α-Fe₂O₃Submicron Spheres with Hollow and Macroporous Structures as High-Performance Anode Materials for Lithium Ion Batteries

Abstract

α-Fe 2 O 3 submicron spheres with different internal structures were prepared as anode materials for lithium ion batteries (LIBs). Using sulfonated polystyrene (SPS) microspheres as a template, we designed a hollow and macroporous α-Fe 2 O 3 particle structure. The sulfonation degree of polystyrene (SPS) microspheres was controlled by sulfonation reaction time in the range of 24−36 h. After introducing Fe metal precursors by adsorption of ferrous ions into the SPS particles and adding a reduction agent, α-Fe 2 O 3 submicron spheres with hollow and macroporous structures were obtained by heat treatment in an air atmosphere. The internal structure of particles was characterized by scanning electron microscopy, transmission electron microscopy, focused ion beam-scanning electron microscopy, and X-ray diffraction. The electrochemical properties of the hollow and macroporous α-Fe 2 O 3 composite electrodes were investigated by galvanostatic cycling at both constant and variable current rates. The α-Fe 2 O 3 submicron spheres with hollow and macroporous structures exhibited excellent cyclability and rate capability. Electrical impedance spectroscopy was employed to prove the structural effects on the cell performances.

Employment of Chitosan–linked Iron Oxides as Mesoporous Anode Materials for Improved Lithium–ion Batteries

“…The subsequent CV shows two oxidation peaks attributed to the consecutive oxidation of Fe 0 to Fe 2+ and Fe 3+ . In addition, the peak position of reduction potential shifts to higher potential around 0.9 V owing to the subsequent formation of amorphous Li 2 O accompanying with SEI layer [41,42]. 1st, 2nd, and 20th cycles, respectively.…”

Carbon-coated Fe2O3 nanocrystals with enhanced lithium storage capability

“…In principle, the capacity of lithium storage for Fe 2 O 3 is mainly achieved through the reversible conversion reaction between Li + and Fe 2 O 3 , leading to the formation of Fe nanoparticles (NPs) embedded in a Li 2 O matrix [4]. However, this conversion reaction usually induces drastic volume change and severe structural destruction of the electrode upon electrochemical cycling, thereby resulting in fast capacity fading and poor cyclability of Fe 2 O 3 [5][6][7]. In addition, the low conductivity and slow electrode kinetics of Fe 2 O 3 are also very unfavorable for its lithium storage [3,8].…”

PVP-assisted synthesis of flower-like hematite microstructures composed of porous nanosheets

“…It is well known that the morphology and size of a-Fe 2 O 3 show strong effects on their varying chemical and physical properties. Considerable efforts have been devoted to the synthesis of a-Fe 2 O 3 with various shapes so far [10][11][12][13][14][15][16][17][18]. Typically, porous Fe 2 O 3 nanocubes composed of fine Fe 2 O 3 nanoparticles were synthesized by simultaneous oxidative decomposition of Prussian blue nanocubes at high temperature, and these Fe 2 O 3 nanocubes showed high specific capacity (*800 mA h g -1 at 200 mA g -1 ) and excellent cycling performance [11].…”