国内球形Ni（OH）2的生产研究现状

本文综述了国内研究制备球形氢氧化镍的现状,液相沉淀法的影响因素,国内外氢氧化镍性能的比较及球形氢氧化镍的未来发展前景。     

我国球形氢氧化镍的生产研究现状

本文综述了国内研究制备球形氢氧化镍的现状,液相沉淀法的影响因素,国内外氢氧化镍性能的比较及球形氢氧化镍的未来发展前景。     

氢氧化镍电极材料制备及展望

氢氧化镍作为Ni-MH二次电池的主要正极活性材料,对电池的容量和寿命起着关键性的作用。本文综述了氢氧化镍电极材料的制备方法,介绍了纳米氢氧化镍制备进展,并从工艺和材料性能改进的角度探讨了其未来研究发展方向。     

电池正极材料纳米氢氧化镍的制备新进展

综述了电池正极材料纳米氢氧化镍的几种制备方法及其工艺条件和主要特点，描述了纳米氢氧化镍的结构特征及电化学性能，探讨了转化温度、表面活性剂、反应物浓度以及硝酸根离子对形成纳米氢氧化镍颗粒尺寸与形貌的影响，指出纳米氢氧化镍作为电池正极材料具有光明的前景，但对生产技术还需进一步研究。     

影响球形氢氧化镍密度主要因素的实验研究

主要讨论了制备工艺条件对球形氢氧化镍密度的影响。通过试验,找到了制备高密度球形氢氧化镍的最佳条件。     

pH值和表面活性剂对纳米氢氧化镍松装密度的影响

利用加表面活性剂（聚乙二醇）的缓冲溶液法制备β相纳米氢氧化镍。研究了pH值及表面活性剂用量对样品纳米氢氧化镍颗粒度及松装密度的影响。结果表明：粒度与松装密度随着pH值的增大先减小后增大,随表面活性剂的比例增大而单调减小,pH值约为10.5时,松装密度达最小值。TEM观察表明,纳米氢氧化镍的微观形貌呈针形。     

钕掺杂非晶态Ni(OH)2的电化学性能

采用微乳液快速冷冻沉淀法制备出Nd掺杂非晶态氢氧化镍粉体材料, 采用Raman, XRD, SEM和IR对其结构形态进行了表征分析, 并对其交流阻抗谱（EIS）和充放电性能进行了测量. 结果发现, Nd的掺入使非晶态氢氧化镍结构缺陷增多, 无序性增强, 电化学反应的电荷转移电阻降低, 材料的电化学性能和结构稳定性提高. 样品作为MH-Ni电池正极材料在恒流80 mA·g^-1下充电5 h, 40 mA·g^-1放电, 终止电压为1.0 V时, 放电电压稳定于1.240 V, 开路电位为1.474 V, 放电容量高达348.89 mAh·g^-1, 并具有优良的电化学循环性能.     

粗制氢氧化镍羰基法提纯技术研究

红土镍矿湿法浸出产出的粗制氢氧化镍仅含镍40%左右,且含有钴、锰、铁、镁、钠等杂质元素,需进一步提纯才能满足市场要求。本文研究了氢氧化镍采用羰基气化冶金工艺生产高附加值羰基镍粉的可行性,通过小型试验和工业化试验,确定了技术路线和工艺参数。研究表明,粗制氢氧化镍经烘干焙烧、还原、活化、羰化和分解,所产的羰基镍粉纯度大于99.5%,能够满足市场要求,镍的直收率大于70%,残留在羰化渣中的镍和富集的锰、钴等有价金属,可作为湿法冶金的原料。     

粗氢氧化镍制备高品质硫酸镍溶液试验研究

采用氧化洗涤浸出法对粗制氢氧化镍原料中的镍进行了高效浸出试验研究,加入氧化剂过硫酸铵可有效实现主金属镍的浸出,抑制原料中Co、Fe、Mn等杂质金属的浸出,氧化后氢氧化镍纯水洗涤可有效去除粗制氢氧化镍中Na、Mg、Cl离子,浸出液可通过萃取工艺一步分离出高品质硫酸镍溶液,直接用于三元电池材料生产,简化了硫酸镍生产工艺,浸...     

