COMBUSTION AND FLAME
·
2024
·
IF 5.8
Xiandie Zhang,Qingqing Zeng,Jie Ji,Haozhe Li,Xinwen Ma,Weiduo Fei,Xiaode Guo,Xiang Zhou
In recent years, metal fluorides are increasingly being investigated as promising oxidants in aluminum-based (Al-based) composite energetic materials to improve the ignition and combustion performance, mainly because of their reaction with the otherwise inert alumina shell. However, the hygroscopicity and relatively high cost of many metal fluorides limit their wide applications. In this work, an effective and mild solvothermal method employing inexpensive raw materials is used to synthesize the otherwise costly anhydrous FeF 2 . A novel Al/FeF 2 energetic composite is then prepared using ultrasound-assisted physical mixing and compared with other more common formulations (Al/PTFE, Al/FeF 3 , Al/Fe 2 O 3 , and Al/FeO) in terms of energetic characteristics. Electric ignition and constant-volume combustion tests show that Al/FeF 2 has a shorter ignition delay time than that of Al/PTFE, as well as a much faster reaction rate and a much greater pressure output capacity than each of Al/FeF 3 , Al/Fe 2 O 3 , and Al/FeO. High-speed photography demonstrates the large flame area and short flame duration of Al/FeF 2 . Moreover, thermal analysis reveals the superior exothermic enthalpy of Al/FeF 2 .Overall, anhydrous FeF 2 prepared in this study shows excellent application potential in Al-based composite energetic materials.
研究领域:
材料科学
·
能源与燃料化学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2023
·
IF 6.2
Yunpeng Liu,Xupo Liu,Cuicui Zhang,Ye Chen,Zhitao Wang,Gangya Wei,Jing Zhang,Tianfang Yang,Fengxian Zhang,Shuyan Gao
Fe-N-C catalysts have served as ideal catalysts for oxygen reduction reaction (ORR), but the strong adsorption to ORR-relevant intermediates and less utilization of Fe-N x sites endow those catalysts with inferior performance. Here, an efficient catalyst consisted of Fe-N x species and FeF 2 /Fe 3 C nanoparticles co-anchored on N, F co-doped carbon nanotubes (Fe-NF-CNTs) has been constructed through a surface modification strategy. Sodium trifluoroacetate as functional linker modified on metal-organic framework surface promotes to form abundant and accessible active sites. FeF 2 /Fe 3 C nanoparticles and hydrogen fluoride generated in pyrolysis process facilitate to construct N, F co-doped CNTs with defects and holes. N, F co-doping modifies the adsorption characteristic of Fe-N x sites, while CNTs improve the accessibility of active sites and the capability of material transport. Therefore, Fe-NF-CNTs exhibits outstanding activity (E 1/2 = 0.85 V) and stabilization (ΔE = 6 mV, 10k cycles). Impressively, Fe-NF-CNTs delivers high power density (144 and 68 mW cm –2 ) and cycle stability (300 and 60 h) in liquid and flexible Zn-air batteries, respectively. This work provides a surface modification strategy to guide the tuning of electronic structure of efficient ORR catalysts designed for renewable green energy.
研究领域:
材料科学
·
电化学
·
催化科学
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2024
·
IF 13.3
Zhouyang Ma,Jiawei Wu,Fuling Yang,Shuli Wang,Huan Wen,Ligang Feng
Given its initially low activity and difficulty in active phase formation, Fe site regulation is rarely touched in FeNi-based oxygen evolution reaction (OER) catalysts. Herein, the Fe sites regulation and activity deciphering are demonstrated by selective phase transformation taking nitrogen-doped carbon confined FeNi nanoparticles derived from Fe 2 Ni-MIL-MOF pyrolysis as an example; driven by the reduction atmosphere and Kirkendall effect assisted by melamine pyrolysis, some Fe and Ni sites were separated to form metallic Fe and FeNi alloy and the subsequent fluorination process induced the ionic compound FeF 2 formation rather than NiF 2 , offering a good platform to evaluate the influence of active Fe phase for OER catalysis. Theoretical calculations combined with ex-situ and in-situ spectral characterization techniques proved the complete convention of FeF 2 into a high-valent and reactive intermediate state of FeOOH. Considering the stable metallic state of Ni, the largely improved catalytic performance could be attributed to the Fe site regulation and the subsequent synergistic catalysis effect. Compared to the traditional iron-based catalyst, theoretically, the electronic structure of FeF 2 was more conducive to the active FeOOH phase formation and significantly lowered the reaction energy barrier for OER. By addressing the aforementioned problems, low overpotential and good stability for OER catalysts were realized. The current work showed valid proof of the FeNi-based catalysts regulation via Fe sites for energy-relevant catalysis reactions.
