KR20030043614A - Lead storage battery comprising gel electrolyte coated with silica powder - Google Patents

Abstract

PURPOSE: A lead storage battery containing a gell electrolyte doped with silica powder is provided to increase the viscosity of a top part electrolyte and promote the re-coupling between oxygen and hydrogen, thereby reducing the exhaust of generated gas and pollution of a bent vale by the exhaust gas together with the exhaustion of the electrolyte. CONSTITUTION: A lead storage battery having positive polarity plates(6) and negative polarity plates(2) includes containing a gell electrolyte(10) doped with silica powder(12) on a top part for increasing the viscosity of the electrolyte from the beginning operation step to prevent the exhaustion of the electrolyte. The silica powder is to be fumed silica.

Description

Lead storage battery comprising a gel electrolyte coated with silica powder {Lead storage battery comprising gel electrolyte coated with silica powder}

The present invention relates to a lead acid battery comprising a cathode, an anode, and a low concentration silica gel electrolyte in which a sulfuric acid aqueous solution and silica are mixed. The present invention relates to a lead acid battery obtained by coating silica powder on top of the gel electrolyte or further injecting a high concentration of silica gel electrolyte. will be.

In general, an industrial lead acid battery used in an uninterruptible power supply is largely composed of an electrode and an electrolyte, and the electrolyte is a mixture of water and sulfuric acid, which serves as a passage for ions generated from the electrode inside the lead acid battery.

Lead-acid batteries provide stable power at all times while preventing power failure due to voltage fluctuations, frequency fluctuations, instantaneous power failures, and transient voltages.

Such lead acid batteries should minimize the depletion of moisture by preventing the release of oxygen / hydrogen decomposed from the electrolyte during floating charge and facilitating recombination of gases for maintenance-free and long life. However, electrolysis of water occurs due to overvoltage, and there is a disadvantage in that distilled water needs to be replenished at regular use periods.

The solution to the depletion of water is to change the composition of the lead-acid battery current collector, to improve the sealability of the battery case, and to change the electrolyte component, among which the glass mat used to prevent the falling of the positive electrode plate active material and oxidation of the separator plate Electrolyte of lead acid batteries such as a method of absorbing sulfuric acid solution in pores of glass mat (Absorptive Glass Mat, hereinafter referred to as "AGM method") and a method of containing sulfuric acid solution in silica gel (hereinafter referred to as "gel electrolyte" method) Many methods are used.

The AGM method is widely used in small industrial cells because of its simple and inexpensive manufacturing process, and the gel electrolyte method has a high effect of inhibiting phase separation of water and sulfuric acid in the electrolyte, and includes a high amount of sulfuric acid solution. Mainly used in large industrial batteries that are required.

The gel electrolyte composed of a mixture of sulfuric acid and silica used in the lead acid battery maintains a viscosity similar to that of the liquid state at the beginning of mixing, but increases in viscosity while forming a three-dimensional network structure by hydrogen bonding over time to form a gel. Change.

However, as the amount of silica used in the gel electrolyte increases, the rate of change to the gel form is faster, and the amount of electrolyte is also relatively insufficient, thereby reducing the capacity performance of the battery. Therefore, the amount of silica added should be kept to a minimum as far as gelling is possible.

In addition, when gelation proceeds, it is easy to change the gel form due to the amount of sulfuric acid emitted in the middle part of the electrode plate, but the amount of sulfuric acid is relatively low at the upper part of the electrode plate, which slows down the rate of gel change.

Therefore, since the viscosity of the upper electrolyte is relatively low at the beginning of the operation of the battery, most of the gas generated during charging cannot be recombined and is discharged to the outside, resulting in high loss. In the horizontal mounting battery, electrolyte leakage occurs.

