CN221947344U - Battery monomer, battery and power consumption device - Google Patents

Abstract

The application relates to the technical field of batteries, and provides a battery monomer, a battery and an electricity utilization device. Wherein, the battery cell includes: a housing having a receiving cavity; the bottom wall of the shell is provided with a pressure relief hole, and the explosion-proof valve is arranged on the bottom wall and covers the Yu Xieya holes; the electrode assembly is arranged in the accommodating cavity, a gas flow passage is defined between the electrode assembly and the bottom wall, and the gas flow passage is correspondingly arranged with the explosion-proof valve and is communicated with the accommodating cavity. By the technical scheme, the use safety of the battery can be at least improved.

Description

Battery monomer, battery and power consumption device

Technical Field

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

Background

This section provides merely background information related to the present disclosure and is not necessarily prior art.

At present, the explosion-proof valve of the battery unit is usually arranged on the top end cover of the battery unit, and connecting devices such as a pole, an electric connecting piece and a connecting wire are usually arranged on the end cover, so that when the battery unit is in thermal runaway, the explosion-proof valve is opened for pressure relief, and the connecting devices can be burnt out by high-temperature ejectors, and the safety of passengers is influenced along with high-pressure ignition.

Disclosure of utility model

The application aims to provide a battery monomer, a battery and an electricity utilization device, which are used for at least improving the use safety of the battery. The aim is achieved by the following technical scheme:

in a first aspect, the present application provides a battery cell comprising: a housing having a receiving cavity; the bottom wall of the shell is provided with a pressure relief hole, and the explosion-proof valve is arranged on the bottom wall and is covered on the pressure relief hole; the electrode assembly is arranged in the accommodating cavity, a gas flow passage is defined between the electrode assembly and the bottom wall, and the gas flow passage is correspondingly arranged with the explosion-proof valve and is communicated with the accommodating cavity.

According to the battery cell provided by the embodiment of the first aspect of the application, the gas flow passage is defined between the electrode assembly and the bottom wall of the shell, the gas flow passage corresponds to the position of the explosion-proof valve and is communicated with the accommodating cavity, and the explosion-proof valve for sealing the pressure relief hole is arranged in the pressure relief hole, so that when the battery cell is out of control, gas in the accommodating cavity can quickly reach the position of the explosion-proof valve through the gas flow passage, and the explosion-proof valve is opened under the action of the gas pressure so as to discharge the spouts in the shell from the bottom of the shell to complete pressure relief, thereby reducing the risk that the high-temperature spouts in the shell burn out the polar posts, the electric connecting pieces, the connecting wires and other connecting devices on the end cover, reducing the risk of high-temperature fire, improving the use safety of the battery, and being beneficial to improving the safety of passengers.

In addition, the battery cell provided by the application can also have the following additional technical characteristics:

In some embodiments of the application, the electrode assembly has a bottom surface disposed toward the bottom wall; the electrode assembly comprises a positive electrode plate, a diaphragm and a negative electrode plate which are sequentially wound or laminated, wherein an avoidance gap is formed between the positive electrode plate and/or the negative electrode plate and the diaphragm, and a gas flow channel is defined between the avoidance gap and the bottom wall.

By arranging the avoidance gap between any one of the positive pole piece and the negative pole piece which are positioned on the bottom surface of the electrode assembly and the diaphragm, or arranging the avoidance gap between the positive pole piece and the negative pole piece which are positioned on the bottom surface of the electrode assembly and the diaphragm, the avoidance gap is communicated with the accommodating cavity of the shell and can be used for limiting a gas flow passage for gas to flow to the explosion-proof valve between the bottom wall of the shell.

In some embodiments of the present application, the positive electrode sheet and/or the negative electrode sheet includes a main body section and a thinned section connected to the main body section, the thinned section being located on a side of the main body section near the bottom wall, the thinned section having a thickness smaller than a thickness of the main body section to define the avoiding gap with the separator.

Namely, the positive pole piece and the negative pole piece comprise a main body section and a thinning section connected with the main body section, or the positive pole piece or the negative pole piece comprises the main body section and a thinning section connected with the main body section, the thinning section is positioned on one side of the bottom surface of the electrode assembly, and the thickness of the thinning section is smaller than that of the main body section, so that an avoidance gap can be formed between the thinning section and an adjacent diaphragm, and gas in the shell flows to the explosion-proof valve when the battery is in thermal runaway.

In some embodiments of the application, the electrode assembly has a top surface disposed opposite the bottom surface, and the thickness of the reduced section gradually increases in a direction from the bottom surface to the top surface.

The direction of the thinning section from the bottom surface to the top surface of the electrode assembly and the distance between the thinning section and the adjacent diaphragm are gradually increased, that is, the position of the maximum distance between the thinning section and the diaphragm and the bottom surface of the electrode assembly are convenient for gas to flow from the top direction of the gas flow channel to the bottom direction of the gas flow channel, so that the explosion-proof valve can be quickly opened to release pressure when the battery unit is in thermal runaway.

