MATERIALS CHEMISTRY AND PHYSICS
·
2021
·
IF 4.094
Faqiang Shi,Limeng Liu,Jiandong Wu,Junfeng Hou,Yujin Wang
TaC x (x = 0.5, 0.55, 0.6 and 0.7) ceramics with 20 mol% Al addition were prepared by hot pressing TaC, Ta and Al powder mixtures. Effects of the overall C:Ta ratios and the Al addition on constituent phases, microstructures and mechanical properties of the consolidated materials were examined. Results showed that O impurity contained in the starting powders was collected in form of Al 2 O 3 due to strong affinity of O with Al. The TaC x -Al composites were easy to densify due to presence of molten Al at its melting point ( T m = 660 °C) and a transient Al–Ta eutectic liquid at higher temperatures. After densification, the metallic liquids were eliminated ultimately by formation of refractory Ta 4 AlC 3 via reaction of Al, Ta and TaC. Reactions between the remnant Ta and TaC after Ta 4 AlC 3 formation resulted in ζ-Ta 4 C 3-z or h-Ta 2 C depending on the initial C:Ta ratio. The Ta 4 AlC 3 compound was compatible with the tantalum carbides. Microstructures of the TaC x -Al (x = 0.5–0.7) composites were consisted of ζ-Ta 4 C 3-z and Ta 4 AlC 3 fine lamellar grains to benefit the mechanical properties of the composites. The TaC 0.7 –20mol% Al composition had satisfying mechanical properties (flexural strength 613 ± 28 MPa and fracture toughness 11.2 ± 0.8 MPa m 1/2 ). TG-DSC evidenced an increase in oxidation resistance of the TaC x ceramics by the addition of 20 mol% Al.
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF ELECTROANALYTICAL CHEMISTRY
·
2021
·
IF 4.464
Shan Wang,Jie Zhu,Yunjiao Li,Guolin Cao,Yongxiang Chen,Dianwei Zhang,Zhouliang Tan,Jiachao Yang,Junchao Zheng,Huacheng Li
The huge capacity loss during cycling is the main obstacle to the industrial application of nickel-rich cathode materials Li[Ni 1−x−y Co x Mn y ]O 2 (NCM, 1 − x − y ≥ 0.8). However, at the same nickel content, another nickel rich Li[Ni 1−x−y Co x Al y ]O 2 (NCA, 1 − x − y ≥ 0.8) materials possess a much better cyclic performance due to the more powerful bond of Al-O compared with the NCM. But NCA yields a lower capacity caused by inactive Al. In this study, using the spray pyrolysis method to fabricate the new quaternary nickel-rich cathode material LiNi 0.8 Co 0.1 Mn 0.1− x Al x O 2 (NCMA, 0 ≤ x ≤ 0.06) is proposed to enhance the cyclic performance of NCM and with a limited capacity decrease for the incomplete substitution of Mn. The materials exhibit the evidently improvements in the electrochemical performance, among which the LiNi 0.8 Co 0.1 Mn 0.06 Al 0.04 O 2 materials present the most excellent performances where the capacity retentions are up to 83.8% (3.0–4.4 V, 25 °C) after 200 cycles and 88.0% at 55 °C after 100 cycles. The satisfying results can be attributed to the inhibition of oxygen release and cationic disorder after the Al introduced, which are strongly confirmed by the results of structure refinement and first principles calculation.
✓ 已验证
产品关联
DOI
高影响因子
ELECTROCHIMICA ACTA
·
2021
·
IF 6.901
Xiao Zheng,Fangfang Zhao,Lei Ma,Ruixian Tang,Yanru Dong,Guolong Kong,Yu Zhang,Sulin Niu,Gen Tang,Yue Wang,Aimin Pang,Wei Li,Liangming Wei
Aluminum batteries have received extensive research because of the safety, abundance and high capacity of Al anode. Most previous works are concentrated on improving the specific capacity of the cathodes, while other important issues such as cheap cathode-electrolyte system and high areal active material loading have often been overlooked. This paper reports that cheap graphite paper (GP) coupled with low price AlCl 3 /Et 3 NHCl ionic liquid (IL) electrolyte can form a practical Al dual-ion battery (ADIB). By adjusting the AlCl 3 content in IL, the energy storage of GP with high-loading is improved. The ADIB exhibits 71 mAh g −1 at 200 mA g −1 with a loading of 15.16 mg cm −2 , which is almost unattenuated over 1400 cycles. The GP cathode presents 47 mAh g −1 at 150 mA g −1 when the loading increased to 30.21 mg cm −2 . Even at an ultrahigh loading of 46.35 mg cm −2 , the cathode can still achieve 75 mAh g −1 (3.5 mAh cm −2 ) at 40 mA g −1 for over 500 stable cycles. The high capacity is contributed by a self-activating process of AlCl 4 − intercalation, which is closer to the diffusion-controlled battery behavior. The GPs simultaneously exhibit high areal capacity, energy/power density and long-life cycling performance which demonstrates their wide commercial prospects.
