CN112798049B - Lithium ion battery thermal runaway gas production rate and gas production quantity measuring device and method - Google Patents
Lithium ion battery thermal runaway gas production rate and gas production quantity measuring device and method Download PDFInfo
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Abstract
A device and a method for measuring the thermal runaway gas production rate and gas production rate of a lithium ion battery are disclosed, wherein under the thermal runaway of the battery, inert gas is controlled to flow through a first mass flow meter and a second mass flow meter at a constant flow rate, and simultaneously, gas released by the thermal runaway flows through the second mass flow meter, so that the gas production rate and the gas production rate in the thermal runaway process can be directly measured without being interfered by external factors such as temperature, pressure and the like. The measuring method has high accuracy, the measuring device is simple to operate, and the battery temperature, the gas concentration and the voltage change condition in the thermal runaway process of the lithium ion battery can be monitored in real time according to the requirement, so that accurate data can be provided for the thermal runaway analysis of the battery, and guidance can be provided for the early warning and prevention and control design aspect of the thermal runaway of the battery in the future.
Description
Technical Field
The invention relates to the technical field of lithium battery safety performance testing, in particular to a device and a method for measuring thermal runaway gas production rate and gas production quantity of a lithium ion battery.
Background
With the rapid increase of the holding capacity of new energy electric vehicles, fire accidents of the electric vehicles attract close attention of people, and under various abuse conditions, such as overheating, overcharging, overdischarging, impact, extrusion, internal and external short circuit and the like of batteries, various materials in the batteries are subjected to chemical reaction to generate a large amount of heat, so that thermal runaway of the batteries is caused, and finally safety accidents such as ignition or explosion of the electric vehicles are induced. In thermal runaway of the lithium ion battery, due to high temperature, the decomposition of a negative electrode SEI film, the decomposition of a positive electrode active substance and the oxidative decomposition of electrolyte can be caused, a large amount of gas is generated, the pressure of gas in the lithium ion battery is increased rapidly, the battery is caused to explode, and a large amount of high-temperature, combustible and toxic gas is released from the battery, so that personal and property safety of passengers can be seriously threatened. With the continuous increase of the size and the capacity of the lithium ion battery, the gas released by thermal runaway is often multiplied, so that it is necessary to perform detailed analysis on the gas production rate and the gas production rate of the large-capacity lithium ion battery in the thermal runaway process so as to take corresponding protective measures in the design and production of the thermal runaway early warning protective product of the lithium ion battery pack.
In the prior art, as for the measurement of gas production rate and gas production rate in the thermal runaway process of the lithium ion battery, a simple device is usually set up to measure the gas production rate of the battery, and a drainage method and a cylinder piston method are mainly used. When the gas volume is measured using the drainage method, the gas to be measured is sufficiently contacted with the liquid. However, the gas generating components of the battery are very complex and may contain components which are easily soluble in water or even react with water, so that the drainage method has the defects of large measurement error and low repeatability. The basic principle of measuring the volume change of gas by using a cylinder piston method is that the gas in a cylinder expands to push a piston, and the gas production is calculated by measuring the displacement of the piston. According to an ideal gas state equation, when the cylinder piston method is used for measuring the volume change of gas, the constant air pressure cannot be ensured because the friction force between the piston and the inner wall of the cylinder cannot be avoided. Therefore, when the gas production volume of the battery is measured by using a cylinder piston method, the gas pressure in the cylinder before and after the gas is released by the battery to be measured is difficult to ensure to be equal, the operability is poor, and the accuracy of the gas production measurement result is not high, so that the subsequent gas component analysis result has larger error with the real result. And the drainage method and the cylinder piston method are affected by temperature and pressure changes in the measuring process, the anti-interference capability is poor, in addition, the total gas production amount can only be tested, and the gas production rate in the thermal runaway process cannot be synchronously tested. In summary, the prior art relates to the problems of large measurement error, poor operability, low repeatability, incapability of synchronously testing the gas production rate in the thermal runaway process and the like of the gas production rate measurement device in the thermal runaway process of the lithium ion battery.
