CN216720104U - Top cap subassembly, battery monomer, battery and power consumption device - Google Patents

Abstract

The application relates to a top cap subassembly, battery monomer, battery and power consumption device, wherein, the top cap subassembly includes: the top cover plate is provided with an exhaust hole in a penetrating way; the explosion-proof valve comprises an explosion-proof sheet hermetically connected with the exhaust hole and a protection sheet arranged above the explosion-proof sheet, and an accommodating cavity is formed between the protection sheet and the explosion-proof sheet at intervals; the protection sheet is provided with a first surface facing the explosion-proof sheet, and the first surface is provided with a ventilation channel communicated between the outside and the accommodating cavity. On the one hand, through set up explosion-proof piece at the exhaust hole internal seal, ensure the gas tightness of battery monomer internal environment to realize the inside exhaust pressure release of battery, improve the security performance of battery. On the other hand, through setting up the screening glass, block external materials such as electrolyte to explosion-proof valve's influence and pollution, improve explosion-proof valve's security performance to the realization holds chamber and outside intercommunication, reduces the error that the inside gas tightness of battery monomer detected.

Description

Top cap subassembly, battery monomer, battery and power consumption device

Technical Field

The application relates to the technical field of lithium ion batteries, in particular to a top cover assembly, a battery monomer, a battery and an electric device.

Background

With the development of new energy technology, power batteries become more and more important in daily life of people. The power battery has the advantages of small volume, high energy density, long service life, environmental protection and the like, and is widely applied to various industries such as vehicles, electronic products, energy storage systems and the like.

When the power battery is used, the power battery needs to be charged. During charging, gas is released due to chemical reaction inside the battery, so that the internal pressure of the battery is increased, and outward expansion force is generated on the battery shell. The expansion force can cause the power battery to deform, and even the power battery has potential safety hazards of explosion and fire when the expansion force is serious. Therefore, when the internal air pressure of the power battery reaches a certain value, air exhaust and pressure relief are needed.

In order to solve the above problems, in the prior art, a method of mounting an explosion-proof valve structure on a battery cell top cover inside a power battery is generally adopted. However, the conventional explosion-proof valve has a complex structure and low safety performance, and is not favorable for subsequent processing of the battery cell.

SUMMERY OF THE UTILITY MODEL

In view of the above, it is necessary to provide a top cap assembly, a battery cell, a battery and an electric device for solving the problems of complicated structure and low safety performance of the conventional explosion-proof valve.

In a first aspect, the present application provides a top cap assembly comprising a top cap sheet and an explosion proof valve. Wherein, the top cover sheet is provided with an exhaust hole in a penetrating way. The explosion-proof valve includes the explosion-proof piece of being connected with exhaust hole sealing and locates the screening glass of explosion-proof piece top, and the interval forms one between screening glass and the explosion-proof piece and holds the chamber. The protection piece has the first surface towards the explosion-proof piece, and the ventilative passageway in outside and holding between the chamber is seted up to the first surface.

Through the structure, the integral structure of the explosion-proof valve is simplified, the explosion-proof sheet can be protected through the protection sheet, the electrolyte is prevented from corroding the explosion-proof sheet, and the safety performance of the explosion-proof valve is improved. In addition, the containing cavity is communicated with the outside by arranging the ventilation channel on the protective sheet, so that the sealing performance of the explosion-proof sheet can be more accurately detected, and the good air tightness in the single battery is ensured.

In some embodiments, the air-permeable channels are recessed relative to the first surface to a depth less than the thickness of the protective sheet at the corresponding location. Therefore, even if the electrolyte drops on the protective sheet, the electrolyte cannot flow into the accommodating cavity and further cannot flow onto the explosion-proof sheet. Therefore, the explosion-proof sheet can be effectively protected from being corroded by the electrolyte.

In some embodiments, the vent channel includes an open end and a closed end connected to the open end, the open end communicating with the outer edge of the first surface to form a vent opening communicating with the exterior. Therefore, the corrosion and pollution of the electrolyte to the explosion-proof sheet can be effectively prevented.

In some embodiments, the top cover plate has a boss surrounding the vent hole, the boss having an inner sidewall facing the vent hole in a direction parallel to the first surface. The distance between the open end and the closed end along the direction parallel to the first surface is larger than the distance between the open end and the inner side wall of the boss along the direction parallel to the first surface. From this, the blind end can exceed the inside wall of boss and locate the top in exhaust hole, makes and holds the chamber and realize breathing freely with outside intercommunication.

