An improved battery housing including an exhaust element and a method for manufacturing a battery including the battery housing

Abstract

A method for manufacturing a battery comprises the steps of: providing a battery housing including a formation vent; adding an electrolyte to the battery housing to form a battery; maintaining the electrolyte within the battery housing for a predetermined period; and applying a charge across a pair of electrodes to precharge the battery, wherein gas generated within the battery housing during the maintenance step and the precharging step is exhausted to the outside of the battery housing through at least one hole. A battery formed by the above method and a formation vent included in the battery are also described.

Description

Technology Field

[0001] The present disclosure relates to an exhaust element, a battery housing including the exhaust element, and a method for manufacturing a battery. Background Technology

[0002] The provision of improved batteries is becoming increasingly important, particularly for mobile electronic devices and electric vehicles, for example.

[0003] Batteries with prismatic can housings or flexible pouch housings are typically manufactured under very specific conditions to ensure that neither water vapor nor liquid moisture enters the battery housing during assembly, aging, and precharging. Typically, the accompanying stringent conditions require the use of drying chambers, which are expensive to operate.

[0004] Typically, during the manufacturing process, gas is generated within the battery housing during the precharging phase. Since the battery housing must be sealed during the precharging phase, the generated gas condenses within the housing, increasing the pressure inside. Before the battery is shipped, it is essential to vent the gas from inside the battery housing. Therefore, the seal for the battery housing is typically broken to allow the gas to be released under vacuum, and then resealed.

[0005] Therefore, there are numerous steps that need to be complied with and performed under strict conditions, which results in high operating costs.

[0006] For larger capacity battery cells (e.g., battery cells exceeding 100 Ah), a single aperture within the battery housing is used for both injecting electrolyte into the battery housing and exhausting gases, and the single aperture is typically plugged during the precharging process. Subsequently, the plug is removed to allow the battery housing to be vented, which often results in electrolyte leakage. Once venting under vacuum is complete, any leaked electrolyte is flushed out of the battery housing, and additional electrolyte is added to the battery housing to replenish the leaked electrolyte before the aperture is sealed. This entire process must be performed under strict dry conditions.

[0007] As an alternative, battery pouch cells containing a flexible battery housing often include an additional section specifically provided to be ruptured or perforated after a precharge phase to allow gases accumulated within the battery housing to be vented. Once the battery housing is vented, the ruptured or perforated section is sealed from the remainder of the battery housing and then removed. Consequently, the flexible battery housing must be larger than required for the final battery pouch cell to be produced, which results in additional material costs.

[0008] It is desirable to provide an improved method for forming a battery that reduces the operating cost of the battery formation process. The problem to be solved

[0009] Accordingly, at least one aspect of the present disclosure relates to providing an improved method for manufacturing a battery or an improved battery housing. means of solving the problem

[0010] According to a first embodiment, an exhaust element comprising an impermeable substrate and a first protective element is provided, wherein the impermeable substrate comprises at least one hole, said or each hole extends from a first side of the impermeable substrate to a second side of the impermeable substrate, said or each hole has a maximum width of 1 μm to 50 μm, and the first protective element is located on the first side of the impermeable substrate to close said or each hole.

[0011] The term "maximum width" as used herein refers to the main cross-sectional dimension of the above or each hole. For example, in the case of a hole with a circular cross-section, the maximum width refers to the diameter of the circular cross-section.

[0012] The above or each hole may have a maximum width of 1 μm to 40 μm. The above or each hole may have a maximum width of 1 μm to 30 μm. The above or each hole may have a maximum width of 1 μm to 20 μm. The above or each hole may have a maximum width of 1 μm to 15 μm. The above or each hole may have a maximum width of 1 μm to 10 μm. The above or each hole may have a maximum width of 1 μm to 9 μm. The above or each hole may have a maximum width of 1 μm to 8 μm. The above or each hole may have a maximum width of 1 μm to 7 μm. The above or each hole may have a maximum width of 1 μm to 6 μm. The above or each hole may have a maximum width of 1 μm to 5 μm. The above or each hole may have a maximum width of 5 μm to 50 μm. The above or each hole may have a maximum width of 10 μm to 50 μm. The above or each hole may have a maximum width of 15 μm to 50 μm. The above or each hole may have a maximum width of 10 μm to 30 μm.

[0013] The above or each hole may have an effective diameter of less than 50 μm. The above or each hole may have an effective diameter of less than 40 μm. The above or each hole may have an effective diameter of less than 20 μm.

[0014] The above or each hole may have an effective diameter of 1 μm to 50 μm. The above or each hole may have an effective diameter of 1 μm to 40 μm. The above or each hole may have an effective diameter of 1 μm to 30 μm. The above or each hole may have an effective diameter of 1 μm to 20 μm. The above or each hole may have an effective diameter of 1 μm to 15 μm. The above or each hole may have an effective diameter of 5 μm to 50 μm. The above or each hole may have an effective diameter of 10 μm to 50 μm. The above or each hole may have an effective diameter of 10 μm to 30 μm.

[0015] The term "effective diameter" used herein refers to the diameter of the above or each hole when it is approximated as circular from the measured cross-sectional area.

[0016] The term "hole" as used herein refers to a path or channel that allows fluid passage from a first side of the substrate to a second side of the substrate. The path may be linear so that the fluid can pass through the substrate in a substantially straight line. The term "hole" as used herein does not include pores that provide a meandering path through the porous substrate, but is rather more direct.

[0017] The above or each hole may form a direct path penetrating the impermeable substrate. The above or each hole may be formed within the impermeable substrate or penetrating the impermeable substrate after the impermeable substrate is formed. Accordingly, the above or each hole is not, for example, a pore of a porous material.

[0018] The above or each hole may have any cross-sectional shape. The above or each hole may have a nearly circular or elliptical cross-section. The above or each hole may have an angular cross-sectional shape with any number of sides, such as a triangle, a square (square or rectangle), a pentagon, a hexagon, or an octagon. The above or each hole may have any cross-sectional shape.

[0019] The above or each hole may include an approximately cylindrical portion. The above or each hole may be approximately cylindrical. Accordingly, the above or each hole may have substantially the same maximum width and substantially the same cross-sectional area when extending from the first side to the second side of the impermeable substrate.

[0020] The above or each hole may include a roughly conical portion. The above or each hole may be roughly conical. Accordingly, the maximum width of the above or each hole may increase or decrease as the above or each hole extends from a first side to a second side.

[0021] The maximum width of at least one hole on the first side of the opaque substrate may be different from the maximum width on the second side of the opaque substrate.

[0022] The maximum width of at least one hole on the first side of the opaque substrate may be at least 30% larger than the maximum width of at least one hole on the second side of the opaque substrate. The maximum width of at least one hole on the first side of the opaque substrate may be at least 40% larger than the maximum width of at least one hole on the second side of the opaque substrate. The maximum width of at least one hole on the first side of the opaque substrate may be at least 50% larger than the maximum width of at least one hole on the second side of the opaque substrate.

[0023] The maximum width of at least one hole on the first side of the opaque substrate may be 10% to 75% larger than the maximum width of at least one hole on the second side of the opaque substrate. The maximum width of at least one hole on the first side of the opaque substrate may be 10% to 50% larger than the maximum width of at least one hole on the second side of the opaque substrate. The maximum width of at least one hole on the first side of the opaque substrate may be 10% to 40% larger than the maximum width of at least one hole on the second side of the opaque substrate. The maximum width of at least one hole on the first side of the opaque substrate may be 10% to 35% larger than the maximum width of at least one hole on the second side of the opaque substrate. The maximum width of at least one hole on the first side of the opaque substrate may be 20% to 75% larger than the maximum width of at least one hole on the second side of the opaque substrate. The maximum width of at least one hole on the first side of the opaque substrate may be 25% to 75% larger than the maximum width of at least one hole on the second side of the opaque substrate. The maximum width of at least one hole on the first side of the opaque substrate may be 30% to 75% larger than the maximum width of at least one hole on the second side of the opaque substrate.

[0024] The maximum width of at least one hole on the first side of the opaque substrate may be at least 30% smaller than the maximum width of at least one hole on the second side of the opaque substrate. The maximum width of at least one hole on the first side of the opaque substrate may be at least 40% smaller than the maximum width of at least one hole on the second side of the opaque substrate. The maximum width of at least one hole on the first side of the opaque substrate may be at least 50% smaller than the maximum width of at least one hole on the second side of the opaque substrate.

[0025] The maximum width of at least one hole on the first side of the opaque substrate may be 10% to 75% smaller than the maximum width of at least one hole on the second side of the opaque substrate. The maximum width of at least one hole on the first side of the opaque substrate may be 10% to 50% smaller than the maximum width of at least one hole on the second side of the opaque substrate. The maximum width of at least one hole on the first side of the opaque substrate may be 10% to 40% smaller than the maximum width of at least one hole on the second side of the opaque substrate. The maximum width of at least one hole on the first side of the opaque substrate may be 10% to 35% smaller than the maximum width of at least one hole on the second side of the opaque substrate. The maximum width of at least one hole on the first side of the opaque substrate may be 20% to 75% smaller than the maximum width of at least one hole on the second side of the opaque substrate. The maximum width of at least one hole on the first side of the opaque substrate may be 25% to 75% smaller than the maximum width of at least one hole on the second side of the opaque substrate. The maximum width of at least one hole on the first side of the opaque substrate may be 30% to 75% smaller than the maximum width of at least one hole on the second side of the opaque substrate.

[0026] The CO2 permeability through the exhaust element may be at least 10 ml / h. The CO2 permeability through the exhaust element may be at least 20 ml / h. The CO2 permeability through the exhaust element may be at least 30 ml / h. The CO2 permeability through the exhaust element may be at least 40 ml / h. The CO2 permeability through the exhaust element may be at least 50 ml / h. The CO2 permeability through the exhaust element may be at least 75 ml / h. The CO2 permeability through the exhaust element may be at least 100 ml / h. The CO2 permeability through the exhaust element may be at least 150 ml / h.

