Mg_（70）（Ni_3La）_（30）合金制备方法及储氢性能研究

为了研究制备方法对Mg70（Ni3La）30合金相结构和储氢性能的影响,分别采用熔铸法（自然冷却法）、浇铸法及快淬法制备了Mg70（Ni3La）30合金,发现随着冷却速率的增大,结晶相逐渐向低温转变,并且快淬法制备的Mg70（Ni3La）30合金为非晶合金。对该非晶合金进行退火处理后发现,在300℃时非晶相转变为Mg2Ni和La2Mg17晶体相,且晶化后的颗粒非常细小。通过PCT（合金吸放氢）曲线发现,快淬法制备的Mg70（Ni3La）30合金的储氢性能最好,浇注法次之,熔铸法最差。这与非晶合金晶化后的微观结构及高的储氢相有关。     

影响Mg2Ni储氢合金电极性能的因素分析

系统分析了球磨工艺、与Mg粉球磨复合以及组元替换对Mg：Ni合金电极性能的影响，X射线衍射分析和模拟电池法测试结果表明，Mg2Ni合金的放电容量与球磨参效的选择密切相关，高的球磨能量有利于吸放氢的微结构迅速形成，故其放电容量显著提高。不同量的Mg粉与Mg2Ni合金球磨制得Mgx／Mg2Ni复合合金，该类复合合金的放电容量随Mg量的增加而有不同程度的提高。以Nd部分替换Mg制得三元Mg2-xNdxNi合金，X为0．05和0．1时制得单相合金；X为0．2时制得由Mg2Ni、NdNi和NdMgNi4相组成的三相合金。同Mg2Ni单相合金相比，包含Mg2Ni相的三元Mg1.8Nd0.2Ni合金，球磨后它们的放电容量显著提高，这与NdMgNi4相的存在和球磨形成的多相复合微结构有关。     

Mo对储氢合金RE0.78Mg0.22(Ni0.84-xCo0.15Al0.01MOx)3.5的结构及电化学性能的影响

采用XRD分析了La0.50Pr0.22Nd0.06Mg0.22(Ni0.84-xCo0.15Al0.01Mox)3.5(x=0.00,0.01,0.02,0.03和0.04)合金的晶体结构,并且系统地研究了合金的气固相储氢特性和电化学性能。结果表明,合金由Ce2Ni7型结构的A2B7主相和少量的具有CaCu5结构的AB5相构成,晶轴比c/a随着Mo含量的增大而增大。合金在吸放氢过程中的熵变DS和焓变DH与AB5型合金的数值相当。合金的电化学容量随Mo含量的增加而减小,由x=0.00时的381.2 mAh/g下降到x=0.01时的379.5 mAh/g,再至x=0.04时合金的容量最大为362.0 mAh/g;合金容量的衰减速率因Mo的掺入而变大,由x=0.00时的-0.23 mAh/(g.次)降为x=0.04时的-0.97 mAh/(g.次);合金的倍率性能在x=0.01时得以改善,改善幅度为4%。研究表明当x≤0.01时不仅保持了合金的高容量,而且改善了合金的高倍率性能。     

氢镍电池用La0.58Nd0.13Mg0.26Ni3.4储氢合金的结构与电化学性能

通过感应熔炼和退火的方法制备了2H-A2B7和3R-A2B7相共存的La0.58Nd0.13Mg0.26Ni3.4合金,研究了退火温度对La0.58Nd0.13Mg0.26Ni3.4合金物相组成、电化学和动力学性能的影响.结果 表明:不同退火温度下La0.58Nd0.13Mg0.26Ni3.4合金的物相组成都为Gd2C...     

MH-Ni电池用Mg2Ni系储氢合金研究进展

Mg2Ni基储氢合金作为MH-Ni电池负极材料实用化须解决两个问题：室温吸放氢动力学差和浓碱溶液中易腐蚀。介绍了改善Mg2Ni基储氢合金的性能而采取的主要方法,包括改进舍金制备方法、掺入其它元素制备多元Mg2Ni基舍金、复合、表面处理。认为：提高Mg2Ni基储氢舍金的电化学储氢性能,满足MH-Ni电池的使用要求,可能要将改进和发展新的制备方法、多元合金化、包覆、使用缓蚀剂等多种手段联合应用。     

Mg-Ni系储氢合金电极研究最新进展

综述了Mg -Ni系储氢合金的研究情况 ,总结了当前提高Mg -Ni系储氢合金、特别是Mg2 Ni型储氢合金电极性能所采用的主要方法 ,如机械合金化、组元调整、复合改性等方法     

