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Preparation and Performance of Highly Stable Cathode Material Ag2V4O11 for Aqueous Zinc-Ion Battery

School of Materials Science and Engineering, Shanghai University of Engineering Science, Shanghai 201620, China
Author to whom correspondence should be addressed.
Crystals 2023, 13(4), 565;
Received: 3 March 2023 / Revised: 19 March 2023 / Accepted: 24 March 2023 / Published: 27 March 2023
(This article belongs to the Special Issue Advances in Composite Electrodes Materials)


One of the hottest research topics at present is the construction of environmentally friendly and secure aqueous zinc-ion batteries (AZIBs) using an aqueous electrolyte instead of an organic electrolyte. As a result of their diverse structure, valence state, high theoretical specific capacity, and other benefits, vanadium-based materials, which are frequently employed as the cathode of AZIBs, have drawn the attention of many researchers. The low cycle stability of zinc ion batteries (ZIBs) is mostly caused by the disintegration of the vanadium-based cathode materials during continuous charge and discharge. In this work, using 3M Zn(CF3SO3)2 as the electrolyte and hydrothermally synthesized Ag2V4O11 as the cathode material, the high-rate performance and extended cycle life of ZIBs were evaluated. The effects of different hydrothermal temperatures on the microstructure, capacity, and cycle stability of the Ag2V4O11 cathode material were examined. The experimental results show that Ag2V4O11 exhibits a typical intercalation-displacement process when used as the cathode material. The multiplicative performance and cycle stability of the cathode material were significantly enhanced at a hydrothermal temperature of 180 °C. Ag2V4O11-180 has a high discharge specific capacity of 251.5 mAh·g−1 at a current density of 0.5 A·g−1 and a long cycle life (117.6 mAh·g−1 after 1000 cycles at a current density of 3 A·g−1). According to the electrochemical kinetic investigation, the cathode material has a high pseudocapacitive charge storage and Zn2+ diffusion coefficient. This is attributed to the large layer spacing and the Ag+ anchored interlayer structure.

1. Introduction

With more and more successful applications in electric vehicles and related facilities, lithium-ion batteries are now the most extensively used batteries, recyclable green energy storage, and conversion technologies. Nevertheless, throughout the use and development of lithium-ion batteries, the numerous benefits of their high energy density, long life, and steady cycling performance cannot disguise their disadvantages, such as the high cost and hazardous and harsh preparation methods [1,2,3,4,5,6,7]. With substantial raw material reserves, low cost, and easy process conditions, Aqueous zinc ion batteries (AZIBs) have the potential to replace lithium-ion batteries as a superior partner for energy storage devices in the future. AZIBs possess a high theoretical specific capacity (820 mAh·g−1) and an acceptable negative electrode potential (−0.76 V vs. SHE), but still lack a corresponding cathode material [8,9].
Vanadium-based materials outperform manganese-based materials, cobalt-based materials, and Prussian blue counterparts in the classification of cathode materials for ZIBs [8,9,10,11]. Vanadium, for example, is plentiful and has various elemental valence states, and the laminar/tunneling structure of vanadium oxides allows the intercalation/de-intercalation of Zn2+, resulting in a high theoretical capacity and structural stability [12,13]. For instance, irregular bulk V2O3 has a discharge specific capacity of 207 mAh·g−1 (0.1 A·g−1) [14]. Muhammad Sufyan Javed et al. fabricated a lamellar V2O5 layer on the surface of a Ti substrate. After 700 cycles at 0.5 A·g−1, this cathode material retained 86% of its original capacity, indicating that it has long-term stability [15]. Shougang Wu et al. compared the electrochemical performance of amorphous α-V2O5 with that of crystalline c-V2O5 cathode materials. They concluded that nano-sheeted α-V2O5 exhibited better cycling stability and Zn2+ diffusion kinetics after 2200 cycles at 5 A·g−1 [16]. Moreover, cathode materials such as V6O13 [17], V10O24·12H2O [18,19], and VO2 [20] have also been reported previously.
In practical applications, researchers have found that the inherent low electronic conductivity of vanadium-based materials and the strong electrostatic interactions between Zn2+ and the crystalline lattice will lead to a slower transfer kinetics of zinc ion and worse cycling stability. It is therefore particularly crucial to improve the electrochemical behavior of vanadium-based materials through different strategies. Previous works include the shielding of the electrostatic effects by crystalline water, the intercalation of metal ions, the formation of special nanostructures, or compounding with conductive materials [8,9,10,11]. The utilization of pre-intercalated Zn2+ and H2O to expand the layer spacing of V2O3 materials has been reported to enhance the structural stability and the diffusion rate of Zn2+. The specific capacity of such a V2O3 cathode material was as high as 435 mAh·g−1 at 0.5 A·g−1, showing considerable capacity and cycling stability [21]. Min Du et al. prepared stable Ca doped vanadium oxide cathode materials with large layer spacing by controlling the amount of Ca2+ addition. After 3000 cycles at 10 A·g−1, this cathode material had a high specific capacity of 187.2 mAh·g−1 with no capacity degradation. This can be attributed to the backbone effect of Ca2+ on the layer structure during the intercalation/de-intercalation process of Zn2+ [22]. In the case of Zn//Cu3(OH)2V2O7·2H2O batteries, the high electrochemical performance is mainly based on a highly reversible combination of the replacement/intercalation mechanism. The Cu0 matrix is produced during the intercalation process of Zn2+, which is oxidized to Cu2+ during the deintercalation process. The reversible redox reaction between Cu2+ and Cu0 and the reversible conversion of Zn0.25V2O5·H2O effectively promote electron transport in the system [23]. In addition, a similar conclusion was reached in a study by Shan Guo et al. The tunnel structure of Ag0.33V2O5 is relatively stable, and the reversible replacement of Ag0 and Zn2+ can be realized. Therefore, it has a higher cycle stability and rate performance than Ag1.2V3O8 [24]. Jing Zeng et al. developed a cathode material composed of electron-conductive phase Ag0.333V2O5 and ionically conductive phase V2O5·nH2O, which has a significantly higher capacity (312.1 mAh·g−1) at 0.5A·g−1 than that of pure Ag0.333V2O5 (244.3 mAh·g−1) [25]. The formation of a network structure between the base phases facilitates electron/ion transport, which in turn enhances the ion/electron conductivity. In summary, metal ion (such as Ag+)-doped vanadium-based materials show promise in maintaining the stability of the main structure during charge and discharge and improving the low Zn2+ diffusion rate and energy density of the matrix.
In this work, high-performance Ag2V4O11 nanoribbons were prepared by hydrothermal synthesis and applied to ZIB systems. The composition and morphology of the material were characterized by XRD, TEM, and SEM. The capacity performance and cycling stability of the material as a cathode material for ZIBs were investigated by a series of electrochemical tests. During the discharge and charge processes, there exists a reversible conversion of Ag+ to Ag0 and a rapid replacement reaction of Zn2+ in Ag2V4O11. The unique layered structure not only facilitates an increase in active sites for high energy storage, but also provides fast diffusion channels for ion transport. The simple synthesis method and excellent electrochemical performance of Ag2V4O11 composites provide a feasible solution for further research on ZIB cathode materials.

