Electrolyte for alkaline aluminum-air battery with high output voltage, aluminum-air battery and application of aluminum-air battery

Abstract

The invention relates to the technical field of alkaline aluminum-air battery electrolytes, and discloses a high-output-voltage alkaline aluminum-air battery electrolyte, an aluminum-air battery and application of the high-output-voltage alkaline aluminum-air battery electrolyte. The electrolyte for the alkaline aluminum-air battery with high output voltage is an aqueous solution of alkaline strong electrolyte, an inorganic corrosion inhibitor and an organic corrosion inhibitor, wherein the concentration of the alkaline strong electrolyte ranges from 5 mol / L to 6 mol / L, the concentration of the inorganic corrosion inhibitor ranges from 0.02 mol / L to 0.03 mol / L, and the concentration of the organic corrosion inhibitor ranges from 0.05 mol / L to 0.12 mol / L. According to the electrolyte disclosed by the invention, through a mode of combining the inorganic corrosion inhibitor and the organic corrosion inhibitor, the inorganic corrosion inhibitor and the organic corrosion inhibitor generate a synergistic effect to form a layer of compact protective film on the surface of the aluminum negative electrode, so that the surface of the aluminum negative electrode is separated from the electrolyte, the self-corrosion of the aluminum negative electrode is inhibited, and the utilization rate of the aluminum negative electrode is improved; therefore, the discharge voltage of the aluminum air battery during working is improved, and the service life of the aluminum air battery is prolonged. The discharge voltage of the aluminum air battery applying the electrolyte can reach 1.432 V.

Description

Technical Field

[0001] The present application relates to the technical field of alkaline aluminum-air battery electrolytes, and in particular to an electrolyte for alkaline aluminum-air batteries with high output voltage, an aluminum-air battery and applications thereof. Background Art

[0002] Aluminum-air battery is a metal fuel cell with abundant material sources, low cost, non-toxic and harmless products and recyclable. It generates Al(OH)3 through ion exchange in an electrolytic environment through the oxidation reaction of the aluminum negative electrode and the reduction reaction of the positive electrode membrane and air. In this process, electrochemical energy is converted into electrical energy. Therefore, it is particularly important to provide an electrolyte environment for the reaction scenario.

[0003] The electrolyte of aluminum-air battery is usually divided into two types: neutral and alkaline. Neutral electrolyte usually uses NaCl solution, and its reaction product Al(OH)3 often exists in the form of flocculent precipitation, which makes the aluminum-air battery have low conductivity and low discharge potential. Therefore, it is usually used in low power density application scenarios, such as salt water lamps, water lamps, etc. Alkaline electrolyte usually uses KOH or NaOH electrolyte. Under this condition, Al(OH)3 is converted into Al(OH)4 – It exists in a form with good conductivity. A higher power density can be obtained by configuring electrolytes of different concentrations. Therefore, this type of aluminum-air battery is often used in high-power density scenarios and is often used in the form of multiple strings.

[0004] However, due to the characteristics of aluminum materials themselves, strong alkaline conditions are highly corrosive to aluminum negative electrode materials. When they are unloaded, a relatively violent self-corrosion reaction will occur to release a large amount of hydrogen. Moreover, after being loaded, most of the energy is converted into electrical energy, but hydrogen will still continue to be produced, causing the loss of aluminum negative electrode materials, making the output voltage of the single cell too low, the amount of hydrogen evolution too large, and the battery overheating, thereby affecting the normal operation and use of the battery. Summary of the invention

[0005] The present application provides an electrolyte for an alkaline aluminum-air battery with a high output voltage, an aluminum-air battery and its application, aiming to solve the problem of large loss of aluminum negative electrode material in the alkaline electrolyte of the existing aluminum-air battery, resulting in too low output voltage and excessive hydrogen evolution of the aluminum-air battery.

[0006] In order to achieve the above objectives, the present application adopts the following technical solutions.

[0007] In a first aspect of the present application, there is provided an electrolyte for an alkaline aluminum-air battery with a high output voltage, which is an aqueous solution of a strong alkaline electrolyte, an inorganic corrosion inhibitor, and an organic corrosion inhibitor;

[0008] The concentration of the alkaline strong electrolyte is 5-6 mol / L, the concentration of the inorganic corrosion inhibitor is 0.02-0.03 mol / L, and the concentration of the organic corrosion inhibitor is 0.05-0.12 mol / L.

