JPH11250913A - Lead-acid battery - Google Patents

Abstract

(57) [Problem] To provide a lead storage battery having a long cycle life and a small decrease in low-temperature capacity. SOLUTION: In a lead storage battery comprising a positive electrode, a negative electrode and an electrolyte, the negative electrode has a negative electrode active material to which a mixed additive is added, and the mixed additive is bisphenol A.
・ A mixture of aminobenzenesulfonic acid / formaldehyde condensate and lignin. The mixing ratio of the bisphenol A / aminobenzenesulfonic acid / formaldehyde condensate in the mixture is 0.5 to 0.75 by weight.
It is preferred that

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lead storage battery which has a small capacity reduction at a low temperature.

[0002]

2. Description of the Related Art Conventionally, in a lead-acid battery comprising a positive electrode, a negative electrode and an electrolyte, the addition of lignin as an additive to the negative electrode active material constituting the negative electrode is effective in maintaining the reactivity related to charge and discharge. It is known. That is, by adding lignin, a decrease in the surface area of the negative electrode and shrinkage (shrinkage) can be suppressed, the reactivity relating to charging and discharging can be maintained, and the cycle life of the lead storage battery can be extended.

[0003]

However, the above-mentioned conventional lignin-added lead storage battery has the following problems.
That is, since the lignin is decomposed by repeated charge and discharge of the lead storage battery, the organic matter generated by the decomposition may be eluted into the electrolytic solution. In this case, the overvoltage of the lead storage battery may increase, and the charging performance thereof may decrease (GS-News, Vol. 37, No. 1, pp. 22-22).
8, 1978).

On the other hand, in order to solve this problem, the present inventors have found that it is effective to use a bisphenol A / aminobenzenesulfonic acid / formaldehyde condensate instead of the lignin as a negative electrode additive. (Japanese Patent Application No. 8-103575). This bisphenol A
-When an aminobenzenesulfonic acid / formaldehyde condensate is used, a lead-acid battery having a long cycle life and excellent charge performance can be obtained.

[0005] However, in recent years, there has been a demand for a lead-acid battery with higher performance. In particular, it has been desired to develop a lead-acid battery capable of greatly suppressing a decrease in charge / discharge capacity (low-temperature capacity) in a low-temperature environment. Was rare.

The present invention has been made in view of such conventional problems, and an object of the present invention is to provide a lead storage battery having a long cycle life and a small decrease in low-temperature capacity.

[0007]

According to a first aspect of the present invention, there is provided a lead-acid battery including a positive electrode, a negative electrode, and an electrolyte, wherein the negative electrode has a negative electrode active material to which a mixed additive is added, and Is bisphenol A, aminobenzenesulfonic acid,
A lead-acid battery comprising a mixture of formaldehyde condensate and lignin.

The most remarkable point in the present invention is that a mixture of bisphenol A / aminobenzenesulfonic acid / formaldehyde condensate and lignin is used as the mixed additive.

As the above lignin, any lignin conventionally used as an additive for lead-acid batteries can be used. Kraft lignin obtained when digested and its modified products can be used.

Next, the operation of the present invention will be described. As described above, in the lead storage battery of the present invention, a mixed additive containing a mixture of the above bisphenol A / aminobenzenesulfonic acid / formaldehyde condensate and lignin is added to the negative electrode active material.

Therefore, first, the above bisphenol A
Aminobenzenesulfonic acid / formaldehyde condensate suppresses the reduction of negative electrode surface area and shrinkage (shrinkage),
The reactivity with respect to charge and discharge can be maintained, and the cycle life of the lead storage battery can be extended. Further, the presence of the lignin can suppress a lowering of the low-temperature capacity as compared with the conventional case.

The reason is considered as follows. That is,
When only bisphenol A / aminobenzenesulfonic acid / formaldehyde condensate is added to the negative electrode active material, it has a relatively high hydrophobic property. The size became small, and the diffusion of the electrolyte into the negative electrode active material tended to be hindered.