In some embodiments of the application, the positive electrode sheet and/or the negative electrode sheet comprises a current collector and a coating applied on a surface of the current collector, the thickness of the coating on the surface of the body section being greater than the thickness of the coating on the surface of the thinned section.

It will be appreciated that the positive and negative electrode sheets require one or more slurry coatings to be applied to their current collectors during the manufacturing process. The coating thickness of the main body section of at least one of the positive pole piece and the negative pole piece is set to be larger than that of the thinning section, so that an avoidance gap for gas flow can be formed between the thinning section and the diaphragm, and the structure and the principle are simple and easy to realize.

In some embodiments of the application, the positive electrode sheet and/or the negative electrode sheet comprises a current collector and a coating coated on a surface of the current collector, and the thickness of the coating on the surface of the thinned section gradually increases along the direction from the bottom surface to the top surface.

That is, when the surface of the current collector of the positive electrode sheet and the negative electrode sheet is coated with the slurry, the thickness of the coating on the surface of the thinned section is gradually increased along the direction from the bottom surface to the top surface of the electrode assembly, so that the distance between the bottom wall of the casing and the diaphragm is increased as the distance between the bottom wall of the casing is increased in the thinned section, and the gas can be improved to flow from the top direction of the gas flow channel to the bottom direction of the gas flow channel rapidly, so that the explosion-proof valve can be opened rapidly for pressure relief when thermal runaway occurs in the battery cell.

In some embodiments of the present application, an insulating section is further disposed on one side of the bottom wall of the thinning Duan Kaojin, the insulating section extends in a direction approaching to the bottom wall, and a surface of the insulating section is coated with a first insulating layer; the thickness of the insulation section is smaller than that of the main body section, and the avoidance gap is defined between the insulation section, the thinning section and the diaphragm.

Through setting up the insulating section in one side of attenuate section towards the diapire, because the insulating section extends to the direction that is close to the diapire of casing, and the thickness of insulating section is less than the thickness of main part section to can be simultaneously with form between attenuate section and the diaphragm and be used for dodging gaseous dodging the clearance, and dodging the clearance and follow electrode assembly's bottom surface to the length of the direction of top surface great relatively, and then can further improve the efficiency of gas flow direction explosion-proof valve position. In addition, the insulating section is located the edge of electrode assembly, and the surface coating of insulating section is equipped with first insulating layer to can also play the emergence that reduces and take place the short circuit phenomenon because of the contact of edge burr between positive pole piece and the negative pole piece that is located the bottom surface position of electrode assembly, help further improve the security that battery monomer used.

In some embodiments of the present application, the positive electrode tab and/or the negative electrode tab located on the bottom surface is provided with an insulating section, and the surface of the insulating section is coated with a first insulating layer; the thickness of the insulating section is smaller than that of the main body sections of the positive pole piece and the negative pole piece, and the avoiding gap is defined between the insulating section and the diaphragm.

The positive pole piece and the negative pole piece which are positioned on the bottom surface of the electrode assembly are respectively provided with an insulating section extending towards the direction close to the bottom wall, or the end part of the positive pole piece or the negative pole piece which is positioned on the bottom surface of the electrode assembly is provided with an insulating section extending towards the direction close to the bottom wall.

In some embodiments of the application, a side of the explosion proof valve facing the electrode assembly is provided with a second insulating layer.

The second insulating layer can play the risk that reduces explosion-proof valve and electrolyte contact for a long time and lead to being easily corroded to improve explosion-proof valve and lead to leaking the problem of liquid from the pressure release hole department because of corroding seriously, can also reduce explosion-proof valve and electrode assembly contact and take place the risk of short circuit simultaneously, in addition, can also help realizing that the cracking pressure of explosion-proof valve remains invariable, and then help improving the free safety in utilization of battery.

In some embodiments of the present application, an end cover is disposed on the top of the housing, the end cover covers the accommodating cavity, and a pole is disposed on the end cover.

The diapire of the relative casing of end cover sets up in the top of casing to the closing cap is provided with the utmost point post in holding the opening of chamber on the end cover, and the utmost point post includes anodal post and negative pole post, because explosion-proof valve locates the diapire of casing, thereby can improve the problem of explosion-proof valve when opening the valve pressure release because of the higher easy burning out utmost point post of blowout thing temperature, has improved the free safety in utilization of battery.

In a second aspect, the application provides a battery comprising at least one battery cell as in any of the embodiments of the first aspect.

The battery according to the second aspect of the present application includes the battery cell according to any one of the first aspect, and therefore has the technical effects of any one of the above embodiments, which are not described herein.

In a third aspect, the present application provides an electrical device comprising a battery according to the second aspect, the battery being configured to power the electrical device.

The power utilization device according to the third aspect of the present application includes the battery according to the second aspect, and therefore has the technical effects of any of the above embodiments, and will not be described in detail herein.

