KR20070029951A - A support of activie material in polar plate used in lead-acid battery - Google Patents

Abstract

Provided is an active material support in a polar plate for a lead storage battery, which has excellent electrolyte-retention and hygroscopicity to improve the battery performance, and has mechanical properties to improve the workability and productivity, together with prolonged battery life. The active material support(5) in a polar plate(1,2) for a lead storage battery(3) is formed of a fabric which is woven with warps of thermoplastic multi-filaments having a circular cross section and wefts of hydrophilic shaped yarns. Preferably, in the fabric, the hydrophilic shaped yarns comprise at least 10 wt% of a hydrophilic resin. The hydrophilic shaped yarns have an oval cross-section with 3-8 protuberances. The fabric has a texture of 5-16 leaf twill or 5-16 leaf satin.

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.

Figure 3 is an exemplary cross-sectional view of the hydrophilic release cross-section yarn used in 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 a lead plate active material support for lead acid batteries, and more particularly, to improve the performance of lead acid batteries due to excellent liquid retention and hygroscopicity (diffusion) of sulfuric acid electrolyte, and to improve workability and working environment due to excellent mechanical strength. The present invention relates to an electrode plate active material support for a lead acid battery, which can be greatly improved and effectively prevents dropping of the electrode plate active material, thereby extending the life of the lead acid battery.

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, thus reducing additional costs and cost reduction 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 solve such a conventional problem, excellent mechanical strength characteristics, workability is improved, harmful working environment can be solved, electrolyte solution and hygroscopicity (diffusion) of the electrolyte is excellent The present invention provides an electrode active material support for a lead acid battery that can improve performance and effectively prevent dropping of the electrode active material, thereby extending the life of the lead acid battery.

The present invention is made of a thermoplastic multifilament having a circular cross section and the weft yarn is a hydrophilic sectional cross-section yarn, instead of a glass fiber mat having a lead-acid active material support for a lead acid battery, which has problems in workability and working environment, and thus has excellent mechanical strength characteristics. It is intended to provide a lead-acid battery active material support for lead-acid batteries that can improve workability, solve a harmful working environment, and have excellent electrolyte solution retention and hygroscopicity (diffusion).

Lead electrode active material support for a lead-acid battery of the present invention for achieving the above problems, characterized in that the inclined cross-section is a thermoplastic multifilament of circular cross section, the weft yarn is made of a hydrophilic release cross-section 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.

The present invention consists of a fabric that is a thermoplastic multifilament with a circular cross section and a weft hydrophilic cross section instead of a conventional fiberglass mat or nonwoven fabric.

The inclination constituting the fabric of the present invention is a thermoplastic multifilament having a circular cross section, and preferably, polyester multifilament, polyolefin multifilament or aromatic polyamide multifilament having excellent acid resistance is preferable.

More preferably, the ramp is a two-component composite fiber which can form micropores in the fabric while the eluting component and the fiber-forming component (acid-resistant thermoplastic resin) is mixed and the eluting component is eluted by an aqueous alkali solution after weaving. good.

On the other hand, the weft constituting the woven fabric of the present invention contains a hydrophilic release cross-section yarn 10% by weight or more.

Specifically, the hydrophilic release cross-section yarn is prepared by spinning a hydrophilic resin into a spinneret for use with a sectional cross-section, or spinning a mixture of hydrophilic resin and hydrophobic resin into a spinneret for use with a cross-section.

The above hydrophilic resin is copolymerized polyester with 3 to 15 mol% sodium dimethylene sulfoisophthalate copolymerized, polyvinyl alcohol, aqueous acrylic resin, aqueous polybutadiene resin, aqueous vinyl acetate resin, aqueous vinyl acetate resin, aqueous poly Urethane resins, mixtures thereof, and the like, and the hydrophobic resin is a polyester resin or a polyolefin resin.

The hydrophilic release cross-sectional yarn contains 10% by weight or more of the hydrophilic resin, thereby improving the liquid retention property and the diffusibility of the electrolyte solution.

The cross-sectional shape of the said hydrophilic shaped cross-section yarn is an elliptical shape etc. which have 3-8 protrusion parts. 3 is an exemplary cross-sectional view of the present hydrophilic sectioned yarn.

In the present invention, since the weft yarn is a hydrophilic sectional cross-section yarn, the electrolyte transfer passage is formed in the weft direction of the fabric, and the diffusivity (hygroscopicity) of the electrolyte solution in the weft direction is greatly improved by a capillary phenomenon or the like.

The structure of the fabric is preferably 5 to 16 twill or 5 to 16 satin in order to further improve the electrolyte diffusion and hygroscopicity in the warp direction.

On the other hand, the fabric is preferably woven in a jacquard bag so that the sewing process for manufacturing the electrode plate active material support can be omitted.

Said 5-16 runners of a weave means 5 to 16 runners of the number of inclinations and wefts in a repeating unit of a tissue, and it is preferable that 5-16 pieces of twills are changeable twills.

Specifically, there are few tissue points in the warp and weft directions so that the length of the warp and weft yarns projected on the surface or the back of the fabric is relatively long.

As described above, the inclined elongated in the warp and weft directions form a void in the fabric, and at the same time, serve as a moving passage of the electrolyte, thereby improving electrolyte hygroscopicity (diffusion) and liquid retention.