[0009] Preferably, the strong alkaline electrolyte is KOH or NaOH.

[0010] Preferably, the inorganic corrosion inhibitor is sodium stannate.

[0011] Preferably, the organic corrosion inhibitor comprises glucose, urea and cetyltrimethylammonium bromide.

[0012] Further preferably, the concentration of the glucose is 0.02-0.04 mol / L; the concentration of the urea is 0.02-0.03 mol / L; and the concentration of the hexadecyltrimethylammonium bromide is 0.01-0.05 mol / L.

[0013] The second aspect of the present application provides the use of the above-mentioned high output voltage alkaline aluminum-air battery electrolyte in aluminum-air batteries.

[0014] The third aspect of the present application provides an aluminum-air battery, wherein the negative electrode is an aluminum plate, the positive electrode is an air membrane electrode, and the electrolyte is the electrolyte for the above-mentioned high output voltage alkaline aluminum-air battery.

[0015] Compared with the prior art, the beneficial effects of this application are:

[0016] The electrolyte of the present application forms a dense protective film on the surface of the aluminum negative electrode through the synergistic effect of the inorganic corrosion inhibitor and the organic corrosion inhibitor, thereby isolating the surface of the aluminum negative electrode from the electrolyte, inhibiting the self-corrosion of the aluminum negative electrode, and improving the utilization rate of the aluminum negative electrode; thereby increasing the discharge voltage of the aluminum-air battery during operation and increasing the service life of the aluminum-air battery.

[0017] The discharge voltage of the aluminum-air battery using the electrolyte of the present application can reach 1.432V. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments recorded in the present application, and for ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0019] Figure 1 The discharge voltage curve of the aluminum-air battery assembled in the embodiments and comparative examples of the present application is shown. DETAILED DESCRIPTION

[0020] The technical solutions in the embodiments of the present application will be described clearly and completely below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, rather than all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0021] In the following description of this embodiment, the terms "include", "comprising", "having" and "containing" are all open terms, meaning including but not limited to.

[0022] In the following description of this embodiment, the term "and / or" is used to describe the association relationship of associated objects, indicating that there may be three relationships. For example, A and / or B can represent: A exists alone, B exists alone, and A and B exist at the same time. A and B can be singular or plural. The character " / " generally indicates that the associated objects before and after are in an "or" relationship.

[0023] In the following description of this embodiment, the term "at least one" refers to one or more, and "plurality" refers to two or more. "At least one of the following" or similar expressions refers to any combination of these items, including any combination of single items or plural items. For example, "at least one of a, b or c", or "at least one of a, b and c", can all represent: a, b, c, ab (i.e., a and b), ac, bc, or abc, where a, b, c can be single or multiple, respectively.

[0024] The terms used in the embodiments of the present application are only for the purpose of describing specific embodiments, and are not intended to limit the present application. The singular forms "a", "an" and "the" used in the embodiments of the present application and the appended claims are also intended to include plural forms, unless the context clearly indicates other meanings.

[0025] Those skilled in the art should understand that in the following description of the embodiments of the present application, the order of serial numbers does not mean the order of execution, some or all of the steps can be executed in parallel or sequentially, and the execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present application.

[0026] Those skilled in the art will appreciate that the numerical ranges in the embodiments of the present application are to be construed as specifically disclosing each intermediate value between the upper and lower limits of the scope. Each smaller range between the intermediate value in any stated value or stated range and any other stated value or intermediate value in the described range is also included in the present application. The upper and lower limits of these smaller ranges may be independently included or excluded in the scope.

[0027] Unless otherwise specified, the technical / scientific terms used herein have the same meanings as those generally understood by those skilled in the art to which this application belongs. Although this application only describes preferred methods and materials, any methods and materials similar or equivalent to those described herein may also be used in the implementation or testing of this application. All documents mentioned in this specification are incorporated by reference to disclose and describe the methods and / or materials related to the documents. In the event of a conflict with any incorporated document, the content of this specification shall prevail.

