Housing assembly, battery cell, and electric device

Abstract

The application relates to the battery technical field, in particular to a shell assembly, a battery monomer and an electric equipment. The shell assembly provided by the application comprises a shell body, a pressure relief unit, a first patch and a limiting plate, the shell body is provided with a first wall; the pressure relief unit is arranged on the first wall; the first patch is arranged on the first surface and covers the pressure relief unit; the limiting plate is arranged on the first surface and fixes the first patch, the limiting plate is provided with a first hole, and the first hole is arranged opposite to the pressure relief unit along the thickness direction of the first wall. The technical problem that the explosion-proof valve is easily damaged or corroded is solved, and the purpose of reducing the failure risk of the explosion-proof valve is achieved.

Description

Technical Field

[0001] This application relates to the field of battery technology, and more particularly to a housing assembly, a battery cell, and an electrical device. Background Technology

[0002] Under abnormal conditions, a large amount of gas will be generated inside the battery. After the gas accumulates, it needs to be released through an explosion-proof valve to prevent the battery from exploding. However, current explosion-proof valves are easily exposed, which can lead to corrosion or physical damage to the pressure relief mechanism, resulting in the failure of the explosion-proof valve. Utility Model Content

[0003] This application provides a housing assembly, a battery cell, and an electrical device, which solves the technical problem of explosion-proof valves being easily damaged or corroded, and achieves the purpose of reducing the risk of explosion-proof valve failure.

[0004] To achieve the above objectives, the main technical solutions adopted in this application include:

[0005] In a first aspect, embodiments of this application provide a housing assembly, including a housing body, a pressure relief unit, a first patch, and a limiting plate. The housing body has a first wall, and the first wall has a first surface. The pressure relief unit is disposed on the first wall. The first patch is disposed on the first surface and covers the pressure relief unit. The limiting plate is disposed on the first surface and fixes the first patch. The limiting plate has a first hole, and along the thickness direction of the first wall, the projection of the pressure relief unit falls into the projection of the first hole.

[0006] The housing assembly proposed in this application includes a limiting plate disposed on the first surface, which presses against the first patch to fix the first patch to the first wall, reducing the risk of the first patch falling off. The first patch covers the pressure relief unit, protecting it and reducing the risk of chemical corrosion or physical damage to the pressure relief unit due to exposure, thereby reducing the risk of pressure relief unit failure. Furthermore, the limiting plate has a first hole to avoid the pressure relief unit, providing a discharge channel for the large amount of gas generated during battery thermal runaway, reducing the occurrence of more serious thermal runaway accidents.

[0007] Secondly, embodiments of this application provide a battery cell including the housing assembly described in any of the above embodiments.

[0008] The battery cell proposed in this application includes the housing assembly in any of the above embodiments and has the same beneficial effects as the housing assembly.

[0009] Thirdly, embodiments of this application provide an electrical device including the battery cell described in the above embodiments.

[0010] The electrical equipment proposed in this application embodiment includes the aforementioned battery cell and has the same beneficial effects as the battery cell. Attached Figure Description

[0011] To more clearly illustrate the technical solutions in the specific embodiments of this application or the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this application. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0012] Figure 1 This is a schematic diagram of the structure of a single battery cell in this application;

[0013] Figure 2 This is a cross-sectional view of a housing assembly in one embodiment of this application;

[0014] Figure 3 For this application Figure 2 Enlarged view of region E in the middle;

[0015] Figure 4 This is a cross-sectional view of the housing assembly in another embodiment of this application;

[0016] Figure 5 For this application Figure 4 Enlarged view of region D in the middle;

[0017] Figure 6 This is a cross-sectional view of a single battery cell in this application;

[0018] Figure 7 for Figure 6 A magnified view of region F in the middle.

[0019] [Explanation of Labels in the Attached Image]

[0020] 1: Shell body; 11: First wall; 111: First surface; 112: Second hole;

[0021] 2: Pressure relief unit; 21: Weak area;

[0022] 3: First patch; 31: Body part; 32: Edge part;

[0023] 4: Limiting plate; 40: First hole;

[0024] 5: First adhesive layer; 51: First part; 52: Second part;

[0025] 6: Second adhesive layer;

[0026] 7: Battery cell;

[0027] A: The thickness direction of the first wall. Detailed Implementation

[0028] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0029] Unless otherwise defined, all technical and scientific terms used in this application have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains; the terminology used in the description of this application is for the purpose of describing particular embodiments only and is not intended to limit the application; the terms "comprising" and "having," and any variations thereof, in the description, claims, and accompanying drawings of this application are intended to cover non-exclusive inclusion. The terms "first," "second," etc., in the description, claims, or accompanying drawings of this application are used to distinguish different objects, not to describe a specific order or hierarchy.

