Long-lasting humidity control material for battery pack and method for manufacturing the same

Abstract

The present invention relates to the field of humidity control materials. The present invention discloses a long-lasting humidity control material for battery packs, which includes an upper sealing layer, a humidity control layer and a lower sealing layer, and a manufacturing method thereof, the humidity control layer is made of polyester as a base material and is coated with a modified humidity control polymer, so that the humidity control material can effectively control the humidity in the battery pack of a vehicle over a long distance, thereby avoiding the phenomenon of "condensation" occurring in the battery pack, and improving the safety and reliability of driving new energy vehicles.

Description

Technical Field

[0001] (Cross - reference to related applications) This application claims the priority of Chinese Patent Application No. 202210839791.1, filed in China on July 18, 2022, and the entire content thereof is incorporated herein by reference.

[0002] The present invention relates to the field of humidity - regulating materials, and particularly to a long - lasting humidity - regulating material for battery packs and a method for manufacturing the same.

Background Art

[0003] Conventional humidity - regulating materials mainly include natural humidity - regulating materials, organic polymer humidity - regulating materials, inorganic mineral humidity - regulating materials, etc. Among these, natural and inorganic mineral humidity - regulating materials have unstable hygroscopicity and moisture - releasing properties, low humidity - regulating effects, while the production of organic polymer humidity - regulating materials is complex, costly, and not easy to scale up. Moreover, conventional humidity - regulating materials mainly use the hygroscopicity of materials as the main evaluation index, lacking an effective control method for the stable release of absorbed moisture. Some products release toxic and harmful substances such as formaldehyde during use, which is likely to cause environmental pollution.

[0004] On the other hand, HCCF is an environmentally friendly material obtained by mixing a microporous polymer water - absorbent polymer with a fiber material. Different from conventional granular or powdery desiccant products, HCCF can automatically achieve "bidirectional" reversible moisture absorption and release in a relatively sealed environment, efficiently control the humidity in the environment, and suppress the occurrence of fog and dew. Using its unique moisture - absorbing fiber skeleton as a water transport pipe, the reversible bidirectionality of moisture absorption and release of HCCF can be ensured by the water storage pool effect formed by the combination with the microporous material.

[0005] Generally, when the air humidity in the environment is relatively high, if the vehicle stops and the temperature inside the vehicle body drops rapidly, or the in-vehicle cooling system is turned on, either of these will cause "condensation" inside the battery pack of new energy vehicles. However, considering that most of the components inside the battery pack are charged components, the occurrence of "condensation" extremely increases the risk level of electrical short circuits. In severe cases, it may cause the battery to catch fire or lead to an "explosion" accident. When the air humidity in the environment is low, even when the battery pack operates under high-temperature and dry conditions for a long time, the risk probability of thermal runaway increases. Therefore, HCCF is applied to control the humidity change inside the battery pack, prevent the occurrence of "condensation", and has a promising market outlook. However, the humidity regulation range of conventional HCCF is limited, and how to achieve long-distance and long-time humidity regulation is one of the technical problems that HCCF needs to urgently solve.

Summary of the Invention

Problems to be Solved by the Invention

[0006] The present invention addresses the technical problem that it is difficult to achieve long-distance and long-time humidity regulation for conventional HCCF materials, and provides a long-time sustainable humidity regulating material for battery packs and its manufacturing method to solve the conventional technical problems.

Means for Solving the Problems

[0007] The present invention solves the above technical problems by the following technical solutions.

[0008] A long-time sustainable humidity regulating material for battery packs, comprising an upper sealing layer, a humidity regulating layer, and a lower sealing layer.

[0009] Furthermore, the upper sealing layer is a waterproof and breathable film layer, and the waterproof and breathable film layer is a hydrophobic swelling polytetrafluoroethylene film.

[0010] Furthermore, the humidity regulating layer is composed of 1 to 5 humidity regulating sheets, the humidity regulating sheet is composed of a base material and a modified humidity regulating polymer coating layer, and the base material is polyester.

[0011] Furthermore, the modified humidity conditioning polymer coating layer is manufactured from raw materials including 3 to 10 parts by weight of a modified superabsorbent polymer, 15 to 25 parts by weight of a potassium salt, 5 to 10 parts by weight of a chloride salt, and 30 to 50 parts by weight of a solvent.

