리튬 이온 전도성 고체 전해질용 Li7La3Zr2O12 가넷에 대한 실리콘, 티타늄의 첨가 효과

Abstract

The garnet type Li7-4xSixLa3Zr2O12 (x=0.07-0.02) and Li7-xLa3Zr2-xTixO12 (x=0.025-0.1) have been successfully synthesized via conventional solid state methods, and evaluated as lithium ion conducting solid electrolytes for all-solid batteries or lithium air batteries. The powders were characterized by X-ray diffraction, scanning emission microscopy, Energy dispersive X-ray spectroscopy and electrochemical impedance spectroscopy. Among the investigated samples, 1.0 mol% Si doped (Li6.72Si0.07La3Zr2O12) sintered at 1,180℃ for 36 h shows a maximum conductivity of 6.416×10-4S/cm, which is almost double the value for pure Li7La3Zr2O12 at room temperature. It was also confirmed that the presence of a small percentage (2.5 mol%) of Ti helped stabilize the cubic phase at lower calcination temperature with improved sinterability.