JOURNAL OF THE EUROPEAN CERAMIC SOCIETY
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2020
·
IF 4.495
Qi Wang,Ming-hao Li,Guo-qing Chen,Xue-song Fu,Wen-long Zhou
Adjusting the growth kinetics of the interfacial compound layers may be a feasible way to enhance joint properties or service performance. In this study, the textured Ti 3 SiC 2 was obtained by hot-deforming the sintered Ti 3 SiC 2 (TSC), and the effects of the texture orientation on the interfacial microstructural evolution and growth kinetics of the interfacial compounds in the diffusion bonded TiAl/Ti 3 SiC 2 joints were investigated. The texture orientation of Ti 3 SiC 2 had little effect on the interfacial microstructural evolution but had a significant effect on the growth kinetics. When bonded at the same temperature, the growth rate of the interfacial compound layers in the TiAl/TSC ∥ joint (TSC ∥ , TSC ⊥ : Ti 3 SiC 2 with [0001] texture orientation parallel, perpendicular to the bonded seam) was fastest; which was slowest in the TiAl/TSC ⊥ joint and was in the middle in the TiAl/TSC joint. The highest shear strengths of the three different joints were similar (about 54 MPa).
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高影响因子
ACS Applied Energy Materials
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2020
·
IF 4.473
Lijing Yan,Huiwen Zhang,Zeheng Li,Xuehui Gao,Hongbo Wang,Zhan Lin,Min Ling,Chengdu Liang
Nanostructured silicon has been regarded as a promising next-generation anode material for high energy density lithium-ion batteries. However, costly synthesis methods and low initial coulombic efficiency are still two major challenges for its practical application. Herein, secondary submicron silicon materials composed of nanoparticles are successfully prepared by a simple, low-cost, and efficient high energy mechanical milling method. The initial coulombic efficiency of the as-prepared silicon anode reaches 89.14% with a first discharge specific capacity of 3233 mA h g–1 at 100 mA g–1. In light of a low-cost precursor, facile approach, and high initial coulombic efficiency, this work may provide guidance and enlightenment in synthesizing nanostructured silicon with a secondary structure as anode materials for lithium-ion batteries.
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高影响因子
ChemElectroChem
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2020
·Vol. 7
·期 21
·4423-4430
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IF 4.154
Chao Yuan,Dujiang Lu,Yongling An,Xiufang Bian
Graphical Grind and coat : A novel nanocomposite of amorphous carbon-coated Si nanosphere and ZIF-67 derived hollow porous cobalt sulfide/carbon polyhedron is fabricated by a simple grinding process. ZIF-67 derived Co 9 S 8 /C can serve as a buffer to alleviate the volume expansion of Si. The vast conductive carbon layer originated from Co 9 S 8 /C and Si@C plays a key role in facilitating the electron transfer and lithium ion transport kinetics. Si@C−Co 9 S 8 /C anodes deliver improved electrochemical performance. Silicon (Si) is regarded as one of the most promising anode materials for lithium-ion batteries (LIBs) due to its high capacity and low working voltage. However, dramatic volume expansion and inferior electrical conductivity greatly impede the commercial use of Si anodes. Herein, we design and synthesize a novel nanocomposite of Si nanosphere coated by carbon (Si@C) and hollow porous Co 9 S 8 /C polyhedron (Si@C−Co 9 S 8 /C). The hollow porous Co 9 S 8 /C derived from Co-based zeolitic imidazolate framework can serve as a buffering matrix to accommodate the volume expansion of Si, which is beneficial to improve the cycle performance. The vast conductive carbon layer originated from Co 9 S 8 /C and Si@C plays a key role in accelerating the electron transfer and lithium ion transport kinetics, which can significantly enhance the rate performance. As a result, the Si@C−Co 9 S 8 /C anodes deliver stable cycle performance with a reversible capacity of 1399 mA h g −1 after 200 cycles at 100 mA g −1 , improved rate performance and high Coulombic efficiency. This simple route sheds light on designing Si-based composites for LIBs anodes.
