CN114639918B

CN114639918B - Composite packaging lithium battery structure with flame retardant function

Info

Publication number: CN114639918B
Application number: CN202210542441.9A
Authority: CN
Inventors: 孟冬梅; 王延延
Original assignee: Jiangsu Frey Battery Technology Co ltd
Current assignee: Jiangsu Frey Battery Technology Co ltd
Priority date: 2022-05-19
Filing date: 2022-05-19
Publication date: 2022-09-06
Anticipated expiration: 2042-05-19
Also published as: CN114639918A

Abstract

The invention relates to the technical field of new energy power batteries, and discloses a composite packaging lithium battery structure with a flame retardant function, which comprises an insulating plate and a conductive groove arranged at the top end of the insulating plate, wherein the bottom of the inner cavity of the conductive groove is provided with a mounting groove, the mounting groove is a T-shaped groove arranged along the length direction of the insulating plate, the bottom of the inner cavity of the mounting groove is fixedly bonded with an expansion bag, and a communication cavity formed by the expansion bag, an exhaust channel and a jet flow channel is filled with gas substances expanded by heating. According to the invention, the flame-retardant plate for flame retardance is additionally arranged on the insulating plate between the traditional battery pack modules, so that when a single battery pack (namely one side of the insulating plate) generates spontaneous combustion open fire, after the expansion bag is heated and expanded, the high-speed airflow is sprayed to the open fire source near the conductive connection mechanism through the jet flow channel so as to block the supplement of oxygen nearby, and thus the open fire source near the conductive connection mechanism is prevented from being rapidly transmitted into the adjacent battery pack modules through the conductive groove, and the time for the spontaneous combustion fire intensity to be increased is prolonged.

Description

Composite packaging lithium battery structure with flame retardant function

Technical Field

The invention relates to the technical field of new energy power batteries, in particular to a composite packaging lithium battery structure with a flame retardant function.

Background

Compared with the traditional lead-acid battery and nickel-hydrogen battery, the lithium ion battery has the advantages of high specific energy, large specific power, easy realization of rapid charge and deep discharge, long service life and the like, and is the main development direction of the current power battery. Lithium ion batteries can be divided into two types of batteries, namely hard-shell batteries and soft-package batteries according to the packaging mode of the lithium ion batteries. The hard shell battery is divided into square and round batteries according to the winding mode of the positive and negative pole pieces.

The development of new energy automobiles needs to consider not only the power endurance performance but also the safety performance. Due to the structural characteristics of the lithium battery (mainly electrolyte which is mostly flammable organic solvents with low boiling points such as diethyl carbonate, diethyl ether and propylene carbonate, and poor thermal stability of the lithium battery, oxygen can be decomposed and released at a temperature of about 200 ℃, and the oxygen can be easily burnt together with the electrolyte and the carbon material). Improper operation behaviors such as collision, extrusion, fire and the like can cause the diaphragm between the anode and the cathode to break, cause short circuit and cause thermal runaway; in addition, overcharge of lithium batteries, especially multiple times of high-power direct current rapid charging, can cause lithium dendrites to be continuously generated inside the battery, pierce through the diaphragm, cause short circuit, and cause thermal runaway.

Based on the structure of the lithium battery and the spontaneous combustion reason, the structure of the power lithium battery is improved so as to improve the safety protection performance. At present, whether square batteries or round batteries form a power source of a new energy automobile, thousands of small batteries are needed to form a module, the specific forming mode is that a plurality of batteries form a battery pack, the plurality of battery packs form a battery assembly of the whole automobile, the battery packs are connected in series by battery harnesses or confluence pieces, the battery packs are isolated by insulating plates, and the surface of the battery assembly is covered by a firm steel shell or an aluminum shell.

