Thermal Shutdown Separators for EV Battery Protection

Battery separator with improved safety and bonding properties compared to existing separators. The separator has a porous substrate coated with a thermally responsive layer containing melting point tunable temperature-sensitive polymer microspheres. At normal operating temperatures, the microspheres do not melt. But at abnormal temperatures, like during overcharge or short circuit, the microspheres melt and seal the separator pores preventing internal shorts. This avoids thermal runaway. The melting temperature tuning allows sealing at lower temperatures than pure polymer layers. The microspheres also improve cold pressing bonding strength between the separator and electrodes.

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Separator for lithium-ion batteries with fire suppression capability to prevent battery cell thermal runaway and propagation. The separator has a microporous layer sandwiched between the electrodes, with fire suppression layers on one or both sides. The fire suppression layers contain a ceramic with interconnected pores filled with a cyclophosphazene compound. The cyclophosphazene quenches and inhibits combustion chain reactions when exposed to high temperatures, preventing thermal runaway propagation in case of battery cell failures.

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Battery separator and secondary battery with improved safety and heat resistance. The separator contains temperature sensitive microspheres that melt and seal the pores at lower temperatures compared to the main separator layers. This prevents internal short circuits at lower temperatures where the main layers haven't fully melted. The microspheres also improve heat resistance by melting and sealing the pores at higher temperatures. This reduces the risk of thermal runaway. The microspheres can be made of materials like polyoxides, polyethylene, polyvinylidene fluoride, ethylene-vinyl acetate copolymers.

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A secondary battery design to improve heat safety and prevent thermal runaway. The battery has a separator between the positive and negative electrodes with a width ratio w where w(width of separator) > width(anode active material) > width(cathode active material). This prevents shrinkage of the separator at high temps from shorting the electrodes. The positive electrode has a ceramic coating close to the tab. The ceramic coating adhesion to the separator (a) is greater than adhesion to the film (c) while the separator adhesion (b) is greater than the ceramic adhesion (d) to the current collector. This balance prevents competitive forces between the separator and film.

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Coating for batteries that improves heat resistance and prevents short circuits. The coating contains negative thermal expansion materials and/or zero thermal expansion materials, like ZrW2O8, HfW2O8, ZrMo2O8, AM2O7 (A=Th, Zr, Hf, Sn, M=P, V), along with ceramic materials and a binder. The coating is applied between the electrodes and separator to prevent fusing, piercing, and short circuits during battery operation. The negative/zero thermal expansion materials expand less than the electrodes or separator during heating, reducing thermal stress and shrinkage. The ceramic materials provide heat resistance. The binder binds the coating to the electrodes/separator.

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Diaphragm for lithium ion batteries with improved thermal stability to prevent short circuiting and explosions at high temperatures. The diaphragm has a base film coated with two ceramic layers. The first layer near the film has spherical ceramic particles with a high melting point additive (>200°C). The second layer farther from the film has flaky ceramic particles with a lower melting point additive (100-135°C). The roughness of the second layer's surface in contact with the first layer is 30-900nm. This two-stage ceramic coating provides better thermal stability compared to single-layer coatings, reducing the risk of short circuiting and explosion at high temperatures.

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Battery separator for high voltage lithium-ion batteries that can operate at 5 volts or higher without degradation. The separator is a microporous membrane with improved oxidation resistance for use in high voltage lithium batteries. It contains a novel polymer, embedded ceramic particles, and ceramic coatings to stabilize the separator at high voltages. The specific compositions and structures allow the separator to function in high energy, high voltage lithium batteries without oxidation issues or trickle charging.

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Battery separator with improved safety and quick charge capability for lithium-ion batteries. The separator has three layers: a ceramic layer, a heat-resistant polymer layer, and a glue layer. The ceramic layer contains microspheres with melting points between 90-130°C that close the separator before thermal runaway. The heat-resistant polymer prevents separator shrinking and breaking at high temperatures. The separator composition and design enables safe high-temperature sealing and prevents internal short circuits. Matching this separator with graphite anodes further improves charge times.

