Alkaline zinc-air battery electrolyte, preparation method thereof and alkaline zinc-air battery

Abstract

The invention relates to the technical field of metal-air batteries, in particular to an alkaline zinc-air battery electrolyte, a preparation method thereof and an alkaline zinc-air battery, the alkaline zinc-air battery electrolyte comprises a hydroxide aqueous solution, a corrosion inhibitor and a dendritic crystal inhibitor, the zinc carboxylate can inhibit the activity of hydroxyl through strong coordination of carboxylate radicals to zinc ions in the electrolyte, further inhibits the hydrogen evolution side reaction of the hydroxyl and a zinc plate, improves the corrosion resistance of the electrolyte, can also be attached to the surface of a zinc anode to form a protective layer, and further plays an excellent corrosion inhibition effect. Glycine or glutamic acid is used as a dendritic crystal inhibitor and can perform chemical adsorption with a zinc anode, so that zinc diffusion and zinc nucleation behaviors are optimized. Therefore, the alkaline zinc-air battery electrolyte provided by the invention can improve the utilization rate of the zinc anode, thereby prolonging the service life of the zinc anode, and can inhibit the growth of zinc anode dendrites in the charging and discharging process of the battery, thereby further prolonging the service life of the anode.

Description

Technical Field

[0001] The present invention relates to the technical field of metal-air batteries, and in particular to an alkaline zinc-air battery electrolyte and a preparation method thereof, and an alkaline zinc-air battery. Background Art

[0002] With the development of social economy, human beings have higher and higher demands for environmental protection and energy. The task of developing new green energy is the primary task in the current energy field. In the field of batteries, the most widely used and applied battery in the world is lithium battery. However, lithium batteries have always had problems with safety, low energy density (120-180Wh / kg) and high lithium prices. In order to solve these problems, researchers have developed metal-air batteries with high energy density, low cost and high safety. Zinc-air batteries, as one of the few rechargeable metal-air batteries, are favored by more and more researchers.

[0003] Among them, alkaline metal air batteries are mainly composed of three parts, metal anode, air cathode and alkaline electrolyte. The metal anode of alkaline zinc air battery is metal zinc, the air cathode is a waterproof and breathable membrane pressed on a stainless steel mesh, and then a precious metal catalyst is coated on one side of the stainless steel mesh. The traditional alkaline electrolyte is potassium hydroxide solution. Finally, the three are combined to form an alkaline zinc air battery. Alkaline zinc air batteries have many advantages, such as simple components, a wide range of metal zinc sources and low prices, good safety, flexible operation, green and pollution-free, etc. Therefore, alkaline zinc air batteries are a very potential battery.

[0004] However, although alkaline zinc-air batteries have many advantages, since the zinc anode needs to work in a strong alkaline electrolyte (potassium hydroxide solution), self-corrosion hydrogen evolution side reaction will occur, thereby reducing the utilization rate of the zinc anode. In addition, oxygen reduction reaction will occur when the battery is discharged. The higher the pH value of the electrolyte, the more half-wave potential it can provide, thereby improving the electrochemical performance of the battery. However, dendrites grow more easily in an alkaline environment, so it is more difficult to suppress dendrites in zinc-air batteries with strong alkaline electrolytes. Therefore, the uncontrollable growth of dendrites during the charge and discharge process of the battery also reduces the service life of the zinc anode. Summary of the invention

[0005] In order to overcome the shortcomings of the prior art, the first object of the present invention is to provide an alkaline zinc-air battery electrolyte, which can inhibit the occurrence of hydrogen evolution side reaction, improve the utilization rate of zinc anode, and at the same time inhibit the generation of dendrites to extend the service life of the anode.

[0006] In order to overcome the shortcomings of the prior art, the second object of the present invention is to provide a method for preparing an alkaline zinc-air battery electrolyte, which is simple and has low production cost.

