Tuning the morphologies of fluorine-doped tin oxides in the three-dimensional architecture of graphene for high-performance lithium-ion batteries

Abstract

The morphology of electrode materials plays an important role in determining the performance of lithium-ion batteries (LIBs). However, studies on determining the most favorable morphology for high-performance LIBs have rarely been reported. In this study, a series of F-doped SnO (F-SnO and F-SnO) materials with various morphologies was synthesized using ethylenediamine as a structure-directing agent in a facile hydrothermal process. During the hydrothermal process, the F-SnO was embedded in situ into the three-dimensional (3D) architecture of reduced graphene oxide (RGO) to form F-SnO @RGO composites. The morphologies and nanostructures of F-SnO , i.e., F-SnO nanocrystals, F-SnO nanosheets, and F-SnO aggregated particles, were fully characterized using electron microscopy, x-ray diffraction, and x-ray photoelectron spectroscopy. Electrochemical characterization indicated that the F-SnO nanocrystals uniformly distributed in the 3D RGO architecture exhibited higher specific capacity, better rate performance, and longer cycling stability than the F-SnO with other morphologies. These excellent electrochemical performances were attributed to the uniform distribution of the F-SnO nanocrystals, which significantly alleviated the volume changes of the electrode material and shortened the Li ion diffusion path during lithiation/delithiation processes. The F-SnO@RGO composite composed of uniformly distributed F-SnO nanocrystals also exhibited excellent rate performance, as the specific capacities were measured to be 1158 and 648 mA h g at current densities of 0.1 and 5 A g, respectively.

Insights into the Plasma-Assisted Fabrication and Nanoscopic Investigation of Tailored MnO2 Nanomaterials

“…In fact, a careful analysis of XRD data revealed a progressive shift of the (101) β-MnO 2 reflection toward lower angular values upon decreasing T G . This effect could be traced back to the parallel increase of fluorine content (Figure ), resulting in a strain of the lattice structure − and in a (101) peak location at 2θ = 36.7°, ∼0.6° lower than the reference β-MnO 2 value . In any case, the absence of peaks related to secondary F-containing phases proved a successful fluorine insertion in the oxide lattice .…”

“…Besides the adopted preparation route, a valuable method to manipulate MnO 2 chemico-physical characteristics involves its controlled doping. ,, So far, various examples on cation-doped MnO 2 systems are present, ,, whereas the use of anionic dopants, such as fluorine, has never been reported. Interestingly, F introduction in the oxide network can not only affect the system composition and morphology, but also yield the passivation of surface defects, thus resulting in an enhanced electrical conductivity and higher Lewis acidity of the metal center, of utmost importance for energy storage, gas sensing, and photocatalytic applications. ,− In particular, in the latter field, defect passivation suppresses the undesired recombination of photogenerated charge carriers, the enhanced material conductivity favors electrons and holes migration toward surface adsorbates, whereas the increased Mn acidity improves the system reactivity. Hence, fluorine doping appears as a flexible and amenable tool to tailor the ultimate material performances.…”

Tin Oxide Based Nanomaterials and Their Application as Anodes in Lithium‐Ion Batteries and Beyond

“…Another strategy to improve the performance of SnO 2 ‐based anode materials is to use doped SnO 2 nanoparticles and graphene as a support material –. Zoller et al.…”

Highly Aligned Graphene Oxide for Lithium Storage in Lithium‐Ion Battery Through A Novel Microfluidic Process: The Pulse Freezing

“…[ 28 ] Similar reports of fluorine‐doped tin oxides decorated graphene are reported with 1158 mAh g −1 at 0.1 A g −1 . [ 29 ] In another example, the self‐standing anodes made of MgMoO 4 /reduced graphene oxide nanosheet arrays are reported with a highly aligned but less porous microstructure. The prepared half cells of the nanosheet arrays show a capacitance of 300 mAh g −1 at the low current density of 0.5 A g −1 .…”