International Journal of Minerals Metallurgy and Materials
·
2024
·Vol. 31
·期 10
·2244-2252
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IF 5.6
Hou Zihan,Guo Lisheng,Fu Xianlong,Zheng Hongxian,Dai Yuqing,Wang Zhixing,Duan Hui,Dong Mingxia,Peng Wenjie,Yan Guochun,Wang Jiexi
Cobalt (Co) serves as a stabilizer in the lattice structure of high-capacity nickel (Ni)-rich cathode materials. However, its high cost and toxicity still limit its development. In general, it is possible to perform transition metal substitution to reduce the Co content. However, the traditional coprecipitation method cannot satisfy the requirements of multielement coprecipitation and uniform distribution of elements due to the differences between element concentration and deposition rate. In this work, spray pyrolysis was used to prepare LiNi 0.9 Co 0.1− x W x O 2 (LNCW). In this regard, the pyrolysis behavior of ammonium metatungstate was analyzed, together with the substitution of W for Co. With the possibility of spray pyrolysis, the Ni–Co–W-containing oxide precursor presents a homogeneous distribution of metal elements, which is beneficial for the uniform substitution of W in the final materials. It was observed that with W substitution, the size of primary particles decreased from 338.06 to 71.76 nm, and cation disordering was as low as 3.34%. As a consequence, the prepared LNCW exhibited significantly improved electrochemical performance. Under optimal conditions, the lithium-ion battery assembled with LiNi 0.9 Co 0.0925 W 0.0075 O 2 (LNCW-0.75mol%) had an improved capacity retention of 82.7% after 200 cycles, which provides insight into the development of Ni-rich low-Co materials. This work presents that W can compensate for the loss caused by Co deficiency to a certain extent.
研究领域:
材料科学
·
能源科学
✓ 已验证
DOI
高影响因子
JOURNAL OF ELECTROANALYTICAL CHEMISTRY
·
2021
·
IF 4.464
Liyan Wu,Jianmei Cen,Asad Ali,Jiecai Li,Pei Kang Shen
Conducting polymers are commonly used as precursors for preparing carbon-based catalysts and have been used in electrocatalytic water splitting. However, so far, most of the catalytic materials synthesized with the assistance of high polymer conducting polymers are non-self-supporting and have only a single-function catalytic effect. Therefore, it is an inevitable trend to synthesize a bifunctional self-supported, highly efficient and long-stable water splitting catalyst. Herein, a self-supporting polypyrrole precursor PPy-PW 12 was prepared by electrodeposition with phosphotungstic acid as a dopant. In addition, the PPy-PW 12 precursor was then calcined. The as-prepared W/Ni 3 (PO 4 ) 2 @NC/NF electrocatalyst exhibits admirable HER and OER performances with overpotentials of 48 mV for HER and 236 mV for OER to reach a current density of 10 mA cm −2 in 1.0 M KOH solution. Additionally, when W/Ni 3 (PO 4 ) 2 @NC/NF is used in overall water splitting as a bifunctional catalyst, it needs only 1.53 V to deliver a current density of 10 mA cm −2 , which is superior to typically integrated Pt/C and RuO 2 counterparts. Our work offers a facile strategy to apply W/Ni 3 (PO 4 ) 2 @NC/NF as practical bifunctional electrocatalysts for large-scale water splitting.
研究领域:
电化学
·
材料科学
·
催化
·
能源材料
✓ 已验证
DOI
高影响因子
ChemElectroChem
·
2020
·Vol. 7
·期 24
·4971-4978
·
IF 4.154
Jianping Zheng,Jianpo Chen,Liping Xiao,Xiaoning Cheng,Hao Cui
Graphical In the hybrid Co 3 W−WN catalyst , the tungsten cobalt alloy not only acts as a water-dissociation promoter to accelerate the Volmer step, thus improving the HER activity, but also transforms in situ into OER active species to facilitate the water-oxidation process. So, the Co 3 W−WN hybrid electrocatalyst exhibits enhanced HER and OER activities with overpotentials of 43 and 273 mV, respectively, at 10 mA cm −2 . Due to the difference of catalytic mechanisms, the design of an efficient alkaline bifunctional catalyst not only needs to organically integrate different active sites, but also has to simultaneously optimize the catalytic activity of both hydrogen evolution reaction (HER) and oxygen evolution reaction (OER). Here, we propose a strategy of killing two birds with one stone to construct the efficient bifunctional electrocatalyst by simultaneously accelerating water dissociation and enhancing oxygen evolution. The self-supported tungsten nitride nanowires decorated with tungsten cobalt alloy nanoparticles (Co 3 W/WN/CC) were synthesized on the flexible carbon cloth. Co 3 W can act as both a water dissociation promoter to enhance HER activity and OER active species to facilitate water oxidation via in situ transformation, thus effectively improving the overall water splitting performance. As expected, compared with pure tungsten nitride catalysts, the hybrid electrocatalyst not only shows enhanced HER activity with an overpotential decrease from 255 to 43 mV, but also achieves an excellent OER performance with overpotential of 273 mV in 1 M KOH aqueous solution. Furthermore, by employing Co 3 W/WN/CC as cathode and anode, the overall water splitting process needs 1.582 V to drive a current density of 10 mA cm −2 and maintains without decay for 80 hours. This work expands the effective strategy for building efficient, stable and low-cost alkaline bifunctional electrocatalysts.
