Vanadium-substituted porous manganese oxides with Li-ion intercalation properties

In this study, vanadium ions were substituted for manganese in the crystal lattice of synthetic cryptomelane, also denoted as OMS-2, via microwave field-assisted syntheses. Doping vanadium into the framework of mixed valence manganese oxide resulted in OMS-2 materials with modified composition, morphology, and electrical properties. Structural properties and morphology of synthesized materials were characterized by XRD and FESEM, respectively. Average oxidation state and resistivity measurements were also taken. The effect of framework doping of vanadium ions on lithium-ion intercalation properties of manganese oxides was investigated in Li-ion cathode half-cells.

Research highlights▶ V5+ ions were substituted for Mn4+ in the crystal lattice of synthetic cryptomelane. ▶ Microwave field-assisted syntheses were used. ▶ Crystal structure of synthetic cryptomelane was retained in new materials. ▶ Conductivity decreased with increasing vanadium content in the framework. ▶ New cathodes had flat discharge profiles and higher voltage than reference.