Cover plate assembly and single battery

Abstract

The utility model belongs to the technical field of batteries, and discloses a cover plate assembly and a single battery. The cover plate assembly comprises a cover plate body, an anti-explosion valve and a shielding piece, the cover plate body comprises a sealing surface used for being in sealing connection with an opening of a battery shell, and a pressure relief hole is formed in the cover plate body; the anti-explosion valve is arranged in the pressure relief hole in a matched mode. The shielding piece is arranged on the sealing face, a shielding space is formed between the shielding piece and the anti-explosion valve, and the shielding piece is provided with a pressure relief through hole communicated with the shielding space. According to the cover plate assembly, through the arrangement of the shielding piece, when the single battery is in thermal runaway, the core package assembly cannot shield the anti-explosion valve, so that the pressure relief of the anti-explosion valve cannot be influenced, and the use safety of the single battery using the cover plate assembly is ensured.

Description

Technical Field

[0001] The utility model relates to the technical field of batteries, in particular to a cover plate assembly and a single battery. Background Art

[0002] As lithium-ion battery technology becomes increasingly mature, lithium-ion batteries have become the representative of modern high-performance batteries due to their advantages such as high operating voltage, high specific energy, large capacity, low self-discharge, good cycle performance, long service life, light weight and small size. They are also widely used as power batteries in electric vehicles and energy storage fields. Therefore, the requirements for the performance and safety of lithium-ion batteries are increasing.

[0003] Existing battery structures are generally short, and the overall capacity improvement space is limited by process conditions. Therefore, the battery structure is developing in the direction of longer batteries. Lithium-ion batteries with long battery structures are usually designed with tabs on both sides. Their structure includes: a cover plate (integrated with the pole column, explosion-proof valve, injection hole, etc.), a shell, a core pack, an electrolyte, etc. After the cover plate and the shell are welded, they form a closed space with a certain mechanical strength to protect the core pack; the core pack is fixed to the pole tabs on both sides by laser welding to achieve electrical connection, and the length direction of the battery is mainly fixed by the plastic insulating material under the cover plate pressing on the core pack; the cover plate is integrated with an explosion-proof valve structure, which is mainly used for the directional discharge of internal high-temperature and high-pressure gases when the battery experiences thermal runaway due to an internal short circuit, thereby improving the battery safety performance.

[0004] In the battery length direction of the above structure, the core pack is mainly insulated and fixed by the plastic under the cover plate. However, the insulating material of this lower plastic is generally PP material, and its strength and high temperature resistance are very limited, generally around 150°C. However, the temperature at which the battery undergoes thermal runaway is usually much higher than the melting point of these insulating materials. Other fixed structures such as the lower plastic inside the battery are prone to melting and failure. At this time, only the core pack is left inside the battery, resulting in an increase in the gap between the core pack and the cover plate and shell. At this time, the core pack has a high degree of freedom inside the battery. Since the high-temperature and high-pressure gas is exhausting in the direction of the explosion-proof valve, the core pack will randomly move with the high-temperature and high-pressure airflow and block the explosion-proof valve on the cover plate, blocking the exhaust channel, greatly reducing the exhaust effect of the explosion-proof valve and reducing the safety performance of the battery.

[0005] Therefore, there is an urgent need to provide a new type of cover plate assembly and single battery to solve the above technical problems in the prior art. Utility Model Content

[0006] The purpose of the utility model is to provide a cover plate assembly, which can protect the explosion-proof valve when thermal runaway occurs in a single battery, ensure the normal pressure relief function of the explosion-proof valve, and improve the safety of the single battery.

[0007] To achieve this purpose, the present invention adopts the following technical solutions:

[0008] The cover assembly includes a cover body, an explosion-proof valve and a shielding member. The cover body includes a sealing surface for sealingly connecting with the opening of the battery shell, and the cover body is provided with a pressure relief hole; the explosion-proof valve is arranged in conjunction with the pressure relief hole; the shielding member is arranged on the sealing surface, and a shielding space is formed between the shielding member and the explosion-proof valve, and the shielding member is provided with a pressure relief through hole connected to the shielding space.

