Cylindrical battery, battery module, and electric device

Abstract

The application discloses a cylindrical battery, a battery module and a power utilization device. The cylindrical battery comprises a shell, an electrode assembly and fire extinguishing material. The shell comprises a side wall, the side wall comprises a side wall body and a convex part, the convex part protrudes from an inner surface of the side wall body, and an outer side of the convex part is provided with a concave part. The electrode assembly is accommodated in the shell, the side wall body surrounds the electrode assembly, at least part of the convex part is arranged on one side of the electrode assembly in the axial direction of the cylindrical battery, and the fire extinguishing material is accommodated in the concave part.

Description

Technical Field

[0001] This application relates to the field of batteries, and in particular to a cylindrical battery, a battery module, and an electrical device. Background Technology

[0002] With the rapid development of the new energy industry, the application of rechargeable batteries in electric vehicles, electric bicycles, power tools, and other fields is becoming a trend. Cylindrical batteries, due to their advantages such as good packability and high stability, are highly favored and are gradually being used in various complex scenarios.

[0003] Due to the harsh operating conditions in different application scenarios, higher requirements have been placed on the safety performance of cylindrical batteries. Improving the safety performance of cylindrical batteries has become a key research and development direction for industry professionals. Utility Model Content

[0004] This application provides a cylindrical battery, a battery module, and an electrical device, which are beneficial for improving safety performance.

[0005] In a first aspect, this application provides a cylindrical battery comprising a housing, an electrode assembly, and a fire extinguishing material. The housing includes a sidewall, which comprises a sidewall body and a protrusion. The protrusion protrudes from the inner surface of the sidewall body, and a recess is provided on the outer side of the protrusion. The electrode assembly is housed within the housing, and the sidewall body surrounds the electrode assembly. In the axial direction of the cylindrical battery, at least a portion of the protrusion is disposed on one side of the electrode assembly, and the fire extinguishing material is housed in the recess.

[0006] In the event of a rise in the temperature of the cylindrical battery itself or an abnormal external temperature, the fire extinguishing material located outside the casing can be activated to extinguish the fire and cool down the battery, helping to reduce its temperature and slow the spread of heat. Simultaneously, the fire extinguishing material can also extinguish and cool the external environment or other external components, thus addressing the fire extinguishing needs of both the cylindrical battery and its surrounding environment or structure, thereby improving the overall safety performance of the cylindrical battery and its surrounding environment or components.

[0007] Furthermore, in the event of an abnormal temperature in a cylindrical battery, the temperature typically rises more significantly at the head region, meaning there is a faster temperature change on the side of the electrode assembly facing the end cap assembly. Therefore, by placing the fire extinguishing material within the recess, allowing it to be positioned on the side of the electrode assembly facing the end cap assembly, the surrounding temperature of the fire extinguishing material will rise rapidly in the event of an abnormal temperature in the cylindrical battery. This enables the fire extinguishing material to respond quickly, thereby further improving safety performance.

[0008] In one or more of the above optional embodiments, the cylindrical battery further includes an insulating film disposed on the outside of the casing, the insulating film covering at least a portion of the recess from the outside. In addition to providing insulation and protection for the casing, the insulating film also covers at least a portion of the recess from the outside, thus blocking and limiting the position of the extinguishing material contained within the recess, improving the positional reliability of the extinguishing material relative to the casing. Simultaneously, the insulating film can also prevent external dust and impurities from entering the recess and adversely affecting the extinguishing material, thereby improving the reliability and service life of the extinguishing material.

[0009] In one or more of the above optional embodiments, the insulating film includes a main body and a weak portion disposed on the main body, with the recess and the weak portion disposed opposite each other along the radial direction of the cylindrical battery. In the event of an abnormal temperature around the extinguishing material, the extinguishing material can activate and break through the insulating film, thereby extinguishing and cooling the cylindrical battery and its surrounding environment or components. Furthermore, by providing a weak portion with lower structural strength to the insulating film, the extinguishing material can more easily break through the weak portion, thus achieving rapid fire extinguishing and cooling, and improving safety performance.

[0010] In one or more of the above optional embodiments, the insulating film includes a plurality of through holes, and the weak portion includes a plurality of sub-weak portions, the plurality of sub-weak portions and the plurality of through holes being alternately arranged along the circumference of the cylindrical cell. Along the radial direction of the cylindrical cell, the recesses are arranged opposite to the through holes.

[0011] The extinguishing material is positioned opposite the through-holes. This allows a portion of the extinguishing material to escape the recess directly through the through-holes in the event of abnormal temperatures around it, thus achieving rapid cooling of the cylindrical battery and its surrounding environment or components. The remaining portion of the extinguishing material can penetrate the weak points between adjacent through-holes. Furthermore, the through-holes make it easier to penetrate these weak points, thereby improving the efficiency of fire extinguishing and cooling.

[0012] In one or more of the above optional embodiments, the fire extinguishing material is entirely contained in the recess, the volume of the fire extinguishing material is V1, the volume of the recess is V2, and 0.5≤V1 / V2≤0.9.

[0013] By setting V1 / V2 to be greater than or equal to 0.5, a certain amount of fire extinguishing material can be incorporated into the cylindrical battery, thereby improving the reliability of fire extinguishing and cooling and enhancing the safety performance of the cylindrical battery. Simultaneously, setting V1 / V2 to be less than or equal to 0.9 ensures that the fire extinguishing material can be completely contained within the recess, thus using the recess to limit the placement of the fire extinguishing material and reducing the risk of it detaching from the recess due to factors such as movement or transportation of the cylindrical battery. This also improves the relative positional reliability between the fire extinguishing material and the casing. Furthermore, this approach helps to reduce the adverse impact of the fire extinguishing material's presence on the overall weight of the cylindrical battery, balancing safety performance and lightweight design.

[0014] In one or more of the above optional embodiments, the protrusion includes an arc-shaped portion and two connecting portions, the two connecting portions being connected to the two ends of the arc-shaped portion respectively, and the fire extinguishing material completely covers the outer surface of the arc-shaped portion.

[0015] The curved section has a larger curvature than the connecting section, and a larger curvature often means a larger amount of deformation. Therefore, the convex section is more prone to cracking on the outer surface of the curved section. At the same time, the curved section is also prone to having lower structural strength. In view of this, by completely covering the outer surface of the curved section with fire extinguishing material, the cracks on the outer surface of the curved section can be protected by the fire extinguishing material, thereby improving the corrosion resistance of the cylindrical battery at the convex section. At the same time, the contact arrangement between the fire extinguishing material and the curved section of the fire extinguishing structure also helps to improve the structural strength in this area and reduce the risk of deformation of the curved section due to external forces and other factors during the transportation or use of the cylindrical battery.

