Electrolyte containing multiple cations, aqueous zinc ion battery and preparation method

Abstract

The application discloses an electrolyte containing multiple cations, a water-based zinc ion battery and a preparation method. The electrolyte comprises a solvent and an electrolyte. The electrolyte comprises zinc salt, manganese salt, copper salt and indium salt. The electrolyte of the application significantly improves the stability of the zinc anode in the acidic medium, improves the cycle life and capacity stability of the battery, improves the performance and life of the battery in the challenging electrochemical environment, and helps the development of the next generation of energy storage systems. The water-based zinc ion battery of the application has excellent cycle life and capacity stability. After 200 cycles under the condition of 1 mA / cm 2 , it still maintains 84.9% of the initial capacity, far exceeding the water-based zinc ion battery using the conventional electrolyte.

Description

Technical Field

[0001] This application belongs to the field of zinc-ion battery technology, specifically relating to an electrolyte containing multiple cations, an aqueous zinc-ion battery, and a preparation method thereof. Background Technology

[0002] Acidic zinc-manganese dioxide batteries possess high safety, environmental friendliness, and affordability, making them a promising candidate for large-scale energy storage systems. These energy storage systems utilize the high H₂ content of acidic zinc-manganese dioxide batteries. + Driven MnO2 / Mn 2+ The conversion mechanism, compared to traditional neutral zinc-manganese dioxide batteries, can achieve a higher discharge voltage (~2.0V vs. Zn). 2+ / Zn) and theoretical capacity (616mAh g) -1 ).

[0003] However, in highly acidic media, zinc anodes face significant challenges, such as severe corrosion and hydrogen evolution reaction (HER), which are major causes of rapid capacity degradation and electrode surface instability. Therefore, acidic zinc-manganese dioxide batteries require high current (≥5 mA cm⁻¹) conditions. -2 ) and large capacity (≥5mA cm) -2 Operating under these conditions presents significant risks. Furthermore, manganese dioxide cathode materials suffer from slow kinetics, uneven deposition, and active material shedding, leading to low reversible capacity and poor cycle performance. Therefore, addressing the stability of zinc anodes in acidic media, particularly by suppressing undesirable side reactions, is crucial for improving battery reliability and performance. Summary of the Invention

[0004] The purpose of this application is to provide an electrolyte containing multiple cations, an aqueous zinc-ion battery, and a preparation method thereof, in order to solve the technical problems of poor stability of the zinc anode in the acidic zinc-manganese dioxide battery in a highly acidic medium, the tendency to undergo adverse side reactions leading to rapid degradation of battery capacity, and the instability of the electrode surface.

[0005] To achieve the above objectives, the first aspect of this application provides an electrolyte containing multiple cations, including a solvent and an electrolyte dissolved in the solvent, the electrolyte including zinc salt, manganese salt, copper salt and indium salt.

[0006] In one or more embodiments, the molar concentration of the zinc salt is 1.8 to 2.2 mol / L, and the molar concentration of the manganese salt is 0.18 to 0.22 mol / L.

[0007] In one or more embodiments, the zinc salt is ZnSO4 and the manganese salt is MnSO4.

[0008] In one or more embodiments, the molar concentration of the copper salt is 45–55 mmol / L, and the molar concentration of the indium salt is 45–55 mmol / L.

[0009] In one or more embodiments, the copper salt is CuCl2 and the indium salt is InCl3.

[0010] In one or more embodiments, the electrolyte further includes a tin salt.

[0011] In one or more embodiments, the molar concentration of the tin salt is 45–55 mmol / L.

[0012] In one or more embodiments, the tin salt is SnCl4.

[0013] In one or more embodiments, the solvent is water.

[0014] The second aspect of this application provides the application of the electrolyte described in any of the above embodiments in the preparation of an aqueous zinc-ion battery.

[0015] A third aspect of this application provides an aqueous zinc-ion battery, including a positive electrode, a negative electrode, a separator, and an electrolyte as described in any of the above embodiments.

[0016] In one or more embodiments, the positive electrode is a manganese dioxide positive electrode, and the negative electrode is a metallic zinc negative electrode.

[0017] In one or more embodiments, the diaphragm is a glass fiber membrane or a cellulose membrane.

[0018] The fourth aspect of this application provides a method for preparing an aqueous zinc-ion battery, comprising:

[0019] KMnO4 was dissolved and reacted fully with MnSO4. The precipitate was collected, washed and dried to obtain MnO2 cathode material.

