Battery cover plate assembly, battery monomer and electric equipment

Abstract

The embodiment of the utility model provides a battery cover plate assembly, a battery monomer and electric equipment, and relates to the technical field of batteries. The battery cover plate assembly comprises a cover plate, an insulating part and a voltage reduction part, an exhaust structure is arranged on the insulating part, an accommodating space is formed between the cover plate and the insulating part, and the accommodating space is communicated with the exhaust structure; the pressure reducing piece is arranged in the accommodating space and is provided with a hollow part; and when the internal pressure of the battery monomer reaches the preset air pressure, the pressure reducing piece is broken, and the gas can be accommodated in the hollow part. In addition, a certain amount of gas can be stored in the accommodating space, and the pressure can be released into the accommodating space when the pressure in the battery monomer is too high, so that the service life of the battery monomer is prolonged. And the pressure-reducing part is provided with the hollow part, so that when the internal air pressure of the battery cell is too high in normal use, the pressure-reducing part is broken, and gas enters the hollow part to be accommodated, thereby reducing the internal pressure of the battery monomer, and the pressure is not required to be released by opening an anti-explosion valve, so that the service life of the battery is further prolonged.

Description

TECHNICAL FIELD

[0001] The utility model relates to battery technology field, specifically, relate to a battery cover plate subassembly, battery monomer and electric equipment. BACKGROUND

[0002] The existing battery is provided with an explosion-proof valve structure on a battery cover plate to prevent the battery from exploding under the condition of overcharge, overdischarge, thermal shock, vibration, extrusion, short circuit and other misuse, so that high-temperature gas and heat generated by chemical and electrochemical reactions in the battery can be released.

[0003] However, when the battery is in thermal runaway, the pressure in the battery will break the explosion-proof valve, and the battery will not be able to charge and discharge, and the battery will be scrapped and cannot be used again. UTILITY MODEL CONTENTS

[0004] The utility model provides a battery cover plate subassembly, battery monomer and electric equipment, it can when battery monomer normal use internal gas pressure is too big, through the rupture of pressure reducing piece, gas is contained in pressure reducing piece, to reduce the pressure in the battery monomer, thereby prolonging the service life of the battery.

[0005] The embodiment of the utility model can be realized as follows:

[0006] The embodiment of the utility model provides a battery cover plate subassembly, which comprises:

[0007] A cover plate;

[0008] An insulating piece, which is provided with an exhaust structure, and has a containing space between the cover plate and the insulating piece, the containing space being communicated with the exhaust structure;

[0009] A pressure reducing piece, which is arranged in the containing space and has a hollow part;

[0010] When the internal pressure of the battery monomer reaches a preset gas pressure, the pressure reducing piece breaks, and the gas can be contained in the hollow part.

[0011] In an optional embodiment, the pressure reducing piece is provided with a weak part on at least one side in a first direction, and the first direction and the thickness direction of the cover plate are perpendicular to each other.

[0012] In an optional embodiment, the weak part is a notch, and the outer surface of the pressure reducing piece is recessed to form the notch, wherein the residual thickness of the pressure reducing piece at the notch position is in the range of 0.2mm to 0.5mm.

[0013] In an optional embodiment, the number of the pressure reducing members is multiple, and the multiple pressure reducing members are arranged in the accommodating space.

[0014] In an optional embodiment, the insulation member is provided with a protruding portion on the side away from the cover plate, and the protruding portion is configured to abut against the battery cell; the insulation member is provided with a recessed portion on the side toward the cover plate, and the position of the recessed portion corresponds to the position of the protruding portion; the recessed portion and the cover plate form the accommodating space.

[0015] In an optional embodiment, the insulation member includes an intermediate portion and an edge portion arranged around the intermediate portion, the edge portion is recessed on the side toward the cover plate to form the annular recessed portion, and the edge portion is protruded on the side away from the cover plate to form the annular protruding portion; the exhaust structure is arranged on the intermediate portion; the cover plate is provided with a groove on the side toward the insulation member; part of the intermediate portion is accommodated in the groove; and the groove and the recessed portion are communicated.