[0030] In this application, the reference to "embodiment" means that a specific feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a mutually exclusive, independent, or alternative embodiment. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described in this application can be combined with other embodiments.

[0031] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," "linking," and "attachment" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal communication between two components. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0032] In this application, the term "and / or" is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, or B existing alone. Additionally, in this application, the character " / " generally indicates that the preceding and following related objects have an "or" relationship.

[0033] In this application, "multiple" refers to two or more (including two), and similarly, "multiple groups" refers to two or more (including two), and "multiple pieces" refers to two or more (including two).

[0034] Currently, in order to reduce physical damage or chemical corrosion of explosion-proof valves, protective patches are installed on the outside of the explosion-proof valves. However, due to the small bonding area of ​​the protective patches on the shell and the insufficient strength of the adhesive, the protective patches are easy to fall off, leaving the explosion-proof valve exposed and unprotected. Therefore, the explosion-proof valve is still susceptible to chemical corrosion or physical damage, which increases the risk of explosion-proof valve failure.

[0035] Based on the problems discovered by the applicant, this application provides a housing assembly that can protect the first patch, reduce the detachment of the first patch, thereby protecting the explosion-proof valve and achieving the purpose of reducing the failure of the explosion-proof valve.

[0036] Firstly, reference Figures 1 to 7 This application provides a housing assembly, which includes a housing body 1, a pressure relief unit 2, a first patch 3, and a limiting plate 4. The housing body 1 has a first wall 11, and the first wall 11 has a first surface 111. The pressure relief unit 2 is disposed on the first wall 11. The first patch 3 is disposed on the first surface 111 and covers the pressure relief unit 2. The limiting plate 4 is disposed on the first surface 111 and fixes the first patch 3. The limiting plate 4 has a first hole 40, and the projection of the pressure relief unit 2 falls into the projection of the first hole 40 along the thickness direction A of the first wall 11.

[0037] The limiting plate 4 is used to press the first patch 3 against the first surface 111, reducing the likelihood of the first patch 3 falling off. When the battery is operating normally, the first patch 3 can protect the pressure relief unit 2, reducing physical or chemical damage to the pressure relief unit 2. Simultaneously, when the battery experiences thermal runaway, the gas accumulated inside the battery can break through the pressure relief unit 2 and the first patch 3 to escape. The limiting plate 4 is located on the first surface 111; it can be fixed to the first surface 111 and abutting against the first patch 3, or the limiting plate 4 can be fixedly connected to both the first surface 111 and the first patch 3. The first surface 111 can be the outer surface of the first wall 11 that faces away from the interior of the shell body 1.

[0038] Along the thickness direction A of the first wall 11, the projection of the pressure relief unit 2 falls within the projection of the first hole 40. The first hole 40 is used to avoid the pressure relief unit 2 and reduce the influence of the limiting plate 4 on the opening of the pressure relief unit 2. When the battery abnormally generates a large amount of gas, the gas can break through the pressure relief unit 2 and be discharged through the first hole 40.

[0039] The housing assembly proposed in this application embodiment has a limiting plate 4 disposed on the first surface 111, which presses against the first patch 3 and fixes the first patch 3 to the first wall 11, reducing the risk of the first patch 3 falling off. The first patch 3 covers the pressure relief unit 2, protecting it and reducing the risk of chemical corrosion or physical damage to the pressure relief unit 2 due to exposure, thereby reducing the risk of failure of the pressure relief unit 2. Furthermore, the limiting plate 4 has a first hole 40 to avoid the pressure relief unit 2, providing a discharge channel for the large amount of gas generated when the battery experiences thermal runaway, reducing the occurrence of more serious thermal runaway accidents.

[0040] It should be understood that the shape of the pressure relief unit 2 can be circular, elliptical, racetrack-shaped or rectangular, the first patch 3 can also be circular, elliptical, racetrack-shaped or rectangular, and the shape of the first hole 40 can also be circular, elliptical, racetrack-shaped or rectangular, depending on the specific circumstances.

[0041] Optionally, refer to Figures 2 to 5 The first patch 3 includes a body portion 31 and an edge portion 32. The edge portion 32 surrounds the body portion 31. Along the thickness direction A of the first wall 11, the projection of the pressure relief unit 2 falls into the projection of the body portion 31. The limiting plate 4 presses against at least a portion of the edge portion 32 to fix the first patch 3 to the first wall 11.

