JPH02158063A - Sealed lead-storage battery - Google Patents

Abstract

PURPOSE:To obtain a sealed lead-storage battery whose discharge performance is remarkably increased by impregnating and holding an electrolyte in a separator made of fine glass fibers and granules of fine silica particles filled around a plate group. CONSTITUTION:A plate group comprising a positive plate, a negative plate, and a separator having high porosity and large surface area, made of fine glass fibers is put in a container by applying pressure. Porous granules prepared with 10-40mum fine silica particles and a binder are filled around the plate group. The amount of sulfuric acid electrolyte necessary and enough for charge- discharge is impregnated and held in the separator and the granules. By tilling the granules around the plate group, larger amount of electrolyte than a retainer type battery is held and specific gravity of the electrolyte is heightened than a gelled type battery. Low rate and high rate discharge performance is increased.

Description

[Detailed description of the invention] Industrial applications The present invention relates to improvements in sealed lead-acid batteries.

Conventional technology and its problems There are two types of sealed lead-acid batteries, the retainer type and the gel type, in which the negative electrode absorbs oxygen gas generated during battery charging. The retainer type inserts a matte separator (glass separator) made of fine glass fiber between the positive and negative electrode plates, which holds the sulfuric acid electrolyte necessary for discharge and isolates the two electrodes. In recent years, it has become widely used as a backup power source for portable devices and computers. However, since the retainer type cannot hold a sufficient amount of electrolyte, it has the disadvantage that the discharge capacity is limited by the amount of electrolyte at low rate discharge, which is an obstacle to the spread of this type of sealed battery. On the other hand, the gel type had the disadvantage that its battery performance was inferior to that of the retainer type.

Means for Solving the Problems The present invention eliminates the drawbacks of the conventional sealed lead-acid batteries mentioned above and provides a sealed 1g storage battery with poor discharge performance. A sufficient amount of sulfuric acid electrolyte necessary for discharge is filled around the separator and the electrode plate group, and is impregnated into porous powder made by granulating silica micropowder with a binder. be. The present invention will be explained below based on examples.

Example Positive and negative electrode grids made of a Pb--Ca--Sn alloy were filled with normal positive and negative electrode pastes and aged to produce unformed electrode plates. Next, an electrode plate group was prepared using these unformed positive and negative electrode plates and a paper separator made of glass w/fiber (fiber diameter 0.5 to 1 micron) having sufficiently high porosity and surface area, and an electrode plate group was prepared using the unformed positive electrode and negative electrode plates and a paper separator made of glass w&fiber (fiber diameter: 0.5 to 1 micron) with sufficiently high porosity and surface area. inserted into the tank.

Therefore, we used fine silica powder with a particle size of 10 to 40 mm and 15% methyl methacrylate as a binder.
The mixture was kneaded with added water, granulated to a particle size of 100 to 200 microns, and dried, and then packed tightly between the container wall and the electrode plate group while applying vibration. The granulated material filled here is made up of secondary particles of 100 to 200 microns by agglomeration of fine primary particles of silica, and the porosity of these granulated particles is over 90%, and the porosity of the granulated particles is 90% or more, and the porosity of the granulated particles is 90% or more. The porosity was about 85%.

After filling the granules in this manner, a lid was attached and an exhaust valve was attached to produce a sealed lead-acid battery with a nominal capacity of Ji4.5^h, which was subjected to a storage test. For comparison, a conventional retainer type battery and a gel type battery were prepared using electrode plates from the same lot, and their performance was compared with the product of the present invention. Table 1 shows the test results.

Table 1 This test result shows that when comparing the retainer type and the gel type, the retainer type had a slightly higher electrolyte specific gravity, so the high rate discharge performance was 1 amount higher than the gel type.

On the other hand, the product of the present invention has improved performance by 10 to 20% in both low rate discharge and high rate discharge compared to these conventional sealed A-bell storage batteries. This is because by filling the periphery of the electrode plate group with silica granules, more electrolyte can be held than in the retainer type, and the specific gravity of the electrolyte can be made higher than in the gel type. Note that if the specific gravity of the electrolyte is increased in a gel type battery, the performance of the gel will change, and the battery performance will actually deteriorate.

Effects of the Invention As is clear from the above embodiments, the sealed lead-acid battery according to the present invention impregnates and retains an electrolyte in the silica fine powder granules placed around the tR fine glass paper separator and the electrode plate group. As a result, the performance of conventional sealed lead-acid batteries can be greatly improved, and its industrial value is great.

Claims (1)

[Claims] 1. In a sealed lead-acid battery in which oxygen gas generated during battery charging is absorbed by the negative electrode, an electrode plate group consisting of a positive electrode plate, a negative electrode plate, and a fine glass fiber paper separator having a sufficiently high porosity and surface area is used. While strongly compressing and storing the battery in a battery case, porous powder made by granulating silica micropowder of 10 to 40 millimicrons with a binder is filled and arranged around the electrode plate group, and the battery is sealed. A sealed lead-acid battery characterized in that an electrolytic solution necessary for charging and discharging is impregnated and retained in the granulated powder arranged around the paper separator and the electrode plate group.