An organic fiber agm separator and its application

Abstract

The application discloses an organic fiber AGM separator and application thereof, and belongs to the field of storage batteries. The organic fiber AGM separator comprises high-alkali glass wool, medium-alkali glass fiber, two-component polyester fiber and slurry containing nitrogen-doped reduced graphene oxide / lead oxide composite material. The nitrogen-doped reduced graphene oxide / lead oxide composite material is prepared by the following steps: uniformly ultrasonic dispersing graphene oxide, deionized water and anhydrous ethanol, slowly dropping aniline, ultrasonic stirring, and obtaining a mixed solution; adding lead acetate powder into the mixed solution, ultrasonic stirring, hydrothermal reaction, washing, freeze-drying, pyrolysis under a rare gas atmosphere, and obtaining the nitrogen-doped reduced graphene oxide / lead oxide composite material. After the nitrogen-doped reduced graphene oxide / lead oxide composite material is prepared into slurry, the slurry is coated on an AGM separator substrate, and then acid immersion and solidification are carried out; the AGM separator has excellent resistance to dendrite penetration and prolongs the service life of a storage battery.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of storage batteries, in particular to an organic fiber AGM separator and its application. BACKGROUND

[0002] The AGM separator is composed of chemical-grade borosilicate glass fibers, the length of which is 1-2 mm, and the thickness of which varies (diameter: 0.1-10 μm). The proportion of different fibers determines the balance between different functions of the separator and the price of the separator. These fibers are hydrophilic and absorb electrolyte. The surface area of the thinner fibers (i.e. fibers with smaller diameter) in the separator is larger, the inner diameter of the micropores formed thereby is smaller, but the price is higher. The AGM separator also contains 15-18% of high molecular fibers such as PP and PE, which improve the mechanical strength of the separator and promote the formation of gas channels, and also reduce the price of the separator.

[0003] The conventional high specific surface AGM separator, although the fibers are thin and the acid absorption performance is good, the mechanical strength is often not enough, and the separator is easily punctured by lead sulfate dendrites and short-circuited during the charging and discharging process of the battery. At the same time, the organic fibers are hydrophobic, which increases the voids of the AGM separator and forms open oxygen meeting channels. After the oxygen is precipitated from the positive plate, it is transported to the negative plate, and then a reduction reaction occurs at the negative plate, which to some extent slows down the problem of the battery single falling behind. At the same time, the organic fibers improve the compression resistance of the separator and slow down the shedding of the active material, thereby improving the cycle life of the battery.

[0004] The patent applications with publication numbers CN103855346A and CN104201319A mainly improve the performance of the AGM separator by adding silica to improve the composition of the fibers in the AGM separator. Further research shows that the above-mentioned AGM separator still has the following technical problems: the specific surface area of the separator is small, the wet elasticity is low, and the capacity of the storage battery decays quickly; in addition, due to the existence of large pores on the glass fiber separator, the prevention performance of lead dendrite puncture leading to short circuit still needs to be further improved, otherwise it will still affect the service life of the storage battery. SUMMARY

[0005] The present application aims to provide an organic fiber AGM separator and its application to solve the problem of poor puncture resistance of the battery separator.

[0006] The purpose of the present application can be achieved by the following technical solutions:

[0007] An organic fiber AGM separator, comprising high-alkali glass wool, medium-alkali glass fibers, bicomponent polyester fibers and a slurry containing a nitrogen-doped reduced graphene oxide / lead oxide composite material;

[0008] The nitrogen-doped reduced graphene oxide / lead oxide composite material is prepared by the following steps:

[0009] The graphene oxide, deionized water and anhydrous ethanol are uniformly ultrasonically dispersed, aniline is slowly dropped, ultrasonic stirring is carried out, a mixed solution is obtained; the lead acetate powder is added into the mixed solution, ultrasonic stirring is carried out, hydrothermal reaction is carried out, washing, freeze-drying, pyrolysis under a rare gas atmosphere, and a nitrogen-doped reduced graphene oxide / lead oxide composite material is obtained.

[0010] Further, the amount ratio of the graphene oxide, deionized water, anhydrous ethanol, aniline and lead acetate is (20-30) mg:(10-20) mL:(10-20) mL:(0.1-0.4) mL:(150-200) mg.

