JP5674246B2 - Lead acid battery and negative electrode plate thereof - Google Patents

Description

  The present invention relates to a lead storage battery and a negative electrode plate thereof.

When forming an electrode plate of a lead storage battery, a battery case formation in which an electrolytic solution is injected into the battery case and energized after the electrode plate is previously incorporated in the battery case has become the main method of manufacturing lead acid batteries. Further, it is required to reduce the manufacturing cost by shortening the battery formation time and performing the battery formation more than twice a day with the same equipment.
In that case, in order to shorten the formation time, it is required to increase the formation efficiency. That is, it is required to increase the ratio of the amount of electricity consumed in the chemical reaction for oxidizing / reducing the lead compound of the unformed electrode plate to the positive / negative electrode active material with respect to the total amount of electricity to be energized.

For this purpose, it is effective to raise the temperature of the lead-acid battery formed in the battery case to, for example, 60 ° C. or higher. However, raising the battery temperature during the formation of the battery case has a side face that particularly deteriorates the discharge performance of the negative electrode plate.
That is, the discharge performance of the lead storage battery subjected to battery case formation in which the battery temperature during formation exceeds 60 ° C. is, for example, 50 ° C., particularly at −15 ° C. compared to the lead storage battery subjected to battery case formation for a longer time. The high rate discharge time is clearly shortened.
This is due to the deterioration of the discharge performance of the negative electrode plate. In particular, when the maximum value of the battery temperature during battery case formation exceeds 65 ° C., this tendency appears remarkably.

Therefore, in order to realize the extension of the low-temperature high-rate discharge time of the battery, in particular, the extension of the low-temperature high-rate discharge time in the battery subjected to the chemical conversion treatment at a high temperature exceeding 60 ° C., lignin sulfonic acid to the negative electrode or its It is known that increasing the amount of salt added is effective. In addition, lignin sulfonic acid is a polymer with a complex structure, and it is impossible for the cation of the functional group to be all protons, or conversely to be substituted with metal salts. The mixing ratio of proton and metal salt changes depending on the conditions. In the following text, lignin sulfonic acid and its salts are collectively referred to as lignin sulfonic acid.
The effect of extending the low-temperature, high-rate discharge time in a battery subjected to chemical conversion treatment at a high temperature exceeding 60 ° C. is that even if a part of lignin sulfonic acid in the negative electrode is eluted or decomposed during high-temperature chemical conversion, the lignin is still in the negative electrode. This is because a large amount of sulfonic acid remains.

  However, on the other hand, an increase in the amount of lignin sulfonic acid added decreases the charge acceptance current of the battery at a low temperature. Therefore, excessive addition of lignin sulfonic acid is disadvantageous in view of the overall battery performance.

  Furthermore, considering the manufacturing process, adjusting the water temperature in a large aquarium is the simplest in terms of designing a manufacturing facility and is suitable for mass production. Due to seasonal changes in the environment and other reasons, the battery temperature may fluctuate significantly above and below a predetermined value unexpectedly. If the formation temperature greatly exceeds a predetermined temperature, the low-temperature high-rate discharge performance and the charge acceptance performance may deviate from the standard values.

  Conventionally, sodium salts, potassium salts, calcium salts, and the like of lignin sulfonic acid have been employed as negative electrode additives that extend the low-temperature, high-rate discharge time (see, for example, Patent Documents 1 and 2). However, these lignin sulfonic acids are insufficient to solve the problems at high temperature formation described so far, and as a negative electrode additive, there is a remarkable effect in extending the low temperature high rate discharge time, and the charge acceptance current Therefore, lignin sulfonic acid, which is difficult to reduce the amount, was expected.

JP 2004-327108 A JP 2003-51307 A

  An object of the present invention is to provide a negative electrode plate and a lead-acid battery in which discharge performance, particularly low temperature and high rate discharge time, is small even when the battery temperature during chemical conversion is high, for example, 75 ° C. or more, and the decrease in charge acceptance current is small And

The first aspect of the present invention, a powder of a mixture of lead oxide powder or lead oxide and metallic lead as the main component, in including a negative electrode plate lignin sulfonate, the lignin sulfonate is a functional group that holds 100 parts of lignin sulfonic acid in which 91% or more of the cationic part ionizable in an acidic aqueous solution or alkaline aqueous solution is substituted with protons, the lead oxide powder as the main component, or a powder of a mixture of lead oxide and metal lead, 100 parts In contrast, a negative electrode plate for a lead storage battery comprising 0.2 part or more and 0.6 part or less of the lignin sulfonic acid.