[0007] The third object of the present invention is to provide an alkaline zinc-air battery, which can inhibit the occurrence of hydrogen evolution side reaction, improve the utilization rate of zinc anode, and inhibit the generation of dendrites to extend the service life of the anode.

[0008] In order to achieve the first object of the above invention, the technical solution adopted by the present invention is as follows:

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

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

[0011] An alkaline zinc-air battery electrolyte of the present invention comprises a hydroxide aqueous solution, a corrosion inhibitor and a dendrite inhibitor. Since the corrosion inhibitor is a carboxylate zinc salt, carboxylates and hydroxides are anions in the alkaline electrolyte and can coordinate with zinc cations in the electrolyte, and the carboxylates and hydroxides are in a competitive coordination relationship. The carboxylate zinc salt can inhibit the activity of hydroxides by strongly coordinating the zinc ions in the electrolyte with carboxylates. Reducing the activity of hydroxides can inhibit the hydrogen evolution side reaction between hydroxides and zinc plates, which will bring a higher electrochemical window. In addition, the zinc ions in the carboxylate zinc salt can increase the corrosion potential of the electrolyte, thereby improving the corrosion resistance of the electrolyte. In addition, in addition to being able to strongly coordinate with zinc ions, the carboxylates in the carboxylate zinc salt can also adhere to the surface of the zinc anode to form a protective layer. This protective layer can effectively prevent the occurrence of the hydrogen evolution side reaction, thereby achieving an excellent corrosion inhibition effect. Therefore, the role of zinc carboxylate corrosion inhibitors will inhibit the hydrogen evolution side reaction during the charge and discharge process. Inhibiting this self-corrosion reaction will increase the utilization rate of the zinc anode, thereby increasing the life of the zinc anode.

[0012] In addition, since the dendrite inhibitor is glycine or glutamic acid, the nitrogen atom in the amino group of glycine and glutamic acid has a strong electronegativity and can be chemically adsorbed with the zinc anode, thereby optimizing zinc diffusion and zinc nucleation behavior. Therefore, the growth of zinc anode dendrites can be inhibited during the battery charging and discharging process, and the formation of dendrites can be inhibited by the stable deposition of zinc during charging, thereby extending the service life of the anode.

[0013] Further, the carboxylate zinc salt is one of zinc acetate, zinc gluconate, zinc propionate or zinc oxalate. Among them, the carboxylates in zinc acetate, zinc gluconate, zinc propionate or zinc oxalate can strongly coordinate the zinc ions in the electrolyte to inhibit the activity of the hydroxide in the alkaline electrolyte, and then inhibit the hydrogen evolution side reaction of the hydroxide and the zinc plate. In addition, the zinc ions in zinc acetate, zinc gluconate, zinc propionate or zinc oxalate can well improve 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 the battery oxygen reduction reaction, the hydroxide in the electrolyte can provide more half-wave potential, thereby improving the electrochemical performance of the battery. The molar ratio of the corrosion inhibitor to the hydroxide can, on the one hand, enable the corrosion inhibitor zinc carboxylate salt to play a good role in inhibiting the hydrogen evolution side reaction, and on the other hand, does not affect the electrochemical performance of the battery.

[0015] Furthermore, the molar ratio of the dendrite inhibitor to the hydroxide is 1:(60-120). The molar ratio of the dendrite inhibitor to the hydroxide can, on the one hand, enable the dendrite inhibitor to inhibit the growth of zinc anode dendrites during the battery charge and discharge process, and on the other hand, does not affect the electrochemical performance of the hydroxide on the battery.

[0016] Further, the concentration of the hydroxide aqueous 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] Among them, the concentration of the hydroxide aqueous solution can make the electrolyte have a suitable pH value, thereby greatly improving the electrochemical performance of the battery. In addition, the concentration of the corrosion inhibitor can make the corrosion inhibitor carboxylate zinc salt play a good role in inhibiting the hydrogen evolution side reaction, while not affecting the electrochemical performance of the battery. In addition, the concentration of the dendrite inhibitor makes the dendrite inhibitor inhibit the growth of zinc anode dendrites during the battery charging and discharging process, while not affecting the electrochemical performance of the battery by the hydroxide.

