US 12,218,379 B2
Multilayer microporous separators for lithium ion secondary batteries and related methods
Xiaomin Zhang, Charlotte, NC (US); Lie Shi, Matthews, NC (US); and William John Paulus, Waxhaw, NC (US)
Assigned to Celgard, LLC, Charlotte, NC (US)
Filed by Celgard, LLC, Charlotte, NC (US)
Filed on Sep. 19, 2023, as Appl. No. 18/370,360.
Application 18/370,360 is a division of application No. 17/189,550, filed on Mar. 2, 2021, granted, now 11,799,169.
Application 17/189,550 is a division of application No. 16/450,143, filed on Jun. 24, 2019, granted, now 10,938,011, issued on Mar. 2, 2021.
Application 16/450,143 is a division of application No. 14/950,625, filed on Nov. 24, 2015, granted, now 10,333,125, issued on Jun. 25, 2019.
Claims priority of provisional application 62/084,655, filed on Nov. 26, 2014.
Prior Publication US 2024/0006712 A1, Jan. 4, 2024
Int. Cl. H01M 50/403 (2021.01); H01M 10/0525 (2010.01); H01M 50/417 (2021.01); H01M 50/457 (2021.01); H01M 50/489 (2021.01); H01M 50/491 (2021.01)
CPC H01M 50/403 (2021.01) [H01M 50/417 (2021.01); H01M 50/457 (2021.01); H01M 50/489 (2021.01); H01M 50/491 (2021.01); H01M 10/0525 (2013.01); H01M 2220/20 (2013.01); Y02E 60/10 (2013.01)] 8 Claims
OG exemplary drawing
 
1. A separator having three layers having the formation of two outer layers and one interior layer, each layer produced according to a dry stretch process in which a polyolefin resin, mix or blend is extruded to form said layers, said resin of each of the outer layers having a melt flow index (MFI) of less than or equal to about 0.8 grams/10 minute; and
wherein said separator having a thickness 12 μm, a porosity in the range of about 35% to about 65%, and an electrical resistance (ER) value of less than or equal to about 1.5 ohm-cm2, and
wherein the separator is a has a puncture strength (PS) of at least 280 gf has a porosity in the range of about 35% to 65%, has an ER of 1.5 ohm-cm2 or less.