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Enhancing Li NiO_(2) cathode materials by concentration-gradient yttrium modification for rechargeable lithium-ion batteries

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Journal of Energy Chemistry 2021年第12期30卷 312-319,I0007页

作者： Yudong Zhang Hang Li Junxiang Liu Jiuding Liu Hua Ma Fangyi Cheng Key Laboratory of Advanced Energy Materials Chemistry(Ministry of Education) Engineering Research Center of High-efficiency Energy Storage(Ministry of Education)College of ChemistryNankai UniversityTianjin 300071China Tianjin EV Energies Company Limited(JEVE) Tianjin 300380China

Lithium nickel oxide(LiNiO_(2)) cathode materials are featured with high capacity and low cost for rechargeable lithium-ion batteries but suffer from severe interface and structure *** we report that rationally designed LiNiO_(2) via concentration-gradient yttrium modification exhibits alleviative side reactions and improved electrochemical *** LiNiO_(2) cathode with LiYO_(2)-Y_(2) O_(3) coating layer delivers a discharge capacity of 225 mAh g^(-1) with a high initial Coulombic efficiency of 93.4%.These improvements can be attributed to the formation of in-situ modified hybrid LiYO_(2)-Y_(2 O3) coating layer,which suppresses phase transformation,electrolyte oxidation and salt dissociation due to the formation of protective cathode electrolyte *** results indicate promising application of concentration-gradient yttrium coating as a facile approach to stabilize nickel-rich cathode materials.

关键词： Lithium-ion battery Concentration gradient Nickel-rich cathode Surface coating yttrium oxide

[Y(dbm)_(3)(H_(2)O)]:Synthesis,thermal behavior and spin-coating precursor for Y_(2)O_(3)layer formation

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Journal of Rare Earths 2017年第12期35卷 1248-1254页

作者： Elaheh Pousaneh Andrea Preuβ Khaybar Assim Julian Noll Alexander Jakob Tobias Rüffer Heinrich Lang Technische Universitat Chemnitz Faculty of Natural SciencesInstitute of ChemistryInorganic Chemistry

The synthesis,structure and thermal behavior of [Y（dbm）3（H2 O）]（3）（dbm = 1,3-diphenyl-1,3-propandionate） and its use as a spin-coating precursor for Y2 O3 deposition is reported. Complex 3 was prepared by the reaction of [Y（NO3）3·6 H2 O]（1） with 3 equiv of Hdbm（2） in presence of NaOH. The molecular structure of 3 in the solid-state was determined by single X-ray crystal diffraction. Both C1 symmetric crystallographically independent species of 3 possess a YO7 coordination setup with minor deviation from an ideal capped octahedron coordination geometry（∧ enantiomer）. Complex 3 forms a1 D chain, due to intermolecular hydrogen bonds between the coordinated H2 O molecule and the 0 atom of the dbm ligand, respectively. The thermal decomposition behavior of 3 was investigated by thermogravimetric studies in the temperature range of 40-800 ℃ and 40-1300 ℃ under an oxygen and argon atmosphere, respectively. Powder X-ray diffraction（PXRD） measurements of the residues confirmed the formation of Y2 O3. Complex 3 was applied as a spin-coating precursor for yttrium oxide film formation on either Si wafers with a continuous 100 nm thick SiO2 film, or with a native oxide *** as-deposited Y2 O3 layers are smooth, conformal, dense and transparent and are of a thickness of 27 and 30 nm, respectively.

关键词： yttrium β-Diketonate yttrium oxide Spin-coating Solid-state structure Vapor pressure

Electrochemical preparation and characterization of brain-like nanostructures of Y_2O_3

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Journal of Rare Earths 2013年第3期31卷 281-288页

作者： Mustafa Aghazadeh Mojtaba Hosseinifard Mohammad Hassan Peyrovi Behrouz Sabour Department of Chemistry Islamic Azad UniversityShar-e-Ray BranchTehranIran Department of Chemistry Faculty of ScienceShahid Beheshti UniversityG.C.P.O.Box 19396-4716TehranIran

Nanostructured Y203 was successfully prepared via a two-step and template-free method. Firstly, yttrium hydroxide precursor was galvanostatically grown on the steel substrate from chloride bath by direct and pulse current deposition modes. Direct cunent deposition was carried out at the constant current density of 0.1 A/dm2 for 600 s. The pulse current was also performed at a typical on-time and off-time （ton=l S and Germ s） with an average current density of 0.05 A/dm2 （la=0.05 A/din2） for 600 s. The obtained hydroxide films were then scraped from the substrates and thermally converted into final oxide product via heat-treatment. Thermal behaviors and phase transformations during the heat treatment of the hydroxide powder samples were investigated by differential scanning calorimetry （DSC） and thermogravimetric analysis （TGA）. The final oxide products were characterized by means of X-ray diffraction （XRD）, Fourier transform infrared spectroscopy （FTIR） and scanning electron microscopy （SEM）. The results showed that the well-crystallized Y203 with brainand sphere-like morphology were achievable via pulse and direct deposition modes, respectively. It was concluded that pulse current cathodic electrodeposition offered a facile route for preparation ofnanostructured Y203.