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

[0021] In order to achieve the second purpose of the above invention, the technical solution adopted by the present invention is as follows:

[0022] The invention provides a method for preparing an alkaline zinc-air battery electrolyte. A corrosion inhibitor and a dendrite inhibitor are added into a hydroxide aqueous solution and stirred evenly to prepare the alkaline zinc-air battery electrolyte.

[0023] The invention discloses a method for preparing an alkaline zinc-air battery electrolyte, which has the characteristics of being green and environmentally friendly in preparation process, simple in process, low in production cost, high in production efficiency and suitable for large-scale production.

[0024] In order to achieve the third purpose of the above invention, the technical solution adopted by the present invention is as follows:

[0025] The invention provides an alkaline zinc-air battery, comprising an air electrode and a metal zinc electrode, and also adopts the alkaline zinc-air battery electrolyte described above.

[0026] An alkaline zinc-air battery of the present invention adopts an alkaline zinc-air battery electrolyte, which includes a hydroxide aqueous solution, a corrosion inhibitor and a dendrite inhibitor; and the corrosion inhibitor is a carboxylic acid zinc salt, and the dendrite inhibitor is glycine or glutamic acid. Therefore, on the one hand, the hydrogen evolution side reaction during the charging and discharging process can be inhibited by the action of the carboxylic acid zinc salt corrosion inhibitor, and inhibiting this self-corrosion reaction will increase the utilization rate of the zinc anode, thereby increasing the life of the zinc anode. On the other hand, glycine or glutamic acid can be used to inhibit the growth of zinc anode dendrites during the battery charging and discharging process, and the formation of dendrites can be inhibited by the stable deposition of zinc during charging, thereby extending the service life of the anode.

[0027] Compared with the prior art, the present invention has the following beneficial effects:

[0028] (1) An alkaline zinc-air battery electrolyte of the present invention comprises a hydroxide aqueous solution, a corrosion inhibitor and a dendrite inhibitor. Since the corrosion inhibitor is a carboxylate zinc salt, carboxylates and hydroxides are anions in the alkaline electrolyte and can coordinate with zinc cations in the electrolyte, and the carboxylates and hydroxides are in a competitive coordination relationship. The carboxylate zinc salt can inhibit the activity of hydroxides by strongly coordinating the carboxylates to zinc ions in the electrolyte. Reducing the activity of hydroxides can inhibit the hydrogen evolution side reaction between hydroxides and zinc plates, which will bring about a higher electrochemical window. Moreover, the zinc ions in the carboxylate zinc salt can increase the corrosion potential of the electrolyte, thereby improving the corrosion resistance of the electrolyte. In addition, in addition to being able to strongly coordinate with zinc ions, the carboxylates in the carboxylate zinc salt can also adhere to the surface of the zinc anode to form a protective layer. This protective layer can effectively prevent the occurrence of the hydrogen evolution side reaction, thereby achieving an excellent corrosion inhibition effect. Therefore, the hydrogen evolution side reaction during the charge and discharge process will be inhibited by the action of the zinc carboxylate corrosion inhibitor, and inhibiting this self-corrosion reaction will increase the utilization rate of the zinc anode, thereby increasing the life of the zinc anode. In addition, since the dendrite inhibitor is glycine or glutamic acid, the nitrogen atoms in the amino groups of glycine and glutamic acid have strong electronegativity and can be chemically adsorbed with the zinc anode, thereby optimizing zinc diffusion and zinc nucleation behavior. Therefore, the growth of zinc anode dendrites can be inhibited during the battery charge and discharge process, and the formation of dendrites can be inhibited by the stable deposition of zinc during charging, thereby extending the service life of the anode.

