Developing Electrochemical Structure-Function Relationships in Non-aqueous Electrolytes

Discovering the fundamental principles that govern electrochemical reactivity is the key to the design of new materials for a range of scientific applications. Such information can only be obtained from model systems with well-defined elemental reaction sites using state-of-the-art instrumental probes. In this collaborative project we aim to extend the study of electrochemical reactions on model single crystal surfaces in non-aqueous electrolytes.
Electrochemistry underpins many current energy applications and plays a crucial role in the development of new energy storage technologies. Advances in all the fields involved in electrochemically based energy technologies will be facilitated by strong synergies between scientific understanding and technological innovation and development. Advances in modern electrochemical surface science offer strong perspectives towards achieving these aims and are central to this application. Indeed detailed in situ characterisation of complex, reactive interfaces is a key area where the tools of electrochemical surface science can meet the challenges of developing technologies. This is particularly true in the case of the lithium-oxygen battery. A greater fundamental understanding of the oxygen cathode interface with respect to the oxygen reduction and oxygen evolution reactions is critical for significant advancement in this area.
Electrochemical processes occur at heterogeneous interfaces within a condensed matter environment and are thus more difficult to examine than gas-solid interfaces. Due to the buried nature of the interface, it is inaccessible to most standard surface science techniques that employ strongly adsorbed electron probes to gain surface sensitivity. Study of the interface is restricted to techniques that employ penetrating radiation, such as x-ray and neutron scattering and optical spectroscopy, or imaging techniques, where the probe is brought in close proximity to the solid surface. Development of these relatively new techniques is providing the main methodological driving force for new investigations of the solid/liquid interface. This has been paralleled by the advancements made in synchrotron radiation, where a third generation of light sources is currently operational around the world. This proposal aims to strengthen the collaboration between scientists at the University of Liverpool and Argonne National Laboratory in the study of this complex interface. The collaboration will involve the sharing of equipment, materials and expertise and the training of PhD students in the use of state-of-the-art experimental equipment. It will also involve the use and development of synchrotron radiation techniques for probing the atomic structure at the interface between a solid electrode and a non-aqueous electrolyte.

Understanding the surface chemistry will impact on the design of future catalysts for promoting both the oxygen reduction and oxygen evolution reaction in non-aqueous aprotic solvents. Such understanding underpins the advancement of metal-air batteries, such as the lithium-air (or lithium-oxygen) battery, which potentially has much greater energy storage than the current state-of-the-art lithium-ion battery.

Therefore the proposed research will have a considerable academic impact, nationally and internationally. It will also have significant potential impact beyond academia into the public and private sectors and society as a whole. Advances in battery research are important to the battery industry and the enormous portable electronics industry (laptops, cameras, mobile phones and other hand-held devices).
A quarter of all manmade CO2 emissions arise from transportation, any breakthroughs in battery technology regarding significant increases in energy density (and therefore driving range) would allow future electric vehicles (EVs) to become a more attractive option for consumers. As a consequence our research will be of interest to the automotive industry in the UK and worldwide. Moreover the UK will depend on more and more intermittent electricity supply from, for example, wind, wave and solar power. Energy storage will become crucial for the smoothing out of supply and demand and allowing for a less centralised grid. Improvements in battery performance will have significant impact on this nascent application and will allow greater adoption of green power and lower dependence on fossil fuel power stations, which will lower CO2 emissions in this sector (approximately 30% of total UK emissions).

The most immediate impact of the research will be on the PhD students who will work at the cutting edge of electrochemical research. Cross-disciplinary research of this kind is likely to grow in importance and this programme will contribute to the pool of skilled people required for future research.