[0042] Along the thickness direction A of the first wall 11, the first hole 40, the main body 31, and the pressure relief unit 2 are arranged opposite to each other. The main body 31 covers the pressure relief unit 2, protecting it and reducing its exposure. The first hole 40 is used to avoid the pressure relief unit 2, reducing the impact of the limiting plate 4 on the pressure relief unit 2 when it is open. The limiting plate 4 at least partially abuts against the edge portion 32 to reduce the edge portion 32 from detaching from the first surface 111. This allows the main body 31 to cover the pressure relief unit 2 when the battery is working normally, thereby reducing the risk of the pressure relief unit 2 being exposed and reducing the chemical or physical corrosion that may occur due to the lack of protection, thus reducing the risk of the pressure relief unit 2 failing.

[0043] The limiting plate 4 can press against the entire edge portion 32, or it can press against a portion of the edge portion 32.

[0044] Optionally, refer to Figure 3 The housing assembly also includes a first adhesive layer 5, which includes a first part 51 and a second part 52 connected along the thickness direction A of the first wall 11. The first part 51 is disposed between the limiting plate 4 and the edge part 32, and the second part 52 is disposed between the first wall 11 and the limiting plate 4 along the thickness direction A of the first wall 11. The size of the second part 52 is d, which satisfies: 0.01mm≤d≤0.15mm.

[0045] The first part 51 is used to fix the limiting plate 4 and the edge part 32, and the second part 52 is used to fix the first wall 11 and the limiting plate 4. That is, the limiting plate 4 is fixed to both the edge part 32 and the first wall 11. Since the limiting plate 4 is fixed to both the edge part 32 and the first wall 11, the connection strength between the limiting plate 4 and the first wall 11 is sufficient. The limiting plate 4 can apply sufficient pressure to the edge part 32, making the connection between the edge part 32 of the first patch 3 and the limiting plate 4 and the first wall 11 firm. The first patch 3 is not easy to fall off, reducing the risk of the pressure relief unit 2 being exposed, thereby reducing the risk of failure of the pressure relief unit 2.

[0046] Along the thickness direction A of the first wall 11, the dimension d of the second part 52 satisfies: 0.01mm ≤ d ≤ 0.15mm. Wherein, along the thickness direction A of the first wall 11, the dimension d of the second part 52 can be 0.01mm, 0.02mm, 0.03mm, 0.04mm, 0.05mm, 0.06mm, 0.07mm, 0.08mm, 0.09mm, 0.10mm, 0.11mm, 0.12mm, 0.13mm, 0.14mm, or 0.15mm, etc.

[0047] Along the thickness direction A of the first wall 11, the size d of the second part 52 cannot be too large. If the size of the second part 52 is too large, it will cause the fixing strength between the limiting plate 4 and the first wall 11 to be too large, and the connection strength between the limiting plate 4 and the edge part 32 to be too large. When the battery malfunctions, when a large amount of gas impacts the pressure relief unit 2, the first patch 3 cannot fall off in time, so the gas cannot be discharged in time, which will lead to more serious thermal runaway.

[0048] Since adhesive layers are provided between the limiting plate 4, the edge portion 32, and the first wall 11, the thickness of the second part 52 of the first adhesive layer 5 can be reduced so that a large amount of gas can be expelled by forcing open the first patch 3 when the battery malfunctions. However, the size d of the second part 52 cannot be too small along the thickness direction A of the first wall 11. If the size of the second part 52 is too small, the fixing strength between the limiting portion and the first wall 11 will be too weak, and the connection strength between the limiting plate 4 and the edge portion 32 will be too weak. The first patch 3 will easily fall off the first wall 11, thereby exposing the pressure relief unit 2, increasing the probability of the pressure relief unit 2 being corroded or physically damaged, and increasing the risk of failure of the pressure relief unit 2.

[0049] Optionally, refer to Figure 5 The housing assembly also includes a second adhesive layer 6. Along the thickness direction A of the first wall 11, the second adhesive layer 6 is disposed between the first wall 11 and the limiting plate 4. No adhesive layer is disposed between the limiting plate 4 and the edge portion 32. Along the thickness direction A of the first wall 11, the size of the second adhesive layer 6 is d, which satisfies: 0.16mm≤d≤0.3mm.

[0050] The first wall 11 and the limiting plate 4 are fixed together by a second adhesive layer 6. The limiting plate 4 is attached to the edge portion 32 and presses against the edge portion 32. Along the thickness direction A of the first wall 11, the dimension d of the second adhesive layer 6 satisfies 0.16mm ≤ d ≤ 0.3mm. The dimension d of the second adhesive layer 6 can be 0.16mm, 0.17mm, 0.18mm, 0.19mm, 0.20mm, 0.21mm, 0.22mm, 0.23mm, 0.24mm, 0.25mm, 0.26mm, 0.27mm, 0.28mm, 0.29mm, or 0.30mm, etc.

