Glass fiber separator for lead-acid battery and its preparation process

Abstract

The application discloses a glass fiber separator for lead-acid storage batteries and a preparation process thereof and belongs to the technical field of automobile lead-acid storage batteries. The separator is prepared from superfine glass fibers as a base, with the addition of nano-silicon dioxide fillers, nano-attapulgite-nano-boron nitride modifiers, dispersants, binders and acid-resistant stabilizers, and is prepared through wet papermaking, segmented drying and hot-pressing shaping. The separator has the advantages of high porosity, fast acid absorption speed, high tensile strength, acid-erosion resistance and low thermal shrinkage rate, and the 100% DOD cycle life of an assembled battery can reach 912 times, the service life of a starting battery for an automobile is significantly prolonged, the process is stable and environment-friendly, and the process is suitable for industrial mass production.

Description

Technical Field

[0001] This invention relates to the field of glass fiber separator technology, specifically to a glass fiber separator for lead-acid batteries and its preparation process. Background Technology

[0002] Lead-acid batteries are the core power components for starting, lighting, and ignition in automobiles. Fiberglass separators are key inner components that determine battery performance and lifespan. Their main functions are to insulate the positive and negative electrodes, absorb electrolyte, prevent active materials from falling off, and ensure efficient hydrogen ion conduction.

[0003] Traditional AGM glass fiber separators have the following defects: (1) uneven pore structure, insufficient acid absorption and liquid retention capacity, and the battery is prone to drying out and failure; (2) low mechanical strength, poor puncture resistance and compression resistance, and easy to cause micro short circuits; (3) insufficient acid resistance and high temperature stability, and shrinkage, powdering and aging quickly after long-term use; (4) single filler modification is prone to agglomeration, and it is impossible to take into account strength, porosity, acid resistance and thermal conductivity.

[0004] Existing technologies mostly employ modification with single nanomaterials, failing to form an efficient synergistic system, thus making it difficult to meet the requirements of long lifespan, high reliability, and resistance to harsh operating conditions for automotive starting batteries. Therefore, this invention provides a glass fiber separator for lead-acid batteries modified with a combination of two nano-additives, solving the aforementioned technical problems. Summary of the Invention

[0005] In view of the deficiencies of the prior art, the purpose of this invention is to provide a glass fiber separator for lead-acid batteries and its manufacturing process, so as to solve the problems mentioned in the background art.

[0006] The present invention solves the technical problem by adopting the following technical solution: This invention provides a glass fiber separator for lead-acid batteries, which is made from the following raw materials in parts by weight: 60-70 parts of ultrafine glass fiber, 8-12 parts of nano-silica filler, 5-8 parts of nano-attapulgite-nano-boron nitride modifier, 1-3 parts of dispersant, 2-4 parts of binder, and 1-2 parts of acid-resistant stabilizer.

[0007] Preferably, the ultrafine glass fiber has a diameter of 0.4–1.2 μm and a length of 1–3 mm; the dispersant is sodium polyacrylate with a molecular weight of 3000–5000; the binder is polyvinyl acetate emulsion with a solid content of 45–50%; and the acid-resistant stabilizer is aluminum dihydrogen phosphate.

[0008] Preferably, the preparation method of the nano-silica filler is as follows: S1: Mix 3-5 parts of mullite whiskers, 1-2 parts of tannic acid, 1-2 parts of β-cyclodextrin and 4-7 parts of sodium citrate solution with a mass fraction of 2-5% and ball mill, filter and dry to obtain mullite whisker agent; S2: Silane coupling agent KH560, ethanol aqueous solution, and mullite whisker agent are mixed evenly in a weight ratio of (2-3):5:(1-2) to obtain a modified silane solution; S3: Nano silica is preheated at 55-60℃ for 1 hour to obtain preheated nano silica, and then added to a modified silane solution of 3-5 times its total volume and stirred thoroughly to obtain nano silica-silane modified solution; S4: Mix 2-3 parts wollastonite, 1-2 parts cerium dioxide, 2-3 parts quartz powder and 5-8 parts barium titanate thoroughly to obtain a filler; mix nano-silica-silane modified liquid and filler at a weight ratio of (11-15):8, ball mill thoroughly, filter and dry to obtain nano-silica filler.

[0009] Preferably, the ball milling speed in S1 is 300-400 r / min, and the time is 40-50 min; the stirring speed in S3 is 500-600 r / min, and the time is 25-35 min; the ball milling speed in S4 is 450-550 r / min, and the time is 35-45 min; the mass fraction of the ethanol aqueous solution is 75%.

[0010] Preferably, the nano-silica has a particle size of 10–30 nm and a specific surface area of ​​200–300 m². / g; the mullite whiskers have a diameter of 0.3-0.8 μm and an aspect ratio of 10-20; The wollastonite is needle-shaped powder with a mesh size of 2000-3000 mesh; the cerium dioxide has a particle size of 30-50 nm; the quartz powder has a mesh size of 1250-2000 mesh; and the barium titanate has a particle size of 50-80 nm.

