Final Report Summary - IMMEDIATE (Innovative autoMotive MEa Development – implementation of Iphe-genie Achievements Targeted at Excellence)
Executive Summary:
IMMEDIATE aimed at developed a medium temperature proton exchange membrane fuel cell membrane electrode assembly for operation at up to 95 °C, with a Pt loading of 0.15 g Pt/kW, and using new materials developed during the project. In WP2, the specification and evaluation activities were focused on two areas: defining performance and durability for the MEAs in the case of city-bus use, and estimation of the cost of an alternative powertrain based on the cost of the MEA. The IMMEDIATE MEA shows excellent durability characteristics, since it degrades <10 % during 500 h of testing in aggressive bus-cycle tests. The cost estimate shows good improvement, with the cost share of the MEA decreasing significantly. Considerable reductions in the estimated total powertrain costs are expected, since the system parts contribute very heavily to the total costs. In WP3, new carbon support materials with intermediate surface area and optimised pore structure were designed and thoroughly characterised. Two catalyst preparation procedures were developed and optimised for the preparation of high-loading platinum catalysts, which were characterised for their Pt loading, Pt size and morphology. The catalysts were further evaluated for their electrochemical surface area, activity and stability. The most promising catalysts were up-scaled and transferred to WP6 for the preparation of MEAs. In WP4, a low equivalent weight short side chain ionomer was developed and short and long side chain cross-linkable ionomers were prepared. Preparation conditions suitable for a modulated degree of ionomer cross-linking were developed. An increased molecular weight short side chain ionomer was prepared and thin reinforced membranes prepared from it and provided to WP6. An effective means for stabilisation of membrane chemical properties was developed by laminating an electrospun ionomer nanofibre web comprising nanometric radical scavenger particles to give a composite membrane with an anode/cathode oriented protective layer. WP5 aimed at the understanding and improvement of gas-diffusion layers (GDLs) for MEAs with low precious metal content for operation under rather dry conditions with high electric efficiency. The activities focused on the improvement of electronic conductivity as well as on a suitable balancing of the gas diffusivity and water retention capabilities of the GDL. Substantial improvements with respect to dry performance and corrosion stability of the GDL were demonstrated with GDLs containing novel microporous layers consisting of graphite–carbon-nanotube blends. In WP6, initial MEA development was focused on the collection and assembling of state of the art component membrane, catalyst and gas diffusion layer materials to ink preparation processes and MEA preparation procedures. These materials were also used for initial ink and electrode optimisation. In the second period a significant amount of materials developed in WP3, WP4 and WP5 were all used for MEA integration and MEA development as they became available during the project period. Design of the electrode structure was done in an iterative way aiming at the manufacturing of the advanced electrodes with (ultra)thin catalytic layers. The optimisation work was guided by characterization of MEAs performed in WP7, where the testing comprised determination of IV performance, accelerated stress testing and diagnostic measurements. The durability of two embodiments of the low PGM loading 2G MEAs, identical apart from the nature of the cathode catalyst, was investigated in duty cycle test and EU harmonised test protocols for endurance testing. IMMEDIATE has achieved a significant reduction in Pt and, more generally, PGM loading with new set of materials and MEA processing developed during the course of the project, culminating in Pt loading of 0.27 g Pt/kW at 0.68 V (0.2 g/kW at maximum power density), for a MEAs of total loading 0.2 mg Pt/cm2. One indicator of IMMEDIATE success is that the performance at rated power is identical to the DoE 2015 status reported in the DoE MultiYear Research, Development and Demonstration Plan 2016 and, even more encouragingly, the performance 0.8 V exceeds the DoE 2015 status, and in fact achieves the DoE 2020 target for this metric, under EU harmonised protocol conditions.
Project Context and Objectives:
The overall objective of the IMMEDIATE project is to develop a medium temperature PEM MEA ºC that will fulfil the OEM requirements with respect to cost, performance and durability and and at the same time is a significant step towards the ultimate goal which is to have a PEM FC able to operate at >100ºC at minimal RH, Pt-loadings <0.15 g/kW at >55% efficiency and >5,000 h lifetime at dynamic operation. IMMEDIATE will do this by developing catalysts for PEM fuel cells to further reduce the use of platinum in the MEAs and increase catalyst performance and electrochemical stability, developing novel materials for gas diffusion layers (GDLs), optimising composition and morphology of both the micro-porous layer (MPL) and the electrodes, and developing new ionomers with high proton conductivity and high thermal and dimensional stability, all in combination with high-quality manufacturing methods and adequate testing of the MEAs.
