Li4SiO4-Li3VO4赝二元系和Li4GeO4-Li4SiO4-Li3VO4赝三元系中新的锂离子导体

本文在室温到300℃的温度范围内研究了Li₄SiO₄-Li₃VO₄和Li₄GeO₄-Li₄SiO₄-Li₃VO₄体系中的离子导电性,发现γ_II相固溶体Li_3+xV_1-xSi_xO₄是好的锂离子导体。所研究的成分中Li_3.3V_0.7Si_0.3O₄的离子电导率最高,室温下为1×10^-5Ω^-1·cm^-1,在42—192℃的电导激活能为0.36eV,电子电导率可以忽略,因而这是迄今所发现的最好的锂离子导体之一。粗略确定了Li₄GeO₄-Li₄SiO₄-Li₃VO₄三元系中电导率高的范围,发现在Li_3.5V_0.5Ge_0.5O₄中Si部分取代Ge可以使电导率进一步提高,Li_3.5V_0.5Ge_0.4Si_0.1O₄的室温电导率可达1.3×10^-5Ω^-1·cm^-1,电导激活能为0.40eV。 关键词：

NEW LITHIUM IONIC CONDUCTORS IN PSEUDOBINARY SYSTEM Li4SiO4-Li3VO4 AND PSEUDOTERNARY SYSTEM Li4GeO4-Li4SiO4-Li3VO4

The ionic conduction in the systems of Li₄SiO₄-Li₃VO₄ and Li₄GeO₄-Li₄SiO₄-Li₃VO₄ has been studied in the temperature range from room temperature to 300℃. It is found that the γ_II-phase solid solution Li_3+xV_1-xSi_xO₄, are good ionic conductors. Among the compositions studied Li_3.3V_0.7Si_0.3O₄ is the highest ionic conductivity which reaches 1×10^-5Ω^-1·cm^-1 at room temperature with activation energy 0.36eV in the temperature range 42°-192℃. It's electronic conductivity is negligible, therefore it is one of the best lithium ionic conductors discovered so far. The high conductivity domains in system Li₄GeO₄-Li₄SiO₄-Li₃VO₄ have been roughly determined. It is found that the substitution Si for Ge in Li_3.5V_0.5Ge_0.5O₄ can cause the ionic conductivity increase. The ionic conductivity of Li_3.5V_0.5Ge_0.4Si_0.1O₄ at room temperature is 1.3×10^-5Ω^-1·cm^-1 with an activation energy 0.4eV.