Referring to fig. 1, the insulating plate between the battery packs can be provided with a conductive groove 2 at the top end of the insulating plate 1 due to the fact that a battery wire harness or a bus sheet needs to pass through the insulating plate, the conductive groove 2 is passed through by a conductive connecting mechanism 3, the conductive connecting mechanism 3 is a wire harness or a bus sheet, when a single battery pack is spontaneously combusted, the temperature of a fire source can be rapidly transmitted to the adjacent battery pack from the conductive groove 2 through the conductive connecting mechanism 3, and therefore the power battery assembly can be caused to burn bear fire in a short time. The application needs to carry out technical improvement on the insulating plate so as to prolong the spontaneous combustion spreading time and create more escape or emergency treatment time for a driver.

Disclosure of Invention

Aiming at the defect of the safety performance of the conventional lithium ion battery assembly in the background technology, the invention provides a composite packaging lithium battery structure with a flame-retardant function, which has the advantages of flame retardance and prolongation of the spreading time of spontaneous combustion open fire, and solves the technical problems in the background technology.

The invention provides the following technical scheme: a composite packaging lithium battery structure with flame retardant function comprises an insulating plate and a conductive groove arranged at the top end of the insulating plate, wherein a conductive connection mechanism passes through the conductive groove, a mounting groove is arranged at the bottom of an inner cavity of the conductive groove, the mounting groove is a T-shaped groove arranged along the length direction of the insulating plate, an expansion bag is fixedly bonded at the bottom of the inner cavity of the mounting groove, the expansion bag is in a flexible bag shape or a corrugated pipe shape, the top end of the expansion bag is fixedly connected with a flame retardant plate, an exhaust passage is arranged towards the center at the bottom of the flame retardant plate and communicated with the inner cavity of the expansion bag, a jet flow passage is also arranged in the horizontal direction of the flame retardant plate, the top end of the exhaust passage is communicated with the middle of the jet flow passage, one end of the jet flow passage extends out of the flame retardant plate and extends towards the center of the conductive groove, and the extension ports are symmetrically arranged left and right by the central axis of the conductive connection mechanism, the extension ports are symmetrically arranged in the left and right directions of the plane central axis of the conductive groove, the extension port of the jet flow channel is provided with a sealing plug, and a communication cavity formed by the expansion bag, the exhaust channel and the jet flow channel is filled with 2 non-flammable gases with standard atmospheric pressure or non-flammable liquid vaporized at 70-100 ℃.

Preferably, the extension port of the spouting passage extends upward outside the flame retardant plate, and the upward arrangement of the extension port of the spouting passage is used for blocking the connection of the rectangular battery bundles in series.

Preferably, the extension port of the spouting passage extends out of the flame retardant plate downwards, and the arrangement mode that the extension port of the spouting passage faces downwards is used for blocking when the round battery packs are connected in series.

Preferably, the bottom of the inner cavity of the mounting groove and the left and right sides of the expansion bag are both provided with supporting springs, the supporting springs are in a compressed state, the joint elasticity of the two supporting springs is used for supporting and keeping the flame-retardant plate and the connecting component thereof at the top edge of the insulating plate, and the conductive connecting mechanism crossing the flame-retardant plate part is a high-temperature fusing conductive metal sheet.

Preferably, the inside of the expansion bag is provided with a plurality of resistance reducing rods in an inserting manner, the resistance reducing rods are arranged at equal intervals from top to bottom, and the length of each resistance reducing rod is smaller than that of the upper top end face and the lower top end face of the expansion bag.

Preferably, the inner diameter of the expansion bag, the inner diameter of the exhaust channel, the inner diameter of the jet channel and the inner diameter of the port of the jet channel are sequentially decreased, the port of the jet channel is in a thin tube shape, and the fineness of the port of the jet channel is 1/5-1/3 of the inner diameter of the exhaust channel.

The invention has the following beneficial effects:

1. according to the invention, the flame-retardant plate for flame retardance is additionally arranged on the insulating plate between the traditional battery pack modules, so that when a single battery pack (namely one side of the insulating plate) generates spontaneous combustion open fire, after the expansion bag is heated and expanded, the high-speed airflow is sprayed to the open fire source near the conductive connection mechanism through the jet flow channel so as to block the supplement of nearby oxygen, and thus the open fire source near the conductive connection mechanism is quickly transmitted into the adjacent battery pack modules through the conductive groove, thus the time for increasing the spontaneous combustion fire potential is prolonged, more time is obtained for drivers and passengers to escape or execute emergency treatment measures, and the actual application safety performance of the new energy power battery is improved.

