Enhanced vent

By using a combined structure of a protective fluoropolymer layer and a reinforcement layer in the ventilation parts, the problem of difficult balance between gas selectivity and strength of the ventilation parts is solved, and higher compressive resistance and CO2 transmittance are achieved.

CN119895643APending Publication Date: 2025-04-25W L GORE & ASSOC GK
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Patent Information

Application Number
CN202380065249.8
Authority / Receiving Office
CN · China
Patent Type
Applications(China)
Current Assignee / Owner
Priority Date
2022-09-12
Filing Date
2023-09-11
Publication Date
2025-04-25

AI Technical Summary

Technical Problem

Existing ventilation parts have difficulty finding a balance between maintaining gas selectivity and strength, resulting in the need to sacrifice selectivity in some applications to obtain sufficient strength.

Method used

The structure is employed of at least one protective fluoropolymer layer and at least one reinforcing layer, wherein the protective fluoropolymer layer is at least partially permeated into the reinforcing layer to improve the compressive resistance and permeability of the ventilation member.

Benefits of technology

By retaining the selectivity of the protective fluoropolymer layer while significantly increasing the strength of the ventilation parts, the compressive resistance and CO2 transmittance of the ventilation parts are significantly improved.

✦ Generated by Eureka AI based on patent content.

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Abstract

Provided herein is a vent for a closed container, the vent comprising at least one protective fluoropolymer layer and at least one reinforcement layer wherein the at least one protective fluoropolymer layer is at least partially infiltrated into the at least one reinforcement layer wherein the at least one protective fluoropolymer layer is at least partially infiltrated into the at least one reinforcement layer, as measured using the method described herein, and the at least one reinforcement layer is at least partially infiltrated into the at least one reinforcement layer. The at least one protective fluoropolymer layer has a carbon dioxide (CO2) selectivity to water (H2O) at 30 DEG C of at least 600 cm3 / g and a carbon dioxide transmission at 30 DEG C of at least 1000 cm3 / (m2 * 24 h * atm).
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Description

Technical Field

[0001] The present disclosure relates to a vent for a closed container and a closed container including the vent, in particular to a vent for a flexible closed container and a flexible closed container including the vent. Background Art

[0002] Breathers and vent assemblies are used to reduce pressure fluctuations and control humidity within closed containers. Such breathers and vents must also prevent the ingress of dust and other contaminants and prevent the ingress of water.

[0003] A closed container for containing liquid requires a vent or vent assembly to prevent leakage of the contained liquid, while also ensuring that any gas generated in the closed container can be discharged through the vent to prevent pressure buildup in the closed container.

[0004] Examples of closed containers for containing liquids include battery pouches for containing battery electrolytes. A typical battery pouch is made of a flexible material and has one or more vents on the wall of the battery pouch. Therefore, the gas generated by the battery electrolyte during use can escape from the battery pouch to ensure that the pressure inside the battery pouch does not rise above a given threshold, thereby ensuring that the battery pouch does not burst or leak, or that the battery pouch does not lose capacity due to increased pressure.

[0005] Such vents need to be selective about the gases allowed to pass therethrough, and generally need to substantially prevent water vapor from entering the closed container while allowing gases (such as carbon dioxide) generated during use of the closed container to exit the closed container through the vent.

[0006] However, selectivity must sometimes be sacrificed in order to provide a breather with sufficient strength to provide a long service life in a given application.

[0007] Therefore, there remains a need for improved vents or vent assemblies for closed containers.

[0008] Accordingly, at least some embodiments are directed to providing improved vent assemblies that address at least one of these issues. Summary of the invention

[0009] According to a first aspect, there is provided a vent for a closed container, the vent comprising at least one protective fluoropolymer layer and at least one reinforcement layer, wherein the at least one protective fluoropolymer layer at least partially penetrates the at least one reinforcement layer, wherein the at least one protective fluoropolymer layer has a selectivity of at least 600 cm2 for carbon dioxide (CO2) to water (H2O) at 30°C as measured using the method described herein. 3 / g, and the carbon dioxide permeability at 30°C is at least 1000 cm 3 / (m 2 *24h*atm)(square meter*24 hours*standard atmospheric pressure).

[0010] It has been discovered that providing a breather with at least one protective fluoropolymer layer at least partially penetrating at least one reinforcement layer allows the breather to substantially retain the selectivity of the at least one protective fluoropolymer layer while significantly increasing the strength of the breather, thereby significantly improving the breather's compression resistance.

[0011] The CO2 permeability of materials used in vents generally decreases as the thickness of the material increases. The CO2 permeability of materials used in vents generally increases as the temperature of the material increases. Typically, the layer thickness of a vent needs to be a compromise between the requirements for permeability and selectivity and the requirements for structural strength to ensure that the vent can withstand the pressures that may be generated during use. However, it was found that the vent according to the present invention retains the good CO2 permeability of at least one protective fluoropolymer layer, while also achieving structural strength to provide higher burst pressure resistance.

[0012] In some embodiments, at least one protective fluoropolymer layer may comprise a fluoropolymer having a melting point below 320°C.

[0013] At least one protective fluoropolymer layer may include a fluoropolymer selected from the group consisting of perfluoroalkoxyalkane (PFA), fluorinated ethylene propylene (FEP), polyvinyl fluoride (PVF), polyvinylidene fluoride (PVDF), polychlorotrifluoroethylene (PCTFE), or polyethylene tetrafluoroethylene (ETFE). At least one protective fluoropolymer layer may include PFA or FEP. For example, at least one protective fluoropolymer layer may include PFA.