[0051] The size of the second adhesive layer 6 cannot be too small. If the size of the second adhesive layer 6 is too small, the connection strength between the limiting plate 4 and the first wall 11 will be insufficient, resulting in insufficient strength of the first patch 3 pressing against the limiting plate 4 and the first wall 11. The first patch 3 will easily fall off the first wall 11, thus exposing the pressure relief unit 2 to the outside, increasing the probability of the pressure relief unit 2 being corroded or physically damaged, and thus increasing the risk of failure of the pressure relief unit 2.

[0052] Since the second adhesive layer 6 is only provided between the first wall 11 and the limiting plate 4, and no adhesive layer is provided between the limiting plate 4 and the edge portion 32, in order to increase the strength of the limiting plate 4 against the first patch 3, the size of the second adhesive layer 6 can be increased to reduce the first patch 3 from falling off the first wall 11, thereby reducing the exposure of the pressure relief unit 2 when the battery is working normally. However, the size of the second adhesive layer 6 cannot be too large. If the size of the second adhesive layer 6 is too large, the connection strength between the limiting plate 4 and the first wall 11 will be too large, and the strength of the limiting plate 4 against the edge portion 32 will also be greater. When the battery is abnormal, the gas will have difficulty breaking through the first patch 3, which may easily cause more serious thermal runaway.

[0053] Optionally, refer to Figure 7 Along the thickness direction A of the first wall 11, the limiting plate 4 partially overlaps with the edge portion 32, and the maximum width of the overlapping portion of the edge portion 32 and the limiting plate 4 is b, which satisfies: 0.8mm≤b≤1.5mm.

[0054] For example, the first patch 3 and the first hole 40 are elliptical, and the edge portion 32 of the first patch 3 overlaps with the limiting plate 4 on one side of the major axis of the ellipse. The maximum width b of the overlapping portion of the edge portion 32 and the limiting plate 4 is between 0.8 mm and 1.5 mm.

[0055] The edge portion 32 is connected to the limiting plate 4. In order to keep the first patch 3 stably between the first wall 11 and the limiting plate 4, the maximum width of the overlapping portion of the edge portion 32 and the limiting plate 4 can be increased. However, the maximum width of the overlapping portion of the edge portion 32 and the limiting plate 4 cannot be too large. If the maximum width of the overlapping portion of the edge portion 32 and the limiting plate 4 is too large, the strength of the limiting plate 4 pressing against the edge portion 32 will also be greater. When the battery experiences thermal runaway, a large amount of gas will be difficult to push open the first patch 3.

[0056] The maximum width of the overlapping portion between the edge portion 32 and the limiting plate 4 should not be too small. If the maximum width of the overlapping portion between the edge portion 32 and the limiting plate 4 is too small, the connection strength between the edge portion 32 and the limiting plate 4 will be too weak, and the first patch 3 will easily fall off from the first wall 11, causing the pressure relief unit 2 to be exposed, increasing the probability of the pressure relief unit 2 being corroded or physically damaged, and thus increasing the risk of failure of the pressure relief unit 2.

[0057] The maximum width b of the overlapping portion between the edge portion 32 and the limiting plate 4 can be 0.8mm, 0.84mm, 0.88mm, 0.90mm, 0.93mm, 0.96mm, 0.98mm, 1.0mm, 1.05mm, 1.08mm, 1.0mm, 1.1mm, 1.12mm, 1.14mm, 1.16mm, 1.18mm, 1.2mm, 1.22mm, 1.25mm, 1.28mm, 1.30mm, 1.33mm, 1.36mm, 1.38mm, 1.40mm, 1.42mm, 1.45mm, 1.48mm, or 1.50mm, etc.

[0058] Optionally, along the thickness direction A of the first wall 11, the projection of the first patch 3 has a first outer periphery, and the projection of the hole wall of the first hole 40 has a second outer periphery. The second outer periphery is located inside the first outer periphery, and the distance between the second outer periphery and the first outer periphery is b, satisfying: 0.5mm≤b≤1.5mm.

[0059] The second outer periphery is located inside the first outer periphery, which means that along the circumference of the first patch 3, the limiting plate 4 and the edge portion 32 have overlapping portions, and the portion between the second outer periphery and the first outer periphery is an overlapping portion.

[0060] Since the limiting part and the edge part 32 have overlapping areas along the circumference of the first patch 3, the overlap size between the limiting part and the edge part 32 can be reduced, that is, the distance between the second outer periphery and the first outer periphery can be reduced. However, the distance between the second outer periphery and the first outer periphery cannot be too small. If the distance between the second outer periphery and the first outer periphery is too small, the connection strength between the edge part 32 and the limiting plate 4 will be too weak, and the first patch 3 will easily fall off from the first wall 11, causing the pressure relief unit 2 to be exposed, increasing the probability of the pressure relief unit 2 being corroded or physically damaged, and thus increasing the risk of failure of the pressure relief unit 2.

