Experimental and modeling investigation on thermal risk evaluation of tabs for pouch-type lithium-ion battery and the relevant heat rejection strategies

Thermal safety is one of the primary requirements for electric vehicles (EVs). Overheating by an external or internal heat source will induce the onset of thermal runaway. An overheating risk caused by tabs of pouch-type lithium-ion batteries was reported and the relevant heat rejection strategies were investigated in this paper. The positive tab showed a much higher temperature rise than that in the body and the negative tab of pouch-type lithium-ion batteries. The temperature reached 70.4 degrees C in the beginning 100 s with a charge rate of 2 C-rate, showing a fast temperature response. Besides, the largest temperature difference between the charge and discharge process was about 20.2 degrees C (2 C-rate), which indicates that the positive tab in the charging process is more dangerous than that in discharging process. Moreover, an electro-thermal model was applied to investigate the potential risk of tabs in the pouch-type lithium-ion battery. An extreme temperature rise ( similar to 350 degrees C) in the positive tab showed a potential thermal risk in a high charging rate (6C). And the temperature at the tab can only be controlled under a relatively high heat transfer coefficient (higher than 100 W middotm -2 middotK -1 ). This work is meaningful for the development of a thermal management strategy in a battery pack with fast charging technologies.(c) 2022 Elsevier Ltd. All rights reserved.

Automated summary

This study investigated the temperature difference between the positive and negative tabs of pouch-type lithium-ion batteries and explored relevant heat rejection strategies. The results showed that the positive tab had a faster and more dangerous temperature rise, reaching 70.4 degrees Celsius during high-rate charging, with a maximum temperature difference of about 20.2 degrees Celsius during charge and discharge. Furthermore, an electro-thermal model revealed the potential risk of extreme temperature rise (up to 350 degrees Celsius) in the positive tab under high charging rates, which requires a relatively high heat transfer coefficient for temperature control.