Laser-perforated porous solid-state films and applications thereof
View Patent ↗The disclosure relates, in one aspect, to porous solid-state films with controlled pore structures obtained by laser perforation. A thin laser-perforated film can comprise a slab defining a plurality of pores distributed in a predetermined arrangement, the plurality of pores having a distribution of sizes bound by a predetermined magnitude. In an aspect, the plurality of pores are formed in the slab with a laser having a wavelength less than about 400 nm and the slab has a transmission of the laser light of equal to or less than about 70% measured at a thickness of the slab of 100 micrometer or less.
1. A perforated film comprising:
a slab defining a plurality of pores distributed in a predetermined arrangement, the plurality of pores having a mean diameter less than about 50 μm;
wherein the plurality of pores are formed in the slab with a laser having a wavelength less than about 400 nm and the slab has a transmission of the laser light of equal to or less than about 70% measured at a thickness of the slab of 100 micrometer or less; and
wherein the slab has a high temperature melt integrity (HTMI) equal to or exceeding about 180° C.
2. The perforated film of claim 1 , wherein the transmission of the laser light is measured according to ASTM D1003-00, Procedure A, using D65 illumination, 10 degrees observer.
3. The perforated film of claim 1 , wherein the slab is formed from a polymer comprising one or more of polymethyl methacrylate, polystyrene, polyethylene, polypropylene, polytetrafluoroethylene, polyvinylidene fluoride, polycarbonate, poly(4-methylpentene), cyclic olefin copolymers, polyamide, aromatic polyamide, poly(amide-imide), polyoxymethylene, polyphthalamide, polysulfone, polyethersulfone, polyphenylsulfone, liquid crystalline polymers, polyetherimide, polybutylene terephthalate, polyethylene terephthalate, polyethylene naphthalate, polyphenylene oxide, polyimide, polyketone, polyetherketone, polyetheretherketone, polyphenylene sulfide, or a copolymer and/or blend thereof.
4. The perforated film of claim 3 , wherein the polymer comprises an ultraviolet absorbing additive selected from hydroxybenzophenones, hydroxybenzotriazoles, hydroxybenzotriazines, cyanoacrylates, oxanilides, benzoxazinones, benzylidene malonates, hindered amine light stabilizers, nano-scale inorganics, or combinations comprising at least one of the foregoing.
5. The perforated film of claim 1 , wherein each of the plurality of pores is formed via laser perforation or laser drilling.
6. The perforated film of claim 1 , wherein each of the plurality of pores is formed via laser perforation of the slab or laser drilling of the slab, a surface of the slab being coupled to a mask, where the mask is locally transparent to electromagnetic radiation emitted from a laser in a pre-defined manner that enables laser perforation of the slab through the areas of the mask that are substantially transparent to the electromagnetic radiation.
7. The perforated film of claim 1 , wherein the slab is formed from a material containing at least one polymeric component that absorbs electromagnetic radiation having wavelengths below about 400 nm.
8. The perforated film of claim 1 , wherein the slab is formed from a material containing at least one component that absorbs electromagnetic radiation having wavelengths below about 400 nm.
9. The perforated film of claim 1 , wherein the slab has a total hole area of 10 to 80%.
10. The perforated film of claim 1 , wherein the slab comprises a plurality of material layers.
11. The perforated film of claim 1 , wherein the slab is integrated as high temperature separator for lithium ion battery or a separator for an electrolytic supercapacitor or a support membrane for a fuel cell membrane.
12. A method, comprising:
providing a slab having a high temperature melt integrity (HTMI) equal to or exceeding about 180° C.; and
removing material from the slab by exposing the slab to a laser having a wavelength less than about 400 nm to produce a plurality of pores in the slab, the plurality of pores having a mean diameter less than about 50 μm and the slab having a transmission of the laser of equal to or less than about 70% measured at a thickness of the slab of 100 micrometer or less.
13. The method of claim 12 , wherein the transmission of the laser light is measured according to ASTM D1003-00, Procedure A, using D65 illumination, 10 degrees observer.
14. The method of claim 12 , further comprising arranging the slab in proximity of a porous thin film.
15. The method of claim 14 , wherein the porous thin film if formed from a process that is different from the process used to form the porous slab.
16. The method of claim 14 , wherein the porous thin film comprises a polymer selected from polymethyl methacrylate, polystyrene, polyethylene, polypropylene, polytetrafluoroethylene, polyvinylidene fluoride, polycarbonate, poly(4-methylpentene), cyclic olefin copolymers, polyamide, aromatic polyamide, poly(amide-imide), polyoxymethylene, polyphthalamide, polysulfone, polyethersulfone, polyphenylsulfone, liquid crystalline polymers, polyetherimide, polybutylene terephthalate, polyethylene terephthalate, polyethylene naphthalate, polyphenylene oxide, polyimide, polyketone, polyetherketone, polyetheretherketone, polyphenylene sulfide, or a copolymer and/or blend thereof.
17. The method of claim 16 , wherein the polymer comprises one or more ultraviolet absorbing additives selected from hydroxybenzophenones, hydroxybenzotriazoles, hydroxybenzotriazines, cyanoacrylates, oxanilides, benzoxazinones, benzylidene malonates, hindered amine light stabilizers, nano-scale inorganics, or combinations comprising at least one of the foregoing.
18. A composite film comprising:
a porous thin film; and
a slab arranged in proximity of the porous thin film and defining a plurality of pores distributed in a predetermined arrangement, the plurality of pores having a mean diameter less than about 50 μm;
wherein the slab has a high temperature melt integrity (HTMI) equal to or exceeding about 180° C. and the slab having a transmission of the laser of equal to or less than about 70% measured at a thickness of the slab of about 100 micrometer or less.
19. The composite film of claim 18 , wherein the transmission of the laser light is measured according to ASTM D1003-00, Procedure A, using D65 illumination, 10 degrees observer.
20. The composite film of claim 18 , wherein the porous thin film is based on polyethylene and melts at temperatures ranging from about 100° C. to about 130° C., thereby providing a shutdown mechanism.
21. The composite film of claim 18 , wherein the polyethylene porous thin film has a thickness of at least 5 microns.
22. The composite film of claim 18 , wherein the composite film is contained in a battery, thereby forming an HTMI battery separator.
23. The composite film of claim 18 , wherein the composite film is contained in an electrolytic capacitor as a separator.
24. The composite film of claim 18 , wherein the composite film is contained in a fuel cell as a support membrane.