In some embodiments, the top cover sheet is provided with a liquid filling opening spaced from the vent hole, and the distance between the vent passage and the liquid filling opening is greater than the shortest distance between the edge of the vent hole and the liquid filling opening. From this, when pouring into electrolyte in to annotating the liquid mouth, can prevent to annotate the interior intracavity that holds of remaining electrolyte inflow through ventilative passageway around the liquid mouth to effectively prevent electrolyte corruption and pollution explosion-proof piece.

In some embodiments, the gas-permeable passage is located on the side of the protective sheet facing away from the pouring opening. Therefore, the distance between the air-permeable passage and the liquid injection port is furthest, and the opening direction of the air-permeable port is opposite to the liquid injection port, so that residual electrolyte around the liquid injection port is more effectively prevented from flowing into the accommodating cavity through the air-permeable passage.

In some embodiments, the protection sheet has a second surface facing away from the first surface, the air-permeable passage penetrates through the first surface and the second surface in the thickness direction of the protection sheet, and the air-permeable membrane is covered in the air-permeable passage. The breathable film can prevent electrolyte from entering the accommodating cavity, and meanwhile, small molecule gases such as helium can be enabled to permeate out. Therefore, the function of protecting the explosion-proof sheet can be realized, and the accommodating cavity and the outside can be communicated.

In some embodiments, the breathable film has a thickness of between 50 μm and 200 μm. This makes it possible to effectively prevent the inflow of a liquid such as an electrolytic solution while achieving better ventilation.

In some embodiments, the breathable film comprises one or more of polystyrene, polypropylene, polyvinyl chloride. The polymer materials have waterproof and breathable properties, namely can prevent liquids such as electrolyte, water and the like from passing through, but can permeate micromolecular gases such as helium and the like, so that the protective effect can be effectively realized.

In a second aspect, the present application provides a battery cell, which includes a housing and the cap assembly as described above, wherein the housing has an opening, and the cap assembly covers the opening.

In a third aspect, the present application provides a battery, which includes a case and a single battery cell disposed in the case, where the single battery cell is as described above.

In a fourth aspect, the present application provides an electric device, including an electric main body and the battery as described above.

Above-mentioned top cap subassembly, battery monomer, battery and power consumption device, on the one hand, through set up explosion-proof piece in the exhaust hole internal seal, ensure the gas tightness of battery monomer internal environment to realize the inside exhaust pressure release of battery, improve the security performance of battery. On the other hand, through setting up the screening glass, block external materials such as electrolyte to explosion-proof valve's influence and pollution, improve explosion-proof valve's security performance to the realization holds chamber and outside intercommunication, reduces the error that the inside gas tightness of battery monomer detected.

Drawings

FIG. 1 is a schematic structural diagram of a vehicle according to an embodiment of the present application;

fig. 2 is an exploded view of a battery according to an embodiment of the present disclosure;

FIG. 3 is a schematic view of the overall structure of a cover assembly according to an embodiment of the present disclosure;

FIG. 4 is a schematic view of the top cover assembly shown in FIG. 3 with the rupture disc and the protective sheet removed;

FIG. 5 is a side cross-sectional view of the cap assembly shown in FIG. 3;

FIG. 6 is an enlarged view of a portion of FIG. 5 at A;

FIG. 7 is a cross-sectional view of a protective sheet according to an embodiment of the present application;

FIG. 8 is a cross-sectional view of a protective sheet in another embodiment of the present application;

in the figure: 1000. a vehicle; 100. a battery; 200. a controller; 300. a motor; 10. a box body; 20. a battery cell; 11. a first portion; 12. a second portion; 21. a cap assembly; 211. a top cover sheet; 212. an explosion-proof valve; 2111. an exhaust hole; 2112. a liquid injection port; 2113. a boss; 2121. an explosion-proof sheet; 2122. a protective sheet; 2123. an accommodating chamber; 2124. a ventilation channel; 2125. a gas permeable membrane; 2122a, a first surface; 2122b, a second surface; 2124a, open end; 2124b and a closed end.

