CN115586449A - Lithium ion battery thermal runaway gas production test system - Google Patents

Abstract

The invention discloses a lithium ion battery thermal runaway gas production test system, which belongs to the technical field of lithium ion battery thermal runaway experimental equipment and comprises a sealed tank body, a clamp which is arranged in the sealed tank body and used for clamping a lithium ion battery and an inducing device for inducing the thermal runaway of the lithium ion battery, wherein the local part of the shell wall of the sealed tank body protrudes outwards to form a heat insulation cabin for installing a data acquisition device, a cover plate for sealing and heat insulation is arranged at the communication position of the heat insulation cabin and an inner cavity of the sealed tank body, a plurality of sensors are distributed in the sealed tank body, a wire inlet is formed in the cover plate, a test wire for connecting the data acquisition device and the sensors penetrates through the wire inlet, and the wire inlet is sealed through a sealing press cap. According to the invention, by arranging the heat insulation cabin, a space isolated from the outside for accommodating the data acquisition device can be formed, and enough sensors in quantity and types can be distributed in the sealed tank body on the basis of not increasing the holes of the sealed tank body, so that the test requirement is met.

Description

Thermal runaway gas production test system for lithium ion battery

Technical Field

The invention relates to the technical field of lithium ion battery thermal runaway experimental equipment, in particular to a lithium ion battery thermal runaway gas production test system.

Background

The safety of the lithium ion battery serving as a core component of an energy storage system-level unit becomes a fatal hidden danger restricting the overall development of the energy storage industry, and particularly the common safety problem of thermal runaway needs to be solved urgently. In the process of triggering thermal runaway of the lithium ion battery, a series of chemical reactions occur among a positive material, a negative material and electrolyte in the battery and release a large amount of combustible and explosive gas, and once the lithium ion battery is mixed with air, the lithium ion battery can explode when encountering ignition sources such as electric sparks, open flames and the like, thereby greatly threatening the life and property safety of people. Therefore, it is important to perform qualitative and quantitative analysis of thermal runaway gas production of the lithium ion battery and provide an explosion suppression strategy of an energy storage system and a development strategy of a high-safety battery according to a test result.

However, the existing devices for measuring thermal runaway gas generation of lithium ion batteries are often single in function and cannot meet the test requirements of multiple inducers of mechanical abuse, electrical abuse and thermal abuse at the same time. Chinese patent with application publication number CN 114740371A discloses an explosion-proof box for lithium cell test use, the power distribution box comprises a box body, the box body is including explosion-proof overcharge case, explosion-proof acupuncture case and explosion-proof extrusion case, the explosion-proof overcharge incasement is equipped with explosion-proof board one, be equipped with lithium cell one on the explosion-proof board one, be equipped with explosion-proof door one on the explosion-proof overcharge case, be equipped with display panel face one on the explosion-proof door one, the stopper is connected with circular slider one, the stopper bottom is equipped with the connecting rod, the air current storehouse left part is equipped with the blast pipe, be equipped with the sliding sleeve on the slide bar, two upper portions of compression spring are equipped with the sliding ring, be equipped with the spout on the pneumatic tube, be equipped with the lifter on the sliding ring, be equipped with the lifter bottom and be equipped with the clamp plate, the clamp plate downside is equipped with lithium cell three, explosion-proof extrusion case back is equipped with pressure release mesh three, explosion-proof extrusion case back is equipped with flue gas calandria two. The scheme solves the problems that the function of the explosion-proof box is single, and the three tests of overcharge, needling and extrusion cannot be simultaneously carried out on one device, but the scheme only discloses mechanical means for realizing overcharge, needling and extrusion, and does not record the structure for testing the experimental result.

Moreover, most of the current thermal runaway gas generation of the lithium ion battery focuses on monomer testing, and a module-level thermal runaway gas generation test is not available, and the analysis reason is mainly that the module-level thermal runaway gas generation needs more temperature sensors and voltage acquisition lines, while a general thermal runaway gas generation tank body is only provided with more than 10 thermocouples on the surface and cannot meet the module-level testing.

For example, chinese patent No. CN 216956296U discloses a device for testing thermal runaway characteristics of lithium ion batteries, which comprises an experimental kettle, a fixing device, a heating device, a needling device, a camera device and a control device. The experimental kettle is designed as a pressure container, and a pressure safety valve is installed to prevent the physical explosion caused by internal overpressure in the experimental process; the upper part and the lower part of the experimental kettle are respectively provided with a valve for air inlet and air outlet; the fixing device is placed in the experimental kettle and used for fixing the heating plate and the lithium ion battery; the heating device is two high-power heating plates; the needling device is fixed in the slot of the fixing device. The scheme can be used for carrying out thermal runaway law experiments of lithium ion batteries with different charge states under three abuse conditions of thermal abuse, acupuncture abuse and overcharge abuse, and also discloses a gas research early warning mechanism for collecting and analyzing gas generated by thermal runaway, wherein a gas sensor is integrally placed in a kettle to test the sensitivity and the effectiveness of the sensor, however, more sensors are often required to be arranged in a module-level thermal runaway gas production test process, and a test device of the scheme cannot meet test requirements and cannot obtain more extensive and accurate experimental data.