[0011] Preferably, the preparation method of the nano-attapulgite-nano boron nitride modifier is as follows: S11: Add nano-attapulgite to a 4-7% sodium lignosulfonate solution with a mass fraction of 5-8 times its total volume and stir evenly to obtain nano-attapulgite liquid. S12: Nano-attapulgite clay liquid and nano-boron nitride modifier are ball-milled at a weight ratio of (8-11):5, filtered, and dried to obtain nano-attapulgite clay-nano-boron nitride modifier.

[0012] Preferably, the preparation method of the nano-boron nitride modifier is as follows: S12a: 2-4 parts of nano-titanium dioxide, 1-3 parts of nano-cellulose, 4-7 parts of 2-5% yttrium nitrate solution and 1-2 parts of basalt fiber are thoroughly mixed to obtain a conditioning solution; S12b: Nano boron nitride and conditioning solution are blended at a weight ratio of 3:(5-6) and ultrasonically treated with an ultrasonic power of 350-400W for 1 hour. After filtration and drying, nano boron nitride conditioning material is obtained.

[0013] Preferably, the stirring speed of S11 is 400-500 r / min, and the time is 20-30 min; the ball milling speed of S12 is 400-500 r / min, and the time is 30-40 min.

[0014] Preferably, the nano-attapulgite has a particle size of 20–40 nm, an aspect ratio of 15–25, and a specific surface area of ​​180–240 m². / g; the nano boron nitride is hexagonal with a particle size of 50-100nm; the nano titanium dioxide is anatase with a particle size of 15-25nm; the nano cellulose has a diameter of 5-10nm and a length of 100-300nm; the basalt fiber has a length of 1-3mm and a diameter of 5-8μm.

[0015] This invention also provides a process for preparing a glass fiber separator for lead-acid batteries, comprising the following steps: Step 1: Add ultrafine glass fiber, nano silica filler, nano attapulgite-nano boron nitride modifier, and dispersant to deionized water according to the specified ratio, and disperse at high speed (1200-1500 r / min) for 20-30 min to obtain a mixed slurry. Step 2: Add binder and acid-resistant stabilizer to the mixed slurry, stir at low speed (300-400 r / min) for 10-15 min; Step 3: Feed the slurry into a wet form-forming machine, with a forming mesh of 200-300 mesh and a forming pressure of 0.2-0.3 MPa; Step 4: Pre-drying: temperature 80-90℃, time 15-25 min; Step 5: Hot pressing and shaping: temperature 150-160℃, pressure 0.5-0.8MPa, time 5-10 min; Step 6: Cooling, cutting, and winding to obtain the glass fiber separator for lead-acid batteries of the present invention.

[0016] Compared with the prior art, the present invention has the following beneficial effects: This invention relates to a glass fiber separator using ultrafine glass fiber as the matrix. Dispersants, binders, and acid-resistant stabilizers are added as functional additives. Simultaneously, nano-silica fillers and nano-attapulgite-nano boron nitride modifiers are added. These two raw materials synergistically enhance each other, resulting in a comprehensive and coordinated improvement in product performance. The nano-silica filler, reinforced with mullite whiskers, dispersed with silane coupling agents, and strengthened by multi-component fillers, forms a continuous and uniform porous network within the glass fiber matrix, achieving a porosity of 93.6% and a tensile strength of 7.8 MPa, significantly improving acid absorption and liquid retention, ion conduction, and puncture resistance. The nano-attapulgite-nano boron nitride modifier, combined with the acid-resistant stabilizer, results in a separator with acid-impregnated weight loss as low as 1.5% and a thermal shrinkage rate as low as 0.22%, maintaining dimensional and structural stability under the high-temperature and highly corrosive environments of automobiles. The synergistic effect of the two nano-additives enables the battery to achieve a 100% DOD cycle life exceeding 900 cycles, resulting in a coordinated and comprehensive improvement in product performance. Detailed Implementation

[0017] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to specific examples. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0018] This embodiment of a glass fiber separator for lead-acid batteries is made from the following raw materials in parts by weight: 60-70 parts of ultrafine glass fiber, 8-12 parts of nano-silica filler, 5-8 parts of nano-attapulgite-nano-boron nitride modifier, 1-3 parts of dispersant, 2-4 parts of binder, and 1-2 parts of acid-resistant stabilizer.

[0019] In this embodiment, the ultrafine glass fiber has a diameter of 0.4–1.2 μm and a length of 1–3 mm; the dispersant is sodium polyacrylate with a molecular weight of 3000–5000; the binder is polyvinyl acetate emulsion with a solid content of 45–50%; and the acid-resistant stabilizer is aluminum dihydrogen phosphate.

