(A04 Best Poster Award Winner) Magnetic Resonance Imaging of Sodium-Ion Batteries - The Quest for Quasimetallic Nanoparticles

Abstract

An increase in the demand for clean energy generation has brought about a need for improved energy storage devices to distribute the power generated by renewable sources. Sodium-ion batteries have been proposed as a lower cost and more sustainable solution. In order to commercialise this emerging technology, new materials and characterisation techniques are required. Magnetic resonance imaging (MRI) is able to characterise both the electrode and electrolyte materials non-invasively, providing a more holistic view of battery chemistry. Furthermore, MRI can spatially resolve electrochemical processes, in real-time, within cells.(1-4) In this study, 23Na and 1H nuclear magnetic resonance (NMR) spectroscopy and MRI experiments have been performed, in operando, on sodium metal cells. At high cycle rates, the growth of dendrites is observed during galvanostatic plating. Operando 23Na NMR experiments on sodium full cells have also been performed, which provide unprecedented insight into the sodiation mechanisms within a hard carbon anode. The formation of metallic and quasimetallic sodium species are observed during the first charge cycle.(5) M. M. Britton, Prog. Nucl. Magn. Reson. Spectrosc., 101, 51 (2017). M. M. Britton, ChemPhysChem, 15, 1731 (2014). A. J. Davenport, M. Forsyth and M. M. Britton, Electrochem. Commun., 12, 44 (2010). J. M. Stratford, P. K. Allan, O. Pecher, P. A. Chater and C. P. Grey, Chem. Commun. (Cambridge, U.K.), 52, 12430 (2016). J. M. Bray, C. L. Doswell, G. E. Pavlovskaya, L. Chen, B. Kishore, H. Au, H. Alptekin, E. Kendrick, M. M. Titirici, T. Meersmann and M. M. Britton, Nat. Commun., 11, 2083 (2020). Figure 1