[0016] In one or more of the above optional embodiments, the cylindrical battery further includes an end cap connected to the housing. A portion of the protrusion is located axially between the end cap and the electrode assembly, and at least a portion of the fire extinguishing material overlaps with the end cap. By overlapping at least a portion of the fire extinguishing material with the end cap axially, the fire extinguishing material helps support the protrusion when it is subjected to stress from the end cap, thereby reducing the risk of deformation of the protrusion and improving the reliability of the cylindrical battery.

[0017] In one or more of the above optional embodiments, the recess includes an overlapping space that overlaps with the end cap in the axial direction, and the extinguishing material fills the overlapping space. By filling the overlapping space with extinguishing material, on the one hand, more of the extinguishing material can be axially aligned with the end cap, thereby helping the protrusion to better resist the stress from the end cap and reducing the risk of deformation of the protrusion; on the other hand, the recess can accommodate more extinguishing material, thereby improving the fire extinguishing and cooling effect.

[0018] In one or more of the above optional embodiments, the cylindrical battery further includes an insulating member, a portion of which is located axially between the protrusion and the electrode assembly, the protrusion being in contact with the insulating member. Furthermore, the fire extinguishing material at least partially overlaps the insulating member axially.

[0019] During the use of cylindrical batteries, the electrode assembly easily generates a significant amount of heat, some of which is transferred to the insulating component. By at least partially overlapping the fire extinguishing material with the insulating component in the axial direction, heat from the electrode assembly can be conducted axially through the insulating component and the protrusions to the fire extinguishing material. This allows the fire extinguishing material to quickly absorb heat from the inside of the casing. Consequently, when the cylindrical battery experiences abnormally high temperatures, the fire extinguishing material can respond rapidly, quickly cooling the cylindrical battery and thus improving its safety performance.

[0020] In one or more of the above optional embodiments, the extinguishing material includes a capsule, the capsule including a capsule wall and an extinguishing agent located within the capsule wall, the capsule being configured such that when the temperature exceeds a threshold, the capsule wall melts or breaks, and the extinguishing agent is released.

[0021] By incorporating a capsule wall and extinguishing agent, the capsule wall isolates the extinguishing agent from the external environment when the temperature is below a threshold. This reduces the impact of the extinguishing agent on the normal operation of the cylindrical battery and the influence of the external environment on the physical or chemical properties of the extinguishing agent itself, thus extending the service life of the extinguishing material. When the temperature exceeds the threshold, the capsule wall melts or breaks, allowing the extinguishing agent to detach and achieve the cooling function during extinguishing. This design meets the requirements for the extinguishing material to remain stationary during normal operation of the cylindrical battery and for activation under high-temperature conditions.

[0022] In one or more of the above optional embodiments, the extinguishing agent includes at least one of perfluorohexanone, perfluorobutyl methyl ether, fluorinated ketone, sodium bicarbonate, potassium bicarbonate, and ammonium phosphate; and / or, the material of the bladder wall includes a polymer material, which includes at least one of polypropylene and polyethylene.

[0023] Perfluorohexanone is a new type of environmentally friendly material that extinguishes fires through a dual action of physical heat absorption (lowering the temperature of the fire source) and chemical inhibition (breaking the combustion chain). Perfluorobutyl methyl ether (PFME) is a fluorinated compound that rapidly absorbs heat and inhibits flame spread, thus extinguishing the fire and cooling it down. Fluorinated ketones are fluorinated ketone compounds that, in addition to physical heat absorption and chemical combustion inhibition, also isolate oxygen, causing the flame to extinguish due to lack of oxygen. Sodium bicarbonate and potassium bicarbonate are both alkaline compounds that can suppress smoke. Ammonium phosphate is a nitrogen-containing compound that can be used as a flame retardant additive.

[0024] Polymer materials, including polypropylene and polyethylene, often possess high density. By incorporating polymer materials into the capsule wall, the extinguishing agent can be tightly encapsulated during normal operation of the cylindrical battery, thereby improving the structural reliability of the extinguishing material. Furthermore, both polypropylene and polyethylene are non-toxic materials with strong chemical stability, effectively protecting the extinguishing agent during storage and transportation, and leaving minimal residue after extinguishing and cooling operations, thus enhancing environmental performance.

[0025] Secondly, this application provides a battery module that includes a cylindrical battery provided in any embodiment of the first aspect.

[0026] Thirdly, this application provides an electrical device that includes a cylindrical battery provided in any embodiment of the first aspect. Attached Figure Description

[0027] The features, advantages, and technical effects of exemplary embodiments of this application will now be described with reference to the accompanying drawings.

[0028] Figure 1 This is a schematic diagram of the structure of a cylindrical battery provided in some embodiments of this application;

[0029] Figure 2 for Figure 1 A cross-sectional schematic diagram of the cylindrical battery shown.

[0030] Figure 3 for Figure 2 Enlarged view at box Q;

[0031] Figure 4 for Figure 3 An enlarged view of box P;

[0032] Figure 5 This is a partial cross-sectional schematic diagram of a cylindrical battery provided in some embodiments of this application;

[0033] Figure 6 A partial front view schematic diagram of the insulating film in a cylindrical battery provided in some embodiments of this application;

[0034] Figure 7 This is a schematic cross-sectional view of the fire extinguishing material in a cylindrical battery provided in some embodiments of this application;

[0035] Figure 8 This is a schematic diagram of the structure of a battery module provided in some embodiments of this application;

[0036] Figure 9 The diagram shows the structure of electrical equipment provided in some embodiments of this application.

[0037] The reference numerals in the accompanying drawings for the specific embodiments are as follows:

[0038]

[0039] Detailed Implementation

[0040] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly described below with reference to the accompanying drawings. Obviously, the described embodiments are some embodiments of this application, but not all embodiments.

[0041] The terms "first," "second," "third," etc., used in the specification, claims, or accompanying drawings of this application are used to distinguish different objects, not to describe a specific order or hierarchy. In the embodiments of this application, the same reference numerals denote the same components, and for the sake of brevity, detailed descriptions of the same components are omitted in different embodiments.

[0042] In this application, the reference to "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places in the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment that is mutually exclusive with other embodiments.

