Aqueous zinc ion battery electrolyte and aqueous zinc ion battery

Abstract

The present invention provides an aqueous zinc ion battery electrolyte and an aqueous zinc ion battery. The aqueous zinc ion battery electrolyte comprises pure water, a soluble zinc ion salt, and an additive, wherein the additive is 1-nitroso-2-naphthol-6-sulfonic acid sodium iron salt. The 1-nitroso-2-naphthol-6-sulfonic acid group generated by ionization in the electrolyte of the present invention can be directionally adsorbed on the surface of the zinc negative electrode, thereby inhibiting dendrite growth and hydrogen evolution reaction on the negative electrode surface; the Fe generated by ionization 3+ Ions can be embedded into the positive electrode material during the battery cycle, increasing the capacity of the battery, thereby solving the problem of capacity attenuation during the battery cycle and improving the battery's cycle stability.

Description

Technical Field

[0001] The present invention belongs to the technical field of aqueous zinc ion battery energy storage, and in particular relates to an aqueous zinc ion battery electrolyte and an aqueous zinc ion battery. Background Art

[0002] With the development of clean energy technologies such as wind, solar, and tidal energy, large-scale energy storage technology has become increasingly important. In recent years, lithium-ion batteries have been widely used in portable electronic devices, electric vehicles, and large-scale energy storage due to their high energy density, long life, and portability. However, limited lithium resources and harsh assembly conditions have increased the cost of commercial lithium-ion batteries. At the same time, the organic electrolyte of lithium-ion batteries is toxic and flammable, and during the operation of lithium-ion batteries, irregular lithium dendrites can cause internal short circuits in lithium-ion batteries, resulting in battery heating and explosion.

[0003] Compared to organic electrolyte-based lithium-ion batteries (LIBs), aqueous metal-ion batteries (AZBs), represented by aqueous Zn-ion batteries (AZBs), offer greater safety and lower cost, demonstrating significant potential for large-scale energy storage. Metallic zinc, a typical Zn-ion battery anode material, offers advantages such as high abundance, low toxicity, low cost, and stability in air and electrolyte. Furthermore, Zn anodes possess high theoretical capacity (820 mAh / g, 5855 mAh / cm³) and low redox potential (-0.76 V vs. standard hydrogen electrode). These properties make AZBs promising for future large-scale energy storage applications. However, side reactions at the anode-electrolyte interface in AZBs lead to anode corrosion and dendrite growth, severely impacting their cycle life. Furthermore, cathode active materials, such as manganese dioxide, often suffer from structural collapse and phase transitions during cycling, resulting in low battery capacity.

[0004] To address these issues, researchers have recently addressed side reactions at the zinc anode-electrolyte interface through strategies such as anode structure design, constructing an interface layer on the anode surface, and optimizing the electrolyte. Electrolyte additives, with their advantages of low cost and ease of operation, hold broad application prospects in achieving long-life aqueous zinc-ion batteries. For example, patent CN119275383 A uses thiazole derivatives as additives to effectively isolate the anode from the electrolyte, mitigating interfacial side reactions. Patent CN118017034 A uses aluminum nitrate as an electrolyte additive to construct an electrostatic shielding layer on the anode surface, promoting uniform zinc ion deposition and inhibiting dendrite growth. Another example is patent CN 118017032 A, which uses fluoroborate as an additive to regulate the solvation structure of zinc ions, reducing the generation of active water molecules during the electroplating process, thereby inhibiting side reactions such as hydrogen evolution and corrosion and passivation of the zinc anode. Although relevant personnel have made many efforts to improve the cycle performance of aqueous zinc-ion batteries based on electrolyte additives, they all focus on the interfacial reaction between the negative electrode and the electrolyte. The capacity attenuation problem caused by the collapse and phase change of the positive electrode material during the cycle still needs to be solved urgently. Summary of the Invention

[0005] In view of this, the present invention aims to overcome the defects in the prior art and proposes an aqueous zinc ion battery electrolyte and an aqueous zinc ion battery. The 1-nitroso-2-naphthol-6-sulfonic acid group generated by ionization in the electrolyte of the present invention can be directionally adsorbed on the surface of the zinc negative electrode, inhibiting the dendrite growth and hydrogen evolution reaction on the negative electrode surface; the Fe 3+ Ions can be embedded into the positive electrode material during the battery cycle, increasing the capacity of the battery, thereby solving the problem of capacity attenuation during the battery cycle and improving the battery's cycle stability.

