Study of Direct Lithiation of Thin Si Membranes with Spatially-Correlative Low Energy Focused Li Ion Beam and Analytical Electron Microscopy Techniques

Published

November 22, 2016

Author(s)

Vladimir P. Oleshko, Christopher L. Soles, Kevin A. Twedt, J J. McClelland

Abstract

Understanding and controlling defect interactions and transport properties of Li ions in silicon is crucial for the development of emerging technologies in energy storage and microelectronics. With a theoretical energy storage capacity of ~4200 mAhg-1, which is more than 10 times over than that of graphite (372 mAhg-1), Si is an attractive anode material for high-performance Li-ion batteries. The practical use of Si-based anodes is, however, hampered by the large volumetric changes (up to ~400%) that occur during electrochemical charge/discharge cycling and the concomitant capacity fading. Further insights into fundamental mechanisms of Li-Si reactions are needed to address these problems. Here, we report on controlled low dose Li+ ion implantation into 9 nm-thick amorphous (a-Si) membranes and 35 nm-thick single crystalline -oriented (c-Si) membranes using a low-energy focused lithium ion beam. With probe sizes of a few tens of nanometers at energies ranging from 500 eV to 6 keV and beam currents of a few pA, the LiFIB enables surface topography and composition sensitive imaging using ion-induced secondary electrons (iSE) and backscattered ions (BSI), respectively [5]. Furthermore, the LiFIB has a unique ability to implant certain amounts of 7Li+ ions into any material with nanoscale precision, making it a potentially powerful tool for advanced battery materials research and material design via defect engineering and surface modification.

Citation

Microscopy and Microanalysis

Pub Type

Journals

Keywords

nanometrology of electrochemical energy storage materials, focused ion and electron beam-based optical measurement methods

Citation

Oleshko, V. , Soles, C. , Twedt, K. and McClelland, J. (2016), Study of Direct Lithiation of Thin Si Membranes with Spatially-Correlative Low Energy Focused Li Ion Beam and Analytical Electron Microscopy Techniques, Microscopy and Microanalysis (Accessed December 22, 2024)