JP4497410B2 - Method for producing alkaline battery electrolyte - Google Patents

Description

  The present invention relates to an electrolytic solution for an alkaline battery and an alkaline battery using the electrolytic solution.

  In recent years, alkaline batteries using anhydrous zinc as a negative electrode agent have been developed from the viewpoint of suppressing environmental pollution. However, such alkaline batteries have a problem that the zinc is corroded to generate hydrogen gas. Further, in the above alkaline battery, there is also a problem that hydrogen gas is generated due to a local battery reaction between copper and zinc covering the negative electrode inner surface (negative electrode terminal plate inner surface) in contact with the negative electrode agent in anticipation of a current collecting effect. is there. For example, when gas is generated inside during storage of an alkaline battery, the battery swells and its capacity deteriorates.

  In order to solve such a problem, an alkaline battery in which a bismuth compound and an indium compound are added to an electrolytic solution has been proposed (Patent Document 1). In the technique of Patent Document 1, the generation of the hydrogen gas is suppressed by the action of the bismuth compound and the indium compound added to the electrolytic solution.

Japanese Patent No. 3317526

  However, at present, there is a demand for suppression of hydrogen gas generation at a level exceeding the technique of Patent Document 1. In particular, in so-called button-type batteries, the batteries themselves may be small, and there is a strong demand for reducing the amount of hydrogen gas generated.

  The present invention provides an electrolytic solution capable of suppressing the generation of internal gas during storage of an alkaline battery and enhancing the storage characteristics of the battery, a method for producing the electrolytic solution, and an alkaline battery having the electrolytic solution. Is an issue.

The present invention provides an alkaline battery electrolyte solution containing at least an alkali metal hydroxide, indium hydroxide and water, wherein the alkali metal hydroxide concentration is 20 to 40% by mass and indium hydroxide is 100 ppm or more ( The above-mentioned problem is solved by dissolving at a concentration of mass reference, the same applies hereinafter.

In the electrolytic solution of the present invention, hydrogen gas generation in the battery is suppressed by the action of indium hydroxide. The presence of indium hydroxide in the electrolyte suppresses the generation of hydrogen gas due to the corrosion of zinc in the negative electrode agent, and a zinc alloy film containing indium is formed on the surface of the negative electrode terminal plate that contacts the negative electrode agent. The local battery reaction between zinc in the negative electrode agent and copper on the surface of the negative electrode terminal plate is suppressed, and hydrogen gas generation is suppressed.

  Even in the electrolytic solution disclosed in Patent Document 1, the indium compound acts as described above to suppress hydrogen gas generation in the battery. However, in the electrolytic solution, the indium compound is hardly dissolved. It is in a distributed state. Thus, it has been found by the present inventors that the indium compound dispersed without being dissolved in the electrolytic solution does not act so effectively in suppressing the generation of hydrogen gas. In the conventional electrolytic solution manufacturing method, the dissolved amount of the indium compound in the electrolytic solution can only be about 20 ppm, for example.

Therefore, as a result of intensive studies on a method for dissolving indium hydroxide at a higher concentration in the electrolytic solution, the present inventors have determined that the production method of the present invention, that is, an alkali metal hydroxide and indium hydroxide, By adopting a method for producing an alkaline battery electrolyte solution having a first step of dissolving in water and a second step of diluting the mixture obtained in the first step by adding water, 100 ppm as described above. The present invention was completed by successfully obtaining an electrolytic solution in which indium hydroxide was dissolved at the above concentration and an alkali metal hydroxide was dissolved at a concentration of 20 to 40% by mass.

  Moreover, the alkaline battery using the electrolyte solution for alkaline batteries of the said invention is also included by this invention.

  According to the alkaline battery electrolyte of the present invention, generation of hydrogen gas inside the battery during storage of the alkaline battery can be suppressed to a high degree, and thus an alkaline battery excellent in storability can be provided. That is, the alkaline battery of the present invention is excellent in storability.

  Moreover, according to the manufacturing method of this invention, the electrolyte solution for alkaline batteries of this invention can be manufactured favorably.

In the electrolytic solution of the present invention, indium hydroxide [In (OH) ₃ ] is used.

