Breathable waterproof structure and lithium battery

Abstract

The utility model discloses a kind of ventilated waterproof structure and lithium battery, it is related to lithium battery technical field, ventilated waterproof structure includes protective shell and exhaust component, protective shell is equipped with containing cavity, the shell is provided with air vent, the air vent is communicated the containing cavity and external air.Gas exhaust component includes cylinder, first air-permeable membrane, second air-permeable membrane and isolation liquid layer, the cylinder is sealed in the air vent, the first air-permeable membrane and the second air-permeable membrane are arranged at the inside of the cylinder, the isolation liquid layer is located between the first air-permeable membrane and the second air-permeable membrane, and for isolating water and air.Containing cavity generated gas can be sequentially through first air-permeable membrane, isolation liquid layer and second air-permeable membrane exhaust, avoid protective shell to produce the phenomenon of bulge.Compared with prior art, the lithium battery of the application is set by ventilated waterproof structure, containing cavity is not released gas by switch sealing plug, and there is no risk of electrolyte leakage.

Description

Technical Field

[0001] This utility model relates to the field of lithium battery technology, specifically to a breathable and waterproof structure and a lithium battery. Background Technology

[0002] Most lithium batteries currently use a completely sealed packaging. The inside of a lithium battery contains the positive electrode, negative electrode, separator, and electrolyte. When a lithium battery is used under abnormal conditions (such as overcharging, over-discharging, high or low temperature), a chemical reaction occurs inside, producing gases. These gases are mostly flammable gases (such as hydrogen, carbon monoxide, hydrocarbons, etc.). The gas pressurizes and causes the lithium battery casing to bulge, reducing the battery's capacity and lifespan. Excessive gas production can even lead to casing rupture, electrolyte leakage, and risks of fire and explosion. Therefore, it is necessary to promptly release the gases generated inside the lithium battery.

[0003] However, existing lithium batteries still have shortcomings. For example, lithium batteries typically have vents on their surface, with sealing plugs installed at these vents. The sealing plugs are opened when gas needs to be released and closed when no gas needs to be released. Not only are the vents cumbersome to open and close, but there is also a risk of electrolyte leakage from inside the battery when the vents are opened. Utility Model Content

[0004] The purpose of this utility model is to overcome the above-mentioned technical deficiencies and propose a breathable and waterproof structure and lithium battery. It solves the technical problem that in the prior art, lithium batteries usually have vents on their surface to release internal gas. The vents are not only cumbersome to open and close, but also pose a risk of electrolyte leakage when the vents are opened.

[0005] To achieve the above-mentioned technical objectives, the present invention adopts the following technical solution: In a first aspect, this utility model provides a breathable and waterproof structure, comprising: A protective outer shell has an internal cavity, and the shell has a vent that connects the cavity to external air; and An exhaust assembly includes a cylinder, a first breathable membrane, a second breathable membrane, and an isolation liquid layer. The cylinder is sealed at the vent. The first and second breathable membranes are spaced apart inside the cylinder. The isolation liquid layer is located between the first and second breathable membranes and is used to isolate water and air.

[0006] In some embodiments, the cylinder is hollow with openings at both ends, and both the first and second breathable membranes are connected to the inner wall of the cylinder.

[0007] In some embodiments, the bottom of the cylinder has a bottom plate, the bottom plate has a first vent hole, and the first vent membrane is connected to the bottom plate and covers the first vent hole.

[0008] In some embodiments, the top of the cylinder has a top plate, the top plate has a second vent hole, and the second vent membrane is connected to the top plate and covers the second vent hole.

[0009] In some embodiments, the protective housing includes a shell and a cover connected together. The housing has the receiving cavity formed inside. The cover protrudes toward the inside of the housing to form a positioning groove. The bottom of the positioning groove has the vent. The cylindrical body is sealed and snapped into the positioning groove.

[0010] In some embodiments, the cover is provided with a spare air hole, which is detachably connected to a sealing plug.