Detailed Description

In order to make the aforementioned objects, features and advantages of the present application more comprehensible, embodiments accompanying the present application are described in detail below with reference to the accompanying drawings. In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present application. This application is capable of embodiments in many different forms than those described herein and that modifications may be made by one skilled in the art without departing from the spirit and scope of the application and it is therefore not intended to be limited to the specific embodiments disclosed below.

In the description of the present application, it is to be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," "circumferential," and the like are used in the orientations and positional relationships indicated in the drawings for convenience in describing the present application and for simplicity in description, and are not intended to indicate or imply that the referenced devices or elements must have a particular orientation, be constructed and operated in a particular orientation, and are therefore not to be considered limiting of the present application.

Furthermore, the terms "first", "second" and "first" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one such feature. In the description of the present application, "plurality" means at least two, e.g., two, three, etc., unless specifically limited otherwise.

In this application, unless expressly stated or limited otherwise, the terms "mounted," "connected," "secured," and the like are to be construed broadly and can include, for example, fixed connections, removable connections, or integral parts; can be mechanically or electrically connected; they may be directly connected or indirectly connected through intervening media, or they may be connected internally or in any other suitable relationship, unless expressly stated otherwise. The specific meaning of the above terms in the present application can be understood by those of ordinary skill in the art as appropriate.

In this application, unless expressly stated or limited otherwise, the first feature "on" or "under" the second feature may be directly contacting the first and second features or indirectly contacting the first and second features through intervening media. Also, a first feature "on," "over," and "above" a second feature may be directly or diagonally above the second feature, or may simply indicate that the first feature is at a higher level than the second feature. A first feature being "under," "below," and "beneath" a second feature may be directly under or obliquely under the first feature, or may simply mean that the first feature is at a lesser elevation than the second feature.

It will be understood that when an element is referred to as being "secured to" or "disposed on" another element, it can be directly on the other element or intervening elements may also be present. When an element is referred to as being "connected" to another element, it can be directly connected to the other element or intervening elements may also be present. The terms "vertical," "horizontal," "upper," "lower," "left," "right," and the like as used herein are for illustrative purposes only and do not denote a unique embodiment.

At present, the application of the power battery is more and more extensive from the development of market situation. The power battery is not only applied to energy storage power supply systems such as hydraulic power, firepower, wind power and solar power stations, but also widely applied to electric vehicles such as electric bicycles, electric motorcycles, electric automobiles and the like, and a plurality of fields such as military equipment and aerospace. With the continuous expansion of the application field of the power battery, the market demand is also continuously expanding.

The production process flow of the power battery generally comprises the following steps: firstly, preparing electrode slurry, namely mixing an electrode active material, a binder, a solvent and the like together, and fully stirring and dispersing to form slurry; step two, coating, namely uniformly coating the slurry prepared in the step one on a current collector with a specified thickness, and drying a solvent; thirdly, punching the pole piece, namely punching the pole piece manufactured in the previous step into a specified size and shape; fourthly, laminating or winding, namely assembling the positive and negative pole pieces and the diaphragm together, and forming a pole core after the gluing is finished; fifthly, assembling the battery, namely filling the pole core produced in the previous step into a shell with a punched pit, and finishing top sealing, side sealing and the like (reserving a liquid injection port) to form the battery without liquid injection; sixthly, injecting liquid, namely injecting a specified amount of electrolyte into the battery monomer; and step seven, sealing the battery, and extracting gas in the battery cell in a vacuum environment to complete sealing.

Therefore, the prepared power battery needs to have good air tightness of the battery cells inside. However, when the power battery is used, it needs to be charged. During the charging process, chemical reaction occurs inside the battery, so that gas is released, the internal pressure of the battery is increased, and potential safety hazards of explosion and fire exist. Therefore, the structure that the explosion-proof valve is arranged on the top cover of the single battery is adopted at present, and the single battery is exhausted and decompressed.

However, the inventor has noticed that, since the existing explosion-proof valve structure is usually exposed outside, during the process of injecting the electrolyte into the battery cell through the injection port, the electrolyte is liable to drop onto the explosion-proof valve, so as to corrode the valve plate of the explosion-proof valve, resulting in failure of the explosion-proof valve. Therefore, a protection structure is required to be arranged on the explosion-proof valve, so that the explosion-proof valve can be protected, and the corrosion of electrolyte to the explosion-proof valve is avoided.