The concentration of indium hydroxide in the electrolytic solution is 100 ppm or more, more preferably 400 ppm or more. If the concentration of indium hydroxide is too small, the effect of suppressing the generation of hydrogen gas when applied to an alkaline battery is reduced. On the other hand, the upper limit of the concentration of indium hydroxide in the electrolytic solution is not particularly limited as long as it is a soluble concentration. However, if the concentration is too large, it takes a very long time to uniformly dissolve indium hydroxide. Therefore, it is difficult to dissolve the electrolyte itself, and it is difficult to dissolve the electrolyte. It is easily affected by the manufacturing conditions (temperature, stirring conditions, etc.), and the variation from lot to lot becomes large. It may be very difficult to stably produce an electrolytic solution having the same concentration of indium oxide. For this reason, it is desirable that the upper limit of the indium hydroxide concentration in the electrolytic solution is, for example, 1500 ppm. In addition, the density | concentration of the indium hydroxide in electrolyte solution here is a value calculated | required by the measuring method employ | adopted in the postscript Example.

Examples of the alkali metal hydroxide used in the electrolytic solution include sodium hydroxide, potassium hydroxide, and lithium hydroxide. These alkali metal hydroxides may be used alone or in combination of two or more. For example, sodium hydroxide and potassium hydroxide may be used in combination, or sodium hydroxide or potassium hydroxide. Or a mixture of sodium hydroxide and potassium hydroxide with a small amount of lithium hydroxide can be used. Among them, the embodiment containing sodium hydroxide (that is, sodium hydroxide alone or a mixture of sodium hydroxide and each of the alkali metal hydroxides exemplified above) can dissolve indium hydroxide more effectively. Is preferable.

  The alkali metal hydroxide concentration in the electrolytic solution is desirably 20% by mass or more and 40% by mass or less (more preferably 35% by mass or less). This is because the conductivity of the electrolytic solution is improved by adjusting the alkali metal hydroxide concentration within this range.

  In addition to the above-described components, various known additives may be added to the electrolytic solution as necessary within a range not impairing the effects of the present invention. For example, zinc oxide may be added to prevent corrosion (oxidation) of zinc used for the negative electrode agent of an alkaline battery.

In producing the electrolytic solution of the present invention, a production method having the following first step and second step is employed. First, in the first step, an alkali metal hydroxide and indium hydroxide are dissolved in water. In this first step, an alkali metal hydroxide and indium hydroxide are added to a portion of the water used to prepare the electrolytic solution, and mixed by stirring or the like. That is, in the first step, not the total amount of water used in the electrolytic solution, but a part thereof, and an alkali metal hydroxide and indium hydroxide are mixed in an aqueous solution rather than the finally obtained electrolytic solution. The alkali concentration is increased (that is, the pH is increased) so that indium hydroxide is more easily dissolved. The amount of water used in the first step is 15% by mass or more, more preferably 20% by mass or more, and 75% by mass or less, more preferably 60% by mass or less, based on the total amount of water used for preparing the electrolytic solution. It is desirable to do. If the amount of water used in the first step is too small, not all of the alkali metal hydroxide to be mixed may be dissolved, and the amount of indium hydroxide dissolved may be reduced. On the other hand, if the amount of water used in the first step is too large, the alkali concentration in the aqueous solution may be too low to effectively dissolve indium hydroxide. Furthermore, it is recommended to select an amount of water that saturates the alkali metal hydroxide. In this case, since the alkali concentration of the mixture (aqueous solution) according to the first step becomes the highest, the solubility of indium hydroxide can be further improved. In the first step, it is not necessary to mix alkali metal hydroxide and indium hydroxide with water at the same time. For example, high concentration aqueous alkali solution is prepared by mixing alkali metal hydroxide with water first. Then, indium hydroxide may be added and mixed.

  In the next second step, of the water used for the preparation of the electrolytic solution, the remainder not used in the first step is added to the mixture obtained in the first step, and the mixture is diluted by mixing, etc. Thus, the electrolytic solution of the present invention is obtained. By this second step, the concentration of alkali metal hydroxide in the electrolytic solution is adjusted. The water added in the second step may be added all at once, or may be added in a plurality of times (for example, twice, three times, etc.).