[0006] To achieve the above object, the technical solution of the present invention is achieved as follows:

[0007] In a first aspect, the present invention provides an aqueous zinc ion battery electrolyte, comprising pure water, a soluble zinc ion salt and an additive, wherein the additive is sodium ferric 1-nitroso-2-naphthol-6-sulfonate (naphthol green B).

[0008] Preferably, the molar concentration of naphthol green B in the electrolyte is 0.01-20 mmol / L.

[0009] More preferably, the molar concentration of naphthol green B in the electrolyte is 0.05 mmol / L.

[0010] Preferably, the soluble zinc ion salt is one or more of zinc sulfate, zinc acetate, zinc chloride, and zinc trifluoromethanesulfonate.

[0011] More preferably, the soluble zinc ion salt is zinc sulfate.

[0012] More preferably, the molar concentration of the soluble zinc ion salt is 1-3 mol / L.

[0013] Preferably, the method for preparing the aqueous zinc ion battery electrolyte comprises the following steps: adding a soluble zinc ion salt and an additive into pure water and dissolving them to obtain the aqueous zinc ion battery electrolyte.

[0014] In a second aspect, the present invention also provides an aqueous zinc ion battery using the above electrolyte.

[0015] Preferably, the aqueous zinc ion battery comprises a positive electrode, a negative electrode, a separator and the above-mentioned electrolyte.

[0016] Compared with the prior art, the present invention has the following advantages:

[0017] (1) The present invention uses sodium ferric 1-nitroso-2-naphthol-6-sulfonate as an additive in aqueous zinc ion battery electrolyte. The additive can ionize in the electrolyte to generate 1-nitroso-2-naphthol-6-sulfonic acid groups, which can be directionally adsorbed on the surface of the zinc negative electrode, thereby spontaneously forming an interface layer containing the above-mentioned groups on the negative electrode surface. The interface layer can isolate the direct contact between the electrolyte and the negative electrode, thereby alleviating the corrosion reaction of the negative electrode. In addition, because the group contains oxygen-containing functional groups such as phenolic hydroxyl groups, it can reduce the nucleation overpotential of zinc ions during battery charging, help induce uniform zinc deposition, and thus inhibit the growth of dendrites on the negative electrode surface.

[0018] (2) The present invention uses 1-nitroso-2-naphthol-6-sulfonic acid sodium iron salt as an additive in the electrolyte of aqueous zinc ion battery, and the additive can also ionize in the electrolyte to generate Fe 3+ ions, which can be spontaneously embedded in the manganese dioxide positive electrode during battery discharge and will not be removed from the active material during charging, which is beneficial to stabilizing the positive electrode structure. 3+ Ions can increase the capacity of the battery and are more conducive to the realization of stable and long-life aqueous zinc-ion batteries. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 1 is a comparison chart of the cycle life of Zn||Zn symmetric batteries of Example 1 of the present invention and Comparative Examples 1, 2 and 3;

[0020] Figure 2 Surface XRD comparison diagram of the Zn||Zn symmetric battery of Example 1 of the present invention and Comparative Example 1;

[0021] Figure 3 SEM photos of the negative electrodes of the Zn||Zn symmetrical batteries of Example 1 and Comparative Example 1 of the present invention after constant current charge and discharge, (a) is Comparative Example 1, and (b) is Example 1;

[0022] Figure 4 A comparison chart of the cycle life of the Zn|Cu half-cells assembled in Application Example 1 of the present invention and Comparative Application Example 1;

[0023] Figure 5 A comparison chart of the cycle performance of aqueous zinc ion full batteries assembled in Application Example 2 of the present invention and Comparative Application Example 2;

[0024] Figure 6 This is the XPS graph of the positive electrode of the aqueous zinc ion full battery assembled in Example 3 of the present invention after 20 cycles. DETAILED DESCRIPTION

[0025] The embodiments of the present invention are described in detail below. The embodiments described below are exemplary and are only used to explain the present invention, and should not be understood as limiting the present invention.

