A battery and battery pack

Abstract

The application discloses a battery and a battery device, comprising a shell and a battery core, the shell comprises a body and a cover plate, at least one end of the body is provided with an opening, the cover plate is connected with the body to block the opening, a first end surface of the shell is provided with an explosion-proof sheet, the explosion-proof sheet comprises a weak part; the battery core comprises a battery core body and a current lead-out end extended from at least one end of the battery core body, the battery core body comprises a pole piece, the projection area of the weak part on the first end surface is Smm 2 In the first direction, the minimum distance between the one end of the pole piece facing the weak part and the weak part is hmm, and hmm x Smm 2 The range of Smm is 15mm 3 ~1500mm 3 The application can ensure that the battery is timely pressure-released and exhausts smoothly when thermal runaway occurs, and the influence of the explosion of the pressure-releasing opening on the safety of adjacent batteries is avoided; meanwhile, the energy density of the battery can be ensured, and the battery endurance is improved.

Description

Technical Field

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

[0002] Rapid thermal runaway and thermal propagation in high-energy-density batteries have become a core challenge for the safety of new energy sources. Once a battery depressurizes, its accumulated high energy will be released instantly in the form of thermal runaway. Due to the rapid rate of thermal runaway, the high-temperature and high-pressure gas inside cannot be released in time, ultimately causing more serious thermal runaway risks, such as the explosion-proof vent rupture.

[0003] Therefore, it is necessary to develop batteries that can release pressure in a timely manner and have a low risk of thermal runaway. Utility Model Content

[0004] In view of this, the purpose of this application is to provide a battery that ensures timely pressure relief and avoids more serious risks of thermal runaway;

[0005] Another object of this application is to provide a battery pack having the above-mentioned battery.

[0006] To achieve the above objectives, this application provides the following technical solution:

[0007] The first aspect of this application provides a battery, including a casing and a cell. The casing includes a body and a cover plate. An opening is formed at at least one end of the body. The cover plate is connected to the body to seal the opening. An explosion-proof sheet is provided on a first end face of the casing. The explosion-proof sheet includes a weak portion.

[0008] The battery cell includes a cell body and a current lead extending from at least one end of the cell body. The cell body includes electrode plates, and the projected area of ​​the weak portion on the first end face is S mm. 2 Along the first direction, the minimum distance between the end of the electrode facing the weak portion and the weak portion is hmm, where hmm × Smm. 2 The range is 15mm 3 ~1500mm 3 ;

[0009] The first direction is the arrangement direction of the battery cell body and the explosion-proof sheet.

[0010] The battery provided by the above technical solution will have an hmm×Smm 2 At 15mm 3 ~1500mm 3 Selecting within the range can avoid the limitations of hmm×Smm. 2 If the value is too small, it can cause poor exhaust. This can also prevent problems caused by hmm×Smm. 2Excessive values ​​can lead to low battery energy density. The battery provided in this application, by controlling the relationship between the distance between the electrode and the weak point, as well as the area of ​​the weak point, ensures timely pressure relief and internal venting during thermal runaway. This results in a relatively high explosion pressure, preventing open flames during venting and avoiding the risk of the pressure relief port exploding and impacting the safety of adjacent batteries, thus mitigating more serious thermal runaway risks. Simultaneously, it avoids stress concentration in the explosion-proof sheet, preventing the battery from prematurely exploding before reaching the preset pressure.

[0011] A second aspect of this application provides a battery device including a support plate and a battery disposed on the support plate, the battery being the battery described in any of the preceding claims.

[0012] The battery device provided in this application has the aforementioned battery, and therefore also has the aforementioned battery, which will not be described again in this application. 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 only 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 end face of a battery cell with an explosion-proof sheet as disclosed in the embodiments of this application;

[0015] Figure 2 for Figure 1 Sectional view along line AA;

[0016] Figure 3 for Figure 1 Sectional view along line BB;

[0017] Figure 4 for Figure 2 A magnified view of part A in the image;

[0018] Figure 5 for Figure 3 A magnified view of part B in the image;

[0019] Figure 6 This is a diagram showing the positional relationship between the battery cell and the explosion-proof sheet as disclosed in the embodiments of this application;

[0020] Figure 7 This is a diagram showing the positional relationship between the battery cell and the explosion-proof sheet, as disclosed in another embodiment of this application.

[0021] Figure 8 This is an exploded view of the battery cell and insulating board disclosed in the embodiments of this application;

[0022] Figure 9 This is a schematic diagram of the shape of the weak portion disclosed in the embodiments of this application;

[0023] Figure 10 This is a schematic diagram of the shape of a weak portion disclosed in another embodiment of this application;

[0024] Figure 11 This is a schematic diagram of the structure of the explosion-proof sheet disclosed in the embodiments of this application.

[0025] The meanings of the various reference numerals in the figure are as follows:

[0026] 100 - Outer shell;

[0027] 200 - Explosion-proof sheet; 201 - Weak point; 2011 - Reinforcing part; 202 - Groove;

[0028] 300 - Cell; 301 - Electrode; 302 - Separator; 303 - Current lead;

[0029] 400 - Insulating board; 401 - Insulating bump;

[0030] 500-Pole Module. Detailed Implementation

[0031] This application discloses a battery to ensure timely pressure relief and avoid more serious thermal runaway risks;

[0032] This application also discloses a battery pack having the above-described battery.