研究领域:
材料科学
·
电化学
·
催化科学
✓ 已验证
产品关联
DOI
高影响因子
ACS Applied Energy Materials
·
2020
·
IF 4.473
Dan Ni,Li Fang,Wang Sun,Bin Shi,Xiaotao Chen,Haijun Li,Zhenhua Wang,Kening Sun
The development of cathode materials with high capacity and superior rate performance is essential for the successful application of future sodium-ion batteries (SIBs). Herein, FeF2@mesoporous hollow carbon spheres are prepared as cathode materials for SIBs. The in situ constructed porous nanocomposites can restrain the particle size, boost the transport of ions/electrons, and buffer the volume change of the electrode materials to yield superior electrochemical performances. The polydopamine-derived carbon matrix can also contribute to the superior capacity through surface oxygen functional groups. The electrode can deliver a capacity reaching 220 mA h g–1 at 0.03 A g–1 and a capacity of 64 mA h g–1 at a high current density of 10 A g–1 and can maintain 112 mA h g–1 after 100 cycles at 0.2 A g–1.
研究领域:
材料科学
·
储能
·
纳米技术
·
电化学
✓ 已验证
DOI
高影响因子
Journal of Energy Chemistry
·
2023
·
IF 13.1
Yulin Xu,Wenjing Xiong,Jiaqi Huang,Xinglin Tang,Hongqiang Wang,Wei Liu,Dan Xiao,Yong Guo,Yongzhi Zhang
Fluoride ferrous (FeF 2 ) is viewed as a promising conversion cathode material for next-generation lithium-ion batteries (LIBs) due to its high theoretical specific capacity and low cost. Unfortunately, issues such as poor intrinsic conductivity, iron dissolution, and phase separation hinder the application of FeF 2 in high-energy cathodes. Here, a pressure-induced morphology control method is designed to prepare coralloid-like FeF 2 nanocrystals with nitrogen-rich carbon coating (c-FeF 2 @NC). The coralloid-like interconnected crystal structure of c-FeF 2 @NC contributes to reducing interfacial resistance and enhancing the topotactic transformation during the conversion reaction, and the nitrogen-rich carbon (NC) coating can enhance interfacial stability and kinetic performance. When used as a conversion cathode for LIBs , c-FeF 2 @NC exhibits a high initial reversible capacity of 503.57 mA h g −1 and excellent cycling stability of 497.61 mA h g −1 with a low capacity decay of 1.19 % over 50 cycles at 0.1 A/g. Even at 1 A/g, a stable capacity of 263.78 mA h g −1 can still be retained after 200 cycles. The capability of c-FeF 2 @NC as a conversion cathode for sodium-ion batteries (SIBs) was also evaluated to expand its field of application. Furthermore, two kinds of full batteries have been assembled by employing c-FeF 2 @NC as cathodes and quantitative limited-Li (LLi) and pre-lithiated reduced graphene oxide (PGO) as anodes, respectively, to envisage the feasibility of practical applications of conversion materials.
研究领域:
材料科学
·
能源存储
·
电化学
✓ 已验证
产品关联
DOI
高影响因子
SYNTHESIS-STUTTGART
·
2019
·Vol. 51
·期 16
·3085-3090
·
IF 2.867
Menglan Wang,Yudong Li,Qing-An Wu,Shuping Luo,Yuehui Li
Indole scaffold synthesis relies primarily on oxidative C–H amination of N-protected alkenylanilines for C–N intramolecular cyclization reactions. Herein, for the first time, without N-protection, various readily prepared 2-alkenylanilines were transformed into the desired indole products in good yields by using K2S2O8 as oxidant in the presence of catalytic amounts of FeF2. The K2S2O8/FeF2 system offers a direct and benign synthetic route to 3-arylindoles and it is applicable to a wide range of substituted indoles including drug intermediates.