[0020] After mixing the MnO2 cathode material, conductive additives and polyvinylidene fluoride, N-methylpyrrolidone was added and stirred to obtain a cathode slurry;

[0021] The positive electrode slurry was coated onto hydrophilic carbon paper, and the loading of the MnO2 positive electrode material was 1.5–3 mg / cm³. 2 After drying, manganese dioxide positive electrode is obtained;

[0022] By assembling the manganese dioxide positive electrode, the zinc metal negative electrode, the separator, and the electrolyte according to any one of claims 1 to 6, an aqueous zinc-ion battery is obtained.

[0023] The advantages of this application, which differ from existing technologies, are:

[0024] The electrolyte in this application includes In 3+ Cu 2+ Sn 4+ Cu 2+ and In 2+ The formation of bimetallic active sites In-CuZn5 on the zinc anode surface provides abundant nucleation sites, thereby promoting efficient Zn deposition and effectively inhibiting hydrogen evolution reaction, thus improving the stability of the zinc anode in acidic environments. 4+ It can hydrolyze in situ to generate SnO2 and HCl, establishing a self-sustaining acidic environment crucial for aqueous zinc-ion batteries without the need for an additional acidic medium. SnO2 has high acid resistance, which greatly enhances the stability of zinc in acidic media, thereby improving the cycle life and capacity stability of the battery. When applied to zinc / zinc symmetric batteries, it can achieve a capacity of 10 mA / cm². 2 Achieving an impressive cycle life of up to 2250 hours under high current density conditions;

[0025] This application employs an innovative electrolyte decoupling strategy, by adding In to the electrolyte... 3+ Cu 2+ Sn 4+ This will improve battery performance and lifespan in challenging electrochemical environments, contributing to the development of next-generation energy storage systems;

[0026] The aqueous zinc-ion battery of this application exhibits excellent cycle life and capacity stability, at 1 mA / cm². 2 After 200 cycles under these conditions, it still retains 84.9% of its initial capacity, far exceeding that of aqueous zinc-ion batteries using conventional electrolytes. Attached Figure Description

[0027] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0028] Figure 1 This is an image of the electrolyte in Example 1 of this application;

[0029] Figure 2 This is a characterization diagram of suspended matter in the electrolyte of Example 2 of this application, where b is an XRD diffraction pattern and c is a SEM image;

[0030] Figure 3 This is the XRD diffraction pattern of the zinc negative electrode of the zinc-ion battery in Example 3 of this application;

[0031] Figure 4 This is a characterization image of the zinc negative electrode of the zinc-ion battery of Embodiment 3 of this application, where e is a surface SEM image of the zinc negative electrode and f is a cross-sectional SEM image of the zinc negative electrode.

[0032] Figure 5 These are the Tafel curves for In-Cu@Zn and Bare Zn;

[0033] Figure 6 These are linear sweep voltammetric curves of In-Cu@Zn and Bare Zn;

[0034] Figure 7 Here are the HER Gibbs free energy data for In-CuZn5 and Zn(101);

[0035] Figure 8 The zinc / zinc symmetric battery using different electrolytes in Example 4 of this application achieves a performance of 10 mA / cm². 2 -5mAh / cm 2 The following is a graph showing the charge / discharge performance data;

[0036] Figure 9 The zinc / zinc symmetric cells using different electrolytes in Example 4 of this application are shown at 10 mA / cm². 2 -10mAh cm 2 The following is a graph showing the charge / discharge performance data;

[0037] Figure 10 This is a graph showing the cyclic performance test data of Example 5 of this application. Detailed Implementation

[0038] To enable those skilled in the art to better understand the technical solutions in this application, the technical solutions in the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments in this application, all other embodiments obtained by those of ordinary skill in the art without creative effort should fall within the scope of protection of this application.

[0039] Currently, the zinc anode of acidic zinc-manganese dioxide batteries is prone to severe corrosion and hydrogen evolution reaction (HER) in highly acidic media. These side reactions lead to rapid capacity degradation and electrode surface instability.

[0040] To address the aforementioned issues, the applicant has introduced an innovative electrolyte decoupling strategy. This strategy, by adding multiple cations to a conventional electrolyte, can significantly suppress the occurrence of the aforementioned undesirable side reactions, greatly enhance the stability of the zinc anode in acidic environments, thereby improving the battery's cycle life and capacity stability, enhancing the battery's performance and lifespan in challenging electrochemical environments, and contributing to the development of next-generation energy storage systems.

