The effect of mechanical stress on lithium distribution and geometry optimisation for multi-material lithium-ion anodes

2019/07/04 by Roper, Ian P. E., Chapman, S. Jon, Please, Colin P.
#Applied Physics (physics.app-ph) #FOS: Physical sciences #Materials Science (cond-mat.mtrl-sci)

paper · doi:10.48550/arxiv.1908.00390

Abstract

A model is presented for predicting the open-circuit voltage (OCV) and lithium distribution within lithium-ion anodes containing multiple materials, coupling linear elasticity with a stress-dependent chemical potential. The model is applied to a spherical radially-symmetric nano-particle with a silicon core and a graphite shell, highlighting the large effect on lithium distribution and OCV caused by the stress-coupling. Various performance measures based on the expanded volume, the amount of lithium intercalated and the maximum stress induced, are calculated for a silicon core with a graphite shell to enable optimisation of the volume of the silicon core.

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