Battery

Abstract

The invention provides a battery. The battery comprises a shell, a battery cell, a pole structure and a pressure relief assembly, the shell comprises a first shell wall, and a first hole and a second hole are formed in the first shell wall. The battery cell is positioned in the shell; the battery cell comprises a first pole piece, a diaphragm and a second pole piece; the second pole piece is connected with the shell; and the pole structure is arranged in the second hole in a penetrating manner and is connected with the first pole piece. The pressure relief assembly comprises a first metal piece, and the first metal piece is arranged in the first hole, covers the first hole and is connected with the shell in a sealed mode. In the molten state, the viscosity A of the first metal piece ranges from 1 mPa.s to 10 mPa.s. Therefore, when the temperature of the battery is abnormal, the first metal piece has better flowability after being heated and melted, so that gas generated in the battery can be timely and smoothly exhausted, and the safety risk caused by explosion due to thermal runaway of the battery is avoided.

Description

Technical Field

[0001] This application relates to the field of battery technology, and more specifically, to a battery. Background Technology

[0002] Batteries, such as lithium-ion batteries, have advantages such as high energy density, good cycle performance, and long storage time, and are therefore widely used in various electrical devices, such as electric vehicles and drones.

[0003] During use, when the battery generates high-temperature gas due to chemical reactions, the gas needs to be released in time to relieve the internal pressure of the battery and avoid serious accidents.

[0004] In related technologies, the timeliness of pressure relief in battery pressure relief structures needs to be improved to enhance battery safety. Summary of the Invention

[0005] In view of this, embodiments of this application provide a battery and an electrical device to solve the problem of limited safety of battery pressure relief structures in related technologies.

[0006] In a first aspect, embodiments of this application provide a battery comprising a casing, a battery cell, an electrode structure, and a pressure relief assembly. The casing includes a first casing wall with a first hole and a second hole. The battery cell is located within the casing. The battery cell includes a first electrode, a separator, and a second electrode, the second electrode being connected to the casing. The electrode structure passes through the second hole and is connected to the first electrode. The pressure relief assembly includes a first metal element, which is disposed in and covers the first hole and is sealed to the casing. In the molten state, the viscosity A of the first metal element is 1 mPa·s to 10 mPa·s.

[0007] In conjunction with the first aspect described above, in one possible implementation, the first metal component comprises a low-melting-point metal, which comprises a first-class metallic element, including bismuth (Bi) and tin (Sn). In the first metal component, the content of Bi is 3 wt% to 70 wt%, and the content of Sn is 5 wt% to 90 wt%.

[0008] In conjunction with the first aspect described above, in one possible implementation, the first metal component further includes a second type of metal element. The second type of metal element includes at least one selected from lead (Pb), cadmium (Cd), zinc (Zn), indium (In), and gallium (Ga). The content of the second type of metal element in the first metal component is 0 wt% to 80 wt%. Preferably, the content of the second type of metal element is 0.5 wt% to 60 wt%.

[0009] In conjunction with the first aspect described above, in one possible implementation, the first metal component is a bismuth-tin alloy, wherein the content of Bi in the bismuth-tin alloy is 20 wt% to 70 wt%, and the content of Sn is 30 wt% to 80 wt%; or, the first metal component is an indium-bismuth-tin-gallium alloy, wherein the content of In in the indium-bismuth-tin-gallium alloy is 40 wt% to 55 wt%, the content of Bi is 20 wt% to 40 wt%, the content of Sn is 12 wt% to 20 wt%, and the content of Ga is 0.5 wt% to 10 wt%; or, the first metal component is a tin-zinc-bismuth alloy, wherein the content of Sn in the tin-zinc-bismuth alloy is 75 wt% to 90 wt%, the content of Zn is 3 wt% to 15 wt%, and the content of Bi is 3 wt% to 18 wt%; or, the first metal component is an indium-bismuth-tin alloy, wherein the content of In in the indium-bismuth-tin alloy is 25 wt% to 60 wt%, and the content of Bi is 20 wt% to 45 wt%. The Sn content is 5 wt% to 30 wt%.

[0010] In conjunction with the first aspect above, in one possible implementation, the first metal member is provided with a protective layer at least on the side facing the housing; the protective layer includes at least one of chromium, nickel, molybdenum, and titanium, and / or the thickness h1 of the protective layer satisfies: 3 μm ≤ h1 ≤ 15 μm.

[0011] In conjunction with the first aspect above, in one possible implementation, the pressure relief assembly further includes a first adhesive element disposed between the first metal part and the housing. The melting point T1 of the first metal part and the melting point T2 of the first adhesive element satisfy: T2 > T1, preferably, T2 ≥ T1 + 20°C, wherein the melting point T1 of the first metal part is 80°C to 150°C, preferably, T1 is 85°C to 140°C; and / or, the thickness h2 of the first metal part satisfies: 0.06 mm ≤ h2 ≤ 2 mm, preferably, 0.08 mm ≤ h2 ≤ 1 mm.

[0012] In conjunction with the first aspect described above, in one possible implementation, the pressure relief assembly further includes a first adhesive member having an opening that at least partially overlaps with the orthographic projection of the first hole along a first direction. The first adhesive member is disposed between the first metal member and the housing. Preferably, the thickness h3 of the first adhesive member is 0.01 mm to 1 mm, and / or the area of ​​the opening is B, where B is in mm. 2 The viscosity A of B and the viscosity of the first metal part satisfy: B ≥ 0.001A² + 0.1A. Here, the first direction is the thickness direction of the first metal part.

[0013] In conjunction with the first aspect described above, in one possible implementation, along the first direction, the orthographic projection of the first adhesive member is at least partially located within the orthographic projection of the first metal member; and / or, the portion of the first metal member extending beyond the first adhesive member contacts the housing.

[0014] In conjunction with the first aspect above, in one possible implementation, along the first direction, the edge of the orthographic projection of the first adhesive member extends beyond or coincides with the edge of the orthographic projection of the first metal member; and / or, the first metal member is recessed toward the housing and contacts the housing.

[0015] In conjunction with the first aspect above, in one possible implementation, the pressure relief assembly further includes a second metal member, which is fixed between the first adhesive member and the housing and is disposed around the first hole; and / or, the pressure relief assembly further includes a second adhesive member, which is bonded to and covers at least a portion of the edge of the first metal member and at least a portion of the housing, wherein the second adhesive member is an insulating adhesive.

[0016] Secondly, embodiments of this application provide an electrical device that includes the battery in any of the above embodiments.

[0017] In related technologies, pressure relief structures are typically used to release pressure in batteries to ensure safety. However, in cases where abnormal heating occurs due to furnace temperature testing or internal short circuits causing cell temperature rise, the metal layer in the pressure relief structure is difficult to melt in time. Furthermore, the melted metal layer in the pressure relief structure has high viscosity and cannot flow to other areas in time to expose the first pore. Therefore, when the internal temperature of the battery is abnormal, the gas generated inside the battery cannot be discharged in time, reducing the battery's thermal safety performance.