[0020] The preparation method of the nano-silica filler in this embodiment is as follows: S1: Mix 3-5 parts of mullite whiskers, 1-2 parts of tannic acid, 1-2 parts of β-cyclodextrin and 4-7 parts of sodium citrate solution with a mass fraction of 2-5% and ball mill, filter and dry to obtain mullite whisker agent; S2: Silane coupling agent KH560, ethanol aqueous solution, and mullite whisker agent are mixed evenly in a weight ratio of (2-3):5:(1-2) to obtain a modified silane solution; S3: Nano silica is preheated at 55-60℃ for 1 hour to obtain preheated nano silica, and then added to a modified silane solution of 3-5 times its total volume and stirred thoroughly to obtain nano silica-silane modified solution; S4: Mix 2-3 parts wollastonite, 1-2 parts cerium dioxide, 2-3 parts quartz powder and 5-8 parts barium titanate thoroughly to obtain a filler; mix nano-silica-silane modified liquid and filler at a weight ratio of (11-15):8, ball mill thoroughly, filter and dry to obtain nano-silica filler.

[0021] In this embodiment, the ball milling speed in S1 is 300-400 r / min, and the time is 40-50 min; the stirring speed in S3 is 500-600 r / min, and the time is 25-35 min; the ball milling speed in S4 is 450-550 r / min, and the time is 35-45 min; the mass fraction of the ethanol aqueous solution is 75%.

[0022] The nano-silica in this embodiment has a particle size of 10–30 nm and a specific surface area of ​​200–300 m². / g; the mullite whiskers have a diameter of 0.3-0.8 μm and an aspect ratio of 10-20; The wollastonite is needle-shaped powder with a mesh size of 2000-3000 mesh; the cerium dioxide has a particle size of 30-50 nm; the quartz powder has a mesh size of 1250-2000 mesh; and the barium titanate has a particle size of 50-80 nm.

[0023] The preparation method of the nano-attapulgite-nano boron nitride modifier in this embodiment is as follows: S11: Add nano-attapulgite to a 4-7% sodium lignosulfonate solution with a mass fraction of 5-8 times its total volume and stir evenly to obtain nano-attapulgite liquid. S12: Nano-attapulgite clay liquid and nano-boron nitride modifier are ball-milled at a weight ratio of (8-11):5, filtered, and dried to obtain nano-attapulgite clay-nano-boron nitride modifier.

[0024] The preparation method of the nano boron nitride modifier in this embodiment is as follows: S12a: 2-4 parts of nano-titanium dioxide, 1-3 parts of nano-cellulose, 4-7 parts of 2-5% yttrium nitrate solution and 1-2 parts of basalt fiber are thoroughly mixed to obtain a conditioning solution; S12b: Nano boron nitride and conditioning solution are blended at a weight ratio of 3:(5-6) and ultrasonically treated with an ultrasonic power of 350-400W for 1 hour. After filtration and drying, nano boron nitride conditioning material is obtained.

[0025] In this embodiment, the stirring speed of S11 is 400-500 r / min, and the time is 20-30 min; the ball milling speed of S12 is 400-500 r / min, and the time is 30-40 min.

[0026] The nano-attapulgite clay of this embodiment has a particle size of 20-40 nm, an aspect ratio of 15-25, and a specific surface area of ​​180-240 m². / g; the nano boron nitride is hexagonal with a particle size of 50-100nm; the nano titanium dioxide is anatase with a particle size of 15-25nm; the nano cellulose has a diameter of 5-10nm and a length of 100-300nm; the basalt fiber has a length of 1-3mm and a diameter of 5-8μm.

[0027] The manufacturing process of a glass fiber separator for lead-acid batteries according to this embodiment includes the following steps: Step 1: Add ultrafine glass fiber, nano silica filler, nano attapulgite-nano boron nitride modifier, and dispersant to deionized water according to the specified ratio, and disperse at high speed (1200-1500 r / min) for 20-30 min to obtain a mixed slurry. Step 2: Add binder and acid-resistant stabilizer to the mixed slurry, stir at low speed (300-400 r / min) for 10-15 min; Step 3: Feed the slurry into a wet form-forming machine, with a forming mesh of 200-300 mesh and a forming pressure of 0.2-0.3 MPa; Step 4: Pre-drying: temperature 80-90℃, time 15-25 min; Step 5: Hot pressing and shaping: temperature 150-160℃, pressure 0.5-0.8MPa, time 5-10 min; Step 6: Cooling, cutting, and winding to obtain the glass fiber separator for lead-acid batteries of the present invention.

[0028] Example 1. This embodiment of a glass fiber separator for lead-acid batteries is made from the following raw materials in parts by weight: 60 parts of ultrafine glass fiber, 8 parts of nano silica filler, 5 parts of nano attapulgite-nano boron nitride modifier, 1 part of dispersant, 2 parts of binder, and 1 part of acid-resistant stabilizer.

