KR20070031033A - A support of activie material in polar plate used in lead-acid battery - Google Patents

Abstract

The present invention relates to a lead plate active material support for lead-acid batteries, wherein the slope is a thermoplastic multifilament having a circular cross section or an island-in-the-sea composite fiber having only a part of sea component eluted and having a heteromorphic cross section, and the weft yarn having a part of a sea component eluted to have a heteromorphic cross section It is characterized by consisting of a woven fabric of the type composite fiber.

The present invention improves the performance of the lead acid battery due to the excellent liquid retention and hygroscopicity (diffusion) of the electrolyte, and also has excellent mechanical properties to improve workability and productivity, and prevents harmful working environment in the battery production process. In addition, the life of the lead acid battery can be extended by effectively preventing the fall of the electrode active material.

Lead Acid Battery, Pole Plate, Active Material, Support, Release Section Yarn, Fabric, Hydrophilic Resin, Liquid, Mechanical Properties, Hygroscopicity, Structure

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 electron micrograph showing a cross-sectional state of the island-in-the-sea composite fiber having only a portion of the sea component eluted with a heteromorphic cross section.

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. Due to the mechanical properties, there is still a decrease in workability and productivity.

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 a thermoplastic multifilament having a circular cross section or a sea island type composite fiber having a heteromorphic cross-section due to eluting a part of sea component instead of a glass fiber mat having a problem in workability and working environment. By manufacturing the seaweed-type composite fiber having a release cross-section with only a part of sea component, it has excellent mechanical strength characteristics, improves workability, solves harmful working environment, and has excellent electrolyte solution retention and hygroscopicity (diffusion). An electrode plate active material support for a lead acid battery is provided.

Lead electrode active material support for a lead-acid battery of the present invention for achieving the above problems, the inclination is a thermoplastic multifilament having a circular cross section or a sea island-like composite fiber having only a part of the sea component eluted cross-section, the weft is only part of the sea component is eluted Characterized in that the fabric is made of island-in-the-sea composite fibers having a release cross section.

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 is a thermoplastic multifilament having a circular cross section instead of a conventional glass fiber mat or nonwoven fabric or a sea island-type composite fiber having only a part of sea component eluted and having a cross-sectional cross-section, and the weft is a sea island type having only a portion of sea component eluted It consists of a fabric which is a composite fiber.

As the thermoplastic multifilament having the circular cross section, polyester multifilament, polyolefin multifilament or aromatic polyamide multifilament having excellent acid resistance is preferable.

On the other hand, the warp and weft or weft yarn is a island-in-the-sea composite fiber of a heteromorphic cross section weave the fabric using the island-in-the-sea composite fiber consisting of sea component and island component as warp and weft or weft yarn, then the sea component as shown in FIG. Fabrics woven so that only a part of them (about 2 to 34%) are eluted can be produced by a method of treating with an aqueous alkaline solution.

The island component constituting the island-in-the-sea composite fiber is polyethylene terephthalate or the like, and the sea component is a copolymerized polyester having 3 to 15 mol% of dimethylene sulfoisophthalate copolymerized.

The cross-sectional shape of the island-in-the-sea composite fiber having a release cross section is an elliptical or the like having 3 to 50 protrusions as shown in FIG. 3.

In the present invention, since the warp yarn and the weft yarn or the weft yarn are the cross-sectional yarns, the electrolyte transfer passage is formed in the warp and weft directions of the fabric, and the diffusivity (hygroscopicity) of the electrolyte in the warp and weft directions is greatly improved by the capillary phenomenon.

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.

The method of impregnating the hydrophilic resin in the fabric can be prepared by dipping the fabric in the hydrophilic resin solution, or by spraying the hydrophilic resin solution on the fabric.

 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, 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.

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

75 denier / 24 filaments x 3 in which the sea component of the polyester copolymer having excellent alkali hydrolyzability is copolymerized by the copolymerization of a polyethylene terephthalate having an average diameter of 3 µm with 7 mol% of sodium dimethylene sulfoisophthalate. Welded polyester island-in-the-sea composite fiber as a weft yarn, and using a conventional 30 denier / 24 filament polyester multifilament as a warp, not a composite fiber, with a warp density of 270 bones / inch and weft density of 110 bones / inch After preparing 10 woven fabrics, the woven fabrics were treated with an aqueous alkali solution so that the dissolution rate of the sea component was 4%, and then the electrode plate active material support for lead-acid batteries having a thickness of 0.15 mm was prepared using the same.

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 filaments x 3 in which the sea component of the polyester copolymer having excellent alkali hydrolyzability is copolymerized by the copolymerization of a polyethylene terephthalate having an average diameter of 3 µm with 7 mol% of sodium dimethylene sulfoisophthalate. Using the polyester islands-in-the-sea composite fiber as warp and weft yarns, five fabrics were produced with a warp density of 270 yarns / inch and a weft density of 100 yarns / inch. After treatment so that the dissolution rate of the sea component is 10%, to prepare a positive electrode 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

Except that the woven fabric was not treated with an aqueous alkali solution to dissolve the seaweed components in the weft yarn was prepared in the same manner as in Example 1. Table 1 shows the results of evaluating various physical properties of the produced lead plate active material support for lead acid batteries.

Property evaluation result division Example 1 Example 2 Comparative Example 1 Thickness (mm) 0.15 0.15 0.15 Tensile Strength (15mm / min, Kgf) Lateral direction (MD) 17.39 17.73 18.94 Longitudinal (TD) 16.84 16.72 18.38 Acid resistance No foreign matter No foreign matter No foreign matter Electric resistance (Ω) 0.00040 0.00039 0.00040 Fluid 1.94 2.17 0.92 Absorption rate (mm / 10 minutes) 49 47 34

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 (9)

The slope is a lead-acid battery, characterized in that it is a thermoplastic multifilament having a circular cross section or an island-in-the-sea composite fiber having a heterogeneous cross-section by dissolving only part of the sea component, and the weft yarn made of a fabric that is an island-in-the-sea composite fiber having a release cross-section by dissolving only a portion of the sea component. Electrode plate active material support for use. The lead plate active material support for a lead acid battery according to claim 1, wherein the island component of the island-in-the-sea composite fiber is polyethylene terephthalate. The lead plate active material support for lead acid batteries according to claim 1, wherein the sea component of the island-in-the-sea composite fiber is a copolyester copolymerized with 3 to 15 mol% of sodium dimethylene sulfoisophthalate. The lead plate active material support for lead acid batteries according to claim 1, wherein the cross-sectional shape of the island-in-the-sea composite fiber having a release cross section is an ellipse having 3 to 50 protrusions. 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. The lead plate active material support for lead acid batteries according to claim 1, wherein the sea component dissolution rate of the island-in-the-sea composite fiber having a release cross section is 2 to 34%.

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