[0014] In some embodiments, the thickness of at least one protective fluoropolymer layer may be from about 5 μm to about 150 μm. The thickness of at least one protective fluoropolymer layer may be from about 5 μm to about 125 μm. The thickness of at least one protective fluoropolymer layer may be from about 5 μm to about 100 μm. The thickness of at least one protective fluoropolymer layer may be from about 5 μm to about 75 μm. The thickness of at least one protective fluoropolymer layer may be from about 5 μm to about 50 μm. The thickness of at least one protective fluoropolymer layer may be from about 5 μm to about 25 μm. The thickness of at least one protective fluoropolymer layer may be from about 10 μm to about 150 μm. The thickness of at least one protective fluoropolymer layer may be from about 20 μm to about 150 μm. The thickness of at least one protective fluoropolymer layer may be from about 30 μm to about 150 μm. The thickness of at least one protective fluoropolymer layer may be from about 40 μm to about 150 μm. The at least one protective fluoropolymer layer may have a thickness of about 50 μm to about 150 μm.

[0015] In some embodiments, the thickness of at least one protective fluoropolymer layer may be from 10 μm to 50 μm. In some embodiments, the thickness of at least one protective fluoropolymer layer may be from 10 μm to 25 μm. In some embodiments, the thickness of at least one protective fluoropolymer layer may be from 12 μm to 25 μm. For example, the thickness of at least one protective fluoropolymer layer may be 10 μm, 12 μm, 15 μm, 20 μm, 25 μm, 30 μm, 40 μm, or 50 μm.

[0016] At least one reinforcement layer may be a mesh.

[0017] The at least one reinforcement layer may have a generally open structure. The at least one reinforcement layer may be porous. The at least one reinforcement layer may be more porous than the at least one protective fluoropolymer layer. The at least one reinforcement layer may have a higher gas permeability than the at least one protective fluoropolymer layer. Thus, the permeability of the vent may depend primarily on the permeability of the at least one protective fluoropolymer layer.

[0018] At least one reinforcing layer may be an expanded polymer layer. At least one reinforcing layer may have a fibrillated structure. At least one reinforcing layer may have a node and fibril structure, wherein the nodes are interconnected by fibrils. Thus, at least one protective fluoropolymer layer may at least partially penetrate into the pores and voids between the nodes and fibrils.

[0019] At least one reinforcement layer may include ePTFE.

[0020] The thickness of at least one reinforcement layer may be from about 1 μm to about 100 μm. The thickness of at least one reinforcement layer may be from about 5 μm to about 100 μm. The thickness of at least one reinforcement layer may be from about 8 μm to about 100 μm. The thickness of at least one reinforcement layer may be from about 10 μm to about 100 μm. The thickness of at least one reinforcement layer may be from about 15 μm to about 100 μm. The thickness of at least one reinforcement layer may be from about 20 μm to about 100 μm. The thickness of at least one reinforcement layer may be from about 30 μm to about 100 μm. The thickness of at least one reinforcement layer may be from about 1 μm to about 80 μm. The thickness of at least one reinforcement layer may be from about 1 μm to about 60 μm. The thickness of at least one reinforcement layer may be from about 1 μm to about 40 μm. The thickness of at least one reinforcement layer may be from about 1 μm to about 30 μm. The thickness of at least one reinforcement layer may be from about 1 μm to about 25 μm.

[0021] The breather may comprise at least two reinforcement layers, wherein the protective fluoropolymer layer is sandwiched between the at least two reinforcement layers.

[0022] The vent may have a carbon dioxide to water vapor selectivity of at least 600 cm at 30°C. 3 / g.

[0023] The selectivity of the venting element for carbon dioxide to water vapor at 30°C can be at least 700 cm 3 / g. The selectivity of the venting element for carbon dioxide to water vapor at 30°C can be at least 800 cm 3 / g. The selectivity of the venting element for carbon dioxide to water vapor at 30°C can be at least 900 cm 3 / g. The selectivity of the venting element for carbon dioxide to water vapor at 30°C may be at least 1000 cm 3 / g.

[0024] The selectivity of carbon dioxide to water vapor of the vent at 30°C can be about 600 cm 3 / g to about 2000cm 3 / g. The selectivity of carbon dioxide to water vapor of the vent at 30°C can be about 700cm 3 / g to about 2000cm 3 / g. The selectivity of carbon dioxide to water vapor of the vent at 30°C can be about 800cm 3 / g to about 2000cm 3 / g. The selectivity of carbon dioxide to water vapor of the vent at 30°C can be about 900cm 3 / g to about 2000cm 3 / g. The selectivity of carbon dioxide to water vapor of the vent at 30°C can be about 1000cm3 / g to about 2000cm 3 / g.

[0025] The carbon dioxide (CO2) permeability of the vent at 30°C can be at least 4000cm 3 / (m 2 *24h*atm). The carbon dioxide (CO2) permeability of the vent at 30°C can be at least 10000cm 3 / (m 2 *24h*atm). The carbon dioxide (CO2) permeability of the vent at 30°C can be at least 25000cm 3 / (m 2 *24h*atm). The carbon dioxide (CO2) permeability of the vent at 30°C can be at least 50,000 cm 3 / (m 2 *24h*atm). The carbon dioxide (CO2) permeability of the vent at 30°C can be at least 75000cm 3 / (m 2 *24h*atm). The carbon dioxide (CO2) permeability of the vent at 30°C can be at least 100,000 cm 3 / (m 2 *24h*atm).

