CN219392237U - Battery thermal runaway testing arrangement - Google Patents

Abstract

The utility model relates to a battery thermal runaway testing device, which comprises a container with a containing cavity and a heater positioned in the containing cavity; the device comprises a container, and is characterized in that a plurality of first assembly holes and a plurality of second assembly holes are formed in the container and communicated with the container, a wire passing device is arranged in each first assembly hole, an air valve is arranged in each second assembly hole, and the device can monitor parameters such as temperature, voltage and air pressure of a tested sample in the test process.

Description

Battery thermal runaway testing arrangement

Technical Field

The utility model relates to the technical field of lithium batteries, in particular to a battery thermal runaway testing device.

Background

With the importance of people on environmental problems, electric automobiles are being promoted, and lithium ion batteries have the characteristic of high energy density and are currently used as the optimal power source of the electric automobiles. However, lithium is the strongest metal activity in known elements, and meanwhile, there is a small potential safety hazard, and the direct reason for influencing the safety performance of the lithium battery is that the thermal runaway condition of the lithium battery is effectively and accurately monitored to ensure personnel safety.

The thermal runaway of the lithium battery may be caused by overcharge, overdischarge, short circuit, high temperature, extrusion, collision, etc. In order to effectively and accurately monitor the thermal runaway state of the lithium battery, a thermal runaway model of the lithium battery needs to be established to monitor the temperature change, the pressure change and the gas overflow under the thermal runaway state of the lithium battery. At present, a lithium battery is directly placed in a pressure container, and then the lithium battery is heated to cause thermal runaway of the lithium battery, so that the method can cause gas pollution, cannot monitor parameters such as temperature, voltage and the like of a measured sample, and has the problems of inaccurate measurement and the like.

Disclosure of Invention

The utility model aims to provide a battery thermal runaway testing device capable of monitoring parameters such as temperature, voltage and the like of a tested sample.

In order to achieve the above purpose, the technical scheme adopted by the utility model is as follows:

a battery thermal runaway testing device comprises a container with a cavity and a heater positioned in the cavity; the container is provided with a plurality of first assembly holes and a plurality of second assembly holes which are communicated with the containing cavity, a wire passing device is arranged in each first assembly hole, and an air valve is arranged in each second assembly hole.

In one embodiment, the wire guide includes a body portion having a wire guide hole penetrating through the body portion, the body portion being sealingly fitted with the first fitting hole, and the body portion further having a sealing portion capable of sealing the wire guide hole.

In one embodiment, the body portion is a resilient member and axial retraction of the body portion seals the via.

In one embodiment, at least one sealing ring is arranged on the outer periphery of the main body, the sealing ring is in sealing contact with the inner wall of the first assembly hole, the main body is pressed, and the through wire hole is sealed by axially shrinking the main body inwards.

In one embodiment, the heater includes a heating unit and a heated member having a fixing surface disposed vertically.

In one embodiment, one of the gas valves is connected to a gas collection bag.

In one embodiment, one of the gas valves is connected to a barometer.

In one embodiment, one of the gas valves is connected to an inert gas cylinder.

In one embodiment, one of the gas valves is connected to a safety valve.

In one embodiment, the container includes a can body having a cavity and a lid body covering the can body, and the first and second mounting holes are located on the lid body.

The battery thermal runaway testing device provided by the utility model has the beneficial effects that the wire passing device and the air valve are arranged on the battery thermal runaway testing device, and the wires of the thermocouple, the wires connected with the heater and the wires connected with the lithium battery to be tested can extend into the accommodating cavity through the wire passing device so as to realize real-time monitoring of temperature and voltage in the test process, thereby observing the pressure release fluctuation characteristics in the lithium battery thermal runaway process; the air valve can exhaust the air in the container to avoid gas pollution, and meanwhile, inert gas can be filled into the container through the air valve to protect the container, so that the lithium battery to be tested is prevented from burning or exploding when in thermal runaway; in addition, the air valve can be directly connected with the gas collection bag to collect gas after thermal runaway, so that the detection of the gas components in thermal runaway is facilitated.

Drawings

Fig. 1 shows a schematic perspective view of a battery thermal runaway testing apparatus.

Fig. 2 shows a schematic cross-sectional view of a battery thermal runaway testing apparatus.

Fig. 3 shows a schematic perspective view of the tank.

Fig. 4 shows a schematic perspective view of the cover.

Fig. 5 shows a top view of the cover.

Fig. 6 shows a schematic cross-sectional view of the wire guide.

Detailed Description

The preferred embodiments of the present utility model will be described in detail below with reference to the attached drawings so that the objects, features and advantages of the present utility model will be more clearly understood. It should be understood that the embodiments shown in the drawings are not intended to limit the scope of the utility model, but rather are merely illustrative of the true spirit of the utility model.

