JPH02267856A - Alkaline battery - Google Patents

Abstract

PURPOSE:To suppress the rise of the inner pressure of a battery and to improve the preservation and storage property of the battery by mixing a fluorine type surface active agent and a zinc alloy anticorrosive agent in an alkaline battery which furnishes a gel-form zinc negative electrode. CONSTITUTION:This electrolyte is formed by using a non-amalgamated zinc or a low-amalgamated zinc powder including mercury up to 500 ppm. A fluorine type surface active agent is mixed at the inclusive amount 0.01-1wt.% to the gel-form zinc negative electrode. A zinc alloy corrosion-suppressive agent includes an element of III B family, IVA family, in the periodic table, or an element of III A family including a lanthanide system, and the total sum of the suppressive agent is made 0.01-10wt.% to the gel-form zinc negative electrode, or 0.01-10wt.% of lithium hydroxide is included to the gel-form zinc negative electrode. As a result, even though a non-amalgamated or a low- amalgamated zinc is used, the pressure rise in the battery can be suppressed and the anti-leakage property is improved.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention suppresses the increase in internal pressure of a battery due to hydrogen gas generated within the battery, and preserves the battery in which zinc is used as the main active material of the negative electrode and an alkaline aqueous solution is used as the electrolyte. sex.

The present invention provides a battery with excellent storage properties.

Conventional technology Conventionally, this type of alkaline battery has been known to generate hydrogen gas due to self-depletion and corrosion of zinc during storage or after partial discharge, so the alloy containing zinc, indium aluminum, and lead has a concentration of 1.5%. Amalgamation was achieved by adding mercury in an amount of % by weight to suppress an increase in battery internal pressure. This prevents the internal pressure of the battery from increasing during storage and ensures storage stability, making it popular as a practical battery with little deterioration in battery performance.

However, as social needs for lower pollution have increased in recent years, it is necessary to further reduce the amount of mercury used and secure the above practical performance without using mercury. It has been carried out since then. but,
Although it is possible to reduce the amount of mercury to some extent, there is currently no means to achieve a fundamental solution, and it is extremely difficult to ensure sufficient corrosion resistance of negative electrode zinc without using much mercury. It is considered.

Problems that the invention aims to solve Such as zinc, indium and aluminum.

The amount of mercury added to zinc alloys containing lead is reduced from 1.5% by weight, and the amount of mercury added to zinc alloys containing lead is reduced to less than 1.5% by weight.
If a battery is constructed using extremely low hydrogenated zinc (pm)=m, during battery storage or after partially discharging the battery, hydrogen gas will be generated due to a corrosion reaction from the zinc, resulting in a significant increase in battery internal pressure. An increase is seen.

The cause of promoting hydrogen gas generation is thought to be due to the fact that the absolute amount of mercury was reduced to the limit, although mercury originally has the effect of increasing the hydrogen overvoltage against zinc and suppressing the corrosion reaction.

If such a significant increase in internal pressure occurs within the battery, this leads to leakage of the electrolytic solution, which significantly impairs the shelf life and storability of the battery, resulting in a problem that practical performance cannot be ensured.

The present invention solves these problems, and aims to remove hydrogen gas generated during storage or after partial discharge of batteries using non- or extremely low-grading zinc into a gel-like alkaline electrolyte using a fluorine-containing solution. The purpose of the present invention is to suppress the increase in battery internal pressure by mixing a surfactant and a zinc alloy corrosion inhibitor, and to provide a battery that has good preservability and storability.

Means for Solving the Problems In order to solve this problem, the present invention uses non-permeable or low-permeability zinc alloy powder with a mercury content of up to 500 ppm as the main active material of the negative electrode, and adds it to a gel-like alkaline electrolyte. In an alkaline battery with a gelled zinc negative electrode formed by mixing,
The gel-like alkaline electrolyte contains a fluorine-based surfactant and a zinc alloy corrosion inhibitor. The content of the fluorine-based surfactant here is preferably 0.01 to 1 part by weight with respect to the gelled zinc negative electrode, and the zinc alloy corrosion inhibitor is preferably 0.01 to 10 parts by weight. .

Function: With this configuration, the fluorine-based surfactant and zinc alloy corrosion inhibitor mixed in the gel-like alkaline electrolyte can reduce the amount of hydrogen gas generated, and as a result, the leakage resistance of the battery is improved.

Although the mechanism of action of the fluorine-based surfactant and zinc alloy corrosion inhibitor used in the present invention is unclear, it is inferred as follows.