[0043] In the description of this application, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0044] In the embodiments of this application, "parallel" includes not only the case of absolute parallelism, but also the case of approximate parallelism as commonly understood in engineering; similarly, "perpendicular" also includes not only the case of absolute perpendicularity, but also the case of approximate perpendicularity as commonly understood in engineering. For example, if the angle between two directions is 85°-95°, the two directions can be considered perpendicular; if the angle between two directions is 0°-10°, the two directions can be considered parallel.

[0045] The cylindrical battery of this application is described below with reference to the accompanying drawings.

[0046] Reference Figures 1 to 4 This application provides a cylindrical battery 1.

[0047] The cylindrical battery 1 can be a lithium-ion battery, a sodium-lithium-ion battery, a sodium-ion battery, a magnesium-ion battery, or other types of batteries.

[0048] Cylindrical battery 1 can be an 18650 battery, a 21700 battery, a 46800 battery, a 49480 battery, a 46950 battery, or other types of cylindrical batteries.

[0049] In some embodiments, the cylindrical battery 1 is a secondary battery. After discharge, the secondary battery can be recharged to activate the active materials and continue to be used.

[0050] In some embodiments, the cylindrical battery 1 includes a housing 10 and an electrode assembly 20 located within the housing 10. The electrode assembly 20 is a core component of the cylindrical battery 1 for realizing the charging and discharging function, and the housing 10 is used to house and protect the electrode assembly 20.

[0051] In some embodiments, the electrode assembly 20 includes a first electrode and a second electrode with opposite polarities. During the charging and discharging process of the cylindrical battery 1, active ions (e.g., lithium ions) are inserted and extracted back and forth between the first electrode and the second electrode. One of the first electrode and the second electrode is a positive electrode, and the other is a negative electrode.

[0052] In some embodiments, the electrode assembly 20 includes a separator disposed between a first electrode and a second electrode, the separator insulating the first electrode and the second electrode. The separator can reduce the risk of short circuit between the positive and negative electrodes while allowing active ions to pass through.

[0053] In some embodiments, the first electrode, the diaphragm, and the second electrode are wound together.

[0054] In some embodiments, the first electrode includes a first current collector and a first active material layer. The first current collector includes a first coated area coated with the first active material layer and a first uncoated foil area. The first coated area and the first uncoated foil area may be arranged along the axial direction X of the cylindrical battery 1.

[0055] In some embodiments, the first empty foil area is wound into multiple turns.

[0056] In some embodiments, the first electrode includes a first tab, which can be formed by flattening or smoothing a first empty foil area. Exemplarily, the first empty foil area can be pressed from the outside to the inside along the radial direction of the electrode assembly 20, and the end of the first empty foil area away from the first coating area is bent to form the first tab.

[0057] In other embodiments, the first tab can be formed by flattening the first empty foil area. Exemplarily, the first empty foil area is pressed in the axial direction X of the electrode assembly 20 from the side of the first empty foil area away from the first coated area, and the end of the first empty foil area away from the first coated area is bent to form the first tab.

[0058] In some embodiments, the second electrode includes a second current collector and a second active material layer. The second current collector includes a second coated area coated with the second active material layer and a second uncoated foil area. The second coated area and the second uncoated foil area may be arranged along the axial direction X of the cylindrical battery 1.

[0059] In some embodiments, the second empty foil area is wound into multiple turns.

[0060] In some embodiments, the second electrode includes a second tab, which can be formed by flattening or smoothing a second empty foil area. Exemplarily, the second empty foil area can be pressed from the outside to the inside along the radial direction of the electrode assembly 20, with the end of the second empty foil area away from the second coating area bent to form the second tab.

[0061] In other embodiments, the second tab can be formed by flattening the second empty foil area. Exemplarily, the second empty foil area is pressed in the axial direction X of the electrode assembly 20 from the side of the second empty foil area away from the second coating area, and the end of the second empty foil area away from the second coating area is bent to form the second tab.

[0062] In some embodiments, along the axial direction X of the cylindrical battery 1, the first tab and the second tab are located at both ends of the electrode assembly 20.

[0063] In some embodiments, the housing 10 has an opening at one end along the axial direction X.

[0064] In some embodiments, the housing 10 includes a bottom wall 12 and a side wall 11, the side wall 11 being connected to the bottom wall 12 and surrounding the electrode assembly 20. An opening is formed at one end of the side wall 11 away from the bottom wall 12 along the axial direction X.

[0065] The bottom wall 12 and the side wall 11 can be integrally formed. Alternatively, the bottom wall 12 and the side wall 11 can also be formed independently and connected by welding or other means.

[0066] In some embodiments, the cylindrical battery 1 includes an end cap assembly 30, which is connected to the housing 10 and covers the opening of the housing 10. The end cap assembly 30 can close the opening of the housing 10, thereby forming a relatively closed receiving space between the housing 10 and the end cap assembly 30, which can accommodate components such as the electrode assembly 20 and the electrolyte.

[0067] In some embodiments, the bottom wall 12 and the end cap assembly 30 are arranged along the axial direction X of the cylindrical battery 1. The end cap assembly 30 and the bottom wall 12 are located on opposite sides of the electrode assembly 20.

[0068] In some embodiments, the end cap assembly 30 is insulated from the sidewall 11.

[0069] In some embodiments, the end cap assembly 30 includes an end cap 31, which is insulated from the sidewall 11.

[0070] In some embodiments, the housing 10 and the end cap 31 may be made of steel, aluminum, composite metal, or other conductive materials. The materials of the housing 10 and the end cap 31 may be the same or different.

[0071] In some embodiments, the first electrode tab is connected to the end cap 31, and the second electrode tab is connected to the bottom wall 12.

[0072] In some embodiments, the end cap assembly 30 includes an insulating structure 34 disposed between the end cap 31 and the sidewall 11. Exemplarily, the insulating structure 34 may be insulating rubber or ceramic.

[0073] In some embodiments, the cylindrical battery 1 includes a current collector 70 disposed between the end cap assembly 30 and the electrode assembly 20, and the current collector 70 is connected to the end cap assembly 30 and the electrode assembly 20.

[0074] In some embodiments, the current collector 70 is connected to the first tab and the end cap 31. By providing the current collector 70, an electrical connection can be achieved between the end cap 31 and the electrode assembly 20, which is beneficial for improving the current carrying capacity and simplifying the assembly process of the cylindrical battery 1.

[0075] In some embodiments, the collector plate 70 is welded to the first electrode tab.

