Browse

Visualization of regulated nucleation and growth of lithium sulfides for high energy lithium sulfur batteries

Cited 23 time in Web of Science Cited 27 time in Scopus
Authors
Xu, Zheng-Long; Kim, Sung Joo; Chang, Donghee; Park, Kyu-Young; Dae, Kyun Seong; Dao, Khoi Phuong; Yuk, Jong Min; Kang, Kisuk
Issue Date
2019-10
Citation
Energy and Environmental Sciences, Vol.12 No.10, pp.3144-3155
Abstract
The formation of lithium sulfides as discharge products imparts high specific energy density to lithium sulfur batteries (LSBs), however, the involvement of soluble intermediates in the battery reaction makes it challenging to achieve it reversibly for extended cycles. The precise understanding of phase transitions from the soluble intermediates to solid discharge products would aid in fundamentally resolving practical issues involving the intermediates, and thus allow the realization of long-lived high-energy-density LSBs. Herein, we utilize liquid in situ transmission-electron-microscopy (TEM) to probe detailed liquid-solid reaction processes. It reveals that the surface nature of the host materials of the polysulfides critically influences the growth mechanism of lithium sulfides. It is elucidated that polar hosts induce instantaneous nucleation of lithium sulfides, followed by diffusion-controlled-to-reaction-limited growth kinetics and a crystalline-to-amorphous phase transition. Moreover, it is verified that polysulfides are better immobilized in polar hosts, whereas polysulfide diffusion through nonpolar hosts is evidently observed, leading to the eventual degradation of cells. Based on these findings, an optimal host structure for sulfur is proposed, where the dual walls of polar (inner)/nonpolar (outer) spheres confine the polysulfides. The new cathode exhibits remarkable electrochemical performance, retaining a capacity of 4.3 mA h cm(-2) over 400 cycles at a low electrolyte/sulfur ratio of 6.8 ml g(-1), which rivals state-of-the-art LSBs. This work contributes the first liquid in situ TEM study of liquid-solid phase evolution for high energy electrode materials.
ISSN
1754-5692
URI
https://hdl.handle.net/10371/164955
DOI
https://doi.org/10.1039/c9ee01338e
Files in This Item:
There are no files associated with this item.
Appears in Collections:
College of Engineering/Engineering Practice School (공과대학/대학원)Dept. of Material Science and Engineering (재료공학부) Journal Papers (저널논문_재료공학부)
  • mendeley

Items in S-Space are protected by copyright, with all rights reserved, unless otherwise indicated.

Browse