[0033] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0034] For safety, the battery casing is equipped with an explosion-proof diaphragm. When high-pressure gas is generated inside the battery due to faults such as overcharging, overheating, or short circuits, the diaphragm will open when the pressure rises to a critical value. At this time, the high-pressure gas inside the battery can be released, reducing the internal pressure and thus preventing the battery from exploding due to pressure buildup.

[0035] When thermal runaway occurs in a battery, the high pressure inside the battery ruptures the explosion-proof diaphragm, releasing pressure and preventing the battery from exploding. However, for high-energy-density batteries, the enormous pressure generated by thermal runaway may cause the pressure relief port and its surrounding casing to rupture, resulting in high-temperature ejected material directly impacting other components within the battery pack or adjacent batteries.

[0036] Research has found that the main causes of rapid thermal runaway in batteries are poor venting and insufficient strength around the explosion-proof plate. These issues lead to an excessively large area of ​​the battery casing bursting open after the explosion-proof plate is activated, causing high-temperature materials to be sprayed onto other parts of the battery and other batteries in the battery pack, affecting the safety of adjacent batteries.

[0037] Based on this, embodiments of this application disclose a battery that reduces the impact on the safety of adjacent batteries in the event of thermal runaway.

[0038] like Figures 1-5 As shown, the battery disclosed in this application embodiment includes a casing 100 and a battery cell 300. The casing 100 includes a body and a cover plate. An opening is formed at at least one end of the body, and the cover plate is connected to the body to seal the opening. The battery cell 300 is disposed inside the casing 100.

[0039] The battery cell 300 includes a battery cell body and a current lead 303 extending from at least one end of the battery cell body. The battery cell body includes an electrode 301, which includes a current collector and an active material layer coated on at least one surface thereon.

[0040] The electrode 301 of the battery cell body generally includes a positive electrode and a negative electrode, and a separator 302 is disposed between the positive electrode and the negative electrode (e.g. Figure 6 and Figure 7 As shown, the battery cell body is formed by winding or stacking the positive electrode sheet, negative electrode sheet, and separator 302. The positive electrode sheet includes a positive current collector and a positive active material. The positive current collector can be made of metal materials such as aluminum foil, nickel foil, and stainless steel, or a composite foil formed by combining metals and insulating materials. The positive active material includes the main positive active material, conductive agent, binder, etc. The main positive active material includes one or more of lithium-containing positive active materials such as lithium iron phosphate, ternary materials containing nickel, cobalt, and manganese, and lithium manganese iron phosphate.

[0041] Similarly, the negative electrode sheet includes a negative electrode current collector and a negative electrode active material. The negative electrode current collector can be made of metal materials such as copper foil, aluminum foil, and stainless steel, or it can be a composite foil material formed by combining metals and insulating materials. The negative electrode active material includes the negative electrode active material, conductive agent, binder, etc. The negative electrode active material includes one or more of the following: artificial graphite, natural graphite, silicon carbide, silicon oxide, lithium titanate, etc.

[0042] The separator 302 is an insulating membrane disposed between the positive electrode and the negative electrode to prevent electrons from passing through while allowing ions to pass through. The material of the separator 302 includes at least one of glass fiber, non-woven fabric, polyethylene, polypropylene, polyvinylidene fluoride, etc.

[0043] The outer casing 100 is the external protective structure for the battery cell 300, used to house the battery cell 300 and isolate it from the external environment. The outer casing 100 is mainly made of metals such as aluminum, iron, and steel. Typically, the outer casing 100 includes a main body and a battery cover plate encapsulated at the open end of the main body. One end of the main body is an open end to facilitate the installation of the battery cell 300 inside the outer casing 100. To close the opening of the main body, the outer casing 100 also includes a battery cover plate disposed on the opening of the main body. In other words, the battery cover plate is a component that covers the opening of the main body to isolate the housing space of the battery cell 300 from the external environment. The shape of the battery cover plate can be adapted to the shape of the main body to fit the casing. The cover plate can be made of a material with a certain degree of hardness and strength (such as aluminum alloy).

[0044] The outer casing 100 can be of various shapes and sizes, such as cuboid, cylindrical, hexagonal prism, etc. The shape of the outer casing 100 can be determined according to the specific shape and size of the battery cell 300. The material of the outer casing 100 can be various, including but not limited to copper, iron, aluminum, stainless steel, aluminum alloy, etc.

[0045] An explosion-proof plate 200 is provided on the first end face of the housing 100. It should be noted that the explosion-proof plate 200 can be formed directly on the first end face of the housing 100 or attached to it. If the explosion-proof plate 200 is attached to the first end face of the housing 100, a pressure relief port needs to be provided on the first end face of the housing 100, and the explosion-proof plate 200 is attached to the pressure relief port to seal it. The connection method can be welding or other connection methods.

[0046] The explosion-proof sheet 200 includes a weak point 201, which is configured to open and release pressure when the internal pressure of the housing 100 is reached. When a large amount of gas is generated inside the battery due to abnormal conditions such as overcharging, overheating, or short circuit, causing the internal pressure to rise to a certain level, the pressure generated by the gas will cause the weak point 201 to detach or bend from the housing 100, thus forming a pressure relief port on the housing 100 to relieve the pressure inside the housing 100.