However, since the interior of the battery cell needs to have good sealing performance, after the power battery is assembled, the interior of the battery cell needs to be subjected to gas tightness detection by using methods such as helium detection and the like. The inventor finds that in order to improve the protection effect of the protection structure on the explosion-proof valve, the protection structure is simply arranged above the explosion-proof valve. When the airtightness of the interior of the battery cell is detected, the protection structure influences the airtightness detection result. Namely, when the air tightness detection result is good, two situations exist, one of which is that the sealing performance of the explosion-proof valve is good; the second is the air leakage of the explosion-proof valve, but the sealing performance of the protection structure is good. Thereby, the accuracy of the airtightness detection will be affected.

Based on the consideration, in order to improve the purpose of the accuracy of the airtightness detection of the single battery while realizing the safety performance of the explosion-proof valve, through intensive research, the applicant designs a top cover assembly, and by improving the structure of the protection plate, the top cover assembly can have the protection effect on the explosion-proof valve and can realize the purpose of communicating the accommodating cavity with the outside, thereby simplifying the structure of the explosion-proof valve and improving the safety performance of the explosion-proof valve.

The battery cell disclosed in the embodiment of the application can be used in electric devices such as vehicles, ships or aircrafts, but not limited thereto. The embodiment of the application provides an electric device using a battery as a power supply, wherein the electric device can be but is not limited to a mobile phone, a tablet, a notebook computer, an electric toy, an electric tool, a battery car, an electric automobile, a ship, a spacecraft and the like. The electric toy may include a stationary or mobile electric toy, such as a game machine, an electric car toy, an electric ship toy, an electric airplane toy, and the like, and the spacecraft may include an airplane, a rocket, a space shuttle, a spacecraft, and the like.

For convenience of description, the following embodiments take an example in which a power consuming apparatus according to an embodiment of the present application is a vehicle 1000.

Referring to fig. 1, fig. 1 is a schematic structural diagram of a vehicle 1000 according to some embodiments of the present disclosure. The vehicle 1000 may be a fuel automobile, a gas automobile, or a new energy automobile, and the new energy automobile may be a pure electric automobile, a hybrid electric automobile, or a range-extended automobile, etc. The battery 100 is provided inside the vehicle 1000, and the battery 100 may be provided at the bottom or the head or the tail of the vehicle 1000. The battery 100 may be used for power supply of the vehicle 1000, for example, the battery 100 may serve as an operation power source of the vehicle 1000. The vehicle 1000 may further include a controller 200 and a motor 300, the controller 200 being configured to control the battery 100 to supply power to the motor 300, for example, for starting, navigation, and operational power requirements while the vehicle 1000 is traveling.

In some embodiments of the present application, the battery 100 may be used not only as an operating power source of the vehicle 1000, but also as a driving power source of the vehicle 1000, instead of or in part of fuel or natural gas, to provide driving power for the vehicle 1000.

Referring to fig. 2, fig. 2 is an exploded view of a battery 100 according to some embodiments of the present disclosure. The battery 100 includes a case 10 and a battery cell 20, and the battery cell 20 is accommodated in the case 10. The case 10 is used to provide a receiving space for the battery cells 20, and the case 10 may have various structures. In some embodiments, the case 10 may include a first portion 11 and a second portion 12, the first portion 11 and the second portion 12 cover each other, and the first portion 11 and the second portion 12 together define a receiving space for receiving the battery cell 20. The second part 12 may be a hollow structure with one open end, the first part 11 may be a plate-shaped structure, and the first part 11 covers the open side of the second part 12, so that the first part 11 and the second part 12 jointly define a containing space; the first portion 11 and the second portion 12 may be both hollow structures with one side open, and the open side of the first portion 11 may cover the open side of the second portion 12. Of course, the case 10 formed by the first and second portions 11 and 12 may have various shapes, such as a cylinder, a rectangular parallelepiped, and the like.

