Water‐Lubricated Intercalation in V₂O₅·nH₂O for High‐Capacity and High‐Rate Aqueous Rechargeable Zinc Batteries

Abstract

Among the aqueous rechargeable batteries, Zn 2+ -based batteries exhibit a series of unique attributes for large-scale energy storage: (i) feasibility of using low-cost Zn metal anode with a high theoretical specific capacity of 819 mA h g −1 ; (ii) replacement of the traditional alkaline electrolytes by mild neutral electrolytes, mitigating the environmental disruption and recycling costs; and (iii) low redox potential of Zn/Zn 2+ (−0.76 V vs standard hydrogen electrode) and two-electron transfer mechanism during cycling responsible for the high energy density. [6,22,23] However, the zinc system also has long-standing challenges, such as the unstable cathode and anode structures in the aqueous environment. On the cathode side, the cycling stability is related to how zinc ions and the electrolyte react with the cathode materials, which is much more complex as compared to the lithium-ion systems. An initial attempt on the hexacyanoferrate system delivered a limited capacity (≈60 mA h g −1 ), although a high operation voltage of ≈1.7 V was achieved. [23][24][25][26][27][28] Recently, Pan et al. demonstrated that the manganese oxide cathode goes through a chemical conversion reaction with the zinc species and H 2 O rather than the simple intercalation process, delivering a high capacity of ≈285 mA h g −1 and an operating voltage of ≈1.44 V. [29] Nazar's group developed a Zn 0.25 V 2 O 5 ·nH 2 O cathode material, which displayed a specific energy of ≈250 Wh kg −1 (based on cathode) and a high capacity of 220 mA h g −1 at 15 C (1 C = 300 mA g −1 ). [30] During cycling, the structural water in Zn 0.25 V 2 O 5 ·nH 2 O was revealed to exchange with Zn 2+ reversibly, thus resulting in good kinetics and rate performance. Furthermore, some other studies have also suggested the importance of H 2 O in metal ion intercalation. [23,31] During cycling, the solvating H 2 O works as a charge shield for the metal ions (Al 3+ , Mg 2+ , Li + , etc.), reducing their effective charges and hence their interactions with the host frameworks. [32,33] This strategy has been investigated to enhance the capacity and rate capability of Li + , Na + , and Mg 2+ batteries. [34][35][36][37][38][39] In this paper, we present a systematic and detailed study of the role of H 2 O in bilayer V 2 O 5 ·nH 2 O (n ≥ 1) as a prototype cathode material for zinc batteries. By coupling the electrochemical measurements, thermogravimetric/differential BatteriesLarge-scale energy storage systems are critical for the integration of renewable energy and electric energy infrastructures. [1][2][3] Among numerous candidates, lithium-ion batteries with organic electrolytes are one of the most attractive options due to their high energy density [4][5][6][7][8][9][10] and mature markets. [11,12] However, for grid scale energy storage, the cost of lithium-ion batteries is still too high, [13,14] and the use of the flammable organic electrolyte in large format batteries poses a severe safety and environmental concern. [15] As an alternative, low-cost aqueous batteries wi...

Electrochromic Battery Displays with Energy Retrieval Functions Using Solution‐Processable Colloidal Vanadium Oxide Nanoparticles

“…The thickness of the V 3 O 7 film was measured to be ≈220 nm by the Alpha-Step (IQ-W1-040). [26] To understand the electrochemical behavior of this electrode, the galvanostatic charge/discharge processes were measured under different current densities. The high-resolution TEM image, inset in Figure 1e, shows clear lattice fringes of 1.91 and 2.92 Å correspond to the and (3)(4)(5)(6)(7)(8)(9)(10)(11)(12)(13)(14)(15)(16)(17)(18)(19)(20) planes, respectively.…”

Stabilized Molybdenum Trioxide Nanowires as Novel Ultrahigh‐Capacity Cathode for Rechargeable Zinc Ion Battery

“…[16][17][18] Despite these advanced features, one of the biggest block for ZIBs developed to date is their relatively low capacity in terms of the substantially inferior capacity of cathode materials than Zn anode. [21][22][23][24] A great variety of materials including MnO 2 , [25][26][27][28] ZnMn 2 O 4 , [17] Zn x Mo 6 S 6 , [29] ZnHCF, [30] Zn 0.25 V 2 O 5 ·nH 2 O, [31] VS 2 , [20] NiOOH, [32] and Co 3 O 4 [9] have been reported as promising cathodes with good electrochemical performance. [21][22][23][24] A great variety of materials including MnO 2 , [25][26][27][28] ZnMn 2 O 4 , [17] Zn x Mo 6 S 6 , [29] ZnHCF, [30] Zn 0.25 V 2 O 5 ·nH 2 O, [31] VS 2 , [20] NiOOH, [32] and Co 3 O 4 [9] have been reported as promising cathodes with good electrochemical performance.…”

Achieving High‐Voltage and High‐Capacity Aqueous Rechargeable Zinc Ion Battery by Incorporating Two‐Species Redox Reaction

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safety, and low cost. Currently, the most studied cathode active materials are manganesebased [6][7][8][9] and vanadium-based [10][11][12][13] composites. Various cathode materials have been developed to navigate these challenges.

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“…[1][2][3][4][5] However, the strong electrostatic interaction with host materials originating from divalent chemistry leads to low output voltage, poor reversibility, and especially sluggish kinetics. Furthermore, poor rate capability limits application of Zn-ion batteries in high-power appliances.The Prussian blue analogues (PBAs) possessing a 3D open framework with large interstitial sites, [4][5][6][7][8][9][10][11][12][13][14][15][16] are considered as a promising host material for reversible Zn-ion intercalation/deintercalation with fast charge/discharge properties and high operational voltage, which is ascribed to its ideal crystal structure and desirable electrochemical properties. Currently, the most studied cathode active materials are manganesebased [6][7][8][9] and vanadium-based [10][11][12][13] composites.…”