[0041] Specifically, this application provides an electrolyte containing multiple cations, the electrolyte comprising a solvent and an electrolyte, wherein the electrolyte comprises zinc salt, manganese salt, copper salt and indium salt.

[0042] In one embodiment, the molar concentration of the zinc salt can be 1.8–2.2 mol / L, and the molar concentration of the manganese salt can be 0.18–0.22 mol / L.

[0043] In one embodiment, the molar concentration of the copper salt can be 45–55 mmol / L, and the molar concentration of the indium salt can be 45–55 mmol / L.

[0044] In one embodiment, the solvent may be water, and in particular, it may be deionized water.

[0045] In one embodiment, the zinc salt can be ZnSO4, the manganese salt can be MnSO4, the copper salt can be CuCl2, and the indium salt can be InCl3.

[0046] In other embodiments, zinc salt, manganese salt, copper salt, and indium salt can be any soluble salt that the corresponding metal cation can form. For example, zinc salt can also be zinc chloride, etc. As long as the electrolyte has a suitable acidic pH value, generally around 3 to 4, the effect of this embodiment can be achieved.

[0047] The electrolyte in this embodiment, compared to the electrolyte of a conventional acidic aqueous zinc-manganese battery, contains Cu. 2+ and In 3+ When this electrolyte is applied to aqueous zinc-ion batteries, Cu 2+ and In 3+ The bimetallic active site In-CuZn5 can spontaneously form on the surface of the zinc anode. The bimetallic active site can provide abundant nucleation sites, thereby promoting the efficient deposition of Zn and effectively inhibiting the hydrogen evolution reaction, thus improving the stability of the zinc anode in acidic environment.

[0048] In another embodiment, the electrolyte of this application may further include a tin salt. The molar concentration of the tin salt may be 45–55 mmol / L.

[0049] The electrolyte in this embodiment further contains Sn compared to the electrolyte in the above embodiment.4+ When applied in aqueous zinc-ion batteries, Sn 4+ It can be hydrolyzed in situ to generate SnO2. SnO2 has a high acid resistance, so the SnO2 layer can greatly enhance the stability of zinc in acidic media.

[0050] In one embodiment, the tin salt can be SnCl4, which can also generate HCl upon in-situ hydrolysis, thereby establishing a self-sustaining acidic environment that is crucial for aqueous zinc-ion batteries without the need for additional acidic media.

[0051] When the electrolytes described in the above embodiments are applied to aqueous zinc-ion batteries, they can significantly suppress adverse side reactions of the zinc anode, greatly enhance the stability of the zinc anode in acidic media, and thus improve the cycle life and capacity stability of the battery.

[0052] This application also provides an aqueous zinc-ion battery, which includes a positive electrode, a negative electrode, a separator, and an electrolyte according to any of the above embodiments.

[0053] Specifically, in one embodiment, the aqueous zinc-ion battery can be a zinc-manganese battery, with the corresponding positive electrode being a manganese dioxide positive electrode and the negative electrode being a metallic zinc negative electrode.

[0054] In one embodiment, the diaphragm may be a glass fiber membrane or a cellulose membrane.

[0055] In other embodiments, the aqueous zinc-ion battery can also be other types of zinc-ion batteries, such as a zinc / zinc symmetric battery, in which case the positive electrode can be Zn. 2+ The negative electrode can be a metallic zinc negative electrode, which can also achieve the effect of this embodiment.

[0056] In one embodiment, the aqueous zinc-ion battery can be a pouch cell; in other embodiments, it can be other types of batteries, such as dry cell batteries, etc., all of which can achieve the effects of this embodiment.

[0057] This application also provides a method for preparing an aqueous zinc-ion battery, comprising:

[0058] S100, KMnO4 is dissolved and reacted with MnSO4 to collect the precipitate, which is then washed and dried to obtain MnO2 cathode material;

[0059] S200: Mix MnO2 cathode material, conductive additives and polyvinylidene fluoride, add N-methylpyrrolidone and stir to obtain cathode slurry;

[0060] In one embodiment, the conductive additive may be conductive carbon black Super P; in other embodiments, other conductive additives may also be used.

[0061] In one embodiment, the mass ratio of MnO2 cathode material, conductive additive, and polyvinylidene fluoride can be 7:1:2; in other embodiments, the ratio can be adjusted according to actual needs, and all can achieve the effect of this embodiment.