[0009] Optionally, the shielding member includes a shielding portion and a supporting portion, the shielding portion covers the explosion-proof valve, the supporting portion is arranged at the circumferential edge of the shielding portion, one end of the supporting portion is connected to the sealing surface, and the other end is connected to the shielding portion.

[0010] Optionally, the shielding portion is provided with a plurality of the pressure relief through holes, and / or the supporting portion is provided with a plurality of the pressure relief through holes.

[0011] Optionally, the supporting portion includes a plurality of supporting legs, and the shielding portion, the sealing surface and two adjacent supporting legs are surrounded to form the pressure relief through hole.

[0012] Optionally, the supporting foot includes a first part and a second part, one end of the first part is connected to the shielding part, and the other end is connected to the second part, the second part is fixedly arranged on the sealing surface, and the cross-sectional area of ​​the second part is larger than the cross-sectional area of ​​the first part.

[0013] Optionally, the shielding portion is provided with a connecting hole, a separating rib is provided in the connecting hole, and the separating rib and the connecting hole are arranged to form the pressure relief through hole.

[0014] Optionally, the connection hole is arranged opposite to the explosion-proof valve, and the coverage area of ​​the connection hole is not less than the coverage area of ​​the pressure relief hole.

[0015] Optionally, the shielding member is made by stamping a plate, and the thickness of the plate is 1.0 mm to 2.0 mm.

[0016] Optionally, the cover plate assembly further includes an insulating member, the insulating member is disposed on the sealing surface, and the shielding member is sandwiched between the insulating member and the sealing surface.

[0017] Another object of the present invention is to provide a single cell battery, which includes the cover plate assembly as described in any of the above solutions.

[0018] Beneficial effects:

[0019] The cover plate assembly of the present invention is provided with a pressure relief hole on the cover plate body, and an explosion-proof valve is provided in the pressure relief hole. When a single battery using the cover plate assembly experiences thermal runaway, pressure is relieved through the explosion-proof valve. The shielding member is provided on the sealing surface of the cover plate body, which can block the core pack assembly in the battery housing, thereby preventing the core pack assembly from blocking the explosion-proof valve and causing the explosion-proof valve to release pressure in a timely manner, thereby avoiding safety hazards caused by excessive internal pressure in the battery cell. The shielding member is provided with a pressure relief through-hole connected to the internal shielding space, so that the shielding member does not affect the normal explosion-proof pressure relief of the explosion-proof valve. The setting of the shielding member ensures that when a single battery experiences thermal runaway, the core pack assembly will not block the explosion-proof valve, thereby not affecting the pressure relief of the explosion-proof valve, thereby ensuring the safety of the single battery using the cover plate assembly. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is an axonometric view of the cover assembly provided by a specific embodiment of the present utility model;

[0021] Figure 2 It is an exploded view of the cover plate assembly provided in a specific embodiment of the present utility model;

[0022] Figure 3 It is an axonometric view of the shielding member provided in a specific embodiment of the present utility model.

[0023] In the picture:

[0024] 100, cover plate body; 110, sealing surface; 120, pressure relief hole;

[0025] 200, explosion-proof valve;

[0026] 300, shielding member; 301, pressure relief hole; 310, shielding portion; 311, connecting hole; 312, separating rib; 320, supporting portion; 3201, supporting foot; 321, first portion; 322, second portion. DETAILED DESCRIPTION

[0027] The present invention will be further described in detail below with reference to the accompanying drawings and examples. It should be understood that the specific embodiments described herein are intended only to illustrate the present invention and are not intended to limit the present invention. It should also be noted that, for ease of description, the accompanying drawings only illustrate portions relevant to the present invention, not all of its components.

