JP2527072B2 - Sealed lead acid battery - Google Patents

Description

TECHNICAL FIELD The present invention relates to a sealed lead storage battery using a gel electrolyte.

[Prior Art] The sealed lead-acid battery enables sealing by recombining oxygen gas generated from the positive electrode plate at the end of charging with the negative electrode plate. Therefore, in order to move the oxygen gas generated in the positive electrode plate to the negative electrode plate and enable the gas absorption reaction, the electrolytic solution in the electrode plate group must be limited. Further, in order to prevent the electrolyte from leaking out of the battery and improve the resistance to leakage, it is necessary to fix and hold the electrolyte in the battery case.

The conventional method for fixing and retaining the electrolytic solution in this type of lead-acid battery is a method of absorbing and retaining the electrolytic solution in a porous body as a separator, and spherical inorganic oxide fine particles 1 as shown in FIG. There is a method of holding it in a gel-like material. In the former method, a non-woven fabric of fine glass fibers is used (retainer type), and in the latter method, silica gel composed of silica particles is used (gel type).

[Problems to be Solved by the Invention] However, the retainer-type electrolytic solution holding method has a problem in that it is expensive because fine glass fibers are used. Further, in the retainer type, there is a problem that the electrolyte solution becomes thin on the upper side in the height direction of the battery case and becomes thicker on the lower side, so-called stratification phenomenon occurs, and the battery performance is likely to be significantly deteriorated.
Moreover, the retainer type is 20 kg due to its close contact with the active material.
Since it is necessary to apply a pressure of more than / cm ^2, it is difficult to assemble a large battery, and the battery case needs to have the strength necessary to withstand it, which increases the cost. .

On the other hand, in the gel-type electrolytic solution holding method, the gel-like electrolytic solution suppresses stratification and has good adhesion with the active material, so that there is an advantage that group pressurization can be reduced, but the internal resistance of the battery is high. Therefore, there is a problem that the discharge characteristics are also deteriorated.

An object of the present invention is to provide a sealed lead-acid battery that takes advantage of the gel method and can improve the drawbacks.

[Means for Solving Problems] To explain the constitution of the present invention for achieving the above-mentioned object, the present invention relates to a battery container containing a gel electrolyte in which an electrolyte solution is held in fine particles of an inorganic oxide. In the sealed lead-acid battery in which the electrode plate group is arranged, elongated particles are used as the fine particles of the inorganic oxide.

[Function] When fine particles of inorganic oxide having a long and narrow shape are used in this manner, the amount and concentration of the electrolytic solution are present evenly in the vertical direction of the battery case, and the adhesiveness with the active material is improved. Good, the internal resistance can be lowered, and the discharge characteristics can be improved.

[Examples] Examples of the present invention will be described in detail below. As shown in the table, in the present invention, as the fine particles 1 of the inorganic oxide, the elongated electrolyte as shown in FIG. 1 was used to prepare the gel electrolyte, while as the conventional product, the fine particles 1 of the inorganic oxide 1 were used. As a result, a gel electrolyte was prepared using a spherical electrolyte as shown in FIG. 2 (note that in the conventional product, two products with different silica concentrations were used as No. 1 and No. 2). The sealed lead acid batteries with electrolyte specific gravities of 1.300 and 200 Ah were produced by using them. Each gel electrolyte was prepared by mixing a solution in which silica particles were dispersed (Snowlux-40, manufactured by OUP Nissan Kagaku) with a dilute sulfuric acid solution.

Then, the internal resistance of these batteries was measured,
A discharge test of 130A discharge was performed, and then a cycle test was performed under the conditions of discharge: 20A, end voltage 1.80V / cell, 25 ℃ charge: 20A cut, 2.3V, 48h, 25 ℃.

As a result, as shown in the table, the battery of the present invention has lower internal resistance and longer discharge time than the battery of the conventional product.
Moreover, stratification was suppressed to the same extent as the conventional product, and the gel strength was better than that of the conventional product of 7 wt% electrolyte, which was equivalent to 20 wt% of the conventional product.

In this way, the internal resistance and discharge characteristics can be improved by
This is probably because of the following reasons. That is, the gel electrolyte used in the present invention uses the elongated silica particles shown in FIG. 1, and is not spherical like the conventional silica particles shown in FIG. Therefore, the viscosity and gel strength are improved, and even if the silica concentration is lowered, it shows the same gel strength as the conventional 20 wt% silica gel. From this, since the silica content in the gel electrolyte can be reduced, the electrolyte is increased accordingly. In other words, the number of sulfate radicals increases and the migration of ions is improved. Therefore, it is considered that the internal resistance and discharge characteristics of the battery are improved.

Also, when a few percent of silica particles are mixed in the electrolytic solution as a thickener, it is preferable to use elongated particles rather than spherical silica particles because the same effect can be obtained with a small amount.

The battery of the present invention exhibits the same oxygen gas absorption characteristics as the battery of the conventional product, and there is no concern about leakage of acid mist or the like outside the battery.

[Effects of the Invention] As described above, the sealed lead-acid battery according to the present invention is
Since the gel electrolyte in which the electrolyte is held by the inorganic oxide fine particles having a long and narrow particle shape is used, there is an advantage that the stratification is suppressed and the adhesion to the active material is improved. Further, the internal resistance and discharge characteristics of the battery can be improved without impairing the gas absorption characteristics and safety. Moreover, according to the present invention, since the silica content in the gel electrolyte can be reduced, the cost can be reduced and the industrial value is extremely large.

[Brief description of drawings]

FIG. 1 shows the shape of silica particles in the gel electrolyte of the battery of the present invention, and FIG. 2 shows the shape of silica particles in the gel electrolyte of the conventional battery. 1 ... Fine particles of inorganic oxide.

Claims (1)

(57) [Claims] 1. A sealed lead-acid battery in which an electrode group is arranged in a battery container containing a gel electrolyte in which an electrolytic solution is held in fine particles of an inorganic oxide. A sealed lead-acid battery characterized by using a shape.