Double-electrolyte additive and application thereof in aqueous zinc ion battery

Abstract

The invention discloses a double-electrolyte additive and application thereof in an aqueous zinc ion battery, and belongs to the field of aqueous zinc ion batteries. The double-electrolyte additive comprises a sulfoxide compound and a quaternary ammonium salt surfactant. A sulfoxide compound and a quaternary ammonium salt surfactant are used as electrolyte additives, the stability performance of a Zn negative electrode of an aqueous zinc ion battery is effectively improved, the ZnZn symmetric battery can stably operate for 200 h under the conditions of 1 mA. Cm <-2 > and 1 mAh. Cm <-2 >, and can stably circulate for more than 120 h under the conditions of high current density and surface capacity of 5 mA. Cm <-2 > and 5 mAh. Cm <-2 >; and the capacity retention ratio of the total battery after 850 cycles under the current density of 1A. G <-1 > is up to 77.6%.

Description

Technical Field

[0001] This application relates to a dual electrolyte additive and its application in aqueous zinc-ion batteries, belonging to the field of aqueous zinc-ion batteries. Background Technology

[0002] With the rapid development of the global economy and the continuous growth of energy demand, traditional fossil fuels are facing increasing depletion, while environmental pollution and greenhouse gas emissions caused by their use are becoming increasingly serious. Renewable energy sources such as solar, wind, and tidal power have the advantages of being clean and renewable, but their intermittency and instability pose challenges to energy storage and supply. High-performance energy storage systems are needed to address the intermittency and instability of renewable energy generation and achieve a stable energy supply. Common energy storage systems include lithium-ion batteries, lead-acid batteries, and flow batteries. Currently, lithium-ion batteries are the most widely used rechargeable batteries. However, because lithium-ion batteries use organic electrolytes, they pose safety hazards such as flammability and explosiveness, and may experience thermal runaway and other safety accidents under conditions of high temperature, overcharging, and over-discharging. Furthermore, lithium resources on Earth are relatively limited and unevenly distributed, and with the increasing demand for energy storage, resource shortages may be imminent. Therefore, finding alternative energy storage systems to lithium-ion batteries is currently a top priority.

[0003] Aqueous zinc-ion batteries are beneficial because of their abundant natural zinc reserves and high specific capacity (820 mAh·g). -1 and 5855mAh·cm -3 Zinc, with its advantages of low redox potential (-0.763V vs. SHE), low cost, high safety, and non-toxicity, is considered a promising next-generation energy storage technology, attracting considerable attention and research from researchers. However, due to the large number of water molecules in aqueous electrolytes, zinc anodes are prone to hydrogen evolution, oxygen absorption corrosion, and zinc dendrite growth during contact with the electrolyte. The accumulation of these side reactions can lead to battery failure and exacerbate zinc dendrite growth, casting a shadow over the application of Zn metal as an anode in AZIBs. Therefore, reducing Zn... 2+ The water content in the solvation layer is necessary to minimize water decomposition. The initial proposed solution for the electrolyte is a high-concentration salt strategy, such as 1 mol·kg⁻¹. -1 Zn(TFSI)2+ 20mol·kg - 1 LiTFSI, 30 mol·kg -1 ZnCl2, these high-concentration salts adjust Zn 2+The coordination environment and solvation layer reduce the activity of water, thereby inhibiting water-induced side reactions. However, its high cost and inability to handle dendrite problems make it uneconomical. Currently, the mainstream modification strategy is to use some organic solvents. These polar molecules disrupt the hydrogen bonds between water molecules, weakening the activity of water. Using organic co-solvents in aqueous electrolytes can reduce the activity of Zn. 2+ Surrounding active water helps to mitigate the occurrence of side reactions. Summary of the Invention

[0004] According to one aspect of this application, a dual electrolyte additive is provided.

[0005] A dual electrolyte additive comprising sulfoxide compounds and quaternary ammonium salt surfactants.

[0006] Optionally, the sulfoxide compound is selected from at least one of dimethyl sulfoxide, diethyl sulfoxide, diphenyl sulfoxide, and benzylphenyl sulfoxide;

[0007] The quaternary ammonium salt surfactant is selected from at least one of polydienedimethylammonium chloride, polymethacryloyloxyethyltrimethylammonium chloride, and polyacryloyloxyethyltrimethylammonium chloride.

