Shutdown-functionalized nonwoven separator with improved thermal and electrochemical properties for lithium-ion batteries

摘要

A shutdown-functionalized nonwoven separator (SFNS) with improved thermal and electrochemical stabilities is prepared by a simple dip coating method for use in lithium-ion battery (LiB) applications. The SFNS shows thermal stability at 200 degrees C, while providing shutdown functionality at approximately 140 degrees C, similar to commercial porous polyethylene separators. The surface -coated polymer prevents leakage current problems and in addition, shows air permeability values similar to that of bare nonwoven separators, while maintaining a thickness of about 20 mu m, which is a desired attribute of effective separators for LiBs. The SFNS also shows increased electrolyte uptake and higher conductivity, compared to a bare polyethylene separator. Therefore, a cell with the SFNS exhibits higher discharge capacity and better cycle property than that with a porous polyethylene separator. These results suggest that SFNS is an effective separator for high-performance LiBs. (C) 2015 Elsevier B.V. All rights reserved.