[0012] Furthermore, the potassium salt is one or more selected from potassium carbonate and potassium bromide.

[0013] Furthermore, the chloride salt is one or more selected from sodium chloride, magnesium chloride, and calcium chloride.

[0014] Furthermore, the solvent is one or more selected from deionized water and ethylene glycol.

[0015] Furthermore, the thickness of the upper sealing layer is 0.05 to 0.3 mm, the thickness of a single-layer humidity conditioning sheet in the humidity conditioning layer is 0.5 to 2.0 mm, and the thickness of the lower sealing layer is 0.1 to 0.3 mm.

[0016] Furthermore, the lower sealing layer is selected from PET, COP, PES, or PI.

[0017] It is a manufacturing method of a long-duration humidity conditioning material for a battery pack including the following steps.

[0018] Step 1: According to parts by weight, 15 to 25 parts by weight of a potassium salt and 5 to 10 parts by weight of a chloride salt are dissolved in 30 to 50 parts by weight of a solvent, and then 3 to 10 parts of a modified superabsorbent polymer are immersed in the above solution and swollen for 4 to 8 h to uniformly coat the polymer surface with the salt.

[0019] Step 2: A substrate is immersed and coated with the above mixture, taken out after 5 to 20 s, and dried at a temperature of 75 to 95°C for 5 to 15 min to manufacture a humidity conditioning sheet.

[0020] Step 3: The humidity conditioning sheet is processed into a sheet material of a certain size by die cutting.

[0021] Step 4: Stack the upper sealing layer, the humidity-adjusting sheet, and the lower sealing layer in sequence, laminate the upper sealing layer and the lower sealing layer using a hot pressing process to manufacture a long-lasting humidity-adjusting material for a battery pack.

[0022] Furthermore, it is a method for manufacturing the modified superabsorbent polymer, characterized by including the following steps.

[0023] S1: According to parts by weight, add 100 - 200 parts of a solvent to a reaction vessel made of glass or polytetrafluoroethylene under a nitrogen atmosphere, then add 17 - 25 parts of acrylamide, 1 - 5 parts of methoxypolyethylene glycol maleimide, 2 - 5 parts of a catalyst, and further add 30 - 45 parts of compound A. Stir at a temperature of 40 - 60 °C for 20 - 40 h, and cool the reaction system to room temperature.

[0024] S2: Add 5 - 10 parts of 1,3-(divinylsulfonyl)propanol, 0.05 - 0.5 parts of vinylferrocene, and 1 - 3 parts of benzoyl peroxide. Stir at a temperature of 60 - 70 °C for 3 - 8 h, filter under reduced pressure, wash with water and methanol, and vacuum dry the solid product at a temperature of 30 - 80 °C for 6 - 12 h to obtain a modified superabsorbent polymer.

[0025] Furthermore, the above solvent is one or more of ethanol, dimethyl sulfoxide, tetrahydrofuran, acetone, or N,N-dimethylformamide.

[0026] Furthermore, the above catalyst is one or more of triphenylphosphine (PPh3), triethylamine, or dipropylamine.

[0027] Furthermore, the above-mentioned Compound A is selected from ethylene glycol di(3-mercaptopropionate) (GDMP), pentaerythritol tetra(3-mercaptopropionate) (PETMP), pentaerythritol tetramercaptoacetate (PETMA), dipentaerythritol tetra(3-mercaptopropionate), dipentaerythritol tetramercaptoacetate, dipentaerythritol penta(3-mercaptopropionate), dipentaerythritol pentamercaptoacetate, dipentaerythritol hexa(3-mercaptopropionate).

[0028] Furthermore, the above-mentioned long-term continuous humidity control material for battery packs has a humidity control accuracy of ≤5% and a saturation moisture absorption rate of ≥200% within the humidity control range.

[0029] The present invention has the following technical advantages compared with the prior art. 1. The humidity control material manufactured according to the present invention has a modified superabsorbent polymer therein having a spatial network structure and a large amount of hydrophilic groups. Therefore, the superabsorbent polymer has excellent porosity and the ability to absorb moisture over a long period of time. 2. In the present invention, after dissolving potassium salt and chloride salt in a solvent to form a solution, the solvated ions occupy a part of the area and can confine some water molecules, inhibiting their evaporation and absorption, and improving the humidity control performance of the humidity control material.