2. Experimental Procedure

2.1. Process and Materials

All of the chemical reagents used in the experiments are of analytical grade. The Ag2V4O11 nanoribbons were prepared through the simple hydrothermal method. The synthesis process mainly includes three steps: (1) first, 0.182 g of V2O5 (Aladdin, ≥99.0%) and 0.170 g of AgNO3 (Aladdin, ≥99.0%) were dissolved in 25 mL deionized water and vigorously stirred at room temperature for 30 min; (2) After stirring, the mixed solution was transferred into a 50 mL Teflon autoclave and then placed in an oven at 180 °C for 24 h. (3) The products obtained were cleaned with deionized water and alcohol several times, and finally placed overnight in a vacuum oven at 70 °C to obtain nano-ribbon Ag2V4O11 composites. In addition, Ag2V4O11-200 and Ag2V4O11-160 composites were prepared at 200 and 160 °C by the same method as the comparison groups.

2.2. Materials Characterization

The crystal structure of the samples was studied by X-ray diffraction (XRD, Rigaku Ultimate IV, Cu Kα source) with a range between 10° and 80° at a scan rate of 5°·min−1. The chemical valence and bonding of the elements were analyzed using X-ray photoelectron spectrometry (XPS, Thermo Scientific K-Alpha, Al Kα source). The microscopic morphologies, microstructures, and elemental distribution of the synthesized samples were characterized by scanning electron microscopy (SEM, Phenom LE) and transmission electron microscopy (TEM, FEI talos F200x G2).

2.3. Electrochemical Measurements

The prepared active material, acetylene black, and polyvinylidene difluoride (PVDF) are ground thoroughly in N-Methylpyrrolidone (NMP) with a weight ratio of 7:2:1 to obtain a black slurry. The slurry was then evenly coated on the surface of stainless steel foil and dried under vacuum at 80 °C for 12 h to produce the cathode material. The CR2032 battery was assembled in air, with zinc metal foil as the anode, 3M Zn(CF3SO3)2 as the electrolyte, and glass fiber as the separator. The galvanostatic charge-discharge curve (GCD), rate performance, and galvanostatic intermittent titration technique (GITT) test of newly assembled batteries were tested by the Battery Testing System (NEWARE) at room temperature. The test voltage range was set as 0.3–1.3 V (vs. Zn2+/Zn) and the test current density range was 0.1–3 A·g−1. The GITT test was performed with a resting time of 1 h, a charge and discharge time of 20 min, and a current density of 0.1 A·g−1. The cyclic voltammetric curves (CV) were tested using an electrochemical workstation (CHI7600E) over a set range (0.3 to 1.3V) and at different scan rates (0.1 to 1.0 mV·s−1). Electrochemical impedance spectroscopy (EIS) was performed by using an electrochemical workstation (CS310H) in the frequency range of 0.01 Hz and 100 kHz.

