CN216720196U - Battery cell, battery and power consumption device - Google Patents

Abstract

The embodiment of the application provides a battery monomer, battery and power consumption device, belongs to battery technical field. The battery cell includes a housing and at least one pressure relief mechanism. The housing has at least one wall portion. The pressure relief mechanism comprises a pressure relief channel and a sealing piece, the pressure relief channel is arranged on at least one wall, and the sum S1 of the sectional areas of all the pressure relief channels on one wall and the area S2 of the corresponding wall meet the following conditions: S1/S2 is more than or equal to 0.1 and less than or equal to 0.8; the closure member closes at least the pressure relief passage. When the pressure or the temperature in the single battery reaches a threshold value, the pressure or the temperature is gathered to the pressure relief mechanism, the closing piece is damaged, and the pressure or the temperature is quickly released to the outside of the shell along at least one pressure relief channel, so that the problem that the single battery explodes due to the fact that the pressure or the temperature cannot be timely discharged out of the shell is solved, and the safety performance of the single battery is improved.

Description

Battery cell, battery and power consumption device

Technical Field

The embodiment of the application relates to the technical field of batteries, in particular to a battery monomer, a battery and an electric device.

Background

The battery can be used as an operation power supply of the vehicle and also can be used as a driving power supply of the vehicle to provide driving power for the vehicle instead of or partially replace fuel oil or natural gas.

In addition to improving the performance of batteries, safety issues are also a considerable problem in the development of battery technology. If the safety problem of the battery cannot be guaranteed, the battery cannot be used. Therefore, how to enhance the safety of the battery is a technical problem to be solved urgently in the battery technology.

SUMMERY OF THE UTILITY MODEL

In view of the above problems, embodiments of the present application provide a battery cell, a battery and an electric device, so as to improve the safety performance of the battery.

According to a first aspect of embodiments herein, a battery cell is provided. The battery cell includes: a housing and at least one pressure relief mechanism. The housing has at least one wall portion. The pressure relief mechanism includes a pressure relief channel and a closure. The pressure relief channel is arranged on at least one wall part, and the sum S1 of the sectional areas of all the pressure relief channels on one wall part and the area S2 of the corresponding wall part meet the following conditions: 0.1 is less than or equal to S1/S2 is less than or equal to 0.8. The closure member closes at least the pressure relief passage. When the pressure or temperature inside the housing reaches a threshold value, the closure is broken and the pressure or temperature is vented through the pressure relief passage.

Through the scheme, when the pressure or the temperature in the single battery reaches the threshold value, the pressure or the temperature is gathered to the pressure relief mechanism, the closing piece is damaged, and the pressure or the temperature is quickly released to the outside of the shell along at least one pressure relief channel, so that the explosion problem caused by the fact that the pressure or the temperature in the single battery cannot be timely discharged is solved, and the safety performance of the single battery is improved. When the battery cell is in normal use, the sealing piece can play a role of physical shielding, so that the interior of the battery cell is kept sealed. In addition, the proportion of the total cross section area of the pressure relief channel on one wall part to the area of the wall part is less than or equal to 0.8, so that the mechanical strength of the wall part in normal use can be ensured.

In some embodiments, the sum of the cross-sectional areas of all pressure relief channels on one wall S1 and the area of the corresponding wall S2 satisfy: 0.3-0.7 of S1/S2.

Through the scheme, the pressure or the temperature can easily damage the sealing piece, the pressure or the temperature can be discharged along the pressure discharge channel more efficiently, and the possibility of explosion of the battery cell is lower.

In some embodiments, the melting point of the closure is 90 ℃ or greater and 150 ℃ or less.

Through setting up the minimum melting point of closure to coincide with the temperature threshold value at battery monomer thermal runaway initial stage, make the closure can melt at thermal runaway's initial stage, with battery monomer inside and outside intercommunication, be convenient for along pressure release channel relief pressure or temperature. In addition, the highest melting point of the sealing part is limited to be below 150 ℃, so that the sealing part can be melted in the process of accelerating the reaction in the battery cell, the interior of the battery cell is communicated with the outside, and the possibility of thermal runaway of the battery cell is reduced.

In some embodiments, the wall includes a plurality of pressure relief mechanisms spaced apart on the wall.

Through the scheme, the pressure or the temperature generated in the single battery can be released at a plurality of parts of the wall part, and the release efficiency of the pressure release mechanism to the pressure or the temperature is improved.

In some embodiments, the plurality of pressure relief passages are configured to decrease in area from a central portion of the wall portion to a peripheral portion.

The design enables the area of the pressure relief channel to be adaptive to the temperature of the position of the pressure relief channel, and all the pressure relief channels can release pressure or temperature when the single battery is out of control due to heat. In addition, the area of the pressure relief channel at the peripheral part is less, and the mechanical strength of the peripheral part of the wall part is favorably ensured.

In some embodiments, the pressure relief channel is circular in cross-section.

Because circular pressure release channel's lateral wall does not have the edges and corners, consequently, at pressure and temperature along the in-process that pressure release channel released, can not receive the influence of edges and corners, the possibility that produces the spark is minimum, and pressure release channel is comparatively safe to the release of pressure or temperature.

In some embodiments, the distance L1 between adjacent pressure relief channels is configured to satisfy: l1 is more than or equal to D/2 and less than or equal to D; wherein D is the diameter of the pressure relief channel.

