posted on 2024-02-13, 08:29authored byZiwei Zhao, Xuanpan Xu, Hong-En Wang
Exploring
novel anode materials plays a crucial role
in further
improving the overall electrochemical performance of rechargeable
Li-ion batteries (LIBs) for emerging applications in large-scale energy
storage. Vanadium dioxide (VO2) has a high theoretical
capacity and low cost, possessing great potential as an alternative
anode material for rechargeable LIBs. Compared to monoclinic VO2-M and metastable VO2-B, the electrochemical Li-ion
storage capability of tetragonal rutile-type VO2-R (particularly
in the nanoscale form) has been less refined, limiting its potential
application in LIBs. Herein, a heterostructure nanocomposite, constructed
by few-layered reduced graphene oxide (rGO) sheets covered by VO2-R nanoparticles (rGO/VO2-R), has been successfully
synthesized by a controlled wet-chemical route. The resultant rGO/VO2-R composite exhibits good electrochemical properties with
high capacity and superior rate and cycling performances owing to
the effective combination of the high electrical conduction of the
flexible rGO substrate and VO2-R nanoparticles with enhanced
redox kinetics. First-principles simulations reveal that the formation
of a graphene/VO2 heterostructure is energetically feasible.
Further, such a heterostructure can benefit the electron/Li+ transfer and afford abundant sites for Li+ storage at
the interface. The presented research can provide some new insights
into the reasonable design and fabrication of carbon-related (nano)composites
with distinct phase and composition control for promising applications
in rechargeable Li-ion batteries and supercapacitors.