Therefore, by adding lignin having high hydrophilicity together with the above-mentioned condensate of bisphenol A / aminobenzenesulfonic acid / formaldehyde, the size of lead sulfate formed on the surface of the negative electrode becomes larger than before, and the Diffusion inhibition into the negative electrode active material can be suppressed.

When only conventional lignin is added to the negative electrode active material, there is a possibility that the organic matter generated by the decomposition of the lignin is eluted into the electrolyte and the charging performance is reduced. However, this drawback can be solved by the addition of the above-mentioned bisphenol A / aminobenzenesulfonic acid / formaldehyde condensate, as will be shown in the following embodiment.

Therefore, according to the present invention, a lead storage battery having a long cycle life and a small decrease in low-temperature capacity can be provided.

Next, as in the second aspect of the present invention, the compounding ratio of the bisphenol A / aminobenzenesulfonic acid / formaldehyde condensate in the mixture is preferably 0.5 to 0.75 by weight. This gives
The charge / discharge performance is further improved. Further, when the weight ratio is 0.1.
When it is less than 5, there is a problem that the regenerative density at a low temperature is reduced. On the other hand, when it exceeds 0.75,
There is a problem that a large decrease in capacity due to temperature rise is large. Here, the above-mentioned compounding ratio means that the whole mixture of bisphenol A / aminobenzenesulfonic acid / formaldehyde condensate and lignin is 1, and that
The ratio occupied by aminobenzenesulfonic acid / formaldehyde condensate.

Further, as in the third aspect of the present invention, the amount of the bisphenol A / aminobenzenesulfonic acid / formaldehyde condensate is determined based on the amount of the negative electrode active material.
Preferably it is 0.2 to 1.5% by weight. When the addition amount is less than 0.2% by weight, there is a problem that the regenerative density particularly at low temperatures is reduced. On the other hand, if the content exceeds 1.5% by weight, more remarkable effects cannot be obtained, and there is a problem that the cost is increased.

Further, as in the invention of claim 4, the mixed additive preferably contains barium sulfate.
Accordingly, the barium sulfate serves as a nucleus for the production of lead sulfate (PbSO ₄ ) at the time of discharging, so that the growth of giant crystals can be suppressed, and the dischargeability, chargeability, and cycle life can be improved.

Further, as in the invention of claim 5, the bisphenol A / aminobenzenesulfonic acid / formaldehyde condensate is preferably a sodium salt. That is, as the above-mentioned bisphenol A / aminobenzenesulfonic acid / formaldehyde condensate, various salts such as sodium salt, potassium salt and magnesium salt can be used. Among them, in the case of sodium salt, particularly excellent charge / discharge performance can be obtained.

[0020]

DESCRIPTION OF THE PREFERRED EMBODIMENTS First Embodiment A lead storage battery according to an embodiment of the present invention will be described with reference to FIGS. In this example, as shown in Table 1, the lead-acid batteries (E1 to
E4, C5, C6) were produced and their performance was evaluated. Each lead storage battery includes a positive electrode, a negative electrode, and an electrolytic solution, and the negative electrode has a negative electrode active material to which a mixed additive is added.

The lead storage batteries (E1 to E1)
In 4), as shown in Table 1, the mixed additive is a mixture of bisphenol A / aminobenzenesulfonic acid / formaldehyde condensate, lignin, carbon, and barium sulfate. In this example, as shown in FIG. 2, the above-mentioned bisphenol A / aminobenzenesulfonic acid / formaldehyde condensate is a sodium salt thereof [Vispers P215 (hereinafter BI) manufactured by Nippon Paper Industries Co., Ltd.
Abbreviated as SP. )] Was used. As the lignin, Vanilex N (manufactured by Nippon Paper Industries Co., Ltd.), which is a partially desulfonated lignin sulfonic acid, was used.

