Structural Modification of V₂O₅ as High-Performance Aqueous Zinc-Ion Battery Cathode

Abstract

We report the NH 4 + intercalated V 2 O 5 , i.e. (NH 4 ) 2 V 10 O 25 •8H 2 O, with excellent electrochemical performance as cathode in aqueous zinc-ion battery (ZIBs), as compared to V 2 O 5 , Na 5 V 12 O 32 and K 2 V 8 O 21 . This work reveals that the ionic conductivity of Zn 2+ can be enhanced by introducing cations into the V 2 O 5 framework and the vanadium oxygen structural units will be rearranged. Compared to a single layer of vanadium pentoxide consisting solely of VO 5 units, the electrochemical performance of the structural units rearranged vanadates shows a significant improvement. As a result, the obtained (NH 4 ) 2 V 10 O 25 •8H 2 O delivers high discharge capacity (376 mA h g −1 at 0.5 A g −1 ), superior rate capability up to 10 A g −1 , excellent cycling stability (a capacity retention over 93% for 1000 cycles) and high energy density (341 Wh kg −1 ).

Multi‐Scale Investigations of δ‐Ni0.25V2O5·nH2O Cathode Materials in Aqueous Zinc‐Ion Batteries

“…Similar phenomenon can be also observed in previous reports on vanadium‐based cathodes. [ 53–55 ] Therefore, the nearly irreversible insertion/extraction reaction and negligible contribution to capacity from proton intercalation indicate that the Zn 2+ intercalation mechanism mainly dominate in as‐prepared cathode material and it will be further confirmed by the following multiple ex situ characterizations. Combined ex situ X‐ray photoelectron spectroscopy (XPS), XRD and TEM analyses were carried out to investigate the possible Zn 2+ insertion/extraction in the Ni 0.25 V 2 O 5 ·nH 2 O electrode.…”

NaV6O15 microflowers as a stable cathode material for high-performance aqueous zinc-ion batteries

“…[9][10][11][12][13][14] To date, layered vanadium-based compounds have displayed better electrochemical performance than manganese-based compounds such as MnO 2 and ZnMn 2 O 4 . 15,16 Among these compounds, sodium or potassium layered vanadate (e.g., Na [17][18][19][20] The large lattice spacing in the layered structure and the "pillar" effect of Na + /K + between the vanadium oxygen interlayers might be responsible for the high capacity and good cycle performance, respectively. However, due to the weak interaction between the triconnected oxygen atoms on the layered surface and the Na + or K + ions along with the strong electrostatic interaction between the inserted Zn 2+ and the unstable layers, the interlayer spacing in layered vanadate decreases, and the structure is destroyed.…”

Beyond Lithium-Based Batteries

“…The relative anode stability results in most of the research focusing on the cathode and electrolyte. The cathode materials can be divided into different categories; metal oxides [103][104][105][106][107][108][109], metal sulfides [110][111][112], vanadium phosphates [113][114][115], carbon [116][117][118][119][120], MoO 2 /Mo 2 N heterostructure nanobelts [121] and potassium copper hexacyanoferrate [122]. Here we focus on those papers that explain the mechanism for each material type.…”

“…As with the sodium and magnesium, the two main metal oxides cathodes for Zn-ion batteries are manganese and vanadium oxides. Yet their storage mechanisms differ: Vanadium oxide intercalates the Zn 2+ ion into its lattice and the reduction of vanadium accommodates for the Zn 2+ ions binding to the oxygen in the cathode material [106,108]. Clear evidence of this mechanism was observed via X-ray diffraction with a (NH 4 ) 2 V 10 O 25 •8H 2 O cathode.…”