CN102169974B - Composite enhanced baffle containing glass fibers and preparation method thereof - Google Patents

Abstract

The invention relates to a separator used for storage batteries, and discloses a glass fiber composite reinforced separator and a preparation method thereof. The preparation method includes the following steps: (1) Weighing each raw material in proportion and placing it in a reaction kettle, stirring Add a solvent under the conditions to mix the system evenly, and control the viscosity of the system to 10.0-200.0Pa.s to obtain the mixture A; (2) Extrude the above mixture A at room temperature, and shape it by calendering, and then extract it with warm water and dry it to obtain Glass fiber composite reinforced partition. Due to the existence of glass fiber, the mechanical strength of the separator is effectively improved, the pore structure is optimized, and the wettability is improved. Using the separator of the present invention to assemble the battery can optimize the internal oxygen cycle of the battery, prevent the growth of lead dendrites, increase the battery capacity, reduce the internal resistance of the battery, avoid premature failure of the battery, effectively improve the performance of the battery, and significantly prolong the service life of the battery.

Description

A glass fiber composite reinforced separator and its preparation method

technical field

The invention relates to a separator for accumulators, in particular to a glass fiber composite reinforced separator.

Background technique

The separator is an important component of the lead-acid battery, known as the "third electrode". It is placed between the positive and negative plates of the battery, which can prevent the short circuit of the positive and negative electrodes in the electrolyte, and at the same time ensure that the electrolyte is It has good electrical conductivity between the positive and negative electrodes, and also has the functions of reducing the bending of the plate, preventing the active material of the positive electrode from falling off, good liquid retention, and providing gas channels. As lead-acid batteries are used more and more widely, the performance of the separator, one of the four major components of lead-acid batteries, directly affects the quality of lead-acid batteries.

A high-quality separator should have the characteristics of high porosity, uniform thickness, strong acid resistance, good resilience and compressibility. At present, the commonly used lead-acid battery separators in our country are: PE type, PVC sintered type, PVC microporous type, 10G type and AGM type. The 10G separator is made of ultra-fine glass fiber as the separator substrate, and then sprayed with an organic binder. Although the porosity is as high as 92% to 94%, due to the low elasticity of the glass fiber, the resilience and The compressibility is low, and more importantly, its strength is not enough. Since the volume of the plate will change during the charging and discharging cycle of the battery, if the volume of the separator cannot change accordingly, a gap will be formed between the plate and the separator, and the supporting effect of the separator on the active material on the plate will gradually disappear, thereby As a result, the active material gradually separates from the plate and enters the electrolyte, shortening the cycle life of the battery. On the other hand, the transformation of the active material during the charging and discharging process of the battery will involve the expansion and contraction of the active material, which will inevitably cause a certain stress on the separator. If there is no certain strength guarantee, the separator may be damaged during mechanical packaging. Fracture occurs, causing premature battery failure, which is not allowed for continuous battery production. Therefore, in order to meet the assembly requirements of the battery, it is necessary to increase the strength of the separator. Although there are clapboards made of PVC resin at home and abroad, their texture is brittle, their strength is low, and they are easily broken or broken during transportation, assembly and use, and the above problems have not been solved. Therefore, in order to promote the development of the lead-acid battery industry, it is urgent to develop a separator with excellent mechanical strength.

Contents of the invention

The object of the present invention is to provide a glass fiber composite reinforced separator with good resilience, compressibility and high strength.

The present invention also provides a preparation method of the glass fiber composite reinforced separator.

A method for preparing a glass fiber composite reinforced partition, characterized in that it comprises the following steps:

(1) Weigh each raw material in proportion and place it in a reaction kettle, add solvent under stirring condition to mix the system evenly, and control the viscosity of the system to 10.0-200.0Pa.s to obtain mixture A; the composition of the raw material is: PVC Resin 35-89%; SiO ₂ powder 9.0-55%; glass fiber 0.9-55%; conductive agent 0.1-5%;

(2) The above-mentioned mixture A is formed by extruding and calendering at room temperature to make a thin sheet with a thickness of 0.1-1.0mm; after forming, it is leached in warm water at a temperature of 30-40°C for 2-10 minutes, and after leaching, it is leached for 40 Dry in a drying tunnel at ~60°C for 20 to 40 minutes to obtain a glass fiber composite reinforced separator.

