US 11,952,475 B2
Base films for impregnation, improved impregnated products, and related methods
Takahiko Kondo, Charlotte, NC (US); Masaaki Okada, Charlotte, NC (US); Stefan Reinartz, Waxhaw, NC (US); and Daniel R. Alexander, Charlotte, NC (US)
Assigned to Celgard, LLC, Charlotte, NC (US)
Appl. No. 16/645,530
Filed by Celgard, LLC, Charlotte, NC (US)
PCT Filed Sep. 12, 2018, PCT No. PCT/US2018/050547
§ 371(c)(1), (2) Date Mar. 9, 2020,
PCT Pub. No. WO2019/055446, PCT Pub. Date Mar. 21, 2019.
Claims priority of provisional application 62/557,424, filed on Sep. 12, 2017.
Prior Publication US 2020/0277465 A1, Sep. 3, 2020
Int. Cl. C08J 9/42 (2006.01); H01G 9/02 (2006.01); H01G 11/52 (2013.01); H01M 8/0239 (2016.01); H01M 10/052 (2010.01); H01M 50/414 (2021.01); H01M 50/489 (2021.01); H01M 50/491 (2021.01); H01M 50/494 (2021.01); H01M 50/497 (2021.01)
CPC C08J 9/42 (2013.01) [H01M 8/0239 (2013.01); H01M 10/052 (2013.01); H01M 50/414 (2021.01); H01M 50/489 (2021.01); H01M 50/491 (2021.01); H01M 50/494 (2021.01); H01M 50/497 (2021.01); C08J 2323/06 (2013.01); C08J 2323/12 (2013.01); H01G 9/02 (2013.01); H01G 11/52 (2013.01)] 23 Claims
OG exemplary drawing
 
1. A dry process polymer membrane adapted for use as or in a separator for a lithium battery, including at least one mesoporous, microporous, or nanoporous impregnated membrane film, with at least one area of surfaces of pores in the polymer membrane having a first thin layer of at least a first impregnate material, comprising a polymer resin (B) as a major component therein wherein the polymer resin (B) is polyvinylidene difluoride (PVdF), polycarbonate (PC) or a combination thereof, at least an about 10% impregnation depth into the thickness of the polymer membrane, and wherein the membrane film has a polymer resin (A) as a major component; and,
and, wherein the dry process polymer membrane has a composite splittiness index of greater than 140 measured where composite splittiness index is defined by the equation below where composite splittiness index is a function of the first load peak, the second load peak, TD tensile strength, MD tensile strength, and TD elongation measured during puncture strength testing:
CSI=(A−|B−A|1.8)×C×(D×E)/106
where:
A=First Load Peak/(Thickness×(1−% Porosity));
B=Second Load Peak/Thickness;
C=TD Elongation;
D=MD Tensile Strength;
E=TD Tensile Strength; and
where First and Second Load Peak are in units of gram-force, thickness values are in microns, MD and TD tensile strength are in gram-force, and TD elongation is expressed as percentage; and
wherein the dry process polymer membrane comprises groups of pores between adjacent lamellae with the lamellae oriented substantially along a transverse direction and fibrils or bridging structures between the adjacent lamellae oriented substantially along a machine direction and an outer surface of at least some of the lamellae being substantially flattened or planar.