An alkaline zinc-air battery electrolyte and its preparation method, and an alkaline zinc-air battery.

Abstract

This invention relates to the field of metal-air battery technology, specifically to an alkaline zinc-air battery electrolyte and its preparation method, and an alkaline zinc-air battery. The alkaline zinc-air battery electrolyte comprises an aqueous hydroxide solution, a corrosion inhibitor, and a dendrite inhibitor. Zinc carboxylate salts can inhibit the activity of hydroxide ions in the electrolyte through strong coordination of carboxylate ions, thereby inhibiting the hydrogen evolution side reaction between hydroxide ions and the zinc plate and improving the corrosion resistance of the electrolyte. It can also adhere to the zinc anode surface to form a protective layer, thus achieving excellent corrosion inhibition. Glycine or glutamic acid, acting as a dendrite inhibitor, can chemically adsorb onto the zinc anode, thereby optimizing zinc diffusion and nucleation behavior. Therefore, the alkaline zinc-air battery electrolyte of this invention can improve the utilization rate of the zinc anode, thereby extending its lifespan, and can inhibit the growth of zinc anode dendrites during battery charging and discharging, further extending the anode's service life.

Description

Technical Field

[0001] This invention relates to the field of metal-air battery technology, specifically to an alkaline zinc-air battery electrolyte and its preparation method, and an alkaline zinc-air battery. Background Technology

[0002] With the development of society and the economy, human demand for environmental protection and energy is increasing, making the development of new green energy sources a top priority in the energy sector. In the battery field, lithium-ion batteries are currently the most widely used and applied type of battery in the world. However, lithium-ion batteries have long suffered from safety issues, low energy density (120-180Wh / kg), and the high price of lithium. To address these problems, researchers have developed metal-air batteries, which offer high energy density, low cost, and high safety. Zinc-air batteries, as one of the few rechargeable metal-air batteries, are gaining increasing favor among researchers.

[0003] The alkaline metal-air battery mainly consists of three parts: a metal anode, an air cathode, and an alkaline electrolyte. In the alkaline zinc-air battery, the metal anode is metallic zinc, and the air cathode is a waterproof and breathable membrane pressed onto a stainless steel mesh, with a precious metal catalyst coated on one side of the mesh. The traditional alkaline electrolyte is a potassium hydroxide solution. Finally, these three components are combined to form the alkaline zinc-air battery. Alkaline zinc-air batteries have many advantages, such as simple components, widely available and inexpensive zinc, good safety, flexible operation, and being environmentally friendly and pollution-free. Therefore, the alkaline zinc-air battery is a very promising battery.

[0004] However, while alkaline zinc-air batteries offer many advantages, the zinc anode requires a strongly alkaline electrolyte (potassium hydroxide solution) environment, which leads to a self-corroding hydrogen evolution side reaction, reducing the anode's utilization rate. Furthermore, during battery discharge, an oxygen reduction reaction occurs; a higher electrolyte pH provides a greater half-wave potential, thus improving the battery's electrochemical performance. However, dendrites grow more readily in alkaline environments, making dendrite suppression more difficult in strongly alkaline zinc-air batteries. Therefore, the uncontrolled dendrite growth during charge and discharge also reduces the zinc anode's lifespan. Summary of the Invention

[0005] To overcome the shortcomings of the prior art, the first objective of this invention is to provide an alkaline zinc-air battery electrolyte that can suppress the occurrence of hydrogen evolution side reactions, improve the utilization rate of zinc anodes, and suppress dendrite formation to extend the service life of anodes.

[0006] To overcome the shortcomings of the prior art, the second objective of this invention is to provide a method for preparing an alkaline zinc-air battery electrolyte, which is simple and has low production costs.

[0007] The third objective of this invention is to provide an alkaline zinc-air battery that can suppress the occurrence of hydrogen evolution side reactions, improve the utilization rate of zinc anodes, and suppress dendrite formation to extend the service life of anodes.

[0008] To achieve the first objective of the invention, the technical solution adopted by the present invention is as follows:

[0009] This invention provides an alkaline zinc-air battery electrolyte, comprising an aqueous hydroxide solution, a corrosion inhibitor, and a dendrite inhibitor;

[0010] The corrosion inhibitor is zinc carboxylate, and the dendrite inhibitor is glycine or glutamic acid.