Disclosure of Invention
In order to solve the defects in the prior art, the invention aims to provide a device and a method for measuring the gas production rate and the gas production rate of a lithium ion battery in thermal runaway, which are not interfered by external factors such as temperature, pressure and the like, have high measurement accuracy and simple operation, can directly measure the gas production rate and the gas production rate in the thermal runaway process, can monitor the battery temperature, the gas concentration and the voltage change condition of the lithium ion battery in the thermal runaway process in real time according to the requirement, provide accurate data for the thermal runaway analysis of the battery, and provide guidance for early warning and prevention and control design of the thermal runaway of the battery later.
The invention adopts the following technical scheme.
A method for measuring thermal runaway gas production rate and gas production quantity of a lithium ion battery comprises the following steps:
step 1, enabling inert gas to flow through a first mass flowmeter and a second mass flowmeter at a constant flow rate, collecting a first instantaneous flow initial value and a first accumulated flow initial value by using the first mass flowmeter, and collecting a second instantaneous flow initial value and a second accumulated flow initial value by using the second mass flowmeter;
step 4, when the thermal runaway gas flows through the first mass flowmeter and the second mass flowmeter, acquiring a first instantaneous flow current value and a first accumulated flow current value by using the first mass flowmeter, and acquiring a second instantaneous flow current value and a second accumulated flow current value by using the second mass flowmeter;
step 5, calculating to obtain the gas production rate of the battery thermal runaway by using a first instantaneous flow current value acquired by the first mass flow meter and a second instantaneous flow current value acquired by the second mass flow meter; and calculating to obtain the gas production rate of the battery thermal runaway by using the first accumulated flow current value acquired by the first mass flow meter and the second accumulated flow current value acquired by the second mass flow meter.
Preferably, the first and second electrodes are formed of a metal,
in step 1, the first mass flowmeter and the second mass flowmeter are both thermal mass flowmeters, and comprise a gas temperature sensor and a gas flow rate sensor;
when the first mass flowmeter and the second mass flowmeter work, a gas temperature sensor is used for collecting the gas temperature; heating the gas flow rate sensor to enable the temperature of the gas flow rate sensor to be higher than the gas temperature collected by the gas temperature sensor; collecting the gas flow rate by using a heated gas flow rate sensor;
the gas temperature sensor and the gas flow rate sensor are both reference grade platinum resistance temperature sensors.
Preferably, the first and second electrodes are formed of a metal,
in step 1, the constant flow rate of the inert gas is within the measurement range of the first mass flow meter and the second mass flow meter;
the inert gas includes: nitrogen and argon; the purity of the inert gas is more than 99%.
Preferably, the first and second electrodes are formed of a metal,
the step 3 comprises the following steps:
step 3.1, when the thermal runaway of the battery is detected, collecting the surface temperature of the battery module, the temperature in the battery box, the gas components in the battery box and the voltage of the battery;
step 3.2, collecting characteristic information of a thermal runaway triggering mode, wherein the characteristic information comprises characteristic information of overheating triggering thermal runaway and characteristic information of overcharging triggering thermal runaway;
3.3, accelerating the release of the thermal runaway gas according to the characteristic information of different thermal runaway trigger modes;
and 3.4, allowing the inert gas to flow through the first mass flow meter and the second mass flow meter at a constant flow rate, and allowing the thermal runaway gas to flow through the second mass flow meter.
In step 3.3, when the thermal runaway triggered by overheat is collected, heating the battery with constant power until the thermal runaway gas is released; and when the thermal runaway is triggered by the overcharge, charging the battery at constant current until the thermal runaway gas is released.
Preferably, the first and second electrodes are formed of a metal,
in step 5, the gas production rate and the gas production rate of the battery thermal runaway are calculated according to the following relations:
in the formula (I), the compound is shown in the specification,
v represents the gas production rate of the battery thermal runaway, unit L/s,
w represents the gas production of thermal runaway of the battery, in units of L,
A 1 the flow rate of the flow meter is represented by a current value of a first instantaneous flow rate collected by the first mass flow meter, in L/s,
A 2 a current value of the first accumulated flow rate, in units of L,
B 1 a second current value of instantaneous flow, in L/s,
B 2 representing the current value of the second accumulated flow, in L, collected by the second mass flow meter.
A lithium ion battery thermal runaway gas production rate and gas production rate measuring device comprises: the device comprises an inert gas bottle, a first mass flow meter, a one-way valve, a battery unit and a second mass flow meter;
the inert gas bottle is sequentially connected with the first mass flowmeter, the one-way valve, the battery unit and the second mass flowmeter;
the check valve controls the flow direction of the gas to flow from the first mass flow meter to the battery cell.
