Augmenting specific capacitance of ammonium vanadate cathode in aqueous zinc-ion batteries via barium doping directed by glutamic acid

Aqueous Zinc -Ion Batteries (AZIB), as a promising class of multivalent metal -ion batteries, have garnered attention for their exceptional safety and extremely high theoretical capacity. Despite these advantages, their adoption has been impeded by a notable capacity shortfall relative to Lithium -Ion Batteries (LIB). Addressing this challenge, our research leverages glutamic acid as a chelating agent to craft barium -doped ammonium vanadate nanoflowers through a hydrothermal approach, serving as an innovative AZIB cathode material. The incorporation of barium ions has notably expanded the doping distance from 9.817 & Aring; to 12.900 & Aring;, markedly diminishing the diffusion resistance of Zn 2+ ions and unveiling a plethora of active sites. These structural enhancements have fostered accelerated ion transport and bolstered redox kinetics. Our fabricated cathode material exhibits exceptional reversibility during the redox transitions between V 5+ /V 4+ and V 3+ and the zinc ion doping process. Utilizing BNVO-3 as the cathode, which presents an ideal crystal configuration, the AZIB achieved near -perfect Coulombic efficiency. Impressively, at a current density of 0.1 A g -1 , it achieved a remarkable peak discharge capacity of 384.91 mAh g -1 . Furthermore, after 1500 cycles at 5A g -1 , it maintained an impressive 92.9 % capacity retention. This study heralds a new era for barium -doped vanadium -based AZIB cathodes, characterized by their high stability, reversibility, and capacity.