A coupled electrochemomechanical model for the cycling of a Cu₁₅Si₄-hosted silicon nanowire

In this paper, we present and analyse a coupled electrochemomechanical model for the cycling of a nanowire composed of amorphous Si coated on Cu₁₅Si₄, using large-deformation theory. This study is motivated by a recent novel design for the anode current collector in a lithium-ion battery, and the modelling efforts are linked to half-cell experiments at three different charging rates (C/10,C/2,2C). The model predicts that nanowire buckling should occur on the first charging cycle, and this agrees with the appearance of fracturing on the corresponding transmission electron microscopy image. In addition, the model predicts some new behaviours that were not discussed in earlier electrochemomechanical models of similar type; among these is the possibility that the electrode may locally reach full charge first in its interior, rather than at its outer surface.