Thermal Runaway Barriers for EV Battery

Process for preparing geopolymer or geopolymer composite without curing, drying, and milling steps. The geopolymer formation is modified by adding water-soluble compounds like phosphoric acid or ammonium polyphosphate during steps f and g. This encapsulates additives like coke, anthracite, graphene oxide, metal oxides, sulfides, or magnesium compounds into the geopolymer matrix. The modified geopolymer or composite has enhanced self-extinguishing properties and reduced thermal conductivity compared to unmodified geopolymer.

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Battery pack assembly for electric vehicles that improves safety during cell thermal runaway. The pack has a frame with integrated channels for exhausting fumes. The channels are integrated into the frame instead of a separate tray. This allows fumes to escape when cells vent during thermal runaway, preventing them from spreading to other cells. It also isolates the fumes from the pack housing. The channels are parallel and vertically connected to the exhaust channels on the frame. The channels are inverted so the cell terminals face the cold plate instead of the pack housing. This prevents fumes from entering the pack housing. The frame structure and channels isolate and evacuate fumes during thermal runaway, reducing the risk of chain reaction in the pack.

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Battery module design to improve safety against thermal events in battery packs for vehicles. The module has a stack of battery cells surrounded by a case. Each cell has an interrupt member covering part of the cell to prevent thermal propagation if a cell overheats. The interrupt member blocks spread of flames and gases to adjacent cells. It also guides vented materials out of the module to prevent internal fire spread. This mitigates chain reactions and explosions in multicell modules.

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Polymeric composite materials with improved insulation properties while maintaining textural properties. The composite contains a continuous polymer matrix with dispersed aerogel particles. The aerogel particles are organic polymer-based aerogels like polyimide aerogels. Adding the aerogel particles to the composite delays the peak exotherm during curing, increases the deflection temperature, and lowers the composite's thermal conductivity and dielectric constant compared to the unfilled composite. The composite can have applications in insulation for electronics, pipes, buildings, etc.

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Battery pack design to prevent overheating, thermal runaway, and ignition in battery packs for vehicles. The pack has a heat dissipation structure between the batteries and lid that helps dissipate heat generated by the batteries. The structure has contact points on the batteries and lid that maintain a gap. This allows gases to vent between the batteries and lid, preventing accumulation and potential ignition. The heat dissipation structure also has connections between the contact points to maintain the gap. The structure is made of a material with higher thermal conductivity than the lid to efficiently transfer heat. This prevents overheating, suppresses chain thermal runaway between batteries, and improves safety of the battery pack.

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Composite material, composite material layer, and thermal barrier composite for high temperature applications like battery packs. The composite has a silicone matrix, reinforcing filler, and a ceramization filler composition. The ceramization filler contains components that promote ceramization, a flux to aid sintering, and a flame retardant. This enables the composite to form a dense ceramic barrier at high temperatures, improving thermal barrier performance compared to traditional silicone-based materials.

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A flame-resistant, compressible, and heat insulating foam material for lithium-ion battery spacers. The foam contains 35-95% organopolysiloxane, 1-30% fire retardant, and 1-35% hollow ceramic particles with 25-300 μm size. The foam has density 0.10-0.90 g/cm3. The foam provides compressibility, insulation, and flame resistance for battery modules to prevent thermal runaway propagation. The foam can be applied between cells and/or fill spaces between cells and end plates.

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Nonaqueous electrolyte secondary battery design to enhance safety against fire spread in battery modules. The battery has an electrode group with a first electrode wound further outside than the second electrode. The first electrode has an excess portion wound around its outer surface without the separator or second electrode interposed. This exposed portion of the first electrode current collector helps prevent cracking of the battery case and allows gas to vent through the safety valve instead of through cracks. The separator interposed between the electrodes during winding can hinder gas flow and increase cracking.

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Separator for rechargeable lithium batteries that reduces the risk of explosion when the battery overheats by capturing and trapping generated gases. The separator has a coating of metal organic framework (MOF) materials like ZIF-8, Fe-BTC, or a combination thereof on the surfaces. These MOFs have pores that adsorb gases like oxygen and hydrogen generated during battery failure to prevent explosive pressure buildup.

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Battery pack design to mitigate fire risk from volatile electrolyte leakage. The pack enclosure contains absorbent material that traps flammable electrolyte vapor if it leaks from the cells. This prevents the vapor from accumulating and potentially igniting. The absorbent material inside the pack catches any leaked volatile electrolyte components before they can build up and pose a fire hazard.