[0028] In a first aspect, the present application provides an electrolyte for an alkaline aluminum-air battery with a high output voltage, which is an aqueous solution of a strong alkaline electrolyte, an inorganic corrosion inhibitor, and an organic corrosion inhibitor;

[0029] The concentration of the alkaline strong electrolyte is 5-6 mol / L, the concentration of the inorganic corrosion inhibitor is 0.02-0.03 mol / L, and the concentration of the organic corrosion inhibitor is 0.05-0.12 mol / L.

[0030] In the present application, the alkaline strong electrolyte can be KOH or NaOH, preferably KOH.

[0031] In the present application, the inorganic corrosion inhibitor is preferably sodium stannate; the organic corrosion inhibitor is selected from a mixture of glucose, urea and hexadecyltrimethylammonium bromide. The molar ratio of glucose, urea and hexadecyltrimethylammonium bromide is preferably (2-4):(2-3):(1-5).

[0032] As a preferred embodiment, in the electrolyte for the high output voltage alkaline aluminum-air battery of the present application, the concentration of the strong alkaline electrolyte is 5 mol to 6 mol / L, the concentration of the inorganic corrosion inhibitor is 0.02 to 0.03 mol / L, the concentration of the glucose is 0.02 to 0.04 mol / L, the concentration of the urea is 0.02 to 0.03 mol / L, and the concentration of the hexadecyltrimethylammonium bromide is 0.01 to 0.05 mol / L.

[0033] The present application forms a dense protective film on the surface of the aluminum negative electrode by compounding an inorganic corrosion inhibitor and an organic corrosion inhibitor in an alkaline strong electrolyte aqueous solution, thereby isolating the surface of the aluminum negative electrode from the electrolyte, inhibiting the self-corrosion of the aluminum negative electrode, and improving the utilization rate of the aluminum negative electrode. The electrolyte of the present application can increase the discharge voltage of the aluminum-air battery during operation and increase the service life of the aluminum-air battery, and can be used to prepare an alkaline aluminum-air battery with a high output voltage.

[0034] The present application also provides an aluminum-air battery, wherein the negative electrode is an aluminum plate, the positive electrode is an air membrane electrode, and the electrolyte is the electrolyte for the above-mentioned high output voltage alkaline aluminum-air battery. Among them, the aluminum plate is preferably a 3N9 high-purity aluminum plate. The aluminum-air battery using the electrolyte of the present application has a discharge voltage of up to 1.432V.

[0035] The present application is further described below by way of examples.

[0036] Example 1

[0037] Prepare potassium hydroxide aqueous solution, add sodium stannate, hexadecyltrimethylammonium bromide, glucose and urea in sequence, stir and dissolve, wait for the solution to cool, and obtain electrolyte. The concentration of each substance in the electrolyte is:

[0038] Potassium hydroxide 6 mol / l, sodium stannate 0.03 mol / l, hexadecyltrimethylammonium bromide 0.05 mol / l, glucose 0.02 mol / l, urea 0.02 mol / l.

[0039] The electrolyte prepared in Example 1 was used as the electrolyte for the aluminum-air battery to assemble the aluminum-air battery, as follows:

[0040] The electrolyte is added into the aluminum-air battery test box. The effective working area of ​​the single cell is 30cm 2 The distance between the two electrodes is 5mm, and the negative electrode is fixed by the upper cover. The negative electrode of the aluminum-air battery is a 3N9 pure aluminum plate, and the positive electrode is a commercial air electrode (mainly composed of manganese dioxide, nickel mesh and acetylene black). Both the positive and negative electrodes are produced by Xing Aluminum New Energy Technology (Xuzhou) Co., Ltd.

[0041] Example 2

[0042] Prepare potassium hydroxide aqueous solution, add sodium stannate, hexadecyltrimethylammonium bromide, glucose and urea in sequence, stir and dissolve, wait for the solution to cool, and obtain electrolyte. The concentration of each substance in the electrolyte is:

[0043] Potassium hydroxide 6 mol / l, sodium stannate 0.03 mol / l, hexadecyltrimethylammonium bromide 0.05 mol / l, glucose 0.04 mol / l, urea 0.03 mol / l.