Drawings

Various other advantages and benefits will become apparent to those of ordinary skill in the art upon reading the following detailed description of the preferred embodiments. The drawings are only for purposes of illustrating the preferred embodiments and are not to be construed as limiting the application. Also, like reference numerals are used to designate like parts throughout the figures. In the drawings:

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

FIG. 2 is a schematic diagram of an exploded structure of a battery according to some embodiments of the present application;

FIG. 3 is a schematic view of a perspective structure of a battery cell according to some embodiments of the application;

FIG. 4 is a schematic view showing a partial structure of an electrode assembly according to some embodiments of the present application;

FIG. 5 is a schematic view showing a partial structure of another electrode assembly according to some embodiments of the present application;

FIG. 6 is a schematic view showing a partial structure of another electrode assembly according to some embodiments of the present application;

The direction of the X axis of the coordinate system in fig. 3 to 6 represents the width direction of the battery cell, the direction of the Y axis represents the length direction of the battery cell, and the direction of the Z axis represents the height direction of the battery cell.

The reference numerals are as follows:

1000. A vehicle;

100. A battery; 200. a controller; 300. a motor;

10. a case; 11. a first portion; 12. a second portion;

20. A battery cell; 21. an end cap; 21a, a pole; 22. a housing; 23. an electrode assembly; 24. a gas flow passage; 25. an explosion-proof valve;

221. A receiving chamber; 222. a bottom wall; 231. a positive electrode sheet; 232. a diaphragm; 233. a negative electrode plate; 241. avoidance gap;

2311. A main body section; 2312. thinning the section; 2313. an insulating section.

Detailed Description

Embodiments of the technical scheme of the present application will be described in detail below with reference to the accompanying drawings. The following examples are only for more clearly illustrating the technical aspects of the present application, and thus are merely examples, and are not intended to limit the 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 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 of the application and the claims and the description of the drawings above are intended to cover a non-exclusive inclusion.

In the description of embodiments of the present application, the technical terms "first," "second," and the like are used merely to distinguish between different objects and are not to be construed as indicating or implying a relative importance or implicitly indicating the number of technical features indicated, a particular order or a primary or secondary relationship. In the description of the embodiments of the present application, the meaning of "plurality" is two or more unless explicitly defined otherwise.

Reference herein to "an embodiment" means that a particular feature, structure, or characteristic described in connection with the embodiment may be included in at least one embodiment of the application. The appearances of such phrases 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. Those of skill in the art will explicitly and implicitly appreciate that the embodiments described herein may be combined with other embodiments.

In the description of the embodiments of the present application, the term "and/or" is merely an association relationship describing an association object, and indicates that three relationships may exist, for example, a and/or B may indicate: a exists alone, A and B exist together, and B exists alone. In addition, the character "/" herein generally indicates that the front and rear associated objects are an "or" relationship.

In the description of the embodiments of the present application, the term "plurality" means two or more (including two), and similarly, "plural sets" means two or more (including two), and "plural sheets" means two or more (including two).

In the description of the embodiments of the present application, the orientation or positional relationship indicated by the technical terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. are based on the orientation or positional relationship shown in the drawings, and are merely for convenience of description and simplification of the description, and do not indicate or imply that the apparatus or element referred to must have a specific orientation, be configured and operated in a specific orientation, and therefore should not be construed as limiting the embodiments of the present application.

In the description of the embodiments of the present application, unless explicitly specified and limited otherwise, the terms "mounted," "connected," "secured" and the like should be construed broadly and may be, for example, fixedly connected, detachably connected, or integrally formed; or may be mechanically or electrically connected; can be directly connected or indirectly connected through an intermediate medium, and can be communicated with the inside of two elements or the interaction relationship of the two elements. The specific meaning of the above terms in the embodiments of the present application will be understood by those of ordinary skill in the art according to specific circumstances.

Currently, the application of power batteries is more widespread 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, aerospace, and the like. With the continuous expansion of the application field of the power battery, the market demand of the power battery is also continuously expanding.

In the related art, a power battery includes a case and a plurality of battery cells provided in the case, and the plurality of batteries are electrically connected in series or in series-parallel by a bus bar or the like. The explosion-proof valve of the battery unit is usually arranged on the top end cover of the battery unit, and connecting devices such as a pole column, an electric connecting piece and a connecting wire are usually arranged on the end cover, so that when the battery unit is in thermal runaway, the explosion-proof valve is opened for pressure relief, and the connecting devices can be burnt out by high-temperature ejectors, and the safety of passengers is influenced along with high-pressure ignition.

In order to solve the problems that an explosion-proof valve is arranged on an end cover of a battery monomer, so that a connecting device on the end cover is easy to burn out by a jet of the explosion-proof valve when the battery monomer is in thermal runaway and the safety of passengers is influenced, the application designs the battery monomer, the explosion-proof valve is arranged on the bottom wall of a shell of the battery monomer, a gas flow passage is arranged between an electrode assembly and the bottom wall, the gas flow passage is communicated with a containing cavity in the shell, and correspond with the position of explosion-proof valve, so, when the battery monomer takes place thermal runaway, just can make the gas in the casing reach the explosion-proof valve position through the gas runner fast, explosion-proof valve opens the pressure release, and the blowout thing such as gas is from the casing bottom blowout to can reduce the condition emergence that the connecting device on the end cover took place to take place the fire, and then help improving the security that the battery was used, and improve passenger's safety.