[0011] Further, the ultrasonic time is 20-30 min; the stirring time is 0.5-1 h.

[0012] Further, the hydrothermal reaction is hydrothermal reaction at 180-200 ℃ for 20-24 h.

[0013] Further, the pyrolysis is heating at a rate of 5-10 ℃ / min to 450-500 ℃, and pyrolysis for 1-2 h.

[0014] A preparation method of an organic fiber AGM separator, comprising the following steps:

[0015] S1, mixing and preparing a slurry according to a proportion of high-alkali glass wool, medium-alkali glass fiber and double-component polyester fiber, and then preparing an AGM separator substrate according to an AGM separator preparation process;

[0016] S2, uniformly mixing the nitrogen-doped reduced graphene oxide / lead oxide composite material, boric acid, lead oxide powder, barium sulfate, humic acid, sodium lignosulfonate, short fibers, acetylene black, deionized water and dilute sulfuric acid to obtain a slurry containing the nitrogen-doped reduced graphene oxide / lead oxide composite material, coating the above slurry on the AGM separator substrate, immersing in a dilute sulfuric acid solution, and solidifying to obtain an organic fiber AGM separator.

[0017] Further, the amount ratio of the nitrogen-doped reduced graphene oxide / lead oxide composite material, boric acid, lead oxide powder, barium sulfate, humic acid, sodium lignosulfonate, short fibers, acetylene black, deionized water and dilute sulfuric acid is (20-40) mg:(5-10) mg:(4-6) g:(30-40) mg:(15-25) mg:(15-25) mg:(2-4) mg:(6-10) mg:(1-2) mL:(0.5-1) mL.

[0018] Further, the mass fraction of the dilute sulfuric acid solution is 20%-30%.

[0019] Further, the immersion time is 10-20 s.

[0020] Further, the curing condition is air humidity 90%~95%, room temperature 60-80℃, curing 20-24h.

[0021] Further, the application of the organic fiber AGM separator in the battery.

[0022] The beneficial effects of the present application are:

[0023] (1) The organic fiber AGM separator provided by the present application has excellent dendrite penetration resistance, prolonging the service life of the battery.

[0024] (2) The nitrogen-doped reduced graphene oxide / lead oxide composite material used in the present application has a large specific surface area, which is beneficial to improve the performance of the battery. The nitrogen-doped reduced graphene oxide avoids the agglomeration of graphene oxide sheets and enhances the binding tightness of the composite material with negatively charged ions. The graphene oxide not only binds tightly with boric acid, improving the dispersion and stability of boron, but also provides abundant deposition sites for lead oxide. In addition, due to the chemical stability of the composite material itself, the mechanical properties and corrosion resistance of the separator are improved, which is also beneficial to improve the dendrite penetration resistance of the separator and prolong the cycle life of the battery.

[0025] (3) The lead oxide used in the present application can improve the conductivity of graphene oxide, and the boric acid can improve the bonding force between the grid and the active material, thereby indirectly improving the conductivity and battery performance. DETAILED DESCRIPTION

[0026] The technical solutions in the embodiments of the present application will be described clearly and completely below in combination with the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application.

[0027] Embodiment 1

[0028] The present embodiment provides an organic fiber AGM separator and its application, which is prepared by the following steps:

[0029] S1, mix high-alkali glass wool, medium-alkali glass fiber and bi-component polyester fiber according to the proportion to prepare a slurry, and then prepare an AGM separator substrate according to the AGM separator preparation process;

[0030] S2, 25 g of graphene oxide, 15 mL of deionized water and 15 mL of anhydrous ethanol were uniformly dispersed by ultrasonic dispersion, 0.3 mL of aniline was slowly dropped, ultrasonic dispersion was performed for 20 min, stirring was performed for 0.5 h, 175 mg of lead acetate powder was added into the mixture, ultrasonic dispersion was performed for 20 min, stirring was performed for 0.5 h, hydrothermal reaction was performed at 180℃ for 24 h, the mixture was washed with anhydrous ethanol and deionized water alternately for 3 times, freezing drying was performed, the mixture was heated to 450℃ at a rate of 5℃ / min under a noble gas atmosphere, pyrolysis was performed for 1.5 h, and a nitrogen-doped reduced graphene oxide / lead oxide composite material was obtained;

