低热固相反应法合成反尖晶石型Zn_(0.5)Ni_(0.5)Fe_2O_4纳米晶

以NiSO4.7H2O,ZnSO4.7H2O,Fe2(SO4)3和NH4HCO3为原料,在表面活性剂PEG-400存在下,先在室温下研磨反应混合物使其进行固相反应,然后用水洗去混合物中的可溶性无机盐后于80℃下烘干,即得纳米晶Zn0.5Ni0.5Fe2O4前驱体。通过煅烧前驱体即得反尖晶石型Zn0.5Ni0.5Fe2O4纳米晶产品。采用TG/DTA,XRD,IR,SEM和VSM对前驱体及其热解产品进行表征。结果表明,800℃下煅烧前驱体3h得到粒径约为35nm的反尖晶石型Zn0.5Ni0.5Fe2O4纳米晶,其比饱和磁化强度为75.4emu/g,矫顽力Hc为40Oe,剩磁Mr为3emu/g。     

低热固相反应法合成反尖晶石型NiFe2O4纳米晶

以NiSO4·7H2O,Fe2(SO4)3和NH4HCO3为原料,在表面活性剂PEG-400存在下,先在室温下研磨反应混合物使其进行固相反应,然后用水洗去混合物中的可溶性无机盐后于80℃下烘干,即得纳米晶NiFe2O4前驱体.通过煅烧前驱体即得反尖晶石型NiFe2O4纳米晶产品.采用TG/DTA,IR,XRD和VSM对前驱体及其热解产品进行表征.结果表明,400℃下煅烧前驱体2h得到粒径约为17.2nm的反尖晶石型NiFe2O4纳米晶,其比饱和磁化强度为32.3emu/g.     

低热固相反应法合成反尖晶石型NiFe_2O_4纳米晶

以NiSO4.7H2O,Fe2(SO4)3和NH4HCO3为原料,在表面活性剂PEG-400存在下,先在室温下研磨反应混合物使其进行固相反应,然后用水洗去混合物中的可溶性无机盐后于80℃下烘干,即得纳米晶NiFe2O4前驱体。通过煅烧前驱体即得反尖晶石型NiFe2O4纳米晶产品。采用TG/DTA,IR,XRD和VSM对前驱体及其热解产品进行表征。结果表明,400℃下煅烧前驱体2h得到粒径约为17.2nm的反尖晶石型NiFe2O4纳米晶,其比饱和磁化强度为32.3emu/g。     

NaSn2（PO4）3纳米晶的低热固相合成及表征

以Na2HPO4·12H2O和SnCl4·5H2O为原料,在适量表面活性剂聚乙二醇(PEG)-400的存在下,先在室温下研磨反应混合物进行固相反应,然后将反应混合物在80℃下保温2h,接着用水洗去混合物中的可溶性无机盐后在80℃下烘干,即得磷酸锡钠纳米晶前驱体.将前驱体在600℃下保温使其转变成高纯NaSn2(PO4)3纳米晶.采用TG/DTA,IR,XRD和SEM对产品进行表征.结果表明,前驱体在600℃下保温1h得到结晶良好、空间群为R-3(148),平均粒径约为49.6nm的球形NaSn2(PO4)3.     

LiNi_(0.5)Mn_(1.5)O_4纳米棒的合成及其储锂性能研究

将化学计量比的LiOH·H_2O、Ni(NO_3)_2·6H_2O与超细α-MnO_2纳米线前驱体均匀混合,在800℃下煅烧12 h合成LiNi_(0.5)Mn_(1.5)O_4纳米棒。通过XRD、TEM和电化学测试对样品的晶体结构、表面形貌及电化学性能进行了表征。结果表明:超细α-MnO_2纳米线平均直径为10 nm,多根α-MnO_2纳米线聚集成簇。LiNi_(0.5)Mn_(1.5)O_4纳米棒直径为50 nm,与α-MnO_2纳米团簇的直径相仿。电化学测试结果表明:LiNi_(0.5)Mn_(1.5)O_4纳米棒的初始放电比能量为475 Wh/kg,循环500圈后容量保持率为99%。     

Ni-Zn铁氧体粉体的水热法制备与磁性研究

采用水热法合成Ni0.5Zn0.5Fe2O4粉体，并用XRD、TEM和VSM对粉体进行表征。实验结果表明：在pH=8时，130℃反应1h才生成比较完整的Ni0.5Zn0.5Fe2O4尖晶石型晶体；温度高和反应时间长有利于得到晶型结构好的粉体；粉体颗粒均匀呈球形，粒子尺寸随反应时间的延长和温度的升高而增大。130—200℃水热反应过程的晶粒生长活化能为41．6kJ／mol。磁性测量表明采用不同温度热处理的Ni0.5Zn0.5Fe2O4粉体，随热处理温度升高，饱和磁化强度增加，矫顽力下降。     