[0029] In this embodiment, the ultrafine glass fiber has a diameter of 0.4 μm and a length of 1 mm; the dispersant is sodium polyacrylate with a molecular weight of 3000; the binder is polyvinyl acetate emulsion with a solid content of 45%; and the acid-resistant stabilizer is aluminum dihydrogen phosphate.

[0030] The preparation method of the nano-silica filler in this embodiment is as follows: S1: Mix 3 parts mullite whiskers, 1 part tannic acid, 1 part β-cyclodextrin and 4 parts 2% sodium citrate solution, ball mill, filter and dry to obtain mullite whisker agent; S2: Silane coupling agent KH560, ethanol aqueous solution, and mullite whisker agent are mixed evenly in a weight ratio of 2:5:1 to obtain modified silane solution; S3: Nano silica is first preheated at 55℃ for 1 hour to obtain preheated nano silica, and then added to a modified silane liquid with a total volume of 3 times the amount of nano silica and stirred thoroughly to obtain nano silica-silane modified liquid. S4: Mix 2 parts wollastonite, 1 part cerium dioxide, 2 parts quartz powder and 5 parts barium titanate thoroughly to obtain a filler; mix nano-silica-silane modified liquid and filler at a weight ratio of 11:8, ball mill thoroughly, filter and dry to obtain nano-silica filler.

[0031] In this embodiment, the ball milling speed in S1 is 300 r / min, and the time is 40 min; the stirring speed in S3 is 500 r / min, and the time is 25 min; the ball milling speed in S4 is 450 r / min, and the time is 35 min; the mass fraction of the ethanol aqueous solution is 75%.

[0032] The nano-silica in this embodiment has a particle size of 10 nm and a specific surface area of ​​200 m². / g; the mullite whiskers have a diameter of 0.3μm and an aspect ratio of 10; The wollastonite is needle-shaped powder with a mesh size of 2000; the cerium dioxide has a particle size of 30 nm; the quartz powder has a mesh size of 1250 mesh; and the barium titanate has a particle size of 50 nm.

[0033] The preparation method of the nano-attapulgite-nano boron nitride modifier in this embodiment is as follows: S11: Add nano-attapulgite to a 4% sodium lignosulfonate solution with a mass fraction of 5 times its total volume and stir evenly to obtain nano-attapulgite liquid. S12: Nano-attapulgite clay liquid and nano-boron nitride modifier are ball-milled at a weight ratio of 8:5, filtered, and dried to obtain nano-attapulgite clay-nano-boron nitride modifier.

[0034] The preparation method of the nano boron nitride modifier in this embodiment is as follows: S12a: Two parts of nano-titanium dioxide, one part of nano-cellulose, four parts of 2% yttrium nitrate solution and one part of basalt fiber are thoroughly mixed to obtain a conditioning solution; S12b: Nano boron nitride and conditioning solution are blended at a weight ratio of 3:5 and ultrasonically treated with an ultrasonic power of 350W for 1 hour. After filtration and drying, nano boron nitride conditioning material is obtained.

[0035] In this embodiment, the stirring speed of S11 is 400 r / min, and the time is 20 min; the ball milling speed of S12 is 400 r / min, and the time is 30 min.

[0036] The nano-attapulgite clay in this embodiment has a particle size of 20 nm, an aspect ratio of 15, and a specific surface area of ​​180 m². / g; the nano boron nitride is hexagonal with a particle size of 50nm; the nano titanium dioxide is anatase with a particle size of 15nm; the nano cellulose has a diameter of 5nm and a length of 100nm; the basalt fiber has a length of 1mm and a diameter of 5μm.

[0037] The manufacturing process of a glass fiber separator for lead-acid batteries according to this embodiment includes the following steps: Step 1: Add ultrafine glass fiber, nano silica filler, nano attapulgite-nano boron nitride modifier, and dispersant to deionized water according to the specified ratio, and disperse at high speed (1200 r / min) for 20 min to obtain a mixed slurry. Step 2: Add binder and acid-resistant stabilizer to the mixed slurry, stir at low speed (300 r / min) for 10 min; Step 3: Feed the slurry into the wet form-forming machine, with a forming mesh of 200 mesh and a forming pressure of 0.2 MPa; Step 4: Pre-drying: temperature 80℃, time 15min; Step 5: Hot pressing and shaping: temperature 150℃, pressure 0.5MPa, time 5min; Step 6: Cooling, cutting, and rolling to obtain the glass fiber separator for lead-acid batteries of the present invention.

[0038] Example 2. This embodiment of a glass fiber separator for lead-acid batteries is made from the following raw materials in parts by weight: 70 parts ultrafine glass fiber, 12 parts nano silica filler, 8 parts nano attapulgite-nano boron nitride modifier, 3 parts dispersant, 4 parts binder, and 2 parts acid-resistant stabilizer.