[0011] This invention discloses an alkaline zinc-air battery electrolyte, comprising an aqueous hydroxide solution, a corrosion inhibitor, and a dendrite inhibitor. Since the corrosion inhibitor is a zinc carboxylate salt, in the alkaline electrolyte, carboxylate and hydroxide ions are anions that can coordinate with zinc cations in the electrolyte, and these coordination relationships are competitive. The zinc carboxylate salt can suppress hydroxide activity through the strong coordination of carboxylate ions with zinc ions in the electrolyte. Reducing hydroxide activity further inhibits the hydrogen evolution side reaction between hydroxide ions and the zinc plate, resulting in a higher electrochemical window. Furthermore, the zinc ions in the zinc carboxylate salt can increase the corrosion potential of the electrolyte, thereby improving its corrosion resistance. In addition, besides strong coordination with zinc ions, the carboxylate ions in the zinc carboxylate salt can also adhere to the zinc anode surface to form a protective layer. This protective layer effectively prevents the hydrogen evolution side reaction, thus providing excellent corrosion inhibition. Therefore, the action of zinc carboxylate corrosion inhibitors will suppress the hydrogen evolution side reaction during the charging and discharging process. Suppressing this self-corrosion reaction will improve the utilization rate of the zinc anode, thereby extending the life of the zinc anode.

[0012] Furthermore, since the dendrite inhibitors are glycine or glutamic acid, the nitrogen atom in the amino group of glycine and glutamic acid has strong electronegativity, enabling it to chemically adsorb onto the zinc anode, thereby optimizing zinc diffusion and nucleation behavior. Therefore, it can suppress the growth of zinc anode dendrites during battery charging and discharging, and extend the anode's lifespan by inhibiting dendrite formation through stable zinc deposition during charging.

[0013] Furthermore, the zinc carboxylate salt is one of zinc acetate, zinc gluconate, zinc propionate, or zinc oxalate. The carboxylate ions in zinc acetate, zinc gluconate, zinc propionate, or zinc oxalate can strongly coordinate with zinc ions in the electrolyte, thereby inhibiting the activity of hydroxide ions in the alkaline electrolyte, and thus suppressing the hydrogen evolution side reaction between hydroxide ions and the zinc plate. Moreover, the zinc ions in zinc acetate, zinc gluconate, zinc propionate, or zinc oxalate can significantly increase the corrosion potential of the electrolyte, thereby improving the corrosion resistance of the electrolyte.

[0014] Furthermore, the molar ratio of the corrosion inhibitor to the hydroxide is 1:(15-60). In this process, the hydroxide in the electrolyte provides a greater half-wave potential during the oxygen reduction reaction in the battery, thereby improving the battery's electrochemical performance. This molar ratio of corrosion inhibitor to hydroxide allows the zinc carboxylate salt to effectively suppress the hydrogen evolution side reaction without affecting the battery's electrochemical performance.

[0015] Furthermore, the molar ratio of the dendrite inhibitor to the hydroxide is 1:(60-120). This molar ratio of dendrite inhibitor to hydroxide enables the dendrite inhibitor to suppress the growth of zinc anode dendrites during battery charging and discharging, while not affecting the electrochemical performance of the battery.

[0016] Furthermore, the concentration of the aqueous hydroxide solution is 5 mol / L to 7 mol / L; and / or

[0017] The concentration of the corrosion inhibitor is 0.1 mol / L to 0.4 mol / L; and / or

[0018] The concentration of the dendrite inhibitor is 0.05 mol / L to 0.1 mol / L.

[0019] The concentration of the hydroxide aqueous solution ensures a suitable pH value for the electrolyte, thereby significantly improving the battery's electrochemical performance. Furthermore, the concentration of the corrosion inhibitor allows the zinc carboxylate salt to effectively suppress the hydrogen evolution side reaction without affecting the battery's electrochemical performance. Additionally, the concentration of the dendrite inhibitor suppresses the growth of zinc anode dendrites during battery charging and discharging without affecting the hydroxide's effect on the battery's electrochemical performance.

[0020] Furthermore, the aqueous hydroxide solution is either a potassium hydroxide solution or a sodium hydroxide solution. Both potassium hydroxide and sodium hydroxide solutions can make the electrolyte alkaline, and the provided hydroxide ions can improve the electrochemical performance of the battery.

[0021] To achieve the second objective of the invention, the technical solution adopted by the present invention is as follows:

[0022] This invention provides a method for preparing an alkaline zinc-air battery electrolyte, wherein a corrosion inhibitor and a dendrite inhibitor are added to an aqueous hydroxide solution and stirred until homogeneous to obtain the alkaline zinc-air battery electrolyte.