In the battery 100, the number of the battery cells 20 may be multiple, and the multiple battery cells 20 may be connected in series or in parallel or in series-parallel, where in series-parallel refers to both series connection and parallel connection among the multiple battery cells 20. The plurality of battery cells 20 can be directly connected in series or in parallel or in series-parallel, and the whole formed by the plurality of battery cells 20 is accommodated in the box body 10; of course, the battery 100 may also be formed by connecting a plurality of battery cells 20 in series, in parallel, or in series-parallel to form a battery module, and then connecting a plurality of battery modules in series, in parallel, or in series-parallel to form a whole, and accommodating the whole in the case 10. The battery 100 may further include other structures, for example, the battery 100 may further include a bus member for achieving electrical connection between the plurality of battery cells 20.

Wherein each battery cell 20 may be a secondary battery or a primary battery; but is not limited to, a lithium sulfur battery, a sodium ion battery, or a magnesium ion battery. The battery cell 20 may be cylindrical, flat, rectangular parallelepiped, or other shape.

Referring to fig. 3 to 7, fig. 3, 4 and 5 are schematic structural views of a top cover assembly according to an embodiment of the present disclosure, fig. 6 is a partially enlarged view of a portion a in fig. 5, and fig. 7 is a schematic structural view of a protective sheet according to an embodiment of the present disclosure. An embodiment of the present application provides a top cover assembly 21, which includes a top cover sheet 211 and an explosion-proof valve 212. Wherein, the top cover sheet 211 is provided with an exhaust hole 2111. The explosion-proof valve 212 includes an explosion-proof sheet 2121 hermetically connected to the exhaust hole 2111, and a protection sheet 2122 disposed above the explosion-proof sheet 2121, wherein a receiving cavity 2123 is defined between the protection sheet 2122 and the explosion-proof sheet 2121. Further, the protective sheet 2122 has a first surface 2122a facing the explosion-proof sheet 2121, and the first surface 2122a is provided with an air-permeable passage 2124 communicating between the outside and the housing chamber 2123.

It should be noted that the battery 100 generally comprises a case and one or more battery cells 20 disposed inside the case, and the battery cells 20 are composed of a housing and a cap assembly 21 covering each other, and an electric core assembly and other functional components disposed inside the housing. Therefore, after the top cover assembly 21 and the housing are sealed and covered, the top cover sheet 211 of the top cover assembly 21 is provided with the exhaust hole 2111, and the explosion-proof sheet 2121 is sealed and disposed in the exhaust hole 2111. Thereby, the explosion-proof sheet 2121 exhausts and releases air from the inside of the battery cell 20.

Specifically, in the present embodiment, the anti-explosion plate 2121 is hermetically disposed in the exhaust hole 2111 by welding, and the anti-explosion plate 2121 has a cracking portion, and the thickness of the cracking portion is smaller than the thickness of the rest positions on the anti-explosion plate 2121. Therefore, when the gas inside the battery cell 20 expands and impacts outward, the impact force can be applied to the cleavage portion to open the explosion-proof sheet 2121 for venting and pressure relief.

The cracking portion is specifically a groove formed in the anti-explosion sheet 2121, and the extending direction of the groove may extend from the center of the anti-explosion sheet 2121 to the edge, so that the anti-explosion sheet 2121 can be better opened when the gas inside the battery cell 20 expands.

Further, the protection sheet 2122 covers the air vent 2111, so that the protection sheet 2122 can protect the explosion-proof sheet 2121 and prevent the electrolyte from dropping on the explosion-proof sheet 2121 to corrode the explosion-proof sheet 2121.

Further, the protective sheet 2122 has a first surface 2122a facing the explosion-proof sheet 2121 and a second surface 2122b facing away from the explosion-proof sheet 2121, both the first surface 2122a and the second surface 2122b are smooth surfaces, and a distance between the first surface 2122a and the second surface 2122b is defined as a thickness of the protective sheet 2122.

The first surface 2122a is provided with a ventilation channel 2124 communicating with the receiving cavity 2123 from the outside, so that the protection sheet 2122 protects the explosion-proof sheet 2121 and does not affect the determination result of the internal airtightness of the battery cell 20. When the internal airtightness of the single battery 20 is detected by helium detection, if air leakage of the single battery 20 is detected, it can be said that the explosion-proof sheet 2121 and the top cover sheet 211 are not tightly connected, or an air leakage position exists on the explosion-proof sheet 2121, and only the explosion-proof sheet 2121 needs to be checked.

