Al-doped Li 7 La 3 Zr 2 O 12 (LLZO) solid electrolyte is a promising candidate for all-solid-state lithium battery (ASSB) due to its high ionic conductivity and stability against metal. Dense LLZO pellets were prepared by high-temperature sintering BO melting agent was used control the microstructure (grain size grain boundary chemistry). An of 0.49 mS·cm −1 measured at room temperature. The LL...