Layered Structures of Enriched V⁵⁺ States of Vanadium Oxide as a Hybrid Cathode Material for Long-Cyclable Aqueous Zinc-Ion Batteries

Abstract

Recently, aqueous zinc-ion batteries (AZIBs) have garnered much attraction because of their ecofriendly nature, cost effectiveness, and reliability. However, there are still many challenges in developing suitable cathode materials for practical usage in ZIBs. In this work, we have synthesized a layered V 5+ -rich vanadium oxide (V 6 O 13 ) flaky structure that provided the electrolyte with a large active surface area. In addition to that, the mixed (V 4+/ V 5+ ) valence states of V have significantly improved the ionic diffusion of Zn 2+ , thereby improving the V 6 O 13 electrical conductivity. Therefore, the AZIBs based on the layered structure V 6 O 13 cathode with 1 M ZnSO 4 electrolyte exhibited a very high specific capacity of 394 mAh g −1 @ 0.1 A g −1 without the addition of any additives or electrode modification. The rate capability and cycle life are investigated at the current density of 2 A g −1 , where the capacity retention was found to be around 94% along with a coulombic efficiency of 96% for over 100 cycles. Such a material with high electrochemical performance can be used for portable electronic devices and electric vehicular applications.

Unveiling the Ultrahigh-Voltage Platform of Hydrated V3O7 in Carbon Network for Enhancing Aqueous Zinc-Ion Batteries Performance

“…Importantly, all these identified peaks precisely match the standard peaks of the hydrated V 3 O 7 @C layered nanosheets sample, confirming the accuracy of the analysis. HRSEM analysis of the V 3 O 7 @C nanosheets, as depicted in Figure c,d, reveals a distinctive multiple layered nanosheet morphology in the as prepared sample Figure e illustrates the distributions of V, O, and C within the cathode material’s HRSEM image, while panels f– i of Figure display the distributions of V, O, and C, along with the EDX images, respectively.…”

Possibilities and challenges of cathode materials for Zn-ion batteries

“…2f exhibits the capacity retention and coulombic efficiency of the layered V 6 O 13 nanostructure at 2 A g −1 , around 94% and 96%, respectively. 11…”

A high valence binary metal–organic framework as an electrode material for aqueous asymmetric supercapacitors

“…This shift is attributed to increased internal diffusion resistance within the redox-active material, as previously reported in the literature. 23,24 The b -value in the equation i p = aν b , calculated from the plot between log( i p ) and log( ν ) (as shown in Fig. S7a and b, ESI†), provides insights into the current contribution in the MOFs.…”