Battery and battery device

Abstract

The utility model provides a kind of battery and battery device, it is related to battery technical field.Battery includes battery shell, battery shell has first side wall, first side wall is provided with the score of anti-explosion sheet, anti-explosion sheet and first side wall are welded to form first weld mark.Score divides anti-explosion sheet into main part and weak part, and first weld mark is located in main part area.The product relationship between the distance between first weld mark and score and the thickness of main part is established, and the relative position of welding heat-affected zone and weak area is limited by the product relationship.By setting the distance relationship between the score of anti-explosion sheet and weld mark and the thickness parameter of main part, it is ensured that weak part can be reliably opened and welding area does not break when pressure relief, which has the advantages of improving pressure relief reliability and avoiding shell damage.

Description

Technical Field

[0001] This utility model relates to the field of battery technology, and in particular to a battery and a battery device. Background Technology

[0002] With the rapid development of new energy vehicles, energy storage cabinets, communication base stations, and electronic products, batteries, as core energy storage and supply devices, are finding increasingly wider applications. Batteries not only need to meet performance requirements such as high energy density and long cycle life, but also require high safety and reliability. However, batteries are prone to thermal runaway under extreme operating conditions or abuse, a problem that has become one of the key bottlenecks restricting the further promotion and application of battery technology.

[0003] During battery thermal runaway, a large amount of heat and gas rapidly accumulates inside, causing a sharp increase in internal pressure. To prevent the battery casing from exploding due to excessive pressure, existing batteries are typically designed with safety structures such as explosion-proof valves or pressure relief ports. However, in actual thermal runaway scenarios, the casing area around the explosion-proof valves and pressure relief ports often experiences localized damage due to stress concentration and insufficient material strength. This damaged area is highly susceptible to becoming a channel for the ejection of high-temperature substances under high pressure. These high-temperature ejected materials can not only directly impact other components inside the battery but may also further ignite or trigger thermal runaway in adjacent batteries, affecting the overall safety performance of the battery device.

[0004] Therefore, how to effectively suppress the ejection of high-temperature substances caused by the rupture of explosion-proof valves or pressure relief ports during battery thermal runaway, and block the rapid spread of thermal runaway within the battery pack, has become a key technical problem that urgently needs to be solved in this field. Utility Model Content

[0005] In view of the above problems, the present invention provides a battery and battery device that have the advantages of improving pressure relief reliability and avoiding shell damage.

[0006] In a first aspect, this utility model provides a battery, comprising:

[0007] Battery housing; the battery housing includes a first sidewall, on which an explosion-proof sheet is provided, the explosion-proof sheet being welded to the first sidewall to form a first weld mark;

[0008] The explosion-proof sheet is provided with grooves that divide the explosion-proof sheet into a main body and a weak part. The grooves surround the weak part. The first solder mark is located on the main body. The weak part is used to open when the internal pressure of the battery reaches the pressure relief threshold to relieve the pressure of the battery.

[0009] The first solder mark is located on the outer periphery of the weak portion;

[0010] The distance between the first solder mark and the notch is d1 mm, and the thickness of the main body within 5 mm of the notch is D mm. d1 mm and D mm satisfy the relationship: 0.2 ≤ d1 × D ≤ 5 (unit: mm). 2 .

[0011] Secondly, embodiments of this application also provide a battery device, at least the battery described above.

[0012] The above-mentioned technical solution provides a battery and battery device that, by setting the spacing relationship between the explosion-proof plate markings and the solder marks, as well as the thickness parameters of the main body, ensures that the weak part can be reliably opened and the welded area is not damaged during pressure relief, thus improving the reliability of pressure relief and avoiding damage to the casing. Attached Figure Description

[0013] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the 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 based on these drawings without creative effort.

[0014] Figure 1 This is a schematic diagram of the battery casing according to an embodiment of the present invention;

[0015] Figure 2 This is a schematic diagram of the structure of the first sidewall in an embodiment of the present utility model;

[0016] Figure 3 This is a top view of the first sidewall of an embodiment of the present utility model;

[0017] Figure 4 This is a schematic diagram of the structure of the explosion-proof sheet according to an embodiment of the present invention;

[0018] Figure 5 This is a cross-sectional view of the explosion-proof sheet according to an embodiment of the present utility model;

[0019] Figure 6 yes Figure 2 Sectional view along the middle AA section;

[0020] Figure 7 yes Figure 6 Enlarged schematic diagram of part B;

[0021] Figure 8 This is a cross-sectional view of the battery casing according to an embodiment of this application.

[0022] Explanation of reference numerals in the attached figures:

[0023] 10. Battery casing; 20. Battery;

[0024] 100. First sidewall; 110. First surface; 120. Second surface;

[0025] 200. Explosion-proof sheet; 210. Main body; 220. Weak part; 230. Groove;

[0026] 310, First solder mark; 320, Scribe; 330, Second solder mark;

[0027] 400. Pole post assembly;

[0028] 500, battery cell; 510, electrode tab;

[0029] 610. Shell body; 620. Cover plate. Detailed Implementation

[0030] To make the above-mentioned objectives, features, and advantages of the embodiments of this application more apparent and understandable, 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 a part of the embodiments of this application, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the scope of protection of this application.

[0031] In related technologies, batteries are widely used as energy storage devices in new energy equipment. However, during battery thermal runaway, the area around the explosion-proof valve and pressure relief port is prone to structural damage. High-temperature substances, along with shell fragments, are splashed into adjacent areas, accelerating the spread of thermal runaway and threatening the overall safety of the battery system. Traditional explosion-proof structures typically use a single-thickness shell with simple groove design, making it difficult to maintain the integrity of the main structure during pressure relief.

[0032] The positional relationship between the welding area and the weak area of ​​the explosion-proof sheet directly affects the fracture morphology of the shell. Research has found that the spacing between the weld marks and the indentation in the relevant technologies lacks quantitative control. Especially within the 5mm range of the weak part, the thermal impact is severe. After the battery valve is opened and pressure is released, the surrounding structure is affected by high temperature and high pressure, the structural strength is weakened, and it softens and deforms rapidly, resulting in an increase in the valve opening area. When the pressure is released, the main body area is affected by thermal stress, resulting in unexpected crack propagation.

[0033] In view of this, the present invention provides a battery and a battery device, including a battery casing with a first sidewall. The first sidewall is provided with a serrated explosion-proof sheet, which is welded to the first sidewall to form a first weld mark. The serration divides the explosion-proof sheet into a main body and a weak part, and the first weld mark is located in the main body area. A product relationship is established between the distance between the first weld mark and the serration and the thickness of the main body, which defines the relative positions of the weld heat-affected zone and the weak part. By setting the distance relationship between the serration and the weld mark and the thickness parameter of the main body, it is ensured that the weak part can reliably open and the welded area does not break during pressure relief, thus improving the reliability of pressure relief and avoiding casing damage.

[0034] The technical solution of this application and how the technical solution of this application solves the above-mentioned technical problems are described in detail below with specific embodiments. These specific embodiments can be combined with each other, and the same or similar concepts or processes may not be described again in some embodiments. The embodiments of this application will now be described with reference to the accompanying drawings.

[0035] Reference Figures 1-8 This application discloses a battery 20, including a battery casing 10. The battery casing 10 includes a first sidewall 100. An explosion-proof sheet 200 is provided on the first sidewall 100. The explosion-proof sheet 200 is welded to the first sidewall 100 to form a first weld mark 310. The explosion-proof sheet 200 is provided with a groove 320, which divides the explosion-proof sheet 200 into a main body 210 and a weak part 220. The groove 320 surrounds the weak part 220. The first weld mark 310 is located on the main body 210. The weak part 220 is used to open when the internal pressure of the battery 20 reaches the pressure relief threshold to relieve pressure on the battery 20.

