CN220873705U

CN220873705U - Battery monomer, cover plate suite, battery and electricity utilization device

Info

Publication number: CN220873705U
Application number: CN202322106766.5U
Authority: CN
Inventors: 侯萌萌; 阎晓洁; 张功良
Original assignee: Contemporary Amperex Technology Co Ltd
Current assignee: Contemporary Amperex Technology Co Ltd
Priority date: 2023-08-07
Filing date: 2023-08-07
Publication date: 2024-04-30
Anticipated expiration: 2033-08-07

Abstract

The embodiment of the utility model provides a battery monomer, a cover plate kit, a battery and an electricity utilization device, wherein the battery monomer comprises a shell, an electrode assembly, a cover plate assembly and a safety piece, a mounting cavity is formed in the shell, one side of the mounting cavity is opened to form a mounting opening, the electrode assembly is arranged in the mounting cavity, the cover plate assembly is covered on the mounting opening, the safety piece is positioned in the mounting cavity, a cavity is formed in the safety piece, a safety agent is filled in the cavity, a weak area is formed in the safety piece, and the weak area can be broken so that the safety agent enters the mounting cavity. According to the battery monomer, the safety piece filled with the safety agent is arranged, so that the weak area on the safety piece is broken to release the safety agent under the condition that the battery monomer is in thermal runaway, and further the thermal runaway is restrained, the risks of severe problems such as further combustion and explosion of the battery monomer are reduced, and the safety of the battery monomer is improved.

Description

Battery monomer, cover plate suite, battery and electricity utilization device

Technical Field

The utility model relates to the technical field of batteries, in particular to a battery monomer, a cover plate kit, a battery and an electric device.

Background

Lithium ion batteries are widely used in the field of power equipment such as mobile communication equipment, portable electric tools, new energy automobiles, energy storage power stations and the like.

Under abnormal conditions such as thermal shock, overcharging, overdischarging, short-circuit, vibration, extrusion and the like of the lithium ion battery, thermal reaction occurs among components such as active substances, electrolyte and the like in the battery, so that the risk of thermal runaway exists in the battery monomer, and further accidents such as explosion and combustion and the like occur in the battery monomer, and the use safety of the lithium ion battery is seriously influenced.

Disclosure of utility model

In view of the foregoing, it is desirable to provide a battery cell, a cover plate kit, a battery and an electric device capable of suppressing occurrence of thermal runaway.

In order to achieve the above object, the technical solution of the embodiment of the present application is as follows:

The embodiment of the utility model provides a battery monomer which comprises a shell, an electrode assembly, a cover plate assembly and a safety piece, wherein an installation cavity is formed in the shell, one side of the installation cavity is opened to form an installation opening, the electrode assembly is arranged in the installation cavity, the cover plate assembly is covered on the installation opening, the safety piece is positioned in the installation cavity, a cavity is formed in the safety piece, a safety agent is filled in the cavity, a weak area is formed in the safety piece, and the weak area can be broken so that the safety agent enters the installation cavity.

According to the battery monomer, the safety piece filled with the safety agent is arranged, so that the weak area on the safety piece is broken to release the safety agent under the condition that the battery monomer is in thermal runaway, and further the thermal runaway is restrained, the risks of severe problems such as further combustion and explosion of the battery monomer are reduced, and the safety of the battery monomer is improved.

In some embodiments, the weakened area is located on a side of the safety member facing the electrode assembly. Therefore, after the weak area is broken, the safety agent can be directly released towards the electrode assembly, so that the inhibition speed of thermal runaway of the electrode assembly is improved, and the safety is improved.

In some embodiments, the region of weakness is capable of breaking under a pressure exceeding a compressive strength value in the range of 0.35MPa to 0.7MPa. Therefore, the weak area can be broken after the battery cell is in thermal runaway, and the pressure release work of the explosion-proof valve is not affected. Meanwhile, the probability of triggering the rupture of the weak area to inhibit further deterioration of the thermal runaway before the problems of high-pressure ignition and the like of the electrode assembly caused by high-temperature eruption generated by the thermal runaway is improved.

In some embodiments, the electrode assembly includes a pole piece and a tab located at an end of the pole piece facing the cap plate assembly and electrically connected to the cap plate assembly, a portion of the cap plate assembly is spaced from the pole piece to form a mounting gap, and the safety piece is located in the mounting gap. Thus, the space of the installation gap can be directly utilized, and the space utilization rate in the battery unit is improved.

In some embodiments, the cover plate assembly includes a cover plate body and a lower plastic, the cover plate body is covered on the mounting opening, and the lower plastic is arranged on a side surface of the cover plate body facing the electrode assembly and is abutted to the pole piece, so that the cover plate body and the pole piece are spaced to form the mounting gap. Therefore, the position of the pole piece is fixed through the cooperation between the lower plastic and the shell, and the probability that the pole piece moves in the mounting cavity to collide with the mounting piece in the mounting gap so as to damage the mounting piece is reduced.

In some embodiments, the safety piece and the cover plate body are arranged at intervals, so that adverse effects on functions of the cover plate body caused by interference between the safety piece and the cover plate body are reduced;

and/or, the safety piece with the interval sets up between the pole piece, on the one hand, has reduced the interference of safety piece to spacing effect between lower plastic and the electrode subassembly, on the other hand, has improved space utilization, under the circumstances that battery monomer volume is certain, is favorable to improving the capacity of battery monomer.

In some embodiments, the lower plastic comprises at least two first lower plastics, a part of the first lower plastics is located at one end of the cover plate body along the first direction, another part of the first lower plastics is located at the other end of the cover plate body along the first direction, and the safety piece is clamped between the two parts of the first lower plastics. Therefore, the limit of the safety piece along the first direction is realized through the two parts of the first lower plastic, and the stability of the safety piece in the installation gap is improved; the first lower plastic is located at two ends of the cover plate body along the first direction, so that the size of the safety piece is increased, more safety agent can be stored in the safety piece, and the inhibition effect on thermal runaway is improved.

