Stein, Peter ; Zhao, Ying ; Xu, Bai-Xiang (2016)
Effects of surface tension and electrochemical reactions in Li-ion battery electrode nanoparticles.
In: Journal of Power Sources, 332
doi: 10.1016/j.jpowsour.2016.09.085
Artikel, Bibliographie
Kurzbeschreibung (Abstract)
The size- and shape-dependency of the chemo-mechanical behavior of spherical and ellipsoidal nanoparticles in Li-ion battery electrodes are investigated by a stress-assisted diffusion model and 3D finite element simulations. The model features surface tension, a direct coupling between diffusion and elasticity, concentration-dependent diffusivity, and a modified Butler-Volmer relation for the description of electrochemical reactions. Simulation results on spherical particles reveal that surface tension causes additional pressure fields in the particles, shifting the stress state towards the compressive regime. This provides mechanical stabilization, allowing, in principle, for higher charge/discharge rates. However, due to this pressure the attainable lithiation for a given potential difference is reduced during insertion, whereas a higher amount of ions is given off during extraction. Ellipsoidal particles with an aspect ratio deviating from that of a sphere with the same volume expose a larger surface area to the intercalation reactions. Consequently, they exhibit accelerated (dis)charge rates. However, due to the enhanced pressure in regions with high curvature, the accessible capacity of ellipsoidal particles is less than that of spherical particles.
| Typ des Eintrags: | Artikel |
|---|---|
| Erschienen: | 2016 |
| Autor(en): | Stein, Peter ; Zhao, Ying ; Xu, Bai-Xiang |
| Art des Eintrags: | Bibliographie |
| Titel: | Effects of surface tension and electrochemical reactions in Li-ion battery electrode nanoparticles |
| Sprache: | Englisch |
| Publikationsjahr: | 28 September 2016 |
| Titel der Zeitschrift, Zeitung oder Schriftenreihe: | Journal of Power Sources |
| Jahrgang/Volume einer Zeitschrift: | 332 |
| DOI: | 10.1016/j.jpowsour.2016.09.085 |
| Kurzbeschreibung (Abstract): | The size- and shape-dependency of the chemo-mechanical behavior of spherical and ellipsoidal nanoparticles in Li-ion battery electrodes are investigated by a stress-assisted diffusion model and 3D finite element simulations. The model features surface tension, a direct coupling between diffusion and elasticity, concentration-dependent diffusivity, and a modified Butler-Volmer relation for the description of electrochemical reactions. Simulation results on spherical particles reveal that surface tension causes additional pressure fields in the particles, shifting the stress state towards the compressive regime. This provides mechanical stabilization, allowing, in principle, for higher charge/discharge rates. However, due to this pressure the attainable lithiation for a given potential difference is reduced during insertion, whereas a higher amount of ions is given off during extraction. Ellipsoidal particles with an aspect ratio deviating from that of a sphere with the same volume expose a larger surface area to the intercalation reactions. Consequently, they exhibit accelerated (dis)charge rates. However, due to the enhanced pressure in regions with high curvature, the accessible capacity of ellipsoidal particles is less than that of spherical particles. |
| Freie Schlagworte: | Lithium-ion batteries, Butler-Volmer equation, Reaction kinetics, Stress-enhanced diffusion, Surface tension, Nanoparticles |
| Fachbereich(e)/-gebiet(e): | 11 Fachbereich Material- und Geowissenschaften 11 Fachbereich Material- und Geowissenschaften > Materialwissenschaft 11 Fachbereich Material- und Geowissenschaften > Materialwissenschaft > Fachgebiet Mechanik Funktionaler Materialien Exzellenzinitiative Exzellenzinitiative > Graduiertenschulen Exzellenzinitiative > Graduiertenschulen > Graduate School of Computational Engineering (CE) |
| Hinterlegungsdatum: | 15 Sep 2016 09:58 |
| Letzte Änderung: | 26 Jan 2024 09:21 |
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