[0016] In an optional embodiment, the pressure reducing member and the insulation member are fixedly connected; in the thickness direction of the cover plate, the distance between the pressure reducing member and the cover plate is a, and 0.5mm≤a.

[0017] In an optional embodiment, the air pressure at the hollow portion is <0.1Mpa.

[0018] The embodiment of the utility model further provides a battery monomer, including battery cell, shell and the battery cover plate subassembly that any one of the above embodiment is described, the battery cell is located in the shell; the battery cover plate subassembly is connected with the shell, and is used for sealing the battery cell together.

[0019] The embodiment of the utility model further provides a kind of electric equipment, including the battery monomer described in the above embodiment.

[0020] The battery cover plate subassembly, the battery monomer and the electric equipment of the embodiment of the utility model have the beneficial effects, for example:

[0021] The battery cover plate assembly comprises a cover plate, an insulating piece and a pressure reducing piece, the insulating piece is provided with an exhaust structure, the cover plate and the insulating piece have a containing space, and the containing space is communicated with the exhaust structure; by arranging the containing space and the exhaust structure, the exhaust structure can discharge the gas generated by the battery monomer in the use process from the exhaust structure into the containing space, a certain amount of gas can be stored in the containing space, the pressure can be released into the containing space when the pressure in the battery monomer is too large, so as to prevent the battery monomer from bulging due to the too large pressure in the battery monomer, thereby prolonging the service life of the battery monomer. The pressure reducing piece is arranged in the containing space, and the pressure reducing piece has a hollow part; when the internal pressure of the battery monomer reaches a preset air pressure, the pressure reducing piece breaks, and the gas can be contained in the hollow part. By arranging the pressure reducing piece and the pressure reducing piece having the hollow part, when the internal pressure of the battery monomer is too large in the normal use of the battery monomer, the pressure reducing piece breaks, the gas enters the containing space, the pressure in the battery monomer is reduced, the pressure limit of the explosion-proof valve opening is improved, and the service life of the battery monomer is further prolonged. BRIEF DESCRIPTION OF DRAWINGS

[0022] In order to more clearly illustrate the technical scheme of the embodiments of the present application, the following will briefly introduce the drawings needed to be used in the embodiments. It should be understood that the following drawings only show some embodiments of the present application, and therefore should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can also be obtained without creative labor on the basis of these drawings.

[0023] Figure 1 An explosion schematic diagram of the battery monomer provided in the embodiments of the present application is shown.

[0024] Figure 2 A schematic diagram of the battery monomer provided in the embodiments of the present application is shown.

[0025] Figure 3 A schematic diagram of the first battery monomer A-A section provided in the embodiments of the present application is shown.

[0026] Figure 4 A schematic diagram of the second battery monomer A-A section provided in the embodiments of the present application is shown.

[0027] Figure 5 An explosion schematic diagram of the battery cover plate assembly provided in the embodiments of the present application is shown.

[0028] Figure 6 A schematic diagram of the first pressure reducing piece provided in the embodiments of the present application is shown.

[0029] Figure 7 A schematic diagram of the B-B section provided in the embodiments of the present application is shown.

[0030] Icon: 1000 - battery monomer; 100 - battery cover plate assembly; 110 - cover plate; 111 - groove; 120 - insulating piece; 121 - middle part; 122 - edge part; 1221 - protruding part; 1222 - recessed part; 130 - pressure reducing piece; 131 - hollow part; 132 - weak part; 133 - notch; 140 - accommodating space; 150 - exhaust structure; 200 - shell; 300 - battery cell. DETAILED DESCRIPTION

[0031] To make the objectives, technical solutions, and advantages of the embodiments of the present application clearer, the following will be combined with the accompanying drawings for the embodiments of the present application to make a clear and complete description of the technical solutions in the embodiments of the present application. Obviously, the described embodiments are some but not all of the embodiments of the present application. The components of the embodiments of the present application described and shown in the accompanying drawings can be arranged and designed in various different configurations.

[0032] Therefore, the following detailed description of the embodiments of the present application provided in the accompanying drawings is not intended to limit the scope of the claimed present application, but only represents selected embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative labor fall within the scope of protection of the present application.