✓ 已验证
产品关联
DOI
高影响因子
POWDER TECHNOLOGY
·
2021
·
IF 5.134
Chendong Zhang,Hangchen Li,Xinxin Guo,Shunchao Li,Han Zhang,Xuhai Pan,Min Hua
A new type of dry powder fire extinguishing agent was prepared, which was called composite superfine dry powder with Aluminum Trihydrate (CSFP-ATH). The CSFP-ATH was characterized by laser particle size analysis , scanning electron microscope (SEM), thermal gravity analyzer (TGA), transform infrared spectroscopy(FTIR) analyzer and differential scanning calorimetry (DSC). The extinguishing performance of different samples was examined in a small-scale experimental platform for the liquid hydrocarbon fire. The tests were proved that the fire-extinguishing performance was as follows: CSFP-ATH > superfine ABC dry powder(SFP) > commercial ABC dry powder(CDP). Besides, the mechanism, kinetics and thermochemical changes in the reaction process were calculated by Gaussian simulation, and the reaction path of the CSFP-ATH with free radicals in the flame was predicted. Experimental and theoretical studies have been proved that the addition of Al(OH) 3 can promote the fire extinguishing performance of superfine ABC dry powder.
✓ 已验证
产品关联
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2021
·
IF 4.527
Enbo Li,Yu Bai,Hongying Dong,Ruiling Jia,Xueping Zhao,Ruijun Wang,Manyu Bao,Wen Ma
The Al-doped SrZrO 3 perovskite powder with low infrared emissivity at high temperatures was prepared. The infrared radiation performance and thermophysical properties of the perovskites at high temperatures were discussed. As a result, the infrared emissivity of the Al-doped SrZrO 3 perovskite powder is associated with Al 3+ -doping content, phase composition and particle morphology . The flaky particles SrZr 0.85 Al 0.15 O 2.925 formed by heat treatment at 1000 °C for 6 h have the lowest infrared emissivity of 0.245 in 3–5 μm wavebands at 590 °C. The perovskite powder's infrared emissivity is positively correlated with its electrical resistivity and has no apparent change after heating over 800 °C for long-term. The SrZr 0.85 Al 0.15 O 2.925 perovskite ceramic formed by pressureless sintering still maintains ideal heat insulation performance with the thermal conductivity from 1.17 to 2.21 W m −1 K −1 below 1400 °C. The Al-doped SrZrO 3 perovskite tablet exhibits significant weak radiation intensity due to its characteristics of both low infrared emissivity and thermal conductivity at high temperatures.
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF MATERIALS SCIENCE
·
2020
·Vol. 56
·期 3
·2549-2558
·
IF 3.553
Liu Fangfang,Xu Zehua,Feng Ying,Li Yongfeng,Dou Yongshen,Liu Sanmao
In this work, we report a facile and economic one-step method under atmospheric pressure and 50 °C water bath for the fabrication of a three-dimensional (3D) upright-standing boehmite (AlOOH) nanosheet array film on a structured Al honeycomb substrate, in which zero-valence palladium (Pd 0 ) nanoparticles were well distributed at the same time. Redox reactions of two galvanic cells where the Al honeycomb substrate acted as the common anode, but the palladium precursor (Pd(NH 3 ) 4 2+ ) and weak base water (H 2 O + OH − ) served as the electrolyte of cathode I and II, respectively, led to simultaneous formation of Pd 0 nanoparticles at cathode I and AlOOH nanosheets at cathode II on the surface of Al substrate. The resultant AlOOH nanosheet array was uniform and about 300–400 nm thick, and the highly dispersed Pd 0 nanoparticles were also rather small with an average size of 8.4 nm. Hence, the as-obtained Pd-AlOOH/Al monolithic catalysts exhibited high specific surface area and large micro/mesopore structure as compared to pristine Al honeycomb substrate, leading to excellent catalytic activity in total oxidation reaction of toluene.
