Flexible, Heat-Resistant, and Flame-Retardant Glass Fiber Nonwoven/Glass Platelet Composite Separator for Lithium-Ion Batteries

• Main Authors: Ulrich Schadeck, Kanat Kyrgyzbaev, Heiko Zettl, Thorsten Gerdes, Ralf Moos
• Format: Article
• Language: English
• Published: MDPI AG 2018-04-01
• Series: Energies
• Subjects: glass platelets; composite separator; high-temperature stability; full-cell configuration cycling tests; lithium-ion battery
• Online Access: http://www.mdpi.com/1996-1073/11/4/999

A new type of high-temperature stable and self-supporting composite separator for lithium-ion batteries was developed consisting of custom-made ultrathin micrometer-sized glass platelets embedded in a glass fiber nonwoven together with a water-based sodium alginate binder. The physical and electrochemical properties were investigated and compared to commercial polymer-based separators. Full-cell configuration cycling tests at different current rates were performed using graphite and lithium iron phosphate as electrode materials. The glass separator was high-temperature tested and showed a stability up to at least 600 °C without significant shrinking. Furthermore, it showed an exceptional wettability for non-aqueous electrolytes. The electrochemical performance was excellent compared to commercially available polymer-based separators. The results clearly show that glass platelets integrated into a glass fiber nonwoven performs remarkably well as a separator material in lithium-ion batteries and show high-temperature stability.