In situ X-ray diffraction studies of (de)lithiation mechanism in silicon nanowire anodes

Sumohan Misra; Nian Liu; Johanna Nelson; Seung Sae Hong; Yi Cui; Michael F Toney

doi:10.1021/nn301339g

In situ X-ray diffraction studies of (de)lithiation mechanism in silicon nanowire anodes

ACS Nano. 2012 Jun 26;6(6):5465-73. doi: 10.1021/nn301339g. Epub 2012 May 10.

Authors

Sumohan Misra¹, Nian Liu, Johanna Nelson, Seung Sae Hong, Yi Cui, Michael F Toney

Affiliation

¹ Stanford Synchrotron Radiation Lightsource, SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, California 94025, USA.

PMID: 22558938
DOI: 10.1021/nn301339g

Abstract

Silicon is a promising anode material for Li-ion batteries due to its high theoretical specific capacity. From previous work, silicon nanowires (SiNWs) are known to undergo amorphorization during lithiation, and no crystalline Li-Si product has been observed. In this work, we use an X-ray transparent battery cell to perform in situ synchrotron X-ray diffraction on SiNWs in real time during electrochemical cycling. At deep lithiation voltages the known metastable Li(15)Si(4) phase forms, and we show that avoiding the formation of this phase, by modifying the SiNW growth temperature, improves the cycling performance of SiNW anodes. Our results provide insight on the (de)lithiation mechanism and a correlation between phase evolution and electrochemical performance for SiNW anodes.

Publication types

Research Support, Non-U.S. Gov't
Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

Electrodes*
Lithium / chemistry*
Macromolecular Substances / chemistry
Materials Testing
Molecular Conformation
Nanotechnology / methods*
Nanotubes / chemistry*
Nanotubes / ultrastructure*
Particle Size
Silicon / chemistry*
Surface Properties
X-Ray Diffraction

Substances

Macromolecular Substances
Lithium
Silicon