High liquid-absorption rate separator for zinc-silver battery and preparation method thereof

Abstract

This invention discloses a high liquid absorption rate separator for zinc-silver batteries and its preparation method, belonging to the field of specialty paper manufacturing technology. It uses mercerized wood pulp, hardwood dissolving pulp, and Tencel fiber as raw materials. The raw materials are prepared in the following mass ratios: 45-55 parts mercerized wood pulp, 25-35 parts hardwood dissolving pulp, and 20 parts Tencel fiber. After beating each material, they are mixed, dispersed evenly with a dispersant, and prepared into a pulp of a certain concentration. This pulp is then fed to an inclined wire paper machine, formed on the wire, pressed, and the wet paper sheet is placed on a drying cylinder. A penetrating agent is then coated onto the cylinder, dried, and finally the paper is wound to obtain the finished separator. The basis weight of this separator is 10.0 ± 1.0 g / m³. 2 Thickness 0.32±0.05mm, alkali absorption rate ≥500%, alkali absorption speed ≥28mm / 3min, tensile strength (longitudinal) ≥0.13kN / m, surface resistivity ≤0.04Ω·cm 2 .

Description

Technical Field

[0001] This invention belongs to the field of specialty paper and its manufacturing technology, specifically relating to a high liquid absorption rate separator for zinc-silver batteries and its preparation method. Background Technology

[0002] Zinc-silver batteries are a type of chemical power source, mainly used in the military industry. They are characterized by a stable voltage platform and high energy density and power.

[0003] The main function of the separator in a zinc-silver battery is to isolate the positive and negative electrode materials and prevent electrons from freely passing through the battery. Simultaneously, it relies on the electrolyte solution adsorbed within the separator material to conduct ions. The separator's ion conductivity, mechanical properties, and chemical stability determine the discharge efficiency and lifespan of the zinc-silver battery. Therefore, the main properties that the separator must possess are: It maintains good chemical stability in the electrolyte. Since the electrolyte of a zinc-silver battery is a high-concentration potassium hydroxide aqueous solution containing zincate, the separator material should have good alkali and oxidation resistance. It should have good wettability and excellent electrolyte absorption capacity, thereby improving ionic conductivity and electrolyte injection efficiency during battery assembly. In other words, the separator should have a high liquid absorption rate (alkali absorption rate) and a fast liquid absorption speed; The diaphragm should be thin, strong, have small pore size, uniform pore size, and good dimensional stability.

[0004] Traditional zinc-silver battery separators include hydrated cellulose membranes, crepe paper, and membranes made from vinylon and plant fibers. Each of these separator materials has its shortcomings. For example, hydrated cellulose membranes have improved oxidation resistance after modification, but increased resistance; crepe paper has uneven pore size distribution and low strength; and membranes made primarily of vinylon have excellent alkali and oxidation resistance, but poor hydrophilicity, resulting in insufficient liquid absorption speed and absorption rate.

[0005] Low basis weight thin separators can save internal space in the battery, leaving more volume for active materials and improving the volumetric energy density of zinc-silver batteries. On the other hand, the thin separator reduces the physical distance and significantly lowers the area resistivity of the separator, which is beneficial for high-rate discharge and maintaining the operating voltage. However, low basis weight thin separators are difficult to fabricate and must have sufficient strength to be successfully formed on a paper machine. Currently, there are no reports on the preparation of low basis weight thin separators. Summary of the Invention

[0006] To address the aforementioned problems in existing diaphragms, this invention aims to provide a high liquid absorption rate diaphragm with low quantitative density, thin thickness, and good strength, as well as a method for its preparation.

[0007] This invention defines a high liquid absorption rate separator for zinc-silver batteries, with a quantitative ratio of 10.0 ± 1.0 g / m³.2 Thickness 0.32±0.05mm, alkali absorption rate ≥500%, alkali absorption speed ≥28mm / 3min, tensile strength (longitudinal) ≥0.13kN / m, surface resistivity ≤0.04Ω·cm 2 .

[0008] Furthermore, the present invention also specifies that the raw materials include the following components in parts by weight: 45-55 parts mercerized wood pulp, 25-35 parts hardwood dissolving pulp, and 20 parts Tencel fiber.

[0009] Furthermore, the present invention also specifies that mercerized wood pulp is pulped to a freeness of 30 using a trough pulper. o SR~45 o SR, wet weight is 5g~7g.

[0010] Furthermore, the present invention also specifies that hardwood dissolving pulp is pulped to a beating degree of 35 using a trough pulper. o SR~45 o SR, wet weight is 3g~5g.

