Fabrication of 3D hexagonal bottle-like Si–SnO2 core–shell nanorod arrays as anode material in on chip micro-lithium-ion-batteries

Abstract

Three-dimensional (3D) Si–SnO₂ composite core–shell nanorod arrays were fabricated as the anode material in lithium ion micro-batteries by nanosphere lithography (NSL) combined with inductive coupled plasma (ICP) dry etching technology. The hexagonal bottle-like Si NR arrays in wafer scale with homogeneous morphology and good mechanical structure provide enough space to accommodate the volume expansion during Li ion insertion/de-insertion processes, while the additionally deposited SnO₂ thin film was prepared to successfully improve the capacities and cycle performance by configuring the 3D Si–SnO₂ NR composite electrode arrays. This fabrication method has the advantages of simplicity, large scale production, easy size and shape manipulations, low cost and Si-process compatibility. This work will facilitate the configuration of solid state micro-batteries for power supply in micro-electronic devices, such as MEMS devices or smart IC chips.