Crystalline-amorphous core-shell silicon nanowires for high capacity and high current battery electrodes

Li Feng Cui, Riccardo Ruffo, Candace K. Chan, Hailin Peng, Yi Cui

Research output: Contribution to journalArticle

943 Scopus citations

Abstract

Silicon is an attractive alloy-type anode material for lithium ion batteries because of its highest known capacity (4200 mAh/g). However silicon's large volume change upon lithium insertion and extraction, which causes pulverization and capacity fading, has limited its applications. Designing nanoscale hierarchical structures is a novel approach to address the issues associated with the large volume changes. In this letter, we introduce a core-shell design of silicon nanowires for highpower and long-life lithium battery electrodes. Silicon crystalline- amorphous core-shell nanowires were grown directly on stainless steel current collectors by a simple one-step synthesis. Amorphous Si shells instead of crystalline Si cores can be selected to be electrochemically active due to the difference of their lithiation potentials. Therefore, crystalline Si cores function as a stable mechanical support and an efficient electrical conducting pathway while amorphous shells store Li ions. We demonstrate here that these core-shell nanowires have high charge storage capacity (̃1000 mAh/g, 3 times of carbon) with ̃90% capacity retention over 100 cycles. They also show excellent electrochemical performance at high rate charging and discharging (6.8 A/g, ̃20 times of carbon at 1 h rate).

Original languageEnglish (US)
Pages (from-to)491-495
Number of pages5
JournalNano Letters
Volume9
Issue number1
DOIs
StatePublished - Jan 1 2009
Externally publishedYes

ASJC Scopus subject areas

  • Bioengineering
  • Chemistry(all)
  • Materials Science(all)
  • Condensed Matter Physics
  • Mechanical Engineering

Fingerprint Dive into the research topics of 'Crystalline-amorphous core-shell silicon nanowires for high capacity and high current battery electrodes'. Together they form a unique fingerprint.

  • Cite this