[0011] Furthermore, the present invention also specifies that Tencel fibers are lightly beaten to a beating degree of 30 using a trough beater. o SR~40 o SR, wet weight is 10g~14g.

[0012] Furthermore, the present invention also specifies that the crystallinity of mercerized wood pulp is ≥0.58 and the α-cellulose content in hardwood dissolving pulp is ≥93%.

[0013] Furthermore, the present invention further specifies that the Tencel fiber is an uncrosslinked Tencel fiber with a single filament fineness of 1.1 dtex and a fiber length of 6 mm.

[0014] Furthermore, the present invention also specifies a method for preparing the high liquid absorption rate separator for zinc-silver batteries, which specifically includes the following steps: 1) Take 45-55 parts by weight of mercerized wood pulp and put it into a trough pulper. Add water to adjust the mercerized wood pulp concentration to 2%-3%. Beat the pulp until the freeness of the pulp is 30. o SR~45 o SR, with a wet weight of 5g~7g, is placed in the pulp mixing tank; 2) Take 25-35 parts by weight of hardwood dissolving pulp, put it into a trough pulper, add water to adjust the hardwood dissolving pulp concentration to 2%-3%, and beat with a blade until the pulp has a freeness of 35. o SR~45 o SR, with a wet weight of 3g~5g, is placed in the mixing tank of step 1); 3) Take 20 parts by weight of Tencel fiber, put it into a trough pulper, add water to adjust the Tencel fiber concentration to 3%, and beat with a light knife until the pulp freeness is 30. o SR~40 o SR, with a wet weight of 10g~14g, is placed in the mixing tank of step 1); 4) Add 0.1%~0.2% of the total mass of oven-dried fiber raw materials as dispersant to the slurry mixing tank, and dilute with water to a total mass concentration of 0.1%~0.2% for all fiber raw materials. Stir thoroughly until the slurry is evenly dispersed, and pump it into the intermediate slurry tank and the pre-slurry tank for storage in sequence. 5) The pulp prepared in step 4) is transported from the pre-papermaking pulp tank to the pulp distributor of the inclined wire paper machine. After being formed on the wire, dewatered, pressed, and the wet paper is placed on the drying cylinder, a penetrating agent is applied to the cylinder and dried before the paper is rolled onto the cylinder to produce a high liquid absorption rate separator for zinc-silver batteries.

[0015] Furthermore, the present invention further specifies that the dispersant in step 4) is one of anionic polyacrylamide or polyethylene oxide.

[0016] Furthermore, the present invention further specifies that the penetrant mentioned in step 5) is a nonylphenol polyoxyethylene ether (NP-10) aqueous solution with a mass concentration of 0.5%, and the amount of penetrant retained in the finished membrane after coating is 0.5‰~1.0‰.

[0017] By employing the above-described technology, the beneficial effects of the present invention compared to the prior art are as follows: 1) This invention adopts a scheme using special plant fiber mercerized wood pulp and hardwood dissolving pulp as the main raw materials. It fully utilizes the advantages of mercerized wood pulp, such as its curled and fluffy fiber morphology and extremely high water retention (≥200%), to maximize the liquid absorption rate of the separator. Combined with the high α-cellulose content, purity, and low impurity content of hardwood dissolving pulp, it avoids negative impacts on the battery and helps reduce battery self-discharge. Furthermore, its shorter fibers, through thorough beating and control of appropriate beating degree and wet weight, increase the interweaving strength between fibers and also regulate the pore structure of the separator. In addition, since paper strength is affected not only by the degree of fiber fibrillation but also by fiber length, fiber length significantly affects the tensile strength, especially tear resistance. Since both mercerized wood pulp and hardwood dissolving pulp have relatively short fibers, this invention also incorporates a limited proportion of fibrillated Tencel fibers with a fiber length of 6mm. Light beating is used to achieve an appropriate beating degree while preserving the fiber length as much as possible, controlling the beating degree to 30. o SR~40 oSR, with a wet weight of 10g~14g, further enhances the strength of the prepared separator. The combination of the above three fiber raw materials balances multiple properties of the separator, such as liquid absorption, liquid retention, strength, and pore structure, achieving complementary advantages. This results in the preparation of a high liquid absorption rate separator for zinc-silver batteries with low quantitative weight, thin thickness, excellent liquid absorption performance, and good strength. 2) To further improve the liquid absorption rate of the separator, this invention employs a technique of coating a penetrant onto the wet paper sheet after drying in a drying cylinder. This significantly enhances the liquid absorption rate of the separator, resulting in a zinc-silver battery separator with a basis weight of 10.0 ± 1.0 g / m³. 2 Thickness 0.32±0.05mm, alkali absorption rate ≥500%, alkali absorption speed ≥28mm / 3min, tensile strength (longitudinal) ≥0.13kN / m, surface resistivity ≤0.04Ω·cm 2 This meets the usage requirements of the new model of rapid activation zinc-silver battery. Detailed Implementation

[0018] The present invention will be further described below with reference to specific embodiments, but the scope of protection of the present invention is not limited thereto.