Brief Description of the Drawings

[0030] To more clearly explain the technical solutions in the embodiments of the present invention or the prior art, the following drawings necessary for the description of the embodiments or the prior art are considered. Obviously, the technical solutions described in conjunction with the drawings are only a part of the embodiments of the present invention. For those skilled in the art, based on the embodiments shown in these drawings, other embodiments and their drawings can be obtained without creative effort.

Figure 1

Figure 2

Embodiments for Carrying Out the Invention

[0031] Hereinafter, in conjunction with the drawings, the technical solutions in each embodiment of the present invention will be described clearly and completely. Obviously, the described embodiments are only a part of the embodiments of the present invention, not all of them. Based on the embodiments described in the present invention, all other embodiments made by those skilled in the art without creative efforts are included within the scope of the claims of the present invention.

[0032] It should be noted that in order to comparatively explain the humidity control performance of the long-duration humidity control material for battery packs, hereinafter, the long-duration humidity control materials for battery packs manufactured in the comparative examples and examples have the same thickness for their upper sealing layer, humidity control layer, and lower sealing layer. Among them, the thickness of the upper sealing layer is 0.13 mm, the thickness of each humidity control sheet in the humidity control layer is 1.1 mm, and the thickness of the lower sealing layer is 0.12 mm.

[0033] [Comparative Example 1] A long-duration humidity control material for battery packs including an upper sealing layer, a humidity control layer, and a lower sealing layer, wherein the upper sealing layer is a waterproof breathable film layer, specifically a hydrophobic swollen polytetrafluoroethylene film, and the humidity control layer is composed of three layers of humidity control sheets, specifically composed of a base material and a modified humidity control polymer coating layer, and the base material is polyester.

[0034] The manufacturing method of the above long-duration humidity control material for battery packs includes the following steps.

[0035] Step 1: 3 kg of modified superabsorbent polymer was immersed in 30 kg of ethylene glycol and swollen for 4 h. Step 2: The base material was immersed and coated with the above mixture, taken out after 5 s, and dried at a temperature of 75 °C for 15 min to produce a humidity control sheet. Step 3: The humidity control sheet was processed into a sheet material of a certain size by die cutting. Step 4: The upper sealing layer, the humidity control sheet, and the lower sealing layer were stacked in order, and the upper sealing layer and the lower sealing layer were laminated using a hot pressure welding process to manufacture a long-lasting humidity control material for a battery pack.

[0036] The method for manufacturing the modified superabsorbent polymer includes the following steps. S1: 100 kg of a solvent was added to a glass reaction vessel under a nitrogen atmosphere. Next, 17 kg of acrylamide, 1 kg of methoxypolyethylene glycol maleimide, and 2 kg of a catalyst were added, and then 30 kg of compound A was added. The mixture was stirred at 40 °C for 20 h, and the reaction system was cooled to room temperature.

[0037] S2: 5 kg of 1,3-(divinylsulfonyl)propanol, 0.05 kg of vinylferrocene, and 1 kg of benzoyl peroxide were added. The mixture was stirred at 60 °C for 3 h, filtered under reduced pressure, washed with water and methanol, and the solid product was vacuum dried at 30 °C for 6 h to obtain a modified superabsorbent polymer.

[0038] The solvent is ethanol.

[0039] The catalyst is triphenylphosphine (PPh3).

[0040] Compound A is ethylene glycol bis(3-mercaptopropionate) (GDMP).

[0041] The lower sealing layer is selected from PET.

Example

[0042] A long-lasting humidity control material for a battery pack including an upper sealing layer, a humidity control layer, and a lower sealing layer. As shown in Figure 2, the upper sealing layer is a waterproof breathable film layer, specifically a hydrophobic swollen polytetrafluoroethylene film. The humidity control layer consists of three layers of humidity control sheets, specifically consisting of a base material and a modified humidity control polymer coating layer, and the base material is polyester.

