Structural, dielectric, and conductivity studies of yttrium-doped LiNiPO4 cathode materials
Structural, dielectric, and conductivity studies of yttrium-doped LiNiPO4 cathode materials
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DOI：
10.1007/s11581-011-0535-5
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发表时间：
2011-04-01
期刊：
影响因子：
2.8
通讯作者：
Sanjeeviraja, C.
中科院分区：
文献类型：
--
作者：
Prabu, M.;Selvasekarapandian, S.;Sanjeeviraja, C.
采用pechini型可聚合前驱体法合成了橄榄石结构的纯LiNiPO4和掺钇的LiNiPO4。用热重法和差热分析法确定了复合地层温度。粉末x射线衍射图证实形成了具有正交结构、晶粒尺寸细小的相纯LiNiPO4化合物。傅里叶变换红外光谱（FTIR）研究表明，优选的局部阳离子环境存在。XRD和FTIR研究表明，掺杂的钇离子进入到LiNiPO4的晶格中。研究发现，掺杂钇后，LiNiPO4的离子电导率提高了约两个数量级。介电光谱显示，随着频率的增加，介电常数减小。介质损耗谱显示样品中直流传导占主导地位。
Olivine-structured pure LiNiPO4 and yttrium-doped LiNiPO4 have been synthesized by a Pechini-type polymerizable precursor method. Compound formation temperature is confirmed from thermogravimetry to differential thermal analysis. Powder X-ray diffraction pattern confirmed the formation of phase pure LiNiPO4 compound with an orthorhombic structure with fine crystallite size. Presence of preferred local cation environment is understood from Fourier transform infrared spectroscopy (FTIR) studies. XRD and FTIR studies show that doped yttrium ion entered in the lattice of LiNiPO4. It has been found that the ionic conductivity of LiNiPO4 is enhanced by around two orders of magnitude by doping yttrium. Dielectric spectra show the decrease in dielectric constant with increase in frequency. Dielectric loss spectra reveal that dc conduction contribution predominates in the sample.