Through the structure, the overall structure of the explosion-proof valve 212 is simplified, the explosion-proof sheet 2121 can be protected through the protection sheet 21222, and when electrolyte is injected into a single battery, the electrolyte is dripped onto the explosion-proof sheet 2121 to corrode the explosion-proof sheet 2121, so that the safety performance of the explosion-proof valve 212 is improved. Further, the protective sheet 2122 is provided with an air passage 2124 to communicate the housing chamber 2123 with the outside, so that the sealing performance of the explosion-proof sheet 2121 can be more accurately detected, and the airtightness of the inside of the battery cell can be ensured to be good.

In some embodiments, the air-permeable passages 2124 are recessed relative to the first surface 2122a to a depth that is less than the thickness of the protective sheet 2122 at the corresponding locations, i.e., the air-permeable passages 2124 do not extend through the first surface 2122a and the second surface 2122 b. Therefore, when the liquid pouring nozzle is detached from the liquid pouring port 2112, the electrolyte remaining in the liquid pouring nozzle does not flow into the housing chamber 2123 nor flows onto the explosion-proof sheet 2121 even if it drops onto the second surface 2122b of the protection sheet 2122. Thereby, the explosion-proof sheet 2121 can be effectively protected from being corroded by the electrolyte.

Further, the ventilation channel 2124 includes an open end 2124a and a closed end 2124b connected to the open end 2124a, and the open end 2124a communicates with the outer edge of the first surface 2122a to form a ventilation opening communicating with the outside. Specifically, the air passage 2124 is a notch communicating with the first surface 2122a and the side surface. Wherein the open end 2124a extends to the side surface and communicates with the side surface to form the ventilation opening. Thus, corrosion and contamination of the explosion-proof sheet 2121 by the electrolyte can be effectively prevented.

It will be appreciated that in some other embodiments, the air-permeable passage 2124 may also be configured to include a first sub-passage and a second sub-passage that are perpendicularly connected to each other. The first sub-channel and the second sub-channel each have an open end 2124a and a closed end 2124b, the open end 2124a of the first sub-channel communicates with the lateral side to form a first ventilation opening, the closed end 2124b of the first sub-channel is connected to the closed end 2124b of the second sub-channel, and the open end 2124a of the second sub-channel communicates with the first surface 2122a to form a second ventilation opening. First ventilative mouthful and the ventilative mouthful intercommunication of second between, from this, the first ventilative mouthful of accessible and the ventilative mouthful realization of second of accessible hold chamber 2123 and outside intercommunication.

In some embodiments, the top cover sheet 211 has a boss 2113 surrounding the discharge hole 2111 on its upper surface, the boss 2113 has an inner sidewall facing the discharge hole 2111 in a direction parallel to the first surface 2122a, and the distance between the open end 2124a and the closed end 2124b in the direction parallel to the first surface 2122a is greater than the distance between the open end 2124a and the inner sidewall of the boss 2113 in the direction parallel to the first surface 2122 a.

Specifically, the protective sheet 2122 is placed over the boss 2113, and the closed end 2124b extends beyond the inner sidewall of the boss 2113 and over the exhaust hole 2111. That is, the air-permeable passage 2124 is at least partially communicated with the air discharge hole 2111 in a direction parallel to the first surface 2122 a.

In the case of filling the interior of the battery cell, the electrolyte is usually filled into the filling port 2112 by fitting the filling nozzle of the filling device to the filling port 2112 of the top lid assembly 21. When the liquid pouring nozzle is detached from the liquid pouring port 2112, the electrolyte remaining in the liquid pouring nozzle may drip onto the explosion-proof sheet 2121. Therefore, the protection sheet 2122 is communicated with the outside from the side through the air-permeable passage 2124, and the second surface 2122b of the protection sheet 2122 is of a closed structure, so that the electrolyte on the injection nozzle is effectively prevented from dropping onto the second surface 2122b and flowing into the accommodating chamber 2123, and further flowing onto the explosion-proof sheet 2121 to the corrosion-proof sheet 2121.

In some embodiments, the top cover sheet 211 has a pouring opening 2112 formed therethrough and spaced from the air discharge opening 2111, and the distance between the air-permeable passage 2124 and the pouring opening 2112 is greater than the shortest distance between the edge of the air discharge opening 2111 and the pouring opening 2112. Thus, when the electrolyte is injected into the injection port 2112 through the injection nozzle, the electrolyte remaining around the injection port 2112 is prevented from flowing into the housing chamber 2123 through the gas-permeable passage 2124, and the electrolyte is effectively prevented from corroding and contaminating the explosion-proof sheet 2121.

