In the pursuit of enhancing ionic conductivity, researchers have explored a fascinating approach involving the substitution of divalent elements within the NASICON framework, leading to the creation of cationic vacancies. A compound of particular interest in this regard is Ba x/2 Li 1-x Ti 2 (PO 4 ) 3 , where the range of substitution was limited to 0.0 < x < 0.83. Intriguingly, the presence of immobile Ba 2+ ions within the framework was found to impede the conduction of cations along specific pathways. However, an optimal composition of x = 0.67, achieved through Ba 2+ /Li + substitutions, exhibited the highest level of conductivity .