[0028] In the description of this utility model, unless otherwise specified or limited, the terms "connected," "connect," and "fixed" should be understood in a broad sense. For example, they can refer to fixed connection, detachable connection, or integration; mechanical connection or electrical connection; direct connection or indirect connection through an intermediate medium; internal communication between two components or interaction between two components. Those skilled in the art will understand the specific meanings of the above terms in this utility model based on the specific circumstances.

[0029] In the present invention, unless otherwise expressly specified or limited, a first feature being "above" or "below" a second feature may include the first and second features being in direct contact, or may include the first and second features being in contact not directly but through another feature between them. Moreover, a first feature being "above," "above," and "above" a second feature may include the first feature being directly above or obliquely above the second feature, or may simply mean that the first feature is higher in level than the second feature. A first feature being "below," "below," and "below" a second feature may include the first feature being directly below or obliquely below the second feature, or may simply mean that the first feature is lower in level than the second feature.

[0030] In the description of this embodiment, the terms "upper," "lower," "right," and other orientations or positional relationships are based on the orientations or positional relationships shown in the accompanying drawings and are intended solely for ease of description and simplified operation. They do not indicate or imply that the devices or components referred to must have a specific orientation, be constructed, or operate in a specific orientation. Therefore, they should not be construed as limitations on the present invention. Furthermore, the terms "first" and "second" are used solely for descriptive purposes and have no special meaning.

[0031] Please refer to Figure 1 and Figure 2 The cover assembly in this embodiment includes a cover body 100, an explosion-proof valve 200 and a shielding member 300. The cover body 100 includes a sealing surface 110 for sealingly connecting with the opening of the battery shell. The cover body 100 is provided with a pressure relief hole 120; the explosion-proof valve 200 is arranged in cooperation with the pressure relief hole 120; the shielding member 300 is arranged on the sealing surface 110, and a shielding space is formed between the shielding member 300 and the explosion-proof valve 200. The shielding member 300 is provided with a pressure relief through hole 301 connected to the shielding space.

[0032] The cover plate assembly in this embodiment has a pressure relief hole 120 formed on the cover plate body 100 and an explosion-proof valve 200 disposed within the pressure relief hole 120. When a single battery cell using the cover plate assembly experiences thermal runaway, pressure is relieved through the explosion-proof valve 200. A shielding member 300, disposed on the sealing surface 110 of the cover plate body 100, blocks the core pack assembly within the battery housing, preventing the core pack assembly from blocking the explosion-proof valve 200 and causing delayed pressure relief from the explosion-proof valve 200. This prevents safety hazards from excessive internal pressure in the battery cell. Furthermore, the shielding member 300 is provided with a pressure relief hole 301 communicating with the internal shielding space, preventing the shielding member 300 from interfering with the normal explosion-proof pressure relief of the explosion-proof valve 200. The provision of the shielding member 300 ensures that the core pack assembly does not block the explosion-proof valve 200 when a single battery cell experiences thermal runaway, thereby preventing pressure relief from the explosion-proof valve 200 and ensuring the safety of the single battery cell using the cover plate assembly.

[0033] like Figure 2 As shown, the shielding member 300 includes a shielding portion 310 and a supporting portion 320. The shielding portion 310 is provided to cover the explosion-proof valve 200, and the supporting portion 320 is provided at the circumferential edge of the shielding portion 310. One end of the supporting portion 320 is connected to the sealing surface 110, and the other end is connected to the shielding portion 310. The shielding portion 310 is used to cover the explosion-proof valve 200 to protect the explosion-proof valve 200, and the supporting portion 320 is used to prop up the shielding portion 310 to prevent the shielding portion 310 from directly contacting the explosion-proof valve 200, thereby increasing the shielding space formed by the shielding member 300, further preventing the core package assembly from blocking the explosion-proof valve 200, and ensuring that the explosion-proof valve 200 can release pressure normally.