[0043] The manufacturing method of the long-lasting humidity control material for the above battery pack includes the following steps. Step 1: Dissolve 15 kg of potassium salt and 5 kg of chloride salt in 30 kg of ethylene glycol. Next, immerse 3 kg of the modified superabsorbent polymer in the above solution and let it swell for 4 h to uniformly coat the polymer surface with salt.

[0044] Step 2: Immerse and coat the substrate with the above mixture, take it out after 5 s, and dry it at a temperature of 75 °C for 15 min to produce a humidity control sheet.

[0045] Step 3: Process the humidity control sheet into a sheet material of a certain size by die cutting.

[0046] Step 4: Stack the upper sealing layer, the humidity control sheet, and the lower sealing layer in sequence, and use a hot pressure welding process to laminate the upper sealing layer and the lower sealing layer to manufacture a long-lasting humidity control material for the battery pack.

[0047] The manufacturing method of the above modified superabsorbent polymer includes the following steps.

[0048] S1: Add 100 kg of solvent to a glass reaction vessel under a nitrogen atmosphere. Next, add 17 kg of acrylamide, 1 kg of methoxypolyethylene glycol maleimide, and 2 kg of catalyst, and further add 30 kg of compound A. Stir at a temperature of 40 °C for 20 h, and cool the reaction system to room temperature.

[0049] S2: Add 5 kg of 1,3-(divinylsulfonyl)propanol, 0.05 kg of vinylferrocene, and 1 kg of benzoyl peroxide. Stir at a temperature of 60 °C for 3 h, filter under reduced pressure, wash with water and methanol, and vacuum dry the solid product at a temperature of 30 °C for 6 h to obtain the modified superabsorbent polymer.

[0050] The solvent is ethanol.

[0051] The catalyst is triphenylphosphine (PPh3).

[0052] Compound A was selected from ethylene glycol bis(3-mercaptopropionate) (GDMP).

[0053] The potassium salt was selected from potassium carbonate, and the chloride salt was selected from sodium chloride.

[0054] The lower sealing layer was selected from PET.

Examples

[0055] A long-lasting humidity control material for a battery pack including an upper sealing layer, a humidity control layer, and a lower sealing layer, wherein the upper sealing layer is a waterproof and breathable film layer, specifically a hydrophobic swelling body polytetrafluoroethylene film, the humidity control layer is composed of three humidity control sheets, specifically composed of a base material and a modified humidity control polymer coating layer, and the base material is polyester.

[0056] The manufacturing method of the above long-lasting humidity control material for a battery pack includes the following steps.

[0057] Step 1: Dissolve 15 kg of potassium salt and 6 kg of chloride salt in 30 kg of deionized water. Next, immerse 5 kg of modified superabsorbent polymer in the above solution and swell it for 5 h to uniformly coat the polymer surface with salt.

[0058] Step 2: Immerse and coat the base material in the above mixture, take it out after 9 s, and dry it at a temperature of 85 °C for 10 min to produce a humidity control sheet.

[0059] Step 3: Process the humidity control sheet into a sheet material of a certain size by die cutting.

[0060] Step 4: Stack the upper sealing layer, the humidity control sheet, and the lower sealing layer in sequence, and use a hot pressing process to laminate the upper sealing layer and the lower sealing layer to produce a long-lasting humidity control material for a battery pack.

[0061] The manufacturing method of the above modified superabsorbent polymer includes the following steps.

[0062] S1: Add 120 kg of a solvent to a glass reaction vessel under a nitrogen atmosphere. Next, add 19 kg of acrylamide, 2 kg of methoxypolyethylene glycol maleimide, and 3 kg of a catalyst. Further add 34 kg of compound A and stir for 25 h at a temperature of 40 °C. Cool the reaction system to room temperature.

[0063] S2: Add 6 kg of 1,3-(divinylsulfonyl)propanol, 0.1 kg of vinylferrocene, and 1 kg of benzoyl peroxide. Stir for 5 h at a temperature of 60 °C, filter under reduced pressure, wash with water and methanol, and vacuum dry the solid product for 8 h at a temperature of 30 °C to obtain a modified superabsorbent polymer.

[0064] The solvent is dimethyl sulfoxide.

[0065] The catalyst is triethylamine.

[0066] Compound A is selected from pentaerythritol tetra(3-mercaptopropionate) (PETMP).

[0067] The potassium salt is selected from potassium carbonate, and the chloride salt is selected from calcium chloride.

