High Modulus, Thermally Stable, and Self-Extinguishing Aramid Nanofiber Separators. Academic Article uri icon


  • Mechanically and thermally robust separators offer an alternative approach for preventing battery failure under extreme conditions such as high loads and temperatures. However, the trade-off between electrochemical performance and mechanical and thermal stability remains an ongoing challenge. Here, we investigate aramid nanofiber (ANF) separators that possess high moduli and self-extinguishing characteristics. The ANF separators are formed from the dissolution of bulk Kevlar fibers and their subsequent vacuum-assisted self-assembly. Thermogravimetric analysis shows a high 5 wt % decomposition temperature of 447 C, which is over 175 C higher than commercial Celgard separators. The ANF separator also possesses a high Young's modulus of 8.8 GPa, which is 1000% higher than commercial separators. Even when dry or when soaked in battery electrolyte, the ANF separators self-extinguish upon exposure to flame, whereas commercial separators melt or drip. We show that these features, although adventitious, present a trade-off with electrochemical performance in which a lithium nickel manganse cobalt (NMC) oxide-based battery possessed a reduced capacity of 123.4 mA h g-1. Considering the separator holistically, we propose that the ANF separator shows an excellent balance of the combined properties of high modulus, flame-resistance, thermal stability, and electrochemical stability and might be suitable for extreme environment applications with further testing.

published proceedings

  • ACS Appl Mater Interfaces

altmetric score

  • 18.984

author list (cited authors)

  • Patel, A., Wilcox, K., Li, Z., George, I., Juneja, R., Lollar, C., ... Lutkenhaus, J. L.

citation count

  • 46

complete list of authors

  • Patel, Anish||Wilcox, Kathryn||Li, Zhuo||George, Ian||Juneja, Rishabh||Lollar, Christina||Lazar, Simone||Grunlan, Jaime||Tenhaeff, Wyatt E||Lutkenhaus, Jodie L

publication date

  • June 2020