Preparation of Li sub(7)La sub(3)(Zr sub(2 - x),Nb sub(x))O sub(12) (x = 0-1.5) and Li sub(3)BO sub(3)/LiBO sub(2) composites at low temperatures using a sol-gel process

Li sub(7)La sub(3)(Zr sub(2 - x)Nb sub(x))O sub(12) (LLZNbO, x = 0-1.5) was prepared using sol-gel process at low temperatures. Additives (LiBO sub(2) and Li sub(3)BO sub(3)) were used to improve the sintering of the ceramic electrolyte at low temperatures. XRD patterns of the calcined powder displayed the formation of cubic garnet phase between 600 and 700 degree C in composition with higher Nb content (LLZNbO, x greater than or equal to 0.5). The density of composites with additives sintered at 900 degree C achieves 90%. In composites sintered with LiBO sub(2), the presence of La sub(2)Zr sub(2)O sub(7) was detected, whereas single cubic phase was obtained for the composites sintered with Li sub(3)BO sub(3). The ion conductivity attained was 7 10 super(- 5) S/cm at 30 degree C using 6.5 wt% Li sub(3)BO sub(3) (900 degree C), representing enhancement by more than two orders of magnitude compared to the material without additives. Improvements of Li ion conductivity can be interpreted by the enhanced relative density as the result of the rearrangement of particles produced by adequate concentration of the additive.