The temperature at the time of producing the electrolytic solution (that is, at the time of the first step and the second step) is not particularly limited. For example, by setting the liquid temperature to 40 to 100 ° C., indium hydroxide is more effectively dissolved. Can be made. In order to set the liquid temperature within the above range, heating may be used, but reaction heat generated when the alkali metal hydroxide is dissolved may be used. The mixing time and stirring conditions in the first step and the second step are not particularly limited. For example, at the end of the first step, all of the added alkali metal hydroxide and indium hydroxide are dissolved. Or it is preferable to set it as the conditions which melt | dissolve until it saturates. In addition, if there remains undissolved indium hydroxide after the second step, it may be removed by filtering or collecting only the supernatant.

In addition, there is no restriction | limiting in particular in the timing in the case of adding components (for example, said zinc oxide) other than alkali metal hydroxide and indium hydroxide to electrolyte solution, It adds in the case of a 1st process or a 2nd process. For example, when adding zinc oxide, it is preferable that the alkali concentration in a liquid is high from a viewpoint of improving solubility, and adding at a 1st process is desirable.

  Next, the alkaline battery of the present invention will be described. The alkaline battery of the present invention is not particularly limited except that it has the alkaline battery electrolyte of the present invention, and a configuration employed in a conventionally known alkaline battery can be applied. The alkaline battery of the present invention uses a negative electrode agent having anhydrous silver zinc or anhydrous silver alloy as a negative electrode active material, and the surface of the negative electrode terminal plate (the surface in contact with the negative electrode agent) is copper or copper alloy. In the case of an alkaline battery (particularly a button-type alkaline battery) coated with, the decrease in capacity due to the generation of hydrogen gas in the battery during storage is suppressed by having the alkaline battery electrolyte of the present invention. In addition, the effect of improving storage characteristics becomes remarkable.

For example, the zinc alloy film containing indium formed on the surface of the negative electrode terminal plate by the indium hydroxide dissolved in the electrolytic solution described above is a copper electrode of the negative electrode terminal plate by a zinc dissolution / precipitation reaction in a normal alkaline battery. It is as thin as the galvanized thickness formed on the surface.

  A preferred example of the alkaline battery of the present invention will be described with reference to the drawings. However, the alkaline battery of the present invention is not limited to those illustrated in the drawings.

  FIG. 1 is a partial sectional view schematically showing an example of the alkaline battery (button-type alkaline battery) of the present invention, and FIG. 2 is an enlarged view of a main part in FIG.

  In the figure, reference numeral 1 denotes a disk-like mixture of a positive electrode active material such as silver oxide, manganese dioxide, silver oxide, nickel hydroxide, and a conductive additive such as carbon black, graphite, or graphite. A positive electrode mixture prepared by pressure molding and impregnated with a part of an alkaline electrolyte, 2 is a separator interposed between the positive electrode mixture 1 and the negative electrode agent 3, The separator 2 is formed by stacking, for example, a hydrophilic microporous polypropylene film, a cellophane film, and a liquid absorbing layer such as vinylon-rayon mixed paper. Reference numeral 3 denotes a negative electrode agent containing a negative electrode active material (for example, powdered material) made of anhydrous silver zinc or an anhydrous silver zinc alloy, and injecting most of the alkaline electrolyte into the negative electrode active material.

  4 is a positive electrode can made of iron with a positive electrode mixture 1 and a separator 2 embedded therein and nickel-plated on the surface. The negative electrode terminal plate 5 in which the negative electrode agent 3 is embedded in the opening is made of various materials such as polyethylene and polypropylene. An annular gasket 6 made of resin or rubber having an L-shaped cross section is interposed and fitted, and the opening end of the positive electrode can 4 is tightened inward to bring the annular gasket 6 into contact with the negative electrode terminal plate 5 to thereby seal it. The inside of the battery has a sealed structure. That is, in this button-type alkaline battery, a power generation element including the positive electrode mixture 1, the negative electrode agent 3, the alkaline electrolyte, and the like is accommodated in a sealed space formed by the positive electrode can 4, the negative electrode terminal plate 5, and the annular gasket 6. ing.

  As shown in FIG. 2, the negative electrode terminal plate 5 is provided with a nickel layer 5b that satisfies aesthetic or corrosion resistance on the outer surface side of the stainless steel plate 5a, and a copper layer 5c on the inner surface side, that is, the surface in contact with the negative electrode agent 3. It is a thing. And this negative electrode terminal plate 5 is normally produced in the shape which has the periphery folding | turning part 5Z by drawing the clad board which consists of the stainless steel plate 5a, the nickel layer 5b, and the copper layer 5c. A zinc alloy film 7 containing indium is formed on the surface of the negative electrode terminal plate 5 in contact with the negative electrode agent 3 of the copper layer 5c. The zinc alloy film 7 containing indium is shown to be thicker in order to facilitate visual recognition on the drawing, but actually it is thinner than the thickness of the negative electrode terminal plate 5.