[0068] The lower sealing layer is selected from PET.

Example

[0069] A long-lasting humidity control material for a battery pack including an upper sealing layer, a humidity control layer, and a lower sealing layer, wherein the upper sealing layer is a waterproof breathable film layer, specifically a hydrophobic swelling body polytetrafluoroethylene film, the humidity control layer is composed of three humidity control sheets, specifically composed of a base material and a modified humidity control polymer coating layer, and the base material is polyester.

[0070] The manufacturing method of the above long-lasting humidity control material for a battery pack includes the following steps.

[0071] Step 1: Dissolve 20 kg of potassium salt and 6 kg of chloride salt in 40 kg of ethylene glycol. Next, immerse 6 kg of the modified superabsorbent polymer in the above solution and let it swell for 6 h, and uniformly coat the polymer surface with salt.

[0072] Step 2: Immerse and coat the substrate with the above mixture, take it out after 12 s, and dry it at a temperature of 85 °C for 10 min to produce a humidity conditioning sheet.

[0073] Step 3: Process the humidity conditioning sheet into a sheet material of a certain size by die cutting.

[0074] Step 4: Stack the upper sealing layer, the humidity conditioning sheet, and the lower sealing layer in sequence, and laminate the upper sealing layer and the lower sealing layer using a hot pressure bonding process to produce a long-lasting humidity conditioning material for a battery pack.

[0075] The manufacturing method of the above modified superabsorbent polymer includes the following steps.

[0076] S1: Add 150 kg of a solvent to a glass reaction vessel under a nitrogen atmosphere. Next, add 21 kg of acrylamide, 3 kg of methoxypolyethylene glycol maleimide, and 3 kg of a catalyst, and further add 36 kg of compound A. Stir at a temperature of 45 °C for 26 h, and cool the reaction system to room temperature.

[0077] S2: Add 7 kg of 1,3-(divinylsulfonyl)propanol, 0.2 kg of vinylferrocene, and 2 kg of benzoyl peroxide. Stir at a temperature of 65 °C for 6 h, filter under reduced pressure, wash with water and methanol, and vacuum dry the solid product at a temperature of 45 °C for 8 h to obtain a modified superabsorbent polymer.

[0078] The solvent is tetrahydrofuran.

[0079] The catalyst is dipropylamine.

[0080] Compound A is selected from pentaerythritol tetramercaptoacetate (PETMA).

[0081] The potassium salt was selected from potassium bromide, and the chloride salt was selected from sodium chloride.

[0082] The lower sealing layer was selected from COP.

Examples

[0083] A long-lasting humidity control material for a battery pack including an upper sealing layer, a humidity control layer, and a lower sealing layer, wherein the upper sealing layer is a waterproof breathable film layer, a hydrophobic swelling body polytetrafluoroethylene film, the humidity control layer is composed of three humidity control sheets, the humidity control sheet is composed of a base material and a modified humidity control polymer coating layer, and the base material is polyester.

[0084] The manufacturing method of the above long-lasting humidity control material for a battery pack includes the following steps.

[0085] Step 1: 20 kg of potassium salt and 8 kg of chloride salt were dissolved in 40 kg of deionized water. Next, 8 kg of modified superabsorbent polymer was immersed in the above solution and swollen for 6 h to uniformly coat the polymer surface with salt.

[0086] Step 2: The base material was immersed and coated with the above mixture and taken out after 18 s, and dried at a temperature of 85 °C for 15 min to produce a humidity control sheet.

[0087] Step 3: The humidity control sheet was processed into a sheet material of a certain size by die cutting.

[0088] Step 4: The upper sealing layer, the humidity control sheet, and the lower sealing layer were stacked in order, and the upper sealing layer and the lower sealing layer were laminated using a hot pressing process to produce a long-lasting humidity control material for a battery pack.

[0089] The manufacturing method of the above modified superabsorbent polymer includes the following steps.

[0090] S1: Add 160 kg of a solvent to a glass reaction vessel under a nitrogen atmosphere. Next, add 21 kg of acrylamide, 4 kg of methoxypolyethylene glycol maleimide, and 4 kg of a catalyst. Then, add 40 kg of Compound A and stir for 25 h at a temperature of 50 °C. Cool the reaction system to room temperature.