[0018] To address the aforementioned problems, embodiments of this application provide a battery and an electrical device. According to the battery of this application, a pressure relief assembly is provided at a first hole in the battery casing. The pressure relief assembly includes a first metal component, which is disposed at and covers the first hole. This prevents electrolyte leakage and the intrusion of external impurity gases into the battery during normal use, thus preventing a reduction in the battery's electrical performance. Furthermore, in its molten state (i.e., liquid state), the viscosity A of the first metal component is 1 mPa·s to 10 mPa·s. This ensures that even when the battery is under abnormal temperature conditions, the first metal component maintains good fluidity after melting, allowing for the timely and efficient release of gases generated inside the battery, preventing thermal runaway and explosion, and avoiding safety risks. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the structure of a battery according to an embodiment of this application.

[0020] Figure 2This is a schematic diagram of a partial explosion structure of a battery according to an embodiment of this application.

[0021] Figure 3 This is a cross-sectional view showing the location of a pressure relief assembly for a battery according to an embodiment of this application.

[0022] Figure 4 for Figure 3 A magnified view of a portion of point A in the middle.

[0023] Figure 5 This is a schematic diagram of another partial exploded structure of a battery provided according to an embodiment of this application.

[0024] Figure 6 for Figure 5 Cross-sectional view of the location of the pressure relief component.

[0025] Figure 7 for Figure 6 A magnified view of a portion of point B in the middle.

[0026] Figure 8 This is a schematic diagram of a partial explosion structure of a battery provided according to an embodiment of this application.

[0027] Figure 9 for Figure 8 Cross-sectional view of the location of the pressure relief component.

[0028] Figure 10 for Figure 9 A magnified view of a portion of point C.

[0029] Figure 11 A partially enlarged schematic diagram of the location of a battery pressure relief assembly according to an embodiment of this application.

[0030] Figure label: 100. Battery; 10. Housing; 11. First housing wall; 111. First hole; 112. Second hole; 12. Terminal structure; 20. Pressure relief assembly; 21. First metal part; 22. First adhesive part; 221. Opening; 23. Second adhesive part; 24. Second metal part. Detailed Implementation

[0031] Batteries, such as lithium-ion batteries, typically consist of cells and a casing. The cells are housed within the casing, which is filled with electrolyte. Batteries can overheat and generate gas under conditions such as overload, short circuit, or furnace temperature testing. To prevent thermal runaway, a pressure relief structure is usually installed in the well-sealed casing to release hot gases promptly, thereby improving battery safety.

[0032] As battery energy density continues to increase and the internal space utilization of the casing becomes more efficient, battery safety requirements are also rising. Common pressure relief structures in related technologies include metal layers.

[0033] The inventors discovered that the metal layer in the aforementioned pressure relief structure cannot melt in time or be blown open by the gas inside the battery cell when the battery is in an abnormal condition and needs to be depressurized, thus preventing the holes on the casing from being exposed and hindering gas discharge.

[0034] To address the aforementioned issues, embodiments of this application provide a battery and an electrical device that employ a pressure relief structure made of metal to improve battery safety performance.

[0035] The battery and electrical device according to embodiments of this application will now be described with reference to the accompanying drawings.

[0036] Exemplary battery refer to Figures 1 to 11 As shown in the figure, this application embodiment provides a battery 100, which includes a casing 10, a battery cell (not shown), an electrode structure 12, and a pressure relief assembly 20. The casing 10 includes a first casing wall 11, on which a first hole 111 (e.g., a first aperture) and a second hole 112 are provided. The battery cell includes a first electrode, a separator, and a second electrode, which is connected to the casing. The electrode structure 12 passes through the second hole 112 and is connected to the first electrode. The pressure relief assembly 20 includes a first metal member 21, which is disposed in and covers the first hole 111 and is sealed to the casing 10. In the molten state, the viscosity A of the first metal member 21 is 1 mPa·s to 10 mPa·s.

[0037] For example, in the molten state, the viscosity A of the first metal part 21 is 2 mPa·s, 3 mPa·s, 4 mPa·s, 5 mPa·s, 6 mPa·s, 7 mPa·s, 8 mPa·s, or 9 mPa·s, etc.

[0038] According to the battery 100 provided in the embodiments of this application, a pressure relief assembly 20 is provided at the first hole 111 of the casing 10 of the battery 100. The pressure relief assembly 20 includes a first metal part 21, which covers the first hole 111 and is sealed to the casing 10 to prevent electrolyte leakage and external impurity gases from entering the battery 100 during normal use. In addition, the viscosity A of the first metal part 21 is 1 mPa·s to 10 mPa·s, which ensures that it has good fluidity after melting when high-temperature gases need to be discharged, thereby exposing the first hole 111 and timely and smoothly discharging the high-temperature gases inside the battery to prevent thermal runaway and explosion of the battery 100.

[0039] For example, the casing 10 can be square. That is, the battery 100, for example, a lithium-ion secondary battery 100, can be a square lithium-ion secondary battery 100. Alternatively, the casing 10 can also be circular. The material of the casing 10 can be the same as conventionally used materials and is not particularly limited. For example, the casing 10 can be made of metal, specifically aluminum (alloy) or iron (alloy), etc.

[0040] Exemplarily, the housing 10 includes a main body portion for accommodating the battery cell, and the aforementioned first housing wall 11 is one of the side walls of the main body portion. The pressure relief assembly 20 and the first hole 111 are disposed on the first housing wall 11 located on the side wall of the housing, facilitating the production and processing of the housing 10. In other embodiments, the housing 10 includes the main body portion and the aforementioned first housing wall 11, i.e., a cover. Exemplarily, the pressure relief assembly 20 and the first hole 111 are disposed on the cover, facilitating pressure relief and installation. It is understood that those skilled in the art can, according to the needs of specific application scenarios, place the first hole 111 and the pressure relief assembly 20 in other suitable locations on the housing 10.

[0041] For example, the battery 100 may include a wound electrode body or a stacked electrode body, which is housed within the housing 10. Taking a wound electrode body as an example, the battery 100 can be manufactured into a wound electrode body by fabricating the positive electrode sheet, negative electrode sheet, and separator according to a conventional winding structure, and then manufactured into the battery 100 through steps such as encapsulation, liquid injection, formation, secondary sealing, and capacity testing.

[0042] The electrolyte can be injected into the casing 10 through the first hole 111. The electrolyte is a commercially available conventional electrolyte, and this application does not make any special requirements for it.

[0043] For example, the first hole 111 can be circular to avoid stress concentration caused by sharp corners. In some embodiments, the first hole 111 can also be other shapes, such as elliptical or square, etc., which are not limited in this application.

[0044] For example, the first metal part 21 is circular to fit the first hole 111. In some embodiments, the first metal part 21 may also be other shapes, such as elliptical or square, etc. This application does not limit this, as long as it can cover the first hole 111.

