A Study of Diffusion in Lithium-ion Electrodes Under Fast Charging Using Electrochemical Impedance Spectroscopy. (20th June 2017)

• Record Type: Journal Article
• Authors: Ahmed, Kazi; Bell, Jeffrey; Ye, Rachel; Dong, Bo; Li, Yige; Ozkan, Cengiz S.; Ozkan, Mihrimah
• Is Part Of: MRS advances. Volume 2:Number 54(2017)
• Page Start: 3309
• Page End: 3315
• Publication Date: 2017-06-20
• Subjects: diffusion, -- energy storage, -- ion-solid interactions; Electrical engineering -- Congresses; Physics -- Congresses; Materials -- Research -- Congresses; Materials science -- Congresses; 620.11
• DOI: 10.1557/adv.2017.451
• Languages: English
• ISSNs: 2059-8521

Abstract

ABSTRACT: An in-depth look at diffusion mechanics within lithium-ion electrodes under fast charging conditions is presented. Electrochemical impedance spectroscopy is used as the primary technique to investigate lithium diffusion within electrode material and in electrolyte near the electrode-electrolyte interface. Half-cells of silicon are charged under varying galvanostatic rates while obtaining impedance data. Collected data is analyzed with the help of an electrical equivalent circuit model that provides mechanical and electrochemical parameters for each instance. The novelty of this equivalent circuit partly lies in its ability to resolve between solid-phase diffusion and liquid-phase diffusion, both of which occur during cycling of a lithium-ion electrode. Observed patterns in the parameters of this circuit provide insight into impact of fast charging on mechanics of lithium diffusion, both inside the electrode matrix and within electrolyte.