研究领域:
材料科学
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电化学
✓ 已验证
产品关联
DOI
高影响因子
ENERGY & FUELS
·
2020
·
IF 3.421
Jie Yu,Esong Zhang,Lele Wang,Zijian Song,Fanhai Kong,Yunlong Ma,Hong Zhao,Lushi Sun
With the wide application of selective catalytic reduction (SCR) systems in power plants for the control of NOx emission in China, a serious problem of catalyst deactivation due to the channel blockage by NH4HSO4 has drawn extensive attention. In this work, a combined experimental and simulation method was utilized to study the interaction between NH4HSO4 and a vanadium–titanium-based catalyst. Initially, the adsorption characteristics of NH4HSO4 onto TiO2, V2O5/TiO2, V2O5-WO3/TiO2, and V2O5-MoO3/TiO2 were simulated following density functional theory. The simulation revealed that during reaction, the NH4HSO4 loaded onto TiO2 can be dissociated into NH4+ and SO42–. The existence of V2O5, WO3, and MoO3 can form a protective layer to inhibit the adsorption of NH4HSO4 onto TiO2, to promote the reduction of sulfur-containing compounds, and to accelerate the reaction of NH4+ with NO. Thermogravimetric analysis also showed the positive effect of V, W, and Mo on NH4HSO4 decomposition. Fixed-bed experiments were then conducted to compare the performance of the studied catalysts and the effect of NH4HSO4 on their performance. It was proven that the V-5Mo/TiO2 catalyst showed better performance at low temperatures. On the V-5Mo/TiO2 catalyst, ∼78 wt % NH4+ in NH4HSO4 was attached onto Lewis acid sites, which can accelerate the reduction reaction of NO by NH4+. Meanwhile, SO42– can comparatively be easily decomposed at lower temperatures.
研究领域:
环境科学
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催化化学
✓ 已验证
产品关联
DOI
高影响因子
ACS Applied Materials & Interfaces
·
2016
·
IF 7.145
Yunfeng Qiu,Jingjing Liu,Yue Lu,Rui Zhang,Wenwu Cao,PingAn Hu
Backing materials play important role in enhancing the acoustic performance of an ultrasonic transducer. Most backing materials prepared by conventional methods failed to show both high acoustic impedance and attenuation, which however determine the bandwidth and axial resolution of acoustic transducer, respectively. In the present work, taking advantage of the structural feature of 3D graphene foam as a confined space for dense packing of tungsten spheres with the assistance of centrifugal force, the desired structural requirement for high impedance is obtained. Meanwhile, superior thermal conductivity of graphene contributes to the acoustic attenuation via the conversion of acoustic waves to thermal energy. The tight contact between tungstate spheres, epoxy matrix, or graphene makes the acoustic wave depleted easily for the absence of air barrier. The as-prepared 3DG/W80 wt %/epoxy film in 1 mm, prepared using ∼41 μm W spheres in diameter, not only displays acoustic impedance of 13.05 ± 0.11 MRayl but also illustrates acoustic attenuation of 110.15 ± 1.23 dB/cm MHz. Additionally, the composite film exhibits a high acoustic absorption coefficient, which is 94.4% at 1 MHz and 100% at 3 MHz, respectively. Present composite film outperforms most of the reported backing materials consisting of metal fillers/polymer blending in terms of the acoustic impedance and attenuation.