[0047] In this embodiment, the area of ​​the weak part 201 is S mm. 2 After the weak part 201 is opened for pressure relief, the larger the area of ​​the weak part 201, the larger the area of ​​the pressure relief port will be, and the smoother the pressure relief will be; the smaller the area of ​​the weak part 201, the smaller the impact on the strength of the outer shell 100.

[0048] Along the first direction, the minimum distance between the end of electrode 301 facing the weak portion 201 and the weak portion 201 is hmm. The first direction is the arrangement direction of the cell body and the explosion-proof sheet 200. Electrode 301 typically includes a positive electrode and a negative electrode. The minimum distance between electrode 301 and the weak portion 201 refers to the distance between the positive electrode and the weak portion 201, whichever electrode is closest to it. The minimum distance hmm between the end of electrode 301 facing the weak portion 201 and the weak portion 201 reflects the smoothness of venting during thermal runaway. A larger hmm indicates a larger venting channel height, smoother venting, and a less likely pressure relief port of the explosion-proof sheet 200 to burst. A smaller hmm indicates a smaller venting channel height, a larger cell volume, higher battery energy density, and longer battery life.

[0049] The battery disclosed in the embodiments of this application has a size of hmm×Smm. 2 At 15mm 3 ~1500mm 3 Selecting within the range can avoid the limitations of hmm×Smm. 2 If the value is too small, it can cause poor exhaust. This can also prevent problems caused by hmm×Smm. 2 Excessive values ​​can lead to low battery energy density and poor casing strength. The battery provided in this application, by controlling the relationship between the distance between the electrode 301 and the weak point 201 and the area of ​​the weak point 201, ensures timely pressure relief and internal venting during thermal runaway. This results in a relatively high explosion pressure, preventing open flames during venting and avoiding the risk of the pressure relief port exploding and affecting the safety of adjacent batteries, thus preventing more serious thermal runaway risks. Simultaneously, it avoids stress concentration on the explosion-proof plate 200, preventing the battery from prematurely exploding before reaching the preset pressure due to abnormal pressure relief.

[0050] For example, hmm×Smm 2 It can be 15mm 3 100mm 3 200mm 3 300mm 3 400mm 3 500mm 3 600mm 3 700mm 3 800mm 3 900mm 3 1000mm 3 1100mm 3 1200mm 3 1300mm 3 1400mm 3 1500mm3 It should be noted that the above values ​​are only specific examples, and those skilled in the art can adjust the values ​​according to their needs within 15mm. 3 ~1500mm 3 Choose any hmm×Smm within the range 2 The specific value.

[0051] In a specific embodiment of this application, the area Smm of the weak portion 201 2 15mm 2 ~300mm 2 In this embodiment, the area of ​​the weak part 201 is 15mm. 2 ~300mm 2 Choosing within a certain range can avoid the problem that the area of ​​the weak part 201 is too large, resulting in an excessively large pressure relief port area and insufficient strength of the outer shell 100; it can also avoid the problem that the area of ​​the weak part 201 is too small, resulting in an excessively small pressure relief port area and inability to relieve pressure in a timely manner.

[0052] For example, Smm 2 It can be 15mm 2 50mm 2 70mm 2 90mm 2 100mm 2 120mm 2 140mm 2 160mm 2 180mm 2 200mm 2 220mm 2 240mm 2 260mm 2 280mm 2 300mm 2 It should be noted that the above values ​​are merely specific examples, and those skilled in the art can adjust the values ​​according to their needs within 15mm. 2 ~300mm 2 Select any Smm within the range 2 The specific value.

[0053] like Figure 9 As shown in a specific embodiment of this application, the edge of the weak portion 201 includes a first endpoint and a second endpoint, which are coincidentally disposed. In the event of thermal runaway, the edge of this type of weak portion 201 remains continuous, and therefore its entire edge will fracture, causing the weak portion 201 to detach entirely from the outer shell 100. The area of ​​the weak portion 201 is S mm. 2 15mm 2 ~280mm2 .

[0054] For example, Smm 2 It can be 15mm 2 40mm 2 60mm 2 80mm 2 100mm 2 110mm 2 130mm 2 150mm 2 170mm 2 190mm 2 210mm 2 230mm 2 250mm 2 270mm 2 280mm 2 It should be noted that the above values ​​are merely specific examples, and those skilled in the art can adjust the values ​​according to their needs within 15mm. 2 ~280mm 2 Select any Smm within the range 2 The specific value.

[0055] In this embodiment, when the first and second endpoints of the weak portion 201 coincide, the area of ​​the pressure relief port formed is larger because the weak portion 201 can be completely detached from the outer casing 100. Based on this, the area of ​​the weak portion 201 is S mm. 2 At 15mm 2 ~280mm 2 By selecting within a range, that is, selecting the area of ​​the weak part 201 within a smaller range, the strength of the outer shell 100 at the pressure relief port can be improved while ensuring smooth exhaust, thus preventing the pressure relief port from bursting open.

[0056] like Figure 10 As shown in a specific embodiment of this application, the edge of the weak portion 201 includes a first endpoint and a second endpoint, which are spaced apart, meaning the edge of the weak portion 201 is not closed. When the battery reaches the pressure relief, the weak portion 201 of this structure will not detach from the end face of the outer casing 100, but will bend open, with the portion between the first endpoint and the second endpoint serving as the bending end. The edge of the weak portion 201 breaks, and the weak portion 201 rotates around the bending end as the center, flipping open to relieve pressure.

