As the Ayrton Challenge on Energy Storage gears up, led by the Faraday Institution, we take a look on what has been achieved as part of the first phase of its sodium-ion research project – NEXGENNA – and what makes this technology suited to transport and static energy storage in emerging economies.
The improving performance and cost characteristics of sodium-ion batteries are increasingly making them of interest to micromobility applications (such as e-mopeds or electric 3-wheelers), and low-cost automotive applications in emerging economies.
Interest is heating up: in 2021 Indian multinational conglomerate Reliance Industries acquired UK sodium-ion battery development company Faradion.
Sodium ion batteries are also a technology of choice for static energy storage, where the potential for batteries is huge to provide cheap, clean electricity to millions of people in low-and-middle-income countries, improving energy access and replacing thousands of polluting diesel generators in the process.
As the Ayrton Challenge on Energy Storage gears up, led by the Faraday Institution, we take a look on what has been achieved as part of the first phase of its sodium-ion research project - NEXGENNA.
NIBs are of interest to micromobility vehicle applications, which is currently the fastest electrifying transport sector globally. The fleet size of electric two- and three-wheelers is expected to increase from around 290 million in 2022 to almost 800 million vehicles in 2040
A portion of NEXGENNA is funded with UK aid from the UK government via Transforming Energy Access (TEA). The TEA platform supports early-stage testing and scale up of innovative technologies and business models that will accelerate access to affordable, clean energy-based services to poor households and enterprises, especially in Africa.
The TEA funding leverages an existing £10 million+ funding commitment from another national programme – the Faraday Battery Challenge – to enhance the project’s scope and capability. The Faraday Institution is a key delivery partner for the Faraday Battery Challenge and is primarily funded through Innovate UK.
Why Sodium-ion?
Sodium-ion batteries (NIBs) are an emerging battery technology, with promising cost, safety, sustainability and performance benefits when compared to lithium-ion batteries. They use widely available and inexpensive raw materials and existing lithium-ion production methods, promising rapid scalability. NIBs are an attractive prospect in meeting global demand for carbon-neutral energy storage, where lifetime operational cost, not weight or volume, is the overriding factor (such as static storage). Increasingly NIBs have performance characteristics comparable to lithium iron phosphate (LFP), making them of interest to micromobility and EV applications.
NEXGENNA Project Highlights
The NEXGENNA project on NIBs is led by Professor John Irvine at the University of St Andrews. It is one of the Faraday Institution’s 10 large, multi-university, multi-disciplinary research projects.
NEXGENNA’s mission is to make research discoveries that could lead to improvements in the energy storage, power, and lifetime of NIBs while maintaining sustainability, safety and cost advantages. This in turn will accelerate the rate of their commercialisation and the number of applications they are suited for.
The project is aiming to develop materials for next generation NIB optimised for different performance: (1) high power (2) high energy (3) sustainable materials (no cobalt, nickel or lithium). Researchers have discovered interesting new chemistries for the anode, cathode and electrolyte that show promise for improved performance and competitive cost.
For example, in the electrolyte space, researchers have developed an elegant and sustainable synthesis method for NaPF6, a salt used in the electrolyte of NIBs, which yields a purer, drier, product and enables much higher salt concentrations. Benchmark cells have been manufactured that have improved cycle life and energy density. The electrolytes have attracted commercial interest.
In the next phase of the project, researchers will continue to investigate, improve, understand and scale up these cell components at a versatile battery scale-up facility at the University of St Andrews. The facility includes state-of-the-art equipment, a dry room, and testing chambers. Researchers will be able to combine and test nascent materials from the various elements of the NEXGENNA project (and beyond) to manufacture cells in commercially relevant formats. It is a powerful tool to support the commercialisation of NIBs and is attracting a lot of industrial interest.
Left to right: coating line, calendering, and cell asssembly at St Andrews battery prototyping facility
The scale up facilities have attracted considerable Ministerial interest. In February 2023, the UK Secretary of State for Scotland Malcolm Offord was given a preview of the new battery prototyping facility and ‘dry lab’ at St Andrews, the first of its kind in Scotland that will enable companies and researchers to develop and evaluate battery prototypes.
Further, the University of Strathclyde hosted a visit by UK Foreign Secretary, James Cleverly, as part of the activities one year on from COP26, which involved members of John Irvine’s research group.
Papers and inventions
In its first three years, NEXGENNA researchers published 33 peer reviewed scientific papers. Significantly, in 2021, the NEXGENNA project team led production of a roadmap for NIBs. The roadmap paper, published in Journal of Physics: Energy, was a highly collaborative endeavour, involving 61 researchers from 28 organisations, which has been downloaded 34,000+ times to March 2023. Click here for a list of NEXGENNA papers, and further discussion on the quality of Faraday Institution research.
The Faraday Institution is tracking four inventions by the NEXGENNA project team. Discussions around potential patents are ongoing.
Relationships to India – academia, industry and policy
The project has a close working relationship with Faradion, a leading UK based NIB technology company. More than five former NEXGENNA researchers have transitioned to working for the industry organisation. In December 2021, Indian-based Reliance New Energy Solar announced the acquisition of Faradion and invested significant growth capital to accelerate commercial roll out. Reliance intends to manufacture NIBs in India for EV applications, keeping the UK as a research base. This is one example of the interest in NIBs for low-cost transport applications in an emerging economy.
Project researchers at the University of St Andrews have an ongoing relationship with IIT Madras (in November 2021 the two organisations signed an MOU to help India reach 100% of its energy requirements through renewable energy). The relationship will be developed further as part of the second phase of the TEA Programme.
Members of the Faraday Institution and the NEXGENNA Principal Investigator met with India’s Chief Scientific Officer in April 2023, where they discussed, amongst other things, research directions, an overview of project progress and the new dry room facility.
Techno-economic analysis
In one area of the NEXGENNA project specifically funded by the TEA programme, in early 2023, Faraday Institution commissioned Exawatt to complete a technoeconomic analysis of NIB technologies. The consultancy used their extensive modelling of lithium-ion battery techno-economics and applied the same methodology to build out forecasts and cost models for NIBs, for various NIB material formulations and cost scenarios.
Under Exawatt’s high-cost scenario NIBs are still cheaper to produce than lithium iron phosphate (LFP) under the low-cost scenario. As expected, the cathode accounts for the majority of the cost of a LFP cell; in contrast, the hard carbon anode of a NIB cell is the largest individual cost component.
Exawatt found that provided that the technology can achieve acceptable cell energy density, which the company believes is increasingly likely, NIB use is expected to grow significantly not just in stationary storage but also for EVs, initially for entry-level EVs. This is demonstrated by recent announcements for NIB-powered EVs. Exawatt expects the total SIB demand to be at least 350 GWh in 2032 across storage and transportation markets, with the possibility of 750 GWh under high uptake scenarios.
Other findings of the study reinforce the Faraday Institution’s thinking on future research directions, for example, the need to focus R&D on increasing the operating voltage of NIBs, enabling greater energy densities to be reached and unlocking the potential for greater electric vehicle market penetration.
Further TEA funding will be directed towards the NEXGENNA programme to September 2025.
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