The corrosion reaction of zinc in an alkaline electrolyte is shown by the following formula, and when the fluorine surfactant is adsorbed to the negative electrode surface and forms a film, the anodic reaction Zn+40H-→Zn(OH)42+2e force sword reaction 2H20+2e-" The approach of hydroxide ions, which are the cause of the 20H-+82 anode reaction, to the zinc negative electrode is blocked, and water molecules necessary for the cathode reaction cannot exist near the surface of the zinc negative electrode, thereby suppressing zinc corrosion. On the other hand, it is known that the corrosion reaction of zinc is promoted by the coexistence of zinc discharge products such as zinc oxide or zinc hydroxide.The mechanism of action of the zinc alloy corrosion inhibitor used here is not clear, but It is thought that this inhibitor acts on these zinc discharge products and suppresses zinc corrosion.In addition, this effect of the zinc alloy corrosion inhibitor has a synergistic effect in the coexistence of a fluorosurfactant. Demonstrate.

As described above, if the configuration of the present invention is used, the synergistic effect of the anticorrosion effect due to the combination of the fluorosurfactant and the zinc alloy corrosion inhibitor reduces the increase in battery internal pressure after storage and partial discharge, resulting in a good This makes it possible to provide an alkaline battery with excellent storability.

EXAMPLE An example will be described in which a gelled zinc negative electrode containing a fluorine-based surfactant and a zinc alloy corrosion inhibitor is applied to an alkaline manganese dry battery.

Figure 1 shows the alkaline manganese battery used in this example, L
It is a structural sectional view of R6. In Figure 1, 1 is a positive electrode mixture, 2 is a fluorine-based surfactant, and Examples 1, 2, and 3 below.
．． 4 is a gel negative electrode using a mercury-free zinc alloy containing a corrosion inhibitor in a gel electrolyte, 3 is a separator, and 4 is a current collector of the gel negative electrode. 5 is a positive electrode cap, 6 is a metal case, 7 is an outer case of the battery, 8 is a resin sealing body, and 9 is a bottom plate.

Example 1 A case of a gel-like zinc negative electrode containing a fluorine-based surfactant and a zinc alloy corrosion inhibitor (hereinafter abbreviated as mB group inhibitor) containing an element of group IIIB of the periodic table will be described.

A gelled zinc negative electrode was prepared as follows.

First, 3% by weight of a polyacrylic acid leader and 1% by weight of carboxymethylcellulose are added to a 40% by weight potassium hydroxide solution (containing ZnO) to form a gel. After this, twice the weight ratio of zinc alloy is added to the gel electrolysis, but before adding the zinc alloy, a fluorosurfactant and III
Add Group B inhibitor and mix thoroughly. These amounts are adjusted to the specified ratio after adding the zinc alloy powder.

The addition ratio of the fluorosurfactant and IIIB group inhibitor is as follows:
This is the ratio to the entire gelled zinc negative electrode. Further, the zinc alloy contains 0.0% of each of indium, lead, and aluminum.
05% by weight was used.

The fluorine surfactant used had both a perfluoroalkyl group and a polyoxyethylene group. The Group IIIB inhibitor is I nzo3.xH2O (75% I n20
3) G a203. Te 20 and potassium borate were used. For convenience, In hereinafter refers to r n203・XH2O (75% In203),
Similarly, Ga is Ga2o3. Te is Te20. B represents potassium borate.

First, the corrosion inhibiting effect on the zinc alloy of the present invention was investigated. The experimental method was to fabricate a prototype alkaline manganese battery as shown in Fig. 1, and conduct a constant resistance discharge of 1Ω for 22 minutes. After that, the battery was disassembled and 2g of gelled zinc negative electrode was collected, and it was kept for 10 days.
The amount of hydrogen gas generated at a temperature of 60°C was measured. The amount of Group IIIB inhibitor added to the gelled zinc negative electrode was 1
weight%.

Table 1 shows the results obtained when the amount of fluorosurfactant added was 0.1% by weight or no addition.

For comparison, measurements were also performed on samples with only the fluorine-based surfactant added and samples with neither added. The amount of gas generated shown in Table 1 is expressed as an index when the case where neither the mB group inhibitor nor the fluorine-containing surfactant is added is set as 100.

(Margin below) Table 1 However, as is clear from Table 1, the index of gas generation amount becomes 60 or less only when the fluorosurfactant and the IfB group inhibitor coexist. In other words, when either one of them has an index of about 81 to 95, when they coexist, they exhibit a synergistic effect, and it is possible to reduce the index to 60 or less.

Next, we investigated the amount of fluorosurfactant added. The experimental method was to vary the concentration of fluorosurfactant and examine the amount of gas generated and discharge performance. The alkaline manganese battery shown in Figure 1 will be prototyped. Gas generation measurement is 1Ω
, 2 g of the gel negative electrode of the battery after 22 minutes of discharge was collected, and the amount of hydrogen gas generated was measured at a temperature of 60° C. for 10 days.