If the distance between adjacent pressure relief channels is larger than the diameter of the pressure relief channel, the number of pressure relief channels distributed on the surface of the wall is small, and the ratio of the sum of the cross-sectional areas of all the pressure relief channels on the wall S1 to the area S2 of the corresponding wall may be less than 0.1, which is not favorable for quick pressure or temperature relief. If the distance between adjacent pressure relief channels 24b is less than D/2 mm, the pressure relief channels are distributed too densely in the wall, so that part of the pressure relief channels will not perform the pressure relief function, and the mechanical strength of the housing will be reduced. Therefore, by limiting the distance between the adjacent pressure relief channels, the arrangement number of the pressure relief mechanisms on the wall part can be balanced, and the pressure or temperature relief rate of the pressure relief mechanisms and the mechanical strength of the wall part are ensured.

In some embodiments, the diameter D of the pressure relief channel satisfies: d is more than or equal to 1um and less than or equal to 1 cm.

Given the pressure inside the enclosure, the size of an individual pressure relief channel is an important factor in affecting the rate at which pressure or temperature is vented along that pressure relief channel. Size through with pressure release channel is injectd between 1um to 1cm, can guarantee the security that pressure release channel released pressure or temperature when guaranteeing pressure release channel to the discharge rate of pressure or temperature.

In some embodiments, the minimum distance L2 between the pressure relief channel and the edge of the wall satisfies: l2 is more than or equal to 1 cm.

Because the edge of the wall part is the part which is seriously worn in the use process of the single battery, the edge part has enough wear allowance through the scheme, the service cycle of the wall part is favorably prolonged, and the service life of the single battery is prolonged.

According to a second aspect of embodiments of the present application, there is provided a battery. The battery includes a plurality of battery cells of the first aspect and a housing. The housing has a vent passage for venting the pressure or temperature of the cell bleed.

Through set up vent channel on the shell for the inside pressure of battery monomer or temperature are discharged from battery monomer after, can discharge to the battery outside through vent channel on the shell, avoid pressure or temperature gathering between a plurality of battery monomer and shell, arouse the explosion, with the security that improves the battery.

According to a third aspect of embodiments of the present application, there is provided an electric device. The power consuming device includes the battery of the second aspect. The battery is used for providing electric energy.

Through set up the discharge passage on the shell in with electric installation, and have pressure relief mechanism's battery on the free casing of battery for when pressure or temperature in the single battery reach the threshold value, pressure relief mechanism on the casing and the discharge passage on the shell can discharge pressure or temperature to the battery outside, avoid the explosion of battery, improve with electric installation's security.

The foregoing description is only an overview of the technical solutions of the embodiments of the present application, and the embodiments of the present application can be implemented according to the content of the description in order to make the technical means of the embodiments of the present application more clearly understood, and the detailed description of the present application is provided below in order to make the foregoing and other objects, features, and advantages of the embodiments of the present application more clearly understandable.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings needed to be used in the description of the embodiments are briefly introduced below, and it is obvious that the drawings in the following description are some embodiments of the present application, and it is obvious for those skilled in the art to obtain other drawings based on the drawings without creative efforts.

FIG. 1 is a schematic illustration of a vehicle according to some embodiments of the present application.

Fig. 2 is an exploded view of a battery according to some embodiments of the present disclosure.

Fig. 3 is an exploded view of a battery cell according to some embodiments of the present disclosure.

FIG. 4 is a first layout of the closure and pressure relief channel in the wall of some embodiments of the present application.

FIG. 5 is a second layout of the closure and pressure relief channel in the wall of some embodiments of the present application.

FIG. 6 is a first profile of a pressure relief mechanism in a wall portion according to some embodiments of the present application.

FIG. 7 is a second profile of a wall portion of a pressure relief mechanism according to some embodiments of the present application.

Description of reference numerals:

a vehicle 1000;

battery 100, controller 200, motor 300;

a box 10, a first part 11, a second part 12;

battery cell 20, end cap 21, casing 22, wall 22a, electrode assembly 23, pressure relief mechanism 24, closure 24a, pressure relief channel 24 b.

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application, and it is obvious that the described embodiments are some embodiments of the present application, but not all embodiments. All other embodiments obtained by a person of ordinary skill in the art based on the embodiments in the present application without making any creative effort belong to the protection scope of the present application.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs; the terminology used in the description of the application herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application.

The terms "comprising" and "having," and any variations thereof, in the description and claims of this application and in the description of the figures are intended to cover, but not exclude, other things. The word "a" or "an" does not exclude a plurality.

Reference herein to "an embodiment" means that a particular feature, structure, or characteristic described in connection with the embodiment can be included in at least one embodiment of the application. The appearances of the phrase "an embodiment" in various places in the specification are not necessarily all referring to the same embodiment, nor are separate or alternative embodiments mutually exclusive of other embodiments. It is explicitly and implicitly understood by one skilled in the art that the embodiments described herein can be combined with other embodiments.

The directional terms appearing in the following description are directions shown in the drawings, and do not limit the specific structure of the battery cell and the battery of the present application. For example, in the description of the present application, the terms "length," "width," "thickness," "top," "bottom," and the like, indicate an orientation or positional relationship based on that shown in the drawings, merely to facilitate the description of the application and to simplify the description, and do not indicate or imply that the referenced device or element must have a particular orientation, be constructed in a particular orientation, and be operated, and therefore should not be construed as limiting the application.

In the description of the present application, unless otherwise specified, "plurality" means two or more (including two), and similarly, "plural groups" means two or more (including two).

In the description of the present application, it should be noted that, unless otherwise explicitly specified or limited, the terms "mounted," "connected," and "connected" are to be construed broadly, e.g., "connected" or "connected" of a mechanical structure may refer to a physical connection, e.g., a physical connection may be a fixed connection, e.g., a fixed connection by a fastener, such as a screw, bolt, or other fastener; the physical connection can also be a detachable connection, such as a mutual clamping or clamping connection; the physical connection may also be an integral connection, for example, a connection made by welding, gluing or integrally forming the connection. The specific meaning of the above terms in the present application can be understood in a specific case by those of ordinary skill in the art.