[0027] The CO2 permeability through the exhaust element may be 10 ml / h to 2000 ml / h. The CO2 permeability through the exhaust element may be 20 ml / h to 2000 ml / h. The CO2 permeability through the exhaust element may be 30 ml / h to 2000 ml / h. The CO2 permeability through the exhaust element may be 40 ml / h to 2000 ml / h. The CO2 permeability through the exhaust element may be 50 ml / h to 2000 ml / h. The CO2 permeability through the exhaust element may be 75 ml / h to 2000 ml / h. The CO2 permeability through the exhaust element may be 100 ml / h to 2000 ml / h. The CO2 permeability through the exhaust element may be 200 ml / h to 2000 ml / h. The CO2 permeability through the exhaust element may be 10 ml / h to 1500 ml / h. The CO2 permeability through the exhaust element may be 10 ml / h to 1000 ml / h. The CO2 permeability through the exhaust element may be 10 ml / h to 750 ml / h. The CO2 permeability through the exhaust element may be 10 ml / h to 500 ml / h.

[0028] CO2 permeability may represent the permeability of other gases having a molecular weight similar to CO2. Other exemplary gases that may be associated with the exhaust element during use may include hydrogen gas (H2), methane (CH4), ethane (C2H6), ethylene (C2H4), propane (C3H8), propylene (C3H6), or carbon monoxide (CO).

[0029] The water vapor permeability through the exhaust element may be less than 2.0 mg / h. The water vapor permeability through the exhaust element may be less than 1.0 mg / h. The water vapor permeability through the exhaust element may be less than 0.5 mg / h. The water vapor permeability through the exhaust element may be less than 0.1 mg / h.

[0030] The water vapor permeability passing through the exhaust element may be 3.0 mg / h to 0.0001 mg / h. The water vapor permeability passing through the exhaust element may be 2.5 mg / h to 0.0001 mg / h. The water vapor permeability passing through the exhaust element may be 2.0 mg / h to 0.0001 mg / h. The water vapor permeability passing through the exhaust element may be 1.0 mg / h to 0.0001 mg / h. The water vapor permeability passing through the exhaust element may be 0.75 mg / h to 0.0001 mg / h. The water vapor permeability passing through the exhaust element may be 0.5 mg / h to 0.0001 mg / h. The water vapor permeability passing through the exhaust element may be 0.01 mg / h to 0.0001 mg / h.

[0031] It will be understood that in the present disclosure, water vapor permeability is preferably as low as possible to minimize or effectively prevent the transmission of water vapor across the exhaust element.

[0032] The water vapor permeability passing through the exhaust element may depend on the direction of passage through the exhaust element. In an embodiment where the maximum width of at least one hole on the first side of the impermeable substrate is different from the maximum width of at least one hole on the second side of the impermeable substrate, the water vapor permeability passing through the exhaust element from the first side of the impermeable substrate to the second side of the impermeable substrate may be different from the water vapor permeability passing through the exhaust element from the second side of the impermeable substrate to the first side of the impermeable substrate. The water vapor permeability may increase as it moves from the side of the impermeable substrate where at least one hole has the largest maximum width to the side of the impermeable substrate where at least one hole has the smallest maximum width.

[0033] At least one hole may have a first end adjacent to a first side of the impermeable substrate and a second end adjacent to a second side of the impermeable substrate, the first end has a first maximum width, the second end has a second maximum width, and the first maximum width may be larger than the second maximum width.

[0034] In an embodiment having at least one hole having a first end and a second end having a maximum width different from the first end, the ratio of CO2 permeability to water vapor permeability from the first end to the second end is at least 3. In an embodiment having a first end having a maximum width smaller than that of the second end, the ratio of CO2 permeability to water vapor permeability from the first end to the second end is at least 3.

[0035] The ratio of CO2 permeability to water vapor permeability from the first side of the impermeable substrate to the second side of the impermeable substrate is at least 3.

[0036] The ratio of CO2 permeability to water vapor permeability from the second side of the impermeable substrate to the first side of the impermeable substrate is at least 3.

[0037] The "ratio of CO2 permeability to water vapor permeability" used herein is calculated by dividing the CO2 permeability by the water vapor permeability of the substrate. The ratio of CO2 permeability to water vapor permeability has no units (i.e., is dimensionless). Therefore, a ratio of at least 2 means that at least twice the volume of CO2 permeates through the housing wall compared to the volume of water vapor permeates through the housing wall at a given pressure.

[0038] The ratio of CO2 permeability to water vapor permeability passing through the exhaust element may be 5 or more. The ratio of CO2 permeability to water vapor permeability passing through the exhaust element may be 10 or more. The ratio of CO2 permeability to water vapor permeability passing through the exhaust element may be 15 or more. The ratio of CO2 permeability to water vapor permeability passing through the exhaust element may be 20 or more. The ratio of CO2 permeability to water vapor permeability passing through the exhaust element may be 30 or more. The ratio of CO2 permeability to water vapor permeability passing through the exhaust element may be 40 or more. The ratio of CO2 permeability to water vapor permeability passing through the exhaust element may be 50 or more.

[0039] The ratio of CO2 permeability to water vapor permeability passing through the exhaust element may be 5 to 2000. The ratio of CO2 permeability to water vapor permeability passing through the exhaust element may be 10 to 2000. The ratio of CO2 permeability to water vapor permeability passing through the exhaust element may be 15 to 2000. The ratio of CO2 permeability to water vapor permeability passing through the exhaust element may be 20 to 2000. The ratio of CO2 permeability to water vapor permeability passing through the exhaust element may be 30 to 2000. The ratio of CO2 permeability to water vapor permeability passing through the exhaust element may be 40 to 2000. The ratio of CO2 permeability to water vapor permeability passing through the exhaust element may be 50 to 2000. The ratio of CO2 permeability to water vapor permeability passing through the exhaust element may be 5 to 1500. The ratio of CO2 permeability to water vapor permeability passing through the exhaust element may be 5 to 1000.

[0040] The above or each hole may be formed within the opaque substrate by any suitable method. The above or each hole may be formed by mechanical drilling. The above or each hole may be formed by laser drilling. In an embodiment in which the above or each hole is formed by laser drilling, the maximum width of the above or each hole may be slightly reduced from the first side where the laser is incident to the second side as the laser passes through the opaque substrate and is attenuated. Accordingly, the above or each hole may have a first maximum width or effective diameter on the first side of the opaque substrate, and the above or each hole may have a second maximum width or effective diameter on the second side of the opaque substrate. The first maximum width or effective diameter may be larger than the second maximum width or effective diameter. The first maximum width or effective diameter may be smaller than the second maximum width or effective diameter.

[0041] The above or each hole may be formed by perforating the impermeable substrate. The above or each hole may be formed by perforating the impermeable substrate by pressing or forcing a perforating element to penetrate the impermeable substrate. The perforating element may be a needle, a capillary, etc.

[0042] In an embodiment in which more than one hole is provided in an impermeable substrate, more than one aperture may be formed by an array of perforation elements. The perforation elements may be arranged in a regular pattern so that more than one hole provided in the impermeable substrate is arranged in a regular pattern.

[0043] The first protective element may include an expansion polymer selected from expanded polytetrafluoroethylene and expanded polyethylene.

[0044] The exhaust element may include a second protective element positioned on the second side of the impermeable substrate to block the hole.

[0045] When present with the first protective element, the second protective element may have a higher CO2 permeability than the above or each hole.

[0046] When present with the first protective element, the second protective element may have an airflow of at least 20 ml / h. When present with the first protective element, the second protective element may have an airflow of at least 40 ml / h. When present with the first protective element, the second protective element may have an airflow of at least 60 ml / h. When present with the first protective element, the second protective element may have an airflow of at least 80 ml / h. When present with the first protective element, the second protective element may have an airflow of at least 100 ml / h. When present with the first protective element, the second protective element may have an airflow of at least 150 ml / h. When present with the first protective element, the second protective element may have an airflow of at least 200 ml / h.

[0047] When present with the first protective element, the second protective element may have an airflow of 10 ml / h to 1000 ml / h. When present with the first protective element, the second protective element may have an airflow of 20 ml / h to 1000 ml / h. When present with the first protective element, the second protective element may have an airflow of 30 ml / h to 1000 ml / h. When present with the first protective element, the second protective element may have an airflow of 40 ml / h to 1000 ml / h. When present with the first protective element, the second protective element may have an airflow of 50 ml / h to 1000 ml / h. When present with the first protective element, the second protective element may have an airflow of 100 ml / h to 1000 ml / h. When present with the first protective element, the second protective element may have an airflow of 200 ml / h to 1000 ml / h.

[0048] As used herein, the term "impermeable substrate" refers to a substrate having low water vapor permeability. As used herein, low water vapor (moisture) permeability is 5 g / (m³) at 100% relative humidity at 40 ℃. 2 less than day or 100,000 cm 3 / ((m 2 It is understood to be a moisture vapor permeability of less than day bar.

[0049] The impermeable substrate may include a polymer. The polymer may be a fluoropolymer. The polymer may be a non-fluoropolymer. The polymer may be an expansion polymer. The polymer may be a high-density expansion polymer.

[0050] To avoid any doubt, the term "high-density expanded polymer membrane" refers to a polymer membrane that is expanded below its melting point and then densified after expansion. Thus, it will be understood that the density of at least one high-density expanded polymer membrane is greater than the density of the corresponding non-densified expanded polymer membrane. It will be understood by those skilled in the art that a polymer membrane expanded below its melting point and then densified may have a lower porosity than the corresponding polymer membrane of the same material that is expanded but not densified. The densification step can close a certain proportion of pores in the expanded polymer membrane. Thus, the degree to which the expanded polymer membrane is densified can be controlled so that the permeability of gas across the membrane is controlled and adapted to the required application.

[0051] The polymer may be selected from polytetrafluoroethylene (PTFE), polypropylene (PP), polyethylene (PE), perfluoro(alkyl vinyl ether) [including "PAVE", perfluoro(methyl vinyl ether), perfluoro(ethyl vinyl ether), perfluoro(propyl vinyl ether), etc.], vinylidene fluoride (VDF), fluorinated ethylene propylene (FEP), chlorotrifluoroethylene (CTFE), or copolymers thereof or combinations thereof.

[0052] The polymer may be selected from polypropylene (PP), polyethylene (PE), polyethylene terephthalate (PET), polyamide, or copolymers thereof.

[0053] The impermeable substrate may include a metal. For example, the impermeable substrate may include aluminum, iron, copper, tin, or an alloy thereof or a combination thereof.