2. According to the invention, through the structural design of the expansion bag, the exhaust channel and the jet flow channel, the upward or downward air injection port can be selected according to the conductive series connection mode of the circular or square battery types, so that the battery type selection can be met, and the application range is wider.

3. The resistance reducing rods are inserted in the expansion bags, so that the expansion and extension performance of the expansion bags can be stably implemented, the safety fault in the practical application level is solved, and the practical application performance is improved.

Drawings

FIG. 1 is a three-dimensional view of a conventional insulating plate and conductive connecting tab configuration;

FIG. 2 is a front view of a structure according to an embodiment of the present invention;

FIG. 3 is a cross-sectional view taken at A-A of FIG. 2 in accordance with the present invention;

FIG. 4 is a front view of a second embodiment of the present invention;

FIG. 5 is a cross-sectional view taken at B-B of FIG. 4 in accordance with the present invention;

FIG. 6 is a front view showing the mounting arrangement of the supporting spring in the second embodiment of the present invention;

FIG. 7 is a cross-sectional view taken at C-C of FIG. 6 in accordance with the present invention;

FIG. 8 is a detail view of a portion of the inflatable bladder of FIG. 7 according to the present invention.

In the figure: 1. an insulating plate; 2. a conductive slot; 3. a conductive connection mechanism; 4. mounting grooves; 5. an inflation bladder; 6. a flame retardant sheet; 7. an exhaust passage; 8. a jet flow passage; 9. a sealing plug; 10. a support spring; 11. a drag reduction rod.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

Example one

Referring to fig. 2-3, a composite packaging lithium battery structure with flame retardant function is used for wire harness series connection between square battery packs, an installation groove 4 is continuously formed at the bottom of an inner cavity of an original conductive groove 2, an expansion bag 5 is fixedly bonded at the bottom of the inner cavity of the installation groove 4, the expansion bag 5 is in a flexible bag shape or a corrugated tube shape and can extend in an extending manner, a flame retardant plate 6 is fixedly connected to the top end of the expansion bag 5, the expansion bag 5 is located in a longitudinal section of the installation groove 4, the flame retardant plate 6 is located in a transverse section of the installation groove 4 (the transverse and longitudinal positions are referred to by the horizontal and vertical directions of fig. 2), an exhaust passage 7 is formed in the bottom of the flame retardant plate 6 towards the center, the exhaust passage 7 is communicated with the inner cavity of the expansion bag 5, a jet flow passage 8 is further formed in the horizontal direction of the flame retardant plate 6, the top end of the exhaust passage 7 is communicated with the middle part of the jet flow passage 8, and the jet flow passage 8 extends towards the left side and the right side of the flame retardant plate 6 respectively, one end of the jet flow channel 8 extends upwards to the outside of the flame-retardant plate 6, the extension ports face the center of the conductive groove 2 (the center of the conductive groove 2 is positioned at the upper edge of the insulating plate 1), the extension ports are arranged in bilateral symmetry by taking the conductive connecting mechanism 3 as a central axis, the extension ports are arranged in bilateral symmetry by taking the plane central axis of the conductive groove 2, the extension port of the jet flow channel 8 is provided with a sealing plug 9, a communication cavity formed by the expansion bag 5, the exhaust channel 7 and the jet flow channel 8 is filled with 2 standard atmospheric non-flammable gases or 70-100 ℃ vaporized non-flammable liquids, the static friction coefficient between the sealing plug 9 and the jet flow channel 8 is determined by that the jet flow channel 8 is filled with 2 standard atmospheric pressures, the temperature variation difference is within 100 ℃, and the sealing plug 9 and the jet flow channel 8 do not generate relative movement.