On the other hand, a terminating agent comprising silica (SiO ₂ ) and the like is directly included in preparing a solid electrolyte, and used as a solvent desiccant in the solid electrolyte (Korean Patent Publication No. 2000-52735, August 25, 2000); A technique for preparing a polymer electrolyte by incorporating silica in a polymer blend membrane composed of a polyvinylidene difluoride (PVdF) polymer and an amorphous polymer (Korean Patent No. 2000-55682, Sep. 15, 2000); And (iii) sulfuric acid, (ii) silica suspended in water, and (iii) a mixture of an emulsion of water / oil in a polymer electrolyte (US Pat. No. 4,937,156). In the case where the silica is directly mixed with other components of the silver electrolyte, the silica powder is applied to the upper surface of the gel electrolyte injected during the production of the lead-acid battery as in the present invention. .

Therefore, the present inventors further apply or inject silica or high concentration silila gel electrolyte on the top of the battery immediately after the injection of the lead electrolyte battery electrolyte to prevent the discharge of gas generated during charging, and leakage of the electrolyte in the horizontal mounting battery. To solve the problems of the battery overcharge and electrolyte depletion.

That is, the present invention injects a low concentration silica gel electrolyte up to the height of the electrode plate when the gel electrolyte is injected into the battery to solve various problems due to the slow gelation rate of the upper electrolyte, and lead-acid battery coated with silica powder It aims to provide.

In addition, the present invention is to inject a low concentration of silica gel electrolyte up to the pole plate height when the gel electrolyte is injected into the cell in order to solve the various problems caused by the slow gelation rate of the upper electrolyte, the lead injecting a high concentration of silica gel electrolyte on the top It is an object to provide a storage battery.

1 is a cross-sectional view of a lead acid battery of the present invention.

<Explanation of symbols for the main parts of the drawings>

2 --- cathode tube 4 --- separator

6 --- positive electrode 8 --- electrode assembly

10 --- low concentration silica gel electrolyte

12 --- Silica powder or high concentration silica gel electrolyte

14 --- Electrode Note 16 --- Rolling

The present invention for achieving the above object is an anode; cathode; And a low concentration silica gel electrolyte in which silica and sulfuric acid are mixed. In the lead acid battery, silica powder is coated on the low concentration silica gel electrolyte in a range of 0.01 to 2 parts by weight to provide viscosity of the upper electrolyte in the initial operation of the battery. It is to provide a lead acid battery that prevents exhaustion of the electrolyte.

In addition, the present invention is an anode; cathode; And a low concentration silica gel electrolyte in which silica and sulfuric acid are mixed, wherein the low concentration gel electrolyte has 20 to 40 wt% sulfuric acid solution 84 to 90 wt% and 10 to 16 wt% silica. Injecting a high concentration of silica gel electrolyte consisting of to increase the viscosity of the upper electrolyte in the initial operation of the battery to provide a lead-acid battery to prevent electrolyte exhaustion.

The silica powder coated on the gel electrolyte is made of fumed silica, and is preferably applied in an amount of 0.01 to 2 parts by weight based on the silica gel electrolyte solution of low concentration. When the silica powder is used at less than 0.01 parts by weight, the gel electrolyte does not form an interface with a low concentration of the gel electrolyte, and when the silica powder is applied at an amount exceeding 2 parts by weight, the volume of silica increases, making it difficult to apply the gel in the precursor. There is no advantage compared to the mixing together when preparing the electrolyte.

On the other hand, it is preferable to inject an electrolyte containing a high concentration of silica KEL electrolyte consisting of 20 to 40% by weight of 84% to 90% by weight of sulfuric acid aqueous solution and 10 to 16% by weight of silica, where the amount of silica is less than 10% by weight In this case, the gelation rate is low and there is no difference with the lower part. On the contrary, when it is used in excess of 16% by weight, the gelation proceeds quickly and it is difficult to inject.

Hereinafter, a configuration of a lead acid battery manufactured according to the present invention will be described with reference to the drawings.

The lead acid battery of the present invention mainly includes a plate group and a gel electrolyte in a precursor 16 made of plastic or avonite.

At this time, the electrode plate group is composed of a negative electrode plate 2, a separator (or separator) 4 and a positive electrode plate 6, the electrode plate group is connected to the electrode assembly (8).

The negative electrode plate 2 covers lead (Pb) as a negative electrode active material on a substrate, and the positive electrode plate 6 covers lead peroxide (PbO ₂ ) as a positive electrode active material on a substrate.