In the following description, for the purposes of explanation of various disclosed embodiments, certain specific details are set forth in order to provide a thorough understanding of the various disclosed embodiments. One skilled in the relevant art will recognize, however, that an embodiment may be practiced without one or more of the specific details. In other instances, well-known devices, structures, and techniques associated with this application may not be shown or described in detail to avoid unnecessarily obscuring the description of the embodiments.

Throughout the specification and claims, unless the context requires otherwise, the word "comprise" and variations such as "comprises" and "comprising" will be understood to be open-ended, meaning of inclusion, i.e. to be interpreted to mean "including, but not limited to.

Reference throughout this specification to "one embodiment" or "an embodiment" means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment. Thus, appearances of the phrases "in one embodiment" or "in an embodiment" in various places throughout this specification are not necessarily all referring to the same embodiment. Furthermore, the particular features, structures, or characteristics may be combined in any suitable manner in one or more embodiments.

As used in this specification and the appended claims, the singular forms "a," "an," and "the" include plural referents unless the context clearly dictates otherwise. It should be noted that the term "or" is generally employed in its sense including "and/or" unless the context clearly dictates otherwise.

In the following description, for the purposes of clarity of presentation of the structure and manner of operation of the present utility model, the description will be made with the aid of directional terms, but such terms as "forward," "rearward," "left," "right," "outward," "inner," "outward," "inward," "upper," "lower," etc. are to be construed as convenience, and are not to be limiting.

Furthermore, the terms "horizontal," "vertical," "overhang," and the like do not denote a requirement that the component be absolutely horizontal or overhang, but rather may be slightly inclined. As "horizontal" merely means that its direction is more horizontal than "vertical", and does not mean that the structure must be perfectly horizontal, but may be slightly inclined.

In the description of the present application, it should also be noted that, unless explicitly specified and limited otherwise, the terms "disposed," "mounted," "connected," and "connected" are to be construed broadly, and may be, for example, fixedly connected, detachably connected, or integrally connected; can be mechanically or electrically connected; can be directly connected or indirectly connected through an intermediate medium, and can be communication between two elements. The specific meaning of the terms in this application will be understood by those of ordinary skill in the art in a specific context.

As shown in fig. 1 and 2, the present embodiment provides a battery thermal runaway testing apparatus including a container 1 and a heater 2 located within the container 1. The container 1 includes a can 11 and a cover 12, the can 11 has a cavity 10, the cover 12 covers the can 11, and the cover 12 is matched with an opening of the cavity 10 of the can 11, so as to seal the opening of the cavity 10 to form a closed cavity.

The materials of the cover 12 and the tank 11 are selected according to the materials used in the various columns of the national standard "pressure vessel" so that the vessel 1 can withstand at least the pressures during the test. Referring to fig. 1-4, a first flange surface 111 and a second flange surface 121 are respectively arranged on the outer peripheral edges of the can body 11 and the cover body 12, a plurality of bolt holes 13 are respectively arranged on the first flange surface 111 and the second flange surface 121, the plurality of bolt holes 13 on the first flange surface 111 and the second flange surface 121 are correspondingly arranged one by one, and after the bolts penetrate through the corresponding bolt holes, the cover body 12 and the can body 11 are locked and fixed through nuts. In order to increase the tightness between the cover body 12 and the tank body 11, a sealing groove 112 is arranged at the edge of the opening of the containing cavity 10 of the tank body 11, a sealing gasket 113 is arranged in the sealing groove 112, and the tightness between the cover body 12 and the tank body 11 is increased through the sealing contact between the sealing gasket 113 and the cover body 12 and the tank body 11.

Referring to fig. 2, the heater 2 is located within the cavity 10 of the container 1. The heater 2 is a product in the prior art, and at least comprises a heating unit 21 and a heating element 22, wherein the heating unit 21 can be an existing heating element such as a heating wire, and the heating element 22 is made of a material with excellent heat transfer performance, such as a steel plate, a ceramic plate, and the like. The heating unit 21 can heat the heat receiving member 22 to raise the temperature of the heat receiving member 22. The heater 2 can be fixed in the cavity 10 of the tank 11 by the existing fixing methods such as screw fixing, so as to avoid the influence of the displacement of the heater 2 on the accuracy of the test in the test process.

The heat receiving member 22 has a fixing surface 221 for fixing the lithium battery to be tested, the fixing surface 221 is usually an outer surface of the heat receiving member 22, and the lithium battery to be tested can be fixed on the fixing surface 221 of the heat receiving member 22 by using existing fixing methods such as screw fixing and pressing block fixing, so that the heater 2 can heat the lithium battery to be tested to trigger thermal runaway of the lithium battery to be tested. Wherein preferably the fixing surface 221 is arranged vertically. The advantage of the vertical arrangement of the fixing surface 221 mainly includes the following two aspects, namely, the fixing surface 221 of the heated member 22 can be far away from the bottom of the tank 11, so that heat conduction between the heated member 22 and the tank 11 is reduced, and heating accuracy of the fixing surface 221 is improved; the other is that the mounting of the lithium battery to be tested on the fixing surface 221 of the different-side tab is more convenient.