Therefore, when the battery packs on the left side and the right side of the insulating plate 1 are heated by spontaneous combustion and the rated temperature exceeds 100 ℃, the incombustible gas in the expansion bag 5 is heated and expanded to burst the sealing plug 9, and high-speed airflow is sprayed to the two sides of the conductive connecting mechanism 3, so that the continuous combustion of the insulating skin layer outside the conductive connecting mechanism 3 is prevented, combustible materials are blocked, the combustion spreading path is cut off, and the spontaneous combustion spreading time is prolonged.

Example two

Referring to fig. 4-5, a composite packaging lithium battery structure with flame retardant function is used for the serial connection of bus bars between round battery packs, different from the first embodiment, taking the front view of fig. 4 as an example, the bottom of the inner cavity of the mounting groove 4 and the left and right sides of the expansion bag 5 are both provided with supporting springs 10, the supporting springs 10 are in a compressed state, the two supporting springs 10 are combined with elastic force to support and maintain the flame retardant plate 6 and the connecting component thereof at the top edge of the insulating plate 1, the conductive connecting mechanism 3 traversing the flame retardant plate 6 part is a high temperature (temperature of 150-.

Because the sealing plug 9 is limited by the installation of the conductive connecting mechanism 3 in the normal working stage, the pressure difference of the expansion capsule 5 and the elastic force of the supporting spring 10 can not push the flame-retardant plate 6 upwards, and the sealing plug 9 does not open the port of the jet flow channel 8. At the initial stage of spontaneous combustion of the battery pack, before the conductive connecting mechanism 3 is not fused, even if gas in the expansion bag 5 expands due to heating, the flame-retardant plate 6 cannot be jacked to ascend, when the temperature reaches the rated fusing condition of the conductive connecting mechanism 3, the ascending limit of the flame-retardant plate 6 is released, the flame-retardant plate 6 ascends and seals the conductive groove 2, high-speed jet gas is discharged to the left side and the right side of the expansion bag 5 through the jet flow channel 8, oxygen near the fusing of the conductive connecting mechanism 3 is removed, so that the trend of preventing spontaneous combustion flame from spreading is achieved, the spontaneous combustion and expansion time is delayed, and the time for drivers and passengers to obtain escape or emergency treatment measures is taken.

Referring to fig. 6 to 7, the damping rods 11 are inserted into the expansion bladder 5, the damping rods 11 are arranged in a plurality of numbers and are arranged at equal intervals from top to bottom, the length of the damping rods 11 is smaller than the length of the upper end face and the lower end face of the expansion bladder 5, and because the expansion bladder 5 is heated and expanded before the conductive connecting mechanism 3 is fused, the expansion bladder 5 is attached to the inner wall of the mounting groove 4 due to high-pressure expansion, and the expansion bladder 5 is difficult to extend after the conductive connecting mechanism 3 is fused due to a negative pressure phenomenon in an attachment area, and a gap exists between an expansion compression surface of the expansion bladder 5 and the attachment area of the inner wall of the mounting groove 4 through the damping rods 11, so that the expansion bladder 5 can be extended smoothly.

Considering that the expansion bag 5 is flexible and corrugated, the resistance-reducing rod 11 can be a rigid rod with threads at two ends, and after the rigid rod is inserted into the inner cavity of the expansion bag 5, the outer wall of the expansion bag 5 is screwed on two ends of the resistance-reducing rod 11 by using nuts, and a silica gel gasket is used for performing extrusion sealing on the rigid rod.

In the first and second embodiments, the inner diameter of the expansion bag 5, the inner diameter of the exhaust passage 7, the inner diameter of the jet passage 8, and the inner diameter of the port of the jet passage 8 are sequentially decreased, and the port of the jet passage 8 is in the shape of a thin tube, and the fineness of the inner diameter of the exhaust passage 7 is 1/5-1/3. After the gas generated or existing in the expansion capsule 5 is expanded by high pressure, the speed of the jet flow from the port of the jet flow channel 8 is high, and the jet time period is enough to isolate the open fire source near the conductive connecting mechanism 3.

Compared with the traditional insulating partition plate, the thickness of the insulating partition plate is at least 1-1.5cm, the depth of the installation groove 4 is at least 4cm, the length of the installation groove 4 is at least 4-5 cm for the volume requirement of the expansion gas in the second embodiment, and the expansion gas can be stored under pressure by adopting gas with high thermal expansion coefficient.