According to a second aspect of the present invention, in a negative electrode plate containing lead oxide powder or a mixture of lead oxide and metal lead as a main component and containing lignin sulfonic acid, the lead oxide powder or lead oxide and metal lead as the main components 100 parts by weight of the mixture of lignin sulphonic acid was contained in an amount of 0.2 part or more and 0.7 part or less, and 91% or more of the ionizable cation part in the lignin sulphonic acid was substituted with protons. amount of lignin sulfonate 0.2 parts or more and less 0.6 parts shall be the the balance being lignin sulfonic acid or 80.5% was replaced by a metal ion of cationic moiety It is a negative electrode plate for lead acid batteries.

A third invention of the present invention is a lead-acid battery using the negative electrode plate of either the first or second invention.

  According to the present invention, it is possible to perform battery case formation in a relatively short time without degrading the low-temperature high-rate discharge performance of the lead-acid battery, and there is an industrially remarkable effect.

It is a top view which shows the structure of the sample battery (44B20 type) used for experiment in the Example, and the measuring method of the cell temperature at the time of chemical formation. It is a figure which shows the relationship between the amount of lignin sulfonic acid addition of the sample battery of Experiment 1, and low temperature high rate discharge time. It is a figure which shows the relationship between the amount of lignin sulfonic acid addition of the sample battery of Experiment 1, and a charge acceptance current. It is a figure which shows the relationship between the amount of lignin sulfonic acid addition of the sample battery of Experiment 2, and low temperature high rate discharge time. It is a figure which shows the relationship between the amount of lignin sulfonic acid addition of the sample battery of Experiment 2, and charge acceptance current. It is a figure which shows the relationship between Na substitution rate of the lignin sulfonic acid added to the sample battery of Experiment 3, and low temperature high rate discharge time. It is a figure which shows the relationship between Na substitution rate of the lignin sulfonic acid added to the sample battery of Experiment 3, and charge acceptance electric current. It is a figure which disassembles the sample battery after the low-temperature, high-rate discharge test of Experiment 3, and shows the relationship between the residual amount of lignin sulfonic acid in the negative electrode active material of each sample and the Na substitution rate of the added lignin sulfonic acid. It is a figure which shows the relationship between the total addition amount of lignin sulfonic acid of the sample battery of Experiment 4, and low-temperature high-rate discharge time. It is a figure which shows the relationship between the total addition amount of lignin sulfonic acid of the sample battery of Experiment 4, and a charge acceptance electric current (D_0-D_3 series). It is a figure which shows the relationship between the total addition amount of lignin sulfonic acid of the sample battery of Experiment 4, and charge acceptance current (D_4-D_6 series).

  The present invention relates to a negative electrode plate for a lead storage battery, the main component of which is a lead oxide powder or a powder of a mixture of lead oxide and metal lead (hereinafter referred to as lead powder), to which lignin sulfonic acid is added, and its negative electrode In a lead-acid battery using a plate, a part or all of the lignin sulfonic acid to be added is a lignin sulfonic acid in which most of the cation portion that can be ionized in an acid or alkaline aqueous solution of the functional group is substituted with protons. It is characterized by being.

More preferably, a part or all of the lignin sulfonic acid is lignin sulfonic acid in which 91% or more of the cation portion is substituted with protons.
Furthermore, with respect to 100 parts of lead powder as a main component in the negative electrode plate for lead acid battery and lead acid battery, 0.2 part of lignin sulfonic acid in which 91% or more of the cation part is substituted with protons, 0.6 part or more The total addition amount of lignin sulfonic acid, which includes the following and 91% or more of the cation portion is replaced with protons, and lignin sulfonic acid whose most cation portion is replaced with metal ions is 0.2 parts or more , 0.7 parts or less.

First, a method for measuring the amount of a cation that can be ionized in an acid or alkaline aqueous solution of a functional group held by lignin sulfonic acid will be described.
Generally, the ionizable portion of the functional group held by commercially available lignin sulfonic acid is occupied by protons or metal ions such as sodium, potassium and calcium.
Therefore, the metal ion ratio of the ionizable portion of the functional group held by lignin sulfonic acid is measured using the following method.

  The sample is exposed to a sufficient amount of lignin sulfonic acid in a 12N sulfuric acid aqueous solution at a liquid temperature of 85 ° C. for 8 hours, and then the precipitate is washed with water and dried.