[0019] In this embodiment of the invention, the mercerized wood pulp has a crystallinity of ≥0.58, the α-cellulose content in the hardwood dissolving pulp is ≥93%, and the Tencel fiber is an uncrosslinked Tencel fiber with a single filament fineness of 1.1 dtex and a fiber length of 6 mm. All three raw materials are commercially available products.

[0020] Example 1: Take 45 kg of mercerized wood pulp and put it into a trough pulper containing 2205 kg of water. First, loosen it for 10 minutes, then beat it with a blade until the measured beating degree is 31. o SR, wet weight 7g, with the blade on, the pulp is placed in the mixing tank; take 35kg of hardwood dissolving pulp and put it into a trough-type pulper already filled with 1715kg of water, first loosen it for 10 minutes, then beat it with the blade until the measured beating degree is 45. o SR, wet weight 3g, with the blade on, the pulp is placed in the mixing tank; take 20kg of Tencel fiber and put it into a trough beater containing 647kg of water, first loosen for 10 minutes, then beat with a light blade until the measured freeness is 36. o SR, wet weight 12g, shake the knife and put the slurry into the mixing tank.

[0021] After the three types of slurry are prepared in the slurry mixing tank, add 0.1 kg of anionic polyacrylamide dispersant (pre-dissolved in water) and dilute with water to a total mass concentration of 0.1% of the fiber raw materials. Stir thoroughly until the slurry is evenly dispersed and then pump it into the intermediate slurry tank and the pre-papering slurry tank in sequence.

[0022] The above-mentioned pulp is fed to the pulp distributor of an inclined wire paper machine. After forming on the wire, dewatering, pressing, and the wet paper sheet is placed on the drying cylinder, a 0.5% (w / w) NP-10 penetrant aqueous solution is coated on the cylinder and dried. The paper is then wound onto the cylinder to produce a high-absorption-rate separator for zinc-silver batteries. The separator has a basis weight of 9.5 g / m³. 2 Thickness 0.30mm, alkali absorption rate 525%, alkali absorption speed 29mm / 3min, tensile strength (longitudinal) 0.16kN / m, surface resistivity 0.03Ω·cm 2 .

[0023] Example 2: Take 55 kg of mercerized wood pulp and put it into a trough pulper containing 1778 kg of water. First, loosen it for 10 minutes, then beat it with a blade until the measured beating degree is 44. o SR, wet weight 5g, with the blade on, the pulp is placed in the mixing tank; take 25kg of hardwood dissolving pulp and put it into a trough-type pulper containing 975kg of water, first loosen it for 10 minutes, then beat it with the blade until the measured beating degree is 36. o SR, wet weight 5g, with the blade on, the pulp is placed in the mixing tank; take 20kg of Tencel fiber and put it into a trough beater containing 647kg of water, first loosen for 10 minutes, then beat with a light blade until the measured freeness is 31. o SR, wet weight 13g, shake the knife and put the slurry into the mixing tank.

[0024] After the three types of slurry are prepared in the slurry mixing tank, add 0.15 kg of anionic polyacrylamide dispersant (pre-dissolved in water) and dilute with water to a total mass concentration of 0.15% of the fiber raw materials. Stir thoroughly until the slurry is evenly dispersed and then pump it into the intermediate slurry tank and the pre-papering slurry tank in sequence.

[0025] The above-mentioned pulp is fed to the pulp distributor of an inclined wire paper machine. After forming on the wire, dewatering, pressing, and the wet paper sheet is placed on the drying cylinder, a 0.5% (w / w) NP-10 penetrant aqueous solution is coated on the cylinder and dried. The paper is then wound onto the cylinder to produce a high-absorption-rate separator for zinc-silver batteries. The basis weight of this separator is 10.8 g / m³. 2 Thickness 0.36mm, alkali absorption rate 538%, alkali absorption rate 31mm / 3min, tensile strength (longitudinal) 0.19kN / m, surface resistivity 0.04Ω·cm 2 .