At present, the application of the power battery is more and more extensive from the development of market situation. The power battery is not only applied to energy storage power supply systems such as hydraulic power, firepower, wind power and solar power stations, but also widely applied to electric vehicles such as electric bicycles, electric motorcycles, electric automobiles and the like, and a plurality of fields such as military equipment and aerospace. With the continuous expansion of the application field of the power battery, the market demand is also continuously expanding.

The development of battery technology needs to consider various design factors, such as energy density, cycle life, discharge capacity, charge and discharge rate, and other performance parameters, and also needs to consider the safety of the battery.

For cells, the main safety hazard comes from the charging and discharging processes, and at the same time, with a suitable ambient temperature design, there are generally at least three protective measures for the cells in order to effectively avoid unnecessary losses. In particular, the protective measures comprise at least a switching element, selection of a suitable isolating membrane material and a pressure relief mechanism. The switching element is an element that can stop charging or discharging the battery when the temperature or resistance in the battery cell reaches a certain threshold value. The isolating membrane is used for isolating the positive plate and the negative plate, and can automatically dissolve away the micron-scale (even nano-scale) micropores attached to the isolating membrane when the temperature rises to a certain value, so that metal ions cannot pass through the isolating membrane, and the internal reaction of the battery monomer is stopped.

For the pressure relief mechanism, in the existing single battery, because the proportion of the area of the pressure relief mechanism to the area of the shell of the single battery is small, when the pressure or the temperature reaches a threshold value, the problem that the pressure or the temperature is not timely released exists, the problem of battery explosion is easily caused, and the safety performance of the single battery is influenced.

In order to solve the technical problem, the inventor finds that at least one pressure relief mechanism comprising a pressure relief channel and a sealing piece can be arranged on at least one wall of a shell in a battery cell, and the pressure or temperature can break the sealing piece and quickly release the pressure or temperature along the pressure relief channel when the pressure or temperature in the battery cell reaches a threshold value by limiting the ratio of the sum of the cross-sectional areas of the at least one pressure relief channel on the wall to the area of the wall, so that the problem of explosion of the battery cell is improved, and the safety performance of the battery cell is improved.

Based on the above findings, the inventors have conducted intensive studies and designed a battery cell. The battery cell includes a housing and at least one pressure relief mechanism. The housing has at least one wall portion. The pressure relief mechanism comprises a sealing piece and a pressure relief channel, the pressure relief channel is arranged on at least one wall part, and the sum S1 of the sectional areas of all the pressure relief channels on one wall part and the area S2 of the corresponding wall part meet the following conditions: S1/S2 is more than or equal to 0.1 and less than or equal to 0.8; the closure member closes at least the pressure relief passage.

Among the above-mentioned battery monomer, when pressure or temperature in the casing reached the threshold value, pressure or temperature can destroy the closure to discharge to the casing outside along at least one pressure release passageway fast, in order to improve the release rate of pressure release mechanism to pressure or temperature, improve battery monomer's security performance.

The battery cell disclosed in the embodiment of the present application can be used in, but not limited to, an electric device for a vehicle, a ship, an aircraft, or the like. A power supply system including the battery cell, the battery, and the like disclosed in the present application may be used.

The embodiment of the application provides an electric device using a battery as a power supply, wherein the electric device can be but is not limited to a mobile phone, a tablet, a notebook computer, an electric toy, an electric tool, a battery car, an electric automobile, a ship, a spacecraft and the like. The electric toy may include a stationary or mobile electric toy, such as a game machine, an electric car toy, an electric ship toy, an electric airplane toy, and the like, and the spacecraft may include an airplane, a rocket, a space shuttle, a spacecraft, and the like.

For convenience of description, the following embodiments are described by taking an electric device according to an embodiment of the present application as an example of a vehicle 1000.

Referring to fig. 1, fig. 1 is a schematic structural diagram of a vehicle 1000 according to some embodiments of the present disclosure. The vehicle 1000 may be a fuel automobile, a gas automobile, or a new energy automobile, and the new energy automobile may be a pure electric automobile, a hybrid electric automobile, or a range-extended automobile, etc. The battery 100 is provided inside the vehicle 1000, and the battery 100 may be provided at the bottom or the head or the tail of the vehicle 1000. The battery 100 may be used to power the vehicle 1000. The vehicle 1000 may further include a controller 200 and a motor 300, the controller 200 being configured to control the battery 100 to supply power to the motor 300, for example, for starting, navigation, and operational power requirements while the vehicle 1000 is traveling.

In some embodiments of the present application, the battery 100 may serve as an operating power source of the vehicle 1000, and may also serve as a driving power source of the vehicle 1000, instead of or in part of fuel or natural gas, to provide driving power for the vehicle 1000.

Referring to fig. 2, fig. 2 is an exploded view of a battery 100 according to some embodiments of the present disclosure. The battery 100 includes a case 10 and a battery cell 20, and the battery cell 20 is accommodated in the case 10.

The case 10 serves to provide a receiving space for the battery cells 20, and the case 10 may take various structures. In some embodiments, the case 10 may include a first portion 11 and a second portion 12, the first portion 11 and the second portion 12 cover each other, and the first portion 11 and the second portion 12 together define a receiving space for receiving the battery cell 20. The second part 12 may be a hollow structure with one open end, the first part 11 may be a plate-shaped structure, and the first part 11 covers the open side of the second part 12, so that the first part 11 and the second part 12 jointly define a containing space; the first portion 11 and the second portion 12 may be both hollow structures with one side open, and the open side of the first portion 11 may cover the open side of the second portion 12. Of course, the box 10 formed by the first and second portions 11 and 12 may have various shapes, such as a cylinder, a rectangular parallelepiped, and the like.

