Sustainable Electrodes for Advanced Flow Batteries

Energy storage is increasingly becoming a topic of great importance worldwide. Wind power and solar energy are promising alternatives to fossil fuels in our aim to decarbonise global energy generation. Total wind power generation capacity is expected to reach 474 GW in 2020. However, unlike fossil fuel-based methods of generating electricity, renewably sourced electricity is now generated discontinuously and current electricity grids are not designed for this type of energy production. Intelligent and flexible energy storage technologies are urgently required to overcome temporal and local deviations in energy production and consumption. Among the electrochemical energy storage alternatives, redox flow batteries (RFBs) are well suited for large-scale energy storage because of their perfect combination of flexible design, long cycle life, high reliability, environmental friendliness and low maintenance. Flow batteries constitute a commercially attractive, viable solution and flexible platform for the UK's energy future. This technology is expected to help stabilise the system, relieving constrained parts of the network and giving homes and businesses the ability to store their own energy.
The research programme proposed in this Fellowship application details a plan to develop alternative electrodes for RFBs using sustainable resources. RFBs often employ carbon felts as electrodes, prepared from non-sustainable polyacrylonitrile (PAN), and their activity towards the redox reactions is poor, leading to low efficiency systems. I propose to use electrospinning, a very versatile processing technique that allows for fine control of the features of the materials prepared, to produce a new generation of freestanding electrodes with unique tailored properties that will increase the power density and voltage efficiency of RFBs. The recent dramatic reduction in cost of Li-ion batteries, driven by the automotive sector, has led Li-ion to be considered for large-scale stationary storage also. However, there are several disadvantages to the use of Li-ion technology for this application, and so RFBs are seen as promising long-term solution to grid-scale storage. This research programme will explore in situ and operando techniques, applied for the first time to RFB systems, which can lead a deeper knowledge of the influence of the electrode on the performance of RFBs.
Additionally, towards the end of the first four years of the Fellowship, I will utilise my expertise in oxygen electrocatalysis and photoelectrochemistry to explore new hybrid energy systems, i.e. solar flow cells and metal-air flow cells. These are innovative technologies that have the potential to become key in the near future in the search for alternative energy conversion and storage systems with high energy densities. My diverse background of previous work relevant to this Fellowship will place me at the vanguard of the next generation of flow battery developments. The freedom granted by this Fellowship to explore advanced and original aspects in the energy field will assist tremendously to advancing my career and becoming a future leader.

The proposed research will have a tremendous impact on society and the economy through the design of advanced sustainable electrodes for redox flow batteries (RFBs), a technology for grid-scale stationary energy storage. The UK Energy White paper and the first RCUK Review of Energy highlight the importance of this area for the UK. Specifically, I will research alternative sustainable materials derived from biomass that can be processed into efficient freestanding electrodes using electrospinning, a flexible, easy-to-scale approach. I will apply innovative in situ and operando coupled characterisation techniques to unravel structure-property relationships, all combined with computational methods. The approach proposed here to design and process RFB sustainable freestanding electrodes and the use of advanced characterisation techniques will lead to a step-change in energy storage technologies, with huge associated impact. I aim to contribute to solving global energy problems through designing and engineering electroactive materials for redox flow batteries from sustainable sources at an acceptable cost.
This fellowship is well aligned with major UK investments in energy programmes, such as the Energy Storage SuperGen Hub. It is also in line with the UK's energy and environmental targets, articulated through the EPSRC Engineering New Priority Area "Engineering Global Challenges for Sustainability and Resilience", where Energy Storage is highlighted as one of the eight Great Technologies that UK should put efforts on in order to boost economy and energy storage capacity. As part of the UK Redox Flow Battery Network funded by the EPSRC Centre of Applied Materials for Integrated Energy Systems (CAM-IES), I am also in contact with colleagues working in RFBs, with the aim to engage with all researchers interested in Electrochemical Energy Storage across the UK and develop new activities that promote collaborations among the network members. This project will link chemistry syntheses, processing and characterisation techniques along with engineering and testing of energy storage devices, combining joint efforts from which researchers and students can benefit. PhD, master's students and postdoctoral researchers will benefit from multidisciplinary research taking place at the interface between chemical engineering, chemistry and material science to develop new relevant materials based on sustainable resources in current energy conversion and storage technologies.
The UK is investing hundreds of millions of pounds in energy storage research. The Faraday Institution is a recent initiative to boost UK research in automobile energy storage and place UK at the forefront of research in batteries for portable applications. The recently awarded Nobel Prize in Chemistry to Professor Goodenough for his pioneering work on the development of lithium-ion batteries highlights the crucial impact of this technology in our society. Similarly, large-scale energy storage will also be key in the near future. Without a reliable technology that provides the infrastructure to store the energy converted from renewable resources, we will not be able to move away from fossil fuels. In this sense, a major initiative such as the Faraday Institution will be soon needed to face the challenges involving grid-scale energy storage in the UK, and this project will contribute hugely to this effort. Through the FLF I aim to place myself at the forefront of grid-scale energy storage research, and therefore be influential in such an endeavour.