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Lithium has been removed electrochemically at 15 μA/cm² from LiMn₂O₄ (spinel) to yield single phase Li_1−xMn₂O₄ for 0 < × ⩽ 0.60. The electrochemical curve suggests that beyond x = 0.60 an electrochemical process other than lithium extraction occurs. Powder X-ray-diffraction spectra indicate that during the extraction process the [Mn₂]O₄ framework of the spinel structure remains intact. Previous results have shown that 1.2 Li⁺ ions can also be inserted into LiMn₂O₄, which suggests that lithium may be cycled in and out of the [Mn₂]O₄ framework of the spinel structure over a wide range of x, at least from Li_0.4Mn₂O₄ to Li₂Mn₂O₄. Discussion of the mechanism of formation of λ-MnO₂ in an acidic environment is extended.