Regarding the discharge performance of the battery, continuous discharge was performed at 10Ω. The gelled zinc negative electrode contains a Group IIB inhibitor I
1.0% by weight of n2oz.XH2O (75% In203)) and a specified amount of fluorine-based surfactant are mixed.

The results obtained are shown in Figure 2. In FIG. 2, the solid line indicates the amount of gas generated, and the broken line indicates the average voltage during continuous discharge of 10Ω. The amount of gas generated was expressed as an index with the case where neither the surfactant nor the inhibitor were added as 100. As is clear from Figure 2, if the amount of fluorosurfactant added increases (up to around 0.05 wt%), the amount of gas generated can be suppressed;
Beyond that, not much will change.

On the other hand, the average voltage gradually decreases as the amount added increases, and 1
It can be seen that the weight decreases rapidly when the weight percentage is exceeded. Therefore, considering the relationship between the two, it is preferable that the amount of the fluorosurfactant added is 0.01 to 1.0% by weight. In addition, as a group IIIB inhibitor, G
a.Ti! , B was used, it was experimentally found that almost the same concentration range is preferable.

Next, the amount of gas generated and the discharge performance were examined as the amount of the Group IIrB inhibitor was changed. The experimental method was to fabricate a prototype alkaline manganese battery as shown in Fig. 1, and conduct a constant resistance discharge of 1Ω for 22 minutes. Thereafter, the battery was electrolyzed, 2 g of gelled zinc negative electrode was collected, and the amount of hydrogen gas generated by raising the temperature to 60° C. for 10 days was measured. Regarding the discharge performance of the battery, continuous discharge was performed at 10Ω. The gelled zinc negative electrode contains 0.1% by weight of a fluorine-based surfactant and I[[B group inhibitor 11 agent (In203.
) is mixed in the specified amount. The results obtained are shown in FIG. In FIG. 3, the solid line indicates the amount of gas generated, and the broken line indicates the average voltage during continuous discharge of 10Ω. The amount of gas generated is an index with the case where neither the surfactant nor the inhibitor is added as 100. As is clear from FIG. 3, as the amount of I[[B group inhibitor added increases up to 0.1% by weight, the amount of gas generated is suppressed, and thereafter becomes almost constant. On the other hand, the average voltage gradually decreases as the amount of inhibitor added increases, and sharply decreases when the amount exceeds 10% by weight. Taking these two phenomena into consideration, the amount of the Group II [B inhibitor added is preferably 0.01 to 10% by weight. It has been found that Ga, Te, and B are preferably added in approximately the same range of amounts.

Finally, In, Ga, Te, B (group IIIB inhibitor)
The corrosion inhibition effect of the combination was investigated.

The experimental method was to prototype the alkaline battery shown in Figure 1.
A constant resistance discharge of Ω is performed for 22 minutes. Thereafter, the battery was disassembled, 2 g of gelled zinc negative electrode was collected, and the amount of hydrogen gas generated was measured at a temperature of 60° C. for 10 days. The results obtained are shown in Table 2. The type and amount of added Group II B inhibitor and the amount of fluorosurfactant added are also shown in the table. Further, the amount of gas generated was expressed as an index when the case where neither the surfactant nor the IIrB group inhibitor was added was set as 100. As is clear from the table, gas generation can be suppressed by combining inhibitors, and may be further suppressed by slightly changing the combination and the amount added. In Table 2, regarding the number of leaking batteries, 20 batteries of each type were produced as prototypes, and 1Ω constant resistance discharge was performed for 22 minutes. After being stored for two months at a temperature of 60° C. after discharge, the battery was observed for leakage.

It can be seen that in the case of not containing both the fluorine surfactant and the Group B inhibitor, a considerable amount of liquid leaked, but in the case of the present invention containing both, there was no leakage.

In this way, by using a gelled zinc negative electrode containing a fluorine-based surfactant and a zinc alloy corrosion inhibitor containing Group IIIB elements, mercury-free or ultra-low hydration zinc batteries can reduce the internal battery pressure due to gas generation. It is possible to suppress the rise in water and improve leakage resistance.

(Left below) Example 2 A case of a gelled zinc negative electrode containing a fluorine-based surfactant and a zinc alloy corrosion inhibitor containing an element of group IVB of the periodic table (hereinafter abbreviated as group IVB inhibitor) will be described.

A gelled zinc negative electrode was prepared as follows.

First, 3% by weight of polyacrylic acid league and 1% by weight of carboxymethylcellulose are added to a 40% by weight potassium hydroxide solution (containing ZnO) to form a gel. After this, twice the weight ratio of zinc alloy is added to the gel electrolyte, but before adding the zinc alloy, a fluorosurfactant and IV
Add Group B inhibitor and mix thoroughly. These amounts are adjusted to the specified ratio after adding the zinc alloy powder.