[0023] The present invention discloses a method for preparing an alkaline zinc-air battery electrolyte, which is environmentally friendly, simple, low in production cost, and highly efficient, making it suitable for large-scale production.

[0024] To achieve the third objective of the invention, the technical solution adopted by the present invention is as follows:

[0025] This invention provides an alkaline zinc-air battery, comprising an air electrode and a metallic zinc electrode, and also employing the alkaline zinc-air battery electrolyte described above.

[0026] This invention discloses an alkaline zinc-air battery. The alkaline zinc-air battery electrolyte comprises an aqueous hydroxide solution, a corrosion inhibitor, and a dendrite inhibitor. The corrosion inhibitor is a zinc carboxylate, and the dendrite inhibitor is glycine or glutamic acid. Therefore, on the one hand, the zinc carboxylate corrosion inhibitor suppresses the hydrogen evolution side reaction during charging and discharging, thereby inhibiting this self-corrosion reaction and improving the utilization rate of the zinc anode, thus extending its lifespan. On the other hand, the glycine or glutamic acid inhibits the growth of zinc anode dendrites during charging and discharging. Through stable zinc deposition during charging, dendrite formation is suppressed, thereby extending the anode's lifespan.

[0027] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0028] (1) An alkaline zinc-air battery electrolyte of the present invention comprises an aqueous hydroxide solution, a corrosion inhibitor, and a dendrite inhibitor. Since the corrosion inhibitor is a zinc carboxylate salt, carboxylate and hydroxide ions are anions in the alkaline electrolyte and can coordinate with zinc cations in the electrolyte, and the carboxylate and hydroxide ions have a competitive coordination relationship. The zinc carboxylate salt can inhibit the activity of hydroxide ions by strongly coordinating the carboxylate ions with zinc ions in the electrolyte. Reducing the activity of hydroxide ions can inhibit the hydrogen evolution side reaction between hydroxide ions and the zinc plate, resulting in a higher electrochemical window. Furthermore, the zinc ions in the zinc carboxylate salt can increase the corrosion potential of the electrolyte, thereby improving the corrosion resistance of the electrolyte. In addition, besides strongly coordinating with zinc ions, the carboxylate ions in the zinc carboxylate salt can also adhere to the zinc anode surface to form a protective layer. This protective layer can effectively prevent the hydrogen evolution side reaction from occurring, thus achieving excellent corrosion inhibition. Therefore, the zinc carboxylate corrosion inhibitor suppresses the hydrogen evolution side reaction during charge and discharge, thus inhibiting this self-corrosion reaction and improving the utilization rate of the zinc anode, thereby extending its lifespan. Furthermore, since the dendrite inhibitors are glycine or glutamic acid, the nitrogen atoms in the amino groups of glycine and glutamic acid have strong electronegativity, enabling them to chemically adsorb onto the zinc anode, thereby optimizing zinc diffusion and nucleation behavior. Therefore, it can suppress the growth of zinc anode dendrites during battery charge and discharge, and through stable zinc deposition during charging, inhibit dendrite formation, thereby extending the anode's lifespan.

[0029] (2) The method for preparing an alkaline zinc-air battery electrolyte of the present invention is green and environmentally friendly, simple in process, low in production cost, high in production efficiency, and suitable for large-scale production.

[0030] (3) An alkaline zinc-air battery of the present invention uses an alkaline zinc-air battery electrolyte comprising an aqueous hydroxide solution, a corrosion inhibitor, and a dendrite inhibitor; wherein the corrosion inhibitor is a zinc carboxylate and the dendrite inhibitor is glycine or glutamic acid. Therefore, on the one hand, the zinc carboxylate corrosion inhibitor can suppress the hydrogen evolution side reaction during charging and discharging, and suppressing this self-corrosion reaction will improve the utilization rate of the zinc anode, thereby extending the lifespan of the zinc anode. On the other hand, glycine or glutamic acid can suppress the growth of zinc anode dendrites during battery charging and discharging, and through the stable deposition of zinc during charging, the generation of dendrites is suppressed, thereby extending the lifespan of the anode. Attached Figure Description

[0031] To more clearly illustrate the technical solutions in the embodiments of the present invention, 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 of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0032] Figure 1 This is a Tafel polarization curve of the electrolytes prepared in Examples 1, 2, 1, and 2 of the present invention.

[0033] Figure 2 This is a Tafel polarization curve of zinc acetate electrolyte at different concentrations.

[0034] Figure 3 This is a Tafel polarization curve of zinc gluconate electrolyte at different concentrations.

