Carbon/Polymer Bilayer-Coated Si-SiOx Electrodes with Enhanced Electrical Conductivity and Structural Stability

Junpo Guo, Guangming Zhao, Tian Xie, Dongqi Dong, Chuanli Ma, Linghao Su, Liangyu Gong, Xiangdong Lou, Xuyun Guo, Jie Wang, Ye Zhu

Research output: Journal article publicationJournal articleAcademic researchpeer-review

19 Citations (Scopus)


Si-based electrodes offer exceptionally high capacity and energy density for lithium-ion batteries (LIBs),but suffer from poor structural stability and electrical conductivity that hamper their practical applications. To tackle these obstacles, we design a C/polymer bilayer coating deposited on Si-SiOx microparticles. The inner C coating is used to improve electrical conductivity. The outer C-nanoparticle-reinforced polypyrrole (CNP-PPy) is a polymer matrix composite that can minimize the volumetric expansion of Si-SiOx and enhance its structural stability during battery operation. Electrodes made of such robust Si-SiOx@C/CNP-PPy microparticles exhibit excellent cycling performance: 83% capacity retention (794 mAh g-1) at a 2 C rate after more than 900 cycles for a coin-type half cell, and 80% capacity retention (with initial energy density of 308 Wh kg-1) after over 1100 cycles for a pouch-type full cell. By comparing the samples with different coatings, an in-depth understanding of the performance enhancement is achieved, i.e., the C/CNP-PPy with cross-link bondings formed in the bilayer coating plays a key role for the improved structural stability. Moreover, a full battery using the Si-SiOx@C/CNP-PPy electrode successfully drives a car model, demonstrating a bright application prospect of the C/polymer bilayer coating strategy to make future commercial LIBs with high stability and energy density.

Original languageEnglish
Pages (from-to)19023-19032
Number of pages10
JournalACS applied materials & interfaces
Issue number16
Publication statusPublished - 22 Apr 2020


  • bilayer
  • C coating
  • C nanoparticle reinforced polypyrrole
  • lithium-ion battery (LIB)
  • polymer matrix composite
  • Si-based electrode

ASJC Scopus subject areas

  • General Materials Science


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