Disclosure of Invention

The invention aims to provide a thermal runaway gas production testing system for a lithium ion battery, which solves the problems in the prior art, and can form a heat insulation cabin by locally protruding the shell wall of a sealed tank body outwards and arranging a cover plate to seal the heat insulation cabin, so that a space isolated from the outside and used for accommodating a data acquisition device can be formed, the data acquisition device is connected with a sensor, and enough sensors and types of sensors can be distributed in the sealed tank body on the basis of not increasing the holes of the sealed tank body, thereby meeting the testing requirements.

In order to achieve the purpose, the invention provides the following scheme:

the invention provides a thermal runaway gas production test system for a lithium ion battery, which comprises a sealed tank body, a clamp which is arranged in the sealed tank body and used for clamping the lithium ion battery, and an inducing device which induces the thermal runaway of the lithium ion battery, wherein the local part of the shell wall of the sealed tank body protrudes outwards to form a heat insulation cabin which is used for installing a data acquisition device, a cover plate which is used for sealing and insulating heat is arranged at the communication position of the heat insulation cabin and an inner cavity of the sealed tank body, a plurality of sensors are distributed in the sealed tank body, a wire inlet is formed in the cover plate, a test wire which is used for connecting the data acquisition device and the sensors is arranged at the wire inlet in a penetrating manner, and the wire inlet is sealed through a sealing press cap.

Preferably, a fire-resistant heat-insulating material layer is arranged inside the heat-insulating cabin, the cover plate comprises a body and a sealed heat-insulating layer connected to the inner side of the body, and the sealed heat-insulating layer comprises a high-temperature-resistant heat-insulating material filled inside and a high-temperature-resistant sealing material coated outside.

Preferably, the sealed tank body is of a horizontally arranged cylindrical structure, observation windows are arranged on two sides of the sealed tank body, a cover body is hinged to the end portion of the sealed tank body, and a door mechanism is arranged between the cover body and the sealed tank body.

Preferably, the door closing mechanism comprises an annular pressing structure and an annular pressure-bearing structure, the annular pressing structure is rotatably connected to the end part of the sealed tank body, the annular pressure-bearing structure is connected to the end part of the cover body, the annular pressing structure comprises a plurality of pressing parts protruding inwards in the radial direction, the annular pressure-bearing structure comprises a plurality of pressure-bearing parts protruding outwards in the radial direction, the pressure-bearing parts can axially pass through gaps among the pressing parts, and the pressing parts are provided with slope surfaces and can rotate to the axial outer sides of the pressure-bearing parts to press the pressure-bearing parts.

Preferably, the inducing device comprises a needling mechanism, the needling mechanism comprises an external needling unit, the external needling unit comprises a first steel needle, a tank body joint which is arranged on the shell wall in a penetrating manner, a high-temperature-resistant conical sealing sleeve which is partially positioned in the tank body joint and a pressing cap which is used for pressing the high-temperature-resistant conical sealing sleeve on the tank body joint, an adjusting pad is further arranged between the pressing cap and the high-temperature-resistant conical sealing sleeve, the first steel needle sequentially penetrates through the pressing cap, the adjusting pad and the high-temperature-resistant conical sealing sleeve to enter the interior of the sealing tank body, and a high-temperature-resistant 0-shaped ring is further arranged at an inlet of the high-temperature-resistant conical sealing sleeve.

Preferably, the needling mechanism further comprises a built-in needling unit, the built-in needling unit comprises a second steel needle and an actuator connected with the second steel needle, the actuator is mounted on a supporting plate through a fixing frame, the clamp is mounted on the supporting plate, the supporting plate is mounted on the inner wall of the sealed tank body, and the second steel needle can be aligned to a lithium ion battery mounted on the clamp.

Preferably, the inducing device comprises a heating mechanism, a heat preservation layer is laid outside the sealed tank body, the heating mechanism comprises a plurality of U-shaped heating pipes located on the inner wall of the sealed tank body, and a support arm of each U-shaped heating pipe is arranged in the length direction of the sealed tank body.

Preferably, the inducing device comprises an over-charging mechanism, the over-charging mechanism comprises a ceramic electrode which penetrates through the shell wall, the electrodes in the ceramic electrode are isolated by ceramic, the part of the ceramic electrode, which is positioned in the sealed tank body, is covered by a ceramic sleeve, and the part, which is positioned outside the sealed tank body, is provided with a ceramic insulating sheet.

Preferably, anchor clamps include the relative panel that sets up and run through the guide bar that the panel set up, be provided with a plurality of mounting holes on the panel, be provided with the picture peg that is used for injecing lithium ion battery in the mounting hole, still be provided with interval adjustment mechanism on the panel.

Preferably, the top of the sealed tank body is provided with an exhaust valve, an outlet of the exhaust valve is communicated with a vent pipe, a pressure release valve is arranged on the side of the sealed tank body, and an outlet of the pressure release valve is communicated with the vent pipe.