[0029] (2) The method for preparing an alkaline zinc-air battery electrolyte of the present invention has the characteristics of being 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 adopts an alkaline zinc-air battery electrolyte, which includes a hydroxide aqueous solution, a corrosion inhibitor and a dendrite inhibitor; and the corrosion inhibitor is a carboxylic acid zinc salt, and the dendrite inhibitor is glycine or glutamic acid. Therefore, on the one hand, the hydrogen evolution side reaction during the charge and discharge process can be inhibited by the action of the carboxylic acid zinc salt corrosion inhibitor, and inhibiting this self-corrosion reaction will increase the utilization rate of the zinc anode, thereby increasing the life of the zinc anode. On the other hand, glycine or glutamic acid can inhibit the growth of zinc anode dendrites during the battery charge and discharge process, and the stable deposition of zinc during charging can inhibit the generation of dendrites, thereby extending the service life of the anode. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0032] Figure 1 It is a Tafel polarization curve diagram of the electrolytes prepared in Example 1, Example 2, Comparative Example 1 and Comparative Example 2 of the present invention.

[0033] Figure 2 It is the Tafel polarization curve of zinc acetate electrolyte with different concentrations.

[0034] Figure 3 It is the Tafel polarization curve of zinc gluconate electrolyte with different concentrations.

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

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

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

[0038] Figure 7 It is a cycle life curve of the zinc symmetrical battery of the alkaline zinc-air battery electrolyte of Example 4. DETAILED DESCRIPTION

[0039] In order to make the technical problems, technical solutions and beneficial effects to be solved by the present invention more clearly understood, the present invention is further described in detail below in conjunction with the embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0040] The terms used in the embodiments of the present invention are only for the purpose of describing specific embodiments, and are not intended to limit the present invention. In the present invention, the singular forms "a", "said" and "the" used in the embodiments and the appended claims are also intended to include plural forms, unless the context clearly indicates other meanings.

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

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

[0043] An alkaline zinc-air battery electrolyte in the embodiment includes a hydroxide aqueous solution, a corrosion inhibitor and a dendrite inhibitor. Since the corrosion inhibitor is a carboxylate zinc salt, carboxylates and hydroxides are anions in the alkaline electrolyte, which can coordinate with zinc cations in the electrolyte, and carboxylates and hydroxides are in a competitive coordination relationship. The carboxylate zinc salt can suppress the activity of the hydroxide by the strong coordination of the carboxylates to the zinc ions in the electrolyte. Reducing the activity of the hydroxide can inhibit the hydrogen evolution side reaction of the hydroxide and the zinc plate, which will bring a higher electrochemical window. In addition, the zinc ions in the carboxylate zinc salt can increase the corrosion potential of the electrolyte, thereby improving the corrosion resistance of the electrolyte. In addition, the carboxylates in the carboxylate zinc salt can not only strongly coordinate with the zinc ions, but also adhere to the surface of the zinc anode to form a protective layer. This protective layer can effectively prevent the hydrogen evolution side reaction from occurring, thereby achieving an excellent corrosion inhibition effect. Therefore, the role of zinc carboxylate corrosion inhibitors will inhibit the hydrogen evolution side reaction during the charge and discharge process. Inhibiting this self-corrosion reaction will increase the utilization rate of the zinc anode, thereby increasing the life of the zinc anode.

[0044] In addition, since the dendrite inhibitor is glycine or glutamic acid, the nitrogen atom in the amino group of glycine and glutamic acid has a strong electronegativity and can be chemically adsorbed with the zinc anode, thereby optimizing zinc diffusion and zinc nucleation behavior. Therefore, the growth of zinc anode dendrites can be inhibited during the battery charging and discharging process, and the formation of dendrites can be inhibited by the stable deposition of zinc during charging, thereby extending the service life of the anode.

