CHEMICAL ENGINEERING JOURNAL
·
2017
·
IF 6.216
Pan Liu,Xiangyu Li,Long Cheng,Xuqiang Zhu,Yanchun Li,Dongming Song
A new type of nanothermite composed of n-Al (metal fuel) and FeF 3 (oxidizer) was investigated in this paper. The thermal behavior and combustion properties of the n-Al/FeF 3 nanothermite were compared with that of n-Al/Fe 2 O 3 nanothermite by TG/DSC-MS, XRD, SEM and high-speed camera. The results showed that the decomposition of FeF 3 begins at 300 °C and releases free F ions. The F ions react with Al 2 O 3 shell covered on the surface of aluminum. The start and exothermic peak temperatures of the major reaction of n-Al/FeF 3 are at 415 °C and 520 °C respectively, which are 95 °C and 34 °C lower than those of n-Al/Fe 2 O 3 . Furthermore, the FeF 3 will be reduced to Fe completely at 700 °C. However, the Fe 2 O 3 could only be converted to Fe 3 O 4 . It demonstrates that the reaction of n-Al/FeF 3 is completely, but only a part of n-Al/Fe 2 O 3 reacts at 700 °C. The n-Al/FeF 3 has larger, brighter flame and shorter burning time than n-Al/Fe 2 O 3 in open air.
研究领域:
材料科学
·
燃烧化学
✓ 已验证
产品关联
DOI
高影响因子
ACS Applied Electronic Materials
·
2024
·
IF 4.3
Zhenyu Xiao,Licai Fu,Jiajun Zhu,Wulin Yang,Deyi Li,Lingping Zhou
H2O, with its mild etching ability, was frequently used to regulate the morphology and crystal structure of substances, thereby enhancing their properties. Inspired by this, we utilized the crystal H2O in FeF3·3H2O to perform an etching process with an aim to improve the conductivity of FeF3, which could enhance its capacity level and rate capabilities. Herein, this research reported that this in-situ etching was conducted during the dehydration of FeF3·3H2O; meanwhile, the surface of the FeF3 grains was roughened, and traces of iron oxyfluoride were produced on it. The conductivity of the FeF3 grains was significantly enhanced, attributed to the semiconducting property of iron oxyfluoride. Moreover, the rough surface increased the effective contact area between the grains and the electrolyte, thereby increasing the exchange flux of Li+. With the increased quantity of iron oxyfluoride compounds, the charge transfer resistance of the electrode was reduced from 61.87 to 37.2 Ω, and the initial discharge capacity increased from 83.5 to 108.1 mAh g–1 at 2C. This finding provided strategies and methods for the surface modification of compound materials. Especially for halogen metal compounds with high theoretical capacity energy density, their chemical performance can be improved by in-situ defect engineering in the process of dehydration of their hydrates.
研究领域:
材料科学
·
电化学
✓ 已验证
产品关联
DOI
高影响因子
GREEN CHEMISTRY
·
2024
·Vol. 26
·期 24
·11924-11933
·
IF 9.3
Jinlong Hu,Weijun Xu,Lingzhi Zhang
Metal fluorides confined in heteroatom-doped carbon nanostructures are viewed as one of the most promising high capacity cathodes for high-performance lithium rechargeable batteries. Herein, we present a facile in situ reaction approach to synthesize nitrogen-doped porous carbon (NPC)-confined metal fluorides, which involves in situ etching toward a Schiff-base organic precursor and fluorination of metal oxides by polytetrafluoroethylene during a one-step heating process. The afforded NPC-confined FeF3 (FeF3@NPC) facilitates fast Li+/e− diffusion kinetics, accommodates severe volume fluctuation and reduces the FeF3 cathode dissolution, thus providing an outstanding high-rate capacity of 181 mA h g−1 at 5 C, accompanied by superior cycle life within 500 cycles at 2 C. This novel approach opens up new horizons to design high-performance nanoconfined metal fluoride-based materials for sustainable energy applications.