[0026] Example 3: Take 50 kg of mercerized wood pulp and put it into a trough pulper containing 1950 kg of water. First, loosen it for 10 minutes, then beat it with a blade until the measured beating degree is 33. o SR, wet weight 6g, with the blade shaker on, the pulp is placed in the mixing tank; take 30kg of hardwood dissolving pulp and put it into a trough-type pulper containing 970kg of water, first loosen it for 10 minutes, then beat it with the blade until the measured beating degree is 41.o SR, wet weight 4g, with the blade on, the pulp is placed in the mixing tank; take 20kg of Tencel fiber and put it into a trough beater containing 647kg of water, first loosen for 10 minutes, then beat with a light blade until the measured freeness is 40. o SR, wet weight 10g, shake the knife and put the slurry into the mixing tank.

[0027] After the three types of slurry are prepared in the mixing tank, add 0.2 kg of polyethylene oxide dispersant (pre-dissolved in water) and dilute with water to a total mass concentration of 0.2% of the fiber raw materials. Stir thoroughly until the slurry is evenly dispersed and then pump it into the intermediate slurry tank and the pre-papering slurry tank in sequence.

[0028] The above-mentioned pulp is fed to the pulp distributor of an inclined wire paper machine. After forming on the wire, dewatering, pressing, and the wet paper sheet is placed on the drying cylinder, a 0.5% (w / w) NP-10 penetrant aqueous solution is coated on the cylinder and dried. The paper is then wound onto the cylinder to produce a high-absorption-rate separator for zinc-silver batteries. The basis weight of this separator is 10.1 g / m³. 2 Thickness 0.33mm, alkali absorption rate 518%, alkali absorption rate 29mm / 3min, tensile strength (longitudinal) 0.18kN / m, surface resistivity 0.02Ω·cm 2 .

[0029] Example 4: The operation is the same as in Example 1, except that the three raw materials are pulped to different degrees of freeness (lower freeness), as detailed below: Take 45 kg of mercerized wood pulp and put it into a trough pulper containing 2205 kg of water. First, loosen it for 10 minutes, then beat it with a blade until the measured beatability is 28. o SR, wet weight 7g, with the blade shaker on, the pulp is placed in the mixing tank; take 35kg of hardwood dissolving pulp and put it into a trough-type pulper already filled with 1715kg of water, first loosen it for 10 minutes, then beat it with the blade until the measured beating degree is 32. o SR, wet weight 4g, with the blade on, the pulp is placed in the mixing tank; take 20kg of Tencel fiber and put it into a trough beater containing 647kg of water, first loosen for 10 minutes, then beat with a light blade until the measured freeness is 27. o SR, wet weight 13g, shake the knife and put the slurry into the mixing tank.

[0030] After the three types of slurry are prepared in the slurry mixing tank, add 0.1 kg of anionic polyacrylamide dispersant (pre-dissolved in water) and dilute with water to a total mass concentration of 0.1% of the fiber raw materials. Stir thoroughly until the slurry is evenly dispersed and then pump it into the intermediate slurry tank and the pre-papering slurry tank in sequence.

[0031] The above-mentioned pulp is fed to the pulp distributor of an inclined wire paper machine. After forming on the wire, dewatering, pressing, and the wet paper sheet is placed on the drying cylinder, a 0.5% (w / w) NP-10 penetrant aqueous solution is coated on the cylinder and dried. The paper is then wound onto the cylinder to produce a high-absorption-rate separator for zinc-silver batteries. The basis weight of this separator is 9.6 g / m³. 2 Thickness 0.31mm, alkali absorption rate 529%, alkali absorption rate 30mm / 3min, tensile strength (longitudinal) 0.09kN / m, surface resistivity 0.03Ω·cm 2 .

[0032] Example 5: The operation is the same as in Example 1, except that the three raw materials are pulped to different degrees of freeness (higher freeness), as detailed below: Take 45 kg of mercerized wood pulp and put it into a trough pulper containing 2205 kg of water. First, loosen it for 10 minutes, then beat it with a blade until the measured beatability is 48. o SR, wet weight 5g, with the blade shaker on, the pulp is placed in the mixing tank; take 35kg of hardwood dissolving pulp and put it into a trough-type pulper already filled with 1715kg of water, first loosen it for 10 minutes, then beat it with the blade until the measured beating degree is 49. o SR, wet weight 3g, with the blade on, the pulp is placed in the mixing tank; take 20kg of Tencel fiber and put it into a trough beater containing 647kg of water, first loosen for 10 minutes, then beat with a light blade until the measured freeness is 43. o SR, wet weight 10g, shake the knife and put the slurry into the mixing tank.