[0091] S2: Add 8 kg of 1,3-(divinylsulfonyl)propanol, 0.4 kg of vinylferrocene, and 3 kg of benzoyl peroxide. Stir for 4 h at a temperature of 70 °C, filter under reduced pressure, wash with water and methanol, and vacuum dry the solid product for 6 h at a temperature of 80 °C to obtain a modified superabsorbent polymer.

[0092] The solvent is acetone.

[0093] The catalyst is triphenylphosphine (PPh3).

[0094] Compound A is selected from dipentaerythritol hexa(3-mercaptopropionate).

[0095] The potassium salt is selected from potassium carbonate, and the chloride salt is selected from magnesium chloride.

[0096] The lower sealing layer is selected from PES.

Example

[0097] A long-lasting humidity control material for a battery pack including an upper sealing layer, a humidity control layer, and a lower sealing layer. The upper sealing layer is a waterproof breathable film layer, specifically a hydrophobic swelling body polytetrafluoroethylene film. The humidity control layer is composed of 5 humidity control sheets, specifically composed of a base material and a modified humidity control polymer coating layer. The base material is polyester.

[0098] The manufacturing method of the above long-lasting humidity control material for a battery pack includes the following steps.

[0099] Step 1: 25 kg of potassium salt and 8 kg of chloride salt were dissolved in 50 kg of ethylene glycol. Next, 9 kg of modified superabsorbent polymer was immersed in the above solution and swollen for 7 h, and the polymer surface was uniformly coated with salt.

[0100] Step 2: The substrate was immersed and coated with the above mixture and taken out after 20 s, and dried at a temperature of 95 °C for 5 min to produce a humidity conditioning sheet.

[0101] Step 3: The humidity conditioning sheet was processed into a sheet material of a certain size by die cutting.

[0102] Step 4: The upper sealing layer, the humidity conditioning sheet and the lower sealing layer were stacked in sequence, and the upper sealing layer and the lower sealing layer were laminated using a hot press process to produce a long-lasting humidity conditioning material for battery packs.

[0103] The manufacturing method of the above modified superabsorbent polymer includes the following steps.

[0104] S1: 180 kg of solvent was added to a glass reaction vessel under a nitrogen atmosphere. Next, 24 kg of acrylamide, 5 kg of methoxypolyethylene glycol maleimide, and 5 kg of catalyst were added, and further 42 kg of compound A was added. The mixture was stirred at 60 °C for 35 h, and the reaction system was cooled to room temperature.

[0105] S2: 9 kg of 1,3-(divinylsulfonyl)propanol, 0.4 kg of vinylferrocene, and 3 kg of benzoyl peroxide were added. The mixture was stirred at 70 °C for 5 h, filtered under reduced pressure, washed with water and methanol, and the solid product was vacuum dried at 80 °C for 8 h to obtain a modified superabsorbent polymer.

[0106] The solvent is N,N-dimethylformamide.

[0107] The catalyst is triethylamine.

[0108] Compound A is selected from dipentaerythritol penta(3-mercaptopropionate).

[0109] The potassium salt was selected from potassium bromide, and the chloride salt was selected from magnesium chloride.

[0110] The lower sealing layer was selected from PI.

Examples

[0111] A long-lasting humidity control material for a battery pack including an upper sealing layer, a humidity control layer, and a lower sealing layer, wherein the upper sealing layer is a waterproof breathable film layer, specifically a hydrophobic swollen body polytetrafluoroethylene film, the humidity control layer is composed of 5 humidity control sheets, specifically composed of a base material and a modified humidity control polymer coating layer, and the base material is polyester.

[0112] The manufacturing method of the above long-lasting humidity control material for a battery pack includes the following steps.

[0113] Step 1: 25 kg of potassium salt and 10 kg of chloride salt were dissolved in 50 kg of deionized water. Next, 10 kg of a modified superabsorbent polymer was immersed in the above solution and swollen for 8 h to uniformly coat the polymer surface with salt.

[0114] Step 2: The base material was immersed and coated with the above mixture, taken out after 20 s, and dried at a temperature of 95 °C for 15 min to produce a humidity control sheet.

