My research interests focus primarily on application driven design, synthesis and characterisation of polymers. Current goals include polymers for next generation rechargeable batteries, flexible electronics and fundamental structure-property correlations of mixed conductors. A particular emphasis is the synthesis of sustainable polymers using bio-based resources and controlled polymerization strategies to enable novel plastic functionalities. By utilizing controlled polymerization strategies, such as ring-opening polymerization, that allow precise functional group spacing, architecture and chain length, we can aid our fundamental understanding of structure-property relationships to meet specific application challenges. Projects are interdisciplinary, incorporating synthetic polymer chemistry, materials characterization and application testing.
Energy Storage Applications
Energy use strongly correlates to environmental problems such as climate change and air pollution. The societal need for greener energy storage and conversion has led to advancements in fuel cells, batteries, supercapacitors and photovoltaics, amongst other areas. For example, the rechargeable lithium-ion battery has transformed energy storage in portable electronics (laptops and mobile phones), but significant advances are still required for widespread implementation in electric vehicles and large-scale grid storage. Our research investigates the many roles polymer can play in improving battery performance. This project is part of a Faraday Institute-funded project in collaboration with Prof Charlotte Williams, Prof Sir Peter Bruce and Prof Mauro Pasta. For example, solid polymer electrolytes can replace flammable liquid electrolytes to improve battery safety. Our well-defined polymers can also be used to modify interphases and as binders or coatings to buffer electrode volume changes leading to performance enhancements. This work encompasses polymer design, synthesis, characterization, and performance evaluation in full battery cells.
Mixed Electron and Ion-conducting Elastomers
Materials that exhibit both ionic and electronic conductivity have the potential to drive technological advances in electrochemical devices, sensing and wearable electronics. Despite this, there are relatively few examples of both types of conductors being incorporated into a single polymer. Our research focuses on developing microphase-separated block copolymers wherein one block is optimized for ionic conductivity and the other for electronic pathways. This approach offers several advantages over alternative blending strategies. First, the two conductor types can be more uniformly distributed in target applications. Second, synergies between conductivity mechanisms resulting in enhanced ion and electron conductivity compared to the separate homopolymers can be exploited and fundamentally understood. Finally, elasticity to mimic skin for wearable electronics can be incorporated by combining hard rigid blocks with soft elastic blocks in nanostructured materials using predictable phase-separation behaviour. Our work will focus on redox-active and conjugated polymers coupled with polyester, -ether and -carbonate ionically conductive materials. This project involves synthetic polymer chemistry and materials characterization to establish design principles (including material properties and electrochemical testing).
Underpinning all the above research areas is using and identifying new sustainable monomers. Bio-derived monomers are often heteroatom rich, making them beneficial for ion conductivity through Li-ion coordination–hopping mechanisms and advantageous for adhesion leading to superior interface properties. A large pool of these building blocks offers a considerable variety of flexible or rigid backbone chemistries for optimizing conductivity (electron and ion transport) and mechanical properties (from soft elastomers to rigid plastics), as well as being beneficial for biocompatible and biodegradable materials discovery for wearable applications.