In the critical area of sustainable energy storage, solid-state batteries have attracted considerable attention due to their potential safety, energy-density and cycle-life benefits. Our research addresses key issues in the areas of multiscale ion transport across the various interfaces present in these next-generation devices. 

A reasonable understanding of ion transport in the bulk solid electrolyte materials at the heart of this promising technology has been achieved through the combined efforts of both experimental and computational researchers, with their conductivity matching and even exceeding that of their liquid counterparts. However, this is not the case for the interfaces of these materials, which now represent the bottlenecks for ion transport and the overall performance of solid-state batteries. 

As a result of their processing advantages, remarkable efficiency and the abundance of their component elements, perovskite solar cells are on track to become mass-produced with multiple start-ups in the UK. These materials also exhibit optoelectronic properties similar to gallium arsenide, but can also be printed. Furthermore, several resistive switching mechanisms of halide perovskite memristors have been proposed.

Understanding ion migration is essential to maximise the performance of a number of perovskite-based devices.  In solar cells,  ion migration determines the hysteresis of the system, while for memristors, it is responsible for the switching behaviour. Our group focuses on understanding and enhancing or reducing (depending on the application) ion transport in hybrid perovskite materials and their interfaces. 

Oxide ion and proton-conducting materials are of great interest due to their application as electrolytes in solid-oxide fuel cells and proton ceramic fuel cells. Fuel cells offer a viable option to produce clean energy from sustainable resources, with low emission of pollutants and high energy conversion rates. The development of next-generation electrolyte materials possessing good ionic conduction at intermediate temperatures (300–600 °C) has led to the discovery of high oxide-ion conductivity in several structural families. High temperature proton conduction has also been reported for many materials, which show proton conductivity when exposed to water vapour or hydrogen-rich atmospheres. 

We utilise a range of atomic-scale computational techniques, with support from experimental collaborators, to study the structural, electronic, defect, doping, hydration and ion transport properties of new and promising oxide-ion and proton conducting materials for state-of-the-art fuel cell applications.