In some embodiments, the lower plastic comprises at least two second lower plastics, a part of the second lower plastics is located at one end of the cover plate body along the second direction, another part of the second lower plastics is located at the other end of the cover plate body along the second direction, the safety piece is clamped between the two parts of the second lower plastics, and the first direction is orthogonal to the second direction. Therefore, the limit of the safety piece along the second direction is realized through the two parts of the second lower plastic, and the stability of the safety piece in the installation gap is improved; the second lower plastic is positioned at the two ends of the cover plate body along the second direction, so that the size of the safety piece is further increased, more safety agent is stored in the safety piece, and the inhibition effect on thermal runaway is improved.

In some embodiments, the cover plate assembly comprises a pole, the safety piece is provided with a first through avoidance hole, and the pole lug penetrates through the first through avoidance hole and is electrically connected with the pole post, so that the size of the safety piece is increased, the pole lug is not shielded, and the normal working requirement of the battery cell is met.

In some embodiments, the cover plate assembly comprises an explosion-proof valve, the safety member is provided with a second through avoidance hole, one end of the second through avoidance hole faces the explosion-proof valve, and the other end of the second through avoidance hole faces the electrode assembly, so that the time for the change of the pressure in the battery cell caused by thermal runaway to act on the explosion-proof valve is reduced, the explosion-proof valve can be opened in time, and the safety of the battery cell is improved.

In some embodiments, the safety member includes a safety plate and a sealing member, the safety plate is connected with the cover plate assembly, the safety plate is of a hollow structure to form the cavity, a release hole for communicating the outside of the safety plate with the cavity is formed in the safety plate, and the sealing member is hermetically covered in the release hole to form the weak area. In this way, after thermal runaway occurs in the battery, the sealing member is broken, and the safety agent in the cavity of the safety plate is released from the release hole, so as to achieve the purpose of inhibiting the thermal runaway.

In some embodiments, the seal is a metal foil. Thus, the sealing element can reduce the weight of the structure and has certain structural strength on the premise that the sealing element meets the cracking requirement.

The embodiment of the utility model also provides a cover plate kit for the battery monomer, which comprises a cover plate assembly and a safety piece, wherein the safety piece is arranged on one side of the cover plate assembly in the thickness direction of the cover plate assembly, a cavity is arranged in the safety piece, a safety agent is filled in the cavity, a weak area is arranged on the safety piece, and the weak area can be broken so that the safety agent can be released out of the safety piece. Therefore, in the state that the battery monomer is out of control, the weak area on the safety piece can be broken to release the safety agent, so that the thermal control is restrained, the risks of severe problems such as further combustion and explosion of the battery monomer are reduced, and the safety of the battery monomer is improved.

In some embodiments, the cover assembly includes a cover body and a lower plastic, the lower plastic is disposed on a side surface of the cover body, and the safety member is connected with the lower plastic and is disposed at an interval between the safety member and the cover body. Therefore, the safety piece is fixed with the cover plate assembly, and adverse effects on functions of the cover plate body due to interference between the safety piece and the cover plate body are reduced.

In some embodiments, the cover plate assembly comprises a pole, the safety member is provided with a first avoidance hole penetrating through the safety member, and one end of the first avoidance hole faces the pole, so that a part of the electrode assembly in the battery cell conveniently penetrates through the first avoidance hole to be electrically connected with the pole;

And/or, the apron subassembly includes the explosion-proof valve, the relief member is equipped with the second of running through and dodges the hole, the one end that the hole was dodged to the second is dodged towards the explosion-proof valve, so, reduced the change effect to the time of explosion-proof valve of the single internal pressure of battery that thermal runaway arouses to make the explosion-proof valve can in time open, improved single security of battery.

The embodiment of the utility model also provides a battery, which comprises the battery cell of any one of the previous embodiments.

The embodiment of the utility model also provides an electric device, which comprises the battery in the embodiment, wherein the battery is used as a power supply of the electric device.

In the battery and the power utilization device, the safety piece is arranged to release the safety agent to inhibit thermal runaway under the condition that the battery unit is in thermal runaway, and meanwhile, the arrangement position of the safety piece utilizes the space between the cover plate body and the electrode assembly, so that the space utilization rate in the battery unit is improved.

Drawings

FIG. 1 is a schematic view of a vehicle according to an embodiment of the utility model;

FIG. 2 is an exploded view of a battery according to an embodiment of the present utility model;

FIG. 3 is an exploded view of a battery cell according to an embodiment of the present utility model;

FIG. 4 is a schematic cross-sectional view of a battery cell according to an embodiment of the utility model;

FIG. 5 is a schematic view of a cover plate assembly according to an embodiment of the utility model;

FIG. 6 is a schematic view of the cover plate kit of the embodiment of FIG. 5 from another perspective;

FIG. 7 is a schematic view of a security element according to an embodiment of the present utility model;

FIG. 8 is a schematic view of the security member of FIG. 7 in section at position A-A;

fig. 9 is an enlarged schematic view of the position B in fig. 8.

Description of the reference numerals

A vehicle 1000; a battery 100; a bottom cover 101; a top cover 102; a controller 200; a motor 300;

A battery cell 10; a housing 11; a mounting cavity 11a; a mounting gap 11b; a mounting port 11b; a cover plate assembly 12; a cover plate body 121; a liquid injection hole 121a; a liquid injection hole column 1211; an explosion-proof valve 122; a post 123; a lower plastic 124; a first lower plastic 1241; a second lower plastic 1242; an electrode assembly 13; a pole piece 131; a tab 132; a safety member 14; a cavity 14a; a weakened area 14b; a first escape hole 14c; a second escape hole 14d; a safety plate 141; a release hole 141a; a seal 142; a safener 143; cover plate kit 15

Detailed Description

It should be noted that, in the case of no conflict, the embodiments of the present application and the technical features of the embodiments may be combined with each other, and the detailed description in the specific embodiments should be interpreted as an explanation of the gist of the present application and should not be construed as unduly limiting 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 utility model, the technical terms "first," "second," "third," etc. are used merely to distinguish between different objects and should not 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 utility model, 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 utility model, 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 this context, the character "/" generally indicates that the associated object is an "or" relationship.

