Investigation on high performance and stabilized surface of AlF3-coated V2O5 micro-flower for zinc energy storage

Vanadium oxide (V 2 O 5 ) cathode material , possessing abundant reserves and high theoretical capacity, has been extensively researched in aqueous zinc ion batteries (ZIBs). However, its electrochemical performance is significantly hindered by insufficient electronic conductivity, vanadium dissolution into electrolyte, and slow diffusion kinetics. In this study, the V 2 O 5 micro-flower was first synthesized by a solvothermal method, and then modified by coating with AlF 3 passivation layer, forming AlF 3 @V 2 O 5 hybrid material . Impressively, AlF 3 @V 2 O 5 exhibits excellent electrochemical and kinetic properties due to the special structure of V 2 O 5 and the interfacial protection of AlF 3 . An exceptional rate property (325 mAh g −1 at 0.1 A g −1 , 188 mAh g −1 at 15 A g −1 ) as well as extraordinary cycling stability with 89.3% capacity retention after 6000 cycles at 10 A g −1 can be attained with 2 wt% AlF 3 addition (that is AF-2@V 2 O 5 ). The computation based on density functional theory (DFT) suggests that AlF 3 coating can reduce the interlayer electrostatic interaction and adsorption energy barrier between the intercalated Zn 2+ and V 2 O 5 host, thereby enabling fast redox kinetics. This study showcases the efficacy of interfacial modification of passivated coatings and presents an influential approach for material design in ZIBs .