ABSTRACT:
Intercalation of Li+ ions into layered crystals, such as graphite, is a key process in the functioning of Li batteries and energy storage. Bilayer graphene is an ultimate building block for intercalated graphite and is therefore an ideal system for investigation of the storage capacity, structural characteristics and dynamics of the intercalation process. I will present our recent results on device-level electrochemical intercalation of bilayer graphene with Li+ ions driven from a solid LiTFSI:PEO electrolyte. We show that Li storage capacity of bilayer graphene is limited by two essential processes: (i) re-stacking of the two constituent graphene layers from the standard AB configuration to AA, which occurs at a threshold concentration of intercalated Li ions, and (ii) strong electrostatic repulsion of Li ions in the bilayer. Effects of residual Li concentration developing under repeated cycling and of the resulting non-uniformities will also be discussed.
BIOGRAPHY:
Irina Grigorieva is Professor of Physics at the University of Manchester. She received her PhD in 1989 at the Institute of Solid State Physics, Russian Academy of Sciences (Chernogolovka, Russia) which was followed by several postdoctoral positions in the UK, Belgium and the Netherlands. In 2001 she joined Condensed Matter Physics group at the University of Manchester. Her current research is focused on electronic and magnetic properties and applications of graphene, other 2D materials and their heterostructures. This includes atomically thin superconductors, either exfoliated from bulk superconducting crystals or made into superconductors by intercalation, applications of graphene and other two-dimensional crystals in spintronics and, most recently, applications of graphene-based structures as ion hosts. She is also closely involved in research on the properties and applications of atomically thin membranes and nanochannels created using van der Waals assembly. Every year since 2017 she has been named as a ‘highly cited researcher’ in physics, in the top 1% worldwide by citations in her research field. In 2019 her contributions to research on physics of two-dimensional materials and nanotechnology have been recognised by the award of David Tabor Medal and Prize and she was elected Fellow of the UK’s Institute of Physics.
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