JP3040718B2 - Lead storage battery - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a lead storage battery.

[0002]

2. Description of the Related Art A conventional lead-acid battery is composed of a lead alloy grid substrate,
A paste made by adding and kneading lead powder to water or sulfuric acid is filled in a lead alloy lattice substrate, dried, and subjected to a chemical conversion treatment to form a positive electrode plate and a negative electrode plate. Then, at least one pair of the positive and negative electrode plates is placed in a battery case. Is assembled by incorporating a group of electrode plates through a separator, a dilute sulfuric acid electrolytic solution is injected, and a lid is provided.

[0003]

However, the lead storage battery manufactured in this manner has a lower utilization rate of the positive electrode active material of the positive electrode plate and a lower energy density than other storage batteries such as a nickel-cadmium storage battery. However, there is a low disadvantage. Therefore, it is desirable to improve the utilization rate of the positive electrode active material and improve the energy density of the lead storage battery.

[0004]

SUMMARY OF THE INVENTION The present invention provides a lead-acid battery which has solved the above-mentioned problems.
It is characterized by having a positive electrode plate mixed with basic lead phosphate. In this case, the amount of the basic lead phosphate added is 0.2 to 4% by weight in terms of the positive electrode active material converted to lead powder.
It is preferred that

[0005]

Next, an embodiment of the present invention will be described. The lead storage battery of the present invention is manufactured as follows. In kneading lead powder (PbO) with water or a dilute sulfuric acid aqueous solution, filling a lead alloy lattice substrate and preparing a paste to be applied,
To this, a basic lead phosphate powder is added and kneaded to prepare a positive electrode active material mixture paste. As basic lead phosphate, for example, any dibasic phosphate such as 2PbO · PbHPO ₃ · 0.5H ₂ O can be used. The addition amount thereof is preferably in the range of 0.2 to 4% by weight in terms of the weight of the positive electrode active material (PbO ₂ ) converted to the amount of (Pb) lead. If it is less than 0.2%, the effect of addition is small. On the other hand, if it exceeds 4%, the effect of addition is the same as that of 4%. However, the amount of active material decreases accordingly, so it should be limited to 4%. Is preferred. Next, each of these positive electrode active material mixtures was filled in a lead alloy substrate and dried,
A large number of each positive electrode plate was produced by chemical conversion treatment. On the other hand, a paste-like active material obtained by kneading lead powder (PbO) with water or a dilute sulfuric acid aqueous solution was filled in a lead alloy substrate, dried, and subjected to a chemical conversion treatment to produce a plurality of negative electrode plates. For lead alloy substrates, Pb
A desired lead alloy substrate such as a -Ca alloy substrate or a Pb-Sb alloy substrate is used. The positive electrode plate filled with the positive electrode active material mixture containing the additive of the present invention thus prepared and the negative electrode plate are combined via a separator, and this is accommodated in a battery case. A positive electrode plate of the present invention in which basic lead phosphate particles are mixed in the predetermined amount in the positive electrode active material (PbO ₂ ), and a negative electrode plate made of a normal negative electrode active material (Pb) are provided. Manufactured lead storage batteries.

[0006] The lead-acid battery of the present invention is characterized in that basic lead phosphate is added to the active material of the positive electrode plate. Among the average pore diameters of the mixture, the ratio of the active material mixture having an average pore diameter in the range of 0.1 to 1 μm mainly contributing to the discharge action is increased, and as a result, the active material utilization rate is improved. Was done.

[0007]

EXAMPLE When 2,000 g of lead powder (PbO) was kneaded with water or a dilute sulfuric acid aqueous solution to prepare a paste, dibasic lead phosphite 2PbO.P was used as dibasic lead phosphate powder.
bHPO ₃ · 0.5H ₂ O (Shinagawa Chemical Industry Co., Ltd. DF-
301) is 0.2%, 0.5% by weight based on the lead powder.
%, 1%, 2.5%, 3.5% and 180 g to this
Of water, and kneaded. Further, 167 g of dilute sulfuric acid having a specific gravity of 1.265 was added and kneaded to prepare pastes of five kinds of positive electrode active material mixtures, and each of the pastes was formed on a Pb-Ca alloy substrate. The mixture was filled and aged at a temperature of 40 ° C. and a humidity of 95% for 11 hours, then dried at 60 ° C. for 5 hours, and then subjected to a chemical conversion for 40 hours.
mm × 2.7 mm). On the other hand, a Pb-Ca alloy substrate is filled with a paste of a negative electrode active material obtained by kneading lead powder with a dilute sulfuric acid aqueous solution by a conventional method, and aging is performed similarly to the positive electrode plate.
After drying and chemical conversion treatment (dimensions 66 mm × 45 mm × 2.
4 mm) A negative electrode plate was produced. Each of the electrode plates, each of which is obtained by laminating one of the above-described positive electrode plates and two of the above-described negative electrode plates with different amounts of the additives interposed therebetween through a separator, is pressed and accommodated in each battery case. The solution was injected, and the battery case was covered. Five types of the lead storage batteries of the present invention having a rated capacity of 1500 mA were produced. Thus, the active material (PbO ₂ ) of the positive electrode plate of each lead storage battery contains 0.2%, 0.5%, 1%, 2.5%, and 3% by weight of dibasic lead phosphite, respectively. A lead-acid battery having a positive electrode plate mixed with 0.5% is obtained. On the other hand, for comparison, a conventional lead-acid battery having a rated capacity of 1500 mA was manufactured in the same manner as described above except that the above-mentioned additive was not added to the positive electrode plate.

