(Invited) Study of Mechanical Behaviour of Si Anode upon Electrochemical Lithium Insertion

Abstract

A battery is one of the representative electrochemical systems studied widely for energy storage applications. In particular, Li-ion batteries are becoming an essential component in mobile electronic devices and electric vehicles, as smaller, lighter, and longer energy storage is required. Silicon is considered as one of the most promising anode materials for Li-ion batteries because of its exceptional specific capacity, which is about ten times that of commercial graphite anodes. However, conventional Si anodes typically suffer from rapid capacity decay due to mechanical fracture caused by large volume changes (300%) during repeated electrochemical lithium insertion and extraction. It this talk, I will present the mechanical behaviour of various structure of single crystalline Si nanopillar upon electrochemical lithiation. Single crystalline Si nanopillar array fabricated by top-down process provides well defined dimension and crystalline orientation. The study of lithiated Si nanopillar exhibited interesting phenomena such as anisotropic expansion, size dependency of mechanical fracture, and temperature dependency [1-4]. Single crystalline Si plate various bending behaviour for the crystalline orientation and its large fracture resistance [5]. These studies will provide better understanding of mechanical behaviour of lithited Si anode for design of robust Si anode electrode. Acknowledgement The contents in this paper were published in references [1-5].