3. Results and Discussions

Figure 1a shows the XRD patterns of the Ag2V4O11 cathode materials. It can be seen from Figure 1a that the Ag2V4O11 synthesized by the one-step hydrothermal method has good crystallinity. The positions of the individual characteristic peaks are in better match with the No.49-0166 PDF card (Ag2V4O11 standard card). This suggests that the synthesis of Ag2V4O11 by a simple hydrothermal method is feasible [26]. The space group of this laminated monoclinic phase is C12/m1 [27]. The lattice parameters are as follows: a = 15.55 Å, b = 3.61 Å, c = 9.61 Å, α = 90.00°, β = 127.07°, γ = 90.00°. The crystalline size of the Ag2V4O11-160/180/200 samples are close to 77, 70, and 71 Å, respectively. As can be seen from the schematic crystal structure in Figure 1a, the continuous [V4O11]n layer formed by the Ag+ is pre-embedded in a distorted VO6 polyhedron. In this case, V5+ has two different sites. Ag+ is bonded to five O2− atoms in a 5-coordinate geometrical configuration, and two different V5+ are bonded to six O2− atoms in a 6-coordinate geometrical configuration, respectively. Following the comparison, it was found that the width and intensity of the diffraction peaks for the Ag2V4O11-180 sample were significantly larger than those of the 160 and 200 °C samples. This suggests that the hydrothermal temperature has an influence on the crystalline properties of the material and may have an influence on the electrochemical properties [24,26,28].
In order to investigate the valence stats of the elements in Ag2V4O11, X-ray photoelectron spectroscopy (XPS) characterization was also performed. Clear peaks for the elements Ag, V, and O can be seen in Figure 1b. Among them, the binding energy peaks of the spin-orbit dual state at 516.91 and 524.14 eV correspond to V 2p3/2 and V 2p1/2 (Figure 1c). Two fitted signal peaks can be seen in the O 1s region at 529.98 and 531.48 eV, corresponding to the bonding of V-O and Ag-O (Figure 1d). The two binding energy peaks located at 367.78 and 373.78 eV correspond to Ag 3d5/2 and Ag 3d3/2 of Ag, respectively (Figure 1e) [24,26].
Figure 2a–c shows that the SEM morphologies of Ag2V4O11 resemble multiple overlapped “feathers”. The “feather rods” are broad, flat, and flaky, and around 1–2 μm in width. The “feather branches” are located on either side of the “feather rods” and appear as parallel bands (Figure 2a–c). They are approximately 0.2–0.5 μm in width and 0.5–10 μm in length. The SEM images also demonstrate that the microstructure of Ag2V4O11 is influenced by the different hydrothermal temperatures. The whole size of Ag2V4O11 increases gradually as the temperature increases from 160 °C to 200 °C. The width of the “feather rod” gradually increases, and the size and number of “feather branches” also show an increasing trend. The elemental mappings of the Ag2V4O11 samples are shown in Figure 2d–f. The results show that the O, Ag, and V elements are uniformly distributed in all three samples. This indicates that Ag was successfully introduced into the Ag2V4O11 nanoribbon using the hydrothermal method and that the hydrothermal temperature did not affect the elemental distribution characteristics. The TEM images (Figure 2g–h) demonstrate that Ag2V4O11-180 is a nanoribbon composite with a width of approximately 300 nm, which is consistent with the microscopic morphology of the SEM images. Figure 2i shows the HRTEM images of Ag2V4O11-180, from which lattice stripes of width can be observed. The lattice spacing is 0.3337 nm, corresponding to the (1 1 0) crystal planes of the Ag2V4O11-180 nm band. This compares favorably with Sn1.5V2O7(OH)2·3.3H2O [29] (0.326 nm), KV12O30−y·nH2O [30] (0.19 nm), V-MOF derived porous V2O5 [31] (0.35 nm), and Cu3V2O7(OH)2·2H2O [32] (0.256 nm), with a moderate advantage. This indicates that the products obtained by hydrothermal treatment at 180 °C have a good crystallinity and a large layer spacing. This nanoribbon structure is beneficial for increasing the interaction between the material and the electrolyte, which in turn increases the transport rate of Zn2+.
To test the electrochemical performance of the Ag+-modified vanadium-based materials, batteries were assembled using Zn foil as the anode and Ag2V4O11 as the cathode material. The voltage test intervals for the Zn//Ag2V4O11 batteries were 0.3–1.3 V (vs. Zn2+/Zn). Figure 3a–c shows the cyclic voltammetry curves for three Ag2V4O11 cathodes at the same scan rate (0.1 mV·s−1) for four consecutive cycles. Two pairs of corresponding redox peaks can be found at 1.0/0.84 V and 0.64/0.57 V (Figure 3b) for Ag2V4O11-180 during the charge-discharge process. Similarly, Ag2V4O11-160 and Ag2V4O11-200 also have redox peaks at 1.01/0.83 V and 0.64/0.56 V (Figure 3a), and at 1.02/0.82 V and 0.68/0.54 V (Figure 3c). During charging/discharging, the two pairs of redox peaks at the cathode of Ag2V4O11 correspond to V5+/V4+ and V4+/V3+, suggesting that Zn2+ intercalation/de-intercalation is a multi-step process. Upon comparison, it is found that the redox peaks of the Ag2V4O11 cathode prepared at a hydrothermal temperature of 180 °C have the highest peak current and the smallest peak spacing (0.16 V and 0.07 V). This also indicates that the degree of electrode polarization that occurs is minimal and its electrochemical kinetics are optimal. The first and subsequent cycles of the cyclic voltammetry curve shown in Figure 3b are slightly different due to the first intercalation of Zn2+ resulting in a partially irreversible phase transition in the Ag2V4O11-180 cathode material. The overlap of the CV curves from the second to the fourth cycle, where the redox potentials are essentially the same, also indicates that the intercalation/de-intercalation behavior of Zn2+ in the Ag2V4O11-180 cathode material is highly reversible [24,25,26,27,28].
Figure 3d–f shows the charge-discharge curves for 1–3 turns of the three Ag2V4O11 cathodes at a current density of 0.5 A·g−1. It can be seen that all of these cathode materials have two charge-discharge plateaus, which are consistent with the redox peaks of the CV curves in Figure 3a–c. The discharge specific capacities of the Ag2V4O11-200, Ag2V4O11-180, and Ag2V4O11-160 cathodes in first cycle are 256.3, 291.4, and 244.7 mAh·g−1, respectively. During the following two cycles, the discharge specific capacities of the three samples are very close to each other, and all were lower than their initial value. After the third cycle, the discharge specific capacity of the Ag2V4O11-180 sample decreases to 276.6 mAh·g−1, but is still higher than that of Ag2V4O11-200 and Ag2V4O11-160 (243.0 and 231.1 mAh·g−1). As shown in Table 1 the Ag2V4O11-180 cathode performed better than most of the reported cathode materials with a similar structure, such as Cu3V2O7(OH)2·2H2O [32] (299.8 mAh·g−1 at 0.2 A·g−1), CrVO3 [33] (188.8 mAh·g−1 at 0.2 A·g−1), CVO [34] (312.9 mAh·g−1 at 0.2 A·g−1), and TiNH4V4O10 [35] (218 mAh·g−1 at 0.5 A·g−1).
As shown in Figure 3g, the discharge specific capacities of the three Ag2V4O11 cathodes are stabilized to 221.3, 251.5, and 195.8 mAh·g−1 after 50 complete discharge/charge cycles, with the capacity retention rates of 86.2%, 86.3%, and 79.6%, respectively. Among them, the regular curves of the Ag2V4O11-180 sample also indicate that it has the best reversibility and a good cycling performance during the reaction process. The capacity of the three cathode materials decays fast during the initial cycling process. This may be due to the occurrence of an irreversible phase transition, where Zn2+ cannot be completely removed from the lamellar structure, resulting in a “dead zinc” site, and thus a lower ion diffusion rate. As the cycling process continues, the reversible substitution between Ag and Zn2+ gradually takes over. This leads to a stabilization of the charge/discharge curve of the Ag2V4O11 cathode. The curves of the rate performance (Figure 3i) prove that the Ag2V4O11-180 cathode has the best tolerance at different current densities. The specific capacity of the Ag2V4O11-180 cathode is 319.2, 294.8, 280.1, 261.8, 230.0, 180.6, and 141.1 mAh·g−1 at 0.1, 0.2, 0.3, 0.5, 1.0, 2.0, and 3.0 A·g−1, respectively. When the current density returns to 0.1 A·g−1, the discharge capacity of this sample remains around 300.4 mAh·g−1, which is close to its initial value. At the same time, its specific capacity is close to or even higher than the other previous reported cathode materials in Table 1, such as CVO [34], TiNH4V4O10 [35], NVO [36], and VO2 [37]. This confirms that the suitable reaction temperature and the introduction of Ag can cause the Ag2V4O11 cathode to exhibit good structural stability and rate performance at different current densities. Figure 3j shows the long-term cycle performance of the cathode material. At a high current density of 3.0 A·g−1, the initial discharge specific capacities of the Ag2V4O11-160/180/200 cathode materials are 215.2, 208.0, and 193.7 mAh·g−1. After 1000 cycles, the Ag2V4O11-180 cathode material still maintains a high capacity of 117.6 mAh·g−1. This value is significantly higher than the long-term cycle stability of the samples prepared at 160 and 200 °C (87.9 and 91.3 mAh·g−1). At the same time, the present sample compares favorably with CVO [34], CaV6O16·3H2O [38], and V2O5 [39], and is only slightly inferior to (NH4)2V6O16·1.5H2O [40], Ni0.25V2O5·0.88H2O [41], and V2O5·4VO2·2.72H2O [42] (Table 1).
