Anomalous Zn2+ Storage Behavior in Dual-Ion-In-Sequence Reconstructed Vanadium Oxides

Vanadium oxides with fast and stable Zn2+ storage are of great significance to the development of high-performance aqueous zinc ion batteries (ZIBs), and yet they commonly suffer from structural instability and sluggish diffusion kinetics. Herein, a new "dual-ion-in-sequence" intercalation strategy based on quenching is proposed to address these issues. Interestingly, it is found that the Zn2+ storage mechanism evolves from the common solid-state ion diffusion kinetic into an intercalation pseudocapacitance as a result of the enlarged interlayer spacing of V2O5. Together with the expanded interlayer spacing arising from the "dual-ion-in-sequence" intercalation, oxygen defects are simultaneously generated at the sub-surface of the reconstructed Li@MnVO materials. Benefitting from the improved ionic diffusivity, intercalation pseudocapacitance, and fast charge transferability, full cell based on Li@MnVO cathode shows impressive rate capability and excellent cycling stability of 5000 cycles with a high energy density of 253 Wh kg(-1) at 10 A g(-1). More importantly, the capacity can maintain at 125 mAh g(-1) at 4 A g(-1) even under a raised mass loading of 10 mg cm(-2). The proposed "dual-ion-in-sequence" intercalation strategy of manipulating V2O5 structure at atomic scales is a viable pathway for the high-performance layered metal oxides, not only for ZIBs but also for other energy storage systems.