[0011] In some embodiments, the cover has a first electrode hole and a second electrode hole, which are located on both sides of the positioning groove.

[0012] In some embodiments, the breathable and waterproof structure further includes a first insulating member and a second insulating member. The protective shell has a first recessed groove and a second recessed groove. The first insulating member and the second insulating member are respectively engaged in the first recessed groove and the second recessed groove. The first insulating member and the second insulating member have a through hole and a through hole. The first through hole and the second through hole are respectively connected to the first electrode hole and the second electrode hole.

[0013] In some embodiments, both the first breathable membrane and the second breathable membrane are eptfe membranes, the surface of which is coated with a silanized nano-silica layer.

[0014] Secondly, this utility model also provides a lithium battery, including a battery cell and the above-mentioned breathable and waterproof structure, wherein the battery cell is disposed in the accommodating cavity of the protective shell, and the positive and negative electrodes of the battery cell extend outward through the side wall of the protective shell.

[0015] Compared with existing technologies, the breathable and waterproof structure provided by this utility model has a protective shell with an internal cavity for storing the lithium battery cells and electrolyte. A first and second breathable membrane allow gas to pass through while isolating the electrolyte. Gas generated in the cavity can be discharged sequentially through the first breathable membrane, the separator layer, and the second breathable membrane, preventing bulging of the protective shell. The separator can be an inert chemical liquid such as perfluoropolyether, which has extremely stable chemical properties, does not dissolve gases such as oxygen and water vapor in the air, and can prevent external air and water from entering the cavity. Therefore, compared with existing technologies, the lithium battery of this application, by setting a breathable and waterproof structure, does not require opening and closing the sealing plug to release gas into the cavity, and there is no risk of electrolyte leakage. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the breathable and waterproof structure provided in this embodiment of the utility model; Figure 2 This is an exploded view of the breathable and waterproof structure provided in this embodiment of the utility model; Figure 3 This is a schematic diagram of the structure of the exhaust assembly provided in this embodiment of the utility model; Figure 4 This is an exploded schematic diagram of the exhaust assembly provided in this embodiment of the present invention; Figure 5 This is a schematic diagram of the structure of the cover provided in an embodiment of the present utility model; Figure 6 This is an exploded schematic diagram of a lithium battery provided in an embodiment of this utility model. Detailed Implementation

[0017] To make the objectives, technical solutions, and advantages of this utility model clearer, the present utility model will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present utility model and are not intended to limit the present utility model.

[0018] To address the technical problems of existing lithium batteries, which typically use vents on their surface to release internal gas and then seal the vents with plugs, making the vents cumbersome to open and close and posing a risk of electrolyte leakage when the vents are opened, this invention provides a breathable and waterproof structure and lithium battery that allows gas generated inside the lithium battery to escape naturally, preventing the lithium battery from bulging and also preventing electrolyte leakage.

[0019] It should be noted that the breathable and waterproof structure described in this utility model is used in, but not limited to, lithium batteries. For ease of explanation, this utility model only uses the application of the breathable and waterproof structure in lithium batteries as an example. The principle of the breathable and waterproof structure applied in other types of equipment is essentially the same as that applied in lithium batteries, and will not be described in detail here.

[0020] Please see Figure 1 and Figure 2 , Figure 1 This is a schematic diagram of a breathable and waterproof structure in one embodiment of the present invention. The breathable and waterproof structure 100 includes a protective shell 1 and an exhaust assembly 2. The protective shell 1 has a receiving cavity 11 and an exhaust port 12. Figure 3 (As shown in the figure), the vent 12 connects the receiving cavity 11 and the outside air. The exhaust assembly 2 includes a cylinder 21, a first breathable membrane 22, a second breathable membrane 23 and an isolation liquid layer (not shown in the figure). The cylinder 21 is sealed at the vent 12. The first breathable membrane 22 and the second breathable membrane 23 are spaced apart inside the cylinder 21. The isolation liquid layer is located between the first breathable membrane 22 and the second breathable membrane 23 and is used to isolate water and air.