[0061] The distance between the second outer periphery and the first outer periphery cannot be too large. If the distance between the second outer periphery and the first outer periphery is too large, the gas will have difficulty breaking through the first patch 3 when the battery experiences thermal runaway.

[0062] The distance b between the second outer perimeter and the first outer perimeter can be 0.5mm, 0.52mm, 0.55mm, 0.58mm, 0.6mm, 0.63mm, 0.68mm, 0.7mm, 0.73mm, 0.75mm, 0.78mm, 0.8mm, 0.84mm, 0.88mm, 0.90mm, 0.93mm, 0.96mm, 0.98mm, or 1.0mm. The sizes of the metal are as follows: mm, 1.05mm, 1.08mm, 1.0mm, 1.1mm, 1.12mm, 1.14mm, 1.16mm, 1.18mm, 1.2mm, 1.22mm, 1.25mm, 1.28mm, 1.30mm, 1.33mm, 1.36mm, 1.38mm, 1.40mm, 1.42mm, 1.45mm, 1.48mm, or 1.50mm, etc.

[0063] Optionally, refer to Figure 7 The pressure relief unit 2 has a weak area 21. The weak area 21 is constructed to connect the internal space and the external space of the shell after being destroyed by the accumulation and expansion of the internal gas. Along the thickness direction A of the first wall 11, the size of the weak area 21 is a, which satisfies: 0.04mm≤a≤2mm. Along the thickness direction A of the first wall 11, the maximum width of the overlapping part of the edge 32 and the limiting plate 4 is b, which satisfies: 0.8mm≤b≤1.2mm.

[0064] Specifically, the weak area 21 can be a notch on the pressure relief unit 2, or it can be a region on the pressure relief unit 2 that has been thinned as a whole. Along the thickness direction A of the first wall 11, the size of the weak area 21 cannot be too small. If the size of the weak area 21 is too small, it is prone to abnormally bursting open during normal charging and discharging of the battery. The size of the weak area 21 also cannot be too large. If the size of the weak area 21 is too large, the high-temperature, high-pressure gas generated during battery malfunctions will be unable to break through the weak area 21, leading to more severe thermal runaway inside the battery.

[0065] Along the thickness direction A of the first wall 11, the maximum width b of the overlapping portion of the edge portion 32 and the limiting plate 4 cannot be too large. If the maximum width of the overlapping portion of the edge portion 32 and the limiting plate 4 is too large, the strength of the limiting plate 4 pressing against the edge portion 32 will also be greater, which will make it difficult for gas to push open the first patch 3 when the battery experiences thermal runaway. The maximum width b of the overlapping portion of the edge portion 32 and the limiting plate 4 cannot be too small either. If the maximum width of the overlapping portion of the edge portion 32 and the limiting plate 4 is too small, the connection strength between the edge portion 32 and the limiting plate 4 will be too weak, and the first patch 3 will easily fall off the first wall 11, causing the pressure relief unit 2 to be exposed, increasing the probability of the pressure relief unit 2 being corroded or physically damaged, and thus increasing the risk of failure of the pressure relief unit 2.

[0066] Wherein, along the thickness direction A of the first wall 11, the dimension a of the weak region 21 can be 0.04mm, 0.05mm, 0.06mm, 0.09mm, 0.1mm, 0.15mm, 0.2mm, 0.25mm, 0.3mm, 0.35mm, 0.4mm, 0.45mm, 0.5mm, 0.6mm, 0.65mm, 0.7mm, 0.8mm, 0.9mm, 1.0mm, 1 .1mm, 1.12mm, 1.14mm, 1.16mm, 1.18mm, 1.2mm, 1.22mm, 1.25mm, 1.28mm, 1.30mm, 1.33mm, 1.3 6mm, 1.38mm, 1.40mm, 1.42mm, 1.45mm, 1.48mm, 1.50mm, 1.6mm, 1.7mm, 1.8mm, 1.9mm or 2.0mm, etc.

[0067] Along the thickness direction A of the first wall 11, the maximum width b of the overlapping portion of the edge portion 32 and the limiting plate 4 can be 0.8mm, 0.82mm, 0.84mm, 0.86mm, 0.88mm, 0.90mm, 0.91mm, 0.93mm, 0.95mm, 0.96mm, 0.98mm, 1.0mm, 1.02mm, 1.05mm, 1.06mm, 1.08mm, 1.09mm, 1.0mm, 1.1mm, 1.12mm, 1.14mm, 1.16mm, 1.18mm, or 1.2mm, etc.

