Atomic-scale combination of germanium-zinc nanofibers for structural and electrochemical evolution.

Author(s) Song, G.; Cheong, J.Young; Kim, C.; Luo, L.; Hwang, C.; Choi, S.; Ryu, J.; Kim, S.; Song, W.J.; Song, H.K.; Wang, C.; Kim, I.D.; Park, S.
Journal Nat Commun
Date Published 2019 05 30
Abstract

Alloys are recently receiving considerable attention in the community of rechargeable batteries as possible alternatives to carbonaceous negative electrodes; however, challenges remain for the practical utilization of these materials. Herein, we report the synthesis of germanium-zinc alloy nanofibers through electrospinning and a subsequent calcination step. Evidenced by in situ transmission electron microscopy and electrochemical impedance spectroscopy characterizations, this one-dimensional design possesses unique structures. Both germanium and zinc atoms are homogenously distributed allowing for outstanding electronic conductivity and high available capacity for lithium storage. The as-prepared materials present high rate capability (capacity of ~ 50% at 20 C compared to that at 0.2 C-rate) and cycle retention (73% at 3.0 C-rate) with a retaining capacity of 546 mAh g even after 1000 cycles. When assembled in a full cell, high energy density can be maintained during 400 cycles, which indicates that the current material has the potential to be used in a large-scale energy storage system.

DOI 10.1038/s41467-019-10305-x
ISSN 2041-1723
Citation Song G, Cheong JY, Kim C, Luo L, Hwang C, Choi S, et al. Atomic-scale combination of germanium-zinc nanofibers for structural and electrochemical evolution. Nat Commun. 2019;10(1):2364.