[0026] Unless defined otherwise herein, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs.

[0027] Where values ​​are described herein as ranges, it should be understood that such disclosure includes disclosure of all possible sub-ranges within that range, as well as specific values ​​falling within that range, regardless of whether a specific value or sub-range is explicitly stated.

[0028] In this document, "a plurality of" and the like, unless otherwise specified, refer to a number greater than or equal to 2. For example, "one or more" means one or more than or equal to two.

[0029] In this document, the terms “preferably” and “more preferably” are only used to describe implementation methods or examples with better effects. It should be understood that they do not limit the scope of protection of the present invention.

[0030] In this document, the word "further" and the like are used for descriptive purposes to indicate differences in content, but should not be construed as limiting the scope of protection of the present invention.

[0031] In this article, the term "and / or" is used to describe the association relationship between objects, indicating that three relationships can exist. For example, A and / or B means: A or B, or A and B.

[0032] As used herein, the term "about" means + / - 10%, preferably + / - 5%, more preferably + / - 1% of the specified value.

[0033] In this document, the terms “include,” “including,” “have,” “contain,” etc. are open-ended terms, meaning including but not limited to.

[0034] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which the invention pertains. Although preferred methods and materials have been described herein, any methods and materials similar or equivalent to those described herein can also be used in the practice or testing of the present invention.

[0035] The present invention will be described in detail below with reference to the embodiments.

[0036] An aqueous zinc-ion battery electrolyte comprises pure water, a soluble zinc ion salt, and an additive. The additive is sodium ferric 1-nitroso-2-naphthol-6-sulfonate (Naphthol Green B). The soluble zinc ion salt is one or more of zinc sulfate, zinc acetate, zinc chloride, and zinc trifluoromethanesulfonate, with a molar concentration of 1-3 mol / L. The molar concentration of Naphthol Green B in the electrolyte is 0.01-20 mmol / L.

[0037] The aqueous zinc ion battery electrolyte is prepared by the following steps:

[0038] Under room temperature conditions, soluble zinc ion salt and additives are added into pure water and dissolved to obtain an aqueous zinc ion battery electrolyte.

[0039] Aqueous zinc ion batteries are prepared by the following steps:

[0040] Step 1: Prepare the positive electrode active material by dissolving potassium permanganate in pure water and adding concentrated hydrochloric acid dropwise while stirring. Place the mixed solution in an autoclave and dry it in a forced-air drying oven. Filter the reaction solution and repeatedly rinse the filtrate with pure water and anhydrous ethanol before drying to obtain the manganese dioxide positive electrode active material.

[0041] Step 2: Prepare the positive electrode material. Using N-methylpyrrolidone as the solvent, evenly grind and mix the manganese dioxide active material, conductive carbon black, and polyvinylidene fluoride (PVDF) obtained in Step 1 in an agate mortar. Apply the resulting slurry evenly to the current collector using a spatula. After drying, the positive electrode material is obtained.

[0042] Step 3: Cutting. Use a manual cutting machine to cut the zinc foil, copper foil, and the above-mentioned positive electrode materials into discs; cut the glass fiber separator into discs.

[0043] Step 4: Assemble the negative electrode shell, negative electrode sheet, glass fiber diaphragm, electrolyte, positive electrode sheet, gasket, shrapnel, and positive electrode shell in the order of a small hydraulic button battery sealing machine.

[0044] It should be noted that, if the positive electrode sheet is a zinc sheet, a Zn|Zn symmetrical battery can be assembled, and if the positive electrode sheet is a copper sheet, a Zn|Cu half-battery can be assembled.