In particular, the amount of the solvent to be used,
the measuring device further comprises: the first straight pipe section, the second straight pipe section, the third straight pipe section and the fourth straight pipe section; the first straight pipe section is connected with the inert gas bottle and the first mass flowmeter; the second straight pipe section is connected with the first mass flow meter and the one-way valve; the third straight pipe section is connected with the battery unit and the second mass flowmeter; one end of the fourth straight pipe section is connected with the second mass flow meter.
The battery unit comprises a thermocouple, a battery module, a heating sheet and a sensor module which are arranged in the battery box; one end of the battery box is connected with the second straight pipe section through a one-way valve, and the other end of the battery box is provided with a hole which is connected with the third straight pipe section;
the battery module is connected with the charging and discharging cabinet machine through a lead, and a heating sheet is arranged on one side of the battery module and a thermocouple is arranged on the other side of the battery module; the battery module comprises a single battery and a battery module;
the sensor module comprises a temperature sensor and a gas sensor; wherein the gas sensor comprises: CO gas sensor, H 2 Gas sensors, volatile Organic Compounds (VOC) gas sensors, and smoke sensors.
When the battery is not out of control thermally, the inert gas bottle is opened, so that the inert gas flows into the first mass flow meter at a constant flow rate after passing through the first straight pipe section, then enters the second straight pipe section, enters the battery box through the one-way valve, flows into the second mass flow meter through the third straight pipe section, and is finally discharged through the fourth straight pipe section.
When the battery is out of control thermally, the out-of-control thermally conductive gas flows into the third straight pipe section through the reserved hole of the battery box, flows into the second mass flow meter after passing through the third straight pipe section, and is finally discharged through the fourth straight pipe section.
When the battery is overheated and thermal runaway occurs, the heating sheet heats the battery module with constant power until the battery module shell bursts and thermal runaway gas is released.
When the battery is overcharged and is out of control due to heat, the charging and discharging cabinet machine charges the battery module with constant current until the shell of the battery module bursts and the out-of-control gas is released.
Compared with the prior art, the invention has the beneficial effects that:
1. the thermal runaway gas production rate and the gas production rate of the lithium ion battery are measured by adopting a mass flow meter; the mass flowmeter works in an accurate measurement range by externally connecting a stable inert gas source, and the gas production rate are obtained through a flow difference value, so that the mass flowmeter has higher accuracy;
2. the measuring method is not influenced by a thermal runaway triggering mode, can measure the gas production rate of the gas generated by thermal runaway triggered by overheating, overcharging, overdischarging, impacting, extruding, internal and external short circuits and the like of the lithium ion battery, and can also measure the gas production rate in the thermal runaway process;
3. the measuring device is not interfered by external factors such as temperature, pressure and the like, and has high measuring accuracy and simple operation.
4. The temperature and gas concentration of the lithium ion battery during thermal runaway can be monitored in real time according to application requirements, such as CO and H 2 Smoke and voltage variations.
Drawings
FIG. 1 is a flow chart of a method for measuring thermal runaway gas production rate and gas production quantity of a lithium ion battery according to the invention;
fig. 2 is a structural diagram of the thermal runaway gas production rate and gas production rate measuring device of the lithium ion battery.
Detailed Description
The present application is further described below with reference to the accompanying drawings. The following examples are only for illustrating the technical solutions of the present invention more clearly, and the protection scope of the present application is not limited thereby.
Referring to fig. 1, a method for measuring thermal runaway gas production rate and gas production quantity of a lithium ion battery comprises the following steps:
step 1, flowing inert gas through a first mass flowmeter and a second mass flowmeter at a constant flow rate, collecting a first instantaneous flow initial value and a first accumulated flow initial value by using the first mass flowmeter, and collecting a second instantaneous flow initial value and a second accumulated flow initial value by using the second mass flowmeter.
In particular, the amount of the solvent to be used,
in step 1, both the first mass flow meter and the second mass flow meter are thermal mass flow meters, namely, a thermal diffusion principle is adopted; the sensor part of the thermal mass flowmeter comprises a gas temperature sensor and a gas flow rate sensor; the gas temperature sensor and the gas flow rate sensor both adopt a reference grade platinum resistor temperature sensor.