Further, the SiO ₂ powder _is SiO 2 particles with a specific surface area of 150-380 m ² /g or SiO ₂ particles with a particle size of 1-3 μm or a mixture thereof.

Further, the glass fiber has a diameter of 1-10 μm and a length of 0.5-5 mm. The glass fiber is one or a mixture of two or more of medium-alkali glass fiber, non-alkali glass fiber and high-alkali glass fiber.

Further, the conductive agent is one or a mixture of two or more of carbon black, carbon nanotubes, and graphite.

Further, the solvent is one or a mixture of two or more of tetrahydrofuran, butanone, acetone, and dimethyl sulfoxide.

Nowadays, there are many types of separators commonly used in the lead-acid battery industry, mainly including: AGM separators, rubber separators, sintered polyvinyl chloride separators (PVC separators), melt-blown polypropylene separators (PP separators) and micro Porous polyethylene separator (Separator). However, due to certain defects in the above-mentioned separators, they cannot fully meet the requirements of high-performance lead-acid batteries, especially gel batteries.

The present invention adopts suitable types and proportions of glass fiber components and PVC to compound, so that the partition has good mechanical strength; adding inorganic fillers can improve the strength, porosity and affinity of the partition with electrolyte. The performance of the battery is significantly improved by applying the separator prepared by the invention, and the service life is longer.

Compared with the prior art, the glass fiber composite reinforced partition of the present invention has the following advantages:

1. The traditional solvent-based PVC separator is made by compounding silica powder and PVC. Due to the poor interface bonding between silica and PVC resin, the separator material is very brittle, which is not conducive to the post-processing and transportation of the separator. and use. The new glass fiber composite reinforced partition provided by the invention adds glass fiber material on this basis. The glass fiber has a certain length-to-diameter ratio, can be better combined with PVC, and greatly enhances the mechanical strength of the partition. Its tensile strength and elongation at break are significantly improved, which can prevent the separator from being damaged or broken during transportation or assembly, prevent the premature failure of the lead-acid battery, and effectively prolong the service life of the battery.

2. The addition of glass fiber changes the internal pore structure of the separator. Not only the porosity has been improved, but also the pore size is small and the pore size distribution is uniform. To control the speed of oxygen recombination, the charge acceptance of the negative electrode of the battery is higher, and the performance of the battery is effectively improved.

3. PVC is a low-polarity material, which has poor hydrophilicity and is not easily infiltrated by electrolyte. The contact angle between glass fiber and sulfuric acid is 0°, which can quickly combine with the electrolyte, effectively improving the wettability of the separator, so that it can be completely soaked within 1s. In addition, the acid displacement of the separator is also reduced, which can absorb more electrolyte, increase the battery capacity, and reduce the internal resistance of the battery.

4. The glass fiber composite reinforced separator provided by the present invention can be widely used in various lead-acid batteries, especially in colloidal batteries. It can be used in traction batteries, stationary batteries, electric vehicle batteries, energy storage batteries and other fields.

Description of drawings

FIG. 1 is a scanning electron micrograph of the surface of the separator prepared in Example 1.

FIG. 2 is a scanning electron micrograph of the surface of the separator prepared in Example 2. FIG.

FIG. 3 is a scanning electron micrograph of the surface of the separator prepared in Example 3. FIG.

FIG. 4 is a scanning electron micrograph of a section of a separator prepared in Example 4. FIG.

FIG. 5 is a scanning electron micrograph of the cross-section of the separator prepared in Example 5. FIG.

FIG. 6 is a scanning electron micrograph of a section of a separator prepared in Example 6. FIG.

FIG. 7 is a scanning electron micrograph of the surface of the separator prepared in Example 7. FIG.

FIG. 8 is a scanning electron micrograph of the surface of the separator prepared in Example 8. FIG.

FIG. 9 is a scanning electron micrograph of the surface of the separator prepared in Example 9. FIG.