[0076] In some embodiments, the end cap assembly 30 further includes an explosion-proof sheet 32 ​​disposed on the end cap 31.

[0077] When the internal pressure of the cylindrical battery 1 exceeds the upper limit that the explosion-proof plate 32 can withstand, the internal pressure of the cylindrical battery 1 can cause the explosion-proof plate 32 to flip and explode away from the electrode assembly 20, thereby achieving the purpose of power cut-off and pressure relief. This helps to reduce the risk of the cylindrical battery 1 exploding due to excessive internal pressure and improves the safety performance of the cylindrical battery 1.

[0078] In some embodiments, the explosion-proof sheet 32 ​​may be attached to the end cap 31 by welding, riveting, bonding or other suitable means.

[0079] In some embodiments, at least a portion of the explosion-proof plate 32 may be located between the end cap 31 and the electrode assembly 20.

[0080] In some embodiments, the explosion-proof plate 32 connects the manifold 70 and the end cap 31.

[0081] In some embodiments, a portion of the explosion-proof sheet 32 ​​is located between the end cap 31 and the electrode assembly 20, and another portion of the explosion-proof sheet 32 ​​is bent outward toward the end cap 31 away from the electrode assembly 20 to cover the edge of the end cap 31. Optionally, an insulating structure 34 is disposed between the explosion-proof sheet 32 ​​and the sidewall 11.

[0082] In some embodiments, the end cap assembly 30 includes a perforated plate 33 disposed between the manifold 70 and the explosion-proof sheet 32. The perforated plate 33 connects the manifold 70 and the explosion-proof sheet 32, enabling electrical connection between them. The end cap 31 is electrically connected to the first tab in sequence via the explosion-proof sheet 32, the perforated plate 33, and the manifold 70.

[0083] In some embodiments, the perforated plate 33 may have an opening, which serves as a channel for gas flow. This allows gas inside the cylindrical battery 1 to act on the explosion-proof sheet 32 ​​through the opening, enabling the explosion-proof sheet 32 ​​to flip over when the internal gas pressure of the cylindrical battery 1 becomes too high, thereby disconnecting it from the perforated plate 33 and reducing safety risks. When the explosion-proof sheet 32 ​​flips over, the scored portion breaks, forming a channel through which gas inside the cylindrical battery 1 is discharged to the outside, further reducing safety risks.

[0084] In some embodiments, the sidewall 11 includes a sidewall body 111 and a protrusion 112. The sidewall body 111 is connected to the bottom wall 12, and the protrusion 112 protrudes from the inner surface of the sidewall body 111. The inner surface referred to here is the surface of the sidewall body 111 facing the electrode assembly 20, that is, in the radial direction of the cylindrical battery 1, the protrusion 112 protrudes from the surface of the sidewall body 111 near the electrode assembly 20.

[0085] As an example, the first protrusion 112 and the bottom wall 12 are respectively connected to the two ends of the side wall body 111.

[0086] As an example, the first protrusion 112 extends around the circumference of the cylindrical battery 1.

[0087] In some embodiments, the sidewall body 111 surrounds the electrode assembly 20. As an example, in the axial direction X, the sidewall body 111 may extend beyond the surface of the electrode assembly 20 toward the end cap assembly 30.

[0088] In some embodiments, at least a portion of the protrusion 112 is disposed on one side of the electrode assembly 20 in the axial direction X, that is, at least a portion of the protrusion 112 is located between the electrode assembly 20 and the end cap assembly 30 in the axial direction X. In some examples, a portion of the protrusion 112 is disposed between the electrode assembly 20 and the end cap assembly 30 in the axial direction X.

[0089] In some embodiments, the sidewall 11 further includes a fixing portion 114, which is located on the side of the protrusion 112 away from the sidewall body 111 in the axial direction X. The protrusion 112 connects the fixing portion 114 and the sidewall body 111.

[0090] In some examples, the retaining portion 114 is disposed around the end cap 31. A portion of the retaining portion 114 is bent to the side of the end cap 31 away from the first protrusion 112. In the axial direction X, a portion of the end cap 31 is located between the first protrusion 112 and the retaining portion 114.

[0091] In some embodiments, a recess 113 is provided on the outer side of the protrusion 112, that is, the recess 113 is disposed on the side of the sidewall 11 away from the electrode assembly 20, and the recess 113 is disposed in a position corresponding to the protrusion 112. Further, the protrusion 112 is a solid structure that extends radially beyond the sidewall body 111, while the recess 113 is a cavity structure formed by the protrusion 112.

[0092] In some embodiments, the housing 10 includes a substrate and a nickel layer. The substrate is the main part of the housing 10. The nickel layer is disposed on the outer surface of the substrate to effectively isolate external corrosive media (such as moisture, salt spray, etc.) and improve the service life of the housing 10. At the same time, the portion of the nickel layer away from the outer surface of the substrate can form a recess 113.

[0093] In some embodiments, the cylindrical battery 1 includes a fire extinguishing material 40, which is housed in a recess 113. In some examples, the fire extinguishing material 40 may fill the entire recess 113. In other examples, the fire extinguishing material 40 occupies only a portion of the space in the recess 113.

[0094] Fire extinguishing material 40 is a material that performs fire extinguishing function. After the temperature of fire extinguishing material 40 reaches the threshold, fire extinguishing material 40 will be activated under high temperature, thereby releasing the internal fire extinguishing agent to achieve the fire extinguishing and cooling function and improve the safety performance of cylindrical battery 1.

[0095] It should be noted that since the recess 113 is located outside the housing 10, the fire extinguishing material 40 is also located outside the housing 10. Therefore, the fire extinguishing material 40 can be activated by the heating of the corresponding cylindrical battery 1, thereby achieving the fire extinguishing and cooling function. Alternatively, the fire extinguishing material 40 can also be activated by temperature changes caused by other external factors, thereby achieving the fire extinguishing and cooling function.

[0096] As an example, the battery module 1000 typically includes multiple cylindrical batteries 1. In some cases, the fire extinguishing material 40 located in the cylindrical battery 1 may be activated due to the increase in temperature of the corresponding cylindrical battery 1, or it may be activated due to the increase in temperature of other adjacent cylindrical batteries 1, thereby achieving the fire extinguishing and cooling function.