[0031] S3, 30 mg of the nitrogen-doped reduced graphene oxide / lead oxide composite material, 8 mg of boric acid, 5 g of lead oxide powder, 40 mg of barium sulfate, 20 mg of humic acid, 20 mg of sodium lignosulfonate, 3 mg of short fibers, 8 mg of acetylene black, 1.5 mL of deionized water and 1 mL of 30% dilute sulfuric acid were uniformly mixed to obtain a slurry containing the nitrogen-doped reduced graphene oxide / lead oxide composite material, the slurry was coated on an AGM separator substrate, was immersed in a dilute sulfuric acid solution for 15 s, and was cured at an air humidity of 95% and a room temperature of 60℃ for 24 h to obtain an organic fiber AGM separator.

[0032] The prepared organic fiber AGM separator was applied to a storage battery.

[0033] Example 2

[0034] Compared with Example 1, the difference lies in that the raw material ratio in S3 is changed, and the specific implementation steps of S3 are as follows:

[0035] S3, 40 mg of the nitrogen-doped reduced graphene oxide / lead oxide composite material, 5 mg of boric acid, 4 g of lead oxide powder, 30 mg of barium sulfate, 25 mg of humic acid, 15 mg of sodium lignosulfonate, 2 mg of short fibers, 10 mg of acetylene black, 2 mL of deionized water and 1 mL of 30% dilute sulfuric acid were uniformly mixed to obtain a slurry containing the nitrogen-doped reduced graphene oxide / lead oxide composite material, the slurry was coated on an AGM separator substrate, was immersed in a dilute sulfuric acid solution for 15 s, and was cured at an air humidity of 95% and a room temperature of 60℃ for 24 h to obtain an organic fiber AGM separator.

[0036] The prepared organic fiber AGM separator was applied to a storage battery.

[0037] The remaining raw materials and preparation process are the same as those of Example 1.

[0038] Example 3

[0039] Compared with Example 1, the difference lies in that the raw material ratio in S3 is changed again, and the specific implementation steps of S3 are as follows:

[0040] S3, 20 mg of nitrogen-doped reduced graphene oxide / lead oxide composite, 10 mg of boric acid, 6 g of lead oxide powder, 40 mg of barium sulfate, 15 mg of humic acid, 25 mg of sodium lignosulfonate, 4 mg of short fibers, 6 mg of acetylene black, 1 mL of deionized water and 0.5 mL of 30% mass fraction dilute sulfuric acid are uniformly mixed to obtain a slurry containing nitrogen-doped reduced graphene oxide / lead oxide composite, the above slurry is coated on the AGM separator substrate, immersed in a dilute sulfuric acid solution for 15 s, and cured at an air humidity of 95% and a room temperature of 60℃ for 24 h to obtain an organic fiber AGM separator.

[0041] The prepared organic fiber AGM separator is applied to a storage battery.

[0042] The remaining raw materials and preparation process are the same as those of Example 1.

[0043] Example 4

[0044] Compared with Example 1, the difference is that "25 g of graphene oxide, 0.3 mL of aniline and 175 mg of lead acetate" in S2 is changed to "30 g of graphene oxide, 0.1 mL of aniline and 150 mg of lead acetate", and the specific implementation steps of S2 are as follows:

[0045] S2, 30 g of graphene oxide, 15 mL of deionized water and 15 mL of anhydrous ethanol are uniformly dispersed by ultrasonic, 0.1 mL of aniline is slowly added dropwise, ultrasonic is performed for 20 min, stirring is performed for 0.5 h to obtain a mixed solution; 150 mg of lead acetate powder is added to the mixed solution, ultrasonic is performed for 20 min, stirring is performed for 0.5 h, hydrothermal reaction is performed at 180℃ for 24 h, the mixed solution is washed with anhydrous ethanol and deionized water alternately for 3 times, freeze-drying is performed, heating is performed to 450℃ at a rate of 5℃ / min under a rare gas atmosphere, and pyrolysis is performed for 1.5 h to obtain a nitrogen-doped reduced graphene oxide / lead oxide composite;

[0046] The prepared organic fiber AGM separator is applied to a storage battery.