Referring to fig. 4 and 5, the cover 12 is further provided with a plurality of first assembly holes 122 and a plurality of second assembly holes 123, and the first assembly holes 122 and the second assembly holes 123 penetrate through the cover 12 to communicate with the cavity 10. A wire guide 3 is installed in each first fitting hole 122, and a gas valve 4 is installed in each second fitting hole. The wire passing device 3 is used for passing through a wire of the thermocouple, a wire connected with the heater 2 and a wire connected with the lithium battery to be tested, and can seal the first assembly hole 122 so as to enable the accommodating cavity 10 to be in a sealed state, and prevent the problem of inaccurate measurement caused by gas leakage in the test process. The gas valve 4 is used for exhausting gas from the cavity 10, inflating gas into the cavity 10 and connecting a pressure gauge to monitor the gas pressure in the cavity 10.

Referring to fig. 6, the wire guide 3 includes a cylindrical main body 31, and the main body 31 has a wire guide hole 32 penetrating the main body 31 in an axial direction thereof, the wire guide hole 32 being for a wire to be guided therethrough. The outside of main part 31 is provided with sealing washer 33, and main part 31 is made by rubber material, and after the wire passed through wire hole 32, inserts main part 31 in the corresponding through-hole on lid 12, and sealing washer 33 is pressed and is let the outside of main part 31 seal with first pilot hole 122, and main part 31 is pressed simultaneously and is sealed wire hole 32, prevents that gas from leaking out from wire hole 32. In general, the wires of the thermocouple, the wires connected to the heater 2 and the wires connected to the lithium battery to be tested enter the cavity 10 through different wire passing devices 3, respectively, so that the wire passing devices 3 can better seal the first assembly holes 122. The lead is led into the accommodating cavity 10 through the wire passing device 3, so that the real-time monitoring of temperature and voltage can be realized in the test process, and the pressure release fluctuation characteristic in the thermal runaway process of the lithium battery can be observed.

Referring to fig. 4 and 5, the air valve 4 assembled in the second assembling hole 123 is a valve structure in the prior art, so the structure thereof is not described in detail herein, and may be, for example, a ball valve, a needle valve, a stop valve, etc., and the size of the valve needs to be matched with the size of the second assembling hole 123. In this embodiment, one of the plurality of air valves 4 is connected to a pressure gauge to monitor the pressure of the air in the cavity 10 in real time; one of the air-sucking holes is connected with a vacuum pump as an air sucking hole so as to exhaust air in the accommodating cavity 10 before a test, and the occurrence of combustion or explosion of the lithium battery to be tested when the temperature of the lithium battery to be tested is out of control due to the excessive oxygen concentration in the air is prevented; one of the charging ports is connected with an inflating device as an inflating port so as to charge inert gas (such as nitrogen) into the accommodating cavity 10 during a test, thereby preventing the lithium battery to be tested from burning or exploding during thermal runaway; one of the valves is connected with a safety valve to automatically release pressure after the gas in the cavity 10 exceeds a set value, so as to avoid safety problems caused by overlarge pressure in the cavity 10; one of them is connected with the gas collection bag so as to drain part of the gas in the cavity 10 into the gas collection bag after the test is finished, and then the gas components generated by the thermal runaway of the battery can be analyzed by a chromatograph.

The operation method of the battery thermal runaway testing device provided in the embodiment in the test process is as follows:

s1, fixing a lithium battery to be tested on a fixing surface 221 of a heater 2, tearing off a heat insulation film on the lithium battery before fixing, and fixing the heater 2 in a containing cavity 10; passing the wires connected to the heater 2, the wires of the thermocouple, and the wires connected to the lithium battery through the corresponding wire passing device 3, and sealing-mounting the wire passing device 3 into the corresponding first fitting hole 122; meanwhile, the thermocouple is adhered to the corresponding position to detect the problem of the corresponding position, such as detecting the temperature of the position of the battery cell explosion-proof valve, the temperature of the position 3cm above the battery cell explosion-proof valve, the temperature of the large surface of the battery cell, the temperature of the large side surface of the battery cell, the ambient temperature inside the container and the temperature of the air valve opening.

S2, the cover body 12 is locked with the tank body 11 by using bolts and nuts, then the interface of the vacuum pump is connected with a corresponding air valve 4, and the air in the cavity 10 is pumped out by using the vacuum pump, so that most of the air in the cavity 10 can be pumped out, the tightness of the battery thermal runaway testing device can be checked, if the air leakage problem occurs in the wire passing device 3, and the corresponding wire passing hole 32 can be plugged by using sealant.