[0036] The explosion-proof plate 200 is a pressure-sensitive element located at a specific position in the battery casing 10. It can be made of metals or alloys such as aluminum alloy, stainless steel, or titanium alloy. Its function is to sense changes in internal battery pressure and initiate directional rupture to achieve precise and directional pressure relief. The notch 320 is formed by laser processing or mechanical stamping to create a weak point. Its specific structural form can be a V-shaped, trapezoidal, or U-shaped groove, used to guide the crack to propagate along a predetermined path under a predetermined pressure.

[0037] The main body 210 is the load-bearing area surrounding the notch 320. Gradient strength can be achieved by adjusting the material thickness distribution to maintain the overall structural stability of the shell. The weak point 220 is the closed area enclosed by the notch 320, which can be designed as a circular or polygonal geometry to establish a priority fracture area. The first weld mark 310 is the connection interface between the explosion-proof plate 200 and the shell sidewall, which can be formed using laser welding or resistance welding processes to ensure a reliable connection between the explosion-proof plate 200 and the shell.

[0038] The distance d1 between the first weld mark 310 and the notch 320 is the shortest distance between the welding area of ​​the explosion-proof sheet 200 and the edge of the notch 320. This distance can be measured using laser ranging or microscopic imaging technology. This parameter is used to balance the structural strength of the welding area with the stress concentration of the weak point 220. The thickness D of the main body 210 is the overall thickness of the area of ​​the explosion-proof sheet 200 not weakened by the notch 320. The thickness distribution can be controlled through stamping or machining. This parameter is used to ensure that the main body 210 maintains structural integrity when the internal pressure of the battery 20 is abnormal.

[0039] Specifically, when the internal pressure of the battery 20 reaches a set threshold, the weak point 220 undergoes directional fracture along the notch 320 under stress concentration, forming a controllable pressure relief channel. The main body 210 effectively reduces the strength interference of the weld heat-affected zone on the notch 320 area by maintaining a specific product relationship between its thickness and the solder joint spacing. This product relationship defines the minimum safe distance between the weld heat-affected zone and the notch 320, preventing premature cracking of the notch 320 area due to residual welding stress. Simultaneously, the coordinated design of the thickness and spacing of the main body 210 ensures that the main body area maintains sufficient structural strength during pressure relief, avoiding secondary fractures.

[0040] Compared to related technologies, traditional solutions use a fixed value for the distance between the weld mark position and the notch 320, failing to consider the impact of shell thickness on welding heat conduction. This solution achieves dynamic parameter adaptation by establishing a product relationship, which can accommodate design requirements for shells of different thicknesses while avoiding excessive expansion of the weld heat-affected zone due to increased thickness. In related technologies, the fracture of the weak point 220 can easily lead to damage to the main body 210. This solution, by precisely controlling the relative position of the weld mark and the notch 320, ensures that the main body 210 maintains structural integrity during pressure relief.

[0041] Through the above technical solution, this application achieves precise control of the pressure relief path, ensuring timely pressure relief while maintaining the integrity of the casing structure to the greatest extent. This design effectively prevents large-scale splashing of casing fragments during pressure relief, reduces the impact of thermal runaway substances on adjacent battery cells 20, and improves the overall safety performance of the battery system 20.

[0042] Reference Figure 1 , Figure 2 , Figure 3 , Figure 6 , Figure 7 This application further proposes that the first solder mark 310 is located on the outer periphery of the weak portion 220, the distance between the first solder mark 310 and the notch 320 is d1 mm, and the thickness of the main body portion within 5 mm of the notch is D mm. d1 mm and D mm satisfy the relationship: 0.2 ≤ d1 × D ≤ 5, in mm. 2 .

[0043] For example, the product of d1 mm and D mm can be 0.2 mm. 2 0.5mm 2 1mm 2 2mm 2 3mm 2 4mm 2 Or 0.2mm 2 However, the embodiments in this application are not limited to these examples, nor are they limited to the examples described above.

[0044] Furthermore, by controlling d1 mm within the range of 0.2 mm to 5 mm, the overlap between the weld heat-affected zone and the notch 320 area can be avoided, thus preventing weld cracking that could lead to premature failure of the explosion-proof sheet 200. Simultaneously, it ensures that the main body 210 has sufficient resistance to deformation when subjected to the internal pressure of the battery 20, while preventing the weak section 220 from failing to open as expected due to excessive thickness. When the internal pressure of the battery 20 reaches the pressure relief threshold, the weak section 220 breaks along the notch 320, and the main body 210 remains connected to the sidewall through the first weld 310, preventing casing fragments from flying and simultaneously achieving directional pressure relief.

[0045] Furthermore, in this embodiment, d1 mm and D mm satisfy the relationship: 1 ≤ d1 × D ≤ 4, in mm. 2 For example, the product of d1 mm and D mm can be 1 mm. 2 1.5mm 2 2mm 2 2.5mm 2 3mm 2 3.5mm 2 Or 4mm 2 However, the embodiments in this application are not limited to these examples, nor are they limited to the examples described above.

[0046] Compared with related technologies, the distance between the weld mark position and the notch 320 in the existing explosion-proof disc 200 design is not clearly defined, which may lead to the superposition of residual welding stress and stress in the notch 320 area, causing unexpected breakage of the explosion-proof disc 200. In addition, if the thickness of the main body 210 is not optimized, it may cause delayed pressure relief due to local thinness, or excessive pressure relief resistance due to excessive thickness. This solution resolves the contradiction between welding reliability and pressure relief response speed by limiting the optimal range of d1 mm and D mm.

[0047] Through the above technical solution, this application can accurately control the rupture location and timing of the explosion-proof sheet 200 when the battery 20 experiences thermal runaway, avoid random damage to the shell structure due to insufficient local strength, and ensure that high-temperature substances are released directionally through the weak part 220, reducing the impact on other areas of the battery 20 and adjacent batteries 20, thereby improving the overall safety of the battery 20 system.

[0048] This application further proposes that the main body 210 includes a first region, a second region, and an intermediate region located between the first region and the second region. The first region is disposed near the weak portion 220, and the second region is disposed near the first solder mark 310. The thickness of the first region is D1 mm, the thickness of the second region is D2 mm, and the thickness of the intermediate region is D3 mm. D1 mm, D2 mm, and D3 mm satisfy the following relationship: D3 is greater than D1, and D3 is greater than D2, in mm.

[0049] The first region is the part of the explosion-proof sheet 200 near the weak point 220, which can be achieved using a stamping thinning process to preferentially bear stress concentration when the weak point 220 is opened. The second region is the part of the explosion-proof sheet 200 near the welded area, which can be adjusted in thickness through local heat treatment to reduce the impact of the weld heat-affected zone on the weak point 220. The middle region is the transition section connecting the first and second regions, which can be achieved using a stepped thickness gradient structure to balance the overall strength of the explosion-proof sheet 200 with the pressure relief response speed.

[0050] Specifically, when the internal pressure of the battery 20 reaches the pressure relief threshold, the weak part 220 fractures due to stress concentration. At this time, the first region, being thinner, deforms first, while the middle region, being the thickest, forms a supporting structure to prevent the explosion-proof sheet 200 from tearing apart entirely. The second region reduces the interference of welding thermal stress on the weak part 220 through a decreasing thickness, while the thickened design of the middle region prevents stress from spreading to the welding area before the weak part 220 is opened.

[0051] Compared to related technologies, traditional explosion-proof discs 200 typically employ a uniform thickness design, which can easily lead to the overall fracture of the main body 210 or damage to the welded areas when the weak part 220 is opened. This solution, however, creates a localized stress isolation zone by setting an intermediate region with increasing thickness, when the weak part 220 is opened. Furthermore, the differentiated thickness design of the first and second regions ensures that the explosion-proof disc 200 maintains its structural integrity during pressure relief.

