Temperature and Alkali Stable Polymer Electrolytes for Hydrogen and Carbon Dioxide Alkaline Electrolysers

The project aims to develop innovative polymer electrolyte based electrolysers with lower life cycle costs (achieved by enhanced efficiency) utilising enhanced materials and components. This proposal is based on adopting alkaline anion-exchange membrane (AEM) and ionomer (AEI) technology to open up the opportunity for low cost electrolysers systems with: i) low cost polymer electrolytes, catalysts (sustainable i.e. non-Pt), and bipolar plate materials; ii) higher energy efficiency; iii) durable long life operation; and iv) flexibility to respond to dynamic load operation. We target electrolysers involving hydrogen production from water electrolysis and involving carbon dioxide reduction for low overpotential (high value) organic chemical synthesis. A major aim is to produce the next generation of AAEMs and AEIs that can be supplied to (current and future) project partners in bulk quantities (including AEIs in a solubilised form).

Hydrogen is an excellent storage medium for renewable and sustainable energy systems. Hydrogen has several advantages as an energy carrier including highly efficient reversible conversion between hydrogen and electricity, good gravimetric energy density of compressed gas compared to most batteries and scalability of hydrogen technologies for grid scale applications. Water electrolysis is a safe option for production of pure hydrogen at point of use as it does not require substantial storage requirements.
Currently, the cost of hydrogen produced by electrolysis is greater than that of other methods such as steam reforming. Two major reasons for this is the capital cost of the cells and the electrical energy consumption. Commercial hydrogen production by water electrolysis is based on one of two technologies: aqueous alkaline (potassium hydroxide) electrolytes and proton exchange membrane electrolytes. Alkaline cells use lower cost electrode materials than acid polymer systems but current densities (and efficiency) are typically lower. The capital cost of proton exchange membrane electrolysers is higher (largely dictated by the high material costs of membranes [perfluorinated polymers] and precious metal [Pt, Ir, Ru] based catalysts) but their production rates (per unit electrode area) are higher based on the higher current densities. We thus seek to transform the latter technology by combing the advantages of alkaline and polymer electrolytes using low cost materials with the aim of improving energy efficiencies. Realistically there is a minimum energy consumption that can be achieved by electrolysis (based on thermodynamic potentials and voltage losses in the cell) and thus we set our target at a voltage of 1.75 V at 1 A cm-2 (based on geometric electrode area).
To maximise the potential impact of the materials being developed, carbon dioxide reducing electrolysers will also be studied (involving the field of carbon dioxide utilisation). The reduction of carbon dioxide into useful chemicals is of great potential value from a sustainability, environmental and societal context. Such syntheses require a significant energy use and thus using renewable electrical energy in such applications could play a major part in their development. Consequently we seek to develop electrochemical technology whereby we synthesis small molecules (formate, synthesis gas, and/or methanol) based on anion exchange membrane electrolyser materials and architectures (including the involvement of carbonate anion conducting electrolytes - which inherently yield higher chemical stabilities compared to hydroxide conducting analogues).
The project aims to deliver a step change in uptake of ultra-low carbon, green-hydrogen production and carbon dioxide reduction systems. This will be based upon the application of the applicants previous technology breakthroughs of alkaline polymer electrolyte materials and non-precious metal catalyst for galvanic and electrolytic electrochemical energy conversion and storage technologies.

A successful result for this project could result in IP generation which may be licensed to a company (e.g. ITM Power) or may allow formation of a spin-out company (and thus including the potential for creation of new jobs). On a broader scale, development of H2 and CO2 electrolyser technologies will reduce global greenhouse gas emissions, improve air quality, contribute to UK energy security and have an enabling role in the move towards a low carbon sustainable energy economy. "Energy Storage" (here via hydrogen and or liquid fuels such as methanol) and "Advanced Materials" are in the list of Willets' Eight Great Technologies and so this proposal provide application pull for these including advanced materials technologies as an enabler to other applications.

This project is aimed at improving the commercialisation opportunities for polymer membrane electrolyser systems. We have as prime collaborators a H2 fuel cell end user (AFC Energy), an electrolyser company (ITM), and a membrane developer (Newcell Tech. Ltd). ITM is a leading UK developer of H2 technologies focusing on proprietary H2 generation technology platforms and embarking on a major programme of providing H2 from renewable energy for several applications. Commercial exploitation of results is expected (managed by the appropriate technical transfer organisation of all institutions). We will use the UK H2 and Fuel Cell Supergen Hub model for this as our basis. A consortium agreement will be put in place between all partners and industrial collaborators before the start of the research project.

There are a range of societal impacts which may result from the efficient commercialisation of this research, which would accelerate deployment of electric vehicles and stationary fuel cell systems due to improved energy efficiencies. This will decrease CO2 emissions, aid the UK achieving CO2 reduction targets, and decrease atmospheric contaminants in urban environments. Efficient energy generation is an intrinsic priority for the EPSRCs Energy programme.

The project will be managed to disperse research results thoroughly once those results have been checked for intellectual property implications. This will be done through a number of processes that include industry and policymaker representation: i) presentations at International conferences on electrochemistry involving renewable energy and hydrogen technologies in order to engage the research community; ii) Results will be distributed through specific workshops targeted at hydrogen technology and carbon dioxide utilisation (e.g. EPSRC H2 & Fuel Cell and Energy Storage SuperGens and CO2Chem network events as well as the specific workshop planned for this project); iii) Exchange of research personnel around the UK; iv) research papers (in journals that have a large industry and stakeholder readership).

The areas of H2 and CO2 reduction energy technologies has recently picked up considerable pace internationally (many papers published in the last 10 years). The key impact areas are sustainable and renewable energy and to reduce the carbon load on the environment. The consortium will seek to provide intensive training opportunities for its own team and other researchers, with a particular focus on UK groups. The training impact of the Consortium programme will therefore be extended nationally and internationally (the proposed workshop will include a small training afternoon on testing electrolyser systems).

The project gives the partners a gateway to broaden the spectrum of application for their expertise in electrochemical systems. The project will fund 2 PDRAs over 3 years. The PDRAs will spend time at appropriate partners during the project and will thus develop skills and know-how in core science and engineering of electrochemical systems. These are important skills for the UK in terms of hydrogen and electrochemical systems research, which is one of the most promising future sustainable themes.