1 research outputs found
Bi<sub>2</sub>S<sub>3</sub> Nanorods Deposited on Reduced Graphene Oxide for Potassium-Ion Batteries
Hierarchical nanocomposites with surface active bonding
features
serve as an efficient electrode material for high-performance Li-/Na-/K-ion
batteries. Tuning the physiochemical properties of these hierarchical
nanocomposites has a great impact on the extremely improved electrochemical
performance, and it is attributed to the synergistic effect of heterogeneous
components. Herein, we report a hydrothermally synthesized bismuth
sulfide (Bi2S3) nanorod bonding on the surface
of the reduced graphene oxide (rGO) matrix and investigate it as an
anode material for potassium-ion batteries. This hierarchical nanocomposite
anode exhibits a high initial reversible capacity (586 mA h g–1 at 100 mA g–1), long-term cycling
stability (410 mA h g–1 after 1000 cycles, 70% capacity
retention), and an outstanding rate capability (140 mA h g–1 at 3 A g–1). This excellent electrochemical performance
of the Bi2S3/rGO nanocomposite is attributed
to the presence of active sites in rGO nanosheets that not only enhances
the electrical conductivity of Bi2S3 nanorods
but also prevents the shuttle effect of polysulfide through the formation
of the in-built C–S bond, which is confirmed by X-ray photoelectron
spectroscopy. Through the ex-situ X-ray diffraction patterns analysis
at different voltage regions, a phase transformation mechanism has
been proposed for K-ion storage in Bi2S3 nanorods.
An ex-situ high-resolution transmission electron microscopy analysis
reveals the structural and morphological stability of Bi2S3 nanorods. Further, the kinetic studies confirmed that
the surface dominated pseudocapacitive K-ion storage also plays a
major role in improving the electrochemical performance of the Bi2S3 nanorods/rGO nanocomposite. The K-ion full cell
is successfully assembled, which exhibits stable cycling performance
after 100 cycles at 1 C rate