KR20060112439A - A support of activie material in polar plate used in lead-acid battery - Google Patents

Abstract

Provided is a support of an electrode active material for a lead acid battery which is excellent in mechanical properties, workability, productivity, hydrophilicity and shape stability, does not use a glass fiber and shows a good electrolyte permeation. The support(5) of an electrode active material comprises a synthetic fiber fabric which contains 10 wt% or more of a micro-filament yarn having an average diameter of 0.1-10 micrometers and has a micropore and where a hydrophilic resin is impregnated. Preferably the synthetic fiber fabric is a textile or knitted product and has a porosity of 80-98 %; and the hydrophilic resin is a poly(vinyl alcohol), a water-soluble acrylic resin, a water-soluble polybutadiene resin, a water-soluble vinyl acetic acid resin, a water-soluble vinyl acetate, a water-soluble polyurethane resin or their mixture.

Description

Pole plate active material support for lead acid battery {A support of activie material in polar plate used in lead-acid battery}

1 is a cross-sectional schematic view of a lead acid battery incorporating the electrode plate active material support of the present invention.

Figure 2 is a perspective schematic view of the electrode plate attached to the electrode plate active material support of the present invention.

Explanation of symbols on the main parts of the drawings

1: positive electrode plate 2: negative electrode plate

3: lead acid battery 4: separator

5: electrode plate active material support

The present invention relates to an electrode plate active material support for lead acid batteries, and more particularly, to an electrode plate active material support for lead acid batteries which can greatly improve workability and working environment due to excellent absorbency of sulfuric acid electrolyte and excellent mechanical strength.

In general, the lead plate manufacturing process of lead acid battery is divided into gravity casting method and expanded grid method.

Among these, the gravity casting method is largely formed through four stages.

In the first step, alloy lead such as lead-antimony alloy or lead-calcium is poured into a mold and cooled to form a substrate, and then cut to form a shape of the substrate.

The second step is to produce a soft foil to paint on the substrate formed earlier.

The soft lake is prepared by adding a small ingot into the soft branch to produce a small powder powder composed of Pb and PbO, and then mixing water and sulfuric acid and other additives.

In the third and fourth steps, PbO and PbSO ₄ , the active materials of the electrode plate, are coated with PbO and PbSO ₄ after the coating process of coating the generated soft foil on the substrate, the drying process and the aging process to reduce the moisture and Pb content in the coating electrode plate. the electrode plate is completed via a second charging step of changing to the ^{₂ +} and Pb.

However, the plate produced in this way is not very productive and needs to be replaced after a certain time has elapsed, thereby causing additional costs due to additional costs.

In addition, the thickness of the electrode plate is not constant because it is made of a mold.

On the other hand, the expanded grid method melts the alloy lead and winds it like a coil, and then uses it to make a mesh-like substrate, and paints the above-mentioned soft foil to dry and mature and supercharge the plate. Complete

The expanded grid plate has good productivity and there is no use of molds, which saves additional costs and costs by simplifying the process.

In addition, since the thickness of the electrode plate manufactured as described above is constant, it is possible to manufacture a uniform cell in the battery manufacturing process.

However, even the expanded grid method, which is an excellent electrode manufacturing technique, does not improve the weak bonding strength of the electrode active material. In other words, when the battery is used for a certain period of time due to the weak bonding force between the electrode plate and the active material, the active material is dropped from the electrode plate, which is a direct cause of the decrease in the output power and the number of charge / discharge cycles.

In order to solve this problem, a method of attaching an electrode plate active material support body composed of glass fiber mats to the electrode plate has been proposed, but the electrode plate active material support of the glass fiber mat has a weak active material holding power, harmfulness of glass fiber and weak mechanical strength. Due to the workability and productivity is low.

In order to improve such a problem, Korean Patent No. 0250381 proposes an electrode plate active material support body composed of a nonwoven fabric instead of a glass fiber mat, but in this case, the electrolyte permeability is relatively low and the electrolyte permeability is excellent. There is still a decrease in workability and productivity due to mechanical properties.

An object of the present invention is to provide a lead-acid battery active material support for a lead-acid battery excellent in mechanical strength characteristics, workability is improved, can solve the harmful working environment, excellent electrolyte permeability, in order to solve such conventional problems.

The present invention manufactures the lead plate active material support for lead acid battery by using a synthetic fiber fabric containing microfine fibers and water-soluble resin instead of glass fibers having workability and work environment, excellent mechanical strength properties, workability is improved, harmful It is possible to solve the working environment, and to provide an electrode active material support for a lead acid battery having excellent electrolyte permeability.

The lead plate active material support for a lead-acid battery of the present invention for achieving the above problems, the microporous fiber having an average diameter of 0.1 ~ 10㎛ 10% by weight or more of the total weight is contained in the synthesis of fine pores, impregnated with a hydrophilic resin It is characterized in that the fiber made of a fabric.

Hereinafter, with reference to the accompanying drawings will be described in detail.