Compared with the prior art, the invention has the following technical effects:

(1) According to the invention, the shell wall of the sealed tank body is locally protruded outwards to form the heat insulation cabin, the cover plate is arranged to seal the heat insulation cabin, a space isolated from the outside and used for accommodating the data acquisition device can be formed, the data acquisition device is connected with the sensors, and enough sensors in quantity and variety can be distributed in the sealed tank body on the basis of not increasing the holes of the sealed tank body, so that the test requirement is met;

(2) According to the invention, through the matching of the annular compression structure and the annular pressure-bearing structure of the door closing mechanism, when the annular compression structure is rotated, the pressure-bearing part can be compressed along the axial direction by utilizing the slope surface of the compression part, so that the cover body is tightly buckled at the end part of the sealed tank body, the sealed tank body is ensured to form an integrally sealed structure, and the smooth operation of an experiment is ensured;

(3) According to the invention, the overcharge connecting wire adopts the ceramic electrode, the electrodes in the ceramic electrode are isolated by ceramic, the part of the ceramic electrode, which is positioned in the sealed tank body, is coated by the ceramic sleeve, and the part, which is positioned outside the sealed tank body, is provided with the ceramic insulating sheet;

(4) The fixture comprises a plugboard for limiting the lithium ion batteries and an interval adjusting mechanism for adjusting the interval between the panels, and can adapt to the installation of the lithium ion batteries or modules with different sizes and quantities by adjusting the positions of the plugboard in the installation holes and the interval adjusting mechanism; in addition, the fixture is arranged on the supporting plate, and the built-in needling unit is arranged on the supporting plate through the fixing frame, so that the built-in needling unit and the fixture can be assembled and assembled at will, and the problem of fixing the position of a thermal runaway needling triggered by needling is solved;

(5) According to the external needling unit, the high-temperature-resistant conical sealing sleeve positioned in the tank body joint is compressed through the compression cap, the conical structure can form an extrusion component force towards the inner diameter side, so that the inner diameter of the high-temperature-resistant conical sealing sleeve is extruded to the outer diameter side of the first steel needle along the radial direction, the first steel needle can be effectively sealed in the radial direction after penetrating through the high-temperature-resistant conical sealing sleeve, meanwhile, a high-temperature-resistant 0-degree ring is further arranged at an inlet of the first steel needle penetrating through the high-temperature-resistant conical sealing sleeve, the radial sealing effect of the first steel needle can be further improved, and the sealing performance of the sealed tank body in the needling process is ensured.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required in the embodiments will be briefly described below, it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art that other drawings can be obtained according to the drawings without creative efforts.

FIG. 1 is a schematic view of the overall structure of the present invention;

FIG. 2 is a schematic view of the structure of FIG. 1 in another direction;

FIG. 3 is a schematic view of the structure of FIG. 1 in another direction;

FIG. 4 is a schematic view of the internal structure of FIG. 1;

FIG. 5 is a schematic view of a mounting clip according to the present invention;

FIG. 6 is a schematic view of another alternative mounting form of the present invention;

FIG. 7 is a schematic structural diagram of a built-in needling unit according to the present invention;

FIG. 8 is a schematic structural diagram of an external needling unit according to the present invention;

FIG. 9 shows the temperature characteristics of thermal runaway gas production in the overcharge triggering mode;

FIG. 10 shows the temperature characteristics of thermal runaway gas production in the needling trigger mode;

FIG. 11 shows the temperature characteristics of thermal runaway gas production in a heating triggering manner;

FIG. 12 is a thermal runaway creep gassing test (internal pressure) for NCM622-50Ah module level;

FIG. 13 is a NCM622-50Ah insulated cabin temperature profile;

wherein, 1, sealing the tank body; 11. an observation window; 12. a pressure relief valve; 13. a temperature sensor; 14. a thermometer; 15. a vacuum gauge; 16. an intake valve; 17. an exhaust valve; 171. an expansion joint; 172. a breather pipe; 18. a thermocouple; 2. an external needling unit; 21. a tank body joint; 22. a high-temperature resistant conical sealing sleeve; 23. a compression cap; 24. a conditioning pad; 25. a first steel needle; 26. a high temperature resistant O-shaped ring; 3. a U-shaped heating pipe; 4. a heat-insulating compartment; 41. a cover plate; 42. a data acquisition device; 5. a cover body; 6. a base; 7. a ceramic electrode; 71. a ceramic insulating sheet; 72. a ceramic sheath; 8. a distribution box; 91. an annular compression structure; 92. a gear; 93. an annular pressure-bearing structure; 94. a rack; 10. a lithium ion battery; 101. a support plate; 102. a panel; 1021. mounting holes; 103. a guide bar; 104. a spacing adjustment mechanism; 105. inserting plates; 106. a fixed mount; 1051. adjusting the bolt; 201. a second steel needle; 202. and an actuator.

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 obtained by a person skilled in the art without making any creative effort based on the embodiments in the present invention, belong to the protection scope of the present invention.

The invention aims to provide a thermal runaway gas production test system for a lithium ion battery, which aims to solve the problems in the prior art.

In order to make the aforementioned objects, features and advantages of the present invention comprehensible, embodiments accompanied with figures are described in further detail below.

