The new version of GB T 36276-2023 "Lithium-ion Batteries for Electric Energy Storage" released on December 28, 2023 has greatly adjusted the relevant content of "adiabatic temperature rise characteristic test", this paper focuses on comparing the test methods and typical experimental data of the old and new standards, and focuses on the design logic of the new method.
Since the official release and implementation of the GB T 36276-2018 "Lithium-ion Batteries for Electric Energy Storage" standard in 2018, it has effectively promoted the development of the electric energy storage and lithium-ion battery industry in a compliant and orderly direction. In the past five years, with the rapid expansion of electrochemical energy storage, lithium battery technology for energy storage has made significant progress, and the application scenarios of batteries have become more complex, so the State Administration for Market Regulation and the Standardization Administration of the People's Republic of China released a new version of GB T 36276-2023 "Lithium-ion Batteries for Power Energy Storage" on December 28, 2023, which will be officially implemented on July 1, 2024. The new national standard adds six safety performance tests, such as overload, vibration, high altitude insulation and voltage resistance, and deletes and modifies the test methods and technical requirements of a number of tests. In particular, the new national standard has made great changes to the adiabatic temperature rise characteristic test in the thermal safety performance test, and corrected the problems of unclear test process, unreasonable technical requirements, and low data guidance value in the old test method.
This paper focuses on comparing and interpreting the design logic of the adiabatic temperature rise test method of the old and new national standards through the measured data, and explains the rationality of the new method, so as to facilitate industry users to understand the requirements of the new national standard and carry out experiments smoothly.
GB T 36276-2023 "Lithium-ion Batteries for Electric Energy Storage" and GB T 36276-2018 version of the standard for adiabatic temperature rise characteristics test requirements
2023 edition
6.7.4.1. Adiabatic temperature rise characteristic test
The adiabatic temperature rise characteristic test of the battery cell will be carried out according to the following steps: a) It will be carried out in accordance with 62.4.1.1. The test sample that has completed the initialization charge is placed in the adiabatic simulation device and connected to the temperature data sampling line; b) Set the adiabatic simulation device to test the starting temperature of 40, the test temperature rise step of 5, the test end temperature of 130, and the temperature data sampling period of 001 min；c) Heat the test sample until the surface temperature reaches 40, keep the current temperature, let it stand for 5 h, and record the time and temperature; d) Continue to heat the test sample until the surface temperature reaches 45, keep the current temperature, stand for 1h, and record the time and temperature; e) Control the test device to keep the current temperature constant for 20min, record the time and temperature, and calculate the temperature rise rate; f) Increment the surface temperature of the test sample to 130 in 5 steps, and repeat step d) e); g) Stop heating, wait for the surface temperature of the test sample to return to room temperature, remove the data sampling line, and take out the test sample; h) Record test phenomena, including swelling, leakage, smoke, shell rupture and rupture location; i) Repeat step a) h) until all test samples have completed the test. 2018 edition
a.2.8. Adiabatic temperature rise test
The adiabatic temperature rise test of the battery cell is carried out according to the following steps: a) the battery cell is initially charged; b) Set the starting temperature of the adiabatic acceleration calorimetry device to 40, set the end temperature to 130, start the device, keep the temperature constant when the temperature reaches 40, and put the battery monomer into the adiabatic cavity and leave it for 5h; c) The heating device is set at 0The temperature is increased at a rate of 5 min, and the current temperature is kept constant for 20 minutes every 10 minutes when the heating amplitude reaches 10, and the temperature accuracy of the device is recommended to be 02. The accuracy of the heating rate is recommended to be 002℃/min；d) Real-time monitoring of the temperature at the center point of the surface of the battery cell, the temperature data sampling period should not be greater than 10ms, and the accuracy of the temperature sensor should be 005℃；e) See Table B of Appendix B6. Record the temperature rise rate of the battery cell corresponding to the temperature point at different temperature constant stages; According to the recorded test data, the temperature-cell temperature rise rate curve was made. 2023 edition
5.6.4.1. Adiabatic temperature rise characteristics.
The adiabatic temperature rise characteristics of the battery cell should meet the following requirements: a) When the surface temperature is less than or equal to the first-level alarm temperature of the battery cell, the temperature rise rate is less than 002 ℃/min;b) No, no, do not rupture outside of the explosion valve or pressure relief point. 2018 edition
5.2.1.5 Adiabatic temperature rise
Data sheets of the temperature rise rate corresponding to different temperature points of the battery cell under adiabatic conditions should be provided, and the temperature-temperature rise rate curve based on the recorded test data should be provided.
