Redox-inactive ions control the redox-activity of molecular vanadium oxides.

ABSTRACT: Polyoxometalates are key materials for energy conversion and storage due to their unique chemical tunability and electrochemical reactivity. Herein, we report that functionalization of molecular vanadium oxides, polyoxovanadates, with redox-inert Ca²⁺ cations leads to a significant increase in their electron storage capabilities. The electrochemical performance of the Ca²⁺-functionalized dodecavanadate [Ca₂V₁₂O₃₂Cl(DMF)₃]^2- (={Ca ₂ V ₁₂ }) was thus compared with that of the precursor compound (H₂NMe₂)₂[V₁₂O₃₂Cl]^3- (={V ₁₂ }). {Ca ₂ V ₁₂ } can store up to five electrons per cluster, while {V ₁₂ } only shows one reversible redox transition. In initial studies, we demonstrated that {Ca ₂ V ₁₂ } can be used as an active material in lithium-ion cathodes. Our results show how redox-inert cations can be used as structural and electrostatic stabilizers, leading to major changes in the redox-chemistry of polyoxovanadates.

SUBMITTER: Greiner S 

PROVIDER: S-EPMC8159454 | biostudies-literature |

REPOSITORIES: biostudies-literature