Detailed ways

The following examples are provided to specifically describe the present invention. It is necessary to point out that the following examples are only used to further illustrate the present invention, and can not be interpreted as limiting the protection scope of the present invention. Those skilled in the art according to the present invention SUMMARY OF THE INVENTION Some non-essential improvements and adjustments made to the present invention still belong to the protection scope of the present invention.

In the following examples, the dry PVC resin powder, _SiO2 powder, glass fiber and conductive agent are weighed according to the weight ratio. Put the weighed raw materials in the reaction kettle, add a solvent under the condition of stirring to make the system mix uniformly, and control the viscosity of the system to 10.0-200Pa.s to obtain the mixture A. The above-mentioned mixture A is shaped by extruding and calendering at room temperature to make a thin sheet with a thickness of 0.1-1.0 mm. After molding, it is leached in warm water at a temperature of 30-40°C for 2-10 minutes, and then dried in a drying tunnel at 40-60°C for 20-40 minutes to obtain a glass fiber composite reinforced separator.

Example 1

Weigh 35.0 g of dry PVC resin powder, 55 g of SiO _particles with a specific surface area of 150 m ² /g, 9.9 g of medium-alkali glass fiber cotton with a length of 0.5 mm in diameter and 0.1 g of carbon black according to weight ratio. Put the weighed raw materials in the reaction kettle, add acetone under the condition of stirring to make the system mix uniformly, and control the viscosity of the system to 200.0 Pa.s to obtain the mixture A. The above-mentioned mixture A was formed by extruding and calendering at room temperature to make a thin sheet with a thickness of 0.1 mm. After molding, it is leached in warm water at 40°C for 2 minutes, and then dried in a drying tunnel at 40°C for 40 minutes to obtain a glass fiber composite reinforced separator. The microscopic morphology of the separator surface is shown in Figure 1. The glass fibers are evenly distributed in the porous structure, and the material has a high porosity and a uniform pore size distribution.

Example 2

Weigh 89.0 g of dried PVC resin powder, 9 g of SiO _particles with a specific surface area of 200 m ² /g, 1.9 g of medium-alkali glass fiber cotton with a diameter of 10 μm and a length of 5 mm, and 0.1 g of graphite according to the weight ratio. Put the weighed raw materials in the reaction kettle, add tetrahydrofuran under stirring condition to make the system mix uniformly, and control the viscosity of the system to 10.0 Pa.s to obtain the mixture A. The above-mentioned mixture A was formed by extruding and calendering at room temperature to make a thin sheet with a thickness of 0.5 mm. After molding, it is leached in warm water at 30°C for 10 minutes, and then dried in a drying tunnel at 60°C for 20 minutes to obtain a glass fiber composite reinforced separator. The microscopic morphology of the separator surface is shown in Figure 2. The glass fibers are evenly distributed in the porous structure, and the material has a high porosity and uniform pore size distribution.

Example 3

Weigh 52g of dried PVC resin powder, 42.1g of _SiO2 particles with a specific surface area of ^200m2 /g, 0.9g of alkali-free glass fiber cotton with a diameter of 5μm and a length of 2.5mm, and 5.0g of carbon black according to weight ratio. Put the weighed raw materials in the reaction kettle, add dimethyl sulfoxide under stirring condition to make the system evenly mixed, and control the viscosity of the system to 102.3Pa.s to obtain the mixture A. The above-mentioned mixture A was formed by extruding and calendering at room temperature to make a thin sheet with a thickness of 1.0 mm. After molding, it is leached in warm water at 35°C for 5 minutes, and then dried in a drying tunnel at 56°C for 34 minutes to obtain a glass fiber composite reinforced separator. The microscopic morphology of the separator surface is shown in Figure 3. The glass fibers are evenly distributed in the porous structure, and the material has a high porosity and a uniform pore size distribution.

