Low-pressure ethane/nitrogen gas mixture plasma surface modification effect on the wetting and electrochemical performance of polymeric separator for lithium-ion batteries

The wettability and electrochemical performance of polymeric separator can be modified by ethane/nitrogen gas mixture plasma chemical vapor deposition. The static water contact angle of the plasma-modified polymeric separator notably decreased with varying treatment time and plasma power. Furthermore, the plasma modified polymeric separator surface was detected by Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy. The surface analyses demonstrate that the improved wettability of the polymeric separator resulted from the increased polar component of surface energy. In addition, the electrochemical characteristic of plasma-modified polymeric separator shows the improved performance in electrochemical impedance spectroscopy measurement. The experimental results show the important role of chemical species in the interaction between ethane/nitrogen gas mixture gas plasma and a separator surface, which can be controlled by surface modification to tailor the wettability and electrolyte retention. (C) 2014 Taiwan Institute of Chemical Engineers. Published by Elsevier B.V. All rights reserved.