Next, 10.0 g of the above-treated sulfuric acid-treated lignin sulfonic acid was dispersed in ion-exchanged water in a beaker to make an aqueous solution A having a volume of 100 ml, and kept at 50 ° C. in a water bath while stirring and stirring at 2 ml or less per minute. A 4N aqueous sodium hydroxide solution is added dropwise at a speed. The pH of the aqueous solution A was measured with a pH meter, and the hydroxide ion [OH calculated from the number M of sodium hydroxide dropped when the pH reached 14 and the volume and pH of the aqueous solution A at that time. ^{Based on the} number of moles of-], the maximum ionizable F amount (mol / g) in 100 g of lignin sulfonic acid is calculated by the following formula (1).

The obtained maximum ionizable ion amount is expressed per 100 g of sample lignin sulfonic acid, and the maximum molar amount of the cation portion of the functional group ionizable in the acid or alkaline aqueous solution of sample lignin sulfonic acid. Represents.
This functional group is mainly a sulfone group, but other carboxyl groups added to the polymer are also considered to correspond to this.

Next, 10.0 g of lignin sulfonic acid as a sample was dispersed in ion-exchanged water in a beaker to obtain an aqueous solution A ′ having a volume of 100 ml, measured by the method described in paragraph 0020, and dropped when the pH reached 14. Based on the number of moles M ′ of sodium hydroxide and the number of moles m ′ of the hydroxide ion OH ⁻ calculated from the volume and pH of the aqueous solution A ′, it can react with the hydroxide ions in 100 g of lignin sulfonic acid. The amount of positive cation F ′ (mol / g) is calculated by the following equation (2).

  Next, the numerical value K is calculated | required by the following formula | equation (3).

This is the Na substitution rate (%) of the functional group of the lignin sulfonic acid used as a sample.
The functional group of the sample lignin sulfonic acid is substituted with K ⁺ , Ca ²⁺ , Mg ^2+, etc. in addition to Na ⁺ as metal ions, but all of them are calculated as Na ⁺ .
In the following description, the state of the functional group of lignin sulfonic acid is represented by this Na substitution rate. In other words, in lignin sulfonic acid in which all of the cation portion that can be ionized in an acidic aqueous solution or an alkaline aqueous solution of the functional group to be retained is replaced with protons, the Na substitution rate is 0%, and all the cation portions are replaced with metal ions. In the obtained lignin sulfonic acid, the Na substitution rate is 100%.

  Hereinafter, the present invention will be described in more detail with reference to examples.

[Experiment 1]
A battery 44B20 having a nominal capacity of 30 Ah (5-hour rate) was assembled using the negative electrode plate listed in Table 1. The structure of this battery is as shown in FIG.
The active material amount of the negative electrode plate used is 254 g per cell, its apparent density is 3.65 g / cm ³ , the active material amount of the positive electrode plate is 270 g per cell, and its apparent density is 3.35 g / cm ³ . In addition to the lignin sulfonic acid shown in Table 1, 0.2 parts of acetylene black and 1 part of barium sulfate were added to 100 parts of lead powder as a main component. A Pb—Ca—Sn alloy was used for the grid of the electrode plate.

The lignin X in Table 1 is a process of substituting a commercially available lignin sulfonic acid (I) produced by the sulfite method with protons for its ionizable cation part to a 12N sulfuric acid aqueous solution at a liquid temperature of 50 ° C. Lignin sulfonic acid applied for 2 hours.
Lignin Y is lignin sulfonic acid (I) itself without any treatment.
The lignin Na substitution rate was approximately 0.6% for lignin X (that is, proton was 99.4%) and approximately 80.5% for lignin Y (19.5%).

An unformed battery was prepared using an unformed negative electrode plate prepared by adding each lignin sulfonic acid to 100 parts of lead powder as a raw material as shown in Table 1. Table 1 shows the relationship between the unformed battery, the amount of lignin sulfonic acid added, and the formation temperature. A plurality of batteries were manufactured.
The X ₇₅ (75 ° C. conversion) series and X ₅₀ (50 ° C. conversion) series batteries are the batteries of the present invention, and the Y ₇₅ and Y ₅₀ series batteries are comparative examples.

_X75 series and _Y75 series non-formed batteries shown in Table 1 were subjected to battery formation for 8 hours in a water tank. The charging current was 19 A, and the water tank temperature was adjusted so that the maximum temperature of the central cell of the battery during battery case formation was in the range of 75 to 77 ° C. The temperature of the central cell was measured by inserting a thermocouple into the electrolyte above the pole group as shown in FIG.

