Monodisperse Manganese-Vanadium-Oxo Clusters with Extraordinary Lithium Storage

Although possessing well-defined nanostructures and excellent multi-electron redox properties, polyoxometalate clusters have poor intrinsic electrical conductivity and are prone to aggregation due to large surface energy, which makes them difficult to be fully utilized when applying as electrode materials for lithium-ion batteries. In this paper, monodisperse K₇MnV₁₃O₃₈ (MnV₁₃) clusters are achieved by rationally utilizing nano-sized high conductive carbon dots (CDs) as stabilizers. Benefiting from the fully exposed redox sites of MnV₁₃ clusters (high utilization rate) and sufficient interfaces with carbon dots (extra interfacial energy storage), the optimized MnV₁₃/10CDs anode delivers a high discharge capacity up to 1348 mAh g^-1 at a current density of 0.1 A g^-1 and exhibits superb rate/cycling capabilities. Density functional theory (DFT) calculations verify that ionic archway channels are formed between MnV₁₃ and CDs, eliminating the bandgap and greatly improving the electron/ion conductivity of MnV₁₃ and CDs. This paper paves a brand-new way for synthesis of monodisperse clusters and maximization of extra interfacial energy storage.