The separator 4 is non-conductive, rich in porosity, and low in battery resistance.

The upper surface of the plate group is injected with a silica gel electrolyte 10 of low concentration using a gravity injection method, and the silica powder 12 is applied to the upper portion using a spray method or a high concentration of silica gel electrolyte is further injected into the present invention. Manufactures lead acid batteries.

When the viscosity of the electrolyte is lowered and injected by using the minimum amount of silica of the electrolyte used in the present invention, the filling is easy, and thus the capacity performance of the battery is improved.

When an additional silica powder is applied immediately after injection of an electrolyte or a high concentration of silica gel electrolyte is injected, an interface is formed between a low concentration of the silica gel electrolyte 10 and a newly added silica powder or a high concentration of silica gel electrolyte 12. Becomes higher.

As a result, since oxygen and hydrogen generated in the electrode plates 2 and 6 during battery charging are combined with each other at a pressure due to the high viscosity of the upper electrolyte, water is generated, thereby preventing the gas from being discharged to the outside. This reduces the contamination of the vent valve and reduces electrolyte leakage in horizontally mounted cells.

In order to verify the effect of the invention the following examples and comparative examples were carried out. However, the examples are only to illustrate the invention and the present invention is not limited by the following examples.

Example 1 Lead Acid Battery Manufacturing Method

4600 g of 35% sulfuric acid solution and 400 g of silica were mixed to prepare a gel electrolyte. The gel electrolyte prepared above was injected into the cell by the gravity injection method.

Immediately after gel electrolyte injection, 50 g of fumed silica (Degussa, Aerosil 200) was applied to the top of the cell by a spraying method to produce lead acid batteries (2 V, 600 Ah).

Experimental Example 1: Performance Comparison of Lead Acid Battery

After the lead-acid battery using the conventional gel electrolyte and the lead-acid battery (2V, 600Ah) of the present invention prepared in the above example was maintained at 50 ° C for 6 weeks at constant voltage charge, the weight change after charge and discharge was compared with the clean state of the vent part. (Table 1).

The electrolyte leakage phenomenon of the vent part was confirmed using litmus paper.

TABLE 1

division Conventional gel battery (8 wt% silica gel) Battery of the present invention (8 wt% silica gel + 1 wt% silica powder) Weight change after charge and discharge 31 g 28 g Vent Electrolyte leakage No change

Due to the change in the weight of the battery after charging and discharging of Table 1, the discharge of gas and the leakage of electrolyte were confirmed.

As described above, the lead acid battery manufactured according to the present invention increases the viscosity of the upper electrolyte by coating silica powder on the gel electrolyte or injecting a silica gel electrolyte in a high concentration, thereby increasing the viscosity of the oxygen and hydrogen when charging the lead acid battery. It promotes recombination, reduces the external discharge of gas generated, reduces the contamination of the vent valve, electrolyte depletion of the lead-acid battery by the electrolyte easily splashed by the discharge gas, and electrolyte leakage occurs in the horizontal mounting battery. The performance of the battery can be improved by solving the problem.

Claims (5)

anode; cathode; And a silica gel electrolyte having a low concentration of silica gel mixed with silica and sulfuric acid, wherein the silica powder is coated on the gel electrolyte to increase electrolyte viscosity in an initial stage of operation of the battery to prevent electrolyte depletion. Lead acid battery. The lead acid battery of claim 1, wherein the silica powder uses fumed silica. The lead acid battery according to claim 1 or 2, wherein the silica powder is applied in an amount of 0.01 to 2 parts by weight based on the silica gel electrolyte solution at a low concentration. anode; cathode; And a low concentration silica gel electrolyte in which silica and sulfuric acid are mixed, wherein the low concentration gel electrolyte is injected into a high concentration of silica gel electrolyte composed of an aqueous sulfuric acid solution and silica in an upper portion of the upper electrolyte in a battery initial operation step. Lead acid battery, characterized in that to increase the viscosity of the electrolyte to prevent exhaustion. The lead acid battery according to claim 1, wherein the high concentration silica gel electrolyte is composed of 20-40 wt% aqueous sulfuric acid solution 84-90 wt% and silica 10-16 wt%.