[0054] The impermeable substrate may have a thickness between the first side and the second side. The ratio of the thickness of the impermeable substrate to the maximum width of the above or each hole may be at least 2. The ratio of the thickness of the impermeable substrate to the maximum width of the above or each hole may be at least 3. The ratio of the thickness of the impermeable substrate to the maximum width of the above or each hole may be at least 5. The ratio of the thickness of the impermeable substrate to the maximum width of the above or each hole may be at least 7. The ratio of the thickness of the impermeable substrate to the maximum width of the above or each hole may be at least 10. The ratio of the thickness of the impermeable substrate to the maximum width of the above or each hole may be at least 15. The ratio of the thickness of the impermeable substrate to the maximum width of the above or each hole may be at least 20. The ratio of the thickness of the impermeable substrate to the maximum width of the above or each hole may be at least 25. Accordingly, the ratio of the thickness of the impermeable substrate to the maximum width of the above or each hole may be at least 3, 5, 7, 10, 15, 20, 25, or a value in between.

[0055] The ratio of the thickness of the opaque substrate to the maximum width of the above or each hole may be 2 to 100. The ratio of the thickness of the opaque substrate to the maximum width of the above or each hole may be 3 to 100. The ratio of the thickness of the opaque substrate to the maximum width of the above or each hole may be 5 to 100. The ratio of the thickness of the opaque substrate to the maximum width of the above or each hole may be 7 to 100. The ratio of the thickness of the opaque substrate to the maximum width of the above or each hole may be 10 to 100. The ratio of the thickness of the opaque substrate to the maximum width of the above or each hole may be 15 to 100. The ratio of the thickness of the opaque substrate to the maximum width of the above or each hole may be 20 to 100. The ratio of the thickness of the opaque substrate to the maximum width of the above or each hole may be 25 to 100. The ratio of the thickness of the opaque substrate to the maximum width of the above or each hole may be 2 to 90. The ratio of the thickness of the opaque substrate to the maximum width of the above or each hole may be 2 to 80. The ratio of the thickness of the opaque substrate to the maximum width of the above or each hole may be 2 to 70. The ratio of the thickness of the opaque substrate to the maximum width of the above or each hole may be 2 to 60.

[0056] In an embodiment where at least one hole is linear (where the maximum width of at least one hole on the first side of the opaque substrate is approximately the same as the maximum width of at least one hole on the second side of the opaque substrate), the ratio of the thickness of the opaque substrate to the maximum width of the or each hole may be at least 10. The ratio of the thickness of the opaque substrate to the maximum width of the or each hole may be at least 15. The ratio of the thickness of the opaque substrate to the maximum width of the or each hole may be at least 20.

[0057] In an embodiment in which at least one hole is tapered (where the maximum width of at least one hole on the first side of the impermeable substrate is different from the maximum width of at least one hole on the second side of the impermeable substrate), the ratio of the thickness of the impermeable substrate to the average maximum width of each of the above or each hole may be at least 2. The ratio of the thickness of the impermeable substrate to the maximum width of each of the above or each hole may be at least 5. The ratio of the thickness of the impermeable substrate to the maximum width of each of the above or each hole may be at least 10.

[0058] The ratio of the cross-sectional area of ​​the above or each hole to the thickness of the opaque substrate may be at least 0.1 per μm. The ratio of the cross-sectional area of ​​the above or each hole to the thickness of the opaque substrate may be at least 0.5 per μm. The ratio of the cross-sectional area of ​​the above or each hole to the thickness of the opaque substrate may be at least 0.6 per μm. The ratio of the cross-sectional area of ​​the above or each hole to the thickness of the opaque substrate may be at least 0.7 per μm. The ratio of the cross-sectional area of ​​the above or each hole to the thickness of the opaque substrate may be at least 0.8 per μm. The ratio of the cross-sectional area of ​​the above or each hole to the thickness of the opaque substrate may be at least 0.9 per μm. The ratio of the cross-sectional area of ​​the above or each hole to the thickness of the opaque substrate may be at least 1 per μm.

[0059] The ratio of the cross-sectional area of ​​the above or each hole to the thickness of the opaque substrate may be 0.1 to 1000 per μm. The ratio of the cross-sectional area of ​​the above or each hole to the thickness of the opaque substrate may be 0.1 to 750 per μm. The ratio of the cross-sectional area of ​​the above or each hole to the thickness of the opaque substrate may be 0.1 to 500 per μm. The ratio of the cross-sectional area of ​​the above or each hole to the thickness of the opaque substrate may be 0.1 to 250 per μm. The ratio of the cross-sectional area of ​​the above or each hole to the thickness of the opaque substrate may be 0.1 to 100 per μm. The ratio of the cross-sectional area of ​​the above or each hole to the thickness of the opaque substrate may be 0.5 to 1000 per μm. The ratio of the cross-sectional area of ​​the above or each hole to the thickness of the opaque substrate may be 1 to 1000 per μm. The ratio of the cross-sectional area of ​​the above or each hole to the thickness of the impermeable substrate may be 2 to 1000 per μm.

[0060] In a second embodiment, a battery comprising a housing wall is provided, wherein the housing wall comprises an impermeable substrate and at least one hole provided in the impermeable substrate, said or each hole extends from a first side of the impermeable substrate to a second side of the impermeable substrate, and said or each aperture has a maximum width of 1 μm to 50 μm.

[0061] The battery can be a battery pouch cell or a battery prismatic cell.

[0062] The housing wall may comprise at least one of a metal, a metal alloy, at least one polymer, or a combination thereof.

[0063] At least one polymer may include a fluoropolymer such as PTFE, PFA, FEP, or a non-fluoropolymer such as polyethylene (PE), polypropylene (PP), polyethylene terephthalate (PET), or copolymers thereof.

[0064] The housing wall may include at least one metal layer and at least one polymer layer.

[0065] The housing wall may include an exhaust aperture, and the impermeable material may close the exhaust aperture. An exhaust element according to the first embodiment may close the exhaust opening, and at least one hole of the exhaust element may correspond to at least one hole of the impermeable material of the present embodiment. The exhaust element may form a plug configured to detachably close or plug the exhaust aperture. The exhaust element may include a sealing element around the perimeter of the exhaust element, and the sealing element may be configured to form a seal between the exhaust element and the housing wall around the perimeter of the exhaust aperture. Thus, at least one hole of the exhaust element is the only path for gas to pass from the inside of the battery housing to the outside of the battery housing. The exhaust element may include a handle element configured to easily grasp the exhaust element and remove it from the exhaust aperture.

[0066] The housing wall may include at least two holes provided in the impermeable substrate. The housing wall may include at least three holes provided in the impermeable substrate. The housing wall may include at least four holes provided in the impermeable substrate. The housing wall may include at least five holes provided in the impermeable substrate. The housing wall may include at least six holes provided in the impermeable substrate. The housing wall may include at least seven holes provided in the impermeable substrate. The housing wall may include at least eight holes provided in the impermeable substrate. The housing wall may include at least nine holes provided in the impermeable substrate. The housing wall may include at least ten holes provided in the impermeable substrate.

[0067] The housing wall may include 1 to 100 holes provided in the opaque substrate. The housing wall may include 1 to 75 holes provided in the opaque substrate. The housing wall may include 1 to 50 holes provided in the opaque substrate. The housing wall may include 1 to 40 holes provided in the opaque substrate. The housing wall may include 1 to 30 holes provided in the opaque substrate. The housing wall may include 1 to 20 holes provided in the opaque substrate. The housing wall may include 1 to 15 holes provided in the opaque substrate. The housing wall may include 1 to 10 holes provided in the opaque substrate.

[0068] In some embodiments, the housing wall may have one hole provided in the impermeable substrate. In some embodiments, the housing wall may have two holes provided in the impermeable substrate. In some embodiments, the housing wall may have three holes provided in the impermeable substrate. In some embodiments, the housing wall may have four holes provided in the impermeable substrate. In some embodiments, the housing wall may have five holes provided in the impermeable substrate.

[0069] The battery can be a secondary battery. The secondary battery can be a lithium-ion battery.

[0070] As used herein, the term "lithium-ion battery" refers to any battery configured to allow lithium ions to move between a negative electrode and a positive electrode during operation. Examples of lithium-ion batteries include, but are not limited to, lithium-ion polymer (LiPo) batteries, lithium-sulfur (Li-S) batteries, and thin-film lithium batteries.

[0071] 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.

[0072] The negative electrode can be selected from lithium, graphite, lithium titanate ("LTO"), tin-cobalt alloy, or any combination thereof.

[0073] In some embodiments, the battery may include at least one separator. The at least one separator may include at least one material selected from 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.

[0074] The electrolyte may be an electrolyte solution, and the electrolyte solution may comprise at least one solvent and at least one electrolyte salt. At least one solvent of the electrolyte solution may comprise at least one organic solvent. 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.

[0075] While it is desirable for the electrolyte to function solely as an electrolyte within the battery housing and facilitate the transport of ions between the electrodes, the electrolyte can degrade during battery use. The electrolyte may engage in chemical side reactions to generate byproducts. These byproducts are CO₂ 2, H2, CO, CH4, It may contain gases such as C2H6, C2H4, C3H6, or C3H8.

[0076] The electrolyte may include at least one additive, and at least one additive may be configured to release at least one gas selected from CO2, H2, CO, CH4, or any combination thereof during operation of the battery. At least one additive may be selected from the group comprising vinylene carbonate (VC), ethylene sulfite (ES), and fluoroethylene carbonate (FEC).

[0077] The electrolyte can be impregnated into at least one separator.

[0078] In some embodiments, the housing wall may be rigid. Thus, the housing wall may be configured to resist deformation and change the shape of the housing wall. Alternatively, the housing may be flexible. Thus, the housing wall may be configured to deform at least partially and change the shape of the housing wall. For example, the housing wall may be a pouch-type housing wall, and the battery housing may be a battery pouch.

[0079] In some embodiments, the housing wall may comprise at least one of a metal, a metal alloy, or a combination thereof. In some embodiments, the housing wall may comprise at least one of iron (Fe), aluminum (Al), or an alloy thereof. In some embodiments, the housing wall may comprise at least one polymer. The at least one polymer may comprise a fluoropolymer such as PTFE, PFA, FEP, or a copolymer thereof. The at least one polymer may comprise a non-fluoropolymer such as polyethylene (PE), polypropylene (PP), polyethylene terephthalate (PET), or a copolymer thereof. The housing wall may comprise a combination of at least one metal layer and at least one polymer layer. The housing wall may comprise at least one metal layer disposed between at least two polymer layers. Thus, the housing wall may comprise at least one metal layer, wherein at least one polymer layer is disposed on a first side of the at least one metal layer and at least one polymer layer is disposed on a second side of the at least one metal layer. Accordingly, the at least one metal layer may be protected by at least one polymer layer on the first side and at least one polymer layer on the second side. At least one polymer layer on the first side may be identical to at least one polymer layer on the second side. At least one polymer layer on the first side may include the same polymer as at least one polymer layer on the second side. At least one polymer layer on the first side may be different from at least one polymer layer on the second side. At least one polymer layer on the first side may include a polymer different from at least one polymer layer on the second side.