It is noted that, herein, relational terms such as first and second, and the like may be used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Also, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus.

Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and alterations can be made in these embodiments without departing from the principles and spirit of the invention, the scope of which is defined in the appended claims and their equivalents.

Claims

1. The utility model provides a composite package lithium battery structure with fire-retardant function, includes insulation board (1) and is located electrically conductive groove (2) that insulation board (1) top was seted up, is through electrically conductive groove (2), its characterized in that by electrically conductive coupling mechanism (3): the bottom of the inner cavity of the conductive groove (2) is provided with a mounting groove (4), the mounting groove (4) is a T-shaped groove arranged along the length direction of the insulating plate (1), the bottom of the inner cavity of the mounting groove (4) is fixedly bonded with an expansion bag (5), the expansion bag (5) is in a flexible bag shape or a corrugated pipe shape, the top end of the expansion bag (5) is fixedly connected with a flame-retardant plate (6), the bottom of the flame-retardant plate (6) is provided with an exhaust passage (7) towards the center, the exhaust passage (7) is communicated with the inner cavity of the expansion bag (5), the horizontal direction of the flame-retardant plate (6) is further provided with a jet flow passage (8), the top end of the exhaust passage (7) is communicated with the middle part of the jet flow passage (8), one end of the jet flow passage (8) extends out of the outer part of the flame-retardant plate (6) and extends towards the center of the conductive groove (2), the extension ports are symmetrically arranged along the central axis of the conductive connection mechanism (3), the extending ports are symmetrically arranged at the left and right sides of the plane central axis of the conductive groove (2), the extending port of the jet flow channel (8) is provided with a sealing plug (9), and a communicating cavity formed by the expansion bag (5), the exhaust channel (7) and the jet flow channel (8) is filled with 2 nonflammable gases with standard atmosphere or nonflammable liquid vaporized at 70-100 ℃.

2. The composite encapsulated lithium battery structure with flame retardant function as claimed in claim 1, wherein: the extending port of the jet flow channel (8) extends upwards to the outside of the flame-retardant plate (6), and the upward arrangement mode of the extending port of the jet flow channel (8) is used for blocking when the square battery pack wire bundles are connected in series.

3. The composite encapsulated lithium battery structure with flame retardant function as claimed in claim 1, wherein: the extension port of the jet flow channel (8) extends out of the flame-retardant plate (6) downwards, and the extension port of the jet flow channel (8) is arranged downwards and used for blocking the round battery pack when the round battery pack collector sheets are connected in series.

4. The composite encapsulated lithium battery structure with flame retardant function as claimed in claim 3, wherein: the bottom of the inner cavity of the mounting groove (4) and the left side and the right side of the expansion bag (5) are respectively provided with a supporting spring (10), the supporting springs (10) are in a compressed state, the joint elasticity of the two supporting springs (10) is used for supporting and keeping the flame-retardant plate (6) and the connecting component thereof at the top edge of the insulating plate (1), and the conductive connecting mechanism (3) crossing the flame-retardant plate (6) is a high-temperature fusing conductive metal sheet.

5. The composite encapsulated lithium battery structure with flame retardant function as claimed in claim 4, wherein: the damping device is characterized in that damping rods (11) are inserted into the expansion bag (5), the damping rods (11) are arranged in a plurality of numbers and are arranged at equal intervals from top to bottom, and the length of the damping rods (11) is smaller than that of the upper top end face and the lower top end face of the expansion bag (5).

6. The composite encapsulated lithium battery structure with flame retardant function as claimed in claim 1, wherein: the inner diameter of the expansion bag (5), the inner diameter of the exhaust channel (7), the inner diameter of the jet flow channel (8) and the inner diameter of the port of the jet flow channel (8) are sequentially reduced in a decreasing mode, the port of the jet flow channel (8) is in a thin tube shape, and the fineness of the port is 1/5-1/3 of the inner diameter of the exhaust channel (7).