[0057] In this embodiment, with the first and second endpoints of the weak portion 201 spaced apart, since the weak portion 201 is folded open and will not detach from the outer casing 100, the area of ​​the resulting pressure relief port is relatively small. Therefore, the area of ​​the weak portion 201 is S mm. 2 At 25mm2 ~300mm 2 Selecting within a range, that is, selecting the area of ​​the weak part 201 within a larger range, can ensure smooth exhaust.

[0058] For example, Smm 2 It can be 25mm 2 50mm 2 75mm 2 100mm 2 125mm 2 150mm 2 175mm 2 200mm 2 225mm 2 250mm 2 275mm 2 300mm 2 It should be noted that the above values ​​are merely specific examples, and those skilled in the art can adjust the values ​​according to their needs within 25mm. 2 ~300mm 2 Select any Smm within the range 2 The specific value.

[0059] At least one surface of the explosion-proof sheet 200 is provided with a groove 202, and the area enclosed by the groove 202 is the weak part 201. That is, the groove 202 can be provided only on the side of the weak part 201 facing the battery cell 300, or only on the side of the weak part 201 away from the battery cell 300; of course, the groove 202 can also be provided on both the side of the weak part 201 facing the battery cell 300 and the side away from the battery cell 300.

[0060] It should be noted that the groove 202 may not be provided, and the weak part 201 may be thinned so that the weak part 201 can burst open when the pressure relief pressure is reached inside the outer shell 100.

[0061] The ratio of the depth of the groove 202 to the thickness of the weak portion 201 is 0.5 to 2. For example, the ratio of the depth of the groove 202 to the thickness of the weak portion 201 can be 0.5, 0.6, 0.7, 0.8, 0.9, 1, 1.1, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, 1.9, 2, etc. It should be noted that the above values ​​are only specific examples, and those skilled in the art can arbitrarily choose the specific value of the above ratio within the range of 0.5 to 2 according to their needs.

[0062] Since the groove 202 is provided on the weak part 201, the depth of the groove 202 can determine the thickness at the location of the groove 202, and the actual thickness at the location of the groove 202 is related to the difficulty of opening the explosion-proof plate 200. In this embodiment, the ratio of the groove depth to the thickness of the weak part 201 is selected in the range of 0.5 to 2. This ensures that the explosion-proof plate 200 can be safely opened after the battery thermal runaway, and also avoids the situation where the weak part 201 breaks due to vibration, collision or other events when thermal runaway pressure is not triggered.

[0063] like Figure 11 As shown in a specific embodiment of this application, a reinforcing portion 2011 is provided on the weak portion 201. The reinforcing portion 2011 can effectively enhance the mechanical strength of the weak portion 201, enabling it to withstand higher internal pressure. During battery use, especially under abnormal conditions (such as overcharging, over-discharging, short circuit, etc.), a large amount of gas is generated inside the battery, causing a sharp increase in pressure. The presence of the reinforcing portion 2011 makes the weak portion 201 less prone to deformation or rupture when subjected to these high pressures, ensuring the sealing and stability of the explosion-proof sheet 200 under normal operating pressure. During the production, transportation, and daily use of the battery, it may be subjected to various external impacts or vibrations. The reinforcing portion 2011 can also improve the ability of the weak portion 201 to resist these external forces, reducing the risk of premature rupture of the weak portion 201 due to accidental impacts, and ensuring that the explosion-proof sheet 200 only opens when it is truly needed.

[0064] The reinforcing part 2011 can be obtained by bending the weak part 201. The reinforcing part 2011 can be a structure that protrudes towards the side of the battery cell body or a structure that is recessed towards the side of the battery cell body. Of course, the side of the weak part 201 facing the battery cell body can simultaneously include both the reinforcing part 2011 with a protruding structure and the reinforcing part 2011 with a recessed structure.

[0065] The design of the reinforcing section 2011 also allows for more precise control over the opening pressure of the weak section 201. By rationally designing the shape, size, and layout of the reinforcing section 2011, the deformation mode and rupture timing of the weak section 201 under specific pressure can be adjusted. This ensures that when the internal pressure of the battery reaches a preset safety limit, the weak section 201 can accurately rupture and open, releasing internal gas and preventing serious damage to the battery or even a safety accident due to excessive pressure.

[0066] The shape of the reinforcing part 2011 can be Z-shaped, arc-shaped, straight, X-shaped, etc. It should be noted that the shape of the reinforcing part 2011 can also be any combination of two or more of the Z-shaped, arc-shaped, straight, and X-shaped shapes. Of course, the shape of the reinforcing part 2011 can also be other shapes, and is not limited to the shapes disclosed above.

[0067] In a specific embodiment of this application, along the second direction, the minimum distance between the edge of the weak portion 201 and the edge of the explosion-proof sheet 200 is 1mm to 10mm. The second direction is the length direction of the battery and is perpendicular to the first direction. For example, the minimum distance between the edge of the weak portion 201 and the edge of the explosion-proof sheet 200 can be 1mm, 1.5mm, 2mm, 2.5mm, 3mm, 3.5mm, 4mm, 4.5mm, 5mm, 5.5mm, 6mm, 6.5mm, 7mm, 7.5mm, 8mm, 8.5mm, 9mm, 9.5mm, 10mm, etc. It should be noted that the above values ​​are only specific examples, and those skilled in the art can arbitrarily choose the specific value of the minimum distance between the edge of the weak portion 201 and the edge of the explosion-proof sheet 200 within the range of 1mm to 10mm according to their needs.