[0062] S300. The positive electrode slurry is coated onto hydrophilic carbon paper, and the loading of MnO2 positive electrode material is 1.5–3 mg / cm³. 2 After drying, manganese dioxide positive electrode is obtained;

[0063] S400: Assemble the manganese dioxide positive electrode, the zinc metal negative electrode, the separator, and the electrolyte of any of the above embodiments to obtain an aqueous zinc-ion battery.

[0064] The beneficial effects of the technical solution of this application will be further explained in detail below with reference to specific embodiments.

[0065] Example 1:

[0066] An electrolyte containing multiple cations is prepared by the following steps:

[0067] 50 mM CuCl2 and 50 mM InCl3 were introduced into an aqueous electrolyte containing 2 M ZnSO4 and 0.2 M MnSO4, respectively. After ultrasonic stirring for 20 min, a homogeneous electrolyte was formed with a pH of 3.3.

[0068] Example 2:

[0069] An electrolyte containing multiple cations is prepared by the following steps:

[0070] 50 mM CuCl2, 50 mM InCl3, and 50 mM SnCl4 were introduced into an aqueous electrolyte containing 2 M ZnSO4 and 0.2 M MnSO4, respectively. After ultrasonic stirring for 20 min, a homogeneous electrolyte was formed with a pH of 1.2.

[0071] Example 3:

[0072] An aqueous zinc-ion battery is prepared using the following steps:

[0073] (1) Weigh 0.8 g of KMnO4 and dissolve it in 80 mL of deionized water. Stir for 30 minutes at room temperature until it is completely dissolved. Then add 2.7 g of MnSO4·H2O and stir for 30 minutes. A dark brown precipitate appears. Transfer the mixed solution to a 100 mL polytetrafluoroethylene reaction flask and react at 180 °C for 6 hours. After cooling to room temperature, collect the dark brown precipitate and wash it three times with deionized water and ethanol. Finally, dry it in an oven at 60 °C for 12 hours to obtain MnO2 cathode material powder.

[0074] (2) Mix polyvinylidene fluoride (PVDF), Super P and MnO2 cathode material powder from step (1) in a mass ratio of 1:2:7, add N-methylpyrrolidone and stir for 12 hours to obtain cathode slurry. Coat the cathode slurry onto hydrophilic carbon paper with an active material (MnO2) loading of 2 mg / cm. Then dry the hydrophilic carbon paper in a vacuum oven at 80°C overnight to obtain manganese dioxide cathode.

[0075] (3) Assembly of zinc-manganese batteries:

[0076] The manganese dioxide positive electrode, zinc foil and glass fiber prepared in step (2) were used as the positive electrode, negative electrode and separator, respectively, and the electrolyte prepared in Example 1 was used as the electrolyte to assemble a pouch battery with an area of ​​25 square centimeters.

[0077] Example 4:

[0078] An aqueous zinc-ion battery is prepared in a manner that is basically the same as in Example 3, except that the electrolyte prepared in Example 2 is used as the electrolyte in this example.

[0079] Comparative Example 1:

[0080] An aqueous zinc-ion battery is prepared in a manner that is basically the same as in Example 3, except that the electrolyte in this comparative example is an aqueous electrolyte (pH 1.21) comprising 2M ZnSO4 and 0.2M MnSO4.

[0081] Example 1: Characterization Analysis

[0082] Images of the electrolytes from Example 1 (In-Cu) and Example 2 (In-Cu-Sn) were acquired. Simultaneously, an aqueous electrolyte consisting only of 2M ZnSO4 and 0.2M MnSO4 (BE, pH 4.5) and an aqueous electrolyte consisting of 50mM InCl3, 2M ZnSO4, and 0.2M MnSO4 (In, pH 3.3) were introduced to obtain... Figure 1 , Figure 1 This is an image of the electrolyte in Example 1 of this application.

[0083] like Figure 1 As shown, the electrolyte in Example 2 has higher turbidity and a large amount of suspended matter compared to other electrolytes.

[0084] To verify the specific composition of the suspended matter, XRD diffraction analysis and electron microscopy analysis were performed to obtain... Figure 2 , Figure 2 This is a characterization diagram of suspended matter in the electrolyte of Example 2 of this application, where b is an XRD diffraction pattern and c is a SEM image.