[0021] In this embodiment, the protective shell 1 is the main body of the breathable and waterproof structure 100, and its interior has a cavity 11 for accommodating key components such as the lithium battery cells. The structural design of the protective shell 1 must ensure sufficient strength and sealing to protect the internal battery cells from the influence of the external environment. Vents 12 are provided on the side wall of the protective shell 1. The main function of the vents 12 is to connect the cavity 11 with the outside air, allowing gas generated in the cavity 11 to escape through the vents 12, preventing excessive air pressure in the cavity 11 from causing the protective shell 1 to bulge. The location and number of vents 12 can be adjusted according to the size of the lithium battery and its heat dissipation requirements to achieve optimal ventilation.

[0022] The venting assembly 2 is the core component of the breathable and waterproof structure 100. It is installed at the vent 12 of the protective shell 1 to achieve both air permeability and waterproofing. The cylinder 21 included in the venting assembly 2 is the main structure of the venting assembly 2. Its shape is typically a hollow cylinder open at both ends, but it can be designed in other shapes according to actual needs. The material of the cylinder 21 must possess good sealing and corrosion resistance to ensure its stable performance in various environments. The cylinder 21 is installed at the vent 12 in a sealed manner to ensure a tight seal between it and the protective shell 1, preventing gas leakage.

[0023] The first breathable membrane 22 and the second breathable membrane 23 of the exhaust assembly 2 are key components for achieving breathability and waterproofing. Both the first breathable membrane 22 and the second breathable membrane 23 can be eptfe (polytetrafluoroethylene) membranes. The eptfe membrane has micropores inside, which allow gas molecules to pass through, thereby achieving good breathability. The micropore size of the eptfe membrane is usually smaller than the size of a water molecule, or its surface is hydrophobic, which can prevent water molecules from passing through. Therefore, the eptfe membrane has good waterproof and breathable properties.

[0024] The isolation liquid layer cannot penetrate the EPTFE membrane, while the gas generated in the containment cavity 11 can pass through the first breathable membrane 22 and the second breathable membrane 23 to be discharged to the outside. To ensure the long-term breathability and waterproof performance of the EPTFE membrane, a silanized nano-silica layer can be coated on its surface. Alternatively, the EPTFE membrane can be a two-layer composite membrane, with one layer having 0.5 micrometer pores and the other having 0.1 micrometer pores. The main function of the exhaust device 2 is to discharge the gas generated in the containment cavity 11 and isolate external moisture, oxygen, and other substances from entering the containment cavity 11, while also preventing the internal electrolyte from flowing out.

[0025] The isolation liquid layer is located between the first breathable membrane 22 and the second breathable membrane 23, and its main function is to further enhance the waterproof performance. The material of the isolation liquid layer needs to have good waterproofness and chemical stability. For example, the isolation liquid layer can be perfluoropolyether (PFPE). When external water molecules come into contact with the isolation liquid layer, they will be blocked by the isolation liquid layer and cannot enter the receiving cavity 11. At the same time, the isolation liquid layer will not affect the normal passage of gas, ensuring the normal realization of the breathability function.

[0026] Through the above structure and working principle, the breathable and waterproof structure 100 of this utility model can effectively realize the breathability and waterproof function of lithium battery, improve the safety and reliability of lithium battery, and avoid the cumbersome opening and closing of the traditional lithium battery vent and the risk of electrolyte leakage.

[0027] When the lithium battery generates gas during use, this gas enters the interior of the cylinder 21 through the first vent 212 due to the pressure difference within the containment cavity 11. The gas first passes through the first vent membrane 22, then through the separator liquid layer, and finally through the second vent membrane 23, exiting into the outside air through the second vent 214. During this process, the separator liquid layer effectively prevents external water molecules from entering the containment cavity 11, ensuring the dryness and safety of the lithium battery interior.