Then the chemical batteries of _{X 75 series, Y 75} series were subjected to low-temperature high-rate discharge test according to JIS D5301.
The result is shown in FIG. Note the low temperature high rate discharge time for each sample cell, the sample cell Y ₇₅ discharge time ₍₁₎ as 100, represents the discharge time of the other batteries in the ratio of the battery Y _{75 (1).}

Then X ₅₀ series, denoted by the unformed cell Y ₅₀ series the battery jar conversion of 8 hours in a water bath. The charging current was 19 A, and the water bath temperature was adjusted so that the maximum temperature of the central cell (third and fourth cells) of the battery during battery case formation was in the range of 50 to 53 ° C.

These X ₅₀ series and Y ₅₀ series formed batteries were subjected to a low temperature high rate discharge test according to JIS D5301.
The result is shown in FIG.

From the results shown in FIG. 2, the low temperature high rate discharge time was extended as the amount of lignin added was increased in any of the series of sample batteries. However, in the 50 ° C. conversion, the Y ₅₀ series batteries to which lignin Y was added had lignin X added. The discharge time was slightly longer than that of the added _X50 series sample batteries.
On the other hand, when comparing the cell with _{X 75} sequence and _{Y 75} series having been subjected to 75 ° C. _{Kasei, X 75} series low temperature high rate discharge it over around the time _{Y 75} series battery cell, in particular a lignin X 0.2 When more than one part was added (X ₇₅ (2) to X ₇₅ (12)), the discharge time significantly increased according to the amount added. Meanwhile adding lignin Y in 0.3 parts or more _{(Y 75 (3) ~Y 75} (12)) Then, with respect to the amount added, but the discharge time is extended substantially linearly, the extent of the increase added lignin X It was not as big as the battery.

Next, each series of formed sample batteries was subjected to a charge acceptance test 2 according to JIS D5301.
The results are shown in FIG.

From the results of FIG. 3, but any sequence of charge acceptance current with increasing lignin sulfonic acid amount in the battery is reduced, the amount is in the following 0.6 parts of X ₇₅ series and Y ₇₅ sequence regardless conversion temperature during or between the X ₅₀ series and Y ₅₀ series, rather than a large difference in the value of the charge acceptance current, whereas, seen the difference in charging current value due to the difference of the chemical conversion temperature, the charge acceptance of 50 ° C. Chemical batteries The current value was larger.
Furthermore, when the addition amount is 0.8 parts or more, the difference in current value due to the conversion temperature is also small, and the magnitude of the charge acceptance current of each series of sample batteries regardless of the difference between the Na substitution rate of lignin sulfonic acid and the conversion temperature. There was no difference.

From Experiment 1, the lead-acid battery using the negative electrode plate according to claim 1 of the present invention does not exhibit its effect at a chemical conversion temperature of about 50 ° C., but it retains its functional group when subjected to high temperature conversion of 75 ° C. It can be seen that this is superior in terms of low-temperature and high-rate discharge time as compared with a battery using a negative electrode plate to which lignin sulfonic acid in which most of the cation portion that can be ionized in an aqueous solution is added with Na ⁺ is added.

In particular, it can be seen that the addition of 0.2 part or more of ligion sulfonic acid significantly extends the low-temperature, high-rate discharge time compared to the conventional example.
On the other hand, it can be seen that the charge acceptance current of the battery of the present invention does not decrease even when compared with the battery of the comparative example.

[Experiment 2]
Next, a battery having the same battery configuration as in Experiment 1 was assembled using the negative electrode plate listed in Table 2.
The lignin V in Table 2 is a process of substituting a commercially available lignin sulfonic acid (II) produced by the Kraft method with protons for its ionizable cation portion to a 12N sulfuric acid aqueous solution at a liquid temperature of 50 ° C. Lignin sulfonic acid applied for 2 hours.
Lignin W is lignin sulfonic acid (II) itself which is not subjected to any treatment.
The lignin sulfonic acid had a Na substitution rate of approximately 0.3% for lignin V (that is, 99.7% protons) and approximately 78.5% (21.5% for lignin W).

An unformed battery was prepared using an unformed anode plate prepared by adding each lignin sulfonic acid as shown in Table 2 to 100 parts of the anode main raw material. Table 2 also shows the relationship between the unformed battery, the amount of lignin sulfonic acid added, and the formation temperature. A plurality of batteries were manufactured.
Note that the V ₇₅ and V ₅₀ series batteries are the batteries of the present invention, and the W ₇₅ and W ₅₀ series batteries are comparative examples.

The V ₇₅ series and W ₇₅ series unformed batteries shown in Table 2 were subjected to battery formation for 8 hours in a water tank. The charging current was 19 A, and the water bath temperature was adjusted so that the maximum temperature of the central cells (third and fourth cells) of the battery during battery case formation was in the range of 75 to 77 ° C.

