Electricity has emerged as a preferred energy vector for both conventional and renewable energy, thanks to its versatility and the vast existing electrical infrastructure. The electrification of the transport sector is a natural development to make use of energy from a wide variety of sources, and to reduce CO2 emissions and combat urban air pollution. The UK government plans to ban sale of all diesel and petrol cars and vans from 2040, following similar moves by France and Germany. Globally, the number of electric vehicles (EVs) is projected to rise from about 1 million in 2015 to 300 million in 2040. Achieving these goals requires dramatically improved performance and lowered costs of batteries for EV use. Lithium-ion batteries (LIBs) are promising, but enhanced materials for electrodes, especially the cathode, are needed to meet the power density and costs requirements for the next-generation EVs and energy storage systems. The research aims to generate fundamental knowledge and develop experimental and numerical tools for the controlled synthesis of high-performance cathode materials for LIBs with the inherent potential to be scaled to large throughput production. The materials will be based on layered, multi-element metal oxides (MOs) and carbon-metal oxides (CMOs). Among these, the nickel manganese cobalt oxides (NMCs) with various metal contents and surface features, which are favoured by mainstream automotive companies, will be the main target for the research, though the research and production techniques will be applicable for a large class of MOs and CMOs. Conventionally, MOs can be produced via solid state, sol-gel, and co-precipitation methods and combinations thereof, followed by high temperature annealing processes without or with carbon coating. Such multi-step synthesis routes are time- and energy-consuming, and require delicate control of the surrounding conditions. A promising alternative is flame spray pyrolysis (FSP), in which a precursor solution is atomised to produce a large number of evaporating droplets that are carried into a heated reactor or burned with a flame to form nanoparticles. FSP can offer a one-step, high throughput, easy-to-handle, scalable and continuous process, with a wide range of precursor solutions. It allows good control and, importantly, decoupling of the production process from the gas-phase chemistry process, creating the potential to produce designer materials at scale and low cost. The project is a collaboration between Cambridge University (Simone Hochgreb in flame synthesis; Adam Boies in nanoparticle synthesis; Michael De Volder in nanomaterial and batteries) and UCL (Kai Luo in modelling and simulation). A combined experimental and numerical study will be conducted to reveal the dynamic processes of and controlling mechanisms behind particle formation, growth and coating. At the microscopic level, the detailed transport and chemical reactions will be unravelled; at the mesoscopic level, factors affecting phase change and particle growth will be identified; and at the macroscopic level, the input parameters and time scales of key processes will be linked with quality of MO and CMO products. The experiments involve cutting-edge in-situ and ex-situ measurements to qualify and quantify the synthesis process. The modelling and simulation include advanced mesoscopic simulations of droplet dynamics and evaporation; and atomistic simulations of precursor pyrolysis, particle formation and growth. The fundamental insights gained, and tools and production techniques developed will be exploited for controlled flame synthesis of materials that are directly tied to battery performance metrics, in collaboration with four companies (CATL, Echion Tech, PV3 Technologies and STFET). These companies' activities cover the technology readiness levels (TRLs) from 2 to 9, providing valuable inputs to the research and multiple routes to exploitation of research outputs.

Technology critical metals (TCMs) are pivotal to achieving Net Zero goals. These metals include for example lithium, cobalt, rare earths and platinum group metals. TCMs are deemed to be "critical" because they are economically important but at risk of short supply. The UK Government's Net Zero Strategy: "Build Back Greener" (2021) highlights the supply of these materials as a key challenge for the UK's energy transition and the need for a circular economy in these materials. They are used in wind-power, EV motors and batteries, LEDs, solar-cells and the hydrogen economy. The Government's (2022) Critical Minerals Strategy, "Resilience for the Future", emphasises the importance of these materials and the global supply-chain pressures. The UK's first critical mineral list identified 18 elements as TCMs (British Geological Survey, 2022). Currently, recycling rates for TCMs are very low, for example < 5% for neodymium , used in rare earth magnets ("Critical Raw Materials Resilience" EU report). There are a number of reasons for this, including a lack of specific incentives or legislation, current product designs often impede separation, in some applications there is a very low concentration of the critical material, often the value chains are fragmented, and current recycling processes, designed for bulk metals, are rather crude resulting in the finely distributed TCMs being lost in a linear economy. The overarching aim of RECREATE is to develop a circular economy for TCMs, keeping the materials or components in the highest value form with the lowest environmental footprint. The project brings together three of the leading research institutes in the UK (Universities of Birmingham, Leicester and Edinburgh) who each specialise in different technologies for the extraction and re-use or recycling of TCMs. The project includes leading industrial and public-sector players and policy makers, all involved in the drive to create a circular economy for critical materials in the UK. The research is informed by a system-wide perspective derived from a deep understanding of the industrial challenges for recycling of these materials, and of the governance structures that drive a circular economy. This project will undertake low TRL transformative research to generate radical improvements in automated sorting, "short loop" recycling, pyrometallurgical and chemical processes with reduced environmental impact, biological processes for dilute effluents, and new materials and product-designs which make re-use or recycling easier. Ultimately the project is developing a toolbox of technologies which can sense, sort, separate and re-use or recycle a broad range of TCMs from a wide range of products. These new technologies will be benchmarked using life cycle and techno economic assessment and the legislative drivers for a circular economy will be explored.

