# US 2026/0100480 A1 · Composite separator, composite electrolyte including the same, and lithium battery including the same > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2026/0100480 A1 - Document ID: US20260100480A1 - Status: Published application - Kind: A1 - Application number: 19/336,968 - Filed: 2025-09-23 - Published: 2026-04-09 - Earliest claimed: 2024-10-04 - Assignees: The Industry & Academic Cooperation in Chungnam National University (IAC) - Applicants: The Industry & Academic Cooperation in Chungnam National University (IAC) - Inventors: Heesu KIM; Youngmin Moon; Sangbaek Park; Woo-Jin Song; Seung-Wan Song - Web page: https://patentgrep.com/patent/US20260100480A1 ## CPC - H01M 50/454: comprising a non-fibrous layer and a fibrous layer superimposed on one another - H01M 10/052: Li-accumulators - H01M 10/0562: Solid materials - H01M 50/414: Synthetic resins, e.g. thermoplastics or thermosetting resins - H01M 50/417: Polyolefins - H01M 50/426: Fluorocarbon polymers - H01M 50/44: Fibrous material - H01M 50/446: Composite material consisting of a mixture of organic and inorganic materials - H01M 50/489: Separators, membranes, diaphragms or spacing elements inside the cells, characterised by their physical properties, e.g. swelling degree, hydrophilicity or shut down properties - H01M 10/0525: Rocking-chair batteries, i.e. batteries with lithium insertion or intercalation in both electrodes; Lithium-ion batteries - H01M 2300/0071: Oxides - Y02E 60/10: Energy storage using batteries - H01M: PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY - Y02E: REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION ## Abstract Disclosed are a composite separator and a composite electrolyte and a lithium battery that include the composite separator, the composite separator including a first porous substrate and an ion-conductive composite film on the first porous substrate, wherein the ion-conductive composite film includes an oxide-based solid electrolyte and a first polymer including a carbonyl group, a content of the oxide-based solid electrolyte is greater than 80 wt % relative to the total weight of the oxide-based solid electrolyte and the first polymer, and the first porous substrate includes a plurality of second polymer fibers aligned in a first direction. ## Claims ### Claim 1 A composite separator comprising: a first porous substrate; and an ion-conductive composite film on the first porous substrate, the ion-conductive composite film including an oxide-based solid electrolyte and a first polymer including a carbonyl group, wherein a content of the oxide-based solid electrolyte is greater than 80 wt % relative to a total weight of the oxide-based solid electrolyte and the first polymer, and the first porous substrate includes a plurality of second polymer fibers aligned in a first direction. ### Claim 2 (depends on 1) The composite separator of claim 1, wherein the oxide-based solid electrolyte includes an oxide-based solid core and a coating layer arranged on a surface of the core, the coating layer includes a lithium-containing compound, and the lithium-containing compound includes lithium carbonate, lithium hydroxide, or a combination thereof. ### Claim 3 (depends on 2) The composite separator of claim 2, wherein the coating layer is arranged between the oxide-based solid electrolyte core and the first polymer, and the coating layer is a conformal coating layer arranged along a surface contour of the oxide-based solid electrolyte core. ### Claim 4 (depends on 2) The composite separator of claim 2, wherein when measuring an X-ray photoelectron spectroscopy (XPS) depth profile for a surface of the oxide-based solid electrolyte, at the start of sputtering, a second oxygen peak derived from lattice oxygen (Olattice) of the oxide-based solid electrolyte appearing at 527.5 eV to 530 eV is free, and after 130 seconds from the start of sputtering, a ratio (P2/P1) of intensity (P2) of a second oxygen peak derived from lattice oxygen (Olattice) of the oxide-based solid electrolyte appearing at 527.5 eV to 530 eV to intensity (P1) of a first oxygen peak derived from lithium carbonate (Li2CO3) appearing at 530 eV to 532.5 eV is 1 or less. ### Claim 5 (depends on 2) The composite separator of claim 2, wherein a thickness of the coating layer is in a range of about 3 nm to about 100 nm. ### Claim 6 (depends on 1) The composite separator of claim 1, wherein the oxide-based solid electrolyte includes an oxide or phosphate including lithium and two or more types of metals other than lithium, the oxide-based solid electrolyte includes a garnet-type solid electrolyte, a Nasicon-type solid electrolyte, a LISICON-type solid electrolyte, a