Binding SnO2 nanoparticles with MoS2 nanosheets towards highly
reversible and cycle-stable lithium/sodium storage
Abstract
SnO2, with its high theoretical capacity, abundant resources, and
environmental friendliness, is widely regarded as a potential anode
material for lithium-ion batteries (LIBs). Nevertheless, the coarsening
of the Sn nanoparticles impedes the reconversion back to SnO2, resulting
in low coulombic efficiency and rapid capacity decay. In this study, we
fabricated a heterostructure by combining SnO2 nanoparticles with MoS2
nanosheets via plasma-assisted milling. The heterostructure consists of
in-situ exfoliated MoS2 nanosheets predominantly in 1T phase, which
tightly encase the SnO2 nanoparticles through strong bonding. This
configuration effectively mitigates the volume change and particle
aggregation upon cycling. Moreover, the strong affinity of Mo, which is
the lithiation product of MoS2, toward Sn plays a pivotal role in
inhibiting the coarsening of Sn nanograins, thus enhancing the
reversibility of Sn to SnO2 upon cycling. Consequently, the SnO2/MoS2
heterostructure exhibits superb performance as an anode material for
LIBs, demonstrating high capacity, rapid rate capability, and extended
lifespan. Specifically, discharged/charged at a rate of 0.2 A g-1 for
300 cycles, it achieves a remarkable reversible capacity of 1173.4 mAh
g-1. Even cycled at high rates of 1.0 and 5.0 A g-1 for 800 cycles, it
still retains high reversible capacities of 1005.3 and 768.8 mAh g-1,
respectively. Moreover, the heterostructure exhibits outstanding
electrochemical performance in both full LIBs and sodium-ion batteries.