Aerosol science, the study of airborne particles from the nanometre to the millimetre scale, has been increasingly in the public consciousness in recent years, particularly due to the role played by aerosols in the transmission of COVID-19. Vaccines and medications for treating lung and systemic diseases can be delivered by aerosol inhalation, and aerosols are widely used in agricultural and consumer products. Aerosols are a key mediator of poor air quality and respiratory and cardiac health outcomes. Improving human health depends on insights from aerosol science on emission sources and transport, supported by standardised metrology. Similar challenges exist for understanding climate, with aerosol radiative forcing remaining uncertain. Furthermore, aerosol routes to the engineering and manufacture of new materials can provide greener, more sustainable alternatives to conventional approaches and offer routes to new high-performance materials that can sequester carbon dioxide. The physical science underpinning the diverse areas in which aerosols play a role is rarely taught at undergraduate level and the training of postgraduate research students (PGRs) has been fragmentary. This is a consequence of the challenges of fostering the intellectual agility demanded of a multidisciplinary subject in the context of any single academic discipline. To begin to address these challenges, we established the EPSRC Centre for Doctoral Training in Aerosol Science in 2019 (CDT2019). CDT2019 has trained 92 PGRs with 40% undertaking industry co-funded research projects, leveraged £7.9M from partners and universities based on an EPSRC investment of £6.9M, and broadened access to our unique training environment to over 400 partner employees and aligned students. CDT2019 revealed strong industrial and governmental demand for researchers in aerosol science. Our vision for CDT2024 is to deliver a CDT that 'meets user needs' and expands the reach and impact of our training and research in the cross-cutting EPSRC theme of Physical and Mathematical Sciences, specifically in areas where aerosol science is key. The Centre brings together an academic team from the Universities of Bristol (the hub), Bath, Birmingham, Cambridge, Hertfordshire, Manchester, Surrey and Imperial College London spanning science, engineering, medical, and health faculties. We will assemble a multidisciplinary team of supervisors with expertise in chemistry, physics, chemical and mechanical engineering, life and medical sciences, and environmental sciences, providing the broad perspective necessary to equip PGRs to address the challenges in aerosol science that fall at the boundaries between these disciplines. To meet user needs, we will devise and adopt an innovative Open CDT model. We will build on our collaboration of institutions and 80 industrial, public and third sector partners, working with affiliated academics and learned societies to widen global access to our training and catalyse transformative research, establishing the CDT as the leading global centre for excellence in aerosol science. Broadly, we will: (1) Train over 90 PGRs in the physical science of aerosols equipping 5 cohorts of graduates with the professional agility to tackle the technical challenges our partners are addressing; (2) Provide opportunities for Continuing Professional Development for partner employees, including a PhD by work-based, part-time study; (3) Deliver research for end-users through partner-funded PhDs with collaborating academics, accelerating knowledge exchange through PGR placements in partner workplaces; (4) Support the growth of an international network of partners working in aerosol science through focus meetings, conferences and training. Partners and academics will work together to deliver training to our cohorts, including in the areas of responsible innovation, entrepreneurship, policy, regulation, environmental sustainability and equality, diversity and inclusion.

An aerosol consists of solid particles or liquid droplets dispersed in a gas phase with sizes spanning from clusters of molecules (nanometres) to rain droplets (millimetres). Aerosol science is a term used to describe our understanding of the collective underlying physical science governing the properties and transformation of aerosols in a broad range of contexts, extending from drug delivery to the lungs to disease transmission, combustion and energy generation, materials processing, environmental science, and the delivery of agricultural and consumer products. Despite the commonality in the physical science core to all of these sectors, doctoral training in aerosol science has been focussed in specific contexts such as inhalation, the environment and materials. Representatives from these diverse sectors have reported that over 90% of their organisations experience difficulty in recruiting to research and technical roles requiring core expertise in aerosol science. Many of these will act as CDT partners and have co-created this bid. We will establish a CDT in Aerosol Science that, for the first time on a global stage, will provide foundational and comprehensive training for doctoral scientists in the core physical science. Not only will this bring coherence to training in aerosol science in the UK, but it will catalyse new collaborations between researchers in different disciplines. Inverting the existing training paradigm will ensure that practitioners of the future have the technical agility and confidence to move between different application contexts, leading to exciting and innovative approaches to address the technological, societal and health challenges in aerosol science. We will assemble a multidisciplinary team of supervisors from the Universities of Bristol, Bath, Cambridge, Hertfordshire, Imperial, Leeds and Manchester, with expertise spanning chemistry, physics, biological sciences, chemical and mechanical engineering, life and medical sciences, pharmacy and pharmacology, and earth and environmental sciences. Such breadth is crucial to provide the broad perspective on aerosol science central to developing researchers able to address the challenges that fall at the boundaries between these disciplines. We will engage with partners from across the industrial, governmental and public sectors, and with the Aerosol Society of the UK and Ireland, to deliver a legacy of training packages and an online training portal for future practitioners. With partners, we have defined the key research competencies in aerosol science necessary for their employees. Partners will provide support through skills-training placements, co-sponsored studentships, and contribution to taught elements. 5 cohorts of 16 doctoral students will follow a period of intensive training in the core concepts of aerosol science with training placements in complementary application areas and with partners. In subsequent years we will continue to build the activity of the cohort through summer schools, workshops and conferences hosted by the Aerosol Society, virtual training and enhanced training activities, and student-led initiatives. The students will acquire a perspective of aerosol science that stretches beyond the artificial boundaries of traditional disciplines, seeing the commonalities in core physical science. A cohort-based approach will provide a national focal point for training, acting as a catalyst to assemble a multi-disciplinary team with the breadth of research activity to provide opportunities for students to undertake research in complementary areas of aerosol science, and a mechanism for delivering the broad academic ingredients necessary for core training in aerosol science. A network of highly-skilled doctoral practitioners in aerosol science will result, capable of addressing the biggest problems and ethical dilemmas of our age, such as healthy ageing, sustainable and safe consumer products, and climate geoengineering.