研究领域:
材料科学
·
声学工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING
·
2017
·
IF 3.094
Kejia Kang,Lianmeng Zhang,Guoqiang Luo,Jian Zhang,Rong Tu,Chuandong Wu,Qiang Shen
In this work, to improve the strain capacity of tungsten , β-SiC was added to form W-Si-C multi-phase composites composed of W, W 2 C, and W 5 Si 3 using the arc-melting method. The relationship between microstructure and mechanical behavior was investigated, and a microstructural evolution mechanism was proposed. The grain size of the W was refined significantly from 1071.8 to 5.4 µm as the SiC content increased. The micro-hardness (3.67–12.79 GPa) and ultimate compressive strength (UCS) (0.90–2.29 GPa) of the W-Si-C multi-phase composite obviously increased as the β-SiC content increased to 4 wt% due to the grain refinement and segregation of the W 2 C and W 5 Si 3 at the grain boundaries. The highest strain of UCS (21.9%) was obtained at 1 wt% SiC, which is three times of that of pure W (7.4%) and is a result of the refined W grain size and the potentiation of W 5 Si 3.
研究领域:
材料科学
·
力学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2023
·
IF 6.2
Lihua Guo,Guoqiang Wang,Feng Zhang,Linyuan Lu,Bin Luo,Hongtao Huang,Jun Lin
The fissile fuel loss in tungsten (W) based ceramic-metal (Cermet) element used in nuclear thermal propulsion is of great importance. In this study, the W-Y 2 O 3 composite matrix was manufactured tentatively by Spark Plasma Sintering (SPS) to relieve the fuel loss. Performance evaluation of hydrogen (H 2 ) permeation and diffusion behaviors in the matrix was carried out by a gas permeation device. The results indicate that the diffusion coefficient of H 2 in the pure W matrix is nearly 10 times larger than that in the W-Y 2 O 3 matrix at a test temperature of 823 K. Based on the results, a careful investigation of the fuel loss mechanism of the Y 2 O 3 dispersed W matrix was performed. SEM and TEM showed that the fine Y 2 O 3 particles are distributed along grain boundaries of the W ternary-phase and present a distinct transition region of about 10 nm between the Y 2 O 3 and W phases. In particular, the crystallographic orientation relationship suggests that a semi-coherent structure is formed at the W/Y 2 O 3 phase interface : (0 1 −1) W || (1 0 −1) Y 2 O 3 and [0 1 1] W || [1 1 1] Y 2 O 3 . This semi-coherent structure is favorable for binding the two phases together tightly, thus hindering the inward diffusion of H 2 greatly. Moreover, the improved density and refined size of the W grains are achieved. Therefore, there is no doubt that the dispersion of Y 2 O 3 is beneficial for lowering the H 2 diffusion rate in the W matrix and thus reducing the fuel loss effectively. This work furthers our understanding of the key role of Y 2 O 3 in the W matrix used in nuclear thermal propulsion.
研究领域:
材料科学
·
核能工程
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2025
·
IF 6.3
Fei Gao,Bo Liao,Wenmiao Li,Rui Yu
Molten salt electrorefining offers a promising approach for green and efficient recycling of waste cemented carbides. However, the conventional halide-based electrolytes suffer from volatile tungsten halide losses and only recover metallic tungsten, necessitating energy-intensive carburization to recover tungsten carbide (WC). Herein, we propose a novel electrolytic refining and recovery method based on an oxygen-containing CaCl 2 -CaO molten salt electrolyte. The introduction of CaO suppresses the formation of volatile tungsten halides, enabling simultaneous dissolution of carbon (C) and tungsten (W) in the WC-Co anode to non-volatile CaCO 3 and CaWO 4 , respectively. Retention of Co in the anode slime is achieved through controlling anodic potential, realizing component separation. The dissolved CaCO 3 and CaWO 4 are reduced at the cathode, resulting in the generation of WC powder. This work accomplishes the direct recycling of WC from spent cemented carbides without intermediate stages. The composite products of WC and carbon are deposited on the cathodes, of which morphologies are comprised of granular aggregates and flakes. The presence of carbon suppresses the formation of W 2 C and W. However, the residual carbon does not affect hard alloy reprocessing since the W/C ratio can be adjusted via controlled W addition during subsequent alloying. This paper proposes a novel short-process green recycling technology for strategic tungsten resources.
