A correlative study on electrochemical and optical properties of LLZO (Li₇La₃Zr₂O₁₂) garnet electrolyte

The demand for alternative power sources for perceiving sustainable/clean energy has created an increas-ing interest and becoming more critical owing to the development of applications such as electric vehi-cles and new type of portable electronic devices currently available in the market. In this regard, relatively safe nature of all solid state batteries (ASSB) makes it distinct as a viable battery over the bat-tery research scenario. Improvement of the technology predominantly depends on the solid electrolyte material employed in the batteries. A very good solid electrolyte must have high ionic conductivity as well as a wide electrochemical window. Lithium Lanthanum Zirconate (LLZO) is one of the promising electrolyte materials for All Solid State Batteries (ASSB). In the present work, LLZO powders have been prepared via a solution route synthesis. The morphology and the purity of the samples were analysed using X-ray Diffraction (XRD), Field Emission Scanning Electron Microscopy (FESEM) and Energy Dispersive X-ray Spectroscopy (EDS) analysis (EIS). The ionic conductivities of the samples were investi-gated using alternating current Electrochemical Impedance Spectroscopy. UV-vis Spectroscopy was employed to determine the optical band gap of LLZO, and the value (similar to 6 V) was in agreement with the potential window of LLZO available in the literature. The high potential window and good ionic conduct-ing properties shows that LLZO is a better alternative electrolyte material for next generation solid-state assemblies. (c) 2020 Elsevier Ltd. All rights reserved. Selection and peer-review under responsibility of the scientific committee of the National Conference on Material Science.