Amorphization driven Na-Alloying in SixGe1-x alloy nanowires for Na-ion batteries
Here we report the use of 1D SixGe1−x (x = 0.25, 0.5, 0.75) alloy nanowires (NWs) as anode materials for Na-ion batteries (NIBs). The strategy involves the synthesis of crystalline SixGe1−x NWs via the solution–liquid–solid (SLS) mechanism, followed by amorphization to activate the material for Na-ion cycling within a NIB. This study demonstrates the successful activation of SixGe1−x amorphous NW alloys, with a-Si0.5Ge0.5 delivering 250 mA h g−1 as compared to a-Ge NWs delivering only 107 mA h g−1 after 100 cycles. Also, amorphization proved to be a critical step, since crystalline NWs failed to activate in NIBs. However, Si NWs performed poorly during Na-ion cycling even after amorphization, and this behavior was explained by poor comparative Na-ion diffusivity. Further investigations on the impact of the relative content of Ge within the amorphized SixGe1−x NWs, Na-ion diffusivity and electrode degradation during cycling were also performed. Notably, the incorporation of Ge in the a-SixGe1−x alloy boosted Na ion diffusivity in the amorphized alloy, resulting in improved cycling performance and rate capability as compared to parent a-Si and a-Ge NWs.
Funding
Multinary Compound Si, Ge and Sn Derived Nanocrystals: Composition, Shape and Heterostructure Control via Solution Methods (NanoIVCrystals)
Science Foundation Ireland
Find out more...History
Publication
Journal of Materials Chemistry A, 36, pp. 20626-20634Publisher
Royal Society of ChemistryOther Funding information
K. M. R. further acknowledges IRCLA/2017/285Rights
© 2021 Royal Society of Chemistry. Personal use of this material is permitted. Permission from Royal Society of Chemistry must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other worksAlso affiliated with
- Bernal Institute
External identifier
Department or School
- Chemical Sciences