Cap assembly, battery and electric equipment

Abstract

The utility model belongs to the technical field of batteries, and discloses a cap assembly, a battery and electric equipment. The cap assembly comprises an anti-explosion piece, a pore plate, an insulating spacer and a conductive adhesive layer, wherein the anti-explosion piece comprises a main body part and a lug boss arranged on the main body part; the pore plate comprises a central part and a connecting part which are connected with each other, the connecting part surrounds the periphery of the central part, and a first pressure relief hole is formed between the central part and the connecting part; the insulating spacer is arranged between the anti-explosion sheet and the pore plate and can cover at least part of the connecting part; the protruding part protrudes towards the central part, and the conductive adhesive layer is clamped between the protruding part and the central part. According to the cap assembly, a circuit can be cut off in time when the battery is in thermal runaway, the CID function is achieved, the safety is improved, meanwhile, the pore plate and the anti-explosion piece can be fixed without adopting a welding mode, the reliability of the cap assembly is improved, the arrangement mode of the conductive adhesive layer is simpler, the process is easier to operate, and the production efficiency can be improved.

Description

TECHNICAL FIELD

[0001] The utility model relates to battery technology field especially relates to a cap subassembly, battery and electric equipment. BACKGROUND

[0002] The cap subassembly of cylindrical lithium ion secondary battery generally includes top cover, explosion-proof sheet, hole plate and insulating gasket arranged between explosion-proof sheet and hole plate, and the first pressure relief hole for pressure relief is arranged on the hole plate.

[0003] In the prior art, CID (Current Interrupt Device) can protect the battery, when the battery cell fails (such as overheating, short circuit, overcharge, etc.), a lot of gas will be generated inside, and when the pressure increases, the explosion-proof sheet breaks and disconnects the current path between the top cover and the internal active material, causing the internal circuit of the battery cell to break, thereby playing a protective role.

[0004] In the process of realizing the cap subassembly CID of the existing lithium battery, welding (i.e. the hole plate and the explosion-proof sheet are welded) is usually used to ensure the CID function of the battery. However, traditional welding may cause material deformation, thermal damage of the cap subassembly and formation of internal stress, unstable CID function, which may affect the performance and safety of the battery.

[0005] Therefore, it is urgent to provide a new cap subassembly, battery and electric equipment to solve the above technical problems in the prior art. UTILITY MODEL CONTENTS

[0006] One purpose of the utility model is to provide a cap subassembly that can improve its safety and reliability, ensure that the battery can realize the CID function, and the production process is simpler, which can improve the production efficiency.

[0007] To achieve this purpose, the utility model adopts the following technical solutions:

[0008] The cap subassembly includes an explosion-proof sheet, a hole plate, an insulating gasket and a conductive adhesive layer, the explosion-proof sheet includes a main body part and a protruding part arranged on the main body part, the hole plate includes a center part and a connecting part connected together, the connecting part is arranged around the outer periphery of the center part, a first pressure relief hole is arranged between the center part and the connecting part, the insulating gasket is arranged between the explosion-proof sheet and the hole plate, and the insulating gasket can cover at least part of the connecting part, the protruding part is arranged protruding towards the center part, and the conductive adhesive layer is arranged between the protruding part and the center part.

[0009] Optionally, a first marking line is arranged on the main body part, and the projection of the first pressure relief hole on the first end surface can cover at least part of the projection of the first marking line on the first end surface of the main body part.

[0010] Optionally, the main body part further comprises a second end face arranged opposite to the first end face, and the first marking line is recessed from the first end face to the second end face.

[0011] Optionally, an end wall surface of the orifice plate close to the first end face is provided with a second marking line, the second marking line is coaxially arranged with the first marking line, and the diameter of the second marking line is greater than the diameter of the first marking line.

[0012] Optionally, a projection of the conductive adhesive layer on the first end face can cover a projection of the second marking line on the first end face.

[0013] Optionally, the insulating gasket is provided with a second pressure relief hole, and the opening area of the second pressure relief hole is not less than the opening area of the first pressure relief hole.

[0014] Optionally, the first pressure relief hole is a waist-shaped hole.

[0015] Optionally, the center axis of the second pressure relief hole is coaxially arranged with the center axis of the waist line of the first pressure relief hole.