[0045] Example 1:

[0046] At room temperature, 57.512 g of ZnSO4•7H2O and 0.0044 g of 1-nitroso-2-naphthol-6-sulfonic acid sodium iron salt were dissolved in pure water and the volume was adjusted to 100 mL with a volumetric flask to obtain an aqueous zinc ion battery electrolyte, in which the molar concentration of zinc sulfate was 2 mol / L and the molar concentration of 1-nitroso-2-naphthol-6-sulfonic acid sodium iron salt was 0.05 mmol / L.

[0047] Aqueous zinc ion batteries are prepared by the following steps:

[0048] Step 1: Prepare the positive electrode active material. Dissolve 3.161g of potassium permanganate in 392.5mL of pure water and add 7.5mL of concentrated hydrochloric acid dropwise while stirring. Place the mixed solution in an autoclave and heat it in a forced air drying oven at 160°C for 12 hours. Filter the reaction solution and repeatedly rinse the filtrate with pure water and anhydrous ethanol. Dry it at 60°C for 8 hours to obtain the manganese dioxide positive electrode active material.

[0049] Step 2: Prepare the positive electrode material. Using N-methylpyrrolidone as the solvent, grind and mix the manganese dioxide active material, conductive carbon black, and polyvinylidene fluoride (PVDF) obtained in Step 1 in a 7:2:1 mass ratio in an agate mortar. Apply the resulting slurry evenly to a 30 μm zinc foil current collector using a 150 mm spatula. Dry at 60°C for 2 hours to obtain the positive electrode material.

[0050] Step 3: Cutting. Use a manual cutter to cut the 30 μm zinc foil and the above-mentioned cathode material into 15 mm diameter discs; cut the glass fiber separator into 20 mm diameter discs.

[0051] Step 4: Assemble the negative electrode shell, negative electrode sheet, glass fiber separator, electrolyte, positive electrode sheet, gasket, spring, and positive electrode shell in the order of 50 MPa using a small hydraulic button cell sealing machine. This yields a Zn|Zn symmetrical battery.

[0052] Example 2:

[0053] At room temperature, dissolve 28.756 g of ZnSO₄•7H₂O and 0.00088 g of 1-nitroso-2-naphthol-6-sulfonic acid sodium ferric salt in pure water and dilute the volume to 100 mL using a volumetric flask to obtain an aqueous zinc ion battery electrolyte. The molar concentration of zinc sulfate is 1 mol / L, and the molar concentration of 1-nitroso-2-naphthol-6-sulfonic acid sodium ferric salt is 0.01 mmol / L. A Zn∥Zn symmetrical battery was prepared according to the preparation steps of the aqueous zinc ion battery in Example 1.

[0054] Example 3:

[0055] At room temperature, dissolve 86.268 g of ZnSO₄•7H₂O and 1.76 g of 1-nitroso-2-naphthol-6-sulfonic acid sodium ferric salt in pure water and dilute the volume to 100 mL using a volumetric flask to obtain an aqueous zinc ion battery electrolyte. The molar concentration of zinc sulfate is 3 mol / L, and the molar concentration of 1-nitroso-2-naphthol-6-sulfonic acid sodium ferric salt is 20 mmol / L. A Zn∥Zn symmetrical battery was prepared according to the preparation steps of the aqueous zinc ion battery in Example 1.

[0056] Example 4:

[0057] The preparation of the Zn||Zn symmetrical battery in this embodiment is the same as that in Example 1, except that the soluble zinc ion salt is zinc acetate.

[0058] Example 5:

[0059] The preparation of the Zn||Zn symmetrical battery in this embodiment is the same as that in Example 1, except that the soluble zinc ion salt is zinc trifluoromethanesulfonate.

[0060] Example 6:

[0061] The preparation of the Zn||Zn symmetrical battery in this embodiment is the same as that in Example 1, except that the soluble zinc ion salt is zinc chloride.

[0062] Comparative Example 1:

[0063] The difference from Example 1 is that 1-nitroso-2-naphthol-6-sulfonic acid sodium iron salt is not added.

[0064] Comparative Example 2:

[0065] The difference from Example 1 is that the molar concentration of 1-nitroso-2-naphthol-6-sulfonic acid sodium iron salt is 0.005 mmol / L.

