Periodic Reporting for period 4 - NanoMMES (Design and NanoEngineering of Microporous Membranes for Energy Storage)
Periodo di rendicontazione: 2024-05-01 al 2025-04-30
To meet the Paris Agreement's target of limiting global warming to 1.5 °C, CO2 emissions must be significantly reduced. The EU 2030 Climate and Energy Framework targets a 40% cut in greenhouse gas emissions and a >27% share of renewable energy. While solar and wind deployment grows rapidly, their intermittency leads to supply-demand mismatch and grid instability. Large-scale, long-duration, cost-effective energy storage systems are urgently needed to integrate renewable energy.
Redox flow batteries (RFBs) are promising due to their ability to decouple energy and power. However, commercialisation is hindered by the cost and limitations of existing membranes, particularly Nafion (~$500/m²), which can represent up to 30% of the stack cost. This project aimed to design new ion-selective membranes combining high conductivity, selectivity, chemical stability, and manufacturability using advanced polymer chemistry and process engineering.
The overall goal was to deliver new membrane design principles that will accelerate the development of affordable, scalable clean energy technologies and contribute to the EU's decarbonisation agenda.
Conclusions of the Action
The project achieved key breakthroughs:
A diverse library of ion exchange membranes was created with improved ion selectivity, conductivity, and chemical stability, including PIM-based and PEEK-based designs (Nature Materials 2020; Angew. Chem. Int. Ed. 2020, 2022; Nature Communications 2022; Joule 2022, 2025).
Mechanistic understanding of ion transport through hydrated nanochannels was developed via in situ characterisation and molecular modelling.
New membranes were successfully integrated into RFB prototypes, demonstrating high efficiency, stability, and long operational life.
One patent application was filed and findings were disseminated via 16+ high-impact publications and major international conferences.
The outcomes laid the groundwork for future membrane and electrochemical device development, fostered industry collaborations, and opened paths for commercialisation and policy impact.
Redox flow batteries (RFBs) are promising due to their ability to decouple energy and power. However, commercialisation is hindered by the cost and limitations of existing membranes, particularly Nafion (~$500/m²), which can represent up to 30% of the stack cost. This project aimed to design new ion-selective membranes combining high conductivity, selectivity, chemical stability, and manufacturability using advanced polymer chemistry and process engineering.
The overall goal was to deliver new membrane design principles that will accelerate the development of affordable, scalable clean energy technologies and contribute to the EU's decarbonisation agenda.
Conclusions of the Action
The project achieved key breakthroughs:
A diverse library of ion exchange membranes was created with improved ion selectivity, conductivity, and chemical stability, including PIM-based and PEEK-based designs (Nature Materials 2020; Angew. Chem. Int. Ed. 2020, 2022; Nature Communications 2022; Joule 2022, 2025).
Mechanistic understanding of ion transport through hydrated nanochannels was developed via in situ characterisation and molecular modelling.
New membranes were successfully integrated into RFB prototypes, demonstrating high efficiency, stability, and long operational life.
One patent application was filed and findings were disseminated via 16+ high-impact publications and major international conferences.
The outcomes laid the groundwork for future membrane and electrochemical device development, fostered industry collaborations, and opened paths for commercialisation and policy impact.
1. Membrane Design and Synthesis
We developed new families of ion-selective membranes through rational polymer engineering. A focus was placed on polymers of intrinsic microporosity (PIMs), where we tuned pore size distribution by manipulating backbone geometry, pendant groups, and contorted monomer structures (Nature Materials, 2020). First-generation PIMs were synthesised by double aromatic nucleophilic substitution and modified into ion-conductive membranes via amidoxime and Tröger’s Base functionalities.
Further design enabled enhanced selectivity and transport (Angew. Chem. Int. Ed., 2022). Sulfonated PIMs were developed and demonstrated high proton/salt conductivity and chemical stability in flow batteries (Angew. Chem. Int. Ed., 2020; Nat. Commun., 2022). We extended sulfonation to spirobifluorene and triptycene-modified PEEK backbones, leading to PIM-PEEK membranes that overcome the typical conductivity-selectivity trade-off (Joule, 2025).
By adjusting pendant group hydrophobicity, we could finely control water channel formation and hydration levels, enhancing selectivity in aqueous organic RFBs (Nature, 2024). Ether-free, fully aromatic PIMs provided superior stability, and one was patented (WO2025056591), with pending publications. Additionally, we explored MOFs as ion-conductive materials for solid-state batteries (Dalton Trans., 2020; manuscript in prep).
2. Membrane Manufacturing and Characterisation
We developed advanced membrane fabrication techniques, including solution-cast dense membranes, thin-film composites, and hybrid architectures. Key characterisation methods included in situ spectroscopy, SAXS, NMR, and electrochemical impedance spectroscopy, allowing us to elucidate ion pathways and water structuring.
Computational modelling was used to generate molecular-level insights into transport mechanisms. The resulting design rules informed the development of membranes with enhanced performance across acidic, neutral, and alkaline conditions.
We also established collaborations with Dalian Institute of Chemical Physics and the University of Cambridge to gain access to roll-to-roll processing facilities, enabling scale-up to square-metre scale production for large-area testing.
3. Integration into Energy Storage Systems
Membranes were tested in aqueous RFBs using anthraquinones and ferro/ferricyanide (Angew. Chem. Int. Ed., 2020; Nat. Commun., 2022), demonstrating high energy efficiency and long cycle life at neutral pH. Alkaline and acidic electrolyte systems (e.g. Zn–Fe, polysulfide, H2–Mn) were also developed (Joule 2022, 2025; Nat. Commun. 2022).