As shown in fig. 1 to 8, the invention provides a thermal runaway gas generation test system for a lithium ion battery, which includes a sealed tank 1, a clamp arranged in the sealed tank 1 and used for clamping the lithium ion battery 10, and an inducing device for inducing the thermal runaway of the lithium ion battery 10. Wherein, the sealed tank body 1 is airtight pressure vessel, can form seal structure to bear the pressure of certain size, have opening and this open-ended lid 5 of switching, after opening lid 5, can place components and parts such as anchor clamps, the lithium ion battery 10 and the sensor that await measuring, number adopt device 42 at relevant position, after closing lid 5, form airtight environment and experiment. The clamp can adopt the existing clamp for clamping the lithium ion battery 10 and can be installed in the sealing tank body 1 so as to fix the lithium ion battery 10 and ensure the smooth proceeding of the experiment. The inducing device can comprise various forms, for example, a needling mechanism, a heating mechanism and an overcharging mechanism can be provided for realizing the thermal runaway gas production experiment under different triggering modes of needling, overcharging, lateral heating, atmosphere heating and the like. The shell wall of the sealed tank body 1 partially protrudes outwards to form a heat insulation cabin 4 for installing the data acquisition device 42, the shell wall of the heat insulation cabin 4 and the shell wall of the sealed tank body 1 are arranged in an integrated structure or are connected in a welding mode and the like with enough strength and tightness, namely, the heat insulation cabin 4 is communicated with the inner cavity of the sealed tank body 1 but is isolated from the outside. The heat insulation cabin 4 is provided with the apron 41 that is used for sealing and thermal-insulated with the inner chamber intercommunication department of the sealed tank body 1, with apron 41 lock behind heat insulation cabin 4, can form the relative isolated space of heat insulation cabin 4 with the inner chamber of the sealed tank body 1, in heating the experimentation in the sealed tank body 1, can not cause the influence of the interior temperature of heat insulation cabin 4, can keep having in the heat insulation cabin 4 and be less than the temperature size that the device 42 can bear of adopting. A plurality of sensors are arranged in the sealed tank body 1, and the sensors can comprise temperature sensors, voltage acquisition lines, pressure sensors and other devices for experimental testing. The cover plate 41 is provided with a wire inlet, the wire inlet is provided with a test wire for connecting the data acquisition device 42 and the sensor in a penetrating manner, and the wire inlet is sealed by a sealing press cap. According to the invention, the heat insulation cabin 4 is formed by locally protruding the shell wall of the sealed tank body 1 outwards, the cover plate 41 is arranged to seal the heat insulation cabin 4, a space isolated from the outside and used for accommodating the data acquisition device 42 can be formed, the data acquisition device 42 is connected with the sensors, and enough sensors in quantity and types can be distributed in the sealed tank body 1 on the basis of not increasing the holes of the sealed tank body 1, so that the test requirement is met.

In the embodiment of the invention, the heat insulation cabin 4 is reserved in the lower area inside the sealed tank body 1, the function of preventing electrolyte corrosion is achieved, the heat insulation effect is achieved, the thermal runaway spread experiment of the module is carried out, the highest temperature in the heat insulation cabin 4 is always lower than 50 ℃ (shown in figure 13), and the data acquisition device 42 cannot be influenced after the data acquisition device 42 is placed in the heat insulation cabin. The problem that module and thermal runaway stretch test collection channel can not satisfy is solved.

Further, a fire-retardant and heat-insulating material layer can be disposed inside the heat-insulating chamber 4, so as to prevent heat transferred from the material (generally, metal material, such as 304 stainless steel) of the sealed tank 1 from affecting the data acquisition device 42 inside the heat-insulating chamber 4, and maintain a relatively low temperature inside the heat-insulating chamber 4. The cover plate 41 may include a body (made of the same material as the sealed tank 1) and a sealing and heat insulating layer connected to the inside of the body, the body mainly plays roles of strength and support, the sealing and heat insulating layer is mainly used for heat insulation and sealing, and specifically, the sealing and heat insulating layer may include a high temperature resistant heat insulating material filled inside and a high temperature resistant sealing material coated outside. The high-temperature-resistant heat-insulating material can be made of a high-temperature-resistant fire-retardant insulating material and a nanoscale high-temperature-resistant ceramic fiber heat-insulating material, the high-temperature-resistant sealing material is similar to the filler inside the outer shell of the leather sofa, and is buckled behind the heat-insulating cabin 4 and extruded with the contact part to play a sealing role, specifically can be a lining comprising outer glass fiber cloth and inner aluminum silicate, and certainly can also be made of other materials on the basis of meeting use requirements.

As shown in fig. 1 to 4, the sealing tank 1 may be a horizontally arranged cylindrical sealing tank 1, the two sides (referred to as tank walls) of the sealing tank 1 are provided with observation windows 11, the internal test conditions of the sealing tank 1 can be observed through the observation windows 11, and the sealing tank 1 can be used together with a high-speed camera to study the thermal runaway firing dynamics of the lithium ion battery 10. The one end opening is sealed to the 1 one end of the sealed jar body, articulates in open-ended one end has lid 5, sets up relevant door mechanism between lid 5 and the sealed jar body 1, and the operation of opening and closing lid 5 is convenient for to articulated mode, is particularly useful for the heavier condition of lid 5 weight. The cover body 5 can be firmly fixed on the sealed tank body 1 through the door closing mechanism and sealed and locked. The specific door closing mechanism can adopt a bolt locking structure, namely a through hole is arranged on the cover body 5, a threaded hole is arranged at a corresponding position on the sealed tank body 1, and the cover body 5 is fixed by penetrating through the through hole and screwing in the threaded hole by using a bolt; the structure of chucking also can be adopted, for example, adopt C type card to press from both sides tightly, the tip of the lid 5 and the sealed jar body 1 all is provided with the flange of looks lock, realizes lid 5 through pressing from both sides tight flange and fixes.