[0052] Through the above technical solution, this application can effectively prevent the explosion-proof sheet 200 from unexpectedly cracking due to uneven stress distribution during the pressure relief process, reduce the interference of the weld heat-affected zone on the opening performance of the weak part 220, and improve the reliability and safety of the battery 20 during the pressure relief process. For example, in the event of thermal runaway of the battery 20, the weak part 220 can be precisely opened to relieve pressure, while the main body 210 maintains its intact structure, preventing secondary thermal runaway caused by shell fragments being ejected with high-temperature materials.

[0053] This application further proposes that the battery casing 10 includes a first sidewall 100, on which an explosion-proof sheet 200 is provided. The explosion-proof sheet 200 is welded to the first sidewall 100 to form a first weld mark 310. The explosion-proof sheet 200 is provided with a groove 320, which divides the explosion-proof sheet 200 into a main body 210 and a weak part 220. The groove 320 surrounds the weak part 220. The first weld mark 310 is located on the main body 210. The weak part 220 is used to open when the internal pressure of the battery 20 reaches the pressure relief threshold to relieve pressure on the battery 20.

[0054] The main body 210 includes a first region, a second region, and an intermediate region located between the first and second regions. The first region is disposed near the weak point 220, and the second region is disposed near the first solder mark 310. The thickness of the first region is D1 mm, the thickness of the second region is D2 mm, and the thickness of the intermediate region is D3 mm. D3 is greater than D1 and D2, in mm. The thicknesses of the first region D1 mm and the second region D2 mm satisfy the relationship: D1 is less than D2, in mm.

[0055] The first region refers to the annular region in the main body 210 of the explosion-proof sheet 200 that is directly adjacent to the weak point 220. Specifically, it can be formed into a gradually varying thickness structure through machining or stamping, with the thickness change direction perpendicular to the extension direction of the notch 320. The second region is the annular region in the main body 210 of the explosion-proof sheet 200 that is adjacent to the first weld mark 310. Specifically, it can be achieved using heat-affected zone thickness control technology formed by laser welding, with its thickness gradually decreasing towards the welding area. The intermediate region is the transition region connecting the first and second regions. Specifically, it can be formed into a stepped thickness transition structure through CNC milling, with a thickness greater than the thickness of the two adjacent regions.

[0056] Specifically, the main body 210 employs a three-segment structure with a thickness gradient distribution. At the junction of the first region and the weak point 220, a support ring with the greatest thickness is formed, while at the junction of the second region and the welding area, a stress buffer zone with the smallest thickness is formed. When internal pressure from the battery 20 acts on the weak point 220, the thickness advantage of the first region effectively resists stress concentration in the notched area 320, preventing accidental breakage in the non-pressure-relief area. The thinning design of the second region absorbs welding thermal stress, preventing crack propagation in the weld area. The thickened structure in the middle region serves as a mechanical transition zone, balancing the stress distribution between regions of different thicknesses.

[0057] Compared with related technologies, the main body 210 of the traditional explosion-proof sheet 200 typically adopts a uniform thickness design or a single gradually varying thickness structure, which is prone to stress abrupt changes at the boundary between the weld heat-affected zone and the weak area of ​​the notch 320. This solution establishes a thickness relationship where D1 mm is less than D2 mm, forming a high-strength protective band at the edge of the weak part 220, while simultaneously forming a low-stress buffer band in the welding area. This allows the explosion-proof sheet 200 to form a directional stress transmission path when subjected to internal pressure, ensuring that the weak part 220 preferentially undergoes controllable fracture. The weld line of the first weld mark 310 has a higher failure risk than the weak part 220, thus avoiding cracking at the weld line and improving the connection strength between the main body 210 and the battery casing 10.

[0058] Through the above technical solution, this application effectively solves the technical problem that the explosion-proof sheet 200 is prone to unexpected cracking at the junction of the heat-affected zone of welding and the weak area of ​​the groove 320. By establishing a specific thickness gradient relationship, the structural reliability of the welding area is guaranteed, and the weak part 220 is guaranteed to open accurately when the pressure relief threshold is reached, thereby avoiding the overall structural damage of the battery casing 10 during thermal runaway.

[0059] Reference Figure 1 , Figure 2 , Figure 3 , Figure 8 This application further proposes that the battery casing 10 includes a cover plate 620 and a casing body 610, at least one end of the casing body 610 is provided with an opening, the cover plate 620 is covered by the opening, and the explosion-proof sheet 200 is disposed on the cover plate 620.

[0060] The cover plate 620 is a metal plate structure used to close the opening of the shell body 610. Specifically, it can be made of materials including but not limited to copper, iron, aluminum, stainless steel, aluminum alloy, etc., and is used to form the sealing end face of the battery shell 10.

[0061] The shell body 610 is a metal shell used to house the battery cell 500. Specifically, it can be made into a cylindrical or square structure by a stretching process, and its open end is used to cooperate with the cover plate 620 to form a closed space.

[0062] The opening is a through area formed at the end of the shell body 610, which can be formed by cutting or stamping, and is used to install the cover plate 620 and achieve internal space sealing.

[0063] Specifically, the cover plate 620 is fixed to the open end of the shell body 610 by welding or riveting to form a sealed structure. The explosion-proof sheet 200 is welded to the outer or inner surface of the cover plate 620, and its grooved area 320 overlaps with the main body area of ​​the cover plate 620. When thermal runaway occurs inside the battery 20, causing the pressure to rise, the weak point 220 of the explosion-proof sheet 200 ruptures preferentially, and the high-temperature material is discharged through the directional pressure relief channel on the cover plate 620. Since the explosion-proof sheet 200 is directly integrated into the cover plate 620, the pressure relief path is limited to the area of ​​the cover plate 620, preventing other parts of the shell body 610 from rupturing uncontrollably due to pressure impact.

[0064] Compared to related technologies, traditional batteries 20 typically place the explosion-proof structure on the side wall of the casing 610, causing high-temperature materials to splash laterally onto adjacent batteries 20 during pressure relief. This solution integrates the explosion-proof sheet 200 onto the cover plate 620, using the cover plate 620 as an independent pressure relief unit. This ensures the pressure relief direction is perpendicular to the battery stacking direction, reducing direct impact on surrounding batteries 20. Furthermore, the planar structure of the cover plate 620 makes it easier to control the welding precision of the explosion-proof sheet 200, resulting in higher processing consistency compared to curved casing side walls.

[0065] Through the above technical solution, this application achieves directional control of the pressure relief path, effectively preventing the diffusion of high-temperature substances in the lateral space and reducing the risk of thermal runaway propagation. The integrated design of the cover plate 620 and the explosion-proof plate 200 simplifies the complexity of the shell structure, improves the reliability of the pressure relief action, and at the same time avoids structural fatigue of the shell body 610 due to repeated pressure impacts.

[0066] This application further proposes that the explosion-proof sheet 200 is welded to the cover plate 620 to form a first weld mark 310, and the cover plate 620 is welded to the opening to form a second weld mark 330. The minimum distance between the first weld mark 310 and the second weld mark 330 is d2 mm, and d2 mm satisfies the relationship: 2≤d2≤10, unit mm.

[0067] The first weld mark 310 is the connection area formed by welding between the explosion-proof sheet 200 and the cover plate 620. This can be achieved using laser welding or ultrasonic welding. Its function is to fix the relative position of the explosion-proof sheet 200 and the cover plate 620 while ensuring sealing. The second weld mark 330 is the connection area formed by welding between the cover plate 620 and the edge of the opening of the shell body 610. This can be achieved using continuous welding or spot welding. Its function is to seal the opening of the shell body 610 and maintain the structural integrity of the battery shell 10.