[0068] Optionally, refer to Figures 2 to 7 The first wall 11 is provided with a second hole 112. Along the thickness direction A of the first wall 11, the second hole 112 penetrates the first wall 11. The pressure relief unit 2 is adapted to block the second hole 112. The edge portion 32 is connected to the first surface 111. Along the thickness direction A of the first wall 11, the width of the overlapping part of the edge portion 32 and the first wall 11 is b1, which satisfies: 1.5mm≤b1≤4mm.

[0069] Along the thickness direction A of the first wall 11, the pressure relief unit 2 is disposed on the side of the first wall 11 near the interior of the housing assembly. In one specific embodiment, along the thickness direction A of the first wall 11, the second hole 112 penetrates the first wall 11. The second hole 112 includes a first segment and a second segment. The second segment extends from the first wall 11 toward the inner side of the cell 7 housing toward the first surface 111 away from the interior of the housing, and the second segment does not penetrate the first wall 11. The inner diameter of the second segment is larger than the inner diameter of the first segment to form a stepped surface. The pressure relief unit 2 is disposed on the stepped surface, and the side of the pressure relief unit 2 toward the interior of the cell 7 housing is flush with the inner side of the first wall 11.

[0070] The first patch 3 is disposed on the first surface 111 of the first wall 11 away from the interior of the housing assembly. The overlapping portion of the edge portion 32 with the first wall 11 forms the connection between the edge portion 32 and the first wall 11. Since gas is generated during battery charging and discharging, the gas pressure causes deformation of the housing assembly, i.e., the first wall 11 deforms. To ensure that the first patch 3 remains connected to the first wall 11 even when it deforms, the width of the overlapping portion of the edge portion 32 of the first patch 3 with the first wall 11 needs to be sufficient. This allows the first patch 3 to maintain its connection with the first wall 11 even as it deforms, thus protecting the pressure relief unit 2.

[0071] However, the width of the overlapping portion between the edge portion 32 and the first wall 11 cannot be too large. If the width of the overlapping portion between the edge portion 32 and the first wall 11 is too large, the connection strength between the edge portion 32 and the first wall 11 will also be greater, which will make it difficult for the gas to break through the first patch 3 when the battery experiences thermal runaway.

[0072] The width of the overlapping portion between the edge portion 32 and the first wall 11 should not be too small. If the width of the overlapping portion between the edge portion 32 and the first wall 11 is too small, the gas pressure generated during the charging and discharging of the battery will cause the housing assembly to deform, which will cause the first patch 3 to lose its connection with the first wall 11. This will cause the first patch 3 to lose its protection for the pressure relief unit 2, increasing the probability that the pressure relief unit 2 will be corroded or physically damaged, and thus increasing the risk of failure of the pressure relief unit 2.

[0073] Optionally, refer to Figure 7 Along the thickness direction A of the first wall 11, the maximum width of the overlapping part of the edge portion 32 and the limiting plate 4 is b, which satisfies: 1.0mm≤b≤1.5mm.

[0074] The edge portion 32 of the first patch 3 is connected between the limiting plate 4 and the first wall 11. During the charging and discharging process of the battery, the first wall 11 deforms. By controlling the width of the overlapping portion between the edge portion 32 and the first wall 11, as well as the maximum width of the overlapping portion between the limiting plate 4 and the edge portion 32, the first patch 3 is prevented from separating from the first wall 11 when the first wall 11 deforms.

[0075] Along the thickness direction A of the first wall 11, the maximum width b of the overlapping portion of the edge portion 32 and the limiting plate 4 cannot be too large. If the maximum width of the overlapping portion of the edge portion 32 and the limiting plate 4 is too large, the strength of the limiting plate 4 pressing against the edge portion 32 will also be too large, which will make it difficult for gas to push open the first patch 3 when the battery experiences thermal runaway. The maximum width b of the overlapping portion of the edge portion 32 and the limiting plate 4 cannot be too small either. If the maximum width of the overlapping portion of the edge portion 32 and the limiting plate 4 is too small, the connection strength between the edge portion 32 and the limiting plate 4 will be too weak, and the first patch 3 will easily fall off the first wall 11, causing the pressure relief unit 2 to be exposed, increasing the probability of the pressure relief unit 2 being corroded or physically damaged, and thus increasing the risk of failure of the pressure relief unit 2.

[0076] The maximum width b of the overlapping portion between the edge portion 32 and the limiting plate 4 can be 1.0mm, 1.1mm, 1.12mm, 1.14mm, 1.16mm, 1.18mm, 1.2mm, 1.22mm, 1.25mm, 1.28mm, 1.30mm, 1.33mm, 1.36mm, 1.38mm, 1.40mm, 1.42mm, 1.45mm, 1.48mm, or 1.50mm, etc.

[0077] Optionally, refer to Figure 7 Along the thickness direction A of the first wall 11, the dimension of the first wall 11 is f, which satisfies: 0.2mm≤f≤0.8mm.