The battery cell disclosed by the embodiment of the application can be used in electric devices such as vehicles, ships or aircrafts, but is not limited to the electric devices. The power supply system with the battery cells, batteries and the like which are disclosed by the application and form the power utilization device can be used, so that the power supply system is beneficial to alleviating and automatically regulating the deterioration of the expansion force of the battery, supplementing the consumption of electrolyte and improving the stability of the battery performance and the service life of the battery.

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 car, a ship, a spacecraft and the like. Among them, the electric toy may include fixed or mobile electric toys, such as game machines, electric car toys, electric ship toys, electric plane toys, and the like, and the spacecraft may include planes, rockets, space planes, and spacecraft, and the like.

For convenience of description, the following embodiment will take an electric device according to an embodiment of the present application as an example of the vehicle 1000.

Referring to fig. 1, fig. 1 is a schematic structural diagram of a vehicle according to some embodiments of the application. The vehicle 1000 may be a fuel oil vehicle, a gas vehicle or a new energy vehicle, and the new energy vehicle may be a pure electric vehicle, a hybrid vehicle or a range-extended vehicle. The battery 100 is provided in the interior of 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 for power supply of the vehicle 1000, for example, the battery 100 may be used as an operating power source of the vehicle 1000. The vehicle 1000 may also include a controller 200 and a motor 300, the controller 200 being configured to control the battery 100 to power the motor 300, for example, for operating power requirements during start-up, navigation, and travel of the vehicle 1000.

In some embodiments of the present application, battery 100 may not only serve as an operating power source for vehicle 1000, but may also serve as a driving power source for vehicle 1000, instead of or in part instead of fuel oil or natural gas, to provide driving power for vehicle 1000.

Referring to fig. 2, fig. 2 is an exploded view of a battery according to some embodiments of the present application. 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 is used to provide an accommodating space for the battery cell 20, and the case 10 may have 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 being overlapped with each other, the first portion 11 and the second portion 12 together defining an accommodating space for accommodating the battery cell 20. The second portion 12 may be a hollow structure with one end opened, the first portion 11 may be a plate-shaped structure, and the first portion 11 covers the opening side of the second portion 12, so that the first portion 11 and the second portion 12 together define a containing space; the first portion 11 and the second portion 12 may be hollow structures each having an opening at one side, and the opening side of the first portion 11 is engaged with the opening side of the second portion 12. Of course, the case 10 formed by the first portion 11 and the second portion 12 may be of various shapes, such as a cylinder, a rectangular parallelepiped, or the like.

In the battery 100, the plurality of battery cells 20 may be connected in series, parallel or a series-parallel connection, wherein the series-parallel connection refers to that the plurality of battery cells 20 are connected in series or parallel. The plurality of battery cells 20 can be directly connected in series or in parallel or in series-parallel, and then the whole formed by the plurality of battery cells 20 is accommodated in the box 10; of course, the battery 100 may also be a battery module formed by connecting a plurality of battery cells 20 in series or parallel or series-parallel connection, and a plurality of battery modules are then connected in series or parallel or series-parallel connection to form a whole and are accommodated in the case 10. The battery 100 may further include other structures, for example, the battery 100 may further include a bus member for making electrical connection between the plurality of battery cells 20.

Wherein each battery cell 20 may be a secondary battery or a primary battery; but not limited to, lithium sulfur batteries, sodium ion batteries, or magnesium ion batteries. The battery cell 20 may be in the shape of a cylinder, a flat body, a rectangular parallelepiped, or other shapes, etc.

Referring to fig. 3, fig. 3 is a schematic perspective view of a battery cell according to some embodiments of the present application. The present application provides a battery cell 20 including a housing 22, an explosion-proof valve 25, and an electrode assembly 23.

Wherein the housing 22 has a receiving cavity 221, and a bottom wall 222 of the housing 22 is provided with a pressure relief hole (not shown in the figure). The explosion-proof valve 25 is arranged on the bottom wall 222 of the shell 22 and seals the Yu Xieya holes; the electrode assembly 23 is disposed in the accommodating chamber 221, and a gas flow passage 24 is defined between the electrode assembly 23 and the bottom wall 222 of the case 22, and the gas flow passage 24 is disposed corresponding to the explosion-proof valve 25 and communicates with the accommodating chamber 221.

In the present embodiment, the accommodation chamber 221 of the case 22 is used to accommodate the electrode assembly 23, the electrolyte, and other components. The housing 22 may be of various 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, such as copper, iron, aluminum, stainless steel, aluminum alloy, plastic, etc., which is not particularly limited in the embodiment of the present application.

The electrode assembly 23 is a component in which electrochemical reactions occur in the battery cell 20. One or more electrode assemblies 23 may be contained within the housing 22. The electrode assembly 23 is mainly formed by winding or stacking the positive electrode tab 231 and the negative electrode tab 233, and a separator 232 is generally provided between the positive electrode tab 231 and the negative electrode tab 233. The portions of the positive electrode tab 231 and the negative electrode tab 233 having the active material constitute the main body of the electrode assembly 23, and the portions of the positive electrode tab 231 and the negative electrode tab 233 having no active material constitute the tabs, respectively. The positive electrode tab and the negative electrode tab can be located at one end of the main body together or located at two ends of the main body respectively. During charge and discharge of the battery, the positive electrode active material and the negative electrode active material react with the electrolyte, and the tab is connected to the post 21a to form a current loop.

