800 mA/cm²@2V in 0.1 M KOH and 50°C. This performance falls down to 100 mA/cm²@ 2 V in pure water at the same operating temperature. However, for the pure water tests relatively thick membranes were used, i.e. further ways to improve performance are seen. Preliminary tests also have shown that PSEBS are thermally quite stable, that means that NEWELY membranes could be operated at higher temperature (70~80°C) with a potential increase in performance.
According to the project plan new AEMWE test cells with 25cm2 area based on a patented hydraulic cell compression system were designed, built, delivered to and commissioned at the research partners for component testing and material screening. A test station for laboratory-scale test cells for the usage of ultra-pure water and optional KOH was developed and set up at the FBK lab.
A novel and innovative high-pressure AEMWE stack technology is recently being worked out.
To address the costs and environmental footprint of AEMWE and compare it the work has been started by collecting the numbers that will be used as a basis for the following techno-economic analysis (TEA) and life cycle assessment (LCA). The development in the NEWELY project will not reach industrial levels, thus it was initially necessary to identify the expected future size and performances of an AEMWE at MW size. Costs, electricity consumption, lifetime and component materials (main variables required to perform TEA and LCA) were collected from the partners as regards the AEMWE while the data for AWE and PEMWE were collected from literature.
IMC has developed novel 60 µm thin non-reinforced block copolymer anion exchange membrane with good mechanical properties, high conductivity (˃ 50 mS cm-1) and low area specific resistance, ASR (< 0.07 Ω cm2), at room temperature. Highly conductive binder, based on the same chemistry, was also developed and its binding capability for used catalyst, as well as high ionic conductivity, was proved. Preliminary stability tests showed high hydroxide stability.
KIST developed a method to measure the true hydroxide conductivity of AEM in water, and set up a tensile testing system, which allows to measure mechanical properties of membranes inside of water. KIST also developed a new membrane system, in which 1) polybenzimidazole nanofiber mats prepared by electrospinning are pore filled with the halogenated AEM precursor polymer (mTPBr or polymer from IMC), 2) the halomethylated polymer reacts with PBI amine groups, 3) the remaining halomethylated groups are quaternized by reaction with an amine. The thus engineered support/matrix interface is expected to mitigate formation of voids during electrolyser operation, which would increase gas crossover.
Ion exchange capacity measurement was acquired and optimized based on the UCTP procedure by the detection of the nitrate ions by UV-VIS spectroscopy. UCTP implemented the method of the true hydroxide conductivity of AEM measurement.
Membrasenz works on membrane upscaling with material and processes which hold potential to be rapid, cost effective and suitable for production of large material quantities.
CENmat upscaled the synthesis of the oxygen evolution reaction (OER) and hydrogen evolution reaction (HER) catalyst free of any critical raw materials and performed multiple tests to determine the catalyst performance in various AEM electrolyser cell configurations in different KOH concentrations. Furthermore, CENmat designed and synthesized various other OER and HER catalysts free of CRM.
The potential of the CENmat non-noble metal catalyst was demonstrated in CENmat test cell using commercial AEM, ionomer and PTL. In 0.1 M KOH 1.85 V @ 2 A/cm2 was achieved.
For a porous transport layer with optimized gas and liquid transport properties and reduced electrical contact resistance plasma-spray coated Nickel microporous layer (MPL) on stainless steel mesh was prepared at DLR. Due to the MPL a reduction of cell voltage was demonstrated. The developments were supported by many characterization methods to determine physical properties.
The methods of direct deposition of the catalyst layers on the surface of the AEM using sonicated dispersion deposition, automatic spray coating, doctor-blade coating and decal method were successfully modified to allow the catalyst coated membrane electrode assembly preparation. The processes were optimized in terms of catalyst layer composition.
Testing at single cell and stack level processes was agreed with the other two consortia involved in AEM WE technology. It is the ambition of the NEWELY project to reach the target performance in pure water or very diluted KOH with non-noble metal catalyst. Applying MEA preparation processes to project materials MEAs with PSEBS membrane from UCTP and catalyst from CENmat were tested in single cell. A sensitivity study with interesting results to the components that constitute the MEA was carried out. Full NEWELY components MEA (UCTP membrane and ionomer and CENmat catalyst) have achieved at the present state of the project 800 mA/cm²@2V in 0.1 M KOH and 50°C. This performance falls down to 100 mA/cm²@ 2 V in pure water at the same operating temperature. However, for the pure water tests relatively thick membranes were used, i.e. further ways to improve performance are seen. Preliminary tests also have shown that PSEBS are thermally quite stable, that means that NEWELY membranes could be operated at higher temperature (70~80°C) with a potential increase in performance.
According to the project plan new AEMWE test cells with 25cm2 area based on a patented hydraulic cell compression system were designed, built, delivered to and commissioned at the research partners for component testing and material screening. A test station for laboratory-scale test cells for the usage of ultra-pure water and optional KOH was developed and set up at the FBK lab.
A novel and innovative high-pressure AEMWE stack technology is recently being worked out.
To address the costs and environmental footprint of AEMWE and compare it the work has been started by collecting the numbers that will be used as a basis for the following techno-economic analysis (TEA) and life cycle assessment (LCA). The development in the NEWELY project will not reach industrial levels, thus it was initially necessary to identify the expected future size and performances of an AEMWE at MW size. Costs, electricity consumption, lifetime and component materials (main variables required to perform TEA and LCA) were collected from the partners as regards the AEMWE while the data for AWE and PEMWE were collected from literature.
By its performance and durability as well as the cost reduction potential the NEWELY stack will outperform current state of the art low temperature electrolysers.
Cells and stack with all NEWELY project material will reach a performance of 2 V @ 1 A/cm2 in pure water or very diluted KOH. The conductivity target of >50 mS/cm for the membrane has already been reached. The SME partners in the project are ambitious to commercialize the project results strengthening the European competitiveness in hydrogen technology.
Cells and stack with all NEWELY project material will reach a performance of 2 V @ 1 A/cm2 in pure water or very diluted KOH. The conductivity target of >50 mS/cm for the membrane has already been reached. The SME partners in the project are ambitious to commercialize the project results strengthening the European competitiveness in hydrogen technology.