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Battery Disconnect Unit (BDU) device for battery packs that improves heat dissipation and reliability compared to conventional designs. The BDU has a heat conductive plate that thermally couples the internal heating elements to an external surface. This allows heat to be dissipated through the plate instead of just through the housing. A gap between the BDU housing and the battery pack prevents contact that could deform the housing. The heat conductive plate is compressible to improve stability during installation and contact with the pack.

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Container design to prevent propagation of thermal runaway between electrochemical cells or batteries inside. The container has a molded body and cover made of a high thermal conductivity material. The body has vertical receptacles for the cells and internal walls separating them laterally. The cover has passages above the receptacles for cell portions to protrude. A vent allows gases to escape. Seals between receptacles and headspace are breakable and selectively permeable to prevent matter transfer. This prevents thermal runaway and material spread between cells.

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A secondary battery pack for electric vehicles that improves thermal management to prevent runaway cell temperatures and propagation of thermal events. The pack uses a syntactic foam made of hollow glass beads in a silicone binder to insulate the battery cells. This foam provides better low-temperature insulation compared to standard foams. It also minimizes thermal propagation between cells. The pack can have coolant channels and heat dissipation members to further manage cell temperatures. The syntactic foam also helps dampen drivetrain oscillations.

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Coating battery electrodes with protective thin films to improve safety and thermal stability. The films are formed by a liquid-phase deposition method that involves exposing the electrodes to reacting solutions containing reagents that bond to the electrode surface. The films provide a protective coating that reduces the propensity for batteries to undergo thermal runaway. The films are grown using a conveyance system that transfers the electrodes between reaction chambers for each reactant exposure.

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A traction battery pack assembly with compartmentalized battery arrays and an exhaust system to manage thermal runaway. The battery pack has multiple compartments, each containing a battery array. An intake manifold delivers air to the compartments, and exhaust manifolds remove air. This allows selective heating or cooling of arrays based on conditions. The exhaust system with multiple manifolds prevents hot gases from one array affecting others during venting events.

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Integrated thermal barrier systems for electric vehicle battery packs to mitigate the effects of battery thermal events. The systems include components with foam and endothermic aerogel that can be placed between the battery cells, over sensitive components, or between the cells and bus bars. These components provide a thermal barrier to contain and suppress thermal runaway propagation within the battery pack in the event of a cell failure. The foam and aerogel materials have properties like intumescence and endothermic reaction to absorb and dissipate heat during a thermal event to prevent spread.

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Thermal insulation layer for batteries that prevents excessive heat buildup during thermal runaway to prevent cover damage and fires. The layer has a high lateral thermal conductivity and low axial thermal conductivity, allowing fast heat dissipation in one direction while blocking heat transfer in the other. This prevents heat from reaching high temperatures on the backside that could damage the cover. The insulation layer is applied to the battery pack to protect against cover damage during thermal runaway when the pack's energy density is high enough to generate extreme temperatures. The insulation thickness varies with cell energy density to maintain backside temperatures below 1200°C. The layer has a first surface facing the battery pack and a second surface away from the pack. The insulation material has lower thermal conductivity in the direction parallel to the pack surface (axial) vs. perpendicular to the pack surface (lateral).

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Thermal shock composite material for battery packs that can block solid flames and heat during battery thermal runaway to improve safety. The composite has three layers: a thermal shock resistant composite layer, an expandable insulation layer, and a support layer. The layers are sequentially applied and cured to form a composite with a three-layer structure. The thermal shock resistant composite layer absorbs flame heat and transfers it to the support layer. The expandable insulation layer expands when heated but is supported by the composite layers to prevent collapse. This prevents flame penetration through the composite. The layers prevent heat transfer from the gap to the far end.

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Battery pack design with thermal barriers and exhaust systems to mitigate inter-cell heat spread during battery thermal events like overcharge or short circuit. The design incorporates expandable heat-absorbing airgel sheets integrated into the cell stack and partition assemblies between cell groups. These airgel sheets expand and absorb heat to limit cell-to-cell propagation when temperatures exceed thresholds. The barriers prevent heat spread between cells, while the exhaust systems vent gases and effluents during thermal events to contain the damage.

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