[0080] In an embodiment in which the housing wall comprises a plurality of layers, it should be understood that the or each hole may extend through each of the plurality of layers to form a penetrating aperture that penetrates the housing wall. Accordingly, in an embodiment in which at least one hole extends through an exhaust element provided across the housing wall or the aperture of the housing wall, the at least one hole extends through the entire thickness of the housing wall or the exhaust element so that gas can permeate from the inside of the housing wall to the outside of the housing wall.

[0081] At least one hole may be approximately conical, and the maximum width on the first side of the opaque substrate may differ from the maximum width on the second side of the opaque substrate.

[0082] The maximum width of at least one hole on the first side of the opaque substrate may be greater than the maximum width of at least one hole on the second side of the opaque substrate.

[0083] The maximum width of at least one hole on the first side of the impermeable substrate may be at least 30% larger than the maximum width of at least one hole on the second side of the impermeable substrate.

[0084] A first side of the opaque substrate may be oriented away from the battery housing, or a first side of the opaque substrate may be oriented toward the battery housing.

[0085] The battery housing may include a protective element provided on at least one of a first main surface and a second main surface of an impermeable substrate and covering the said or each hole.

[0086] The battery housing may include two protective elements.

[0087] The two protective elements may include a first protective element provided on a first surface and a second protective element provided on a second surface, and accordingly, the above or each hole is covered by the first protective element and the second protective element.

[0088] At least one protective element may include an expansion polymer.

[0089] At least one protective element may include expanded polytetrafluoroethylene (ePTFE) or expanded polyethylene (ePE).

[0090] A battery housing may include at least one protective element provided on at least one of a first side and a second side of an impermeable substrate and may cover said or each hole. At least one protective element may prevent particle intrusion into said or each hole. At least one protective element may prevent liquid intrusion into said or each hole. A battery housing may include two protective elements. The two protective elements may include a first protective element provided on the first side and a second protective element provided on the second side, so that said or each hole is covered by both the first protective element and the second protective element. Accordingly, a first end of said or each hole may be covered by the first protective element, and a second end of said or each hole may be covered by the second protective element.

[0091] At least one protective element may include an open material.

[0092] The term "open material" as used herein refers to a material having high porosity and low resistance to gas flow. In the content of the present embodiment, the open material has a CO2 permeability higher than the CO2 permeability passing through the housing wall, and accordingly does not limit the CO2 permeability passing through the said or each hole within the impermeable substrate of the housing wall.

[0093] At least one protective element may comprise a highly porous material. At least one protective element may comprise a material having a CO2 permeability higher than that of the housing wall. Accordingly, the CO2 permeability across the battery housing is not limited by the at least one protective element, but rather is limited by the CO2 permeability of the housing wall. At least one protective element is at least 200,000,000 cm 3 / (m 2 It can have a CO2 transmittance of (day bar). At least one protective element is at least 300,000,000 cm 3 / (m 2 It can have a CO2 transmittance of (day bar). At least one protective element is at least 400,000,000 cm 3 / (m 2 It can have a CO2 transmittance of (day bar). At least one protective element is at least 500,000,000 cm 3 / (m 2 It can have a CO2 transmittance of (day bar). At least one protective element is at least 600,000,000 cm 3 / (m 2 It can have a CO2 transmittance of (day bar). At least one protective element is at least 700,000,000 cm 3 / (m 2 It can have a CO2 transmittance of (day bar). At least one protective element is at least 800,000,000 cm 3 / (m 2 It can have a CO2 transmittance of (day bar). At least one protective element is at least 1,000,000,000 cm 3 / (m 2 It can have a CO2 transmittance of (day bar). At least one protective element is approximately 200,000,000 cm² 3 / (m 2 day bar) to about 50,000,000,000 cm 3 / (m2 It can have a CO2 transmittance of (day bar). At least one protective element is approximately 300,000,000 cm² 3 / (m 2 day bar) to about 50,000,000,000 cm 3 / (m 2 It can have a CO2 transmittance of (day bar). At least one protective element is approximately 400,000,000 cm² 3 / (m 2 day bar) to about 50,000,000,000 cm 3 / (m 2 It can have a CO2 transmittance of (day bar). At least one protective element is approximately 500,000,000 cm² 3 / (m 2 day bar) to about 50,000,000,000 cm 3 / (m 2 It can have a CO2 transmittance of (day bar). At least one protective element is approximately 600,000,000 cm 3 / (m 2 day bar) to about 50,000,000,000 cm 3 / (m 2 It can have a CO2 permeability of (day bar).

[0094] At least one protective element is approximately 700,000,000 cm 3 / (m 2 day bar) to about 50,000,000,000 cm 3 / (m 2 It can have a CO2 transmittance of (day bar). At least one protective element is approximately 800,000,000 cm² 3 / (m 2 day bar) to about 50,000,000,000 cm 3 / (m 2 It can have a CO2 permeability of (day bar).

[0095] According to a third embodiment, a method for manufacturing a battery is provided, and the method

[0096] - A step of providing a battery housing comprising a formation exhaust port within a housing wall and a pair of electrodes, wherein the formation exhaust port comprises an impermeable substrate and at least one hole provided in the impermeable substrate, and the at least one hole has a maximum width of 1 μm to 50 μm;

[0097] - A step of adding an electrolyte to a battery housing to form a battery;

[0098] - A step of applying charge across a pair of electrodes to precharge the battery

[0099] Gas generated within the battery housing during the maintenance phase and pre-charging phase is exhausted to the outside of the battery housing through at least one hole.

[0100] The above method may include a step of maintaining the electrolyte in the battery housing for a period of at least 5 minutes after the step of adding the electrolyte in the battery housing and before the step of applying a charge across a pair of electrodes ("aging"). The step of maintaining the electrolyte in the battery housing may allow the electrolyte to penetrate through the battery housing to the electrodes. The step of maintaining the electrolyte in the battery housing may allow the electrolyte to penetrate through the electrodes.

[0101] The step of maintaining the electrolyte within the battery housing may be for a period of at least 10 minutes. The step of maintaining the electrolyte within the battery housing may be for a period of at least 20 minutes. The step of maintaining the electrolyte within the battery housing may be for a period of at least 30 minutes.

[0102] The step of maintaining the electrolyte within the battery housing may be for a period of 5 minutes to 3 hours. The step of maintaining the electrolyte within the battery housing may be for a period of 10 minutes to 3 hours. The step of maintaining the electrolyte within the battery housing may be for a period of 20 minutes to 3 hours. The step of maintaining the electrolyte within the battery housing may be for a period of 30 minutes to 3 hours. The step of maintaining the electrolyte within the battery housing may be for a period of 40 minutes to 3 hours. The step of maintaining the electrolyte within the battery housing may be for a period of 50 minutes to 3 hours. The step of maintaining the electrolyte within the battery housing may be for a period of 1 hour to 3 hours. The step of maintaining the electrolyte within the battery housing may be for a period of 5 minutes to 2.5 hours. The step of maintaining the electrolyte within the battery housing may be for a period of 5 minutes to 2 hours. The step of maintaining the electrolyte within the battery housing may be for a period of 5 minutes to 1.5 hours. The step of maintaining the electrolyte within the battery housing may be for a period of 5 minutes to 1 hour.

[0103] The battery housing may include an electrolyte inlet, and the electrolyte may be added to the battery housing through the electrolyte inlet. The electrolyte inlet may be sealed after the electrolyte is added. The step of adding the electrolyte to the battery housing may be performed under vacuum conditions. The step of adding the electrolyte to the battery housing may be performed under dry conditions. Accordingly, the interior of the battery housing may be protected from liquid water and water vapor during the step of adding the electrolyte to the battery housing.

[0104] The step of maintaining the electrolyte within the battery housing can be performed under normal conditions (i.e., not under dry or vacuum conditions). The formation exhaust port can protect the interior of the battery housing from the entry of liquid water, water vapor, and other contaminants so that dry or vacuum conditions are not required.

[0105] The step of maintaining the electrolyte within the battery housing can allow the entire battery to reach or approach equilibrium.

[0106] The above method may further include a step of allowing the charged battery to rest or age after the step of precharging the battery.

[0107] The formation exhaust port may be an exhaust element of the first embodiment. Accordingly, the feature of the exhaust element of the first embodiment may be a feature of the formation exhaust port of the third embodiment.

[0108] At least one hole may extend from a first side of the opaque substrate to a second side of the opaque substrate, and the maximum width of at least one hole on the first side of the opaque substrate may be at least 30% larger than the maximum width of at least one hole on the second side of the opaque substrate.

[0109] A first side of the opaque substrate may be oriented away from the battery housing. A first side of the opaque substrate may be oriented toward the battery housing. In an embodiment where the maximum width of at least one hole on the first side of the opaque substrate is at least 30% greater than the maximum width of at least one hole on the second side of the opaque substrate, the first side of the opaque substrate may be oriented toward the inside of the battery housing such that the side of the hole having the smaller maximum width faces toward the outside of the battery housing.

[0110] The step of precharging the battery may be performed until the battery holds at least 10 Ah. The step of precharging the battery may be performed until the battery holds at least 20 Ah. The step of precharging the battery may be performed until the battery holds at least 50 Ah. The step of precharging the battery may be performed until the battery holds at least 100 Ah. The step of precharging the battery may be performed until the battery holds at least 150 Ah. The step of precharging the battery may be performed until the battery holds at least 200 Ah.

[0111] The step of precharging the battery may be performed until the battery holds 10 Ah to 500 Ah. The step of precharging the battery may be performed until the battery holds 10 Ah to 250 Ah. The step of precharging the battery may be performed until the battery holds 10 Ah to 200 Ah. The step of precharging the battery may be performed until the battery holds 10 Ah to 1500 Ah. The step of precharging the battery may be performed until the battery holds 10 Ah to 100 Ah. The step of precharging the battery may be performed until the battery holds 50 Ah to 500 Ah. The step of precharging the battery may be performed until the battery holds 100 Ah to 500 Ah. The step of precharging the battery may be performed until the battery holds 150 Ah to 500 Ah.