[0045] In some embodiments, the first metal component 21 comprises a low-melting-point metal, which includes a first class of metallic elements, including bismuth (Bi) and tin (Sn). In the first metal component 21, the content of Bi is 3 wt% to 70 wt%, and the content of Sn is 5 wt% to 90 wt%.

[0046] For example, in the first metal component 21, the Bi content is 5 wt%, 10 wt%, 20 wt%, 30 wt%, 40 wt%, 50 wt%, 60 wt%, or 65 wt%. For example, in the first metal component 21, the Sn content is 5 wt%, 10 wt%, 20 wt%, 30 wt%, 40 wt%, 50 wt%, 60 wt%, 70 wt%, 80 wt%, or 85 wt%.

[0047] In some embodiments, the first metal element 21 further includes a second type of metallic element. The second type of metallic element includes at least one selected from lead (Pb), cadmium (Cd), zinc (Zn), indium (In), and gallium (Ga). The content of the second type of metallic element in the first metal element 21 is 0 wt% to 80 wt%, for example, 1 wt%, 5 wt%, 10 wt%, 15 wt%, 20 wt%, 30 wt%, 40 wt%, 50 wt%, 60 wt%, or 70 wt%. Preferably, the content of the second type of metallic element is 0.5 wt% to 60 wt%, for example, 0.6 wt%, 1.5 wt%, 4 wt%, 8 wt%, 12 wt%, 16 wt%, 21 wt%, 28 wt%, 35 wt%, 45 wt%, or 55 wt%.

[0048] In some embodiments, the first metal component 21 is a bismuth-tin alloy, wherein the content of Bi in the bismuth-tin alloy is 20 wt% to 70 wt%, for example, the content of Sn is 25 wt%, 30 wt%, 35 wt%, 40 wt%, 45 wt%, 50 wt%, 55 wt%, 60 wt% or 65 wt%, etc.; and the content of Sn is 30 wt% to 80 wt%, for example, 35 wt%, 40 wt%, 45 wt%, 50 wt%, 55 wt%, 60 wt%, 65 wt%, 70 wt% or 75 wt%, etc.

[0049] In some alternative embodiments, the first metal component 21 is an indium bismuth tin gallium alloy, wherein the In content is 40 wt% to 55 wt%, for example, 42 wt%, 44 wt%, 46 wt%, 48 wt%, 50 wt%, or 53 wt%; the Bi content is 20 wt% to 40 wt%, for example, 23 wt%, 26 wt%, 31 wt%, 33 wt%, 35 wt%, 37 wt%, or 39 wt%; the Sn content is 12 wt% to 20 wt%, for example, 13 wt%, 14 wt%, 15 wt%, 16 wt%, 17 wt%, 18 wt%, or 19 wt%; and the Ga content is 0.5 wt% to 10 wt%. For example, the Ga content is 1 wt%, 1.5 wt%, 2 wt%, 3 wt%, 4 wt%, 5 wt%, 6 wt%, 7 wt%, 8 wt%, or 9 wt%, etc.

[0050] In some alternative embodiments, the first metal component 21 is a tin-zinc-bismuth alloy, in which the Sn content is 75 wt% to 90 wt%, for example, 78 wt%, 80 wt%, 83 wt%, 85 wt%, 88 wt% or 89 wt%; the Zn content is 3 wt% to 15 wt%, for example, 4 wt%, 6 wt%, 7 wt%, 8 wt%, 10 wt%, 12 wt% or 14 wt%; and the Bi content is 3 wt% to 18 wt%, for example, 4 wt%, 5 wt%, 6 wt%, 7 wt%, 8 wt%, 10 wt%, 12 wt%, 14 wt%, 16 wt% or 17 wt%, etc.

[0051] In some alternative embodiments, the first metal component 21 is an indium bismuth tin alloy, wherein the In content is 25 wt% to 60 wt%, for example, 30 wt%, 35 wt%, 40 wt%, 45 wt%, 50 wt% or 55 wt%; the Bi content is 20 wt% to 45 wt%, for example, 22 wt%, 25 wt%, 28 wt%, 30 wt%, 35 wt%, 38 wt%, 40 wt% or 43 wt%; and the Sn content is 5 wt% to 30 wt%, for example, 6 wt%, 8 wt%, 10 wt%, 15 wt%, 18 wt%, 20 wt%, 25 wt% or 28 wt%.

[0052] In this way, different alloy systems can be selected according to the specific application scenario to adapt to specific pressure relief and normal use requirements. Furthermore, by adjusting the content of different components within the same alloy system, further fine-tuning can be achieved, thus more precisely matching pressure relief and normal use requirements.

[0053] It is understood that, unless otherwise specified, the contents of the above-mentioned metal elements include endpoint values.

[0054] In some embodiments, the first metal component 21 is provided with a protective layer on at least one side facing the housing 10 to prevent the electrolyte from corroding the first metal component 21.

[0055] When the electrolyte comes into direct contact with the first metal component 21, especially when trace amounts of moisture or HF (generated from the decomposition of LiPF6) are present in the electrolyte, corrosion of both the first metal component 21 and the casing 10 can easily occur, affecting the safety of the battery 100. Specifically, corrosion weakens the strength of the first metal component 21 and alters its melting point, causing premature failure of the pressure relief assembly 20 and affecting the battery's sealing safety. Simultaneously, corrosion produces corrosion products. The metal ions (Sn²⁺, Sn²⁺) generated by corrosion... 4 The dissolution of other metal ions (such as ⁺, Bi³⁺, etc.) into the electrolyte may disrupt the stability of the SEI and CEI films formed by the reaction of the electrolyte with the positive and / or negative electrodes, catalyze side reactions, consume active lithium, accelerate capacity decay, and affect the lifespan of the battery 100. Furthermore, when the first metal component 21, for example a tin-bismuth alloy component, is in direct contact with the casing 10 (e.g., a steel casing, typically nickel-plated steel) and an electrolyte passage exists, galvanic corrosion may occur due to the potential difference between the two components, accelerating localized corrosion of the first metal component 21 or the casing 10 and affecting the safety of the battery 100.

[0056] By providing a plating layer on the side of the first metal part 21 facing the housing 10, the electrolyte can be prevented from corroding the first metal part 21 or the housing 10, thereby further improving the safety of the battery 100 and ensuring the performance of the battery 100.

[0057] For example, the protective layer includes at least one of chromium, nickel, molybdenum, and titanium. The thickness h1 of the protective layer satisfies: 3μm ≤ h1 ≤ 15 μm, for example, h1 is 4 μm, 5 μm, 6 μm, 7 μm, 9 μm, 11 μm, 12 μm, 13 μm, or 14 μm, etc. By controlling the thickness of the protective layer, it is possible to avoid the protective layer being too thin and unable to effectively provide protection, or the protective layer being too thick, resulting in high strength of the first metal part 21, which is not conducive to breaking through during venting, or the first metal part 21 not being able to melt in time at high temperature and have a suitable viscosity under test conditions such as furnace temperature of the battery 100, thereby preventing the timely exposure of the pressure relief hole (first hole 111) on the casing 10, so that the gas generated inside the battery 100 cannot be discharged in time, affecting the safety of the battery 10.

