The Effects of Film Thickness and Evaporation Rate on Si-Cu Thin Films for Lithium Ion Batteries

Polat B. D., Keleş Ö.

JOURNAL OF NANOSCIENCE AND NANOTECHNOLOGY, vol.15, no.12, pp.9788-9796, 2015 (SCI-Expanded) identifier identifier identifier

  • Publication Type: Article / Article
  • Volume: 15 Issue: 12
  • Publication Date: 2015
  • Doi Number: 10.1166/jnn.2015.10484
  • Journal Name: JOURNAL OF NANOSCIENCE AND NANOTECHNOLOGY
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED)
  • Page Numbers: pp.9788-9796
  • Keywords: SiCu Thin Film, Anode, Electron Beam Deposition, Lithium Ion Batteries, ELECTRICAL-PROPERTIES, ANODE, MORPHOLOGY, INSERTION, COPPER, SN
  • Istanbul Technical University Affiliated: Yes

Abstract

The reversible cyclability of Si based composite anodes is greatly improved by optimizing the atomic ratio of Si/Cu, the thickness and the evaporation rates of films fabricated by electron beam deposition method. The galvanostatic test results show that 500 nm thick flim, having 10%at. Cu-90%at. Si, deposited with a moderate evaporation rate (10 and 0.9 angstrom/s for Si and Cu respectively) delivers 2642.37 mAh g(-1) as the first discharge capacity with 76% Coulombic efficiency. 99% of its initial capacity is retained after 20 cycles. The electron conductive pathway and high mechanical tolerance induced by Cu atoms, the low electrical resistivity of the film due to Cu3Si particles, and the homogeneously distributed nano-sized/amorphous particles in the composite thin film could explain this outstanding electrochemical performance of the anode.