[0115] Step 3: The humidity control sheet was processed into a sheet material of a certain size by die cutting.

[0116] Step 4: The upper sealing layer, the humidity control sheet, and the lower sealing layer were stacked in order, and the upper sealing layer and the lower sealing layer were laminated using a hot press process to manufacture a long-lasting humidity control material for a battery pack.

[0117] The manufacturing method of the above modified superabsorbent polymer includes the following steps.

[0118] S1: Add 200 kg of solvent to a glass reaction vessel under a nitrogen atmosphere. Next, add 25 kg of acrylamide, 5 kg of methoxypolyethylene glycol maleimide, and 5 kg of catalyst. Then, add 45 kg of Compound A and stir at 60 °C for 40 h. Cool the reaction system to room temperature.

[0119] S2: Add 10 kg of 1,3-(divinylsulfonyl)propanol, 0.5 kg of vinylferrocene, and 3 kg of benzoyl peroxide. Stir at 70 °C for 8 h, filter under reduced pressure, wash with water and methanol, and vacuum dry the solid product at 80 °C for 12 h to obtain a modified superabsorbent polymer.

[0120] The solvent is N,N-dimethylformamide.

[0121] The catalyst is triphenylphosphine (PPh3).

[0122] Compound A is selected from dipentaerythritol penta-mercaptoacetate.

[0123] The potassium salt is selected from potassium bromide, and the chloride salt is selected from calcium chloride.

[0124] The lower sealing layer is selected from PI.

[0125] Evaluation of the example:

[0126] Humidity control accuracy test: Using the test waiting container shown in Fig. 1 (diameter 0.12 m, length 1.2 m), hygrometers were placed at the tip, center, and end (one point at 0.6 m intervals) to monitor the humidity. Humidity control materials manufactured in Examples 1 to 6 with a size of 95 mm × 135 mm × 3.5 mm were placed at the tip or end of the container. After being placed in a constant temperature and humidity environment with a temperature of 45°C and a humidity of 95% for 10 h, the humidity values at the above three detection points were recorded. Based on the minimum value among the three detection points, the moisture absorption accuracy of the three detection points was calculated. Furthermore, after the test waiting container was placed in a constant temperature and humidity environment with a temperature of 45°C and a humidity of 25% for 10 h, the humidity values at the above three detection points were recorded. Based on the minimum value among the three detection points, the moisture desorption accuracy of the three detection points was calculated.

[0127] Moisture Absorption Capacity Test: The humidity control materials manufactured in Examples 1 to 6 with a size of 95 mm × 135 mm × 3.5 mm were taken out and weighed every 1 h in a constant temperature and humidity environment with a temperature of 45°C and a humidity of 95%, and the moisture absorption rate of the humidity control material was calculated. The calculation formula is moisture absorption rate = (moisture absorption weight - original weight) / original weight. The saturated moisture absorption rate of the final humidity control material, that is, the moisture absorption rate when the weight of the humidity control material does not increase any further under the environmental conditions, was recorded.

[0128] Long-Term Continuous Humidity Control Capacity Test: The humidity control materials manufactured in Examples 1 to 6 with a size of 95 mm × 135 mm × 3.5 mm were weighed as m1, placed in a constant temperature and humidity environment with a temperature of 35°C and a humidity of 85% for 24 h, and then placed in a constant temperature and humidity environment with a temperature of 35°C and a humidity of 30% for 24 h and then weighed as m2. By calculation, M1 = │m2 - m1│ was obtained, and this was taken as one detection cycle. After 10 test cycles, M1, M2......M10 were calculated respectively.

[0129] [Judgment Criteria] When any one of M1, M2......M10, i.e., one M value ≤ 2 g, it is judged as "OK". When any one of M1, M2......M10, i.e., one M value > 2 g, it is judged as "NG". The test results are shown in Table 1.

