Numerical Simulation of Intercalation-Induced Stress in Li-Ion Battery Electrode Particles

Abstract

Severe, particle-level strains induced during both production and cycling have been putatively linked to lifetime limiting damage in lithium-ion cells. Because of the presently unknown contributions of manufacturing and intercalation induced stresses in Li cells, this correlation is critical in determining optimal materials and manufacturing methods for these cells. Both global and localized loads must be estimated, in order to select materials able to resist fracture. Here, we select the LiMn 2 O 4 system for study. We present results of a set of simulation techniques, ranging from one-dimensional finite difference simulations of spherical particles, to fully three-dimensional ͑3D͒ simulations of ellipsoidal particles, to systematically study the intercalation-induced stresses developed in particles of various shapes and sizes, with the latter 3D calculations performed using a commercial finite element code. Simulations of spherical particles show that larger particle sizes and larger discharge current densities give larger intercalation-induced stresses. Simulations of ellipsoidal particles show that large aspect ratios are preferred to reduce the intercalation-induced stresses. In total, these results suggest that it is desirable to synthesize electrode particles with smaller sizes and larger aspect ratios to reduce intercalation-induced stress during cycling of lithium-ion batteries.

Fundamentals of flexoelectricity in solids

“…We are interested in the displacement of the top electrode caused by the charge transport (linear response). This phenomenon is controlled by a number of factors, such as the deformation potential [98,99], Vegard expansion [100], and the converse flexoelectric effect. The contribution of the latter can be described using the constitutive equation for the converse flexoelectric effect, taken in the form (14): (91) and the Poisson equation…”

Optimisation of interface roughness and coating thickness to maximise coating–substrate adhesion – a failure prediction and reliability assessment modelling

“…Therefore, it is possible to calculate diffusion-induced stress by analogy to thermal stress. Prussin [54] and Zhang et al [55], previously treated concentration gradients c 0 k analogously to those generated by temperature gradients DT and partial molar volume V P k analogous to thermal expansion a. Therefore, Equation (15) can be modified to obtain the expressions for normal stresses in coating and substrate as:…”

Chemomechanical modeling of lithiation-induced failure in high-volume-change electrode materials for lithium ion batteries

“…In parallel to these experiments, models of different length scales have been established, ranging from first-principles simulations, [25][26][27][28][29][30][31][32][33][34][35][36] molecular dynamics with empirical force fields on the atomic scale, [37][38][39][40][41][42] continuum-level simulations that couple field equations dictating Li transport and mechanical equilibrium. 9,12,[43][44][45][46][47][48][49][50][51][52][53][54][55] Together, this has opened a bottom-up avenue for developing high-performance LIBs, in contrast to the top-down approach adopted by the conventional battery development.…”