The prime focus of the IMMEDIATE project was to the develop high-performing membrane–electrodes (MEAs) through materials R&D and process optimisation.
The technical targets for IMMEDIATE are as follows:
• Development of a durable membrane with
- Proton conductivity of at least 0.1 S/cm at 120ºC and <25% RH
- Proton conductivity >10 mS/cm at -0ºC
- Thermal stability up to 160ºC
- Low dimensional changes (<10%, <25% RH/>99% RH, 10 000 cycles)
• Development of a GDL with
- Through plane conductivity >2 S/cm at nominal operating conditions
- In plane conductivity >100 S/cm at nominal operating conditions
• Development of MEAs with the following targets
- Platinum loading of <0.15 g Pt/kW
- BOL performance of >1.0 W/cm2 @ UCell=0.68 V, nominal operating conditions
- EOL performance of >0.9 W/cm2 @ UCell=0.68 V, nominal operating conditions
- The produced MEAs will be subject to automotive accelerated stress test (AST) protocols to ensure that the EOL performance is probable after 5,000 hours of operation
- Operation temperature range -25ºC to 130ºC, nominal 120ºC
- Production method that can be scaled to produce MEA’s with >300 cm2 active surface area
The achievement of the overall targets for the MEA requires comprehensive component integration and MEA testing. The reduction of the MEA cost is largely related to the catalyst loading, whereas the per-formance, stability, and durability of the MEA is dependent on all the involved components and the inter-play between them, which again depends on the applied MEA processing technology.
The approach on the IMMEDIATE project was based on improvement and incorporation of com-mercially available pre-cursers and during the project incoporate the new innovative materials for which the proof of concept has already been given. The aim is to significantly increase existing automotive per-formance and durability by developing:
• Novel catalyst support materials with tailored surfaces and pore structure will be developed, tuned to optimise both the Pt utilisation and the mass transport of the reactants and products
• Innovative low equivalent weight cross-linking PFSA ionomers and catalysts that survive the high temperature and low RH by improvement of the oxidation durability and the proton conductivity
• Innovative (cross-linked) low-equivalent weight ionomer will be used for the fabrication of the membrane ensuring an enhanced proton transport and improved oxidation stability
• In order to further improve proton conduction in the catalytic layer under the conditions of quasi-dry operation at elevated temperature routes to modify the ionomer with inorganic particles such as zirconium phosphate or silica will be explored
• GDL materials and MPL will be further optimised for improved water and gas management
The mutual compatibility of materials and their durability shall be verified by assembling high perfor-mance MEAs for benchmarking purposes and for testing, in which use will be made of commonly accept-ed automotive test cycles (including start-stop and freeze/thaw cycles) to prove their potential.
Specific WP objectives
WP1: Coordination and Management
The main objective in coordination and management for the project is:
• Financial management
• Communication and interface between the FCH-JU officers, the project and its partners
• Coordinate the scientific and technical activities of the project
• Establish communication tools and interactions between the partners
• Coordinate and finalise deliverable and milestone reports, technical progress reports and financial reports
WP2: Specification and evaluation
The specific objective of WP2 on the 0M-18M period was to specify MEA test protocols with the operational window to be applied in WP7 and the delivery test protocol defining the real-life load on/off cycles of the final fuel cell system.
WP3: Catalyst
The overall objectives of WP3 (as described in the DOW) are as follows:
• Develop durable carbon supports with tailored mesopores in the range of 10-50 nm
• Develop non-carbon oxide, carbide and nitride supports for Pt catalysts
• Precipitate high load platinum catalyst on the developed supports
WP4: Membrane and ionomer
The overall WP objective is to develop a new, durable ionomer and membrane, including a composite membrane system comprising radical scavengers, based on low equivalent weight cross-linkable PFSA-polymers that possess high proton conductivity (>100 mS/cm @ 120°C & 25% RH), high thermal stability (up to 160°C), and high dimensional stability (<10% change upon wetting/drying) enabling automobile fuel cell operation in a wide temperature range (–25°C to 95°C) and in a low humidity (<25% RH) environment.