The door closing mechanism may include an annular compression structure 91 rotatably connected to the end of the sealed tank 1 and an annular pressure-bearing structure 93 connected to the end of the cover 5. The annular compression structure 91 can rotate and axially move on the sealed tank body 1, but cannot be separated from the sealed tank body 1 along the opening direction, a flange can be arranged on the sealed tank body 1, an annular accommodating space for accommodating the flange is arranged on the inner diameter side of the annular compression structure 91, and the position of the annular compression structure 91 is limited through the matching of the annular accommodating space and the flange. Can be connected with gear 92 on the annular compact structure 91, gear 92 rotates the one end that sets up at the back shaft, and the back shaft is fixed on annular compact structure 91, and the position that corresponds gear 92 is provided with rack 94, and rack 94 fixes on the conch wall surface of the sealed tank body 1, and gear 92 is connected with the handle, can rotate gear 92 through pulling the handle, and then can drive annular compact structure 91 and rotate. The annular pressure-bearing structure 93 is fixed on the cover body 5, a plurality of pressure-bearing parts which protrude outwards in the radial direction are arranged, the annular pressing structure 91 is provided with a plurality of pressing parts which protrude inwards in the radial direction, when the cover body 5 is closed, the pressure-bearing parts can axially pass through gaps between the pressing parts, and as the pressing parts are provided with slope surfaces, when the annular pressing structure 91 is rotated, the slope surfaces of the pressing parts gradually extrude the pressure-bearing parts in the axial direction, so that the annular pressing structure 91 can be pressed at the end part of the sealed tank body 1 in the axial direction outside of the pressure-bearing parts along with the rotation of the annular pressing structure 91. Of course, sealing structures such as sealing rings can be arranged between the annular pressing structure 91 and the sealing tank body 1 and between the annular pressing structure 91 and the cover body 5, so as to further ensure the sealing effect.

The inducing device can comprise a needling mechanism, the needling mechanism can comprise an external needling unit 2 positioned outside the sealed tank body 1, as shown in fig. 8, the external needling unit 2 comprises a first steel needle 25, a tank body joint 21 penetrating through the wall of the sealed tank body 1, a high-temperature-resistant conical sealing sleeve 22 partially positioned inside the tank body joint 21, and a pressing cap 23 pressing the high-temperature-resistant conical sealing sleeve 22 on the tank body joint 21, the tank body joint 21 and the wall of the sealed tank body 1 are in sealing connection in the existing sealing mode, a conical hole is formed in the middle of the tank body joint 21, the conical end of the high-temperature-resistant conical sealing sleeve 22 abuts against the conical section of the conical hole, an adjusting pad 24 is further arranged between the pressing cap 23 and the high-temperature-resistant conical sealing sleeve 22, and the pressing cap 23 is connected to the tank body joint 21 through threads to press the high-temperature-resistant conical sealing sleeve 22. The high temperature resistant conical sealing sleeve 22 may be made of PEEK material as a main seal. The first steel needle 25 sequentially penetrates through the pressing cap 23, the adjusting pad 24 and the high-temperature-resistant conical sealing sleeve 22 and then enters the inside of the sealed tank body 1, and a high-temperature-resistant O-shaped ring 26 is further arranged at an inlet of the first steel needle 25 penetrating through the high-temperature-resistant conical sealing sleeve 22. The high temperature O-ring 26 may be a fluorine rubber O-ring as an auxiliary seal. The first steel needle 25 is connected with a driver for driving the first steel needle to move, the driver can adopt electric (for driving a linear motor, a servo electric cylinder and the like) or hydraulic (for driving a telescopic cylinder and the like) and the like as a power source, and during electric driving, a 750W servo motor can be adopted, 220V power supply is adopted, and the power source is sufficient. In addition, the diameter of the first steel needle 25 can be adjusted and replaced, and the needling speed can be controlled by adjusting, so that the device is suitable for needling thermal runaway gas production experiments with different needling diameters and different needling speeds. The external needling unit 2 compresses the high-temperature-resistant conical sealing sleeve 22 positioned in the tank body joint 21 through the compression cap 23, and the conical structure can form extrusion component force towards the inner diameter side, so that the inner diameter of the high-temperature-resistant conical sealing sleeve 22 is extruded to the outer diameter side of the first steel needle 25 along the radial direction, the first steel needle 25 can be effectively sealed along the radial direction of the first steel needle 25 after penetrating through the high-temperature-resistant conical sealing sleeve 22, meanwhile, a high-temperature-resistant O-shaped ring 26 is further arranged at an inlet of the first steel needle 25 penetrating through the high-temperature-resistant conical sealing sleeve 22, the radial sealing effect of the first steel needle 25 can be further improved, and the sealing performance of the sealed tank body 1 in the needling process is ensured.

