JPH07296844A - Lead-acid battery - Google Patents

Abstract

PURPOSE:To reduce the amount by which the capacity of a negative plate decreases as a lead-acid battery is used in cycles by installing a slowly releasing body containing a shrink-proofing agent inside a battery jar. CONSTITUTION:A shrink proofing agent composed of a lignin compound which is 0.2 parts by mass in 100 parts by mass of lead powder is added to the active material of the negative plate 3 of a lead-acid battery. A microporous film composed mainly of polyvinyl chloride with an average micropore diameter of 0.1mum and a thickness of 0.2mm is used as a slowly releasing body 5, and the shrink proofing agent composed of the lignin compound is wrapped in the microporous film as if in a bag by 0.05 mass % of the electrolyte. When the battery is in use the shrink proofing agent is gradually eluted from the surface of the slowly releasing body 5 and dissolves into the electrolyte 9. The shrink proofing agent compensates for the functional degradation of the shrink proofing agent in the anode active material, thus enhancing the life of the negative plate 3.

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, and more particularly to a lead storage battery negative electrode plate having an improved life.

[0002]

2. Description of the Related Art In conventional lead-acid batteries, a shrink-proofing agent such as a lignin compound has been added to the negative electrode active material in order to suppress deterioration of the negative electrode active material due to cycle use. However, there is a problem in that the function of this shrink-proofing agent deteriorates as the cycle is used and the capacity of the negative electrode plate decreases.

The present invention has been made in view of the above problems, and an object of the present invention is to provide a lead storage battery in which the capacity of the negative electrode plate is less likely to decrease due to cycle use.

[0004]

In order to achieve the above object, the present invention is characterized in that a sustained release body 5 containing a shrink-proofing agent therein is installed in a battery case 1. The sustained-release body 5 may be a substance having pores such as a microporous membrane or a porous capsule, or a substance such as a swellable synthetic resin pellet that causes an internal substance to be eluted to the outside over time. Some are shown in the examples.

[0005]

[Function] During use of the battery, the shrinkproofing agent gradually elutes from the surface of the sustained-release body 5 and dissolves in the electrolytic solution 9. This shrinkproofing agent compensates for the deterioration of the function of the shrinkproofing agent in the negative electrode active material and improves the life of the negative electrode plate 3. It is reported that the shrink-proofing agent may react with hydrogen gas and oxygen gas generated in the battery to accelerate the deterioration of the function. However, the shrink-proofing agent of the present invention contains the inside of the sustained-release body 5. It is difficult to react with hydrogen gas and oxygen gas because it is present in, and elution occurs slowly over a long period of time.
It is considered to react with the negative electrode active material and suppress the functional deterioration of the negative electrode plate 3.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. (Embodiment 1) FIG. 1 is a sectional view showing an embodiment of the present invention, in which 1 is a battery case, 2 is a positive electrode plate, 3 is a negative electrode plate, 4 is a separator, and 5 is a sustained release agent containing a shrinkproof agent. A body, 6 is a strap, 7 is a positive pole, 8 is a negative pole, and 9 is an electrolytic solution. The active material of the negative electrode plate 3 has a mass of 0.2 with respect to 100 of lead powder.
Of the lignin compound is added, and the sustained-release body 5 has an average micropore diameter of 0.1 μm and a thickness of 0.2 m.
A microporous membrane mainly composed of polyvinyl chloride of m is used, and a shrinkproof agent composed of a lignin compound is wrapped in a bag shape in an amount of 0.05 mass% with respect to the electrolytic solution. A liquid lead-acid battery A of the present invention having a capacity of 35 Ah and a voltage of 12 V having such a structure was produced. Further, for comparison, the above battery A which does not include the sustained-release body 5 encapsulating the shrink-proofing agent
A conventional liquid lead-acid battery X having the same capacity and the same voltage as was produced.

(Test) Next, the battery A of the present invention and the conventional battery X were used as a discharge battery 14A at an ambient temperature of 40.degree.
Time discharge, charge current is 3.5A, charge is repeated for 5 hours, discharge current 70A at -15 ° C every 25 cycles.
A cycle life test was conducted to examine the capacity (low rate high rate discharge capacity) when discharged at. The result is shown in FIG. As shown in FIG. 2, the conventional battery X has a life of about 140 cycles, while the battery A of the present invention has a life of about 200 cycles, which is about 1.5 times longer than that of the conventional battery X. It was Further, it was found from the measurement of the unipolar potential of both batteries A and X that the decrease in the capacity of the negative electrode plate 3 causes the decrease in the battery capacity. The lifespans of the batteries A and X were set at the time when the battery capacity dropped to 80% of the initial capacity.

