Three-Dimensional Mesoscale Modeling of Anisotropic Mechanical Deformation in Lithium-Ion Electrodes

Capacity fade in Lithium-ion batteries is dependent on a number of processes, one of which may be physical deterioration of the electron transport network formed by the solid particles which make up the electrodes.  One cause of progressive capacity deterioration is the evolution of inter-particle stresses caused by cyclic swelling processes from intercalation and phase transformations.  Intercalation reactions as lithium insert into the crystal lattice lead to anisotropic deformation and complex mechanical behaviors on the mesoscale.

In this presentation, we demonstrate our recent efforts in performing three-dimensional simulations of Lithium-Ion electrode materials at the mesoscale, with hundreds of particles included.  Our focus will be on anisotropic mechanical deformation, with additional physics (such as thermal and species transport) included to appropriately drive the mechanical deformation.  The simulations will include anisotropy within individual particles and demonstrate stochastic initiation of lithiation.  This simulation approach will be deployed on multiple configurations, including spherical particles packs generated from measured particle size distributions and reconstructed geometries from FIB-SEM cuts of actual electrode materials.

^* Sandia National Laboratories is a multi-program laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for the U.S. Department of Energy’s National Nuclear Security Administration under contract DE-AC04-94AL85000.