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A new lanthanum coordination polymer formulated as {[La2(pyda) 2(μ4-SO4) ·5H2O]· 2H2O}n(1,H2pyda = 2,6-pyridine-dicarboxylic acid) has been synthesized from the reaction of H2pyda with lanthanide nitrate in the presence of sulfate as a counter anion. The compound was characterized by elemental analysis,IR spectroscopy and X-ray single-crystal diffraction. It crystallizes in the orthorhombic system,space group Pna21,with a = 18.8558(19) ,b = 6.5831(7) and c = 18.7543(19) . The compound is a 2D hybrid,in which the La(Ⅲ) ions were doubly connected by the carboxylic group of pyda2-ligand to form the La(Ⅲ) dimer followed by being grafted into 1D zig-zag chains which are further connected into a 2D network containing {[La(SO4) ]+}n helical chains. The interchain hydrogen bonding and π-π stacking interactions extended the 2D networks into a 3D supramolecular edifice. 相似文献
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固态聚合物电解质是发展柔性全固态锂离子电池的核心,但是目前室温离子电导率低限制了其应用.本研究以热聚合方法制备石墨相氮化碳(g-C_3N_4),并将其与聚氧化乙烯/高氯酸锂(PEO/LiClO_4)共混制备复合聚合物固态电解质.采用X射线衍射(XRD)、傅里叶变换红外光谱(FTIR)、光学显微镜(OM)、扫描电子显微镜(SEM)、差示扫描量热仪(DSC)和电化学工作站对复合聚合物电解质膜进行表征.结果表明,通过120℃退火-淬冷热处理及复合聚合物电解质内部的相互作用,可以较大程度抑制PEO的结晶,从而使该复合聚合物固态电解质膜的离子电导率在25℃时达到2.4×10~(-5)S cm~(-1),提高了3个数量级. 相似文献
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针对充放电模式对电极储锂性能的影响开展综合实验研究与机理分析.设计了4种充放电模式,进行不同充放电模式下还原氧化石墨烯电极的储锂性能实验,并从电极动态反应性能和应变两方面开展实验分析充放电模式对储锂时间和容量的影响机理.实验结果显示,不同充放电模式下电极储锂时间越短容量折损越多,综合数据分析指出电荷转移阻抗、扩散系数、过电位和应变均表现出了非线性和阶段性的特点.最后提出“大电流-小电流”模式为可行的充放电优化方案,利用电化学进程的非线性平衡了快充技术中时间和容量之间的矛盾,为快速充电技术的设计和优化提供了一定的指导. 相似文献
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In an attempt to synthesize a new pyrimidine complex of copper(H) in a solution reaction of CuBr2 with 2,2‘-bis(hexahydropydmidine) and hydro-chloric acid, we unexpectedly obtained a bright yellow chip-like crystal of CuCl4(H2tn) [H2tn=(H3NCH2CH2CH2NH3)^2 ]. Its structure was determined by single-crystal X-ray diffraction analysis. The crystal belongs to orthorhombic system, space group Pnma, with cell parameters: a=0.7216(2)nm, b=1.8308(6)nm, c=0.7553(3)nm, V=0.9953(6)nm^3, Z=4, F(000)=564, Mr=281.49, Dc=1.879 g/cm^3. u(Mo Ka)=3.204 mm^-1, R1=0.0248, wR2=0.0575. The analysis of the crystal structure indicates that the complex has a three-dimensional network structure, which is formed by hydrogen bonds and electrostatic interaction. 相似文献
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在HgI_2-HI-H_2O溶液体系中,采用静电场诱导技术生长了HgI_2晶体。利用紫外-可见光谱分析了溶液中分子/离子的存在形式;通过改变电场强度和溶液浓度等因素,得到了不同形貌的HgI_2晶体。结果表明,HgI_2-HI-H_2O溶液中存在[HgI_3]~-,[HgI_4]~(2-)和HgI_2等3种主要成分。静电场诱导离子发生定向迁移,形成取向性生长的晶体,晶体形貌受电场诱导和结构因素(分子键力)共同制约。溶质(负离子)向正极迁移,形成颗粒度大的HgI_2晶体;负极主要是由中性HgI_2键合并相变形成的小颗粒HgI_2晶体。分析认为,HgI_2-HI-H_2O溶液中负离子可以成为晶体生长的基本单元。 相似文献
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