On the other hand, as shown in Table 1, the comparative product C5
BISP and lignin are removed from the mixed additives in the products E1 to E4 of the present invention. The comparative product C6 is
As shown in Table 1, lignin was removed from the mixed additives in the products E1 and E2 of the present invention. Table 1 shows the blend ratio of BISP in the mixture of BISP and ligulin for each sample.

Next, the configuration of each lead storage battery of this embodiment will be described in detail. As shown in FIG. 1, a lead-acid battery 1 manufactured in the present example has a positive electrode plate 1 containing lead dioxide, which is a positive electrode active material, inside a container including a container 102 and a cover 101.
1, a retainer 15 and a negative electrode plate 12 containing sponge-like lead as a negative electrode active material are sequentially combined and stored. The container 102 is filled with an aqueous solution of sulfuric acid as an electrolytic solution.

In preparing the negative electrode plate 12, first, a mixing additive having a mixing ratio as shown in Table 1 is added to 100% by weight of the lead oxide powder as a raw material, and water and diluted sulfuric acid are added and kneaded. To make a paste. Next, this is applied to an electrode grid, and then aged and initially charged to form a negative electrode plate 12.

The retainer 15 is made of a non-woven glass fiber material. The positive electrode plate 11, the negative electrode plate 12, and the retainer 15 are sequentially combined and stored in the container to configure the lead storage battery 1. The structure shown in FIG. 1 may be used as one unit cell, and a plurality of the unit cells may be connected in series to form a large-capacity lead-acid battery. In this example, after the electrolyte solution was injected into each of the lead storage batteries E1 to E4, C5, and C6, initial charging was performed to obtain a sealed battery having a nominal capacity of 10 AH.

[0026]

[Table 1]

Next, in this example, as shown in FIG. 3, the low-temperature capacity cycle of each lead storage battery was evaluated. First, each lead-acid battery was discharged under a temperature of 30 ° C. with a discharge current of 3 A until it reached 1.65 V / cell.
A cycle of charging up to 2.5 V / cell with a current of 2 A, then charging for 10 hours with a constant current of 0.1 A and fully charging is defined as one cycle, and this cycle is repeated. Then,
When the charge / discharge cycle at a temperature of 30 ° C. was repeated 20 to 30 times, each lead storage battery was kept in an atmosphere of −10 ° C., and the low-temperature capacity (3 / 2C capacity) was measured. Here, the low-temperature capacity refers to a discharge capacity when discharging is performed to 1.65 V / cell with a discharge current of 15 A.

A / b where a is the low temperature capacity at −10 ° C. and b is the discharge capacity at the charge / discharge cycle at 30 ° C. immediately before the measurement.
The value of (x100%) was used as the evaluation value. In addition, the product E of the present invention
The low-temperature capacities of the samples 1 to E4 and the comparative product C5 were measured at the above-mentioned −10 ° C. in the 30, 65, and 85 charge / discharge cycles at 30 ° C. The comparative product C6 was subjected to the charge / discharge cycle of 40, 60, 75, 90, 110, 120,
At 150 times, the low-temperature capacity at -10 ° C was measured.

FIG. 3 shows the measurement results. In the figure, the horizontal axis is 3
The number of charge / discharge cycles at 0 ° C. is plotted on the vertical axis with the ratio (a / b (× 100%)) between the low-temperature capacity and the capacity immediately before it. As can be seen from FIG.
It can be seen that the amount of decrease in the low-temperature capacity is significantly improved as compared with the comparative products C5 and C6.

Embodiment 2 In this embodiment, various lead-acid batteries in which the amount of BISP or the like was changed based on the product E1 of the present invention in Embodiment 1 were prepared, and their chargeability was evaluated. Each of the mixed additives in the prepared lead storage battery contains a fixed amount of a mixture (or a single substance) of BISP and lignin in total. The contents were all unified at a ratio of 0.9% by weight with respect to the negative electrode active material. And in each lead-acid battery,
By changing the blending amount of the mixture of BISP and lignin,
The influence on the following regeneration density by the change of the compounding amount was evaluated.

