New Low-Cost, Thin, Highly-Permeable, Ductile Polypropylene Separators for High-Power Li-Ion Batteries
TP-AAB-AABC_2009_P_12
06/10/2009
- Content
- Battery separators have played a tremendous role in the commercialization success of Li-ion batteries in the past 17 years. Separators are passive components but play a key role of influencing the lithium battery performance actively and directly, such as safety, cycle life, energy density and power. Battery manufacturers want separators to be as inexpensive as non-wovens but, at the same time, they demand separators to be microporous, strong and shutdown. In the past commercialization, the oxides of Co, Ni and Mn were the main cathode materials for Li-ion batteries for consumer electronic applications such as cell phones, computers, and digital cameras. Since the oxides of such transition metals are inherently unstable at elevated temperatures, the batteries need to be prepared for shutdown at anytime when the internal heating occurs. To deal with such an issue of the internal instability in the battery, the separators have been demanded to provide a shutdown function. In the very recent years, Lithium Iron Phosphate as the cathode material has developed tremendously for use in Li-ion batteries. The phosphate is relatively stable. From the chemical point of view, phosphorus is on the right hand side of period table. The oxide of phosphorous is relatively stable internally. The shutdown function is not the major demand from the separator. Instead, such a type of batteries are being planned to be used in a more violent environment, such as automotive and power tool. In this type of application, the battery will demand high power and safety from external abuse. Again, the separators are demanded to support of dealing with the safety issue from the external abuse.
- Citation
- Yu, W., "New Low-Cost, Thin, Highly-Permeable, Ductile Polypropylene Separators for High-Power Li-Ion Batteries," SAE Technical Paper TP-AAB-AABC_2009_P_12, 2009, .