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A heat-resistant battery separator with improved integrity and shutdown capability for lithium-ion batteries. The separator has three layers: two microporous layers sandwiched between a heat-resistant layer. This configuration provides separation and integrity at high temperatures during thermal runaway. The heat-resistant layer can be made of a high melt integrity material like polyaramid, polyimide, or polyamideimide. The microporous layers can have functional groups on their surfaces that increase adhesion to the heat-resistant layer. This prevents curling and delamination during thermal runaway.

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Diaphragm for lithium-ion batteries that improves needling safety and prevents thermal runaway without affecting battery performance. The diaphragm is made by coating a thin layer of a high-temperature resistant polymer like polyimide on one side of the separator. This layer melts and seals the cell when punctured during needle penetration testing, preventing internal short circuits and thermal runaway. The coated separator provides high needling safety while maintaining normal battery operation.

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Integrated preparation method for lithium battery diaphragms and batteries that improves battery safety without sacrificing capacity. The method involves coating a heat-stable material on the base film of the battery separator during diaphragm preparation. This coating provides improved thermal stability compared to the base film alone. The coated separator is then used to assemble the battery. This integrated preparation enables a single-step process to enhance battery safety without adding extra steps or materials. The heat-stable coating prevents separator contraction or fusion during high-temperature conditions, reducing internal short circuits and improving battery safety.

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A separator for lithium-ion batteries that improves thermal management during charging and discharging cycles. The separator has an electrically insulating, porous support material containing an electrically insulating but thermally conductive ceramic filler. The filler is selected from carbides, nitrides, borides, or mixtures thereof. This allows the separator to conduct heat between the electrodes, preventing internal hotspots and improving thermal distribution compared to traditional separators. The coated separator is used in lithium-ion cells to reduce temperature gradients and improve heat dissipation during charging and discharging.

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Ceramic separator for lithium-ion batteries with improved performance and safety compared to conventional separators. The ceramic separator has a diaphragm with ceramic coatings on specific areas. The functional area contacting the electrodes has larger porosity ceramic coatings for ion conduction and electrode isolation. The overhang areas extending beyond the electrodes have smaller porosity ceramic coatings for better thermal stability and shrinkage resistance. This provides optimized separator properties for each region to balance electrochemical performance and safety.

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Low temperature shutdown ceramic separator for lithium batteries that prevents battery failures at low temperatures. The separator has a polymer porous base film coated with PEO and alumina layers. The PEO layer helps the ceramic seal at lower temperatures compared to ceramic alone. This allows the separator to close before violent battery reactions occur, preventing further cell damage. The coated separator improves safety by preventing battery runaway at lower temperatures.

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Battery module design for electric vehicles that prevents cell rupture and thermal runaway propagation in the event of a cell failure. The module has an intermediate space between adjacent cells lined with a silicone-based wrapping material. This absorbs swelling forces and disintegrates into a stable ceramic layer at high temperatures. If a cell fails, it can't breach the module as the wrapping seals the gap and prevents gas or fire escape. The wrapping also provides thermal insulation to contain cell temperature spikes.

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Lithium battery diaphragm with improved safety by preventing thermal runaway and explosions. The diaphragm has a coated separator film with multiple layers to dissipate localized heat. The layers are: 1) a ceramic coating on the base film to prevent shrinking, 2) a first heat-conducting coating on the ceramic surface, and 3) a second heat-conducting coating on the first coating. When a local hotspot occurs inside the battery, the first and second heat-conducting coatings rapidly conduct heat to the battery ends and case, preventing accumulation and mitigating risk of fire or explosion.

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Separator for lithium-ion batteries with improved heat resistance to enable high energy density and capacity lithium-ion batteries used in applications like electric vehicles. The separator has a heat-resistant layer containing inorganic oxide particles with a high heat absorption capacity. This layer prevents ignition during short circuits and thermal runaway. It also has a coating on the oxide particles to prevent side reactions with the electrolyte. The coating has a melting point above 120°C to avoid fusing with the oxide particles. The separator has a standard separator substrate with the heat-resistant layer added.