[0058] For example, the protective layer can be prepared by methods such as electroplating, magnetron sputtering or spraying. The specific preparation process is based on conventional techniques and will not be described in detail here.

[0059] In some examples, protective layers are provided on both sides of the first metal part 21.

[0060] In some embodiments, the pressure relief assembly 20 further includes a first adhesive member 22, which is disposed between the first metal member 21 and the housing 10. The melting point T1 of the first metal member 21 and the melting point T2 of the first adhesive member 22 satisfy the condition that T2 > T1, to ensure the normal and safe use of the battery 100 and to prevent the melting point of the first adhesive member 22 from being too low, which would affect the bonding strength and sealing effect. Preferably, T2 ≥ T1 + 20°C.

[0061] In some examples, the melting point T1 of the first metal part 21 is 80 ℃~150 ℃, such as 90 ℃, 100 ℃, 110 ℃, 130 ℃ or 130 ℃, to meet the safety requirements and normal use requirements of different battery 100 systems, and to avoid the melting point being too low, the strength being too low, making it easy to crack or melt at a low temperature and thus failing to meet the normal use of the battery 100, or the melting point being too high, the strength being too high, and thus failing to melt in time and affecting the timeliness of pressure relief.

[0062] Preferably, T1 is 85 ℃~140 ℃, for example, 95 ℃, 105 ℃, 115 ℃, 120 ℃, 125 ℃, or 135 ℃, to better ensure the safety and normal use of battery 100.

[0063] In some embodiments, the thickness h2 of the first metal part 21 satisfies: 0.06 mm ≤ h2 ≤ 2 mm, for example, 0.1 mm, 0.2 mm, 0.3 mm, 0.4 mm, 0.6 mm, 0.8 mm, 0.9 mm, 1 mm, 1.2 mm, 1.4 mm, 1.6 mm or 1.8 mm, to adapt to the safety requirements and normal use requirements of different battery 100 systems, and to avoid excessive thickness and strength, which may prevent rapid melting or accumulation after melting when pressure relief is required, thus affecting the pressure relief process, or excessive thickness and low strength, which may affect the normal use of battery 100. For example, if the thickness is too large, the melting speed of the first metal part 21 will be slow during the hot box test and it will not be able to flow to expose the hole on the shell, thus failing to release pressure in time, resulting in the battery 100 exploding and burning. If the thickness is too small, the strength of the first metal part 21 will be low. When the battery 100 is dropped, the first metal part 21 is easily blown open or torn, causing moisture to enter the battery 100, resulting in the battery 100 swelling and failing, affecting the normal use of the battery 100.

[0064] Alternatively, 0.08 mm ≤ h2 ≤ 1 mm, for example, 0.15 mm, 0.25 mm, 0.35 mm, 0.45 mm, 0.55 mm, 0.65 mm, 0.75 mm, 0.85 mm or 0.95 mm.

[0065] refer to Figures 2 to 10 In some embodiments, the pressure relief assembly 20 further includes a first adhesive member 22. The first adhesive member 22 has an opening 221, which at least partially overlaps with the orthographic projection of the first hole 111 along a first direction. The first adhesive member 22 is disposed between the first metal member 21 and the housing 10 to achieve connection and sealing between the first metal member 21 and the housing 10. Furthermore, the first adhesive member 22 facilitates the removal of the first metal member 21 for electrolyte filling of the battery 100. It should be noted that the first adhesive member 22 has an opening 221, meaning its central portion is hollow, exposing the first metal member 21 and ensuring that the first metal member 21 directly contacts the gas for timely pressure relief, further improving safety. Here, the central portion does not refer to the absolute center; it simply needs to be located in the middle of the first adhesive member 22.

[0066] In some alternative examples, the first metal part 21 may also be sealed to the housing 10 in other ways, such as by welding it to the housing 10.

[0067] For example, the first adhesive member 22 is provided with a circular opening. It is understood that in some examples, the opening 221 on the first adhesive member 22 may also be other shapes, such as elliptical, square, etc., and this application does not limit it.

[0068] In some embodiments, the first adhesive 22 is at least one of pressure-sensitive adhesive or low-melting-point adhesive. Preferably, the pressure-sensitive adhesive includes rubber-type pressure-sensitive adhesive, acrylic-type pressure-sensitive adhesive, thermoplastic elastomer-type pressure-sensitive adhesive, and silicone-type pressure-sensitive adhesive; the low-melting-point adhesive mainly includes polypropylene (PP) structural adhesive, unsaturated carboxylic acid, unsaturated carboxylic anhydride or unsaturated epoxy modified polypropylene, or polypropylene random copolymer, polyethylene structural adhesive, copolymer acrylic structural adhesive, polyurethane hot melt adhesive, and EVA (ethylene-vinyl acetate copolymer) type hot melt adhesive, etc.

[0069] In some examples, the thickness h3 of the first adhesive 22 is 0.01 mm to 1 mm, such as 0.02 mm, 0.03 mm, 0.04 mm, 0.05 mm, 0.07 mm, 0.09 mm, 0.1 mm, 0.15 mm, 0.2 mm, 0.25 mm, 0.3 mm, 0.32 mm, 0.45 mm, 0.5 mm, 0.6 mm, 0.7 mm, 0.8 mm or 0.9 mm, etc., to ensure the bonding strength while avoiding excessive thickness that increases the ineffective thickness of the battery 100 and reduces the energy density.

[0070] In some embodiments, the area of ​​the opening 221 in the hollow portion of the first adhesive member 22 is B, where B is in mm. 2 The viscosity A of B and the viscosity of the first metal component 21 satisfy the following value: B ≥ 0.001A² + 0.1A. This ensures that the area of ​​the opening 221 in the hollow portion is matched with the viscosity A of the first metal component 21, and that the viscosity A of the first metal component 21 is matched with the heat-receiving area of ​​the first metal component 21, so as to timely discharge the gas inside the battery 100 and improve the safety of the battery 100.

[0071] refer to Figures 5 to 7 As shown, in some embodiments, along the first direction, the orthographic projection of the first adhesive member 22 is at least partially located within the orthographic projection of the first metal member 21, and the portion of the first metal member 21 extending beyond the first adhesive member 22 contacts the housing 10. In this application, the first direction is the thickness direction of the first metal member. That is, at least a portion of the outer edge of the first adhesive member 22 is located inside the outer edge of the first metal member 21, so that the outer edge of the first metal member 21 directly contacts the housing 10 to form a thermal contact area. This facilitates the rapid melting of the first metal member 21 in cases where the battery 100 is in an abnormally high temperature condition, thereby timely venting of high-temperature gases and improving the safety of the battery 100.

[0072] In some embodiments, along the first direction, the orthographic projection of the first adhesive 22 is entirely within the orthographic projection of the first metal part 21, so as to have a larger thermal contact area, which is more conducive to the rapid melting of the first metal part 21, thereby timely exhausting the high-temperature gas and improving the safety of the battery 100.