[0068] It is understandable that d2 mm is the minimum spacing between the first weld mark 310 and the second weld mark 330. This spacing can be controlled by adjusting the welding path or welding parameters. Its purpose is to avoid the superposition of the heat-affected zones of the two welding areas, which would lead to a decrease in local material strength and thus reduce the risk of unexpected rupture of the shell during thermal runaway.

[0069] Specifically, when the explosion-proof sheet 200 is installed on the cover plate 620, the heat conduction path between the first weld mark 310 and the second weld mark 330 can be effectively isolated by controlling the distance between them within a specific range. When the internal pressure of the battery 20 increases, the weak part 220 of the explosion-proof sheet 200 will rupture first to release pressure, while the area between the first weld mark 310 and the second weld mark 330 will be separated due to the heat-affected zone, thus maintaining the material strength and preventing the surrounding shell from being damaged by high temperature and high pressure caused by thermal runaway. In addition, this distance control can balance welding process efficiency and structural reliability, ensuring that the deformation of the cover plate 620 during welding is within a controllable range.

[0070] In this embodiment, d2 mm satisfies the relationship: 3≤d2≤9, with the unit being mm. For example, in this embodiment, d2 can be 3mm, 4mm, 5mm, 6mm, 7mm, 8mm, or 9mm, etc.

[0071] Compared with related technologies, the welding area of ​​the explosion-proof sheet 200 of the traditional battery cover 620 and the welding area of ​​the casing are usually not clearly defined, resulting in a high risk of overlapping heat-affected zones. This application defines the d2 mm range to make the two welding areas form independent heat-affected zones, avoiding lattice distortion or stress concentration of the material due to repeated heating, thereby improving the casing's compressive strength under extreme conditions and reducing the possibility of secondary accidents caused by casing fragments flying during thermal runaway.

[0072] Through the above technical solution, this application can effectively prevent the welded area of ​​the cover plate 620 from cracking during thermal runaway of the battery 20, ensure that the pressure relief path is precise and controllable, reduce the risk of high-temperature materials carrying shell fragments being ejected, and improve the safety and stability of the battery 20 system.

[0073] This application further proposes that the battery casing 10 includes a cover plate 620 and a casing body 610. At least one end of the casing body 610 is provided with an opening. The cover plate 620 covers the opening. An explosion-proof sheet 200 is disposed on the cover plate 620. The explosion-proof sheet 200 is welded to the cover plate 620 to form a first weld mark 310. The cover plate 620 is welded to the opening to form a second weld mark 330. The minimum distance between the second weld mark 330 and the weak part 220 is d3 mm. d3 mm satisfies the relationship: 3≤d3≤15, unit: mm.

[0074] The second weld mark 330 is the connection mark formed by welding the cover plate 620 and the shell body 610 at the opening. It can be achieved using laser welding or resistance welding, and is used to ensure the sealing and structural strength of the cover plate 620 and the shell body 610. The weak part 220 is a local area on the explosion-proof sheet 200 defined by the notch 320. It can be achieved using mechanical stamping or laser engraving, and is used to preferentially rupture when the internal pressure of the battery 20 reaches the pressure relief threshold to achieve pressure relief. The minimum distance d3 is the shortest straight-line distance from the edge of the second weld mark 330 to the edge of the weak part 220. It can be achieved by adjusting the welding position or the layout of the notch 320, and is used to control the spatial relationship between the heat-affected zone of the second weld mark 330 and the weak part 220. In this embodiment, d3 mm can be 3 mm, 5 mm, 7 mm, 10 mm, 13 mm, 14 mm, or 15 mm, etc.

[0075] Specifically, during the welding process between the cover plate 620 and the shell body 610 to form the second weld mark 330, the welding heat may cause changes in the material properties of local areas of the cover plate 620. If the distance between the second weld mark 330 and the weak part 220 is too small, the heat-affected zone may cover the weak part 220, causing an abnormal increase in the mechanical strength of the weak part 220, making it unable to break in time under the predetermined pressure; if the distance is too large, it may increase the overall size of the cover plate 620 or affect the layout of other components. By limiting the range of d3, the compactness of the cover plate 620 structure can be maintained while avoiding interference with the function of the weak part 220 due to heat. When the internal pressure of the battery 20 increases, the weak part 220 preferentially breaks along the notch 320 under pressure, while the area where the second weld mark 330 is located will not fail prematurely due to sufficient distance, thereby ensuring the reliable opening of the pressure relief path.

[0076] Compared with related technologies, in the traditional battery 20 design, the distance between the second weld mark 330 and the weak part 220 is not strictly controlled. The welding heat-affected zone may cause the actual rupture pressure of the weak part 220 to deviate from the design value, resulting in premature rupture or delayed opening. This application, by limiting the range of d3 mm, clearly isolates the functional area of ​​the welding heat-affected zone from the weak part 220, so that the two are physically isolated in space, which not only ensures the welding quality, but also maintains the structural sensitivity of the weak part 220.

[0077] Through the above technical solution, this application can accurately control the rupture behavior of the weak part 220 when it is overpressurized inside the battery 20, avoid abnormal pressure relief function caused by welding heat, and optimize the structural layout of the cover plate 620 to balance the welding strength requirements and pressure relief reliability in a limited space, thereby reducing the risk of disordered spraying of high temperature materials during thermal runaway.

[0078] Reference Figure 2 , Figure 3 , Figure 6This application further proposes that the thickness of the cover plate 620 located between the first solder mark 310 and the second solder mark 330 is D4 mm, and D4 mm satisfies the relationship: D4 mm is greater than or equal to 1.5 mm.

[0079] The first weld mark 310 is the welding mark formed by welding the explosion-proof sheet 200 and the cover plate 620. Specifically, it can be achieved by laser welding or resistance welding process, and is used to fix the connection between the explosion-proof sheet 200 and the cover plate 620.

[0080] The second weld mark 330 is a welding mark formed by welding the cover plate 620 to the opening of the shell body 610. It can be achieved by continuous welding or spot welding process and is used to seal the opening of the shell body 610.

[0081] The thickness D4 mm of the cover plate 620 is the material thickness of the cover plate 620 in the area between the first weld mark 310 and the second weld mark 330. The thickness can be controlled by stamping or machining. This area is prone to structural strength reduction under the influence of welding heat. The structural integrity of the cover plate 620 can be maintained by setting a lower limit for the thickness.

[0082] Specifically, when the internal pressure of the battery 20 increases, the weak point 220 of the explosion-proof sheet 200 opens to release pressure. At this time, the cover plate 620 area between the first weld mark 310 and the second weld mark 330 bears bidirectional stress from the shell body 610 and the explosion-proof sheet 200. If the thickness of this area is insufficient, it may crack under the high temperature and high pressure impact generated by thermal runaway, resulting in the destruction of the shell structure integrity. By controlling D4 to be greater than or equal to a specific threshold, it can be ensured that this area maintains sufficient tear resistance during the pressure release process, avoiding secondary shell cracking caused by insufficient strength of the weld heat-affected zone.

[0083] Compared to related technologies, the thickness of the cover plate 620 of the traditional battery 20 between the welding areas is not specially designed. During the depressurization process, this area may become a weak point due to material thinning or welding heat damage. This solution, by limiting the thickness to a minimum of D4 mm, creates a continuous high-strength transition zone between the welding areas of the cover plate 620, effectively blocking the crack propagation path.

[0084] Through the above technical solution, this application can prevent unexpected structural fractures between the welding areas of the cover plate 620 during the pressure relief process, avoid high-temperature substances from spreading to the outside of the battery 20 through the fracture area, thereby suppressing the risk of thermal runaway propagation and improving the overall safety performance of the battery 20 system.