In the description of the embodiments of the present utility model, the technical term "thickness direction" orientation or positional relationship is based on the orientation or positional relationship shown in fig. 5, and the technical term "first direction" orientation or positional relationship is based on the orientation or positional relationship shown in fig. 6, merely for convenience of describing the embodiments of the present utility model and simplifying the description, and does not indicate or imply that the apparatus or element referred to must have a specific orientation, be configured, operated, or used in a specific orientation, and thus should not be construed as limiting the embodiments of the present utility model.

In the description of the embodiments of the present utility model, 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 utility model will be understood by those of ordinary skill in the art according to specific circumstances.

In the description of the embodiments of the present utility model, unless explicitly specified and limited otherwise, the term "contact" is to be understood in a broad sense as either direct contact or contact across an intermediate layer, as either contact with substantially no interaction force between the two in contact or contact with interaction force between the two in contact.

The following describes embodiments of the present utility model in detail.

Currently, batteries are increasingly used in life and industry. The 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, as well as a plurality of fields such as military equipment, aerospace, and the like. With the continuous expansion of the battery application field, the market demand thereof is also continuously expanding.

In the process of transporting and working the battery, if the battery is in abnormal states such as thermal shock, overcharge, overdischarge, short circuit, vibration, extrusion and the like, thermal reaction occurs among chemical components such as active substances, electrolyte and the like in the battery monomer in the battery, so that the battery monomer has a probability of thermal runaway.

Referring to fig. 3 and 4, an embodiment of the present utility model provides a battery cell 10, where the battery cell 10 includes a case 11, an electrode assembly 13, a cover plate assembly 12, and a safety member 14, a mounting cavity 11a is provided in the case 11, one side of the mounting cavity 11a is opened to form a mounting opening 11b, the electrode assembly 13 is disposed in the mounting cavity 11a, the cover plate assembly 12 is covered on the mounting opening 11b, the safety member 14 is disposed in the mounting cavity 11a, a cavity 14a is provided in the safety member 14, a safety agent 143 is filled in the cavity 14a, a weak area 14b is provided on the safety member 14, and the weak area 14b can be ruptured to allow the safety agent 143 to enter the mounting cavity 11 a.

The case 11 provides a mounting space for components in the battery cell 10 such as the electrode assembly 13 by forming the mounting cavity 11 a. The outer surface of the case 11 forms part of the exterior surface of the battery cell 10.

The case 11 is used to house the electrode assembly 13, electrolyte, and the like. The shell 11 may be a steel shell, an aluminum shell, a plastic shell (such as polypropylene), a composite metal shell (such as a copper-aluminum composite shell), an aluminum-plastic film, or the like.

Electrode assembly 13. Electrode assembly 13 includes a positive electrode, a negative electrode, and a separator. During charge and discharge of the battery cell 10, active ions (e.g., lithium ions) are inserted and extracted back and forth between the positive electrode and the negative electrode. The separator is arranged between the positive electrode and the negative electrode, can play a role in preventing the positive electrode and the negative electrode from being short-circuited, and can enable active ions to pass through.

The cover plate assembly 12 is configured to cover the mounting opening 11b to form an exterior surface of the battery cell 10 together with the housing 11, that is, the cover plate assembly 12 forms a part of the exterior surface of the battery cell 10.

The housing 11 may be provided with one or more mounting openings 11b. The cover plate assembly 12 may also be provided with one or more.

A safety member 14 for releasing the safety agent 143 into the installation cavity 11a after the environment within the installation cavity 11a reaches a trigger condition.

The safety agent 143 refers to a liquid, gas, or solid powder capable of increasing the internal resistance of the battery cell 10 and/or reducing the flammability of the battery cell 10. The internal resistance of the battery cell 10 is understood to be the resistance to which the battery cell 10 is subjected when the battery cell 10 is in operation, such as: the internal resistance consists of electrode material, electrolyte, diaphragm resistance, contact resistance of parts, etc. Flammability refers to the difficulty of burning a material, and various data testing modes are available, such as: and judging the combustibility of the material according to the combustion speed, the combustion time, the anti-dripping capability, whether the dripping beads burn or not and the like.

The cavity 14a refers to an accommodation space within the safety member 14 for storing the safety agent 143.

The weak area 14b refers to a portion of the safety member 14 that is capable of being broken in the event of an increase in temperature or pressure inside the case 11 caused by thermal runaway of the battery cell 10, or the like, such that a through-break is formed in the weak area 14b or a through-break is formed between the other portion of the safety member 14 and the weak area 14b, thereby enabling the release of the safety agent 143 inside the cavity 14a from the safety member 14, thereby functioning to suppress or stop thermal runaway inside the battery cell 10.

According to the battery cell 10 provided by the embodiment of the utility model, the safety piece 14 provided with the safety agent 143 is arranged, so that the weak area 14b on the safety piece 14 is broken to release the safety agent 143 in the state that the battery cell 10 is in thermal runaway, and further the thermal runaway is restrained, thereby reducing the risk that the battery cell 10 is further subjected to severe problems such as combustion, explosion and the like, and improving the safety of the battery cell 10.

The specific type of safener 143 is not limited, such as one or more of a flame retardant, a fire extinguishing agent, an insulating liquid, and a poisoning agent.