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高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
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2020
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IF 4.65
Rui Fan,Ying Huang,Xiaopeng Han,Xuanyi Peng
To obtain high performance composites for thermal management fields, we adopt a new route to prepare the graphite flakes (Gf)/aluminum (Al) composites via vacuum pressure infiltration process. In this study, aluminum nitride (AlN) particles were used as supporting particles to obtain infiltration pathways for the penetration of the molten Al matrix. Gf, starch , urea and AlN were mixed evenly in the mass ratio of 1: 0.035: 0.058: 0.3 and then sintered at 330 °C to prepare porous preforms. It was observed that these substances had excellent chemical compatibility using characterization equipment. The improvement of the thermal transfer and mechanical properties of the composites for silicon coating was also studied. When the volume fraction of graphite was about 54%, compared with the samples without coating, the samples with SiC coating displayed an excellent thermal conductivity (TC) of 467.8 W/m·K and a promising bending strength of 58.8 Mpa, which increased about 82.1 and 238.0%, respectively. The coefficient of thermal expansion (CTE) of composites also decreased about 23.3% from 2.19 × 10 −5 K −1 to 1.68 × 10 −5 K −1 from room temperature to 380 °C.
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高影响因子
CHEMISTRY OF MATERIALS
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2020
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IF 9.567
Yangfan Lin,Jingwei Jiang,Yaguang Zhang,Xueqin He,Jianguo Ren,Peng He,Chunlei Pang,Chengmao Xiao,Deren Yang,Ning Du
The promoting effect of hydroxyls on a silicon surface on the decomposition of an electrolyte is studied by comparing the performance of silicon–hydroxyl (Si–OH) and silicon–alkyl (Si–C3H7) electrodes. X-ray photoelectron spectroscopy (XPS) characterization of solid electrolyte interphase (SEI) layers on both electrodes demonstrates the influencing mechanism that hydroxyls can react with LiPF6 to form POF3, which further induces the decomposition of the electrolyte solution. This study provides a new consideration that limiting the amount of hydroxyls on the silicon surface in an appropriate range is significant to the electrochemical performance of silicon-based anode materials.
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高影响因子
ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH
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2020
·Vol. 27
·期 18
·22639-22647
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IF 3.056
Ren Qiangqiang,He Limo,Hu Song,Li Hanjian,Li Shanxue,Deng Zengtong,Song Gongxiang,Su Sheng,Wang Yi,Xiang Jun
The formation of highly graphitic phenolic resin chars (GPFCs) during catalytic carbonization at relatively low reaction temperature (1200–1600 °C) using novel Ni-Zn-B alloy catalyst with small amount of addition (5–15%) was systematically studied. Only two kinds of graphites (turbostratic graphite and ordered graphite) can be found in GPFCs after catalytic carbonization with Ni-Zn-B and their proportions were changed with reaction conditions. When Ni-Zn-B was involved at 1200–1600 °C, the phenolic resin char was fully transformed to be graphite, and ordered graphite content increased to 28.42% at 1400 °C, which was also almost twice of ordered graphite content in the char catalyzed by pure Ni. But the order graphite content would decrease due to sintering at higher reaction temperature. The addition of Zn and B can promote nickel-based alloy catalytic action by reducing melt point and accelerating graphitization respectively. It was also found that ordered graphite content could be used as a key evaluation parameter to directly reflect the quality of GPFCs based on detailed characteristics analysis. The model between three reaction conditions (reaction temperature, retention time, catalyst content) and ordered graphite content was built with artificial neural network (ANN), and the prediction accuracy of ANN was high up to 91.48%.