[0085] This application further proposes that an electrode post assembly 400 be provided on the cover plate 620, and the distance between the electrode post assembly 400 and the first solder mark 310 is d4 mm, where d4 mm satisfies the relationship: 30≤d4≤120, in mm. In this embodiment, d4 mm can be 30 mm, 35 mm, 40 mm, 55 mm, 65 mm, 75 mm, 85 mm, 100 mm, 110 mm, 120 mm, etc.

[0086] The terminal post assembly 400 is a conductive structure used to connect the internal tabs 510 of the battery 20 to the external circuit. Specifically, it can be implemented using a combination of a copper-aluminum composite column and an insulating sealant. Its function is to maintain the electrical connection and sealing of the battery 20. The distance d4 mm is the straight-line distance from the edge of the terminal post assembly 400 to the boundary of the molten zone of the first weld mark 310. This distance can be adjusted by changing the installation position of the terminal post and the layout of the welding area of ​​the explosion-proof sheet 200. This distance is used to control the range of thermal shock to the terminal post assembly 400 from high-temperature ejected materials during thermal runaway.

[0087] Specifically, when the internal pressure of the battery 20 triggers the opening of the weak point 220 of the explosion-proof sheet 200, high-temperature material will be directionally ejected along the outer area of ​​the first solder mark 310. By controlling the distance between the terminal assembly 400 and the first solder mark 310 within a specific range, the direct impact of the jet stream on the insulating sealing structure of the terminal assembly 400 can be effectively prevented. For example, when the lower limit of d4 mm is set to a certain value, it can be ensured that the sealing ring of the terminal assembly 400 is outside the safe distance of the jet path; when the upper limit of d4 mm is set to a certain value, it can prevent the structural strength of the cover plate 620 from decreasing due to excessive distance. This distance range was determined through experimental verification, ensuring both the effectiveness of the pressure relief channel and maintaining the functional integrity of the terminal assembly 400.

[0088] Compared with related technologies, the traditional battery 20 design does not clearly define the distance between the welding area of ​​the terminal assembly 400 and the explosion-proof sheet 200, which poses a risk of terminal seal failure due to high-temperature material impact. This solution establishes a thermal shock protection zone at the structural layout level by limiting the distance between the terminal assembly 400 and the first solder mark 310, thus solving the secondary short circuit problem caused by unreasonable layout in related technologies.

[0089] Through the above technical solution, this application can effectively isolate the thermal shock generated during the pressure relief process, preventing leakage or short circuit of the sealing structure of the terminal assembly 400 due to high-temperature erosion. This design maintains the normal electrical performance of the battery 20 while improving the safety protection level under thermal runaway conditions, preventing systemic failures caused by localized failures.

[0090] Reference Figure 1 , Figure 3 , Figure 4 , Figure 8This application further proposes that the battery 20 also includes a cell 500, which includes a tab 510 electrically connected to the terminal assembly 400. The distance between the tab 510 and the first solder mark 310 is d5 mm, and the distance between the terminal assembly 400 and the first solder mark 310 is d4 mm. d5 mm and d4 mm satisfy the relationship: d5 < d4, in mm. Furthermore, d5 mm also satisfies the relationship: 5 ≤ d5 ≤ 30, in mm.

[0091] The tab 510 is a conductive component inside the battery cell 500 used to conduct current. It can be implemented using a metal foil or a conductive coating, and it connects to the terminal assembly 400 to form a current path. The limitation that d5 mm is less than d4 mm ensures that the distance between the tab 510 and the first solder mark 310 is less than the distance between the terminal assembly 400 and the first solder mark 310. This arrangement reduces the risk of high-temperature materials impacting the tab 510 during thermal runaway. In this embodiment, d5 mm can be 5 mm, 15 mm, 20 mm, 25 mm, 30 mm, etc.

[0092] Specifically, when the internal pressure of the battery 20 abnormally increases, the weak point 220 of the explosion-proof sheet 200 opens to release pressure, at which time structural deformation may occur in a local area of ​​the casing. Since the distance between the tab 510 and the first solder mark 310 is relatively close, if this distance is too large, casing deformation may cause the tab 510 to contact the solder mark area, leading to a short circuit or structural damage. By limiting d5 mm to less than d4 mm, the tab 510 is positioned closer to the terminal assembly 400, away from the area of ​​the first solder mark 310 where deformation may occur, thereby preventing the tab 510 from being subjected to mechanical stress during pressure release. Simultaneously, d5 is controlled within a specific range, ensuring a safe distance between the tab 510 and the solder mark while maintaining an effective conductive path between the cell 500 and the terminal assembly 400.

[0093] In some specific embodiments, the pole post assembly 400 can be disposed on the side of the cover plate 620 away from the explosion-proof sheet 200, and the pole tab 510 extends to the bottom of the pole post by bending or stacking to adapt to the spacing relationship between d5 mm and d4 mm.

[0094] Compared with related technologies, the distance between the tab 510 and the solder mark in the traditional battery 20 design is not specifically defined, which poses a risk of the casing deforming and pulling the tab 510 during pressure relief. This solution optimizes the spatial layout of electrical connection components by clarifying the spacing relationship between the tab 510, the terminal assembly 400 and the solder mark, which significantly reduces the probability of the tab 510 being subjected to mechanical stress during pressure relief.

[0095] Through the above technical solution, this application effectively prevents damage to the tab 510 or short circuit caused by shell deformation during thermal runaway pressure relief, ensuring the electrical safety and structural integrity of the battery 20 under extreme conditions, thereby suppressing the spread of thermal runaway and improving the overall reliability of the battery 20 system.

[0096] Reference Figure 1 , Figure 3 , Figure 4 This application further proposes that the battery casing 10 includes a cover plate 620 and a casing body 610, with an opening at at least one end of the casing body 610, and the cover plate 620 covering the opening. An electrode assembly 400 is also provided on the cover plate 620, and an explosion-proof sheet 200 is provided on the casing body 610. This helps to achieve thermal and electrical separation and improves the safety performance of the battery 20.

[0097] The casing 610 is a rigid container for housing the internal components of the battery 20. It can be made of aluminum alloy or steel and is stamped to form a closed space for the battery 20. The cover plate 620 covers the opening of the casing 610 and can be connected to the casing 610 by laser welding or riveting to seal the internal space of the battery 20.

[0098] Specifically, the explosion-proof plate 200 is directly installed on the side wall area of ​​the casing 610, forming a spatial isolation with the terminal assembly 400 on the cover plate 620. When thermal runaway occurs inside the battery 20, the high-temperature and high-pressure substances are directionally depressurized through the explosion-proof plate 200 on the side wall of the casing 610, avoiding interference between the depressurization path and the terminal assembly 400 on the cover plate 620. As the main load-bearing structure, the explosion-proof plate 200 on the side wall area of ​​the casing 610 can effectively disperse the pressure relief impact force and prevent the cover plate 620 from structural failure due to simultaneously bearing the terminal connection stress and the pressure relief impact.

[0099] Compared to related technologies, traditional solutions typically integrate the explosion-proof plate 200 onto the cover plate 620. However, the cover plate 620 must simultaneously support the pole assembly 400 and the welded sealing structure, making it prone to increased rupture extent due to the superposition of multiple stresses during thermal runaway. This solution, by transferring the explosion-proof plate 200 to the housing body 610, completely separates the pressure relief path from the electrical connection area, ensuring the structural integrity of the pole assembly 400 while avoiding secondary damage to the welded area of ​​the cover plate 620.

