Chamber-confined silicon-carbon nanofiber composites for prolonged cycling life of Li-ion batteries


Fu K., Lu Y., Dirican M., Chen C., Yanilmaz M. , Shi Q., ...More

NANOSCALE, vol.6, no.13, pp.7489-7495, 2014 (Journal Indexed in SCI) identifier identifier

  • Publication Type: Article / Article
  • Volume: 6 Issue: 13
  • Publication Date: 2014
  • Doi Number: 10.1039/c4nr00518j
  • Title of Journal : NANOSCALE
  • Page Numbers: pp.7489-7495

Abstract

Silicon is a promising high capacity (4200 mA h g(-1)) anode material for lithium ion batteries but the significant volume change (over 300%) of silicon during lithiation/delithiation remains a challenge in terms of silicon pulverization and solid-electrolyte-interphase (SEI) accumulation in the silicon composite electrode. To alleviate the volumetric change of silicon, we built a flexible and self-supporting carbon-enhanced carbon nanofiber (CNF) structure with vacant chamber to encapsulate Si nanoparticles (vacant Si@CNF@C). This composite was tested directly without any polymer and current collector. The confined vacant chamber allowed the increasing volume of silicon and SEI accumulates to be well retained for a long cycle life. This chamber-confined silicon-carbon nanofiber composite exhibited an improved performance in terms of good cycling performance (620 mA h g(-1)), high coulombic efficiency (99%), and good capacity retention (80%) after 200 cycles. This self-supported silicon-carbon nanofiber structure showed high flexibility and good electrochemical performance for the potential as flexible electrode for lithium-ion batteries.