Coating Techniques to Prevent Thermal Runaway in EV Batteries

A secondary battery pack for electric vehicles that improves thermal management to prevent thermal runaway and propagation between cells. The pack uses a syntactic foam insulation made of hollow glass beads in a silicone binder. This foam provides thermal insulation and minimizes temperature differences between cells. It also has low water absorption to prevent swelling in wet conditions. The pack also has thermal barriers and spacers to isolate cells and prevent thermal propagation. The spacers maintain cell position during thermal events. The pack may also have coolant channels to dissipate heat. This comprehensive thermal management strategy mitigates cell-to-cell thermal effects and risks.

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A secondary battery pack with improved thermal management to prevent propagation of thermal runaway between cells and minimize the effects of extreme temperatures. The pack uses a specific syntactic foam made of silicone rubber binder and hollow glass beads. This foam is sandwiched between the battery cells to insulate them from each other and the pack enclosure. It also absorbs thermal energy to reduce temperature spikes. The foam has low water absorption to prevent swelling in wet conditions. The pack may also have thermal management features like cooling channels, heat sinks, and spacers to further isolate cells and dissipate heat.

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Reducing thermal energy transfer between battery arrays of a battery pack to prevent venting during high temperature events. The technique involves using a phase change material (PCM) sandwiched between adjacent battery arrays and a thermal exchange device like a liquid coolant channel. The PCM absorbs excess heat from one array to prevent it transferring to the other array. This prevents one array overheating and venting due to thermal runaway, as the PCM acts as a thermal barrier. The PCM can be adhesively secured to the thermal exchange device.

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Power supply device for batteries that reduces thermal propagation (fire spread) between cells and allows adaptability to swelling. The device uses separators made of flexible, heat insulating materials with restoring force. The separators deform when pressed by cells but recover shape to prevent thermal runaway spread. They have mesh structures or coatings to allow air pockets for insulation. This prevents fire propagation between cells while accommodating cell swelling.

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Cure-in-place, lightweight, thermally conductive interface between a thermal energy source like a battery and adjacent structures to prevent thermal runaway propagation. The interface has a thermally conductive foam pad with filler material like graphite or boron nitride. The foam pad is disposed between the battery and adjacent components like other batteries. It absorbs and conducts heat from the battery to prevent neighboring batteries from overheating if one enters thermal runaway. The foam pad density is below 0.5 g/cm3 for lightweight contact with the batteries.

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Temperature management system for lithium-ion battery modules used in hybrid vehicles that prevents short circuits and cell damage when the heat conducting element separates from the heat exchanger or cells. A reinforcement layer with higher stiffness than the heat exchanger is sandwiched between the heat conducting element and heat exchanger. This prevents contact loss between the heat conducting element and exchanger/cells during vibrations, shocks, and temperature cycling. The reinforcement layer's higher modulus of elasticity compared to the heat exchanger prevents separation and maintains thermal conductivity between the heat conducting element and heat exchanger/cells.

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Electrical energy storage device with improved thermal management between adjacent cells to prevent overheating and aging issues. The device has compressible, flexible, heat-conducting layers sandwiched between cell interfaces. These layers abut the cell interfaces under pressure. Heat-conducting devices in the layers transfer thermal energy from charging/discharging cells to dissipate heat from the cell interfaces. This prevents hotspots and uniformly manages cell temperatures.

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Electrode, separator, and battery designs with improved thermal stability and safety in lithium-ion batteries. The electrode design involves coating the electrode surface with an organic/inorganic composite separator layer that contains heat-absorbing inorganic particles like antimony compounds, metal hydroxides, guanidine compounds, boron compounds, or zinc tartrate. These particles absorb or consume heat generated inside the battery to prevent overheating and combustion. The separator can also be made by coating the heat-absorbing particles onto a substrate. The composite separator/coating layer improves battery safety by preventing short circuits and suppressing thermal runaway.

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Battery enclosure for automotive applications that improves battery thermal stability, safety, and longevity using multi-layer construction with thermal insulation, airflow management, and active cooling. The enclosure has a shaped outer case with an aperture and separable lid. The inner case and lid provide insulation with thickness less than 5 cm. Spacer pads between the inner and outer cases direct airflow. An air inlet draws outside air into the enclosure, and an outlet exhausts warmer air. Thermoelectric pads, cooling coils, or aerogel insulation regulate battery temperature. The multi-layer design prevents heat buildup, isolates the battery, and allows controlled airflow to cool the battery.

