Search results for "elektrolyytit"
showing 5 items of 5 documents
In-Operando Lithium-Ion Transport Tracking in an All-Solid-State Battery.
2022
An all-solid-state battery is a secondary battery that is charged and discharged by the transport of lithium ions between positive and negative electrodes. To fully realize the significant benefits of this battery technology, for example, higher energy densities, faster charging times, and safer operation, it is essential to understand how lithium ions are transported and distributed in the battery during operation. However, as the third lightest element, methods for quantitatively analyzing lithium during operation of an all-solid-state device are limited such that real-time tracking of lithium transport has not yet been demonstrated. Here, the authors report that the transport of lithium …
Grand canonical ensemble approach to electrochemical thermodynamics, kinetics, and model Hamiltonians
2021
The unique feature of electrochemistry is the ability to control reaction thermodynamics and kinetics by the application of electrode potential. Recently, theoretical methods and computational approaches within the grand canonical ensemble (GCE) have enabled to explicitly include and control the electrode potential in first principles calculations. In this review, recent advances and future promises of GCE density functional theory and rate theory are discussed. Particular focus is devoted to considering how the GCE methods either by themselves or combined with model Hamiltonians can be used to address intricate phenomena such as solvent/electrolyte effects and nuclear quantum effects to pr…
Mechanistic Origins of the pH Dependency in Au-Catalyzed Glycerol Electro-oxidation: Insight from First-Principles Calculations
2021
Electrocatalytic oxidation of glycerol (EOG) is an attractive approach to convert surplus glycerol to value-added products. Experiments have shown that EOG activity and selectivity depend not only on the electrocatalyst but also on the electrode potential, the pH, and the electrolyte. For broadly employed gold (Au) electrocatalysts, experiments have demonstrated high EOG activity under alkaline conditions with glyceric acid as a primary product, whereas under acidic and neutral conditions Au is almost inactive producing only small amounts of dihydroxyacetone. In the present computational work, we have performed an extensive mechanistic study to understand the pH and potential dependency of …
Ravinnon vaikutus happo-emästasapainoon ja elektrolyytteihin levossa
2006
Ravinnolla voidaan vaikuttaa elimistön happo-emästasapainoon, joka saattaa edelleen vaikuttaafyysiseen suorituskykyyn. Emäksisyyden lisääminen elimistössä näyttäisi parantavan suorituskykyäkasvaneen puskurointi- eli vetyionien sitomiskyvyn myötä hidastaen happamuuden aiheuttamanlihasväsymyksen syntymistä. Ravinnon aiheuttamaa happojen tai emästen muodostustavoidaan arvioida ruoka-aineelle ominaisen PRAL-arvon (potential renal acid load) avulla. Happo-emästasapainon tila on yhteydessä myös veren elektrolyyttipitoisuuksiin kuten natrium-,kalium-, kalsium-, magnesium-, kloridi- ja laktaatti-ionipitoisuuksiin. Vahvojen ionien pitoisuuseroneli SID:n (strong ion difference) muutokset aiheuttavat …
Frozen or dynamic? : An atomistic simulation perspective on the timescales of electrochemical reactions
2023
Electrochemical systems span a wide range of timescales, and several recent works have put forth the idea that the reaction environment should remain frozen and out of equilibrium during electrochemical electron or proton transfer reactions. Furthermore, simplified treatments of the electrochemical interface model the solvent and ions as frozen molecules. However, the claims and practices of a frozen environment strongly clash with most theoretical and simulation approaches developed to study electrochemical reaction rates. It has also been suggested that the electrode potential should not be fixed when simulating reaction rates due to conductivity limitations, which indicates constant pote…