[0045] In some embodiments, the carboxylic acid zinc salt is one of zinc acetate, zinc gluconate, zinc propionate or zinc oxalate. Among them, the carboxylates in zinc acetate, zinc gluconate, zinc propionate or zinc oxalate can strongly coordinate the zinc ions in the electrolyte, thereby inhibiting the activity of the hydroxide in the alkaline electrolyte, and then inhibiting the hydrogen evolution side reaction of the hydroxide and the zinc plate. In addition, the zinc ions in zinc acetate, zinc gluconate, zinc propionate or zinc oxalate can well improve 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 the battery oxygen reduction reaction, the hydroxide in the electrolyte can provide more half-wave potential, thereby improving the electrochemical performance of the battery. The molar ratio of the corrosion inhibitor to the hydroxide can, on the one hand, enable the corrosion inhibitor zinc carboxylate salt to play a good role in inhibiting the hydrogen evolution side reaction, and on the other hand, does not affect the electrochemical performance of the battery.

[0047] In some embodiments, the molar ratio of the dendrite inhibitor to the hydroxide is 1:(60-120). The molar ratio of the dendrite inhibitor to the hydroxide can, on the one hand, enable the dendrite inhibitor to inhibit the growth of zinc anode dendrites during the battery charge and discharge process, and on the other hand, does not affect the electrochemical performance of the hydroxide on the battery.

[0048] In some embodiments, the concentration of the hydroxide aqueous 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] Among them, the concentration of the hydroxide aqueous solution can make the electrolyte have a suitable pH value, thereby greatly improving the electrochemical performance of the battery. In addition, the concentration of the corrosion inhibitor can make the corrosion inhibitor carboxylate zinc salt play a good role in inhibiting the hydrogen evolution side reaction, while not affecting the electrochemical performance of the battery. In addition, the concentration of the dendrite inhibitor makes the dendrite inhibitor inhibit the growth of zinc anode dendrites during the battery charging and discharging process, while not affecting the electrochemical performance of the battery by the hydroxide.

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

[0053] In an embodiment of the present invention, a method for preparing an alkaline zinc-air battery electrolyte is provided. A corrosion inhibitor and a dendrite inhibitor are added to a hydroxide aqueous solution and stirred evenly to prepare the alkaline zinc-air battery electrolyte.

[0054] The method for preparing an alkaline zinc-air battery electrolyte in the embodiment has the characteristics of being green and environmentally friendly in the preparation process, simple in process, low in production cost, high in production efficiency, and suitable for large-scale production.

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

[0056] An alkaline zinc-air battery in the embodiment adopts an alkaline zinc-air battery electrolyte, which includes a hydroxide aqueous solution, a corrosion inhibitor and a dendrite inhibitor; and the corrosion inhibitor is a carboxylic acid zinc salt, and the dendrite inhibitor is glycine or glutamic acid. Therefore, on the one hand, the hydrogen evolution side reaction during the charge and discharge process can be inhibited by the action of the carboxylic acid zinc salt corrosion inhibitor, and inhibiting this self-corrosion reaction will increase the utilization rate of the zinc anode, thereby increasing the life of the zinc anode. On the other hand, glycine or glutamic acid is used to inhibit the growth of zinc anode dendrites during the battery charge and discharge process, and the formation of dendrites is inhibited by the stable deposition of zinc during charging, thereby extending the service life of the anode.

[0057] The following describes the invention in conjunction with specific embodiments.

[0058] Example 1

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

[0060] In this embodiment, the concentration of the 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 comprises adding a corrosion inhibitor and a dendrite inhibitor into a hydroxide aqueous solution and stirring the mixture evenly to prepare the alkaline zinc-air battery electrolyte.

[0063] Example 2

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

[0065] Example 3

[0066] An alkaline zinc-air battery electrolyte. The difference between this embodiment and embodiment 1 is that the corrosion inhibitor of this embodiment is zinc gluconate, and the other components and preparation method are the same as those of embodiment 1.

[0067] Example 4

[0068] An alkaline zinc-air battery electrolyte. The difference between this embodiment and embodiment 1 is that the concentration of glycine is 0.05 mol / L, and the other components and preparation method are the same as those in embodiment 1.

