Today’s Li-ion batteries use electrodes that are made using a “slurry casting” process in which the active materials are mixed in a wet slurry and coated onto thin metallic foils, then dried and compressed. For the anode, the active material is typically graphite (a form of carbon), while for the cathode it usually a more complex Li-based oxide. The slurry casting process is highly effective for mass production, but has been developed through trial and error. When the active material or the electrode formulation is changed, the time-consuming trial and error optimisation of the manufacturing process and the electrode microstructure must start again. The process also has limited opportunities for more careful tailoring of the electrode structure, which recent lab-scale and simulation work is beginning to show could be very effective in boosting battery power, energy density and/or lifetime. However, until now, no such manufacturing technologies have been available at anything like approaching required scale and throughput.
Professor Patrick Grant from the Department of Materials and Pro-Vice-Chancellor for Research, who will lead the project, comments:
“Nextrode aims to strengthen the scientific understanding of existing electrode manufacturing, which we can then apply to bring more flexibility to slurry casting in order to realise battery performance improvements at industrial scale. At the same time, we will also develop a new generation of manufacturing approaches for ‘smart” electrodes where the different electrode materials are arranged with greater precision and provide even greater performance benefits. This part of the work will be focused in Oxford, drawing on the expertise of our partners at Sheffield, Birmingham, Warwick, Southampton and UCL. We anticipate the benefits could be realised for almost any type of battery chemistry. We will also be working with a group of industrial partners who will help us apply our insights and ideas at industrial scale, supporting the UK’s strategic need to dramatically expand its battery manufacturing capacity”.
In the image of a graded composition electrode above, the false-coloured green particles are the active cathode material and the black is a mixture of carbon particles and small pores. This graded structure electrode – previously difficult to manufacture – shows approximately double the energy storage capacity of a conventional, non-graded electrode of exactly the same material combinations and amounts. Guided by simulations and optimization routines, the Oxford team will now explore other elegant arrangements of different electrode materials and porosity to provide new combinations of battery energy, power and lifetime.
Nextrode is one of five new projects announced on 4 September by the Faraday Institution, with additional Oxford involvement in projects concerned with new cathode materials and lithium-sulphur batteries. In total, the Faraday Institution will award up to £55M to the five UK-based consortia to conduct application-inspired research over the next four years to make step changes in the understanding of battery chemistries, systems and manufacturing methods.
Business Minister, Nadhim Zahawi comments:
“Today’s funding backs scientists and innovators to collaborate on projects that will deliver a brighter, cleaner future on our roads. We are committed to ensuring that the UK is at the forefront of developing the battery technologies needed to achieve our aim for all cars and vans to be effectively zero emission by 2040.”
Neil Morris, CEO of the Faraday Institution comments:
“It is imperative that the UK takes a lead role in increasing the efficiency of energy storage as the world moves towards low carbon economies and seeks to switch to clean methods of energy production. Improvements in EV cost, range and longevity are desired by existing EV owners and those consumers looking to purchase an EV as their next or subsequent car. Our research to improve this web of battery performance indicators (which are different for different sectors) are being researched, with a sense of urgency, by the Faraday Institution and its academic and industrial partners. Our fundamental research programmes are putting the UK at the forefront of this disruptive societal, environmental and economic change.”
UK Research and Innovation Chief Executive, Professor Sir Mark Walport, comments:
“Bringing together experts across industry and academia, this exciting research will grow our understanding of battery chemistries and manufacturing methods, with the potential to significantly improve the UK’s ability to develop the high-performance electric vehicles of the future.”