关键词： cathodic electrodeposition heat-treatment electrochemical growth yttrium oxide brain-like nanostructure rare earths

Reaction between Ti–6Al–4V and Y_2O_3–SiO_2 based face shell for investment casting

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Rare Metals 2016年第12期35卷 901-908页

作者： Ya-Meng Wei Zhi-Gang Lu Guang-Peng Wu Xing-Quan Long Department of Mechanical Engineering Tsinghua University State Key Laboratory of Tribology Tsinghua University Guizhou Anji Aviation Investment Casting Co. Ltd.

The pH value and viscosity of Y2O3-SiO2 （Y-Si） slurry made by Y2O3 powders and silica sol for the face coat of Ti-6Al-4V investment casting were measured. The thermal behavior of the shell made by the Y-Si face coat system was investigated by differential scanning calorimeter （DSC）, thermal gravimetric （TG） analysis combined with mass spectrometry （MS）, and the phase transformations were determined by X-ray diffraction （XRD）. Hot strength, residual strength, linear expansion coefficient, and wearing resistance performance of the shell were also tested. The microstructure and elements distri- bution of the interaction layer were studied by scanning electron microscope （SEM） and energy-dispersive spectrometer （EDS）, respectively. The microhardness tester was applied for the microhardness. The results showed that the slurry was stable for at least 60 h. A very small amount of YZrO3 was formed below 1050℃ and Y2SiO5 was formed around 1450℃. The shell made by Y-Si system had good mechanical property which could reduce cracks during the procedure of dewaxing and inclusions during pouring. Some Al volatilized from the melt, permeated the surface of the face coat shell, and formed the black reaction layer, which blocked the permeation of O so that O penetration was limited to 5μm. The depth of Si penetration was about 60 μm. The hard layer was also around 60 μm.

关键词： Investment casting Titanium alloy Silica sol yttrium oxide Interface reaction

High quality thin film phosphors of Y_2O_3:Eu^(3+) deposited via chemical bath deposition

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Journal of Rare Earths 2010年第5期28卷 684-687页

作者：王娇张志军郭向欣赵景泰陈昊鸿杨昕昕 Key Laboratory of Transparent Opto-functional Inorganic Materials Shanghai Institute of Ceramics Chinese Academy of Sciences Graduate School of Chinese Academy of Science

High transparency in visible region was required for red-light-emitting Y2O3:Eu3+ thin film phosphors. Such films were obtained via chemical bath deposition on bare SiO2 glass substrates through heterogeneous nucleation with further heat treatment. Thin amorphous yttrium basic carbonate films could be completely transformed to crystalline Y2O3 at 650 °C. X-ray diffraction and field-emission scanning electron microscopy were used to characterize these products. The deposition temperature and the post-anneali...

关键词： yttrium oxide thin film chemical solution deposition luminescence rare earths

Porous Y_2O_3 microcubes:synthesis and characterization

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Rare Metals 2011年第6期30卷 577-582页

作者： DENG Bin DING Liwen CHEN Jianjun ZHONG Shengliang Department of Chemistry and Life Sciences Xiangnan University Chenzhou 423000 China College of Chemistry and Chemical Engineering Jiangxi Normal University Nanchang 330022 China Division of Nanomaterials and Chemistry Hefei National Laboratory for Physical Sciences at Microscale University of Science and Technology of China Hefei 230026 China

In this work, a facile route using a simple solvothermal reaction and sequential heat treatment process to prepare porous Y2O3 microcubes is presented. The as-synthesized products were characterized by X-ray powder diffraction （XRD）, scanning electronic microscope （SEM）, energy dispersive spectrometer （EDS）, thermogravimetric analysis （TG）, and differential thermal analysis （DTA）. The thermal decomposition process of the Y203 precursor was investigated. SEM results demonstrated that the as-prepared porous Y203 microcubes were with an average width of about 20 μm and thickness of about 8μm. It was found that the morphology of the Y2O3 precursor could be readily tuned by varying the molar ratio of S2O2- to y3＋. Y203：Eu3＋（6.6%） microcubes were also prepared and their photoluminescence properties were investigated.