[0112] The above method may include a step of sealing the formation exhaust port after a pre-charging step. The step of sealing the formation exhaust port may include a step of covering the formation exhaust port with a sealing impermeable material and a step of fixing the sealing impermeable material on the formation vent. The sealing impermeable material may be configured to prevent flow when gas crosses the formation exhaust port. The step of sealing the formation exhaust port may include a step of applying a condition to the formation exhaust port to close at least one hole. In an embodiment in which the formation exhaust port includes a first protective element on the outside of the battery housing, the step of sealing the formation exhaust port may include a step of applying a condition to the first protective element to block at least one hole of the formation exhaust port. For example, the step of sealing the formation exhaust port may include a step of applying a laser to the formation exhaust port or the first protective element to cut or weld the material of the first protective element over at least one hole or to block or otherwise close or occlude at least one hole.

[0113] The gas generated during the step of applying charge across the electrode pair can be continuously exhausted from inside the battery housing through at least one hole.

[0114] The battery housing may include an exhaust element of the first embodiment, and the exhaust element may cross an aperture formed by the battery housing. Thus, the exhaust element may correspond to a formation exhaust port.

[0115] The battery may be a prismatic cell, and the battery housing may include a non-flexible prismatic wall.

[0116] The battery may be a battery pouch cell, and the battery housing may include a flexible pouch wall.

[0117] A battery housing may include a battery portion and an exhaust portion, the battery portion includes a pair of electrodes, and the exhaust portion includes at least one hole, and the method

[0118] - A step of sealing the battery portion from the exhaust portion; and

[0119] - Step of separating the exhaust port from the battery port

[0120] It may include more, and the remaining battery part corresponds to the battery.

[0121] The step of sealing the battery portion from the exhaust portion may include the step of forming a heat seal between the battery portion and the exhaust portion. The heat seal may attach the inner wall of a first side on the flexible pouch wall to the inner wall of a second side on the opposite side on the flexible pouch wall. The heat seal may fuse the inner wall of the first side on the flexible pouch wall to the inner wall of the second side on the opposite side on the flexible pouch wall. The heat seal may extend along the flexible pouch wall to completely separate the battery portion from the exhaust portion.

[0122] The exhaust port portion may include a gas absorbent. The gas absorbent may be configured to absorb gas formed during the step of applying charge across the electrode pair. The gas absorbent may be provided in an absorbent retainer. The absorbent retainer may separate the gas absorbent from the electrolyte of the battery portion. The absorbent retainer may include a retainer wall. The retainer wall may include a material identical or similar to the housing wall. The retainer wall may include at least one polymer. The retainer wall may include at least one polymer. The at least one polymer may include a fluoropolymer such as PTFE, PFA, FEP, or a copolymer thereof. The at least one polymer may include a non-fluoropolymer such as polyethylene (PE), polypropylene (PP), polyethylene terephthalate (PET), or a copolymer thereof. The retainer wall may include a combination of at least one metal layer and at least one polymer layer. The retainer wall may include at least one metal layer provided between at least two polymer layers.

[0123] The retainer wall may include at least one hole. Accordingly, the gas generated during the step of applying a charge across the electrode pair may pass from the electrolyte into the absorbent retainer through at least one hole.

[0124] The retainer wall may be permeable to the gas generated during the step of applying charge across the electrode pair, and thus the gas may pass through the retainer wall from the exhaust port portion to be absorbed by the gas absorbent.

[0125] The absorbent retainer may share a wall with the exhaust port portion. Since the shared wall may include at least one hole, gas from the absorbent retainer can be exhausted to the outside of the exhaust port portion through at least one hole.

[0126] The gas absorbent may comprise any material configured to absorb or absorb the gas generated during the step of applying a charge across the electrode pair. For example, the gas absorbent may comprise activated carbon. The gas absorbent may comprise a zeolite. The zeolite may be selected from the following types of zeolites: Type A zeolite, Type L zeolite, Type β zeolite, MFI type zeolite, or faujasite-type zeolite. In some embodiments, the zeolite may be an MFI type zeolite selected from ZSM-5 type zeolite or ZSM-11 type zeolite. The gas absorbent may comprise carbon black, a metal, a metal oxide, a metal nitride, or an intermetallic compound.

[0127] In a fourth embodiment, a battery manufacturing method is provided, and the method

[0128] - A step of providing a battery housing comprising an aperture formed in the housing wall and a pair of electrodes;

[0129] - A step of adding a first amount of electrolyte to the battery housing through an aperture;

[0130] - A step of installing a formation exhaust port within a battery housing so that the formation exhaust port blocks the configuration; and

[0131] - A step of applying charge across a pair of electrodes to precharge the battery

[0132] It includes, and the gas generated in the battery housing during the pre-charging phase is exhausted to the outside of the battery housing through at least one hole.

[0133] The above method may include the step of maintaining the electrolyte in the battery housing for a period of at least 5 minutes. The step of maintaining the electrolyte in the battery housing may be performed prior to the step of applying a charge across the electrode pair.

[0134] The formation exhaust port can be removed after the battery pre-charging stage.

[0135] The above method may include the step of adding a second amount of electrolyte to the battery housing through an aperture after the formation exhaust port has been removed.

[0136] The above method may include a step of sealing the aperture after the step of removing the formation exhaust port or after the step of adding a second amount of electrolyte to the battery housing.

[0137] The step of adding a first amount of electrolyte to the battery housing through an aperture and, if present, adding a second amount of electrolyte to the battery housing through an aperture can be performed under dry conditions.

[0138] The step of charging the battery can be performed outside of dry conditions due to a formation exhaust port that protects the inside of the battery housing from the entry of liquid water, water vapor, or other contaminants.

[0139] The step of sealing the aperture may include the step of covering the aperture with a sealing impermeable material and the step of fixing the sealing impermeable material on the aperture. The sealing impermeable material may be configured to prevent flow when gas crosses the aperture. The step of sealing the aperture may include the step of applying conditions to the aperture to close the aperture. For example, the step of sealing the aperture may include the step of applying a laser to the aperture to cut or weld the aperture in order to block, otherwise close, or occlude the aperture. Brief explanation of the drawing

[0140] Now, embodiments of the present invention will be described as non-limiting examples with reference to the attached drawings. Fig. 1: Schematic side view of a test setup for measuring CO2 permeability; Fig. 2: Schematic side view of a test setup for measuring water vapor permeability; FIG. 3: A schematic method for manufacturing a prismatic cell (< 100Ah cell) known in the art; FIG. 4: A schematic method for manufacturing a prismatic cell (< 100Ah cell) known in the art; FIG. 5: A schematic method for manufacturing a pouch battery cell known in the art; FIG. 6: Rectangular battery cell according to an embodiment; FIG. 7: Schematic side view of an exhaust element mounted over an aperture formed on the battery housing wall; FIG. 8: Schematic method for manufacturing a rectangular cell according to an embodiment; FIG. 9: Pouch battery cell according to an embodiment; FIG. 10: Schematic method for manufacturing a pouch battery cell according to an embodiment; FIG. 11: A pouch battery cell housing to be formed into a pouch battery cell using a method according to an embodiment; FIG. 12: During the method according to the embodiment, the separated gas portion removed from the pouch battery cell housing of FIG. 11 and the pouch battery cell; FIG. 13: Schematic method for manufacturing a pouch battery cell according to an embodiment; FIG. 14: SEM of a conical hole formed in an impermeable substrate, A) a first side of the impermeable substrate and B) a second side of the impermeable substrate; FIG. 15: Schematic side view of a conical hole extending through an impermeable substrate; Fig. 16: Scanning electron microscope (SEM) image of a hole formed in an opaque substrate; FIG. 17: Schematic side view of a cylindrical hole extending through an impermeable substrate; FIG. 18: Plot of gas flow rate according to hole size in straight holes and tapered holes; FIG. 19: Plot of gas flow rate according to hole size in straight holes and tapered holes; Fig. 20: Plot of gas flow rate according to the aspect ratio of the substrate thickness to the maximum hole width; Fig. 21: Plot of gas flow rate according to the aspect ratio of substrate thickness to the maximum hole width; Fig. 22: Plot of the ratio of CO2 transmittance to water vapor transmittance according to hole size; Fig. 23: Plot of the ratio of CO2 transmittance to water vapor transmittance according to hole size; Fig. 24: Plot of the ratio of CO2 transmittance to water vapor transmittance as a function of the substrate thickness aspect ratio relative to the maximum hole width; Fig. 25: Plot of the ratio of CO2 permeability to water vapor permeability according to the aspect ratio of substrate thickness to the maximum hole width; FIG. 26: A pouch battery cell housing to be formed into a pouch battery cell using a method according to an embodiment; FIG. 27: During the method according to the embodiment, the separated gas portion removed from the pouch battery cell housing of FIG. 11 and the pouch battery cell; FIG. 28: Schematic method for manufacturing a pouch battery cell according to an embodiment. Specific details for implementing the invention

[0141] Although the formation and use of various embodiments of the present invention are described in detail below, the present invention provides many applicable concepts that can be implemented in various specific ways. The specific embodiments described herein are merely examples of specific ways of forming and using the present invention and do not limit the scope of the present invention.

[0142] To aid in understanding the present invention, a number of terms are defined below. The terms defined herein have the same meaning as generally understood by those skilled in the art related to the present invention. Terms in the singular form are not intended to refer only to singular entities, but include general classes in which specific embodiments may be used for illustrative purposes. These terms are used to describe specific embodiments of the present invention, but the use of the terms does not limit the invention, except as described in the claims.

[0143] Test method

[0144] CO 2 transmittance

[0145] The determination of CO2 permeability through the substrate was performed according to ASTM D1434-82 (Standard test method for determining gas permeability characteristics of plastic films and sheets). A differential pressure test method was used. The test setup is shown in Fig. 1.

[0146] 3,000,000 cm 3 / (m 2 For samples having a relatively high CO2 permeability exceeding 1 / day / bar, the GTR series gas permeation analyzer (model number GTR-11MJGG) from GTR Tec Corporation of Japan, utilizing a Shimadzu GC-2014 gas chromatograph, was used to measure the gas permeability of the substrate. The sample substrate was 15.2 cm in the center. 2It was placed on an aluminum mask holder having an opening. The mask was cut to approximately 6 x 6 cm. Subsequently, the mask was attached inside the instrument test cell and sealed within the chamber. A vacuum was applied for 10 minutes to remove air from the test chamber. Then, dry CO2 gas was introduced into the chamber on the first side of the substrate. For the measurement, a differential pressure of 99 kPa was conditioned across the substrate. CO2 passing through the sample substrate into the second side of the substrate was detected to provide the permeability to the substrate. The test temperature was set to 30 °C. The analyte collection time was set to 5 to 10 seconds, and the GC analysis time was set to 10 minutes. The CO2 permeability was measured by the instrument in cm⁻¹. 3 / (m 2 It was reported in units of (·day·atm). As defined above, CO2 permeability is the volume value at standard temperature and pressure in cm³. 3 .cm / (cm 2 It was converted to .s.bar units.