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Multilayer film for thermal stability and puncture resistance in lithium-ion battery separators. The film has a diaphragm body with ceramic coatings on each side. Non-woven fabric layers are attached to the ceramic coatings. The ceramic coatings are spaced strip shapes with staggered placement. This configuration improves thermal stability and prevents short circuits by reducing shrinking and piercing compared to traditional polymer separators.

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A lithium-ion battery separator with improved thermal resistance for preventing overheating and improving safety. The separator has a thin film made of heat-resistant material, a thin heat-conducting ceramic coating, and a thin thermally fuse layer. The film prevents electrode material diffusion, the coating disperses heat, and the fuse seals micropores to prevent electrolyte leakage if overheating occurs. The thinness of the layers balances thermal performance with battery energy density.

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Lithium-ion battery with improved safety during overcharge. The battery has a separator with a meltable polymer layer coated on one side. When overcharged, the polymer melts and forms a barrier on the cathode surface to prevent short circuiting and thermal runaway. The polymer melting temperature is optimized to match the battery's overcharge conditions. The separator is arranged with the polymer layer facing the cathode. This allows the polymer to prevent thermal runaway if the battery overcharges by melting and forming a barrier on the cathode surface. The polymer layer can also contain inorganic materials for better performance.

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Non-aqueous electrolyte secondary battery with improved short circuit performance to prevent thermal runaway. The battery has a separator with a unique intermediate layer sandwiched between the electrodes. The intermediate layer contains a ceramic filler with specific particle size and porosity. The ceramic filler prevents excessive heat generation during short circuits by absorbing impact energy and reducing current density. The filler also maintains sufficient separator porosity to avoid battery resistance increase. The optimized filler size and porosity balance heat suppression and capacity retention during short circuits.

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A separator for rechargeable electrochemical cells that prevents runaway reactions and fires when the cell overheats. The separator has a conductive layer and a melting layer. The melting layer has a lower melting point than the cell's critical temperature. If the cell overheats, the melting layer softens and contacts the electrodes, gradually discharging the cell without explosive venting. The conductive layer prevents complete short circuits. The separator allows safe shutdown of the cell if overheated, unlike conventional shutdown separators that leave the cell dangerous.

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A separator for lithium batteries like lithium-ion or lithium-sulfur batteries that improves battery life and thermal stability compared to traditional polymer separators. The separator is made of a flexible, electrically insulative, porous, and thermally tolerant ceramic material. It allows ion transport between the battery electrodes while preventing electrical shorting. The ceramic separator has advantages like better thermal stability, mechanical strength, and dimensional stability compared to organic polymer separators. It can withstand higher temperatures without shrinking or melting. This reduces the risk of battery failures due to thermal runaway.

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Electrochemical battery with separators that have different types of porous coatings to improve safety by preventing short circuits and explosions. The separators have layers on their porous substrates that limit thermal compression and prevent contact between the electrodes during overheating. This prevents short circuits. In addition, the coatings on the separators close the pores to stop current flow and slow temperature rise during rapid overheating, preventing battery ignition or explosion.

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A separator for lithium-ion batteries that prevents short circuits between the positive and negative electrodes when the battery overheats. The separator has three layers: a porous base layer, a ceramic layer between the bases, and another porous base layer. The porous layers allow ion transport while the ceramic layer prevents melting and shrinking during overheating. The layers are stacked and extruded in sequence to form the separator.

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Lithium-ion battery with improved safety and cycling performance at high charge voltages. The battery uses a separator with a heat-resistant insulating layer containing oxidation-resistant ceramic particles and a polyolefin layer. The insulating layer is between the polyolefin and positive electrode. This prevents meltdown and short circuits at high charge voltages. The insulating layer contains 80-90% ceramic particles and 10-20% resin. The resin contains aromatic polyamide. The ceramic particles prevent oxidation and melting at high temperatures.

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A secondary battery with improved thermal stability to prevent internal short circuits and fires. The battery has a ceramic coating layer on the electrode surfaces to prevent electrical shorts between the electrodes. The ceramic coating is made of a ceramic powder with specific surface area of 1.5-15 m2/g and particle size distribution with a D10 value above 0.05 microns and D90 value below 3 microns. This ceramic coating prevents electrical shorts between the electrodes and prevents thermal runaway by preventing melting and cracking of the separator.

