Necklace-like Si@C nanofibers as robust anode materials for high performance lithium ion batteries

Xiangzhong Kong; Yuchao Zheng; Yaping Wang; Shuquan Liang; Guozhong Cao; Anqiang Pan

doi:10.1016/j.scib.2019.01.015

Necklace-like Si@C nanofibers as robust anode materials for high performance lithium ion batteries

Sci Bull (Beijing). 2019 Feb 28;64(4):261-269. doi: 10.1016/j.scib.2019.01.015. Epub 2019 Jan 30.

Authors

Xiangzhong Kong¹, Yuchao Zheng¹, Yaping Wang¹, Shuquan Liang¹, Guozhong Cao², Anqiang Pan³

Affiliations

¹ School of Materials Science & Engineering, Central South University, Changsha 410083, China.
² Department of Materials Science & Engineering, University of Washington, Seattle, WA 98195, USA.
³ School of Materials Science & Engineering, Central South University, Changsha 410083, China; Key Laboratory of Nonferrous Metal Materials and Engineering Ministry of Education, Central South University, Changsha 410083, China. Electronic address: pananqiang@csu.edu.cn.

PMID: 36659716
DOI: 10.1016/j.scib.2019.01.015

Abstract

Silicon is believed to be a promising anode material for lithium ion batteries because of its highest theoretical capacity and low discharge potential. However, severe pulverization and capacity fading caused by huge volume change during cycling limits its practical application. In this work, necklace-like N-doped carbon wrapped mesoporous Si nanofibers (NL-Si@C) network has been synthesized via electrospinning method followed by magnesiothermic reduction reaction process to suppress these issues. The mesoporous Si nanospheres are wrapped with N-doped carbon shells network to form yolk-shell structure. Interestingly, the distance of adjacent Si@C nanospheres can be controllably adjusted by different addition amounts of SiO₂ nanospheres. When used as an anode material for lithium ion batteries, the NL-Si@C-0.5 exhibits best cycling stability and rate capability. The excellent electrochemical performances can be ascribed to the necklace-like network structure and N-doped carbon layers, which can ensure fast ions and electrons transportation, facilitate the electrolyte penetration and provide finite voids to allow large volume expansion of inner Si nanoparticles. Moreover, the protective carbon layers are also beneficial to the formation of stable solid electrolyte interface film.

Keywords: Carbon shells network; Lithium ion batteries; Mesoporous silicon; N-doped; Necklace-like.