The role of universities in the development of sustainable battery supply chains
The University of Warwick highlights the breadth of important work in the university sector to advance the development of a sustainable battery supply chain in the UK
The battery supply chain race
Adoption of electrification has been led by the automotive industry, but other sectors are increasingly embracing electrification, from marine and aviation to energy storage. Due to this, governments across the globe are in a race to create globally competitive battery supply chains, which in turn support economic prosperity and the Net Zero transition.
Electric vehicles are by far the biggest market for batteries, and they require cost effective energy dense batteries. Research teams within universities play an important role in developing solutions to optimise the performance, durability, sustainability and cost efficiency of batteries and are a critical feature in EV battery supply chains, working across all Technology Readiness Levels (TRL) levels.
Take for example WMG, an academic department at the University of Warwick, which works in partnership with organisations such as Innovate UK, as well as industry players like JLR, BMW, Nissan and Agratas (Tata Group’s global battery business), which earlier this year announced a £4 billion investment in Somerset to build one of the UK’s proposed gigafactories.
Figure 1 – UK Funding Framework and Support Mechanisms
The existing funding framework for battery development in the UK is split by TRL, which can be classified as fundamental research, proof of concept, product pre-production and series manufacture.
WMG is supporting the UK battery sector with new discoveries and improvements in battery chemistries, by piloting manufacturing techniques, as well as developing solutions for battery end of life and skills supply to meet future industry demands. And they are not alone. The Faraday Institution which is the UK’s independent institute for electrochemical energy storage research, skills development, market analysis and early-stage commercialisation spans ten major research projects in lithium-ion and beyond lithium-ion technologies, together with 27 UK universities, 500 researchers and 120 industry partners. There is a concerted effort across the university sector to make the transition to electrification a reality.
Finding solutions to battery chemistry challenges
Despite steady growth in the EV market, the introduction of new technologies can be hindered if those technologies are less durable than those we have today. This issue is especially critical for companies using very nickel-rich cathodes in their high-end EV batteries. Replacing cobalt with nickel in these batteries improves performance but also speeds up degradation. Recently, Professor Louis Piper and his team at WMG developed an x-ray technique to study these nickel-rich lithium-ion batteries in real-time, offering insights into why they degrade and how to extend their lifespan.
Microscopy studies suggest that degradation occurs as oxygen escapes from the nickel-rich cathodes but to understand this better, researchers need to observe the internal reactions during battery charge and discharge cycles, which has previously been difficult due to the complex, multilayer structure of these batteries.
Professor Piper and his team tackled this by using industry-grade nickel-rich lithium-ion batteries produced on a precommercial production line at WMG. They subjected these batteries to accelerated charge-discharge cycles and used x-ray diffraction to monitor them in real-time. The data revealed chemical changes on the cathode surface at high voltages, with oxygen loss leading to a buildup of an oxygen-poor layer that trapped lithium ions. This caused a 10% capacity drop after 100 cycles. Piper explained that a thin nickel oxide crust forms, slowing lithium movement. Slowing the charge-discharge rate could help alleviate this issue and decrease the degradation rate, though not entirely fix it.
Materials characterisation techniques, like the one developed by Piper offer new insights for designing better batteries.
Looking beyond lithium-ion technology
Sodium-ion batteries also known as Na-ion batteries replace lithium with sodium as a charge carrying element. Sodium is more earth abundant and can be refined more sustainably. In addition, as aluminium can be used at the anode current collector, instead of the more expensive and heavy copper used in lithium-ion batteries, sodium-ion batteries can also be stored at 0V which represent a crucial benefit in terms of safety and transportation.
Generally, sodium-ion batteries are not quite as energy dense as lithium-ion batteries, but they will be cheaper and are already proving adequate for lower range city cars such as the BYD Dolphin. Companies are now emerging in the sodium-ion market scenario, but different companies are betting on different chemistries according to their final application requirements and as such there is not a catch-all solution.