The addition ratio of the fluorine-based surfactant and IVB group inhibitor is the ratio to the entire gelled zinc negative electrode. In addition, the zinc alloy contains 0.00.0% each of indium, lead, and aluminum.
The one containing 5% by weight was used.

The fluorine-based surfactant used had both a perfluoroalkyl group and a polyoxyethylene group. Group IVB inhibitors include Pb(OH)2. GeO2°5n02 was used. For convenience, Pb hereinafter represents Pb (OH)2, and similarly, Ge represents GeO2°Sn represents 5n02.

First, the corrosion inhibiting effect on the zinc alloy of the present invention was investigated. The experimental method was to fabricate a prototype alkaline manganese battery as shown in Fig. 1, and conduct a constant resistance discharge of 1Ω for 22 minutes. After that, the battery was disassembled and 2g of gelled zinc negative electrode was collected, and it was kept for 10 days.
The amount of hydrogen gas generated at a temperature of 60°C was measured. The amount of the IVB group inhibitor added to the gelled zinc negative electrode was 1% by weight.

Table 3 shows the results obtained when the amount of fluorosurfactant added was 0.1% by weight or no addition.

For comparison, measurements were also performed on samples with only the fluorine-based surfactant added and samples with neither added. The amount of gas generated shown in Table 3 is expressed as an index when the case where neither the IVB group inhibitor nor the fluorine-containing surfactant is added is set as 100.

(Margin below) Table 3 When Pb is used as a group IVB inhibitor, the amount of gas generated can be suppressed even when it is not mixed with a fluorosurfactant.

However, as is clear from Table 3, the index of gas generation amount becomes 60 or less only when the fluorosurfactant and the IVB group inhibitor coexist.

In other words, when one of them is used alone, the index is about 80 to 96, but when they coexist, a synergistic effect is exerted, and it is possible to reduce the index to 6o or less.

Next, we investigated the amount of fluorosurfactant added. The experimental method was to vary the concentration of fluorosurfactant and examine the amount of gas generated and discharge performance. In the same manner as that shown in Example 1, the alkaline manganese battery shown in FIG. 1 is manufactured as a prototype. To measure gas generation, 2g of the gel negative electrode of the battery was collected after 22 minutes of discharge at 1Ω, and the amount of hydrogen gas generated was measured at a temperature of 60° C. for 10 days. Regarding the discharge performance of the battery, continuous discharge was performed at 10Ω. The rVB group inhibitor (Pb (OH)2) is contained in the gelled zinc negative electrode at 1.0
% by weight and a specified amount of fluorosurfactant. The results obtained are shown in FIG.

In Figure 4, the solid line indicates the amount of gas generated, and the broken line indicates 10Ω.
The average voltage during continuous discharge is shown. Regarding the amount of gas generated, it was expressed as an index with the case where neither surfactant nor inhibitor were added as 100. As is clear from FIG. 4, the amount of gas generated is suppressed as the amount of fluorosurfactant added increases (until the amount added is around 0.1 wt%), and does not change much beyond that amount. On the other hand, it can be seen that the average voltage gradually decreases as the amount added increases, and suddenly decreases when the amount exceeds 1% by weight. Therefore, considering the relationship between these two, the amount of fluorosurfactant added should be 0.01~
1.0! It is preferable that it is fi%. It has been experimentally found that almost the same concentration range is preferable when Ge and Sn are used as group IVB inhibitors.

Next, the amount of gas generated and the discharge performance were examined as the amount of the IVB group inhibitor added changed. The experimental method was to fabricate a prototype alkaline manganese battery as shown in Fig. 1, and conduct a constant resistance discharge of 1Ω for 22 minutes. Thereafter, the battery was disassembled, 2 g of the gelled zinc negative electrode was collected, and the amount of hydrogen gas generated by raising the temperature to 60° C. for 10 days was measured. Regarding the discharge performance of the battery, continuous discharge was performed at 10Ω. The gelled zinc negative electrode contains 0.1% by weight of a fluorochemical surfactant and a group IVB inhibitor (
A specified amount of Pb (OHM>) is mixed.

The results obtained are shown in FIG. In FIG. 5, the solid line indicates the amount of gas generated, and the broken line indicates the average voltage during continuous discharge of 10Ω. Regarding the amount of gas generated, it is an index with the case where neither surfactant nor inhibitor is added as 100. As is clear from FIG. 5, when the amount of the IVB group inhibitor added is increased to 0.1% by weight, the amount of gas generated is suppressed, and thereafter becomes approximately constant.