WP5: GDL
WP5 aims at identifying the specific material properties, which are required for the gas diffusion layers (GDL) under the rather unusual operating conditions given within IMMEDIATE. In particular, this work package is dedicated to the development of a novel gas diffusion layer grade, which effectively prevents dehydration of the proton exchange membrane at elevated temperatures. In order to attain the desired power density at the desired electric efficiency (55%), additional improvement of the thermal and electrical conductivity will become necessary.
WP6: MEA
The overall objective of WP6 is to fabricate durable high yielding MEAs with low catalyst loading (<0.15mg Pt/cm2). The final key-target for the IMMEDIATE project is a MEA capable of dynamic opera-tion starting at temperatures down to -25ºC yielding 1.0 W/cm2 @ @ ηel >55% at the nominal operational conditions (T=95ºC, RH ≤25% & P <1.5 bar(abs).
The goal defined for the 1XG MEA is a performance >0.5 W/cm2 @ ηel >55%, Temperature ≥80ºC, RH ≤ 50%/30% & P≤ 2.3/2.5 Bar and < 0.3 mg Pt/cm2
The goal defined for the 2G MEA is a performance > 1.0 W/cm2 @ ηel >55%, Temperature ≥95ºC, RH ≤25% and P ≤1.5 Barabs and <0.15 mg Pt/cm2 but with special focus at the EU harmonized protocol as a standard for the FC community agreed upon (T ≥ 80 ºC, RH ≤ 50%/30% & P≤ 2.3/2.5 Bar and < 0.15 mg Pt/cm2
.
WP7: Test
The objective is to assess the performance and durability of the MEAs developed in IMMEDIATE, on the basis of MEA single cell tests and in the second period of the project in short stack tests.
WP8: Dissemination
To ensure that the results and developments of the project are disseminated. The dissemination will be done by presenting the project results through a dedicated website, in workshops, conferences and publi-cations in scientific journals and the general press. The specific objective for RP1 was to release the pro-ject web site, and to initiate the presentation of non-confidential results at international conferences.
Project Results:
Please refer to uploaded document
Potential Impact:
Please refer to uplaoded document
List of Websites:
• Public website: http://www.immediate.ird.dk/
Madeleine Odgaard: maod@ewii.com
IMMEDIATE aimed at developed a medium temperature proton exchange membrane fuel cell membrane electrode assembly for operation at up to 95 °C, with a Pt loading of 0.15 g Pt/kW, and using new materials developed during the project. In WP2, the specification and evaluation activities were focused on two areas: defining performance and durability for the MEAs in the case of city-bus use, and estimation of the cost of an alternative powertrain based on the cost of the MEA. The IMMEDIATE MEA shows excellent durability characteristics, since it degrades <10 % during 500 h of testing in aggressive bus-cycle tests. The cost estimate shows good improvement, with the cost share of the MEA decreasing significantly. Considerable reductions in the estimated total powertrain costs are expected, since the system parts contribute very heavily to the total costs. In WP3, new carbon support materials with intermediate surface area and optimised pore structure were designed and thoroughly characterised. Two catalyst preparation procedures were developed and optimised for the preparation of high-loading platinum catalysts, which were characterised for their Pt loading, Pt size and morphology. The catalysts were further evaluated for their electrochemical surface area, activity and stability. The most promising catalysts were up-scaled and transferred to WP6 for the preparation of MEAs. In WP4, a low equivalent weight short side chain ionomer was developed and short and long side chain cross-linkable ionomers were prepared. Preparation conditions suitable for a modulated degree of ionomer cross-linking were developed. An increased molecular weight short side chain ionomer was prepared and thin reinforced membranes prepared from it and provided to WP6. An effective means for stabilisation of membrane chemical properties was developed by laminating an electrospun ionomer nanofibre web comprising nanometric radical scavenger particles to give a composite membrane with an anode/cathode oriented protective layer. WP5 aimed at the understanding and improvement of gas-diffusion layers (GDLs) for MEAs with low precious metal content for operation under rather dry conditions with high electric efficiency. The activities focused on the improvement of electronic conductivity as well as on a suitable