Preparation of Tough, Binder-Free, and Self-Supporting LiFePO4 Cathode by Using Mono-Dispersed Ultra-Long Single-Walled Carbon Nanotubes for High-Rate Performance Li-Ion Battery

Mingyi Guo, Zengqiang Cao, Yukang Liu, Yuxiang Ni, Xianchun Chen, Mauricio Terrones, Yanqing Wang

Research output: Contribution to journalArticlepeer-review

14 Scopus citations

Abstract

Low-contents/absence of non-electrochemical activity binders, conductive additives, and current collectors are a concern for improving lithium-ion batteries' fast charging/discharging performance and developing free-standing electrodes in the aspects of flexible/wearable electronic devices. Herein, a simple yet powerful fabricating method for the massive production of mono-dispersed ultra-long single-walled carbon nanotubes (SWCNTs) in N-methyl-2-pyrrolidone solution, benefiting from the electrostatic dipole interaction and steric hindrance of dispersant molecules, is reported. These SWCNTs form a highly efficient conductive network to firmly fix LiFePO4 (LFP) particles in the electrode at low contents of 0.5 wt% as conductive additives. The binder-free LFP/SWCNT cathode delivers a superior rate capacity of 161.5 mAh g−1 at 0.5 C and 130.2 mAh g−1 at 5 C, with a high-rate capacity retention of 87.4% after 200 cycles at 2 C. The self-supporting LFP/SWCNT cathode shows excellent mechanical properties, which can withstand at least 7.2 MPa stress and 5% strain, allowing the fabrication of high mass loading electrodes with thicknesses up to 39.1 mg cm−2. Such self-supporting electrodes display conductivities up to 1197 S m−1 and low charge-transfer resistance of 40.53 Ω, allowing fast charge delivery and enabling near-theoretical specific capacities.

Original languageEnglish (US)
Article number2207355
JournalAdvanced Science
Volume10
Issue number13
DOIs
StatePublished - May 5 2023

All Science Journal Classification (ASJC) codes

  • Medicine (miscellaneous)
  • General Chemical Engineering
  • General Materials Science
  • Biochemistry, Genetics and Molecular Biology (miscellaneous)
  • General Engineering
  • General Physics and Astronomy

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