不同制备方法对正极材料0.5Li_2MnO_3·0.5Li(Ni_(1/3)Co_(1/3)Mn_(1/3))O_2结构、形貌、电化学性能的影响

分别采用氢氧化物共沉淀、碳酸盐共沉淀、喷雾干燥的方法合成了层状α-Na Fe O2结构的富锂正极材料0.5Li2Mn O3·0.5Li(Ni1/3Co1/3Mn1/3)O2,通过X射线衍射分析(XRD)、扫描电子显微镜(SEM)和电化学性能测试对不同合成方法所得的样品进行了表征。实验结果表明:氢氧化物共沉淀合成的前驱体所制备的正极材料0.5Li2Mn O3·0.5Li(Ni1/3Co1/3Mn1/3)O2具有良好的电化学性能,0.05C倍率下首次放电容量可达247.1 m A·h/g,0.2C倍率条件下经过50次循环,容量保持率为98.7%。     

一维NiFe_2O_4纳米丝的制备与磁性能

采用静电纺丝法制备了表面光滑、直径均匀、连续的一维NiFe_2O_4纳米丝。利用傅立叶变换红外光谱仪(FTIR)、X射线电子衍射(XRD)、扫描电子显微镜(SEM)和振动样品磁强计(VSM)对Ni Fe2O4纳米丝的结构、形貌和磁性能进行表征。结果表明,经500~900℃煅烧后均得到直径约为60 nm的纯相尖晶石型NiFe_2O_4纳米丝,且NiFe_2O_4纳米丝具有良好的软磁特性,其饱和磁化强度(Ms)和剩余磁化强度(Mr)随煅烧温度的升高而增大,900℃煅烧后Ms和Mr分别达到最大值35.56、13.29 A·m2/kg。经600℃焙烧后的Ni Fe2O4纳米丝Ms为30.56 A·m2/kg,矫顽力(Hc)达到最大值2.76 A/m,表明NiFe_2O_4的单畴临界尺寸约为28 nm。     

油酸改性的二甲苯基Fe3O4磁流体的制备及表征

以FeCl3和FeSO4为铁源,采用化学共沉淀法合成磁性Fe3O4纳米磁胶粒,然后以二甲苯为溶剂,用油酸对Fe3O4纳米微粒进行表面改性,制备二甲苯基Fe3O4磁流体.该磁流体具有良好的稳定性及超顺磁性.磁流体中Fe3O4磁性颗粒的平均粒径为10～20nm,晶型为反尖晶石型.     

油酸改性的二甲苯基Fe3O4磁流体的制备及表征

以FeCl3和FeSO4为铁源,采用化学共沉淀法合成磁性Fe3O4纳米磁胶粒,然以二甲苯为溶剂,用油酸对Fe3O4纳米微粒进行表面改性,制备二甲苯基Fe3O4磁流体．该磁流体具有良好的稳定性及超顺磁性．磁流体中Fe3O4磁性颗粒的平均粒径为10～20nm,晶型为反尖晶石型．     

Research on preparation of layered LiNi0.5 Mn0.5O2

An O2-type layered LiNi0. 5 Mn0. 5 O2 was prepared by rapidly-quenched method, and the structural feature was studied by X-Ray Diffraction. The material synthesized at 950℃ was with a single O2-type structure. Charge and discharge in a voltage range of 2.0-4.35V, the discharge specific capacity of material at the 1st cycle is 143.1 mAh/g in a current density of 0.5 mA/cm2 , and the plot of discharge was with two voltage plat at 3.6 V and 2.8V.     

Research on preparation of layered LiNi0.5 Mn0.5O2

An O2-type layered LiNi0. 5 Mn0. 5 O2 was prepared by rapidly-quenched method, and the structural feature was studied by X-Ray Diffraction. The material synthesized at 950℃ was with a single O2-type structure. Charge and discharge in a voltage range of 2.0-4.35V, the discharge specific capacity of material at the 1st cycle is 143.1 mAh/g in a current density of 0.5 mA/cm2 , and the plot of discharge was with two voltage plat at 3.6 V and 2.8V.     