研究领域:
材料科学
·
能源存储
✓ 已验证
产品关联
DOI
高影响因子
ELECTROCHIMICA ACTA
·
2018
·
IF 5.116
Jia Li,Licai Fu,Zhanwei Xu,Jiajun Zhu,Wulin Yang,Deyi Li,Lingping Zhou
Iron fluorides have drawn much attention in Li-ion batteries due to high theoretical capacity. However, its application progress is hampered by the inferior electrode cyclability and rate capability. The main issue in this work is to find effective ways to improve the electrochemical activity of iron fluoride (FeF 3 ), and enhance the electrochemical properties. Herein, carbon wrapped FeF 3 nanocomposite has been synthesized progressively by carbon coating and fluorination . This structure not only keeps the grain size of FeF 3 about 60 nm, but also immerses the electrode in the electrolyte fully. So the electrode shows excellent electrochemical activity. This nano-composite exhibits an initial discharge capacity of ∼166.4 mAh g −1 in the voltage of 2.0–4.5 V at 20 mA g −1 . After 100 cycle, the discharge capacity keeps about 126.3 mAh g −1 , with the fading rate of ∼0.24%. Furthermore, the EIS of carbon winded FeF 3 indicates that the transmission ability of lithium ion improved greatly. This structure is very meaningful to provide a synthetic approach to prepare the cathode material.
研究领域:
材料科学
·
电化学
✓ 已验证
DOI
高影响因子
ENERGY & FUELS
·
2024
·
IF 5.2
Tingting Chen,Hanghui Liu,Mingqing Sun,Bowen Yang,Peixiang Ning,Xiaohui Zhu,Serguei V. Savilov,Sergey M. Aldoshin,Jing Xu,Hui Xia
As a promising high-energy-density cathode material for lithium-ion batteries, the application of FeF3 is significantly impeded by its sluggish kinetics. In this study, we propose a straightforward method to fabricate quasi-two-dimensional (quasi-2D) oxygen-doped FeF3 nanosheets through the thermal decomposition and liquid-phase exfoliation of commercial FeF3·3H2O. During the thermal decomposition process, some fluorine atoms are substituted by oxygen atoms, resulting in enhanced electrical conductivity and a reduction in the dissociation energy of Fe–F bonds. In addition, the quasi-2D geometrical feature reduces the diffusion length of Li ions. Consequently, this free-standing electrode delivers a high specific capacity (∼600 mAh g–1 at a low current density of 0.03 A g–1), a stable cycling performance over 200 cycles at a current density of 0.3 A g–1 (with a capacity retention of 82%), and excellent rate capability (350 mAh g–1 at 2 A g–1). A more profound insight into the kinetics of this electrode reveals that Li ions preferentially diffuse along the thickness of the non-layered nanosheets, significantly contributing to the outstanding rate performance. Thus, this study tackles the kinetic challenges of FeF3 in terms of the electronic and geometrical structures, offering valuable insights for the development of high-performance electrode materials based on the conversion reaction mechanism.
研究领域:
材料科学
·
能源存储
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF THE ELECTROCHEMICAL SOCIETY
·
2021
·Vol. 168
·期 3
·030501
·
IF 4.316
Liuyang Zhao,Huimin Xu,Hao Ru,Yueli Shi,Quanchao Zhuang,Yongli Cui,Zhicheng Ju,Yanhua Cui
Conversion-type lithium–metal fluoride batteries with high energy density, are considered to be very promising candidates for the next generation of low-cost lithium-ion batteries. Unfortunately, metal fluoride cathodes generally suffer from poor conductivity, sluggish reaction kinetics, and irreversible structural changes. Reducing particle size to nanoscale is an effective way to solve the large volume change and poor electronic conductivity of metal fluoride cathodes. In this study, a nano-control strategy was proposed, using n-propanol as an auxiliary solvent to achieve the conversion of micrometer-scale FeF3·3H2O to nanoscale FeF3·0.33H2O. Meanwhile, the particle size and morphology of iron fluorides could be controlled by regulating the synthesis temperature. The distribution of relaxation times (DRT) was used to analyze the electrochemical impedance spectroscopy (EIS). FeF3·0.33H2O synthesized at 180 °C with lower resistance showed a high capacity of 200 mAh g−1 after 160 cycles with excellent rate performance and cycle stability.