The battery cells 20 may be multiple, and the multiple battery cells 20 may be connected in series, in parallel, or in series-parallel, where in series-parallel refers to that the multiple battery cells 20 are connected in series or in parallel. The plurality of battery cells 20 can be directly connected in series or in parallel or in series-parallel, and the whole formed by the plurality of battery cells 20 is accommodated in the box body 10; of course, the battery 100 may also be formed by connecting a plurality of battery cells 20 in series, in parallel, or in series-parallel to form a battery module, and then connecting a plurality of battery modules in series, in parallel, or in series-parallel to form a whole, and accommodating the whole in the case 10. The battery 100 may further include other structures, for example, the battery 100 may further include a bus member for achieving electrical connection between the plurality of battery cells 20. Each battery cell 20 may be a secondary battery or a primary battery; but is not limited to, a lithium sulfur battery, a sodium ion battery, or a magnesium ion battery. The battery cell 20 may be cylindrical, flat, rectangular parallelepiped, or other shape.

Referring to fig. 3, fig. 3 is an exploded schematic view of a battery cell 20 according to some embodiments of the present disclosure. The battery cell 20 includes an end cap 21, a case 22, an electrode assembly 23, and other functional components.

The end cap 21 is a member that covers an opening of the case 22 to isolate the internal environment of the battery cell 20 from the external environment. Without limitation, the shape of the end cap 21 may be adapted to the shape of the housing 22 to fit the housing 22. Alternatively, the end cap 21 may be made of a material (e.g., an aluminum alloy) having a certain hardness and strength, so that the end cap 21 is not easily deformed when being impacted, and the battery cell 20 may have a higher structural strength and improved safety. The end cap 21 may be provided with functional components such as electrode terminals. The electrode terminals may be used to electrically connect with the electrode assembly 23 for outputting or inputting electric energy of the battery cell 20. In some embodiments, the end cap 21 may further include a pressure relief mechanism for relieving the internal pressure when the internal pressure or temperature of the battery cell 20 reaches a threshold value. The material of the end cap 21 may also be various, such as copper, iron, aluminum, stainless steel, aluminum alloy, plastic, etc., which is not limited in this embodiment. In some embodiments, insulation may also be provided on the inside of the end cap 21, which may be used to isolate the electrical connection components within the housing 22 from the end cap 21 to reduce the risk of short circuits. Illustratively, the insulator may be plastic, rubber, or the like.

The case 22 is an assembly for mating with the end cap 21 to form an internal environment of the battery cell 20, wherein the formed internal environment may be used to house the electrode assembly 23, electrolyte, and other components. The housing 22 and the end cap 21 may be separate components, and an opening may be provided in the housing 22, and the opening may be covered by the end cap 21 to form the internal environment of the battery cell 20. Without limitation, the end cap 21 and the housing 22 may be integrated, and specifically, the end cap 21 and the housing 22 may form a common connecting surface before other components are inserted into the housing, and when it is necessary to enclose the inside of the housing 22, the end cap 21 covers the housing 22. The housing 22 may be a variety of shapes and sizes, such as rectangular parallelepiped, cylindrical, hexagonal prism, etc. Specifically, the shape of the case 22 may be determined according to the specific shape and size of the electrode assembly 23. The material of the housing 22 may be various materials, such as copper, iron, aluminum, stainless steel, aluminum alloy, plastic, etc., which is not limited in the embodiments of the present invention.

The electrode assembly 23 is a part in which electrochemical reactions occur in the battery cell 100. One or more electrode assemblies 23 may be contained within the case 22. The electrode assembly 23 is mainly formed by winding or stacking a positive electrode sheet and a negative electrode sheet, and a separator is generally disposed between the positive electrode sheet and the negative electrode sheet. The portions of the positive and negative electrode sheets having the active material constitute the body portion of the electrode assembly, and the portions of the positive and negative electrode sheets having no active material each constitute a tab. The positive electrode tab and the negative electrode tab may be located at one end of the main body portion together or at both ends of the main body portion, respectively. During the charging and discharging process of the battery, the positive active material and the negative active material react with the electrolyte, and the tabs are connected with the electrode terminals to form a current loop.

Please continue to refer to fig. 3 and further refer to fig. 4-5. Fig. 4 shows a first arrangement of the closure element 24a and the pressure relief duct 24b in the wall 22 a. Fig. 5 shows a second arrangement of the closure element 24a and the pressure relief duct 24b in the wall 22 a.

According to some embodiments of the present application, a battery cell 20 is provided. As shown in fig. 3, the battery cell 20 includes the housing 22 and at least one pressure relief mechanism 24. As shown in fig. 4 to 5, the housing 22 has at least one wall portion 22 a. The pressure relief mechanism 24 includes a closing member 24a and a pressure relief passage 24b, the pressure relief passage 24b is provided to at least one wall portion 22a, the sum of the sectional areas of all the pressure relief passages 24b on one wall portion 22a is S1, the area of the corresponding wall portion 22a is S2, and the following conditions are satisfied: S1/S2 is more than or equal to 0.1 and less than or equal to 0.8; the closing member 24a closes at least the pressure relief passage 24 b. When the pressure or temperature inside the housing 22 reaches a threshold value, the closure 24a is broken and the pressure or temperature is vented through the vent passage 24 b.

The wall portion 22a refers to a wall forming the housing 22. The wall portion 22a may be injection molded based on the shape of the electrode assembly 23, or may be assembly molded based on the shape of the electrode assembly 23. Illustratively, the wall portion 22a may be injection molded into a cylindrical shape to form a cylindrical housing 22; the wall 22a may also be assembled from two side walls, two large faces, and a bottom wall to form a square housing 22.