S3, the gas cylinder of the inert gas is connected with a corresponding gas valve 4, the inert gas is filled into the containing cavity 10 to reach standard atmospheric pressure, and the inert gas can prevent the lithium battery from being burnt seriously under the condition of thermal runaway. In addition, the steps S2 and S3 may be repeated a plurality of times to maintain the chamber 10 in a substantially oxygen-free state to avoid combustion of the lithium battery.

S4, heating the lithium battery to be detected in the accommodating cavity 10 until the lithium battery to be detected is out of control, and stopping heating; and simultaneously, the temperature, pressure, sample voltage and other information in the thermal runaway process of the lithium battery are recorded in real time.

S5, after the gas pressure and the gas temperature in the accommodating cavity 10 are stable, measuring the gas pressure in the closed space, and then obtaining the thermal runaway gas yield of the battery to be measured according to the measured gas pressure. And opening a gas valve connected with the gas collection bag to hold the gas in the cavity 10, and analyzing the collected gas to obtain the thermal runaway gas production components of the battery to be measured.

The battery thermal runaway testing device provided by the embodiment can ensure that the lithium battery thermal runaway is measured and collected in the environment of sealing protective gas, so that the lithium battery thermal runaway is not polluted by air, the measurement of the battery thermal runaway gas generation amount is accurate, and the measurement of the collected gas components is also accurate. In addition, the real-time monitoring of pressure, temperature and voltage can be realized in the test process, so that the pressure release fluctuation characteristic of the storage battery in the thermal runaway process can be observed, the gas component generated by the thermal runaway of the battery can be effectively and timely analyzed through the chromatograph, and the gas leakage and pollution are reduced.

The calculation method of the thermal runaway gas generation amount of the battery is as follows:

according to the ideal gas state equation

Pv=nrt (formula 1)

In a fixed volume canister, a gas balance equation can be established at any time, assuming that the volume va=52.0l of the chamber.

According to the test

Pava=nrta (formula 2)

Converted to normal temperature (tb=298.15K) and normal pressure (pb=101.3 kPa),

the gas balance equation is

Pbvb=nrtb (formula 3)

From (equation 2) and (equation 3) can be obtained

The measured pressure and temperature data can be converted into a gas volume at normal temperature and pressure according to (formula 4). The relevant data for the sample calculated, for example, according to (equation 4) are shown in the following table:

Sample	Pi(kPa)	Pa(kPa)	Pb(kPa)	Ta(K)	Va(L)	Vb(L)
							#	10.359	111.40	101.3	290.95	52.0	53.15

from the above table, it can be seen that 53.15L of air is produced by the lithium battery to be tested under thermal runaway.

While the preferred embodiments of the present utility model have been described in detail, it will be appreciated that those skilled in the art, upon reading the above teachings, may make various changes and modifications to the utility model. Such equivalents are also intended to fall within the scope of the claims appended hereto.

Claims (10)

1. A battery thermal runaway testing device is characterized by comprising a container with a containing cavity and a heater positioned in the containing cavity; the container is provided with a plurality of first assembly holes and a plurality of second assembly holes which are communicated with the containing cavity, a wire passing device is arranged in each first assembly hole, and an air valve is arranged in each second assembly hole.

2. The battery thermal runaway testing apparatus of claim 1, wherein the wire guide includes a body portion having a wire guide hole penetrating therethrough, the body portion being sealingly assembled with the first assembly hole, and the body portion further having a sealing portion capable of sealing the wire guide hole.

3. The battery thermal runaway testing apparatus of claim 2, wherein the body portion is a resilient member and axial retraction of the body portion seals the wire through hole.

4. A battery thermal runaway testing apparatus according to claim 3, wherein at least one seal ring is provided on an outer peripheral side of said main body portion, said seal ring being in sealing contact with an inner wall of said first fitting hole and pressing said main body portion so that an axial retraction of said main body portion seals said wire passing hole.

5. The battery thermal runaway testing apparatus according to claim 1, wherein the heater includes a heating unit and a heated member having a fixing surface, the fixing surface being vertically disposed.

6. The battery thermal runaway testing apparatus of claim 1, wherein one of said gas valves is connected to a gas collection bag.

7. The battery thermal runaway testing apparatus of claim 1, wherein one of said gas valves is connected to a barometer.

8. The battery thermal runaway testing apparatus of claim 1, wherein one of said gas valves is connected to an inert gas cylinder.

9. The battery thermal runaway testing apparatus of claim 1, wherein one of said gas valves is connected to a safety valve.

10. The battery thermal runaway testing apparatus of claim 1, wherein the container comprises a can and a lid, the can having a cavity, the lid covering the can, the first and second mounting holes being located on the lid.