[0147] Moisture permeability

[0148] The determination of water vapor permeability through the substrate was performed according to ASTM F1249-20 (Standard Test Method for Water Vapor Permeability of Plastic Films and Sheets Using Modulated Infrared Sensors). An isobaric method was used. The test setup is illustrated in Fig. 2. Specifically, the instrument used to test the water vapor permeability of the material was a Lyssy water vapor permeability analyzer (Model L-80). The sample substrate was placed 5 cm in the center. 2It was placed on an aluminum mask holder having an opening. Subsequently, the mask was secured to the instrument test cell and sealed within the chamber. A sample substrate was provided to divide the sample chamber into a first section (high humidity chamber) and a second section (low humidity chamber). The first section retains water to create the high humidity side of the sample substrate. Dry nitrogen gas was passed to the second side to provide the low humidity side of the sample substrate. Both the first and second sections of the chamber are maintained at ambient pressure. The test was performed on the high humidity side at 40°C and 90% relative humidity. The amount of water vapor passing through the same substrate was measured by detecting water vapor penetrating the substrate from the first side on the high humidity side to the second side on the low humidity side at the "dry gas" outlet. The water vapor transmittance was determined by the instrument in g / (m²). 2 It was reported in units of ·day.

[0149] Using the ideal gas law, divide the water vapor permeability by the water vapor partial pressure difference (0.066 bar) to obtain cm 3 .cm / (cm 2 It was converted to units (s.bar), where volume was converted to units for standard temperature and pressure as previously specified. cm 3 .cm / (cm 2 Using both the carbon dioxide (CO2) and water vapor (moisture) permeability of the units (e.g., s.bar)—wherein volume was converted to units for standard temperature and pressure as previously defined—the ratio of CO2 permeability to water vapor (moisture) permeability was calculated by dividing the CO2 permeability by the water vapor permeability. The ratio of CO2 permeability to water vapor permeability has no units (i.e., it is dimensionless).

[0150] physical parameters

[0151] Image analysis is used to calculate the surface area of ​​the hole from the SEM image. The effective diameter of the hole is calculated from the measured area of ​​the hole on the laser-emitting side. Image analysis is used to estimate the maximum width of the hole from the SEM image.

[0152] The substrate thickness of the polymer film was measured using a Mitutoyo Litematic VL50S thickness gauge. The substrate thickness of the aluminum foil was measured using a Mitutoyo 547-400S Digimatic thickness gauge.

[0153] Batteries comprising prismatic or pouch-type battery housings are typically manufactured by assembling the battery housings in the first step. Once the battery housings are assembled, it is necessary to add an electrolyte, charge the battery, and seal the battery housings before the battery is ready to be shipped to a customer.

[0154] Referring to FIG. 3, a medium-sized battery manufactured with a rectangular can battery housing ("rectangular cell") and designed to maintain a charge of less than 100 ampere-hours (< 100 Ah) is often manufactured using the following process (1) while the battery housing is kept in a dry condition.

[0155] Electrolyte is injected (2) into the battery housing through an opening formed in the battery housing. Once the electrolyte is injected, the battery is aged (4) for a certain period of time. Subsequently, a charge (6) is applied between the electrodes of the battery to precharge (6) the battery. As the charge is applied between the electrodes, gas is often generated within the battery housing and exhausted through the aperture. Once the battery is charged, the aperture is sealed, and the battery is aged (8) for an additional period of time before the battery is ready for shipment.

[0156] The entire process must be carried out under dry conditions to ensure that moisture does not enter the battery housing; therefore, the process is often performed in a drying room that is specially tuned and entails additional costs and complexity.

[0157] Referring to FIG. 4, a large-sized battery manufactured with a rectangular can battery housing ("rectangular cell") and designed to maintain a charge of more than 100 Ah (> 100 Ah) is often manufactured using the following process (20) while the battery housing is kept in a dry condition.

[0158] Electrolyte is injected (22) into the battery housing through an aperture formed in the battery housing. The aperture is then plugged (24) with a rubber plug, and the battery is left for a certain period of time. Subsequently, an electric charge is applied between the electrodes of the battery to precharge (26) the battery. As gas is generated within the battery housing, the pressure within the battery housing increases. Subsequently, the rubber plug is removed (28), and the gas generated within the battery housing during the precharging phase (26) is exhausted (30) from the battery housing under vacuum. Additionally, due to the increase in pressure, the electrolyte often overflows from within the battery housing through the aperture. As a result, additional electrolyte is injected (32) into the battery housing to replace the overflowed electrolyte, and the aperture is then sealed before the battery is ready for shipment.

[0159] The entire process must be carried out under dry conditions to ensure that moisture does not enter the battery housing; therefore, the process is often performed in a drying room that is specially tuned and entails additional costs and complexity.

[0160] A pouch cell battery typically comprises a flexible housing made of a laminate material. The laminate material often comprises a polypropylene (PP) layer, an aluminum (Al) foil layer, and a polyethylene terephthalate (PET) / nylon (NL) layer. The PP layer is provided on the inner side of the pouch cell, the PET / NL layer is provided on the outer side of the pouch cell, and the Al layer is provided between them.

[0161] Pouch cell batteries are often manufactured using the following process (40) (see FIG. 5). The flexible housing includes a gas exhaust port portion and a body portion.

[0162] The electrolyte is injected (42) into the flexible housing through an aperture within the flexible housing, and then the aperture is sealed. The flexible housing is then aged (44) for a certain period before a charge is applied (46) between the electrodes of the flexible housing. As the charge is applied, gas is often generated within the flexible housing, thereby increasing the internal pressure of the flexible housing. Therefore, to relieve the increased pressure, a gas exhaust port (48) of the flexible housing is perforated, and the gas is discharged under vacuum. The gas exhaust port is then sealed (50) from the main body, and then the gas exhaust port portion is removed (52).

[0163] The initial step (42) of injecting the electrolyte into the flexible housing must be performed under dry conditions, and the steps of perforating the gas exhaust port (48) and sealing it (50) are performed under vacuum. These strict conditions increase the cost of the process. Additionally, the removal of the gas exhaust port requires the initial flexible housing to be significantly larger than that required for the pouch cell battery to be manufactured.

[0164] Example 1

[0165] Referring to FIGS. 6 and 7, a rectangular cell battery (80) comprises a battery housing (86), a pair of electrodes (82), an electrolyte aperture (84), and a formation exhaust port (88, 160) (functioning as an exhaust element). The formation exhaust port (88, 160) comprises an aluminum substrate (164) and a protective element (168) (functioning as a first protective element). An exhaust hole (functioning as at least one hole) (166) is formed through the aluminum substrate (164) and is covered by the protective element (168). The formation exhaust port (88, 160) extends across an aperture (170) formed within the battery housing (86) and closes the aperture (170).

[0166] A method (60) for manufacturing a prismatic cell battery (80) is generally illustrated in FIG. 8. An electrolyte is injected (62) into the prismatic cell battery (80) through an electrolyte aperture (84). Then, the electrolyte aperture (84) is sealed (64). Subsequently, the prismatic cell battery (80) is left or aged (66) for a certain period before a charge is applied between a pair of electrodes (82) during a pre-charging phase (68), and any gas generated within the battery housing (86) during the pre-charging phase (68) is continuously exhausted through a formation exhaust port (88, 160) so as not to increase the substantial pressure within the battery housing (86). Subsequently, the prismatic cell battery (80) is left or aged (70) before the formation exhaust port (88, 160) is sealed and the prismatic cell battery (80) is ready for shipment.

[0167] The formation exhaust port (88, 160) protects the interior of the battery housing (86) from external contaminants such as water vapor or particulates, and thus, when the electrolyte aperture (84) is sealed (64), the prismatic cell battery can be manufactured outside of strict drying conditions. Thus, the prismatic cell battery requires strict drying conditions only during the electrolyte injection step (62), significantly simplifying the process and thereby reducing manufacturing costs.

[0168] Example 2

[0169] A pouch cell battery (90) (Fig. 9) comprises a flexible housing (94), a pair of electrodes (92), and a formation exhaust port (96) (functioning as an exhaust element). The flexible housing (94) is a laminate of a PP layer, an aluminum foil layer, and a PET layer. The PP layer is provided inside the flexible housing (94), and the PET layer is provided outside the flexible housing (94). The flexible housing (94) forms an exhaust opening (not shown), and the formation exhaust port (96) extends across the exhaust aperture. The formation exhaust port (96) comprises an aluminum substrate, a first protective layer provided on a first side of the aluminum substrate, and a second protective layer provided on a second side of the aluminum substrate facing the first side.

[0170] A method (100) for manufacturing a pouch cell battery (90) is generally illustrated in FIG. 10. An electrolyte is injected (102) into the pouch cell battery (90) through an electrolyte aperture (not illustrated). The electrolyte aperture is then sealed. Subsequently, the pouch cell battery (90) is left or aged (104) for a certain period before a charge is applied between a pair of electrodes (92) during a pre-charging phase (106), and any gas generated within the flexible housing (94) during the pre-charging phase (106) is continuously exhausted through a formation exhaust port (96) so as not to increase substantial pressure within the flexible housing (94). Subsequently, the formation exhaust port (96) is sealed, and the pouch cell battery (90) is ready for shipment.

[0171] The formation exhaust port (96) protects the interior of the flexible housing (94) from external contaminants such as water vapor or particulates, and thus, when the electrolyte aperture (84) is sealed (64), the pouch cell battery (90) can be manufactured outside of strict dry conditions. Additionally, providing the formation exhaust port (96) within the flexible housing (94) means that there is no need to provide a gas section of the flexible housing (94) that is perforated to allow the gas generated within the flexible housing (94) to be discharged. Thus, the amount of laminate material used to form the flexible housing is significantly reduced, and the risk of the electrolyte overflowing during exhaust is completely eliminated.

