 The present study synthesized Mo-doped δ-MnO2 powders with different doping ratios by implementing hydrothermal method. Various analyses, namely X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), the Brunauer–Emmett–Teller (BET) method, Raman spectroscopy, X-ray photoelectron spectroscopy (XPS), X-ray fluorescence spectrometer (XRF), and electrochemical measurements, were applied to characterize the dependence of the δ-MnO2 structure, morphology and electrochemical performance on Mo-doping. The experimental results indicated Mo6+ ions entered into the δ-MnO2 crystal lattice and occupied the Mn sites. Appropriate amount of Mo6+ ions doping decreases the charge transfer resistance and increases the Li+ ion diffusion coefficient, thus producing optimal electrochemical performance. The Mo 5% sample with Mo6+/Mn2+ molar ratio of 5:100 in the original solution presented a specific charge capacity of 476.8 mAh g−1 after 100 cycles at 1000 mA g−1 as well as capacity retention ratio of 112.7%.