[0047] The remaining raw materials and preparation process are the same as those of Example 1.

[0048] Example 5

[0049] Compared with Example 1, the difference is that "25 g of graphene oxide, 0.3 mL of aniline and 175 mg of lead acetate" in S2 is changed to "20 g of graphene oxide, 0.4 mL of aniline and 200 mg of lead acetate", and the specific implementation steps of S2 are as follows:

[0050] S2, 20 g of graphene oxide, 15 mL of deionized water and 15 mL of anhydrous ethanol were uniformly dispersed by ultrasonic dispersion, 0.4 mL of aniline was slowly dropped, ultrasonic dispersion was performed for 20 min, stirring was performed for 0.5 h, a mixed solution was obtained; 200 mg of lead acetate powder was added into the mixed solution, ultrasonic dispersion was performed for 20 min, stirring was performed for 0.5 h, hydrothermal reaction was performed at 180 ℃ for 24 h, the mixed solution was washed with anhydrous ethanol and deionized water alternately for 3 times, freeze drying was performed, heating was performed to 450 ℃ at a rate of 5 ℃ / min under a rare gas atmosphere, pyrolysis was performed for 1.5 h, and a nitrogen-doped reduced graphene oxide / lead oxide composite material was obtained;

[0051] The prepared organic fiber AGM separator was applied to a storage battery.

[0052] The remaining raw materials and preparation process were the same as those in Example 1.

[0053] Comparative Example 1

[0054] The comparative example was different from Example 1 in that aniline was not added, and the specific implementation steps of S2 were as follows:

[0055] S2, 25 g of graphene oxide, 15 mL of deionized water and 15 mL of anhydrous ethanol were uniformly dispersed by ultrasonic dispersion, a mixed solution was obtained; 175 mg of lead acetate powder was added into the mixed solution, ultrasonic dispersion was performed for 20 min, stirring was performed for 0.5 h, hydrothermal reaction was performed at 180 ℃ for 24 h, the mixed solution was washed with anhydrous ethanol and deionized water alternately for 3 times, freeze drying was performed, heating was performed to 450 ℃ at a rate of 5 ℃ / min under a rare gas atmosphere, pyrolysis was performed for 1.5 h, and a graphene oxide / lead oxide composite material was obtained.

[0056] The prepared organic fiber AGM separator was applied to a storage battery.

[0057] The remaining raw materials and preparation process were the same as those in Example 1.

[0058] Comparative Example 2

[0059] The comparative example was different from Example 1 in that lead acetate was not added, and the specific implementation steps of S2 were as follows:

[0060] S2, 25 g of graphene oxide, 15 mL of deionized water and 15 mL of anhydrous ethanol were uniformly dispersed by ultrasonic dispersion, 0.3 mL of aniline was slowly dropped, ultrasonic dispersion was performed for 20 min, stirring was performed for 0.5 h, a mixed solution was obtained; hydrothermal reaction was performed at 180 ℃ for 24 h, the mixed solution was washed with anhydrous ethanol and deionized water alternately for 3 times, freeze drying was performed, heating was performed to 450 ℃ at a rate of 5 ℃ / min under a rare gas atmosphere, pyrolysis was performed for 1.5 h, and a nitrogen-doped reduced graphene oxide was obtained.

[0061] The prepared organic fiber AGM separator was applied to a storage battery.

[0062] The remaining raw materials and preparation process are the same as those of Example 1.

[0063] Comparative Example 3

[0064] This comparative example is different from Example 1 in that both aniline and lead acetate are not added, and the specific implementation steps are as follows:

[0065] S1, high-alkali glass wool, medium-alkali glass fiber, and bi-component polyester fiber are mixed in a proportion to prepare a slurry, and then an AGM separator matrix is prepared according to an AGM separator preparation process;

[0066] S2, 30 mg of graphene oxide, 8 mg of boric acid, 5 g of lead oxide powder, 40 mg of barium sulfate, 20 mg of humic acid, 20 mg of sodium lignosulfonate, 3 mg of short fibers, 8 mg of acetylene black, 1.5 mL of deionized water, and 1 mL of 30% dilute sulfuric acid are uniformly mixed to obtain a slurry, the slurry is coated on the AGM separator matrix, immersed in a dilute sulfuric acid solution for 15 s, and cured at an air humidity of 95% and a room temperature of 60℃ for 24 h to obtain an organic fiber AGM separator.

