Development of Nanofiber Separator for Li-Ion Battery with High Meltdown Temperature
TP-AAB-AABC_2009_P_08
06/10/2009
- Content
- To meet the increasing demand for the environmentally friendly vehicles including both pure electric vehicles and hybrid vehicles, the most important technical challenge for both automobile and battery industries is the improvement of secondary battery performance. Lithium-ion battery (LIB) is considered to be the most promising next generation battery for these vehicles. One of the important technical issues that need improvement is safety of the LIB. When the LIB is overcharged, it begins to self-heat and causes thermal runaway reactions which may induce explosions and fire. As part of the battery safety system, separators play important role in preventing these thermal runaway reactions. Control of separator shutdown capability (ability to close its pores at elevated temperature) and meltdown property (ability to maintain its dimension at elevated temperature) are extremely important for the safety of the LIB. The conventional LIB separator is made of microporous polyethylene membrane which has a shutdown temperature around 130 ºC and the meltdown temperature in the vicinity of 160 ºC. Since the meltdown temperature is close to the shutdown temperature, the safety of the LIB cannot be 100% guaranteed because, when the thermal runway occurs, due to the time lag for complete shutdown of the reaction, the battery temperature may exceed the separator meltdown temperature. There are three properties which are essential for the safety function of the LIB separator: 1) shutdown function, 2) high meltdown temperature, and 3) prevention of short circuits. Recently, Hirose Paper has succeeded in developing the first “Nanofiber Separator” for the LIB that has above mentioned functions. The excellent safety performance of this Nanofiber Separator (NFS) will be presented in this paper.
- Citation
- Kishimoto, Y., Ichihara, K., Okada, S., Kadota, T. et al., "Development of Nanofiber Separator for Li-Ion Battery with High Meltdown Temperature," SAE Technical Paper TP-AAB-AABC_2009_P_08, 2009, .