[0033] After the three types of slurry are prepared in the slurry mixing tank, add 0.1 kg of anionic polyacrylamide dispersant (pre-dissolved in water) and dilute with water to a total mass concentration of 0.1% of the fiber raw materials. Stir thoroughly until the slurry is evenly dispersed and then pump it into the intermediate slurry tank and the pre-papering slurry tank in sequence.

[0034] The above-mentioned pulp is fed to the pulp distributor of an inclined wire paper machine. After forming on the wire, dewatering, pressing, and the wet paper sheet is placed on the drying cylinder, a 0.5% (w / w) NP-10 penetrant aqueous solution is coated on the cylinder and dried. The paper is then wound onto the cylinder to produce a high-absorption-rate separator for zinc-silver batteries. The basis weight of this separator is 9.4 g / m³. 2 Thickness 0.28mm, alkali absorption rate 484%, alkali absorption rate 27mm / 3min, tensile strength (longitudinal) 0.21kN / m, surface resistivity 0.04Ω·cm 2 .

[0035] Example 6: The operation is the same as in Example 1, except that the wet weights of the three raw materials are different (lower wet weight), as detailed below: Take 45 kg of mercerized wood pulp and put it into a trough pulper containing 2205 kg of water. First, loosen it for 10 minutes, then beat it with a blade until the measured beatability is 30.o SR, wet weight 4g, with the blade shaker on, the pulp is placed in the mixing tank; take 35kg of hardwood dissolving pulp and put it into a trough-type pulper already filled with 1715kg of water, first loosen it for 10 minutes, then beat it with the blade until the measured beating degree is 45. o SR, wet weight 2g, with the blade on, the pulp is placed in the mixing tank; take 20kg of Tencel fiber and put it into a trough beater containing 647kg of water, first loosen for 10 minutes, then beat with a light blade until the measured freeness is 35. o SR, wet weight 7g, shake the knife and put the slurry into the mixing tank.

[0036] After the three types of slurry are prepared in the slurry mixing tank, add 0.1 kg of anionic polyacrylamide dispersant (pre-dissolved in water) and dilute with water to a total mass concentration of 0.1% of the fiber raw materials. Stir thoroughly until the slurry is evenly dispersed and then pump it into the intermediate slurry tank and the pre-papering slurry tank in sequence.

[0037] The above-mentioned pulp is fed to the pulp distributor of an inclined wire paper machine. After forming on the wire, dewatering, pressing, and the wet paper sheet is placed on the drying cylinder, a 0.5% (w / w) NP-10 penetrant aqueous solution is coated on the cylinder and dried. The paper is then wound onto the cylinder to produce a high-absorption-rate separator for zinc-silver batteries. The basis weight of this separator is 9.7 g / m³. 2 Thickness 0.30mm, alkali absorption rate 515%, alkali absorption rate 28mm / 3min, tensile strength (longitudinal) 0.11kN / m, surface resistivity 0.04Ω·cm 2 .

[0038] Example 7: The operation is the same as in Example 1, except that the pulping degree of the mercerized wood pulp, which accounts for the largest proportion, is different (lower beating degree). The rest remains the same, as follows: Take 45 kg of mercerized wood pulp and put it into a trough pulper containing 2205 kg of water. First, loosen it for 10 minutes, then beat it with a blade until the measured beatability is 26. o SR, wet weight 7g, with the blade on, the pulp is placed in the mixing tank; take 35kg of hardwood dissolving pulp and put it into a trough-type pulper already filled with 1715kg of water, first loosen it for 10 minutes, then beat it with the blade until the measured beating degree is 45. o SR, wet weight 3g, with the blade on, the pulp is placed in the mixing tank; take 20kg of Tencel fiber and put it into a trough beater containing 647kg of water, first loosen for 10 minutes, then beat with a light blade until the measured freeness is 36. o SR, wet weight 12g, shake the knife and put the slurry into the mixing tank.

[0039] After the three types of slurry are prepared in the slurry mixing tank, add 0.1 kg of anionic polyacrylamide dispersant (pre-dissolved in water) and dilute with water to a total mass concentration of 0.1% of the fiber raw materials. Stir thoroughly until the slurry is evenly dispersed and then pump it into the intermediate slurry tank and the pre-papering slurry tank in sequence.

[0040] The above-mentioned pulp is fed to the pulp distributor of an inclined wire paper machine. After forming on the wire, dewatering, pressing, and the wet paper sheet is placed on the drying cylinder, a 0.5% (w / w) NP-10 penetrant aqueous solution is coated on the cylinder and dried. The paper is then wound onto the cylinder to produce a high-absorption-rate separator for zinc-silver batteries. The separator has a basis weight of 9.5 g / m³. 2 Thickness 0.30mm, alkali absorption rate 528%, alkali absorption rate 30mm / 3min, tensile strength (longitudinal) 0.12kN / m, surface resistivity 0.03Ω·cm 2 .