As shown in fig. 7, the needling mechanism may further include a built-in needling unit located inside the sealed tank 1, the built-in needling unit may include a second steel needle 201 and an actuator 202 connected to the second steel needle 201, the actuator 202 is mounted on the support plate 101 through the fixing frame 106, a fixture for holding the lithium ion battery 10 is mounted on the support plate 101, the support plate 101 is mounted on the inner wall of the sealed tank 1, and a needling position of the second steel needle 201 on the lithium ion battery 10 may be adjusted by adjusting a positional relationship between the fixture and the fixing frame 106, so that the second steel needle 201 may be aligned with the lithium ion battery 10 mounted on the fixture, and a needling experiment may be performed on different positions after adjusting the position. Therefore, the fixture is arranged on the supporting plate 101, and the built-in needling unit is arranged on the supporting plate 101 through the fixing frame 106, so that the built-in needling unit and the fixture can be assembled and assembled at will, needling requirements of different areas such as the side surface, the front surface, the bottom and the lug of the lithium ion battery 10 are met, and the problem of position fixing caused by needling triggering thermal runaway needling is solved.

As shown in fig. 10, the temperature characteristic of thermal runaway gas generation in a needling trigger manner in the specific experiment is specifically the surface temperature, internal temperature and voltage characteristic of the single body of the lithium ion battery 10 collected in the thermal runaway experiment process of the lithium ion battery 10.

As shown in fig. 1 and 4, the inducing device may include a heating mechanism for heating the internal cavity of the can body 1, so as to simulate thermal runaway of the lithium ion battery 10 in a high-temperature environment. Specifically, the heat preservation layer is laid outside the sealed tank body 1, so that heat loss is reduced, and the internal temperature of the sealed tank body 1 is kept. The heating mechanism can comprise a plurality of U-shaped heating pipes 3 positioned on the inner wall of the sealed tank body 1, and the support arms of the U-shaped heating pipes 3 are arranged along the length direction of the sealed tank body 1. The quantity and the size of U type heating pipe 3 carry out reasonable adjustment and design according to the experiment temperature demand, for example be provided with 6U type heating pipes 3, can rise to 300 ℃ with the temperature in the sealed tank body 1 to keep for a long time, realize the hot box function. And through the setting of heat preservation, realize the inside complete heat preservation of jar body, the external temperature of jar is less than 35 ℃.

As shown in fig. 11, the temperature characteristic of thermal runaway gas generation in a heating triggering manner in the specific experiment is specifically the surface temperature, internal temperature, and voltage characteristic of the single body of the lithium ion battery 10 collected in the thermal runaway experiment process of the lithium ion battery 10.

As shown in fig. 1 to 4, the induction device may further include an overcharge mechanism, and a large-current fast adapter is installed at a port, so that an overcharge-induced thermal runaway experiment with different charge and discharge multiplying factors of 0 to 300A can be realized. The overcharge mechanism comprises a ceramic electrode 7 which penetrates through the shell wall of the sealed tank body 1, the ceramic electrode 7 can be installed at one end of the sealed tank body 1 without an opening, the electrodes in the ceramic electrode 7 are isolated by ceramic, the part of the ceramic electrode 7, which is positioned in the sealed tank body 1, is coated by a ceramic sleeve 72, and the part, which is positioned outside the sealed tank body 1, is provided with a ceramic insulating sheet 71. Through the arrangement of the ceramic electrode 7, the high-temperature and high-pressure resistant lithium ion battery can resist high temperature and high pressure, the problem that the insulation failure of the sealing tank body 1 is easily caused by the electrolyte sprayed in the thermal runaway gas production experiment process of the lithium ion battery 10 is solved, and the thermal runaway gas production requirement of the overcharge trigger battery is met.

As shown in fig. 9, the temperature characteristic of the thermal runaway gas generation in the overcharge triggering manner in the specific experiment is specifically the surface temperature, the internal temperature, and the voltage characteristic of the single body of the lithium ion battery 10 collected in the thermal runaway experiment process of the lithium ion battery 10.

The thermal runaway inducement of the lithium ion battery 10 can be divided into thermal abuse, electrical abuse and mechanical abuse, the current traditional test method generally depends on three sets of systems, and the waste of experimental resources is often caused. In conclusion, the invention can realize the research of the thermal runaway gas generation, the module thermal runaway spreading behavior and the gas generation rule of the lithium ion battery 10 monomer in various triggering modes of different rates of needling, different heating power lateral heating, environmental atmosphere heating, overcharging and the like. Referring to table 1, the initial data of thermal runaway gas production of the NCM523 battery under different triggering modes is shown.

TABLE 1 original data of thermal runaway gas production of NCM523 battery under different triggering modes