[0097] In the event of an increase in the temperature of the cylindrical battery 1 or an abnormal external temperature, the fire extinguishing material 40 located outside the casing 10 can be activated to achieve fire extinguishing and cooling functions, helping to reduce the temperature of the cylindrical battery 1 and slow down the spread of heat. At the same time, the fire extinguishing material 40 can also extinguish and cool the external environment or other external components outside the casing 10, thus taking into account the fire extinguishing needs of both the cylindrical battery 1 and the surrounding environment or structure, and improving the overall safety performance of the cylindrical battery 1 and its surrounding environment or components.

[0098] Furthermore, in the event of a temperature anomaly in the cylindrical battery 1, the temperature rise is typically more pronounced at the head of the battery, meaning there is a faster temperature change on the side of the electrode assembly 20 facing the end cap assembly 30. Therefore, by placing the fire extinguishing material 40 within the recess 113, allowing it to be positioned on the side of the electrode assembly 20 facing the end cap assembly 30, the surrounding temperature of the fire extinguishing material 40 will rise rapidly in the event of a temperature anomaly in the cylindrical battery 1. This enables the fire extinguishing material 40 to respond quickly, thereby further improving safety performance.

[0099] Furthermore, the recess 113 itself is a hollow structure. By placing the fire extinguishing material 40 inside the recess 113, it helps to improve the deformation resistance of the cylindrical battery 1 at the recess 113, reducing the risk of deformation of the recess 113 due to external impact, and improving the reliability of the cylindrical battery 1. This design also does not increase the overall size of the cylindrical battery 1 or occupy the internal space of the casing 10, thus balancing the energy density and safety performance of the cylindrical battery 1.

[0100] In some embodiments, the extinguishing material 40 covers at least a portion of the nickel layer.

[0101] A portion of the outer surface of the nickel layer can form a recess 113. During the formation of the recess 113, the nickel layer is stretched and thinned, which may lead to micro-cracks in the nickel layer, thereby affecting the rust resistance of the casing 10. Therefore, by covering at least a portion of the nickel layer with fire extinguishing material 40, the fire extinguishing material 40 can provide some protection to the nickel layer, improving the impact resistance of the cylindrical battery 1 at the recess 113. Furthermore, the fire extinguishing material 40 can work together with the nickel layer to block external corrosive media, improving rust resistance.

[0102] In some embodiments, the cylindrical battery 1 further includes an insulating film 50 disposed on the outside of the housing 10, the insulating film 50 covering at least a portion of the recess 113 from the outside.

[0103] The recess 113 has a recess opening, and the insulating film 50 covers at least a portion of the recess opening; for example, the insulating film 50 covers the entire recess opening.

[0104] In some embodiments, the fire extinguishing material 40 and the insulating film 50 are spaced apart in the radial direction of the cylindrical battery 1. Alternatively, in other embodiments, the fire extinguishing material 40 and the insulating film 50 are in contact.

[0105] In some embodiments, the insulating film 50 covers at least a portion of the outer surface of the sidewall body 111; for example, the insulating film 50 covers the entire sidewall body 111. Optionally, the insulating film 50 may include a first portion 54 and a second portion 55, the first portion 54 covering the sidewall body 111 and the second portion 55 covering the recessed opening, wherein the first portion 54 and the second portion 55 are integrally connected in the axial direction X.

[0106] As an example, both the first part 54 and the second part 55 extend around the circumference of the cylindrical battery 1.

[0107] In some embodiments, the insulating film 50 further includes a third portion 56 connected to the second portion 55, the third portion 56 covering at least a portion of the outer surface of the fixing portion 114.

[0108] In some embodiments, the fixing portion 114 includes a main body portion 114a and a bending portion 114b. The main body portion 114a surrounds the end cap 31 and is connected to the second portion 55. The bending portion 114b extends from the end of the main body portion 114a away from the second portion 55 and bends toward the axis L of the cylindrical battery 1. A portion of the third portion 56 covers the entire main body portion 114a, and another portion of the third portion 56 is located on the side of the bending portion 114b away from the electrode assembly 20.

[0109] In some embodiments, the insulating film 50 further includes a fourth portion 57 connected to the first portion 54, the fourth portion 57 being located on the side of the bottom wall 12 opposite to the electrode assembly 20.

[0110] In some embodiments, the insulating film 50 can be a heat-shrinkable film. During the production process of the cylindrical battery 1, the heat-shrinkable film can be first placed on the outside of the casing, and then the heat-shrinkable film is heated, causing it to shrink and adhere tightly to the surface of the casing 10, forming an insulating film 50 that tightly covers the casing 10.

[0111] In some embodiments, the insulating film 50 may include a polyolefin material, such as polyethylene, polypropylene, or other suitable materials.

[0112] In addition to providing insulation protection for the housing 10, the insulating film 50 also covers at least a portion of the recess 113 from the outside. This allows the insulating film 50 to block and limit the position of the extinguishing material 40 contained within the recess 113, improving the positional reliability of the extinguishing material 40 relative to the housing 10. Simultaneously, the insulating film 50 also prevents external dust and impurities from entering the recess 113 and adversely affecting the extinguishing material 40, thereby improving the reliability and service life of the extinguishing material 40.

[0113] In some embodiments, please refer to Figure 5 and Figure 6 The insulating film 50 includes a body portion 51 and a weak portion 52 disposed on the body portion 51.

[0114] The main body 51 is a major component of the insulating film 50. The weak part 52 is located on the main body 51, and its structural strength is less than that of the main body 51. Structural strength refers to the ability of a component to resist failure under load. The lower the structural strength, the easier it is for the component to be damaged under external force. In other words, the weak part 52 is more likely to be damaged under external force than the main body 51.

[0115] In some embodiments, the weak portion 52 and the main body 51 can be separate structures and made of different materials. That is, by reasonably selecting the material of the weak portion 52, the weak portion 52 can have a smaller structural strength. Alternatively, in other embodiments, a through hole 53 can be provided on the insulating film 50, and the weak portion 52 can be located near the through hole 53. The presence of the through hole 53 also helps to reduce the structural strength of the weak portion 52.

[0116] In some embodiments, the recess 113 is disposed opposite to the weak portion 52 in the radial direction, that is, the weak portion 52 corresponds to the fire extinguishing material 40 in the radial direction.

[0117] In the event of an abnormal temperature around the extinguishing material 40, the extinguishing material 40 can be activated and break through the insulating membrane 50, thereby extinguishing and cooling the cylindrical battery 1 and its surrounding environment or components. Furthermore, by incorporating a weak point 52 in the insulating membrane 50 with lower structural strength, the extinguishing material 40 can more easily break through the insulating membrane 50 via the weak point 52, thus achieving rapid fire extinguishing and cooling and improving safety performance.