Next, these V ₇₅ row and W ₇₅ row formed batteries were subjected to a low-temperature high-rate discharge test according to JIS D5301.
The results are shown in FIG. The low-temperature high-rate discharge time is represented by the ratio of the discharge time of each battery to the battery Y ₇₅ (1), where 100 is the discharge time of the sample battery Y ₇₅ (1), as in Experiment 1.

Next, V ₅₀ series, the unformed cell W ₅₀ series were subjected to battery container conversion of 8 hours in a water bath. The charging current was 19 A, and the water tank temperature was adjusted so that the maximum temperature of the central cell (third and fourth cells) of the battery during battery case formation was in the range of 50 to 53 ° C.
These V ₅₀ series and W ₅₀ series formed batteries were subjected to a low-temperature high-rate discharge test according to JIS D5301.
The results are shown in FIG.

As is clear from FIG. 4, the discharge time of each sample battery increased as the amount of lignin sulfonic acid added increased. However, in the case of 50 ° C. conversion, the W ₅₀ series battery added with lignin W was more lignin. discharge time than the sample cell of V ₅₀ series was added V is longer.
On the other hand, in the comparison between the V ₇₅ series battery subjected to 75 ° C. conversion and the W ₇₅ series battery, when 0.2 parts or more of lignin V is added (V ₇₅ (2) to V ₇₅ (12)), the addition amount Accordingly, the discharge time is remarkably extended. In addition, when lignin W is added in the range of 0.3 part or more and 1.0 part or less (W ₇₅ (3) to W ₇₅ (10)), the discharge time extends almost linearly with respect to the addition amount. However, the degree of increase was not as great as that of the lignin V-added battery.

Next, each series of formed sample batteries was subjected to a charge acceptance test 2 according to JIS D5301. The results are shown in FIG.
As is clear from FIG. 5, the charge acceptance current decreased with the increase in the amount of lignin sulfonic acid in any series of batteries, but the charge acceptance current value of the battery to which lignin V was added at each conversion temperature was lignin W. It was bigger than or almost equal to

As described above, in Experiment 2, as in Experiment 1, the lead-acid battery using the negative electrode plate according to claim 1 of the present invention does not exhibit its effect at a chemical conversion temperature of about 50 ° C., but is as high as 75 ° C. It can be seen that the chemical conversion is superior to the comparative example in terms of low-temperature high-rate discharge time, and the degree of increase in discharge time accompanying the amount of lignin sulfonic acid added is greater.
On the other hand, it is clear that the charge acceptance current of the battery using the negative electrode plate of the present invention does not decrease even when compared with the conventional battery.

  From the above experiments 1 and 2, regardless of the type of lignin sulfonic acid, the present invention, that is, the addition of lignin sulfonic acid in which most of the cationic part ionizable in the aqueous solution of the functional group held therein is substituted with protons is added. The lead-acid battery using the negative electrode plate shows a significant improvement in low-temperature, high-rate discharge performance over conventional batteries when it is formed at a high temperature of about 75 ° C. without deteriorating the charge acceptance performance. .

[Experiment 3]
Next, when the same lignin sulfonic acid (I) as in Experiment 1 was treated with an aqueous sulfuric acid solution, the lignin sulfonic acid with the Na substitution rate changed by adjusting the pH of the aqueous solution was prepared as shown in Table 3. .
A non-chemical cell was produced using a negative electrode plate in which 0.3 part of these lignin sulfonic acids was added to 100 parts of the main raw material of the negative electrode. Table 3 shows the A series.
A non-chemical battery was produced by producing a negative electrode plate under the same production conditions as those of the A-series negative electrode plate except that the amount of lignin sulfonic acid added was 0.6 part. Table 3 shows the B series.

Next, these non-chemical cells were formed into a battery case at a maximum temperature of 75 to 77 ° C. The formation current value and energization time are the same as in Experiment 1.
Next, each of these A and B series batteries was subjected to a low-temperature high-rate discharge test according to JIS D5301.
The result is shown in FIG. The low-temperature high-rate discharge time of each battery is expressed as a ratio to this value, assuming that the discharge time of the battery Y ₇₅ (1) of Experiment 1 is 100.