As shown in fig. 5 and 6, the jig for clamping the lithium ion battery 10 may include oppositely disposed panels 102 and guide rods 103 disposed through the panels 102, the guide rods 103 may restrict and constrain the movement of the panels 102 so that the panels 102 may move relatively or away from each other, and the lithium ion battery 10 may be placed between the panels 102 to be clamped with the panels 102. The panel 102 may further have a plurality of mounting holes 1021, and the mounting holes 1021 are provided with plug boards 105 for limiting the lithium ion batteries 10, so that the size of the lithium ion batteries 10 can be adapted by changing the positions of the plug boards 105, and the mounting positions of the lithium ion batteries 10 on the fixture can be changed. Adjusting bolts 1051 can be arranged on the plug board 105, the lithium ion battery 10 can be compressed by rotating the adjusting bolts 1051, and in order to avoid damage to the lithium ion battery 10 caused by excessive local pressure of the adjusting bolts 1051 on the lithium ion battery 10 during compression, a baffle plate can be arranged between the adjusting bolts 1051 and the lithium ion battery 10, so that pressure can be dispersed to protect the lithium ion battery 10. The panels 102 are further provided with a distance adjusting mechanism 104, the distance adjusting mechanism 104 may include a hand wheel and a screw rod, the screw rod penetrates through one of the panels 102 and is in threaded connection, when the screw rod is rotated, the panel 102 can move axially along the screw rod, and the end of the screw rod is rotatably connected (rotatably and non-axially) to the other panel 102, so that the hand wheel is rotated to rotate the screw rod, and the distance between the panels 102 can be adjusted. According to the clamp, the distance adjusting mechanism 104 for limiting the distance between the plug board 105 of the lithium ion battery 10 and the adjusting panel 102 is arranged, the positions of the plug boards 105 in the mounting holes 1021 are adjusted, the distance adjusting mechanism 104 is adjusted, the lithium ion batteries 10 or modules with different sizes and numbers can be mounted in a suitable mode, the clamping position is adjusted correspondingly according to experiment requirements, and different parts face the second steel needle 201. The whole material of the clamp can be 304 stainless steel, 1-10 sections of lithium ion batteries 10 with different numbers can be pre-tightened according to test requirements, the adjusting bolts 1051 can be adjusted according to the sizes, the thicknesses and the like of the lithium ion batteries 10, the multifunctional function of the clamp can be realized, and the assembled module can be placed in the sealed tank body 1 to be used for developing module-level thermal runaway and gas production experiments.

As shown in fig. 1 to 3, an exhaust valve 17 is disposed at the top of the sealed tank 1, an outlet of the exhaust valve 17 is communicated with a vent pipe 172 through a telescopic joint 171, and when the generated waste gas needs to be exhausted, the exhaust valve 17 can be opened to exhaust the waste gas to the outdoor exhaust gas treatment system along the vent pipe 172. The exhaust valve 17 can adopt a ball valve of DN80 or an electric valve to realize numerical control exhaust, the vent pipe 172 can adopt a stainless steel seamless pipe, and the stainless steel seamless pipe penetrates into a wall to realize exhaust emission. The lateral part of the sealed tank body 1 is also provided with a pressure release valve 12, the outlet of the pressure release valve 12 is communicated with a vent pipe 172, when the internal pressure of the sealed tank body 1 exceeds the limit, for example, when the internal pressure of the sealed tank body 1 reaches 3Mpa, the pressure release valve 12 automatically releases pressure, so that the potential safety hazard caused by overhigh pressure can be prevented, and meanwhile, waste gas is introduced into the vent pipe 172 to avoid environmental pollution and injury to operators caused by waste gas leakage.

For guaranteeing the smooth operation of system, can be provided with block terminal 8, the 8 outward appearances of block terminal are 304 stainless steel box, establish control circuit in, steerable U type heating pipe 3, drive structure, vacuum pump and air compressor machine etc. of the first steel needle 25 of drive and second steel needle 201, the built-in 220V socket of system.

The sealed tank body 1 can be made of 304 stainless steel materials and is designed into a cylindrical cavity with the thickness of 22mm and the long axis d =1600mm, and the volume is 320L. The sealed tank body 1 is installed on the base 6, the base 6 is formed by welding channel steel, and 4 trundles are installed at the bottom of the sealed tank body, so that the sealed tank body 1 and accessories of the sealed tank body can be conveniently moved. In addition, an air inlet valve 16, thermocouples 18, temperature sensors 13, a thermometer 14, a vacuum gauge 15 and other accessories can be arranged on the shell wall of the sealed tank body 1, and a vacuum pump and an air compressor are respectively equipped for vacuum test and pressure test of the sealed tank body 1. The sealed tank body 1 can be embedded with 11K-type thermocouples 18, so that the full coverage of the atmosphere temperature of the closed space is realized, the feedback and adjustment of the atmosphere temperature are enhanced, and the temperature difference of different areas in an atmosphere heating experiment is ensured to be less than or equal to 1.5 ℃. And a pressure sensor is also arranged, the highest pressure resistance of the sealed tank body 1 is 3MPa, and the module test of the whole capacity less than or equal to 2000Ah is realized.

The sealed tank body 1 can be provided with a quick pressure reduction interface and can be quickly connected with instruments such as GC, FTIR and the like, so that real-time analysis and detection of thermal runaway gas generation are realized; the test program meets the national standard GB 38031-2020 Power storage battery safety requirements for electric vehicles and the domestic industry standard QC/T743-2012 lithium ion Power storage batteries for electric vehicles. The invention can comprehensively test the thermal safety performance of the lithium ion battery 10 monomer and the module, further guide the upgrading and optimization of the battery material, reduce the thermal runaway gas production and combustible and explosive components of the lithium ion battery 10, improve the safety performance of the lithium ion battery 10, solve the safety bottleneck problem in the vigorous development process of the lithium ion battery 10 and promote the large-scale application of the lithium ion battery 10.

