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 Å to 12.900 Å, markedly diminishing the diffusion resistance of Zn2+ 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 V5+/V4+ and V3+ 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. •Innovative cathode material with barium ions intercalation for aqueous Zinc-Ion batteries.•Enhanced interlayer distance from 9.817 Å to 12.900 Å.•Impressive Performance with 384.91 mAh g−1 at a current density of 0.1 A g−1.•An impressive capacity retention of 92.9 % after 1500 cycles at 5 A g−1.