Dr. An and Prof. Jiang will be completing work begun at LLNL during Dr. Ans term as a Lawrence Scholar, in conjunction with LDRD 12-ER-053, Multiscale Capabilities for Exploring Transport Phenomena in Batteries. The current subcontract is for a three-month duration in order to allow Dr. An to extend his current models of large-scale mechanical deformation of silicon anodes to a phase-field formalism. It is expected that a final report will be provided at the projects conclusion. Silicon is considered as one of the most promising anode materials for next generation of Lithium ion batteries, due to its high theoretical capacity. Experiments have confirmed the initial lithiation of crystal silicon during discharging of batteries always involve huge volume expansion, plastic flow of material, phase transformation from crystal to amorphous, and mass diffusion of lithium ions, which in together govern the performance of this electrode materials. Despite progresses in continuum mechanics modeling and atomic calculations to address this problem, a phase field modeling has its own advantages, especially to capture the widely observed sharp phase boundary, and electrochemically driven anisotropic amorphization. For this subcontract, a phase-field based model will be rigorously developed under the framework of large deformation, considering the coupling of phase transformation and deformation. The derived stress-dependent Ginsberg-Landau equation will be implemented using finite element method through commercial package, which also serves as the nonlinear elastic-plastic deformation solver. The model will be interfaced with our atomic calculations as part of the current LDRD in order to expand our capability on multi-scale simulation of transport phenomena in alloying electrodes in lithium ion batteries.
|Effective start/end date||4/21/14 → 9/30/14|
- DOE: National Nuclear Security Administration (NNSA): $25,000.00