Accelerated ion/electron transport kinetics and increased active sites via local internal electric fields in heterostructured VO2-carbon cloth for enhanced zinc-ion storage

Although the performance of the self-standing electrode has been enhanced for aqueous zinc-ion batteries (AZIBs), it is necessary to explore and analyse the deep modification mechanism (especially interface effects). Herein, density functional theory (DFT) calculations are applied to investigate the high-performance cathode based on the VO2/carbon cloth composites with heterostructures interface (H-VO2@CC). The adsorption energy comparisons and electron structure analyses verify that H-VO2@CC has extra activated sites at the interface, enhanced electrical conductivity, and structural stability for achieving high-performance AZIBs due to the presence of built-in electric field at the interfaces. Accordingly, the designed self-standing H-VO2@CC cathode delivers higher rate capacity, longer-life cyclability, and faster electronic/ion transmission kinetics benefiting from the synergistic effects. The risks of active material shedding and dissolution during the dis/charge process of two cathodes were evaluated via ex-situ ultraviolet-visible (UV-vis) spectrum and inductively coupled plasma-atomic emission spectroscopy (ICP-AES) technique. Finally, this investigation also explores the charge storage mechanism of H-VO2@CC through various ex-situ and in-situ characterization techniques. This finding can shed light on the significant potential of heterostructures interface engineering in practical applications and provide a valuable direction for the development of cathode materials for AZIBs and other metal-ion batteries.