Tuning the Li diffusivity of poor ionic conductors by mechanical treatment: High Li conductivity of strongly defective LiTaO3 nanoparticles

摘要: Lithium tantalum oxide, LiTaO3, with an average particle size in the µm range is known as a very poor Li ion conductor. It shown here that its conductivity can be drastically increased by ball milling. The so-obtained nanostructured powder of about 20 nm shows dc conductivity, σdc, 3 × 10−6 S cm−1 at T = 450 K (σdcT 1.4 10−3 K) which 5 orders magnitude larger than corresponding microcrystalline same temperature. activation energy EA reduced one-third, i.e., it decreased from 0.90(1) eV to 0.63(1) eV. effect different milling times on ionic studied. Furthermore, thermal stability nanocrystalline materials against grain growth has been examined situ impedance spectroscopy. Interestingly, sample milled for 16 h does not change much even when material exposed 700 several hours. Moreover, Li...