As is clear from FIG. 6, in the A-series sample batteries, when the Na substitution rate was 9% or less (A1 to A4), good low-temperature high-rate discharge time was shown, but the Na substitution rate was 9%. The discharge time of the battery suddenly decreased between 22.3% and almost the same discharge time was exhibited at 22.3% or more.
On the other hand, the B-series sample batteries showed good low-temperature high-rate discharge times when the Na substitution rate was also 9% or less (B1 to B4), but the Na substitution rate was 9% and 38.5%. The discharge time of the battery decreased abruptly, and almost the same discharge time was exhibited at 38.5% or more.
In other words, the effect of lignin sulfonic acid that prolongs the low-temperature high-rate discharge time is remarkable when the Na substitution rate is 9% or less (proton is 91% or more). It can be seen that the effect on the discharge time is small regardless.

Next, the A and B series formed batteries were subjected to a charge acceptance test 2 according to JIS D5301. The result is shown in FIG.
As is clear from FIG. 7, the charge acceptance current is almost constant regardless of the Na substitution rate of the lignin sulfonic acid to be added in any of the A and B series sample batteries, and JIS D 5301 Table 1 ( The standard value of the charge acceptance current described in the 2006 edition) was sufficiently higher than 4.0A.

  As described above, the battery using the negative electrode plate of the present invention to which lignin sulfonic acid having a Na substitution rate of 9% or less is added exhibits a remarkably good low-temperature high-rate discharge time even when it is formed at a high temperature of about 75 ° C. However, since the variation in the charge acceptance current is generally not small, the following numerical value Q is further calculated based on the above data to obtain the charge acceptance current. The evaluation of was done in detail.

  Based on the data of the above measurement, the average value of the charge acceptance current for each lot of the sample battery and the standard deviation of the difference between the measured value and the average value for each lot over all data (this is the mother standard) The estimated value of the deviation is calculated, and the average value (this is the "estimated value of the population average of charge acceptance current for each lot") and the lower limit standard value of charge acceptance current of 4.0A for each lot. The value (Q value) obtained by dividing the difference between the two by the estimated value of the mother standard deviation was calculated. The results are shown in Table 3. Moreover, the calculation formula is shown in the following formula (4).

Then, assuming that the measured value follows a normal distribution, when the batteries of each series are mass-produced from the Q value, the probability that the charge acceptance current of the battery is below 4.0 A was examined based on the normal distribution table. In addition, it is 0.3% or less that the probability is industrially acceptable, and the corresponding Q value is 2.75 or more.
As a result, the probability of the A series was 0.1% or less, and that of the B series was 0.2% or less. Therefore, in the embodiment of Experiment 3, the probability that the charge acceptance current is lower than the standard value can be ignored in practical use.

  From the result of Experiment 3, in the battery 44B20 in which the cell maximum temperature during chemical conversion is 75 to 77 ° C., 0.3 part or 0.6 part of lignin sulfonic acid in which the Na substitution rate is changed with respect to 100 parts of the main raw material of the negative electrode. In each case, when the Na substitution rate of lignin sulfonic acid was 9% or less, the effect of remarkably extending the low-temperature high-rate discharge time without decreasing the charging current was observed.

The technical reasons for the phenomena shown in Experiments 1, 2, and 3 are not completely explained, but are generally considered as follows.
That is, lignin sulfonic acid is first kneaded with water and lead powder in the negative electrode manufacturing process, but the pH of this kneaded product is approximately 10, and the lignin sulfonic acid is well dissolved and adsorbed on the surface of the lead powder. Is done. However, when most of the ionizable cation portion of the functional group of lignin sulfonic acid is occupied by metal ions such as Na ^{+ in the} high-temperature chemical conversion step, the lignin sulfonic acid has a relatively low electrolysis with a pH of 7 or less. Elution is easy even in liquid. In particular, the electrolytic solution inside the electrode plate before the start of chemical conversion or for a while after the start reacts with the unformed active material of the electrode plate to have a pH of 4 to 6, and at this time also has an effect of high temperature, lignin sulfonic acid The elution of the lignin sulfonic acid remaining in the negative electrode plate decreases.

On the other hand, lignin sulfonic acid, in which most of the ionizable cation portion of the functional group is occupied by protons, is difficult to dissolve in an acidic aqueous solution having a pH of 7 or less. It is difficult to elute and the amount remaining on the electrode plate is relatively large.
For this reason, it is considered that the negative electrode plate added with lignin sulfonic acid, in which most of the ionizable cation portion of the functional group is occupied by protons, improves the low-temperature high-rate discharge performance after high-temperature formation.

