NMR Beyond Li: New Approaches in Studying Na, Mg and Li-air Batteries

Thursday, 23 June 2016: 08:15
Grand Ballroom (Hyatt Regency)
C. P. Grey (NECCES at University of Cambridge), T. Liu, G. Kim, R. Clement, P. Allan, J. Stratford, J. Lee, I. Seymour, and Z. Liu (University of Cambridge)
This talk will describe the use of NMR spectroscopy to characterize a series of “beyond-Li” electrode materials.  The NMR results are combined with complementary techniques such as pair distribution function analysis of (X-ray) scattering data.  In the sodium-ion battery case, 23Na NMR spectroscopy can be used to follow changes in local structure in a manner very similar to that performed on lithium-ion battery materials.  Our work using the method to study local structure and Na+ and electronic ordering in positive layered materials and intermetallic anodes will be described. 25Mg NMR is more challenging, but the use of DFT calculations to predict shift positions and help interpret the spectra speeds up the analysis considerably.  This will be illustrated for paramagnetic positive electrode materials.  The use of NMR and MRI (magnetic resonance imaging) to link structural changes with electrolyte concentrations will be demonstrated for lithium metal anodes.  Finally, new developments in the field of lithium-oxygen batteries will be described.  In particular NMR spectroscopy allows the different discharge products and many side-reactions to be followed.  For example, 1H and 7Li NMR spectroscopy can be used to separate Li2O2 from LiOH, allowing the formation and removal of LiOH to be quantified.  Our recent studies with LiI redox mediators and r-GO electrodes will be described.