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Secondary battery pack for electric vehicles with improved thermal management and low temperature insulation. The pack contains the battery cells, surrounded by a syntactic foam made of hollow glass microspheres bonded with a silicone rubber. This foam provides thermal insulation and suppresses propagation of thermal excursions between cells. It also helps prevent damage at low temperatures. The foam is formed by mixing the microspheres, silicone rubber, and curing agent, then foaming and curing the mixture. The foam density can be adjusted by varying the glass sphere size and silicone rubber content.

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Containing thermal runaway and fires in lithium battery cells to prevent spread and damage. The method involves compartmentalizing battery cells into smaller isolated sections to contain a localized fire within that section. The compartments can be inside a larger container made of materials like cardboard, fiberglass, or aluminum that is coated with an intumescent fire retardant. This coating expands when heated to insulate and contain the fire. The compartments themselves can also be coated or made of fire-resistant materials.

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A thermal insulation material for preventing cascading thermal runaway in electrical energy storage devices like batteries. The insulation contains a ceramic matrix with an inorganic endothermic material that absorbs heat and generates non-flammable gases at temperatures above normal operating levels but below runaway temperatures. This slows heat transfer, absorbs energy, vents gases, and dilutes toxic fumes to prevent runaway chain reactions. The insulation structure can be shaped using methods like dry pressing, infiltration, vacuum forming, or molding to optimize gas generation and distribution.

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Lithium ion battery cells with improved performance, safety, and longevity for electric vehicles. The battery cells have a core wrapped in a rectangular shell with gaskets to prevent contact between the core and end caps. This prevents short circuits. The core can have coiled electrode layers for high power density. The electrode materials are mixed crystal lithium iron phosphate with additional metal oxides for better cycling. The gaskets compress the core away from the caps to prevent internal hotspots. The rectangular shape reduces stress concentrations compared to cylindrical cells. The improved cell design prevents failures like internal shorts, hotspots, and thermal runaway.

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A busbar for electrically connecting cells in a battery module that breaks apart at high temperatures to prevent current and heat transfer between cells in case of a thermal runaway. The busbar has an inner core made of a material with a higher coefficient of thermal expansion than the outer shell. When the core expands due to heat, it breaks the shell connection, disconnecting the cells. The shell is electrically conductive while the core can be insulating.

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Electrode, separator, and battery design for lithium-ion batteries that improve thermal stability and safety. The electrode has a porous coating layer made of heat-absorbing inorganic particles and a binder. The separator can contain heat-absorbing particles as well. These components absorb or consume heat generated inside the battery during charging and discharging, preventing runaway reactions and thermal runaway. The heat-absorbing particles also reduce the risk of ignition and explosion if an internal short circuit occurs. The coating layer and separator designs provide thermal management and short circuit protection without adding mass or thickness.

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Electrode and separator design for lithium-ion batteries that improves safety and thermal stability. The electrode has a porous coating layer containing heat-absorbing inorganic particles like antimony compounds, metal hydroxides, boron compounds, or zinc tartrate. These particles absorb or consume heat when the battery overheats, preventing runaway reactions. The separator can also contain heat-absorbing particles to prevent internal shorts. The porous coating and separator layers provide a path for ions while absorbing/consuming heat.

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Lithium ion capacitor with enhanced safety by using a separator that melts and shorts the electrodes at high temperatures to prevent rupture and ignition. The separator is made of a polyolefin like polyethylene with specific thickness and pore size distribution. It melts and short circuits the capacitor before the outer casing opens due to vapor pressure at very high temperatures. This prevents rupturing and igniting when high energy density and output are promoted.

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Barrier apparatus between battery modules in electric vehicles to prevent thermal runaway propagation between modules. The barrier has two layers: a thermally insulating layer and an intumescent layer on top. The insulating layer prevents heat transfer between modules, and the intumescent layer expands and seals gaps during thermal events to contain failures.

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Electric vehicle power source module design to improve safety and thermal management. The module uses a potting material between the cells and a cooling plate. Spacers surround the cell vents to prevent potting intrusion. The potting material joins the cells and plate into a solid unit. The spacers also create expansion areas around the vents. This allows vented pressure to escape through the spacers and cooling plate holes instead of intruding into the potting. The potting provides thermal conduction between cells and plate, joins them, and prevents contact.

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A thermal insulation and/or electrical insulation and fire protection material for electrochemical battery cells, modules and packs. The material is an inorganic platelet composition that is applied to battery cell surfaces, interstitial spaces between cells, and battery module/pack housings to prevent thermal runaway propagation and electrical short circuits. It isolates cells to stop thermal runaway from spreading, insulates cells to prevent shorts, and contains fires. The inorganic platelet composition can be coated, impregnated, or wrapped onto support layers like films, felts, or papers.

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