[0041] Example 8: The operation is the same as in Example 1, except that the pulping degree of the mercerized wood pulp, which accounts for the largest proportion, is different (higher beating degree). The rest remains the same, as follows: Take 45 kg of mercerized wood pulp and put it into a trough pulper containing 2205 kg of water. First, loosen it for 10 minutes, then beat it with a blade until the measured beatability is 49. o SR, wet weight 5g, with the blade shaken, the pulp is placed in the mixing tank; take 35kg of hardwood dissolving pulp and put it into a trough-type pulper already filled with 1715kg of water, first loosen it for 10 minutes, then beat it with the blade until the measured beating degree is 45. o SR, wet weight 3g, with the blade on, the pulp is placed in the mixing tank; take 20kg of Tencel fiber and put it into a trough beater containing 647kg of water, first loosen for 10 minutes, then beat with a light blade until the measured freeness is 36. o SR, wet weight 12g, shake the knife and put the slurry into the mixing tank.

[0042] After the three types of slurry are prepared in the slurry mixing tank, add 0.1 kg of anionic polyacrylamide dispersant (pre-dissolved in water) and dilute with water to a total mass concentration of 0.1% of the fiber raw materials. Stir thoroughly until the slurry is evenly dispersed and then pump it into the intermediate slurry tank and the pre-papering slurry tank in sequence.

[0043] The above-mentioned pulp is fed to the pulp distributor of an inclined wire paper machine. After forming on the wire, dewatering, pressing, and the wet paper sheet is placed on the drying cylinder, a 0.5% (w / w) NP-10 penetrant aqueous solution is coated on the cylinder and dried. The paper is then wound onto the cylinder to produce a high-absorption-rate separator for zinc-silver batteries. The basis weight of this separator is 10.5 g / m³. 2 Thickness 0.32mm, alkali absorption rate 496%, alkali absorption rate 28mm / 3min, tensile strength (longitudinal) 0.18kN / m, surface resistivity 0.04Ω·cm 2 .

[0044] Example 9: The operation is the same as in Example 1, except that the mercerized wood pulp, which accounts for the largest proportion, is pulped to a low wet weight, while the rest remains unchanged, as follows: Take 45 kg of mercerized wood pulp and put it into a trough pulper containing 2205 kg of water. First, loosen it for 10 minutes, then beat it with a blade until the measured beatability is 31. o SR, wet weight 3g, with the blade shaker on, the pulp is placed in the mixing tank; take 35kg of hardwood dissolving pulp and put it into a trough-type pulper already filled with 1715kg of water, first loosen it for 10 minutes, then beat it with the blade until the measured beating degree is 45. o SR, wet weight 3g, with the blade on, the pulp is placed in the mixing tank; take 20kg of Tencel fiber and put it into a trough beater containing 647kg of water, first loosen for 10 minutes, then beat with a light blade until the measured freeness is 36. o SR, wet weight 12g, shake the knife and put the slurry into the mixing tank.

[0045] After the three types of slurry are prepared in the slurry mixing tank, add 0.1 kg of anionic polyacrylamide dispersant (pre-dissolved in water) and dilute with water to a total mass concentration of 0.1% of the fiber raw materials. Stir thoroughly until the slurry is evenly dispersed and then pump it into the intermediate slurry tank and the pre-papering slurry tank in sequence.

[0046] The above-mentioned pulp is fed to the pulp distributor of an inclined wire paper machine. After forming on the wire, dewatering, pressing, and the wet paper sheet is placed on the drying cylinder, a 0.5% (w / w) NP-10 penetrant aqueous solution is coated on the cylinder and dried. The paper is then wound onto the cylinder to produce a high-absorption-rate separator for zinc-silver batteries. The basis weight of this separator is 10.1 g / m³. 2 Thickness 0.33mm, alkali absorption rate 533%, alkali absorption rate 30mm / 3min, tensile strength (longitudinal) 0.12kN / m, surface resistivity 0.03Ω·cm 2 .

[0047] Example 10: The operation is the same as in Example 1, except that the wet weight of Tencel fibers is lower, as detailed below: Take 45 kg of mercerized wood pulp and put it into a trough pulper containing 2205 kg of water. First, loosen it for 10 minutes, then beat it with a blade until the measured beatability is 31. o SR, wet weight 7g, with the blade on, the pulp is placed in the mixing tank; take 35kg of hardwood dissolving pulp and put it into a trough-type pulper already filled with 1715kg of water, first loosen it for 10 minutes, then beat it with the blade until the measured beating degree is 45. o SR, wet weight 3g, with the blade on, the pulp is placed in the mixing tank; take 20kg of Tencel fiber and put it into a trough beater containing 647kg of water, first loosen for 10 minutes, then beat with a light blade until the measured freeness is 37. oSR, wet weight 7g, shake the knife and put the slurry into the mixing tank.