[0078] The size of the first wall 11 cannot be too large. If the size of the first wall 11 is too large, the pressure relief unit 2 will not be easy to open, which may cause a large amount of gas in the battery to not be discharged in time, thus causing more serious thermal runaway. The size of the first wall 11 cannot be too small either. If the size of the first wall 11 is too small, the explosion-proof valve will be easy to open, which may lead to electrolyte leakage and reduce the battery life.

[0079] Wherein, along the thickness direction A of the first wall 11, the dimension f of the first wall 11 can be 0.20mm, 0.23mm, 0.26mm, 0.28mm, 0.30mm, 0.33mm, 0.35mm, 0.38mm, 0.40mm, 0.42mm, 0.45mm, 0.47mm, 0.48mm, 0.5mm, 0.52mm, 0.55mm, 0.58mm, 0.6mm, 0.63mm, 0.68mm, 0.7mm, 0.73mm, 0.75mm, 0.78mm, or 0.8mm, etc.

[0080] Optionally, refer to Figure 7 Along the thickness direction A of the first wall 11, the dimension e of the limiting plate 4 satisfies: 0.03mm≤e≤0.5mm. Along the thickness direction A of the first wall 11, the dimension e of the limiting plate 4 should satisfy: the limiting plate 4 can press against the first patch 3 and hold it on the first wall 11 to protect the pressure relief unit 2, and the first patch 3 can be detached from the first wall 11 when the pressure relief unit 2 is punctured.

[0081] Along the thickness direction A of the first wall 11, the size of the limiting plate 4 cannot be too large. If the size of the limiting plate 4 is too large, the pressure of the limiting plate 4 against the edge 32 will also be too large. When the battery experiences thermal runaway, the gas will have difficulty breaking through the first patch 3.

[0082] If the size of the limiting plate 4 is too small, the pressure of the limiting plate 4 against the edge 32 will also be too small, and the first patch 3 will easily fall off from the first wall 11, causing the pressure relief unit 2 to be exposed, increasing the probability of the pressure relief unit 2 being corroded or physically damaged, and thus increasing the risk of the pressure relief unit 2 failing.

[0083] The dimension e of the limiting plate 4 along the thickness direction A of the first wall 11 can be 0.03mm, 0.05mm, 0.08mm, 0.1mm, 0.12mm, 0.14mm, 0.16mm, 0.18mm, 0.20mm, 0.23mm, 0.26mm, 0.28mm, 0.30mm, 0.33mm, 0.35mm, 0.38mm, 0.40mm, 0.42mm, 0.45mm, 0.47mm, 0.48mm, or 0.5mm, etc.

[0084] Optionally, the material of the limiting plate 4 includes at least one of polyethylene terephthalate, polypropylene, and polycarbonate. The material of the limiting plate 4 can be polyethylene terephthalate, polypropylene, polycarbonate, a mixture of two of polyethylene terephthalate, polypropylene, and polycarbonate, or a mixture of polyethylene terephthalate, polypropylene, and polycarbonate, depending on the specific circumstances.

[0085] Secondly, embodiments of this application provide a battery cell including the housing assembly described in any of the above embodiments.

[0086] The battery cell in this embodiment includes the housing assembly in any of the above embodiments, and has the same beneficial effects as the housing assembly. That is, the housing assembly includes a housing body 1, a pressure relief unit 2, a first patch 3, and a limiting plate 4. The limiting plate 4 is disposed on the first surface 111 and presses against the first patch 3, fixing the first patch 3 to the first wall 11, reducing the risk of the first patch 3 falling off. The first patch 3 covers the pressure relief unit 2, protecting it and reducing the risk of chemical corrosion or physical damage to the pressure relief unit 2 due to exposure, thereby reducing the risk of pressure relief unit 2 failure. Furthermore, the limiting plate 4 has a first hole 40 to avoid the pressure relief unit 2, providing a discharge channel for the gas generated when the battery experiences thermal runaway, reducing the occurrence of more serious thermal runaway accidents.

[0087] Thirdly, embodiments of this application provide an electrical device including the battery cell described in the above embodiments.

[0088] The electrical device in this embodiment includes the aforementioned battery cell and has the same beneficial effects as the battery cell. The battery cell includes a housing assembly, which includes a housing body 1, a pressure relief unit 2, a first patch 3, and a limiting plate 4. The limiting plate 4 is disposed on the first surface 111 and presses against the first patch 3, fixing the first patch 3 to the first wall 11 and reducing the risk of the first patch 3 falling off. The first patch 3 covers the pressure relief unit 2, protecting it and reducing the risk of chemical corrosion or physical damage to the pressure relief unit 2 due to exposure, thereby reducing the risk of pressure relief unit 2 failure. Furthermore, the limiting plate 4 has a first hole 40 to avoid the pressure relief unit 2, providing a discharge channel for the large amount of gas generated when the battery experiences thermal runaway, reducing the occurrence of more serious thermal runaway accidents.