[0068] When the weak part 201 is provided with a groove 202, the edge of the weak part 201 refers to the position of the groove 202. In this embodiment, the minimum distance between the edge of the weak part 201 and the edge of the explosion-proof sheet 200 is selected within the range of 1mm to 10mm. This avoids the welding strength between the explosion-proof sheet 200 and the end face of the outer shell being affected due to the distance being too close, and also avoids the problem of the weak part 201 being too small due to the distance being too far, resulting in untimely pressure relief.

[0069] For ease of understanding, in this embodiment, the end face of the housing 100 with the explosion-proof plate 200 is defined as the pressure relief end face. Along the second direction, the minimum distance between the edge of the explosion-proof plate 200 and one edge of the pressure relief end face is 3mm to 20mm. For example, the minimum distance between the edge of the explosion-proof plate 200 and one edge of the pressure relief end face can be 3mm, 4mm, 5mm, 6mm, 7mm, 8mm, 9mm, 10mm, 11mm, 12mm, 13mm, 14mm, 15mm, 16mm, 17mm, 18mm, 19mm, 20mm, etc. It should be noted that the above values ​​are only specific examples, and those skilled in the art can arbitrarily choose the specific value of the minimum distance between the edge of the explosion-proof plate 200 and one edge of the pressure relief end face within the range of 3mm to 20mm according to their needs.

[0070] Those skilled in the art will understand that the edge of the explosion-proof disc 200 and the edge of the pressure relief end face should not be too close, otherwise it will affect the strength of the pressure relief end face; similarly, the edge of the explosion-proof disc 200 and the edge of the pressure relief end face should not be too far apart, otherwise it will affect the area of ​​the pressure relief port. In this embodiment, the minimum distance from the edge of the explosion-proof disc 200 to the edge of the pressure relief end face is selected within the range of 3mm to 20mm. This avoids the problem of insufficient pressure relief due to an excessively large distance resulting in an insufficiently small pressure relief port area, and also avoids the problem of low shell strength due to an excessively small distance.

[0071] like Figure 8 As shown in a specific embodiment of this application, an insulating bump 401 is provided between the pressure relief end face and the cell body, and at least one end face of the insulating bump 401 abuts against the cell body. It should be noted that during thermal runaway, the battery generates a large amount of high-temperature, high-pressure gas. This high-temperature, high-pressure gas needs to be discharged and depressurized through the explosion-proof sheet 200. The insulating bump 401 can guide the flow of these gases, causing the high-temperature, high-pressure thermal runaway gas to be discharged in a predetermined, safe direction, away from the casing or other critical components that may cause a short circuit.

[0072] The insulating bumps 401 create gaps between the pressure relief face and the cell 300, which serve as channels for the rapid discharge of thermal runaway gases. Compared to designs without insulating bumps 401, the design with insulating bumps 401 increases the space and smoothness of gas flow, allowing thermal runaway gases to escape from the battery more quickly. Faster venting speed helps reduce excessive pressure inside the battery caused by the accumulation of thermal runaway gases, reducing the likelihood of extreme events such as battery explosions.

[0073] The greater the height of the insulating bump 401, the smoother the venting; the smaller the height of the insulating bump 401, the less space it occupies in the battery. In this embodiment, the height of the insulating bump 401 along the first direction is Lmm, where Lmm is 0.5mm to 3mm. For example, the height of the insulating bump 401 can be 0.5mm, 0.7mm, 1mm, 1.3mm, 1.5mm, 1.7mm, 2mm, 2.2mm, 2.5mm, 2.8mm, 3mm, etc. It should be noted that the above values ​​are only specific examples, and those skilled in the art can arbitrarily choose the specific value of the height of the insulating bump 401 within the range of 0.5mm to 3mm according to their needs.

[0074] To prevent the insulating bump 401 from melting and blocking gas exhaust after thermal runaway, in this embodiment, the melting point of the insulating bump 401 is 500℃~1000℃. This ensures that after battery thermal runaway, the insulating bump 401 does not melt or its melting rate is slowed down, allowing the thermal runaway gas to escape from the battery more quickly.

[0075] The insulating bump 401 can be made of one or more of the following materials: phenolic resin, mica, stainless steel, aluminum alloy, nickel-based alloy, titanium alloy, etc.

[0076] Those skilled in the art can select materials with appropriate melting points to fabricate the insulating bump 401 according to their needs. For example, materials with melting points of 500℃, 550℃, 600℃, 650℃, 700℃, 750℃, 800℃, 850℃, 900℃, 950℃, and 1000℃ can be selected to fabricate the insulating bump 401.

[0077] Furthermore, the ratio of the projected area of ​​the insulating bump 401 on the pressure relief end face to the area of ​​the pressure relief end face is 0.02 to 0.5. For example, the ratio of the projected area of ​​the insulating bump 401 on the pressure relief end face to the area of ​​the pressure relief end face can be 0.02, 0.05, 0.1, 0.15, 0.2, 0.25, 0.3, 0.35, 0.4, 0.45, 0.5, etc. It should be noted that the above values ​​are only specific examples, and those skilled in the art can arbitrarily choose the specific value of the above ratio within the range of 0.02 to 0.5 according to their needs.