[0066] Comparative Example 3:

[0067] The difference from Example 1 is that the molar concentration of 1-nitroso-2-naphthol-6-sulfonic acid sodium iron salt is 30 mmol / L.

[0068] Performance testing:

[0069] The performance of the Zn||Zn symmetrical batteries of Example 1, Comparative Example 1, Comparative Example 2 and Comparative Example 3 was tested. -2 The current density and 1 mAh cm -2 Constant current charge and discharge tests were carried out under the area capacity.

[0070] like Figure 1The cycle time-voltage curves of a Zn|Zn symmetric cell using the electrolyte systems of Example 1 and Comparative Examples 1, 2, and 3 are shown. It can be seen that the addition of 0.005 mmol / L of sodium ferric 1-nitroso-2-naphthol-6-sulfonate to the electrolyte does not significantly change the cycle life of the Zn|Zn symmetric cell, indicating that at this concentration, the additive has no significant effect on the battery life. When the molar concentration of sodium ferric 1-nitroso-2-naphthol-6-sulfonate in the electrolyte is 30 mmol / L, the battery cycle life is approximately 800 h, indicating that while high concentrations of the additive can improve battery life, the effect is unsatisfactory. However, when the additive concentration is 0.05 mmol / L, the battery cycle life is extended to 3500 h, and the voltage fluctuation range is smaller, indicating that the addition of sodium ferric 1-nitroso-2-naphthol-6-sulfonate significantly improves the cycle life and cycling stability of the Zn|Zn symmetric cell.

[0071] like Figure 2 The XRD patterns of the Zn|Zn symmetric battery after 20 cycles in the electrolyte system of Example 1 and Comparative Example 1 are shown. Figure 2 It can be seen that before and after the addition of 1-nitroso-2-naphthol-6-sulfonic acid sodium iron salt to the electrolyte, the deposits on the surface of the negative electrode are all zinc, without any other substances, especially the iron species in 1-nitroso-2-naphthol-6-sulfonic acid sodium iron salt.

[0072] like Figure 3 The following is the SEM image of the Zn|Zn symmetric battery after 20 cycles in the electrolyte system of Example 1 and Comparative Example 1. Figure 3 a It can be seen that in the electrolyte without the addition of 1-nitroso-2-naphthol-6-sulfonic acid sodium iron salt (Comparative Example 1), a large number of dendrites were generated on the negative electrode surface of the Zn|Zn symmetric battery after multiple cycles; Figure 3 b It can be seen that in the electrolyte system with the addition of 1-nitroso-2-naphthol-6-sulfonic acid sodium iron salt (Example 1), the negative electrode surface of the Zn|Zn symmetrical battery is still dense and uniform, indicating that 1-nitroso-2-naphthol-6-sulfonic acid sodium iron salt has a significant inhibitory effect on the dendrite growth of the negative electrode.

[0073] Application Example 1:

[0074] At room temperature, dissolve 57.512 g of ZnSO₄•7H₂O and 0.0044 g of 1-nitroso-2-naphthol-6-sulfonic acid sodium ferric salt in pure water and dilute to 100 mL using a volumetric flask. This provides an aqueous zinc-ion battery electrolyte solution with a molar concentration of 2 mol / L zinc sulfate and 0.05 mmol / L sodium 1-nitroso-2-naphthol-6-sulfonic acid sodium ferric salt. A Zn∥Cu half-cell was prepared according to the above-described aqueous zinc-ion battery preparation steps.

[0075] Comparative application example 1:

[0076] The difference from Application Example 1 is that sodium 1-nitroso-2-naphthol-6-sulfonate iron salt is not added.

[0077] Performance testing:

[0078] The performance test was carried out using the aqueous zinc ion battery electrolyte in the Zn|Cu half-cell corresponding to the application example 1 and the comparative application example 1: the Zn|Cu half-cell was placed in the electrolyte system of the application example 1 and the comparative application example 1, and ... -2 The current density and 1 mAh cm -2 Constant current charge and discharge tests were carried out under the area capacity.