[0048] After the three types of slurry are prepared in the slurry mixing tank, add 0.1 kg of anionic polyacrylamide dispersant (pre-dissolved in water) and dilute with water to a total mass concentration of 0.1% of the fiber raw materials. Stir thoroughly until the slurry is evenly dispersed and then pump it into the intermediate slurry tank and the pre-papering slurry tank in sequence.

[0049] The above-mentioned pulp is fed to the pulp distributor of an inclined wire paper machine. After forming on the wire, dewatering, pressing, and the wet paper sheet is placed on the drying cylinder, a 0.5% (w / w) NP-10 penetrant aqueous solution is coated on the cylinder and dried. The paper is then wound onto the cylinder to produce a high-absorption-rate separator for zinc-silver batteries. The basis weight of this separator is 9.9 g / m³. 2 Thickness 0.31mm, alkali absorption rate 513%, alkali absorption rate 29mm / 3min, tensile strength (longitudinal) 0.11kN / m, surface resistivity 0.03Ω·cm 2 .

[0050] Example 11: The operation is the same as in Example 1, except that the mass proportions of the three raw materials are different (the proportion of Tencel is reduced), as detailed below: Take 48 kg of mercerized wood pulp and put it into a trough pulper containing 2352 kg of water. First, loosen it for 10 minutes, then beat it with a blade until the measured beatability is 30. o SR, wet weight 7g, with the blade shaker on, the pulp is placed in the mixing tank; take 37kg of hardwood dissolving pulp and put it into a trough-type pulper already filled with 1813kg of water, first loosen it for 10 minutes, then beat it with the blade until the measured beating degree is 44. o SR, wet weight 3g, with the blade on, the pulp is placed in the mixing tank; take 15kg of Tencel fiber and put it into a trough beater containing 485kg of water, first loosen for 10 minutes, then beat with a light blade until the measured beating degree is 37. o SR, wet weight 13g, shake the knife and put the slurry into the mixing tank.

[0051] After the three types of slurry are prepared in the slurry mixing tank, add 0.1 kg of anionic polyacrylamide dispersant (pre-dissolved in water) and dilute with water to a total mass concentration of 0.1% of the fiber raw materials. Stir thoroughly until the slurry is evenly dispersed and then pump it into the intermediate slurry tank and the pre-papering slurry tank in sequence.

[0052] The above-mentioned pulp is fed to the pulp distributor of an inclined wire paper machine. After forming on the wire, dewatering, pressing, and the wet paper sheet is placed on the drying cylinder, a 0.5% (w / w) NP-10 penetrant aqueous solution is coated on the cylinder and dried. The paper is then wound onto the cylinder to produce a high-absorption-rate separator for zinc-silver batteries. The basis weight of this separator is 10.1 g / m³. 2Thickness 0.32mm, alkali absorption rate 491%, alkali absorption rate 29mm / 3min, tensile strength (longitudinal) 0.12kN / m, surface resistivity 0.03Ω·cm 2 .

[0053] Example 12: The procedure is the same as in Example 1, except that no penetrant is applied, as follows: Take 45 kg of mercerized wood pulp and put it into a trough pulper containing 2205 kg of water. First, loosen it for 10 minutes, then beat it with a blade until the measured beatability is 32. o SR, wet weight 7g, with the blade shaker on, the pulp is placed in the mixing tank; take 35kg of hardwood dissolving pulp and put it into a trough-type pulper already filled with 1715kg of water, first loosen it for 10 minutes, then beat it with the blade until the measured beating degree is 44. o SR, wet weight 3g, with the blade on, the pulp is placed in the mixing tank; take 20kg of Tencel fiber and put it into a trough beater containing 647kg of water, first loosen for 10 minutes, then beat with a light blade until the measured freeness is 35. o SR, wet weight 13g, shake the knife and put the slurry into the mixing tank.

[0054] After the three types of slurry are prepared in the slurry mixing tank, add 0.1 kg of anionic polyacrylamide dispersant (pre-dissolved in water) and dilute with water to a total mass concentration of 0.1% of the fiber raw materials. Stir thoroughly until the slurry is evenly dispersed and then pump it into the intermediate slurry tank and the pre-papering slurry tank in sequence.