[0035] Figure 4 This is a cycle life curve of a zinc symmetric battery using the blank electrolyte solution of Comparative Example 1.

[0036] Figure 5 This is a cycle life curve of a zinc symmetric battery using the 0.2 mol / L zinc acetate electrolyte of Comparative Example 2.

[0037] Figure 6 This is a cycle life curve of a zinc symmetric battery using the alkaline zinc-air battery electrolyte of Example 1.

[0038] Figure 7 This is a cycle life curve of a zinc symmetric battery using the alkaline zinc-air battery electrolyte of Example 4. Detailed Implementation

[0039] To make the technical problem to be solved, the technical solution, and the beneficial effects of the present invention clearer, the present invention will be further described in detail below with reference to embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present invention and are not intended to limit the present invention.

[0040] The terminology used in the embodiments of this invention is for the purpose of describing particular embodiments only and is not intended to limit the invention. The singular forms “a,” “the,” and “the” used in this invention, the embodiments, and the appended claims are also intended to include the plural forms unless the context clearly indicates otherwise.

[0041] In this embodiment of the invention, an alkaline zinc-air battery electrolyte includes an aqueous hydroxide solution, a corrosion inhibitor, and a dendrite inhibitor.

[0042] The corrosion inhibitor is zinc carboxylate, and the dendrite inhibitor is glycine or glutamic acid.

[0043] An alkaline zinc-air battery electrolyte in this embodiment includes an aqueous hydroxide solution, a corrosion inhibitor, and a dendrite inhibitor. Since the corrosion inhibitor is a zinc carboxylate salt, in the alkaline electrolyte, carboxylate and hydroxide ions are anions that can coordinate with zinc cations in the electrolyte, and these coordination relationships are competitive. The zinc carboxylate salt can inhibit hydroxide activity through the strong coordination of carboxylate ions with zinc ions in the electrolyte. Reducing hydroxide activity further inhibits the hydrogen evolution side reaction between hydroxide ions and the zinc plate, resulting in a higher electrochemical window. Furthermore, the zinc ions in the zinc carboxylate salt can increase the corrosion potential of the electrolyte, thereby improving its corrosion resistance. In addition, besides strong coordination with zinc ions, the carboxylate ions in the zinc carboxylate salt can also adhere to the zinc anode surface to form a protective layer. This protective layer effectively prevents the hydrogen evolution side reaction, thus providing excellent corrosion inhibition. Therefore, the action of zinc carboxylate corrosion inhibitors will suppress the hydrogen evolution side reaction during the charging and discharging process. Suppressing this self-corrosion reaction will improve the utilization rate of the zinc anode, thereby extending the life of the zinc anode.

[0044] Furthermore, since the dendrite inhibitors are glycine or glutamic acid, the nitrogen atom in the amino group of glycine and glutamic acid has strong electronegativity, enabling it to chemically adsorb onto the zinc anode, thereby optimizing zinc diffusion and nucleation behavior. Therefore, it can suppress the growth of zinc anode dendrites during battery charging and discharging, and extend the anode's lifespan by inhibiting dendrite formation through stable zinc deposition during charging.

[0045] In some embodiments, the zinc carboxylate salt is one of zinc acetate, zinc gluconate, zinc propionate, or zinc oxalate. The carboxylate ions in zinc acetate, zinc gluconate, zinc propionate, or zinc oxalate can strongly coordinate with zinc ions in the electrolyte, thereby inhibiting the activity of hydroxide ions in the alkaline electrolyte, and thus suppressing the hydrogen evolution side reaction between hydroxide ions and the zinc plate. Furthermore, the zinc ions in zinc acetate, zinc gluconate, zinc propionate, or zinc oxalate can significantly increase the corrosion potential of the electrolyte, thereby improving the corrosion resistance of the electrolyte.

[0046] In some embodiments, the molar ratio of the corrosion inhibitor to the hydroxide is 1:(15-60). In this process, the hydroxide in the electrolyte provides a greater half-wave potential during the oxygen reduction reaction in the battery, thereby improving the battery's electrochemical performance. This molar ratio of corrosion inhibitor to hydroxide allows the zinc carboxylate salt to effectively suppress the hydrogen evolution side reaction without affecting the battery's electrochemical performance.

[0047] In some embodiments, the molar ratio of the dendrite inhibitor to the hydroxide is 1:(60-120). This molar ratio of dendrite inhibitor to hydroxide enables the dendrite inhibitor to suppress the growth of zinc anode dendrites during battery charging and discharging, while not affecting the electrochemical performance of the battery.