The sealing member 24a is a member that isolates the inside of the battery cell 20 from the outside together with the wall portion 22 a. The material of the sealing member 24a may be the same as that of the separation membrane in the electrode assembly 23.

The pressure relief passage 24b is a path for relieving pressure or temperature to the outside of the housing 22. The pressure relief passage 24b penetrates the wall portion 22 a. Illustratively, when the housing 22 is cylindrical, the pressure relief passage 24b penetrates the circumferential surface of the wall portion 22 a; when the housing 22 is square, the pressure relief passage 24b may extend through a side wall, a large face and/or a bottom wall of the wall portion 22 a. For example, when the pressure relief channel 24b is disposed on the sidewall, the pressure relief channel 24b penetrates the sidewall; when the pressure relief channel 24b is arranged on the large surface, the pressure relief channel 24b penetrates through the large surface; when the pressure relief passage 24b is provided in the bottom wall, the pressure relief passage 24b penetrates the bottom wall.

When the closing member 24a closes at least the pressure relief passage 24b, as shown in fig. 4, the closing member 24a may be provided on a surface of the wall portion 22a facing the inner cavity of the case 22, and the size of the closing member 24a may be set larger than that of the pressure relief passage 24 b. The seal member 24a may be bonded to a surface of the wall portion 22a facing the cavity of the housing 22 by an adhesive, or may be fixed to a surface of the wall portion 22a facing the cavity of the housing 22 by a fixing member. As shown in fig. 5, a groove may be provided in the side wall of the pressure relief passage 24b, a closing member 24a may be provided in the groove, and the closing member 24a may be sized to be the same as the groove. The closure 24a may be retained by the side walls of the recess and secured by adhesive.

The threshold at which the pressure or temperature inside the housing 22 reaches may vary depending on design requirements. The threshold may depend on the material of one or more of the positive electrode tab, the negative electrode tab, the electrolyte, and the separator in the battery cell 20. The closure 24a is broken, which means that the closure 24a is broken by being pressed under pressure or by being melted under temperature. The breaking of the closure 24a may be at least partial breaking, tearing or opening of the closure 24a, or the like. The pressure or temperature relief channel 24b is to indicate that the pressure or temperature inside the housing 22 is vented to the outside of the housing 22 along the pressure relief channel 24 b. The pressure relief passage 24b may also vent other emissions as well when the pressure is relieved. Other emissions include, but are not limited to: electrolyte, dissolved or split positive and negative electrode sheets, fragments of separator film, flame, etc.

If the sum S1 of the sectional areas of all the pressure relief passages 24b on one wall portion 22a and the area S2 of the corresponding wall portion 22a satisfy: if S1/S2 is less than 0.1, the area of the distribution area of the pressure release channel 24b on the wall 22a is too small, and the pressure release channel 24b cannot release the pressure or temperature quickly, which is not favorable for preventing thermal runaway of the battery cell 20. For example, when S1/S2 is equal to 0.09 under otherwise identical conditions, the distribution area of the pressure relief channel 24b in the wall 22a is too small, and the pressure or temperature cannot be rapidly discharged along the pressure relief channel 24b, and the temperature inside the battery cell 20 will rapidly rise to 350 ℃ after the test, which greatly increases the possibility of explosion of the battery cell 20.

If the sum S1 of the sectional areas of all the pressure relief passages 24b on one wall portion 22a and the area S2 of the corresponding wall portion 22a satisfy: S1/S2 is greater than 0.8, the distribution area of the pressure relief channel 24b on the wall portion 22a is too large. During assembly of the battery cells 20 into a module, the sealing member 24a is susceptible to breakage. The mechanical strength of the case 22 is not secured during normal use of the battery cell 20. During thermal runaway of the battery cell 20, the closure member 24a is less susceptible to pressure or temperature damage, and does not facilitate pressure or temperature venting. For example, when the pressure relief channel 24b is distributed over the wall 22a in an area that is too large when S1/S2 is equal to 0.9, the number or area of the sealing members 24a is too large, the sealing members 24a are not easily damaged by pressure or temperature, and the temperature inside the battery cell 20 rises rapidly to 300 ℃ through testing, so that the possibility of explosion of the battery cell 20 is greatly increased.

When the sum S1 of the cross-sectional areas of all the pressure relief channels 24b on one wall portion 22a and the area S2 of the corresponding wall portion 22a satisfy 0.1 ≦ S1/S2 ≦ 0.8, it is advantageous for both the pressure and temperature to break the closure 24a and for the pressure and temperature to quickly escape along the pressure relief channel 24 b. For example, in the case where other conditions are consistent, when S1/S2 is equal to 0.1, the maximum temperature inside the battery cell 20 is 113 ℃ through the test, and when S1/S2 is equal to 0.8, the maximum temperature inside the battery cell 20 is 112 ℃ through the test. It can be seen that when S1/S2 satisfies that S1/S2 is not less than 0.1 and not more than 0.8, the rate of pressure and temperature release along the pressure release mechanism 24 is greatly increased, the amount of pressure or temperature inside the battery cell 20 is reduced, and the possibility of explosion of the battery cell 20 is low.

The other conditions described above are the same as: the pressure relief channels 24b are of uniform shape, the cross-sectional area of each pressure relief channel 24b is uniform, the pressure relief channels 24b are of uniform size with the edges of the wall portion 22a, the distance between adjacent pressure relief channels 24b is uniform, and the melting point of the closure 24 is uniform.