✓ 已验证
产品关联
DOI
高影响因子
ENERGY CONVERSION AND MANAGEMENT
·
2020
·
IF 8.208
Rui Han,Jihui Gao,Siyu Wei,Fei Sun,Qingling Liu,Yukun Qin
Thermochemical energy storage based on the Calcium-Looping process characterized high energy density, low cost, and scalability, which is an advantageous candidate for the heat storage systems of Concentrated Solar Power plants. The main disadvantage of Calcium-Looping technology is the rapid decrease in the reactivity of CaO during cycling due to sintering. Many methods have been developed to synthesize high-cycling-behavior CaO-based materials. However, the state-of-the-art synthesized CaO-based materials remain far from the requirements due to the lack of consideration from an application perspective, which not only demands high-cycling-behavior but also needs to consider volumetric energy density. In this work, dense CaO/Al 2 O 3 composites were fabricated using the space-confined chemical vapor deposition method and considering both stability and volumetric energy density. Among different Ca-precursors, calcium formate does not expand during calcination, thus possesses a relatively dense structure, and taken together with the deposition of Al 2 O 3 on the surface of CaO grains obtained composites possessing high density and excellent stability. The optimized composite with 10 mol.% Al achieves a high volumetric energy density of 2.07 GJ/m 3 after 20 cycles, which is 1.58, 4.31, and 6.68 times of the capacity of limestone-derived CaO, sol–gel based CaO/Al 2 O 3 composites, and wet-mixing based CaO/Al 2 O 3 composites, respectively. This study presents a design principle for CaO-based heat storage materials, which are becoming denser and more stable.
✓ 已验证
产品关联
DOI
高影响因子
Frontiers of Chemical Science and Engineering
·
2020
·Vol. 15
·期 2
·269-278
·
IF 3.552
Hou Yuexin,Li Xiaoyun,Sun Minghui,Li Chaofan,Bakhtiar Syed ul Hasnain,Lei Kunhao,Yu Shen,Wang Zhao,Hu Zhiyi,Chen Lihua,Su Bao-Lian
Hierarchical single-crystal ZSM-5 zeolites with different Si/Al ratios (Hier-ZSM-5- x , where x = 50, 100, 150 and 200) were synthesized using an ordered mesoporous carbon-silica composite as hard template. Hier-ZSM-5- x exhibits improved mass transport properties, excellent mechanical and hydrothermal stability, and higher catalytic activity than commercial bulk zeolites in the benzyl alcohol self-etherification reaction. Results show that a decrease in the Si/Al ratio in hierarchical single-crystal ZSM-5 zeolites leads to a significant increase in the acidity and the density of micropores, which increases the final catalytic conversion. The effect of porous hierarchy on the diffusion of active sites and the final catalytic activity was also studied by comparing the catalytic conversion after selectively designed poisoned acid sites. These poisoned Hier-ZSM-5- x shows much higher catalytic conversion than the poisoned commercial ZSM-5 zeolite, which indicates that the numerous intracrystalline mesopores significantly reduce the diffusion path of the reactant, leading to the faster diffusion inside the zeolite to contact with the acid sites in the micropores predominating in ZSM-5 zeolites. This study can be extended to develop a series of hierarchical single-crystal zeolites with expected catalytic performance.
✓ 已验证
产品关联
DOI
高影响因子
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
·
2020
·
IF 3.573
Yajie Chen,Siyuan Xia,Wei Ren,Zilong Zheng,Junhong Chen,Kefeng Ma,Chunpei Yu,Xinli Zhou,Wenchao Zhang
In this paper, sheet-like porous CuO (p-CuO), which was prepared using a hydrothermal-annealing method, has been first selected as an oxidizer to prepare n-Al/p-CuO/GO nanoenergetic composites. The n-Al/p-CuO/GO nanoenergetic materials were fabricated by means of vacuum-assisted self-assembly. Moreover, the effect from the quantity of added GO was studied on the morphology and reaction performance of the n-Al/p-CuO/GO nanoenergetic composites. The characterizations show that the resulting n-Al/p-CuO/GO composites have a uniform distribution of reaction components for an improved reactivity. The total heat release of the composite energetic material gradually rises up to 2306.7 J/g with the increasing GO content till 5 wt % but decreases as the GO content continues going up. Most importantly, the maximum value of the reaction exothermic heat is approximately 2.2 times higher in value than that of the as-prepared composite without GO addition. It is found out that the n-Al/p-CuO/GO nanothermite with 5 wt % GO can be successfully ignited by a semiconductor bridge at a 1 A current to produce a big and bright flame, thus indicating that its combustion performance is excellent. Therefore, the new nanoenergetic composites from a combination of GO and n-Al/p-CuO have a bright application prospect in the field of energetic materials.