It is noted that the type of gas temperature sensor and gas flow rate sensor can be selected by those skilled in the art as needed to meet the operating requirements of the thermal mass flow meter, and the reference grade platinum resistance temperature sensor employed in the preferred embodiment is a non-limiting preferred choice.
When the first mass flowmeter and the second mass flowmeter work, the gas temperature T is uninterruptedly collected by the gas temperature sensor 1 (ii) a At the same time addHot gas flow rate sensor such that the gas flow rate sensor temperature T 2 Higher than the gas temperature T collected by the gas temperature sensor 1 (ii) a And collecting the gas flow rate by using the heated gas flow rate sensor.
When gas flows through the gas flow rate sensor, the gas flow rate sensor temperature T is caused because gas molecules continuously collide with the gas flow rate sensor and take away heat therefrom 2 To keep the temperature difference Δ T between the two sensors constant, the supply current of the gas flow rate sensor needs to be increased.
The faster the gas flow velocity, the more heat is carried away by the gas, so that a fixed functional relationship f (v, Δ T) exists between the flow velocity of the gas and the increment of the heat; however, when the gas flow speed is slow, the amount of heat carried away by the gas is small, the relationship between the flow speed and the increment of the amount of heat of the gas and the function f (v, Δ T) have a large error, and the instantaneous mass flowmeter has a large test error at the position of the near-zero point of the gas flow speed.
The invention provides an external stable gas source, and inert gas flows through a first mass flow meter and a second mass flow meter at constant flow rate, and simultaneously gas released when the battery is out of control due to thermal runaway flows through the second mass flow meter, so that the first mass flow meter and the second mass flow meter work in an accurate measurement range, and the gas yield of the lithium ion battery out of control due to thermal runaway can be accurately obtained.
In step 1, it is noted that one skilled in the art can select different types of inert gases, including but not limited to: nitrogen and argon; these inert gases do not react during thermal runaway of the lithium ion battery. The purity of the inert gas is more than 99%.
The constant flow rate of the inert gas is within the measurement ranges of the first mass flow meter and the second mass flow meter, and in the preferred embodiment, the lower limit value of the measurement range of the mass flow meters is used as the constant flow rate of the inert gas.
And 2, calibrating the first mass flowmeter and the second mass flowmeter to ensure that the first instantaneous flow initial value is equal to the first accumulated flow initial value, and the second instantaneous flow initial value is equal to the second accumulated flow initial value.
It is noted that the calibration operation of the first mass flow meter and the second mass flow meter needs to be performed under the same conditions, including but not limited to: the flow rate of the inert gas flowing through the reactor is the same, and the environmental parameters are the same.
And 3, when the thermal runaway of the battery is detected, starting to acquire battery characteristic information and thermal runaway trigger mode characteristic information, and accelerating the release of the thermal runaway gas according to different thermal runaway trigger mode characteristic information, so that the thermal runaway gas flows through the second mass flow meter while the inert gas flows through the first mass flow meter and the second mass flow meter at a constant flow rate.
In particular, the amount of the solvent to be used,
the step 3 comprises the following steps:
step 3.1, when the battery is detected to be out of control thermally, collecting the surface temperature of the battery module, the temperature in the battery box, the gas components in the battery box and the voltage of the battery;
step 3.2, collecting characteristic information of a thermal runaway triggering mode, wherein the characteristic information comprises characteristic information of overheating triggering thermal runaway and characteristic information of overcharging triggering thermal runaway;
step 3.3, when the thermal runaway is triggered by overheat collection, heating the battery with constant power until the thermal runaway gas is released; when the thermal runaway triggered by overcharge is collected, charging the battery with constant current until thermal runaway gas is released;
and 3.4, flowing the inert gas through the first mass flow meter and the second mass flow meter at a constant flow rate, and simultaneously flowing the thermal runaway gas through the second mass flow meter.
It is noted that the thermal runaway modes collected in the preferred practice of the invention include, but are not limited to: overheating, overcharge, overdischarge, impact, extrusion, internal and external short circuit. The technical personnel in the field can collect the characteristic information of different thermal runaway trigger modes according to the safety performance detection requirement of the battery, and adopt different thermal runaway acceleration measures according to the application environment of the battery so as to obtain the thermal runaway gas with a certain flow rate. The preferred embodiment of the present invention is only one preferred option, which is not limitative.