balancing of the gas diffusivity and water retention capabilities of the GDL. Substantial improvements with respect to dry performance and corrosion stability of the GDL were demonstrated with GDLs containing novel microporous layers consisting of graphite–carbon-nanotube blends. In WP6, initial MEA development was focused on the collection and assembling of state of the art component membrane, catalyst and gas diffusion layer materials to ink preparation processes and MEA preparation procedures. These materials were also used for initial ink and electrode optimisation. In the second period a significant amount of materials developed in WP3, WP4 and WP5 were all used for MEA integration and MEA development as they became available during the project period. Design of the electrode structure was done in an iterative way aiming at the manufacturing of the advanced electrodes with (ultra)thin catalytic layers. The optimisation work was guided by characterization of MEAs performed in WP7, where the testing comprised determination of IV performance, accelerated stress testing and diagnostic measurements. The durability of two embodiments of the low PGM loading 2G MEAs, identical apart from the nature of the cathode catalyst, was investigated in duty cycle test and EU harmonised test protocols for endurance testing. IMMEDIATE has achieved a significant reduction in Pt and, more generally, PGM loading with new set of materials and MEA processing developed during the course of the project, culminating in Pt loading of 0.27 g Pt/kW at 0.68 V (0.2 g/kW at maximum power density), for a MEAs of total loading 0.2 mg Pt/cm2. One indicator of IMMEDIATE success is that the performance at rated power is identical to the DoE 2015 status reported in the DoE MultiYear Research, Development and Demonstration Plan 2016 and, even more encouragingly, the performance 0.8 V exceeds the DoE 2015 status, and in fact achieves the DoE 2020 target for this metric, under EU harmonised protocol conditions.
Project Context and Objectives:
The overall objective of the IMMEDIATE project is to develop a medium temperature PEM MEA ºC that will fulfil the OEM requirements with respect to cost, performance and durability and and at the same time is a significant step towards the ultimate goal which is to have a PEM FC able to operate at >100ºC at minimal RH, Pt-loadings <0.15 g/kW at >55% efficiency and >5,000 h lifetime at dynamic operation. IMMEDIATE will do this by developing catalysts for PEM fuel cells to further reduce the use of platinum in the MEAs and increase catalyst performance and electrochemical stability, developing novel materials for gas diffusion layers (GDLs), optimising composition and morphology of both the micro-porous layer (MPL) and the electrodes, and developing new ionomers with high proton conductivity and high thermal and dimensional stability, all in combination with high-quality manufacturing methods and adequate testing of the MEAs.
The prime focus of the IMMEDIATE project was to the develop high-performing membrane–electrodes (MEAs) through materials R&D and process optimisation.
The technical targets for IMMEDIATE are as follows:
• Development of a durable membrane with
- Proton conductivity of at least 0.1 S/cm at 120ºC and <25% RH
- Proton conductivity >10 mS/cm at -0ºC
- Thermal stability up to 160ºC
- Low dimensional changes (<10%, <25% RH/>99% RH, 10 000 cycles)
• Development of a GDL with
- Through plane conductivity >2 S/cm at nominal operating conditions
- In plane conductivity >100 S/cm at nominal operating conditions
• Development of MEAs with the following targets
- Platinum loading of <0.15 g Pt/kW
- BOL performance of >1.0 W/cm2 @ UCell=0.68 V, nominal operating conditions
- EOL performance of >0.9 W/cm2 @ UCell=0.68 V, nominal operating conditions
- The produced MEAs will be subject to automotive accelerated stress test (AST) protocols to ensure that the EOL performance is probable after 5,000 hours of operation
- Operation temperature range -25ºC to 130ºC, nominal 120ºC
- Production method that can be scaled to produce MEA’s with >300 cm2 active surface area
The achievement of the overall targets for the MEA requires comprehensive component integration and MEA testing. The reduction of the MEA cost is largely related to the catalyst loading, whereas the per-formance, stability, and durability of the MEA is dependent on all the involved components and the inter-play between them, which again depends on the applied MEA processing technology.
