Axial Si–Ge Heterostructure Nanowires as Lithium-Ion Battery Anodes

Killian Stokes^†‡, Grace Flynn^†‡, Hugh Geaney^† , Gerard Bree^†, and Kevin M. Ryan*^† 

^† Bernal Institute and Department of Chemical Sciences, University of Limerick, Limerick, V94 T9PX Ireland

Nano Lett., 2018, 18 (9), pp 5569–5575

DOI: 10.1021/acs.nanolett.8b01988

Publication Date (Web): August 6, 2018

Copyright © 2018 American Chemical Society

*E-mail: Kevin.M.Ryan@ul.ie.

Cite this:Nano Lett.  18, 9, 5569-5575

Here, we report the application of axially heterostructured nanowires consisting of alternating segments of silicon and germanium with a tin seed as lithium-ion battery anodes. During repeated lithiation and delithiation, the heterostructures completely rearrange into a porous network of homogeneously alloyed Si_1–xGe_x ligaments. The transformation was characterized through ex situ TEM, STEM, and Raman spectroscopy. Electrochemical analysis was conducted on the heterostructure nanowires with discharge capacities in excess of 1180 mAh/g for 400 cycles (C/5) and capacities of up to 613 mAh/g exhibited at a rate of 10 C.

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