Table 1. Summary of electrochemical performance of cathode materials in ZIBs.
Table 1. Summary of electrochemical performance of cathode materials in ZIBs.
Cathode MaterialPotential Window (V)ElectrolyteSpecific Capacity (mAh·g−1)Cycle Performance (mAh·g−1)Ref.
Ag1.2V3O80.4–1.42 M ZnSO4~350 (0.05 A·g−1)/[24]
Ag0.333V2O5@V2O5·nH2O0.2–1.83 M Zn(CF3SO3)2312.1 (0.5 A·g−1)261.7, (after 500 cycles at 0.5 A·g−1)[25]
Ag2V4O11@rGO-900.3–1.61 M ZnSO4328 (0.1 A·g−1)~150, (after 3000 cycles at 5.0 A·g−1)[26]
Ag0.333V2O50.2–1.62 M Zn(CF3SO3)2215 (0.1 A·g−1)~80, (after 700 cycles at 3.0 A·g−1)[28]
V2O50.3–1.53 M Zn(CF3SO3)2300 (0.1 A·g−1)120, (after 3000 cycles at 2.0 A·g−1)[31]
Cu3V2O7(OH)2·2H2O0.2–1.62.5 M Zn(CF3SO3)2216 (0.1 A·g−1)92, (after 500 cycles at 0.5 A·g−1)[32]
CrVO30.4–1.63 M Zn(CF3SO3)2188 (0.05 A·g−1)112.8, (after 1000 cycles at 5.0 A·g−1)[33]
Cu3V2O7(OH)2·2H2O0.4–1.63 M Zn(CF3SO3)2269.2 (0.2 A·g−1)101.6, (after 3000 cycles at 4.0 A·g−1)[34]
VO20.3−1.53 M Zn(CF3SO3)2375 (0.1 A·g−1)220, (after 2000 cycles at 5.0 A·g−1)[37]
CaV6O16·3H2O0–1.43 M Zn(CF3SO3)2320 (0.05 A·g−1)125, (after 70 cycles at 4.0 A·g−1)[38]
Ag2V4O110.3–1.33 M Zn(CF3SO3)2251.5 (0.5 A·g−1)117.6, (after 1000 cycles at 3.0 A·g−1)Our work
The presence of the pseudocapacitive effect can strongly explain the excellent rate performance and stable cycling performance at high current densities for the Ag2V4O11-180 cathode material. Therefore, the electrochemical kinetics of the Zn//Ag2V4O11 batteries were further analyzed [25,31,41]. The CV curves of the Ag2V4O11 cathode material at different scanning rates are shown in Figure 4a. As the scanning rate increases, the shapes of the curves remain similar, but the oxidation and reduction peaks become wider and shift towards higher (oxidation peak) or lower (reduction peak) potentials, respectively. This can be attributed to the polarization that occurs at the electrodes.
The parameter b can be calculated from the relationship (1) between the peak current (i) and the scan rate (v), and the result is shown in Figure 4b.
i = a v b
It is simplified as follows:
log ( i ) = log ( a ) + b log ( v )
where i is the peak current (mA), v is the scan rate (mV·s−1), and a and b are variables (0.5 ≤ b ≤ 1.0). Generally speaking, b = 0.5 indicates that the kinetic process of an electrode reaction is dominated by diffusive behavior, whereas b = 1.0 suggests a reaction kinetic controlled by capacitive behavior [26,28]. Combined with Figure 4b,c, the redox peaks of V5+/V4+ and V4+/V3+ correspond to b values of 0.92, 0.76, 0.70, and 0.81, respectively. This indicates that the electrochemical reactions occurring at the electrode are the result of the synergistic effect of diffusion and capacitance.
At a set scan rate, the contribution of the capacitance and ion diffusion can be calculated from the peak current (i), the scan rate (v), and the relationship between k1 and k2 (3).
i = k 1 v + k 2 v 1 / 2
Here, i is the peak current (mA), v is the scan rate (mV s−1), and k1v and k2v1/2 correspond to the capacitive contribution and ion diffusion contribution values, respectively. As shown in Figure 4c, the percentage of the capacitive contribution is approximately 69.9% at a scan rate of 1.0 mV·s−1. It can also be concluded that the capacitive contribution of the V5+/V4+ redox peak is more than the contribution of the V4+/V3+ redox peak. This is consistent with the b values, indicating that the V5+/V4+ redox peaks are mainly capacitively controlled in terms of kinetics. Figure 4d is a histogram of the capacitance percentage at different scan rates. As the scan rate increases from 0.2 to 1.0 mV·s−1, the corresponding capacitance contribution shows an increasing trend, which is gradually increased from 50.7% to 69.9%. This indicates that the dominance of the pseudocapacitive effect in the zinc storage process of the Ag2V4O11-180 cathode gradually increases.
In addition, the kinetics of Zn2+ diffusion in the cathode electrode of Ag2V4O11-180 were investigated by GITT. The Zn2+ diffusion rate (DGITT) was calculated by the following formula [25,28]:
D GITT = 4 π τ ( m B v M M B S ) 2 ( E s E τ ) 2
Among them, τ, mB, vM, and MB are the constant pulse relaxation time, mass of active substance, molar volume, and molar mass of the electrode material, respectively. S is the interface area between the electrode and the electrolyte, while ΔES and ΔEτ represent the pulse-induced change in the steady-state voltage and total cell voltage, respectively. The assembled cells were charged and discharged at a constant current (0.1 A·g−1) at an interval of 20 min. The high specific capacity of the Ag2V4O11-180 cathode is attributed to its laminar structure, which facilitates the charge transfer and shortens the ion transport path. The Zn2+ diffusion coefficient in the Ag2V4O11-180 anode can be calculated to be approximately 10−9–10−11 cm2·s−1, which is comparable to that of the previously reported cathode materials [43,44,45,46]. The above electrochemical test results indicate that the fast electrochemical kinetics of the Zn//Ag2V4O11 system can promote the efficient transfer of Zn2+ and show an excellent electrochemical performance. EIS tests were performed to further understand the electrochemical behavior of the Ag2V4O11 cathode [47,48]. As shown in Figure 4f, the small semicircle observed at high frequencies represents the charge transfer resistance (Rct) at the electrode/electrolyte interface, and the straight line with a slope (Zw) corresponds to the diffusion-controlled process of the Zn2+ ions. It is clear that the ohmic resistance is similar before and after cycling for the three Ag2V4O11 cathodes, while the diameter of the semicircle is smaller for the Ag2V4O11-180 cathode material (Table 2). This indicates that the appropriate hydrothermal temperature gives this material a higher electronic conductivity than the other two materials, which is consistent with the results of the rate performance.
In summary, the Ag2V4O11 cathode material exhibits excellent electrochemical properties. The reasons for this are as follows: during the discharge process, Zn2+ participates in a reversible substitution/intercalation reaction with part of the Ag+; Zn2+ is embedded in the main structure of the Ag2V4O11 occupying the Ag+ site, forming the ZnAg2−xV4O11 phase [24,26]; Ag+ is reduced to Ag0 after deintercalation from the laminate structure and deposited on the surface of the cathode material. The in-situ generated Ag0 particles contribute to the electrical conductivity of the material. Liang et al. report that the silver vanadium oxide electrode material may generate by-products during the first discharge, such as ZnV2O6 [24], Zn4(SO4)(OH)6·nH2O [26], Zn2(V3O8)2 [28,49], and Zn3V2O7(OH)2·2H2O [50]. This may be related to the structure of the electrode materials.
The cathode electrode reaction is as follows:
Zn 2 + + Ag 2 V 4 O 11 + 2 e ZnAg 2 x V 4 O 11 + xAg 0
During the charging process, Ag0 is oxidized to Ag+ and embedded again in the Ag2V4O11 structure, while some of the Zn2+ will come out of the new phase ZnAg2−xV4O11 into the electrolyte.
The cathode electrode reaction is as follows:
ZnAg 2 x V 4 O 11 + 2 yAg 0 Zn 1 y Ag 2 x + 2 y + yZn 2 + + 4 ye
The layered structure formed by the Ag+ intercalation layer is beneficial for enhancing the diffusion rate of Zn2+ and improve the kinetic behavior of the reaction. In addition, this also effectively improves the poor electrical conductivity of the cathode material and the easy collapse of the crystal structure during cycling.