研究领域:
有机化学
·
合成化学
·
药物化学
✓ 已验证
产品关联
DOI
高影响因子
ACS Nano
·
2025
·
IF 16
Runyuan Cao,Zichun Zhou,Xianhui Nie,Yongfeng Li,Chuanzhong Lai,Keyi Chen,Chilin Li
Conventional intercalation-type cathodes for lithium batteries are plagued by rapid capacity decay and unsatisfactory cycling lifespans when operating at subzero temperatures. Conversion-type iron fluoride seems to compensate for these setbacks due to its dramatic theoretical capacity via a three-electron transfer mechanism, but suffers from an irreversible solid–solid phase transition with the collapse of the charge-transporting tunnel and insulating LiF precipitation over the cathode–electrolyte interphase (CEI) layer. Herein, we propose a metal–organic framework in situ etching-fluorination strategy to construct a porous micron-brick monolithic grain cathode with rich heterojunctions of hexagonal tungsten bronze (HTB) FeF3 and rutile FeF2 with an epitaxial intergrowth mode. Owing to the optimized configuration with a self-healing built-in interfacial electric field, open diffusional channels, as well as topotactic conversion and catalyzing functions of FeF2 on Li–F splitting, this heterostructure fluoride enables a high energy density (1114 Wh kg–1 at 215 W kg–1) and high-rate performance (337 mAh g–1 at 1000 mA g–1) at room temperature. These effects also endow the cathode with outstanding low-temperature performance with an average capacity of 170 mAh g–1 for 100 cycles and a discharge capacity of 50 mAh under a 6-layer pouch cell configuration at −20 °C.
研究领域:
材料科学
·
电化学
·
储能技术
·
纳米材料
·
电池技术
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ADVANCED FUNCTIONAL MATERIALS
·
2024
·Vol. 34
·期 19
·2312415
·
IF 18.5
Chuanzhong Lai,Keyi Chen,Meng Lei,Jiulin Hu,Shuangqiang Chen,Chilin Li
Conversion-reaction metal fluoride cathodes have the advantages of low cost, environmental friendliness, and high energy density. However, their tailored synthesis and structure design under safe, facile, and scalable conditions have always been a puzzle, which limits the popularization of conversion-type cathodes in lithium metal batteries. To address these challenges, here an iron fluoride heterostructure with FeF 2 and FeF 3 binary phases is proposed and prepared by deep eutectic solvent method under the assistance of cobalt cation as an oxidization promoter. The compact heterogeneous contact between tetragonal FeF 2 and hexagonal tungsten bronze FeF 3 phases enables the promotion and stabilization of interface charge transfer and topotactic conversion reaction. The narrower band gap of FeF 2 , higher theoretical capacity and thermodynamic potential of FeF 3 synergistically contribute to the balance between cycling reversibility and capacity. The heterostructure cathode with an optimized molar ratio of FeF 2 /FeF 3 can realize a highly reversible capacity of ≈520 mAh g −1 in the first tens of cycles and 305 mAh g −1 after 200 cycles. The typical two-stage reaction plateaus are well preserved even under the high current density of 1000 mA g −1 . The green synthesis strategy and heterostructure fluoride design open a new horizon for the development of high-energy-density metal fluoride batteries.
研究领域:
材料科学
·
电化学
·
储能
·
电池技术
✓ 已验证
DOI
高影响因子
ACS Applied Energy Materials
·
2025
·
IF 5.5
Guoquan Na,Wen-Gang Cui,Hangyan Shi,Zhenglong Li,Fan Gao,Xingqiang Wang,Ke Wang,Yong Gao,Yaxiong Yang,Zichao Shen,Yanxia Liu,Jian Miao,Hongge Pan
LiBH4 has attracted significant interest due to its high-hydrogen storage capacity (18.5 wt % H2). However, its practical application is severely impeded by the high dehydrogenation temperature, sluggish hydrogen release kinetics, and poor reversibility. In this work, a graphene-supported rodlike FeF2/FeOX additive (FeF2/FeOX@G) is prepared and introduced into LiHB4 by a simple ball-milling. With an optimized LiBH4-to-FeF2/FeOX@G weight ratio of 7:3, the 7LiBH4-3(FeF2/FeOX@G) system starts dehydrogenation at a low temperature of 100 °C below and 8.7 wt % H2 is released upon heating to 400 °C, while 1.1 wt % H2 is released for pristine LiBH4. Moreover, the system releases rapidly 7.0 wt % H2 at 350 °C within 80 min, and a dehydrogenation capacity of 5.5 wt % is reached after 10 reversible hydrogen absorption and desorption cycles. The in situ formed FeB, Li3BO3, and Fe2B during the first dehydrogenation process acted as a synergistic catalysis, effectively improving the reversible hydrogen storage of LiBH4. This work provides insights into the design of unique additives to introduce multiple catalyst synergies to enhance the hydrogen storage performance of LiBH4.
✓ 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）