On the other hand, the average voltage gradually decreases as the amount of inhibitor added increases, and sharply decreases when the amount exceeds 10% by weight. These 2
Considering these two phenomena, the amount of Group IVB inhibitor added is 0.
01 to 10% by weight is preferred.

It has been found that approximately the same addition amount range is preferable for Ge and Sn as well.

Finally, the corrosion inhibiting effect of a combination of Pb, Ge, and Sn (IVB group inhibitor) was investigated. The experimental method is
The alkaline battery shown in Fig. 1 was prototyped and discharged at a constant resistance of 1Ω for 22 minutes. Thereafter, the battery was disassembled, 2 g of gelled zinc negative electrode was collected, and the amount of hydrogen gas generated was measured at a temperature of 60° C. for 10 days. The results obtained are shown in Table 4. The type and amount of the IVB group inhibitor added and the amount of fluorosurfactant added are also shown in the table. Furthermore, the amount of gas generated was expressed as an index, with the case where neither the surfactant nor the IVB group inhibitor were added as 100.

(Margin below) As is clear from the table, gas generation can be suppressed by combining inhibitors, and may be further suppressed by subtly changing the combination and amount added. In Table 4, regarding the number of leaking batteries, 20 batteries of each type were manufactured as a prototype, and 1Ω constant resistance discharge was performed for 22 minutes. After being stored for two months at a temperature of 60° C. after discharge, the battery was observed for leakage. It can be seen that in the case where both the fluorine surfactant and the IVB group inhibitor were not included, a considerable amount of liquid leaked, but in the case containing both according to the present invention, no liquid leaked.

In this way, by using a gelled zinc negative electrode containing a fluorine-based surfactant and a zinc alloy corrosion inhibitor containing group IVB elements, mercury-free or polar low-fragility zinc batteries can be produced by gas generation. It is possible to suppress the rise in internal pressure and improve leakage resistance.

Example 3 Fluorine surfactant and periodic table] Zinc alloy corrosion inhibitor containing elements of group 11rA (hereinafter abbreviated as group IIIA inhibitor)
The case of a gel-like zinc negative electrode containing the following will be explained.

A gelled zinc negative electrode was prepared as follows.

First, 3% by weight of polyacrylic acid league and 1% by weight of carboxymethylcellulose are added to a 40% by weight potassium hydroxide solution (containing ZnO) to form a gel. After this, twice the weight ratio of zinc alloy to the gel electrolyte is added, but before adding the zinc alloy, a fluorosurfactant and I[
Add Group IA inhibitor and mix thoroughly. These amounts are
After adding zinc alloy powder, adjust to the specified ratio.

The addition ratio of the fluorine surfactant and IIIA group inhibitor is the ratio to the entire gelled zinc negative electrode. In addition, the zinc alloy contains 0.00.0% each of indium, lead, and aluminum.
The one containing 5% by weight was used. Fluorine surfactants include
A material having both a perfluoroalkyl group and a polyoxyethylene group was used.

The Group 111A inhibitor is 5c203. Y2O3, La2O3
゜CeO2, Nd2O3, and Sm2O3 were used. For convenience, Sc is 5c203. Y is Y2O3, Ce is Ce 0
2°Nd represents Nd2O3, and Sm represents Sm2o3.

First, the corrosion inhibiting effect on the zinc alloy of the present invention was investigated. The experimental method was to fabricate a prototype alkaline manganese battery as shown in Figure 1, and perform constant resistance discharge of 1Ω for 22 minutes. After that, the battery was disassembled and 2g of gelled zinc negative electrode was collected.
The amount of hydrogen gas generated was measured at a temperature of ℃. Table 5 shows the results obtained when the amount of Group IA inhibitor added to the gelled zinc negative electrode was 1% by weight, and the amount of fluorosurfactant was 0.1% by weight or no addition. . For comparison, measurements were also performed on samples with only the fluorine-based surfactant added and samples with neither added. The amount of gas generated shown in Table 5 is expressed as an index when the case where neither IA group inhibitor nor fluorosurfactant is added is set as 100. Y
, Nd as a group IIIA inhibitor, the amount of gas generated can be suppressed even when no fluorine surfactant is mixed.

(Margin below) Table 5 However, as is clear from Table 5, only when a fluorine-based surfactant and an NlA group inhibitor containing a lanthanide-based inhibitor are present, the index of gas generation amount becomes 60 or less. In other words, when either one of them has an index of about 80 to 95, the coexistence of the two produces a synergistic effect, and it is possible to reduce the index to 60 or less.