  In addition, as shown in FIG. 2, the annular gasket 6 may be brought into pressure contact with the peripheral folded portion 5Z of the negative electrode terminal plate 5 via a liquid packing material (for example, asphalt pitch, aliphatic polyamide, fluorine oil, etc.). Preferably, a film 9 made of an N-aminomethyl derivative of a benzotriazole-based compound represented by the following general formula (I) is also formed on the surface 8 of the negative electrode terminal plate 5 where the annular gasket 6 is pressed. preferable. This coating 9 is chemically strong and densely bonded to the surface of the copper layer 5c due to the strong activity of the benzotriazole-based compound with respect to copper, and an alkaline electrolyte solution based on the electrochemical creep phenomenon on the surface of the copper layer 5c. Strongly prevents leakage. Although not shown, a liquid packing material is interposed between the coating 9 and the annular gasket 6, and the liquid packing material leaks alkaline electrolyte from between the coating 9 and the annular gasket 6. Is prevented from occurring.

（式中、Ｒ₁ は水素、ハロゲンまたはアルキル基、Ｒ₂ およびＲ₃ は水素またはアルキル基であり、Ｒ₂ とＲ₃ とは同一でもよくまた異なっていてもよい。）

(In the formula, R ₁ is hydrogen, a halogen or an alkyl group, R ₂ and R ₃ are hydrogen or an alkyl group, and R ₂ and R ₃ may be the same or different.)

  Hereinafter, the present invention will be described in detail based on examples. However, the following examples are not intended to limit the present invention, and all modifications made without departing from the spirit of the preceding and following descriptions are included in the technical scope of the present invention.

Example 1
<Preparation of electrolyte>
Sodium hydroxide (purity 96%): 550 g, zinc oxide (purity 99%): 100 g, and indium hydroxide: 10 g are added to water: 340 g (25% by mass of a predetermined amount) and stirred for 20 minutes (stirring speed: 1500 rpm) The remaining water: 1010 g (75% by mass of the predetermined amount) was added and stirred for 20 minutes (stirring speed: 1500 rpm). The mixed solution was allowed to stand at room temperature for 3 days, and the undissolved indium hydroxide was removed by collecting the supernatant. The collected supernatant was used as an alkaline battery electrolyte.

<Preparation of alkaline battery>
A clad plate composed of a nickel layer / stainless steel (SUS-304) plate / copper layer was punched out with a press machine and processed into a shape having a peripheral folded portion as shown in FIG. 1 to prepare a negative electrode terminal plate.

  For the positive electrode, a mixture of 110 mg of silver oxide as the positive electrode active material, 20 mg of manganese dioxide as the positive electrode active material, and 2 mg of graphite as the conductive auxiliary agent was formed into a disc shape (outer diameter 6.3 mm, thickness 0.9 mm) was used. As the negative electrode agent, 37 mg of anhydrous silver zinc powder as a negative electrode active material was used. A button-type alkaline battery having the structure shown in FIG. 1 and an outer diameter of 6.8 mm and a thickness of 2.6 mm was prepared using the above electrolyte solution, positive electrode, negative electrode agent, and negative electrode terminal plate.

Example 2
An alkaline battery was produced in the same manner as in Example 1 except that the electrolytic solution produced as follows was used. Sodium hydroxide (purity 96%): 550 g, zinc oxide (purity 99%): 100 g, and indium hydroxide: 10 g are added to water: 675 g (50% by mass of a predetermined amount) and stirred for 20 minutes (stirring speed: 1500 rpm) ), The remaining water: 675 g (50% by mass of the predetermined amount) was added and stirred for 20 minutes (stirring speed: 1500 rpm). The mixed solution was allowed to stand at room temperature for 3 days, and the undissolved indium hydroxide was removed by collecting the supernatant. The collected supernatant was used as an alkaline battery electrolyte.

