Vertically aligned ultrathin MoS
2
nanosheets grown on graphene-
wrapped hollow carbon microtubes derived from loofah sponge as
advanced anodes for highly reversible lithium storage
Yan Guo
a
,
b
,
1
, Yingge Zhang
a
,
b
,
1
, Yange Wang
a
,
b
,
1
, Deyang Zhang
a
,
b
, Yang Lu
a
,
b
,
Rongjie Luo
a
,
b
, Yangbo Wang
a
,
b
, Xianming Liu
c
, Jang-Kyo Kim
d
, Yongsong Luo
a
,
b
,
*
a
School of Physics and Electronic Engineering, Xinyang Normal University, Xinyang 46400 0, PR China
b
Key Laboratory of Microelectronics and Energy of Henan Province, Xinyang Normal University, Xinyang 464000, PR China
c
College of Chemistry and Chemical Engineering, Luoyang Normal University, Luoyang 471934, PR China
d
Department of Mechanical and Aerospace Engineering, Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, China
article info
Article history:
Received 6 September 2018
Received in revised form
31 October 2018
Accepted 21 November 2018
Available online 22 November 2018
Keywords:
Biomass hollow microtubes
Graphene
Loofah sponge
MoS
2
nanosheets
Lithium-ion batteries
abstract
Using low cost, environment-friendly, and sustainable biomass is a unique approach to the preparation
carbon-based composites for lithium ion batteries. In our research, hollow, derived microtubes (HMD)
were fabricated from graphene/loofah sponge. Each microtube was wrapped with graphene, resulting in
conductivity improvement, and facilitated easily controlled growth of ultra-thin MoS
2
nanosheets. The
method employed a simple process of soaking the HMD in graphene oxide (GO) dispersion liquid, and
subsequent carbonization and activation of the HMD/rGO. When ultrathin MoS
2
nanosheets were
vertically and uniformly grown on the surface of the HMD/rGO, via the hydrothermal method, the HMD/
rGO/MoS
2
composite was obtained, and exhibited reversible lithium storage capacity of 838.2 mAh g
1
at
a current density of 0.2 A g
1
after 200 cycles. This excellent electrochemical performance could be due
to the high conductivity of HMD/rGO, a synergistic effect between HMD/rGO and MoS
2
nanosheets, a
reasonable structural design, and the high theoretical specific capacity of MoS
2
. Such a structure not only
provides a novel, high-quality carbon template/matrix from cheap loofah sponge, but also provides a
new way to design sustainable electrodes for electrochemical energy storage, and makes economical,
multifunctional, carbon-based hybrids available for other applications.
© 2018 Elsevier Ltd. All rights reserved.
1. Introduction
Lithium-ion batteries (LIBs) have become a major source of
stored power, due to their high energy density, high operating
voltage, cycling stability, and to being environmentally benign.
They are widely used in electronic products, especially in portable
electronics, in consumer electronics, and as renewable energy
storage devices [1,2]. Now, it is very promising to exploit the gra-
phene nanosheets as a perfect conductive support for nanoparticles
to form hybrid nanocomposites [3,4]. Graphite is currently used as
the anode material for LIBs, but cannot fully meet LIBs high energy
density requirements, due to its relatively small theoretical specific
capacity (372 mAh g
1
), and low lithium intercalation voltage [5,6].
Therefore, exploring alternative anode materials, such as graphene-
based composites, could be a useful direction for LIBs [5], although
currently, various sulfide anode materials, especially transition-
metal dichalcogenide (TMDC), have been intensively investigated,
due to their low cost, and superior electrochemical performance
[7]. Among TMDC materials, layered structure MoS
2
, has drawn
considerable attention, due to its high theoretical specific capacity
(~670 mAh g
1
), and small volume change during lithiation/deli-
thiation cycles [8e10]. Nevertheless, limited conductivity, inevi-
table volume change, and aggregation of nanoparticles at the MoS
2
anode during repeated charge/discharge processes, lead to its poor
rate and cycling performances, and significant capacity loss
[11e14].
To address these issues, various studies have been performed,
and results have shown that compositing nanostructured MoS
2
with carbon materials has the potential to improve its performance,
* Corresponding author. School of Physics and Electronic Engineering, Xinyang
Normal University, Xinyang 464000, PR China.
E-mail address: ysluo@xynu.edu.cn (Y. Luo).
1
Y. G., Y. G. Z., and Y. G. W. contributed equally to this work.
Contents lists available at ScienceDirect
Electrochimica Acta
journal homepage: www.elsevier.com/locate/electacta
https://doi.org/10.1016/j.electacta.2018.11.148
0013-4686/© 2018 Elsevier Ltd. All rights reserved.
Electrochimica Acta 296 (2019) 989e998