HIGH performing uLtrA-durable membraNe electroDe assEmblies for tRucks

Project Information

HIGHLANDER

Grant agreement ID: 101101346

DOI

10.3030/101101346

Project closed

EC signature date 8 December 2022

Start date 1 January 2023

End date 31 December 2025

Funded under

• Climate, Energy and Mobility

Total cost

€ 3 331 247,50

EU contribution

€ 3 331 247,50

Coordinated by

CENTRE NATIONAL DE LA RECHERCHE SCIENTIFIQUE CNRS
France

Periodic Reporting for period 2 - HIGHLANDER (HIGH performing uLtrA-durable membraNe electroDe assEmblies for tRucks)

Reporting period: 2024-07-01 to 2025-12-31

Summary of the context and overall objectives of the project

The objective of HIGHLANDER is to develop membrane electrode assemblies (MEAs) for Heavy-Duty Vehicles (HDV) with disruptive, novel components, targeting stack cost and size, durability, and fuel efficiency. The project will design, fabricate, and validate the HDV MEAs at cell and short stack level against heavy-duty relevant accelerated stress test and load profile test protocols. The unique approach of HIGHLANDER is to develop core fuel cell components in tandem, ensuring their greatest compatibility and lowest interface resistance: ionomer and reinforcement, catalyst and catalyst support, catalyst layer composition and property gradient in tune with the bipolar plate flow-field geometry. Materials screening efforts will be supported by the development and use of improved predictive degradation models bridging scales from reaction sites to cell level. Model parameterisation is implemented using experimental characterisation data at materials, component, and cell level. HIGHLANDER brings together a European supply chain of fuel cell materials and components producers and an OEM stack developer that makes this approach possible. HIGHLANDER aims to bring about a significant reduction in stack cost and fuel consumption through improvement of CCM performance and development of a new, lower cost single-layer gas diffusion layer. It will aim to achieve the 1.2 W/cm² at 0.65 V performance target at 0.3 g Pt/kW or below meeting a lifetime target of 20,000 h. Sustainability considerations include the development and benchmarking of fluorine-free membranes for HDV MEA application, the development of high performing and durable CCMs achieving <0.3 g Pt/kW, and re-use of platinum in the context of a circular economy.

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

Libraries of novel ordered intermetallic electrocatalysts for the oxygen reduction reaction at the fuel cell cathode were prepared and characterised ex situ and in situ for their activity and durability using internationally recognised accelerated stress test protocols. Dissolution trends of platinum-based intermetallic catalysts toward the acidic oxygen reduction reaction were monitored in-line using ICP-MS.
Cathode catalyst layers were developed having lower voltage decay rate in a single cell when using AST protocols and improved tolerance to multiple (air-air) start-up cycles compared to the project baseline.
Polymer nanofibre reinforced perfluorosulfonic acid membranes were prepared on a development coating line and target properties relating to performance and durability were demonstrated.
Three generations of novel sulfonated hydrocarbon ionomers were developed and their properties benchmarked against reference perfluorosulfonic acid membranes. The final analysis of hydrocarbon ionomers has helped define the gap in both performance and durability of these materials for use in heavy duty vehicles; this work will be invaluable for future strategic research directions.
A physics-based modelling framework for predicting polymer electrolyte membrane fuel cell performance and degradation over lifetime was developed and validated, fully coupling electrochemical, structural, and transport phenomena across multiple scales, from individual catalyst particles to the complete membrane electrode assembly.
A new low-cost single layer gas diffusion layer for both the anode and cathode side was developed. Produced with fewer and less expensive process steps, and with optimised material selection and pore structure, the low-cost GDL demonstrates benchmark performance up to 2 A/cm² under relevant conditions.
Final full-size cell catalyst coated membranes manufactured with a volume manufacturing compatible process with upscaled project catalyst and membrane materials and associated with the HIGHLANDER low cost GDL were operated in a short stack using a 500-hour accelerated stress test protocol correlated with a load profile test that was developed previously in the IMMORTAL project.
HIGHLANDER MEA performance in the short stack is 96% of the final target, being 1.16 W/cm2 at 1.85 A/cm2, with a catalyst loading of 0.26 g Pt/kW. The observed performance loss allows lifetime prediction exceeding 20,000 hours.
The HIGHLANDER project outcome simultaneously achieves the project KPIs of performance, PGM loading and durability, these targets also being those of the 2022 annual work programme and the SRIA low TRL targets for HDV for 2024.

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)

Development of fluorine-free (hydrocarbon) membranes that meet the properties of state of the art perfluorosulfonic acid membrane benchmark in specific scenarios, such as high-temperature, high-humidity conditions.
Development of high-performance polymer nanofibre-reinforced low equivalent weight perfluorosulfonic acid membranes integrating advanced chemical stabilisation additives with high durability in combined open circuit voltage – relative humidity cycles in a fuel cell at 90 °C.
Development of libraries of high mass activity ordered platinum-base metal alloy catalysts, and of a catalyst that demonstrated performance and durability better than that used in the existing commercial MEA.
Development of a low-cost single layer GDL for anode and cathode demonstrating benchmark performance up to 2 A/cm² under relevant conditions.
Development and validation of an integrated physics-based modelling framework for predicting polymer electrolyte membrane fuel cell performance and degradation over lifetime. This model links particle level degradation mechanisms to microstructural degradation and then to device level lifetime-performance.
Demonstration of achievement of all project KPIs with the HIGHLANDER MEA comprising HIGHLANDER catalyst, HIGHLANDER reinforced membrane and HIGHLANDER low-cost GDL reaching target performance with a catalyst loading of 0.26 g Pt/kW. This is significantly lower loading (factor 2) than the 0.5 g Pt/kW that was required with the baseline CCM associated with a commercial GDL.