Heat/Flame-Resistant Polymer Composite-Based Solid Electrolyte Separator, Lithium Secondary Battery, and Manufacturing Method

A flame-resistant composite separator for use in a lithium battery, wherein the composite separator comprises a porous layer of a first polymer, having pores and a thickness from 50 nm to 200 μm, and a second polymer permeating into or residing in said pores, wherein:

• a) the first polymer comprises a flame-resistant polymer selected from the group consisting of epoxy, epoxy novolac, polyurethane, phenolic resin or phenol formaldehyde, polyester, vinyl ester resins, melamine resin, polyamide, polyamide-imide, bismaleimide, cyanate ester, silicone, polyurea-urethane, Diallyl-phthalate, benzoxazines, polyimide, poly(amide imide), poly(ether imide), aromatic polyamide, polyoxadiazole, polybenzoxazole, polybenzobisoxazole, polythiazole, polybenzothiazole, polybenzobisthiazole, poly(p-phenylene vinylene), polybenzimidazole, polybenzobisimidazole, polysuccinonitrile, polyquinolines, poly[2,2′-(m-phenylene)-5,5′-bibenzimidazole], poly(arylene ethers), polycarboranes, poly (p-xylylene), poly(phenylene ether), polymers from 1,4,5,8-naphthalenetetracarboxylic acid and aromatic tetraamines, poly(1,3,4oxadiazoles), poly(1,2,4-oxa-diazoles), poly(1,2,4- and 1,2,5-oxadiazole-N-oxides), polythiadiazoes, polypyromellitimidlnes, poly-1,3,4-thiazidazoie, poly(benzimidazobenzophenanthroline) ladders (BBL), poly(imidazoisoquinoline) ladders, polydicyclopentadiene (pDCPD), polyether ether ketone (PEEK), rigid-rod polymers, ladder polymers, sulfonated versions thereof, copolymers thereof, interpenetrating networks thereof, and combinations thereof;
• b) the second polymer comprises either a polymer that is obtained by in situ polymerizing and/or curing a reactive mass in the pores or a polymer solidified from a polymer solution inside the pores of the first polymer layer;
• and
• c) the first polymer or the second polymer has a lithium-ion conductivity from 10−8 S/cm to 2×10−2 S/cm at room temperature.