[0016] Optionally, the insulating gasket comprises a first part and a second part bently connected to the first part, and the second part is wrapped around the circumferential outer wall of the orifice plate.

[0017] Optionally, the projection area of the conductive adhesive layer on the first end face of the main body part is not less than 60% of the projection area of the protruding part on the first end face.

[0018] Another purpose of the utility model is to provide a battery, which comprises the cap assembly according to any one of the above schemes.

[0019] Still another purpose of the utility model is to provide an electric device, which comprises the battery according to the above scheme.

[0020] Advantages:

[0021] The cap assembly in the utility model can realize the CID function and improve the safety, and the raised portion of the main body of the rupture disc is connected with the center portion of the hole plate through the conductive adhesive layer, the conductive connection between the hole plate and the rupture disc is realized, the hole plate and the rupture disc are fixed through the conductive adhesive layer without welding, the deformation of the material caused by high-temperature welding is avoided, the thermal stress and thermal damage caused by welding are also avoided, the internal resistance of the welding position is reduced, the reliability of the cap assembly is improved, the setting mode of the conductive adhesive layer is simpler, the process is easier to operate, and the production efficiency is improved. BRIEF DESCRIPTION OF DRAWINGS DETAILED DESCRIPTION OF THE INVENTION BRIEF DESCRIPTION OF DRAWINGS

[0022] Figure 1 is the longitudinal sectional view of the cap assembly provided by the embodiment of the utility model;

[0023] Figure 2 is the longitudinal sectional view of the insulating gasket and the hole plate after installation provided by the embodiment of the utility model;

[0024] Figure 3 is the isometric view of the hole plate provided by the embodiment of the utility model.

[0025] In the drawings:

[0026] 100, rupture disc; 110, main body; 111, first end face; 112, raised portion; 113, second end face; 114, first scale line; 120, support portion;

[0027] 200, hole plate; 210, center portion; 211, second scale line; 220, connecting portion; 221, first pressure relief hole;

[0028] 300, insulating gasket; 310, second pressure relief hole; 321, first portion; 322, second portion;

[0029] 400, conductive adhesive layer; 500, top cover; 600, sealing sleeve. DETAILED DESCRIPTION

[0030] The utility model will be further explained in detail in combination with the drawings and examples. It can be understood that the specific examples described here are only used to explain the utility model, and not limited to the utility model. In addition, it should be noted that, in order to facilitate the description, only the part related to the utility model is shown in the drawings, not all structures.

[0031] In the description of the utility model, unless another definite provision and limitation, the term "link", "connect", "fix" should be broad sense understanding, for example, can be fixed connection, also can be detachable connection, or be integrated;Can be mechanical connection, also can be electrical connection;Can be directly connected, also can be indirectly connected through the intermediate medium, can be two elements inside the communication or two elements of the interaction relationship.For the ordinary skilled in the art, the specific meaning of the above-mentioned terms in the utility model can be understood according to the specific circumstances.

[0032] In the utility model, unless another definite provision and limitation, the first feature is "on" or "under" the second feature can include the first and second features direct contact, also can include the first and second features are not direct contact but contact through the additional features between them.Moreover, the first feature is "on", "above" and "on" the second feature includes the first feature is directly above and obliquely above the second feature, or just indicates that the horizontal height of the first feature is higher than the second feature.The first feature is "under", "below" and "under" the second feature includes the first feature is directly below and obliquely below the second feature, or just indicates that the horizontal height of the first feature is less than the second feature.

[0033] In the description of the embodiment, the terms "on", "under", "right", etc. Orientation or positional relationship is based on the orientation or positional relationship shown in the drawing, only for the convenience of description and simplification operation, and does not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, therefore cannot be understood as a limitation on the utility model.In addition, the terms "first", "second" are only used to distinguish in the description, and have no special meaning.

[0034] As Figure 1 As shown in the figure, the cap assembly includes a rupture disc 100, a hole plate 200, an insulating gasket 300 and a conductive adhesive layer 400, the rupture disc 100 includes a main body part 110 and a protruding part 112 arranged on the main body part 110, the hole plate 200 includes a center part 210 and a connecting part 220 connected, the connecting part 220 is arranged around the outer periphery of the center part 210, and a first pressure relief hole 221 is arranged between the center part 210 and the connecting part 220, the insulating gasket 300 is arranged between the rupture disc 100 and the hole plate 200, wherein the insulating gasket 300 can cover at least part of the connecting part 220, the protruding part 112 is arranged protruding towards the center part 210, and the conductive adhesive layer 400 is arranged between the protruding part 112 and the center part 210.