[0033] It should be noted that: similar reference numerals and letters represent similar items in the following drawings, therefore, once an item is defined in one drawing, it does not need to be further defined and explained in the subsequent drawings.

[0034] In the description of the present application, it should be noted that if the terms "upper", "lower", "inner", "outer" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, or the orientation or positional relationship of the product of the present application when it is usually placed, which is only for the convenience of describing the present application and simplifying the description, and does not indicate or imply that the indicated device or element must have a particular orientation, be constructed and operated in a particular orientation, therefore, it cannot be understood as a limitation on the present application.

[0035] In addition, if the terms "first", "second" and the like appear, they are only used to distinguish the description, and cannot be understood as indicating or implying relative importance.

[0036] It should be noted that the features in the embodiments of the present application can be combined with each other without conflict.

[0037] The existing battery is provided with an explosion-proof valve structure on the battery cover plate to prevent the battery from exploding. When the internal pressure of the battery is too high, the explosion-proof valve opens, and the internal pressure and heat of the battery are released from the position of the explosion-proof valve. That is, when the internal pressure of the battery exceeds the design limit due to the generation of too much gas caused by chemical reactions (such as side reactions caused by overcharging or overdischarging), the explosion-proof valve will start to release the gas. Or in a high-temperature environment, the internal chemical reaction rate of the battery may accelerate, which may generate more gas and increase the internal pressure; when the temperature reaches a certain threshold, the explosion-proof valve may start. In addition, the battery may be damaged by external impact or other forms of physical damage, which may affect the pressure balance inside the battery, and the explosion-proof valve may start. Internal short circuit of the battery can also cause a sharp increase in current, generating a large amount of heat and gas, thereby rapidly increasing the internal pressure and triggering the explosion-proof valve. Electrolyte leakage may also cause an imbalance in the chemical composition inside the battery, causing abnormal reactions and increasing internal pressure, ultimately triggering the explosion-proof valve.

[0038] However, when the battery experiences thermal runaway, the internal pressure of the battery breaks through the explosion-proof valve and is released, the battery cannot be charged or discharged, and the battery is scrapped and cannot be used again. After the explosion-proof valve is opened, the electrolyte inside the battery may leak, causing a significant decrease in battery capacity, or even complete failure; even if there is no immediate physical damage, the performance of the battery will be greatly reduced. After the explosion-proof valve is opened, the battery case may be deformed or damaged, which not only affects the sealing of the battery, but also may expose the chemicals inside the battery to the outside, causing harm to the environment and human health. Therefore, after the explosion-proof valve of the battery is opened, the battery cannot be used again.

[0039] Based on this, please refer to Figure 1 、 Figure 2 and Figure 3 The battery cover plate assembly 100 provided in the embodiments of the present utility model can effectively improve the above-mentioned technical problems. The battery cover plate assembly 100 can reduce the internal pressure of the battery monomer 1000 by breaking the pressure reduction piece 130 when the internal pressure of the battery monomer 1000 is too high during normal use, and containing the gas in the pressure reduction piece 130, thereby increasing the opening limit of the explosion-proof valve and prolonging the service life of the battery. The battery cover plate assembly 100 is applied to the battery monomer 1000, and the battery monomer 1000 can be applied to various electric devices, such as battery packs and electric vehicles. The battery monomer 1000 and the electric device with the battery cover plate 110 both have the above-mentioned functions, which are not limited here.

[0040] The power consuming device provided in the embodiment includes a battery monomer 1000, and the power consuming device can be a battery pack, a plurality of battery monomers 1000 jointly constitute the battery pack, and the battery pack is used for providing electric energy for other electric energy consuming devices. Of course, the power consuming device can also be an electric vehicle, a mobile power supply, a smart home, etc., which is not limited here.

[0041] Figure 1 An explosion schematic view of the battery monomer 1000 provided in the embodiment of the utility model; Figure 2 A schematic view of the battery monomer 1000 provided in the embodiment of the utility model; Figure 3 A schematic view of a first battery monomer 1000-A cross section provided in the embodiment of the utility model.