[0048] In some embodiments, the concentration of the aqueous hydroxide solution is 5 mol / L to 7 mol / L; and / or

[0049] The concentration of the corrosion inhibitor is 0.1 mol / L to 0.4 mol / L; and / or

[0050] The concentration of the dendrite inhibitor is 0.05 mol / L to 0.1 mol / L.

[0051] The concentration of the hydroxide aqueous solution ensures a suitable pH value for the electrolyte, thereby significantly improving the battery's electrochemical performance. Furthermore, the concentration of the corrosion inhibitor allows the zinc carboxylate salt to effectively suppress the hydrogen evolution side reaction without affecting the battery's electrochemical performance. Additionally, the concentration of the dendrite inhibitor suppresses the growth of zinc anode dendrites during battery charging and discharging without affecting the hydroxide's effect on the battery's electrochemical performance.

[0052] In some embodiments, the aqueous hydroxide solution is an aqueous solution of potassium hydroxide or sodium hydroxide. Both the aqueous solution of potassium hydroxide and sodium hydroxide can make the electrolyte alkaline, and the hydroxide ions provided can improve the electrochemical performance of the battery.

[0053] In this embodiment of the invention, a method for preparing an alkaline zinc-air battery electrolyte involves adding a corrosion inhibitor and a dendrite inhibitor to an aqueous hydroxide solution and stirring until homogeneous to obtain the alkaline zinc-air battery electrolyte.

[0054] The method for preparing an alkaline zinc-air battery electrolyte in this embodiment is characterized by its green and environmentally friendly preparation process, simple technology, low production cost, high production efficiency, and suitability for large-scale production.

[0055] In this embodiment of the invention, an alkaline zinc-air battery includes an air electrode and a metallic zinc electrode, and also uses the alkaline zinc-air battery electrolyte described above.

[0056] One embodiment of the alkaline zinc-air battery utilizes an alkaline zinc-air battery electrolyte comprising an aqueous hydroxide solution, a corrosion inhibitor, and a dendrite inhibitor. The corrosion inhibitor is a zinc carboxylate, and the dendrite inhibitor is glycine or glutamic acid. Therefore, on one hand, the zinc carboxylate corrosion inhibitor suppresses the hydrogen evolution side reaction during charging and discharging, thereby inhibiting this self-corrosion reaction and improving the utilization rate of the zinc anode, thus extending its lifespan. On the other hand, the glycine or glutamic acid inhibits the growth of zinc anode dendrites during charging and discharging, and the stable deposition of zinc during charging suppresses dendrite formation, thereby extending the anode's lifespan.

[0057] The following description is based on specific embodiments.

[0058] Example 1

[0059] An alkaline zinc-air battery electrolyte includes an aqueous potassium hydroxide solution, a corrosion inhibitor, and a dendrite inhibitor; wherein the corrosion inhibitor is a zinc carboxylate, and in this embodiment, the zinc carboxylate is zinc acetate; and the dendrite inhibitor is glycine.

[0060] In this embodiment, the concentration of potassium hydroxide aqueous solution is 6 mol / L; the concentration of zinc acetate is 0.2 mol / L; and the concentration of glycine is 0.1 mol / L.

[0061] In this embodiment, the molar ratio of zinc acetate to potassium hydroxide is 1:30. The molar ratio of glycine to potassium hydroxide is 1:80.

[0062] The above-mentioned method for preparing an alkaline zinc-air battery electrolyte involves adding a corrosion inhibitor and a dendrite inhibitor to an aqueous hydroxide solution and stirring until homogeneous to obtain the alkaline zinc-air battery electrolyte.

[0063] Example 2

[0064] An alkaline zinc-air battery electrolyte is disclosed. The difference between this embodiment and Example 1 is that the dendrite inhibitor in this embodiment is glutamic acid, while the remaining components and preparation method are the same as in Example 1.

[0065] Example 3

[0066] An alkaline zinc-air battery electrolyte is disclosed. The difference between this embodiment and Example 1 is that the corrosion inhibitor in this embodiment is zinc gluconate, while the remaining components and preparation method are the same as in Example 1.

[0067] Example 4

[0068] An alkaline zinc-air battery electrolyte is described in this embodiment, which differs from Example 1 in that the concentration of glycine is 0.05 mol / L, while the remaining components and preparation method are the same as in Example 1.

[0069] Example 5

[0070] An alkaline zinc-air battery electrolyte includes an aqueous potassium hydroxide solution, a corrosion inhibitor, and a dendrite inhibitor; wherein the corrosion inhibitor is a zinc carboxylate, and in this embodiment, the zinc carboxylate is zinc propionate; and the dendrite inhibitor is glycine.