[0089] It should also be noted that the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0090] The various embodiments in this specification are described in a progressive manner. Similar or identical parts between embodiments can be referred to mutually. Each embodiment focuses on describing the differences from other embodiments. In particular, the system embodiments are basically similar to the method embodiments, so the description is relatively simple; relevant parts can be referred to the descriptions in the method embodiments.

[0091] The above description is merely an embodiment of this application and is not intended to limit the scope of this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the scope of the claims of this application.

[0092] Although embodiments of this application have been described in conjunction with the accompanying drawings, those skilled in the art can make various modifications and variations without departing from the spirit and scope of this application, and such modifications and variations all fall within the scope defined by the appended claims.

Claims

1. A housing assembly, characterized in that, include: The shell body has a first wall, and the first wall has a first surface; The pressure relief unit is disposed on the first wall; A first patch is disposed on the first surface to cover the pressure relief unit; A limiting plate is disposed on the first surface and fixes the first patch. The limiting plate has a first hole, and the projection of the pressure relief unit falls into the projection of the first hole along the thickness direction of the first wall.

2. The housing assembly according to claim 1, characterized in that, The first patch includes a body portion and an edge portion, the edge portion surrounding the body portion, and the projection of the pressure relief unit falls within the projection of the body portion along the thickness direction of the first wall; The limiting plate presses against at least a portion of the edge portion to fix the first patch to the first wall.

3. The housing assembly according to claim 2, characterized in that, It also includes a first adhesive layer, which includes a first part and a second part connected along the thickness direction of the first wall. The first part is disposed between the limiting plate and the edge part, and the second part is disposed between the first wall and the limiting plate along the thickness direction of the first wall. The size of the second part is d, which satisfies: 0.01mm≤d≤0.15mm.

4. The housing assembly according to claim 2, characterized in that, It also includes a second adhesive layer, which is disposed between the first wall and the limiting plate along the thickness direction of the first wall. No adhesive layer is disposed between the limiting plate and the edge portion. The size of the second adhesive layer along the thickness direction of the first wall is d, which satisfies: 0.16mm≤d≤0.3mm.

5. The housing assembly according to claim 2, characterized in that, Along the thickness direction of the first wall, the limiting plate partially overlaps with the edge portion, and the maximum width of the overlapping portion of the edge portion and the limiting plate is b, which satisfies: 0.8mm≤b≤1.5mm.

6. The housing assembly according to claim 1, characterized in that, Along the thickness direction of the first wall, the projection of the first patch has a first outer periphery, and the projection of the hole wall of the first hole has a second outer periphery. The second outer periphery is located inside the first outer periphery, and the distance between the second outer periphery and the first outer periphery is b, which satisfies: 0.5mm≤b≤1.5mm.

7. The housing assembly according to claim 2, characterized in that, The pressure relief unit has a weak area, which is constructed to connect the internal space and the external space of the shell after being destroyed by the accumulation and expansion of internal gas. Along the thickness direction of the first wall, the size of the weak area is a, which satisfies: 0.04mm≤a≤2mm. Along the thickness direction of the first wall, the maximum width of the overlapping portion of the edge and the limiting plate is b, which satisfies: 0.8mm≤b≤1.2mm.

8. The housing assembly according to claim 2, characterized in that, The first wall has a second hole that penetrates the first wall along its thickness direction. The pressure relief unit is adapted to block the second hole. The edge portion is connected to the first surface. Along the thickness direction of the first wall, the width of the overlapping portion of the edge portion and the first wall is b1, which satisfies: 1.5mm≤b1≤4mm.

9. The housing assembly according to claim 8, characterized in that, Along the thickness direction of the first wall, the maximum width of the overlapping portion of the edge and the limiting plate is b, which satisfies: 1.0mm≤b≤1.5mm.

10. The housing assembly according to claim 1, characterized in that, Along the thickness direction of the first wall, the dimension of the first wall is f, which satisfies: 0.2mm≤f≤0.8mm.

11. The housing assembly according to claim 1, characterized in that, Along the thickness direction of the first wall, the dimension of the limiting plate is e, which satisfies: 0.03mm≤e≤0.5mm.

12. The housing assembly according to claim 1, characterized in that, The limiting plate is made of at least one of polyethylene terephthalate, polypropylene, and polycarbonate.

13. A single battery cell, characterized in that, Includes the housing assembly according to any one of claims 1-12.

14. An electrical appliance, characterized in that, Includes the battery cell as described in claim 13.

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