Therefore, the sample battery after the low-temperature, high-rate discharge test of Experiment 3 was disassembled, and the amount of lignin sulfonic acid remaining in the negative electrode active material of each sample was measured. The remaining amount was expressed as a percentage (%) with respect to the amount of active material. The result is shown in FIG.
From FIG. 8, it can be seen that the amount of lignin sulfonic acid in both the A series sample with 0.3 parts of lignin sulfonic acid added and the B series sample with 0.6 parts of the lignin sulfonic acid increased rapidly when the Na substitution rate exceeded 9%. It is confirmed that Further, the residual amount of lignin sulfonic acid having a Na substitution rate of 9% or less is generally proportional to the amount of lignin sulfonic acid added at the time of producing the negative electrode paste, but as the Na substitution rate of lignin sulfonic acid greatly exceeds 9%, A It is shown that the difference in the remaining amount ratio between the series and the B series is small between samples.

As is clear from FIG. 8, there was a clear relationship between the Na substitution rate of lignin sulfonic acid and the residual rate of lignin sulfonic acid after conversion.
On the contrary, with respect to each of the lignin sulfonic acids as the basis, the remaining amount (%) in the negative electrode active material with respect to the addition amount (part) and the Na substitution rate in advance as shown in FIG. If the time and charge acceptance current are measured, the amount added in the production stage can be estimated from the remaining amount in the active material.

On the other hand, the effects of the amount of lignin sulfonic acid added and the Na substitution rate on the charge acceptance current are considered to be more complex.
In other words, lignin sulfonic acid is said to limit the rate of the charging reaction because it is adsorbed on the active part of the metal lead crystal, which is the negative electrode active material. On the other hand, it increases the surface area involved in the charging reaction of the metal lead during formation. Therefore, it also has the effect of increasing the charging current.
Therefore, in the region where the amount of lignin sulfonic acid added is relatively low, the charge acceptance current at 50 ° C. formation is larger than that at 75 ° C., and lignin sulfonic acid with a low Na substitution rate at 75 ° C. formation is Na substitution. It seems that the latter effect appears when the charge acceptance current is made slightly larger than that with a larger rate.

[Experiment 4]
Next, according to Experiment 4, lignin sulfonic acid in which most of the ionizable cation portion of the functional group is occupied by protons alone or a mixture with lignin sulfonic acid in which the majority of functional groups are occupied by metal ions In the case of adding, an appropriate range of the addition amount for exhibiting a more preferable effect is shown.

  A lignin sulfonic acid having a Na substitution rate of 9.0% is prepared in the same manner as in Experiment 3, and this is designated as lignin S. Also prepared in Experiment 1 is lignin sulfonic acid (lignin Y) having a Na substitution rate of 80.5%.

Sample battery 44B20 shown in Table 4 was produced by changing the addition amount of the produced lignin S alone or as a mixture with lignin Y. The produced sample battery was formed at 75 to 77 ° C. under the same conditions as in Experiment 1.
The formed sample battery was subjected to a low-temperature, high-rate discharge test and a charge acceptance test under the same conditions as in Experiment 1. FIG. 9 shows the duration of the low-temperature high-rate discharge, and FIGS. 10 and 11 show the charge acceptance current values.
The bold portions in Table 4 are examples of the present invention. A sample battery added with 0.3 parts of lignin S has the same contents as A4 in Experiment 3, and a sample battery added with 0.6 parts of lignin S has the same contents as B4.

The results of the low temperature high rate discharge test of these batteries are shown in FIG. Discharge time, similarly as in Experiment 1, are expressed as 100 the discharge duration of the battery Y ₇₅ Experiment 1 _(1), the discharge time of each cell by the ratio of the battery Y _{75 (1).}
9, in order to characterize the amount of lignin Y added when displaying each lot in the vertical column of Table 4, from the left, D_0 series, D_1 series, D_2 series, D_3 series, D_4 series, D_5 series, D_6 It is displayed as a series. For example, the D_0 series includes D20, D30, D40, D60, D70, D80, D90, and D100.
For comparison, the results of the X-series and Y-series sample batteries of Experiment 1 are also displayed.

As is clear from FIG. 9, when a negative electrode plate to which lignin sulfonic acid (lignin S) having a Na substitution rate of 9.0% was added alone was used, the Na substitution rate was 0.6 at any addition amount. % Of the lignin sulfonic acid added (X series sample battery of Experiment 1) exhibited a low temperature and high rate discharge time almost the same as that of 0.2 part or more.
In addition, when a mixture of lignin S and lignin sulfonic acid (lignin Y in this experiment) in which most of the ionizable cation portion of the functional group is occupied by Na ⁺ is added, the total amount of the addition is increased. The low temperature high rate discharge time was extended, and between samples with the same amount of lignin S added, the sample to which lignin Y was also added exhibited a longer low temperature high rate discharge time. For example, comparing D60 with 0.6% lignin S alone and D61 with 0.6% lignin S and 0.1% lignin Y shows that the latter low temperature high rate discharge time is longer.

