# US 11,909,006 B2 · Thin battery separators and methods > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,909,006 B2 - Document ID: US11909006B2 - Status: Granted - Kind: B2 - Application number: 18/113,640 - Filed: 2023-02-24 - Published: 2023-06-29 - Granted: 2024-02-20 - Earliest claimed: 2012-09-20 - Assignees: Celgard, LLC - Applicants: Celgard, LLC - Inventors: Paul M. Halmo; Xiaomin Zhang; Paul D. Vido; Zhengming Zhang; Lie Shi; Daniel R. Alexander; Jill V. Watson - Web page: https://patentgrep.com/patent/US11909006B2 ## CPC - H01M 10/4235: {Safety or regulating additives or arrangements in electrodes, separators or electrolyte (H01M10/4242 takes precedence)} - H01M 10/0525: Rocking-chair batteries, i.e. batteries with lithium insertion or intercalation in both electrodes; Lithium-ion batteries - H01M 50/403: Manufacturing processes of separators, membranes or diaphragms - H01M 50/409: Separators, membranes or diaphragms characterised by the material - H01M 50/411: Organic material - H01M 50/417: Polyolefins - H01M 50/426: Fluorocarbon polymers - H01M 50/449: having a layered structure - H01M 50/451: comprising layers of only organic material and layers containing inorganic material - H01M 50/457: comprising three or more layers - H01M 50/491: Porosity - Y02E 60/10: Energy storage using batteries - Y02E 60/50: Fuel cells - 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 In accordance with at least selected aspects, objects or embodiments, optimized, novel or improved membranes, battery separators, batteries, and/or systems and/or related methods of manufacture, use and/or optimization are provided. In accordance with at least selected embodiments, the present invention is related to novel or improved battery separators that prevent dendrite growth, prevent internal shorts due to dendrite growth, or both, batteries incorporating such separators, systems incorporating such batteries, and/or related methods of manufacture, use and/or optimization thereof. In accordance with at least certain embodiments, the present invention is related to novel or improved ultra thin or super thin membranes or battery separators, and/or lithium primary batteries, cells or packs incorporating such separators, and/or systems incorporating such batteries, cells or packs. In accordance with at least particular certain embodiments, the present invention is related to shutdown membranes or battery separators, and/or lithium primary batteries, cells or packs incorporating such separators, and/or systems incorporating such batteries, cells or packs. ## Claims ### Claim 1 A multilayer battery separator for a lithium secondary battery that comprises a microporous membrane comprising: at least three coextruded dry-stretch process polypropylene (PP) layers that each has a thickness of less than or equal to 4 microns; and wherein the microporous membrane has a thickness in the range of 2 to 12 microns and has a ceramic coating or a polymer coating on at least one side thereof; and wherein one PP layer of the at least three coextruded dry-stretch process PP layers is of a different PP material. ### Claim 2 (depends on 1) The separator of claim 1, wherein the microporous membrane has a thickness from 2 to 10 microns. ### Claim 3 (depends on 1) The separator of claim 1, wherein the microporous membrane has a thickness in the range of 3 to 9 microns. ### Claim 4 (depends on 1) The separator of claim 1, wherein the microporous membrane has a thickness in the range from 8 to 12 microns. ### Claim 5 (depends on 1) The separator of claim 1, wherein the microporous membrane has a thickness from 6 to 9 microns. ### Claim 6 (depends on 1) The separator of claim 1, wherein the microporous membrane has a thickness in the range of 6 to 8 microns. ### Claim 7 (depends on 1) The separator of claim 1, wherein at least one layer of the microporous membrane is less than 4 microns thick. ### Claim 8 (depends on 1) The separator of claim 1 having a ceramic coating on at least one side thereof. ### Claim 9 (depends on 1) The separator of claim 1 having a ceramic coating on both sides thereof. ### Claim 10 (depends on 1) The separator of claim 1 having a PVDF coating on at least one side thereof. ### Claim 11 (depends on 1) The separator of claim 1 having a PVDF:HFP coating on at least one side thereof. ### Claim 12 (depends on 1) The separator of claim 1, wherein the separator has a thickness less than 20 microns. ### Claim 13 (depends on 12) The separator of claim 12, wherein the thickness is less than 16 microns. ### Claim 14 (depends on 12) The separator of claim 12, wherein the thickness is less than 14 microns. ### Claim 15 (depends on 1) A battery comprising the separator of claim 1. ### Claim 16 (depends on 1) The separator of claim 1 having a trilayer construction of PP1/PP2/PP. ### Claim 17 (depends on 1) The separator of claim 1 having a trilayer construction of at least one of the following: each of the layers being about 1 μm to 4 μm thick, each of the layers being about 1 μm to 3 μm thick, or each of the layers being about 1 μm to 2 μm thick. ### Claim 18 (depends on 1) The separator of claim 1 wherein the separator has a puncture strength of at least 112 g. ### Claim 19 A multilayer battery separator for a lithium secondary battery that comprises a microporous membrane comprising: at least three coextruded dry-stretch process polypropylene (PP) layers that each has a thickness of less than or equal to 4 microns; and wherein the microporous membrane has a thickness in the range of 2 to 12 microns and has a puncture strength of at least 112 g; and wherein one PP layer of the at least three coextruded dry-stretch process PP layers is of a different PP material. ### Claim 20 (depends on 19) The separator of claim 19 wherein the separator has a ceramic coating or a polymer coating on at least one side thereof. ### Claim 21 (depends on 20) The separator of claim 20 wherein the coating is a ceramic coating, a PVDF coating, or a PVDF:HFP coating.