[0073] refer to Figures 8 to 10 In some alternative embodiments, along the first direction, the edge of the orthographic projection of the first adhesive member 22 extends beyond the edge of the orthographic projection of the first metal member 21 (i.e., the outer edge of the first adhesive member 22 is outside the outer edge of the first metal member 21) or coincides with the edge of the first metal member 21. The first metal member 21 is recessed toward and in contact with the housing 10, for example... Figure 10 As shown, the edge of the first hole 111 on the first shell wall 11 of the first metal part 21 is in contact with the shell 10 to form a thermal contact area. This facilitates the rapid melting of the first metal part 21 in the event of an abnormally high temperature in the battery 100, thereby timely venting of high-temperature gases and improving the safety of the battery 100. The first direction is described above and will not be repeated here.

[0074] refer to Figure 11 In some embodiments, the pressure relief assembly 20 further includes a second metal part 24, which is fixed between the first adhesive part 22 and the housing 10 and surrounds the first hole 111. For example, the second metal part 24 is welded to the housing 10 around the first hole 111. During liquid injection, residual electrolyte remains near the first hole 111, which reduces the bonding strength between the first adhesive part 22 and the housing 10, affecting the connection stability and sealing effect of the first metal part 21. By placing the second metal part 24 between the first adhesive part 22 and the housing 10, and then bonding the first adhesive part 22 to the second metal part 24, a more stable connection of the first metal part 21 to the housing 10 can be ensured, allowing the pressure relief assembly 20 to function better.

[0075] For example, the second metal part 24 can be stainless steel, such as 304 stainless steel or 316 stainless steel.

[0076] refer to Figures 2 to 10 In some embodiments, the pressure relief assembly 20 further includes a second adhesive 23, which adheres to and covers at least a portion of the edge of the first metal component 21 and the housing 10. The second adhesive 23 is an insulating adhesive to prevent the first metal component 21 from contacting other conductive structures and causing a short circuit, while further sealing and fixing the first metal component 21 to prevent premature damage to the first metal component 21 due to accidents such as battery drops or collisions.

[0077] In some embodiments, the insulating adhesive includes ultraviolet-curing adhesive (UV adhesive). Preferably, the UV-curing adhesive includes at least one of acrylate-based UV adhesive, modified acrylate-based UV adhesive, epoxy resin-based UV adhesive, polyurethane-based UV adhesive, and vinyl ether-based UV adhesive.

[0078] It should be noted that the structure of other aspects of the battery 100 can be the same as that of the conventional battery 100. For the sake of simplicity, the embodiments of this application will not be described in detail.

[0079] It should be noted that in this application, "battery 100" refers to an energy storage device capable of repeated charging and discharging, which can be interpreted as the concept of "secondary battery 100". In the embodiments of this application, the concept of "secondary battery 100" may include lithium-ion secondary batteries 100, etc.

[0080] It should be noted that, for clarity, the entire structure of the battery 100 described above is not depicted. To achieve its necessary functions, those skilled in the art can configure other structures according to specific application scenarios, and the embodiments of this application do not impose such limitations. Similarly, for clarity, the entire preparation process and technology of the battery 100 described above is not depicted. To realize the preparation of the battery 100, those skilled in the art can select preparation engineering and processes according to specific application scenarios, and the embodiments of this application do not impose such limitations.

[0081] Exemplary electrical equipment Secondly, this application provides an electrical device that includes the aforementioned battery 100. Exemplarily, this electrical device can be a charging device or a power-consuming device. For example, the electrical device can be a pure electric vehicle, a hybrid electric vehicle, a range-extended electric vehicle, or a drone, etc.

[0082] The battery 100 provided according to the embodiments of this application has the corresponding effects of the battery 100 described above, as detailed above, and will not be repeated here.

[0083] The present application is described in detail below with reference to specific embodiments, which are used to understand rather than limit the present application.

[0084] Unless otherwise specified, all materials and reagents used in the following examples are commercially available. Unless otherwise specified, the processing procedures and techniques involved are conventional technical methods.

[0085] Example 1 Negative electrode preparation: The negative electrode active material (i.e., the negative electrode active material: silicon-carbon composite material and graphite), sodium carboxymethyl cellulose, styrene-butadiene rubber, and conductive carbon black are dispersed in deionized water (or water) at a mass percentage of 93:2.5:1.5:3 and mixed evenly to obtain a slurry. The prepared negative electrode slurry is uniformly coated on copper foil, dried at 100℃, and then rolled and slit to obtain the negative electrode sheet. The negative electrode active material is a graphite and silicon-carbon composite material. In the negative electrode active material, the silicon content x is 19%, and in the silicon-carbon composite material, the silicon content y is 45%. The silicon content is controlled by controlling the content of the silicon-carbon composite material in the negative electrode active material.

[0086] Positive electrode preparation: The positive electrode active material lithium nickel cobalt manganese oxide (NCM), the binder polyvinylidene fluoride, and the conductive agent carbon black are mixed in a mass percentage ratio of 97.2:1.8:1. An appropriate amount of N-methylpyrrolidone is added as a solvent, and the mixture is stirred evenly to form a uniformly dispersed electrode slurry with a solid content of 65 wt%. The prepared positive electrode slurry is uniformly coated on aluminum foil, and then rolled and slit to form a positive electrode sheet.

[0087] Then, following a conventional winding structure, the positive electrode, negative electrode, and separator are made into a wound electrode body.

[0088] Then, the wound electrode body is housed in the casing 10, and the battery 100 is formed through steps such as encapsulation, electrolyte injection, formation, secondary sealing, and capacity testing. Here, the electrolyte is a commercially available electrolyte.

[0089] A pressure relief assembly 20 is provided on the top of the housing 10. The pressure relief assembly 20 includes a first metal part 21, a first adhesive part 22, and a second metal part 24. The outer edge of the first metal part 21 extends beyond the outer edge of the first adhesive part 22. The first metal part 21 is a bismuth-tin alloy with a bismuth content of 58 wt% and a tin content of 42 wt%. It is in a molten state and has a viscosity of 2 mPa·s. The thickness h2 of the first metal part 21 is 0.5 mm, and its melting point T1 is 114 ℃ and T2 is 180 ℃. The melting point T2 of the first adhesive component 22 is 66°C higher than the melting point T1 of the first metal component 21. The area B of the opening 221 of the hollow part of the first adhesive component 22 and the viscosity of the first metal component 21 satisfy the numerical relationship that B ≥ 0.001A² + 0.1A, where B is 7.068. The thickness h1 of the nickel plating layer on the side of the first metal component 21 facing the housing 10 is 9 μm, and the thickness h3 of the first adhesive component 22 is 0.03 mm.

[0090] Example 2 This embodiment is based on Embodiment 1, except that the bismuth content is 40 wt%, the tin content is 60 wt%, the viscosity of the bismuth-tin alloy is 4.3 mPa·s, T1 is 120℃, and T2 is 60℃ higher than T1.