[0078] This configuration avoids the problem of low battery energy density caused by excessively large internal space occupied by the insulating bumps 401 due to an excessively large ratio; it also avoids the problem of insufficient support strength of the insulating bumps 401 due to an excessively small ratio.

[0079] Cell 300 is the core component for generating and storing electrical energy, operating at high voltage. The casing 100 is typically made of metal and serves to protect cell 300 and provide structural support. Under certain circumstances, such as when the battery is subjected to vibration or pressure, cell 300 may come into contact with casing 100, causing a short circuit. A short circuit can instantly generate a large current, potentially leading to serious safety incidents such as battery overheating, fire, or even explosion.

[0080] Based on this, such as Figure 4 and Figure 8 As shown in a specific embodiment of this application, an insulating plate 400 is provided between the pressure relief end face of the casing 100 and the cell body. The insulating plate 400 can effectively block the conductive path between the cell 300 and the pressure relief end face of the casing 100, avoiding such a dangerous situation. The insulating plate 400 can also typically act as a buffer, reducing the direct impact on the cell when the battery is subjected to external impact or vibration. When the battery is hit, the insulating plate 400 can absorb part of the impact force, reducing the risk of damage to the cell 300 due to vibration and impact, and extending the service life of the cell 300.

[0081] An insulating protrusion 401 is disposed on an insulating plate 400. The insulating protrusion 401 can be integral with the insulating plate 400, or it can be fixed to the insulating plate 400 by a fixing method. The fixing method is not limited to bonding, welding, or fastener connection.

[0082] The insulating plate 400 can be made of one or more of the following materials: PP (Polypropylene), PET (Polyethylene terephthalate), PPS (Polyphenylene sulfide), PI (Polyimide), stainless steel, aluminum alloy, nickel-based alloy, and titanium alloy. Understandably, at least one of the insulating plate 400 and the insulating bump 401 needs to provide insulation. If both are conductive metals, an insulating coating can be sprayed onto their surfaces. Because the insulating plate 400 has a larger dimension in the second direction, the position of the insulating bump 401 can be symmetrical about the center of the weak part 201 along the second direction to ensure more stable support for the battery cell body. It should be noted that the second direction is perpendicular to the first direction and parallel to the large surface of the outer casing 100; in other words, the second direction is parallel to the length direction of the insulating plate 400, which is the length direction of the battery.

[0083] The insulating bump 401 can be provided in one or more ways. In this embodiment of the application, the number of insulating bumps 401 is not limited.

[0084] The area corresponding to the weak part 201 of the insulating plate 400 is provided with a hollow area 402. The thermal runaway gas between the insulating plate 400 and the cell 300 will pass through the hollow area 402, pass through the insulating plate 400, and be discharged into the weak part 201 on the outer casing 100. Finally, the battery will be discharged through the area where the weak part 201 is located.

[0085] The cutout area 402 may include several through holes, that is, the cutout area 402 may include only one larger through hole (e.g., Figure 8 (As shown in the illustration), multiple small through holes arranged at intervals can also be opened in this area. This embodiment does not limit the way the holes in the hollow area 402 are opened, as long as thermal runaway gas can pass through.

[0086] In one specific embodiment of this application, the minimum distance hmm between the end of the electrode 301 facing the weak portion 201 and the weak portion 201 is 1mm to 5mm. For example, hmm can be 1mm, 1.3mm, 1.5mm, 1.7mm, 1.9mm, 2.2mm, 2.4mm, 2.8mm, 3.1mm, 3.3mm, 3.5mm, 3.7mm, 4mm, 4.3mm, 4.6mm, 4.8mm, 5mm, etc. It should be noted that the above values ​​are only specific examples, and those skilled in the art can arbitrarily choose the specific value of hmm within the range of 1mm to 5mm according to their needs.

[0087] In this embodiment, hmm is selected within the range of 1mm to 5mm. This avoids the problem of poor venting caused by hmm being too small, and also avoids the problem of low battery energy density caused by h being too large.

[0088] Furthermore, along the first direction, the height dimension Hmm of the electrode 301 is 50mm to 3000mm. For example, Hmm can be 50mm, 100mm, 300mm, 500mm, 700mm, 900mm, 1100mm, 1300mm, 1500mm, 1700mm, 1900mm, 2100mm, 2300mm, 2500mm, 2700mm, 2900mm, 3000mm, etc. It should be noted that the above values ​​are only specific examples, and those skilled in the art can arbitrarily choose the specific value of Hmm within the range of 50mm to 3000mm according to their needs.

[0089] It should be noted that the greater the height of the electrode 301, the larger its area, and the higher the energy density of the battery. In this embodiment, the h / H ratio is selected within the range of 0.005 to 0.03. This avoids the problem of insufficient venting space and poor venting caused by an excessively small h / H value, and also avoids the problem of low battery energy density caused by an excessively large h / H value.

[0090] For example, the h / H ratio can be 0.005, 0.008, 0.01, 0.015, 0.018, 0.02, 0.025, 0.028, 0.03, etc. It should be noted that the above values ​​are only specific examples, and those skilled in the art can arbitrarily choose the specific value of the h / H ratio within the range of 0.005 to 0.03 according to their needs.