[0008] The pore size distribution of the active material mixture of the positive electrode plate of the above five lead-acid batteries of the present invention and the pore size distribution of the active material of the positive electrode plate of the conventional lead-acid battery are sampled from the respective electrode plates, and the mercury porosimeter ( Micromeritics). The results are shown in FIG. 1 (a) and FIG.
(B), FIG. 1 (c), FIG. 1 (d), FIG. 1 (e) and FIG.
Respectively. As is clear from these figures, by adding basic lead phosphate to the positive electrode active material, the positive electrode plate of the present invention has a range of 0.1 to 1 μm in which the positive electrode active material mainly reacts by discharge. It was recognized that the distribution ratio of the pore diameter was significantly increased, and as a result, the result that the utilization rate of the positive electrode active material was increased, as described later, was obtained.
Therefore, it was found that the energy density of the lead storage battery was increased accordingly.

For the above five types of lead storage batteries of the present invention and the conventional lead storage batteries, a charge / discharge cycle test with a DOD of 80% was performed, and the discharge capacity at the 75th cycle was measured. More specifically, (a) a DOD 80% test was performed to discharge each of the above batteries to a rated capacity of 1500 mAh to an 80% capacity of 1200 mAh, and then to a 1
The charging of 10% of electricity is repeated, and when the voltage drops below 1.65 V at the time of discharging, the life is determined. In the course of this cycle test, (b) a capacity test was performed, and the discharge capacity at the 75th cycle of each battery during the cycle test was confirmed. Specifically, these (a) and (b)
The charge / discharge conditions of the test are as follows. (A) DOD 80% capacity test Discharge; 500 mA x 2.4 hours (finished when the voltage drops to 1.65 V) Charging; 2-stage constant current charging First stage 600 mA x 1.83 hours Second stage 120 mA x 1.76 hours ( b) Capacitance test Discharge; continue at 500 mA until it drops to 1.65 V;
Measure the capacity. Charging; constant voltage charging 2.35 V (maximum current value 300 mA) × 10 hours With respect to the battery capacity at the 75th cycle of each battery measured in this way, all of the positive electrode active material of the positive electrode plate of each battery was discharged. The utilization rate of the active material was calculated by assuming that the capacity used for the reaction as 100, and the relationship between the added amount and the utilization rate of the active material is shown in FIG. As is clear from FIG. 3, when the dibasic lead phosphite is added, the active material utilization rate of the positive electrode plate is higher than that in the case where no addition is made, particularly at an addition amount of 0.2 to 4%. It turns out that it improves remarkably. In particular, the addition rate of 1% had the highest utilization rate of the active material. The same effect can be obtained when the amount of addition exceeds 4%. However, the amount of active material decreases as the amount of addition increases, so it is preferable to keep the amount to this extent.

[0010]

As described above, according to the present invention, as the positive electrode plate of the lead storage battery, basic lead phosphate is added to the active material, so that the utilization rate of the positive electrode active material can be improved, and the lead storage battery can be used. This leads to an increase in energy density. In particular, the addition amount of 0.2 to 4 wt. % Significantly improves the utilization.

[Brief description of the drawings]

1 (a) to 1 (e) are diagrams showing the relationship between the addition of basic lead phosphate and the pore size distribution of a positive electrode plate in the lead storage battery of the present invention.

FIG. 2 is a pore size distribution diagram of a positive electrode plate of a conventional lead storage battery.

FIG. 3 is a graph showing the relationship between the amount of dibasic lead phosphite added and the positive electrode active material utilization.

Continuation of the front page (58) Field surveyed (Int. Cl. ⁷ , DB name) H01M 4/14-4/23 H01M 4/56-4/57 H01M 4/62

Claims (2)

(57) [Claims] 1. A lead storage battery comprising a positive electrode plate in which a basic lead phosphate is mixed in a positive electrode active material. 2. The lead-acid battery according to claim 1, wherein the basic lead phosphate is added in an amount of 0.2 to 4% by weight in terms of weight of the positive electrode active material in terms of lead powder (PbO).