Y^(3+),S^(6+)掺杂的矿物锂快离子导体Li_(1.2+x-y)Y_xTi_(1.9-x)Al_(0.1)Si_(0.1)S_yP_(2.9-y)O_(12)系统的合成与表征

Synthesis and Characterization of Y^(3+), S^(6+)-Doped Mineral Lithium Fast Ion Conductor Li_(1.2+x-y)Y_xTi_(1.9-x)Al_(0.1)Si_(0.1)S_yP_(2.9-y)O_(12) System

以LiTi2(PO4)3为母体,以天然高岭石为起始原料,经高温固相反应制得了一系列新的锂快离子导体Li1.2+x-yYxTi1.9-xAl0.1Si0.1SyP2.9-yO12(以下简称Y S Lisicon)。X射线粉末衍射分析结果表明在x≤0.3,y<(0.2+x)的组成范围内均能得到类似于Nasicon三方结构的相,同时还存在其他杂相。应用交流阻抗技术测定电导率的结果表明起始组成为x=0.1,y=0.15的合成物电导率最高,其在室温下的电导率为2.93×10-5S·cm-1,在673K时可达3.62×10-2S·cm-1,其在473～673K间的活化能为37.19kJ·mol-1,分解电压为3.0V。

New lithium fast ion conductors of Li_(1.2+x-y)Y_xTi_(1.9-x)Al_(0.1)Si_(0.1)S_yP_(2.9-y)O_(12) based on LiTi_2(PO_4)_3 were prepared by high temperature solid state reaction using refined natural kaolinite as a starting material. X-ray powder diffraction analysis indicates that a phase with Nasicon-like structure exists together with other phases in the composition range of x≤0.3, y<0.2+x. AC impedance measurements show that the initial composition with x=0.1, y=0.15 possesses the highest ionic conductivities of 2.93×10^(-5) S·cm^(-1) at room temperature and 3.62×10^(-2) S·cm^(-1) at 673 K with activation energy of 37.19 kJ·mol^(-1) in the temperature range of 473～673 K. DC polarizing measurement shows that its decomposing voltage is 3.0 V.