刘欣艳
,
赵煜娟
,
夏定国
功能材料
LiNi0.8Co0.2O2是锂离子电池界公认的最有希望取代商业化正极材料LiCoO2的新型正极材料之一.本文所研究的复合正极材料LiNi0.8Co0.2O2是由细小的晶粒构成的球形颗粒,单一相,属于R3m空间群.对复合材料LiNi0.8Co0.2O2的Co-K和Ni-K的XANES分析可知,在600～850℃范围温度对于钴元素的影响不明显,而对于镍元素的影响比较显著,随着Ni-K边位置向高能量移动LiNi0.8Co0.2O2正极材料的放电容量升高.复合材料LiNi0.8Co0.2O2和LiNiO2的Ni-K边XANES相似,表明少量钴的引入对晶体结构的改变不是太多,但是峰的强度较高和峰的位置向高能量移动,表明钴Co对Ni的局域结构进行了调制.
关键词:
LiNi0.8Co0.2O2
,
XANES
,
正极材料
,
局域结构
Journal of Materials Research
The morphology of the dark and bright regions observed by transmission electron microscopy for the Zr(64.13)Cu(15.75)Ni(10.12)Al(10) bulk metallic glass strongly depends on the ion beam parameters used for ion milling. This indicates that the ion beam could introduce surface fluctuation to metallic glasses during ion milling.
关键词:
room-temperature
材料科学技术（英）
The effect of interstitial hydrogen on the cohesion of the Al Sigma=11(113) grain boundary (GB) is investigated based on the thermodynamic model of Rice-Wang using the first-principles density function calculation. The results indicate that interstitial H behaves as an embrittler from "strengthening energy" analysis. The reduced GB cohesion due to the presence of H at the GB is attributed to the low affinity between H and Al, and the weakened bonding of Al atomic pairs perpendicular to GB plane.
关键词:
hydrogen;grain boundary;Al-Mg alloys;pseudopotentials;1st-principles
Xiaoguang LIU
,
Xiaowei WANG
材料科学技术（英）
The effect of interstitial hydrogen on the cohesion of the Al ∑=11(113) grain boundary (GB) is investigated based on the thermodynamic model of Rice-Wang using the first-principles density function calculation. The results indicate that interstitial H behaves as an embrittler from "strengthening energy" analysis. The reduced GB cohesion due to the presence of H at the GB is attributed to the low affinity between H and Al, and the weakened bonding of Al atomic pairs perpendicular to GB plane.
关键词:
Hydrogen
,
null
,
null
吴运军
,
张武
,
马怀柱
稀土
doi:10.3969/j.issn.1004-0277.2003.06.004
采用Schlenk技术,在干燥纯氩气保护下,用无水三氯化稀土LnCl3与2-苯基茚以1∶2的摩尔比在THF中反应,得到8种新配合物:(2-ph-Ind)2LnCl (A)[Ln=La(1), Pr(2), Nd(3), Sm(4), Gd(5), Dy(6), Yb(7), Y(8)].再用(A)和LiN(TMS)2在THF中反应,得到两种新的二(2-苯基茚)稀土有机配合物:(2-ph-Ind)2LnN(TMS)2 (B)[Ln=Y(1), Sm(2)].所有配合物都经元素分析、红外和质谱鉴定.配合物(B)在甲基丙烯酸甲酯(MMA)的聚合反应中显示出一定的活性.
关键词:
稀土合成
,
配合物
,
聚合
,
2-苯基茚
贺慧
,
程璇
,
张颖
,
杨勇
功能材料
利用溶胶-凝胶预处理固相方法合成了锂离子电池正极材料LiM0.9Ti0.1O2(M=Ni,Co),通过XRD对合成的材料进行结构分析,并将其组装成电池进行了电化学测试,对两种材料LiN0.9Ti0.1和LiCo0.9Ti0.1进行了比较.结果发现,LiCo0.9Ti0.1O2的结构和性能要好于LiNi0.9Ti0.1O2,根据实验结果对其原因进行了初步的分析.
关键词:
锂离子电池
,
正极材料
,
电化学性能
Physical Review B
By use of the linear-combination-of-atomic-orbital (LCAO) method for a cluster model, we studied the electronic structure of gamma-from Sigma 11 [1 (1) over bar0](11 (3) over bar) grain boundary doping with N and Mn atoms. The effect of the segregation on the cohesion of the grain boundary is investigated based on the Rice-Wang thermodynamic model. It is found that N could not only largely enhance the cohesion of the grain boundary but also eliminate the detrimental effect of Mn. The cosegregation effect of Mn and N on the cohesion of the grain boundary depends on where they segregate. Nitrogen could be reliably used in alloyed steels as an efficient strengthening element.
关键词:
electronic-structure;phosphorus segregation;stainless-steel;embrittlement;austenite;nitrogen;boron;impurities;fracture;metals