In the technical solution of the embodiment of the present application, when the pressure or the temperature inside the battery cell 20 reaches a threshold value, the pressure or the temperature is gathered to the pressure relief mechanism 24 of the wall portion 22a, the sealing member 24a is damaged, and the pressure or the temperature is released to the outside of the case 22 along the at least one pressure release channel 24b, so as to improve the explosion problem caused by the fact that the pressure or the temperature inside the battery cell 20 cannot be timely discharged, and improve the safety performance of the battery cell 20; the closure 24a can act as a physical shield so that the interior of the cell 20 remains sealed during normal use of the cell 20. In addition, by making the ratio of the total cross-sectional area of the relief passage 24b in one wall portion 22a to the area of the wall portion 22a equal to or less than 0.8, the mechanical strength of the wall portion 22a in normal use can be ensured.

According to other embodiments of the present application, the sum S1 of the cross-sectional areas of all the pressure relief channels 24b on one wall portion 22a and the area S2 of the corresponding wall portion 22a satisfy: 0.3-0.7 of S1/S2.

On the basis of the previous embodiment, under the condition that other conditions are consistent, when S1/S2 is equal to 0.3, the highest temperature of thermal runaway of the battery cell 20 is 108 ℃ through testing; when S1/S2 equals 0.7, the maximum temperature of the battery cell 20 thermal runaway was tested to be 106 ℃. It can be seen that S1/S2 satisfies that when S1/S2 is not less than 0.7 and not more than 0.3, the rate of pressure and temperature venting along the pressure relief mechanism 24 is higher, and the possibility of explosion of the battery cell 20 is lower.

In the technical solution of the embodiment of the present application, the sum S1 of the cross-sectional areas of all the pressure relief channels 24b on one wall portion 22a and the area S2 of the corresponding wall portion 22a satisfy: 0.3 ≦ S1/S2 ≦ 0.7, so that the sealing member 24a is more easily damaged by pressure and temperature, the pressure or temperature is more efficiently released along the pressure release passage 24b, and the possibility of explosion of the battery cell 20 is lower.

According to other embodiments of the present application, closure 24a has a melting point of 90 ℃ or greater and 150 ℃ or less.

Typically, the optimal intervention temperature for thermal runaway of the battery cell 20 is between 90 ℃ and 150 ℃, and the earliest trigger temperature for thermal runaway is 90 ℃. If the internal temperature of the battery cell 20 reaches 90 ℃, no intervention is performed, the reaction inside the battery cell 20 is accelerated, the temperature rapidly rises, and finally the thermal runaway of the battery cell 20 is caused, so that a very serious safety accident is caused.

On the basis of the foregoing, if the melting point of the sealing member 24a is less than 90 ℃, the sealing member 24a may melt at the normal use temperature of the battery cell 20, communicating the inside of the battery cell 20 with the outside, and making the battery cell 20 incapable of further use.

If the closure member 24a has a melting point greater than 150 c, the closure member 24a remains intact after thermal runaway of the battery cell 20 occurs and the pressure relief mechanism 24 does not function to relieve pressure or temperature.

In the technical solution of the embodiment of the present application, the lowest melting point of the sealing member 24a is defined to be matched with the temperature threshold of the battery cell 20 at the initial stage of thermal runaway, so that the sealing member 24a can be melted at the initial stage of thermal runaway, the inside of the battery cell 20 is communicated with the outside, and the pressure or the temperature is conveniently discharged along the pressure discharge channel 24 b. In addition, the highest melting point of the sealing part 24a is limited below 150 ℃ so as to ensure that the sealing part 24a can be melted in the process of accelerating the reaction inside the battery unit 20, the inside of the battery unit 20 is communicated with the outside, and the possibility of thermal runaway of the battery unit 20 is reduced.

Referring now to fig. 6-7, fig. 6 illustrates a first distribution pattern of the pressure relief mechanism 24 in the wall 22a according to some embodiments of the present application; fig. 7 is a second profile of the pressure relief mechanism 24 in the wall portion 22a in some embodiments of the present application.

According to other embodiments of the present application, as shown in fig. 6 and 7, the wall 22a includes a plurality of pressure relief mechanisms 24, and the plurality of pressure relief mechanisms 24 are spaced apart from the wall 22 a.

When the plurality of pressure relief mechanisms 24 are spaced apart from each other in the wall portion 22a, a region having a predetermined shape may be defined in the wall portion 22a, and the plurality of pressure relief mechanisms 24 may be uniformly distributed in the region. For example, as shown in fig. 6, a rectangular area may be defined in the wall portion 22a, and the plurality of pressure relief mechanisms 24 may be uniformly distributed in the rectangular area; as shown in fig. 7, a circular region may be defined in the wall portion 22a, and the plurality of pressure relief mechanisms 24 may be uniformly distributed in the circular region. The embodiment of the present application does not limit the form in which the plurality of pressure relief mechanisms 24 are spaced apart from each other in the wall portion 22 a.

In general, since the size of the case 22 in the battery cell 20 is large, the installation area of the wall portion 22a is large. When one pressure relief mechanism 24 is provided in the wall portion 22a, a path along which the pressure or temperature inside the casing 22 is accumulated to the one pressure relief mechanism 24 is long, and a rate of the pressure or temperature being discharged along the one pressure relief passage 24b is slow, so that a phenomenon that the discharge is not fast easily occurs.

In the technical scheme of this application embodiment, through set up a plurality of pressure relief mechanism 24 at the wall portion 22a interval for pressure or the temperature that battery cell 20 inside produced can be let off at a plurality of positions of wall portion 22a, improve the efficiency of pressure or temperature that pressure relief mechanism 24 is let off.

According to other embodiments of the present application, with continued reference to FIG. 7, the plurality of pressure relief passages 24b are configured to decrease in area from a central portion to a peripheral portion of the wall portion 22 a.