[0026] The carbon dioxide (CO2) permeability of the vent at 30°C can be about 1000cm 3 / (m 2 *24h*atm) to about 200000cm 3 / (m 2 *24h*atm). The carbon dioxide (CO2) permeability of the vent at 30°C can be about 4000cm 3 / (m 2 *24h*atm) to about 200000cm 3 / (m 2 *24h*atm). The carbon dioxide (CO2) permeability of the vent at 30°C can be about 10000cm 3 / (m 2 *24h*atm) to about 200000cm 3 / (m 2 *24h*atm). The carbon dioxide (CO2) permeability of the vent at 30°C can be about 25000cm 3 / (m 2 *24h*atm) to about 200000cm 3 / (m 2*24h*atm). The carbon dioxide (CO2) permeability of the vent at 30°C can be about 50,000 cm 3 / (m 2 *24h*atm) to about 200000cm 3 / (m 2 *24h*atm). The carbon dioxide (CO2) permeability of the vent at 30°C can be about 75000cm 3 / (m 2 *24h*atm) to about 200000cm 3 / (m 2 *24h*atm). The carbon dioxide (CO2) permeability of the vent at 30°C can be about 1000cm 3 / (m 2 *24h*atm) to about 190000cm 3 / (m 2 *24h*atm). The carbon dioxide (CO2) permeability of the vent at 30°C can be about 1000cm 3 / (m 2 *24h*atm) to about 180000cm 3 / (m 2 *24h*atm). The carbon dioxide (CO2) permeability of the vent at 30°C can be about 1000cm 3 / (m 2 *24h*atm) to about 170000cm 3 / (m 2 *24h*atm). The carbon dioxide (CO2) permeability of the vent at 30°C can be about 1000cm 3 / (m 2 *24h*atm) to about 160000cm 3 / (m 2 *24h*atm). The carbon dioxide (CO2) permeability of the vent at 30°C can be about 10000cm 3 / (m 2 *24h*atm) to about 190000cm 3 / (m 2 *24h*atm). The carbon dioxide (CO2) permeability of the vent at 30°C can be about 10000cm 3 / (m 2 *24h*atm) to about 180000cm 3 / (m 2 *24h*atm). The carbon dioxide (CO2) permeability of the vent at 30°C can be about 10000cm 3 / (m2 *24h*atm) to about 170000cm 3 / (m 2 *24h*atm). The carbon dioxide (CO2) permeability of the vent at 30°C can be about 10000cm 3 / (m 2 *24h*atm) to about 160000cm 3 / (m 2 *24h*atm).

[0027] The protective fluoropolymer layer may have a carbon dioxide transmission rate of at least 4000 cm at 30°C. 3 / (m 2 *24h*atm). The protective fluoropolymer layer may have a carbon dioxide permeability of at least 10,000 cm at 30°C. 3 / (m 2 *24h*atm). The protective fluoropolymer layer may have a carbon dioxide permeability of at least 25000 cm at 30°C. 3 / (m 2 The protective fluoropolymer layer may have a carbon dioxide (CO2) permeability of at least 50,000 cm at 30°C. 3 / (m 2 *24h*atm). The protective fluoropolymer layer may have a carbon dioxide (CO2) permeability of at least 75,000 cm at 30°C. 3 / (m 2 *24h*atm). The protective fluoropolymer layer may have a carbon dioxide (CO2) permeability of at least 100,000 cm at 30°C. 3 / (m 2 *24h*atm).

[0028] The protective fluoropolymer layer can have a carbon dioxide (CO2) permeability of about 1000 cm at 30°C. 3 / (m 2 *24h*atm) to about 200000cm 3 / (m 2 *24h*atm). The carbon dioxide (CO2) permeability of the protective fluoropolymer layer at 30°C can be about 4000cm 3 / (m 2 *24h*atm) to about 200000cm 3 / (m 2 *24h*atm). The carbon dioxide (CO2) permeability of the protective fluoropolymer layer at 30°C can be about 10,000 cm 3 / (m 2*24h*atm) to about 200000cm 3 / (m 2 *24h*atm). The carbon dioxide (CO2) permeability of the protective fluoropolymer layer at 30°C can be about 25000cm 3 / (m 2 *24h*atm) to about 200000cm 3 / (m 2 *24h*atm). The carbon dioxide (CO2) permeability of the protective fluoropolymer layer at 30°C can be about 50,000 cm 3 / (m 2 *24h*atm) to about 200000cm 3 / (m 2 *24h*atm). The carbon dioxide (CO2) permeability of the protective fluoropolymer layer at 30°C can be about 75000cm 3 / (m 2 *24h*atm) to about 200000cm 3 / (m 2 *24h*atm). The carbon dioxide (CO2) permeability of the protective fluoropolymer layer at 30°C can be about 10,000 cm 3 / (m 2 *24h*atm) to about 190000cm 3 / (m 2 *24h*atm). The carbon dioxide (CO2) permeability of the protective fluoropolymer layer at 30°C can be about 10,000 cm 3 / (m 2 *24h*atm) to about 180000cm 3 / (m 2 *24h*atm). The carbon dioxide (CO2) permeability of the protective fluoropolymer layer at 30°C can be about 10,000 cm 3 / (m 2 *24h*atm) to about 170000cm 3 / (m 2 *24h*atm). The carbon dioxide (CO2) permeability of the protective fluoropolymer layer at 30°C can be about 10,000 cm 3 / (m 2 *24h*atm) to about 160000cm 3 / (m 2 *24h*atm).

[0029] The carbon dioxide (CO2) permeability of the vent at 60°C can be at least 4000cm 3 / (m2 *24h*atm). The carbon dioxide (CO2) permeability of the vent at 60°C can be at least 10000cm 3 / (m 2 *24h*atm). The carbon dioxide (CO2) permeability of the vent at 60°C can be at least 25000cm 3 / (m 2 *24h*atm). The carbon dioxide (CO2) permeability of the vent at 60°C can be at least 50,000 cm 3 / (m 2 *24h*atm). The carbon dioxide (CO2) permeability of the vent at 60°C can be at least 75000cm 3 / (m 2 *24h*atm). The carbon dioxide (CO2) permeability of the vent at 60°C can be at least 100,000 cm 3 / (m 2 *24h*atm). The carbon dioxide (CO2) permeability of the vent at 60°C can be at least 150,000 cm 3 / (m 2 *24h*atm).