[0100] Through the above technical solution, this application effectively solves the technical problem of mutual interference between the pressure relief path and the electrical connection area during thermal runaway. While maintaining the sealing performance of battery 20, the controllability of the pressure relief process is achieved through structural layout optimization, which significantly reduces the risk of secondary short circuit caused by high temperature material impact.

[0101] Reference Figure 1 , Figure 2 , Figure 3 , Figure 4 This application further proposes that the orthographic projection of the pole assembly 400 on the first sidewall 100 does not at least partially coincide with the area enclosed by the first solder mark 310 on the first sidewall 100.

[0102] The non-overlapping of the orthographic projection areas is due to the spatial misalignment between the vertical projection range of the pole post assembly 400 on the side wall plane and the welding area of ​​the first solder mark 310. This can be achieved by adjusting the installation position of the pole post assembly 400 or changing the welding path of the first solder mark 310, thus avoiding complete overlap of their projections on the side wall plane.

[0103] Specifically, when the internal pressure of the battery casing 10 reaches the pressure relief threshold, the weak point 220 of the explosion-proof sheet 200 ruptures to release the pressure. At this time, the area where the first solder mark 310 is located may deform due to high temperature or mechanical stress. By offsetting the projection area of ​​the terminal assembly 400 from the welding area of ​​the first solder mark 310, the direct impact of deformation or heat conduction on the terminal assembly 400 can be avoided, thereby maintaining the sealing stability between the terminal assembly 400 and the casing. For example, the terminal assembly 400 can be located on the side of the cover plate 620 away from the first solder mark 310, or the welding path can be adjusted to avoid the projection range of the terminal assembly 400.

[0104] Compared with related technologies, the existing battery 20 design lacks a targeted layout for the positional relationship between the welding areas of the terminal assembly 400 and the explosion-proof sheet 200. This results in heat or stress in the welding areas during pressure relief potentially being conducted to the terminal assembly 400 through the casing, causing sealing failure or structural deformation. This solution effectively isolates the terminal assembly 400 from interference during pressure relief through a staggered spatial projection design.

[0105] Through the above technical solution, this application can reduce the structural impact on the terminal assembly 400 when the battery 20 is depressurized, avoid terminal seal failure caused by deformation of the welding area, and reduce the risk of high temperature substances being conducted to the terminal through the shell, thereby improving the safety and reliability of the battery 20 in thermal runaway scenarios.

[0106] This application further proposes that the orthographic projection of the pole post assembly 400 on the first sidewall 100 is offset from the area enclosed by the first solder mark 310 on the first sidewall 100. Furthermore, the distance between the orthographic projection of the pole post assembly 400 on the first sidewall 100 and the area enclosed by the first solder mark 310 on the first sidewall 100 is d7 mm, where d7 mm satisfies the relationship: 20 ≤ d7 ≤ 130 (unit: mm).

[0107] The distance d7 mm is the shortest gap between the edge of the projection area of ​​the pole post assembly 400 and the edge of the projection area of ​​the first solder mark 310. This gap can be precisely controlled through laser ranging or 3D modeling to ensure an effective isolation buffer zone is formed between the two, reducing the risk of simultaneous damage to the pole post assembly 400 and the solder area by high-temperature substances during thermal runaway. In this embodiment, d7 mm can be 20 mm, 50 mm, 100 mm, or 130 mm, etc.

[0108] Specifically, on the first sidewall 100 of the battery casing 10, the projected areas of the terminal assembly 400 and the first solder mark 310 are physically isolated by staggered arrangement. When abnormal internal pressure in the battery 20 causes the weak point 220 to open and release pressure, high-temperature material is ejected from the weak point 220. Since a preset distance d7mm is maintained between the projected areas of the terminal assembly 400 and the first solder mark 310, the ejection path does not directly overlap with the mounting area of ​​the terminal assembly 400, thereby preventing the high-temperature material from directly impacting the terminal assembly 400 or causing secondary cracking of the solder mark area. In addition, the range of this distance d7mm can be set based on the size of the battery 20 and the thermal runaway energy release characteristics to balance structural compactness and safety isolation requirements.

[0109] Compared to related technologies, in traditional battery designs, the projected areas of the terminal post assembly 400 and the first solder mark 310 may partially overlap or have insufficient spacing, causing high-temperature materials to simultaneously impact the terminal post and the solder area during thermal runaway, exacerbating the risk of casing damage. This solution effectively cuts off the energy transfer path during thermal runaway and reduces the probability of damage to critical components through forced staggered layout and spacing control.

[0110] Through the above technical solution, this application can prevent the high-temperature substances ejected by thermal runaway from acting simultaneously on the electrode assembly 400 and the first solder mark 310 area, reduce the possibility of chain damage to the shell structure, thereby slowing down the spread of thermal runaway and improving the overall safety performance of the battery 20.

[0111] Reference Figure 1 , Figure 6 , Figure 7 This application further proposes that the first sidewall 100 includes a first surface 110 facing the interior of the battery housing 10 and a second surface 120 facing the exterior of the battery housing 10, and a weak portion 220 is formed as a groove 230 recessed from at least one of the first surface 110 and the second surface 120 toward the other. The thickness of the weak portion 220 is d8 mm, and the depth of the groove 230 is h mm, wherein d8 mm and h mm satisfy: 0.2 ≤ d8 / (d8+h) ≤ 0.7.

[0112] Wherein, the thickness d8 mm is the remaining material thickness of the weak part 220 after the groove 230 is formed, which can be controlled by adjusting the processing parameters. This thickness, together with the depth of the groove 230, determines the compressive strength of the weak part 220. The depth h mm is the vertical distance from the bottom of the groove 230 to the surface, which can be determined by measuring tools or optical inspection equipment. The ratio between the depth and the thickness affects the structural stability of the weak part 220.

[0113] For example, in the embodiments of this application, the value of d8 / (d8+h) can be 0.2, 0.3, 0.4, 0.5, 0.6 or 0.7, etc. The embodiments of this application do not limit this value, nor are they limited to the above examples.

[0114] Specifically, the groove 230 is formed on the first surface 110 or the second surface 120. By controlling the ratio of the depth of the groove 230 to the remaining thickness of the weak portion 220, the weak portion 220 is made to rupture along a predetermined path under internal pressure. When the internal pressure of the battery 20 increases, the weak portion 220 deforms preferentially due to stress concentration at the groove 230. The ratio of the depth of the groove 230 to the remaining thickness ensures that the rupture process is controllable, preventing damage to other areas of the casing. The position and shape design of the groove 230 concentrates the rupture path on the weak portion 220, preventing the disorderly ejection of high-temperature materials.

[0115] Compared to related technologies, the explosion-proof disc 200 of those technologies typically employs a single notch 320 or an opening structure, which is prone to uneven stress distribution leading to misalignment of the rupture location or insufficient overall shell strength. This solution optimizes the stress distribution of the weak point 220 by setting a groove 230 and defining the ratio of its depth to thickness, resulting in a more precise rupture path while maintaining the overall mechanical strength of the shell structure. Related technologies do not disclose a method for controlling the rupture path through the synergistic control of the groove 230 formed by surface indentation and its thickness ratio; this solution achieves a balance between pressure relief reliability and shell integrity through structural design.

[0116] Through the above technical solution, this application can ensure that the explosion-proof sheet 200 breaks precisely along a preset path when the internal pressure of the battery 20 reaches the threshold, avoiding accidental damage to other areas of the casing due to stress concentration. At the same time, by controlling the ratio of the groove 230 to the remaining thickness, the compressive stability of the weak part 220 is improved, reducing the risk of disordered ejection of high-temperature materials during thermal runaway, thereby improving the safety performance of the battery 20.