Next, we investigated the amount of fluorosurfactant added. The experimental method was to vary the concentration of fluorosurfactant and examine the amount of gas generated and discharge performance. In the same manner as that shown in Example 1, the alkaline manganese battery shown in FIG. 1 is manufactured as a prototype. To measure gas generation, 2g of the gel negative electrode of the battery was collected after 22 minutes of discharge at 1Ω, and the amount of hydrogen gas generated was measured at a temperature of 60° C. for 10 days. Regarding the discharge performance of the battery, continuous discharge was performed at 10Ω. The gelled zinc negative electrode contained 1.0% by weight of IIIA inhibitor (Y2O2).
A specified amount of fluorine-based surfactant is mixed in. The results obtained are shown in FIG. In FIG. 6, the solid line indicates the amount of gas generated, and the broken line indicates the average voltage during continuous discharge of 10Ω. Regarding the amount of gas generated, it was expressed as an index with the case where neither surfactant nor inhibitor were added as 100. As is clear from FIG. 6, as the amount of fluorosurfactant added increases (up to around 0.05 wt%), the amount of gas generated is suppressed, and beyond that amount, it does not change much. On the other hand, it can be seen that the average voltage gradually decreases as the amount added increases, and suddenly decreases when the amount exceeds 1% by weight. Therefore, considering the relationship between the two, it is preferable that the amount of the fluorosurfactant added is 0.01 to 1.0% by weight. In addition, I[Y, La, as a group IA inhibitor,
Ce.

Experiments have shown that almost the same concentration range is preferable when Nd and Sm are used.

Next, the amount of gas generated and the discharge performance were investigated as a result of changes in the amount of the Group IA inhibitor added. The experimental method was to fabricate a prototype alkaline manganese battery as shown in Fig. 1, and conduct a constant resistance discharge of 1Ω for 22 minutes. Thereafter, the battery was disassembled, 2 g of gelled zinc negative electrode was collected, and the amount of hydrogen gas generated by heating to 60° C. for 10 days was measured. Regarding the discharge performance of the battery, continuous discharge was performed at 10Ω. The gelled zinc negative electrode contains 0.1% by weight of a fluorosurfactant and a specified amount of a group IIIA inhibitor (Y 203 ). The results obtained are shown in FIG. In FIG. 7, the solid line indicates the amount of gas generated, and the broken line indicates the average voltage during continuous discharge of 10Ω. Regarding the amount of gas generated, it is an index with the case where neither surfactant nor inhibitor is added as 100. As is clear from FIG. 7, when the amount of Group IIIA inhibitor added is increased to 0.05% by weight, the amount of gas generated is suppressed, and thereafter becomes approximately constant. On the other hand, the average voltage gradually decreases as the amount of inhibitor added increases, and sharply decreases when the amount exceeds 10% by weight.

Taking these two phenomena into consideration, the amount of the Group IA inhibitor added is preferably 0.01 to 10% by weight. In addition, Sc, L
It has been found that approximately the same addition amount range is preferable for a, Ce, Nd, and Sm.

Finally, the group IIIA inhibitors S c , L a +
Nd.

The corrosion inhibiting effect of some combinations of Sm, Y, and Ce was investigated. The experimental method was to fabricate a prototype alkaline battery as shown in Figure 1, and conduct a constant resistance discharge of 1Ω for 22 minutes. Thereafter, the battery was disassembled, 2 g of gelled zinc negative electrode was collected, and the amount of hydrogen gas generated was measured at a temperature of 60° C. for 10 days. The results obtained are shown in Table 6. The table also shows the added amount of the Group IIIA inhibitor Wi and the amount of the fluorosurfactant added.

Further, regarding the amount of gas generated, it was expressed as an index when the case where neither the surfactant nor the IIIA inhibitor were added was set as 100.

(Margin below) As is clear from the table, gas generation can be suppressed by combining inhibitors, and may be further suppressed by subtly changing the combination and amount added. In Table 6, regarding the number of leaking batteries, 20 batteries of each type were manufactured as a prototype, and 1Ω constant resistance discharge was performed for 22 minutes. After being stored for two months at a temperature of 60° C. after discharge, the battery was observed for leakage. It can be seen that in the case where both the fluorine surfactant and the IIIA group inhibitor are not included, a considerable number of liquid leaks, but in the case where both are contained according to the present invention, no liquid leaks.

In this way, by using a gelled zinc negative electrode containing a fluorine-based surfactant and a zinc alloy corrosion inhibitor containing Group IA elements, mercury-free or ultra-low mercury-zinc batteries can be produced by gas generation. It is possible to suppress the rise in internal pressure and improve leakage resistance.

Example 4 A case of a gelled zinc negative electrode containing a fluorine-based surfactant and lithium hydroxide as a zinc alloy corrosion inhibitor will be described.

A gelled zinc negative electrode was prepared as follows.