[0030] The carbon dioxide (CO2) permeability of the vent at 60°C can be about 1000cm 3 / (m 2 *24h*atm) to about 500000cm 3 / (m 2 *24h*atm). The carbon dioxide (CO2) permeability of the vent at 60°C can be about 4000cm 3 / (m 2 *24h*atm) to about 500000cm 3 / (m 2 *24h*atm). The carbon dioxide (CO2) permeability of the vent at 60°C can be about 10000cm 3 / (m 2 *24h*atm) to about 500000cm 3 / (m 2 *24h*atm). The carbon dioxide (CO2) permeability of the vent at 60°C can be about 25000cm 3 / (m 2 *24h*atm) to about 500000cm 3 / (m 2 *24h*atm). The carbon dioxide (CO2) permeability of the vent at 60°C can be about 50,000 cm 3 / (m2 *24h*atm) to about 500000cm 3 / (m 2 *24h*atm). The carbon dioxide (CO2) permeability of the vent at 60°C can be about 75000cm 3 / (m 2 *24h*atm) to about 500000cm 3 / (m 2 *24h*atm). The carbon dioxide (CO2) permeability of the vent at 60°C can be about 1000cm 3 / (m 2 *24h*atm) to about 450000cm 3 / (m 2 *24h*atm). The carbon dioxide (CO2) permeability of the vent at 60°C can be about 1000cm 3 / (m 2 *24h*atm) to about 400000cm 3 / (m 2 *24h*atm). The carbon dioxide (CO2) permeability of the vent at 60°C can be about 1000cm 3 / (m 2 *24h*atm) to about 350000cm 3 / (m 2 *24h*atm). The carbon dioxide (CO2) permeability of the vent at 60°C can be about 1000cm 3 / (m 2 *24h*atm) to about 300000cm 3 / (m 2 *24h*atm). The carbon dioxide (CO2) permeability of the vent at 60°C can be about 10000cm 3 / (m 2 *24h*atm) to about 450000cm 3 / (m 2 *24h*atm). The carbon dioxide (CO2) permeability of the vent at 60°C can be about 10000cm 3 / (m 2 *24h*atm) to about 400000cm 3 / (m 2 *24h*atm). The carbon dioxide (CO2) permeability of the vent at 60°C can be about 10000cm 3 / (m 2 *24h*atm) to about 350000cm 3 / (m 2*24h*atm). The carbon dioxide (CO2) permeability of the vent at 60°C can be about 10000cm 3 / (m 2 *24h*atm) to about 300000cm 3 / (m 2 *24h*atm).

[0031] The protective fluoropolymer layer may have a carbon dioxide transmission rate of at least 4000 cm at 60°C. 3 / (m 2 *24h*atm). The protective fluoropolymer layer may have a carbon dioxide permeability of at least 10,000 cm at 60°C. 3 / (m 2 *24h*atm). The protective fluoropolymer layer may have a carbon dioxide permeability of at least 25000 cm at 60°C. 3 / (m 2 *24h*atm). The protective fluoropolymer layer may have a carbon dioxide (CO2) permeability of at least 50,000 cm at 60°C. 3 / (m 2 *24h*atm). The protective fluoropolymer layer may have a carbon dioxide (CO2) permeability of at least 75,000 cm at 60°C. 3 / (m 2 *24h*atm). The protective fluoropolymer layer may have a carbon dioxide (CO2) permeability of at least 100,000 cm at 60°C. 3 / (m 2 *24h*atm).

[0032] The protective fluoropolymer layer can have a carbon dioxide (CO2) permeability of about 1000 cm at 60°C. 3 / (m 2 *24h*atm) to about 200000cm 3 / (m 2 *24h*atm). The protective fluoropolymer layer can have a carbon dioxide (CO2) permeability of about 4000cm at 60°C. 3 / (m 2 *24h*atm) to about 200000cm 3 / (m 2 *24h*atm). The carbon dioxide (CO2) permeability of the protective fluoropolymer layer at 60°C can be about 10,000 cm 3 / (m 2 *24h*atm) to about 500000cm 3 / (m 2*24h*atm). The carbon dioxide (CO2) permeability of the protective fluoropolymer layer at 60°C can be about 25000cm 3 / (m 2 *24h*atm) to about 500000cm 3 / (m 2 *24h*atm). The carbon dioxide (CO2) permeability of the protective fluoropolymer layer at 60°C can be about 50,000 cm 3 / (m 2 *24h*atm) to about 500000cm 3 / (m 2 *24h*atm). The carbon dioxide (CO2) permeability of the protective fluoropolymer layer at 60°C can be about 75000cm 3 / (m 2 *24h*atm) to about 500000cm 3 / (m 2 *24h*atm). The carbon dioxide (CO2) permeability of the protective fluoropolymer layer at 60°C can be about 10,000 cm 3 / (m 2 *24h*atm) to about 450000cm 3 / (m 2 *24h*atm). The carbon dioxide (CO2) permeability of the protective fluoropolymer layer at 60°C can be about 10,000 cm 3 / (m 2 *24h*atm) to about 400000cm 3 / (m 2 *24h*atm). The carbon dioxide (CO2) permeability of the protective fluoropolymer layer at 60°C can be about 10,000 cm 3 / (m 2 *24h*atm) to about 350000cm 3 / (m 2 *24h*atm). The carbon dioxide (CO2) permeability of the protective fluoropolymer layer at 60°C can be about 10,000 cm 3 / (m 2 *24h*atm) to about 300000cm 3 / (m 2 *24h*atm).