Specifically, in this embodiment, the air-permeable passage 2124 is located on the side of the protective sheet 2122 that faces away from the liquid pouring port 2112. This makes it possible to further effectively prevent the electrolyte remaining around the injection port 2112 from flowing into the housing 2123, by making the distance between the gas-permeable passage 2124 and the injection port 2112 the longest.

Referring to fig. 8, fig. 8 is a schematic structural view of a protective sheet according to another embodiment of the present application. In some embodiments, the protective sheet 2122 has a second surface 2122b facing away from the first surface 2122a, an air-permeable passage 2124 extends through the first surface 2122a and the second surface 2122b in the thickness direction of the protective sheet 2122, and an air-permeable membrane 2125 is disposed within the air-permeable passage 2124. Specifically, the air-permeable passage 2124 penetrates the first surface 2122a and the second surface 2122b in the thickness direction of the protective sheet 2122, thereby achieving communication between the housing chamber 2123 and the outside. The gas permeable membrane 2125 covering the gas permeable passage 2124 can block the electrolyte from entering the accommodating chamber 2123, and at the same time, allow small molecule gas such as helium to permeate. Therefore, the explosion-proof sheet 2121 can be protected and the accommodation chamber 2123 can communicate with the outside.

Further, the thickness of the air-permeable film 2125 is 50 μm to 200 μm. This makes it possible to effectively prevent the inflow of a liquid such as an electrolytic solution while achieving better ventilation.

Still further, breathable film 2125 comprises one or more of polystyrene, polypropylene, polyvinyl chloride. The polymer materials have waterproof and breathable properties, namely can prevent liquids such as electrolyte, water and the like from passing through, but can permeate micromolecular gases such as helium and the like, so that the protective effect can be effectively realized. It is understood that the air-permeable membrane 2125 can be made of other similar polymer materials, which are not described in detail herein.

Based on the same concept as the top cap assembly 21, the present application provides a battery cell 20, which includes a housing and the top cap assembly 21 as described above. Wherein, the shell has an opening, and the top cover component 21 covers the opening.

Based on the same concept as the battery cell 20, the present application provides a battery 100, which includes a case and the battery cell 20 disposed in the case. The battery cell 20 is the battery cell 20 described above.

Based on the same concept as the battery 100, the present application provides an electric device including an electric main body and the battery 100 as described above.

Further, referring to fig. 5-7, the present application provides a top cap assembly 21 comprising a top cover flap 211 and an explosion proof valve 212. An exhaust hole 2111 is opened through the top cover sheet 211, and an explosion-proof sheet 2121 is hermetically provided in the exhaust hole 2111. In addition, the top surface of the top cover sheet 211 has bosses 2113 surrounding the exhaust holes 2111, and the protection sheet 2122 is placed on the bosses 2113 to close the exhaust holes 2111. The protective sheet 2122 is provided with an air passage 2124, a first end of the air passage 2124 is opened to a side surface of the protective sheet, and the other end is opened to the first surface 2122 a. Thereby, the housing chamber 2123 is communicated with the outside. Not only can prevent the electrolyte from entering the housing chamber 2123 to contaminate the explosion-proof sheet, but also can realize the communication between the housing chamber 2123 and the outside so as to check the airtightness of the inside of the battery cell.

In a specific use of the present invention, the anti-explosion sheet 2121 is sealed in the air discharge hole 2111, and the protective sheet 2122 is placed over the anti-explosion sheet 2121 and on the boss 2113, so that the air vent of the air passage 2124 is exposed. The electrolyte is injected into the injection port 2112 by using the injection nozzle, and after the injection is finished, the injection nozzle is removed. In the process of removing the liquid injection nozzle, if the residual electrolyte on the liquid injection nozzle drops on the protective plate 2122, the protective plate 2122 can block the electrolyte, so as to prevent the electrolyte from flowing into the accommodating cavity 2123 further, and the electrolyte can contact with the explosion-proof plate 2121 to corrode the explosion-proof plate 2121.