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PubMed
高影响因子
PHYSICA STATUS SOLIDI A-APPLICATIONS AND MATERIALS SCIENCE
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2020
·Vol. 217
·期 15
·1901035
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IF 1.759
Shaoping Chen,Yanzuo Chen,Saneyuki Ohno,Libin Xu,Wenhao Fan,Lin Xue,Marhoun Ferhat,Yucheng Wu
The phase component and its evolution during aging at the joint between thermoelectric (TE) materials and electrodes are of much importance to the quality and the performance of the TE devices. While the figure of merit zT of TE materials determines the maximum efficiency of TE devices, undesired side reactions causing the growing interfacial resistance or mechanical failures between TEs and metal electrodes limit the actual performance of devices. Herein, the candidate electrode materials (Mg 2 Ni and Mg 2 SiNi 3 ) for Mg 2 Si are explored, which is one of the cost-effective and environmentally friendly TE materials exhibiting high zT . The electrodes are directly bonded to Mg 2 Si by field-activated pressure-Assisted sintering (FAPAS) in one-step process. The interfaces of fabricated joints with different sintering times are monitored by electron microscopy, followed by the measurement of shear strength and the contact resistances. Outperforming strength (28.29 MPa) and contact resistance (63 μΩ cm 2 ) are observed with Mg 2 SiNi 3 at the joint bonded for 30 min. A long-term stability test on Mg 2 SiNi 3 /Mg 2 Si joint reveals a minute increase in the contact resistance as well as sufficient mechanical stability, suggesting that Mg 2 SiNi 3 is a great candidate of the electrode materials for Mg 2 Si.
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高影响因子
JOURNAL OF THE EUROPEAN CERAMIC SOCIETY
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2020
·
IF 4.495
Lairong Xiao,Xueqing Xu,Sainan Liu,Ziqi Shen,Siyu Huang,Wentao Liu,Yuqing Peng,Yali Huang,Jianfei Liu,Yanchun Nie,Xiaojun Zhao,Zhenyang Cai
Tantalum (Ta) alloys are important ultra-high-temperature structural materials owing to their excellent high-temperature mechanical properties and processability. However, they exhibit poor high-temperature oxidation resistance. In this study, a dense MoSi 2 ceramic coating was prepared on a Ta substrate using an innovative multi-arc ion plating process and halide activated pack cementation in order to improve its ultra-high-temperature oxidation resistance. This ceramic coating exhibited a low roughness space arithmetic (287.1 ± 26.3 nm) and a dense structure. The relationship between the thickness of the coating and the duration of pack-cementation at 1250 ℃ was parabolic. The coating had a service life of more than 12 h at 1750 ℃, and showed excellent high-temperature oxidation resistance because of the uniform and dense structure of the coating and the rapid formation of a dense SiO 2 layer with low O 2 permeability during high-temperature oxidation.
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高影响因子
JOURNAL OF THE EUROPEAN CERAMIC SOCIETY
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2020
·
IF 4.495
Qianglong He,Shi Tian,Jingjing Xie,Cuili Xiang,Hao Wang,Weimin Wang,Zhengyi Fu
B 6.5 C-TiB 2 -SiC-BN composite ceramics were prepared by a novel solid-state reaction using TiCN, B, and Si as raw materials. The final products obtained by hot pressing at 1950 °C possessed a fine microstructure, homogeneous distribution, and excellent mechanical properties . The obtained bulk B 6.5 C-TiB 2 -SiC-BN composite ceramic shows a high relative density (98.8 %). The mechanical properties of the composites are anisotropic because of the orientation growth and structural characteristics of TiB 2 and h-BN grains. The values of hardness, bending strength , and fracture toughness measured along the hot-pressing direction were 19.6 GPa, 801 MPa, and 4.30 MPa m 1/2 , respectively, which were higher than those measured perpendicular to the hot-pressing direction. The formation of twin structures in B 6.5 C and SiC grains and the crack deflections induced by h-BN and TiB 2 grains are beneficial for improving the mechanical properties of these composites.