In general, the middle portion of the wall portion 22a is less likely to be affected by the external ambient temperature to dissipate heat during use of the battery cell 20, and the temperature is higher. This is because the middle portion of the wall portion 22a does not need to be connected to the adjacent wall portion 22a as compared with the peripheral portion, and therefore the adjacent wall portion 22a does not largely affect the temperature of the middle portion of the wall portion 22 a; the peripheral portion of the adjacent wall portion 22a needs to be connected to the peripheral portion of the wall portion 22a, and the peripheral portion of the wall portion 22a and the peripheral portion of the adjacent wall portion 22a are both in contact with the environment, and the temperature of the peripheral portion of the wall portion 22a is more easily affected by the peripheral portion of the adjacent wall portion 22a, so that the temperature of the peripheral portion of the wall portion 22a is more easily lowered.

Under the above-mentioned phenomenon, if the temperature at the peripheral part of the wall portion 22a is low and the area of the pressure relief passage 24b is large, since the size of the sealing member 24a at least corresponds to the size of the pressure relief passage 24b, the sealing member 24a at the peripheral part is not easily damaged by the temperature, even by the low temperature, and thus, a part of the pressure relief mechanism 24 cannot release the pressure or the temperature.

Further, when the size of the pressure discharge passage 24b distributed in the peripheral portion of the wall portion 22a is large, the area ratio of the pressure discharge passage 24b in the peripheral portion is large, the mechanical strength of the peripheral portion is small, and the peripheral portion is more likely to be damaged by the influence of external factors.

In the technical scheme of this application embodiment, the area of pressure release channel 24b sets up to reduce to peripheral part along the middle part of wall portion 22a, makes pressure release channel 24 b's area can adapt to the temperature of its position, when battery cell 20 takes place thermal runaway, makes all pressure release channels 24b homoenergetic realize releasing pressure or temperature. In addition, the area of the pressure release passage 24b in the peripheral portion is small, which contributes to the mechanical strength of the peripheral portion of the wall portion 22 a.

According to other embodiments of the present application, the pressure relief channel 24b is circular in cross-section.

In the technical scheme of this application embodiment, because circular pressure release channel 24 b's lateral wall does not have the edges and corners, consequently, along the in-process that pressure release channel 24b was released, can not receive the influence of edges and corners at pressure or temperature, the possibility that produces mars is minimum, and pressure release channel 24b is comparatively safe to the release of pressure or temperature.

In other embodiments, the cross-section of the pressure relief channel 24b may be square, star-shaped, etc. When the cross section of the pressure relief channel 24b is provided in a square, star shape, the pressure relief channel 24b can also achieve relief of pressure or temperature. The cross-sectional shape of the pressure release channel 24b is not particularly limited in the embodiment of the present application.

According to other embodiments of the present application, the distance L1 between adjacent pressure relief channels 24b is configured to satisfy: l1 is more than or equal to D/2 and less than or equal to D; where D is the diameter of the pressure relief channel 24 b.

If the distance between adjacent pressure relief channels 24b is greater than the diameter of the pressure relief channel 24b, there are fewer pressure relief channels 24b distributed on the surface of the wall 22a, and the ratio of the sum of the cross-sectional areas S1 of all pressure relief channels 24b on the wall 22a to the area S2 of the corresponding wall 22a may be less than 0.1, which is not conducive to rapid pressure or temperature relief.

If the distance between adjacent pressure relief channels 24b is less than D/2 mm, the pressure relief channels 24b are distributed too densely in the wall portion 22a, so that a part of the pressure relief channels 24b may not perform the pressure relief function, and the mechanical strength of the housing 22 may be reduced.

In the technical scheme of this application embodiment, through the distance between the adjacent pressure release channel 24b of injecing, can balance pressure release mechanism 24 in the quantity that sets up of wall portion 22a, guarantee pressure release channel 24b to the efficiency of releasing of pressure or temperature to and the mechanical strength of wall portion 22 a.

According to other embodiments of the present application, the diameter D of the pressure relief channel 24b satisfies: d is more than or equal to 1um and less than or equal to 1 cm.

Given the pressure within the housing 22, the size of the individual pressure relief passages 24b is an important factor in affecting the rate at which pressure or temperature is relieved along the passages.

If the size of a single pressure relief channel 24b is set large (greater than 1cm), the rate at which pressure or temperature is vented through that pressure relief channel 24b is small, which is detrimental to rapid venting of pressure or temperature.

In contrast, if the size of a single pressure relief channel 24b is set small (less than 1um), the rate at which pressure or temperature is released through that pressure relief channel 24b is large, and sparks may be generated when the high-speed pressure or temperature rubs against the side wall of the pressure relief channel 24b during the release.

Among the technical scheme of this application embodiment, prescribe a limit to between 1um to 1cm through the size with pressure release channel 24b, can guarantee the security when pressure release channel 24b is released to pressure or temperature when guaranteeing pressure release channel 24b to the discharge rate of pressure or temperature.

According to other embodiments of the present application, the minimum distance L2 between the pressure relief channel 24b and the edge of the wall portion 22a satisfies: l2 is more than or equal to 1 cm.

The edge portion of the wall portion 22a is a place where the wear is severe during the use of the battery cell 20.

If the minimum distance between the pressure relief channel 24b and the edge of the wall portion 22a is less than 1cm, the mechanical strength of the edge portion of the wall portion 22a is not secured, and the wear of the edge portion is accelerated during the use of the battery cell 20.

In the technical scheme of this application embodiment, through the minimum distance between the edge of injecing pressure release channel 24b and wall portion 22a, make the edge part have sufficient wearing and tearing allowance, be favorable to prolonging the life cycle of wall portion 22a, prolong battery cell 20's life.

The present application also provides, according to some embodiments of the present application, a battery including a plurality of the aforementioned battery cells 20 and a housing. Wherein the case has a discharge passage for discharging the pressure or temperature discharged from the battery cells 20.