[0028] The cylinder 21 is mainly used to provide installation positions for the first breathable membrane 22 and the second breathable membrane 23. The installation positions of the first breathable membrane 22 and the second breathable membrane 23 on the cylinder 21 are not limited. They can be installed at the top and bottom of the cylinder 21, or between the top and bottom of the cylinder 21. The structure of the cylinder 21 is not limited. For example, it can be hollow or non-hollow with openings at both ends.

[0029] In one embodiment, the cylinder 21 is hollow with openings at both ends (not shown in the figure), and the first breathable membrane 22 and the second breathable membrane 23 are both connected to the inner wall of the cylinder 21. When manufacturing the exhaust assembly 2, the cylinder 21 is first made into a hollow structure with openings at both ends, for example, by injection molding, using a plastic material with good sealing and corrosion resistance, such as polytetrafluoroethylene (PTFE). Then, positions for installing the first breathable membrane 22 and the second breathable membrane 23 are reserved on the inner wall of the cylinder 21. These positions can be designed according to the size and shape of the breathable membranes, typically circular or square grooves. Next, the first breathable membrane 22 and the second breathable membrane 23 are respectively installed onto the corresponding positions on the inner wall of the cylinder 21, and can be fixed by bonding, heat fusion, or other methods to ensure a sealed connection between the breathable membranes and the inner wall of the cylinder, thereby forming an internally spaced breathable membrane structure. This allows the gas in the accommodating cavity 11 to flow through the space between the first breathable membrane 22 and the second breathable membrane 23, while the breathable membranes also prevent electrolyte leakage.

[0030] In one embodiment, please refer to Figure 4 The bottom of the cylinder 21 has a bottom plate 211 with a first vent hole 212. A first vent membrane 22 connects to the bottom plate 211 and covers the first vent hole 212. The top of the cylinder 21 has a top plate 213 with a second vent hole 214. A second vent membrane 23 connects to the top plate 213 and covers the second vent hole 214. In this embodiment, the cylinder 21 is designed with a bottom plate 211 and a top plate 213 at the bottom and top, respectively. The bottom plate 211 and the top plate 213 can be integrally formed with the cylinder 21 and are made of materials with good sealing and corrosion resistance. The first vent hole 212 is provided on the bottom plate 211. The size and number of the vent holes can be designed according to the ventilation requirements. For example, multiple small holes with a diameter of 1-2 mm can be provided. Then, the first breathable membrane 22 is installed on the base plate 211, covering the first vent 212. The first breathable membrane 22 can be fixed to the base plate 211 by adhesive or other means, ensuring a tight and secure seal between the first breathable membrane 22 and the base plate 211. Similarly, a second vent 214 is opened on the top plate 213, and a second breathable membrane 23 is installed on the top plate 213, covering the second vent 214, using the same fixing method as the first breathable membrane 22. In this way, the gas generated in the accommodating cavity 11 can enter the cylinder 21 through the first vent 212 and the first breathable membrane 22, and then exit through the second vent 214 via the second breathable membrane 23. External moisture and dust are blocked by the second breathable membrane 23 and cannot enter the cylinder 21. The electrolyte in the accommodating cavity 11 is blocked by the first breathable membrane 22, thus achieving both breathability and waterproofing.

[0031] In one embodiment, please refer to Figure 1 and Figure 2 The protective outer shell 1 includes a shell 13 and a cover 14 connected together. The shell 13 has an internal cavity 11. The cover 14 protrudes into the shell 13 to form a positioning groove 15. The bottom of the positioning groove 15 has the aforementioned vent 12. The cylindrical body 21 is sealed and engaged with the positioning groove 15. This structure makes the protective outer shell 1 more compact, and the positioning groove 15 effectively fixes the cylindrical body 21, ensuring the stability and reliability of the breathable and waterproof structure 100.

