title: Thin-film electrodes for high-capacity lithium-ion batteries: influence of phase transformations on stress.
abstract: In this study, we revisit experiments by Sethuramanet al.(2010J. Power Sources,195, 5062-5066. (doi:10.1016/j.jpowsour.2010.02.013)) on the stress evolution during the lithiation/delithiation cycle of a thin film of amorphous silicon. Based on recent work that show a two-phase process of lithiation of amorphous silicon, we formulate a phase-field model coupled to elasticity in the framework of Larché-Cahn. Using an adaptive nonlinear multigrid algorithm for the finite-volume discretization of this model, our two-dimensional numerical simulations show the formation of a sharp phase boundary between the lithiated and the amorphous silicon that continues to move as a front through the thin layer. We show that our model captures the non-monotone stress loading curve and rate dependence, as observed in recent experiments and connects characteristic features of the curve with the structure formation within the layer. We take advantage of the thin film geometry and study the corresponding one-dimensional model to establish the dependence on the material parameters and obtain a comprehensive picture of the behaviour of the system.
authors.affiliation: Weierstrass Institute , Mohrenstraße 39, 10117 Berlin, Germany.
authors.forename: Esteban
authors.identifier: 0000-0001-8258-7818
authors.initials: E
authors.lastname: Meca
authors.affiliation: Mathematical Institute , University of Oxford, Andrew Wiles Building, Radcliffe Observatory Quarter, Woodstock Road , Oxford OX2 6GG, UK.
authors.forename: Andreas
authors.initials: A
authors.lastname: Münch
authors.affiliation: Weierstrass Institute, Mohrenstraße 39, 10117 Berlin, Germany; Institute of Mathematics, Technische Universität Berlin, Straße des 17. Juni 136, 10623 Berlin, Germany.
authors.forename: Barbara
authors.initials: B
authors.lastname: Wagner
keywords: Li-ion batteries; phase separation; phase-field modelling; strain energy; thin film