[0035] In use, the cap assembly in the embodiment can allow the high-pressure gas in the battery to be discharged outwardly through the first pressure relief hole 221 on the hole plate 200, so that the rupture disc 100 above the hole plate 200 is broken, the exhaust pressure relief is achieved, and after the rupture disc 100 is broken, the main body 110 is separated from the rupture disc 100. At the same time, the insulating gasket 300 blocks the rupture disc 100 and the hole plate 200, and the circuit of the cap assembly is broken. When the battery is in thermal runaway, the circuit is cut off in time, the CID function is achieved, and the safety is improved. At the same time, the protruding portion 112 is arranged on the main body 110 of the rupture disc 100, so that the protruding portion 112 is connected between the center portion 210 of the hole plate 200 and the conductive adhesive layer 400, the conductive connection between the hole plate 200 and the rupture disc 100 is achieved, the conductive adhesive layer 400 is arranged without welding, the deformation of the material caused by high-temperature welding is avoided, and the thermal stress and thermal damage caused by welding are also avoided. The internal resistance at the welding position is reduced, the reliability of the cap assembly is improved, the arrangement of the conductive adhesive layer 400 is simpler, the process is easier to operate, and the production efficiency is improved.

[0036] In the embodiment, the cap assembly further includes a top cover 500 and a sealing sleeve 600. The sealing sleeve 600 has a first end and a second end arranged oppositely. The first end of the sealing sleeve 600 is open, the outer side wall of the sealing sleeve 600 is sealingly connected with the inner side wall of the shell, the top cover 500 is installed close to the top opening of the sealing sleeve 600, and part of the top cover 500 is exposed through the top opening of the sealing sleeve 600. The top cover 500, the rupture disc 100, the insulating gasket 300, and the hole plate 200 are arranged in the sealing sleeve from top to bottom, and the support portion 120 of the rupture disc 100 directly abuts against the inner bottom wall of the sealing sleeve 600. The support portion 120 is a structure surrounding the outer peripheral edge of the main body 110, and is integrally formed with the main body 110. The center portion 210 and the connecting portion 220 are also integrally formed, and details are not repeated here.

[0037] Further, the main body 110 is provided with a first score line 114, and the main body 110 further comprises a second end surface 113 opposite to the first end surface 111. The first score line 114 is recessed from the second end surface 113 to the first end surface 111. A projection of the first pressure relief hole 221 on the first end surface 111 can cover at least part of a projection of the first score line 114 on the first end surface 111. In the embodiment, the first score line 114 has a longitudinal section in the shape of an inverted triangle with a pointed end downward, and the first score line 114 is annularly distributed on the first end surface 111. Such a configuration can cause the first score line 114 to break first when the internal pressure of the battery increases, so that the high-pressure gas pushes up the middle part of the main body 110 surrounded by the first score line 114, disconnects the connection between the main body 110 and the center part 210 of the hole plate 200, and realizes the disconnection of the battery.

[0038] As a preferred embodiment, the hole plate 200 is provided with a second score line 211 on an end wall surface close to the first end surface 111. The second score line 211 is coaxially arranged with the first score line 114, and the diameter of the second score line 211 is greater than that of the first score line 114. When the internal pressure of the battery increases, the first score line 114 breaks first. If the high-pressure gas does not push up the middle part surrounded by the first score line 114, the second score line 211 will break with the increase of the pressure, so that the part surrounded by the second score line 211 is lifted with the rupture of the explosion-proof sheet 100, forming an outlet of the high-pressure gas flow, realizing explosion-proof pressure relief, and being more reliable and safe.

[0039] Optionally, a projection of the conductive adhesive layer 400 on the first end surface 111 can cover a projection of the second score line 211 on the first end surface 111. The conductive adhesive layer 400 in the embodiment is coated with epoxy conductive adhesive, and has a volume resistivity of 10 -3 Ω·cm to 10 -4 Ω·cm, which can meet the conductive requirements of the battery. The epoxy conductive adhesive has various curing agents and modifiers, and can be adjusted and designed by the ratio of ingredients to meet the temperature and strength requirements of the battery, and the size of the CID value can be controlled by adjusting the amount of the conductive adhesive layer 400. The prepared conductive adhesive layer 400 can be cured at a relatively low temperature, but its melting temperature is much higher than this temperature, which can ensure that the conductive adhesive layer 400 will not melt in the use scenario during the charging and discharging process of the battery.