[0067] The prepared organic fiber AGM separator is applied to a storage battery.

[0068] The remaining raw materials and preparation process are the same as those of Example 1.

[0069] Comparative Example 4

[0070] This comparative example is different from Example 1 in that both boric acid and aniline are not added, and the specific implementation steps are as follows:

[0071] S1, high-alkali glass wool, medium-alkali glass fiber, and bi-component polyester fiber are mixed in a proportion to prepare a slurry, and then an AGM separator matrix is prepared according to an AGM separator preparation process;

[0072] S2, 25 g of graphene oxide, 15 mL of deionized water, and 15 mL of anhydrous ethanol are uniformly dispersed by ultrasonic to obtain a mixed solution; 175 mg of lead acetate powder is added to the mixed solution, ultrasonic is performed for 20 min, stirring is performed for 0.5 h, hydrothermal reaction is performed at 180℃ for 24 h, washing with anhydrous ethanol and deionized water is alternately performed for 3 times, freeze-drying is performed, heating to 450℃ at a rate of 5℃ / min under a rare gas atmosphere, and pyrolysis is performed for 1.5 h to obtain a graphene oxide / lead oxide composite material;

[0073] S3, 30 mg of graphene oxide / lead oxide composite, 5 g of lead oxide powder, 40 mg of barium sulfate, 20 mg of humic acid, 20 mg of lignin sodium sulfonate, 3 mg of short fibers, 8 mg of acetylene black, 1.5 mL of deionized water and 1 mL of 30% mass fraction dilute sulfuric acid were uniformly mixed to obtain a slurry containing graphene oxide / lead oxide composite, the above slurry was coated on the AGM separator substrate, immersed in a dilute sulfuric acid solution for 15 s, and cured at an air humidity of 95% and a room temperature of 60°C for 24 h to obtain an organic fiber AGM separator.

[0074] The prepared organic fiber AGM separator was applied to a storage battery.

[0075] The remaining raw materials and preparation process were the same as those of Example 1.

[0076] Comparative Example 5

[0077] This comparative example is different from Example 1 in that no nitrogen-doped reduced graphene oxide / lead oxide composite is added, and the specific implementation steps are as follows:

[0078] S1, high-alkali glass wool, medium-alkali glass fiber and bi-component polyester fiber were mixed according to a proportion to prepare a slurry, and then an AGM separator substrate was prepared according to an AGM separator preparation process;

[0079] S3, 8 mg of boric acid, 5 g of lead oxide powder, 40 mg of barium sulfate, 20 mg of humic acid, 20 mg of lignin sodium sulfonate, 3 mg of short fibers, 8 mg of acetylene black, 1.5 mL of deionized water and 1 mL of 30% mass fraction dilute sulfuric acid were uniformly mixed to obtain a slurry, the above slurry was coated on the AGM separator substrate, immersed in a dilute sulfuric acid solution for 15 s, and cured at an air humidity of 95% and a room temperature of 60°C for 24 h to obtain an organic fiber AGM separator.

[0080] The prepared organic fiber AGM separator was applied to a storage battery.

[0081] The remaining raw materials and preparation process were the same as those of Example 1.

[0082] Performance test:

[0083] According to GB / T 28535-2018 "Lead-acid storage battery separator", the performance of the organic fiber AGM separators prepared in Example 1-Example 5 and Comparative Example 1-Comparative Example 5 was tested.

[0084] The results are shown in Table 1:

[0085] Table 1

[0086]

[0087] It can be seen from the combination of the examples, the comparative examples and the test data in Table 1 that the organic fiber AGM separator prepared by the application has a tensile strength of 0.96-1.03 KN / m, a tensile elongation of 4.25%-4.56%, a capillary acid absorption height of 105-113 mm / 5 min and an acid immersion weight loss of 0.96%-1.18%. Compared with Example 1, Examples 2-5 only differ in the change of the raw material ratio within a reasonable range, and excellent organic fiber AGM separators can be obtained according to the test results.

