Constructing a High-Performance Aqueous Rechargeable Zinc-Ion Battery Cathode with Self-Assembled Mat-like Packing of Intertwined Ag(I) Pre-Inserted V₃O₇·H₂O Microbelts with Reduced Graphene Oxide Core

Abstract

Orthorhombic crystal structure of the V 3 O 7 •H 2 O material has large interlayer spacing with an open tunnel, making it promising as an intercalation-based cathode for aqueous zinc-ion batteries. However, structural degradation and dissolution cause quick capacity fading for V 3 O 7 •H 2 O. We addressed this issue via a dual modification of the V 3 O 7 •H 2 O material by pre-intercalation with Ag(I) inside the layers (henceforth will be mentioned as Ag x V 3 O 7 •H 2 O) and simultaneous in situ composite formation with reduced graphene oxide (rGO). Computationally, we showed that Ag(I) preintercalation in V 3 O 7 facilitates the Zn 2+ intercalation process by thermodynamically stabilizing the material with an intercalation energy of −34.3 eV. The Ag x V 3 O 7 •H 2 O cathode showed ∼1.44-fold improved capacity (270 mA h g −1 ) with much improved rate capability, over the pristine V 3 O 7 •H 2 O. The specific capacity and cycle stability was further significantly improved in the graphene constructed conductive flexible architecture with hydrothermally assisted self-assembled packing of several intertwined Ag x V 3 O 7 • H 2 O microbelt mats with rGO core (Ag x V 3 O 7 •H 2 O@rGO). The Ag x V 3 O 7 •H 2 O@rGO cathode enabled a reversible Zn 2+ insertion/ de-insertion process during charge/discharge (as observed in ex situ XRD study) and a significantly decreased (>27 times) charge transfer resistance over pristine V 3 O 7 •H 2 O to promote high specific capacity of 437 and 170 mA h g −1 at both low (100 mA g −1 ) and high (2000 mA g −1 ) current, respectively. The morphological analysis of the Ag x V 3 O 7 •H 2 O@rGO before and after 1000 cycles reveals that, although the structural breakdown of the Ag x V 3 O 7 •H 2 O is inevitable during repetitive cycling, the rGO support provides strong interaction with the Ag x V 3 O 7 •H 2 O mat and buffers the structural strain, prevents the agglomeration of the active material, and slows down the structural dissolution at the interface. The synergistic interaction enabled ∼2.3-fold improved cycle stability over the pristine V 3 O 7 •H 2 O with only 0.028% capacity loss per cycle over 1000 cycles.

Boosted Zn2+ storage performance of hydrated vanadium oxide by defect and heterostructure

“…12 Yet, the performance of hydrated vanadium oxides remains unsatisfactory. For further improvement, the pre-intercalation of cation or polymer (Zn 0.25 V 2 O 5 · n H 2 O, 13 Na 2 V 6 O 16 ·1.63H 2 O, 14 Co 0.247 V 2 O 5 ·0944H 2 O, 15 Ag x V 3 O 7 ·H 2 O, 16 (PANI) x V 2 O 5 ·H 2 O, 17 Sr 0.19 V 2 O 5 ·1.3H 2 O 18 has been regarded as a strategy to tune the interlayer spacing. However, the presence of these cations and polymers could make the space between layers more crowded and increase the molar mass.…”

Recent Developments and Challenges of Vanadium Oxides (VxOy) Cathodes for Aqueous Zinc‐Ion Batteries

“…Except for the above researches, the novel heterogeneous vanadium oxide nanowires (named h‐VOW with V 2 O 5 ⋅ nH 2 O shell and V 3 O 7 ⋅ H 2 O core) demonstrated by Zhi et al [89] . and the Ag x V 3 O 7 ⋅ H 2 O@rGO described by Ghosh et al [90] . by pre‐intercalation Ag (I) within the layer and simultaneous in‐situ formation of rGO have allowed the corresponding cathode materials to deliver superior electrochemical performance in aqueous ZIBs.…”

“…As an example, the solid-state ZIBs retained a capacity of 152.5 mAh g À 1 (0.5 A g À 1 ) even at À 18 °C. Except for the above researches, the novel heterogeneous vanadium oxide nanowires (named h-VOW with V 2 O 5 • nH 2 O shell and V 3 O 7 • H 2 O core) demonstrated by Zhi et al [89] and the Ag x V 3 O 7 • H 2 O@rGO described by Ghosh et al [90] by preintercalation Ag (I) within the layer and simultaneous in-situ formation of rGO have allowed the corresponding cathode materials to deliver superior electrochemical performance in aqueous ZIBs. This unprecedented discussion presents exceptional insights into the V 3 O 7 • H 2 O system for large-scale energy storage.…”

Recent progress in quantum dots based nanocomposite electrodes for rechargeable monovalent metal-ion and lithium metal batteries

“…3,4 This has triggered a significant research interest in improving the electrochemical performance of the electrodes and electrolytes of the existing LIBs to meet the immediate demand, as well as in exploring other rechargeable battery chemistries beyond Li-ion for applications where the battery cost and maintenance are rather more important factors than the energy density. 5–10…”