The explosion-proof valve 25 is a pressure relief mechanism for releasing the internal pressure when the internal pressure or temperature of the battery cell 20 reaches a threshold value.

When the explosion-proof valve 25 opens for pressure relief, the gas passage communicates with the pressure relief hole and the accommodation chamber 221. Illustratively, the gas channel may be a notch partially provided on the bottom surface of the electrode assembly 23, and the notch communicates with the accommodating cavity 221 and is at least partially provided corresponding to the pressure release hole; the gas flow channel 24 may also be a channel that partially penetrates the electrode assembly 23 along the thickness direction of the battery cell 20 at the bottom surface of the electrode assembly 23; the bottom surface of the motor assembly may partially penetrate through a channel in the electrode assembly 23 along the length direction of the battery cell 20, and the projection of the pressure release hole on the bottom surface of the electrode assembly 23 may at least partially coincide with the channel. The number of the gas flow passages 24 may be one or a plurality.

Through set up the pressure release hole on the diapire 222 of casing 22 to set up the explosion-proof valve 25 that is used for closing the pressure release hole in the pressure release hole, simultaneously, set up gas runner 24 in electrode assembly 23 towards one side of diapire 222, gas runner 24 is corresponding with explosion-proof valve 25's position, and be linked together with holding chamber 221, thus, when battery cell 20 takes place thermal runaway, gas in holding chamber 221 can reach explosion-proof valve 25's position fast through gas runner 24, explosion-proof valve 25 opens under the effect of gas pressure, in order to discharge the blowout in the casing 22 from casing 22 bottom and accomplish the pressure release, thereby play the risk that reduces the inside high temperature blowout of casing 22 burns out connecting devices such as post 21a on the end cover 21, electric connector and connecting wire, reduce the risk of high temperature fire, the safety in utilization of battery has been improved, thereby help improving passenger's safety.

It will be appreciated that when thermal runaway occurs in the battery cell 20, the electrolyte in the case 22 changes from a liquid state to a gas state, and the gas flows from the top to the bottom through the gas flow passage 24 under the action of the gas pressure due to the closed state of the receiving chamber 221, and then flows to the position of the explosion-proof valve 25, and when the internal pressure or temperature of the case 22 reaches a threshold value, the explosion-proof valve 25 is opened to release the internal pressure of the case 22.

According to some embodiments of the present application, electrode assembly 23 has a bottom surface disposed toward bottom wall 222; the electrode assembly 23 includes a positive electrode sheet 231, a separator 232, and a negative electrode sheet 233, which are sequentially wound or stacked, an avoiding gap 241 is provided between the positive electrode sheet 231 and/or the negative electrode sheet 233 and the separator 232, which are positioned on the bottom surface, and a gas flow channel 24 is defined between the avoiding gap 241 and the bottom wall 222.

In this embodiment, the positive electrode tab 231, the separator 232, and the negative electrode tab 233 are wound in order, and the gaps between the positive electrode tab 231 and the negative electrode tab 233 and the separator 232 are small under normal conditions, so that it is difficult to realize an air flow channel when thermal runaway occurs in the battery cell 20.

Therefore, by providing the avoiding gap 241 between the separator 232 and either the positive electrode tab 231 or the negative electrode tab 233 located on the bottom surface of the electrode assembly 23, or by providing the avoiding gap 241 between the separator 232 and either the positive electrode tab 231 or the negative electrode tab 233 located on the bottom surface of the electrode assembly 23, the avoiding gap 241 is opened toward the bottom wall 222, and the avoiding gap 241 communicates with the accommodation chamber 221 of the case 22, the gas flow passage 24 for the gas to flow to the explosion-proof valve 25 can be defined between the bottom wall 222 of the case 22.

Referring to fig. 4, fig. 4 is a schematic view showing a partial structure of an electrode assembly according to some embodiments of the present application. According to some embodiments of the present application, positive electrode tab 231 and/or negative electrode tab 233 include a main body section 2311 and a thinned section 2312 connected to main body section 2311, thinned section 2312 being located on a side of main body section 2311 adjacent bottom wall 222, thinned section 2312 having a thickness less than the thickness of main body section 2311 to define a relief gap 241 with separator 232.

In the present embodiment, that is, the positive electrode tab 231 and the negative electrode tab 233 each include a main body section 2311 and a thinned section 2312 connected to the main body section 2311, or the positive electrode tab 231 or the negative electrode tab 233 includes a main body section 2311 and a thinned section 2312 connected to the main body section 2311.

The coating layer is formed on the bottom surface side of the electrode assembly 23 by the thinned section 2312, and the thickness of at least one end of the thinned section 2312 away from the main section 2311 is smaller than the thickness of the main section 2311, so that the avoidance gap 241 is formed between the adjacent diaphragms 232, and the gas flow channel 24 for allowing the gas in the case 22 to flow to the explosion-proof valve 25 during thermal runaway of the battery is formed between the bottom wall 222 and the separator.