[0039] In this embodiment, the ultrafine glass fiber has a diameter of 1.2 μm and a length of 3 mm; the dispersant is sodium polyacrylate with a molecular weight of 5000; the binder is polyvinyl acetate emulsion with a solid content of 50%; and the acid-resistant stabilizer is aluminum dihydrogen phosphate.

[0040] The preparation method of the nano-silica filler in this embodiment is as follows: S1: Mix 5 parts mullite whiskers, 2 parts tannic acid, 2 parts β-cyclodextrin and 7 parts 5% sodium citrate solution, ball mill, filter and dry to obtain mullite whisker agent; S2: Silane coupling agent KH560, ethanol aqueous solution, and mullite whisker agent are mixed evenly in a weight ratio of 3:5:2 to obtain modified silane solution; S3: Nano silica is first preheated at 60℃ for 1 hour to obtain preheated nano silica, and then added to 5 times its total volume of modified silane liquid and stirred thoroughly to obtain nano silica-silane modified liquid. S4: Mix 3 parts wollastonite, 2 parts cerium dioxide, 3 parts quartz powder and 8 parts barium titanate thoroughly to obtain a filler; mix nano-silica-silane modified liquid and filler at a weight ratio of 15:8, ball mill thoroughly, filter and dry to obtain nano-silica filler.

[0041] In this embodiment, the ball milling speed in S1 is 400 r / min, and the time is 50 min; the stirring speed in S3 is 600 r / min, and the time is 35 min; the ball milling speed in S4 is 550 r / min, and the time is 45 min; the mass fraction of the ethanol aqueous solution is 75%.

[0042] The nano-silica in this embodiment has a particle size of 30 nm and a specific surface area of ​​300 m². / g; the mullite whiskers have a diameter of 0.8μm and an aspect ratio of 20; The wollastonite is needle-shaped powder with a mesh size of 3000; the cerium dioxide has a particle size of 50 nm; the quartz powder has a mesh size of 2000; and the barium titanate has a particle size of 80 nm.

[0043] The preparation method of the nano-attapulgite-nano boron nitride modifier in this embodiment is as follows: S11: Add nano-attapulgite to a 7% sodium lignosulfonate solution with a mass fraction of 8 times its total volume and stir evenly to obtain nano-attapulgite liquid. S12: Nano-attapulgite clay liquid and nano-boron nitride modifier are ball-milled at a weight ratio of 11:5, filtered, and dried to obtain nano-attapulgite clay-nano-boron nitride modifier.

[0044] The preparation method of the nano boron nitride modifier in this embodiment is as follows: S12a: 4 parts of nano-titanium dioxide, 3 parts of nano-cellulose, 7 parts of 5% yttrium nitrate solution and 2 parts of basalt fiber are thoroughly mixed to obtain a conditioning solution; S12b: Nano boron nitride and conditioning solution are blended at a weight ratio of 3:6 and ultrasonically treated with an ultrasonic power of 400W for 1 hour. After filtration and drying, nano boron nitride conditioning material is obtained.

[0045] In this embodiment, the stirring speed for S11 is 500 r / min, and the time is 30 min; the ball milling speed for S12 is 500 r / min, and the time is 40 min.

[0046] The nano-attapulgite clay in this embodiment has a particle size of 40 nm, an aspect ratio of 25, and a specific surface area of ​​240 m². / g; the nano boron nitride is hexagonal with a particle size of 100nm; the nano titanium dioxide is anatase with a particle size of 25nm; the nano cellulose has a diameter of 10nm and a length of 300nm; the basalt fiber has a length of 3mm and a diameter of 8μm.

[0047] The manufacturing process of a glass fiber separator for lead-acid batteries according to this embodiment includes the following steps: Step 1: Add ultrafine glass fiber, nano silica filler, nano attapulgite-nano boron nitride modifier, and dispersant to deionized water according to the specified ratio, and disperse at high speed (1500 r / min) for 30 min to obtain a mixed slurry. Step 2: Add binder and acid-resistant stabilizer to the mixed slurry, stir at low speed (400 r / min) for 15 min; Step 3: Feed the slurry into the wet paper forming machine, with a forming mesh of 300 mesh and a forming pressure of 0.3 MPa; Step 4: Pre-drying: temperature 90℃, time 25min; Step 5: Hot pressing and shaping: temperature 160℃, pressure 0.8MPa, time 10min; Step 6: Cooling, cutting, and rolling to obtain the glass fiber separator for lead-acid batteries of the present invention.

[0048] Example 3. This embodiment of a glass fiber separator for lead-acid batteries is made from the following raw materials in parts by weight: 65 parts of ultrafine glass fiber, 10 parts of nano silica filler, 6.5 parts of nano attapulgite-nano boron nitride modifier, 2 parts of dispersant, 3 parts of binder, and 1.5 parts of acid-resistant stabilizer.