[0117] This application further proposes that the distance between the first solder mark 310 and the etch mark 320 is d1 mm, and the distance d1 mm satisfies the relationship: 1≤d1≤5, unit mm; the thickness of the main body 210 is D mm, and the thickness D mm satisfies the relationship: 0.15≤D≤1.5, unit mm.

[0118] For example, in the embodiments of this application, the distance d1 mm between the first solder mark 310 and the notch 320 can be 1 mm, 1.5 mm, 2 mm, 2.5 mm, 3 mm, 3.5 mm, 4 mm, 4.5 mm, or 5 mm, etc. The thickness D mm of the main body 210 can be 0.15 mm, 0.3 mm, 0.45 mm, 0.6 mm, 0.75 mm, 0.9 mm, 1 mm, 1.2 mm, or 1.5 mm, etc.

[0119] The main body 210 includes a first region, a second region, and an intermediate region located between the first region and the second region. The first region is located near the weak point 220, and the second region is located near the first solder mark 310. The thickness of the first region is D1 mm, the thickness of the second region is D2 mm, and the thickness of the intermediate region is D3 mm. D3 is greater than D1 and D3 is greater than D2, and D1 is greater than D2. The units are mm.

[0120] The distance d1 mm between the first weld mark 310 and the notch 320 is the minimum spacing between the welding area and the notch 320. This can be achieved using laser ranging or optical positioning technology to balance the welding strength and the opening pressure of the explosion-proof disc 200. The thickness D mm of the main body 210 is the average thickness of the main body area of ​​the explosion-proof disc 200. This can be achieved through stamping or machining to ensure the matching of structural strength and pressure relief performance.

[0121] Specifically, by limiting the ranges of d1 mm and D mm (in this embodiment, 1.5 ≤ d1 ≤ 3 mm, 0.3 ≤ D ≤ 1 mm), sufficient distance is maintained between the welding area and the notch 320 to avoid the welding heat affecting the structure of the notch 320, while thickness control ensures that the main body 210 stably supports the weak part 220 during pressure relief. The thickness D3 mm of the middle region is greater than the thicknesses D1 mm and D2 mm of the two side regions, thereby forming a gradual stress distribution when the weak part 220 is opened, avoiding local stress concentration that could lead to accidental breakage of the main body 210.

[0122] Compared with related technologies, the existing explosion-proof sheet 200 design lacks correlation constraints on the distance between the welding area and the notch 320 and the thickness of the main body, which can easily lead to insufficient strength of the welding heat-affected notch 320 structure or the main body. However, this solution optimizes the welding stability and pressure relief reliability by limiting the range of d1 mm and Dmm and combining the thickness gradient distribution.

[0123] Through the above technical solution, this application solves the problem of premature breakage or delayed opening of the explosion-proof sheet 200 due to improper distance between the welding area and the notch 320 or uneven body thickness during thermal runaway. It ensures that the explosion-proof sheet 200 opens accurately under the preset pressure threshold, while avoiding damage to the notch 320 structure by the welding heat-affected zone, thereby improving the controllability and safety of the battery 20 pressure relief process.

[0124] This application further proposes a battery 20, including a battery casing 10. The battery casing 10 includes a first sidewall 100, on which an explosion-proof sheet 200 is provided. The explosion-proof sheet 200 is welded to the first sidewall 100 to form a first weld mark 310. The explosion-proof sheet 200 has a groove 320, which divides the explosion-proof sheet 200 into a main body portion 210 and a weak portion 220. The groove 320 surrounds the weak portion 220. The first weld mark 310 is located on the main body portion 210. The weak portion 220 is used to open when the internal pressure of the battery 20 reaches a pressure relief threshold to relieve pressure on the battery 20. The distance between the first weld mark 310 and the groove 320 is d1 mm, and the thickness of the main body portion 210 is D mm. The distance d1 mm between the first weld mark 310 and the groove 320 satisfies the following relationship: 0.5 mm ≤ d1 ≤ 3 mm, in mm. The thickness D mm of the main body 210 satisfies the following relationship: 0.8 mm ≤ D ≤ 2.5 mm.

[0125] The distance d1 mm between the first weld mark 310 and the notch 320 is the shortest distance between the welding area of ​​the explosion-proof sheet 200 and the edge of the notch 320. This distance can be measured using laser ranging or microscopic imaging technology. This parameter is used to balance the structural strength of the welding area and the stress concentration in the weak point 220. The thickness D mm of the main body 210 is the overall thickness of the area of ​​the explosion-proof sheet 200 not weakened by the notch 320. The thickness distribution can be controlled through stamping or machining. This parameter ensures that the main body 210 maintains structural integrity when the internal pressure of the battery 20 is abnormal.

[0126] Specifically, by controlling d1 mm within the range of 0.8 mm to 2.5 mm, the overlap between the weld heat-affected zone and the etched area 320 can be avoided, thus preventing weld cracking that could lead to premature failure of the explosion-proof sheet 200. Simultaneously, this ensures that the main body 210 has sufficient resistance to deformation when subjected to the internal pressure of the battery 20, while preventing the weak section 220 from failing to open as expected due to excessive thickness. When the internal pressure of the battery 20 reaches the pressure relief threshold, the weak section 220 breaks along the etched area 320, and the main body 210 remains connected to the sidewall through the first weld 310, preventing casing fragments from flying and simultaneously achieving directional pressure relief.

[0127] Compared with related technologies, the distance between the weld mark position and the notch 320 in the existing explosion-proof disc 200 design is not clearly defined, which may lead to the superposition of residual welding stress and stress in the notch 320 area, causing unexpected breakage of the explosion-proof disc 200. In addition, if the thickness of the main body 210 is not optimized, it may cause delayed pressure relief due to local thinness, or excessive pressure relief resistance due to excessive thickness. This solution resolves the contradiction between welding reliability and pressure relief response speed by limiting the optimal range of d1 mm and D mm.

[0128] Through the above technical solution, this application can accurately control the rupture location and timing of the explosion-proof sheet 200 when the battery 20 experiences thermal runaway, avoid random damage to the shell structure due to insufficient local strength, and ensure that high-temperature substances are released directionally through the weak part 220, reducing the impact on other areas of the battery 20 and adjacent batteries 20, thereby improving the overall safety of the battery 20 system.

[0129] Secondly, this application also proposes a battery device comprising at least two of the aforementioned batteries 20.

[0130] The battery device is an integrated energy storage unit composed of multiple batteries 20, which can be implemented by connecting the battery 20 modules in series or in parallel.

[0131] Specifically, the battery device achieves pressure relief through the welded structure between the explosion-proof plate 200 and the battery casing 10. When the internal pressure of the battery 20 abnormally increases, the weak point 220 ruptures preferentially due to the presence of the notch 320, and high-temperature materials are discharged directionally through the rupture, preventing damage to other areas of the casing. The thickness distribution design of the main body 210 ensures that the middle area bears the main stress, and the thickness gradient change between the first and second areas further disperses the pressure concentration. The welding position between the cover plate 620 and the casing body 610 is controlled by distance parameters to ensure that the pressure relief path is isolated from the terminal assembly 400, preventing high-temperature materials from directly impacting the electrical connection components.

[0132] Compared to related technologies, the explosion-proof structure of traditional batteries 20 typically uses a single-thickness explosion-proof sheet 200, with the welding area close to the weak point 220, making it prone to premature cracking due to welding stress. This solution, however, optimizes the thickness distribution and solder pattern layout of the explosion-proof sheet 200, ensuring welding sealing while preventing the heat-affected zone from interfering with the weak point 220. Furthermore, the double solder pattern design of the cover plate 620 and the shell body 610 further enhances the overall structural reliability and reduces the risk of secondary shell cracking during pressure relief.