[0044] The electrolyte is added into the aluminum-air battery test box. The effective working area of ​​the single cell is 30cm 2 The distance between the two electrodes is 5mm, and the negative electrode is fixed by the upper cover. The negative electrode of the aluminum-air battery is a 3N9 pure aluminum plate, and the positive electrode is a commercial air electrode (mainly composed of manganese dioxide, nickel mesh and acetylene black). Both the positive and negative electrodes are produced by Xing Aluminum New Energy Technology (Xuzhou) Co., Ltd.

[0045] Example 3

[0046] Prepare potassium hydroxide aqueous solution, add sodium stannate, hexadecyltrimethylammonium bromide, glucose and urea in sequence, stir and dissolve, wait for the solution to cool, and obtain electrolyte. The concentration of each substance in the electrolyte is:

[0047] Potassium hydroxide 5 mol / l, sodium stannate 0.02 mol / l, hexadecyltrimethylammonium bromide 0.01 mol / l, glucose 0.04 mol / l, urea 0.03 mol / l.

[0048] The electrolyte is added into the aluminum-air battery test box. The effective working area of ​​the single cell is 30cm 2 The distance between the two electrodes is 5mm, and the negative electrode is fixed by the upper cover. The negative electrode of the aluminum-air battery is a 3N9 pure aluminum plate, and the positive electrode is a commercial air electrode (mainly composed of manganese dioxide, nickel mesh and acetylene black). Both the positive and negative electrodes are produced by Xing Aluminum New Energy Technology (Xuzhou) Co., Ltd.

[0049] Comparative Example 1

[0050] The difference between Comparative Example 1 and Example 1 is that there is no inorganic corrosion inhibitor and organic corrosion inhibitor.

[0051] A potassium hydroxide aqueous solution with a concentration of 6 mol / L was prepared as an electrolyte.

[0052] The electrolyte is added into the aluminum-air battery test box. The effective working area of ​​the single cell is 30cm 2 The distance between the two electrodes is 5mm, and the negative electrode is fixed by the upper cover. The negative electrode of the aluminum-air battery is a 3N9 pure aluminum plate, and the positive electrode is a commercial air electrode (mainly composed of manganese dioxide, nickel mesh and acetylene black). Both the positive and negative electrodes are produced by Xing Aluminum New Energy Technology (Xuzhou) Co., Ltd.

[0053] Comparative Example 2

[0054] The difference between Comparative Example 2 and Example 1 is that there is no glucose and urea in the organic corrosion inhibitor.

[0055] Prepare a potassium hydroxide aqueous solution, add sodium stannate and hexadecyltrimethylammonium bromide in sequence, stir and dissolve, and wait for the solution to cool to obtain an electrolyte. The concentration of each substance in the electrolyte is:

[0056] Potassium hydroxide 6 mol / l, sodium stannate 0.03 mol / l, hexadecyltrimethylammonium bromide 0.05 mol / l.

[0057] The electrolyte is added into the aluminum-air battery test box. The effective working area of ​​the single cell is 30cm 2The distance between the two electrodes is 5mm, and the negative electrode is fixed by the upper cover. The negative electrode of the aluminum-air battery is a 3N9 pure aluminum plate, and the positive electrode is a commercial air electrode (mainly composed of manganese dioxide, nickel mesh and acetylene black). Both the positive and negative electrodes are produced by Xing Aluminum New Energy Technology (Xuzhou) Co., Ltd.

[0058] The discharge performance test of the aluminum-air batteries assembled in Example 1, Example 2, and Comparative Example 1 and Comparative Example 2 was conducted, specifically:

[0059] The positive and negative electrodes of each aluminum-air battery were connected to the Jinfan battery test cabinet, and the discharge voltage curve of each aluminum-air battery was tested at a constant power of 1.5W for 1800S. The test results are shown in Figure 2. Figure 1 shown.

[0060] The electrolyte of the aluminum-air battery in Comparative Example 1 is potassium hydroxide electrolyte, and its discharge voltage fluctuates greatly over time, showing a trend of first increasing and then decreasing. The reason is that as the test progresses, the aluminum cathode is gradually corroded, resulting in large hydrogen evolution losses. Its average discharge voltage is 1.141V, and the maximum discharge voltage is 1.175V.