And 4, when the thermal runaway gas flows through the first mass flowmeter and the second mass flowmeter, acquiring a first instantaneous flow current value and a first accumulated flow current value by using the first mass flowmeter, and acquiring a second instantaneous flow current value and a second accumulated flow current value by using the second mass flowmeter.
Step 5, calculating to obtain the gas production rate of the battery thermal runaway by using a first instantaneous flow current value acquired by the first mass flow meter and a second instantaneous flow current value acquired by the second mass flow meter; and calculating to obtain the gas production rate of the battery thermal runaway by using the first accumulated flow current value acquired by the first mass flow meter and the second accumulated flow current value acquired by the second mass flow meter.
In particular, the amount of the solvent to be used,
in step 5, the gas production rate and the gas production rate of the battery thermal runaway are calculated according to the following relations:
in the formula (I), the compound is shown in the specification,
v represents the gas production rate of the battery thermal runaway, unit L/s,
w represents the gas production of thermal runaway of the battery, in units of L,
A 1 the flow rate of the flow meter is represented by a current value of a first instantaneous flow rate collected by the first mass flow meter, in L/s,
A 2 a current value, in units of L,
B 1 a second current value of instantaneous flow, in L/s,
B 2 representing the current value of the second accumulated flow, in L, collected by the second mass flow meter.
As shown in fig. 2, a device for measuring thermal runaway gas production rate and gas production rate of a lithium ion battery comprises: the device comprises an inert gas bottle 1, a first straight pipe section 2, a first mass flow meter 3, a second straight pipe section 4, a check valve 5, a battery unit, a third straight pipe section 12, a second mass flow meter 13, a fourth straight pipe section 14 and a charging and discharging cabinet machine 6.
The inert gas bottle 1 is sequentially connected with a first straight pipe section 2, a first mass flow meter 3, a second straight pipe section 4, a check valve 5, a battery unit, a third straight pipe section 12, a second mass flow meter 13 and a fourth straight pipe section 14.
The working temperature of the first mass flowmeter 3 and the second mass flowmeter 13 is more than 350 ℃, the range ratio is more than 1; the measurement ranges of the first mass flow meter 3 and the second mass flow meter 13 are both M to 1000M, where M represents the lower limit value of the measurement range, i.e., the upper limit value of the measurement range is 1000 times the upper limit value.
In order to ensure the speed of gas flowing through the first mass flowmeter and the second mass flowmeter, the lengths of the first straight pipe section and the third straight pipe section are both larger than 10d, and the lengths of the second straight pipe section and the fourth straight pipe section are both larger than 5d, wherein d represents the inner diameters of the first mass flowmeter and the second mass flowmeter.
The one-way valve 5 controls the flow direction of the gas to flow from the second straight pipe section 2 to the battery unit, and prevents a large amount of gas released after the thermal runaway of the battery from flowing from the battery unit to the first mass flow meter.
The battery unit includes a thermocouple 7, a battery module 8, a heater chip 9, and a sensor module 10 disposed in a battery case 11; wherein, one end of the battery box 11 is connected with the second straight pipe section 4 through the one-way valve 5, and the other end is connected with the third straight pipe section 12 with a reserved hole.
The heating power of the heating plate is 200W-1000W; the charging current of the charging and discharging cabinet machine is 0.5C-5C, wherein C represents the charging and discharging speed of the battery and is a measure of the charging and discharging speed of the battery.
The battery module 8 is connected with the charging and discharging cabinet machine 6 through a lead, one side of the battery module 8 is provided with a heating sheet 9, and the other side is provided with a thermocouple 7; the battery module 8 includes a single battery and a battery module.
The sensor module 10 includes a temperature sensor and a gas sensor. It is noted that one skilled in the art can select different types of gas sensors, including but not limited to: CO gas sensor, H 2 Gas sensor and VOC gasSensors and smoke sensors; the type of gas sensor employed in the preferred embodiment of the present invention is a non-limiting preferred choice.
Example 1.
The method comprises the steps of taking a single battery with the capacity of 40Ah as a measuring object, adopting a measuring device to carry out measurement preparation when the battery is not out of thermal runaway, opening an inert gas bottle, enabling inert gas to flow into a first mass flowmeter at a constant flow rate after passing through a first straight pipe section, then enter a second straight pipe section, enter a battery box through a one-way valve, flow into a second mass flowmeter through a third straight pipe section, and finally be discharged through a fourth straight pipe section.