2023 edition
6.1.2.4 Adiabatic simulator.
The main technical indicators of the insulation simulation device should meet the requirements of Table 5.
Table 1 Comparison of technical requirements for adiabatic temperature rise test.
Click here for a detailed comparison of the standards.
Analyzing the adjustment of the new national standard test method, the following changes can be summarized:
01 The test method is closer to the HWS model.
The test method is closer to the well-recognized and mature HWS battery thermal runaway test method, which is more scientific to characterize the self-heat release characteristics of the battery.
02 For the first time, the battery inspection qualification standard was clarified.
For the first time, the inspection qualification standard of battery samples is clarified, and the judgment conclusion of the insulation temperature rise characteristic is related to the safety early warning conditions provided by the manufacturer, and the standard requirements are more reasonable and enforceable.
03 Clarified the technical specifications of the measuring device for the first time.
For the first time, the technical index requirements of the measuring device are clarified, and it is necessary to use adiabatic simulation devices such as battery adiabatic calorimeters with adiabatic test functions, which avoids the use of non-standard equipment such as ovens that are difficult to achieve adiabatic conditions in the industry.
04 The test method and record content are improved.
In addition to detecting the temperature rise rate of the battery, it is clear that the phenomena of the battery in the experiment need to be observed, so as to comprehensively evaluate the thermal safety of the battery.
1.Sample preparation
Experimental sample: 280Ah lithium iron phosphate cell*2.
2.Experimental conditions
Experimental instruments: Hangzhou Yangyi Science and Technology ***BAC-420A large battery adiabatic calorimeter;
Working mode: Adiabatic Temperature Rise Mode-2018, Adiabatic Temperature Rise Mode-2023;
Ambient temperature: 20-3.
3.Experimental results
Fig.3 (A) GB T 36276-2018 and (B) GB T 36276-2023 adiabatic temperature rise characteristics test cell temperature rise curves.
Fig.4 (A) A-B T 36276-2018 and (B) Gb-T 36276-2023 adiabatic temperature rise characteristics test cell temperature rise rate-temperature curves.
Table 2 Data record table of adiabatic temperature rise characteristics of battery cells.
When the old national standard adiabatic temperature rise test is carried out, because only the temperature of the adiabatic accelerated calorimetry device is controlled by the specified program, and the temperature of the battery sample is relatively lagging due to its own large heat capacity, the temperature difference between the battery sample and the adiabatic calorimeter furnace body is large (as shown in Fig. 3a), and the furnace body has a serious overheating phenomenon on the battery sample, and the temperature rise rate of the battery corresponding to the measured temperature points at different temperature points is obviously large, as shown in Fig. 4a and Table 2; The new national standard avoids the above problems, and clarifies that the battery sample needs to continue to maintain a constant temperature for 60min after reaching the target step temperature, so that the battery is in a good adiabatic environment in the thermal insulation simulation device and then continue to search for 20min to detect its temperature rise rate. As shown in Figure 4b, the temperature rise rate of the battery is completely dependent on the internal self-release heat reaction of the battery, which can reflect the side reaction, self-discharge rate and apparent reaction kinetic characteristics of the battery at the target temperature, and scientifically characterize its thermal stability, which is more instructive for the thermal management and safety early warning of lithium-ion batteries in the power storage industry. 
Fig.5 Local characteristics of the temperature rise curve of the adiabatic temperature rise characteristic test of GB T 36276-2023: (a) the first step; (b) In the test of adiabatic temperature rise characteristics of the new national standard for rate detection steps, the battery cell should be kept constant for 5 hours after reaching the target temperature of the first step for 40 hours (Fig. 5a), so that the internal and external temperatures of the battery can fully reach equilibrium; On the other hand, as shown in Figure 5b, the temperature rise step of the new national standard test step is set to 5, and the temperature of each step is balanced for 1h and the search is continued for 20min, and the temperature rise rate within 20min is calculatedThe temperature rise rate of this cell reaches 0The corresponding temperature step of 02 min is 105, which should be greater than the first-level alarm temperature of the battery cell as declared by the battery manufacturer。According to the analysis and measurement results, the adiabatic temperature rise characteristic test of GB T 36276-2023 "Lithium-ion batteries for power energy storage" can scientifically and accurately determine the self-release temperature rise rate of batteries in adiabatic environments, and provide guidance for the safer use of lithium-ion batteries in power energy storage related industries.