[0091] Example 3 This embodiment is based on Embodiment 1, except that the bismuth content is 20.1 wt%, the tin content is 71.9 wt%, the viscosity of the bismuth-tin alloy is 6.2 mPa·s, and the melting point T2 of the first adhesive component 22 is 62°C higher than the melting point T1 of the first metal component 21, with T1 being 118°C.

[0092] Example 4 This embodiment is based on Embodiment 1, except that the bismuth content is 70 wt%, the tin content is 30 wt%, the viscosity of the bismuth-tin alloy is 1.5 mPa·s, and the melting point T2 of the first adhesive 22 is 52°C higher than the melting point T1 of the first metal part 21, where T1 is 128°C.

[0093] Example 5 This embodiment is based on embodiment 4, except that h1 is 3 μm, h2 is 0.08 mm, h3 is 0.8 mm, T1 is 126℃, and T2 is 54℃ higher than T1.

[0094] Example 6 This embodiment is based on Embodiment 1, except that the bismuth content is 19 wt%, the tin content is 81 wt%, the viscosity of the bismuth-tin alloy is 10.6 mPa·s, T1 is 235 ℃, and T2 is 55 ℃ lower than T1.

[0095] Example 7 This embodiment is based on Embodiment 1, except that the bismuth content is 71 wt%, the tin content is 29 wt%, the viscosity of the bismuth-tin alloy is 0.9 mPa·s, T1 is 185 ℃, and T2 is 5 ℃ lower than T1.

[0096] Example 8 This embodiment is based on Embodiment 1, except that the first metal part 21 is an indium bismuth tin gallium alloy with an In content of 50 wt%, a Bi content of 20 wt%, a Sn content of 20 wt%, a Ga content of 10 wt%, h1 of 15 μm, h2 of 1 mm, and T1 of 106 °C. The melting point T2 of the first adhesive part 22 is 67 °C higher than the melting point T1 of the first metal part 21. The viscosity of the first metal part 21 is 3.1 mPa·s, h1 of 15 μm, h2 of 1 mm, and h3 of 0.5 mm.

[0097] Example 9 This embodiment is based on Embodiment 8, except that the content of In is 40 wt%, the content of Bi is 40 wt%, the content of Sn is 12 wt%, the content of Ga is 8 wt%, T1 is 127°C, T2 is 53°C higher than T1, and the viscosity of the first metal part 21 is 1.7 mPa·s.

[0098] Example 10 This embodiment is based on Embodiment 8, except that the content of In is 47.1 wt%, the content of Bi is 29.9 wt%, the content of Sn is 13.6 wt%, the content of Ga is 9.4 wt%, T1 is 118°C, T2 is 62°C higher than T1, and the viscosity of the first metal part 21 is 2.2 mPa·s.

[0099] Example 11 This embodiment is based on Embodiment 8, except that the In content is 50 wt%, the Bi content is 30 wt%, the Sn content is 15 wt%, the Ga content is 5 wt%, T1 is 112°C, T2 is 68°C higher than T1, and the viscosity of the first metal part 21 is 1.9 mPa·s.

[0100] Example 12 This embodiment is based on Embodiment 8, except that the In content is 55 wt%, the Bi content is 15 wt%, the Sn content is 202 wt%, the Ga content is 10 wt%, T1 is 135°C, T2 is 45°C higher than T1, and the viscosity of the first metal part 21 is 8 mPa·s.

[0101] Example 13 This embodiment is based on Embodiment 8, except that the content of In is 55 wt%, the content of Bi is 25 wt%, the content of Sn is 10 wt%, the content of Ga is 10 wt%, T1 is 67°C, T2 is 113°C higher than T1, and the viscosity of the first metal part 21 is 0.3 mPa·s.

[0102] Example 14 This embodiment is based on Embodiment 8, except that the In content is 58 wt%, the Bi content is 15 wt%, the Sn content is 20 wt%, the Ga content is 7 wt%, T1 is 225°C, T2 is 45°C lower than T1, and the viscosity of the first metal part 21 is 10 mPa·s.

[0103] Example 15 This embodiment is based on Embodiment 8, except that the In content is 53 wt%, the Bi content is 15 wt%, the Sn content is 20 wt%, the Ga content is 12 wt%, T1 is 134°C, T2 is 46°C higher than T1, and the viscosity of the first metal part 21 is 10.3 mPa·s.

[0104] Example 16 This embodiment is based on Embodiment 8, except that the content of In is 56 wt%, the content of Bi is 20 wt%, the content of Sn is 12 wt%, the content of Ga is 12 wt%, T1 is 156°C, T2 is 24°C higher than T1, and the viscosity of the first metal part 21 is 3 mPa·s.

[0105] Example 17 This embodiment is based on Embodiment 8, except that the content of In is 35.7 wt%, the content of Bi is 40.5 wt%, the content of Sn is 23.5 wt%, the content of Ga is 0.3 wt%, T1 is 205°C, T2 is 25°C lower than T1, and the viscosity of the first metal part 21 is 28 mPa·s.

[0106] Example 18 This embodiment is based on Embodiment 1, except that the first metal part 21 is a tin-zinc-bismuth alloy with a Sn content of 90 wt%, a Zn content of 7 wt%, a Bi content of 3 wt%, a T1 temperature of 123°C, a T2 temperature 57°C higher than T1, and a viscosity of 8 mPa·s.

[0107] Example 19 This embodiment is based on embodiment 18, except that the Sn content is 79 wt%, the Zn content is 3 wt%, the Bi content is 18 wt%, T1 is 112°C, T2 is 68°C higher than T1, and the viscosity of the first metal part 21 is 6 mPa·s.

[0108] Example 20 This embodiment is based on Embodiment 18, except that the Sn content is 75 wt%, the Zn content is 15 wt%, the Bi content is 10 wt%, T1 is 127°C, T2 is 53°C higher than T1, and the viscosity of the first metal part 21 is 5.5 mPa·s.

[0109] Example 21 This embodiment is based on Embodiment 18, except that the Sn content is 85 wt%, the Zn content is 5 wt%, the Bi content is 10 wt%, T1 is 116°C, T2 is 64°C higher than T1, and the viscosity of the first metal part 21 is 7.4 mPa·s.

[0110] Example 22 This embodiment is based on Embodiment 18, except that the Sn content is 75 wt%, the Zn content is 5 wt%, the Bi content is 20 wt%, T1 is 144°C, T2 is 36°C higher than T1, and the viscosity of the first metal part 21 is 0.5 mPa·s.

[0111] Example 23 This embodiment is based on Embodiment 18, except that the Sn content is 72 wt%, the Zn content is 10 wt%, the Bi content is 18 wt%, T1 is 134°C, T2 is 46°C higher than T1, and the viscosity of the first metal part 21 is 0.7 mPa·s.