Wherein, the working temperature of the first mass flowmeter and the second mass flowmeter is more than 350 ℃, the range ratio is more than 1 and 1000, the inner caliber is 50mm, and the measuring range is 0.7-700 Nm 3 H; the first straight tube section and the third straight tube section are 500mm in length, and the second straight tube section and the fourth straight tube section are 250mm in length.
Example 2.
When the single battery with the capacity of 40Ah is triggered to be thermally runaway by overheating, the heating sheet is started, the heating sheet continuously heats one side of the battery module at the power of 400W, the battery is continuously thermally runaway until the shell bursts, released thermally runaway gas flows into the third straight pipe section through the reserved hole of the battery box, flows into the second mass flow meter after passing through the third straight pipe section, and is finally discharged through the fourth straight pipe section.
At this time, the gas production rate and the gas production rate of the battery triggered by thermal runaway due to overheating are calculated according to the following relational expressions:
in the formula (I), the compound is shown in the specification,
v' represents the gas generation rate of the battery triggered by thermal runaway by overheating, unit L/s,
w' represents the gas production rate of the battery triggered by thermal runaway from overheating, in units of L,
A′ 1 represents the current value of the first instantaneous flow collected by the first mass flowmeter in unitsL/s，
A′ 2 A current value, in units of L,
B′ 1 a second current value of instantaneous flow, in L/s,
B′ 2 representing the current value of the second accumulated flow, in L, collected by the second mass flow meter.
Example 3.
When the single battery with the capacity of 40Ah is triggered to be out of control by overcharging, the charging and discharging cabinet machine is started, the battery is continuously charged by 1C current, the battery is continuously out of control until the shell bursts, released out-of-control thermal gas flows into the third straight pipe section through the reserved hole of the battery box, flows into the second mass flow meter after passing through the third straight pipe section, and is finally discharged through the fourth straight pipe section.
At the moment, the gas production rate and the gas production rate of the battery triggered thermal runaway by overcharging are calculated according to the following relational expression:
in the formula (I), the compound is shown in the specification,
v "represents the gas production rate of the battery triggered by overcharge and thermal runaway, unit L/s,
w "represents the amount of gas produced by the battery triggered by thermal runaway from overcharge, in units of L,
A″ 1 the flow rate of the flow meter is represented by a current value of a first instantaneous flow rate collected by the first mass flow meter, in L/s,
A″ 2 a current value of the first accumulated flow rate, in units of L,
B″ 1 a second current value of instantaneous flow, in L/s,
B″ 2 representing the current value of the second accumulated flow, in L, collected by the second mass flow meter.
Compared with the prior art, the invention has the beneficial effects that:
1. the thermal runaway gas production rate and the gas production quantity of the lithium ion battery are innovatively measured by adopting a mass flowmeter; the mass flowmeter works in an accurate measurement range by externally connecting a stable inert gas source, and the gas production rate are obtained by a flow difference value, so that the mass flowmeter has higher accuracy;
2. the measuring method is not influenced by a thermal runaway triggering mode, can measure the gas production rate of the gas generated by thermal runaway triggered by overheating, overcharging, overdischarging, impacting, extruding, internal and external short circuits and the like of the lithium ion battery, and can also measure the gas production rate in the thermal runaway process;
3. the measuring device is not interfered by external factors such as temperature, pressure and the like, and has high measuring accuracy and simple operation.
4. The temperature and gas concentration of the lithium ion battery during thermal runaway can be monitored in real time according to application requirements, such as CO and H 2 Smoke and voltage variations.
The present applicant has described and illustrated embodiments of the present invention in detail with reference to the accompanying drawings, but it should be understood by those skilled in the art that the above embodiments are merely preferred embodiments of the present invention, and the detailed description is only for the purpose of helping the reader to better understand the spirit of the present invention, and not for limiting the scope of the present invention, and on the contrary, any improvement or modification made based on the spirit of the present invention should fall within the scope of the present invention.