[0008] Optionally, the dual electrolyte additive is composed of dimethyl sulfoxide and polydienedimethylammonium chloride.

[0009] Dimethyl sulfoxide (DMSO) has strong polarity and a unique molecular structure, enabling it to react with Zn. 2+ It forms a specific solvation sheath. In the electrolyte, it alters the Zn... 2+ The solvation environment of Zn 2+ The solvation structure is more stable and uniform. Compared with traditional solvents, the coordination environment around zinc ions in the solvation structure formed by DMSO is more conducive to their uniform desolvation and deposition on the electrode surface, thereby reducing the uneven growth of zinc dendrites. Polydiallyl dimethyl ammonium chloride (PDDA) can modulate the electric field at the zinc anode / electrolyte interface to improve the Zn... 2+ The deposition behavior of PDDA enables long-term and highly reversible Zn anodes. PDDA constructs an N-containing adsorption layer, which reduces the contact between the Zn anode and water molecules, thereby reducing side reactions such as hydrogen evolution and corrosion. Furthermore, the adsorbed molecular layer can modulate the deposition behavior of Zn. 2+ The spread of.

[0010] According to two aspects of this application, an electrolyte is provided.

[0011] An electrolyte comprising water, zinc salt, and the dual electrolyte additive described above.

[0012] An electrolyte comprising water, a zinc salt, a sulfoxide compound, and a quaternary ammonium salt surfactant.

[0013] Optionally, the volume ratio of the sulfoxide compound to water is 0.3 to 0.5:1.

[0014] Optionally, the volume ratio of the sulfoxide compound to water is selected from any value of 0.3:1, 0.35:1, 0.4:1, 0.45:1, 0.5:1, or any range between the two.

[0015] Optionally, the amount of the quaternary ammonium salt surfactant added is 0.5% to 1.5%, calculated as the sum of the volumes of the sulfoxide compound and water.

[0016] Optionally, the amount of the quaternary ammonium salt surfactant added is selected from any value or a range between 0.5%, 0.6%, 0.7%, 0.8%, 0.9%, 1.0%, 1.1%, 1.2%, 1.3%, 1.4%, and 1.5%.

[0017] Optionally, the zinc salt is selected from at least one of zinc sulfate, zinc chloride, zinc nitrate, zinc trifluoromethanesulfonate, zinc trifluoroformylsulfonate, and zinc acetate.

[0018] The electrolyte preparation process includes: mixing sulfoxide compounds and water evenly, dissolving zinc salt in the mixture, and adding quaternary ammonium salt surfactants to obtain the electrolyte.

[0019] Specifically, water and sulfoxide compounds are first thoroughly mixed in a volume ratio of 7:3, then 2M ZnSO4·7H2O is dissolved in the solvent, and then 1% by volume of quaternary ammonium salt surfactant is added to the above electrolyte.

[0020] According to three aspects of this application, an aqueous zinc-ion battery is provided.

[0021] An aqueous zinc-ion battery, the aqueous zinc-ion battery comprising a positive electrode, a negative electrode and an electrolyte;

[0022] The positive electrode includes at least one of manganese compound, vanadium compound, Prussian blue compound, zinc, and copper.

[0023] The negative electrode comprises zinc;

[0024] The electrolyte is the electrolyte described above.

[0025] Optionally, the manganese compound is selected from at least one of manganese monoxide, manganese dioxide, manganese trioxide, and manganese tetroxide;

[0026] The vanadium compound is selected from at least one of vanadium pentoxide, lithium vanadate, sodium vanadate, potassium vanadate, magnesium vanadate, calcium vanadate, and barium vanadate.

[0027] The Prussian blue compound is selected from at least one of ferric hexacyanoferrate, zinc hexacyanoferrate, and copper hexacyanoferrate.

[0028] Optionally, the negative electrode is selected from at least one of zinc foil, zinc sheet, zinc foam, zinc powder, and zinc rod.