[0042] As shown in Figure 1 , Figure 2 and Figure 3 , the battery monomer 1000 in the embodiment includes a battery core 300, a shell 200 and a battery cover plate assembly 100, the battery core 300 is located in the shell 200; the battery cover plate assembly 100 is connected with the shell 200, and is used for sealing the battery core 300 together. That is, the cover plate 110 is connected with the shell 200 to seal the battery core 300, the battery core 300 is arranged in the mounting space formed by the shell 200 and the cover plate 110, the insulating piece 120 is located between the battery core 300 and the cover plate 110, the insulating piece 120 directly contacts the battery core 300, the battery core 300 tab is exposed from the tab mounting hole on the insulating piece 120 and the cover plate 110, so as to be connected with other power consuming devices. Of course, the battery monomer 1000 can also include other structural members to realize other various functions, which is not limited here.

[0043] Specifically, please refer to Figure 5 , Figure 5The battery cover plate assembly 100 provided in the embodiment of the utility model has the explosion-proof structure, and the battery cover plate assembly 100 comprises a cover plate 110, an insulating piece 120 and a pressure reducing piece 130; the insulating piece 120 is provided with an exhaust structure 150; the cover plate 110 and the insulating piece 120 have a containing space 140; the containing space 140 is communicated with the exhaust structure 150; the pressure reducing piece 130 is arranged in the containing space 140; the pressure reducing piece 130 has a hollow part 131; when the internal pressure of the battery monomer 1000 reaches the preset air pressure, the pressure reducing piece 130 is broken, and the gas can be contained in the hollow part 131. That is, when the internal pressure of the battery monomer 1000 is too large, the battery monomer 1000 can discharge the gas to the containing space 140 through the exhaust structure 150 of the insulating piece 120 for storage. When the pressure of the discharged gas further increases, the air pressure in the containing space 140 is greater than the air pressure in the pressure reducing piece 130, so that the pressure reducing piece 130 is broken, and the gas can be stored in the hollow part 131 of the pressure reducing piece 130, thereby improving the pressure limit of the explosion-proof valve of the battery cell 300, prolonging the service life of the battery monomer 1000. That is, within a certain range of the air pressure increase of the battery cell 300, the battery cover plate assembly 100 can make the explosion-proof valve of the battery cell 300 not open at the first time, and also can reduce the internal pressure of the battery monomer 1000, thereby ensuring that the battery monomer 1000 can continue to be normally used, and prolonging the service life of the battery monomer 1000. The preset air pressure in the embodiment is 0.5 MPa, of course, the preset air pressure can also be other values, and the preset air pressure is determined according to the application scene of the actual battery monomer 1000, which is not limited here.

[0044] By arranging the containing space 140 and the exhaust structure 150, the exhaust structure 150 can discharge the gas generated in the use process of the battery monomer 1000 from the exhaust structure 150 to the containing space 140, a certain amount of gas can be stored in the containing space 140, and the pressure can be released to the containing space 140 when the internal pressure of the battery monomer 1000 is too large, so as to prevent the internal pressure of the battery monomer 1000 from being too large and causing the battery monomer 1000 to bulge outward, thereby prolonging the service life of the battery monomer 1000. By arranging the pressure reducing piece 130, and the pressure reducing piece 130 has the hollow part 131, when the internal air pressure of the battery cell 300 is too large in normal use, the pressure reducing piece 130 is broken, and the gas is contained in the hollow part 131, so as to reduce the internal pressure of the battery monomer 1000, and the pressure does not need to be released by opening the explosion-proof valve, thereby further prolonging the service life of the battery.