1 and 2, the present invention is attached to and used in the form of wrapping a pole plate of a lead acid battery, that is, a positive electrode plate 1 and a negative electrode plate 2, or simultaneously.

1 is a cross-sectional schematic view of a lead acid battery incorporating the present invention, and FIG. 2 is a perspective schematic view of a pole plate to which a pole plate active material support of the present invention is attached.

In the present invention, in place of the conventional glass fiber mat or non-woven fabric (i) contains 10% by weight or more of the ultrafine fibers having an average diameter of 0.1 ~ 10㎛ relative to the total weight to form micropores, (ii) the hydrophilic resin It is composed of impregnated synthetic fibers.

When the average diameter of the ultrafine fibers exceeds 10㎛, fine pores are not effectively formed on the fabric, and when the average diameter is less than 0.1㎛, the mechanical properties of the fabric are lowered and the manufacturing cost is increased.

In addition, when the weight ratio of the ultrafine fibers is less than 10% by weight, micropores are not sufficiently formed on the fabric, thereby decreasing porosity.

The synthetic fiber fabric is in the form of a woven or knitted fabric.

The hydrophilic resin impregnated in the synthetic fiber fabric is polyvinyl alcohol, water soluble acrylic resin, water soluble polybutadiene resin, water soluble vinyl acetate resin, water soluble vinyl acetate resin, water soluble polyurethane resin, or a mixture thereof.

The present invention in the form of a woven fabric using two-component composite fibers composed of the eluting component and the fiber-forming component alone as a warp and weft, or weaving the fabric, or the conventional synthetic fibers other than the two-component composite fibers and composite fibers After weaving the fabric using warp and weft together, the prepared fabric is treated with an aqueous alkali solution to elute the elution components in the fabric to form micropores in the fabric, and then the fabric having the micropores formed is dipped in a hydrophilic resin solution. It can be prepared by spraying a hydrophilic resin solution on the fabric.

On the other hand, the present invention in the form of knitted fabric by using the two-component composite fibers alone or by using a conventional synthetic fibers other than the two-component composite fibers and composite fibers as a knitting yarn, after knitting the knitted dough It was prepared by treating the solution with an aqueous alkali solution to elute the elution component in the knitted fabric to form micropores in the knitted fabric, and then duffing the knitted fabric in which the micropores were formed in a hydrophilic resin solution or spraying the hydrophilic resin solution on the knitted fabric.

In the present invention, since the micropores are contained in 10% by weight or more, micropores are formed to increase the porosity, and the hydrophilic resin is included, thereby improving hydrophilicity and excellent stiffness, thereby improving workability.

In the present invention, the porosity is 80 to 98%, and the average diameter of the micropores is preferably 0.5 to 15㎛.

In the present invention, the thickness of the present invention is set to 0.1 to 0.4 mm, more preferably 0.2 to 0.3 mm, in order to prevent the internal short circuit phenomenon caused by the resin crystal phase (Dendrite) and to determine the absolute sulfuric acid absorption amount and the smooth oxygen transfer cycle. It is good. If the average thickness is less than 0.1 mm, it is difficult to apply the electrode active material support for lead acid batteries.

Further, the present invention has a thickness of 0.1 to 0.4 mm, a tensile strength of 5 kgf or more in the transverse direction and a longitudinal direction, and a liquid retention (absorbed amount per volume) of 1 g / cc or more.

The higher the liquid retention property, the more stable and excellent the charge / discharge characteristics are when the battery is applied.

In the present invention, various physical properties of the electrode plate active material support were evaluated (measured) by the following method.

Tensile strength (Kgf) / Elongation (%)

The size of the sample was 15 mm in width x 70 mm in length, and the tensile speed was 20 mm / minute.

Porosity (%)

The mercury penetration method (device name: Autopore IV9500) is used to measure the pressure applied to the mercury using a porosity analyzer to inject it into different pores. The size of the micropores of the polymer layer is measured before forming the voids.

Absorption rate (mm / 10 minutes)

Measure the height of the sulfuric acid solution raised through the specimen after immersing the bottom 20 mm of the specimen 15 mm wide x 70 mm long in a sulfuric acid solution having a specific gravity of 1.3 at 25 ° C. for 10 minutes.

Acid resistance

A 50 × 50 mm sample was left for 3 days in sulfuric acid (specific gravity: 1.300 / 25 ° C., 150 cc, temperature 65 ° C.) to determine whether foreign matter was produced.

Electrical resistance

A 70 × 70 mm specimen was immersed in dilute sulfuric acid (1.280 / 20 ℃) at 25 ± 2 ℃ for 5 hours while applying a DC current of 1A between electrodes to measure the voltage drop due to liquid resistance. Calculated.

[Wherein R is the resistance of the separator (Ω, 100 cm 2 / sheet), R ₁ is the resistance when the test piece is inserted, R ₂ is the resistance when no test piece is inserted, and n is the test It is convenience number]

· Liquidity

After 15 × 70 mm sample was immersed in sulfuric acid (specific gravity: 1.3000 / 25 ℃) for 30 seconds, and maintained for 5 minutes on a PVC plate of 45 ℃, the liquid retention was calculated by the following formula.

