Issue 6, 2018

MOF-derived porous N–Co3O4@N–C nanododecahedra wrapped with reduced graphene oxide as a high capacity cathode for lithium–sulfur batteries

Abstract

The lithium–sulfur (Li–S) battery has been regarded as a highly promising rechargeable energy-storage system due to its high energy density of 2567 W h kg−1. However, moderating the dissolution of lithium polysulfides (LiPSs) and enhancing the conductivity of the sulfur cathode are the main limitations for its successful application. Herein, we demonstrate an approach to simultaneously tackle these two barriers by designing a porous N–Co3O4@N–C nanododecahedral composite. This composite was derived from ZIF-67 via a facile pyrolysis method, which realizes the effective doping of nitrogen into both Co3O4 and the carbon framework, simultaneously achieving a well-defined porous structure. After wrapping with reduced graphene oxide (rGO), this porous N–Co3O4@N–C/rGO cathode supported a high sulfur loading (5.89 mg cm−2) and exhibited excellent stability (611 mA h g−1 at 2C after 1000 cycles). Furthermore, ex situ Raman spectroscopy, ex situ X-ray photoelectron spectroscopy, UV-vis absorption spectroscopy and first-principles calculations confirm that the N–Co3O4@N–C/rGO nanododecahedra effectively bind LiPSs in the electrode over multiple cycles. This proved that the cobalt oxides in the porous N–Co3O4@N–C nanododecahedra have strong affinity for binding LiPSs. The simultaneous doping of nitrogen both into the cobalt oxides and carbon framework not only strengthened the binding energy for LiPSs absorption, but also improved the overall conductivity of the nanododecahedra. Moreover, the interconnected porous structure contributes to the electron transfer and alleviates the volume changes of active materials during cycling.

Graphical abstract: MOF-derived porous N–Co3O4@N–C nanododecahedra wrapped with reduced graphene oxide as a high capacity cathode for lithium–sulfur batteries

Supplementary files

Article information

Article type
Paper
Submitted
22 11月 2017
Accepted
11 1月 2018
First published
11 1月 2018

J. Mater. Chem. A, 2018,6, 2797-2807

MOF-derived porous N–Co3O4@N–C nanododecahedra wrapped with reduced graphene oxide as a high capacity cathode for lithium–sulfur batteries

J. Xu, W. Zhang, Y. Chen, H. Fan, D. Su and G. Wang, J. Mater. Chem. A, 2018, 6, 2797 DOI: 10.1039/C7TA10272K

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