[0032] In one embodiment, please refer to Figure 2 The cover 14 has a spare vent 16, which is detachably connected to a sealing plug 17. In this embodiment, the spare vent 16 can be opened by pulling out the sealing plug 17 when necessary to allow for additional gas release or pressure regulation, increasing the flexibility and applicability of the breathable and waterproof structure 100.

[0033] In one embodiment, please refer to Figure 2 The cover 14 has a first electrode hole 18 and a second electrode hole 19, which are located on both sides of the positioning groove 15. This structure allows the electrodes of the lithium battery to be easily connected to the external circuit through the first electrode hole 18 and the second electrode hole 19. At the same time, the position design of the first electrode hole 18 and the second electrode hole 19 can avoid conflict with the vent 12, ensuring the normal operation of the breathable and waterproof structure.

[0034] In one embodiment, please refer to Figure 2 The breathable and waterproof structure 100 also includes a first insulating member 33 and a second insulating member 34. The protective shell 1 has a first recessed groove 35 and a second recessed groove 36. The first insulating member 33 and the second insulating member 34 are respectively engaged in the first recessed groove 35 and the second recessed groove 36. The first insulating member 33 and the second insulating member 34 have a through hole 331 and a through hole 341, which are respectively connected to the first electrode hole 18 and the second electrode hole 19. In this embodiment, by setting the first insulating member 33 and the second insulating member 34 to be engaged in the first recessed groove 35 and the second recessed groove 36, the stability of the installation of the first insulating member 33 and the second insulating member 34 can be improved. The first insulating member 33 and the second insulating member 34 have corresponding through holes so that the battery cell electrode of the accommodating cavity can pass through, and at the same time, they can also provide a fixed insulation function for the battery cell electrode.

[0035] Please see Figure 2 and Figure 5The breathable and waterproof structure 100 also includes a first electrode adapter 31 and a second electrode adapter 32. The first electrode adapter 31 and the second electrode adapter 32 are respectively engaged in the slots on the top of the first insulating member 33 and the second insulating member 34 for fixing. After the battery cell electrode passes through the corresponding through hole, it connects to the corresponding electrode adapter and is electrically connected to external electrical equipment or charging power supply through the electrode adapter.

[0036] Secondly, please refer to Figure 6 This utility model also provides a lithium battery 200, including a battery cell 4 and the aforementioned breathable and waterproof structure 100. The battery cell 4 is disposed in the receiving cavity 11 of the protective shell 1, and the positive and negative electrodes of the battery cell 4 pass through the side wall of the protective shell 1 and extend to the outside. The receiving cavity 11 also contains an electrolyte, and the battery cell 4, in conjunction with the electrolyte, enables the lithium battery to be charged or discharged.

[0037] The positive and negative terminals of the battery cell 4 are respectively connected to a first current collector 41 and a second current collector 42. The first current collector 41 and the second current collector 42 have a first electrode post 411 and a second electrode post 421. The first electrode post 411 and the second electrode post 421 respectively pass through a first electrode hole 18 and a second electrode hole 19, a first through hole 331 and a second through hole 341 of the breathable and waterproof structure 100, and are then respectively connected to a first electrode adapter 31 and a second electrode adapter 32. When an electrical device is connected to the first electrode adapter 31 and the second electrode adapter 32, the lithium battery 200 can supply power to the device, allowing the device to operate normally. When the lithium battery's power is insufficient, the first electrode adapter 31 and the second electrode adapter 32 can be connected to a charging power source to charge the lithium battery.

[0038] The breathable and waterproof structure 100 also includes a first rubber sleeve 37 and a second rubber sleeve 38. Both the first rubber sleeve 37 and the second rubber sleeve 38 are made of plastic and have good insulation properties. The first rubber sleeve 37 and the second rubber sleeve 38 are respectively fitted onto the first pole post 411 and the second pole post 421. The cover plate 14 is made of metal and is connected to the housing 13 by welding. In this embodiment, by setting the first rubber sleeve 37 and the second rubber sleeve 38, the cover plate 14 and the two pole posts can be isolated to ensure safe electricity use.

