The electrochemical oxidation of aqueous solutions of mixtures of VOSO 4 and MSO 4 (M=Ni, Cu or Mn) leads to solid deposits on the electrode, of general formulation M x V 2O 5+ y . nH 2O. These compounds present great similarities with the layered hydrated vanadic acids e-V 2O 5 obtained when oxidizing pure VOSO 4 solutions. In the case of solutions containing NiSO 4 and CuSO 4, the M 2+ cations are incorporated, without any change in their oxidation state, into the interlayer space of the vanadic acid, thus replacing a part of the exchangeable protons of e-V 2O 5. In the case of mixtures of VOSO 4 and MnSO 4, there is simultaneous oxidation of Mn 2+ and of VO 2+, leading to a vanadic acid in which the exchangeable protons of the interlayer space are replaced by Mn IV cations. As for e-V 2O 5 compounds, the electrochemical intercalation of lithium into these compounds shows two main phenomena in the 4–2 V/Li range. Among the title materials, the manganese-containing compound presents the largest reversible capacity (1.6 Li per formula unit in the 4–2 V/Li voltage range at C/10), with the best cycling behavior. Whereas, by annealing at 400 and 450°C, respectively, the copper and nickel-containing compounds transform irreversibly to a mixture of α-V 2O 5 and MV 2O 6, annealing the manganese-containing compound at 300°C leads to a new material structurally related to α-V 2O 5 but with a completely different lithium intercalation behavior.