[0091] like Figure 8 As shown, in this embodiment, the battery also includes a terminal assembly 500. The current lead 303 is electrically connected to the terminal assembly 500. The core function of the terminal assembly 500 is to realize the electrical connection between the battery and the external circuit. When the battery is working, current is conducted from the internal electrodes of the battery to the external load through the terminal assembly 500. Alternatively, during charging, current flows from the charger into the internal electrodes of the battery through the terminal assembly 500. Good electrical connection performance ensures that the battery can efficiently output and receive electrical energy, reducing energy loss and heat generation.

[0092] When a large amount of gas and pressure is generated inside the battery due to a fault (such as overcharging or overheating), the explosion-proof plate 200 opens to release the pressure and prevent the battery from exploding. If the explosion-proof plate 200 and the terminal assembly 500 are on the same end of the battery, the gas ejected may impact the terminal assembly 500, causing problems such as loose connection or short circuit in the terminal assembly 500, leading to a more serious safety accident.

[0093] Based on this, the terminal assembly 500 and the explosion-proof plate 200 are disposed on two opposite end faces of the housing 100. In other words, the battery disclosed in this embodiment adopts a thermoelectric separation structure. By disposing of the terminal assembly 500 and the explosion-proof plate 200 on different end faces of the housing 100 in this embodiment, the aforementioned dangerous chain reaction can be effectively avoided, ensuring that the battery can safely release pressure under abnormal conditions and protecting the safety of the operating environment. When this battery is applied in the battery pack of an electric vehicle, this design can prevent one safety hazard from triggering another safety problem, reducing the risk of vehicle fire and explosion.

[0094] For ease of wiring, the terminal assembly 500 is typically located at the top (second end face) of the housing 100, while the explosion-proof plate 200 is positioned at the first end face of the housing 100. The first and second end faces are opposite to each other on the housing 100; when the second end face is at the top, the first end face is at the bottom. With this configuration, in the event of battery thermal runaway, the downward ejection of thermal runaway material can cause the cell 300 to sink and block the venting channel supported by the insulating bump 401 (the venting channel is located at the bottom of the battery, making it more prone to blockage). Therefore, in this embodiment, the height of the insulating bump 401 is 0.3mm to 3.7mm. For example, the height of the insulating bump 401 can be 0.3mm, 0.5mm, 0.7mm, 1mm, 1.2mm, 1.5mm, 1.8mm, 2mm, 2.3mm, 2.5mm, 2.8mm, 3mm, 3.3mm, 3.5mm, 3.7mm, etc. It should be noted that the above values ​​are only specific examples, and those skilled in the art can arbitrarily choose the specific value of the height of the insulating bump 401 within the range of 0.3mm to 3.7mm according to their needs.

[0095] In this embodiment, the height of the insulating bump 401 is selected within a large range to ensure that the insulating bump 401 has a high height, thereby generating a larger exhaust channel cross-sectional area and improving the smoothness of exhaust.

[0096] The terminal assembly 500 and the explosion-proof plate 200 can also be disposed on the same end face of the housing 100, that is, both the terminal assembly 500 and the explosion-proof plate 200 are located on the first end face (e.g., the top) of the housing 100. With this arrangement, in the event of battery thermal runaway, when thermal runaway material is sprayed upwards, the cell 300 is less likely to block the venting channel supported by the insulating bump 401 (in addition, since the venting channel is located at the top of the battery, impurities sink to the bottom of the battery, and the venting channel located at the top is also less likely to be blocked by impurities).

[0097] Based on this, in this embodiment, the height of the insulating bump 401 is 0.1mm to 3.5mm. For example, the height of the insulating bump 401 can be 0.1mm, 0.3mm, 0.5mm, 0.7mm, 1mm, 1.2mm, 1.5mm, 1.8mm, 2mm, 2.3mm, 2.5mm, 2.8mm, 3mm, 3.3mm, 3.5mm, etc. It should be noted that the above values ​​are only specific examples, and those skilled in the art can arbitrarily choose the specific value of the height of the insulating bump 401 within the range of 0.1mm to 3.5mm according to their needs.

[0098] In this embodiment, the height of the insulating bump 401 is selected within a small range to improve the space utilization of the cell and increase the energy density of the battery.

[0099] This application also discloses a battery pack, which includes a support plate and at least two batteries disposed on the upper part of the support plate. The batteries are those disclosed in the above embodiments. Because it has the above-described batteries, it possesses all the technical effects of the aforementioned batteries, which will not be repeated here. Furthermore, the first end face of the battery casing 100 faces the support plate; in other words, the battery is the one protruding from the explosion-proof sheet 200.

[0100] As illustrated in this application, unless the context clearly indicates otherwise, the words "a," "an," "an," and / or "the" do not specifically refer to the singular and may also include the plural. Generally speaking, the terms "comprising" and "including" only indicate the inclusion of expressly identified steps and elements, which do not constitute an exclusive list, and the method or apparatus may also include other steps or elements. An element defined by the phrase "comprising an..." does not exclude the presence of other identical elements in the process, method, product, or apparatus that includes the element.

[0101] In the description of this application, unless otherwise expressly defined, terms such as "setup," "installation," and "connection" should be interpreted broadly, and those skilled in the art can reasonably determine the specific meaning of the above terms in this application in conjunction with the specific content of the technical solution.