perovskite-type solid electrolyte, a LiPON-type solid electrolyte, an amorphous solid electrolyte, or a combination thereof, the oxide-based solid electrolyte includes lithium-lanthanum-zirconium-oxide (LLZO), lithium-aluminum-titanium-phosphate (LATP), lithium-lanthanum-titanium-oxide (LLTO), lithium-aluminum-germanium-phosphate (LAGP), or a combination thereof, and a lithium content per mol of the lithium-lanthanum-zirconium-oxide is 6.8 mols or more. ### Claim 7 (depends on 1) The composite separator of claim 1, wherein the oxide-based solid electrolyte includes a garnet-type oxide, the garnet-type oxide includes a cubic phase, and the garnet-type oxide is represented by Formula 1: wherein, in the formulae above, M1 is H, Fe, Ga, Al, B, Be, or a combination thereof, M2 is Ba, Ca, Sr, Y, Bi, Pr, Nd, Ac, Sm, Gd, or a combination thereof, M3 is Al, Ga, Ta, Nb, Hf, Ti, V, Cr, Co, Ni, Cu, Mo, W, Mg, Tc, Ru, Pd, Sc, Cd, In, Sb, Te, Tl, Pt, Si, Ir, Ru, Mn, Sn, or a combination thereof, and 6≤a≤8, 0≤b<2, 2.5≤c≤3.5, 0≤d<0.2, 1.5≤e≤2.5, and 0≤f<1. ### Claim 8 (depends on 2) The composite separator of claim 2, wherein the first polymer includes an ester group-containing polymer, an amide group-containing polymer, or a combination thereof, and the first polymer is a non-fluorinated polymer. ### Claim 9 (depends on 1) The composite separator of claim 1, wherein the first polymer includes an acetate-based polymer, an acrylic-based polymer, a urethane-based polymer, or a combination thereof, and the first polymer includes ethylene-vinyl acetate (EVA), polyvinyl acetate (PVAc), polyurethane (PU), poly(methyl methacrylate) (PMMA), polyethylene terephthalate (PET), or a combination thereof. ### Claim 10 (depends on 1) The composite separator of claim 1, wherein a thermal decomposition temperature during thermogravimetric analysis (TGA) of the first polymer is 300° C. or more. ### Claim 11 (depends on 1) The composite separator of claim 1, wherein the ion-conductive composite film is a free-standing film. ### Claim 12 (depends on 1) The composite separator of claim 1, wherein the first porous substrate includes a porous nonwoven web including the plurality of second polymer fibers aligned in the first direction, the first direction is perpendicular to a thickness direction of the composite separator, and the second polymer fiber includes polyacrylonitrile (PAN), polyimide (PI), polyamide-imide (PAI), or a combination thereof. ### Claim 13 (depends on 1) The composite separator of claim 1, wherein a tensile strength of the first porous substrate in the first direction is 50 MPa or more, and a tensile strength of the composite separator in the first direction is 40 MPa or more. ### Claim 14 (depends on 1) The composite separator of claim 1, further comprising a second porous substrate including a plurality of second polymer fibers aligned in a second direction distinct from the first direction, wherein the second porous substrate is arranged on one surface of the ion-conductive composite film, or the second porous substrate is arranged on one surface of the first porous substrate. ### Claim 15 (depends on 1) The composite separator of claim 1, wherein a thickness ratio (T1/T2) of a thickness (T1) of the first porous substrate to a thickness (T2) of the ion-conductive composite film is greater than 1, a thickness of the ion-conductive composite film is in a range of about 10 μm to about 50 μm, and a thickness of the first porous substrate is in a range of about 20 μm to about 100 μm. ### Claim 16 (depends on 1) The composite separator of claim 1, wherein a porosity of the ion-conductive composite film is less than 30%, and a porosity of the first porous substrate is 30% or more. ### Claim 17 (depends on 1) The composite separator of claim 1, wherein a thermal shrinkage ratio of the composite separator after 30-minute exposure at 180° C. is 3% or less, an ionic conductivity of the composite separator is 0.5 mS/cm or more at 25° C. and 1 atm, and an electrochemical stability voltage window of the composite separator with an oxidation current of 10 μA or less is 4.5 V (vs. Li) or more. ### Claim 18 (depends on 1) A composite electrolyte comprising: the composite separator of claim 1; and an electrolyte arranged in the first porous substrate of the composite separator. ### Claim 19 (depends on 1) A lithium battery comprising: a cathode; an anode; and the composite separator of claim 1 arranged between the cathode and the anode. ### Claim 20 (depends on 19) The lithium battery of claim 19, wherein the anode includes a lithium metal, a lithium alloy, or a combination thereof, and the ion-conductive composite film of the composite separator is arranged adjacent to the anode.