[0033] The CO2 permeability of the vent may be at least 60% of the CO2 permeability of the at least one protective fluoropolymer layer alone. The CO2 permeability of the vent may be at least 65% of the CO2 permeability of the at least one protective fluoropolymer layer alone. The CO2 permeability of the vent may be at least 70% of the CO2 permeability of the at least one protective fluoropolymer layer alone. The CO2 permeability of the vent may be at least 75% of the CO2 permeability of the at least one protective fluoropolymer layer alone. The CO2 permeability of the vent may be at least 80% of the CO2 permeability of the at least one protective fluoropolymer layer alone.

[0034] The breather may include at least two protective fluoropolymer layers and a bonding layer connecting the two protective fluoropolymer layers together. The bonding layer may be a reinforcement layer. The breather may include at least two reinforcement layers, and the at least two protective fluoropolymer layers are sandwiched between the at least two reinforcement layers.

[0035] The breather may include at least two reinforcement layers, and the at least one protective fluoropolymer layer may be sandwiched between the at least two reinforcement layers. The at least one protective fluoropolymer layer may penetrate into each of the at least two reinforcement layers.

[0036] The burst pressure of the breather may be at least 400 kPa at 5 mm diameter, measured using the method described herein. The burst pressure of the breather may be at least 450 kPa at 5 mm diameter. The burst pressure of the breather may be at least 500 kPa at 5 mm diameter.

[0037] The vent may be configured to be installed in a closed container. The closed container may be a battery housing. Thus, the vent may be adapted for use in the battery housing. The battery housing may be part of a battery. The battery may be a secondary battery. The secondary battery may be a lithium-ion battery. The battery may include a positive electrode and a negative electrode. The positive electrode may be selected from: lithium nickel manganese cobalt oxide ("NMC"), lithium nickel cobalt aluminum oxide ("NCA"), lithium manganese oxide ("LMO"), lithium iron phosphate ("LFP"), lithium cobalt oxide ("LCO"), or any combination thereof. The negative electrode may be selected from: lithium, graphite, lithium titanate ("LTO"), tin-cobalt alloy, or any combination thereof.

[0038] In some embodiments, the battery may include at least one separator. The at least one separator may include at least one material selected from the group consisting of polypropylene, polyethylene, at least one tetrafluoroethylene (TFE) polymer or copolymer, at least one homopolymer of vinylidene fluoride, at least one hexafluoropropylene (HFP)-vinylidene fluoride copolymer, or any combination thereof.

[0039] The electrolyte may be an electrolyte, wherein the electrolyte may include at least one solvent and at least one electrolyte salt. The at least one solvent of the electrolyte may include at least one organic solvent. The at least one organic solvent of the electrolyte may be selected from propylene carbonate, ethylene carbonate, diethyl carbonate (DEC), dimethyl carbonate (DMC), ethyl methyl carbonate (EMC) or a mixture thereof.

[0040] The electrolyte may include at least one additive, wherein the at least one additive may be configured to release at least one gas selected from the group consisting of CO2, H2, CO, CH4, or any combination thereof during battery operation. The at least one additive may be selected from the group consisting of vinylene carbonate (VC), vinyl sulfite (ES), and fluoroethylene carbonate (FEC).

[0041] The electrolyte may be impregnated within at least one separator.

[0042] The closed container may be a soft pack. The closed container may be a battery soft pack. The closed container may be configured to contain a battery fluid that allows ions to transfer from the first electrode to the second electrode through the battery fluid. Thus, the closed container may contain at least two electrodes and at least two electrical contacts, the at least two electrical contacts being configured to connect the at least two electrodes to an external circuit. At least one container wall may be configured to be substantially impermeable to the fluid contained in the closed container. For example, the battery soft pack may be a lithium (Li) ion soft pack battery.

[0043] At least one of the plurality of container walls may be a rigid container wall. The rigid container wall may include a rigid polymer material. The rigid container wall may include a thermoplastic material. The rigid container wall may include a reinforced thermoplastic material. For example, the rigid container wall may include a thermoplastic material such as polypropylene (PP), polyethylene (PE), polybutylene terephthalate (PBT), or polyethylene terephthalate (PET) reinforced with fiberglass or similar fibers. The rigid container may include a rigid metal material. For example, the rigid container wall may include aluminum, steel, stainless steel, copper, brass, bronze, tin, or lead.

[0044] In a second aspect, a vent for a closed container comprises: at least one perfluoroalkoxy alkane (PFA) layer or at least one fluorinated ethylene propylene (FEP) layer; and at least one ePTFE layer, wherein at least one PFA layer or at least one FEP layer at least partially penetrates into at least one ePTFE layer, wherein the thickness of at least one PFA or FEP layer is 5 μm to 150 μm.

[0045] The breather may include at least two ePTFE layers, and at least one PFA layer or at least one FEP layer may be sandwiched between the at least two ePTFE layers.

[0046] At least one PFA layer or at least one FEP layer may at least partially penetrate into both of the at least two ePTFE layers.

[0047] The thickness of at least one PFA layer or at least one FEP layer may be 10 μm to 25 μm.

[0048] According to a third aspect, a method for manufacturing the ventilator according to the first aspect is provided, the method comprising the following steps:

[0049] providing at least one reinforcement layer and at least one protective fluoropolymer layer;

[0050] disposing at least one reinforcement layer to at least partially shield at least one protective fluoropolymer layer; and

[0051] applying heat and pressure to at least one reinforcement layer,

[0052] Therein, at least one protective fluoropolymer layer at least partially penetrates into at least one reinforcement layer.

[0053] The heat applied to the at least one reinforcement layer corresponds to applying a temperature of 100°C to 325°C to the at least one reinforcement layer. The heat applied to the at least one reinforcement layer corresponds to applying a temperature of 300°C to 325°C.

[0054] The pressure applied to the at least one reinforcement layer may be 200 kPa to 10000 kPa.