[0029] The beneficial effects that this application can produce include:

[0030] The dual electrolyte additive provided in this application uses sulfoxide compounds and quaternary ammonium salts as electrolyte additives, which can effectively improve the stability of the Zn anode in aqueous zinc-ion batteries. The Zn||Zn symmetric cell achieves stability at 1 mA·cm⁻¹. -2 and 1mAh·cm -2 It can operate stably for 200 hours under certain conditions, exceeding the 60 hours specified in ZSO, at 5 mA·cm -2 and 5mAh·cm -2 It can stably cycle for over 120 hours at high current density and areal capacity (compared to 40 hours in ZnSO). Using NaV3O8·1.5H2O (NVO) as the positive electrode material, the Zn||NVO full cell achieves a 1 A·g -1 The capacity retention rate after 850 cycles at the specified current density is as high as 77.6%, which is much higher than the 40.44% after 850 cycles in ZSO electrolyte. Attached Figure Description

[0031] Figure 1 For Zn||Zn symmetric cells at 1 mA·cm -2 and 1mAh·cm -2 Long-cycle performance under certain conditions;

[0032] Figure 2 For (a)Zn||Zn symmetric cells at 5mA·cm -2 and 5mAh·cm -2 (b) Long-cycle performance under the given conditions; 10 mA·cm -2 and 10mAh·cm -2 Long-cycle performance under certain conditions;

[0033] Figure 3 For 1mA·cm -2 and 1mAh·cm -2 Under the conditions, the thickness changes of symmetric cells with ZSO and ZSO / DMSO+PDDA as electrolytes after 20 cycles and the corresponding SEM images;

[0034] Figure 4For Zn anode at 1mA·cm -2 and 1mAh·cm -2 Below are XRD images of symmetric cells using ZSO and ZSO / DMSO+PDDA as electrolytes after 20 cycles.

[0035] Figure 5 (a) LSV plot and (b) Tafel plot for different electrolytes;

[0036] Figure 6 (a) Schematic diagram of nucleation overpotential under different electrolytes; (b) Enlarged view of a portion of the nucleation overpotential.

[0037] Figure 7 For (a) comparison of coulombic efficiency of Zn||Cu batteries in different electrolytes; (b) selected cyclic electroplating-stripping curves in ZSO and (c) ZSO / DMSO-PDDA electrolytes;

[0038] Figure 8 For full cell characterization: (a) CV curve; (b) EIS curve;

[0039] Figure 9 For Zn||NVO in 1Ag -1 Long-cycle curves at current densities. Detailed Implementation

[0040] The present application is described in detail below with reference to the embodiments, but the present application is not limited to these embodiments.

[0041] Unless otherwise specified, the raw materials such as dimethyl sulfoxide (DMSO), polydiallyl dimethyl ammonium chloride (PDDA), zinc sulfate heptahydrate (ZnSO4·7H2O), vanadium pentoxide (V2O5), and sodium chloride (NaCl) used in the embodiments of this application were all purchased commercially.

[0042] Unless otherwise specified, all test methods are standard and all instrument settings are those recommended by the manufacturer.

[0043] The electrochemical testing protocol is as follows:

[0044] (1) Three-electrode test

[0045] The LSV and Tafel tests in this application were performed using a three-electrode system in ZSO, ZSO / DMSO, and ZSO / DMSO+PDDA electrolytes. Zinc foil served as the working cell; a platinum electrode as the counter electrode; and a silver chloride electrode as the reference electrode. The LSV test used a WaveDriver 200 dual potentiostat as the workstation. The scan rate was set to 5 mV·s. -1The scanning potential range was -1.25V to -0.75V (vs. Ag / AgCl). The Tafel test was performed using a CHI660E electrochemical workstation as the testing platform.

[0046] (2) Two-electrode test

[0047] Symmetrical cell test (Zn||Zn): The positive and negative electrodes of the cell are both zinc foil, and the electrolytes are ZSO and ZSO / DMSO+PDDA. Constant current fixed areal capacity test.

[0048] Asymmetric cell: Zn||Cu cell, with copper foil as the positive electrode and zinc foil as the negative electrode, has a discharge current of 1 mA·cm. -2 The discharge capacity is 1 mAh·cm -2 The charging current is 1 mA·cm. -2 The charging cutoff voltage is 0.6V. Cyclic voltammetry tests were performed on the Zn||Ti battery, with a scan potential of -0.2V to 0.3V and a scan rate of 5mV·s. -1 .