[0172] Example 3

[0173] A pouch cell battery (120) (Figs. 11 and 12) comprises a flexible housing (124), a pair of electrodes (122), and a formation exhaust port (130) (functioning as an exhaust element). The flexible housing (124) is a laminate of a PP layer, an aluminum foil layer, and a PET layer. The PP layer is provided inside the flexible housing (124), and the PET layer is provided outside the flexible housing (124). The flexible housing (124) comprises a main body portion (126) and a gas portion (128) (functioning as an exhaust portion). The flexible housing defines an exhaust aperture (not shown) of the gas portion (128), and the formation exhaust port (130) extends across the exhaust aperture. The formation exhaust port (130) comprises an aluminum substrate, a first protective layer provided on a first side of the aluminum substrate, and a second protective layer provided on a second side of the aluminum substrate facing the first side.

[0174] A method (140) for manufacturing a pouch cell battery (120) is generally illustrated in FIG. 13. An electrolyte is injected (142) into the pouch cell battery (120) through an electrolyte aperture (not illustrated). The electrolyte aperture is then sealed. Subsequently, the pouch cell battery (120) is left or aged (144) for a certain period of time before a charge is applied between a pair of electrodes (122) during a pre-charging phase (146), and any gas generated within the flexible housing (124) during the pre-charging phase (146) is continuously exhausted through a formation exhaust port (130) so as not to increase the substantial pressure within the flexible housing (124). Subsequently, a heat seal (148) is formed between the gas portion (128) and the main body portion (126) to seal the main body portion (126) from the gas portion (128). Next, the gas section (128) is cut off from the main body (126) so that the electrolyte within the main body (126) remains sealed within the main body (126).

[0175] Providing a formation exhaust port (130) within the gas section (128) allows for the conventional process of forming a pouch cell battery (e.g., the process described with reference to FIG. 5 above) without requiring perforation of the gas section, thus preventing the electrolyte from overflowing and not requiring the pouch cell battery to be under vacuum conditions during this step. Accordingly, the provided method reduces the strict conditions required for manufacturing a pouch cell battery and reduces the costs incurred by this.

[0176] Example 4

[0177] A formation exhaust port (functioning as an exhaust element), with a cross-section shown in FIG. 15 and SEM images of the first and second sides shown in FIG. 14, comprises a polytetrafluoroethylene (PTFE) substrate having a thickness (180) and a laser-drilled hole (functioning as at least one hole) extending from the first side (174) to the second side (178). The hole has a first maximum width (172) on the first side (174) of the substrate and a second maximum width (176) on the second side (178) of the substrate. The first maximum width (172) is larger than the second maximum width (176), and the hole tapers from the first side (174) to the second side (176).

[0178] Another formation exhaust port (functioning as an exhaust element), with a cross-section shown in FIG. 17 and a first side shown in FIG. 16, comprises a PTFE substrate having a thickness (198) and a laser-drilled hole (functioning as at least one hole) extending from the first side (192) to the second side (196). The hole has a first maximum width (190) on the first side (192) of the substrate and a second maximum width (194) on the second side (196) of the substrate. The first maximum width (190) is equal to the second maximum width (194) within a measurement tolerance range, and the hole is approximately cylindrical from the first side (192) to the second side (196).

[0179] It was found that exhaust elements containing tapered holes (or conical holes) can provide improved resistance to water vapor permeation (i.e., have reduced water vapor permeability) compared to linear or cylindrical holes. In particular, exhaust elements containing tapered holes oriented so that the side of the hole with the smallest maximum width becomes the side of water vapor incident provide even reduced water vapor permeation. Gas flow rates according to hole size are shown in FIGS. 18 and 19. Gas flow rates according to the substrate-to-hole size aspect ratio are shown in FIGS. 20 and 21. The CO2 permeability to water vapor permeability ratio (CO2 / H2O ratio) for various hole sizes for linear and tapered holes is shown in FIGS. 22 and 23, and it is clearly shown that tapered holes have an improved ratio compared to linear holes.

[0180] Additionally, Figures 24 and 25 show the CO2 / H2O ratio according to the aspect ratio of substrate thickness versus maximum hole width. As can be seen, the CO2 / H2O ratio is significantly increased for tapered holes compared to straight holes.

[0181] Examples 5 to 12

[0182] Further specific embodiments of the exhaust element are provided in Table 1 below, comprising a 100 μm thick aluminum substrate having a single hole formed by penetrating the substrate by laser drilling. Examples 5 to 8 are straight holes having a cylindrical shape and equal maximum widths (HS1 = HS2) on both sides of the substrate. Examples 9 to 12 are tapered in a conical shape, and the maximum width on the first side of the substrate is greater than the maximum width on the second side of the substrate (HS1 > HS2).

[0183] Examples hole shape Hole size, first side (HS1), µm Hole size, 2nd side (HS2), µm Substrate thickness (Sub), μm Sub / HS1 Sub / HS2 5 Straight type 10 10 100 10 10 6 Straight type 15 15 100 6.7 6.7 7 Straight type 20 20 100 5 5 8 Straight type 30 30 100 3.3 3.3 9 Tapered type 15 10 100 6.7 10 10 Tapered type 25 15 100 4.0 6.7 11 Tapered type 35 20 100 2.9 5 12 Tapered type 18 12 100 5.6 8.3

[0184] Table 1: Exemplary exhaust elements with straight and tapered laser-drilled holes

[0185] The carbon dioxide permeability ("CO2GTR"), water vapor permeability ("MVTR"), or water vapor permeability, representing gas permeability, and the ratio of CO2GTR to MVTR are provided in Table 2 below as measured from the first aspect to the second aspect for each example, and as measured from the second aspect to the first aspect for Examples 9 to 12.

[0186] Examples CO2GTR HS1-> HS2 CO2GTR HS2-> HS1 MVTR, HS1 -> HS2 MVTR, HS2 -> HS1 CO2 / H2O HS1-> HS2 CO2 / H2OHS2-> HS1 5 3.71E-6 - 7.73E-9 - 480 - 6 1.12E-5 - 2.78E-7 - 40 - 7 1.87E-5 - 8.35E-7 - 22 - 8 5.46E-5 - 3.09E-6 - 18 - 9 6.09E-6 7.19E-6 9.98E-9 4.99E-9 610 1442 10 7.56E-6 1.65E-5 2.5E-8 2.0E-8 303 827 11 2.44E-5 2.59E-5 4.99E-8 3.49E-8 489 744 12 4.36E-6 4.75E-6 9.98E-9 7.49E-9 437 635

[0187] Table 2: Gas permeability ("CO2GTR"), water vapor permeability ("MVTR"), and gas permeability to water vapor permeability ratio ("CO2 / H2O") for Examples 5 to 12. GTR and MVTR are in cm⁻¹ 3 .cm / (cm 2 Provided in units of .s.bar.

[0188] Examples CO2GTR HS1-> HS2, ml / h CO2GTR HS2 -> HS1, ml / h MVTR, HS1 -> HS2, mg / h MVTR, HS2 -> HS1, mg / h CO2 / H2O HS1-> HS2 CO2 / H2O HS2-> HS1 5 41 - 0.006 - 480 - 6 124 - 0.233 - 40 - 7 207 - 0.698 - 22 - 8 605 - 2.583 - 18 - 9 68 80 0.008 0.004 610 1442 10 84 183 0.021 0.017 303 827 11 271 288 0.042 0.029 489 744 12 48 53 0.008 0.006 437 635

[0189] Table 3: Gas permeability ("CO2GTR"), water vapor permeability ("MVTR"), and gas permeability to water vapor permeability ratio ("CO2 / H2O") for Examples 5 to 12.

[0190] As can be seen, all embodiments have a good CO2 permeability to water vapor permeability ratio (greater than 15). Also, CO2 to The ratio of water vapor permeation is significantly increased in the cases of Examples 9 to 12 when measured from the second side (having a smaller maximum hole width) to the first side (having a larger maximum hole width).

[0191] Therefore, the exhaust element described herein is particularly useful for a method of protecting the interior of a battery housing during battery manufacturing to allow gases generated within the battery housing to be safely and efficiently exhausted to the outside of the battery housing, while effectively preventing water vapor from entering the battery housing.

[0192] Example 13

[0193] A pouch cell battery (200) (Figs. 26 and 27) comprises a flexible housing (202) and a pair of electrodes (204). The flexible housing (202) is a laminate of a PP layer, an aluminum foil layer, and a PET layer. The PP layer is provided inside the flexible housing (202), and the PET layer is provided outside the flexible housing (202). The flexible housing (202) comprises a main body portion (206) and a gas portion (208) (functioning as an exhaust port). The gas portion (208) comprises an absorbent retainer (210). The absorbent retainer portion (210) comprises a retainer wall (212) and retains zeolite (functioning as a gas absorbent). The retainer wall (212) comprises a formation exhaust port (214) (functioning as an exhaust element). A retainer wall (212) defines an exhaust opening (not shown) of the absorbent retaining portion (210), and a formation exhaust port (214) extends across the exhaust aperture. The formation exhaust port (214) includes an aluminum substrate, a first protective layer provided on a first side of the aluminum substrate, and a second protective layer provided on a second side of the aluminum substrate facing the first side.

[0194] A method (220) for manufacturing a pouch cell battery (200) is generally illustrated in FIG. 28. An electrolyte is injected (222) into the pouch cell battery (200) through an electrolyte aperture (not illustrated). The electrolyte aperture is then sealed. Subsequently, the pouch cell battery (200) is left or aged (224) for a certain period before a charge is applied between a pair of electrodes (204) during a pre-charging phase (226), and any gas generated within the flexible housing (202) during the pre-charging phase (226) is continuously exhausted through a formation exhaust port (214) to an absorbent retainer (210), and the gas is absorbed by the zeolite so that there is no substantial increase in pressure within the flexible housing (202). Next, a heat seal (228) is formed between the gas section (208) and the main body (206) to seal the main body (206) from the gas section (208). Then, the gas section (208) is cut off from the main body (206) so that the electrolyte within the main body (206) remains sealed within the main body (206) (230).

[0195] Providing a formation exhaust port (214) within the gas section (208) allows for the conventional process of forming a pouch cell battery (e.g., the process described with reference to FIG. 5 above) without requiring perforation of the gas section, thus preventing the electrolyte from overflowing and not requiring the pouch cell battery to be under vacuum conditions during this step. Accordingly, the provided method reduces the strict conditions required for manufacturing a pouch cell battery and reduces the costs incurred by this.

[0196] Although the above-described method, battery, and exhaust elements have been described in relation to battery capacities of less than 100 Ah (< 100Ah) and greater than 100 Ah (>100 Ah), it will be understood that they are suitable for battery capacities of any size applicable to portable electronic devices and automotive applications.