(Example 2) Next, the same positive electrode plate 2 and negative electrode plate 3 as in Example 1 were used, and hollow porous capsules (sustained release bodies) were used instead of the usual separator made of fine glass mat. A sealed lead storage battery B of the present invention having a capacity of 38 Ah and a voltage of 12 V was prepared by forming a group of electrodes by using a separator sandwiched with a wrapped shrinkproof agent. In addition, as the hollow porous capsule, an average capsule diameter of 20 μm made of silica is used.
m, the surface pore diameter was 0.01 to 0.1 μm, and a shrinkproof agent consisting of 0.2% by mass of the lignin compound in the electrolytic solution was wrapped in the capsule. For comparison, a conventional sealed lead-acid battery Y having the same capacity and voltage as the battery B of the present invention, which does not include the shrink-proofing agent encapsulated in the capsule, was prepared.

(Test) Battery B of the present invention and conventional battery Y
On the other hand, the same cycle life test as in Example 1 was performed. The result is shown in FIG. From FIG. 2, it was found that the conventional battery Y had a life of about 100 cycles, whereas the battery B of the present invention had a life of about 150 cycles, which was superior to the conventional battery Y. Further, it has been found that the shrink-proofing agent wrapped with the sustained-release material can be applied to a sealed lead-acid battery in which a fluid electrolyte does not exist like the battery B of the present invention.

Example 3 A negative electrode plate 3 was prepared by adding the same shrinkage preventive agent as in Example 1 to the negative electrode active material, and further adding a shrink preventive agent enclosed in a porous capsule (sustained release body). Example 1
A pole group was assembled using the same positive electrode plate 1 and a separator 4 made of a normal fine glass mat to prepare a sealed lead acid battery C of the present invention having a capacity of 38 Ah and a voltage of 12V. still,
The above-mentioned porous capsule is made of silica and has an average capsule diameter of 3 μm and a surface pore diameter of 0.01 to 0.1 μm, and a shrink-proofing agent composed of 0.2% by mass of a lignin compound with respect to the negative electrode active material is used. I wrapped it up.

(Test) Next, the same cycle life test as in Example 1 was carried out using the battery C of the present invention. The result is shown in FIG. From FIG. 2, the battery C of the present invention is the battery B of the present invention.
The life characteristics almost equal to were obtained.

(Example 4) A shrink preventive agent which constitutes the same pole group as in Example 1 and is dispersed and mixed in a swelling synthetic resin pellet (sustained release body) on a splash-proof plate of the pole group. Was placed to prepare a liquid lead acid battery D of the present invention having a capacity of 35 Ah and a voltage of 12V. Here, as the swelling synthetic resin, a resin obtained by compounding sodium polyacrylate and a polyolefin resin, which are generally used as a water-absorbing resin, is used.
A shrinkproof agent consisting of a mass% of lignin compound was filled. The amount of lignin compound was adjusted to be 0.05% by mass with respect to the electrolytic solution.

(Test) Next, the battery D of the present invention was subjected to the same cycle life test as in Example 1. The result is shown in FIG. As shown in FIG. 2, the battery D of the present invention has a life of about 240 cycles, which is about 1.7 times that of the conventional battery X. It is considered that this is because the shrinkproof agent contained in the resin gradually elutes as the resin swells and suppresses the functional deterioration of the negative electrode plate.

(Example 5) A pole group similar to that of Example 1 was constructed, and a polyvinyl chloride resin pellet (sustained release body) was prepared by blending rubber and a liquid plasticizer on the splash-proof plate of this pole group. Dispersion-mixed shrinkproof agent is placed in a capacity of 35 Ah, voltage of 15
A V type liquid lead acid battery E of the present invention was produced. The shrinkproof agent in the pellets was composed of a lignin compound, and the amount was adjusted to 40% by mass with respect to the resin and 0.05% by mass with respect to the electrolytic solution.

(Test) Next, for the battery E of the present invention,
The same cycle life test as in Example 1 was performed. The result is shown in FIG. From FIG. 2, the battery E of the present invention is the battery D of the present invention.
The cycle life almost equal to was obtained. The polyvinyl chloride resin blended with rubber and liquid plasticity used in this example is known as a resin that easily causes migration (a phenomenon of migration of molecules included therein), and the shrinkage agent is gradually eluted by this phenomenon. Then, it is considered that the function of the negative electrode plate is exerted.

The material and the micropore diameter and shape of the microporous membrane and the porous capsule, the material and shape of the synthetic resin that causes swelling and migration, the method of installation in the battery, and the kind and amount of the shrink-proofing agent, etc. It goes without saying that various methods can be applied depending on the type and structure, and the method is not limited to the embodiment.

[0017]

Since the present invention is constructed as described above, it is possible to provide a long-life lead-acid battery in which the capacity of the negative electrode plate is less likely to decrease due to cycle use.

[Brief description of drawings]

FIG. 1 is a sectional view showing an embodiment of the present invention.

FIG. 2 is a graph showing cycle life characteristics of an example of the present invention and a conventional product.

[Explanation of symbols]

 1 Battery case 5 Sustained release body

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Kazuo Murata 6-6 Josaimachi, Takatsuki City, Osaka Prefecture Yuasa Corporation

Claims (1)

[Claims] 1. A lead storage battery, characterized in that a sustained-release material (5) containing a shrink-proofing agent inside is installed in a battery case (1).