研究领域:
材料科学
·
电化学
·
能源存储技术
✓ 已验证
DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2021
·
IF 5.316
Yi Yang,Ling Gao,Liming Shen,Ningzhong Bao
With the revival of lithium metal anodes , there is an urgent need for matching cathodes to form the next generation batteries with high-capacity and low-cost. A porous hierarchical structure containing FeF 3 nanocrystals (3–9 nm) capsulated in conductive carbon nanocages (40–110 nm) was fabricated. The morphology and size of the FeF 3 nanocrystals were influenced by the existence of carbon nanocage. During the preparation process, the carbon nanocage inhibited the growth of FeF 3 crystals. During the dis/charge process, the carbon nanocages not only restricted the complex conversion reaction (Fe 3+ ⇄ Fe 2+ ⇄ Fe) within the confined space, but also functioned as a bridge for the transmission of electrons, thus enhancing the electrochemical performance of the electrode. As a result, the FeF 3 /C electrode delivered an excellent reversible capacity of 410 mA h g −1 over 120 cycles at 100 mA g −1 .
研究领域:
材料科学
·
能源存储与转换
✓ 已验证
DOI
高影响因子
NEW JOURNAL OF CHEMISTRY
·
2021
·Vol. 45
·期 38
·18019-18024
·
IF 3.591
Jing Ding,Xiangyang Zhou,Chucheng Luo,Juan Yang,Jingjing Tang
FeF3·0.33H2O with a special one-dimension tunnel structure has been considered as a potential cathode material. However, the low electron conductivity of FeF3·0.33H2O prevents its practical application. FeF3·0.33H2O coupled with a carbon material is an effective method to solve the low electric conductivity of FeF3·0.33H2O. Hence, we apply a facile approach using the catalyzed pyrolysis of melamine and a fluorination–annealing process to synthesize the N-doped CNTs/FeF3·0.33H2O composite with a bamboo-like morphology. The as-prepared composite displays a good cycling performance with a reversible discharge capacity of 160.7 mA h g−1 at 40 mA g−1 after 100 cycles and a good rate performance, as well as a good electrochemical performance even at a relatively high mass loading. The good electrochemical properties can be mainly ascribed to the fact that N-doped CNTs play the role of a cross-linked conductive network to provide an electron-transport expressway in the active material. This simple catalyzed pyrolysis and fluorination–annealing approach provides a promising avenue for the application of iron fluoride as a cathode material.
研究领域:
材料科学
·
能源存储与转换
✓ 已验证
DOI
高影响因子
ELECTROCHIMICA ACTA
·
2013
·
IF 3.777
Qingxin Chu,Zhicai Xing,Xinbang Ren,Abdullah M. Asiri,Abdulrahman O. Al-Youbi,Khalid Ahmad Alamry,Xuping Sun
In this paper, we demonstrate the preparation of reduced graphene oxide (rGO) decorated with FeF 3 nanoparticles (FeF 3 NPs) by adding FeF 3 aqueous solution to the rGO ethanol/water dispersion. The obtained FeF 3 /rGO nanocomposite is further tested as a cathode material for rechargeable lithium batteries and found to have high discharge capacities, good rate capabilities and cycling performance. It can deliver a high discharge capacity of 476 mAh g −1 at a current density of 50 mA g −1 in the voltage range 1.0–4.5 V. It still delivers a discharge capacity of 146 mAh g −1 with 81% capacity retention after 50 charge–discharge cycles under a current density of 1000 mA g −1 in the voltage range 1.7–4.5 V.