[0034] Furthermore, the shielding portion 310 is provided with a plurality of the aforementioned pressure relief holes 301, and / or the support portion 320 is provided with a plurality of the aforementioned pressure relief holes 301. The pressure relief holes 301 provided in the shielding portion 310 can connect the internal space of the single cell and the shielding space from the wall surface of the shielding member 300 opposite the explosion-proof valve 200, ensuring smooth pressure relief. The pressure relief holes 301 provided in the support portion 320 can connect the internal space of the single cell and the shielding space from the circumference of the shielding member 300. Thus, even after the core pack assembly covers the pressure relief holes 301 of the shielding portion 310, pressure relief can still be performed, further improving the safety of the cover plate assembly.

[0035] like Figure 3As shown, the support portion 320 includes a plurality of support legs 3201. The shielding portion 310, the sealing surface 110, and two adjacent support legs 3201 enclose the pressure relief hole 301. The support legs 3201 support the shielding portion 310, and the space between the support legs 3201 forms the pressure relief hole 301. This increases the flow area of ​​the pressure relief hole 301 and ensures normal pressure relief of the pressure relief hole 301 on the support portion 320.

[0036] Furthermore, the support leg 3201 includes a first portion 321 and a second portion 322. One end of the first portion 321 is connected to the shielding portion 310, and the other end is connected to the second portion 322. The second portion 322 is fixedly mounted on the sealing surface 110, and the cross-sectional area of ​​the second portion 322 is greater than the cross-sectional area of ​​the first portion 321. The cross-sectional area herein refers to a horizontal plane parallel to the sealing surface 110. Since the cross-sectional area of ​​the second portion 322 is greater than that of the first portion 321, the contact area between the support leg 3201 and the sealing surface 110 is increased, thereby improving the stability of the connection between the shielding member 300 and the sealing member, ensuring that the shielding member 300 will not fall off.

[0037] In this embodiment, the shielding portion 310 is provided with a connecting hole 311, within which a separating rib 312 is disposed. The separating rib 312 and the connecting hole 311 enclose the pressure relief hole 301. In other words, the pressure relief hole 301 on the shielding portion 310 is a smaller pressure relief hole 301 formed by dividing a larger connecting hole 311 by the separating rib 312. This improves the mechanical strength of the shielding portion 310, prevents the shielding portion 310 from being damaged by pressure from the core package assembly, thereby preventing the explosion-proof valve 200 from being blocked, and ensures that the pressure relief function of the explosion-proof valve 200 is not affected.

[0038] Optionally, the connection hole 311 is disposed directly opposite the explosion-proof valve 200, and the coverage area of ​​the connection hole 311 is no less than the coverage area of ​​the pressure relief hole 120. The coverage area referred to herein refers to the projected area parallel to the sealing surface 110. Since the coverage area of ​​the connection hole 311 is no less than the coverage area of ​​the pressure relief hole 120, if thermal runaway of a single cell occurs again, the flow area through the connection hole 311 will not be too small as the flow from the connection hole 311 to the explosion-proof valve 200 through the pressure relief hole 120, thereby ensuring that the pressure relief capacity of the explosion-proof valve 200 is not affected and improving the safety of the cover plate assembly.

[0039] In this embodiment, the shielding member 300 is stamped from a plate having a thickness of 1.0 mm to 2.0 mm. Specifically, the shielding member 300 is stamped from an aluminum plate, and the cover body 100 is also made of an aluminum plate. The shielding member 300 is welded to the cover body 100.

[0040] Furthermore, the cover assembly further includes an insulating member, which is disposed on the sealing surface 110, and the shielding member 300 is sandwiched between the insulating member and the sealing surface 110. The insulating member is also a lower plastic member commonly used in the art and will not be described in detail here.

