In Operando Magnetic Resonance Imaging for Next-Generation Battery Chemistries.
Friday, March 12, 2021: 9:05 AM - 9:40 AM
The demand for improved batteries is driving research towards the development of new electrode and electrolyte materials. However, the search for optimised materials can sometimes fall short in our aim of developing improved batteries. This is because the improvement of individual battery components cannot, on their own, provide the step-change in performance we are searching for. It is the collective performance of these materials that is going to enable us to make the batteries of the future. As battery components work collectively together, we need to develop analytical techniques that can also probe multiple components and characterise the performance of battery components holistically. In the last 10 years, magnetic resonance imaging (MRI) has shown promise for non-invasively visualising the spatial distribution, speciation, and mobility of molecules and ions in batteries, across electrodes and electrolytes, integrating atomic information across mesoscopic and macroscopic length scales. In this talk, I present MRI of lithium-ion (LIBs), sodium-ion (NIBs) and aqueous Zn-air (ZABs) batteries. In LIBs and NIBs, it is possible to image directly the electroactive species using 7Li or 23Na MRI. In the case of ZABs, it is not possible to perform 67Zn MRI. However, ZAB battery chemistry can be visualised using 1H MRI of the aqueous electrolyte, which is sensitive to the Zn-oxygen electrochemistry of the battery. The use of 1H MRI is also valuable in LIBs and NIBs, enabling the visualisation of microstructural changes and dendrite formation with greater spatial and temporal resolution than by 7Li or 23Na MRI. Operando 1H, 7Li and 23Na MRI experiments are presented, which identify and map electroactive species across the electrode and electrolyte during charge cycling and galvanostatic plating. In the case of NIBs, the formation and evolution of dendrites are observed and mapped by 23Na MRI and their 3D microstructure visualised by 1H MRI of the electrolyte.
Keywords: Please select up to 4 keywords ONLY:
Method Development,Microscopy,Physical Measurements,Spectroscopy