[0045] Figure 6 The first pressure reducing piece 130 provided in the embodiment of the utility model is shown in the schematic diagram; Figure 7The B-B sectional view provided in the embodiment of the utility model is a schematic diagram. In order to make the pressure-reducing piece 130 easily break when the internal pressure of the battery monomer 1000 reaches the preset air pressure, please refer to Figure 5 , and in combination with Figure 6 and Figure 7 , the gas is contained in the hollow part 131, the pressure-reducing piece 130 in the embodiment is provided with a weak part 132 on at least one side in the first direction, and the first direction and the thickness direction of the cover plate 110 are perpendicular to each other. When the pressure in the battery monomer 1000 reaches the preset air pressure, the gas discharged by the battery monomer 1000 enters the containing space 140 through the exhaust structure 150, and then breaks the pressure-reducing piece 130 at the weak part 132 to expose the hollow part 131, contains part of the gas, and reduces the pressure in the battery monomer 1000.

[0046] Specifically, the weak part 132 in the embodiment is a notch 133, and the outer surface of the pressure-reducing piece 130 is recessed to form the notch 133, wherein the residual thickness of the pressure-reducing piece 130 at the position of the notch 133 is in the range of 0.2mm-0.5mm. The residual thickness here specifically refers to the thickness of the pressure-reducing piece 130 at the position of the notch 133. The residual thickness of the pressure-reducing piece 130 at the position of the notch 133 can be 0.2mm, 0.25mm, 0.3mm, 0.35mm, 0.4mm, 0.45mm, 0.5mm, etc. Of course, the residual thickness of the pressure-reducing piece 130 at the position of the notch 133 can also be other values or other value ranges, which are determined according to the actual size of the battery monomer 300 and the preset voltage and other factors, and are not limited here, as long as the pressure-reducing piece 130 can easily break at the position of the notch 133 when the internal pressure of the battery monomer 1000 reaches the preset pressure.

[0047] In addition, the weak part 132 can also be designed as a split line structure, similar to the split line of toilet paper. Of course, the weak part 132 can also be designed as other structure forms, as long as the pressure-reducing piece 130 can break at the weak part 132 to achieve pressure reduction when the pressure of the battery monomer 1000 is large, which is not limited here.

[0048] The number of the pressure reducing pieces 130 in the embodiment is multiple, and the multiple pressure reducing pieces 130 are arranged in the accommodating space 140; and / or, the pressure reducing pieces 130 are annular or block-shaped. The pressure reducing pieces 130 can be multiple annular structures, the multiple annular structures are connected end to end to form a complete closed annular structure, and are arranged in the accommodating space 140. Of course, the number of the pressure reducing pieces 130 can also be one, and one annular structure with a hollow part 131 is arranged in the accommodating space 140. The pressure reducing pieces 130 can also be block-shaped, and multiple blocks are arranged in the accommodating space 140 in a spaced or interconnected manner. The pressure reducing pieces 130 can fill the entire accommodating space 140, or can not fill the entire accommodating space 140, which is not limited herein. In addition, the shape of the pressure reducing pieces 130 in the embodiment can be a regular shape, such as a cuboid or a cube. The shape of the pressure reducing pieces 130 can also be an irregular shape, such as an ellipsoid, and the shape of the pressure reducing pieces 130 is not limited herein. The shape and number of the pressure reducing pieces 130 are determined according to actual pressure reduction requirements and specifications of the battery cell 300, which is not limited herein.

[0049] Please refer to Figure 5 , in combination with Figure 3 and Figure 4 , Figure 4 is a schematic view of a second battery monomer 1000-A cross section provided in the embodiment of the utility model, the side of the insulating piece 120 away from the cover plate 110 is formed with a convex part 1221, the convex part 1221 is configured to abut against the battery cell 300; the side of the insulating piece 120 towards the cover plate 110 is provided with a recessed part 1222, the position of the recessed part 1222 corresponds to the position of the convex part 1221; the recessed part 1222 and the cover plate 110 constitute an accommodating space 140. By arranging the recessed part 1222 and the convex part 1221 in the insulating piece 120, the accommodating space 140 can be formed between the insulating piece 120 and the cover plate 110 to accommodate part of the gas discharged by the battery cell 300 or the pressure reducing piece 130.