[0041] The specific assembly process of the cover assembly is as follows: 1. The bare aluminum sheet is stamped into the cover body 100; 2. The explosion-proof valve 200 is welded to the pressure relief hole 120 of the cover body 100; 3. The aluminum sheet is stamped into the shielding member 300; 4. The shielding member 300 is welded to the sealing surface 110 of the cover body 100; 5. The insulating member is installed on the sealing surface 110.

[0042] This embodiment also provides a single cell battery, which includes a cover plate assembly as described in any of the above schemes. The single cell battery uses the above cover plate assembly to seal the opening of the battery housing, which can prevent the core pack assembly from blocking the explosion-proof valve 200 when thermal runaway occurs in the internal core pack assembly. The shielding member 300 plays a role in protecting the explosion-proof valve 200, thereby allowing the explosion-proof valve 200 to perform normal explosion protection and pressure relief, thereby improving the safety of the single cell battery. The single cell battery can power electrical equipment such as battery packs, pure electric vehicles, hybrid electric vehicles, ships, and energy storage equipment, which will not be described in detail here. The above electrical equipment uses the above single cell battery for power supply, thereby having all the beneficial effects of the above single cell battery and cover plate assembly, which will not be described in detail here.

[0043] Obviously, the above-described embodiments of the present invention are merely examples for the purpose of clearly illustrating the present invention and are not intended to limit the manner in which the present invention is to be implemented. A person skilled in the art would be able to make various obvious changes, readjustments, and substitutions without departing from the scope of protection of the present invention. It is not necessary and impossible to enumerate all embodiments here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention shall be included within the scope of protection of the claims of the present invention.

Claims

1. Cover plate assembly, characterized in that, include: a cover body, the cover body comprising a sealing surface for sealingly connecting with the opening of the battery housing, the cover body being provided with a pressure relief hole; An explosion-proof valve, the explosion-proof valve being cooperatively arranged in the pressure relief hole; A shielding member is provided on the sealing surface, a shielding space is formed between the shielding member and the explosion-proof valve, and the shielding member is provided with a pressure relief through hole communicated with the shielding space.

2. The cover plate assembly according to claim 1, wherein: The shielding member includes a shielding portion and a supporting portion. The shielding portion covers the explosion-proof valve. The supporting portion is arranged at the circumferential edge of the shielding portion. One end of the supporting portion is connected to the sealing surface, and the other end is connected to the shielding portion.

3. The cover plate assembly according to claim 2, wherein: The shielding portion is provided with a plurality of the pressure relief through holes, and / or the supporting portion is provided with a plurality of the pressure relief through holes.

4. The cover plate assembly according to claim 3, wherein: The support portion includes a plurality of support legs, and the shielding portion, the sealing surface and two adjacent support legs are surrounded to form the pressure relief through hole.

5. The cover plate assembly according to claim 4, wherein: The supporting foot includes a first part and a second part, one end of the first part is connected to the shielding part, and the other end is connected to the second part, the second part is fixedly arranged on the sealing surface, and the cross-sectional area of ​​the second part is larger than the cross-sectional area of ​​the first part.

6. The cover plate assembly according to claim 3, wherein: The shielding portion is provided with a connecting hole, a separating rib is provided in the connecting hole, and the separating rib and the connecting hole are surrounded to form the pressure relief through hole.

7. The cover plate assembly according to claim 6, wherein: The connecting hole is arranged opposite to the explosion-proof valve, and the covering area of ​​the connecting hole is not less than the covering area of ​​the pressure relief hole.

8. The cover plate assembly according to any one of claims 1 to 7, characterized in that: The shielding member is made by stamping a plate, and the thickness of the plate is 1.0 mm to 2.0 mm.

9. The cover plate assembly according to any one of claims 1 to 7, characterized in that: The cover plate assembly further includes an insulating member, which is disposed on the sealing surface, and the shielding member is sandwiched between the insulating member and the sealing surface.

10. A single cell battery, characterized in that: The invention comprises the cover plate assembly according to any one of claims 1 to 9.

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