[0049] In this embodiment, the ultrafine glass fiber has a diameter of 0.8 μm and a length of 2 mm; the dispersant is sodium polyacrylate with a molecular weight of 4000; the binder is polyvinyl acetate emulsion with a solid content of 47.5%; and the acid-resistant stabilizer is aluminum dihydrogen phosphate.

[0050] The preparation method of the nano-silica filler in this embodiment is as follows: S1: Mix 4 parts mullite whiskers, 1.5 parts tannic acid, 1.5 parts β-cyclodextrin and 5.5 parts 3.5% sodium citrate solution, ball mill, filter and dry to obtain mullite whisker agent; S2: Silane coupling agent KH560, ethanol aqueous solution, and mullite whisker agent are mixed evenly in a weight ratio of 2.5:5:1.5 to obtain modified silane solution; S3: Nano silica is first preheated at 58℃ for 1 hour to obtain preheated nano silica, and then added to a modified silane liquid of 4 times its total volume and stirred thoroughly to obtain nano silica-silane modified liquid. S4: 2.5 parts wollastonite, 1.5 parts cerium dioxide, 2.5 parts quartz powder and 6.5 parts barium titanate are thoroughly mixed to obtain a filler; nano silica-silane modified liquid and filler are ball-milled at a weight ratio of 13:8, filtered and dried to obtain nano silica filler.

[0051] In this embodiment, S1 ball milling speed is 350 r / min, time is 5 min; S3 stirring speed is 550 r / min, time is 30 min; S4 ball milling speed is 500 r / min, time is 40 min; the mass fraction of the ethanol aqueous solution is 75%.

[0052] The nano-silica in this embodiment has a particle size of 20 nm and a specific surface area of ​​250 m². / g; The mullite whiskers have a diameter of 0.45μm and an aspect ratio of 15; The wollastonite is needle-shaped powder with a mesh size of 2500; the cerium dioxide has a particle size of 40 nm; the quartz powder has a mesh size of 1550; and the barium titanate has a particle size of 65 nm.

[0053] The preparation method of the nano-attapulgite-nano boron nitride modifier in this embodiment is as follows: S11: Add nano-attapulgite to a 5.5% sodium lignosulfonate solution with a mass fraction of 6.5 times its total volume and stir until homogeneous to obtain nano-attapulgite liquid; S12: Nano-attapulgite clay liquid and nano-boron nitride modifier are ball-milled at a weight ratio of 9:5, filtered, and dried to obtain nano-attapulgite clay-nano-boron nitride modifier.

[0054] The preparation method of the nano boron nitride modifier in this embodiment is as follows: S12a: 3 parts of nano-titanium dioxide, 2 parts of nano-cellulose, 5.5 parts of 3.5% yttrium nitrate solution and 1.5 parts of basalt fiber are thoroughly mixed to obtain a conditioning solution; S12b: Nano boron nitride and conditioning solution are blended at a weight ratio of 3:5.5 and ultrasonically treated with an ultrasonic power of 375W for 1 hour. After filtration and drying, nano boron nitride conditioning material is obtained.

[0055] In this embodiment, the stirring speed for S11 is 450 r / min, and the time is 25 min; the ball milling speed for S12 is 450 r / min, and the time is 35 min.

[0056] The nano-attapulgite clay in this embodiment has a particle size of 30 nm, an aspect ratio of 20, and a specific surface area of ​​210 m². / g; the nano boron nitride is hexagonal with a particle size of 75nm; the nano titanium dioxide is anatase with a particle size of 20nm; the nano cellulose has a diameter of 7.5nm and a length of 200nm; the basalt fiber has a length of 2mm and a diameter of 6.5μm.

[0057] The manufacturing process of a glass fiber separator for lead-acid batteries according to this embodiment includes the following steps: Step 1: Add ultrafine glass fiber, nano silica filler, nano attapulgite-nano boron nitride modifier, and dispersant to deionized water according to the specified ratio, and disperse at high speed (1350 r / min) for 5 min to obtain a mixed slurry. Step 2: Add binder and acid-resistant stabilizer to the mixed slurry, stir at low speed (350 r / min) for 12.5 min; Step 3: Feed the slurry into the wet paper forming machine, with a forming mesh of 200 mesh and a forming pressure of 0.25 MPa; Step 4: Pre-drying: temperature 85℃, time 20min; Step 5: Hot pressing and shaping: temperature 155℃, pressure 0.65MPa, time 7.5min; Step 6: Cooling, cutting, and winding to obtain the glass fiber separator for lead-acid batteries of the present invention.

[0058] Comparative Example 1: Compared with Example 3, the only difference is that no nano-silica filler was added.

[0059] Comparative Example 2: Compared with Example 3, the only difference is that no filler was added in the preparation of the nano silica filler.

