Regulated Breathing Effect of Silicon Negative Electrode for Dramatically Enhanced Performance of Li-Ion Battery

Regulated Breathing Effect of Silicon Negative Electrode for Dramatically Enhanced Performance of Li-Ion Battery

TitleRegulated Breathing Effect of Silicon Negative Electrode for Dramatically Enhanced Performance of Li-Ion Battery
Publication TypeJournal Article
Year of Publication2015
AuthorsXingcheng Xiao, Weidong Zhou, Youngnam Kim, Ill Ryu, Meng Gu, Chongmin Wang, Gao Liu, Zhongyi Liu, Huajian Gao
JournalAdvanced Functional Materials
Volume25
Issue9
Pagination1426 - 1433
Date Published01/2015
Abstract

Si is an attractive negative electrode material for lithium ion batteries due to its high specific capacity (≈3600 mAh g–1). However, the huge volume swelling and shrinking during cycling, which mimics a breathing effect at the material/electrode/cell level, leads to several coupled issues including fracture of Si particles, unstable solid electrolyte interphase, and low Coulombic efficiency. In this work, the regulation of the breathing effect is reported by using Si–C yolk–shell nanocomposite which has been well-developed by other researchers. The focus is on understanding how the nanoscaled materials design impacts the mechanical and electrochemical response at electrode level. For the first time, it is possible to observe one order of magnitude of reduction on breathing effect at the electrode level during cycling: the electrode thickness variation reduced down to 10%, comparing with 100% in the electrode with Si nanoparticles as active materials. The Si–C yolk–shell nanocomposite electrode exhibits excellent capacity retention and high cycle efficiency. In situ transmission electron microscopy and finite element simulations consistently reveals that the dramatically enhanced performance is associated with the regulated breathing of the Si in the new composite, therefore the suppression of the overall electrode expansion.

DOI10.1002/adfm.v25.910.1002/adfm.201403629
Short TitleAdv. Funct. Mater.
Refereed DesignationRefereed