[0118] In some embodiments, the battery module 1000 includes a plurality of cylindrical batteries 1, each cylindrical battery 1 including fire extinguishing material 40 housed in a recess 113 and an insulating film 50 including a weak point 52. Based on this, when some cylindrical batteries 1 experience abnormal temperature rise or thermal runaway, in addition to fire extinguishing and cooling achieved by the fire extinguishing material 40 located within the abnormal cylindrical battery 1 itself, the fire extinguishing material 40 of adjacent cylindrical batteries 1 can also be activated due to the surrounding high-temperature environment, thereby breaking through the corresponding weak point 52 to extinguish and cool the adjacent abnormal cylindrical batteries 1, thus improving the overall safety performance of the battery module 1000.

[0119] In some embodiments, the insulating film 50 includes a plurality of through holes 53, and the weak portion 52 includes a plurality of sub-weak portions 521. The through holes 53 are disposed radially through the insulating film 50, and the plurality of through holes 53 are spaced apart from each other in the circumferential direction. In the circumferential direction, the sub-weak portions 521 are located between two adjacent through holes 53, and the plurality of sub-weak portions 521 are spaced apart from each other in the circumferential direction.

[0120] In some embodiments, the circumferential dimension of a single sub-weak portion 521 may be equal to the circumferential dimension of a single through-hole 53. Alternatively, in other embodiments, the circumferential dimension of a single sub-weak portion 521 may be less than or greater than the circumferential dimension of a single through-hole 53.

[0121] In some embodiments, a plurality of sub-weak portions 521 and a plurality of through holes 53 are alternately arranged along the circumference of the cylindrical battery 1. That is, in the circumferential direction, there is a sub-weak portion 521 between two adjacent through holes 53, and there is a through hole 53 between two adjacent sub-weak portions 521. The arrangement of the through holes 53 makes the sub-weak portions 521 more susceptible to being broken by external forces, thereby making the weak portions 521 have less structural strength relative to the main body portion 51.

[0122] In some embodiments, the recess 113 is arranged radially opposite to the through hole 53. In other words, the extinguishing material 40 is arranged opposite to the through hole 53, so that in the event of an abnormal temperature around the extinguishing material 40, a portion of the extinguishing material 40 can directly exit the recess 113 via the through hole 53, thereby achieving rapid cooling of the cylindrical battery 1 and its surrounding environment or components. Other portions of the extinguishing material 40 can break through the weak portion 521 between adjacent through holes 53. Furthermore, the arrangement of the through holes 53 makes the weak portion 521 easier to break through, thus helping to improve the extinguishing and cooling efficiency.

[0123] In some embodiments, the extinguishing material 40 is entirely contained within the recess 113, the volume of the extinguishing material 40 is V1, the volume of the recess 113 is V2, and 0.5 ≤ V1 / V2 ≤ 0.9. Exemplarily, V1 / V2 is one of 0.5, 0.55, 0.6, 0.65, 0.7, 0.75, 0.8, 0.85, and 0.9.

[0124] By setting V1 / V2 to be greater than or equal to 0.5, a certain amount of fire extinguishing material 40 can be contained in the cylindrical battery 1, thereby improving the reliability of fire extinguishing and cooling and enhancing the safety performance of the cylindrical battery 1. Simultaneously, setting V1 / V2 to be less than or equal to 0.9 ensures that the fire extinguishing material 40 can be completely contained within the recess 113. This recess 113 can then be used to limit the position of the fire extinguishing material 40, reducing the risk of the fire extinguishing material 40 detaching from the recess 113 due to movement or transportation of the cylindrical battery 1, and improving the relative positional reliability between the fire extinguishing material 40 and the casing 10. Furthermore, this also helps to reduce the adverse impact of the presence of the fire extinguishing material 40 on the overall weight of the cylindrical battery 1, thus balancing the safety performance and lightweight design of the cylindrical battery 1.

[0125] In some embodiments, the protrusion 112 includes an arcuate portion 112a and two connecting portions 112b, which are respectively connected to the two ends of the arcuate portion 112a.

[0126] In a cross-section parallel to the axial direction X, the arc-shaped portion 112a is a portion of the protrusion 112 that has an arc-shaped structure, and the arc-shaped portion 112a protrudes radially towards the central axis of the cylindrical battery 1. Two connecting portions 112b are respectively connected to the two ends of the arc-shaped portion 112a. One connecting portion 112b is used to connect the arc-shaped portion 112a to the sidewall body 111, and the other connecting portion 112b is used to connect the arc-shaped portion 112a to the fixing portion 114. The arc-shaped portion 112a and the two connecting portions 112b together enclose and form the recess 113.

[0127] In some embodiments, the cross-sectional shape of the connecting portion 112b may be rectangular, or in other embodiments, the cross-sectional shape of the connecting portion 112b may also have a certain curvature. The specific shape of the connecting portion 112b is affected by factors such as the rolling process.

[0128] In some embodiments, the fire extinguishing material 40 completely covers the outer surface of the arcuate portion 112a, that is, the fire extinguishing material 40 completely covers the surface in the arcuate portion 112a used to define the recess 113.

[0129] The curved portion 112a has a larger curvature than the connecting portion 112b, and a larger curvature often means a larger amount of deformation. Therefore, the convex portion 112 is more prone to cracking on the outer surface of the curved portion 112a. At the same time, the curved portion 112a is also prone to having lower structural strength. In view of this, by completely covering the outer surface of the curved portion 112a with the fire extinguishing material 40, the cracks on the outer surface of the curved portion 112a can be shielded and protected by the fire extinguishing material 40, thereby improving the corrosion resistance of the cylindrical battery 1 at the convex portion 112. At the same time, the contact arrangement between the fire extinguishing material 40 and the curved portion 112a also helps to improve the structural strength in this area and reduce the risk of deformation of the curved portion 112a due to external forces or other factors during transportation or use of the cylindrical battery 1.

[0130] In addition, the outer surface of the arc-shaped portion 112a is arc-shaped, and at least a portion of the fire extinguishing material 40 is in arc-shaped contact with the arc-shaped portion 112a. The arc-shaped contact design can limit the fire extinguishing material 40 to a certain extent, thereby improving the positional reliability of the fire extinguishing material 40 relative to the recess 113.

[0131] In some embodiments, the extinguishing material 40 may be disposed in contact with at least one connecting portion 112b, or in other embodiments, the extinguishing material 40 may be disposed in a manner that does not contact either of the two connecting portions 112b.

