EQCM-D-Based Surface-Acoustic-Wave Spectroscopy
It is our delight to invite Prof. Mikhael Levi from Bar-Ilan University, Israel give us a talk on the EQCM-D-Based Surface-Acoustic-Wave Spectroscopy Emerging Innovations in Material Characterizations for Energy Storage and Conversion on next Monday 23rd April, 2:00-3:00pm in the Grid Room, CB 04.05.430.
The following is the abstract of the talk. All are welcome.
EQCM-D-Based Surface-Acoustic-Wave Spectroscopy: Emerging Innovations in Material Characterizations for Energy Storage and Conversion
Mikhael D. Levi
Department of Chemistry, Bar-Ilan University, Ramat-Gan 52900, Israel
E-mail: levimi@biu.ac.il
Depending on stiffness/softness of the electrode coatings (attached with no-slip to quartz crystal surface), their thickness and morphology, the quartz crystal resonator can operate in either gravimetric or beyond-gravimetric modes providing important information about the mechanical properties of the electrodes.
Starting from a simple gravimetric monitoring of dynamics of ions adsorption into nanoporous carbon supercapacitors, we have demonstrated a couple of years ago that the use of multiharmonic Electrochemical Quartz Crystal Microbalance with Dissipation Monitoring (EQCM-D) constitutes the basis of a new powerful in situ method of highly sensitive tracking intercalation-induced dimensional and porous structure changes in operating battery and supercapacitor electrodes.
The resonance frequency and dissipation changes caused by contact of a porous solid electrode with electrolyte solutions are recorded on multiple harmonics and fitted to a suitable hydrodynamic impedance model returning the structural parameters of the electrode.
Later on this new methodology was extended to a continuous monitoring of viscoelastic changes in binder-free 2D electrodes such as Mxene (Ti3C2(OH)x) caused by insertion of water molecules modulated by intercalation-deintercalation of Li-ions in aqueous solutions.
Monitoring viscoelastic properties of solid-electrolyte interface (SEI) on a high-voltage anode such as LTO was shown to be an extremely effective means for fast optimization of cycling behavior of this electrode.
Our recent paper makes focus on in situ acoustic diagnostics of particle-binder interactions in battery electrodes: accommodation of intercalation-induced volume changes significantly depend on the stiffness/softness of the binder used, on one hand, and on the extent to which the size of the guest cation matches the size of the host sites in which the cations are accommodated.
The different worked examples of the successful use of EQCM-D-based surface-acoustic-wave spectroscopy for material characterization of energy storage electrodes have been summarized in a recent review.