[0112] Example 24 This embodiment is based on Embodiment 18, except that the Sn content is 80 wt%, the Zn content is 18 wt%, the Bi content is 4 wt%, T1 is 66°C, T2 is 114°C higher than T1, and the viscosity of the first metal part 21 is 4.6 mPa·s.

[0113] Example 25 This embodiment is based on Embodiment 18, except that the Sn content is 72 wt%, the Zn content is 18 wt%, the Bi content is 10 wt%, T1 is 85°C, T2 is 95°C higher than T1, and the viscosity of the first metal part 21 is 0.6 mPa·s.

[0114] Example 26 This embodiment is based on Embodiment 16, except that the Sn content is 96 wt%, the Zn content is 2 wt%, the Bi content is 2 wt%, T1 is 228°C, T2 is 48°C lower than T1, and the viscosity of the first metal part 21 is 14 mPa·s.

[0115] Example 27 This embodiment is based on Embodiment 1, except that the first metal part 21 is an indium bismuth tin alloy, with an In content of 60 wt%, a Bi content of 35 wt%, a Sn content of 5 wt%, a T1 temperature of 118 ℃, a T2 temperature 62 ℃ higher than T1, and a viscosity of 2 mPa·s.

[0116] Example 28 This embodiment is based on embodiment 27, except that the content of In is 55 wt%, the content of Bi is 20 wt%, the content of Sn is 25 wt%, T1 is 120°C, T2 is 60°C higher than T1, and the viscosity of the first metal part 21 is 6.3 mPa·s.

[0117] Example 29 This embodiment is based on embodiment 27, except that the content of In is 40 wt%, the content of Bi is 40 wt%, the content of Sn is 20 wt%, T1 is 123°C, T2 is 57°C higher than T1, and the viscosity of the first metal part 21 is 5.7 mPa·s.

[0118] Example 30 This embodiment is based on embodiment 27, except that the content of In is 25 wt%, the content of Bi is 45 wt%, the content of Sn is 30 wt%, T1 is 128°C, T2 is 52°C higher than T1, and the viscosity of the first metal part 21 is 7.3 mPa·s.

[0119] Example 31 This embodiment is based on embodiment 27, except that the In content is 60 wt%, the Bi content is 15 wt%, the Sn content is 25 wt%, T1 is 98°C, T2 is 82°C higher than T1, and the viscosity of the first metal part 21 is 0.5 mPa·s.

[0120] Example 32 This embodiment is based on embodiment 27, except that the In content is 45 wt%, the Bi content is 20 wt%, the Sn content is 35 wt%, T1 is 104°C, T2 is 76°C higher than T1, and the viscosity of the first metal part 21 is 14 mPa·s.

[0121] Example 33 This embodiment is based on embodiment 27, except that the content of In is 65 wt%, the content of Bi is 20 wt%, the content of Sn is 15 wt%, T1 is 76°C, T2 is 104°C higher than T1, and the viscosity of the first metal part 21 is 3.6 mPa·s.

[0122] Example 34 This embodiment is based on embodiment 27, except that the In content is 56 wt%, the Bi content is 40 wt%, the Sn content is 4 wt%, T1 is 80°C, T2 is 100°C higher than T1, and the viscosity of the first metal part 21 is 0.3 mPa·s.

[0123] Example 35 This embodiment is based on embodiment 27, except that the In content is 20 wt%, the Bi content is 48 wt%, the Sn content is 32 wt%, T1 is 134°C, T2 is 46°C higher than T1, and the viscosity of the first metal part 21 is 13.2 mPa·s.

[0124] Example 36 This embodiment is based on Embodiment 1, except that h1 is 17 μm.

[0125] Example 37 This embodiment is based on Embodiment 1, except that h1 = 2.5 μm.

[0126] Example 38 This embodiment is based on Embodiment 1, except that h2 = 0.05 mm.

[0127] Example 39 This embodiment is based on Embodiment 1, except that h2 = 2.5 mm.

[0128] Example 40 This embodiment is based on Embodiment 1, except that the values ​​of B and A do not satisfy: ≥ 0.001A² + 0.1A, B = 0.1256 mm. 2 .

[0129] Example 41 This embodiment is based on Embodiment 1, except that T2 is 10°C lower than T1, and T2 is 104°C.

[0130] Example 42 This embodiment is based on Embodiment 1, except that h3 is 0.008 mm.

[0131] Example 43 This embodiment is based on Embodiment 1, except that h3 is 1.2 mm.

[0132] Material property testing 1. Method for measuring the area B of the opening 221 in the hollow part of the first adhesive component 22: Lay the first adhesive component 22 flat on the worktable, use a measuring tool to measure the width and length of the opening, or its diameter, and calculate B = width × length, or B = (diameter / 2). 2 ×π.

[0133] 2. h1, h2, and h3 were obtained by microscopy or scanning electron microscopy.

[0134] 3. Viscosity testing shall be performed in accordance with GB / T 41079.3-2024.

[0135] 4. Furnace temperature test conditions and methods (including sample quantity): 1) Sample grouping: 20 battery samples were tested for each embodiment; 2) Test methods: Conduct the experiment at 25℃±5℃ using the following steps: a. Discharge at 0.2C to the lower limit voltage.

[0136] b. Let stand for 5 minutes.

[0137] c. Charge to the upper limit voltage at 0.7C, with a cutoff current of 0.02C.

[0138] d. Test the voltage, internal resistance, and thickness of a fully charged 100 battery at 25℃ + 5℃, and take a picture before the test.

[0139] e. Place the fully charged battery in an oven and heat it at a rate of 5℃±2℃ / min. When the temperature inside the oven reaches 130℃, keep it at that temperature for 10 minutes.

[0140] f. Continue heating using this procedure. Once the oven temperature reaches 130°C, maintain the temperature for 10 minutes and observe the failure status of battery 100.

[0141] Experimental results: If the battery does not catch fire or explode during the 10-minute heat preservation process after the temperature rises to 130℃, it is considered to have passed the furnace temperature performance test. For example, 10P / 20T means that 10 out of 20 batteries passed the test, that is, 10 out of the 20 tested batteries passed the furnace temperature test described above.

[0142] 5. Cyclic performance pass rate conditions and methods (including sample quantity): 1) Sample grouping: The number of samples for each embodiment is 20.

[0143] 2) Test methods: Conduct the experiment at 25℃±+5℃ using the following steps: a. Charge at a constant current rate of 2C, cut off at a rate of 0.05C, then discharge at a constant current rate of 4C, with a voltage range of 2.0V~4.3V. This constitutes one charge-discharge cycle.

[0144] b. Record the discharge capacity Q1 in week 1 and the discharge capacity Q1000 in week 1000. Calculate the cycle capacity retention rate of the battery after 1000 cycles by Q1000 / Q1×100%.

[0145] Experimental results: If the cycle capacity retention rate of the battery cell is greater than 80% after 1000T cycles, it is considered to have passed. For example, 10P / 20P means that 10 out of 20 batteries pass the test, that is, 10 out of the 20 tested batteries have a cycle capacity retention rate greater than 80%.