Specifically, first, the DOD of each lead-acid battery is set to 3
It was adjusted to 0%. This DOD is “Depth of
Discharge ”and“ discharge depth ”.
DOD = 30% discharged state from 100% charged state
DOD = 50% when discharged at 30% and 50%.

Next, each lead storage battery was charged. At this time, the current is 1CA-9CA (10A-90A)
Was changed. Then, the voltage of the lead storage battery 10 seconds after the start of charging was measured. The current (Ip) when the voltage reaches the limit voltage from the relationship between the measured current and the voltage
Was measured, and the value obtained by multiplying the current by the limiting voltage was divided by the weight of the battery to obtain the "regeneration density". Therefore, “regeneration density” = Ip × limit voltage / battery weight. Here, the above-mentioned limit voltage is a lower limit value of a voltage at which electrolysis of the electrolytic solution starts in the lead storage battery.

In this example, the measurement of the regenerative density was performed at a temperature of 30 ° C. and 0 ° C., respectively. FIG. 4 shows the measurement results of the regeneration density. In the figure, the horizontal axis is BIS
With respect to the mixing ratio of P, the vertical axis indicates the regenerative density (W / kg), and A is shown at a temperature of 30 ° C. and B is shown at a temperature of 0 ° C.

As can be seen from the figure, as the blending ratio of BISP increases, the regenerative density increases at any temperature. In particular, when the blending ratio was 0.5 or more, the regenerative density was significantly improved as compared with the case where the blending ratio was less than 0.5. On the other hand, if the mixing ratio exceeds 0.75, the regenerative density B at a low temperature (0 ° C.) gradually decreases.

From the above results, it was found that the mixing ratio of BISP in the mixture of BISP and lignin was 0.5 to 0.75.
Thus, it can be seen that a lead storage battery with a small decrease in low-temperature capacity can be obtained.

[0036]

As described above, according to the present invention, a lead storage battery having a long cycle life and a small decrease in low-temperature capacity can be provided.

[Brief description of the drawings]

FIG. 1 is an explanatory view showing a structure of a lead storage battery in a first embodiment.

FIG. 2 is an explanatory view showing a bisphenol A / aminobenzenesulfonic acid / formaldehyde condensate according to the first embodiment.

FIG. 3 is an explanatory diagram showing a ratio of a low-temperature capacity and a previous capacity to the number of charge / discharge cycles in the first embodiment.

FIG. 4 is an explanatory diagram showing a relationship between a BISP mixing ratio and a regenerative density in the second embodiment.

[Explanation of symbols]

 1. . . Lead-acid battery, 11. . . Positive electrode plate, 12. . . Negative electrode plate, 16. . . Electrolyte,

Claims (5)

[Claims] 1. A lead-acid battery comprising a positive electrode, a negative electrode and an electrolyte, wherein the negative electrode has a negative electrode active material to which a mixed additive is added, and the mixed additive is bisphenol A
-A lead-acid battery containing a mixture of aminobenzenesulfonic acid / formaldehyde condensate and lignin. 2. The composition according to claim 1, wherein the mixture ratio of the bisphenol A / aminobenzenesulfonic acid / formaldehyde condensate in the mixture is 0.5 to 0.5 by weight.
75. A lead-acid battery characterized by being 75. 3. The method according to claim 1, wherein the amount of the bisphenol A / aminobenzenesulfonic acid / formaldehyde condensate is 0.2% based on the amount of the negative electrode active material.
A lead-acid battery characterized in that the content is 1.5 to 1.5% by weight. 4. The method according to claim 1, wherein:
A lead-acid battery, wherein the mixed additive contains barium sulfate. 5. The method according to claim 1, wherein:
The lead storage battery, wherein the bisphenol A / aminobenzenesulfonic acid / formaldehyde condensate is a sodium salt.