Synthesis of rGO-Fe3O4-SnO2-C Quaternary Hybrid Mesoporous Nanosheets as a High-performance Anode Material for Lithium Ion Batteries

Abstract

Graphical abstractHighlights  rGO-Fe3O4-SnO2-C quaternary hierarchical nanosheets were synthesized. Nano pores with an average size of 5.8 nm were fabricated within the nanosheets. rGO-Fe3O4-SnO2-C nanosheets exhibits excellent cycling performances. rGO-Fe3O4-SnO2-C anode displays low resistance and high structural stability. Abstract: A quaternary hierarchical nanocomposite, rGO-Fe3O4-SnO2-C, is rationally designed and synthesized via layer-by-layer constructions of reduced graphene oxide (rGO) flexible films, Fe3O4 nanoparticles, SnO2 nanoparticles and an omnidirectional amorphous carbon layer. SEM and TEM observations show that the Fe3O4 and SnO2 nanoparticles are uniformly dispersed on the rGO nanosheets and fully encapsulated by the outmost carbon layers, forming a sandwich-like buffering structure for excellent dimensional integrity. Furthermore, nanopores with an average size of 5.8 nm are fabricated within the quaternary hybrid nanosheets via a layer-by-layer packing of Fe3O4 and SnO2 nanoparticles, which possess the different shapes and sizes.Galvanostatic charge/discharge measurements demonstrate that rGO-Fe3O4-SnO2-C 1 exhibits a reversible capacity of 868.6 mAh g −1 after 100 cycles at a current density of 200 mA g −1 . Even at a current density of 2.0 A g −1 , it can be stably operated during the discharge/charge processes and deliver a reversible capacity of 414.7 mAh g −1 . The excellent electrochemical properties of rGO-Fe3O4-SnO2-C can be attributed to the microstructural stability of the hybrid and the synergistic effects of the components inside the nanosheets.

Exfoliation of Nanosized α-Zirconium Phosphate in Methanol

“…Two-dimensional (2D) inorganic materials have been extensively applied in the field of catalysis, − soft photonics, − functional devices, − CO 2 adsorbents, − energy storage devices, − and gas barrier coating. − As a type of unique 2D material, crystalline α-zirconium phosphate (Zr­(HPO 4 ) 2 ·H 2 O, α-ZrP) is a layered inorganic material first synthesized by Clearfield and Stynes . Its distinctive structure has attracted researchers’ high attention, − and α-ZrP thereafter can also find various applications, including as cation exchangers, , proton conductors, − acid catalysts, ,− and drug delivery carriers. − Very often, single-layer or few-layer nanosheets are highly desired for applications instead of as-synthesized multilayered microcrystals to maximize surface activity, and herein the exfoliation of α-ZrP microcrystals into individual single-layer nanosheets is necessary.…”

Rational Design and Controllable Synthesis of Multishelled Fe2O3@SnO2@C Nanotubes as Advanced Anode Material for Lithium-/Sodium-Ion Batteries

“…In this work, multishelled Fe 2 O 3 @SnO 2 @C (FSC) nanotubes were designed and synthesized by using Fe 2 O 3 (FO) nanotube templates and the Ostwald interaction method. The as-resulted multishelled FSC nanotubes deliver the following characteristics and are especially suitable for applications in LIBs/SIBs: (i) novel nanostructure, uniform particle size, and carbon-coated network can inhibit the agglomeration, improve the conductivity, and stabilize the structure in the charge–discharge process; (ii) special multigap porous tubular structure can act as active sites for lithium/sodium storage and inhibition of volume change improvement of electrochemical performance; , (iii) using Fe 2 O 3 and SnO 2 , combined with fabrication of active/inactive substances, can alleviate volume changes, when one substance reacts with Na at a certain potential, while another inactive substance acts as a buffer . In order to further highlight the remarkable electrochemical performances, differential capacity plots of FO nanotubes and Fe 2 O 3 @SnO 2 (FS) double-shelled nanotubes were also studied.…”

Heterogeneous Double-Shelled Constructed Fe3O4 Yolk–Shell Magnetite Nanoboxes with Superior Lithium Storage Performances

“…Compared with α-Fe 2 O 3 @SnO 2 and α-Fe 2 O 3 , the redox peaks Fe 3 O 4 @SnO 2 @C–N in the subsequent two cycles are nearly overlapped, suggesting that the Fe 3 O 4 @SnO 2 @C–N nanocomposites have better stability and reversibility. In this case, metal oxides composite might show the unique synergistic effect, which can enhance the electrochemical performance of composites. ,− While one metal oxide reacts with lithium, the other may adsorb the relevant volume change. , Furthermore, Fe and Sn are alternately generated due to their different charging and discharging plateaus. Fe or Sn regarded as a conductive matrix promotes the electrochemistry reaction of each other …”