4. Conclusions

In this work, layered Ag2V4O11 nanoribbons were prepared by a one-step hydrothermal method and their structural properties, microscopic morphology, and elemental valence stats were characterized. The Zn//Ag2V4O11 cell was assembled based on this material, and its electrochemical properties and electrochemical kinetics in the Zn(CF3SO3)2 system were investigated.
(1) Hydrothermally synthesized Ag2V4O11 is an overlapping feather-like nanoribbon material with a width of about 1–2 μm. Increasing the hydrothermal temperature promotes an increase in the spread of the “feather bone” and an increase in the number of “feather branches”.
(2) The Zn//Ag2V4O11-180 battery exhibited an excellent high specific capacity (276.6 mAh·g−1 at 0.5 A·g−1), rate performance (141.1 mAh·g−1 at 3 A·g−1), and long-term cycle stability (117.6 mAh·g−1 after 1000 cycles at 3 A·g−1). The Ag2V4O11-180 cathode material showed the best electrochemical performance compared to the samples treated at other hydrothermal temperatures.
(3) The reason for the high specific capacity and long-term cycle stability exhibited by the Ag2V4O11 cathode material is the reversible conversion of Ag+ to Ag0 with the interlayer structure after the intercalation anchor of Ag+. This not only provides a fast transport channel for the intercalation and deintercalation of Zn2+, but also stabilizes the charge storage and release processes during charging and discharging.
(4) The above results show that the capacity and rate performance of Ag2V4O11 nanoribbons as cathode materials for zinc-ion batteries is very promising, but some improvements can still be made regarding their electron and ion conductivity. Such improvements could be achieved by compounding some special materials, such as Graphene, CNT, MXenes, Polypyrrole, Polyvinylpyrrolidone, and Polyaniline.

Author Contributions

Conceptualization, X.T. and F.Z.; Methodology, X.T.; Funding acquisition, F.Z.; Investigation, X.T. and J.Z.; Software, X.H.; Supervision, F.Z.; Writing—original draft, X.T.; Writing—review & editing, X.T. and F.Z. All authors have read and agreed to the published version of the manuscript.


This work is financially supported by Class III Peak Discipline of Shanghai—Materials Science and Engineering (High-Energy Beam Intelligent Processing and Green Manufacturing).

Institutional Review Board Statement

Not applicable.

Informed Consent Statement

Not applicable.

Data Availability Statement

Not applicable.

Conflicts of Interest

The authors declare no conflict of interest.


