溶胶-凝胶法合成超细锂快离子导体Li_1.3Al_0.3Ti_1.7(PO₄)₃粉体及其表征

苏明如，王志兴，李新海，郭华军，彭文杰

(中南大学 冶金科学与工程学院，长沙 410083)

摘 要：以Ti(OC₄H₉)₄、Li(CH₃COO)·2H₂O、Al(NO₃)·9H₂O和NH₄H₂PO₄为原料，采用溶胶-凝胶法合成Li_1.3Al_0.3Ti_1.7(PO₄)₃粉体，并研究热处理温度对粉体结构的影响。通过X射线衍射仪(XRD)、扫描电镜(SEM)和电化学阻抗谱(EIS)对制备粉体的结构与性能进行表征。结果表明：溶胶凝胶法可合成纯相LATP粉体，降低热处理温度，且粉体结晶性良好，粒径小于1 μm，室温下电导率为1.32×10^-3 S/cm，673 K时电导率达到8.94×10^-2 S/cm，473~673 K下活化能为31.55 kJ/mol。

关键词：锂快离子导体；Li_1.3Al_0.3Ti_1.7(PO₄)₃；离子电导率；溶胶-凝胶

Preparation and characterization of lithium fast ion conductor Li_1.3Al_0.3Ti_1.7(PO₄)₃ ultrafine powders by sol-gel method

SU Ming-ru, WANG Zhi-xing, LI Xin-hai, GUO Hua-jun, PENG Wen-jie

(School of Metallurgical Science and Engineering, Central South University, Changsha 410083, China)

Abstract:Li_1.3Al_0.3Ti_1.7(PO₄)₃ powders were prepared by sol-gel method using Ti(OC₄H₉)₄, Li(CH₃COO)·2H₂O, Al(NO₃)·9 H₂O and NH₄H₂PO₄ as starting materials. The influence of synthesis temperature on the structure of Li_1.3Al_0.3Ti_1.7(PO₄)₃ powders was studied. The structure and the characterization of the powders were characterized by X-ray diffractometry (XRD), scanning electron microscopy (SEM)and electrochemical impedance spectroscopy (EIS). The results show that pure Li_1.3Al_0.3Ti_1.7(PO₄)₃ powders with good crystallinity and particle size below 1 μm are obtained by sol-gel method, and the heating temperature decreases. The lithium ion conductivity is 1.32×10^-3 S/cm at room temperature, while it reaches its maximum 8.94×10^-2 S/cm at 673 K, and its activation energy is 31.55 kJ/mol at the temperature range of 473-673 K

Key words:lithium fast ion conductor; Li_1.3Al_0.3Ti_1.7(PO₄)₃; ionic conductivity; sol-gel method