The flame retardant means that the flame retardant can be mixed with the electrolyte to improve the flame retardance of the battery cell 10 so as to reduce the flammability of the battery cell 10, and the flame retardant can be an organic flame retardant or an inorganic flame retardant. Among them, the organic flame retardant may be, but is not limited to, trioctyl phosphate, triphenyl phosphate, diphenyl octyl phosphate, tris (chloroethyl) phosphate/chlorinated paraffin. The inorganic flame retardant may be, but is not limited to, aluminum hydroxide, calcium aluminate, and the like.

Fire extinguishing agents are also meant to be mixed with an electrolyte to reduce the flammability of the battery cell 10, but unlike flame retardants, fire extinguishing agents are focused on reducing the flammability of the battery cell 10 after a fire, such as: phosphoric acid compounds, and the like.

The insulating liquid refers to a liquid material having insulating properties, which increases the internal resistance of the battery cell 10. Such as: the insulating liquid may be, but is not limited to, silicone oil, dodecylbenzene, polybutene, and the like.

The poisoning agent is a substance that reacts with the negative electrode material before oxygen gas reacts with the negative electrode material, and increases the internal resistance of the battery cell 10. Such as: the polymer has the property of blocking C, H free radicals and combining lithium ions, and is NaHCO ₃ or KHCO ₃; or have the property of binding C, H or O radicals or inhibiting C, H or O radical activity. Including one or more of carbonates, tetrafluoroethane, heptafluoropropane, tetrafluoropentane, perfluoropentane, ethylenediamine, dibenzylamine.

The battery cells in the embodiment of the utility model are combined in a plurality of ways to form a battery module or a battery pack.

The battery module may be used in, but not limited to, electrical devices such as vehicles, boats or aircraft. A power supply system having a battery cell, a battery, or the like in the embodiment of the utility model constituting the power utilization device may be used.

The battery pack can also be used in, but not limited to, energy storage power systems, vehicles, boats or aircraft, and other electrical devices. The use of a battery pack can provide a higher total energy. Moreover, the battery pack is formed by arranging a plurality of grouped batteries in the sealed box body, thereby having more reliable dustproof and waterproof performance, and being applicable to scenes where the use environment is worse, moist and even immersed.

The embodiment of the utility model provides an electricity utilization device comprising the battery module or the battery pack for providing electric energy, wherein the electricity utilization 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. 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.

In the following embodiments, for convenience of explanation, the electric device according to an embodiment of the present application will be described by taking the vehicle 1000 as an example. The following description refers to the accompanying drawings.

Fig. 1 is a schematic structural diagram of a vehicle 1000 according to an embodiment of the utility model. 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. As shown in fig. 1, 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 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 utility model, battery 100 may be used not only as an operating power source for vehicle 1000, but also 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.

Fig. 2 and 3 are exploded perspective views of a battery 100 according to an embodiment of the present utility model. The battery 100 includes a bottom cover 101, a top cover 102, and at least one battery cell 10, the top cover 102 covering over the bottom cover 101, thereby forming an accommodating space between the bottom cover 101 and the top cover 102 for placing the battery cell 10.

In the battery 100, the number of the battery cells 10 may be plural, and the plural battery cells 10 may be connected in series, parallel, or series-parallel, and series-parallel refers to both of the plural battery cells 10 being connected in series and parallel. The plurality of battery cells 10 can be directly connected in series or in parallel or in series-parallel, and then the whole body formed by the plurality of battery cells 10 is placed in the accommodating space formed by the bottom plate 1 and the cover body 2; of course, the battery 100 may be a battery module formed by connecting a plurality of battery cells 10 in series or parallel or series-parallel connection, and a plurality of battery modules are connected in series or parallel or series-parallel connection to form a whole and are accommodated in an accommodating space formed by the bottom cover 101 and the top cover 102. 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 10.

In the embodiment of the present utility model, the battery cell 10 may be a secondary battery, and the secondary battery refers to the battery cell 10 that can be continuously used by activating the active material in a charging manner after the battery cell 10 is discharged.

The battery cell 10 may be a lithium ion battery, a sodium lithium ion battery, a lithium metal battery, a sodium metal battery, a lithium sulfur battery, a magnesium ion battery, a nickel hydrogen battery, a nickel cadmium battery, a lead storage battery, or the like, which is not limited by the embodiment of the utility model.

As an example, the battery cell 10 may be a cylindrical battery cell, a prismatic battery cell, a pouch battery cell, or other shaped battery cell, and the prismatic battery cell includes a square-case battery cell, a blade-shaped battery cell, a polygonal-prismatic battery cell, such as a hexagonal-prismatic battery cell, etc., and embodiments of the present utility model are not particularly limited.

The battery cell 10 in some embodiments of the present utility model will be described in detail below.

It can be appreciated that after the weakened areas 14b are ruptured, the safety agent 143 is brought into contact with the electrode assembly 13 as soon as possible to suppress thermal runaway of the electrode assembly 13 as soon as possible.

Specifically, referring to fig. 4, the weakened area 14b is located at a side of the safety member 14 facing the electrode assembly 13. In this way, the safety agent 143 can be directly released toward the electrode assembly 13 after the breakage of the weakened region 14b, thereby improving the speed of suppressing the occurrence of thermal runaway of the electrode assembly 13 and improving safety.

The specific manner in which the frangible region 14b is caused to fracture is not limited. Such as an externally triggered rupture or a spontaneous rupture.

The external trigger rupture refers to the rupture of other mechanical structures in the battery cell 10 after thermal runaway of the battery cell 10 to act on the weak area 14b by striking, cutting, etc. and cause the structure thereof to be broken.

Spontaneous rupture refers to rupture of the self-structure of the weakened region 14b by cleavage after thermal runaway of the battery cell 10.

The specific manner in which the autogenous rupture occurs is not limited.