[0071] In this embodiment, the concentration of potassium hydroxide aqueous solution is 5 mol / L; the concentration of zinc propionate is 0.1 mol / L; and the concentration of glycine is 0.05 mol / L.

[0072] In this embodiment, the molar ratio of zinc propionate to potassium hydroxide is 1:15. The molar ratio of glycine to potassium hydroxide is 1:60.

[0073] The above-mentioned method for preparing an alkaline zinc-air battery electrolyte involves adding a corrosion inhibitor and a dendrite inhibitor to an aqueous hydroxide solution and stirring until homogeneous to obtain the alkaline zinc-air battery electrolyte.

[0074] Example 6

[0075] An alkaline zinc-air battery electrolyte includes an aqueous potassium hydroxide solution, a corrosion inhibitor, and a dendrite inhibitor; wherein the corrosion inhibitor is a zinc carboxylate, and in this embodiment, the zinc carboxylate is zinc oxalate; and the dendrite inhibitor is glutamic acid.

[0076] In this embodiment, the concentration of potassium hydroxide aqueous solution is 7 mol / L; the concentration of zinc oxalate is 0.4 mol / L; and the concentration of glutamic acid is 0.1 mol / L.

[0077] In this embodiment, the molar ratio of zinc oxalate to potassium hydroxide is 1:60. The molar ratio of glutamic acid to potassium hydroxide is 1:120.

[0078] The above-mentioned method for preparing an alkaline zinc-air battery electrolyte involves adding a corrosion inhibitor and a dendrite inhibitor to an aqueous hydroxide solution and stirring until homogeneous to obtain the alkaline zinc-air battery electrolyte.

[0079] Example 7

[0080] An alkaline zinc-air battery electrolyte includes an aqueous potassium hydroxide solution, a corrosion inhibitor, and a dendrite inhibitor; wherein the corrosion inhibitor is a zinc carboxylate, and in this embodiment, the zinc carboxylate is zinc acetate; and the dendrite inhibitor is glycine.

[0081] In this embodiment, the concentration of potassium hydroxide aqueous solution is 7 mol / L; the concentration of zinc acetate is 0.3 mol / L; and the concentration of glycine is 0.08 mol / L.

[0082] In this embodiment, the molar ratio of zinc acetate to potassium hydroxide is 1:25. The molar ratio of glycine to potassium hydroxide is 1:100.

[0083] The above-mentioned method for preparing an alkaline zinc-air battery electrolyte involves adding a corrosion inhibitor and a dendrite inhibitor to an aqueous hydroxide solution and stirring until homogeneous to obtain the alkaline zinc-air battery electrolyte.

[0084] Example 8

[0085] An alkaline zinc-air battery electrolyte includes an aqueous potassium hydroxide solution, a corrosion inhibitor, and a dendrite inhibitor; wherein the corrosion inhibitor is a zinc carboxylate, and in this embodiment, the zinc carboxylate is zinc gluconate; and the dendrite inhibitor is glutamic acid.

[0086] In this embodiment, the concentration of potassium hydroxide aqueous solution is 5 mol / L; the concentration of zinc gluconate is 0.3 mol / L; and the concentration of glutamic acid is 0.07 mol / L.

[0087] In this embodiment, the molar ratio of zinc gluconate to potassium hydroxide is 1:40. The molar ratio of glutamic acid to potassium hydroxide is 1:80.

[0088] The above-mentioned method for preparing an alkaline zinc-air battery electrolyte involves adding a corrosion inhibitor and a dendrite inhibitor to an aqueous hydroxide solution and stirring until homogeneous to obtain the alkaline zinc-air battery electrolyte.

[0089] Example 9

[0090] An alkaline zinc-air battery electrolyte is disclosed. The difference between this embodiment and Embodiment 1 is that an aqueous solution of sodium hydroxide is used instead of an aqueous solution of potassium hydroxide in this embodiment, while the remaining components and preparation method are the same as in Embodiment 1.

[0091] Example 10

[0092] An alkaline zinc-air battery includes an air electrode and a metallic zinc electrode, and also uses any one of the alkaline zinc-air battery electrolytes from Examples 1 to 9.

[0093] Comparative Example 1

[0094] An electrolyte is provided. The difference between this comparative example and Example 1 is that this comparative example uses 6 mol / L potassium hydroxide as a blank solution, which is used as a control electrolyte.

