Unraveling Energy Storage Performance and Mechanism of Metal-Organic Framework-Derived Copper Vanadium Oxides with...

Achieving high-performance aqueous zinc (Zn)-ion batteries (AZIBs) requires stable and efficient cathode materials capable of reversible Zn-ion intercalation. Although layered vanadium oxides possess high Zn-ion storage capacity, their sluggish kinetics and poor conductivity present significant hurdles for further enhancing the performance of AZIBs. In response to this challenge, a dissolution-regrowth and conversion approach is formulated using metal-organic frameworks (MOFs) as a sacrificial template, which enables the in situ creation of copper vanadium oxides (CuVO_x) with porous 1D channels and distinctive nanoarchitectures. Owing to their distinctive structure, the optimized CuVO_x cathode experiences a reaction involving the synergistic insertion/extraction of Zn²⁺, resulting in rapid Zn²⁺ diffusion kinetics and enhanced electrochemical activity postactivation. Specifically, the activated electrode delivers a reversible capacity of 519 mAh g^-1 at 0.5 A g^-1 for AZIBs. It is noteworthy that the electrode exhibits a remarkable reversible rate capacity of 220 mAh g^-1 at 5 A g^-1 with excellent durable cycleability, retaining 88% of its capacity even after 3000 cycles. Various ex situ testing methods endorse the reversible insertion/extraction of Zn²⁺ in the CuVO_x cathode. This study provides a novel insight into high-performance MOF-derived unique structure designs for AZIB electrodes.