pH值和表面活性剂对纳米氢氧化镍松装密度的影响

利用加表面活性剂(聚乙二醇)的缓冲溶液法制备β相纳米氩氧化镍.研究了pH值及表面活性剂用量对样品纳米氢氧化镍颗粒度及松装密度的影响.结果表明:粒度与松装密度随着pH值的增大先减小后增大,随表面活性剂的比例增大而单调减小,pH值约为10.5时,松装密度达最小值.TEM观察表明,纳米氢氧化镍的微观形貌呈针形.     

Ultrasonic synthesis, characterization and formation mechanism of aggregated nanorings of EuF3

The aggregated nanorings of EuF3 were synthesized via ultrasonic irritation in aqueous solution. The products were characterized by X-ray powder diffraction （XRD）, scanning electron microscopy （SEM）, and transmission electron microscopy （TEM）. XRD pattern proved that the crystalline phase of the EuF3 rings was hexagonal. The SEM and TEM images indicated that the as-prepared EuF3 nanocrystals had ring-like morphology and were aggregated by numerous small crystallites （about 10-15 nm in diameter）; the outer diameter of the rings was in the range of 200--300 nm, while the inner diameter was in the range of 50-80 nm with a thickness of 30-40 nm. Moreover, the time-depend experiments were carried out to disclose the formation mechanism of the as-prepared ring-like nanostructures.     

羟基氧化镍的制备及电化学性能研究

采用液相化学氧化法研究了β相羟基氧化镍的制备条件,并对产物形貌和电化学性能进行了分析。通过正交试验和单因素试验,得出反应的最佳制备条件。以XRD和SEM测试手段,对样品的晶体结构和形貌进行了研究。XRD分析表明,合成的样品为六方晶系的β-Ni OOH。SEM分析表明,制取的β-Ni OOH晶体形状为球形。通过恒流放电和循环伏安测试表明,样品具有良好的初始放电性能和电化学可逆性,适合于作镍锌电池的正极材料。     

Preparation and Sinterability of Mn-Zn Ferrite Powders by Sol-Gel Method

Mn-Zn spinel ferrites were synthesized by sol-gel method. Effects of calcined temperature on structure and particle size of MnZnFe2O4 were investigated by X-ray diffraction (XRD) and scanning electron microscopy (SEM). XRD patterns indicate that the ultra fine Mn-Zn ferrite exhibits a spinel crystal structure. SEM images show that the powder fired at 900 ℃ for 2 h has an average diameter of 60～90 nm. The particle size becomes larger with the increasing of calcined temperature and the distribution of particle becomes even more homogeneous. Sintering behaviors of synthesized ferrite powders depend on the powder characteristics and high temperatures have induced the good crystallization of particles.     

Blue-green BaAl_2O_4：Eu~（2＋）,Dy~（3＋） phosphors synthesized via combustion synthesis method assisted by microwave irradiation

Blue-green luminescent BaAl2O4:Eu2+,Dy3+ phosphor powders were synthesized via combustion synthesis method assisted by microwave irradiation in air. The phosphors were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and fluorescence spectrophotometer. The XRD results revealed that when the concentration of urea was over 3 times higher than theoretical quantities, a BaAl2O4 single hexagonal phase was obtained. The SEM results revealed that the surface of the BaAl2O4:Eu2+,Dy3+ pow...     