研究领域:
材料科学
·
冶金学
·
电化学
·
回收技术
·
可持续加工
✓ 已验证
产品关联
DOI
高影响因子
MINERALS ENGINEERING
·
2018
·
IF 2.707
Dandan Gong,Kanggen Zhou,Changhong Peng,Junjie Li,Wei Chen
Extraction of tungsten from scheelite is important for the processing of tungsten resources for tungsten metallurgical companies. However, there are many difficulties to leach scheelite compared to wolframite. Compared with calcium tungstate (CaWO 4 ), magnesium tungstate (MgWO 4 ) is a readily soluble substance in NaOH solution. In this paper, conversion of CaWO 4 to MgWO 4 through roasting a mixture of scheelite and MgCl 2 was investigated systematically. The leaching performance of the roasted products in NaOH solution was also studied. Thermodynamic analyses and experimental results showed that MgWO 4 could be prepared through reaction of CaWO 4 with MgCl 2 . Increasing roasting temperature and MgCl 2 dosage could increase the extent of conversion of CaWO 4 to MgWO 4 . Additionally, leaching experiments showed a good leachability of the roasted products with a tungsten leaching efficiency of 98.79% in 4 M NaOH solution at 90 °C. This work may provide an alternative approach for the extraction of tungsten from scheelite.
研究领域:
冶金工程
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
·
2023
·
IF 5.2
Xun Wang,Ruiqi Xie,Jie Liu,Yimin Zhu
Owing to the similar surface properties of scheelite and fluorite , the separation of them is very difficult by only using the traditional collectors of fatty acids. In this study, Nitrilotri(methylphosphonic acid) (ATMP) was used as a depressant to realize the efficient separation of these two minerals. The separation performance and the adsorption mechanism of ATMP on scheelite and fluorite were explored by the flotation experiments and surface analyses. Flotation results indicated that ATMP exhibited strong inhibition on the fluorite flotation but did not affect that of scheelite, and a satisfactory separation of scheelite from fluorite was achieved at the reagent regime of 60 mg/L ATMP, 40 mg/L sodium oleate (NaOL) and pH 10.0. Zeta potential measurements and AFM detections showed that the intense adsorption of ATMP onto fluorite was occurred and which could prevent the subsequent adsorption of NaOL on fluorite, while the adsorption of ATMP onto scheelite was weak and the further interaction between NaOL and scheelite was hardly influenced by it. Moreover, Fourier transform infrared (FTIR) spectroscopy and X-ray photoelectron spectroscopy (XPS) analyses confirmed that the interaction between calcium ions exposed on fluorite surface and the phosphate groups of ATMP accounted for the chemisorption of ATMP on fluorite. As a result, ATMP can be selected as a potential depressant for separating scheelite from fluorite.
研究领域:
矿物加工工程
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
METALS AND MATERIALS INTERNATIONAL
·
2021
·Vol. 27
·期 12
·5389-5398
·
IF 3.642
Hong S. F.,Lu Z. C.,Liu Y. H.,He Q. M.,Jiang W.,Zeng M. Q.
Abstract Supersaturated solid–solutions in a W–Cr alloy system were fabricated by conventional milling and plasma milling. The different extension mechanisms of the solid solubility that were created by ball milling with and without discharge plasma were studied. The solid–solubility of Cr in W for the P-milling W–Cr alloy system was higher, which indicates that plasma milling promotes the formation of W(Cr) solid–solution more easily than conventional milling. According to Miedema’s model, in the W–Cr alloy system, the free-energy change to form a W(Cr) solid solution by plasma milling is reduced compared with conventional milling because of the heating effect of the discharge plasma. Therefore, a higher stored energy in the grain boundaries and dislocations of the W–Cr nanograins during plasma milling makes it easier to overcome the thermodynamic barrier in the formation of a solid–solution, when compared with conventional milling. Graphic Abstract
研究领域:
材料科学
·
物理学
✓ 已验证
产品关联
DOI
高影响因子
INTERNATIONAL JOURNAL OF REFRACTORY METALS & HARD MATERIALS
·
2013
·
IF 1.858
Pingping Liu,Fang Peng,Fangming Liu,Haikuo Wang,Chao Xu,Qiming Wang,Xiaoling Zhou,Wenwen Yin,Shuai Yin,Yong Li,Duanwei He
In this work, we present a novel method to sinter tungsten bulk material under high pressure without any additives. The sintering temperatures were greatly reduced in our experiments. The sintered samples can achieve near-full densification (relative density of 99.5%), and have fracture toughness of about 50% higher than that from the traditional methods, without sacrificing hardness. Moreover, the grain sizes of the sintered samples maintained in the initio range. The sintering kinetics, microstructure evolutions, and relationships of mechanical properties versus pressure–temperature conditions were also discussed.
研究领域:
材料科学
·
力学
✓ 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）