  1. Shang, Z.; Wang, S.; Zhang, H.; Zhang, W.; Lu, S.; Lu, K. Advances in the regulation of kinetics of cathodic H+/Zn2+ interfacial transport in aqueous Zn/MnO2 electrochemistry. Nanoscale 2022, 14, 14433–14454. [Google Scholar] [CrossRef] [PubMed]
  2. Xu, X.; Chen, Y.; Liu, D.; Zheng, D.; Dai, X.; Shi, W.; Cao, X. Metal-Organic Framework-Based Materials for Aqueous Zinc-Ion Batteries: Energy Storage Mechanism and Function. Chem. Rec. 2022, 22, e202200079. [Google Scholar] [CrossRef]
  3. Grignon, E.; Battaglia, M.A.; Schon, B.T.; Seferos, S.D. Aqueous zinc batteries: Design principles toward organic cathodes for grid application. iScience 2022, 25, 104204. [Google Scholar] [CrossRef]
  4. Reddy, N.I.; Akkinepally, B.; Manjunath, V.; Neelima, G.; Reddy, M.V.; Shim, J. SnO2 Quantum Dots Distributed along V2O5 Nanobelts for Utilization as a High-Capacity Storage Hybrid Material in Li-Ion Batteries. Molecules 2021, 26, 7262. [Google Scholar] [CrossRef] [PubMed]
  5. Akkinepally, B.; Reddy, I.N.; Manjunath, V.; Reddy, M.V.; Mishra, Y.K.; Ko, T.J.; Zaghib, K.; Shim, J. Temperature effect and kinetics, LiZr2(PO4)3 and Li1.2Al0.2Zr1.8(PO4)3 and electrochemical properties for rechargeable ion batteries. Int. J. Energy Res. 2022, 46, 14116–14132. [Google Scholar] [CrossRef]
  6. Imran, M.; Afzal, M.A.; Iqbal, M.W.; Hegazy, H.H.; Iqbal, M.Z.; Mumtaz, S.; Qureshi, R. Manganese (Sulfide/Oxide) based electrode materials advancement in supercapattery devices. Mater. Sci. Semicond. Process. 2023, 158, 107366. [Google Scholar] [CrossRef]
  7. Daskalakis, S.; Wang, M.; Carmalt, C.J.; Vernardou, D. Electrochemical Investigation of Phenethylammonium Bismuth Iodide as Anode in Aqueous Zn2+ Electrolytes. Nanomaterials 2021, 11, 656. [Google Scholar] [CrossRef]
  8. Sun, Q.; Cheng, H.; Nie, W.; Lu, X.; Zhao, H. A Comprehensive Understanding of Interlayer Engineering in Layered Manganese and Vanadium Cathodes for Aqueous Zn-Ion Batteries. Chem. Asian J. 2022, 17, e202200067. [Google Scholar] [CrossRef]
  9. Huang, M.; Wang, X.; Liu, X.; Mai, L. Fast Ionic Storage in Aqueous Rechargeable Batteries: From Fundamentals to Applications. Adv. Mater. 2022, 34, e2105611. [Google Scholar] [CrossRef]
  10. Zhou, Y.; Chen, F.; Arandiyan, H.; Guan, P.; Liu, Y.; Wang, Y.; Zhao, C.; Wang, D.; Chu, D. Oxide-based cathode materials for rechargeable zinc ion batteries: Progresses and challenges. J. Energy Chem. 2021, 57, 516–542. [Google Scholar] [CrossRef]
  11. Liu, Y.; Wu, X. Review of vanadium-based electrode materials for rechargeable aqueous zinc ion batteries. J. Energy Chem. 2021, 56, 223–237. [Google Scholar] [CrossRef]
  12. Chen, D.; Lu, M.; Cai, D.; Yang, H.; Han, W. Recent advances in energy storage mechanism of aqueous zinc-ion batteries. J. Energy Chem. 2021, 54, 712–726. [Google Scholar] [CrossRef]
  13. Zhang, Y.; Ang, E.H.; Dinh, K.N.; Rui, K.; Lin, H.; Zhu, J.; Yan, Q. Recent advances in vanadium-based cathode materials for rechargeable zinc ion batteries. Mater. Chem. Front. 2021, 5, 744–762. [Google Scholar] [CrossRef]
  14. Deng, L.; Chen, H.; Wu, J.; Yang, Z.; Rong, Y.; Fu, Z. V2O3 as cathode of zinc ion battery with high stability and long cycling life. Ionics 2021, 27, 3393–3402. [Google Scholar] [CrossRef]
  15. Javed, S.M.; Lei, H.; Wang, Z.; Liu, B.; Cai, X.; Mai, W. 2D V2O5 nanosheets as a binder-free high-energy cathode for ultrafast aqueous and flexible Zn-ion batteries. Nano Energy 2020, 70, 104573. [Google Scholar] [CrossRef]
  16. Wu, S.; Ding, Y.; Hu, L.; Zhang, X.; Huang, Y.; Chen, S. Amorphous V2O5 as high performance cathode for aqueous zinc ion battery. Mater. Lett. 2020, 277, 128268. [Google Scholar] [CrossRef]
  17. Hu, J.; Chen, H.; Xiang, K.; Xiao, L.; Chen, W.; Liao, H.; Chen, H. Preparation for V6O13@hollow carbon microspheres and their remarkable electrochemical performance for aqueous zinc-ion batteries. J. Alloys Compd. 2021, 856, 157085. [Google Scholar] [CrossRef]
  18. Wei, T.; Li, Q.; Yang, G.; Wang, C. High-rate and durable aqueous zinc ion battery using dendritic V10O24·12H2O cathode material with large interlamellar spacing. Electrochim. Acta 2018, 287, 60–67. [Google Scholar] [CrossRef]
  19. Liu, W.; Dong, L.; Jiang, B.; Huang, Y.; Wang, X.; Xu, C.; Kang, Z.; Mou, J.; Kang, F. Layered vanadium oxides with proton and zinc ion insertion for zinc ion batteries. Electrochim. Acta 2019, 320, 134565. [Google Scholar] [CrossRef]
  20. Zhang, W.; Xiao, Y.; Zuo, C.; Tang, W.; Liu, G.; Wang, S.; Cai, W.; Dong, S.; Luo, P. Adjusting the Valence State of Vanadium in VO2 (B) by Extracting Oxygen Anions for High-Performance Aqueous Zinc-Ion Batteries. ChemSusChem 2021, 14, 971–978. [Google Scholar] [CrossRef]
  21. Hu, K.; Jin, D.; Zhang, Y.; Ke, L.; Shang, H.; Yan, Y.; Lin, H.; Rui, K.; Zhu, J. Metallic vanadium trioxide intercalated with phase transformation for advanced aqueous zinc-ion batteries. J. Energy Chem. 2021, 61, 594–601. [Google Scholar] [CrossRef]
  22. Du, M.; Zhang, F.; Zhang, X.; Dong, W.; Sang, Y.; Wang, J.; Liu, H.; Wang, S. Calcium ion pinned vanadium oxide cathode for high-capacity and long-life aqueous rechargeable zinc-ion batteries. Sci. China Chem. 2020, 63, 1767–1776. [Google Scholar] [CrossRef]