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高影响因子
CERAMICS INTERNATIONAL
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2020
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IF 3.83
Junxiao Tang,Wei Ji,Jingjing Xie,Yunwei Shi,Yuexu Zhu,Qianglong He,Weimin Wang
In this study, B 6.5 C-TiB 2 -SiC-BN composite was fabricated via reactive hot pressing from a powder mixture of TiCN, B, and Si. The reaction process of the powder mixture was investigated by heat treatment at elevated temperatures. The as-reacted powder products possessed a core-shell structure of TiB 2 surrounded by h-BN. During densification, the h-BN in this structure acts as a diffusion channel and lubricant, which promoted the densification process. The extremely small size, fresh surface of in-situ formed phases, and uniform dispersion in synthesized powders also contributed to sintering. The designed reactive hot-pressing sintering effectively resolves the difficulty of obtaining uniformly-dispersed BN. The obtained bulk B 6.5 C-TiB 2 -SiC-BN composite ceramic shows high relative density (98.8%) and good comprehensive mechanical properties including hardness, bending strength , and fracture toughness of 19.6 GPa, 801 MPa, and 5.31 MPa m 1/2 , respectively.
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高影响因子
APPLIED ENERGY
·
2021
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IF 9.746
Qingyang Luo,Xianglei Liu,Haolei Wang,Qiao Xu,Yang Tian,Ting Liang,Qibin Liu,Zhan Liu,Xiaohu Yang,Yimin Xuan,Yongliang Li,Yulong Ding
Phase change materials (PCMs) based thermal energy storage techniques are promising to bridge the gap between thermal energy demand and intermittent supply. However, the low specific heat capacity ( C p ) and thermal conductivity of PCMs preclude the simultaneous realization of high energy density and high power density thermal charging/discharging. Here, concurrent enhancement of C p and thermal conductivity are demonstrated to be possible based on SiO 2 nanoparticles decorated LiNO 3 /NaCl eutectics inlaid in three-dimensional (3D) hierarchical ultralight silicon carbide (SiC) foams. The average C p is 4.86% higher than that of pure PCMs due to the high surface energy and interfacial thermal resistance induced by weak interaction between SiO 2 nanoparticles and eutectics, as confirmed by molecular dynamics (MD) simulations. The thermal conductivity of composites achieves an ultrahigh value of 2.78 W·m −1 ·K −1 , which is 259% of LiNO 3 /NaCl, accompanied with a large phase change enthalpy of 331.9 kJ/kg. Continuous heat transport paths provided by ultralight SiC foams have dominant contributions to the enhancement of thermal conductivity, although the presence of SiO 2 nanoparticles deteriorates it slightly. In addition, the full-spectrum solar absorptance is enhanced from 25.2% to 76.3%. Rapid thermal transport and enhanced solar absorptance of composites enable heat charging rate to rise by 150% compared with SiO 2 nanoparticles decorated eutectics. This work provides a strategy for the realization of high energy density and power density compatible thermal energy storage technology.
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高影响因子
SOLID STATE IONICS
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2021
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IF 3.785
Yawen He,Zhongbin Ye,Mohamad Chamas,Moulay Tahar Sougrati,Pierre-Emmanuel Lippens
The silicon based composite Si/Cu-Zn(ox)/C was prepared by ball milling from Si microparticles , Cu-Zn nanopowder heated at air and carbon black. The composite is formed by Si submicrometer particles, Cu-rich Cu x Zn, CuO , ZnO and C nanoparticles . The two oxides are electrochemically active during the first discharge, improving the nanostructuration of the composite and providing Cu nanoparticles that enhance the electronic conductivity with Cu x Zn and C. The nanostructuration helps to buffer the volume variations due to Li-Si alloying reactions during cycling. The composite is further nanostructured during the first cycles as shown by XRD and electrochemical measurements. The material was tested as anode material for Li-ion batteries, providing a reversible capacity of 800 mAh.g −1 during 100 cycles at current of 300 mA.g −1 and a good rate capability. The reversible capacity is mainly due to Li-Si alloying reactions and is stable after few cycles while the solid electrolyte interphase is stabilized after about ten cycles as shown by electrochemical impedance spectroscopy .
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危险品化学品经营许可证（带存储）