[Wherein, W ₁ : weight before test, W ₂ : weight after test, L: length (mm), W: width (mm), T: thickness (mm)]

·thickness

When 40 kgf / dm 2 force was applied to the specimen, the thickness was measured.

Hereinafter, the present invention will be described in more detail with reference to Examples and Comparative Examples.

However, the present invention is not limited only to the following examples.

Example 1

75 denier / 36 filament poly with a sea component of a polyester copolymer polymer having excellent alkali hydrolyzability by copolymerization of an island component of polyethylene terephthalate having an average diameter of 3 µm and 7% by mol of sodium dimethylene sulfoisophthalate. After weaving the islands-in-the-sea composite fiber as a weft yarn and using plain 75 denier / 36 filament polyester multifilament as a warp yarn as a warp yarn, weaving the woven fabric with an aqueous alkali solution, The powder was eluted (removed) to prepare a fabric (porosity 92%) in which micropores with an average diameter of 1.8 µm were formed, and then the fabric was dipped into an aqueous polyacrylic solution and then the aqueous polyacrylic resin content. Squeeze it to 3 weight%, and it is then dried at 120 degreeC, and the electrode plate active material for lead acid batteries whose thickness is 0.21 mm. A delay was prepared.

Evaluation results of the various physical properties of the prepared lead plate active material support for a lead acid battery are shown in Table 1 below.

Example 2

75 denier / 36 filament poly with a sea component of a polyester copolymer polymer having excellent alkali hydrolyzability by copolymerization of an island component of polyethylene terephthalate having an average diameter of 3 µm and 7% by mol of sodium dimethylene sulfoisophthalate. After preparing the warp knitted paper using polyester multifilament of 75 denier / 36 filament of polyester islands-in-the-sea composite fiber and non-composite fiber at 50:50 weight ratio, respectively, the knitted warp knitted paper was used as alkaline aqueous solution. Treatment to elute (remove) the sea component to prepare a warp knitted fabric (porosity 85%) in which micropores having an average diameter of 2.3 mu m are formed, and then dipping the prepared warp knitted fabric into an aqueous polyurethane solution and then aqueous poly Squeeze the urethane content to 3% by weight, and continue drying at 120 ° C. to form a lead-acid battery electrode active material support having a thickness of 0.22 mm Was prepared.

The properties of each layer of the prepared electrode plate active material support for a lead acid battery are shown in Table 1 below.

Comparative Example 1

A 75 denier / 36 filament polyester multifilament short fiber (not a composite fiber) was carded, cross-wrapped, and water punched to form a nonwoven fabric type electrode plate active material support for a lead-acid battery having a thickness of 0.21 mm.

The results of measuring various physical properties of the manufactured lead plate active material support for a lead acid battery are shown in Table 1 below.

Property evaluation result division Example 1 Example 2 Comparative Example 1 Thickness (mm) 0.21 0.22 0.21 Porosity 92 85 88 Tensile Strength (15mm / min, Kgf) Lateral direction (MD) 11.46 17.22 1.24 Longitudinal (TD) 18.25 18.25 4.02 Acid resistance No foreign matter No foreign matter No foreign matter Electric resistance (Ω) 0.00040 0.00041 0.00055 Fluid 2.92 2.68 1.23 Absorption rate (mm / 10 minutes) 39.0 50.0 42.02

The present invention is composed of a woven or knitted fabric of excellent mechanical properties and excellent workability and productivity.

In addition, it is possible to prevent the working environment from being harmful by not using glass fiber.

In addition, the present invention is excellent in the permeability of the electrolyte is formed by the fine pores, it contains a hydrophilic resin is also excellent in hydrophilicity and shape stability.

Claims (6)

A lead plate active material support for lead acid batteries, characterized in that the microfibers having an average diameter of 0.1 to 10 μm or more are contained in a synthetic fiber fabric having fine pores and impregnated with a hydrophilic resin. The electrode plate active material support for a lead acid battery according to claim 1, wherein the synthetic fiber fabric is woven or knitted. The cathode plate active material support for a lead acid battery according to claim 1, wherein the hydrophilic resin is a polyvinyl alcohol, a water-soluble acrylic resin, a water-soluble polybutadiene resin, a water-soluble vinyl acetate resin, a water-soluble vinyl acetate resin, a water-soluble polyurethane resin, or a mixture thereof. . The pole plate active material support for a lead acid battery according to claim 1, wherein the porosity of the synthetic fiber fabric is 80 to 98%. The cathode plate active material support for a lead acid battery according to claim 1, wherein the average diameter of the micropores in the synthetic fiber fabric is 0.5 to 15 µm. The lead-acid battery according to claim 1, wherein the thickness of the electrode active material support is 0.1 to 0.4 mm, the tensile strength in the transverse and longitudinal directions is 5 kgf or more, and the liquid retention (absorbed amount per volume) is 1 g / cc or more. Electrode plate active material support.

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