Ion Dynamics in Porous Carbon Electrodes in Supercapacitors Using in situ Infrared Spectroelectrochemistry
Francis W Richey , Boris Dyatkin , Yury Gogotsi , Yossef A Elabd
Abstract
Electrochemical double layer capacitors (EDLC), or supercapacitors, rely on electrosorption of ions by porous carbon electrodes and offer a higher power and a longer cyclic lifetime compared to batteries. Ionic liquid (IL) electrolytes can broaden the operating voltage window and increase the energy density of EDLCs. Herein, we present direct measurements of ion dynamics of 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide (EMIm-TFSI) in an operating EDLC with electrodes composed of porous nanosized carbide-derived carbons (CDCs) and non-porous onion-like carbons (OLCs) with the use of in situ infrared spectroelectrochemistry. For CDC electrodes, IL ions (both cations and anions) were directly observed entering and exiting CDC nanopores during charging and discharging of the EDLC.
Conversely, for OLC electrodes, IL ions were observed in close proximity to the OLC surface without any change in the bulk electrolyte concentration during charging and discharging of the EDLC. This provides experimental evidence that charge is stored on the surface of OLCs in OLC EDLCs without long-range ion transport through the bulk electrode. In addition, for CDC EDLCs with mixed electrolytes of IL and propylene carbonate (PC), the IL ions were observed entering and exiting CDC nanopores, while PC entrance into the nanopores was IL concentration dependent.
This work provides direct experimental confirmation of EDLC charging mechanisms that previously were restricted to computational simulations and theories. The experimental measurements presented here also provide deep insights about the molecular level transport of IL ions in EDLC electrodes that will impact the design of electrode materials’ structure for electrical energy storage.
Here we demonstrate a new developed method for depositing Ti3C2Tx MXenes onto hydrophobic electrospun PCL membranes using oxygen plasma treatment. These novel patches hold tremendous potential for providing mechanical support to damaged heart tissue and enabling electrical signal transmission,thereby mimicking the crucial electroconductivity required for normal cardiac function. After a detailed investigation of scaffold-to-cell interplay, including electrical stimulation, novel technology has the potential for clinical application not only for cardiac regeneration, but also as neural and muscular tissue substitutes.
MX-MAP project participants from MRC Dr. Oleksiy Gogotsi and Veronika Zahorodna performed split secondment visit to project partner organization University of Padova (Italy). MX-MAP project works on development of the key strategies for MXene medical applications. 
CanbioSe Project Meeting and Project Workshop was held at European Institute of Membranes (IEM), University of Montpellier, France on September 26-27, 2023. The workshop was focused on the theme of "Commercializing Biosensors, Intellectual Property, and Knowledge Transfer from Academia to Industry.
Dr. Oleksiy Gogotsi and Veronika Zahorodna visited IEEE NAP 2023 conference held in Bratislava on September 10-15, 2023. The prime focus of the IEEE NAP-2023 was on nanoscale materials with emphasis on interdisciplinary research exploring and exploiting their unique physical and chemical proprieties for practical applications.
Director of MRC and Carbon-Ukraine Dr. Oleksiy Gogotsi visited CEST labs in Wiener Neustadt (Low Energy Ion Scattering, Batteries development) and TU Vienna (ELSA, SFA). He meet with Dr. Pierluigi Bilotto, Dr. Chriatian Pichler and their colleagues, discussing novel materials and r&d activities for new technologies.
MX-MAP Session was held during the YUCOMAT Conference 2023 titled: "Towards MXenes’ biomedical applications by high-dimensional immune MAPping", HORIZON-MSCA-2021-SE-01 project MX-MAP.
CANBIOSE project participants from MRC Dr. Oleksiy Gogotsi and Veronika Zahorodna performed secondment visit to project partner organization European Institute of Membranes in Montpellier (France) on August -September 2023.
MRC researchers Dr. Oleksiy Gogotsi and Veronika Zahorodna were visiting Nanobiomedical Centre, Adam Mickewicz University in Poznan, Poland due to close collaboration with AMU team led by Dr. Igor Iatsunskiy. 
Meeting during the MXene international conference held in Drexel University on Aug. 3, 2022, and discussing the roadmap for launching MX-MAP research project on MXenes for medical applications.