Slurry for a separator, a separator and a preparation method thereof

Abstract

A slurry for a separator includes an aromatic polyamide, a solvent, and an additive including a hydrophilic nanofiber. On the one hand, the hydrophilic nanofiber increases the internal tension of the slurry, thereby increasing the mechanical strength of the final separator. On the other hand, the additive in this disclosure can significantly increase the rotational viscosity of the slurry for a separator, which can further reduce the mass fraction of aramid in the slurry while meeting the lowest requirements of rotational viscosity in casting the separator, If the mass fraction of aramid decreases, the mass fraction of solvent increases, and the porosity of the separator obtained by non-solvent induced phase separation (NIPS) increases. Therefore, the separator made using the additive in this disclosure can obtain both high porosity and high mechanical strength, thereby improving the cycle life and safety performance of a lithium battery.

Dependencies are inferred from the claim text.