Yusuf Hamied Department of Chemistry
University of Cambridge, UK
Wednesday, October 20, 2021 - 12:00pm
MRL Room 2053
Prof. Raphaele Clement
This talk delves into Na+ ion mobility, structural changes and charge compensation mechanisms in the Na0.67[Mg0.28Mn0.72]O2 cathode using local (NMR, ESR) and bulk (XRD, XANES, and bulk magnetic susceptibility) structure probes in conjunction with first-principles calculations. Notably, we identify the phase changes during the first charge-discharge cycle and associate the large voltage hysteresis with Mg2+ migration. The Na+ ion mobility is quantified and the high capacity of Nax[Mg0.28Mn0.72]O2 is identified with the formation high-energy, redox-accessible states on O (generated by Mg2+ migration) stabilised by strong antiferromagnetic exchange interactions with neighboring Mn centres. Finally, a set of design rules for long lifetime, fast charging and high capacity Na cathodes is presented.
This talk is also being presented via Zoom. Please contact Sylvia (sylvia [at] mrl [dot] ucsb [dot] edu) for the link.