Ion Diffusivity through the Solid Electrolyte Interphase in Lithium-Ion Batteries. Issue 11 (17th May 2017)

• Record Type: Journal Article
• Authors: Benitez, Laura; Seminario, Jorge M.
• Is Part Of: Journal of the Electrochemical Society. Volume 164:Issue 11(2017)
• Page Start: E3159
• Page End: E3170
• Publication Date: 2017-05-17
• Subjects: diffusion -- LAMMPS -- Li-ion Battery -- molecular dynamics -- nanotechnology -- SEI; Electrochemistry -- Periodicals; 541.3705
• DOI: 10.1149/2.0181711jes
• Languages: English
• ISSNs: 0013-4651

Abstract

Abstract : Understanding the transport properties of the solid electrolyte interphase (SEI) is a critical piece in the development of lithium ion batteries (LIB) with better performance. We studied the lithium ion diffusivity in the main components of the SEI found in LIB with silicon anodes and performed classical molecular dynamics (MD) simulations on lithium fluoride (LiF), lithium oxide (Li2 O) and lithium carbonate (Li2 CO3 ) in order to provide insights and to calculate the diffusion coefficients of Li-ions at temperatures in the range of 250 K to 400 K, which is within the LIB operating temperature range. We find a slight increase in the diffusivity as the temperature increases and since diffusion is noticeable at high temperatures, Li-ion diffusion in the range of 1300 K to 1800 K was also studied and the diffusion mechanisms involved in each SEI compound were analyzed. We observed that the predominant mechanisms of Li-ion diffusion included vacancy assisted and knock-off diffusion in LiF, direct exchange in Li2 O, and vacancy and knock-off in Li2 CO3 . Moreover, we also evaluated the effect of applied electric fields in the diffusion of Li-ions at room temperature.