Layered VS₂ Nanosheet‐Based Aqueous Zn Ion Battery Cathode

Abstract

class of materials show great potential for the insertion/extraction of multivalent ions (Zn 2+ , Mg 2+ , Al 3+ ) owing to the characteristic of large layer spacing and high conductivity. Among all the TMDs, VS 2 is a typical family member of TMDs with hexagonal system, which shows similar crystal structure to that of graphite lamellar with an interlayer spacing of 5.76 Å. [25,30] There is a vanadium layer between two sulfur layers to form a kind of sandwich structure. In VS 2 crystal structure, each V atom is arranged around six S atoms and connected with S atoms with covalent bonds. The interlayer spacing of VS 2 is so large that enables the convenient insertion/extraction of lithium ions (0.69 Å), sodium ions (1.02 Å), zinc ions (0.74 Å) or their solvation sheath in electrolyte. However, to the best of our knowledge, there is no report about VS 2 as the electrode materials for ZIBs.Herein, the VS 2 nanosheets are synthesized via a facile hydrothermal reaction (Supporting Information), which deliver a high capacity of 190.3 mA h g −1 at a current density of 0.05 A g −1 and exhibit long-term cyclic stability as the cathode for ZIBs. The electrochemical reaction mechanism of such VS 2 electrodes is further investigated systematically through a series of measurements including ex situ X-ray diffraction (XRD), ex situ X-ray photoelectron spectroscopy (XPS), in situ Raman, ex situ transmission electron microscopy (TEM). A reversible insertion/extraction process can be observed from all aspects. Both the ex situ TEM and ex situ XRD results demonstrate that the interlayer space of VS 2 can self adapt to the intercalation of Zn 2+ with an expansion along the c-axis (only 1.73%) and a slightly shrink along the a-and b-axes, which plays a key role in the realization of long-life ZIBs. All the above evidences reveal that the VS 2 is a promising cathode material with high capacity and good cyclic stability for ZIBs.The crystal structure of the as-prepared VS 2 is tested by XRD. All characteristic peaks are in accordance with the standard card of VS 2 (JCPDS NO. 01-089-1640) (Figure 1a). The Raman spectrum of the VS 2 in the range of 100-1100 cm −1 is shown in Figure 1b. Six peaks located at 140.4, 192.0, 282.0, 406.6, 687.8, and 993.2 cm −1 are observed, which correspond to the rocking and stretching vibrations of V-S bonds or their combination. [25] The morphology and microstructures of as-prepared VS 2 are investigated by field emission scanning electron microscopy (SEM) and high-resolution TEM (HRTEM). As shown in Figure 1c, The VS 2 flowers are assembled by nanosheets with a diameter of 5-8 µm and a thickness of 50-100 nm. The d-spacing calculated from selected area electron diffraction (SAED) patterns are 2.89 and 1.64 Å (Figure 2f), which match the d-spacing values of (002) and (110) crystal planes of VS 2 , respectively. TEM and corresponding HRTEM images in Figure 2e show VS 2 nanosheets with a d-spacing of ≈5.76 Å,The continuous researches of energy-storage devices have gained considerable attention in our world ...

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

“…[9][10][11][12][13][14][15] In addition, the aqueous ambient of the electrodes also accelerates the ion diffusion owing to the high ionic conductivity, which enables them a better rate capability. [19][20][21] To this end, numerous research efforts have been focused on the exploiting of high-capacity cathode materials over the past few decades. [19][20][21] To this end, numerous research efforts have been focused on the exploiting of high-capacity cathode materials over the past few decades.…”

“…[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.…”

“…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. [17] Recently, hexacyanometallates with a typical formula of A x M′[M″(CN) 6 ] y ⋅nH 2 O (simply denoted as M′/M″ PBA) are investigated as cathode active materials for aqueous batteries including Li-, Na-, Mg-, Ca-, and Zn-ion batteries, where the A…”