JPH02165570A - Closed lead battery - Google Patents

Abstract

PURPOSE:To intend better discharge performance in a great measure with low cost by filling grain material consisting of a specific silica fine powder element in a battery for retaining electrolyte and isolating a positive electrode from a negative electrode. CONSTITUTION:A group of electrode plates, that a synthetic-resin isolating rod 1 of a certain thickness is inserted in between a positive electrode plate 5 and a negative electrode plate 4, is housed in a battery case 3. Then, in a gap between the positive electrode plate 5 and the negative electrode plate 4 and in the vicinity of a group of electrode plates, a cellar powder element 6 which is grained with a silica fine powder element of 10-40 millimicron by the use of a binder is filled and arranged to impregnate and retain a necessary and full amount of sulfuric acid electrolyte for discharge in the grain powder element 6. It is thus possible to realize excellent discharge performance for low-cost manufacture.

Description

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

Conventional technology and its challenges There are two types of sealed lead-acid batteries: a retainer type and a gel type, in which the negative electrode absorbs oxygen gas generated during battery charging.
There is. The retainer type has rRII between the positive and negative plates.
! A: A matte separator (glass separator) made of glass fiber is inserted, which holds the sulfuric acid electrolyte necessary for discharge and isolates both poles.In recent years, it has been widely used as a backup power source for portable devices and computers. It has come to be used. However, the cage type has the drawback that the discharge capacity is limited by the amount of electrolyte at low rate discharge because the glass separator is expensive and cannot hold a sufficient amount of electrolyte, and this type of sealed battery is becoming popular. It has become IIIW.

On the other hand, although the gel type is cheaper than the retainer type, it has the disadvantage that its battery performance is inferior to the liquid type and retainer type.

Means for Solving the Problems The present invention eliminates the drawbacks of the conventional sealed lead-acid batteries mentioned above and provides an inexpensive sealed lead-acid battery with excellent discharge performance. A sufficient amount of sulfuric acid electrolyte necessary for charging and discharging is impregnated into a porous powder made by granulating silica micropowder with a binder, which is filled and arranged around the electrode plate group, and is made to hold M. . The present invention will be explained below based on examples.

Example Positive and negative electrode grids made of pb-Ca-8n alloy were filled with normal positive and negative electrode pastes, respectively, and then aged to produce unformed electrode plates. The isolation rod 1 shown in Figure 9 is made of acid-resistant synthetic resin. It is molded into an E-shape, with corrugations 2 attached to the vertical isolation rods. FIG. 2 shows a front view of the electrode plate group produced in this way inserted into a battery case, and FIG. 3 shows a cross section taken along line A-A in FIG. 5 is a negative electrode plate, and 5 is a positive electrode plate.

When the electrode plate group is inserted into the battery case, the gap between the battery case and the electrode plate group and the gap between the electrode plates is filled with an electrolyte holder. This electrolyte holder was prepared as follows. first,
Fine silica powder having a particle size of 10 to 40 millimeters was kneaded with water to which 15% of methyl methacrylate was added as a binder, then granulated to a particle size of 100 to 200 microns, and then dried. Granulated silica powder is made up of fine silica particles agglomerated to form secondary particles of 100 to 200 microns, and the granulated powder itself is a free-flowing powder with a porosity of 90% or more.

FIGS. 2 and 3 show the state filled with granulated silica powder.

The silica powder was filled into the battery while applying vibration.

As shown in the figure, the granulated silica powder was densely packed around the electrode plate group and between the electrode plates. The granulated silica powder filled between the electrode plates also has the function of a separator. After filling the granulated silica powder, a lid 7 was glued on and an exhaust valve 8 was attached. The porosity in the filled state was about 85%.

Next, we conducted a capacity test on the prototype battery. The test battery had a nominal capacity of 4.5 Ah, and for comparison, a conventional retainer type battery and a gel type battery using positive and negative electrode plates from the same lot were also tested. The results are shown in Table 1.

When compared in Table 1, the retainer type had a slightly higher specific gravity of the electrolyte, so the high rate discharge performance was superior to the gel type. Also, low rate release @
The gel type had a slightly higher capacity due to the larger amount of electrolyte. On the other hand, the products of the present invention have improved performance by 10 to 20% in both low rate discharge and high rate discharge compared to these conventional sealed lead acid batteries. This is because the specific gravity of the electrolyte is slightly higher than that of the gel type, and the amount of electrolyte that can be impregnated is larger than that of the retainer type.Furthermore, there is no need to use a separator that acts as a resistance during discharge, and acid diffusion is reduced. 5 Effects of the Invention This is due to synergistic effects such as excellent properties.As is clear from the above-mentioned examples, the sealed lead-acid battery according to the present invention retains the electrolyte and isolates the positive and negative electrodes using silica fine powder. With the simple operation of filling the battery with body granules,
It is of great industrial value because it can significantly improve the discharge performance of conventional sealed lead-11 batteries.

[Brief explanation of the drawing]

FIG. 1 is a perspective view of a separator bar, and FIGS. 2 and 3 are a front view and a sectional view of a sealed lead-acid battery according to the present invention. 1... Isolation rod, 3... Battery case, 4... Negative electrode plate, 5...
...Positive electrode plate, 6... Granules of silica fine powder, 7...
Battery container lid, 8...Exhaust valve

Claims (1)

[Claims] 1. In a sealed lead-acid battery where the negative electrode absorbs oxygen gas generated during charging of the battery, a group of electrode plates made by inserting a synthetic resin isolation rod of a certain thickness between the positive electrode plate and the negative electrode plate is used as a battery case. At the same time, the gap between the positive electrode plate and the negative electrode plate and around the electrode plate group are filled with porous powder made by granulating silica micropowder of 10 to 40 millimicrons using a binder, A sealed lead-acid battery characterized in that the granulated powder is impregnated with and held in a sufficient amount of sulfuric acid electrolyte necessary for discharge.