WMG’s Dr Ivana Hasa and team have been working on the development and investigation of several sodium-ion battery materials projects working with companies at the forefront of this battery technology including Altris (Sweden) and Faradion (UK). By understanding the structure-property correlation of cathode materials such as Prussian White, layered oxides and polyanionic compounds and anodes such as Hard carbon and Sn-based composite electrodes, the team is contributing to overcoming challenges in the manufacturing of industrially relevant sodium-ion cells prototypes produced by adopting aqueous processing methods, in line with the sustainability principle of sodium-ion batteries. Dr Hasa’s multidisciplinary approach combines cutting-edge characterisation techniques with expertise in electrochemistry to unravel the complex mechanisms governing sodium-ion batteries. Recent results achieved in the multi partner SIMBA (Sodium-ion and Sodium Metal Batteries) project have led to a comprehensive understanding of the dehydration process of Prussian white cathodes, their gas evolution upon cycling and the successful scaling up of 1Ah multilayer pouch cells.
The investigation of upscaled sodium-ion batteries is of primary importance to obtain realistic data to benchmark the progress of the technology, as well as the adoption of a common reporting methodology in the scientific community enabling a fair comparison among performance results.
Battery scale up and manufacture
Characterisation and validation work is essential, but scaling up battery production is just as crucial for the large-scale manufacturing that is required to meet projected global demand. Significant cost reductions in batteries over the last decade are due to advances in high-volume, high-quality manufacturing processes often pioneered by the research community. Projects like WMG’s Battery Scale-Up (BSU) prototyping line have been pivotal in this work, enabling the transition from bench-scale to industry-relevant quantities for commercial testing.
With £36 million from Faraday’s Battery Challenge, a new Flexible Pilot Line at The UK Battery Industrialisation Centre (UKBIC) in Coventry, will be launched by UKBIC and WMG to fill the strategic gap between WMG’s prototyping lines and UKBIC’s full-scale manufacturing capability. The facility will allow companies to produce sample batches of many thousands of innovative cells, speeding up commercial development and to validate that product can be made in much higher volumes. Similar initiatives are happening globally, such as the Stanford University and SLAC National Accelerator Laboratory in the US.
Battery Recycling
Recycling of batteries is an essential part of the EV supply chain. Not only will recycling result in a more environmentally friendly outcome at end of life but in the process, it also generates value from end-of-life disposal for the vehicle manufacturer and provides the input material for the manufacture of new batteries.
RECOVAS is a partnership which brings together WMG and EMR, a world leader in sustainable materials, with major UK car manufacturers (BMW, Jaguar Land Rover and Bentley) and specialist engineering and energy companies (Autocraft Solutions, UKBIC and Connected Energy). RECOVAS is part-funded by the UK Government’s Advanced Propulsion Centre.
The aim of the project is to create standardised processes, design guidelines and a physical pilot facility to recover vehicle batteries, allowing packs and materials to be re-used or recycled. It will develop a process for the analysis of used batteries, directing them to the most appropriate recycling stream – from pack and cell re-use to recycling of materials. It will also define the requirements for recyclability to be designed into future vehicle battery packs.
WMG have been looking at how to safeguard the valuable materials that go into batteries. Lithium is by far the most valuable material in the battery, and the department has applied for a patent for a new process that recovers around 95% of the lithium within the cell to a purity of 99.8%.
Battery Skills
Alongside industrial digitalisation, the electrification revolution represents the largest shift in industrial skills in a generation. We are seeing efforts across educational institutions, industry, and governments to address impending skills challenges and to come up with new solutions.
Dr Ben Silverstone, WMG’s lead on Workforce Transformation Strategy and Policy with the High Value Manufacturing Catapult and the Faraday Institution initiated the National Electrification Skills Framework. Together they laid out a blueprint for a collaborative approach to meet this new skills demand. There are now 100 industry stakeholders involved and with this now very thoroughly researched and clear plan of what capabilities are needed, efforts are underway to engage further education providers, colleges and schools to enable delivery and to ensure that once the opportunities in the battery sector workforce are made available that people are engaged and ready to respond. There is a holistic and rapid approach to this through reskilling, university courses and apprenticeships. However, the next step for Silverstone is to undertake “workforce fore sighting”, so understanding individual needs on a granular level. The real opportunity now is to create equity in this process to build a workforce that is built from all parts of our society, engaging those that are not currently employed, or are uninspired or underutilised.
Skills are ultimately that final jigsaw piece that create truly sustainable battery supply chains. Without the people, the technology and infrastructure can only take nations so far.
Professor David Greenwood, CEO of the High Value Manufacturing Catapult and Director for Industrial Engagement at WMG