锂离子电池正极材料锂镍钴氧化物的研究

采用共沉淀法合成了镍钴氧化物前驱体,再与LiOH·H2O固相混合,在氧气氛下高温焙烧合成锂离子电池正极材料锂镍钴氧化物LiNi0.5Co0.5O2,对所得化合物进行了合成条件及电化学性能的研究;同时也进行了相关的XRD、SEM、CV表征研究。得到的LiNi0.5Co0.5O2化合物性能比较优良,其首次充电比容量可达157.6mA·h/g,放电比容量达142.8mA·h/g。     

Research on preparation of layered LiNi_(0.5)Mn_(0.5)O_2

1IntroductionLithium secondary batteries have been rapidly developed because of their well performances such ashigh voltage,high specific energy,high capacity and light weight since appeared at last century.It waspromising to be the main power source of electric vehicles and electric tools.The more practical interestcathode materialsincluded mainlylithiumcobalt oxide,lithiumnickel oxide andlithium manganese oxideetal.At present,lithiumcobalt oxygen was the most widely usedin comerical,andits s…     

高效光催化分解水产氢Ni2P/Cd0.5Zn0.5S复合材料的共催化效应

采用沉淀-水热法和低温热磷化法分别制备了Cd0.5Zn0.5S纳米颗粒和Ni2P纳米片，利用超声空化效应合成了价格低廉、分散良好、高效的非贵金属磷化物助催化的Ni2P/Cd0.5Zn0.5S复合材料。通过XRD、SEM、UV-vis、PL以及电化学测试等手段进行了表征测试。以Na2S-Na2SO3为牺牲剂，在可见光(λ ≥ 420 nm)照射下对样品的光催化分解水产氢性能进行评价。结果表明，Ni2P显著提高了Cd0.5Zn0.5S的光催化产氢活性。当Ni2P含量为10 wt%时，复合材料的光催化产氢速率达到19133 μmol?g-1?h-1，为Cd0.5Zn0.5S产氢速率(7865 μmol?g-1?h-1)的2.4倍，且七次光催化循环实验后的产氢速率仍为初始值的91%。这可以归因于复合材料在具有更好的光吸收性能和较低的禁带宽度的同时，Ni2P为Cd0.5Zn0.5S提供的活性中心和界面效应有效地促进了光生载流子的有效分离和快速迁移。     

Influence of deposition temperature on ionic conductivity of perovskite (Li0.5 La0.5) TiO3 solid state electrolyte thin film

Thin film microbattery is a promising micropower source for its high energy density and good cell performances, and the application of fast lithium ion conducting solids as electrolytes is thus very important. (Li0.5 La0.5 )TiO3 (LLTO) thin film electrolytes for thin film microbattery were prepared onto Pt/Si substrates using magnetron sputtering. As-deposited LLTO thin films showed amorphous-like phases and when deposition temperature increases the ionic conductivity raises accordingly. The ionic conductivity of LLTO thin film reaches 8. 7 × 10-6 S/cm when the deposition temperature is 400℃, which shows that the LLTO thin films deposited by magnetron sputtering are suitable for application as an electrolyte for thin film microbattery.     

高纯Al-0.5％Cu合金的轧制织构

采用取向分布函数(ODF)研究轧制形变量对高纯Al-0.5％ Cu合金织构的影响.结果表明,30％轧制变形量主要有{112} ＜351＞,50％时{114} ＜110＞织构,70％时出现了较强的铜式织构｛ 211｝ ＜111＞和{111｝纤维织构,在形变量达到90％后,由于出现了剪切力,织构为非常强烈的旋转立方{001｝ ＜110＞.分析Al-0.5％Cu合金的α和β线,发现随着变形量的增大,织构向C取向聚集.     

Influence of deposition temperature on ionic conductivity of perovskite (Li0.5 La0.5) TiO3 solid state electrolyte thin film

Thin film microbattery is a promising micropower source for its high energy density and good cell performances, and the application of fast lithium ion conducting solids as electrolytes is thus very important. (Li0.5 La0.5 )TiO3 (LLTO) thin film electrolytes for thin film microbattery were prepared onto Pt/Si substrates using magnetron sputtering. As-deposited LLTO thin films showed amorphous-like phases and when deposition temperature increases the ionic conductivity raises accordingly. The ionic conductivity of LLTO thin film reaches 8. 7 × 10-6 S/cm when the deposition temperature is 400℃, which shows that the LLTO thin films deposited by magnetron sputtering are suitable for application as an electrolyte for thin film microbattery.