Illustratively, the weakened area 14b is capable of breaking under a pressure exceeding a compressive strength value in the range of 0.35MPa (MEGA PASCAL MPa) to 0.7MPa. That is, the compressive strength value of the weakened region 14b is any value in the range of 0.35MPa to 0.7MPa. In this way, the weakened area 14b is allowed to rupture after thermal runaway of the battery cell 10 without affecting the pressure relief operation of the explosion-proof valve 122. Meanwhile, the probability of triggering the rupture of the weakened region 14b to suppress further deterioration of the thermal runaway before the high-pressure ignition of the electrode assembly 13 due to the high-temperature spray generated by the thermal runaway is raised.

The compressive strength value refers to the stress intensity at which the object is broken under the action of pressure.

The specific manner of measuring the compressive strength value of the weakened area 14b is not limited, for example, in the case where the weakened area 14b is made of a metal material, the safety member 14 is placed in a pressure testing machine, the position of the safety member 14 is restrained by a restraining means, the pressure head of the pressure testing machine is controlled to press the weakened area 14b at a constant displacement rate until the weakened area 14b is broken, the maximum actual compressive force F _mc is determined from a force-deformation diagram measured by the pressure testing machine, and the corresponding compressive strength is calculated according to the following formula:

R_mc＝F_mc/S

In the above equation, R _mc is the compressive strength value, and S is the original cross-sectional area of the weakened region 14 b.

In a state where the pressure in the battery cell 10 is less than 0.35MPa, thermal runaway does not occur in the battery cell 10, and the weak area 14b does not rupture.

It will be appreciated that during long-term use of the battery cell 10, the electrode assembly 13 generates gas due to electrochemical reaction, so that the pressure in the battery cell 10 is continuously increased, and therefore, the compressive strength value of the weak area 14b is not less than 0.35MPa, so that the probability of the weak area 14b being ruptured due to the pressure increase caused by normal use of the battery cell 10 in the whole life cycle of the battery cell 10 can be reduced.

The compressive strength value of the weak area 14b is lower than 0.7MPa so that the compressive strength value of the weak area 14b is lower than the trigger value of the battery cell 10 to safely release the high-temperature and high-pressure gas therein. The specific way of safely releasing the high-temperature and high-pressure gas inside the battery cell 10 is not limited, for example, an explosion-proof valve 122 capable of being selectively opened and closed is arranged on the battery cell 10, and after the weak area 14b is broken, if the safety agent 143 cannot completely inhibit thermal runaway, the thermal runaway continues to be deteriorated, so that the pressure in the battery cell 10 continues to rise until the opening pressure of the explosion-proof valve 122 is reached, and the explosion-proof valve 122 is triggered to be opened, thereby reducing the probability of explosion of the battery cell 10. That is, the rupture of the weakened area 14b occurs before the explosion proof valve 122 opens.

The specific placement of the safety element 14 in the safety chamber is not limited.

Illustratively, referring to fig. 4, the electrode assembly 13 includes a pole piece 131 and a tab 132, the tab 132 being located at an end of the pole piece 131 facing the cap assembly 12 and being electrically connected to the cap assembly 12, a portion of the cap assembly 12 being spaced from the pole piece 131 to form a mounting gap 11b, and the safety member 14 being located in the mounting gap 11 b.

And a pole piece 131 for generating an electrochemical reaction to generate an electric current.

Tab 132 for conducting the current generated in pole piece 131 away from electrode assembly 13. Tab 132 includes a positive tab 132 and a negative tab 132.

The pole piece 131 and the cover plate assembly 12 are separated to form a mounting gap 11b so as to avoid short circuit caused by contact between the cover plate assembly 12 and the pole piece 131.

The safety material 14 is directly provided in the installation gap 11b, so that the space of the installation gap 11b can be directly utilized, and the space utilization rate in the battery cell 10 can be improved.

In some embodiments, referring to fig. 4 and 5, the cover assembly 12 includes a cover body 121 and a lower plastic 124, the cover body 121 is covered on the mounting opening 11b, and the lower plastic 124 is disposed on a side surface of the cover body 121 facing the electrode assembly 13 and abuts against the pole piece 131, so that the cover body 121 and the pole piece 131 are spaced apart to form a mounting gap 11b.

A cap plate body 121 provided to cover the mounting opening 11b to form a portion of the outer surface of the battery cell 10,

The lower plastic 124 refers to a member for restraining the positions of the electrode assembly 13 and the cap body 121. In the state that the cover plate body 121 covers and locates the casing 11, lower plastic 124 is located in the installation cavity 11a, and the terminal surface that one side of lower plastic 124 kept away from the cover plate body 121 can contact with the electrode assembly 13 to play the effect of restraining the position of electrode assembly 13 in installation cavity 11a, reduced the probability that the electrode assembly 13 is damaged because of moving and bumping, reduced the probability that the electrode assembly 13 is moved and is caused the short circuit in the casing 11. Meanwhile, the lower plastic 124 can be abutted against the housing 11 to limit the relative position of the cover body 121 and the housing 11, so that the probability of short circuit of the electrode assembly 13 and leakage of electrolyte caused by sliding between the cover body 121 and the electrode assembly 13 is reduced.

The lower plastic 124 is made of an insulating material to reduce the risk of short circuit in the case of contact with the electrode assembly 13.

It will be appreciated that the pole piece 131 is sandwiched between the inner wall of the mounting cavity 11a and the lower plastic 124. Thus, the position of the pole piece 131 is fixed by the cooperation between the lower plastic 124 and the shell 11, and the probability that the pole piece 131 moves in the mounting cavity 11a to collide with the mounting piece in the mounting gap 11b so as to damage the mounting piece is reduced.

It will be appreciated that the cover body 121 is in sealing engagement with the housing 11.

In some embodiments, referring to fig. 5 and 6, in the projection perpendicular to the thickness direction of the cover body 121, the projection of the lower plastic 124 is located within the projection range of the cover body 121, so as to reduce the overall external dimension of the cover assembly 12 and reduce the interference generated by the sealing cover of the cover body 121 on the housing 11.

