Na+-doped V2O5 as a high-performance cathode material for aqueous zinc-ion batteries

Na + doping via a one-step hydrothermal method partially substitutes V 5+ sites in V 2 O 5 , inducing lattice contraction and a morphological transformation into nanoparticles. • The optimized Na 2/3 VO cathode exhibits a high reversible capacity of 428.33 mAh g −1 at 0.1 A g −1 and retains 82.4% of its initial capacity after 1500 cycles at 2 A g −1 . • Na + incorporation enhances structural stability, electrical conductivity, and Zn 2+ diffusion kinetics, providing a simple strategy for developing high-performance cathode materials for aqueous zinc-ion batteries. Aqueous zinc-ion batteries (AZIBs) have attracted considerable research interest in recent years due to their facile fabrication, environmental friendliness, inherent safety, and non-toxicity. Among various cathode candidates, V 2 O 5 stands out as a promising material owing to its layered structure that facilitates ion migration, high theoretical capacity, and multivalent redox capability. However, the practical application of V 2 O 5 is severely hindered by phase transitions during Zn 2+ intercalation/deintercalation, leading to poor cycling stability, along with inherently sluggish diffusion kinetics and low electronic conductivity. In response to these problems, Na + -doped V 2 O 5 was prepared via a hydrothermal method in this work. The results indicate that Na + doping effectively stabilized the crystal structure and enhanced the electrical conductivity of V 2 O 5 . Among the investigated compositions, the Na 0.328 V 2 O 5 electrode exhibited highly reversible Zn 2+ storage performance, delivering a specific capacity of 428.33 mAh g −1 at 0.1 A g −1 , along with excellent long-term cycling stability, retaining 82.4% of its initial capacity after 1500 cycles at 2 A g −1 . This work provides a promising strategy for developing stable, high-capacity cathode materials for advanced AZIBs. The as-prepared Na 2/3 VO achieves high specific capacity, superior rate capability and long cycling stability, and its reversible Zn 2+ storage mechanism is clearly revealed. Download: Download high-res image (203KB) Download: Download full-size image