The principle and the implementation mode of the invention are explained by applying a specific example, and the description of the embodiment is only used for helping to understand the method and the core idea of the invention; meanwhile, for a person skilled in the art, according to the idea of the present invention, the specific embodiments and the application range may be changed. In view of the above, the present disclosure should not be construed as limiting the invention.

Claims (10)

1. A lithium ion battery thermal runaway gas production test system is characterized in that: including the sealed tank body, set up be used for centre gripping lithium ion battery's the anchor clamps of sealed tank body and induce lithium ion battery thermal runaway's induction device, the local outside protrusion of conch wall of the sealed tank body forms the heat-insulating cabin that is used for installing the number to adopt the device, heat-insulating cabin with the inner chamber intercommunication department of the sealed tank body is provided with and is used for sealed and thermal-insulated apron, the internal a plurality of sensors that have laid of sealed tank, the incoming line mouth has been seted up on the apron, the incoming line mouth runs through to be provided with and connects the number adopt the device with the test wire of sensor, just the incoming line mouth seals through sealed gland.

2. The thermal runaway gas production test system for the lithium ion battery according to claim 1, characterized in that: the heat insulation cabin is characterized in that a fire-resistant heat insulation material layer is arranged in the heat insulation cabin, the cover plate comprises a body and a sealed heat insulation layer connected to the inner side of the body, and the sealed heat insulation layer comprises a high-temperature-resistant heat insulation material filled in the body and a high-temperature-resistant sealing material coated outside the body.

3. The thermal runaway gas production test system for the lithium ion battery according to claim 1 or 2, wherein: the sealed tank body adopts a horizontally arranged cylindrical structure, observation windows are arranged on two sides of the sealed tank body, a cover body is hinged to the end portion of the sealed tank body, and a door mechanism is arranged between the cover body and the sealed tank body.

4. The thermal runaway gas production test system for the lithium ion battery according to claim 3, characterized in that: the door closing mechanism comprises an annular pressing structure and an annular pressure-bearing structure, the annular pressing structure is rotatably connected to the end portion of the sealed tank body, the annular pressure-bearing structure is connected to the end portion of the cover body, the annular pressing structure comprises a plurality of pressing portions protruding inwards in the radial direction, the annular pressure-bearing structure comprises a plurality of pressure-bearing portions protruding outwards in the radial direction, the pressure-bearing portions can axially pass through gaps among the pressing portions, and the pressing portions are provided with slope surfaces and can rotate to the axial outer sides of the pressure-bearing portions to press the pressure-bearing portions tightly.

5. The thermal runaway gas production test system for the lithium ion battery according to claim 3, wherein: the inducing device comprises a needling mechanism, the needling mechanism comprises an external needling unit, the external needling unit comprises a first steel needle, a tank body joint on the shell wall, and a compression cap, wherein the tank body joint and the part of the high-temperature-resistant conical sealing sleeve are positioned in the tank body joint, the high-temperature-resistant conical sealing sleeve is compressed on the tank body joint, the compression cap is provided with a regulating pad, the first steel needle penetrates through the compression cap, the regulating pad and the high-temperature-resistant conical sealing sleeve in sequence and then enters the interior of the sealing tank body, and the first steel needle penetrates into the inlet of the high-temperature-resistant conical sealing sleeve and is further provided with a high-temperature-resistant 0-shaped ring.

6. The thermal runaway gas production test system for the lithium ion battery according to claim 5, characterized in that: the needling mechanism further comprises a built-in needling unit, the built-in needling unit comprises a second steel needle and an actuator connected with the second steel needle, the actuator is installed on the supporting plate through a fixing frame, the clamp is installed on the supporting plate, the supporting plate is installed on the inner wall of the sealed tank body, and the second steel needle can be installed in an aligning mode to a lithium ion battery on the clamp.

7. The thermal runaway gas production test system for the lithium ion battery according to claim 3, characterized in that: the induction device comprises a heating mechanism, a heat-insulating layer is laid outside the sealed tank body, the heating mechanism comprises a plurality of U-shaped heating pipes located on the inner wall of the sealed tank body, and a support arm of each U-shaped heating pipe is arranged in the length direction of the sealed tank body.

8. The thermal runaway gas production test system for the lithium ion battery according to claim 3, characterized in that: the inducing device comprises an over-charging mechanism, the over-charging mechanism comprises ceramic electrodes penetrating through the shell wall, the electrodes inside the ceramic electrodes are isolated through ceramics, the part, located inside the sealed tank, of the ceramic electrodes is coated by a ceramic sleeve, and the part, located outside the sealed tank, of the ceramic electrodes is provided with a ceramic insulating sheet.

9. The thermal runaway gas production test system for the lithium ion battery according to claim 3, characterized in that: the fixture comprises a panel and a guide rod, wherein the panel is arranged oppositely, the guide rod penetrates through the panel, a plurality of mounting holes are formed in the panel, inserting plates used for limiting the lithium ion battery are arranged in the mounting holes, and an interval adjusting mechanism is further arranged on the panel.

10. The thermal runaway gas production test system for the lithium ion battery according to claim 3, characterized in that: the top of the sealed tank body is provided with an exhaust valve, an outlet of the exhaust valve is communicated with a vent pipe, a pressure release valve is arranged on the side of the sealed tank body, and an outlet of the pressure release valve is communicated with the vent pipe.

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