[0050] Specifically, the insulating piece 120 in the embodiment includes an intermediate portion 121 and an edge portion 122 arranged at the outer circumferential side of the intermediate portion 121, the edge portion 122 is recessed towards one side of the cover plate 110 to form a ring-shaped recessed portion 1222, and the edge portion 122 is protruded away from one side of the cover plate 110 to form a ring-shaped protruded portion 1221; the exhaust structure 150 is arranged at the intermediate portion 121; the cover plate 110 is provided with a groove 111 towards one side of the insulating piece 120; a part of the intermediate portion 121 is accommodated in the groove 111; and the groove 111 and the recessed portion 1222 are communicated. The exhaust structure 150 in the embodiment is a plurality of gas permeable holes arranged side by side and spaced apart, and the shape of the gas permeable holes is long strip-shaped. Of course, the shape of the gas permeable holes can also be circular or other shapes, which are not limited herein. In order to expand the accommodation space 140, the intermediate portion 121 in the embodiment is recessed towards the side away from the cover plate 110 at the position where the exhaust structure 150 is arranged, and a plurality of gas permeable holes are arranged at the recessed position to communicate the battery cell 300 and the accommodation space 140.

[0051] Please refer to Figure 5 , in combination with Figure 1 and Figure 4 , the pressure reducing piece 130 and the insulating piece 120 in the embodiment are fixedly connected; in the thickness direction of the cover plate 110, the distance between the pressure reducing piece 130 and the cover plate 110 is a, and 0.5mm≤a. By arranging the pressure reducing piece 130 and the cover plate 110 in a spaced apart manner, the gas entering the battery monomer 1000 from the exhaust structure 150 can easily fill the entire accommodation space 140 from the gap between the pressure reducing piece 130 and the cover plate 110, so as to apply pressure to all pressure reducing pieces 130.

[0052] In order to make the pressure reducing piece 130 easily broken when the battery monomer 1000 reaches a preset air pressure, the air pressure at the hollow portion 131 in the embodiment is <0.1Mpa. The air pressure at the hollow portion 131 should be as low as possible to make the pressure reducing piece 130 easily broken, so as to reduce the internal air pressure of the battery cell 300 and prolong the service life of the battery monomer 1000. The air pressure at the hollow portion 131 can also be less than other values, which is determined according to the actual application.

[0053] The pressure reducing piece 130 in the embodiment is made of nano injection molding material, which will not introduce metal chips after the pressure reducing piece 130 is broken, so as to avoid the influence of metal chips on the normal use of the battery monomer 1000. Of course, the pressure reducing piece 130 can also be made of metal material or other materials, which are not limited herein.

[0054] The working principle of the battery cover plate assembly 100 provided in the embodiment is as follows:

[0055] When the internal pressure of the battery monomer 1000 is too large, the battery monomer 1000 can discharge the discharged gas into the storage space 140 through the exhaust structure 150 of the insulating piece 120. When the pressure of the discharged gas is further increased, the gas pressure in the storage space 140 is greater than the gas pressure in the pressure reduction piece 130, which can cause the pressure reduction piece 130 to break, and the gas can enter the hollow part 131 of the pressure reduction piece 130 to be stored, thereby increasing the pressure limit of the explosion-proof valve of the battery cell 300 to prolong the service life of the battery monomer 1000. That is, within a certain range of the increase of the gas pressure of the battery cell 300, the battery cover plate assembly 100 can make the explosion-proof valve of the battery cell 300 not open at the first time, and can also reduce the internal pressure of the battery monomer 1000, thereby ensuring that the battery monomer 1000 can continue to be normally used to prolong the service life of the battery monomer 1000.