[0095] Comparative Example 2

[0096] A zinc acetate electrolyte is provided. This comparative example differs from Example 1 in that the zinc acetate electrolyte in this example is prepared by adding 0.2 mol / L zinc acetate to 6 mol / L potassium hydroxide. The molar ratio of zinc acetate to potassium hydroxide is the same as in Example 1.

[0097] Comparative Example 3

[0098] A zinc acetate electrolyte is prepared by adding zinc acetate of different concentrations to five portions of 6 mol / L potassium hydroxide solution, wherein the zinc acetate concentrations are 0 mol / L, 0.1 mol / L, 0.2 mol / L, 0.3 mol / L, and 0.4 mol / L, respectively.

[0099] Comparative Example 4

[0100] A zinc gluconate electrolyte is prepared by adding zinc gluconate of different concentrations to five portions of 6 mol / L potassium hydroxide solution, wherein the zinc gluconate concentrations are 0 mol / L, 0.1 mol / L, 0.2 mol / L, 0.3 mol / L, and 0.4 mol / L, respectively.

[0101] Experimental testing

[0102] (I) Effect of dendrite inhibitor addition on the corrosion resistance of electrolyte

[0103] The electrolytes prepared in Examples 1, 2, Comparative Example 1, and Comparative Example 2 (with Comparative Example 1 serving as a blank electrolyte) were poured into different electrolytic cells, and Tafel polarization curves were tested using a three-electrode system. The test results are available in [reference needed]. Figure 1 .

[0104] Depend on Figure 1 The test results can yield their corrosion current and equilibrium voltage data, and the specific experimental data results are shown in Table 1.

[0105] Table 1. Test results of Tafel polarization curves for Examples 1, 2, Comparative Examples 1 and 2.

[0106]

[0107] As shown in Table 1, the addition of glycine or glutamic acid dendrite inhibitors does not affect the corrosion resistance of the electrolyte.

[0108] (II) Effect of different concentrations of zinc acetate on improving the performance of alkaline electrolytes

[0109] Five zinc acetate electrolytes of different concentrations prepared in Comparative Example 3 were poured into an electrolytic cell, and Tafel polarization curves were tested using a three-electrode system to obtain corrosion current and equilibrium voltage. The counter electrode of the three-electrode system was a platinum electrode, the reference electrode was a 3.5M silver chloride electrode, and the working electrode had an exposure area of ​​2 cm². 2 The zinc plate. Please refer to the test results. Figure 2 .

[0110] Depend on Figure 2 The corrosion current and equilibrium voltage data of the five samples were obtained from the Tafel polarization curve test results. The specific experimental data results are shown in Table 2.

[0111] Table 2. Tafel polarization curve test results for zinc acetate additives at different concentrations.

[0112] additive Balance voltage V Corrosion current mA Corrosion inhibition efficiency % blank solution -1.623 0.001011 / +0.1 mol / L zinc acetate -1.552 0.001031 -2.01 +0.2 mol / L zinc acetate -1.534 0.0009283 8.16 +0.3 mol / L zinc acetate -1.520 0.0008551 15.40 +0.4 mol / L zinc acetate -1.509 0.0008571 15.20

[0113] As shown in Table 2, a zinc acetate concentration of 0.2 mol / L significantly inhibits the hydrogen evolution side reaction. This demonstrates that adding zinc acetate to the electrolyte can improve the performance of alkaline electrolytes.

[0114] (III) Effect of different concentrations of zinc gluconate on improving the corrosion resistance of alkaline electrolyte

[0115] Five zinc gluconate electrolytes of different concentrations prepared in Comparative Example 4 were subjected to Tafel polarization curve testing to obtain corrosion current and equilibrium voltage. The test results are available in the [link to test results]. Figure 3 .

[0116] Depend on Figure 3 The corrosion current and equilibrium voltage data of the five samples were obtained from the Tafel polarization curve test results. The specific experimental data results are shown in Table 3.

[0117] Table 3. Test results of Tafel polarization curves for zinc gluconate additives at different concentrations.

[0118] additive Balance voltage V Corrosion current mA Corrosion inhibition efficiency % blank solution -1.611 0.001152 / +0.1 mol / L zinc gluconate -1.553 0.0009723 15.60 +0.2 mol / L zinc gluconate -1.537 0.0009974 13.42 +0.3 mol / L zinc gluconate -1.526 0.0009853 14.47 +0.4 mol / L zinc gluconate -1.516 0.0009820 14.76

[0119] As can be seen from Table 3, zinc gluconate at various concentrations can exhibit good anti-corrosion performance against alkaline electrolytes.

