<p>Impedance spectroscopy is a sophisticated diagnostic technique that probes the electrical behaviour and polarization mechanisms of the components in Li-ion batteries, such as electrodes and electrolytes. In this investigation, lithium manganese oxide (Li₂MnO₃), an alternative to Mn-based cathode material, is synthesized using the solid-state method. We have analysed the impedance, dielectric, and conduction mechanism in pristine Li₂MnO₃, using impedance spectroscopy. The crystallinity and morphology of Li₂MnO₃ were analysed using X-ray diffraction spectroscopy (XRD) and scanning electron microscopy (SEM). An average crystallite size of around ~ 47 nm with a densely sintered pellet was observed. Electrochemical impedance spectroscopy and cyclic voltammetry were performed on the lithium half-cell to analyse the electrochemical properties of the material. The DC conductivity and activation energy are calculated as 1.2 × 10^–5 S-cm⁻¹ and 0.34 eV, respectively. At room temperature, the AC conductivity has been calculated as 0.1 × 10^–3 S-cm⁻¹. Theoretically, the conduction mechanism in the synthesized material (Li₂MnO₃) was analysed using various models, including quantum mechanical tunnelling (QMT), correlated barrier hopping (CBH), non-overlapping small polaron tunnelling (NSPT), and overlapping large polaron tunnelling (OLPT). The overlapping large polaron tunnelling model best suits the material.</p>