[0056] In summary, the battery cover plate assembly 100 includes a cover plate 110, an insulating piece 120, and a pressure reduction piece 130, the insulating piece 120 is provided with an exhaust structure 150, the cover plate 110 and the insulating piece 120 have a storage space 140, the storage space 140 is communicated with the exhaust structure 150; the pressure reduction piece 130 is arranged in the storage space 140, and the pressure reduction piece 130 has a hollow part 131; when the internal pressure of the battery monomer 1000 reaches a preset gas pressure, the pressure reduction piece 130 breaks, and the gas can be accommodated in the hollow part 131. By arranging the storage space 140 and the exhaust structure 150, the exhaust structure 150 can discharge the gas generated in the use process of the battery monomer 1000 from the exhaust structure 150 to the storage space 140, and a certain amount of gas can be stored in the storage space 140, which can release the pressure to the storage space 140 when the internal pressure of the battery monomer 1000 is too large, so as to prevent the battery monomer 1000 from bulging outward due to the excessive internal pressure of the battery monomer 1000, thereby prolonging the service life of the battery monomer 1000. By arranging the pressure reduction piece 130, and the pressure reduction piece 130 has the hollow part 131, when the internal gas pressure of the battery cell 300 is too large during normal use, the pressure reduction piece 130 breaks, the gas enters the hollow part 131 to be stored, thereby reducing the internal pressure of the battery monomer 1000, thereby increasing the opening limit of the explosion-proof valve of the battery, and further prolonging the service life of the battery monomer 1000.

[0057] The above is only a specific embodiment of the present application, but the protection scope of the present application is not limited thereto, any skilled person in the art can easily think of changes or replacements within the technical range disclosed by the present application, which should be covered within the protection scope of the present application.

Claims

1. A battery cover plate assembly, characterized by, The application relates to a battery cell (1000) comprising: a cover plate (110); an insulation piece (120) provided with an exhaust structure (150), the cover plate (110) and the insulation piece (120) having a containing space (140) therebetween, the containing space (140) being in communication with the exhaust structure (150); a pressure reduction piece (130) arranged in the containing space (140), the pressure reduction piece (130) having a hollow part (131); when the internal pressure of the battery cell (1000) reaches a preset air pressure, the pressure reduction piece (130) is broken, and gas can be contained in the hollow part (131).

2. The battery cover plate assembly of claim 1, wherein, The pressure reduction piece (130) is provided with a weak part (132) on at least one side in a first direction, the first direction being perpendicular to the thickness direction of the cover plate (110).

3. The battery cover plate assembly of claim 2, wherein, The weak part (132) is a notch (133), and the notch (133) is recessed on the outer surface of the pressure reduction piece (130), wherein the residual thickness of the pressure reduction piece (130) at the position of the notch (133) is 0.2mm-0.5mm.

4. The battery cover plate assembly of claim 1, wherein, The number of the pressure reduction pieces (130) is multiple, and the multiple pressure reduction pieces (130) are arranged in the containing space (140); and / or the pressure reduction pieces (130) are annular or block-shaped.

5. The battery cover plate assembly of any one of claims 1 to 4, wherein, The side of the insulation piece (120) away from the cover plate (110) is formed with a protruding part (1221) configured to abut against an electric core (300); the side of the insulation piece (120) towards the cover plate (110) is provided with a recessed part (1222) corresponding to the position of the protruding part (1221); and the recessed part (1222) and the cover plate (110) form the containing space (140).

6. The battery cover plate assembly of claim 5, wherein, The insulation piece (120) comprises an intermediate part (121) and an edge part (122) annularly arranged on the outer circumferential side of the intermediate part (121), the side of the edge part (122) away from the cover plate (110) is recessed to form the annular recessed part (1222), and the side of the edge part (122) towards the cover plate (110) is protruded to form the annular protruding part (1221); the exhaust structure (150) is arranged on the intermediate part (121); the side of the cover plate (110) towards the insulation piece (120) is provided with a groove (111); part of the intermediate part (121) is contained in the groove (111); and the groove (111) and the recessed part (1222) are in communication.

7. The battery cover plate assembly of any one of claims 1 to 4, wherein, The pressure reduction piece (130) and the insulation piece (120) are fixedly connected; in the thickness direction of the cover plate (110), the distance between the pressure reduction piece (130) and the cover plate (110) is a, and 0.5mm<=a.

8. The battery cover plate assembly (100) according to any one of claims 1 to 4, characterized in that The air pressure at the hollow part (131) is <0.1Mpa.

9. A battery cell characterized by, The battery cover plate assembly (100) of any one of claims 1-8, wherein the battery cover plate assembly (100) is connected with the shell (200) to seal the battery cell (300) together with the shell (200).

10. An electric device, characterized by The battery cell (1000) of claim 9.

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