关键词： yttrium oxide yttrium sulfate solvothermal synthesis porous material

Preparation and Luminescence Properties of Y_2O_3:Eu^(3+) Nanorods via Post Annealing Process

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Journal of Rare Earths 2006年第Z2期24卷 111-114页

作者：徐珍秀洪樟连赵起超彭丽霞张朋越 Department of Materials Science and Engineering Zhejiang University Magnetism Key Laboratory of Zhejiang Province College of ScienceChina Jiliang UniversityHangzhou 310018China

yttrium oxide doped with europium has a great prospective for FED and PDP phosphor application. In present study, the precursor of yttrium oxide hydroxide nitrate nanorod, which was prepared via hydrotherma] reaction route using PEG-6000 as template from the starting Y(NO3)3 and KOH reactant system, was used to prepare Y2O3:Eu3 + nanorod via a post annealing process during which the precursor with adjustable shape and size was transformed to final Y2O3: Eu3 + product. XRD, field emission scanning electron microscopy (FE-SEM) and photoluminescence spectra (PL) were used to characterize the crystalline, morphology and luminescence properties of as-formed Y2O3: Eu3+ products synthesized at different post annealing temperatures, respectively. The results indicate that. grain morphology of obtained Y2O3:Eu3+ product was nanorod with a mean diameter of about 40 ~ 60 nm and length of about 500 ~ 700 nm, the nanorod structure and morphology of obtained Y2O3: Eu + product maintained during post annealing process and the size varied slightly with different annealing temperatures. Pure cubic Y2O3:Eu3 + phase was formed and the size was the smallest at annealing treatment of 500℃. Under the annealing temperature below 500℃its diameter increased with increasing annealing temperature , and remained in a stable size when the annealing temperature was above 500℃. The PL spectra of excitation spectra of Y2O3:Eu3+ product show that it exhibits excitation band located at about 395 and 468 nm, respectively. Above two excitation bands could be ascribed to the transition 4f-4f of Eu3+ ions in the Y2O3 host. On the other hand, the main emission peaks of the as-prepared products could be ascribed to the Eu3 + ions transition from 5D0 to 7F2. Furthermore, the luminescent intensity was improved about three times when the annealing temperature increased from 500 to 1000℃.

关键词： yttrium oxide nanorods annealing temperature hydrothermal method rare earths

Synthesis of Y_2O_3 phosphor by a hydrolysis and oxidation method

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Journal of Rare Earths 2015年第7期33卷 706-711页

作者：王晓旭胡业旻孟详海李瑛朱明原金红明 Laboratory for Microstructures School of Materials Science and Engineering Shanghai University Department of Mechanical Engineering Tangshan Polytechnic College

A novel and convenient hydrolysis and oxidation method was first used in preparation of carbon contained Y2O3 phosphor powders. The alloy was hydrolyzed in deionized water and the obtained Y（OH）3 powders were heat treated in air atmosphere. The final products - Y2O3 powders were micron clusters which were aggregated by hundreds of nanoparticles with the size of about 5 nm. The chemical composition, structural and morphological features of the samples were characterized by means of X-ray powder diffraction （XRD） analysis, transmission electron microscopy （TEM）, Fourier-transform infrared （FT-IR） spectra, X-ray photoelectron spectra （XPS） and carbon sulfur analyzer. The obtained powders showed good bluish-white photoluminescence （PL） emissions （ranging from 430 to 600 nm, peaking at 468 nm and 578 nm） under the xenon light excitation. The luminescent mechanism was ascribed to the carbon impurities in the Y2O3 host.

关键词： yttrium oxide hydrolysis and oxidation method phosphors optical properties rare earths

Preparation and Electrorheological Property of NaNO_3-Doped Y_2O_3 Material

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Journal of Rare Earths 2006年第1期24卷 39-43页

作者：霍莉马淑珍商艳丽贾云玲许明远李俊然张少华 State Key Laboratory of Rare Earth Materials Chemistry and Applications College of Chemistry and Molecular Engineering Peking University Beijing 100871 ChinaDepartment of Chemistry Baoding Teacher's College Baoding 071051 China Department of Chemistry Baoding Teacher's College Baoding 071051 China State Key Laboratory of Rare Earth Materials Chemistry and Applications College of Chemistry and Molecular Engineering Peking University Beijing 100871 ChinaDepartment of Chemistry Hebei Normal University Shijiazhuang 050091 China State Key Laboratory of Rare Earth Materials Chemistry and Applications College of Chemistry and Molecular Engineering Peking University Beijing 100871 China School of Vehicle and Transmission Engineering Beijing Institute of Technology Beijing 100081 China

A new class of electrorheological （ER） material using rare earth （RE = Y） oxide as the substrate, NaNO3- doped Y2O3 materials, were synthesized using Na2CO3 and Y（NO3）3 as starting materials. Their ER performance, dielectric property, and crystal structure were studied. The results show that doping NaNO3 can markedly enhance the ER activity of the Y2O3 material. For the suspensions of these materials in dimethyl silicone oil, a clear dependence of the shear stress on the doping degree of NANO3 was observed, and the optimal value of Na/Y molar ratio of 0.6 in doping degree was discovered, the relative viscosity ηr（ ηE/η0, E = 4.2 kV·mm^-1） of the suspensions is nine times higher than that of pure Y2O3 material. The new results of the relationship between ER effect and the microstructure were obtained, which are helpful for further understanding the mechanism of ER effect and synthesizing a good ER material.

关键词： electrorheological property yttrium oxide NaNO3 doping microstructure rare earths