ABSTRACT
We report the influence of the partial substitution of Ge with Ti on the properties of NASICON Li1.5Al0.5Ge1.5(PO4)3 (LAGP) nanofibers prepared by electrospinning. Replacing a small amount of Ge (up to 20%) with Ti is advantageous for enhancing both the purity and morphology of LAGP fibers, as observed by X-ray diffraction, electron microscopy and nuclear magnetic resonance spectroscopy. When Ti-substituted LAGP (LAGTP) fibers are used as filler to develop composite polymer electrolytes, the ionic conductivity at 20 °C improves by a factor of 1.5 compared to the plain polymer electrolyte. Additionally, above 40 °C the LAGTP fiber-based composite electrolytes were more conductive than the equivalent LAGP fiber-based one. We believe that these findings can make a substantial contribution to optimizing current methods and developing novel synthesis approaches for NASICON based electrolytes.
ABSTRACT
Recently, the formation of the ceramic-ionic liquid composite has attracted huge interest in the scientific community. In this work, we investigated the chemical reactions occurring between NASICON LAGP ceramic electrolyte and ionic liquid pyr13TFSI. This study allowed us to identify the cation exchange reaction pyr13-Li occurring on the LAGP surface, forming a LiTFSI salt that was detected by the nuclear magnetic resonance analysis. In addition, using 6Li foils, we succeeded in demonstrating that both LAGP and LiTFSI:pyr13TFSI participate in the diffusion of Li ions by the formation of an ionic bridge between two species.
