Depositions or layers for microporous membranes, improved membranes, improved lithium battery separators, improved batteries, improved high voltage lithium batteries, and related methods
A microporous membrane or substrate for an electrochemical device having a layer of a metal and/or metal oxide on at least one side of a polymeric porous membrane, wherein said layer is applied using a deposition method or technique such as vapor deposition, and wherein said layer contains one or more phases of a reactive metal oxide.
1. A microporous membrane comprising a first layer that is conductive and comprised of aluminum, said first layer applied on a side of a polymeric porous membrane, and a ceramic layer comprising multi-crystalline phase alumina, said ceramic layer is applied with a physical vapor deposition method, wherein the ceramic layer is solely on top of the first layer and wherein the ceramic layer is non-conductive, and wherein the first layer has a thickness of twenty nanometers and the ceramic layer has a thickness of four microns.
2. The microporous membrane of claim 1 wherein said membrane is a component of an electrochemical device.
3. The microporous membrane of claim 1 wherein said membrane is a lithium battery separator.
4. The microporous membrane of claim 1 wherein said membrane is a lithium secondary battery separator that is stable against oxidation in a lithium ion battery with a cell voltage up to or equal to 5.2 volts or more, and the cell voltage is a measure of a potential difference between two electrodes in the lithium ion battery.
5. The microporous membrane of claim 1 wherein the polymeric porous membrane comprises polyolefin, polyvinylidene fluoride (PVdF), polyethylene terephthalate (PET), woven fibers, and/or nonwoven fibers.
6. The microporous membrane of claim 1 wherein the membrane or substrate is a monolayer or a multilayer membrane or substrate produced using a dry process, a wet process, a particle stretch process, a biaxially oriented polypropylene (BOPP) process, a beta nucleated biaxially oriented polypropylene (BN-BOPP) process, a nonwoven membrane process, or a combination thereof.
7. The microporous membrane of claim 3 wherein said first layer is on a side of the separator facing the cathode.
8. The microporous membrane of claim 3 wherein the microporous membrane or substrate is part of a lithium battery with an electrolyte comprising solvent and lithium salt.
9. A primary or secondary battery comprising a microporous membrane according to claim 1 .
10. The microporous membrane of claim 1 wherein said membrane is a lithium secondary battery separator that is stable against oxidation in a lithium ion battery with a positive electrode potential of up to 5.4 volts or more versus a Li/Li+ reference electrode.
11. The microporous membrane of claim 6 wherein the membrane or substrate is a monolayer or a multilayer membrane or substrate produced using dry process.
12. The microporous membrane of claim 1 , wherein the ceramic layer further comprises a binder.
13. A method of producing the ceramic layer of the microporous membrane of claim 12 , comprising forming a slurry by combining the binder and the alumina, coating the microporous membrane or substrate or layers thereof with said slurry, and drying the coated microporous membrane or substrate.
14. The method of claim 13 , wherein coating the microporous membrane or layers thereof with said slurry comprises a physical vapor deposition process.