[0061] The electrolyte of the aluminum-air battery in Comparative Example 2 is a compound of the potassium hydroxide electrolyte with the inorganic corrosion inhibitor sodium stannate and the organic corrosion inhibitor hexadecyltrimethylammonium bromide. The discharge voltage is slightly increased compared with that in Comparative Example 1, but there are still fluctuations. The addition of sodium stannate and hexadecyltrimethylammonium bromide slows down the self-corrosion and hydrogen evolution loss of the aluminum negative electrode to a certain extent. The average discharge voltage is 1.23V, and the maximum discharge voltage is 1.253V.

[0062] The electrolyte of the aluminum-air battery of Example 1 and Example 2 is a potassium hydroxide electrolyte in which an inorganic corrosion inhibitor sodium stannate and an organic corrosion inhibitor hexadecyltrimethylammonium bromide, urea and glucose are added in combination. The discharge voltage gradually increases over time, and the curve is smooth, indicating that the electrolyte effectively inhibits the self-corrosion and hydrogen evolution loss of the aluminum negative electrode. The average discharge voltage and the maximum discharge voltage of the aluminum-air battery of Example 1 and Example 2 are greatly improved. Among them, the average discharge voltage of the aluminum-air battery of Example 1 is 1.351v, and the maximum discharge voltage is 1.432v; while the average discharge voltage of the aluminum-air battery of Example 2 is 1.3341v, and the maximum discharge voltage is 1.406v.

[0063] After testing, the discharge voltage of the aluminum-air battery of Example 3 gradually increases with time, and the curve is smooth. Its average discharge voltage and maximum discharge voltage are close to those of Example 2.

[0064] from Figure 1The test results show that in potassium hydroxide solution, the inorganic corrosion inhibitor sodium stannate within the dosage range of this application, and the organic corrosion inhibitors hexadecyltrimethylammonium bromide, urea and glucose are added in combination. Through the synergistic effect of sodium stannate, hexadecyltrimethylammonium bromide, urea and glucose, the solution conductivity can be significantly improved, the output voltage of the battery can be improved, the negative electrode hydrogen evolution can be inhibited, and the battery life can be extended. However, outside the dosage range of this application, when the amount of corrosion inhibitor is too high, the output voltage of the battery will be reduced; when the amount of corrosion inhibitor is too low, it cannot significantly increase the output voltage of the battery.

[0065] Although the present application has been described in detail in general terms and in specific embodiments in this specification, it is obvious to those skilled in the art that some modifications or improvements may be made to the present application. Therefore, these modifications or improvements made without departing from the spirit of the present application are within the scope of protection claimed in the present application.

Claims

1. An electrolyte for an alkaline aluminum-air battery with a high output voltage, characterized in that: It is an aqueous solution of a strong alkaline electrolyte, an inorganic corrosion inhibitor, and an organic corrosion inhibitor; The concentration of the alkaline strong electrolyte is 5-6 mol / L, the concentration of the inorganic corrosion inhibitor is 0.02-0.03 mol / L, and the concentration of the organic corrosion inhibitor is 0.05-0.12 mol / L.

2. The electrolyte for alkaline aluminum-air battery with high output voltage according to claim 1, characterized in that: The alkaline strong electrolyte is KOH or NaOH.

3. The electrolyte for alkaline aluminum-air battery with high output voltage according to claim 1, characterized in that: The inorganic corrosion inhibitor is sodium stannate.

4. The electrolyte for alkaline aluminum-air battery with high output voltage according to claim 1, characterized in that: The organic corrosion inhibitor includes glucose, urea and hexadecyltrimethylammonium bromide.

5. The electrolyte for alkaline aluminum-air battery with high output voltage according to claim 4, characterized in that: The concentration of the glucose is 0.02-0.04 mol / L, the concentration of the urea is 0.02-0.03 mol / L, and the concentration of the hexadecyltrimethylammonium bromide is 0.01-0.05 mol / L.

6. Use of the high output voltage alkaline aluminum-air battery electrolyte according to any one of claims 1 to 5 in aluminum-air batteries.

7. An aluminum-air battery, characterized in that: The negative electrode is an aluminum plate, the positive electrode is an air membrane electrode, and the electrolyte is the electrolyte for alkaline aluminum-air battery with high output voltage as described in any one of claims 1-5.

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