  23. Shan, L.; Zhou, J.; Han, M.; Fang, G.; Cao, X.; Wu, X.; Liang, S. Reversible Zn-driven reduction displacement reaction in aqueous zinc-ion battery. J. Mater. Chem. A 2019, 7, 7355–7359. [Google Scholar] [CrossRef]
  24. Guo, S.; Fang, G.; Liang, S.; Chen, M.; Wu, X.; Zhou, J. Structural perspective on revealing energy storage behaviors of silver vanadate cathodes in aqueous zinc-ion batteries. Acta Mater. 2019, 180, 51–59. [Google Scholar] [CrossRef]
  25. Zeng, J.; Chao, K.; Wang, W.; Wei, X.; Liu, C.; Peng, H.; Zhang, Z.; Guo, X.; Li, G. Silver vanadium oxide@water-pillared vanadium oxide coaxial nanocables for superior zinc ion storage properties. Inorg. Chem. Front. 2019, 6, 2339–2348. [Google Scholar] [CrossRef]
  26. Puttaswamy, R.; Beere, H.K.; Yadav, P.; Jalalah, M.; Faisal, M.; Harraz, F.A.; Ghosh, D. Troubleshooting the Limited Zn2+ Storage Performance of the Ag2V4O11 Cathode in Zinc Sulfate Electrolytes via Favorable Synergism with Reduced Graphene Oxides. ACS Appl. Energy Mater. 2022, 5, 8292–8303. [Google Scholar] [CrossRef]
  27. Cao, X.; Zhan, H.; Xie, J.; Zhou, Y. Synthesis of Ag2V4O11 as a cathode material for lithium battery via a rheological phase method. Mater. Lett. 2006, 60, 435–438. [Google Scholar] [CrossRef]
  28. Lan, B.; Peng, Z.; Chen, L.; Tang, C.; Dong, S.; Chen, C.; Zhou, M.; Chen, C.; An, Q.; Luo, P. Metallic silver doped vanadium pentoxide cathode for aqueous rechargeable zinc ion batteries. J. Alloys Compd. 2019, 787, 9–16. [Google Scholar] [CrossRef]
  29. Xu, W.; Sun, C.; Wang, N.; Liao, X.; Zhao, K.; Yao, G.; Sun, Q.; Cheng, H.; Wang, Y.; Lu, X. Sn stabilized pyrovanadate structure rearrangement for zinc ion battery. Nano Energy 2021, 81, 105584. [Google Scholar] [CrossRef]
  30. Tian, M.; Liu, C.; Zheng, J.; Jia, X.; Jahrman, E.P.; Seidler, G.T.; Long, D.; Atif, M.; Alsalhi, M.; Cao, G. Structural engineering of hydrated vanadium oxide cathode by K+ incorporation for high-capacity and long-cycling aqueous zinc ion batteries. Energy Storage Mater. 2020, 29, 9–16. [Google Scholar] [CrossRef]
  31. Ding, Y.; Peng, Y.; Chen, W.; Niu, Y.; Wu, S.; Zhang, X.; Hu, L. V-MOF derived porous V2O5 nanoplates for high performance aqueous zinc ion battery. Appl. Surf. Sci. 2019, 493, 368–374. [Google Scholar] [CrossRef]
  32. Chen, L.; Yang, Z.; Wu, J.; Chen, H.; Meng, J. Energy storage performance and mechanism of the novel copper pyrovanadate Cu3V2O7(OH)2·2H2O cathode for aqueous zinc ion batteries. Electrochim. Acta 2020, 330, 135347. [Google Scholar] [CrossRef]
  33. Bai, Y.; Zhang, H.; Xiang, B.; Zhou, Y.; Dou, L.; Dong, G. Chemically assembling chromium vanadate into an urchin-like porous rich matrix with ultrathin nanosheets for rapid Zn2+ storage. J. Colloid Interface Sci. 2021, 597, 422–428. [Google Scholar] [CrossRef] [PubMed]
  34. Bai, Y.; Zhang, H.; Xiang, B.; Hao, J.; Yan, L.; Zhu, C. Oxygen vacancy-rich, binder-free copper pyrovanadate for zinc ion storage. Chem. Eng. J. 2021, 420, 130474. [Google Scholar] [CrossRef]
  35. He, D.; Peng, Y.; Ding, Y.; Xu, X.; Huang, Y.; Li, Z.; Zhang, X.; Hu, L. Suppressing the skeleton decomposition in Ti-doped NH4V4O10 for durable aqueous zinc ion battery. J. Power Sources 2021, 484, 229284. [Google Scholar] [CrossRef]
  36. Liu, Y.; Wu, X. Hydrogen and sodium ions co-intercalated vanadium dioxide electrode materials with enhanced zinc ion storage capacity. Nano Energy 2021, 86, 106124. [Google Scholar] [CrossRef]
  37. Li, Z.; Ren, Y.; Mo, L.; Liu, C.; Hsu, K.; Ding, Y.; Zhang, X.; Li, X.; Hu, L.; Ji, D.; et al. Impacts of Oxygen Vacancies on Zinc Ion Intercalation in VO2. ACS Nano 2020, 14, 5581–5589. [Google Scholar] [CrossRef]
  38. Xu, N.; Lian, X.; Huang, H.; Ma, Y.; Li, L.; Peng, S. CaV6O16·3H2O nanorods as cathode for high-performance aqueous zinc-ion battery. Mater. Lett. 2021, 287, 129285. [Google Scholar] [CrossRef]
  39. Qin, H.; Chen, L.; Wang, L.; Chen, X.; Yang, Z. V2O5 hollow spheres as high rate and long life cathode for aqueous rechargeable zinc ion batteries. Electrochim. Acta 2019, 306, 307–316. [Google Scholar] [CrossRef]
  40. Chen, S.; Zhang, Y.; Geng, H.; Yang, Y.; Rui, X.; Li, C.C. Zinc ions pillared vanadate cathodes by chemical pre-intercalation towards long cycling life and low-temperature zinc ion batteries. J. Power Sources 2019, 441, 227192. [Google Scholar] [CrossRef]
  41. Feng, J.; Wang, Y.; Liu, S.; Chen, S.; Wen, N.; Zeng, X.; Dong, Y.; Huang, C.; Kuang, Q.; Zhao, Y. Electrochemically Induced Structural and Morphological Evolutions in Nickel Vanadium Oxide Hydrate Nanobelts Enabling Fast Transport Kinetics for High-Performance Zinc Storage. ACS Appl. Mater. Interfaces 2020, 12, 24726–24736. [Google Scholar] [CrossRef] [PubMed]
  42. Lv, T.; Liu, Y.; Wang, H.; Yang, S.; Liu, C.; Pang, H. Crystal water enlarging the interlayer spacing of ultrathin V2O5·4VO2·2.72H2O nanobelts for high-performance aqueous zinc-ion battery. Chem. Eng. J. 2021, 411, 128533. [Google Scholar] [CrossRef]
  43. Jiang, H.; Zhang, Y.; Xu, L.; Gao, Z.; Zheng, J.; Wang, Q.; Meng, C.; Wang, J. Fabrication of (NH4)2V3O8 nanoparticles encapsulated in amorphous carbon for high capacity electrodes in aqueous zinc ion batteries. Chem. Eng. J. 2020, 382, 122844. [Google Scholar] [CrossRef]
