The solid electrolyte interphase of sodium-ion batteries

Research Project, 2016 – 2018

Here we will study the interface between the anode and the electrolyte of sodium-ion batteries (SIB) – the cheaper and more sustainable version of lithium-ion batteries. This interface, in praxis a thin layer, the solid electrolyte interphase (SEI) has been proven to have tremendous effect on the capacity and cyclability (lifetime) of SIBs – critical to the functioning of the battery. However, its composition is still not known in detail and even less is known about the reactions creating the SEI. The SEI and its creation will be studied with a combination of computational, i.e. density functional theory (DFT), theoretical, and spectroscopic techniques, such as nuclear magnetic resonance spectroscopy (NMR). DFT can be used to predict properties of compounds, here in particular their NMR spectra, allowing us to rapidly narrow down the list of compounds whereof the SEI is composed. This will also be combined with extensive studies of plausible reactions creating the SEI. Armed with the understanding obtained, it will be possible to optimise the formation of the SEI, instead of the current quasi-random developments. Prof. Grey's group at the University of Cambridge is at the forefront of research involving solid-state electrochemical materials, i.e. electrodes of batteries – including SIBs, and also in applied NMR spectroscopy. This would be the ideal group for studying the SEI and the host institution has also additional training on offer for a future researcher.