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A separator for high energy rechargeable lithium batteries that prevents dendrite growth and thermal runaway. The separator has at least one ceramic composite layer and at least one polymeric microporous layer. The ceramic composite layer contains a mixture of inorganic particles and matrix material to block dendrite growth and prevent electrical short circuits. The polymeric microporous layer prevents ion flow between the electrodes during thermal runaway to prevent thermal runaway propagation.

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A separator for lithium-ion batteries that provides improved safety in high temperature environments. The separator has a unique structure with two layers. The first layer is a microporous film made of a thermoplastic resin. The second layer contains a filler with a melting point of 150°C or higher, like mica flakes. The filler helps the separator shut down and prevent short circuits when the battery overheats. The filler also prevents shrinkage and distortion of the separator at high temperatures.

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Separator for lithium-ion batteries that improves safety and prevents internal short circuits during thermal runaway. The separator has a porous matrix made of filler grains containing boehmite with a diameter above 0.1 microns. This matrix is integrated with a heat-resistant adhesive. The separator also contains a fusing point resin with a range of 80-130°C. The matrix expands with electrolyte absorption and the resin dilates with temperature rise. This prevents emptying apertures from closing as the battery heats up. The separator's porous structure, heat resistance, and expansion properties improve thermal runaway safety by preventing internal short circuits.

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Separator for lithium-ion batteries with improved safety and cycling performance at high charge voltages. The separator has a heat-resistant insulating layer containing oxidation-resistant ceramic particles on one or both sides of a polyolefin layer. The insulating layer prevents short circuits and suppresses deterioration during overcharge or overheating. The ceramic particles improve thermal stability. By using this separator, batteries can operate at higher charge voltages without degradation, enabling higher energy densities.

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Lithium secondary battery with improved thermal endurance and short circuit safety. The battery uses a separator made of a perforated membrane composite with ceramic particles and a crosslinked acrylic rubber binder. The composite separator provides high porosity and thermal stability compared to film separators. The ceramic particles prevent shrinking and melting at high temperatures. The crosslinked rubber binds the ceramic and prevents swelling in electrolyte. This composite separator improves thermal endurance and short circuit safety compared to film separators.

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Secondary battery with improved thermal stability at high temperatures. The battery has a separator between the electrodes made of a ceramic separator material. The ceramic filler used in the separator has a heat absorbing property, like barium titanate. This allows the separator to rapidly absorb heat generated during battery abnormalities, improving thermal stability compared to separators with non-absorbing fillers.

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Electrochemical element separator that is inexpensive, has good dimensional stability at high temperatures, and enables safe operation of electrochemical elements like lithium batteries at elevated temperatures. The separator contains a porous base material, heat-resistant filler particles, a melting point resin, and a swellable resin. The melting point resin shuts down the separator pores when the battery temperature reaches its melting point. The swellable resin absorbs electrolyte and expands when heated, blocking pores and reducing electrolyte flow. This provides shutdown capability at high temperatures to prevent internal short circuits and thermal runaway.

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A lithium ion battery separator design to prevent explosions due to thermal runaway. The separator has a microporous polyethylene film with conductive material and heat conductive material coated on one side. This film is used in place of the standard separator between the positive and negative electrodes of the battery. The conductive and heat conductive layers allow heat and ions to transfer away from localized hotspots, preventing excessive heating that can lead to explosions. The polyethylene film has a melting point lower than lithium to prevent electrode contact and further heating.

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Battery separator that balances improved short-circuit resistance with load characteristics in non-aqueous electrolyte batteries like lithium-ion. The separator contains fibrous material that does not deform at high temperatures and a porous film with inorganic particles that don't deform at high temps. The fibrous material provides strength and prevents short circuits. The inorganic particles provide shutdown functionality to prevent runaway. The separator composition balances short circuit prevention with shutdown capability by using fibrous material and inorganic particles that don't deform at high temps.

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Electrochemical element separator that provides improved safety in high temperature environments by shutting down electrochemical reactions when the battery overheats. The separator contains filler particles with melting point resin and swellable resin. At low temperatures, the filler particles provide mechanical strength. But when the battery overheats and the filler melts, the swellable resin absorbs electrolyte and swells, blocking pores and shutting down the reaction.