Next, the charge acceptance current of each sample battery was measured, and the results are shown in FIGS.
10 and 11 also use the same notation as in FIG. 9 to characterize the amount of lignin Y added when displaying each lot in the vertical column of Table 4.

  As is apparent from FIGS. 10 and 11, the charge acceptance current of each sample battery tends to decrease as the total amount of lignin sulfonic acid increases, and the charge acceptance current of some sample batteries is the same as the standard value. It was just a little over.

  Therefore, in order to determine the upper limit of the amount of lignin added, the Q value was calculated in the same manner as in Experiment 3 based on these data.

Here, since it can be assumed that the measured value of each sample battery of the charge acceptance current follows a normal distribution, this Q value is the standard value of the charge acceptance current value of each content battery when each content battery is mass-produced. Corresponds to the probability of falling below 4.0A. In order to reduce the probability to 0.3% or less at which it is determined that there is no problem in industrial production, a product having a Q value of 2.75 or more may be selected.
According to Table 4, the combination of lignin sulfonic acids that meet this condition in this experiment is that lignin S alone is a negative electrode plate having an addition amount of 0.6 parts or less, and lignin is used in combination with lignin Y. This is a case where a negative electrode plate having an addition amount of S of 0.6 parts or less and a total addition amount of 0.7 parts or less is used.

From the above results and further from the results of Experiment 3, when lignin sulphonic acid, in which most of the ionizable cation portion is more than 91%, preferably occupied by protons, is added alone, the charge acceptance current decreases. More preferably, the addition amount range in which the effect of extending the low-temperature high-rate discharge time is remarkably exhibited is 0.2 part or more and 0.6 part or less.
Also, a mixture of lignin sulfonic acid in which 91% or more of the ionizable cation portion of the functional group is occupied by protons and lignin sulfonic acid in which the majority of the ionizable cation portion of the functional group is occupied by Na ⁺ Is added to the negative electrode plate of a lead-acid battery, the charge acceptance current of the battery is not reduced, and the low-temperature high-rate discharge time is limited to lignin sulfonic acid in which most of the ionizable cation portion is occupied by protons. In some cases, the lignin sulfonic acid is added in an amount of 0.2 parts or more and 0.6 parts or less, and 91% or more of the ionizable cation portion is occupied by protons. This is the case when the total amount of sulfonic acid added is 0.7 parts or less.

In Experiment 4, lignin Y having a Na substitution rate of 80.5% was used as the lignin sulfonic acid in which most of the ionizable cation portion of the functional group is occupied by Na ⁺ . Claim 3 is not limited to this case, and it is easily assumed that the effects of the present invention can be achieved if the lignin sulfonic acid has the same Na substitution rate.

  As described above from the above experiments, according to the present invention, it is possible to perform battery formation in a relatively short time without degrading the low-temperature high-rate discharge performance of the lead-acid battery. It has a remarkable effect.

1 Positive terminal
2 Negative terminal
3 3rd cell 4 4th cell
5 strap 6 pole group
7 battery case
8 Thermocouple

Claims (3)

In the negative electrode plate containing lead oxide powder or powder of a mixture of lead oxide and metal lead as a main component and containing lignin sulfonic acid,
The lignin sulfonic acid is a lignin sulfonic acid in which 91% or more of the cationic moiety ionizable in an acidic aqueous solution or an alkaline aqueous solution of a functional group to be held is substituted with a proton,
The lead storage battery characterized by containing 0.2 parts or more and 0.6 parts or less of the lignin sulfonic acid with respect to 100 parts of the lead oxide powder as the main component or powder of a mixture of lead oxide and metal lead. Negative electrode plate. In the negative electrode plate containing lead oxide powder or powder of a mixture of lead oxide and metal lead as a main component and containing lignin sulfonic acid,
0.2 parts or more and 0.7 parts or less of lignin sulfonic acid with respect to 100 parts of the powder of the lead oxide powder or lead oxide and metal lead as the main component,
Of the lignin sulfonic acid, 91% or more of the ionizable cation portion is substituted with protons, and the addition amount of lignin sulfonic acid is 0.2 parts or more and 0.6 parts or less , and the remainder is the cation part. negative electrode plate for a lead storage battery you characterized in that more than 80.5% is substituted lignin sulfonate to a metal ion. The lead acid battery which used the negative electrode plate of Claim 1 or 2 for the negative electrode plate.

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