[0102] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. The same or similar parts between the various embodiments can be referred to each other.

[0103] This document uses specific examples to illustrate the principles and implementation methods of this application. The descriptions of the embodiments above are only for the purpose of helping to understand the method and core ideas of this application. It should be noted that those skilled in the art can make several improvements and modifications to this application without departing from the principles of this application, and these improvements and modifications also fall within the protection scope of the claims of this application.

Claims

1. A battery, characterized in that, It includes a housing (100) and a battery cell (300). The housing includes a body and a cover plate. At least one end of the body has an opening. The cover plate is connected to the body to seal the opening. An explosion-proof plate (200) is provided on the first end face of the housing (100). The explosion-proof plate (200) includes a weak part (201). The battery cell (300) includes a cell body and a current lead-out terminal (303) extending from at least one end of the cell body. The cell body includes an electrode (301), and the projected area of ​​the weak portion (201) on the first end face is S mm. 2 Along the first direction, the minimum distance between the end of the electrode (301) facing the weak portion (201) and the weak portion (201) is hmm, hmm×Smm. 2 The range is 15mm 3 ~1500mm 3 ; The first direction is the arrangement direction of the battery cell body and the explosion-proof sheet (200).

2. The battery as described in claim 1, characterized in that, The area of ​​the weak part (201) is S mm. 2 15mm 2 ~300mm 2 .

3. The battery as described in claim 2, characterized in that, The edge of the weak portion (201) includes a first endpoint and a second endpoint, which are coincidentally arranged. The area of ​​the weak portion (201) is S mm. 2 15mm 2 ~280mm 2 .

4. The battery as described in claim 2, characterized in that, The edge of the weak portion (201) includes a first endpoint and a second endpoint, which are spaced apart. The area of ​​the weak portion (201) is S mm. 2 25mm 2 ~300mm 2 .

5. The battery as described in claim 1, characterized in that, At least one side surface of the explosion-proof sheet (200) is provided with a groove (202), the area enclosed by the groove (202) is the weak part (201), and the ratio of the depth of the groove (202) to the thickness of the weak part (201) is 0.5~2.

6. The battery as claimed in claim 1, characterized in that, The weak part (201) is provided with a reinforcing part (2011), and the shape of the reinforcing part (2011) includes at least one of Z-shape, arc shape, straight line shape and X-shape.

7. The battery as claimed in claim 1, characterized in that, Along the second direction, the minimum distance between the edge of the weak part (201) and the edge of the explosion-proof sheet (200) is 1mm to 10mm. The second direction is the length direction of the battery and is perpendicular to the first direction.

8. The battery as claimed in claim 1, characterized in that, Along the second direction, the end face of the outer casing (100) with the explosion-proof sheet (200) is a pressure relief end face, and the minimum distance between the edge of the explosion-proof sheet (200) and one side edge of the pressure relief end face is 3mm~20mm. The second direction is the length direction of the battery and is perpendicular to the first direction.

9. The battery as claimed in claim 1, characterized in that, The outer casing (100) has an end face of the explosion-proof sheet (200) as a pressure relief end face, and an insulating bump (401) is provided between the pressure relief end face and the battery cell body. At least one end face of the insulating bump (401) abuts against the battery cell body.

10. The battery as claimed in claim 9, characterized in that, Along the first direction, the height dimension Lmm of the insulating bump (401) is 0.5mm~3mm.

11. The battery as claimed in claim 9, characterized in that, The ratio of the projected area of ​​the insulating bump (401) on the pressure relief end face to the area of ​​the pressure relief end face is 0.02~0.

5.

12. The battery according to any one of claims 9-11, characterized in that, An insulating plate (400) is provided between the battery cell body and the pressure relief end face, and an insulating protrusion (401) is provided on the insulating plate (400); Along the second direction, the position of the insulating bump (401) is symmetrical about the center position of the weak part (201), the second direction is the length direction of the battery and is perpendicular to the first direction.

13. The battery as claimed in claim 1, characterized in that, Along the first direction, the end of the electrode (301) facing the weak part (201) has a minimum distance hmm between it and the weak part (201) of 1mm to 5mm.

14. The battery as claimed in claim 13, characterized in that, Along the first direction, the height dimension of the electrode (301) is Hmm, where Hmm is 50mm~3000mm and h / H ranges from 0.005 to 0.

03.

15. The battery as claimed in claim 10, characterized in that, It also includes a pole assembly (500), the current lead (303) is electrically connected to the pole assembly (500), the pole assembly (500) is disposed on the first end face of the housing (100), and the height of the insulating bump (401) along the first direction is 0.1mm~3.5mm.

16. The battery as claimed in claim 10, characterized in that, It also includes a pole assembly (500), the current lead (303) is electrically connected to the pole assembly (500), the pole assembly (500) is disposed on the second end face of the housing (100), the first end face and the second end face are two opposite end faces of the housing (100), and the height of the insulating bump (401) along the first direction is 0.3mm~3.7mm.

17. A battery pack, characterized in that, It includes a support plate and at least two batteries disposed on the upper part of the support plate, wherein the batteries are batteries as described in any one of claims 1-16.

18. The battery pack as claimed in claim 17, characterized in that, The first end face of the battery casing (100) is the end face facing the support plate.

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