[0060] Comparative Example 3: The only difference from Example 3 is that wollastonite and cerium dioxide were not added during the preparation of the filler.

[0061] Comparative Example 4: Compared with Example 3, the only difference is that quartz powder and barium titanate were not added in the preparation of the filler.

[0062] Comparative Example 5: Compared with Example 3, the only difference is that mullite whiskers were not added in the preparation of the modified silane liquid.

[0063] Comparative Example 6: Compared with Example 3, the only difference is that the nano-attapulgite-nano boron nitride modifier was not added.

[0064] Comparative Example 7: Compared with Example 3, the only difference is that no nano-attapulgite liquid was added in the preparation of nano-attapulgite-nano-boron nitride modifier.

[0065] Comparative Example 8: Compared with Example 3, the only difference is that no nano-boron nitride modifier was added in the preparation of the nano-attapulgite clay-nano-boron nitride modifier.

[0066] Comparative Example 9: Compared with Example 3, the only difference is that nano-titanium dioxide and nano-cellulose were not added to the conditioning solution.

[0067] Comparative Example 10: Compared with Example 3, the only difference is that basalt fiber was not added to the conditioning solution, and yttrium nitrate solution was replaced with water.

[0068] The products of Examples 1-3 and Comparative Examples 1-10 were subjected to performance tests. Tensile strength: GB / T28535-2018, universal testing machine, tensile rate 50mm / min; Porosity: Immersion method, porosity (%) = (W1 - W0) / (ρ × V) × 100%; Capillary acid adsorption height: using a density of 1.280 g / cm³ Sulfuric acid, measured the rise height over 5 min / 24 h; Wetting time: the time it takes for sulfuric acid droplets to be completely absorbed on the surface of the partition; Immersion weight loss: the mass loss rate is calculated after immersion in 5% sulfuric acid solution for 24 hours. Heat shrinkage rate: Dimensional change rate was measured after baking at 100℃ for 2 hours; Cycle life: GB / T22199-2017, using a 12V 60Ah AGM automotive starting battery, 100% DOD cycle, 1C charge / discharge, the life was considered to end when the capacity dropped to 80% of the initial capacity; Test results are as follows: The cycle life test results are as follows: The performance of Examples 1-3 of this invention is significantly better than that of the comparative examples, with Example 3 being the best, exhibiting a porosity of 93.6%, tensile strength of 7.8 MPa, wetting time of 2.6 s, acid immersion weight loss of 1.5%, thermal shrinkage rate of 0.22%, and a cycle life of 912 cycles. Comparative Example 1, lacking nano-silica filler, showed a significant decrease in pore structure, strength, acid absorption and liquid retention, and a significantly reduced cycle life, indicating that it plays a decisive role in the basic performance of the separator. Comparative Examples 2-5 lacked fillers, wollastonite / cerium dioxide, quartz powder / barium titanate, and mullite whiskers, respectively, all of which resulted in uneven filler dispersion, decreased interfacial bonding, and poor pore structure stability, leading to a comprehensive reduction in performance. Comparative Example 6, without the addition of nano-attapulgite-nano-boron nitride modifier, showed the most significant deterioration in thermal stability, aging resistance, and acid corrosion resistance, with cycle life decreasing to 497 cycles, indicating that it is a core component for improving battery life. Comparative Examples 7-10 lacked nano-attapulgite liquid, nano-boron nitride modifier, nano-titanium dioxide / nano-cellulose, and basalt fiber / yttrium nitrate, all of which disrupted the synergistic modification effect, resulting in decreased cycle stability and mechanical properties. Only the nano-silica filler obtained by the specific method of this invention, combined with the nano-attapulgite-nano-boron nitride modifier, showed the most significant performance effect due to their synergistic effect. Using other methods to replace the raw materials of this invention did not yield the same significant results as this invention.

[0069] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from the spirit or essential characteristics of the invention. Therefore, the embodiments should be considered in all respects as exemplary and non-limiting, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, it is intended that all variations falling within the meaning and scope of equivalents of the claims be included within the present invention.

[0070] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. A glass fiber separator for lead-acid batteries, characterized in that, It is made from the following raw materials in parts by weight: 60-70 parts of ultrafine glass fiber, 8-12 parts of nano silica filler, 5-8 parts of nano attapulgite-nano boron nitride modifier, 1-3 parts of dispersant, 2-4 parts of binder, and 1-2 parts of acid-resistant stabilizer.

2. The glass fiber separator for lead-acid batteries according to claim 1, characterized in that, The ultrafine glass fiber has a diameter of 0.4–1.2 μm and a length of 1–3 mm; the dispersant is sodium polyacrylate with a molecular weight of 3000–5000; the binder is polyvinyl acetate emulsion with a solid content of 45–50%; and the acid-resistant stabilizer is aluminum dihydrogen phosphate.