[0085] like Figure 2 As shown in Figure b, the XRD diffraction pattern of the suspended matter matches PDF number 01-0625, confirming that the suspended matter is SnO2. Figure 2 As shown in Figure c, the suspended matter is granular with a particle size of less than 1 μm.

[0086] As can be seen from the above experiments, in the electrolyte of Example 2, Sn 4+ In-situ hydrolysis generates SnO2. Due to its high acid resistance, when this electrolyte is used in aqueous zinc-ion batteries, SnO2 can adhere to the zinc anode surface, thereby greatly enhancing the stability of zinc in acidic media.

[0087] Example 2:

[0088] XRD diffraction pattern analysis was performed on the zinc anode in the zinc-ion battery of Example 3, and electron microscopy analysis was performed on the surface and cross-section of the zinc anode to obtain... Figure 3 and Figure 4 , Figure 3 This is the XRD diffraction pattern of the zinc anode of the zinc-ion battery in Example 3 of this application. Figure 4 This is a characterization image of the zinc anode of the zinc-ion battery of Embodiment 3 of this application, where e is a surface SEM image of the zinc anode and f is a cross-sectional SEM image of the zinc anode.

[0089] like Figure 3 As shown, after analysis and comparison, the diffraction pattern shows that in addition to the Zn peak matching PDF number 01-1238, it also includes the CuZn5 peak matching PDF number 35-1151 and the In peak matching PDF number 01-1042; therefore, it can be concluded that a bimetallic active site In-CuZn5 has been formed on the zinc anode.

[0090] like Figure 4 As shown in Figure e, the zinc anode surface has uniformly distributed granular bimetallic active sites, and simultaneously... Figure 4 As shown in Figure f, the bimetallic active sites on the zinc anode surface form a layered structure, which can provide abundant nucleation sites, thereby promoting the efficient deposition of Zn and effectively inhibiting the hydrogen evolution reaction, thus improving the stability of the zinc anode in an acidic environment.

[0091] Example 3: Electrochemical Performance Analysis

[0092] The zinc anode (In-Cu@Zn) and bare zinc (Bare Zn) of the zinc-ion battery in Example 3 were used for electrochemical performance analysis. The specific experimental contents included:

[0093] (1) Using a platinum sheet as the auxiliary electrode, Ag / AgCl as the reference electrode, In-Cu@Zn and Bare Zn as the working electrodes, and a solution containing ZnSO4 and SnCl4 (pH 1.2) as the electrolyte, a three-electrode system was formed. The scan rate was 1 mV / s, and the voltage range was -1.1 to 0.85 V. The Tafel curves of In-Cu@Zn and Bare Zn were measured.

[0094] (2) Using a platinum sheet as the auxiliary electrode, Ag / AgCl as the reference electrode, In-Cu@Zn and Bare Zn as the working electrodes, and Na2SO4 solution (pH 1.2) as the electrolyte, a three-electrode system was formed. The scan rate was 1 mV / s, and the voltage range was -1.1 to -1.8 V. The linear scan voltammetric curves of In-Cu@Zn and Bare Zn were measured.

[0095] (3) The Gibbs free energy of the bimetallic active sites In-CuZn5 and Zn(101) on the zinc anode surface of the zinc-ion battery in Example 3 during the hydrogen evolution reaction kinetics was measured respectively.

[0096] Based on the above experiments, we obtained Figure 5 , Figure 6 and Figure 7 , Figure 5 These are the Tafel curves for In-Cu@Zn and Bare Zn. Figure 6 These are linear sweep voltammetry curves for In-Cu@Zn and Bare Zn. Figure 7 This is a plot of HER Gibbs free energy data for In-CuZn5 and Zn(101).

[0097] like Figure 5 As shown, using bare zinc (Bare Zn) as a control, the corrosion behavior of In-Cu@Zn was evaluated using Tafel polarization curve testing. The corrosion potential of In-Cu@Zn was -0.956V (compared to Ag / AgCl), which is much higher than that of bare zinc (-0.983V), indicating that it has stronger corrosion resistance under acidic conditions.