First, 3% by weight of sodium polyacrylate and 1% by weight of carboxymethyl cellulose are added to a 40% by weight potassium hydroxide solution (containing ZnO) to form a gel. Thereafter, a zinc alloy is added in an amount twice the weight of the gel electrolyte, but before adding the zinc alloy, a fluorine-based surfactant and lithium hydroxide are added and thoroughly mixed. These amounts are adjusted to the specified ratio after adding the zinc alloy powder. The addition ratio of the fluorine-based surfactant and lithium hydroxide is the ratio to the entire gelled zinc negative electrode. Further, the zinc alloy includes indium and lead.

The materials each containing 0.05% by weight of aluminum were used.

The fluorine-based surfactant used had both a perfluoroalkyl group and a polyoxyethylene group.

First, the corrosion inhibiting effect on the zinc alloy of the present invention was investigated. The experimental method was to fabricate a prototype alkaline manganese battery as shown in Fig. 1, and conduct a constant resistance discharge of 1Ω for 22 minutes. After that, the battery was disassembled and 2g of gelled zinc negative electrode was collected, and it was kept for 10 days.
The amount of hydrogen gas generated at a temperature of 60°C was measured. The amount of lithium hydroxide added to the gelled zinc negative electrode was set to 0.
Table 7 shows the results obtained when the amount of fluorosurfactant added was 0.1% by weight or no addition.

Table 7 For comparison, measurements were also carried out with the addition of only a fluorine-based surfactant and with neither addition. Table 7
The amount of gas generated shown in is shown as an index when the case where neither lithium hydroxide nor fluorine-based surfactant 2 were added was set as 100. As is clear from Table 7, the index of gas generation amount significantly decreases to 51 only when the fluorine-based surfactant and lithium hydroxide coexist. In other words, when only one of them is used, the coexistence of those having an index of about 78 to 81 produces a synergistic effect, and the amount of gas generated can be significantly suppressed.

Next, we investigated the amount of fluorosurfactant added. The experimental method was to vary the concentration of fluorosurfactant and examine the amount of gas generated and discharge performance. In the same manner as that shown in Experimental Example 1, the alkaline manganese battery shown in FIG. 1 is manufactured as a prototype. To measure gas generation, 2g of the gel negative electrode of the battery was collected after 22 minutes of discharge at 1Ω, and the amount of hydrogen gas generated was measured at a temperature of 60° C. for 10 days. Regarding the discharge performance of the battery, continuous discharge was performed at 10Ω. The gelled zinc negative electrode contains 0.5% by weight of lithium hydroxide and a specified amount of a fluorine-based surfactant. The obtained results are shown in the 8th
Shown in the figure. In Figure 8, the solid line indicates the amount of gas generated,
The broken line indicates the average voltage during continuous discharge of 10Ω. Regarding the amount of gas generated, it was expressed as an index with the case where neither surfactant nor lithium hydroxide were added as 100. As is clear from FIG. 8, the amount of gas generated is suppressed as the amount of fluorosurfactant added increases (up to around ff1o, 05 wt% addition), and does not change much beyond that point.

On the other hand, the average voltage gradually decreases as the amount added increases, and 1
It can be seen that the weight decreases rapidly when the weight percentage is exceeded. Therefore, considering the relationship between the two, it is preferable that the amount of the fluorosurfactant added is 0.01 to 1.0% by weight.

Next, we investigated the amount of gas generated and the discharge performance as a result of changes in the amount of lithium hydroxide added. The experimental method was to fabricate a prototype alkaline manganese battery as shown in Fig. 1, and conduct a constant resistance discharge of 1Ω for 22 minutes. Thereafter, the battery was disassembled, 2 g of gelled zinc negative electrode was used, and the amount of hydrogen gas generated by heating the battery to 60° C. for 10 days was measured. Regarding the discharge performance of the battery, continuous discharge was performed at 10Ω. The gelled zinc negative electrode contains 0.1% by weight of a fluorine-based surfactant and a specified amount of lithium hydroxide. The results obtained are shown in FIG. In Figure 9, the solid line indicates the amount of gas generated,
The broken line indicates the average voltage during continuous discharge of 10Ω. Regarding the amount of gas generated, the index is based on the case where neither surfactant nor lithium hydroxide is added as 100. As is clear from FIG. 9, when the amount of lithium hydroxide added increases to 0.05% by weight, the amount of gas generated is suppressed, and thereafter becomes constant. On the other hand, the average voltage gradually decreases as the amount of lithium hydroxide added increases, and sharply decreases when the amount reaches 10% by weight.

Considering these two phenomena, the amount of lithium hydroxide added is preferably 0.01 to 10% by weight.

In this way, by using a gelled zinc negative electrode containing a fluorine-based surfactant and lithium hydroxide as a zinc alloy corrosion inhibitor, a mercury-free or extremely low zinc oxide battery can be produced.
It is possible to improve leakage resistance by suppressing an increase in battery internal pressure due to gas generation.