[0088] It can be seen from the comparison of Comparative Examples 1-3, Comparative Example 5 and Example 1 that, after not adding aniline, the aggregation of graphene oxide sheets reduces the tightness of the combination of the composite material and the negatively charged ions, thereby reducing the performance of the separator. After adding lead acetate, the conductivity of the graphene oxide is improved, and the performance of the separator is also improved. As can be seen from the acid immersion weight loss data, the performance of the material is further reduced when aniline and lead acetate are not added and nitrogen-doped reduced graphene oxide / lead oxide composite material is not added, which indicates the synergistic effect between nitrogen doping and lead oxide. In addition, it can be seen from the comparison of Comparative Example 4 and Comparative Example 1 that there is a synergistic effect between boric acid and nitrogen doping. Nitrogen doping can adjust the pore structure of graphene and increase the specific surface area. Boric acid can improve the binding force between the grid and the active material, so that it can better combine with the active material, thereby improving the cycle performance of the battery.

[0089] In summary, the organic fiber AGM separator and the application thereof provided by the application have good dendrite penetration resistance, can prolong the service life when applied to the battery and have good application prospects.

[0090] It should be noted that, in this document, the terms such as first and second are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between the entities or operations. Moreover, the terms "include", "contain" or any other variants thereof are intended to cover non-exclusive inclusion, so that the process, method, article or equipment including a series of elements not only includes those elements, but also includes other elements not explicitly listed or inherent to such process, method, article or equipment.

[0091] Although the embodiments of the application have been shown and described, it can be understood by those of ordinary skill in the art that various changes, modifications, replacements and variations can be made to the embodiments without departing from the principles and spirits of the application, and the scope of the application is defined by the appended claims and their equivalents.

Claims

1. An organic fiber AGM separator characterized in that, Preparation by the following steps: S1, high-alkali glass wool, medium-alkali glass fiber, two-component polyester fiber are mixed according to the proportion to prepare slurry, and then AGM separator matrix is prepared according to AGM separator preparation process; S2, 20-30mg graphene oxide, 10-20mL deionized water and 10-20mL anhydrous ethanol are uniformly dispersed by ultrasonic, 0.1-0.4mL aniline is slowly dropped, ultrasonic stirring is carried out, a mixed solution is obtained; 150-200mg lead acetate powder is added into the mixed solution, ultrasonic stirring is carried out, hydrothermal reaction is carried out, washing, freeze-drying, pyrolysis under rare gas atmosphere, nitrogen-doped reduced graphene oxide / lead oxide composite material is obtained; S3, 20-40mg nitrogen-doped reduced graphene oxide / lead oxide composite material, 5-10mg boric acid, 4-6g lead oxide powder, 30-40mg barium sulfate, 15-25mg humic acid, 15-25mg sodium lignosulfonate, 2-4mg short fiber, 6-10mg acetylene black, 1-2mL deionized water and 0.5-1mL dilute sulfuric acid are uniformly mixed, slurry containing nitrogen-doped reduced graphene oxide / lead oxide composite material is obtained, the above slurry is coated on the AGM separator matrix, immersed in dilute sulfuric acid solution, solidified, and an organic fiber AGM separator is obtained.

2. An organic fiber AGM separator according to claim 1, characterized in that, The ultrasonic time is 20-30min; the stirring time is 0.5-1h.

3. An organic fiber AGM separator according to claim 1, wherein The hydrothermal reaction is hydrothermal reaction at 180-200℃ for 20-24h.

4. An organic fiber AGM separator according to claim 1, wherein The pyrolysis is heated to 450-500℃ at a rate of 5-10℃ / min, and pyrolysis is carried out for 1-2h.

5. An organic fiber AGM separator according to claim 1, wherein The mass fraction of the dilute sulfuric acid solution is 20%-30%; the immersion time is 10-20s.

6. An organic fiber AGM separator according to claim 1, wherein The solidification conditions are air humidity 90%-95%, room temperature 60-80℃, and solidification time 20-24h.

7. The application of the organic fiber AGM separator in the battery according to any one of claims 1-6.

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