  44. Hu, F.; Xie, D.; Zhao, D.; Song, G.; Zhu, K. Na2V6O16·2.14H2O nanobelts as a stable cathode for aqueous zinc-ion batteries with long-term cycling performance. J. Energy Chem. 2019, 38, 185–191. [Google Scholar] [CrossRef][Green Version]
  45. Qiu, W.; Xiao, H.; Feng, H.; Lin, Z.; Gao, H.; He, W.; Lu, X. Defect modulation of ZnMn2O4 nanotube arrays as high-rate and durable cathode for flexible quasi-solid-state zinc ion battery. Chem. Eng. J. 2021, 422, 129890. [Google Scholar] [CrossRef]
  46. Sun, J.; Li, D.; Wang, S.; Xu, J.; Liu, W.; Ren, M.; Kong, F.; Wang, S.; Yang, L. Mn5O8—Graphene hybrid electrodes for high rate capability and large capacity aqueous rechargeable zinc ion batteries. J. Alloys Compd. 2021, 867, 159034. [Google Scholar] [CrossRef]
  47. Ni, Q.; Jiang, H.; Sandstrom, S.; Bai, Y.; Ren, H.; Wu, X.; Guo, Q.; Yu, D.; Wu, C.; Ji, X. A Na3V2(PO4)2O1.6F1.4 Cathode of Zn-Ion Battery Enabled by a Water-in-Bisalt Electrolyte. Adv. Funct. Mater. 2020, 30, 2003511. [Google Scholar] [CrossRef]
  48. Wu, S.; Liu, S.; Hu, L.; Chen, S. Constructing electron pathways by graphene oxide for V2O5 nanoparticles in ultrahigh-performance and fast charging aqueous zinc ion batteries. J. Alloys Compd. 2021, 878, 160324. [Google Scholar] [CrossRef]
  49. Shan, L.; Yang, Y.; Zhang, W.; Chen, H.; Fang, G.; Zhou, J.; Liang, S. Observation of combination displacement/intercalation reaction in aqueous zinc-ion battery. Energy Storage Mater. 2019, 18, 10–14. [Google Scholar] [CrossRef]
  50. Liu, H.; Wang, J.; Sun, H.; Li, Y.; Yang, J.; Wang, C.; Kang, F. Mechanistic investigation of silver vanadate as superior cathode for high rate and durable zinc-ion batteries. J. Colloid Interface Sci. 2020, 560, 659–666. [Google Scholar] [CrossRef]
Figure 1. XRD patterns (a), XPS spectra (b), V 2p spectrum (c), O 1s spectrum (d) and Ag 3d spectrum (e) of Ag2V4O11.
Figure 1. XRD patterns (a), XPS spectra (b), V 2p spectrum (c), O 1s spectrum (d) and Ag 3d spectrum (e) of Ag2V4O11.
Crystals 13 00565 g001
Figure 2. SEM images of Ag2V4O11-160 (a), Ag2V4O11-180 (b) and Ag2V4O11-200 (c); elemental mapping images for Ag2V4O11-160 (d), Ag2V4O11-180 (e) and Ag2V4O11-200 (f) showing the presence of O, V, and Ag; TEM images at different magnifications (g,h) and HRTEM image of Ag2V4O11-180 (i).
Figure 2. SEM images of Ag2V4O11-160 (a), Ag2V4O11-180 (b) and Ag2V4O11-200 (c); elemental mapping images for Ag2V4O11-160 (d), Ag2V4O11-180 (e) and Ag2V4O11-200 (f) showing the presence of O, V, and Ag; TEM images at different magnifications (g,h) and HRTEM image of Ag2V4O11-180 (i).
Crystals 13 00565 g002
Figure 3. CV curves of (a) Ag2V4O11-200, (b) Ag2V4O11-180 and (c) Ag2V4O11-160 at 0.1 mV·s−1; charge-discharge profiles of (d) Ag2V4O11-200, (e) Ag2V4O11-180 and (f) Ag2V4O11-160 during the first three cycles; (g) Cycle performance at 0.5 A·g−1, (h) rate performance and (i) long-term cycle stability at 3 A·g−1 of Ag2V4O11-160, Ag2V4O11-180 and Ag2V4O11-200, respectively.
Figure 3. CV curves of (a) Ag2V4O11-200, (b) Ag2V4O11-180 and (c) Ag2V4O11-160 at 0.1 mV·s−1; charge-discharge profiles of (d) Ag2V4O11-200, (e) Ag2V4O11-180 and (f) Ag2V4O11-160 during the first three cycles; (g) Cycle performance at 0.5 A·g−1, (h) rate performance and (i) long-term cycle stability at 3 A·g−1 of Ag2V4O11-160, Ag2V4O11-180 and Ag2V4O11-200, respectively.
Crystals 13 00565 g003
Figure 4. CV curves at various scan rate from 0.2 mV·s−1 to 1.0 mV·s−1 (a); log(i)-log(v) plots at specific peak currents (b); Capacitive contribution at 1.0 mV·s−1 (c); the pseudocapacitive contribution (orange region) at various scan rate from 0.2 mV·s−1 to 1.0 mV·s−1 (d); GITT curves and diffusion coefficient for Zn2+ in the second charge-discharge process (e); Nyquist plots of Zn//Ag2V4O11 batteries (f).
Figure 4. CV curves at various scan rate from 0.2 mV·s−1 to 1.0 mV·s−1 (a); log(i)-log(v) plots at specific peak currents (b); Capacitive contribution at 1.0 mV·s−1 (c); the pseudocapacitive contribution (orange region) at various scan rate from 0.2 mV·s−1 to 1.0 mV·s−1 (d); GITT curves and diffusion coefficient for Zn2+ in the second charge-discharge process (e); Nyquist plots of Zn//Ag2V4O11 batteries (f).
Crystals 13 00565 g004
Table 2. Parameters of the equivalent circuit model.
Table 2. Parameters of the equivalent circuit model.
SampleRs (Ω)Rct (Ω)W0-R (Ω)
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Tong, X.; Zhong, J.; Hu, X.; Zhang, F. Preparation and Performance of Highly Stable Cathode Material Ag2V4O11 for Aqueous Zinc-Ion Battery. Crystals 2023, 13, 565.

AMA Style

Tong X, Zhong J, Hu X, Zhang F. Preparation and Performance of Highly Stable Cathode Material Ag2V4O11 for Aqueous Zinc-Ion Battery. Crystals. 2023; 13(4):565.

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Tong, Xiangling, Junyuan Zhong, Xinxin Hu, and Fan Zhang. 2023. "Preparation and Performance of Highly Stable Cathode Material Ag2V4O11 for Aqueous Zinc-Ion Battery" Crystals 13, no. 4: 565.

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