Claims (14)
1. A method for measuring thermal runaway gas production rate and gas production quantity of a lithium ion battery is characterized in that,
the measuring method comprises the following steps:
step 1, flowing inert gas through a first mass flowmeter and a second mass flowmeter at a constant flow rate, acquiring a first instantaneous flow initial value and a first accumulated flow initial value by using the first mass flowmeter, and acquiring a second instantaneous flow initial value and a second accumulated flow initial value by using the second mass flowmeter;
step 2, the first mass flowmeter and the second mass flowmeter are calibrated, so that the first instantaneous flow initial value is equal to the first accumulated flow initial value, and the second instantaneous flow initial value is equal to the second accumulated flow initial value;
step 3, when the thermal runaway of the battery is detected, starting to acquire battery characteristic information and thermal runaway trigger mode characteristic information, and accelerating the release of the thermal runaway gas according to different thermal runaway trigger mode characteristic information, so that the thermal runaway gas flows through the second mass flow meter while the inert gas flows through the first mass flow meter and the second mass flow meter at a constant flow rate;
step 4, when the thermal runaway gas flows through a second mass flowmeter, acquiring a second instantaneous flow current value and a second accumulated flow current value by using the second mass flowmeter;
step 5, calculating to obtain the gas production rate of the battery thermal runaway by using a first instantaneous flow current value acquired by the first mass flow meter and a second instantaneous flow current value acquired by the second mass flow meter; calculating to obtain the gas production rate of the battery thermal runaway by using a first accumulated flow current value acquired by the first mass flow meter and a second accumulated flow current value acquired by the second mass flow meter;
in step 5, the gas production rate and the gas production rate of the battery thermal runaway are calculated according to the following relations:
2. The method of claim 1, wherein the gas generation rate and the gas generation amount are measured by a thermal runaway analyzer,
in step 1, the first mass flowmeter and the second mass flowmeter are both thermal mass flowmeters, and comprise a gas temperature sensor and a gas flow rate sensor;
when the first mass flowmeter and the second mass flowmeter work, a gas temperature sensor is used for collecting the gas temperature; heating the gas flow rate sensor to enable the temperature of the gas flow rate sensor to be higher than the gas temperature collected by the gas temperature sensor; and collecting the gas flow rate by using the heated gas flow rate sensor.
3. The method of claim 2, wherein the gas generation rate and gas generation amount are measured by a thermal runaway gas generator,
the gas temperature sensor and the gas flow rate sensor are both reference grade platinum resistance temperature sensors.
4. The method of claim 1, wherein the gas generation rate and the gas generation amount are measured by a thermal runaway analyzer,
in step 1, the constant flow rate of the inert gas is within the measurement range of the first mass flow meter and the second mass flow meter.
5. The method of claim 1, wherein the gas generation rate and gas generation amount are measured by a thermal runaway gas generator,
the inert gas includes: nitrogen and argon; the purity of the inert gas is more than 99%.
6. The method of claim 1, wherein the gas generation rate and the gas generation amount are measured by a thermal runaway analyzer,
the step 3 comprises the following steps:
step 3.1, when the thermal runaway of the battery is detected, collecting the surface temperature of the battery module, the temperature in the battery box, the gas components in the battery box and the voltage of the battery;
step 3.2, collecting characteristic information of a thermal runaway triggering mode, wherein the characteristic information comprises characteristic information of overheating triggering thermal runaway and characteristic information of overcharging triggering thermal runaway;
3.3, accelerating the release of the thermal runaway gas according to the characteristic information of different thermal runaway trigger modes;
and 3.4, allowing the inert gas to flow through the first mass flow meter and the second mass flow meter at a constant flow rate, and allowing the thermal runaway gas to flow through the second mass flow meter.
7. The method of claim 6, wherein the gas generation rate and the gas generation amount are measured by a thermal runaway analyzer,
step 3.3, when the thermal runaway is triggered by overheat collection, heating the battery with constant power until the thermal runaway gas is released; and when the thermal runaway is triggered by the overcharge, charging the battery at constant current until the thermal runaway gas is released.
8. The measuring device for measuring the thermal runaway gas production rate and gas production rate of the lithium ion battery according to any one of claims 1 to 7,
the measuring device includes: the device comprises an inert gas bottle, a first mass flow meter, a one-way valve, a battery unit and a second mass flow meter;
the inert gas bottle is sequentially connected with the first mass flowmeter, the one-way valve, the battery unit and the second mass flowmeter;
the check valve controls the flow direction of the gas to flow from the first mass flow meter to the battery cell.