In some embodiments, referring to fig. 5 and 6, in the projection perpendicular to the thickness direction of the cover body 121, the projection of the safety member 14 is located within the projection range of the cover body 121. In this way, the overall external dimensions of the cover assembly 12 are advantageously reduced, while at the same time reducing the interference of the safety member 14 with the cover body 121 sealing the cover provided to the housing 11.

In some embodiments, referring to fig. 5 and 6, the safety member 14 is spaced apart from the cover body 121. In this way, the interference between the safety member 14 and the cover body 121 is reduced to adversely affect the function of the cover body 121.

In some embodiments, referring to fig. 5 and 6, the cover body 121 is provided with a liquid injection hole 121a penetrating along the thickness direction, the cover body 121 protrudes toward one side surface of the safety member 14 to form a liquid injection hole pillar 1211, and the liquid injection hole 121a is disposed in the liquid injection hole pillar 1211. After the cap assembly 12 is covered on the case 11, the electrolyte is injected into the battery cell 10 through the injection hole 121 a. The safety member 14 and the injection hole pillars 1211 are disposed at intervals in the thickness direction of the cap plate body 121, so that the electrolyte can flow into the battery cell 10 without being blocked by the safety member 14, and the injection efficiency is improved.

In some embodiments, referring to fig. 4, the safety member 14 is spaced from the pole piece 131. That is, the safety member 14 is configured not to protrude from the lower plastic 124 in the thickness direction of the cap plate body 121, on one hand, the interference of the safety member 14 to the limiting action between the lower plastic 124 and the electrode assembly 13 is reduced, and on the other hand, the space utilization is improved, which is advantageous to improve the capacity of the battery cell 10 in case that the volume of the battery cell 10 is fixed.

The specific material of the cover body 121 is not limited, and may be one of iron alloy, aluminum alloy, carbon fiber composite material, and the like.

The material of the safety member 14 may be different from the specific material of the cap body 121; the same may be used to simplify the overall manufacturing process of the cover plate assembly 12.

In some embodiments, referring to fig. 5 and 6, the safety member 14 is connected to the lower plastic 124, so that the lower plastic 124 is directly used to fix the safety member 14, which reduces modification to the cover body 121, and is beneficial to reducing manufacturing cost.

The connection between the safety member 14 and the lower plastic 124 is not limited, and for example, the safety member and the lower plastic 124 are fixedly connected by laser welding.

The specific manner in which the lower plastic 124 implements the restraint on the position of the security element 14 is not limited.

In some embodiments, referring to fig. 4 to 6, the lower plastic 124 includes at least two first lower plastic 1241, a portion of the first lower plastic 1241 is located at one end of the cover body 121 along the first direction, another portion of the first lower plastic 1241 is located at the other end of the cover body 121 along the first direction, and the safety element 14 is sandwiched between the two portions of the first lower plastic 1241.

Therefore, the limit of the safety piece 14 along the first direction is realized through the two parts of the first lower plastic 1241, which is beneficial to improving the stability of the safety piece 14 in the installation gap 11 b; the first lower plastic 1241 is located at two ends of the cover body 121 along the first direction, so as to be beneficial to increasing the size of the safety piece 14, so that more safety agent 143 can be stored in the safety piece 14, and the thermal runaway inhibition effect can be improved.

In some embodiments, referring to fig. 4 to 6, the lower plastic 124 includes at least two second lower plastic 1242, a portion of the second lower plastic 1242 is located at one end of the cover body 121 along the second direction, another portion of the second lower plastic 1242 is located at the other end of the cover body 121 along the second direction, and the safety element 14 is sandwiched between the two portions of the second lower plastic 1242, where the first direction is orthogonal to the second direction.

Therefore, the limit of the safety piece 14 along the second direction is realized through the two parts of the second lower plastic 1242, which is beneficial to improving the stability of the safety piece 14 in the installation gap 11 b; the second lower plastic 1242 is located at two ends of the cover body 121 along the second direction, so as to be beneficial to further increasing the size of the safety piece 14, thereby being beneficial to storing more safety agent 143 in the safety piece 14 and improving the effect of inhibiting thermal runaway.

The first direction and the second direction are both directions perpendicular to the thickness direction of the cover body 121.

In some embodiments, the first direction is the length direction of the cover body 121, and the second direction is the width direction of the cover body 121.

It will be appreciated that the particular configuration of the safety member 14 is required to cooperate with the electrode assembly 13.

Referring to fig. 4 to 8, for example, the plate assembly includes a pole 123, the safety member 14 is provided with a first relief hole 14c therethrough, and the tab 132 is electrically connected to the pole 123 through the first relief hole 14 c.

The post 123 refers to a portion of the cap plate assembly 12 for electrical connection with the tab 132 of the electrode assembly 13. The number of the posts 123 is at least two, one of which serves as the positive electrode of the battery cell 10 and the other serves as the negative electrode of the battery cell 10.

The tab 132 in the electrode assembly 13 can pass through the first avoiding hole 14c to be electrically connected with the pole 123, so that the volume of the safety piece 14 is increased, the tab 132 is not shielded, and the normal working requirement of the battery cell 10 is met.

It can be understood that the tab 132 is disposed at a distance from the inner wall of the first avoiding hole 14c, or is disposed in a fitting manner.

In some embodiments and referring to fig. 4-8, the cover assembly 12 includes an explosion-proof valve 122, and the safety member 14 is provided with a second relief aperture 14d therethrough, one end of the second relief aperture 14d facing the explosion-proof valve 122 and the other end facing the electrode assembly 13.

The explosion-proof valve 122 is used for triggering the explosion-proof valve 122 to open after thermal runaway occurs in the battery cell 10, so that the gas and/or liquid in the battery cell 10 is discharged out of the battery cell 10 under the action of pressure, and the explosion probability of the battery cell 10 is reduced.