[0133] Through the above technical solution, this application can effectively control the pressure relief path during thermal runaway of the battery 20, prevent the disorderly ejection of high-temperature materials, and reduce the damage to other parts of the battery device caused by heat propagation. At the same time, by precisely controlling the distance between the welding position and the weak part 220, the structural stability of the explosion-proof sheet 200 under normal operating conditions is ensured, avoiding the problem of accidental triggering.

[0134] Additionally, in this embodiment, the battery device may further include a support plate, with at least two batteries 20 disposed on the upper part of the support plate, and the weak point 220 disposed towards the support plate. This bottom-mounted explosion-proof valve prevents it from being sprayed towards the passenger compartment after opening, thereby improving the safety of the battery 20 during depressurization.

[0135] The various embodiments or implementation methods described in this specification are presented in a progressive manner. Each embodiment focuses on the differences from other embodiments, and the same or similar parts between the embodiments can be referred to each other.

[0136] It should be noted that the embodiments referred to in the specification, such as "one embodiment," "embodiment," "exemplary embodiment," and "some embodiments," may include specific features, structures, or characteristics, but not every embodiment necessarily includes that specific feature, structure, or characteristic. Furthermore, such phrases do not necessarily refer to the same embodiment. Moreover, when a specific feature, structure, or characteristic is described in connection with an embodiment, implementing such a feature, structure, or characteristic in conjunction with other embodiments, whether explicitly described or not, is within the knowledge scope of those skilled in the art.

[0137] Generally speaking, terms should be understood at least in part by their use in context. For example, at least in part by context, the term "one or more" as used in the text can be used to describe any feature, structure, or characteristic of the singular meaning, or a combination of features, structures, or characteristics of the plural meaning. Similarly, at least in part by context, terms such as "a" or "the" can also be understood to convey either singular or plural usage.

[0138] It should be readily understood that the terms “on,” “above,” and “on top of” in this disclosure should be interpreted in the broadest possible sense, such that “on” means not only “directly on something” but also “on something” with an intermediate feature or layer therebetween, and that “above” or “on top of” means not only “on top of something” but also “on top of something” without an intermediate feature or layer therebetween (i.e., directly on something).

[0139] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application.

Claims

1. A battery, characterized in that, include: Battery housing (10); the battery housing (10) includes a first sidewall (100), on which an explosion-proof sheet (200) is provided, the explosion-proof sheet (200) being welded to the first sidewall (100) to form a first weld mark (310); The explosion-proof sheet (200) is provided with a notch (320), the notch (320) divides the explosion-proof sheet (200) into a main body (210) and a weak part (220), the notch (320) surrounds the weak part (220), the first solder mark (310) is located on the main body (210), and the weak part (220) is used to open when the internal pressure of the battery (20) reaches the pressure relief threshold to relieve pressure on the battery (20); The first solder mark (310) is located on the outer periphery of the weak portion; The distance between the first solder mark (310) and the notch (320) is d1 mm, and the thickness of the main body (210) within 5 mm of the notch is D mm. d1 mm and D mm satisfy the relationship: 0.2 ≤ d1 × D ≤ 5, in mm. 2 .

2. The battery according to claim 1, characterized in that, The main body (210) includes a first region, a second region and an intermediate region located between the first region and the second region, the first region being disposed near the weak portion (220) and the second region being disposed near the first solder mark (310); The thickness of the first region is D1 mm, the thickness of the second region is D2 mm, and the thickness of the intermediate region is D3 mm. D1, D2, and D3 satisfy the following relationship: D3 is greater than D1 and D3 is greater than D2.

3. The battery according to claim 2, characterized in that, The thickness D1 mm of the first region and the thickness D2 mm of the second region satisfy the following relationship: D1 is less than D2, in mm.

4. The battery according to claim 1, characterized in that, The battery casing (10) includes a cover plate (620) and a casing body (610), wherein at least one end of the casing body (610) is provided with an opening, and the cover plate (620) covers the opening; The explosion-proof sheet (200) is disposed on the cover plate (620).

5. The battery according to claim 4, characterized in that, The explosion-proof sheet (200) is welded to the cover plate (620) to form the first weld mark (310), and the cover plate (620) is welded to the opening to form the second weld mark (330).

6. The battery according to claim 5, characterized in that, The minimum distance between the first solder mark (310) and the second solder mark (330) is d2, and d2 satisfies the relationship: 2mm≤d2≤10mm.

7. The battery according to claim 5, characterized in that, The minimum distance between the second solder mark (330) and the weak part (220) is d3 mm, and d3 mm satisfies the relationship: 3≤d3≤15, unit mm.

8. The battery according to claim 5, characterized in that, The cover plate (620) located between the first solder mark (310) and the second solder mark (330) has a thickness of D4 mm, which satisfies the relationship: D4 mm is greater than or equal to 1.5 mm.

9. The battery according to claim 4, characterized in that, The cover plate (620) is also provided with a pole post assembly (400), and the distance between the pole post assembly (400) and the first solder mark (310) is d4 mm, where d4 mm satisfies the relationship: 30≤d4≤120, unit mm.

10. The battery according to claim 9, characterized in that, Also includes: A battery cell (500) includes a tab (510) electrically connected to the terminal assembly (400); The distance between the tab (510) and the first solder mark (310) is d5 mm, and the distance between the pole post assembly (400) and the first solder mark (310) is d4 mm. The relationship between d5 mm and d4 mm is: d5 is less than d4. Furthermore, d5 mm also satisfies the relationship: 5≤d5≤30, unit mm.

11. The battery according to any one of claims 1-10, characterized in that, The battery casing (10) includes a cover plate (620) and a casing body (610). At least one end of the casing body (610) is provided with an opening, and the cover plate (620) covers the opening. The cover plate (620) is also provided with a terminal post assembly (400). The explosion-proof sheet (200) is disposed on the shell body (610).

12. The battery according to claim 11, characterized in that, The orthographic projection of the pole assembly (400) on the first sidewall (100) does not at least partially coincide with the area enclosed by the first solder mark (310) on the first sidewall (100).

13. The battery according to claim 11, characterized in that, The orthographic projection of the pole post assembly (400) on the first sidewall (100) is offset from the area enclosed by the first solder mark (310) on the first sidewall (100); Furthermore, the distance between the orthographic projection of the pole post assembly (400) on the first sidewall (100) and the area enclosed by the first solder mark (310) on the first sidewall (100) is d7 mm, and d7 mm satisfies the relationship: 20≤d7≤130, unit mm.

14. The battery according to any one of claims 1-10, characterized in that, The first sidewall (100) includes a first surface (110) facing the interior of the battery housing (10) and a second surface (120) facing the exterior of the battery housing (10). The weak portion (220) is formed as a groove (230) in which at least one of the first surface (110) and the second surface (120) is recessed toward the other. The thickness of the weak part (220) is d8 mm, and the depth of the groove (230) is h mm. The d8 mm and h mm satisfy: 0.2≤d8 / (d8+h)≤0.

7.

15. The battery according to claim 1, characterized in that, The distance d1 mm between the first solder mark (310) and the groove (320) satisfies the following relationship: 1≤d1≤5, unit mm; And / or, the thickness D mm of the main body (210) satisfies the relationship: 0.15≤D≤1.5, unit mm.

16. The battery according to claim 15, characterized in that, The distance d1 mm between the first solder mark (310) and the groove (320) satisfies the following relationship: 1.5≤d1≤3, unit mm; The thickness D mm of the main body (210) satisfies the following relationship: 0.3≤D≤1, unit mm.

17. A battery device, characterized in that, It includes at least two batteries as described in any one of claims 1-16 above.

18. The battery device according to claim 17, characterized in that, It also includes a support plate, with at least two of the batteries disposed on the upper part of the support plate, and the weak part facing the support plate.

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