Mechanical Properties of the Solid Li-ion Conducting Electrolyte: Li0.33La0.57TiO3.

摘要

Li0.33La0.57TiO3 (LLTO) is a potential Li-ion conducting membrane for use in aqueous Li-air batteries. To be in this configuration its mechanical properties must be determined. Dense LLTO was prepared using a solidstate (SS) or sol gel (SG) procedure and was hot-pressed to yield a high relative density material ( 95 %). Young s modulus, hardness, and fracture toughness of the LLTO- SS and sol gel LLTO-SG materials was determined and compared to other solid Li- ion conducting electrolytes. The Young s modulus for LLTO-SG and LLTO-SS was 186 4 and 200 3 GPa, respectively. The Vickers hardness of LLTO-SG and LLTO-SS was 9.7 0.7 and 9.2 0.2 GPa, respectively. The fracture toughness, KIC, of both LLTO-SG and LLTO-SS was *1 MPa m1/2; the fracture toughness of LLTO-SG was slightly higher than that of LLTO-SS. Both LLTO-SG and LLTO-SS have a Young s modulus and hardness greater than the other possible solid Li-ion conducting membranes; Li7La3Zr2O12 and Li1 +x+yAlxTi2-xSiyP3-yO12. Based on modulus and hardness hot-pressed LLTO exhibits sufficient mechanical integrity to be used as a solid Li-ion conducting membrane in aqueous Li-air batteries but, its fracture toughness needs to be improved without degrading its ionic conductivity.