[0055] In a fourth aspect, a closed container is provided, comprising the vent according to the first aspect or the second aspect, wherein the closed container comprises at least one wall and the wall comprises an opening, and wherein the vent covers the opening.

[0056] The vent may cover the opening so that during use, gas within the closed container may escape from the closed container through the opening and the vent.

[0057] The closed container may be a battery housing. Thus, the vent may be adapted for use with the battery housing. The secondary battery may be a lithium-ion battery.

[0058] The positive electrode may be selected from: lithium nickel manganese cobalt oxide ("NMC"), lithium nickel cobalt aluminum oxide ("NCA"), lithium manganese oxide ("LMO"), lithium iron phosphate ("LFP"), lithium cobalt oxide ("LCO"), or any combination thereof.

[0059] The negative electrode may be selected from: lithium, graphite, lithium titanate ("LTO"), tin-cobalt alloy or any combination thereof.

[0060] In some embodiments, the battery may include at least one separator. The at least one separator may include at least one material selected from the group consisting of polypropylene, polyethylene, at least one tetrafluoroethylene (TFE) polymer or copolymer, at least one homopolymer of vinylidene fluoride, at least one hexafluoropropylene (HFP)-vinylidene fluoride copolymer, or any combination thereof.

[0061] The electrolyte may be an electrolyte, wherein the electrolyte may include at least one solvent and at least one electrolyte salt. The at least one solvent of the electrolyte may include at least one organic solvent. The at least one organic solvent of the electrolyte may be selected from propylene carbonate, ethylene carbonate, diethyl carbonate (DEC), dimethyl carbonate (DMC) or a mixture thereof.

[0062] The electrolyte may include at least one additive, wherein the at least one additive may be configured to release at least one gas selected from the group consisting of CO2, H2, CO, CH4, or any combination thereof during battery operation. The at least one additive may be selected from the group consisting of vinylene carbonate (VC), vinyl sulfite (ES), and fluoroethylene carbonate (FEC).

[0063] The electrolyte may be impregnated within at least one separator.

[0064] The closed container may be a flexible bag.

[0065] The closed container may be a battery pouch. The closed container may be configured to contain a battery fluid that allows ions to transfer from the first electrode to the second electrode through the battery fluid. Thus, the closed container may contain at least two electrodes and at least two electrical contacts, the at least two electrical contacts being configured to connect the at least two electrodes to an external circuit. At least one container wall may be configured to be substantially impermeable to the fluid contained in the closed container. For example, the battery pouch may be a lithium (Li) ion pouch battery.

[0066] At least one of the plurality of container walls may be a rigid container wall. The rigid container wall may include a rigid polymer material. The rigid container wall may include a thermoplastic material. The rigid container wall may include a reinforced thermoplastic material. For example, the rigid container wall may include a thermoplastic material such as polypropylene (PP), polyethylene (PE), polybutylene terephthalate (PBT), or polyethylene terephthalate (PET) reinforced with fiberglass or similar fibers. The rigid container may include a rigid metal material. For example, the rigid container wall may include aluminum, steel, stainless steel, copper, brass, bronze, tin, or lead.

[0067] The features of the vents of the first and second aspects are the features of the vents of the third and fourth aspects. BRIEF DESCRIPTION OF THE DRAWINGS

[0068] Embodiments of the invention will now be described, by way of non-limiting examples, with reference to the accompanying drawings.

[0069] Figure 1 : A) 30°C and B) 60°C gas transmission rate (GTR) and CO2 transmission rate of venting materials;

[0070] Figure 2 : Relationship between thickness and burst pressure of PFA film;

[0071] Figure 3 : A cross-sectional view of a ventilator according to one embodiment;

[0072] Figure 4 : A cross-sectional view of a ventilator on an opening according to one embodiment;

[0073] Figure 5 : A scanning electron microscope (SEM) side view of a vent according to one embodiment;

[0074] Figure 6 : A graph of burst pressures of a breather according to an embodiment on openings with diameters of 5 mm and 16 mm for a breather comprising A) a 12 μm PFA layer and B) a 25 μm PFA layer;

[0075] Figure 7 : A graph of burst pressures of a vent according to an embodiment on openings of 5 mm and 16 mm diameters compared to a protective fluoropolymer layer alone;

[0076] Figure 8 : A) 30°C and B) 60°C, CO2 transmission rate (GTR) versus selectivity for a vent and a separate protective fluoropolymer layer according to an embodiment;

[0077] Fig. 9 : A schematic side view of a process for making a reinforced ventilator according to one embodiment;

[0078] Fig.10 : A graph of burst pressures of a vent including 12 μm on openings of 5 mm and 16 mm diameter according to an embodiment;

[0079] Fig.11 : A) 30° C. and B) 60° C., CO 2 transmission rate (GTR) versus selectivity for a vent and a separate protective fluoropolymer layer according to an embodiment; and

[0080] Fig.12 : A cross-sectional view of a vent according to one embodiment. DETAILED DESCRIPTION

[0081] Although the manufacture and use of various embodiments of the present invention are discussed in detail below, it should be understood that the present invention provides many applicable inventive concepts that can be embodied in various specific situations. The specific embodiments discussed herein only illustrate specific ways to manufacture and use the present invention, and do not limit the scope of the present invention.

[0082] To facilitate understanding of the present invention, some terms are defined below. The terms defined herein have the meanings commonly understood by those of ordinary skill in the art related to the present invention. The terms "a", "one / kind", and "the / said" do not refer to only a single entity, but include general categories that can be illustrated using specific examples. The terms herein are used to describe specific embodiments of the present invention, but their use does not limit the present invention unless described in the claims.