It should be noted that, when the plurality of battery cells 20 are all set as the square-casing battery cells 20, the plurality of battery cells 20 are stacked in a certain direction to form an arrangement structure, and in the process of forming the arrangement structure, structural glue needs to be arranged between the large surfaces of the casing 22 to fix the plurality of battery cells 20 together, and at this time, the pressure relief mechanism 24 arranged on the large surfaces cannot perform the pressure relief function. Therefore, it is necessary to dispose the pressure relief mechanisms 24 on the bottom wall, the side wall and/or the large surface without structural adhesive of the housing 22 to ensure that each pressure relief mechanism 24 can perform the pressure relief function.

On the basis of the above, one or more discharge passages may be provided in the housing. When the plurality of discharge channels are provided, the plurality of discharge channels may correspond to the pressure relief channel 24b on the case 22 of the battery cell 20, so as to be discharged from the discharge channel on the housing to the outside of the battery along the shortest route after the pressure or temperature is discharged from the battery cell 20.

Among the technical scheme of this application embodiment, through set up vent passage on the shell for the inside pressure of battery cell 20 or temperature are discharged the back from battery cell 20, can discharge to the battery outside through vent passage on the shell, avoid pressure or temperature gathering between a plurality of battery cells 20 and shell, avoid the explosion of battery, improve the security of battery.

According to some embodiments of the present application, there is also provided a powered device including the aforementioned battery, wherein the battery is used for providing electric energy.

The powered device may be any of the aforementioned battery-powered devices.

In the technical scheme of this application embodiment, through set up the vent passage on the shell in the power consumption device, and have pressure relief mechanism 24's battery on single battery 20's the casing 22 for when pressure or temperature in single battery 20 reach the threshold value, pressure or temperature can be released to the battery outside to vent 24 on the casing 22 and the vent passage on the shell, avoid the explosion of battery, improve power consumption device's security.

Referring to fig. 3-7, a battery cell 20 is provided according to some embodiments of the present disclosure. The battery cell 20 includes a housing 22 and a plurality of pressure relief mechanisms 24. The case 22 is provided in a square shape, and the square case 22 includes five wall portions 22 a. The plurality of pressure relief mechanisms 24 are provided at regular intervals on the large surface of the housing 22. The pressure relief mechanism 24 includes a pressure relief passage 24b at a large face and a closing member 24a that closes at least the pressure relief passage 24 b. The seal member 24a is fixed to a surface of the wall portion 22a facing the inner cavity of the housing 22 by an adhesive. The sum S1 of the sectional areas of all the relief passages 24b on the large face and the area S2 of the corresponding wall portion 22a satisfy: 0.1 is less than or equal to S1/S2 is less than or equal to 0.8.

When the pressure or temperature inside the battery cell 20 reaches a threshold value, the pressure or temperature is gathered to the large-area pressure relief mechanism 24, the sealing piece 24a is damaged, and the pressure or temperature is quickly released to the outside of the casing 22 along the plurality of pressure relief channels 24b on the large area, so that the problem of explosion caused by the fact that the pressure or temperature inside the battery cell 20 cannot be timely discharged is solved, and the safety performance of the battery cell 20 is improved.

Those skilled in the art will appreciate that while some embodiments herein include some features included in other embodiments, rather than others, combinations of features of different embodiments are meant to be within the scope of the application and form different embodiments. For example, in the claims, any of the claimed embodiments may be used in any combination.

The above embodiments are only used for illustrating the technical solutions of the present application, and not for limiting the same; although the present application has been described in detail with reference to the foregoing embodiments, it should be understood by those of ordinary skill in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some technical features may be equivalently replaced; and such modifications or substitutions do not depart from the spirit and scope of the corresponding technical solutions in the embodiments of the present application.

Claims (11)

1. A battery cell, comprising:

a housing having at least one wall portion;

at least one pressure relief mechanism comprising a pressure relief channel and a closure, said pressure relief channel being disposed in at least one of said walls, said closure at least closing said pressure relief channel; when the pressure or temperature inside the housing reaches a threshold value, the closure is broken and the pressure or temperature is vented through the pressure relief channel;

the sum of the sectional areas of all the pressure relief channels on one of the wall parts is S1, the area of the corresponding wall part is S2, and the following conditions are met: 0.1 is less than or equal to S1/S2 is less than or equal to 0.8.

2. The battery cell of claim 1, wherein the S1 and the S2 satisfy: S1/S2 is more than or equal to 0.3 and less than or equal to 0.7.

3. The battery cell as recited in claim 1 wherein the closure member has a melting point of 90 ℃ or higher and 150 ℃ or lower.

4. The battery cell as recited in any of claims 1-3 wherein the wall comprises a plurality of the pressure relief mechanisms, the plurality of pressure relief mechanisms being spaced apart from the wall.

5. The battery cell according to claim 4, wherein the pressure relief channels are arranged such that the area thereof gradually decreases from the center portion to the peripheral portion of the wall portion.

6. The battery cell of claim 5, wherein the pressure relief channel is circular in cross-section.

7. The battery cell as claimed in claim 6, wherein the distance L1 between adjacent pressure relief channels is configured to satisfy: l1 is more than or equal to D/2 and less than or equal to D;

wherein D is the diameter of the pressure relief channel.

8. The battery cell as recited in claim 7, wherein the diameter D of the pressure relief channel satisfies: d is more than or equal to 1um and less than or equal to 1 cm.

9. The battery cell according to claim 5, wherein the minimum distance L2 between the pressure relief channel and the edge of the wall portion satisfies: l2 is more than or equal to 1 cm.

10. A battery, comprising:

a plurality of battery cells of any one of claims 1 to 9; and

a housing having a discharge passage for discharging a pressure or temperature of the cell discharge.

11. An electrical device comprising a battery as claimed in claim 10 for providing electrical energy.

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