[0146] Table 1 shows the test results.

[0147] Table 1 The data above shows that when the viscosity of the first metal part 21 is too high or too low, the furnace temperature performance of the battery 100 is poor.

[0148] When the melting point of the first metal part 21 is too high, it is not conducive to pressure relief, and the furnace temperature performance of the battery 100 is poor.

[0149] If h1 is too small, the protective layer is too thin and cannot effectively provide protection, resulting in poor cycle performance of battery 100. If h1 is too large, the protective layer is too thick, resulting in high strength of the first metal part 21, which is not conducive to breaking through during exhaust, leading to poor furnace temperature performance.

[0150] When T2 is less than T1, the melting point of the first adhesive 22 is lower, which makes the first adhesive 22 more prone to adhesion failure, failing to meet the normal use requirements of the battery 100, resulting in a decrease in furnace temperature performance and cycle performance.

[0151] When h2 is too large, the thickness of the first metal part 21 is too large, which will cause the melting speed of the first metal part 21 to be slow during the hot box test and it will not be able to flow to expose the hole on the shell, thus failing to release pressure in time and resulting in poor furnace temperature performance. When h2 is too small, the thickness of the first metal part 21 is too small, which will result in the lower strength of the first metal part 21. The first metal part 21 is easy to break during use, causing water vapor to enter the battery 100, resulting in the battery 100 swelling and failure, affecting the normal use and cycle performance of the battery 100.

[0152] When h3 is too large, the adhesive force of the first adhesive component 22 is relatively large, which to some extent affects the timeliness of temperature transfer to the first metal component and the furnace temperature performance. When h3 is small, the adhesive force of the first adhesive component 22 is low, resulting in a decrease in furnace temperature performance and cycle performance, which cannot meet the normal use requirements of battery 100.

[0153] It should be understood that the term "comprising" and its variations used in the embodiments of this application are open-ended, meaning "including but not limited to". The term "according to" means "at least partially according to". The term "one embodiment" means "at least one embodiment"; the term "another embodiment" means "at least another embodiment". The term "a plurality of" means "more than one", which implies covering two, three or more cases.

[0154] It should be understood that although terms such as "first" or "second" may be used in embodiments of this application to describe various elements, such as a first positive electrode active material layer and a second positive electrode active material layer, these elements are not defined by these terms, which are only used to distinguish one element from another.

[0155] The scope of protection of the embodiments of this application is not limited to the above embodiments. Any variations or substitutions that can be conceived by those skilled in the art within the technical scope disclosed in the embodiments of this application should be included within the scope of protection of the embodiments of this application. Therefore, the scope of protection of the embodiments of this application should be determined by the scope of the claims.

Claims

1. A battery, characterized in that, include: A housing, the housing including a first housing wall, the first housing wall having a first hole and a second hole; A battery cell, located within the housing, comprising a first electrode, a separator, and a second electrode, wherein the second electrode is connected to the housing; as well as A pole post structure is inserted into the second hole and connected to the first pole piece; A pressure relief assembly includes a first metal component, which is disposed in and covers the first hole and is sealed to the housing. In the molten state, the viscosity A of the first metal component is 1 mPa·s to 10 mPa·s.

2. The battery according to claim 1, characterized in that, The first metal component comprises a low-melting-point metal, which comprises a first class of metallic elements, including bismuth (Bi) and tin (Sn). In the first metal component, the content of Bi is 3 wt% to 70 wt%, and the content of Sn is 5 wt% to 90 wt%.

3. The battery according to claim 2, characterized in that, The first metal component further includes a second type of metallic element, which includes at least one of lead (Pb), cadmium (Cd), zinc (Zn), indium (In), and gallium (Ga). The content of the second type of metallic element in the first metal component is 0 wt% to 80 wt%. Preferably, The content of the second type of metallic element is 0.5 wt%-60 wt%.

4. The battery according to claim 3, characterized in that, The first metal component is a bismuth-tin alloy, wherein the Bi content is 20 wt%~70 wt% and the Sn content is 30 wt%~80 wt%; or The first metal component is an indium bismuth tin gallium alloy, wherein the indium bismuth tin gallium alloy contains 40 wt%~55 wt% indium, 20 wt%~40 wt% inbi, 12 wt%~20 wt% in tin, and 0.5 wt%~10 wt% in tin; or The first metal component is a tin-zinc-bismuth alloy, wherein the content of Sn is 75 wt%~90 wt%, the content of Zn is 3 wt%~15 wt%, and the content of Bi is 3 wt%~18 wt%; or The first metal component is an indium bismuth tin alloy, wherein the indium bismuth tin alloy contains 25 wt% to 60 wt% of In, 20 wt% to 45 wt% of Bi, and 5 wt% to 30 wt% of Sn.

5. The battery according to claim 1, characterized in that, The first metal component has a protective layer on at least one side facing the housing; the protective layer includes at least one of chromium, nickel, molybdenum, and titanium, and / or the thickness h1 of the protective layer satisfies: 3 μm ≤ h1 ≤ 15 μm.

6. The battery according to claim 1, characterized in that, The pressure relief assembly further includes a first adhesive component, which is disposed between the first metal component and the housing. The melting point T1 of the first metal component and the melting point T2 of the first adhesive component satisfy: T2 > T1; preferably, T2≥T1+20℃, wherein the melting point T1 of the first metal part is 80℃~150℃, preferably T1 is 85℃~140℃; and / or The thickness h2 of the first metal part satisfies: 0.06 mm ≤ h2 ≤ 2 mm, preferably 0.08 mm ≤ h2 ≤ 1 mm.

7. The battery according to any one of claims 1 to 6, characterized in that, The pressure relief assembly further includes a first adhesive member having an opening along a first direction, the opening at least partially overlapping the orthographic projection of the first hole, and the first adhesive member being disposed between the first metal part and the housing; preferably, the thickness h3 of the first adhesive member is 0.01 mm to 1 mm, and / or The area of ​​the opening is B, and the unit of B is mm. 2 The viscosity A of B and the first metal component satisfies: B ≥ 0.001A² + 0.1A, where, The first direction is the thickness direction of the first metal part.

8. The battery according to claim 7, characterized in that, Along the first direction, the orthographic projection of the first adhesive element lies at least partially within the orthographic projection of the first metal element; and / or, The portion of the first metal part that extends beyond the first adhesive part contacts the housing.

9. The battery according to claim 7, characterized in that, Along the first direction, the edge of the orthographic projection of the first adhesive member extends beyond the edge of the orthographic projection of the first metal member or coincides with the edge of the first metal member; and / or, The first metal part is recessed toward the housing and in contact with the housing.

10. The battery according to claim 7, characterized in that, The pressure relief assembly further includes a second metal component, which is fixed between the first adhesive component and the housing, and is disposed around the first hole; and / or The pressure relief assembly further includes a second adhesive element that adheres to and covers at least a portion of the edge of the first metal component and at least a portion of the housing, the second adhesive element being an insulating adhesive.

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