One end of the second avoidance hole 14d faces the electrode assembly 13, so that high-temperature and high-pressure gas generated after thermal runaway of the electrode assembly 13 can enter the second avoidance hole 14d more rapidly; the other end of the second avoidance hole 14d faces the explosion-proof valve 122, so that the high-temperature and high-pressure gas in the second avoidance hole 14d can directly act on the explosion-proof valve 122 after leaving the second avoidance hole 14 d. In this way, the time for the pressure change in the battery cell 10 to act on the explosion-proof valve 122 due to thermal runaway is reduced, so that the explosion-proof valve 122 can be opened in time, and the safety of the battery cell 10 is improved.

It will be appreciated that the compressive strength value of the weakened area 14b is less than the opening pressure of the explosion proof valve 122, i.e., after thermal runaway occurs, the weakened area 14b breaks before the explosion proof valve 122 opens.

The particular configuration of the security element 14 in which the weakened region 14b is formed is not limited.

Referring to fig. 7 to 9, the safety member 14 includes a safety plate 141 and a sealing member 142, the safety plate 141 is connected with the cap plate assembly 12, the safety plate 141 is hollow to form a cavity 14a, a release hole 141a communicating the outside of the safety plate 141 with the cavity 14a is provided in the safety plate 141, and the sealing member 142 is hermetically covered in the release hole 141a to form a weak area 14b. In this way, after thermal runaway occurs in the battery, the seal 142 is ruptured, and the safety agent 143 in the cavity 14a of the safety plate 141 is released from the release hole 141a, so as to suppress thermal runaway.

In the process of manufacturing the safety member 14, the safety agent 143 may be first placed into the cavity 14a through the release hole 141a, and then the sealing member 142 is covered on the release hole 141a, thereby realizing sealed storage of the safety agent 143.

The specific type of seal 142 is not limited.

Illustratively, the seal 142 is a metal foil. In this manner, the seal 142 is reduced in weight and has a certain structural strength while meeting the rupture requirements.

The particular type of metal used for the seal 142 is not limited, for example, the seal 142 is aluminum foil.

Referring to fig. 4 to 9, a battery cell 10 according to an embodiment of the present utility model is described as follows:

The battery cell 10 comprises a shell 11, an electrode assembly 13, a cover plate assembly 12 and a safety piece 14, wherein a mounting cavity 11a is arranged in the shell 11, one side of the mounting cavity 11a is opened to form a mounting opening 11b, the electrode assembly 13 is arranged in the mounting cavity 11a, the cover plate assembly 12 is covered on the mounting opening 11b, the safety piece 14 is arranged in the mounting cavity 11a, the electrode assembly 13 comprises a pole piece 131 and a pole lug 132, the pole lug 132 is arranged at one end of the pole piece 131 facing the cover plate assembly 12 and is electrically connected with the cover plate assembly 12, the cover plate assembly 12 comprises a cover plate body 121, a lower plastic 124, a pole post 123 and an explosion-proof valve 122, the cover plate body 121 is covered on the mounting opening 11b, the lower plastic 124 is arranged on one side surface of the cover plate body 121 facing the electrode assembly 13 and is abutted against the pole piece 131, so that the cover plate body 121 and the pole piece 131 form a mounting gap 11b at intervals, the safety piece 14 is arranged in the mounting gap 11b, the safety piece 14 and the cover plate body 121 are arranged at intervals, the safety piece 14 and the pole piece 131 are arranged at intervals, the safety piece 14 is provided with a first through avoiding hole 14c, the pole lug 132 penetrates through the first avoiding hole 14c to be electrically connected with the pole post 123, the safety piece 14 is provided with a second through avoiding hole 14d, one end of the second through avoiding hole 14d faces the explosion-proof valve 122, the other end faces the electrode assembly 13, the lower plastic 124 comprises at least two first lower plastics 1241 and at least two second lower plastics 1242, the safety piece 14 comprises a safety plate 141 and a sealing piece 142, one part of the first lower plastics 1241 is positioned at one end of the cover plate body 121 along the first direction, the other part of the first lower plastics 1241 is positioned at the other end of the cover plate body 121 along the first direction, the safety plate 141 is clamped between the two parts of the first lower plastics 1241, one part of the second lower plastics 1242 is positioned at one end of the cover plate body 121 along the second direction, the other part of the second lower plastics 1242 is positioned at the other end of the cover plate body 121 along the second direction, the safety plate 141 is sandwiched between two parts of the second lower plastic 1242, the first direction is orthogonal to the second direction, the safety plate 141 is of a hollow structure to form a cavity 14a, a release hole 141a for communicating the outside of the safety plate 141 with the cavity 14a is formed in the safety plate 141, the sealing element 142 is hermetically covered on the release hole 141a to form a weak area 14b, the cavity 14a is filled with the safety agent 143, the weak area 14b can be broken, the safety agent 143 enters the installation cavity 11a, and the sealing element 142 is a metal foil.

An embodiment of the present utility model provides a cover plate kit 15 for a battery unit 10, referring to fig. 5 and 6, the cover plate kit 15 includes a cover plate assembly 12 and a safety member 14, the safety member 14 is disposed on one side of the cover plate assembly 12 along the thickness direction of the cover plate assembly 12, a cavity 14a is disposed in the safety member 14, a safety agent 143 is filled in the cavity 14a, a weak area 14b is disposed on the safety member 14, and the weak area 14b can be ruptured to release the safety agent 143 out of the safety member 14. In this way, in the state that the battery cell 10 is in thermal runaway, the weak area 14b on the safety member 14 can be broken to release the safety agent 143, so as to inhibit thermal runaway, thereby reducing the risk that the battery cell 10 further generates severe problems such as combustion, explosion and the like, and improving the safety of the battery cell 10.