[0069] Example 5

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

[0071] In this embodiment, the concentration of the 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 comprises adding a corrosion inhibitor and a dendrite inhibitor into a hydroxide aqueous solution and stirring the mixture evenly to prepare the alkaline zinc-air battery electrolyte.

[0074] Example 6

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

[0076] In this embodiment, the concentration of the 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 comprises adding a corrosion inhibitor and a dendrite inhibitor into a hydroxide aqueous solution and stirring the mixture evenly to prepare the alkaline zinc-air battery electrolyte.

[0079] Example 7

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

[0081] In this embodiment, the concentration of the 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 comprises adding a corrosion inhibitor and a dendrite inhibitor into a hydroxide aqueous solution and stirring the mixture evenly to prepare the alkaline zinc-air battery electrolyte.

[0084] Example 8

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

[0086] In this embodiment, the concentration of the 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 comprises adding a corrosion inhibitor and a dendrite inhibitor into a hydroxide aqueous solution and stirring the mixture evenly to prepare the alkaline zinc-air battery electrolyte.

[0089] Example 9

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

[0091] Example 10

[0092] An alkaline zinc-air battery comprises an air electrode and a metal zinc electrode, and also uses any one of the alkaline zinc-air battery electrolytes of embodiments 1 to 9.

[0093] Comparative Example 1

[0094] An electrolyte. 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 comparative electrolyte.

[0095] Comparative Example 2

[0096] A zinc acetate electrolyte, the difference between this comparative example and Example 1 is that this comparative example prepares the zinc acetate electrolyte 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 that in Example 1.

[0097] Comparative Example 3

[0098] A zinc acetate electrolyte is prepared by adding zinc acetate of different concentrations into five portions of 6 mol / L potassium hydroxide solution, wherein the concentrations of zinc acetate 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 into five parts of 6 mol / L potassium hydroxide solution, wherein the concentrations of zinc gluconate 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) Test on the effect of adding dendrite inhibitor on the corrosion resistance of electrolyte

[0103] The electrolytes prepared in Example 1, Example 2, Comparative Example 1 and Comparative Example 2, where Comparative Example 1 is a blank electrolyte, were poured into different electrolytic cells, and Tafel polarization curve tests were performed using a three-electrode system. The test results are shown in Figure 1 .

[0104] Depend on Figure 1 The test results can be used to obtain their corrosion current and equilibrium voltage data. The specific experimental data results are shown in Table 1.

[0105] Table 1 Tafel polarization curve test results of Example 1, Example 2, Comparative Example 1 and Comparative Example 2

[0106]

[0107] From the experimental data results in Table 1, it can be seen that the addition of glycine or glutamic acid dendrite inhibitors will not affect the corrosion resistance of the electrolyte.

[0108] (II) Test on the effect of different concentrations of zinc acetate on improving the performance of alkaline electrolyte

[0109] Five portions of zinc acetate electrolyte of different concentrations prepared in Comparative Example 3 were poured into the electrolytic cell respectively, and Tafel polarization curve test was performed using a three-electrode system to obtain corrosion current and equilibrium voltage. The counter electrode of the three-electrode system was a metal platinum electrode, the reference electrode was a 3.5M silver-silver chloride electrode, and the working electrode was an exposed area of ​​2 cm 2 The test results can be found in Figure 2 .

[0110] Depend on Figure 2 The Tafel polarization curve test results of the five samples can be used to obtain their corrosion current and equilibrium voltage data. The specific experimental data results are shown in Table 2.

[0111] Table 2 Tafel polarization curve test results of different concentrations of zinc acetate additives

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

[0113] It can be seen from Table 2 that zinc acetate has a significant effect of inhibiting the hydrogen evolution side reaction when the concentration reaches 0.2 mol / L. This proves that adding zinc acetate to the electrolyte can improve the performance of the alkaline electrolyte.

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

[0115] The five zinc gluconate electrolytes of different concentrations prepared in Comparative Example 4 were subjected to Tafel polarization curve tests to obtain corrosion current and equilibrium voltage. Figure 3 .