[0083] Test Method

[0084] Method for measuring CO2 transmission rate

[0085] - Examples 1-6

[0086] The CO2 permeation rate was measured using a gas detector (model GTR-11MJGG, from GTR Tech). The sample breather was placed in the evaluation cell to cover an area of ​​15.2 cm 2 CO2 was supplied to the evaluation cell at a temperature of 30°C to 60°C and a supply pressure of 99 kPa for 0.1 to 10 minutes.

[0087] - Examples 7 and 9

[0088] The CO2 transmission rate was measured using a gas detector (model VAC-V2, from Labthink). The sample vent was placed in the evaluation cell to cover an area of ​​38.48 cm 2 CO2 was supplied to the evaluation cell at a supply pressure of 1 atmosphere at a temperature of 30°C to 60°C.

[0089] Method for measuring moisture vapor transmission rate

[0090] When measuring moisture (gaseous H2O) transmission rate, the sample vent divides the chamber into a high humidity area (containing liquid water) and a low humidity area, where dry gas flows through the sample vent and the humidity in the low humidity area is measured. The exposed area of ​​the sample vent is 5.0x10 -3 m 2 .

[0091] Method for calculating the selectivity of CO2 to H2O

[0092] When calculating the selectivity of CO2 to H2O of the sample vent, the CO2 gas transmission rate (GTR, in cm 3 / (m 2 x 24h x atm)) and moisture vapor transmission rate (MVTR, in g / (m 2 x days)) into their respective permeability coefficients (CO2: cm 3 / (cm 2 xsx cmHg); moisture: unit is g / (cm 2 xsx cmHg)), the selectivity is calculated as the CO2 permeability coefficient divided by the moisture permeability coefficient.

[0093] Methods for measuring burst pressure

[0094] The burst pressure of the sample vent was measured by mounting the sample vent under a support screen. The support screen defined an opening with a diameter of 5 mm or 11 mm. Water was sprayed at a pressure of 550 kPa towards the opening for 30 minutes. The time it took for the sample vent to burst at this pressure was recorded.

[0095] Such vents need to be selective about the gases allowed to pass through, and generally need to substantially prevent water vapor from entering the closed container while allowing gases (such as carbon dioxide) generated during use of the closed container to exit the closed container through the vent. Vents for closed containers containing water-sensitive liquids (such as batteries and battery pouches) need to be able to prevent liquid water and water vapor from entering the closed container while also allowing waste gases (such as carbon dioxide) to exit the closed container.

[0096] For a battery or a battery pouch, the vent must include a material with good carbon dioxide permeability to ensure that carbon dioxide generated in the battery or the battery pouch can be discharged from the closed container through the vent. However, the vent must include a material that is substantially impermeable to water vapor. Therefore, the material of the vent must selectively allow carbon dioxide to be discharged through the vent while preventing water from entering.

[0097] Exemplary materials that have been found to be permeable to carbon dioxide but not to water include fluoropolymers such as PFA and FEP. The carbon dioxide permeability of a material at a given temperature is generally related to the thickness of the material. For example, Figure 1 The permeability ("gas transmission rate" or GTR) of PFA, FEP and ePTFE (labeled DM18C) is shown. It is therefore preferred to make the breather material as thin as possible to maximize the permeability of the material.

[0098] However, during use, as the pressure in the closed container increases, the breather material must also be able to withstand the pressure exerted on it. Thin fluoropolymer layers are usually unable to withstand large pressures. Figure 2 The burst pressure of PFA is shown as a function of thickness.

[0099] Therefore, the vents commonly used in the art either use thicker fluoropolymer layers or fluoropolymer films to ensure structural stability while also compromising breathability, or include other fluoropolymers such as expanded polytetrafluoroethylene (ePTFE) or densified ePTFE (i.e., expanded PTFE that is densified after the original PTFE is expanded).

[0100] Example 1 (BZ8 / PFA12 / BZ8)

[0101] Reference Figure 3 , the reinforced breather 1 (as the breather) includes a PFA layer 2 (as a protective fluoropolymer layer), a first ePTFE layer 4 (as a first reinforcement layer) and a second ePTFE layer 6 (as a second reinforcement layer). The PFA layer 2 is sandwiched between the first ePTFE layer 4 and the second ePTFE layer 6, and the PFE layer 2 penetrates into the pores of the first ePTFE layer 4 and the second ePTFE layer 6.

[0102] The thickness of the PFA layer 2 is 12 μm, and includes PFA Neoflon A provided by Daikin Japan. The thickness of the first ePTFE layer 4 and the second ePTFE layer 6 are both 8 μm, and include ePTFE provided by WL Gore & Associates, Inc.

[0103] Reference Fig. 9 , the PFA layer 2 is arranged between the first ePTFE layer 4 and the second ePTFE layer 6 to form a laminate, and then the laminate is placed on the first plate 20, thereby making a reinforced breather 1. The second plate 22 is placed on the laminate. The first plate and the second plate are heated to heat the laminate to 300° C., and a pressure of 6500 kPa is applied to the laminate. The PFA layer 2 at least partially melts and penetrates into the pores of the first ePTFE layer 4 and the pores of the second ePTFE layer 6.

[0104] Figure 4 A side view of a reinforced breather 1 is shown enclosing an opening 8 in a container.

[0105] Figure 5 A scanning electron microscope image of the reinforced breather 1 is shown, showing the penetration of PFA into the ePTFE.

[0106] Example 2 (BZ8 / PFA25 / BZ8)

[0107] Another reinforced breather includes a PFA layer having a thickness of 25 μm, a first ePTFE layer having a thickness of 8 μm, and a second ePTFE layer having a thickness of 8 μm.

[0108] Example 3 (BZ8 / FEP12 / BZ8)

[0109] Another reinforced breather includes a FEP layer having a thickness of 12 μm, a first ePTFE layer having a thickness of 8 μm, and a second ePTFE layer having a thickness of 8 μm.