[0197] Although approved embodiments of the present invention have been described above, it will be readily apparent that many different changes and modifications can be made to the form, design, structure and arrangement of parts for other embodiments without departing from the invention as defined in the appended claims, and it will be understood that all such changes and modifications are considered as embodiments as part of the present invention.

Claims

Claim 1 An exhaust element comprising an impermeable substrate and a first protective element, wherein the impermeable substrate comprises at least one hole, and each of the holes extends from a first side of the impermeable substrate to a second side of the impermeable substrate, and each of the holes has a maximum width of 1 μm to 50 μm, and the first protective element is located on the first side of the impermeable substrate to close each of the holes. Claim 2 An exhaust element according to claim 1, wherein the above or each hole has a maximum width of 10 μm to 30 μm. Claim 3 An exhaust element according to claim 1 or 2, wherein the first protective element comprises an expansion polymer selected from expanded polytetrafluoroethylene and expanded polyethylene. Claim 4 An exhaust element according to any one of claims 1 to 3, wherein the exhaust element comprises a second protective element positioned on a second side of an impermeable substrate to block the or each hole. Claim 5 An exhaust element according to any one of claims 1 to 4, wherein each of the first protective element and, if present, the second protective element has a CO2 permeability higher than that of the or each hole. Claim 6 An exhaust element according to any one of claims 1 to 5, wherein each of the first protective element and, if present, the second protective element has an air flow rate of at least 20 ml / h. Claim 7 An exhaust element according to any one of claims 1 to 6, wherein the CO2 permeability through the exhaust element is at least 10 ml / h. Claim 8 An exhaust element according to any one of claims 1 to 7, wherein the water vapor permeability through the exhaust element is less than 1.0 mg / h. Claim 9 An exhaust element according to any one of claims 1 to 8, wherein the CO2 permeability to water vapor permeability through the exhaust element is at least 5. Claim 10 An exhaust element according to any one of claims 1 to 9, wherein the CO2 permeability to water vapor permeability through the exhaust element is 5 to 2000. Claim 11 An exhaust element according to any one of claims 1 to 10, wherein the at least one hole is approximately conical, and the maximum width on the first side of the impermeable substrate is different from the maximum width on the second side of the impermeable substrate. Claim 12 An exhaust element according to claim 11, wherein the maximum width of at least one hole on the first side of the impermeable substrate is at least 30% larger than the maximum width of at least one hole on the second side of the impermeable substrate. Claim 13 An exhaust element according to claim 11, wherein the maximum width of at least one hole on the first side of the impermeable substrate is at least 30% smaller than the maximum width of at least one hole on the second side of the impermeable substrate. Claim 14 An exhaust element according to any one of claims 11 to 13, wherein the at least one hole has a first end adjacent to a first side of an impermeable substrate and a second end adjacent to a second side of the impermeable substrate, the first end has a first maximum width and the second end has a second maximum width, the first maximum width is greater than the second maximum width, and the ratio of CO2 permeability to water vapor permeability from the second side of the impermeable substrate to the first side of the impermeable substrate is at least 2. Claim 15 A battery comprising a housing wall, wherein the housing wall comprises an impermeable substrate and at least one hole provided in the impermeable substrate, wherein each of the holes extends from a first side of the impermeable substrate to a second side of the impermeable substrate, and each of the holes has a maximum width of 1 μm to 50 μm. Claim 16 In paragraph 15, the battery is a battery that is a battery pouch cell or a battery prismatic cell. Claim 17 A battery according to claim 15 or 16, wherein the housing wall comprises one or more of a metal, a metal alloy, at least one polymer, or a combination thereof. Claim 18 A battery according to claim 17, wherein at least one polymer comprises a fluoropolymer such as PTFE, PFA, FEP, or a non-fluoropolymer such as polyethylene (PE), polypropylene (PP), polyethylene terephthalate (PET), or a copolymer thereof. Claim 19 A battery according to any one of claims 15 to 18, wherein the housing wall comprises at least one metal layer and at least one polymer layer. Claim 20 A battery according to any one of claims 15 to 19, wherein the housing wall comprises an exhaust aperture and the impermeable material blocks the exhaust aperture. Claim 21 A battery according to any one of claims 15 to 20, wherein the at least one hole is approximately conical, and the maximum width on the first side of the opaque substrate is different from the maximum width on the second side of the opaque substrate. Claim 22 A battery according to claim 21, wherein the maximum width of at least one hole on the first side of the opaque substrate is greater than the maximum width of at least one hole on the second side of the opaque substrate. Claim 23 A battery according to claim 21 or 22, wherein the maximum width on the first side of the opaque substrate is at least 30% greater than the maximum width on the second side of the opaque substrate. Claim 24 A battery according to claim 22 or 23, wherein the first side of the opaque substrate faces away from the battery housing, or the first side of the opaque substrate faces toward the battery housing. Claim 25 A battery according to any one of claims 15 to 24, wherein the battery housing is provided on one or more of the first main surface and the second main surface of an impermeable substrate and includes at least one protective element covering the or each of the holes. Claim 26 In claim 25, the battery housing comprises two protective elements. Claim 27 A battery according to claim 26, wherein the two protective elements comprise a first protective element provided on a first main surface and a second protective element provided on a second main surface, and accordingly, the or respective holes are covered by the first protective element and the second protective element. Claim 28 A battery according to any one of claims 15 to 27, wherein at least one protective element comprises an expandable polymer. Claim 29 A battery housing according to claim 28, wherein at least one protective element comprises expanded polytetrafluoroethylene (ePTFE) or expanded polyethylene (ePE). Claim 30 A battery housing according to any one of claims 15 to 29, wherein the battery housing comprises an exhaust element according to any one of claims 1 to 14. Claim 31 A method for manufacturing a battery, comprising: - a step of providing a battery housing including a formation vent within a housing wall and a pair of electrodes, wherein the formation vent includes an impermeable substrate and at least one hole provided in the impermeable substrate, and the at least one hole has a maximum width of 1 μm to 50 μm; - a step of adding an electrolyte to the battery housing to form a battery; and - a step of applying a charge across a pair of electrodes to precharge the battery, wherein gas generated within the battery housing during the maintenance step and the precharging step is exhausted to the outside of the battery housing through at least one hole. Claim 32 A battery manufacturing method according to claim 31, wherein the battery manufacturing method comprises the step of maintaining an electrolyte in a battery housing for a period of at least 5 minutes. Claim 33 A battery manufacturing method according to claim 32, wherein the step of maintaining the electrolyte within the battery housing is for a period of 5 minutes to 3 hours. Claim 34 A battery manufacturing method according to claim 31 or 33, wherein the formation exhaust port has a carbon dioxide to water vapor ratio of at least 10. Claim 35 A battery manufacturing method according to any one of claims 31 to 34, wherein the formation exhaust port has a carbon dioxide to water vapor ratio of 10 to 2000. Claim 36 A battery manufacturing method according to any one of claims 31 to 35, wherein the at least one hole has a maximum width of 1 to 40 μm. Claim 37 A battery manufacturing method according to claim 36, wherein at least one hole has a maximum width of 10 to 30 μm. Claim 38 A method for manufacturing a battery according to any one of claims 31 to 37, wherein the at least one hole extends from a first side of an impermeable substrate to a second side of an impermeable substrate, and the maximum width of the at least one hole on the first side of the impermeable substrate is at least 30% greater than the maximum width of the at least one hole on the second side of the impermeable substrate. Claim 39 A battery manufacturing method according to claim 38, wherein the first side of the above-mentioned opaque substrate faces away from the battery housing. Claim 40 A battery manufacturing method according to claim 39, wherein the first side of the above-mentioned opaque substrate faces the battery housing. Claim 41 A battery manufacturing method according to any one of claims 31 to 40, wherein the battery manufacturing method includes the step of sealing a formation exhaust port after a pre-charging step. Claim 42 A battery manufacturing method according to any one of claims 31 to 41, wherein the gas generated during the step of applying a charge across the pair of electrodes is continuously exhausted from the battery housing through at least one hole. Claim 43 A method for manufacturing a battery according to any one of claims 31 to 42, wherein the battery housing comprises an exhaust element according to any one of claims 1 to 14, and the exhaust element extends across an aperture defined by the battery housing. Claim 44 A method for manufacturing a battery according to any one of claims 31 to 43, wherein the battery is a battery pouch cell and the battery housing comprises a flexible pouch wall. Claim 45 A battery manufacturing method according to claim 44, wherein the battery housing comprises a battery portion and an exhaust portion, the battery portion comprises a pair of electrodes, and the exhaust portion comprises at least one hole, and the battery manufacturing method further comprises: a step of sealing the battery portion from the exhaust portion; and a step of separating the exhaust portion from the battery portion, wherein the remaining battery portion corresponds to the battery. Claim 46 A battery manufacturing method according to claim 45, wherein the step of sealing the battery portion from the exhaust portion includes forming a heat seal between the battery portion and the exhaust portion. Claim 47 A method for manufacturing a battery according to claim 44 or 45, wherein the exhaust port portion comprises a gas absorbent provided within an absorbent retainer, and the gas absorbent is configured to absorb gas during the step of applying a charge across a pair of electrodes. Claim 48 A method for manufacturing a battery according to any one of claims 31 to 43, wherein the battery is a battery prismatic cell and the battery housing comprises a non-flexible prismatic wall. Claim 49 A battery manufacturing method comprising: - providing a battery housing including an aperture formed in a housing wall and a pair of electrodes; - adding a first amount of electrolyte to the battery housing; - installing a formation exhaust port within the battery housing such that the formation exhaust port blocks the aperture; and - applying a charge across a pair of electrodes to precharge the battery, wherein gas generated within the battery housing during the maintenance step and the precharging step is exhausted to the outside of the battery housing through at least one hole. Claim 50 A battery manufacturing method according to claim 49, wherein the battery manufacturing method comprises the step of maintaining an electrolyte within a battery housing for a period of at least 5 minutes prior to the step of applying a charge across a pair of electrodes. Claim 51 A battery manufacturing method according to claim 49 or 50, wherein the formation exhaust port is removed after the battery pre-charging step. Claim 52 A battery manufacturing method according to claim 51, wherein the battery manufacturing method comprises the step of adding a second amount of electrolyte to the battery housing after removing the formation exhaust port. Claim 53 A battery manufacturing method according to claim 51 or 52, wherein the battery manufacturing method comprises the step of sealing an aperture after the step of removing a formation exhaust port or after the step of adding a second amount of electrolyte to a battery housing.

Images