In some embodiments, the thinner section 2312 may be provided at both top and bottom surfaces of the electrode assembly 23, so that it is unnecessary to adjust the direction of the thinner section 2312 when the electrode assembly 23 is mounted, thereby facilitating the mounting of the product and contributing to the improvement of the assembly efficiency of the product.

Referring to fig. 4, according to some embodiments of the present application, electrode assembly 23 has a top surface disposed opposite a bottom surface, and the thickness of thinned segment 2312 gradually increases in a bottom-to-top direction.

In the present embodiment, the length of the thinned segment 2312 is set in the range of 1mm to 20mm, illustratively, in the bottom-to-top direction of the electrode assembly 23.

Illustratively, the weight of the applied slurry coating of thinned segment 2312 is gradually reduced from 300mg to 0mg, which is the same as the coating weight of main body segment 2311, in the top-to-bottom direction of electrode assembly 23.

Illustratively, the thickness direction of the positive electrode tab 231 and the negative electrode tab 233 is the same direction as the thickness direction of the battery cell 20.

The distance between the thinned segment 2312 and the adjacent separator 232 is gradually increased from the bottom surface to the top surface of the electrode assembly 23, that is, the maximum distance between the thinned segment 2312 and the separator 232 and the bottom surface of the electrode assembly 23, so that the gas can flow from the top direction of the gas flow channel 24 to the bottom direction thereof rapidly, and the explosion-proof valve 25 can be opened rapidly for pressure relief when thermal runaway occurs in the battery cell 20.

According to some embodiments of the application, positive electrode tab 231 and/or negative electrode tab 233 include a current collector and a coating applied to a surface of the current collector, the thickness of the coating on the surface of body segment 2311 being greater than the thickness of the coating on the surface of thinned segment 2312.

In this embodiment, it can be appreciated that the positive electrode tab 231 and the negative electrode tab 233 need to be coated with one or more slurry coatings on their current collectors during the manufacturing process.

The current collector may be, for example, aluminum foil or copper foil, etc. The coating is a liquid slurry coating, and can be converted into a film layer with special functions through oven drying or other fixed-line modes.

The coating thickness of the main body section 2311 of at least one of the positive electrode pole piece 231 and the negative electrode pole piece 233 is set to be larger than the coating thickness of the thinning section 2312, so that an avoidance gap 241 for gas flow is formed between the thinning section 2312 and the diaphragm, and the structure and the principle are simpler and easy to realize.

According to some embodiments of the present application, positive electrode tab 231 and/or negative electrode tab 233 include a current collector and a coating applied to the surface of the current collector, with the thickness of the coating on the surface of thinned segment 2312 gradually increasing in the bottom-to-top direction.

In this embodiment, that is, when the current collector surfaces of the positive electrode tab 231 and the negative electrode tab 233 are coated with the slurry, the thickness of the coating layer on the surface of the thinned section 2312 is gradually increased in the direction from the bottom surface to the top surface of the electrode assembly 23, so that the distance between the bottom wall of the case and the separator in the thinned section 2312 is larger, and thus, the gas can be improved to flow from the top direction of the gas flow channel 24 to the bottom direction thereof rapidly, so that the explosion-proof valve can be opened rapidly to release pressure when thermal runaway occurs in the battery cell.

Referring to fig. 5, fig. 5 is a schematic view showing a partial structure of another electrode assembly according to some embodiments of the present application. According to some embodiments of the present application, an insulating section 2313 is further disposed on a side of the thinned section 2312 near the bottom wall 222, the insulating section 2313 extends toward the direction near the bottom wall 222, and a surface of the insulating section 2313 is coated with a first insulating layer; wherein the thickness of insulating segment 2313 is less than the thickness of main segment 2311, and wherein relief gap 241 is defined between insulating segment 2313 and thinned segment 2312 and septum 232.

In the present embodiment, the length of the thinned segment 2312 is set in the range of 1mm to 20mm, illustratively, in the bottom-to-top direction of the electrode assembly 23. The extension length of insulating segment 2313 is also set in the range of 1mm-20 mm.

The side of the insulating segment 2313 facing the bottom wall 222 may be flush with the side of the diaphragm 232 facing the bottom wall 222, or the side of the insulating segment 2313 facing the bottom wall 222 may protrude from the side of the diaphragm 232 facing the bottom wall 222.

Illustratively, the first insulating layer may be ceramic particles, which are insulating and resistant to chemical attack, while having a relatively high melting point, which helps to improve the safety of the battery cell 20 in use.

Through setting up insulating section 2313 in the one side of thinning section 2312 towards diapire 222, because insulating section 2313 extends to the direction of being close to diapire 222 of casing 22, and insulating section 2313's thickness is less than the thickness of main part section 2311 to can simultaneously with thinning section 2312 and diaphragm 232 between form the clearance 241 that dodges that is used for dodging gas, and dodging the clearance 241 along the length of the direction of the bottom surface to the top surface of electrode assembly 23 relatively great, and then can further improve the efficiency of gas flow direction explosion-proof valve 25 position. In addition, the insulating segment 2313 is positioned at the edge of the electrode assembly 23, and the surface of the insulating segment 2313 is coated with the first insulating layer, thereby reducing the occurrence of a short circuit phenomenon between the positive electrode tab 231 and the negative electrode tab 233 positioned at the bottom surface of the electrode assembly 23 due to the contact of the edge burrs, and further improving the safety of the use of the battery cell 20.

