JPH05234595A - Sealed lead-acid battery - Google Patents

Abstract

PURPOSE:To provide a sealed lead-acid battery, restraining the corrosion and extension quantity of a positive electrode grid body in a low degree, and prolonging a life. CONSTITUTION:A sealed lead-acid battery is composed by using positive electrode plates having structure so that the value of V2/V1 is made 0.4 or more, where V1: the total volume of lateral frames 5 excepting frame skeletons of positive electrode plates, and V2: the volume of lateral frames 5' existing on 1/3 of the upper part in a height direction of the positive electrode plate. By such composition, capacity against the corrosion and elongation of positive electrode grids, produced in using, can be improved, and resultantly the life of the closed type lead-acid battery is possible to be prolonged.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sealed lead acid battery used in an emergency power supply device or communication equipment.

[0002]

2. Description of the Related Art Recently, a large amount of sealed lead-acid batteries in which an electrolytic solution is kept in a non-fluid state are used in place of a conventional lead-acid battery in which a dilute sulfuric acid which is an electrolytic solution is kept in a fluid state in a battery. It started to come.

Such sealed lead-acid batteries are roughly classified into the following two types. One is a lead-acid battery in which the electrolytic solution is made non-fluidized by using a gelling agent, and the other is to retain the electrolytic solution in a liquid absorbent separator mainly composed of glass fiber to eliminate the fluidity. It is a lead acid battery.

In any of these sealed lead-acid batteries, the positive electrode plate is a lead or lead alloy grid body coated with a reactive substance and activated by chemical conversion. The lattice of the sealed lead-acid battery has a function of holding a reactant and collecting a current generated by an electrochemical reaction.

As shown in FIG. 3, the positive electrode plate used in the conventional sealed lead-acid battery has a frame frame 1 composed of a horizontal frame frame 2 and a vertical frame frame 3 existing outside the electrode plate. Inside, vertical bone 4
And the horizontal bone 5 are arranged. The number of transverse bones 5,
It is customary that the thickness is determined in consideration of the amount of the reactant 7 on the positive electrode plate or the electric resistance of the grid itself which affects the current collecting ability. As a result, the upper part of the positive electrode plate in the height direction 1 /
The volume of the transverse bone 5 ′ existing in 3 is 30 to 30
It was 35%.

[0006]

The conventional sealed lead-acid battery has the following problems. That is, the sealed lead-acid battery is used as an emergency power source, which is the main application, or as an auxiliary power source for communication equipment. At this time, the sealed lead-acid battery is charged for a long period of time with a minute current. In such a usage method, the positive electrode plate, particularly the lattice body, is often corroded and stretched to reach the end of its life.

FIG. 4 shows a schematic view of the state of the positive electrode plate when the sealed lead-acid battery which has reached the end of its life is disassembled. As shown in the figure, it can be seen that the positive electrode plate of the sealed lead-acid battery that has reached the end of its life is corroded and greatly expanded and deformed. In particular, the current collecting ear portion 6 provided for connection with another positive electrode plate
The extension of the lattice in the lateral direction in the portion close to is significantly larger than that in the lower portion of the positive electrode plate. This is because the electric current generated by the electrochemical reaction of the entire positive electrode plate is concentrated in the connecting ear portion 6, and a large current flows in the current collecting portion near this, that is, the positive electrode grid body, and as a result, the amount of corrosion of the grid body increases. This is because.

Further, the sealed lead-acid battery has a structure for absorbing oxygen gas generated from the positive electrode plate at the time of charging by utilizing the oxygen absorption reaction of metallic lead which is a negative electrode reactant.
Most of the generated oxygen gas fills the space above the electrode plate. As a result, the oxygen gas absorption reaction occurs vigorously especially at the upper portion of the negative electrode plate. When the oxygen absorption reaction occurs on the negative electrode plate, metallic lead, which is a reaction material, changes to lead oxide,
Further, it reacts with sulfuric acid in the electrolytic solution to form lead sulfate. Since lead sulfate is a discharge product of the negative electrode and the negative electrode plate cannot be discharged in this state, it needs to be converted into metallic lead which is a reaction material by a charging reaction. Therefore, in the portion where the oxygen absorption reaction is actively occurring in the negative electrode, a large amount of current flows in order to change the lead oxide and the lead sulfate generated by the oxygen absorption reaction into metallic lead.

As described above, since the charging current flowing in the upper part of the electrode plate becomes large, corrosion and expansion of the positive electrode grid body increase.

The present invention suppresses the elongation of the lattice transverse bones above the positive electrode plate which occurs in such a conventional sealed lead-acid battery,
The present invention provides a sealed lead acid battery with a dramatically extended life.

[0011]

That is, in the sealed lead-acid battery of the present invention, the total volume of the lateral bones of the positive electrode plate excluding the frame bones is V
1. When the volume of the transverse bone existing in the upper 1/3 of the height direction of the positive electrode plate is V2, the volume of the transverse bone is increased so that the value of V2 / V1 is 0.4 or more. To do.