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A separator for lithium-ion batteries that improves safety by preventing internal short circuits and external overheating. The separator has a highly heat-resistant porous layer integrated with a nonwoven fabric and a shutdown layer. The heat-resistant porous layer prevents expansion of short circuits as it doesn't shrink when heated. The shutdown layer stops ion flow and raises resistance if the battery gets too hot. The separator structure allows high capacity, high output batteries to operate safely at high temperatures.

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Lithium secondary battery separator with improved safety and cycle life for high capacity batteries. The separator has a microporous polymer film with shutdown function sandwiched between two heat-resistant porous layers, one with ceramic filler and the other with heat-resistant polymer and ceramic filler. This prevents shrinkage and expansion of the separator during internal short circuits, preventing electrode contact and improving safety compared to just a heat-resistant layer. The integrated heat-resistant layers also provide mechanical support to suppress separator shrinkage.

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Secondary battery with improved safety by adding a layer containing an endothermic inorganic material on the surface of the electrode in contact with the separator and/or the separator surface. This layer absorbs heat and prevents rapid temperature rise and ignition when the battery is impacted or overcharged. It allows the battery to dissipate energy without exploding. The layer contains materials that absorb heat when they undergo endothermic reactions, preventing rapid heating of the battery during abuse conditions.

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Battery design to prevent short circuits during extreme temperature events without sacrificing shutdown functionality. The battery has a separator made of a low melting point material (90-160°C) between the electrodes. Additionally, a high temperature resistant porous insulating layer is added between the separator and one of the electrodes. This provides two benefits: 1) The low melting point separator has shutdown functionality if the battery overheats and the separator melts. 2) The high temperature insulating layer prevents short circuits if the separator melts and flows, as it provides an additional barrier between the electrodes.

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Electric separator for lithium batteries with shutdown mechanism to prevent internal short circuits and explosions. The separator has a porous ceramic layer with a closing layer on top made of a material with lower melting point than the ceramic. This closing layer seals the pores in the ceramic and prevents ion flow if the battery overheats. The lower melting point material fuses before the ceramic and prevents complete fusion and short circuiting. The porous ceramic layer provides electrical insulation and mechanical strength.

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Lithium-ion battery with improved internal short circuit prevention and current interruption capability by using a unique separator. The separator is a porous film made by binding sintered or recrystallized ceramic particles with a binder. This porous separator layer is formed directly on the electrode surface instead of using a separate separator. The porous separator allows ionic conduction while preventing electrode contact. The ceramic particles have a bandgap that stops ionic conductivity at high temperatures. The porous structure prevents short circuits by preventing lithium plating and allows current interruption. The binder keeps the separator shape stable during battery cycling.

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Separator for lithium batteries with a shutdown mechanism to prevent runaway cell reactions. The separator has a thin inorganic coating on a porous substrate. Melting particles called shutdown particles are added to the coating. At elevated temperatures, the shutdown particles melt and fill the coating pores, shorting the cell. This prevents further overheating. The coating is made by applying a suspension of particles on a carrier, followed by solidification. An adhesion promoter can be added to the suspension to improve particle adhesion. The shutdown particles can be inorganic oxides or organic polymers. The coating thickness is <30 microns.

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Separator for lithium batteries that prevents short circuiting and overheating during abuse conditions like external shorts. The separator has a ceramic sheet with micropores for electrolyte impregnation. It also has a thin layer of polyolefin on the ceramic. When the battery overheats, the polyolefin melts and clogs the ceramic pores, stopping electrode contact. This prevents further heating and possible explosion. The ceramic prevents complete separator meltdown unlike conventional polymer separators.

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Non-aqueous electrolyte battery separator containing a heat-resistant nitrogen-containing aromatic polymer and ceramic powder to improve safety and performance of lithium-ion batteries. The separator has a heat-resistant polymer that melts below 260°C and ceramic powder dispersed in it. This provides high short-circuit temperature and prevents melting even at high temps. The separator can be made by coating a substrate with a slurry of the polymer, ceramic, and a thermoplastic binder that melts at low temps.

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