Design of a porous gel polymer electrolyte for sodium ion batteries

• Published in: Journal of membrane science Vol. 566; pp. 122 - 128
• Main Authors: Kim, Jin Il, Chung, Kyung Yoon, Park, Jong Hyeok
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 15.11.2018
• Subjects: Gel polymer electrolyte; Non-solvent induced phase separation; Selective positioning engineering; Sodium ion battery; Sodium ion battery; Non-solvent induced phase separation; Gel polymer electrolyte; Selective positioning engineering
• ISSN: 0376-7388; 1873-3123
• DOI: 10.1016/j.memsci.2018.08.066

A separator is essential component for securing the safety and stability of secondary batteries. Sodium ion batteries (SIBs) have been considered as a highly powerful next generation energy storage device, but the conventionally used glass fibre (GF) separators for SIBs do not meet the necessary standards due to their randomly distributed pore structure, which causes severe safety problems and capacity decay. Although many studies have been performed to address these drawbacks, there are still difficulties of controlling the inner pore structure of GF. Herein, a strategy is introduced to control the inner porous nanostructure of GF via non-solvent induced phase separation (NIPS) engineering for the gel-polymer electrolyte in SIBs. We report how different types of porous polymer gel electrolyte inside the GF matrix affect SIB performance in terms of both pore nanostructure and vertical position of polymer layer. As a result of NIPS, the optimized gel-polymer electrolyte in GF facilitates increased ionic conductivity via modified ion transport and displays superior cell characteristics with excellent stability. Gel polymer electrolyte with controlled morphology for sodium ion battery exhibits excellent cell characteristic for various current density and long-term cycle, resulting from effective inside pore structure and enhanced compatibility with electrodes. [Display omitted] •Porous glass fibre (GF) separator is introduced.•Controlled GF separator affects sodium ion battery performances.•The sodium ion battery with modified GF displays superior cell characteristics.