[0132] In some embodiments, in the axial direction X, a portion of the protrusion 112 is located between the end cap 31 and the electrode assembly 20, and at least a portion of the extinguishing material 40 overlaps with the end cap 31.

[0133] During the use or transportation of the cylindrical battery 1, external stress may act directly on the protrusion 112 from one radial side of the cylindrical battery 1, or indirectly from one axial X side of the cylindrical battery 1. Specifically, since a portion of the protrusion 112 is located between the end cap 31 and the electrode assembly 20, external stress acting directly or indirectly on the end cap 31 may be transmitted axially X to the protrusion 112, thereby increasing the risk of deformation of the protrusion 112. Further, referring to the accompanying drawings... Figure 3 In other words, the stress on the end cap 31 may be transmitted to the protrusion 112 in sequence through the explosion-proof sheet 32 ​​and the insulating structure 34.

[0134] In view of this, by overlapping at least a portion of the fire extinguishing material 40 with the end cap 31 in the axial X direction, the fire extinguishing material 40 can help support the protrusion 112 when the protrusion 112 is subjected to stress from the end cap 31, thereby reducing the risk of deformation of the protrusion 112 and improving the reliability of the cylindrical battery 1.

[0135] In some embodiments, the recess 113 includes an overlapping space that coincides with the end cap 31 in the axial direction X, and the fire extinguishing material 40 fills the overlapping space.

[0136] The overlapping space is the portion of the recess 113 that is axially opposite to the end cap 31 in the X direction. The overlapping space and the recess opening are arranged radially at intervals. By filling the overlapping space with the extinguishing material 40, on the one hand, more of the extinguishing material 40 can be axially opposite to the end cap 31, thereby helping the protrusion 112 to better resist the stress from the end cap 31 and reducing the risk of deformation of the protrusion 112. On the other hand, it allows the recess 113 to accommodate more extinguishing material 40, thereby improving the fire extinguishing and cooling effect.

[0137] In some embodiments, the cylindrical battery 1 further includes an insulating member 60, a portion of which is located between the protrusion 112 and the electrode assembly 20 in the axial direction X, and the protrusion 112 is in contact with the insulating member 60.

[0138] The insulating member 60 can separate the protrusion 112 from the electrode assembly 20 to reduce the risk of short circuit caused by the contact between the protrusion 112 and the electrode assembly 20. When the cylindrical battery 1 is subjected to external force, the insulating member 60 can reduce the amplitude of the axial movement of the electrode assembly 20 in the X direction, reduce the risk of damage to the electrode assembly 20, and improve the shock resistance and drop resistance of the cylindrical battery 1.

[0139] In some embodiments, the extinguishing material 40 at least partially overlaps with the insulating element 60 in the axial direction X.

[0140] During the use of the cylindrical battery 1, the electrode assembly 20 easily generates a lot of heat, and some of this heat is transferred to the insulating member 60. Based on this, by at least partially overlapping the fire extinguishing material 40 and the insulating member 60 in the axial direction X, the heat from the electrode assembly 20 can be conducted along the axial direction X through the insulating member 60 and the protrusion 112 to the fire extinguishing material 40. This allows the fire extinguishing material 40 to quickly absorb heat from inside the casing 10, enabling it to respond rapidly when the cylindrical battery 1 experiences abnormally high temperatures, thereby quickly cooling the cylindrical battery 1 and improving its safety performance.

[0141] In addition, the fire extinguishing material 40 can also assist the protrusion 112 in compressing the electrode assembly 20 and reduce the risk of deformation of the protrusion 112 during vibration, thereby reducing the movement of the electrode assembly 20 and improving the positional reliability of the electrode assembly 20 within the housing 10.

[0142] In some embodiments, please refer to Figure 7 The extinguishing material 40 includes a capsule 41, which includes a capsule wall 411 and an extinguishing agent 412 located within the capsule wall 411.

[0143] The capsule 41 is the core structure in the fire extinguishing material 40 used to achieve the fire extinguishing effect. The capsule 41 includes a capsule wall 411 and a fire extinguishing agent 412. The capsule wall 411 is a hollow structure, and the fire extinguishing agent 412 is contained within the capsule wall 411. The arrangement of the capsule wall 411 can, on the one hand, restrict the position of the fire extinguishing agent 412, so that the fire extinguishing agent 412 can be kept within the recess 113, and on the other hand, reduce the influence of the external environment on the physical or chemical properties of the fire extinguishing agent 412 itself. For example, during the normal operation of the cylindrical battery 1, the fire extinguishing agent 412 can be a liquid structure, or it can be a solid structure or a gaseous structure.

[0144] In some embodiments, the capsule 41 is configured such that when the temperature is above a threshold, the capsule wall 411 melts or breaks, and the extinguishing agent 412 is released.

[0145] In some embodiments, the threshold is A and may satisfy: 140℃≤A≤200℃. For example, A is one of 140℃, 150℃, 160℃, 170℃, 180℃, 190℃, and 200℃.

[0146] In some embodiments, when the temperature is below a threshold, the extinguishing agent 412 is in a liquid state, while when the temperature is above the threshold, the extinguishing agent 412 vaporizes, causing the air pressure inside the capsule wall 411 to rise. When the air pressure rises to a certain level, the capsule wall 411 ruptures due to the high pressure. At this time, the extinguishing agent 412 located inside the capsule wall 411 can detach from the capsule wall 411 and come into contact with the cylindrical battery 1 or the components around the cylindrical battery 1, thereby achieving the fire extinguishing and cooling function.

[0147] In some embodiments, the melting point of the capsule wall 411 may not be higher than the threshold. When the temperature of the capsule wall 411 is higher than the threshold, the extinguishing agent 412 located in the capsule wall 411 can detach from the capsule wall 411 and come into contact with the cylindrical battery 1 or the components around the cylindrical battery 1, thereby achieving the function of extinguishing fire and cooling down.

[0148] By incorporating the capsule wall 411 and the extinguishing agent 412, when the temperature is below a threshold, the capsule wall 411 can isolate the extinguishing agent 412 from the external environment, thereby reducing the impact of the extinguishing agent 412 on the normal operation of the cylindrical battery 1 and reducing the impact of the external environment on the physical or chemical properties of the extinguishing agent 412 itself, thus improving the service life of the extinguishing material 40. When the temperature exceeds the threshold, the capsule wall 411 can melt or break, allowing the extinguishing agent 412 to detach from the capsule wall 411, thereby achieving the fire extinguishing and cooling function. This design can meet the needs of the extinguishing material 40 for static placement during the normal operation of the cylindrical battery 1, as well as the needs of the extinguishing material 40 for activation under high temperature conditions.