研究领域:
材料科学
·
电化学
·
能源存储
✓ 已验证
产品关联
DOI
高影响因子
SOLID STATE IONICS
·
2016
·
IF 2.38
Cheng-Dong Li,Jin Xu,Ji-Sheng Xia,Wei Liu,Xin Xiong,Zhu-An Zheng
The FeF 3 -coated Li[Li 0.2 Mn 0.54 Ni 0.13 Co 0.13 ]O 2 cathode materials were synthesized via a wet chemical process followed by a solid state reaction . The physical properties of the as-prepared samples were conducted using X-ray diffraction, scanning electron microscopy, and transmission electron microscopy . The results indicated that the surface of cathode particles was covered by FeF 3 film (about 5–15 nm thick). Compared with the bare cathode, the FeF 3 -coated Li[Li 0.2 Mn 0.54 Ni 0.13 Co 0.13 ]O 2 one delivered the higher coulombic efficiency, better rate capability, longer cycle life, and better structure stability. A high capacity retention of 95% (190 mAh g − 1 ) after 100 cycles at 0.5 C rate was obtained for the FeF 3 -coated Li[Li 0.2 Mn 0.54 Ni 0.13 Co 0.13 ]O 2 cathode. Besides, the results from cyclic voltammetry and electrochemical impedance spectra revealed that the noteworthy enhanced electrochemical properties of the surface-modified sample were due to the presence of FeF 3 coating layer , which suppressed the side reaction between the Li[Li 0.2 Mn 0.54 Ni 0.13 Co 0.13 ]O 2 particles with electrolyte and further stabilized the Li[Li 0.2 Mn 0.54 Ni 0.13 Co 0.13 ]O 2 structure with cycling.
研究领域:
材料科学
·
电化学
✓ 已验证
产品关联
DOI
高影响因子
Materials Today
·
2024
·
IF 21.1
Xuanfeng Chen,Ziang Jiang,Qihou Li,Shunrui Luo,Yujie Wang,Fulu Chu,Chunhao Qin,Feixiang Wu
Lithium-metal fluoride batteries with higher energy density than commercial lithium-ion batteries are promising candidates for future energy storage. However, challenges such as poor electronic and Li + conductivity, active material dissolution, and volume expansion during cycling hinder their practical application. Here, a well-designed yolk-shell FeF 3 @C is aimed to address these issues. The outer carbon shell, derived from an organic carbon source, enhances the electronic conductivity of the embedded FeF 3 nanoparticles and protects them from unfavorable dissolution. The hollow design is utilized to provide sufficient space for FeF 3 nanoparticles to expand during cycling, preserving the carbon shell to not be destroyed. Post-mortem studies reveal the in-situ formation of Fe/O shell during cycling, which further prevents the loss and shuttle of Fe. Consequently, the FeF 3 @C nanocomposites deliver a capacity of 400 mAh g −1 at 1.0 C over 1500 cycles with a high capacity retention close to 95 %, and achieve super-rate capability up to 40 C. Moreover, the produced yolk-shell FeF 3 @C nanocomposites demonstrate air stability, which can simplify the manufacturing process of metal fluoride cathodes. Our study offers a promising direction for designing FeF 3 cathodes that achieve both outstanding electrochemical performance and air stability for practical Li-FeF 3 batteries.
研究领域:
材料科学
·
电化学
✓ 已验证
DOI
高影响因子
Advanced Energy Materials
·
2022
·Vol. 12
·期 31
·2200959
·
IF 29.698
Juyan Zhang,Lan Zhang,Yunlong Zhao,Jiashen Meng,Bohua Wen,Kashem M. Muttaqi,Md. Rabiul Islam,Qiong Cai,Suojiang Zhang
Rechargeable aluminum ion batteries (AIBs) are one of the most promising battery technologies for future large-scale energy storage due to their high theoretical volumetric capacity, low-cost, and high safety. However, the low capacity of the intercalation-type cathode materials reduces the competitiveness of AIBs in practical applications. Herein, a conversion-type FeF 3 -expanded graphite (EG) composite is synthesized as a novel cathode material for AIBs with good conductivity and cycle stability. Combined with the introduction of a single-wall carbon nanotube modified separator, the shuttle effect of the intermediate product, FeCl 2 , is significantly restrained. Moreover, enhanced coulombic efficiency and reversible capacity are achieved. The AIB exhibits a satisfying reversible specific capacity of 266 mAh g −1 at 60 mA g −1 after 200 cycles, and good Coulombic efficiency of nearly 100% after 400 cycles at a current density of 100 mA g −1 . Ex situ X-ray diffraction and X-ray photoelectron spectroscopy are applied to explore the energy storage mechanism of FeF 3 in AIBs. The results reveal that the intercalation of Al 3+ species and the reduction of Fe 3+ species occurrs in the discharge process. These findings are meaningful for the fundamental understanding of the FeF 3 cathode for AIBs and provide unprecedented insight into novel conversion type cathode materials for AIBs.
研究领域:
材料科学
·
电化学
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）