Referring to fig. 6, fig. 6 is a schematic view showing a partial structure of another electrode assembly according to some embodiments of the present application. According to some embodiments of the present application, the positive electrode tab 231 and/or the negative electrode tab 233 located at the bottom surface is provided with an insulation section 2313, the insulation section 2313 extends in a direction away from the bottom surface, and the surface of the insulation section 2313 is coated with a first insulation layer; wherein the thickness of insulating segment 2313 is less than the thickness of main segment 2311 of positive electrode tab 231 and negative electrode tab 233, and a relief gap 241 is defined between insulating segment 2313 and separator 232.

In the present embodiment, that is, the ends of the positive electrode tab 231 and the negative electrode tab 233 located at the bottom surface of the electrode assembly 23 are each provided with an insulating section 2313 extending in a direction away from the bottom surface, or the ends of the positive electrode tab 231 or the negative electrode tab 233 located at the bottom surface of the electrode assembly 23 are each provided with an insulating section 2313 extending in a direction away from the bottom surface.

Illustratively, the thickness direction of the positive electrode tab 231 and the negative electrode tab 233 is the same direction as the thickness direction of the battery cell 20.

The length of insulating segment 2313 in the direction from the bottom surface to the top surface of electrode assembly 23 is set in the range of 1mm to 20 mm.

By setting the thickness of the insulating segment 2313 coated with the first insulating layer smaller than the thickness of the main body segment 2311 of the positive electrode tab 231 and the negative electrode tab 233, a relief gap 241 for gas flow is defined between the insulating segment 2313 and the diaphragm 232, and thus a gas flow passage 24 for gas flow to the explosion-proof valve 25 can be formed between the relief gap 241 and the bottom wall 222 of the case 22.

In some embodiments, insulating segments 2313 may also be provided at both top and bottom surfaces of electrode assembly 23, so that it is unnecessary to adjust the direction of insulating segments 2313 when electrode assembly 23 is mounted, thereby facilitating the mounting of the product and contributing to the improvement of the assembly efficiency of the product.

According to some embodiments of the present application, the explosion-proof valve 25 is provided with a second insulating layer (not shown) on a side facing the electrode assembly 23.

In this embodiment, the second insulating layer may be an insulating material layer made of polyethylene, polypropylene or other polyester compounds. The insulating layer can play the risk that reduces explosion-proof valve 25 and electrolyte contact for a long time and lead to being liable to be corroded to improve explosion-proof valve 25 and lead to the problem of leaking from the pressure release hole department because of the corruption is serious, can also reduce explosion-proof valve 25 and electrode assembly 23 contact and take place the risk of short circuit simultaneously, in addition, can also help realizing that explosion-proof valve 25's opening pressure keeps invariable, and then help improving the safety in utilization of battery monomer 20.

According to some embodiments of the application, the top of the housing 22 is provided with an end cap 21, the end cap 21 covers the accommodating cavity 221, and the end cap 21 is provided with a pole 21a.

In the present embodiment, the end cap 21 refers to a member that is covered at the 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. Optionally, the end cover 21 may be made of a material (such as an aluminum alloy) with a certain hardness and strength, so that the end cover 21 is not easy to deform when being extruded and collided, so that the battery cell 20 can have higher structural strength, and the safety performance can be improved. The end cap 21 may be provided with functional components such as a pole 21 a. The post 21a may be used to electrically connect with the electrode assembly 23 for outputting or inputting electric power of the battery cell 20. The material of the end cap 21 may be various, such as copper, iron, aluminum, stainless steel, aluminum alloy, plastic, etc., which is not particularly limited in the embodiment of the present application. In some embodiments, an insulating spacer may also be provided on the inside of the end cap 21, which may be used to isolate electrical connection components within the housing 22 from the end cap 21 to reduce the risk of short circuits. By way of example, the insulating spacer may be plastic, rubber, or the like.

The case 22 and the end cap 21 may be separate members, and an opening may be provided in the case 22, and the interior of the battery cell 20 may be formed by covering the opening with the end cap 21 at the opening. It is also possible to integrate the end cap 21 and the housing 22, but specifically, the end cap 21 and the housing 22 may form a common connection surface before other components are put into the housing, and when it is necessary to encapsulate the inside of the housing 22, the end cap 21 is then put into place with the housing 22.

Because the end cover 21 is arranged at the top of the shell 22 relative to the bottom wall 222 of the shell 22, and the explosion-proof valve 25 is arranged at the bottom wall 222 of the shell 22, the problem that the electrode column 21a is easy to burn due to higher temperature of the ejected material when the explosion-proof valve 25 is opened for pressure relief can be solved, and the use safety of the battery cell 20 is improved.