Example 4

Weigh 35g of dry PVC resin powder, 9.0g of _SiO2 particles with a specific surface area of ^150m2 /g, 55g of high-alkali glass fiber cotton with a length of 2.5mm in diameter and 1.0g of carbon black according to weight ratio. Put the weighed raw materials in the reaction kettle, add methyl ethyl ketone under the condition of stirring to make the system mix uniformly, and control the viscosity of the system to 90.1Pa.s to obtain the mixture A. The above-mentioned mixture A was formed by extruding and calendering at room temperature to make a thin sheet with a thickness of 0.3 mm. After molding, it is leached in warm water at 35°C for 8 minutes, and then dried in a drying tunnel at 55°C for 35 minutes to obtain a glass fiber composite reinforced separator. The microscopic morphology of the partition section is shown in Figure 4. The glass fibers are evenly distributed in the porous structure, and the material has a high porosity and a uniform pore size distribution.

Example 5

Weigh 41.5g of dried PVC resin powder, 9.0g of SiO ₂ particles with a specific surface area of 380m ² /g, 46g of high-alkali glass fiber cotton with a diameter of 5μm and a length of 3.5mm and 3.5g of carbon black according to the weight ratio. Put the weighed raw materials in the reaction kettle, add a mixed solvent of dimethyl sulfoxide and acetone (volume ratio 1:1) under stirring conditions to mix the system uniformly, and control the viscosity of the system to 120.4Pa.s to obtain the mixture A . The above-mentioned mixture A was formed by extruding and calendering at room temperature to make a thin sheet with a thickness of 0.35 mm. After molding, it is leached in warm water at 40°C for 5 minutes, and then dried in a drying tunnel at 55°C for 30 minutes to obtain a glass fiber composite reinforced separator. The microscopic morphology of the partition section is shown in Figure 5. The glass fibers are evenly distributed in the porous structure, and the material has a high porosity and a uniform pore size distribution.

Example 6

Take by weight ratio 65.5g of dry PVC resin powder, 12.0g of SiO _particles with a specific surface area of 250m ² /g, a diameter of 3.5 μm, and a length of 1.5mm of high-alkali and low-alkali mixed glass fiber cotton 18.5g (1:2 by weight ratio) and 4.0g of a mixture of carbon black and graphite (1:3 by weight ratio). Put the weighed raw materials in the reaction kettle, add methyl ethyl ketone under the condition of stirring to make the system mix uniformly, and control the viscosity of the system to 179.5Pa.s to obtain the mixture A. The above-mentioned mixture A was formed by extruding and calendering at room temperature to make a thin sheet with a thickness of 0.65 mm. After molding, it is leached in warm water at 32°C for 8 minutes, and then dried in a drying tunnel at 45°C for 28 minutes to obtain a glass fiber composite reinforced separator. The microscopic morphology of the partition section is shown in Figure 6. The glass fibers are evenly distributed in the porous structure, and the material has a high porosity and a uniform pore size distribution.

Example 7

Weigh 36.5g of dry PVC resin powder, 17.1g of a mixture of SiO ₂ particles with a specific surface area of 150m ² /g and SiO ₂ particles with a particle size of 2μm (the mixing weight ratio is 2:1), diameter 43.6g of non-alkali and high-alkali glass fiber cotton with a length of 2μm and a length of 4mm (the weight ratio is 1:5), and 2.8g of carbon nanotubes. Put the weighed raw materials in the reaction kettle, add a mixed solvent of tetrahydrofuran and acetone (volume ratio 1:1) under stirring conditions to mix the system uniformly, and control the viscosity of the system to 175.6Pa.s to obtain the mixture A. The above-mentioned mixture A was formed by extruding and calendering at room temperature to make a thin sheet with a thickness of 0.90 mm. After molding, it is leached in warm water at 32°C for 3 minutes, and then dried in a drying tunnel at 47°C for 38 minutes to obtain a glass fiber composite reinforced separator. The microscopic morphology of the separator surface is shown in Figure 7. The glass fibers are evenly distributed in the porous structure, and the material has a high porosity and a uniform pore size distribution.

