CPC H01M 50/42 (2021.01) [B01D 69/1212 (2022.08); B01D 69/1213 (2022.08); B01D 71/024 (2013.01); B01D 71/261 (2022.08); B01D 71/262 (2022.08); B01D 71/403 (2022.08); H01M 10/0525 (2013.01); H01M 50/417 (2021.01); H01M 50/426 (2021.01); H01M 50/443 (2021.01); H01M 50/449 (2021.01); H01M 50/491 (2021.01); H01M 50/489 (2021.01)] | 20 Claims |
1. A separator for rechargeable battery, comprising:
a porous substrate; and
a coating layer on at least one surface of the porous substrate, wherein the coating layer includes a filler and a binder including a fluorine-based binder and a (meth)acryl-based binder,
wherein the fluorine-based binder includes a first fluorine-based binder having a weight average molecular weight of 800,000 to 1,500,000 and a second fluorine-based binder having a weight average molecular weight of less than or equal to 600,000,
wherein each of the first fluorine-based binder and the second fluorine-based binder includes a first structural unit derived from vinylidene fluoride and a second structural unit derived from at least one monomer of hexafluoropropylene, chlorotrifluoroethylene, trifluoroethylene, ethylene tetrafluoride, and ethylene monomers, and the second structural unit is included in an amount of 10 wt % or less with respect to the fluorine-based binder, and
wherein the (meth)acryl-based binder has pencil hardness of 5H or higher.
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