Li_3PO_4助熔剂添加对Li_(1.3)Al_(0.3)Ti_(1.7)(PO_4)_3性质的影响

Influence of Li_3PO_4 Addition on the Properties of Lithium Ion-conductive Electrolyte Li_(1.3)Al_(0.3)Ti_(1.7)(PO_4)_3

采用溶胶-凝胶法合成Li1.3Al0.3Ti1.7(PO4)3粉末,向Li1.3Al0.3Ti1.7(PO4)3粉末中添加不同摩尔分数的Li3PO4助熔剂烧结制备锂离子固体电解质Li1.3Al0.3Ti1.7(PO4)3烧结片。通过X射线衍射仪、扫描电子显微镜研究合成产物的结构与形貌,采用循环伏安及交流阻抗技术研究合成产物的氧化-还原电位、离子电导率和活化能。结果表明,添加与未添加Li3PO4助熔剂的Li1.3Al0.3Ti1.7(PO4)3烧结片具有相似的X射线衍射结果。添加Li3PO4的Li1.3Al0.3Ti1.7(PO4)3烧结片空隙率较小,更为致密。添加Li3PO4对Li1.3Al0.3Ti1.7(PO4)3的氧化-还原电位影响不大。在所有添加Li3PO4助熔剂的Li1.3Al0.3Ti1.7(PO4)3烧结片中,添加摩尔分数1%Li3PO4的烧结片具有最高的离子电导率6.15×10-4S.cm-1和最低的活化能0.314 2 eV。

Li1.3Al0.3Ti1.7（PO4）3 pellets sintered with Li3PO4 of different mole fraction were prepared by sol-gel method.The structural identification,surface morphology,electrochemical window,ionic conductivity and activation energy of the sintered pellets were studied by means of X-ray diffraction,scanning electron microscopy,cyclic voltammetry,and electrochemical impedance spectroscopy.The results show that the Li1.3Al0.3Ti1.7（PO4）3 pellets sintered with Li3PO4 of different mole fraction have X-ray diffraction patterns similar to those without the addition of Li3PO4.The Li1.3Al0.3Ti1.7（PO4）3 pellets sintered with Li3PO4 have lower porosity and are denser than the pellets without Li3PO4.The addition of Li3PO4 has relatively greater effect on the porosity and density of the sintered pellets,however,it has little effect on the electrochemical window of Li1.3Al0.3Ti1.7（PO4）3.Among the Li1.3Al0.3Ti1.7（PO4）3 pellets sintered with Li3PO4 of different mole fraction,those sintered with x（Li3PO4）=1% exhibit the lowest activation energy of 0.314 2 eV and the highest ionic conductivity of 6.15×10-4 S·cm-1.