Towards a Net Zero World: Developing and applying new tools to understand how materials for Li and “beyond-Li” battery technologies function

Professor Dame Clare P. Grey

• 18:00 - 19:00 Bristol-Myers Squibb Lecture Theatre Lent Term Honorary Fellows Lecture

More powerful, longer-lasting, faster-charging batteries – made from increasingly more sustainable resources and manufacturing processes – are required for low-carbon transport and stable electricity supplies in a “net zero” world. Rechargeable batteries are the most efficient way of storing renewable electricity; they are required for electrifying transport as well as for storing electricity on both micro and larger electricity grids when intermittent renewables cannot meet electricity demands. The first rechargeable lithium-ion batteries were developed for, and were integral to, the portable electronics revolution. The development of the much bigger batteries needed for transport and grid storage comes, however, with a very different set of challenges, which include cost, safety and sustainability. New technologies are being investigated, such as those involving reactions between Li and oxygen/sulfur, using sodium and magnesium ions instead of lithium, or involving the flow of materials in an out of the electrochemical cell (in redox flow batteries). Importantly, fundamental science is key to producing non-incremental advances and to develop new strategies for energy storage and conversion.  

This talk will start by describing existing battery technologies, what some of the current and more long-term challenges are, and touch on strategies to address some of the issues.  I will then focus on my own work – together with my research group and collaborators – to develop new characterisation (NMR, MRI, and X-ray diffraction and optical) methods that allow batteries to be studied while they are operating (i.e., operando). These techniques allow transformations of the various cell components to be followed under realistic conditions without having to disassemble and take apart the cell. We can detect key side reactions involving the various battery materials, in order to determine the processes that are responsible ultimately for battery failure.  We can watch ions diffusing in, and moving in and out of, the active “electrode” materials that store the (lithium) ions and the electrons, to understand how the batteries function.  Finally, I will discuss the challenges in designing batteries that can be rapidly charged and discharged.  
 

Acoustics of musical instruments - why is a saxophone like a violin?

Professor Jim Woodhouse

• 18:00 - 19:00 Bristol-Myers Squibb Lecture Theatre Lent Term

Musical instruments like the clarinet and saxophone do not obviously have anything in common with a bowed violin string. This talk will explore the physics behind how these instruments work, and it will reveal some unexpectedly strong parallels between them. This is all the more surprising because all of them rely on strongly nonlinear phenomena, and nonlinear systems are notoriously tricky: significant commonalities between disparate systems are rare. For all the instruments, computer simulations will be used to give some insight into questions a musician may ask: What variables must a player control, and how? Why are some instruments “easier to play” than others?