Preparation and evaluation of a separator with an asymmetric structure for lithium-ion batteries. Issue 107 (4th November 2016)

• Record Type: Journal Article
• Authors: Wang, Yanqing; Zhu, Shaoyin; Sun, Deye; Jin, Yongcheng
• Is Part Of: RSC advances. Volume 6:Issue 107(2016)
• Page Start: 105461
• Page End: 105468
• Publication Date: 2016-11-04
• Subjects: Chemistry -- Periodicals; 540.5
• DOI: 10.1039/c6ra21089a
• Languages: English
• ISSNs: 2046-2069

Abstract

Abstract : Asymmetric separators with high porosity and thermal stability can provide different functionalities corresponding to the different interface properties at the cathode and anode surfaces. Abstract : The different electrochemical characteristics stemming from the cathode and anode of lithium-ion batteries may have different effects on the surface properties of contacted separators. Herein, a series of composite separators with an asymmetric porous structure are fabricated by a one-step phase inversion method coupled with the settling of SiO2 nanoparticles due to gravity within the poly(vinylidenefluoride- co -hexafluoropylene) (PVDF-HFP) polymer matrix. The unique asymmetric porous separators are composed of a PVDF-HFP-rich layer with high porosity on the front surface, which is in contact with the air, and a SiO2 -rich layer on the back surface, which is in contact with the substrate. Besides their excellent thermal stability and high safety towards fire, these asymmetric porous separators result in a high discharge capacity, enhanced cycling performance and excellent rate capability when assembled with a LiNi0.5 Mn1.5 O4 cathode in coin cells, indicating that the asymmetric porous composite separators could be a promising candidate to improve the performance of lithium-ion batteries.