Effects of the Invention As described above, according to the present invention, by containing a fluorine-based surfactant and a zinc alloy corrosion inhibitor in the gelled zinc negative electrode of an alkaline battery, it is possible to improve Even when zinc is used, the effect of suppressing the increase in battery internal pressure and improving leakage resistance can be obtained.

[Brief explanation of drawings]

FIG. 1 is a cross-sectional view of a battery in an embodiment of the present invention,
FIGS. 2 to 9 are diagrams showing the relationship between the amount of corrosion inhibitor added, the gas generation index, and the average voltage during discharge. 1... Positive electrode mixture, 2... Gel-like negative electrode using a mercury-free zinc alloy containing a fluorine-based surfactant and a zinc alloy corrosion inhibitor in the gel electrolyte, 3... ...Separator. Name of agent: Patent attorney Shigetaka Awano and one other person 1--if
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Claims (15)

[Claims] (1) Aqueous or mercury content 5 as the main active material of the negative electrode
An alkaline battery equipped with a gelled zinc negative electrode made by using zinc gold powder with a low flux of up to 0.00ppm and mixing it with a gelled alkaline electrolyte, wherein the gelled alkaline electrolyte contains a fluorine-based surfactant. and an alkaline battery characterized by containing a zinc alloy corrosion inhibitor containing an element of group IIIB of the periodic table. (2) Zinc alloy corrosion inhibitors include indium, gallium,
2. The alkaline battery according to claim 1, wherein at least one oxide in the group of thallium and boron is a hydroxide or an alkali metal salt thereof. (3) The alkaline battery according to claim 1, wherein the content of the fluorine-based surfactant is 0.01 to 1% by weight based on the gelled zinc negative electrode. (4) The alkaline battery according to claim 1 or 2, wherein the total amount of the zinc alloy corrosion inhibitor is 0.01 to 10% by weight based on the gelled zinc negative electrode. (5) Aqueous or mercury content 5 as the main active material of the negative electrode
An alkaline battery equipped with a gelled zinc negative electrode made by using zinc alloy powder with a low flux of up to 0.000 ppm and mixing it with a gelled alkaline electrolyte, the alkaline battery having a fluorine-based surfactant in the gelled alkaline electrolyte. and a zinc alloy corrosion inhibitor containing an element of group IVB of the periodic table. (6) The zinc alloy corrosion inhibitor is at least one oxide or hydroxide of the group consisting of lead, tin, and germanium, or an alkali metal salt thereof. alkaline battery. (7) The alkaline battery according to claim 5, wherein the content of the fluorine-based surfactant is 0.01 to 1% by weight based on the gelled zinc negative electrode. (8) The alkaline battery according to claim 5 or 6, wherein the total amount of the zinc alloy corrosion inhibitor is 0.01 to 10% by weight based on the gelled zinc negative electrode. (9) Aqueous or mercury content 5 as the main active material of the negative electrode
An alkaline battery equipped with a gelled zinc negative electrode made by using zinc alloy powder with a low flux of up to 0.000 ppm and mixing it with a gelled alkaline electrolyte, the alkaline battery having a fluorine-based surfactant in the gelled alkaline electrolyte. and periodic table including lanthanide series
An alkaline battery characterized by containing a zinc alloy corrosion inhibitor containing a group IIIA element. (10) A patent claim characterized in that the zinc alloy corrosion inhibitor is at least one oxide or hydroxide of the group consisting of scandium, yttrium, lanthanum, cerium, neodymium, and samarium, or an alkali metal salt thereof. The alkaline battery according to item 9. (11) The alkaline battery according to claim 9, wherein the content of the fluorine-based surfactant is 0.01 to 1% by weight based on the gelled zinc negative electrode. (12) The alkaline battery according to claim 9 or 10, wherein the total amount of the zinc alloy corrosion inhibitor is 0.01 to 10% by weight based on the gelled zinc negative electrode. (13) In an alkaline battery equipped with a gelled zinc negative electrode, a non-grading or low-grading zinc alloy powder with a mercury content of up to 500 ppm is used as the main active material of the negative electrode, and a gelled alkaline electrolyte is mixed therein. An alkaline battery characterized in that the gel-like alkaline electrolyte contains a fluorine-based surfactant and lithium hydroxide as a zinc alloy corrosion inhibitor. (14) The alkaline battery according to claim 13, wherein the content of the fluorine-based surfactant is 0.01 to 1% by weight based on the gelled zinc negative electrode. (15) The alkaline battery according to claim 13, wherein the total amount of lithium hydroxide is 0.01 to 10% by weight based on the gelled zinc negative electrode.