[0040] Optionally, the projection area of the conductive adhesive layer 400 on the first end surface 111 of the main body 110 is not less than 60% of the projection area of the protruding portion 112 on the first end surface 111. The proportion of the area covered by the conductive adhesive layer 400 on the protruding portion 122 is determined by a person skilled in the art according to the use requirements, and specifically is determined by the projection position of the second score line 211 on the protruding portion 122, so as to ensure that the conductive adhesive layer 400 completely covers the second score line 211. If the proportion of the area covered by the conductive adhesive layer 400 is too large, the cost will be high, and if the proportion of the area covered by the conductive adhesive layer 400 is too small, the protruding portion 112 will easily fall off on the center portion 210, affecting the conductive effect.

[0041] As shown in Figure 2 and Figure 3 The insulating gasket 300 is provided with a second pressure relief hole 310, and the opening area of the second pressure relief hole 310 is not less than the opening area of the first pressure relief hole 221. The opening area of the second pressure relief hole 310 is greater than the opening area of the first pressure relief hole 221, which is beneficial to the high-pressure airflow passing through the first pressure relief hole 221 and the second pressure relief hole 310 to form a high-pressure impact on the first score line 114, thereby breaking the first score line 114, and facilitating the rapid release of the high-pressure airflow.

[0042] Optionally, the first pressure relief hole 221 is a waist-shaped hole, which increases the pressure relief capacity of the first pressure relief hole 221 while maintaining the strength of the insulating gasket 300. Further, the first pressure relief hole 221 is provided with a plurality of first pressure relief holes 221, which are uniformly distributed with respect to the center of the hole plate 200, and the number of the first pressure relief holes 221 can be 2, 3, 4, 5 or 6.

[0043] In the embodiment, the center axis of the second pressure relief hole 310 is coaxially arranged with the center axis of the waist line of the first pressure relief hole 221. The waist line herein is the part where the center circle between the outer diameter and the inner diameter of the waist-shaped hole of the first pressure relief hole 221 coincides. By arranging the second pressure relief hole 310 coaxially with the waist line of the first pressure relief hole 221, the high-pressure airflow passing through the first pressure relief hole 221 can directly impact the explosion-proof sheet 100 without being affected by the rigidity of the insulating gasket 300, thereby preventing the insulating gasket 300 from affecting the pressure relief effect of the first pressure relief hole 221 on the hole plate 200.

[0044] Optionally, the insulating gasket 300 comprises a first portion 321 and a second portion 322 connected to the first portion 321 by bending, and the second portion 322 wraps the circumferential outer wall of the hole plate 200. Such arrangement can increase the wrapping area of the insulating gasket 300 on the circumferential outer wall of the hole plate 200, prevent the hole plate 200 from contacting the explosion-proof sheet 100 during deformation, effectively prevent the hole plate 200 from short-circuiting with the explosion-proof sheet 100 during the pressure relief of the battery, and further effectively improve the service life of the battery and the safety performance of the battery.

[0045] The embodiment also provides a battery comprising the cap assembly according to any one of the above-mentioned solutions. The battery is exemplified by a cylindrical lithium ion secondary battery, and the battery comprises a shell, the cap assembly, a positive electrode, a negative electrode, a separator, and an electrolyte. The shell is preferably a hollow cylindrical structure with an open top end, which is prepared from a nickel-plated steel plate material. The cap assembly is connected to and seals the open top end of the shell. The shell and the cap assembly enclose an internal cavity of the battery. The separator is preferably a polyethylene film material, and the separator is used to separate the positive electrode and the negative electrode. The positive electrode, the negative electrode, and the separator are spirally wound in the internal cavity of the battery.

[0046] The positive electrode is further electrically connected to the cap assembly through a positive electrode bus bar, and the negative electrode is further electrically connected to the shell through a negative electrode bus bar. Alternatively, the positive electrode is further electrically connected to the shell through a positive electrode bus bar, and the negative electrode is further electrically connected to the cap assembly through a negative electrode bus bar.

