Abdel Basset Dalia M, Mulmi Suresh, El-Bana Mohammed S, Fouad Suzan S, Thangadurai Venkataraman
Department of Chemistry, University of Calgary, 2500 University Drive Northwest, Calgary, Alberta, Canada T2N 1N4.
Nano-Science & Semiconductor Laboratories, Department of Physics, Faculty of Education, Ain Shams University, Cairo, 11566, Egypt.
Dalton Trans. 2017 Jan 17;46(3):933-946. doi: 10.1039/c6dt04021g.
In this article, we report the preparation and characterization of novel Li-stuffed garnets LiLaTaGdO (0 ≤ x ≤ 0.55) for all-solid-state Li ion batteries. The conventional solid-state method was used to prepare LiLaTaO in air at 1200 °C and LiLaTaGdO at 1150 °C. Rietveld refinements for the powder X-ray diffraction (PXRD) patterns confirmed the formation of a cubic garnet-like structure (space group Ia3[combining macron]d) with cell constant increased from 12.8176(4) Å (x = 0) to 12.9372(2) Å (x = 0.55). However, small amounts of second phases were observed for higher Gd-doped samples. Scanning electron microscopy revealed that LiLaTaGdO exhibits the highest density among all investigated samples in this study. The AC impedance spectroscopy data of the samples have been analyzed in relation to ionic conductivity, dielectric constants, and loss tangent. Among the investigated electrolytes, the LiLaTaGdO composition demonstrated the highest bulk ionic conductivity of 8.18 × 10 S cm at 25 °C, which is significantly higher than that of the parent garnet LiLaTaO (1.65 × 10 S cm at 25 °C). The appearance of a relaxation peak in the loss tangent plots for all samples seems to be due to the dipolar rotations of Li ions in Li-stuffed garnets.
在本文中，我们报道了用于全固态锂离子电池的新型锂填充石榴石LiLaTaGdO（0≤x≤0.55）的制备与表征。采用传统固态法在空气中1200℃制备LiLaTaO，1150℃制备LiLaTaGdO。对粉末X射线衍射（PXRD）图谱进行的Rietveld精修证实形成了立方石榴石状结构（空间群Ia3[组合宏]d），晶胞常数从12.8176(4) Å（x = 0）增加到12.9372(2) Å（x = 0.55）。然而，对于高钆掺杂样品观察到少量第二相。扫描电子显微镜显示，LiLaTaGdO在本研究中所有研究样品中密度最高。已结合离子电导率、介电常数和损耗角正切对样品的交流阻抗谱数据进行了分析。在所研究的电解质中，LiLaTaGdO组成在25℃时表现出最高的体相离子电导率，为8.18×10 S cm，显著高于母体石榴石LiLaTaO（25℃时为1.65×10 S cm）。所有样品的损耗角正切图中出现的弛豫峰似乎是由于锂填充石榴石中锂离子的偶极旋转所致。