[0098] Typically, the corrosion rate of Zn in acidic environments is influenced by the hydrogen evolution reaction (HER) kinetics. Figure 6 LSV curves of bare zinc (Bare Zn) and In-Cu@Zn in 1M pure Na₂SO₄ electrolyte (pH 1.2) are shown. Notably, the In-Cu@Zn electrode exhibits a lower hydrogen evolution current density in the voltage range of 1.1–1.8 V. Compared to bare zinc, the onset potential of the hydrogen evolution reaction (HER) of In-Cu@Zn (-1.64 V, relative to Ag / AgCl) is significantly negatively shifted (-1.48 V), confirming that In-CuZn₅ has the ability to mitigate the HER of the zinc electrode.

[0099] The Gibbs free energy (ΔG) is a key parameter for evaluating the activity of the hydrogen evolution reaction (HER). To further investigate this, we used DFT calculations to compare the Gibbs free energy changes (ΔGH*) of adsorbed H between In-CuZn5 and bare zinc (Bare Zn), such as... Figure 7 As shown, the ΔGH* of bare zinc is approximately 0.22 eV, close to the thermally neutral state, indicating that the zinc surface is more prone to HER. In contrast, the ΔGH* of In-CuZn5 is significantly higher, at 0.68 eV, suggesting a much lower tendency for H2 formation on the In-CuZn5 surface. This calculation result is in excellent agreement with the improvement in corrosion potential and HER overpotential observed in In-Cu@Zn.

[0100] The above experiments show that the bimetallic active site In-CuZn5 formed on the zinc anode of the battery in Example 3 can significantly inhibit the HER reaction of the zinc electrode, improve the corrosion resistance and stability of the zinc electrode in acidic media, and thus help improve the cycle performance and capacity stability of the zinc-ion battery.

[0101] Example 4: Charge and Discharge Performance Analysis

[0102] The long-cycle charge-discharge performance of zinc / zinc symmetric batteries using different electrolytes under high current density and equal capacity conditions was investigated.

[0103] The electrolytes used in the specific tests included: the electrolyte of Example 1 (In-Cu); the electrolyte of Example 2 (In-Cu-Sn); an aqueous electrolyte (BE) comprising 2M ZnSO4 and 0.2M MnSO4; an aqueous electrolyte (In) comprising 50mM InCl3, 2M ZnSO4 and 0.2M MnSO4; an aqueous electrolyte (Cu) comprising 50mM CuCl2, 2M ZnSO4 and 0.2M MnSO4; and an aqueous electrolyte (Sn) comprising 50mM MnCl4, 2M ZnSO4 and 0.2M MnSO4.

[0104] The specific current density and capacity conditions tested included: 10 mA / cm². 2 -5 mAh / cm 2 and 10mA / cm 2 -10 mAhcm 2 .

[0105] Based on the above tests, we obtain Figure 8 and Figure 9 , Figure 8 The zinc / zinc symmetric battery using different electrolytes in Example 4 of this application achieves a performance of 10 mA / cm². 2 -5 mAh / cm 2The following is a graph showing the charge and discharge performance data. Figure 9 The zinc / zinc symmetric cells using different electrolytes in Example 4 of this application are shown at 10 mA / cm². 2 -10 mAh cm 2 The following is a graph showing the charge and discharge performance data.

[0106] like Figure 8 As shown, the zinc / zinc symmetric cell using the electrolyte (In-Cu-Sn) of Example 2 operates at 10 mA / cm². 2 - Achieving an astonishing cycle life of up to 2250 hours under high current density conditions, far exceeding other electrolytes, is due to: on the one hand, Cu 2+ and In 2+ The formation of bimetallic active sites In-CuZn5 on the zinc anode surface provides abundant nucleation sites, thereby promoting efficient Zn deposition and effectively inhibiting hydrogen evolution reaction, thus improving the stability of the zinc anode in acidic environments; on the other hand, Sn 4+ It can hydrolyze in situ to generate SnO2 and HCl, establishing a self-sustaining acidic environment that is crucial for aqueous zinc-ion batteries without the need for additional acidic media. SnO2 has high acid resistance, which can greatly enhance the stability of zinc in acidic media.

[0107] Additionally, the zinc / zinc symmetric cell using the electrolyte (In-Cu) of Example 1 operates at 10 mA / cm². 2 - A cycle life of 1600 hours was achieved under high current density conditions, while zinc / zinc symmetric cells using electrolyte (In) only achieved 800 hours of cycle life, and zinc / zinc symmetric cells using electrolyte (Cu) only achieved 100 hours of cycle life; it can be seen that the In in the electrolyte of this application 3+ and Cu 2+ They have a synergistic effect, working together to form the bimetallic active site In-CuZn5, and none of them can be missing.

