We report on ionic conductivity studies of three different Ruddlesden-Popper layered perovskite (RP-LP) materials such as Li₂SrTa₂O₇, Li₂SrNb₂O₇, and Li₂CaTa₂O₇ in composite with polyethylene oxide composite. The developed RP-LP materials of n=2 in A_nA’B_nO_3n+1 general crystal structure presents a two-dimensional lithium (Li⁺) ion conduction pathway is simulated using bond valence sum mapping. The temperature dependence of conductivity is modelled using the Vogel-Tamman-Fulcher (VTF) -type relationship for PEO RP-LP and pure PEO samples. The PEO RP-LP composites deliver the ionic conductivities in the range of 3.32 to 4.09 x 10^-06 σ cm^-2 at 80°C, and their corresponding activation energies in the range of 6.37 to 7.01 kJ mol^-1 at the calculated temperature slope range of 50 to 80°C. They also deliver appreciable lithium transference numbers of 0.20 to 0.58 at 30°C and an excellent wide potential window stability of 4 V.