1. EVS-GTR TF5 Update Progress
TF5 task force –thermal propagation
Prof. Xiao Chengwei
2015/6/3

2. TF5 F2F meeting held in Beijing on May 12th
Chairman: Ms. Chen Chunmei (MIIT of China)
Attendees:
China Experts: Prof. Xiao Chengwei, Dr. Wang Fang, Prof. LIU Guibin
Japan Experts: Dr. Terunao KAWAI(MLITIAI), Mr. Shigeo Komatsu(Nissan), Mr. Yoshitaka Asakura(Toyota), Mr. Masato Komatsuki (JASIC)
OICA experts: Dr. Fengliang BAI(Jaguar Land Rover China), the others via teleconference
Two presentations were given respectively by Japan and China.

3. Objectives of TF5
China: Both cell and pack safety are two important measures to ensure vehicle safety; propagation test is important to be considered in GTR.
Japan: Propagation is necessary to address the internal short circuit issue caused by the manufacturing defect; In this requirement, we should assess that all occupants can safely escape even if the internal short circuit of a cell occurs.
 OICA: The vehicle safety can be assured by the safety design of battery pack BMS; the occupants have enough time to escape if the objective of propagation test is for vehicle safety.

4. Test methods discussed
China: Method to simulate the internal short circuit: Overcharge, nail and heating; the overcharge test method is suggested to simulate the internal short circuit on different material battery pack;
Japan: Methods which can easily cause a cell internal short circuit including in battery pack are different depending on cell type and battery structure; Difference of short circuit level causes difference of battery pack phenomenon in spite of a same battery.
OICA: The test method proposed by China need more test data covering wider range of battery technologies and types.  It could be difficult to set up the pass/fail criteria as the different pack phenomenon in Japan’s presentation. There are safe pack designs which are not necessary designed for this type of test. The test itself could be a technical barrier for certain types of battery technologies.
See the presentations by China and Japan in Beijing

5. Conclusion reached
The meeting was productive; all parties had lively discussions about the objectives and test methods. It needs deeper communications to achieve a common understanding on the necessity of the propagation test. All members have agreed to conduct a follow-up meeting as soon as the following information is available.
China and Japan: Agreed on the necessity of thermal propagation test;
OICA: To provide evidence that the occupants have enough time to escape when the thermal propagation occurs.

6. Thanks！