Controlled Synthesis of Metal–Organic-Framework-Derived V₂O₅ Nanostructures with Polypyrrole Coating for Zinc-Ion Batteries

Here, the vanadium (V) metal–organic-frameworks (MOFs) used as templates are synthesized to obtain nanostructured V 2 O 5, including nanorods, nanowires, nanosheets, and nanoflowers. The formation mechanism for the V-MOF precursors and their derived V 2 O 5 with morphology control is investigated. Engineering oxygen vacancies by manipulating the active sites and electrical conductivity has been demonstrated as a promising method for superior zinc-ion storage in V 2 O 5 . Benefiting from the high electronic conductivity and improved structural integrity for the induction of PPy and oxygen defects, the V 2 O 5 @PPy-based ZIBs exhibit a high capacity (404.3 mA h g –1 at 0.2 A g –1 ), enhanced energy conversion efficiency (a superior energy density of 346 W h kg –1 and a power density of 3834.2 W kg –1 ), and long-term life span (80.7% of the initial capacity remained after 1000 cycles). The assembled quasi-solid-state ZIBs exhibit a stable capacity of 167.9 mA h g –1 after 300 cycles at 3.0 A g –1 . This work develops a method to make a promising V 2 O 5 cathode for aqueous ZIBs.