Li-rich garnet-type Li6.5La2.5Ba0.5ZrTaO12(LLBZT) electrolyte is characterized as a Li protecting layer for potential application in aqueous Li-O-2 battery. AC impedance spectroscopy and DC electrical measurements, high temperature powder X-ray diffraction (HT-PXRD), scanning electron microscopy (SEM) and thermogravimetic analysis (TGA) were used to investigate the electrochemical and chemical properties of Li/LLBZT and LLBZT/aqueous interfaces. Stable open circuit voltage (OCV) of 3 V was observed for Li/LLBZT/0.1 M LiOH, Li/LLBZT/1 M LiOH and Li/LLBZT/1 M LiCI at 25 degrees C. DC galvanostatic Li plating/stripping cycle at varying current density was performed and the area specific polarization resistance (ASK) for Li+ ion charge transfer was found to be 473 Omega cm(2) at 25 T. The impedance of LLBZT was found to be improved after treating the samples with 1 M LiOH, and 1 M LiCl, and retains its crystal structure and electrochemical stability with Li; thus, Li-rich LLBZT garnet can be successfully employed in next generation beyond Li-ion batteries.