Jessica Doherty, David McNulty, Subhajit Biswas, Kalani Moore, Michele Conroy, Ursel Bangert, Colm O'Dwyer and Justin D Holmes

2020

January

Nanotechnology

Germanium tin alloy nanowires as anode materials for high performance Li-ion batteries

Published

()

31

165402

165402

The combination of two active Li-ion materials (Ge and Sn) can result in improved conduction paths and higher capacity retention. Here we report for the first time, the implementation of Ge1–x Sn x alloy nanowires as anode materials for Li-ion batteries. Ge1−x Sn x alloy nanowires have been successfully grown via vapor–liquid–solid technique directly on stainless steel current collectors. Ge1−x Sn x (x = 0.048) nanowires were predominantly seeded from the Au0.80Ag0.20 catalysts with negligible amount of growth was also directly catalyzed from stainless steel substrate. The electrochemical performance of the the Ge1−x Sn x nanowires as an anode material for Li-ion batteries was investigated via galvanostatic cycling and detailed analysis of differential capacity plots (DCPs). The nanowire electrodes demonstrated an exceptional capacity retention of 93.4% from the 2nd to the 100th charge at a C/5 rate, while maintaining a specific capacity value of ~921 mAh g−1 after 100 cycles. Voltage profiles and DCPs revealed that the Ge1−x Sn x nanowires behave as an alloying mode anode material, as reduction/oxidation peaks for both Ge and Sn were observed, however it is clear that the reversible lithiation of Ge is responsible for the majority of the charge stored.

https://iopscience.iop.org/article/10.1088/1361-6528/ab6678

https://doi.org/10.1088/1361-6528/ab6678