Oxygen Vacancies of Commercial V₂O₅ Induced by Mechanical Force to Enhance the Diffusion of Zinc Ions in Aqueous Zinc Battery

Abstract

Rechargeable aqueous batteries with Zn 2 + as a media-ion are promising candidates for large-scale energy storage because of their intrinsic safety, low-cost and high energy-intensity. Vanadium based cathodic materials have gained significant attention in aqueous zinc-ion batteries (AZIBs) due to their high capacity and satisfactory cycle stability. However, more facile and efficient fabrication methods should be explored when considering future realistic application. Herein, commercial V 2 O 5 cathodes with oxygen vacancies were fabricated through a simple mechanical ball milling method. The results suggest that mechanical force can directly induce the oxygen vacancies in commercial V 2 O 5 , which significantly enhance the diffusion of Zn ions. The oxygen vacancyÀ V 2 O 5 (O v À V 2 O 5 ) shows much higher capacity than the pristine commercial V 2 O 5 and the cyclic stability reached 2500 times. O v À V 2 O 5 cathode with a facile synthesis technology is a promising candidate for future highperformance, low-cost, safe, and environment-friendly Zn battery devices.

Oxygen-Related Defect Engineering of Amorphous Vanadium Pentoxide Cathode for Achieving High-Performance Thin-Film Aqueous Zinc-Ion Batteries

“…Interestingly, the activation barrier is reduced by 0.10 eV in the presence of O(1) vacancies but increases when the other two types of oxygen vacancies are present, indicating that the O(1) vacancies make it easier for Zn 2+ -ions to diffuse while the O(2) and O(3) vacancies make it more difficult. Because of this O(1) pathway, we may conclude that the O v present in V 2 O 5 effectively promote Zn 2+ -ion migration. ,, We also simulated Zn-ion migration along the [010] path when O(1) vacancies are present. As shown in Figure b, the activation energy for Zn-ion migration in pristine V 2 O 5 is 1.71 eV but decreases sharply to 0.63 eV when O(1) vacancies are present.…”

Electrochemically induced amorphous and porous VOx/N-doped carbon spheres as a cathode for advanced aqueous zinc-ion batteries

“…Particularly, vanadium-based oxides have captured con-siderable attention for ZIB cathodes benefiting from their rich valences and superior theoretical capacity. [20][21][22][23][24][25][26] For example, Yang et al reported that VO 2 (B) nanofibers with tunnel-like frameworks displayed a reversible capacity (357 mA h g −1 at 0.25 C upon 50 cycles). 7 Cheng et al reported that porous V 2 O 5 nanofibers exhibited a sustainable capacity (166 mA h g −1 at 2 C upon 500 cycles).…”

Boosting the Rate Capability of Aqueous Zinc-Ion Batteries Using VNxOy/C Spheres Derived from a Self-Assembled V-polydopamine Complex

“…This mainly results from low electronic conductivity, electrochemical inertia, dissolution of vanadium element, volume change during cycling, and sluggish zinc-ion diffusion dynamics . Taking an example of commercial V 2 O 5 , the rate performance of this cathode for AZIBs can only achieve a capacity of 105 mAh g –1 at 2 A g –1 …”

“…20 Taking an example of commercial V 2 O 5 , the rate performance of this cathode for AZIBs can only achieve a capacity of 105 mAh g −1 at 2 A g −1 . 21 Recently, there are several strategies to tackle the abovementioned issues: (1) ion preinsertion (for example, H 2 O, 22 K + , 23 Co 2+ , 24 Zn 2+ , 3 NH 4 + , 25 Ca 2+ , 26 Na + , 27 ) acting as "pillars" to expand the interlayer spacing; (2) incorporation of heteroatom doping (S, N, etc.) into the inner structure to enhance the electronic conductivity; 28 and (3) structure engineering of V-based compounds by integrating some carbonaceous materials (graphene, 29,30 carbon nanotubes, 31,32 etc.)…”

“…39 By subtly exploiting this feature of DA, the precursor Vpolydopamine (V-PDA) coordination complex could be synthesized derived from the chelation of VO 3 − with DA and further self-polymerization. Superior to conventional methods (hydrothermal method 40 or ball-milling 21 ), this strategy could ensure that the nanosized V-containing compound is uniformly distributed on the whole framework when further calcining the V-PDA composite, which can effectively increase the electrochemical activity of the electrode material. Second, compared with reported vanadium oxide cathode materials, vanadium nitride (VN) with high conductivity (1.67 × 10 6 S m −1 ), 41 high theoretical specific capacity (1043 mAh g −1 in lithium-ion batteries), and high electronegativity tends to adsorb Zn 2+ , which may have an efficient impact on AZIBs.…”