Beyond RFBs, membranes were applied to water electrolysers and electrodialysis for lithium extraction. In alkaline water electrolysis, membranes enabled efficient and durable hydrogen production, with work presented at major conferences.
Main Achievements
20+ advanced membranes developed and validated in multiple energy and separation applications.
20 high-impact publications (e.g. Nature Materials, Joule, Nat. Commun., Angew. Chem., Adv. Mater., JACS).
One patent application filed for new membrane chemistries and processes.
Presentations at major international conferences (IMSTEC, ICOM, EuroMembrane, MRS, ACS, NMSUM, MC16, IUPAC 2023).
Collaborations established with academic and industrial partners.
Exploitation and Dissemination
Dissemination was achieved through open-access publications, conferences, webinars, and stakeholder events. Results were also communicated to policymakers and the public via institutional channels.
Exploitation outcomes include:
Patent evaluations for licensing.
Two potential spin-out ventures in membrane materials and electrochemical systems.
Follow-on EU and national funding secured (e.g. ERC PoC 2023, 2025).
We developed new families of ion-selective membranes through rational polymer engineering. A focus was placed on polymers of intrinsic microporosity (PIMs), where we tuned pore size distribution by manipulating backbone geometry, pendant groups, and contorted monomer structures (Nature Materials, 2020). First-generation PIMs were synthesised by double aromatic nucleophilic substitution and modified into ion-conductive membranes via amidoxime and Tröger’s Base functionalities.
Further design enabled enhanced selectivity and transport (Angew. Chem. Int. Ed., 2022). Sulfonated PIMs were developed and demonstrated high proton/salt conductivity and chemical stability in flow batteries (Angew. Chem. Int. Ed., 2020; Nat. Commun., 2022). We extended sulfonation to spirobifluorene and triptycene-modified PEEK backbones, leading to PIM-PEEK membranes that overcome the typical conductivity-selectivity trade-off (Joule, 2025).
By adjusting pendant group hydrophobicity, we could finely control water channel formation and hydration levels, enhancing selectivity in aqueous organic RFBs (Nature, 2024). Ether-free, fully aromatic PIMs provided superior stability, and one was patented (WO2025056591), with pending publications. Additionally, we explored MOFs as ion-conductive materials for solid-state batteries (Dalton Trans., 2020; manuscript in prep).
2. Membrane Manufacturing and Characterisation
We developed advanced membrane fabrication techniques, including solution-cast dense membranes, thin-film composites, and hybrid architectures. Key characterisation methods included in situ spectroscopy, SAXS, NMR, and electrochemical impedance spectroscopy, allowing us to elucidate ion pathways and water structuring.
Computational modelling was used to generate molecular-level insights into transport mechanisms. The resulting design rules informed the development of membranes with enhanced performance across acidic, neutral, and alkaline conditions.
We also established collaborations with Dalian Institute of Chemical Physics and the University of Cambridge to gain access to roll-to-roll processing facilities, enabling scale-up to square-metre scale production for large-area testing.
3. Integration into Energy Storage Systems
Membranes were tested in aqueous RFBs using anthraquinones and ferro/ferricyanide (Angew. Chem. Int. Ed., 2020; Nat. Commun., 2022), demonstrating high energy efficiency and long cycle life at neutral pH. Alkaline and acidic electrolyte systems (e.g. Zn–Fe, polysulfide, H2–Mn) were also developed (Joule 2022, 2025; Nat. Commun. 2022).
Beyond RFBs, membranes were applied to water electrolysers and electrodialysis for lithium extraction. In alkaline water electrolysis, membranes enabled efficient and durable hydrogen production, with work presented at major conferences.
Main Achievements
20+ advanced membranes developed and validated in multiple energy and separation applications.
20 high-impact publications (e.g. Nature Materials, Joule, Nat. Commun., Angew. Chem., Adv. Mater., JACS).
One patent application filed for new membrane chemistries and processes.
Presentations at major international conferences (IMSTEC, ICOM, EuroMembrane, MRS, ACS, NMSUM, MC16, IUPAC 2023).
Collaborations established with academic and industrial partners.
Exploitation and Dissemination
Dissemination was achieved through open-access publications, conferences, webinars, and stakeholder events. Results were also communicated to policymakers and the public via institutional channels.
Exploitation outcomes include:
Patent evaluations for licensing.
Two potential spin-out ventures in membrane materials and electrochemical systems.
Follow-on EU and national funding secured (e.g. ERC PoC 2023, 2025).
This project delivered a new class of hydrocarbon membranes that surpass the conventional trade-off between ionic conductivity and selectivity. Through molecular-level design, we achieved precise control over pore structure and transport pathways. These membranes offer a cost-effective and environmentally safer alternative to PFAS-based Nafion, with implications for both economic scalability and sustainability.
Roll-to-roll manufacturing at metre-scale has been demonstrated, showing feasibility for integration into kW-scale systems. As the project progresses, we will expand our synthetic platform for accelerated materials discovery (in collaboration with computational partners) and explore additional applications in green hydrogen production and CO2 electroreduction.
The knowledge and materials developed here provide a solid foundation for the next generation of electrochemical devices addressing climate and energy challenges.
Roll-to-roll manufacturing at metre-scale has been demonstrated, showing feasibility for integration into kW-scale systems. As the project progresses, we will expand our synthetic platform for accelerated materials discovery (in collaboration with computational partners) and explore additional applications in green hydrogen production and CO2 electroreduction.
The knowledge and materials developed here provide a solid foundation for the next generation of electrochemical devices addressing climate and energy challenges.