[0130]

Table 1

[0131] In addition, although this specification is described according to embodiments, each embodiment does not only include one independent technical solution. Such descriptions in the specification are only for clarification, and those skilled in the art should understand the specification as a whole. It should be understood that the technical solutions in each example can be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. A method for manufacturing a long-lasting humidity control material for a battery pack, comprising: The long-lasting humidity control material for the battery pack includes an upper sealing layer, a humidity control layer, and a lower sealing layer. The upper sealing layer is a waterproof and breathable film layer, and the waterproof and breathable film layer is a hydrophobic swelling body polytetrafluoroethylene film. The humidity control layer is composed of 1 to 5 layers of humidity control sheets. The humidity control sheet is composed of a base material and a modified humidity control polymer coating layer. The base material is polyester. The modified humidity control polymer coating layer is manufactured from raw materials including 3 to 10 parts by weight of a modified superabsorbent polymer, 15 to 25 parts by weight of a potassium salt, 5 to 10 parts by weight of a chloride salt, and 30 to 50 parts by weight of a first solvent. The manufacturing process of the modified superabsorbent polymer is as follows: According to the parts by weight, in a nitrogen atmosphere, 100 to 200 parts of a second solvent are added to a reaction vessel made of glass or polytetrafluoroethylene. Next, 17 to 25 parts of acrylamide, 1 to 5 parts of methoxypolyethylene glycol maleimide, and 2 to 5 parts of a catalyst are added. Then, 30 to 45 parts of compound A are added. The mixture is stirred at a temperature of 40 to 60 °C for 20 to 40 h, and the reaction system is cooled to room temperature in step S1. 5 to 10 parts of 1,3-(divinylsulfonyl)propanol, 0.05 to 0.5 parts of vinylferrocene, and 1 to 3 parts of benzoyl peroxide are added. The mixture is stirred at a temperature of 60 to 70 °C for 3 to 8 h, filtered under reduced pressure, washed with water and methanol, and the solid product is vacuum dried at a temperature of 30 to 80 °C for 6 to 12 h to obtain a modified superabsorbent polymer in step S2. Compound A is selected from ethylene glycol bis(3-mercaptopropionate) (GDMP), pentaerythritol tetra(3-mercaptopropionate) (PETMP), pentaerythritol tetramercaptoacetate (PETMA), dipentaerythritol tetra(3-mercaptopropionate), dipentaerythritol tetramercaptoacetate, dipentaerythritol penta(3-mercaptopropionate), dipentaerythritol pentamercaptoacetate, dipentaerythritol hexa(3-mercaptopropionate). The method for manufacturing the long-lasting humidity control material for the battery pack, characterized by the above.

2. According to the parts by weight, 15 to 25 parts by weight of potassium salt and 5 to 10 parts by weight of chloride salt are dissolved in 30 to 50 parts by weight of a first solvent, and then 3 to 10 parts of a modified superabsorbent polymer are immersed therein and swollen for 4 to 8 h to uniformly coat the polymer surface with salt, step 1; The substrate is immersed and coated with the mixture of step 1, taken out after 5 to 20 s, and dried at a temperature of 75 to 95 °C for 5 to 15 min to produce a humidity conditioning sheet, step 2; Step 3 of processing the humidity conditioning sheet into a sheet material of a certain size by die cutting; Step 4 of manufacturing a long-lasting humidity conditioning material for a battery pack by stacking an upper sealing layer, a humidity conditioning sheet, and a lower sealing layer in sequence and laminating the upper sealing layer and the lower sealing layer using a hot press welding process, including; A method for manufacturing a long-lasting humidity conditioning material for a battery pack according to claim 1, characterized in that.

3. The potassium salt is one or two selected from potassium carbonate and potassium bromide, the chloride salt is one or more selected from sodium chloride, magnesium chloride, and calcium chloride, and the first solvent is one or two selected from deionized water and ethylene glycol. A method for manufacturing a long-lasting humidity conditioning material for a battery pack according to claim 1 or 2, characterized in that.

4. The lower sealing layer is selected from PET, COP, PES, or PI. A method for manufacturing a long-lasting humidity conditioning material for a battery pack according to claim 1 or 2, characterized in that.

5. The second solvent is one or more of ethanol, dimethyl sulfoxide, tetrahydrofuran, acetone, or N,N-dimethylformamide. A method for manufacturing a long-lasting humidity conditioning material for a battery pack according to claim 1 or 2, characterized in that.

6. The catalyst is one or more of triphenylphosphine (PPh3), triethylamine, or dipropylamine. A method for manufacturing a long-lasting humidity conditioning material for a battery pack according to claim 1 or 2, characterized in that.

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