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VideosISEECap 2019 Plenary Lectures
>< Quick links >< [Go to] Going toward high energy electrochemical capacitor: the essential role of the electrolyte, ***
Going toward high energy electrochemical capacitor: the essential role of the electrolyte,
Prof. Andrea Balducci
Several studies indicate that if the energy of EDLCs could be increased from the actual values to 15-20 Wh/kg, the number of applications in which these devices could be introduced would heavily be higher. The most convenient way to increase the energy of EDLCs is to increase their operative voltage, which is directly related to the stability (chemical and electrochemical) of the electrolyte. In this lecture the alternative electrolytes proposed in past years, based on organic solvent and ionic liquids, will be considered and critically analyzed. Particular attention will be dedicated to the identification and the chemical physical characterization of novel electrolytes. Additionally, the impact of novel electrolytes on the active and inactive components of EDLCs will be analyzed in detail: great attention will be dedicated to the suppression of detrimental processes occurring at high potentials.
*** A 25-year journey from Los Alamos to the east along the Saint-Laurent and Loire rivers, to investigate electrode materials and aqueous electrolytes for electrochemical capacitors, ***
Electrolytes in electrochemical capacitors: beyond capacitive storage,
Prof. Elżbieta Frąckowiak Electrochemical capacitors (EC) are the devices based on the reversible storage of energy by electrostatic (capacitive) attraction of ions. Performance of EC are strongly governed by the type of electrolytes, namely aqueous, organic and ionic liquids. As a consequence, practical voltage range of EC in these electrolytes varies from 0.8 V to 3.5 V, respectively. Capacitive charge storage can be increased by faradaic reactions, frequently called pseudocapacitive effects. Exploring redox active species from electrolytic solution is another possibility for energy increase by pseudocapacitive effects. Practical application of such redox pairs will be determined by reversibility, pH of solution, concentration, price, availability, toxic character. Some of them can be used only as additive to electrolyte. This talks will present and discuss the use of differentes chemical species in electrochemical capacitors.
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High-power, high-energy storage enabled by 2D metallic materials,
Prof. Yury Gogostsi Electronic conductivity is a key factor in achieving fast charging and high-power performance of electrical energy storage devices. The ‘beyond graphene’ march led to the discovery of new types of conductive 2D materials, like MXenes, produced by wet chemical or electrochemical extraction of interleaved ‘A’ atomic layers from the layered ternary carbide or nitride precursors.
This presentation will describe the potential use of MXenes in electrochemical capacitors. Ion transport 2D gallery spaces, redox chemistry at the transition metal oxide-like surface and metallic conductivity provided by electrons of the transition metals, make MXenes promising as candidates for high-rate energy storage applications. The ability of MXenes to spontaneously intercalate a variety of cations, while promoting fast charge transfer rates, endorses them for hybrid metal-ion capacitor applications. The use of MXenes to replace polymer binders and metal current collectors will also be addressed. ***
A tale of two technologies: capacitive deionization and supercapacitors,
Prof. Volker Presser
The interfacial process of reversible ion electrosorption at the interface of a liquid electrolyte and a solid electrode enables not only fast energy storage via electrical double-layer capacitors but also effective water desalination via capacitive deionization (CDI). Both technologies share similarities, such as the usefulness of highly nanoporous carbon as the electrode material, careful design of surface functional groups, and the importance of adequately choosing the electrochemical operation parameters in respect to the electrolyte stability window.
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3- and 2-Dimensional materials for capacitive energy storage,
Prof. Patrice Simon This presentation will give an overview of the research work we achieved on capacitive and pseudocapacitive materials and the challenges/limitations associated with the development of these materials. We will present first the state-of-the art of the fundamental of ion adsorption mechanism in porous carbons and its practical applications before moving to solid-state supercapacitor electrodes and devices. A second part of the talk will be dedicated to pseudocapacitive materials, starting with an introduction where we will remind some key difference between battery and pseudocapacitive materials. Key results obtained with 2-D MXene carbides but also metal oxides materials will be presented and discussed. A last part of the talk will be dedicated to the development of micro-devices for Internet of Things (IOT). Exemples of on-chip and flexible micro-devices will be presented and discussed.
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All these videos are available on University of Nantes webTV |
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