9. The measurement device of claim 8,
the measuring device further includes: the first straight pipe section, the second straight pipe section, the third straight pipe section and the fourth straight pipe section;
the first straight pipe section is connected with an inert gas bottle and a first mass flowmeter;
the second straight pipe section is connected with the first mass flow meter and the one-way valve;
the third straight pipe section is connected with the battery unit and the second mass flow meter;
and one end of the fourth straight pipe section is connected with a second mass flow meter.
10. The measurement arrangement according to claim 9,
the battery unit comprises a thermocouple, a battery module, a heating sheet and a sensor module which are arranged in a battery box; one end of the battery box is connected with the second straight pipe section through a one-way valve, and the other end of the battery box is provided with a hole which is connected with the third straight pipe section;
the battery module is connected with the charging and discharging cabinet machine through a lead, a heating sheet is arranged on one side of the battery module, and a thermocouple is arranged on the other side of the battery module; the battery module comprises a single battery and a battery module;
the sensor module comprises a temperature sensor and a gas sensor; wherein the gas sensor comprises: CO gas sensor, H 2 Gas sensors, volatile organic compound gas sensors, and smoke sensors.
11. The measurement arrangement according to claim 9,
when the battery is not out of control thermally, the inert gas bottle is opened, so that the inert gas flows into the first mass flow meter at a constant flow rate after passing through the first straight pipe section, then enters the second straight pipe section, enters the battery box through the one-way valve, flows into the second mass flow meter through the third straight pipe section, and is finally discharged through the fourth straight pipe section.
12. The measurement device of claim 10,
when the battery is out of control thermally, the out-of-control thermally conductive gas flows into the third straight pipe section through the reserved hole of the battery box, flows into the second mass flow meter after passing through the third straight pipe section, and is finally discharged through the fourth straight pipe section.
13. The measurement arrangement according to claim 12,
when the battery is overheated and thermal runaway occurs, the heating sheet heats the battery module with constant power until the shell of the battery module bursts and thermal runaway gas is released.
14. The measurement arrangement according to claim 12,
when the battery is overcharged and is out of control due to heat, the charging and discharging cabinet machine charges the battery module with constant current until the shell of the battery module bursts and the out-of-control gas is released.
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Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2009031014A (en) * | 2007-07-24 | 2009-02-12 | Hitachi Ltd | Thermal gas mass flowmeter |
| CN106769642A (en) * | 2017-01-12 | 2017-05-31 | 浙江零跑科技有限公司 | A kind of method for measuring inner pressure of battery and gas production |
| CN109270111A (en) * | 2018-09-13 | 2019-01-25 | 南京工业大学 | Lithium ion battery thermal runaway product collection and test method |
| CN110455363A (en) * | 2019-09-24 | 2019-11-15 | 江西黑猫炭黑股份有限公司 | Gas mass flow meter and gas mass flow measuring method |
| CN110542861A (en) * | 2019-08-26 | 2019-12-06 | 华南理工大学 | Power battery air leakage testing device and method |
| AU2020100862A4 (en) * | 2018-09-13 | 2020-07-02 | Nanjing Tech University | Method For Collecting And Testing Lithium Ion Battery Thermal Runaway Products |
-
2021
- 2021-01-28 CN CN202110120120.5A patent/CN112798049B/en active Active
Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2009031014A (en) * | 2007-07-24 | 2009-02-12 | Hitachi Ltd | Thermal gas mass flowmeter |
| CN106769642A (en) * | 2017-01-12 | 2017-05-31 | 浙江零跑科技有限公司 | A kind of method for measuring inner pressure of battery and gas production |
| CN109270111A (en) * | 2018-09-13 | 2019-01-25 | 南京工业大学 | Lithium ion battery thermal runaway product collection and test method |
| AU2020100862A4 (en) * | 2018-09-13 | 2020-07-02 | Nanjing Tech University | Method For Collecting And Testing Lithium Ion Battery Thermal Runaway Products |
| CN110542861A (en) * | 2019-08-26 | 2019-12-06 | 华南理工大学 | Power battery air leakage testing device and method |
| CN110455363A (en) * | 2019-09-24 | 2019-11-15 | 江西黑猫炭黑股份有限公司 | Gas mass flow meter and gas mass flow measuring method |
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