[0116] Depend on Figure 3 The Tafel polarization curve test results of the five samples can be used to obtain their corrosion current and equilibrium voltage data. The specific experimental data results are shown in Table 3.

[0117] Table 3 Tafel polarization curve test results of different concentrations of zinc gluconate additives

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

[0119] It can be seen from Table 3 that zinc gluconate at various concentrations can have good corrosion resistance to alkaline electrolyte.

[0120] (IV) Cyclic charge and discharge experiment with zinc acetate addition test

[0121] The electrolytes obtained in 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 added to zinc symmetrical batteries for cyclic charge and discharge experiments, wherein the discharge zinc plate area was 2 cm 2 , the current density is 10 mA cm -2 , the discharge capacity is 1 mAh cm -2 .

[0122] Among them, the cycle life curve of the zinc symmetric battery using the blank solution electrolyte of Comparative Example 1 is as follows: Figure 4 The cycle life curve of the zinc symmetric battery using the 0.2 mol / l zinc acetate electrolyte of Comparative Example 2 is shown in FIG. Figure 5 shown.

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

[0124] (V) Cyclic charge and discharge experiment with different concentrations of glycine added

[0125] The alkaline zinc-air battery electrolytes prepared in Example 1 and Example 4 were used as electrolytes for zinc symmetrical batteries, and then the zinc symmetrical batteries were subjected to cyclic charge and discharge experiments, wherein the discharge zinc plate area was 2 cm 2 , current density is 10mAcm -2 , the discharge capacity is 1 mAh cm -2 .

[0126] Among them, the cycle life curve of the zinc symmetrical battery using the alkaline zinc-air battery electrolyte of Example 1 is as follows: Figure 6 The cycle life curve of the zinc symmetrical battery using the alkaline zinc-air battery electrolyte of Example 4 is shown in FIG. Figure 7 shown.

[0127] Depend on Figure 6 and Figure 7It can be seen that the alkaline zinc-air battery electrolyte prepared in Example 1 increases the cycle life of the zinc symmetrical battery to 269 times (0.1 mol / L glycine), and the alkaline zinc-air battery electrolyte prepared in Example 4 increases the cycle life of the zinc symmetrical battery to 240 times (0.05 mol / L glycine). This shows that the introduction of glycine can inhibit the growth of dendrites. By stably depositing zinc during charging, the generation of dendrites is inhibited, thereby extending the service life of the anode. Similarly, the introduction of glutamic acid can also inhibit the growth of dendrites (experimental data omitted).

[0128] The above description is only a preferred embodiment of the present application and is not intended to limit the present application. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present application should be included in the protection scope of the present 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 a zinc carboxylate salt, and the dendrite inhibitor is glycine or glutamic acid.

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

3. An alkaline zinc-air battery electrolyte as claimed in claim 1, characterized in that: The molar ratio of the corrosion inhibitor to the hydroxide is 1:(15-60).

4. An alkaline zinc-air battery electrolyte as claimed in claim 1, characterized in that: The molar ratio of the dendrite inhibitor to the hydroxide is 1:(60-120).

5. An alkaline zinc-air battery electrolyte as claimed 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 corrosion inhibitor is 0.1 mol / L to 0.4 mol / L; and / or The concentration of the dendrite inhibitor is 0.05 mol / L to 0.1 mol / L.

6. An alkaline zinc-air battery electrolyte as claimed in claim 1, characterized in that: The hydroxide aqueous solution is a potassium hydroxide aqueous solution or a sodium hydroxide aqueous solution.

7. A method for preparing an alkaline zinc-air battery electrolyte according to any one of claims 1 to 6, characterized in that: The corrosion inhibitor and the dendrite inhibitor are added into the hydroxide aqueous solution and stirred evenly to obtain the alkaline zinc-air battery electrolyte.

8. An alkaline zinc-air battery comprising an air electrode and a metal zinc electrode, characterized in that: An alkaline zinc-air battery electrolyte as described in any one of claims 1 to 6 is also used.

Images