Example 8

Weigh 64.0g of dry PVC resin powder, mixed SiO ₂ particles with a specific surface area of 200m ² /g and a specific surface area of 380m ² /g (weight ratio 3:1) and SiO particles with a particle size of 1μm according to the weight ratio. 12.4g of the mixture of ₂ particles (the mixing weight ratio is 1:1), 20.3g of medium-alkali glass fiber cotton with a diameter of 7μm and a length of 1mm, and 3.3g of the mixture of carbon nanotubes and graphite (the mixing weight ratio is 1:1) . Put the weighed raw materials in the reaction kettle, add a mixed solvent of tetrahydrofuran and dimethyl sulfoxide (volume ratio: 2:1) under stirring conditions to mix the system uniformly, and control the viscosity of the system to 90.0Pa.s to obtain a mixture First. The above-mentioned mixture A was formed by extruding and calendering at room temperature to make a thin sheet with a thickness of 0.5 mm. After molding, it is leached in warm water at 36°C for 10 minutes, and dried in a drying tunnel at 48°C for 20 minutes after leaching to obtain a glass fiber composite reinforced separator. The microscopic morphology of the separator surface is shown in Figure 8. The glass fibers are evenly distributed in the porous structure, and the material has a high porosity and a uniform pore size distribution.

Example 9

Weigh 45.5g of dry PVC resin powder, 29.4g of a mixture of SiO ₂ particles with a particle size of 1μm and 2μm (mixing weight ratio is 4:1), medium alkali with a diameter of 8μm and a length of 4.5mm according to the weight ratio 23.3g of glass fiber cotton, 1.8g of a mixture of carbon nanotubes and carbon black (the mixing weight ratio is 1:1). Put the weighed raw materials in the reaction kettle, add a mixed solvent of dimethyl sulfoxide and butanone (volume ratio: 1:3) under stirring conditions to mix the system uniformly, and control the viscosity of the system to 125.5Pa.s to obtain a mixture First. The above-mentioned mixture A was formed by extruding and calendering at room temperature to make a thin sheet with a thickness of 0.25 mm. After molding, it is leached in warm water at 40°C for 5 minutes, and then dried in a drying tunnel at 50°C for 36 minutes to obtain a glass fiber composite reinforced separator. The microscopic morphology of the separator surface is shown in Figure 9. The glass fibers are evenly distributed in the porous structure, and the material has a high porosity and a uniform pore size distribution.

According to the JB/T7630.2-2008 standard, the separators of the above examples were analyzed for routine items, and the results are shown in Table 1. It can be seen that the glass fiber composite separator material has good mechanical and electrical properties.

Table 1: Composition and performance of composite microporous separator

Claims (6)

1. the preparation method of the composite enhanced dividing plate of glass is characterized in that may further comprise the steps:

(1) takes by weighing each raw material in proportion and place reactor, under stirring condition, add solvent system is evenly mixed, and hierarchy of control viscosity is that 10.0～200.0Pa.s obtains the mixture first; The composition of raw material is by weight percentage: polyvinyl chloride resin 35～89%; SiO ₂Powder 9.0～55%; Glass 0.9～55%; Conductive agent 0.1～5%;

(2) with the said mixture first by normal temperature extrude, the calendering technology moulding, make the thin slice that thickness is 0.1～1.0mm; Moulding is 30～40 ℃ warm water lixiviate 2～10 minutes by excess temperature, and the drying tunnel oven dry through 40～60 ℃ after the lixiviate namely obtained the composite enhanced dividing plate of glass in 20～40 minutes.

2. preparation method according to claim 1 is characterized in that described SiO ₂Powder is that specific area is 150～380m ²The SiO of/g ₂Particle or particle diameter are the SiO of 1～3 μ m ₂Particle or its mixture.

3. preparation method according to claim 1, the diameter that it is characterized in that described glass is 1～10 μ m, length is 0.5～5mm.

4. preparation method according to claim 1 is characterized in that described glass is one or more the mixture in medium-alkali glass fiber, alkali-free glass fiber, the high-alkali glass.

5. preparation method according to claim 1 is characterized in that described conductive agent is one or more the mixture in carbon black, carbon nano-tube, the graphite.

6. preparation method according to claim 1 is characterized in that described solvent is one or more the mixed solvent in oxolane, butanone, acetone, the methyl-sulfoxide.

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