RU2249884C2 - Glass fiber blanket separator for sealed absorbed-electrolyte lead batteries - Google Patents

Abstract

FIELD: electrical engineering; separators for sealed absorbed-electrolyte lead batteries.

SUBSTANCE: proposed glass fiber blanket separator characterized in optimal porous structure aiding in complete absorption of electrolyte is, essentially, composition of microporous spatula glass fibers of microscopic thinness, fiber mean diameter being 0.35 to 0.40 and 0.22 to 0.25 μm and chemically resistant latex as binder, proportion of components being as follows, mass percent: fiber whose mean diameter is between 0.35 and 0.40 μm, 78 - 80; fiber whose mean diameter is between 0.22 and 0.25 μm, 15 - 17; chemically resistant latex, the rest.

EFFECT: reduced electrical resistance and enhanced mechanical strength ensuring high separating properties.

1 cl, 1 tbl, 4 ex

Description

The invention relates to the electrical industry and can be used for the production of separation materials for lead storage batteries with an absorbed electrolyte of a traditional type, also cylindrical and prismatic.

BACKGROUND

Analysis of patent information sources on the creation of separation materials that absorb sulfate electrolyte was carried out taking into account the functions assigned to this type of separator as part of a sealed battery, i.e. the separator should serve not only as an insulator against short circuits, but also as an electrolyte reservoir. In addition, oxygen released during the electrochemical reaction and reduced at the negative electrode should pass unhindered through the separator. In this case, the pores of the separator are substantially filled with electrolyte. Therefore, the absorbing separator must have two types of pores: one for the transport of gas of 2-4 microns in size, and the other for the transport of electrolyte ions of 10-25 microns in size.

Currently, there are many patents for the creation of an absorbent separator. Glass fibers of various diameters with the addition of organic polymer fibers and inorganic fillers are used. At the same time, there is a tendency for manufacturers of absorbent separators to achieve good absorption characteristics of the electrolyte and its uniform distribution by varying various types of fibers.

A known separator for a sealed lead-acid battery according to international application WO No. 80/01969, class. H 01 M 2/16, 1980

The material is made from a composition containing 30-80 wt.% Perlite and 20 - 70 wt.% Glass fibers with a diameter of 03 to 1.0 microns; perlite particles have a size of 3-100 microns.

A composition containing 15-75 wt.% Perlite, 20 - 70% of May. Glass fibers and 5 - 20 wt.% Insoluble heat-resistant fibers, has the function of an electrolyte collector.

A disadvantage of the known material is that it has a large-pore structure and therefore low electrolyte retention capabilities.

Known separator for sealed lead-acid battery according to international application WO No. 9800875, class. H 01 M 2/16, 1998

The separator is made of a mixture of glass fibers, most of which have a diameter not exceeding 20 microns, and with a diameter of less than 1 micron, about 5% and 0.2 to 20% of cellulose fibers. A separator made from such a mixture has a higher strength than that formed from a conventional mixture of glass fibers.

The disadvantage of this technical solution is the large-porous structure of the known material and, therefore, low holding capacity for electrolyte.

The closest in technical essence and the achieved result is a separator for sealed lead-acid batteries according to the application of Japan No. 61-259452, class H 01 M 2/16, 1980 (adopted as a prototype).

The separator is made by mixing glass fiber with a diameter of 3 μm with micropowder of an acid-resistant inorganic substance, for example, aluminum dioxide or foamed perlite, which makes up 30 - 39% of the total mass of the separator, and gelatin or starch in the amount of 2 - 5% of the total mass of the separator is used as a binder.

A disadvantage of the known material is that it is made of coarse fiber, as a result of which a separation material with a large-pore structure is obtained, which leads to a low holding capacity with respect to the electrolyte. In addition, the disadvantage of this known material is that it contains food components as a binder, and this is impractical.