[0049] (3) Full battery test

[0050] The positive electrode of the full cell is NaV3O8·1.5H2O, the negative electrode is zinc foil, and the electrolytes are ZnSO and ZnSO / DMSO+PDDA, respectively. The electrochemical window for CV testing is 0.3V–1.6V, and the scan rate is 0.1mV·s. -1 .

[0051] Example 1

[0052] (1) Preparation of electrolyte

[0053] First, thoroughly mix DMSO and H2O at a volume ratio of 3:7. Then, dissolve 2M ZnSO4·7H2O in the solvent, denoted as ZSO / DMSO. Next, add 1% (v / v) of polydiallyldimethylammonium chloride (PDDA) to the above electrolyte, denoted as ZSO / DMSO+PDDA.

[0054] (2) Synthesis and preparation of cathode materials

[0055] The preparation method of the cathode material follows existing methods. 1 gram of commercial V₂O₅ powder was added to 15 mL of 2M NaCl aqueous solution. After stirring at 30°C for 96 hours, the mixture was washed several times with deionized water. Finally, a dark red powder, sodium vanadate (NVO), was obtained by freeze-drying.

[0056] The obtained sodium vanadate material, conductive carbon black (SUPER P Li), and polyvinylidene fluoride (PVDF) were placed in a ball mill at a mass ratio of 7:2:1, along with an appropriate amount of N-methylpyrrolidone (NMP). The mill was first operated at 50 r·min. -1 Stir for 30 minutes, then at 300 rpm. -1 The mixture was stirred at a high speed for 150 minutes, then coated onto graphite paper with a diameter of 14 mm and dried in an oven at 120°C. The NVO loading at the positive electrode was approximately 2 mg·cm³. -2 .

[0057] (3) Anode material

[0058] The negative electrode material is made directly from high-purity zinc foil with a thickness of 50μm, forming a zinc foil with a diameter of Φ=16mm.

[0059] (4) Battery assembly

[0060] 1) Zn||Zn symmetric cell: Two identical zinc foils are used as the positive and negative electrodes. One cut zinc foil is placed in the positive electrode shell, followed by a glass fiber separator. 70 μL of electrolyte is added using a pipette. Then, another zinc foil is placed on top of the separator, followed by a stainless steel gasket. A spring clip is then attached, and finally, the negative electrode shell is closed. The battery is then sealed using a battery packaging machine to obtain a Zn||Zn symmetric cell.

[0061] 2) Zn||Cu half cell: Place a zinc foil as the negative electrode and a cut copper foil as the positive electrode material into the positive electrode shell. Place a glass fiber separator in the shell and use a pipette to drop 70μL of electrolyte. Then place another zinc foil negative electrode on top of the separator, followed by a stainless steel gasket. Then use a spring clip and finally close the negative electrode shell. Use a battery packaging machine to seal the battery to obtain a Zn||NVO full cell.

[0062] 3) Zn||NVO Full Cell: A zinc foil is used as the negative electrode. A cut piece of vanadium-based positive electrode material is placed in the positive electrode shell, followed by a glass fiber separator. 70 μL of electrolyte is added using a pipette. Then, another zinc foil negative electrode is placed on top of the separator, followed by a stainless steel gasket. A spring clip is then attached, and finally, the negative electrode shell is closed. The battery is then sealed using a battery packaging machine to obtain a Zn||NVO full cell.

[0063] Comparative Example 1

[0064] The operation was the same as in Example 1, except that DMSO and PDDA were not added. Instead, 2M ZnSO4·7H2O was dissolved in water and labeled as ZSO. The solution was then assembled into a battery and its performance was tested.

[0065] The effect of electrolyte on the performance of zinc anode

[0066] Zn||Zn symmetric cells with different electrolytes were assembled using a CR2025 battery case to investigate the cycle stability of the Zn anode under different electrolytes. First, the cells were subjected to 1 mA·cm⁻¹. -2 and 1mAh·cm -2 The tests were conducted at the current density and areal capacity. For example... Figure 1 As shown, the cycle life of batteries using ZSO / DMSO+PDDA as the electrolyte increased to 200 hours, a significant improvement compared to ZSO (approximately 60 hours). The depth of discharge (DOD) is a crucial indicator for measuring battery status and evaluating battery performance; generally, a higher DOD negatively impacts battery performance. Therefore, conducting deep charge-discharge tests and assessing battery performance under extreme conditions is essential for stable battery operation. Figure 2 As shown, a Zn||Zn symmetric cell using ZnSO / DMSO+PDDA as the electrolyte operates at 5 mA·cm⁻¹. -2 and 5mAh·cm -2 At a high current density (DOD = 17.1%), it can stably cycle for over 130 hours, far exceeding the performance of batteries using ZSO electrolyte (50 hours). Even at 10 mA·cm⁻¹ -2 and 10mAh·cm -2 Even under harsh conditions (DOD = 34.2%), the battery can cycle for nearly 60 hours.