[0149] In some embodiments, the extinguishing material 40 includes at least one of perfluorohexanone, perfluorobutyl methyl ether, fluorinated ketone, sodium bicarbonate, potassium bicarbonate, and ammonium phosphate.

[0150] Perfluorohexanone is a new type of environmentally friendly material that extinguishes fires through a dual action of physical heat absorption (lowering the temperature of the fire source) and chemical inhibition (breaking the combustion chain). Perfluorobutyl methyl ether (PFME) is a fluorinated compound that rapidly absorbs heat and inhibits flame spread, thus extinguishing the fire and cooling it down. Fluorinated ketones are fluorinated ketone compounds that, in addition to physical heat absorption and chemical combustion inhibition, also isolate oxygen, causing the flame to extinguish due to lack of oxygen. Sodium bicarbonate and potassium bicarbonate are both alkaline compounds that can suppress smoke. Ammonium phosphate is a nitrogen-containing compound that can be used as a flame retardant additive.

[0151] In some embodiments, the material of the capsule wall 411 includes a polymer material, which includes at least one of polypropylene and polyethylene.

[0152] Polymer materials, including polypropylene and polyethylene, often possess strong density. By incorporating polymer materials into the capsule wall 411, the capsule wall 411 can tightly encapsulate the extinguishing agent 412 during normal operation of the cylindrical battery 1, thereby improving the structural reliability of the extinguishing material 40. Furthermore, both polypropylene and polyethylene are non-toxic materials with strong chemical stability, effectively protecting the extinguishing agent 412 during storage and transportation, and leaving minimal residue after extinguishing and cooling operations, thus improving environmental performance.

[0153] In some embodiments, the extinguishing material 40 further includes an adhesive that binds the capsule 41 and forms a mixture, thereby producing extinguishing materials 40 in various shapes.

[0154] According to the second aspect of this application, please refer to Figure 8 This application also provides a battery module 1000, which includes a plurality of cylindrical batteries 1 provided according to any embodiment of this application.

[0155] In some embodiments, the battery module 1000 further includes a plurality of busbars. The busbars connect to the cylindrical batteries 1. At least two cylindrical batteries 1 can be connected in series or in parallel via the busbars.

[0156] According to the third aspect of this application, please refer to Figure 9 This application also provides an electrical device 2000, which includes a battery module 1000 provided in any embodiment of this application. The battery module 1000 can provide electrical energy to the electrical device 2000.

[0157] The electrical equipment used in the embodiments of this application can be portable devices, electric toys, drones, power tools, energy storage systems, etc. Power tools include metal cutting power tools, cleaning tools, etc., such as electric drills, electric wrenches, vacuum cleaners, robot vacuum cleaners, etc. The embodiments of this application do not impose any special limitations on the above-mentioned electrical equipment.

[0158] Although this application has been described with reference to preferred embodiments, various modifications can be made thereto and components can be replaced with equivalents without departing from the scope of this application. In particular, the technical features mentioned in the various embodiments can be combined in any manner, provided there is no structural conflict. This application is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

Claims

1. A cylindrical battery, characterized in that, include: A housing includes a sidewall, the sidewall comprising a sidewall body and a protrusion, the protrusion protruding from the inner surface of the sidewall body, and a recess provided on the outer side of the protrusion; An electrode assembly is housed within the housing, the sidewall body surrounds the electrode assembly, and at least a portion of the protrusion is disposed on one side of the electrode assembly along the axial direction of the cylindrical battery. Fire extinguishing material is contained in the recess.

2. The cylindrical battery according to claim 1, characterized in that, It also includes an insulating film disposed on the outside of the housing, the insulating film covering at least a portion of the recess from the outside.

3. The cylindrical battery according to claim 2, characterized in that, The insulating film includes a body portion and a weak portion disposed on the body portion. Along the radial direction of the cylindrical battery, the recess is disposed opposite to the weak portion.

4. The cylindrical battery according to claim 3, characterized in that, The insulating film includes multiple through holes, and the weak portion includes multiple sub-weak portions. The multiple sub-weak portions and the multiple through holes are alternately arranged along the circumference of the cylindrical battery. Along the radial direction of the cylindrical battery, the recess is positioned opposite to the through hole.

5. The cylindrical battery according to claim 1, characterized in that, The fire extinguishing material is entirely contained within the recess, the volume of the fire extinguishing material is V1, the volume of the recess is V2, and 0.5≤V1 / V2≤0.

9.

6. The cylindrical battery according to claim 1, characterized in that, The protrusion includes an arc-shaped portion and two connecting portions, the two connecting portions being respectively connected to the two ends of the arc-shaped portion, and the fire extinguishing material completely covering the outer surface of the arc-shaped portion.

7. The cylindrical battery according to claim 1, characterized in that, The cylindrical battery also includes an end cap, which is connected to the housing; In the axial direction, a portion of the protrusion is located between the end cap and the electrode assembly, and at least a portion of the extinguishing material overlaps with the end cap.

8. The cylindrical battery according to claim 7, characterized in that, The recess includes an overlapping space that overlaps with the end cap in the axial direction, and the fire extinguishing material fills the overlapping space.

9. The cylindrical battery according to claim 1, characterized in that, It also includes an insulating element, a portion of which is located between the protrusion and the electrode assembly in the axial direction, the protrusion being in contact with the insulating element; In the axial direction, the fire extinguishing material at least partially overlaps with the insulating element.

10. The cylindrical battery according to any one of claims 1 to 9, characterized in that, The extinguishing material includes a capsule, the capsule comprising a capsule wall and an extinguishing agent located within the capsule wall, the capsule being configured such that when the temperature exceeds a threshold, the capsule wall melts or breaks, and the extinguishing agent is released.

11. The cylindrical battery according to claim 10, characterized in that, The extinguishing agent is one of perfluorohexanone, perfluorobutyl methyl ether, fluorinated ketone, sodium bicarbonate, potassium bicarbonate, and ammonium phosphate; and / or, The capsule wall is made of a polymer material, which includes either polypropylene or polyethylene.

12. A battery module, characterized in that, Includes multiple cylindrical batteries according to any one of claims 1-11.

13. An electrical appliance, characterized in that, Including the cylindrical battery according to any one of claims 1-11.

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