Mg2Ni+Ni型贮氢合金相形成及电化学性能

采用压制烧结和随后机械合金化的方法制备了Mg2Ni Ni型电极合金。研究了Al、Mn替代Mg后对Mg2Ni Ni型合金相形成及电化学性能的影响。XRD测试显示:各合金在610～620℃经过5h烧结后的相结构大部分为Mg2Ni相,与Ni粉混合球磨72h后全部转变为均匀的非晶相。电化学性能测试结果表明:Al、Mn替代后再与Ni粉球磨后的合金,其放电容量、高倍率性能较Mg2Ni Ni合金均有显著提高,其中Mg1.8Al0.15Mn0.05Ni Ni合金的综合性能最佳。     

化学镀Ni对Mg2Ni贮氢合金性能的影响

研究了化学镀Ni处理对Mg2Ni贮氢合金电化学性能的影响,结果发现:化学镀Ni处理可显著提高Mg2Ni合金的放电容量,但不能有效提高合金的循环寿命;放电电流对经化学镀Ni处理的Mg2Ni合金的循环寿命影响较大.XRD和SEM分析表明:经化学镀Ni处理的Mg2Ni合金表面覆盖有一层致密的金属Ni细小颗粒;循环伏安(CV)和电化学阻抗谱(EIS)分析表明:化学镀Ni处理降低了合金表面的电子转移阻抗和氢原子扩散阻抗,提高了合金表面的电化学反应活性.     

球磨La0.92Mg2.08Ni9合金的结构及性能研究

用差热分析仪、X射线衍射仪、扫描电子显微镜及电池综合性能测试仪研究了球磨La0.92Mg2.08Ni9样品的组织结构、形貌、热稳定性及贮氢性能等。结果表明：经400r／min球磨35～50h后,La0.91Mg2.08Ni9样品由非晶组成,颗粒形状为球形或近球形,颗粒尺寸为0．2～5μm。随着球磨时间的延长,非晶样品的热稳定性能增加,颗粒尺寸减小,电化学活化性能降低。经400r／min球磨35h的样品具有较好的室温贮氢性能,首次电化学充放电即达到最大的放电容量405mAh．g^-1。     

LaMgNi4储氢合金的制备及工艺优化

采用正交实验对LaMgNi4储氢合金的制备工艺条件进行优化,系统研究了LaMgNi4制备工艺中易于损耗的La、Mg的附加添加量、烧结温度和烧结时间,并用X射线衍射（XRD）对其结构进行了表征。结果表明,La、Mg的附加添加量分别为4％和5％,样品由400℃以3℃／min的速度升温到750℃,并在750℃保温烧结2．5h可以获得电化学性能较好的LaMgNi4单相合金。     

Processing of (La,Sr)(Ga,Mg)O3 Solid Electrolyte

The preparation of La_0.8Sr_0.2Ga_0.8Mg_0.2O₃ (LSGM) powders by the mixed oxide route requires significantly longer annealing times of about 60 h compared to the combustion synthesis and Pechini method which requires less than 6 h. In comparison to the mixed oxide route the soft chemical synthesis methods produce significantly smaller grain sizes after solid-state reactive sintering, which is due to the significantly shorter annealing times in order to achieve well crystallized ceramics. It is emphasized that at 1400°C in air single phase LSGM samples with the composition La_0.8Sr_0.2Ga_0.8Mg_0.2O₃ could be prepared neither by the mixed oxide route nor the combustion synthesis or the Pechini method, but only at higher temperatures, for example 1500°C. Taking the results of the dilatometric studies for processing of LSGM ceramics into account, it is obviously that sinter temperatures of above 1300°C in air are required in order to prepare dense LSGM ceramics.     

铸态及快淬态La2 Mg(Ni0.85Co0.15)9B0.1贮氢合金

铸态及快淬态La2Mg(Ni0.85Co0.15)9B0.1贮氢合金主要由(La,Mg)Ni3相(PuNi3型结构)、LaNi5相及少量LaNi2相组成,铸态合金还含有微量的Ni2B相.用高于15 m/s的淬速快淬后,Ni2B相几乎消失,各相的含量与快淬淬速有关.与铸态合金相比,快淬态合金放电平台电压降低,但随着淬速提高,放电容量、放电平台电压都存在一个最大值;快淬使合金的循环寿命有不同程度的提高.铸态和快淬态合金均具有良好的活化性能.     