[0067] To reveal the effects of adding DMSO and PDDA on the zinc anode, Zn||Zn symmetric cells using ZnSO and ZnSO / DMSO+PDDA as electrolytes were tested at 1 mA·cm⁻¹. -2 and 1mAh·cm -2 The battery was cycled 20 times under the specified conditions, then disassembled, and the Zn negative electrode was subjected to XRD and morphology analysis. Figure 3 As shown, the initial thickness of the battery using ZSO as the electrolyte increased from 2.546 mm to 2.635 mm, representing a 3.3% expansion. Conversely, the battery thickness did not increase significantly after cycling with ZSO / DMSO+PDDA electrolyte. The increased battery thickness is mainly due to numerous internal side reactions. The hydrogen evolution reaction produces H2, which causes battery swelling, making it easier for zinc dendrites to grow. These zinc dendrites can puncture the separator, severely affecting the battery's cycle life. The cycled Zn||Zn symmetric battery was disassembled, and XRD and SEM tests were performed on the Zn anode. Figure 4XRD results show that the Zn foil after cycling in ZSO electrolyte exhibits obvious diffraction peaks of the post-cycling byproduct (Zn4SO4(OH)6·xH2O). The diffraction intensity of Zn4SO4(OH)6·xH2O significantly decreases after the addition of DMSO and PDDA to the ZSO electrolyte. Figure 3 As shown in the optical photographs of the Zn negative electrode after cycling, it is clear that the zinc foil surface after cycling in ZSO electrolyte exhibits obvious black dendrites. These dendrites adhere to the separator, leading to battery failure. In contrast, the Zn negative electrode after cycling in ZSO / DMSO electrolyte is smooth and glossy, with very few black dendrites. SEM images also confirm this; the Zn foil after cycling in ZSO electrolyte clearly shows adhered glass fiber separators, and the Zn foil surface is uneven, with protruding Zn dendrites. The SEM image of the Zn foil after cycling in ZSO / DMSO+PDDA electrolyte is smooth, without obvious Zn dendrites.

[0068] To further verify the anti-corrosion effect of the ZSO / DMSO+PDDA electrolyte on the Zn anode, LSV and Tafel tests were performed on the battery. The test was conducted at a current density of 5 mA·cm⁻¹. -2 At that time, the HER onset potential of the Zn anode in ZSO / DMSO+PDDA electrolyte (-1.2305V) was lower than that of the Zn anode in ZSO / DMSO (-1.1355V) and ZSO (-1.1006V), which means that the hydrogen evolution reaction can be better suppressed during zinc plating and stripping. Figure 5 (a) This is because the addition of DMSO alters the solvation structure of water, significantly reducing the content of active water and thus inhibiting the hydrogen evolution reaction. PDDA can also inhibit the hydrogen evolution reaction; PDDA preferentially adsorbs onto the zinc anode, reducing the direct contact between water molecules and the anode. Tafel curves demonstrate that ZSO / DMSO+PDDA can effectively inhibit the corrosion reaction of the Zn anode. Figure 5 As shown in (b), after the addition of DMSO and PDDA, the corrosion potential of the Zn anode increased from -1.028V to -0.998V (vs. Ag / AgCl), and the corrosion current density increased from 1.77 mA·cm⁻¹. -2 Reduced to 0.59 mA·cm -2 This indicates that the corrosion reaction of the Zn anode was effectively suppressed after the addition of DMSO and PDDA.