According to some embodiments of the present application, referring to fig. 1 to 4, the present application provides a battery cell 20 comprising: an end cap 21, a case 22, an electrode assembly 23, and an explosion-proof valve 25. The housing 22 has a receiving cavity 221, an opening is formed at a top of the receiving cavity 221, the end cover 21 covers the opening, and a pole 21a is disposed on the end cover 21. The bottom wall 222 of the shell 22 is provided with a pressure relief hole, the pressure relief hole is provided with an explosion-proof valve 25 in a right opposite direction, and the explosion-proof valve 25 is used for plugging the pressure relief hole and can be opened when the pressure or the temperature inside the shell 22 reaches a preset threshold value. The electrode assembly 23 is arranged in the accommodating cavity 221, the electrode assembly 23 comprises a positive electrode plate 231, a diaphragm 232 and a negative electrode plate 233 which are sequentially wound, a thinning section 2312 is arranged at the end parts of the positive electrode plate 231 and the negative electrode plate 233 which are positioned on the bottom surface of the electrode assembly 23, the thinning section 2312 is locally thinned so as to form an avoidance gap 241 with the diaphragm 232, an air flow channel 24 is defined between the avoidance gap 241 and the bottom wall 222 of the shell 22, and the air flow channel 24 is communicated with the accommodating cavity 221 and corresponds to the position of the explosion-proof valve 25. Further, when the explosion-proof valve 25 is opened to release the pressure, the gas flow passage 24 communicates with the pressure release hole. In this way, the explosion-proof valve 25 is depressurized from the bottom wall 222 of the casing 22, which helps to reduce the occurrence of burning out the pole 21a and the connection device on the end cap 21 due to the excessive temperature of the spouted material during depressurization, thereby helping to improve the use safety of the battery and the safety of the vehicle occupants.

The present application is not limited to the above-mentioned embodiments, and any changes or substitutions that can be easily understood by those skilled in the art within the technical scope of the present application are intended to be included in the scope of the present application. Therefore, the protection scope of the application is subject to the protection scope of the claims.

Claims (12)

1. A battery cell, comprising:

A housing having a receiving cavity;

The bottom wall of the shell is provided with a pressure relief hole, and the explosion-proof valve is arranged on the bottom wall and is covered on the pressure relief hole;

The electrode assembly is arranged in the accommodating cavity, a gas flow passage is defined between the electrode assembly and the bottom wall, and the gas flow passage is correspondingly arranged with the explosion-proof valve and is communicated with the accommodating cavity.

2. The battery cell of claim 1, wherein the electrode assembly has a bottom surface disposed toward the bottom wall;

The electrode assembly comprises a positive electrode plate, a diaphragm and a negative electrode plate which are sequentially wound or laminated, wherein an avoidance gap is formed between the positive electrode plate and/or the negative electrode plate and the diaphragm, and a gas flow channel is defined between the avoidance gap and the bottom wall.

3. The battery cell of claim 2, wherein the positive electrode tab and/or the negative electrode tab includes a main body section and a thinned section connected to the main body section, the thinned section being located on a side of the main body section adjacent to the bottom wall, the thinned section having a thickness less than a thickness of the main body section to define the relief gap with the separator.

4. The battery cell as recited in claim 3, wherein the electrode assembly has a top surface disposed opposite the bottom surface, the reduced section having a thickness that gradually increases in a direction from the bottom surface to the top surface.

5. The battery cell of claim 4, wherein the positive electrode tab and/or the negative electrode tab comprises a current collector and a coating applied to a surface of the current collector, the thickness of the coating on the surface of the body segment being greater than the thickness of the coating on the surface of the thinned segment.

6. The battery cell according to claim 4, wherein the positive electrode tab and/or the negative electrode tab includes a current collector and a coating layer coated on a surface of the current collector, and a thickness of the coating layer on a surface of the thinned section gradually increases in a direction from the bottom surface to the top surface.

7. The battery cell according to claim 3, wherein an insulating section is further provided on one side of the bottom wall of the thinned Duan Kaojin, the insulating section extends in a direction close to the bottom wall, and a first insulating layer is coated on a surface of the insulating section;

The thickness of the insulation section is smaller than that of the main body section, and the avoidance gap is defined between the insulation section, the thinning section and the diaphragm.

8. The battery cell according to claim 2, wherein the positive electrode tab and/or the negative electrode tab located on the bottom surface is provided with an insulating section, and the surface of the insulating section is coated with a first insulating layer;

The thickness of the insulating section is smaller than that of the main body sections of the positive pole piece and the negative pole piece, and the avoiding gap is defined between the insulating section and the diaphragm.

9. The battery cell according to any one of claims 1 to 8, wherein a side of the explosion-proof valve facing the electrode assembly is provided with a second insulating layer.

10. The battery cell of any one of claims 1-8, wherein an end cap is provided on the top of the housing, the end cap is capped in the receiving cavity, and a post is provided on the end cap.

11. A battery comprising at least one cell according to any one of claims 1-10.

12. An electric device comprising the battery according to claim 11, the battery is used for supplying power to the power utilization device.