[0039] To better understand this utility model, the following is combined with... Figures 1 to 5 The technical solution of this utility model is described in detail below: The breathable and waterproof structure 100 provided by this utility model has a protective shell 1 with an internal cavity 11 for storing the lithium battery cell 4 and electrolyte. The venting assembly 2 has a first breathable membrane 22 and a second breathable membrane 23, which allow gas generated in the cavity 11 to pass through while isolating the electrolyte. The gas generated in the cavity can be discharged sequentially through the first breathable membrane 22, the separator liquid layer, and the second breathable membrane 23, preventing bulging of the protective shell 1. The separator liquid layer can be an inert chemical liquid such as perfluoropolyether, which has extremely stable chemical properties, does not dissolve gases such as oxygen and water vapor in the air, and can prevent external air and water from entering the cavity 11. Therefore, compared with the prior art, the lithium battery of this application, by setting a breathable and waterproof structure, does not need to release gas into the cavity 11 by opening and closing the sealing plug, and there is no risk of electrolyte leakage.

[0040] The specific embodiments of this utility model described above do not constitute a limitation on the scope of protection of this utility model. Any other corresponding changes and modifications made based on the technical concept of this utility model should be included within the scope of protection of the claims of this utility model.

Claims

1. A breathable and waterproof structure, characterized in that, include: A protective outer shell has an internal cavity, and the protective outer shell has a vent that connects the cavity to the outside air. and An exhaust assembly includes a cylinder, a first breathable membrane, a second breathable membrane, and an isolation liquid layer. The cylinder is sealed at the vent. The first and second breathable membranes are spaced apart inside the cylinder. The isolation liquid layer is located between the first and second breathable membranes and is used to isolate water and air.

2. The breathable and waterproof structure according to claim 1, characterized in that, The cylinder is hollow with openings at both ends, and both the first and second breathable membranes are connected to the inner wall of the cylinder.

3. The breathable and waterproof structure according to claim 1, characterized in that, The bottom of the cylinder has a base plate, and the base plate has a first vent hole. The first vent membrane is connected to the base plate and covers the first vent hole.

4. The breathable and waterproof structure according to claim 3, characterized in that, The top of the cylinder has a top plate, and the top plate has a second vent hole. The second vent membrane is connected to the top plate and covers the second vent hole.

5. The breathable and waterproof structure according to claim 1, characterized in that, The protective outer shell includes a shell and a cover connected to each other. The shell has the receiving cavity inside. The cover protrudes into the shell to form a positioning groove. The bottom of the positioning groove has the vent. The cylinder is sealed and snapped into the positioning groove.

6. The breathable and waterproof structure according to claim 5, characterized in that, The cover has a spare air hole, which is detachably connected to a sealing plug.

7. The breathable and waterproof structure according to claim 6, characterized in that, The cover has a first electrode hole and a second electrode hole, which are located on both sides of the positioning groove.

8. The breathable and waterproof structure according to claim 7, characterized in that, The breathable and waterproof structure also includes a first insulating component and a second insulating component. The protective shell has a first sinking groove and a second sinking groove. The first insulating component and the second insulating component are respectively engaged in the first sinking groove and the second sinking groove. The first insulating component and the second insulating component have a through hole and a through hole. The first through hole and the second through hole are respectively connected to the first electrode hole and the second electrode hole.

9. The breathable and waterproof structure according to claim 1, characterized in that, Both the first and second breathable membranes are eptfe membranes, and their surfaces are coated with a silanized nano-silica layer.

10. A lithium battery, characterized in that, The device includes a battery cell and a breathable and waterproof structure as described in any one of claims 1-9, wherein the battery cell is disposed in the receiving cavity of the protective housing, and the positive and negative electrodes of the battery cell extend outward through the side wall of the protective housing.

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