✓ 已验证
产品关联
DOI
高影响因子
Nano Research
·
2020
·Vol. 13
·期 2
·419-429
·
IF 8.183
Chen Li-Li,Li Na,Shi Huifeng,Zhang Yuefei,Song Wei-Li,Jiao Shuqiang,Chen Haosen,Fang Daining
To achieve stable positive electrode for promoting the overall electrochemical performance of Al batteries (ABs), here novel cobalt boride (CoB) nanoclusters are synthesized to construct composite electrodes with few-layer graphene (FLG). Due to the presence of amorphous channels in the employed CoB nanoclusters, the ABs with FLG/CoB composite positive electrodes exhibit high rate capability and both mechanical and electrochemical stability in the ABs. With assistance of in situ scanning electron microscopy (SEM), the observation results suggest that the positive electrode of CoB nanoclusters holds almost ignorable volume variation upon electrochemical processes, which substantially alleviates the massive electrode expansion induced by the anion intercalation in the composite positive electrode. Interestingly, the composite positive electrodes provide stable reversible energy storage capability within a broadened temperature range (−30–60 °C), promising a novel strategy to design advanced ABs positive electrodes with enhanced overall energy storage performance.
✓ 已验证
产品关联
DOI
高影响因子
VACUUM
·
2021
·
IF 3.627
Lixia Xi,Shuang Guo,Kai Ding,Konda Gokuldoss Prashanth,Baran Sarac,Jürgen Eckert
The coarsening of primary silicon phases is one of the main challenges in the preparation and application of Al-high Si content alloys. In this work, AlSi40 alloys were manufactured by selective laser melting (SLM). The influence of ceramic nanoparticles on the morphology and size of primary Si phase(s) is investigated. With addition of ceramic nanoparticles, large snow-shaped primary Si changes towards a polygonal shape in coarse regions, while blocky primary Si in fine regions shows insignificant change. The size of primary Si in the modified alloy decreases by ~27.1% and ~25.2% in the respective coarse and fine regions compared to that of the unmodified alloy. Due to the refinement and smoothening of primary Si in the modified alloy, the microhardness distribution becomes homogeneous and an average value of ~233 HV 0.2 was obtained. The coefficient of friction (COF) value and the wear rate are ~0.44 and ~4.5 × 10 −5 mm 3 N −1 m −1 , respectively. An ultimate compressive strength of ~0.76 GPa and a maximum compressive strain of ~7.99% are obtained, increasing by ~21.0% and ~18.0% compared to those of the unmodified alloy. The SLM-fabricated AlSi40 alloys upon heat treatment showed an improved plasticity and slightly decreased strength due to the coarsening of primary Si and grains, decreased solid solution of Si in the matrix as well as accommodation of residual stresses after heat treatment.
✓ 已验证
产品关联
DOI
高影响因子
THERMOCHIMICA ACTA
·
2021
·
IF 3.115
Baozhong Zhu,Weiqi Chen,Yunlan Sun,Peng Guo,Jianzhong Liu
Nanofluid fuels can be used in scramjet . However, the interactions among fuel droplets in spray and combustion process are still a gray area. The study on the evaporation and combustion of the double droplets can better demonstrate the role of nanofluid droplets. In this paper, the evaporation and combustion characteristics of the double droplets of aluminum/n-heptane based nanofluid fuels were investigated by a droplet-suspension method, whose results were compared to those of the single droplet at 973 K and 0.1 MPa. The effect of the distance of the double droplets on their evaporation behavior, ignition delay time, combustion phenomena, and micro-explosion time were studied. The influence of thermocouple wire was also analyzed. The double droplets have a synergistic effect on the evaporation behavior, ignition delay time, and micro-explosion. The ignition delay time of double droplets of the aluminum/n-heptane based nanofluid fuel droplet has debased 25.3% compared with that of the single droplet, while the maximum micro-explosion duration has increased 7.2%. With the increase of the distance of both droplets, the synergistic effect is first strengthened and then weakened.
✓ 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）