[0012]

The presence of 40% or more of the volume of the transverse bone in the upper ⅓ portion of the positive electrode plate in the height direction means that the volume of each bone above the positive electrode plate is increased. .. It is known that the amount of corrosion or elongation of the grid of the positive electrode plate is inversely proportional to the bone thickness of the grid. Therefore, as in the present invention, by arranging the volume of the transverse bone arranged in the upper ⅓ portion in the height direction of the positive electrode plate at 40% or more of the volume of the entire transverse bone, corrosion and elongation of this portion can be improved. The durability of the sealed lead-acid battery can be greatly extended as a result.

[0013]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 shows that the 20HR capacity according to the present invention is 18
1 shows a positive electrode plate of an Ah sealed lead acid battery. This positive plate is
The dimensions are 3.5 mm in thickness, 130 mm in height, and 70 mm in width. The positive electrode plate is composed of a lattice and a positive electrode reactive material 7.

The lattice body is a frame bone 1 composed of a horizontal frame bone 2 and a vertical frame bone 3, and two vertical bones 4 arranged inside the frame bone 1.
It consists of nine transverse bones 5. Horizontal frame 2 and vertical frame 3
Has a thickness of 3.3 mm, a width of 3.0 mm, and the longitudinal bone 4 has a thickness of 3.3 mm and a width of 2.5 mm. The thickness of the horizontal bone 5 ′ existing in the upper third of the positive electrode plate of the horizontal bone 5 is 3.3 m.
m, width 2.5 mm, other transverse bone thickness 2.0 m
m and width were 2.0 mm.

With such a lattice structure, the volume of the lateral bones 5 present in the upper third of the positive electrode plate is 1.6 cubic centimeters, which is 51% of the total lateral bone volume 3.1 cubic centimeters. Will occupy.

The volume ratio (V2 / V of the transverse bone shown in FIG.
1) uses a positive electrode plate of 0.51 and is composed of a combination of 4 positive electrode plates and 5 negative electrode plates per cell, 12V, 1
An 8 Ah sealed lead-acid battery was prototyped and tested as follows.

The prototype battery was placed in an atmosphere of 40 ° C. for 1
Constant-voltage charging of 3.8 V was continuously performed, and the capacity of the storage battery was measured every 6 months on the way. The capacity of the storage battery is returned to an atmosphere of 25 ° C, and a constant current discharge of 18A is applied to the battery voltage of 10.0V
The storage battery capacity was calculated from the product of the time and the current value at that time.

The results of this test are shown in FIG. For comparison, the volume ratio of the transverse bone (V2 / V1) is 0.35,
A conventional sealed lead-acid battery of 0.30 was also tested at the same time. In the figure, ◯ shows the test results of the storage battery of the present invention, and □ and Δ show the test results of the conventional storage batteries having the volume ratios of 0.35 and 0.30, respectively.

As can be seen from FIG. 2, the capacity of the conventional sealed lead-acid battery began to gradually decrease after 1 to 1.5 years, and the capacity became 1/2 of the initial capacity in 2.5 years. .. As a result of disassembling and examining these storage batteries, it was found that in most of the cells, the grid plate of the positive electrode plate spread laterally and was cut.

However, the sealed lead-acid battery according to the present invention maintained the capacity of 90% or more of the initial value even after 3.5 years, and showed the initial capacity of 70% even after 4 years. When this storage battery was disassembled and examined, it was found that the electrolyte was depleted mainly due to the fact that the grid of the positive electrode plate had a slight elongation but reached the end of its life.

[0022]

As described above, the sealed lead acid battery according to the present invention has an effect that the life is greatly extended as compared with the conventional sealed lead acid battery.

[Brief description of drawings]

FIG. 1 is a diagram showing a structure of a positive electrode plate of a sealed lead acid battery according to the present invention.

FIG. 2 is a characteristic diagram showing the results of the life test evaluation of the sealed lead acid battery according to the present invention and the conventional sealed lead acid battery.

FIG. 3 is a diagram showing a structure of a positive electrode plate of a conventional sealed lead-acid battery.

FIG. 4 is a schematic diagram showing the state of the positive electrode plate at the time when the life of a conventional sealed lead-acid battery has been reached.

[Explanation of symbols]

 1 Frame bone 2 Horizontal frame bone 3 Vertical frame bone 4 Vertical bone 5 Horizontal bone 5'Horizontal bone arranged in the upper 1/3 of the height direction of the positive electrode plate 6 Current collecting ear 7 Positive electrode reactive substance

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Tsushinori Yoshimura 1006 Kadoma, Kadoma City, Osaka Prefecture Matsushita Electric Industrial Co., Ltd.

Claims (1)

[Claims] 1. The total volume of the transverse bone excluding the frame bone of the positive electrode plate is V
1. The sealed lead-acid battery is characterized in that the value of V2 / V1 is 0.4 or more, where V2 is the volume of the horizontal bone existing in the upper 1/3 of the positive electrode plate in the height direction. ..