Synthesis and Spectral Properties of Nd3+:Gd3Ga5O12 Nanopowder for Transparent Laser Ceramics

Nd3 :Gd3Ga5O12 (Nd:GGG) nanopowder for transparent laser ceramics was synthesized using sol-gel method. XRD, SEM, and fluorescence spectrum were used to study the properties of Nd3 :Gd3Ga5O12 nanopowder. XRD patterns of samples show that it has a cubic structure. Meanwhile, pure Nd:GGG crystals were obtained at 1000 ℃ for 12 h. SEM photographs show that dispersed, uniform, ball-like Nd:GGG nanopowder is obtained. Both XRD and SEM results show that the crystallization degree and the grain size increase with the increase in calcining temperature. Analysis of fluorescence spectrum shows that fluorescence emission occurs at 1062.7 nm, which is the result of Nd3 (4F3/2→4I11/2) transition. Homogenous Nd:GGG nanopowder with a small grain size synthesized using the sol-gel method is favorable for sintering the transparent ceramic, which proves that the nanopowder obtained is suitable as a precursor for preparing GGG transparent ceramics.     

Preparation and Characterization of Red Luminescent Ca0.8Zn0.2TiO3: Pr3+, Na+ Nanophosphor

Nanophosphor with the nominal composition of Ca0.8Zn0.2TiO3∶Pr3 , Na (CZTOPN) was synthesized at relatively low temperature by the sol-gel method. Metal ions were dispersed by citric acid in ethylene glycol solvent and then react with Ti(OC4H9)4 to form sol and gel. The decomposition process of the precursor, and crystallization and particle size of CZTOPN were examined by thermal analysis (TG-DSC), powder X-ray diffraction (XRD), and scan election microscopy (SEM). Results of TG-DSC and XRD reveal that the composition of Ca0.8Zn0.2TiO3∶Pr3 , Na changes with the sintering temperature. SEM data indicate that the diameter of particles is under 50 nm even if the sintering temperature increases to 1000 ℃. In contrast to a solid state reaction, the excitation spectra of samples synthesized by the sol-gel method shift blue about 10 nm and the emission intensity at 617 nm increases significantly.     

Influence of dispersant on Y_2O_3:Eu~(3+) powders synthesized by combustion method

Y2O3:Eu3+ powders were synthesized by combustion method and the influence of dispersant was investigated.XRD analysis indicated that the particle size increased with a small amount of dispersant firstly and then decreased with a further increase of dispersant.The morphologies of the powders were studied by scanning electron microscopy(SEM) and high-resolution transmission electron microscopy(HRTEM).SEM images revealed that an appropriate amount of dispersant could reduce the agglomeration significantly.Due ...     

Synthesis of Long Afterglow SrAl2O4 :Eu2+, Dy3+ Phosphor by Microemulsion Method

Long afterglow SrAl2 O4: Eu2 , Dy3 phosphor was synthesized by microemulsion method. The synthesized phosphor was characterized by XRD. XRD pattern indicates that the phosphor has monoclinic SrAl2 O4 crystal structre.The microstructure of the phosphor was investigated by SEM and TEM. The excitation spectrum, emission spectrum and afterglow decay curve were measured, the wide range of excitation wavelength indicated that the luminescent material could be excited by the light from ultraviolet ray to visible light, and the emission maximum was found to peak mainly at λem of 525 nm. The sample excited by ultraviolet visible light could emit bright green light.     

高饱和磁化强度Fe_3O_4纳米粒子的制备及表征

实验采用反滴定化学共沉淀工艺在无任何惰性气体保护情况下合成了纯度高、结晶性好的四氧化三铁纳米粒子,测试结果显示,其饱和磁化强度高达104．6emu／g。用X射线衍射仪、扫描电镜、选区电子衍射和X射线光电子能谱表征了四氧化三铁纳米粒子的形貌结构及化学成分等性质,用振动磁强计测试其磁性质。详细的讨论了pH值、陈化温度、陈化时间等因素对磁性质的影响机制。     

Influence of Doping Rare Earth on Performance of Lithium Manganese Oxide Spinels as Cathode Materials for Lithium-Ion Batteries

The cathode material plays an important role inthe performance of lithium ion batteries. Commerciallithium cells use lithium cobalt oxide cathodes and thehigh cost of this material has prompted the design andsynthesis of alternate insertion hosts. Among these al ternatives, spinel LiMn2O4 has been found to bepromising in terms of specific energy, non toxicity,and low cost[1~3]. It is thought that lithium man ganese oxides will be used in lithium ion batteries forel…