Iron Fluoride Packaged into 3D Order Mesoporous Carbons as High-Performance Sodium-Ion Battery Cathode Material

Abstract

The FeF 3 · 0.33H 2 O nanoparticles packaged into three-dimensional order mesoporous carbons (3D-OMCs) as cathode material of sodium-ion batteries (SIBs) was deliberately designed and fabricated by a facile nanocasting technique and mesoporous silica KIT-6 template. The structure, morphology, elemental distribution and electrochemical performance of FeF 3 · 0.33H 2 O@3D-OMCs nanocomposite are investigated by X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM), transmission electron microscope (TEM), energy-dispersive X-ray spectroscope (EDS), Raman spectroscopy and electrochemical measurement. The results show that the as-synthesized FeF 3 · 0.33H 2 O nanoparticles are perfectly packaged in 3D-OMCs matrix, and the size and morphology of FeF 3 · 0.33H 2 O nanoparticles can be effectively controlled. Furthermore, it has been found that the FeF 3 · 0.33H 2 O@3D-OMCs nanocomposite can deliver a high first discharge capacity of 386 mAh g −1 and excellent capacity reservation after 100 cycles at a rate of 20 mA g −1 in the voltage range of 1.0-4.0 V. Especially, even up to 100 mA g −1 , the discharge capacity is still as high as 201 mAh g −1 , indicating a remarkable rate capability. The excellent electrochemical properties of FeF 3 · 0.33H 2 O@3D-OMCs nanocomposite can be because the 3D mesoporous structure of 3D-OMCs can provide an expressway of electron transfer for Na + insertion/extraction, and alleviate the drastic volume variation of FeF 3 · 0. In recently years, lithium-ion batteries (LIBs) have been generally used as an effective energy storage approach in the consumer electronics and electric vehicles (EVs) because of their high energy density, long cycle life and environmentally friendly.1,2 However, the limited resource and high price of lithium salts restrict its further application and development, thus seeking alternative new energy materials have become a hot topic of concern and research. Sodium ion batteries (SIBs) have aroused considerable attention owing to the same high energy density as LIBs, abundant sodium resource, low price and appropriate redox potential for battery applications (E Na + /Na = −2.71 V only 0.3 V above that of lithium). [3][4][5] In addition, sodium, as the second lightest and smallest alkali metal next to lithium, is similar to lithium in physical and chemical properties.

Mn-Doped Fe1–xMnxF3·0.33H2O/C Cathodes for Li-Ion Batteries: First-Principles Calculations and Experimental Study

“…In addition, the existence of crystal water can stabilize the structure and decrease the band gap as well as enhance the electronic conductivity. Therefore, these advantages make it a promising cathode material for LIBs. , In the charge–discharge process, it undergoes two continuous insertion and conversion reactions. During the initial intercalation of Li-ions, intercalated LiFeF 3 ·0.33H 2 O is produced (225 mA h g –1 , 1e – transfer).…”

“…Li et al modified FeF 3 ·0.33H 2 O with single-wall carbon nanotubes, which showed outstanding electrochemical features. Recently, FeF 3 ·0.33H 2 O nanoparticles were packaged into three-dimensional order mesoporous carbon to relieve the volume effect and improve the electronic conductivity . Furthermore, mixing FeF 3 ·0.33H 2 O with acetylene black (AB) via ball-milling is another simple and effective route to improve electronic conductivity.…”

Synthesis and Study of Cathode Materials Based on Carbon Nanotubes for Lithium-Ion Batteries

“…The most presently applied oxide and phosphate cathode materials possess specific capacity not greater than 170 mAh/g, which limits the use of anode materials in them with significantly larger specific capacity [1][2][3][4]. Iron fluoride can also be used to obtain cathode material of LIA [5,6]. However, this material has low conductivity and poor stability to cycling.…”

The State of Research Regarding Ordered Mesoporous Materials in Batteries

“…For instance, batteries have been applied in many fields, such as portable electronic devices and large‐scale energy storage . Notably, they have also been recommended for use in electric vehicles to relieve environmental pollution . To improve energy storage space, energy density, long‐term cycling stability and safety, developing better electrodes for batteries is of significant importance.…”