Based on the Study on Preparation and Properties of Co(II) and La3+-Doped TiO2 Electrochromic Film

Abstract

In order to improve the optical properties and coloration effect. Co(II) and La³⁺ doped TiO₂ thin films were synthesized via a sol–gel, by using butyl titanate as precursor on the surface of ITO conductive glass substrate. Several techniques were used to characterize produces. Adopting the Sol-gel technology, [CH₃(CH₂)₃O]₄Ti, La₂O₃, CoC_l2?6H₂O as the precursor, the composite membranes with different molar ratio of Ti, Ti/La, Ti/Co to be prepared on the ITO glass substrate, the optimum technological parameters for preparation of the base material of the electro-induced discoloration glass are determined. The structure and surface morphology optical and electrochromic properties of Co(II) and La³⁺-doped TiO₂ films were examined with X-ray diffraction (XRD) analysis, energy dispersive spectrometer (EDS), scanning electron microscopy (SEM), and ultraviolet-visible spectrophotometer (UV-vis) DTA-TG analysis. It was found that:

1. The sintering temperature coating number, [CH₃(CH₂)₃O]₄Ti content of the TiO₂ film sample, and the doping category are the main factors that affect the structure and properties of the membrane based material;

2. Using two alcohol amine as chelating agent can effectively inhibit the formation of Ti (OH)₄ precipitation;

3. The properties of the TiO₂ glass film prepared by La₂O₃ and CoCl₂·6H₂O are fine;

4. Materials based on the preparation of a radiochromic film transmittance, high cyclic reversibility, cyclic voltammetry characteristics significantly, the results of the study for the electric induced radiochromic film-based material development and application provide a theoretical and experimental basis.

     

Study of the Electrical Properties of Pb(Mg,Ni)1/3Nb2/3O3-PbTiO3 System Across the Morphotropic Phase Boundary

Phase transitional behavior and electrical properties of (1 – x)Pb(Mg,Ni)_1/3Nb_2/3O₃-xPbTiO₃ ceramics (PMNN-PT with Mg/Ni = 1:1, x = 0.20–0.40) across the morphotropic phase boundary (MPB) were examined. X-ray diffraction and dielectric measurement reveal that two phases, pseudocubic and tetragonal phases, coexist in the composition range x = 0.30–0.36. The maximum d ₃₃ (about 570 pC/N) was observed at the composition x = 0.32–0.34. Dielectric and ferroelectric properties exhibit abnormal high near the MPB. An unusual peak shoulder occurred in the dielectric measurement upon thermal cycling for poled samples. This phenomenon was considered to be associated with the macro to micro domain transition and depolarization.     

La0.75Mg0.25Ni3.1-xCo0.4Alx合金的微观结构及性能

通过铸造工艺制备La0.75Mg0.25Ni3.1-xCo0.4Alx(x=0、0.05、0.10、0.15和0.20)贮氢合金,并对x=0.10的合金进行退火处理。分析了Al替代量x和退火温度对合金的影响。合金均含有(La,Mg)Ni3相(PuNi3结构)、LaNi5相和一定量的LaNi2相。铸态合金中LaNi5相的量由x=0时的14.28%增至x=0.20时的24.07%。Al的替代提高了合金的循环稳定性,但比容量由x=0时的398.7mAh/g降至x=0.20时的350.1mAh/g。合金均有优良的活化性能。在900℃下的退火处理,使合金的容量和循环稳定性得到提高。     

环氧树脂纳米复合电介质制备方法及其绝缘性能的研究进展

环氧树脂或树脂浸渍纤维板是电力设备中重要的绝缘材料,过去通过掺杂微米级的无机氧化物填料以提高材料的机械性能。近年,开始使用纳米颗粒掺杂环氧树脂,对于提高材料的绝缘性能,特别是对提高击穿场强、耐电晕性、耐电痕化、导热性、耐低温性、耐辐射性和耐候性等方面具有重要意义。文中以纳米复合电介质的绝缘性能为出发点,概述了纳米复合电介质的常用制备方法,给出了环氧树脂纳米复合电介质的制备流程,总结分析了环氧树脂纳米复合电介质的介电性、局部放电腐蚀、绝缘击穿强度及机械性能。综述了环氧树脂纳米复合电介质在电机绝缘系统中的应用和最新研究进展,为环氧树脂纳米复合电介质在电机主绝缘中的应用提供了思路。     

空心微珠表面BaFe_9(Ni_(0.5)Cu_(0.5)Zr)_(3/2)O_(19)包覆层的制备及电磁性能

采用溶胶-凝胶法在空心微珠表面制备出BaFe9(Ni0.5Cu0.5Zr)3/2O19铁氧体颗粒包覆层。利用X射线衍射仪(XRD)和扫描电镜(SEM)对其进行分析表征。将这种复合材料与石蜡均匀混合,压制成内径3mm、外径7mm的圆环形试样。用矢量网络分析仪测其复电磁参数,计算并分析了它的电磁性能。结果表明:与溶胶-凝胶法制备的BaFe9(Ni0.5Cu0.5Zr)3/2O19单相材料相比,它们的介电损耗角正切、磁损耗角正切在不同的频段有不同的表现形式。吸波材料厚度为3mm时,空心微珠表面包覆BaFe9(Ni0.5Cu0.5Zr)3/2O19样品在10.8～18GHz频率范围内吸波性能要优于BaFe9(Ni0.5Cu0.5Zr)3/2O19的吸波性能。