Ce ions intercalation and structural engineering assist MOF-derived porous V2O5 with enhanced Zn2+diffusion kinetics for high-rate and ultra-stable aqueous zinc-ion batteries

Aqueous zinc-ion batteries (ZIBs) have attracted extensive attention in the energy storage systems owing to the high safety, low toxicity, and environmental friendliness. However, the sluggish reaction kinetics and inferior cycling stability of the cathode materials severely hinder the development of aqueous ZIBs. Therefore, in this work, novel Ce ions intercalated porous V2O5 nanobelts is exquisitely designed through a MOF-assisted approach, and used as stable cathode for ZIBs. Benefiting from the hierarchical porous structure and ultrahigh specific surface area, the Ce-V2O5 nanobelts possess more Zn2+ diffusion pathways and electrochemical active sites, thus exhibiting a high discharge capacity (395 mAh g-1 at 0.1 A g-1 and 99.2 % capacity retention after 100 cycles). Moreover, the pre-intercalated Ce ions can effectively enhance the conductivity of the whole material and serve as stable pillars to expand the interlayer spacing of V2O5, as well as weaken the electrostatic interaction between Zn2+ and the host structure during the charge/discharge process, thereby simultaneously obtaining excellent rate capability (328.5 mAh g-1 at 2.0 A g-1) and favorable cycling stability (94.6 % capacity retention after 2000 cycles at 2.0 A g-1). The ingenious synergistic strategy of rare earth ion intercalation and structural engineering opens up a new avenue for the development of high-performance cathode materials.