After the liquid injection process is completed, the battery cell 20 needs to be sealed, and the airtightness is checked by helium testing. At this time, since the protective sheet 2122 has the air-permeable passage 2124, the housing chamber 2123 communicates with the outside. If the air leakage of the battery cell 20 is detected, it can be determined that the anti-explosion sheet 2121 is not tightly connected to the top cover sheet 211, or the anti-explosion sheet 2121 is cracked, and the hidden danger can be eliminated by only performing centralized inspection on the anti-explosion sheet 2121.

The top cover assembly 21, the battery cell 20, the battery 100 and the electric device in the above embodiments have at least the following advantages:

1) the protective sheet 2122 can prevent the electrolyte from polluting and corroding the explosion-proof sheet 2121, so that the safety performance of the explosion-proof sheet 2121 is improved;

2) the upper side surface of the protection plate 2122 is provided with a ventilation channel 2124, so that the accommodating cavity 2123 can be communicated with the outside, the protection effect of the protection plate 2122 on the anti-explosion plate 2121 is not influenced, the helium detection passage can be prevented from being blocked, and the accuracy of the helium detection result is effectively improved;

3) an air permeable passage 2124 is provided along the thickness direction of the protection plate 2122, and an air permeable membrane 2125 is covered in the air permeable passage 2124, and the air permeable membrane 2125 can not only prevent the electrolyte from entering the accommodating chamber 2123, but also can permeate small molecule gas such as helium gas, thereby not affecting helium detection.

The technical features of the embodiments described above may be arbitrarily combined, and for the sake of brevity, all possible combinations of the technical features in the embodiments described above are not described, but should be considered as being within the scope of the present specification as long as there is no contradiction between the combinations of the technical features.

The above-mentioned embodiments only express several embodiments of the present application, and the description thereof is more specific and detailed, but not construed as limiting the claims. It should be noted that, for a person skilled in the art, several variations and modifications can be made without departing from the concept of the present application, which falls within the scope of protection of the present application. Therefore, the protection scope of the present patent application shall be subject to the appended claims.

Claims (12)

1. A header assembly, comprising:

the top cover plate is provided with an exhaust hole in a penetrating way;

the explosion-proof valve comprises an explosion-proof sheet which is hermetically connected with the exhaust hole and a protection sheet which is arranged above the explosion-proof sheet, and an accommodating cavity is formed between the protection sheet and the explosion-proof sheet at intervals;

the protection sheet is provided with a first surface facing the explosion-proof sheet, and the first surface is provided with a ventilation channel communicated between the outside and the accommodating cavity.

2. The cap assembly of claim 1, wherein the air-permeable channels are recessed relative to the first surface to a depth less than the thickness of the protective sheet at the respective locations.

3. The header assembly of claim 2, wherein the venting channel comprises an open end and a closed end connected to the open end, the open end communicating with the outer edge of the first surface to form a venting port communicating with the exterior.

4. The lid assembly of claim 3, wherein the lid top surface has a boss disposed around the vent hole, the boss having an inner sidewall facing the vent hole in a direction parallel to the first surface, the distance between the open end and the closed end in the direction parallel to the first surface being greater than the distance between the open end and the inner sidewall of the boss in the direction parallel to the first surface.

5. The top cover assembly of claim 2, wherein a liquid filling opening is formed in the top cover sheet and spaced from the air vent, and the distance between the air vent channel and the liquid filling opening is greater than the shortest distance between the edge of the air vent and the liquid filling opening.

6. The lid assembly of claim 5, wherein the vent channel is located on a side of the protective sheet facing away from the pour opening.

7. The cap assembly of claim 1, wherein the protective sheet has a second surface facing away from the first surface, the air-permeable passage extending through the first and second surfaces in a thickness direction of the protective sheet, the air-permeable passage being covered with an air-permeable membrane.

8. The header assembly of claim 7, wherein the gas permeable membrane has a thickness of between 50 μ ι η and 200 μ ι η.

9. The header assembly of claim 7, wherein the vented membrane comprises one or more of polystyrene, polypropylene, polyvinyl chloride.

10. A battery cell comprising a housing and the cap assembly of any one of claims 1-9, wherein the housing has an opening and the cap assembly covers the opening.

11. A battery, characterized in that, includes the box and locates the battery monomer in the box, battery monomer is as claim 10 battery monomer.

12. An electric device comprising an electric main body and the battery according to claim 11.

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