SUMMARY OF THE INVENTION

The purpose of the invention is to provide a glass mat separator suitable for use in sealed lead-acid batteries with absorbed electrolyte of any design (traditional with a flat separator, cylindrical and prismatic), capable of preventing short circuit, fully absorb the electrolyte in an amount sufficient for electrochemical processes in the battery . Also, the separator should be distinguished by the necessary strength, low electrical resistance, small pore diameter and high specific absorbency of the sulfate electrolyte.

This goal is achieved by the fact that the composition containing microporous microfine microfine glass staple fibers with an average diameter (0.35 - 0.40) microns, an average diameter (0.22 - 0.25) microns and chemically resistant latex as a binder in the following ratio of components, wt.%:

Fiber with an average diameter (0.35 - 0.40) μm - 78 - 80

Fiber with an average diameter (0.22 - 0.25) microns - 15-17

Chemically resistant latex - the rest is up to 100.

Fibers with an average diameter (0.35 - 0.40) microns were produced in accordance with the technical requirements of TU 6-11-483-79, fibers with an average diameter (0.32 - 0.40) microns were produced in accordance with the technical requirements of TU 6-19-062-87, and chemically resistant polymethylmethacrylate latex was produced in accordance with TU 6-01-479-79.

Glass separator is made using paper technology. The microfine glass staple fibers mentioned above were pre-treated in a grinding roll at a concentration of 0.8 - 1.0%. Fibers of each diameter were processed separately, because in the initial state they have different lengths. When grinding, the fibers are combed, split and shortened.

Any chemically stable binder, for example nitrile butadiene rubber, polymethyl methacrylate latex and others, is added to the mass prepared in this way.

The prepared mass is diluted with water to a concentration of 0.2 - 0.3% and fed to the ebb. Cast samples are pressed and dried.

The obtained samples of glass mat separators were tested according to standard methods for physicomechanical properties.

The following samples were manufactured and tested.

Sample 1.

A glass mat sample was made consisting of a mixture of microfine staple fibers with the addition of chemically resistant latex in the ratio, wt.%:

Fiber with an average diameter of M20 - MTV - (0.35 - 0.40) microns - 76

Fiber with an average diameter of M20 - MTV - (0.22 - 0.25) microns - 20

Chemically resistant latex - 4.

The resulting material has a thickness of 0.7 mm, a tensile strength of 0.25 MPa, an electrical resistance of 0.12 Ohm · cm ² , a maximum pore diameter of 20 μm, a minimum of 6 μm, a specific absorption of a sulfate electrolyte of 12.5 g / g, insufficient elasticity and resistance to mechanical damage.

The specific absorbency of the sulfate electrolyte is characterized by the amount of sulfuric acid in grams absorbed by the separation material in 10 minutes when completely immersed in sulfuric acid, referred to the mass of an absolutely dry separator in grams.

The determination of this parameter was carried out according to the method described in TU OP 13-0248643-251-92 "Separation material for acid current sources".

Sample 2.

A glass mat sample was made consisting of a mixture of microfine staple fibers with the addition of chemically resistant latex in the ratio, wt.%:

Fiber with an average diameter of M20 - MTV - (0.35 - 0.40) microns - 78 - 80

Fiber with an average diameter of M20 - MTV - (0.22 - 0.25) μm - 15 - 17

Chemically resistant latex - the rest is up to 100.

The resulting material has a thickness of 0.7 mm, tensile strength is 0.42 MPa, electrical resistance is 0.06 Ohm · cm ² , the maximum pore diameter is 10 μm, the minimum is 2 μm, the specific absorption of the sulfate electrolyte is 18.7 g / g, has the ability to bend without mechanical damage.

Sample 3.

A glass mat sample was made consisting of a mixture of microfine staple fibers with the addition of chemically resistant latex in the ratio, wt.%:

Fiber with an average diameter of M20 - MTV - (0.35 - 0.40) microns - 78 - 80

Fiber with an average diameter of M20 - MTV - (0.22 - 0.25) μm - 15 - 17

Chemically resistant latex - the rest is up to 100.