[0079] like Figure 4 The graph shows the cycle number-coulombic efficiency of the Zn|Cu half-cell in the electrolyte system of Application Example 1 and Comparative Application Example 1. Figure 4 It can be seen that after adding 1-nitroso-2-naphthol-6-sulfonic acid sodium iron salt to the electrolyte, the cycle number of the Zn‖Cu half-cell is significantly increased from 229 to 2500 cycles, and the coulombic efficiency is increased from 98.42% to 99.87%, indicating that the addition of 1-nitroso-2-naphthol-6-sulfonic acid sodium iron salt can significantly improve the cycle life and coulombic efficiency of the Zn‖Cu half-cell.

[0080] Application Example 2:

[0081] At room temperature, 57.512 g of ZnSO₄•7H₂O, 3.3802 g of manganese sulfate monohydrate, and 0.0044 g of 1-nitroso-2-naphthol-6-sulfonic acid sodium ferric salt were dissolved in pure water and the volume was adjusted to 100 mL using a volumetric flask. This prepared the aqueous zinc-ion battery electrolyte solution, where the molar concentration of zinc sulfate was 2 mol / L, the concentration of manganese sulfate was 0.2 mol / L, and the molar concentration of 1-nitroso-2-naphthol-6-sulfonic acid sodium ferric salt was 0.05 mmol / L. A Zn-MnO₂ full cell was prepared according to the above-mentioned preparation steps for aqueous zinc-ion batteries.

[0082] Comparative application example 2:

[0083] The difference from Application Example 2 is that sodium 1-nitroso-2-naphthol-6-sulfonate iron salt is not added.

[0084] Performance testing:

[0085] Performance testing was performed using the aqueous zinc ion battery electrolyte in Application Example 2 and Comparative Application Example 2 for the Zn-MnO2 full battery: the Zn-MnO2 full battery was placed in the electrolyte systems of Application Example 2 and Comparative Application Example 2, respectively, and constant current charge and discharge tests were performed at a current density of 0.2 A / g.

[0086] like Figure 5 The comparison chart of the cycle performance of the aqueous zinc ion full battery assembled under the electrolyte system of Application Example 2 and Comparative Application Example 2 is shown in FIG. Figure 5 It can be seen that after 250 cycles of testing, the specific capacity of the battery in Comparative Application Example 2 decays to 60 mAh / g, while the specific capacity of the battery in Application Example 2 increases to 373 mAh / g, indicating that the addition of 1-nitroso-2-naphthol-6-sulfonic acid sodium iron salt can significantly improve the battery capacity.

[0087] like Figure 6 As shown in the figure, in the electrolyte system of application example 2, an obvious Fe 2p peak was observed in the XPS graph of the positive electrode of the aqueous zinc ion battery after 20 cycles, indicating that Fe 3+ The ions can enter the active material of the positive electrode, thereby increasing the capacity of the battery.

[0088] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. An aqueous zinc ion battery, characterized in that: The aqueous zinc ion battery includes a positive electrode, a negative electrode, a separator and an electrolyte. The electrolyte includes pure water, a soluble zinc ion salt and an additive. The additive is 1-nitroso-2-naphthol-6-sulfonic acid sodium iron salt; the molar concentration of the 1-nitroso-2-naphthol-6-sulfonic acid sodium iron salt in the electrolyte is 0.01-20 mmol / L; the soluble zinc ion salt is one or more of zinc sulfate, zinc acetate, zinc chloride and zinc trifluoromethanesulfonate; and the positive electrode is manganese dioxide.

2. The aqueous zinc ion battery according to claim 1, wherein: The molar concentration of the sodium ferric 1-nitroso-2-naphthol-6-sulfonate in the electrolyte is 0.05 mmol / L.

3. The aqueous zinc ion battery according to claim 1, wherein: The soluble zinc ion salt is zinc sulfate.

4. The aqueous zinc ion battery according to claim 1, wherein: The molar concentration of the soluble zinc ion salt is 1-3 mol / L.

5. The aqueous zinc ion battery according to claim 1, wherein: The preparation method of the electrolyte comprises the following steps: adding a soluble zinc ion salt and an additive into pure water and dissolving them to obtain the electrolyte.

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