A coupled penetration-tension method for evaluating the reliability of battery separators

The mechanical failure of battery separators could lead to catastrophic consequences such as explosion and thermal runway due to overheating and short circuiting. Therefore, there is an urgent need for mechanically charactering the separators in the way that they are mechanically loaded in the batteries. Here we report a mechanical characterization method that is able to measure the penetration strength of a battery separator under the pre-stressed condition. The experimental results unveiled that the pre-tensile stress has the potential to dramatically decrease the penetration strength of the separator, which highlights a new potential safety hazard that was not found before. © 2014 The Electrochemical Society.