[0047] The embodiment also provides an electric device comprising the battery according to the above-mentioned solution.

[0048] The battery of the electric device can be used in a portable electric device in a combined manner. The electric device comprises a battery cavity in the interior of the electric device, and the battery cavity can accommodate one or more batteries. The capacity of the battery is matched according to the required capacity of the electric device. The electric device can be any device that requires a lithium ion battery to provide power supply in the related art.

[0049] The electric device can also be powered by using a battery pack. The multiple batteries in the battery pack can be connected in series, or the multiple single batteries can be connected in parallel, or the multiple batteries can be connected in a mixed manner of series and parallel connection, so that the battery pack has a capacity and power suitable for the electric device. The electric device to which the battery pack can be applied includes a mobile phone, a portable device, a notebook computer, an electric bicycle, an electric vehicle, an electric ship, an electric toy, an electric tool, and the like, which will not be described herein again.

[0050] Obviously, the above embodiments of the present application are merely examples for clearly illustrating the present application, and are not intended to limit the implementation modes of the present application. For those skilled in the art, various obvious changes, re-adjustments and replacements can be made without departing from the protection scope of the present application. Here, it is not necessary and also impossible to enumerate all the implementation modes. Any modification, equivalent replacement and improvement made within the spirit and principle of the present application shall be included in the protection scope of the present application claim.

Claims

1. A cap assembly, characterized in that, include: An explosion-proof sheet (100) includes a main body (110) and a protrusion (112) disposed on the main body (110); An orifice plate (200) includes a central portion (210) and a connecting portion (220) connected to each other. The connecting portion (220) surrounds the outer periphery of the central portion (210), and a first pressure relief hole (221) is provided between the central portion (210) and the connecting portion (220). An insulating gasket (300) is disposed between the explosion-proof sheet (100) and the perforated plate (200), wherein the insulating gasket (300) can cover at least a portion of the connecting portion (220); A conductive adhesive layer (400) is provided, wherein the protrusion (112) protrudes toward the center portion (210), and the conductive adhesive layer (400) is sandwiched between the protrusion (112) and the center portion (210).

2. The cap assembly according to claim 1, characterized in that, The main body (110) is also provided with a first scribe line (114), and the projection of the first pressure relief hole (221) on the first end face (111) of the main body (110) can cover at least part of the projection of the first scribe line (114) on the first end face (111).

3. The cap assembly according to claim 2, characterized in that, The main body (110) also includes a second end face (113) disposed opposite to the first end face (111), and the first scribe line (114) is recessed from the first end face (111) toward the second end face (113).

4. The cap assembly according to claim 3, characterized in that, The perforated plate (200) has a second scribe line (211) on one end wall near the first end face (111). The second scribe line (211) is coaxial with the first scribe line (114), and the diameter of the second scribe line (211) is larger than the diameter of the first scribe line (114).

5. The cap assembly according to claim 4, characterized in that, The projection of the conductive adhesive layer (400) on the first end face (111) can cover the projection of the second scribe line (211) on the first end face (111).

6. The cap assembly according to claim 1, characterized in that, The insulating pad (300) is provided with a second pressure relief hole (310), and the opening area of ​​the second pressure relief hole (310) is not less than the opening area of ​​the first pressure relief hole (221).

7. The cap assembly according to claim 6, characterized in that, The first pressure relief hole (221) is a waist-shaped hole.

8. The cap assembly according to claim 7, characterized in that, The central axis of the second pressure relief hole (310) is coaxial with the central axis of the waistline of the first pressure relief hole (221).

9. The cap assembly according to claim 6, characterized in that, The insulating pad (300) includes a first part (321) and a second part (322) bent and connected to the first part (321), the second part (322) being wrapped around the circumferential outer wall of the perforated plate (200).

10. The cap assembly according to any one of claims 1-9, characterized in that, The projected area of ​​the conductive adhesive layer (400) on the first end face (111) of the main body (110) is not less than 60% of the projected area of ​​the protrusion (112) on the first end face (111).

11. A battery, characterized in that, Includes the cap assembly as described in any one of claims 1-10.

12. Electrical equipment, characterized in that, Includes the battery as described in claim 11.

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