[0108] Additionally, the zinc / zinc symmetric cell using the electrolyte (In-Cu) of Example 1 operates at 10 mA / cm². 2 - A cycle life of 1600 hours was achieved under high current density conditions, while the zinc / zinc symmetric battery using electrolyte (Sn) only achieved a cycle life of 300 hours, both far lower than the electrolyte (In-Cu-Sn) of Example 2; it can be seen that In in the electrolyte of this application 3+ Cu 2+ and Sn 4+ It has a synergistic effect.

[0109] Please continue reading. Figure 9 At 10mA / cm 2 -10 mAh cm 2The zinc / zinc symmetric battery using the electrolyte (In-Cu) of Example 1 still retains 85.5% of its initial capacity after 1000 hours of cycling, while the zinc / zinc symmetric battery using the conventional electrolyte BE has a cycle life of less than 100 hours. It can be seen that the electrolyte of Example 2 can significantly improve the cycle life and capacity stability of zinc-ion batteries.

[0110] Example 5: Cyclic Performance Analysis

[0111] At 1mA / cm 2 The cycle performance of the batteries in Example 4 and Comparative Example 1 was tested under the specified conditions to obtain... Figure 10 , Figure 10 This is a graph showing the cyclic performance test data of Example 5 of this application.

[0112] like Figure 10 As shown, the battery in Example 4 operates at 1 mA / cm². 2 After 200 cycles under the same conditions, the battery retained 84.9% of its initial capacity; while the battery in Comparative Example 1 retained only 35.8% of its initial capacity under the same conditions.

[0113] As can be seen from the above data, the electrolyte of this application can significantly improve the cycle life and capacity stability of the battery.

[0114] It will be apparent to those skilled in the art that this application is not limited to the details of the exemplary embodiments described above, and that this application can be implemented in other specific forms without departing from the spirit or essential characteristics of this application. Therefore, the embodiments should be considered illustrative and non-limiting in all respects, and the scope of this application is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of equivalents of the claims are intended to be included within this application. No reference numerals in the claims should be construed as limiting the scope of the claims.

[0115] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. An electrolyte for an aqueous zinc-ion battery containing multiple cations, characterized in that, It includes solvents and electrolytes, wherein the electrolytes include zinc salts, manganese salts, copper salts, and indium salts; The zinc salt has a molar concentration of 1.8~2.2 mol / L, the manganese salt has a molar concentration of 0.18~0.22 mol / L, the copper salt has a molar concentration of 45~55 mmol / L, and the indium salt has a molar concentration of 45~55 mmol / L.

2. The electrolyte according to claim 1, characterized in that, The zinc salt is ZnSO4, and the manganese salt is MnSO4.

3. The electrolyte according to claim 1, characterized in that, The copper salt is CuCl2, and the indium salt is InCl3.

4. The electrolyte according to claim 1, characterized in that, The electrolyte also includes tin salts.

5. The electrolyte according to claim 4, characterized in that, The molar concentration of the tin salt is 45-55 mmol / L; and / or, The tin salt is SnCl4.

6. The electrolyte according to claim 1, characterized in that, The solvent is water.

7. The use of the electrolyte according to any one of claims 1 to 6 in the preparation of an aqueous zinc-ion battery.

8. An aqueous zinc-ion battery, characterized in that, It includes a positive electrode, a negative electrode, a separator, and the electrolyte as described in any one of claims 1 to 6.

9. The aqueous zinc-ion battery according to claim 8, characterized in that, The positive electrode is manganese dioxide, and the negative electrode is zinc; and / or, The diaphragm is a glass fiber membrane or a cellulose membrane.

10. A method for preparing an aqueous zinc-ion battery, characterized in that, include: KMnO4 was dissolved and reacted fully with MnSO4. The precipitate was collected, washed and dried to obtain MnO2 cathode material. After mixing the MnO2 cathode material, conductive additives and polyvinylidene fluoride, N-methylpyrrolidone was added and stirred to obtain a cathode slurry; The positive electrode slurry was coated onto hydrophilic carbon paper, and the loading of the MnO2 positive electrode material was 1.5~3 mg / cm³. 2 After drying, manganese dioxide positive electrode is obtained; By assembling the manganese dioxide positive electrode, the zinc metal negative electrode, the separator, and the electrolyte according to any one of claims 1 to 6, an aqueous zinc-ion battery is obtained.

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