Sample 3 has a thickness of 1.1 mm, a maximum pore diameter of 10 μm, a minimum of 2 μm, has a low electrical resistance of 0.07 Ohm · cm ² , is capable of bending without mechanical damage, has a tensile strength of 0.45 MPa and specific the absorption of the sulfate electrolyte is 18.7 g / g.

Sample 4.

A glass mat sample was made consisting of a mixture of microfine staple fibers with the addition of chemically resistant latex in the ratio, wt.%:

M20 - MTV - (0.35 - 0.40) μm - 83

M20 - MTV - (0.22 - 0.25) μm - 13

Chemically resistant latex - 4

The obtained glass mat sample has a thickness of 0.7 mm, an electrical resistance of 0.12 Ohm • cm ² , a maximum pore diameter of 30 μm, a minimum of 8 μm, a tensile strength of 0.25 MPa and a specific absorption of sulfate electrolyte of 11, 6 g / g

The results are presented in table 1.

As can be seen from the above examples (Table 1), a decrease in the content of microfine staple fiberglass with a diameter of (0.35-0.40) μm below 78% (sample 1) leads to a decrease in mechanical strength, elasticity and specific absorption of sulfate electrolyte. The structure of the glass separator in this case is porous.

An increase in the content in the composition of fiberglass with a diameter of (0.35 - 0.40) μm above 80% (sample 4) also impairs the physical, mechanical and structural characteristics of the glass mat separator.

A change in the quantitative composition in the inventive composition of the second component - fiberglass with an average diameter (0.22 - 0.25) microns also leads to a deterioration in the physico-mechanical properties of the glass mat separator.

Thus, the claimed composition (samples 2 and 3) has a significant advantage over the prototype:

- optimal finely porous structure, contributing to good absorption of the electrolyte, as evidenced by the high specific absorbency of the sulfate electrolyte and a small pore diameter;

- low electrical resistance;

- sufficient mechanical strength and elasticity, providing high separating properties of glass mat;

- excludes from its composition food components.

Table 1 - Characteristics of the samples of the inventive separator-glass mat No. p
Samples The composition of the samples of the claimed separator glass mat wt.% Glass mat characteristics Thickness under load 10 MPa, mm Tensile Strength, MPa Elasticity (180 ° bend without mechanical damage) Resistance, Ohm · cm ²

Specific Absorption of Sulfate Electrolyte

Pore diameter, microns maximum average minimum 1 - Fiber with an average diameter (0.35-0.40) microns - 78 - 80
- A
- Fiber with an average diameter (0.22-0.25) μm-15-17
- IN
- Chemically resistant latex - C
A - 76
IN 20
C - 4 0.7 0.25 not 0.12 12.5 twenty 8.5 6.0 2 A - 78-80
B - 15-17
C - the rest is up to 100 0.7 0.42 Yes 0.06 18.7 10 6-8 1.0-3.0 3 A - 78-80
B - 15-17
C - the rest is up to 100 1,1 0.45 Yes 0,07 18.7 10 6-8 1.0-3.0 4 A - 83
B - 13
C - 4 0.7 0.20 not 0.12 11.6 thirty 10 8

SOURCES OF INFORMATION

1. International application WO No. 80/01969, cl. H 01 M 2/16, 1980.

2. International application WO No. 980875, cl. H 01 M 2/16, 1998.

3. Japanese application No. 61-259452, cl. H 01 M 2/16, 1980 (prototype).

Claims (1)

Glass separator for a sealed lead-acid storage battery containing glass fiber and a binder, characterized in that the composition containing microporous microfine glass microfine staple fibers with an average diameter (0.35 ÷ 0.40) μm and an average diameter (0.22 ÷ 0.25) microns and chemically resistant latex as a binder in the following ratio of components, wt.%: Fiber with an average diameter (0.35 ÷ 0.40) μm - 78 ÷ 80 Fiber with an average diameter (0.22 ÷ 0.25) μm - 15 ÷ 17 Chemically resistant latex Else up to 100