[0069] The role of electrolyte in regulating uniform zinc deposition

[0070] DMSO and PDDA additives not only mitigate water-induced side reactions but also improve the uneven interfacial electric field distribution caused by byproduct accumulation, thus contributing to uniform Zn deposition. To investigate Zn... 2+ Deposition and diffusion behavior on the Zn anode surface. First, Zn||Ti cells containing different electrolytes were assembled and nucleation overpotential tests were performed, such as... Figure 6 As shown, the addition of DMSO and PDDA helps to increase Zn 2+ The nucleation overpotential, a difference of 32 mV, means that after the addition of DMSO and PDDA, Zn 2+ The increased nucleation driving force provides more nucleation sites on the negative electrode surface, thereby reducing the nucleation radius and making it more conducive to obtaining a uniform and dense Zn deposition morphology.

[0071] Furthermore, to evaluate the reversibility of Zn anode deposition / stripping, Zn||Cu half-cells were assembled to measure coulombic efficiency (CE), such as... Figure 7 As shown, in ZSO / DMSO+PDDA electrolyte, the Zn||Cu battery can cycle for more than 200 cycles with an average coulombic efficiency exceeding 99.5%. However, in ZSO electrolyte, the battery exhibits severe vibration after 30 cycles, and the overlap of its plating / stripping curves is much lower than that of the battery in ZSO / DMSO+PDDA electrolyte, demonstrating poor cycle stability and reversibility.

[0072] Zn||NVO full battery test

[0073] A practical application evaluation of ZSO / DMSO+PDDA electrolyte was conducted using NaV3O8·1.5H2O as the positive electrode.

[0074] Full cells using ZnSO and ZnSO / DMSO+PDDA electrolytes were subjected to CV scan tests. The similar CV scan peaks in both electrolytes indicate that the charge storage mechanism of the NVO anode is the same in both electrolytes. The CV curves in the ZnSO / DMSO+PDDA electrolyte showed an earlier redox peak and a relatively small polarization voltage, indicating the protective effect of DMSO and PDDA on the Zn anode, and suggesting good reversibility of the battery. Figure 8 As shown in (b), the charge transfer resistance (Rct) of the battery was fitted according to the equivalent circuit diagram. The fitted resistances of the full cell in ZSO and ZSO / DMSO+PDDA electrolytes were 67.9Ω and 113.9Ω, respectively. The increase in Rct may be related to the addition of organic electrolytes, which increases electrolyte viscosity, reduces ion mobility, and increases solution resistance. An increase in Rct may lead to a decrease in the battery's initial discharge specific capacity, which is related to... Figure 9 The corresponding cyclic curve. For example... Figure 9As shown, the full-cell cycling curve of Zn||NVO was tested at 1Ag. -1 At current densities of 1 Ag, the ZSO / DMSO+PDDA electrolyte exhibits significantly better cycle stability and reversibility than the full cell using ZSO as the electrolyte. While the addition of DMSO increases the electrolyte viscosity, preventing the battery from reaching its initial capacity in the first cycle, it significantly improves cycle stability and reversibility. The Zn||NVO battery in the ZSO / DMSO+PDDA electrolyte at 1 Ag... -1 After 850 cycles at the specified current density, the battery still maintained a capacity retention of 77.8%, with a coulombic efficiency approaching 100%. In contrast, at the same current density, the battery with ZSO electrolyte only maintained a capacity retention of 40.44% after 850 cycles. This indicates that the ZSO / DMSO+PDDA electrolyte has better cycle stability than ZSO, mainly due to the reduction of side reactions at the Zn anode.

[0075] Example 2-3

[0076] The operation was the same as in Example 1, except that dimethyl sulfoxide (DMSO) was replaced with diethyl sulfoxide and diphenyl sulfoxide, respectively, and the batteries were assembled and their performance was tested.

[0077] Examples 4-5

[0078] The operation was the same as in Example 1, except that polydiene dimethyl ammonium chloride (PDDA) was replaced with polymethacryloyloxyethyltrimethylammonium chloride and polyacryloyloxyethyltrimethylammonium chloride, respectively, and then assembled into a battery for performance testing.

[0079] Examples 6-7

[0080] The operation was the same as in Example 1, except that the amount of polydimethylammonium chloride added was 0.5% or 1.5% by volume, and the batteries were assembled and their performance was tested.

[0081] Examples 8-9

[0082] The operation was the same as in Example 1, except that the volume ratio of dimethyl sulfoxide (DMSO) to water was 0.3 and 0.5, and the mixture was assembled into a battery for performance testing.

[0083] Comparative Example 2

[0084] The operation is the same as in Example 1, except that only DMSO is added and PDDA is not added. The battery is then assembled and its performance is tested.