The fabric includes a fabric compressed with a calendering roller.

 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.

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, an absorption rate of 40 to 60 mm / min, and a liquid retention (absorption per volume) of 0.6 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, 100cm 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 piece inserted Is the number of

· 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  One

A polyester copolymer (hydrophilic polymer) and a polyester polymer (hydrophobic polymer) in which a 50-denier / 24-filament circular cross-section polyester multifilament is used as a slope and copolymerized with 7 mol% of sodium dimethylene sulfoisophthalate are 20: Using a 75 denier / 36 filament hydrophilic shaped cross-section yarn prepared by mixed spinning in the cross-sectional shape of FIG. 3 at a weight ratio of 80 as a weft yarn, 5 runners with a warp density of 270 bones / inch and a weft density of 110 bones / inch After manufacturing the woven fabric, the woven fabric was treated with an aqueous alkali solution to elute (remove) the sea component to prepare a fabric (porosity 68%) in which micropores having an average diameter of 1.8 µm were formed. To prepare an electrode plate active material support for a lead acid battery having a thickness of 0.17 mm.

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 / 24 filament poly with a sea component of a polyester copolymer polymer having excellent alkali hydrolyzability by copolymerizing the island component of polyethylene terephthalate with an average diameter of 3 µm and 7% by mol of sodium dimethylene sulfoisophthalate. 270 yarns / inch using a cross-sectional yarn of 75 denier / 36 filaments prepared by spinning the ester island-in-the-sea composite fiber as a warp yarn and spinning the polyester copolymer resin (hydrophilic resin) in the cross-sectional form of FIG. After fabricating five main fabrics with warp density and weft density of 110 bones / inch, the woven fabrics were treated with alkaline aqueous solution to elute (remove) the sea component to form micropores with an average diameter of 2.3 μm. After preparing the fabric (porosity 74%), using this to prepare a lead-acid active material support for a lead-acid battery having a thickness of 0.15mm.

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  One

50 denier / 24 filament polyester multifilament with a circular cross section is used as a warp yarn, and 75 denier / 36 filament polyester multifilament with a circular cross section is used as a weft yarn. After weaving a plain weave fabric with a weft density of inches, it was used to prepare an electrode plate active material support for a lead acid battery having a thickness of 0.17 mm.

The properties of each layer of the prepared electrode 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) 0.15 0.15 0.22 Porosity 68 74 70 Tensile Strength (15mm / min, Kgf) Lateral direction (MD) 16.32 16.56 14.11 Longitudinal (TD) 15.30 16.32 12.11 Acid resistance No foreign matter No foreign matter No foreign matter Electric resistance (Ω) 0.00041 0.00039 0.00078 Fluid 2.08 2.01 1.45 Absorption rate (mm / 10 minutes) 50 48 26

The present invention is composed of a fabric 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 provides an electrolyte transport passage in the inclined and / or weft direction, which is excellent in liquid retention and hygroscopicity (diffusion) of the electrolyte, and also contains a hydrophilic resin, which is excellent in hydrophilicity and shape stability.

Claims (10)

The slope is a thermoplastic multifilament having a circular cross section, the weft yarn pole plate active material support for a lead acid battery, characterized in that made of a woven hydrophilic cross-section yarn. The electrode plate active material support for a lead acid battery according to claim 1, wherein the hydrophilic sectional cross-section yarn contains 10% by weight or more of the hydrophilic resin. The hydrophilic resin according to claim 2, wherein the hydrophilic resin is copolymerized polyester copolymerized with sodium dimethylene sulfoisotalate of 3 to 15 mol%, polyvinyl alcohol, aqueous acrylic resin, aqueous polybutadiene resin, aqueous vinyl acetate resin, aqueous vinyl acetate resin, It is an aqueous polyurethane resin or a mixture thereof, The electrode plate active material support body for lead acid batteries. The cross-sectional shape of the hydrophilic shaped cross-section yarn is an ellipse having 3 to 8 protrusions, characterized in that the electrode plate active material support for a lead acid battery. The electrode plate active material support for a lead acid battery according to claim 1, wherein the hydrophilic release cross-section yarn is manufactured by spinning a hydrophilic resin into a spinneret for release release. The cathode plate active material support for a lead acid battery according to claim 1, wherein the hydrophilic release cross-section yarn is manufactured by spinning a mixture of a hydrophilic resin and a hydrophobic resin with a spinneret for release die use. The electrode plate active material support according to claim 1 has a thickness of 0.1 to 0.4 mm, a tensile strength in the transverse direction and a longitudinal direction of 5 kgf or more, an absorption rate of 40 to 60 mm / min, and a liquid retention (absorption per volume) of 0.6 g / cc or more. An electrode plate active material support for a lead acid battery, characterized by the above-mentioned. The cathode plate active material support for a lead acid battery according to claim 1, wherein the fabric is pressed by a pressing roller. The electrode plate active material support for a lead acid battery according to claim 1, wherein the structure of the fabric is 5-16 sheets of Twill or 5-16 sheets of Satin. The electrode plate active material support for a lead acid battery according to claim 1, wherein the woven fabric is in the form of an envelope woven with a jacquard.

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