US 12,237,538 B2
Separator for secondary battery and secondary battery including the same
Hye-Jin Kwon, Daejeon (KR); Su-Jin Yoon, Daejeon (KR); Jong-Heon Kwak, Daejeon (KR); and Jeong-Ae Yoon, Daejeon (KR)
Assigned to LG ENERGY SOLUTION, LTD., Seoul (KR)
Appl. No. 17/625,052
Filed by LG ENERGY SOLUTION, LTD., Seoul (KR)
PCT Filed Jul. 6, 2020, PCT No. PCT/KR2020/008809
§ 371(c)(1), (2) Date Jan. 5, 2022,
PCT Pub. No. WO2021/006583, PCT Pub. Date Jan. 14, 2021.
Claims priority of application No. 10-2019-0082290 (KR), filed on Jul. 8, 2019.
Prior Publication US 2022/0285791 A1, Sep. 8, 2022
Int. Cl. H01M 50/451 (2021.01); H01M 50/403 (2021.01); H01M 50/417 (2021.01); H01M 50/431 (2021.01)
CPC H01M 50/451 (2021.01) [H01M 50/403 (2021.01); H01M 50/417 (2021.01); H01M 50/431 (2021.01)] 14 Claims
 
1. A separator for a secondary battery, comprising:
a porous polymer substrate having a plurality of pores; and
a porous coating layer on at least one surface of the porous polymer substrate, the porous coating layer comprising a plurality of inorganic particles, a binder polymer and a urethane bond-containing crosslinked polymer, wherein the binder polymer and the urethane bond-containing crosslinked polymer are on at least a part of a surface of the plurality of inorganic particles to connect and fix the plurality of inorganic particles with one another,
wherein the urethane bond-containing crosslinked polymer has a weight average molecular weight of 100,000 to 5,000,000,
the urethane bond-containing crosslinked polymer is included in an amount of 6 parts by weight to 60 parts by weight based on 100 parts by weight of a total weight of the binder polymer and the urethane bond-containing crosslinked polymer, and
the urethane bond-containing crosslinked polymer is obtained by a crosslinking reaction of at least one crosslinkable polymer during activation of the secondary battery.