The approach on the IMMEDIATE project was based on improvement and incorporation of com-mercially available pre-cursers and during the project incoporate the new innovative materials for which the proof of concept has already been given. The aim is to significantly increase existing automotive per-formance and durability by developing:
• Novel catalyst support materials with tailored surfaces and pore structure will be developed, tuned to optimise both the Pt utilisation and the mass transport of the reactants and products
• Innovative low equivalent weight cross-linking PFSA ionomers and catalysts that survive the high temperature and low RH by improvement of the oxidation durability and the proton conductivity
• Innovative (cross-linked) low-equivalent weight ionomer will be used for the fabrication of the membrane ensuring an enhanced proton transport and improved oxidation stability
• In order to further improve proton conduction in the catalytic layer under the conditions of quasi-dry operation at elevated temperature routes to modify the ionomer with inorganic particles such as zirconium phosphate or silica will be explored
• GDL materials and MPL will be further optimised for improved water and gas management
The mutual compatibility of materials and their durability shall be verified by assembling high perfor-mance MEAs for benchmarking purposes and for testing, in which use will be made of commonly accept-ed automotive test cycles (including start-stop and freeze/thaw cycles) to prove their potential.
Specific WP objectives
WP1: Coordination and Management
The main objective in coordination and management for the project is:
• Financial management
• Communication and interface between the FCH-JU officers, the project and its partners
• Coordinate the scientific and technical activities of the project
• Establish communication tools and interactions between the partners
• Coordinate and finalise deliverable and milestone reports, technical progress reports and financial reports
WP2: Specification and evaluation
The specific objective of WP2 on the 0M-18M period was to specify MEA test protocols with the operational window to be applied in WP7 and the delivery test protocol defining the real-life load on/off cycles of the final fuel cell system.
WP3: Catalyst
The overall objectives of WP3 (as described in the DOW) are as follows:
• Develop durable carbon supports with tailored mesopores in the range of 10-50 nm
• Develop non-carbon oxide, carbide and nitride supports for Pt catalysts
• Precipitate high load platinum catalyst on the developed supports
WP4: Membrane and ionomer
The overall WP objective is to develop a new, durable ionomer and membrane, including a composite membrane system comprising radical scavengers, based on low equivalent weight cross-linkable PFSA-polymers that possess high proton conductivity (>100 mS/cm @ 120°C & 25% RH), high thermal stability (up to 160°C), and high dimensional stability (<10% change upon wetting/drying) enabling automobile fuel cell operation in a wide temperature range (–25°C to 95°C) and in a low humidity (<25% RH) environment.
WP5: GDL
WP5 aims at identifying the specific material properties, which are required for the gas diffusion layers (GDL) under the rather unusual operating conditions given within IMMEDIATE. In particular, this work package is dedicated to the development of a novel gas diffusion layer grade, which effectively prevents dehydration of the proton exchange membrane at elevated temperatures. In order to attain the desired power density at the desired electric efficiency (55%), additional improvement of the thermal and electrical conductivity will become necessary.
WP6: MEA
The overall objective of WP6 is to fabricate durable high yielding MEAs with low catalyst loading (<0.15mg Pt/cm2). The final key-target for the IMMEDIATE project is a MEA capable of dynamic opera-tion starting at temperatures down to -25ºC yielding 1.0 W/cm2 @ @ ηel >55% at the nominal operational conditions (T=95ºC, RH ≤25% & P <1.5 bar(abs).
The goal defined for the 1XG MEA is a performance >0.5 W/cm2 @ ηel >55%, Temperature ≥80ºC, RH ≤ 50%/30% & P≤ 2.3/2.5 Bar and < 0.3 mg Pt/cm2
The goal defined for the 2G MEA is a performance > 1.0 W/cm2 @ ηel >55%, Temperature ≥95ºC, RH ≤25% and P ≤1.5 Barabs and <0.15 mg Pt/cm2 but with special focus at the EU harmonized protocol as a standard for the FC community agreed upon (T ≥ 80 ºC, RH ≤ 50%/30% & P≤ 2.3/2.5 Bar and < 0.15 mg Pt/cm2
.
WP7: Test
The objective is to assess the performance and durability of the MEAs developed in IMMEDIATE, on the basis of MEA single cell tests and in the second period of the project in short stack tests.
WP8: Dissemination
To ensure that the results and developments of the project are disseminated. The dissemination will be done by presenting the project results through a dedicated website, in workshops, conferences and publi-cations in scientific journals and the general press. The specific objective for RP1 was to release the pro-ject web site, and to initiate the presentation of non-confidential results at international conferences.
Project Results:
Please refer to uploaded document
Potential Impact:
Please refer to uplaoded document
List of Websites:
• Public website: http://www.immediate.ird.dk/
Madeleine Odgaard: maod@ewii.com
