Understanding reaction pathways in alkali metal-air batteries for high energy storage

A major breakthrough in energy density is required to satisfy the energy storage needs of society in the long-term. Metal-oxygen batteries have theoretical energy densities up to 10 times that of the state-of-the-art Li-ion battery technology. The goal of this proposal is to enable the uptake of this technology by fully understanding the reduction and oxidation pathways taking place in alkali metal-oxygen batteries.

In situ electrochemical Raman is a surface sensitive technique which is able to follow at the molecular level these pathways in various Li+ containing non-aqueous solvents and also ionic liquids. What sets this work apart is that oxygen reduction reaction and oxygen evolution reaction will be investigated with Raman on multiple substrates, not just on Au, but also transition metal oxide catalysts, such as manganese dioxide (MnO2), noble metal catalysts, such as Pt and on practical electrode materials, such as carbon. The work will go further in the characterisation of oxygen reduction and oxygen evolution in the presence of other alkali metal cations (Na+ and K+) that also offer great gains in energy density as metal-O2 cells over Li-ion. These elements are much more abundant than lithium and therefore would offer a more sustainable energy storage solution for even beyond the long-term.

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 would impact on 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 have a major impact on 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).