In some embodiments, referring to fig. 5 and 6, the cover assembly 12 includes a cover body 121 and a lower plastic 124, the lower plastic 124 is disposed on a side surface of the cover body 121, and the safety member 14 is connected to the lower plastic 124 and is spaced from the cover body 121. In this way, the safety member 14 is fixed to the cover assembly 12, and adverse effects on the function of the cover body 121 caused by interference between the safety member 14 and the cover body 121 are reduced.

In some embodiments, referring to fig. 5 and 6, the cover assembly 12 includes a post 123, and the safety member 14 is provided with a first relief hole 14c therethrough, with one end of the first relief hole 14c facing the post 123. In this way, it is convenient for a portion of the electrode assembly 13 in the battery cell 10 to be electrically connected with the post 123 through the first escape hole 14 c.

In some embodiments, referring to fig. 5 and 6, the cover assembly 12 includes an explosion proof valve 122, and the safety member 14 is provided with a second relief aperture 14d therethrough, with one end of the second relief aperture 14d facing the explosion proof valve 122. In this way, the time for the pressure change in the battery cell 10 to act on the explosion-proof valve 122 due to thermal runaway is reduced, so that the explosion-proof valve 122 can be opened in time, and the safety of the battery cell 10 is improved.

The embodiment of the present utility model also provides a battery including the battery cell 10 of any of the foregoing embodiments.

In the above battery and power consumption device, the safety member 14 is provided such that the safety agent 143 can be released to suppress thermal runaway in the case where the thermal runaway occurs in the battery cell 10, and at the same time, the arrangement position of the safety member 14 utilizes the space of the cap plate body 121 and the electrode assembly 13, thereby improving the space utilization rate in the battery cell 10.

The various embodiments/implementations provided by the application may be combined with one another without contradiction.

The above description is only of the preferred embodiments of the present application and is not intended to limit the present application, but various modifications and variations can be made by those skilled in the art. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application should be included in the protection scope of the present application.

Claims

1. The utility model provides a battery monomer, its characterized in that, battery monomer includes casing, electrode assembly, apron subassembly and safety spare, be equipped with the installation cavity in the casing, one side of installation cavity is opened and is formed the installing port, electrode assembly locates in the installation cavity, the apron subassembly lid is located the installing port, the safety spare is located the installation intracavity, be equipped with the cavity in the safety spare, it has the safener to pack in the cavity, be equipped with weak area on the safety spare, weak area can take place to break, so that the safener enters into in the installation cavity.

2. The battery cell of claim 1, wherein the weakened area is located on a side of the safety feature that faces the electrode assembly.

3. The battery cell of claim 1, wherein the weakened area is capable of breaking under a pressure exceeding a compressive strength value in the range of 0.35MPa to 0.7MPa.

4. The battery cell of claim 1, wherein the electrode assembly includes a pole piece and a tab, the tab being located at an end of the pole piece facing the cap assembly and electrically connected to the cap assembly, a portion of the cap assembly being spaced from the pole piece to form a mounting gap, the safety member being located in the mounting gap.

5. The battery cell as recited in claim 4, wherein the cover assembly includes a cover body and a lower plastic, the cover body covering the mounting opening, the lower plastic being disposed on a side surface of the cover body facing the electrode assembly and abutting the pole piece such that the cover body and the pole piece are spaced apart to form the mounting gap.

6. The battery cell of claim 5, wherein the safety member is disposed in spaced relation to the cover body;

And/or the safety piece and the pole piece are arranged at intervals.

7. The battery cell of claim 5, wherein the lower plastic comprises at least two first lower plastics, a portion of the first lower plastics being located at one end of the cover body in the first direction, and another portion of the first lower plastics being located at the other end of the cover body in the first direction, the safety element being sandwiched between the two portions of the first lower plastics.

8. The battery cell of claim 7, wherein the lower plastic comprises at least two second lower plastics, a portion of the second lower plastics being located at one end of the cover body in a second direction, another portion of the second lower plastics being located at the other end of the cover body in the second direction, the safety element being sandwiched between two portions of the second lower plastics, the first direction being orthogonal to the second direction.

9. The battery cell of claim 4, wherein the cover assembly includes a post, the safety member is provided with a first relief hole therethrough, and the tab is electrically connected to the post through the first relief hole.

10. The battery cell of claim 1, wherein the cover assembly includes an explosion-proof valve, the safety member is provided with a second relief hole therethrough, one end of the second relief hole is directed toward the explosion-proof valve, and the other end is directed toward the electrode assembly.

11. The battery cell as recited in claim 1, wherein the safety member includes a safety plate and a sealing member, the safety plate is connected to the cap plate assembly, the safety plate is of a hollow structure to form the cavity, a release hole is formed in the safety plate to communicate an outside of the safety plate with the cavity, and the sealing member is hermetically covered in the release hole to form the weak area.

12. The battery cell of claim 11, wherein the seal is a metal foil.

13. The utility model provides a apron external member for battery monomer, its characterized in that, the apron external member includes apron subassembly and safety piece, the safety piece is located apron subassembly is followed one side of apron subassembly thickness direction, be equipped with the cavity in the safety piece, it has the safener to pack in the cavity, be equipped with weak area on the safety piece, weak area can take place to break, so that safener release outside the safety piece.

14. The cover plate kit of claim 13, wherein the cover plate assembly comprises a cover plate body and a lower plastic, the lower plastic is disposed on a side surface of the cover plate body, and the safety piece is connected with the lower plastic and is disposed at a distance from the cover plate body.

15. The cover plate kit of claim 13, wherein the cover plate assembly includes a pole, the safety member having a first relief aperture therethrough, one end of the first relief aperture being oriented toward the pole;

and/or, the cover plate assembly comprises an explosion-proof valve, the safety piece is provided with a second through avoidance hole, and one end of the second through avoidance hole faces to the explosion-proof valve.

16. A battery comprising a plurality of said cells of any one of claims 1-12.

17. An electric device, characterized in that it comprises the battery as claimed in claim 16 as a power source for the electric device.