We investigate the contribution of pseudocapacitance to the overall capacitance of MnO₂ electrodes in pure and alkaline-doped ionic liquids via two spectroscopic methods: step potential electrochemical spectroscopy (SPECS) and in situ Raman spectroscopy. For both characterization methods, thin-film electrodes of birnessite-like amorphous MnO₂ were cycled in Ethyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide, pure or doped with lithium or sodium. SPECS allows determination of the influence of the electrolyte composition on the electrochemical behavior of the MnO₂ electrodes. Pseudocapacitive charge storage can account for over half of the total capacitance with alkaline-doped ionic liquids. In situ Raman spectroscopy provided insight into the reversible ion intercalation in the MnO₂ structure, which appears to be controlled by EMIm⁺ cations. These findings are supported by density functional theory (DFT) calculations, which further help unveil the charge storage mechanism in birnessite-like amorphous MnO₂ thin films operated in pure and alkaline-doped ionic liquids.