[0085] Comparative Example 3

[0086] The operation is the same as in Example 1, except that only PDDA is added and DMSO is not added. The battery is then assembled and its performance is tested.

[0087] The Zn||NVO full cells prepared in Examples 1-9 and Comparative Examples 1-3, after 850 cycles at a current density of 1 Ag⁻¹, have the capacity retention data shown in Table 1.

[0088] Table 1

[0089]

[0090]

[0091] In summary, by simultaneously adding sulfoxide compounds such as DMSO and quaternary ammonium salt surfactants such as PDDA, side reactions at the zinc (AZIBs) metal anode in aqueous zinc-ion batteries can be mitigated, resulting in stable AZIBs and improving their practicality. Combined with various electrochemical characterizations, the ZSO / DMSO+PDDA electrolyte can effectively suppress the hydrogen evolution reaction and regulate the Zn content on the anode surface. 2+ The deposition structure achieves uniform Zn nucleation and dendrite-free deposition. Therefore, Zn||Zn symmetric cells can cycle stably for over 200 hours; Zn||Cu cells can also cycle for over 200 cycles while maintaining close to 100% coulombic efficiency; in Zn||NVO full cells, at 1 Ag... -1 At this current density, the battery retains 77.6% of its capacity after 850 cycles, providing an effective solution for high-performance AZIBs.

[0092] The above description is merely a few embodiments of this application and is not intended to limit this application in any way. Although this application discloses preferred embodiments as described above, it is not intended to limit this application. Any changes or modifications made by those skilled in the art without departing from the scope of the technical solution of this application using the disclosed technical content are equivalent to equivalent implementation cases and fall within the scope of the technical solution.

Claims

1. A dual-electrolyte additive, characterized in that, The dual electrolyte additive contains sulfoxide compounds and quaternary ammonium salt surfactants.

2. The dual electrolyte additive according to claim 1, characterized in that, The sulfoxide compound is selected from at least one of dimethyl sulfoxide, diethyl sulfoxide, diphenyl sulfoxide, and benzylphenyl sulfoxide; The quaternary ammonium salt surfactant is selected from at least one of polydienedimethylammonium chloride, polymethacryloyloxyethyltrimethylammonium chloride, and polyacryloyloxyethyltrimethylammonium chloride.

3. An electrolyte, characterized in that, The electrolyte comprises water, zinc salt, and the dual electrolyte additive as described in claim 1 or 2.

4. The electrolyte according to claim 3, characterized in that, The electrolyte includes water, zinc salt, sulfoxide compounds, and quaternary ammonium salt surfactants.

5. The electrolyte according to claim 4, characterized in that, The volume ratio of the sulfoxide compound to water is 0.3 to 0.5:

1.

6. The electrolyte according to claim 4, characterized in that, The amount of the quaternary ammonium salt surfactant added is 0.5% to 1.5%, calculated as the sum of the volumes of the sulfoxide compound and water.

7. The electrolyte according to claim 4, characterized in that, The zinc salt is selected from at least one of zinc sulfate, zinc chloride, zinc nitrate, zinc trifluoromethanesulfonate, zinc trifluoroformylsulfonate, and zinc acetate.

8. An aqueous zinc-ion battery, characterized in that, The aqueous zinc-ion battery includes a positive electrode, a negative electrode, and an electrolyte; The positive electrode includes at least one of manganese compound, vanadium compound, Prussian blue compound, zinc, and copper. The negative electrode comprises zinc; The electrolyte is the electrolyte according to any one of claims 3 to 7.

9. The aqueous zinc-ion battery according to claim 8, characterized in that, The manganese compound is selected from at least one of manganese monoxide, manganese dioxide, manganese trioxide, and manganese tetroxide; The vanadium compound is selected from at least one of vanadium pentoxide, lithium vanadate, sodium vanadate, potassium vanadate, magnesium vanadate, calcium vanadate, and barium vanadate. The Prussian blue compound is selected from at least one of ferric hexacyanoferrate, zinc hexacyanoferrate, and copper hexacyanoferrate.

10. The aqueous zinc-ion battery according to claim 8, characterized in that, The negative electrode is selected from at least one of zinc foil, zinc sheet, zinc foam, zinc powder, and zinc rod.

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