[0110] Example 4 (SP25 / PFA12 / SP25)

[0111] Another reinforced breather includes a PFA layer having a thickness of 12 μm, a first ePTFE layer having a thickness of 25 μm, and a second ePTFE layer having a thickness of 25 μm.

[0112] Example 5 (BZ8 / PFA12 / BZ8)

[0113] Another reinforced breather includes a PFA layer having a thickness of 12 μm, a first ePTFE layer having a thickness of 8 μm, and a second ePTFE layer having a thickness of 8 μm.

[0114] Example 6 (PFA12 / BZ8)

[0115] Reference Fig.12 , another reinforced breather 100 includes a PFA layer 102 having a thickness of 12 μm and a single ePTFE layer 104 having a thickness of 8 μm disposed on only one side.

[0116] The enhanced breathers of the examples were tested to determine the burst pressure, CO2 permeability, and selectivity of each enhanced breather.

[0117] like Figure 6 and Figure 7 As shown, the enhanced breather in the examples has a significantly higher burst pressure compared to the protective fluoropolymer layer (PFA or FEP) alone.

[0118] Figure 8 The selectivity versus CO2 permeability was shown to be comparable to that of the protective fluoropolymer layer alone.

[0119]

[0120] Table 1: CO2 permeability and CO2 / H2O selectivity of cut fluoropolymer (DeWAL DW200, Rogers Corporation, Examples 7 and 8) and PFA membranes (Neoflon PFA, Examples 9 and 10). The CO2 permeability of Examples 8 and 10 was calculated based on the measured values ​​of Examples 7 and 9, respectively.

[0121] The table provides a comparison of CO2 permeation and CO2 / H2O selectivity of cut fluoropolymer materials (Examples 7 and 8, trade name DeWAL DW200) that can be used as protective fluoropolymer layers, which are expected to benefit from the enhanced structure of the present disclosure, and compared with the properties of PFA membranes (Examples 9 and 10, Neoflon PFA). The permeation of the 150 μm thick layer is calculated based on the values ​​of 61 or 100 μm, respectively, and the calculation formula is as follows ("Variation in membrane thickness altered the permeation rate but not the separation characteristics of the polymer", McKeen, Laurence W., "Permeability Properties of Plastics and Elastomers: Permeation Reference Guide and Databook", 2016):

[0122] Transmittance x thickness = permeability coefficient (1)

[0123] Although intended embodiments of the invention have been described above, many and various changes and modifications in form, design, structure and arrangement of parts may be made to other embodiments without departing from the invention, and it will be understood that all such changes and modifications are regarded as embodiments of a part of the invention as defined in the appended claims.

Claims

1. A vent for a closed container, the vent comprising at least one protective fluoropolymer layer and at least one reinforcement layer, wherein: At least one protective fluoropolymer layer at least partially penetrates at least one reinforcement layer, wherein the at least one protective fluoropolymer layer has a selectivity of at least 600 cm2 for carbon dioxide (CO2) to water (H2O) at 30°C as measured by the method described herein. 3 / g, and the carbon dioxide permeability at 30°C is at least 1000 cm 3 / (m 2 *24h*atm).

2. The ventilator according to claim 1, wherein: The at least one protective fluoropolymer layer has a thickness of 5 μm to 150 μm.

3. The ventilator according to claim 1 or 2, wherein: The at least one protective fluoropolymer layer has a carbon dioxide transmission rate of at least 4000 cm at 30°C as measured by the method described herein. 3 / (m 2 *24h*atm).

4. The ventilator according to claim 3, wherein: The at least one protective fluoropolymer layer has a carbon dioxide transmission rate of at least 10,000 cm at 30°C as measured by the method described herein. 3 / (m 2 *24h*atm).

5. A ventilator according to any one of the preceding claims, wherein: The at least one protective fluoropolymer layer comprises a fluoropolymer having a melting point below 320°C.

6. A ventilator according to any one of the preceding claims, wherein: The at least one protective fluoropolymer layer comprises a fluoropolymer selected from the group consisting of perfluoroalkoxyalkane (PFA), fluorinated ethylene propylene (FEP), polyvinyl fluoride (PVF), polyvinylidene fluoride (PVDF), polychlorotrifluoroethylene (PCTFE) or polyethylene tetrafluoroethylene (ETFE).

7. A ventilator according to any one of the preceding claims, wherein: The at least one reinforcement layer is porous.

8. A ventilator according to any one of the preceding claims, wherein: The breather comprises at least two reinforcement layers, wherein a protective fluoropolymer layer is sandwiched between the at least two reinforcement layers.

9. A ventilator according to any one of the preceding claims, wherein: The vent has a carbon dioxide to water vapor selectivity of at least 800 cm at 30°C. 3 / g.

10. The ventilator according to claim 9, wherein: The breather comprises at least two reinforcement layers, and at least two protective fluoropolymer layers are sandwiched between the at least two reinforcement layers.

11. A method of manufacturing a ventilator as claimed in any one of the preceding claims, the method comprising the steps of: providing at least one reinforcement layer and at least one protective fluoropolymer layer; disposing at least one reinforcement layer to at least partially obscure at least one protective fluoropolymer layer; as well as applying heat and pressure to at least one reinforcement layer, Therein, at least one protective fluoropolymer layer at least partially penetrates into at least one reinforcement layer.

12. The method of claim 11, wherein: The heat applied to the at least one reinforcement layer corresponds to applying a temperature of 100°C to 325°C, preferably 300°C to 325°C.

13. A closed container comprising an opening and the vent member according to any one of claims 1 to 10, wherein: The vent covers the opening so that gas within the closed container can escape from the closed container through the opening and the vent during use.

14. The closed container according to claim 13, wherein: The closed container is a battery.

15. A closed container as claimed in claim 13 or 14, wherein: The closed container comprises at least one flexible wall.