Example 3
An alkaline battery was produced in the same manner as in Example 1 except that the electrolytic solution produced as follows was used. Sodium hydroxide (purity 96%): 550 g, zinc oxide (purity 99%): 100 g, and indium hydroxide: 10 g are added to water: 900 g (predetermined amount of 67% by mass) and stirred for 20 minutes (stirring speed: 1500 rpm) ), The remaining water: 450 g (33% by mass of the predetermined amount) was added and stirred for 20 minutes (stirring speed: 1500 rpm). The mixed solution was allowed to stand at room temperature for 3 days, and the undissolved indium hydroxide was removed by collecting the supernatant. The collected supernatant was used as an alkaline battery electrolyte.

Example 4
An alkaline battery was produced in the same manner as in Example 1 except that the electrolytic solution produced as follows was used. Sodium hydroxide (purity 96%): 550 g and zinc oxide (purity 99%): 100 g were added to water: 900 g (67% by mass of a predetermined amount), and the mixture was stirred for 20 minutes (stirring speed: 1500 rpm). Thereafter, 10 g of indium hydroxide was added and stirred for 20 minutes (stirring speed: 1500 rpm), and then the remaining water: 450 g (33% by mass of the predetermined amount) was added and stirred for 20 minutes (stirring speed: 1500 rpm). The mixed solution was allowed to stand at room temperature for 3 days, and the undissolved indium hydroxide was removed by collecting the supernatant. The collected supernatant was used as an alkaline battery electrolyte.

Example 5
An alkaline battery was produced in the same manner as in Example 1 except that the electrolytic solution produced as follows was used. Potassium hydroxide (purity 85%): 850 g, zinc oxide (purity 99%): 110 g, and indium hydroxide: 10 g are added to water: 260 g (25% by mass of a predetermined amount) and stirred for 20 minutes (stirring speed: 1500 rpm). ), The remaining water: 790 g (75% by mass of the predetermined amount) was added and stirred for 20 minutes (stirring speed: 1500 rpm). The mixed solution was allowed to stand at room temperature for 3 days, and the undissolved indium hydroxide was removed by collecting the supernatant. The collected supernatant was used as an alkaline battery electrolyte.

Example 6
An alkaline battery was produced in the same manner as in Example 1 except that the electrolytic solution produced as follows was used. Potassium hydroxide (purity 85%): 850 g, zinc oxide (purity 99%): 110 g, and indium hydroxide: 10 g are added to water: 525 g (50% by mass of a predetermined amount) and stirred for 20 minutes (stirring speed: 1500 rpm). After that, the remaining water: 525 g (50% by mass of the predetermined amount) was added and stirred for 20 minutes (stirring speed: 1500 rpm). The mixed solution was allowed to stand at room temperature for 3 days, and the undissolved indium hydroxide was removed by collecting the supernatant. The collected supernatant was used as an alkaline battery electrolyte.

Example 7
An alkaline battery was produced in the same manner as in Example 1 except that the electrolytic solution produced as follows was used. Potassium hydroxide (purity 85%): 850 g, zinc oxide (purity 99%): 110 g, and indium hydroxide: 10 g are added to water: 700 g (predetermined amount of 67% by mass) and stirred for 20 minutes (stirring speed: 1500 rpm) The remaining water: 350 g (33% by mass of the predetermined amount) was added and stirred for 20 minutes (stirring speed: 1500 rpm). The mixed solution was allowed to stand at room temperature for 3 days, and the undissolved indium hydroxide was removed by collecting the supernatant. The collected supernatant was used as an alkaline battery electrolyte.

Comparative Example 1
An alkaline battery was produced in the same manner as in Example 1 except that the electrolytic solution produced as follows was used. Sodium hydroxide (purity 96%): 550 g, zinc oxide (purity 99%): 100 g, water: 1350 g (100% by mass of a predetermined amount) was added and stirred for 20 minutes (stirring speed: 1500 rpm), then at room temperature Cooled down. To this, 10 g of indium hydroxide was added and stirred for 20 minutes (stirring speed: 1500 rpm). The mixed solution was allowed to stand at room temperature for 3 days, and the undissolved indium hydroxide was removed by collecting the supernatant. The collected supernatant was used as an alkaline battery electrolyte.

Comparative Example 2
An alkaline battery was produced in the same manner as in Example 1 except that the electrolytic solution produced as follows was used. Sodium hydroxide (purity 96%): 550 g, zinc oxide (purity 99%): 100 g, water: 1350 g (100% by mass of a predetermined amount) was added and stirred for 20 minutes (stirring speed: 1500 rpm), then at room temperature After cooling, this was used as an alkaline battery electrolyte.

