Issue 28, 2023

Facile synthesis of cobalt fluoride (CoF2)/multi-walled carbon nanotube (MWCNT) nanocomposites and improvement of their electrochemical performance as cathode materials for Li-ion batteries

Abstract

Conversion-type metal fluoride cathodes are considered promising candidates for electrochemical applications owing to their large specific capacities and high operating voltages. However, harnessing the potentially high energy-density of metal fluorides is challenging because of their inherent chemical and electrochemical properties and synthesis issues. Cobalt fluoride (CoF2) is an attractive cathode material among metal fluorides, but it has the common limitations of metal fluorides as above. In this study, a facile synthesis method for CoF2 nanocomposites is developed through the precipitation of cobalt precursors onto multi-walled carbon nanotubes (MWCNTs), followed by heat treatment with ammonium fluoride under an inert atmosphere. This simple and versatile method produces CoF2/MWCNT nanocomposites with improved reversible capacities (554 mA h g−1 at 0.2C) through conversion reactions and superior rate capabilities (a capacity retention of 84.7% at 2C versus 0.2C) at high current densities. In addition, to prevent capacity fading caused by cobalt dissolution during battery cycling, further in situ and ex situ strategies for surface protection are adopted: in situ formation of cathode–electrolyte interphase layers using a fluoroethylene carbonate-containing electrolyte and ex situ coating of aluminum oxide thin layers on the electrode by atomic layer deposition. Consequently, the CoF2/MWCNT nanocomposites maintain a capacity of more than 200 mA h g−1 even after 500 cycles. This study is expected to promote the development of advanced metal fluoride cathodes with high energy densities and long cycle lives.

Graphical abstract: Facile synthesis of cobalt fluoride (CoF2)/multi-walled carbon nanotube (MWCNT) nanocomposites and improvement of their electrochemical performance as cathode materials for Li-ion batteries

Supplementary files

Article information

Article type
Paper
Submitted
31 Marts 2023
Accepted
14 Jūn. 2023
First published
14 Jūn. 2023

J. Mater. Chem. A, 2023,11, 15319-15328

Facile synthesis of cobalt fluoride (CoF2)/multi-walled carbon nanotube (MWCNT) nanocomposites and improvement of their electrochemical performance as cathode materials for Li-ion batteries

H. Park, I. Jang, B. Song, Y. C. Kang, S. Kim and J. Chun, J. Mater. Chem. A, 2023, 11, 15319 DOI: 10.1039/D3TA01918G

To request permission to reproduce material from this article, please go to the Copyright Clearance Center request page.

If you are an author contributing to an RSC publication, you do not need to request permission provided correct acknowledgement is given.

If you are the author of this article, you do not need to request permission to reproduce figures and diagrams provided correct acknowledgement is given. If you want to reproduce the whole article in a third-party publication (excluding your thesis/dissertation for which permission is not required) please go to the Copyright Clearance Center request page.

Read more about how to correctly acknowledge RSC content.

Social activity

Spotlight

Advertisements