New Catalytic Processes and Polymers for Lithium-Ion Batteries

Electric vehicles are important for ensuring sustainable transport, with the Faraday Institution expecting that by 2030, 64% of new cars bought in the UK will be electric. A key component of electric vehicles is the lithium-ion battery. It must meet several performance requirements, including; fast charging speeds; high capacity (i.e., be able to store a large amount of energy); long lifetime; and have high safety standards. Conventional batteries contain a liquid electrolyte (the medium in which ions travel through). However, this is flammable so it is a safety risk. It can also cause degradation of the battery.
An alternative is to use polymer electrolytes. Polymers are long molecular chains, formed by joining small units called monomers. Some polymers, mostly those containing oxygen atoms in their structure such as polyethers, polycarbonates, and polyesters, are able to conduct lithium ions. This makes them a target for future electrolytes. As they can be solid, they do not have the flammability risks of liquid electrolytes, plus polymers are renowned for being highly processable. Polymers can also be used in batteries as a binder material to provide structural integrity and inhibit degradation.
When producing polymers, the types of monomers used and how they are sequenced can be controlled. This affects the polymer's properties. It is possible to join together different types of polymers into one, longer polymer chain - these are called block co-polymers. In 2014, a new approach to producing block co-polymers was reported, called switch catalysis. It achieves high sequence control and can proceed from a monomer mixture in one-pot. It has been shown to operate for a range of monomers to produce oxygenated polymers with different properties.
This project aims to develop new polymers for use in batteries, using a facile production method with high control. It falls within the EPSRC Energy research area. Switch catalysis will be used to systematically study series of novel copoly(ester-b-carbonate)s, which will be studied with respect to their suitability as battery materials. There are only limited reports of the study of copoly(ester-carbonate)s for use in batteries, and switch catalysis has not previously been used to produce battery materials. Properties of importance include ionic conductivity (> 10-4 S cm-1), electrochemical stability (> 4 V), adhesion strength, flexibility, and structural stability. Polymers with promising properties will be thoroughly tested for use in batteries.

The primary impact of the OxICFM CDT will be the highly-trained world-class scientists that it delivers. This impact will encompass both the short term (during their doctoral studies), the medium term (subsequent employment) and ultimately the longer timescale defined by their future careers and consequent impact on science, engineering and policy in the UK.

The impact of OxICFM students during their doctoral studies will be measured by the culture change in graduate training that the Centre brings about - in working at the interface between inorganic synthesis and manufacturing, and fostering cross-sector industry/academia working practices. By embedding not only from larger companies, but also SMEs, we have developed a training regime that has broader relevance across the sector, and the potential for building bridges by fostering new collaborations spanning enormous diversity in scientific focus and scale. Moreover, at a broader level, OxICFM offers to play a unique role as a major focus (and advocate) for manufacturing engagement with academic inorganic synthetic science in the UK.

From a scientific perspective, OxICFM will be uniquely able to offer a broad training programme incorporating innovative and challenging collaborative projects spanning all aspects of fundamental and applied inorganic synthesis, both molecular and materials based (40+ faculty). These will address key challenges in areas such as energy provision/storage, catalysis, and resource provision/renewal necessary to enhance the capability and durability of UK plc in the medium term. To give some idea of perspective, the output from previous CDTs in Oxford's MPLS Division include two start-up companies and in excess of 30 patents.

It is not only in the industrial and scientific realms that students will have impact during their timeframe of their doctorate. Part of the training programme will be in public engagement: team-based challenges in resource development/training and outreach exercises/implementation will form part of the annual summer school. These in turn will constitute a key part of the impact derived from the CDT by its engagement with the public - both face-to-face and through electronic/web-based media. As the centre matures, our aspiration is that our students - from diverse backgrounds - will act as ambassadors for the programme and promote even higher levels of inclusion from all parts of society.

For our partners, and businesses both large and small in the manufacturing sector, it will be our students who are considered the ultimate output of the OxICFM CDT. Our programme has been shaped by the need of such companies (frequently expressed in preliminary discussions) to recruit doctoral graduates who can apply themselves to a broad spectrum of multi-disciplinary challenges in manufacturing-related synthesis. OxICFM's cohort-based training programme integrates significant industry-led training components and has been designed to deliver a much broader skill set than standard PhD schemes. The current lack of CDT training at the interface of inorganic chemistry and manufacturing (and the relevance of inorganic molecules/materials to numerous industrial sectors) heightens the need for - and the potential impact of - the OxICFM CDT. Our students will represent a tangible and valuable asset to meet the long-term skills demand for scientists to develop new materials and nanotechnology identified in the UK Government's 2013 Foresight report.

In the longer term, the broad and relevant training delivered by OxICFM, and the uniquely wide perspective of the manufacturing sector it will deliver, will allow our graduates to obtain (and thrive in) positions of significant responsibility in industry and in research facilities/institutes. Ultimately we believe that many will go on to be future research leaders, driving innovation and changing research culture, and thereby making a lasting contribution to the UK economy.