Comparative Example 3
An alkaline battery was produced in the same manner as in Example 1 except that the electrolytic solution produced as follows was used. Potassium hydroxide (purity 85%): 850 g, zinc oxide (purity 99%): 110 g, water: 1050 g (100% by mass of a predetermined amount) was added and stirred for 20 minutes (stirring speed: 1500 rpm), then at room temperature. Cooled down. To this, 10 g of indium hydroxide was added and stirred for 20 minutes (stirring speed: 1500 rpm). The mixed solution was allowed to stand at room temperature for 3 days, and the undissolved indium hydroxide was removed by collecting the supernatant. The collected supernatant was used as an alkaline battery electrolyte.

Comparative Example 4
An alkaline battery was produced in the same manner as in Example 1 except that the electrolytic solution produced as follows was used. Potassium hydroxide (purity 85%): 850 g, zinc oxide (purity 99%): 110 g, water: 1050 g (100% by mass of a predetermined amount) was added and stirred for 20 minutes (stirring speed: 1500 rpm), then at room temperature. After cooling, this was used as an alkaline battery electrolyte.

The amount of indium compound (indium hydroxide) dissolved in the produced electrolyte and the capacity retention of the alkaline battery were measured by the following method. The results are shown in Table 1.

[Amount of indium compound dissolved in electrolyte]
“IRIS 1000” manufactured by Nippon Jarrell-Ash Co., Ltd. was used as a measuring device. A calibration curve representing the relationship between the emission intensity at a wavelength of 325.609 nm for In and the concentration of the indium compound was prepared in advance using solutions with known indium compound concentrations (0 ppm, 0.1 ppm, 1 ppm and 10 ppm). And about each electrolyte solution, the emitted light intensity of a wavelength of 325.609 nm was measured, and the indium compound density | concentration was calculated | required using the said calibration curve.

[Alkaline battery capacity retention]
The capacity retention rate of the alkaline battery was measured by discharging 10 batteries before storage to 20 V, 15 kΩ to a final voltage of 1.2 V, and measuring the discharge capacity. After storage at 40 ° C. for 40 days, the discharge capacity was measured by discharging to 20 ° C. and 15 kΩ to a final voltage of 1.2 V, and the ratio of the discharge capacity after storage to the discharge capacity before storage determined by the following formula was used.
Capacity retention (%) = 100 × (discharge capacity after storage) / (discharge capacity before storage)

  As can be seen from Table 1, in the alkaline batteries of Examples 1 to 7 in which the amount of indium hydroxide dissolved in the electrolyte is suitable, gas generation is well suppressed, the capacity retention is high, and excellent storage characteristics. Is secured. On the other hand, in the alkaline batteries of Comparative Examples 1 to 4 in which indium hydroxide is not dissolved in the electrolytic solution or the dissolved amount is small, the capacity retention is low compared to the alkaline batteries of Examples 1 to 7, Storage characteristics are inferior.

It is a fragmentary sectional view which shows an example of the alkaline battery of this invention. It is a principal part enlarged view of FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Positive electrode mixture 2 Separator 3 Negative electrode agent 4 Positive electrode can 5 Negative electrode terminal board 5a Stainless steel plate 5b Nickel layer 5c Copper layer 5Z Peripheral folding part 6 Annular gasket 7 Zinc alloy film 8 The negative electrode terminal which press-contacts an annular gasket through a liquid packing material Surface 9 of the plate A coating comprising an N-aminomethyl derivative of a benzotriazole compound represented by the general formula (I)

Claims (3)

A method for producing an alkali metal hydroxide, an electrolyte for an alkaline cell having an indium hydroxide Contact and water,
A first step of dissolving an alkali metal hydroxide and indium hydroxide in water;
The second step in which the mixture obtained in the first step is diluted by adding water to make the alkali metal hydroxide dissolution concentration 20 to 40% by mass and the indium hydroxide dissolution concentration to 100 ppm or more. The manufacturing method of the electrolyte solution for alkaline batteries characterized by having. The manufacturing method according to claim 1, wherein 15 to 75% by mass of the total amount of water used for the preparation of the electrolytic solution is used in the first step, and the remaining water is used in the second step. The production method according to claim 2 , wherein, in the first step, the alkali metal hydroxide is saturated.

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