[0120] (iv) Zinc acetate addition test cyclic charge-discharge experiment

[0121] The electrolytes obtained from Comparative Example 1 (blank solution of 6 mol / L potassium hydroxide) and Comparative Example 2 (zinc acetate electrolyte of 6 mol / L potassium hydroxide + 0.2 mol / L zinc acetate) were respectively added to a zinc symmetric battery for cyclic charge-discharge experiments. The zinc plate area during discharge was 2 cm². 2 The current density is 10 mA cm⁻¹ -2 The discharge capacity is 1mAh cm⁻¹ -2 .

[0122] The cycle life curve of the zinc symmetric cell using the blank electrolyte of Comparative Example 1 is shown below. Figure 4 As shown in the figure, the cycle life curve of the zinc symmetric cell using the 0.2 mol / L zinc acetate electrolyte of Comparative Example 2 is shown in the figure. Figure 5 As shown.

[0123] Depend on Figure 4 and Figure 5 It can be seen that the cycle life of the zinc symmetric cell with the blank solution is 16 cycles, while the zinc acetate electrolyte with 0.2 mol / L zinc acetate has a cycle life of over 150 cycles. This indicates that the addition of zinc acetate can suppress the occurrence of hydrogen evolution side reactions, thereby improving the utilization rate of the Zn anode during discharge and enhancing the performance of the zinc-air battery.

[0124] (V) Cyclic charge-discharge test with different concentrations of glycine.

[0125] The alkaline zinc-air battery electrolytes prepared in Examples 1 and 4 were used as electrolytes for zinc symmetric batteries. Cyclic charge-discharge experiments were then conducted on the zinc symmetric batteries, with the discharge zinc plate area being 2 cm². 2 The current density is 10 mA / cm². -2 The discharge capacity is 1mAh cm⁻¹ -2 .

[0126] The cycle life curve of the zinc symmetric battery using the alkaline zinc-air battery electrolyte of Example 1 is shown in the figure. Figure 6 As shown in the figure, the cycle life curve of a zinc symmetric battery using the alkaline zinc-air battery electrolyte of Example 4 is as follows. Figure 7 As shown.

[0127] Depend on Figure 6 and Figure 7It can be seen that the alkaline zinc-air battery electrolyte prepared in Example 1 increased the cycle life of the zinc symmetric battery to 269 cycles (0.1 mol / L glycine), and the alkaline zinc-air battery electrolyte prepared in Example 4 increased the cycle life of the zinc symmetric battery to 240 cycles (0.05 mol / L glycine). This indicates that the introduction of glycine can inhibit dendrite growth. By stably depositing zinc during charging, dendrite formation is inhibited, thereby extending the anode's lifespan. Similarly, the introduction of glutamic acid can also inhibit dendrite growth (experimental data omitted).

[0128] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. An alkaline zinc-air battery electrolyte, characterized in that, Including aqueous hydroxide solutions, corrosion inhibitors, and dendrite inhibitors; The corrosion inhibitor is zinc carboxylate, and the dendrite inhibitor is glycine or glutamic acid; The molar ratio of the corrosion inhibitor to the hydroxide is 1:(15~60). The molar ratio of the dendrite inhibitor to the hydroxide is 1:(60~120). The concentration of the corrosion inhibitor is 0.1 mol / L to 0.4 mol / L.

2. The alkaline zinc-air battery electrolyte as described in claim 1, characterized in that, The zinc carboxylate salt is one of zinc acetate, zinc gluconate, zinc propionate, or zinc oxalate.

3. The alkaline zinc-air battery electrolyte as described in claim 1, characterized in that, The concentration of the hydroxide aqueous solution is 5 mol / L to 7 mol / L; and / or The concentration of the dendrite inhibitor is 0.05 mol / L to 0.1 mol / L.

4. The alkaline zinc-air battery electrolyte as described in claim 1, characterized in that, The aqueous hydroxide solution is either a potassium hydroxide solution or a sodium hydroxide solution.

5. A method for preparing an alkaline zinc-air battery electrolyte according to any one of claims 1 to 4, characterized in that, The alkaline zinc-air battery electrolyte is prepared by adding corrosion inhibitors and dendrite inhibitors to an aqueous hydroxide solution and stirring until homogeneous.

6. An alkaline zinc-air battery, comprising an air electrode and a metallic zinc electrode, characterized in that, It also uses an alkaline zinc-air battery electrolyte as described in any one of claims 1 to 4.

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