3. The glass fiber separator for lead-acid batteries according to claim 1, characterized in that, The preparation method of the nano-silica filler is as follows: S1: Mix 3-5 parts of mullite whiskers, 1-2 parts of tannic acid, 1-2 parts of β-cyclodextrin and 4-7 parts of sodium citrate solution with a mass fraction of 2-5% and ball mill, filter and dry to obtain mullite whisker agent; S2: Silane coupling agent KH560, ethanol aqueous solution, and mullite whisker agent are mixed evenly in a weight ratio of (2-3):5:(1-2) to obtain modified silane solution; S3: Nano silica is preheated at 55-60℃ for 1 hour to obtain preheated nano silica, and then added to a modified silane solution of 3-5 times its total volume and stirred thoroughly to obtain nano silica-silane modified solution; S4: Mix 2-3 parts wollastonite, 1-2 parts cerium dioxide, 2-3 parts quartz powder and 5-8 parts barium titanate thoroughly to obtain a filler; mix nano-silica-silane modified liquid and filler at a weight ratio of (11-15):8, ball mill thoroughly, filter and dry to obtain nano-silica filler.

4. A glass fiber separator for lead-acid batteries according to claim 3, characterized in that, S1 Ball milling speed 300-400 r / min, time 40-50 min; S3 stirring speed 500-600 r / min, time 25-35 min; S4 ball milling speed 450-550 r / min, time 35-45 min; the ethanol aqueous solution has a mass fraction of 75%.

5. A glass fiber separator for lead-acid batteries according to claim 3, characterized in that, The nano-silica has a particle size of 10–30 nm and a specific surface area of ​​200–300 m². / g; the mullite whiskers have a diameter of 0.3-0.8 μm and an aspect ratio of 10-20; The wollastonite is needle-shaped powder with a mesh size of 2000-3000 mesh; the cerium dioxide has a particle size of 30-50 nm; the quartz powder has a mesh size of 1250-2000 mesh; and the barium titanate has a particle size of 50-80 nm.

6. A glass fiber separator for a lead-acid battery according to claim 3, characterized in that, The preparation method of the nano-attapulgite-nano boron nitride modifier is as follows: S11: Add nano-attapulgite to a 4-7% sodium lignosulfonate solution with a mass fraction of 5-8 times its total volume and stir evenly to obtain nano-attapulgite liquid. S12: Nano-attapulgite clay liquid and nano-boron nitride modifier are ball-milled at a weight ratio of (8-11):5, filtered, and dried to obtain nano-attapulgite clay-nano-boron nitride modifier.

7. A glass fiber separator for a lead-acid battery according to claim 6, characterized in that, The preparation method of the nano boron nitride modifier is as follows: S12a: 2-4 parts of nano-titanium dioxide, 1-3 parts of nano-cellulose, 4-7 parts of 2-5% yttrium nitrate solution and 1-2 parts of basalt fiber are thoroughly mixed to obtain a conditioning solution; S12b: Nano boron nitride and conditioning solution are blended at a weight ratio of 3:(5-6) and ultrasonically treated with an ultrasonic power of 350-400W for 1 hour. After filtration and drying, nano boron nitride conditioning material is obtained.

8. A glass fiber separator for a lead-acid battery according to claim 6, characterized in that, S11 stirring speed 400-500 r / min, time 20-30 min; S12 ball milling speed 400-500 r / min, time 30-40 min.

9. A glass fiber separator for a lead-acid battery according to claim 7, characterized in that... The nano-attapulgite has a particle size of 20–40 nm, an aspect ratio of 15–25, and a specific surface area of ​​180–240 m². / g; the nano boron nitride is hexagonal with a particle size of 50-100nm; the nano titanium dioxide is anatase with a particle size of 15-25nm; the nano cellulose has a diameter of 5-10nm and a length of 100-300nm; the basalt fiber has a length of 1-3mm and a diameter of 5-8μm.

10. A process for preparing a glass fiber separator for a lead-acid battery as described in any one of claims 1-9, characterized in that, Includes the following steps: Step 1: Add ultrafine glass fiber, nano silica filler, nano attapulgite-nano boron nitride modifier, and dispersant to deionized water according to the specified ratio, and disperse at high speed (1200-1500 r / min) for 20-30 min to obtain a mixed slurry. Step 2: Add binder and acid-resistant stabilizer to the mixed slurry, stir at low speed (300-400 r / min) for 10-15 min; Step 3: Feed the slurry into a wet form-forming machine, with a forming mesh of 200-300 mesh and a forming pressure of 0.2-0.3 MPa; Step 4: Pre-drying: temperature 80-90℃, time 15-25 min; Step 5: Hot pressing and shaping: temperature 150-160℃, pressure 0.5-0.8MPa, time 5-10 min; Step 6: Cooling, cutting, and winding to obtain the glass fiber separator for lead-acid batteries of the present invention.

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