[0055] The above-mentioned pulp is fed to the pulp distributor of an inclined wire paper machine, where it undergoes web forming, dewatering, pressing, drying in the drying cylinder, and then being wound onto the cylinder to produce a high-absorption-rate separator for zinc-silver batteries. This separator has a basis weight of 9.8 g / m³. 2 Thickness 0.30mm, alkali absorption rate 523%, alkali absorption rate 16mm / 3min, tensile strength (longitudinal) 0.15kN / m, surface resistivity 0.03Ω·cm 2 .

Claims

1. A high liquid absorption rate separator for zinc-silver batteries, characterized in that... Its quantitative value is 10.0±1.0 g / m³. 2 Thickness 0.32±0.05mm, alkali absorption rate ≥500%, alkali absorption speed ≥28mm / 3min, tensile strength (longitudinal) ≥0.13kN / m, surface resistivity ≤0.04Ω·cm 2 .

2. The high liquid absorption rate separator for zinc-silver batteries according to claim 1, characterized in that... Its raw materials include the following components in parts by weight: 45-55 parts mercerized wood pulp, 25-35 parts hardwood dissolving pulp, and 20 parts Tencel fiber.

3. The high liquid absorption rate separator for zinc-silver batteries according to claim 1, characterized in that... Mercerized wood pulp is pulped to a beater ratio of 30. o SR~45 o SR, wet weight is 5g~7g.

4. The high liquid absorption rate separator for zinc-silver batteries according to claim 1, characterized in that... Hardwood dissolving pulp is pulped using a trough pulper to a beatness of 35. o SR~45 o SR, wet weight is 3g~5g.

5. The high liquid absorption rate separator for zinc-silver batteries according to claim 1, characterized in that... Tencel fiber is lightly beaten with a trough beater to a freeness of 30. o SR~40 o SR, wet weight is 10g~14g.

6. The high liquid absorption rate separator for zinc-silver batteries according to any one of claims 1-5, characterized in that... The crystallinity of mercerized wood pulp is ≥0.58, and the α-cellulose content in hardwood dissolving pulp is ≥93%.

7. The high liquid absorption rate separator for zinc-silver batteries according to any one of claims 1-5, characterized in that... Tencel fiber is an uncrosslinked Tencel fiber with a single filament fineness of 1.1 dtex and a fiber length of 6 mm.

8. The method for preparing a high liquid absorption rate separator for zinc-silver batteries according to claim 1, characterized in that... Includes the following steps: 1) Take 45-55 parts by weight of mercerized wood pulp and put it into a trough pulper. Add water to adjust the mercerized wood pulp concentration to 2%-3%. Beat the pulp until the freeness of the pulp is 30. o SR~45 o SR, with a wet weight of 5g~7g, is placed in the pulp mixing tank; 2) Take 25-35 parts by weight of hardwood dissolving pulp, put it into a trough pulper, add water to adjust the hardwood dissolving pulp concentration to 2%-3%, and beat with a blade until the pulp has a freeness of 35. o SR~45 o SR, with a wet weight of 3g~5g, is placed in the mixing tank of step 1); 3) Take 20 parts by weight of Tencel fiber, put it into a trough pulper, add water to adjust the Tencel fiber concentration to 3%, and beat with a light knife until the pulp freeness is 30. o SR~40 o SR, with a wet weight of 10g~14g, is placed in the mixing tank of step 1); 4) Add 0.1%~0.2% of the total mass of oven-dried fiber raw materials as dispersant to the slurry mixing tank, and dilute with water to a total mass concentration of 0.1%~0.2% for all fiber raw materials. Stir thoroughly until the slurry is evenly dispersed, and pump it into the intermediate slurry tank and the pre-slurry tank for storage in sequence. 5) The pulp prepared in step 4) is transported from the pre-papermaking pulp tank to the pulp distributor of the inclined wire paper machine. After being formed on the wire, dewatered, pressed, and the wet paper is placed on the drying cylinder, a penetrating agent is applied to the cylinder and dried before the paper is rolled onto the cylinder to produce a high liquid absorption rate separator for zinc-silver batteries.

9. A high liquid absorption rate separator for zinc-silver batteries according to claim 8 and its preparation method, characterized in that... The dispersant mentioned in step 4) is either anionic polyacrylamide or polyethylene oxide.

10. A high liquid absorption rate separator for zinc-silver batteries according to claim 8 and its preparation method, characterized in that... The penetrant mentioned in step 5) is a 0.5% (w / w) aqueous solution of nonylphenol polyoxyethylene ether (NP-10), and the amount of penetrant retained in the finished membrane after coating is 0.5‰~1.0‰.