The dynamics of Na ions in amorphous Na₂Si₂O₅, a potential solid electrolyte material for Na battery, have been investigated by employing. the quasielastic neutron scattering (QENS) technique in the temperature range 300 to 748 K. To understand the diffusion pathways and relaxation timescales of Na ionic diffusion, the experimental studies are complemented by ab initio and force-field molecular dynamics simulations. The QENS data are fairly well described by a jump-diffusion model with a mean jump length of about 3 Å and residence time about 9 ps. Our molecular dynamics simulations have predicted that the diffusion of Na⁺ ions occurs in the amorphous phase of Na₂Si₂O₅ while absent in the crystalline orthorhombic phase even up to 1100 K. The molecular dynamics simulations have revealed that in the amorphous phase, due to different orientations of silicon polyhedral units, several accessible pathways are opened up for Na⁺ diffusions. These pathways are not available in the crystalline phase of Na₂Si₂O₅ due to rigid spatial arrangement of silicon polyhedral units.