Passive Cooling Techniques for EV Batteries

Passive thermal management system for cooling electrical components like battery modules in UAVs without active cooling systems. The system uses a movable chamber filled with sublimable coolant like dry ice. A smart material actuator thermally attaches the chamber to the component housing. As the component heats up, the actuator expands and pulls the chamber into contact with the component to extract heat. The sublimable coolant absorbs the heat and changes state from solid to gas. This passive cooling method leverages smart materials and phase change coolants to extract heat from components without complex active cooling systems.

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Battery module housing design with fins and channels to improve thermal management and dissipation of internal heat. The housing has a grid of fins extending from the walls. The fins absorb heat from the battery cells and dissipate it to air. The fins have channels between them to facilitate airflow. This allows natural convection cooling to distribute the heat more evenly. A heat sink can also be used to absorb heat from the fins and further enhance dissipation.

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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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Battery assembly and power supply apparatus with improved thermal management and safety features. The battery assembly has a distributed heat sink made of interconnects between the batteries. This allows equalizing battery temperatures and preventing hot spots. The heat sink is integrated into the battery pack design. The pack also has a thermal exchange device with surfaces for heat exchange and a contact surface in thermal contact with the interconnects. This allows transferring battery terminal heat to the heat sink. This aids cooling and prevents terminal overheating. The pack has battery management circuitry and a housing with a discharge chamber to contain thermal runaway. The housing has insulated upper walls to prevent air exchange and improve temperature sensing accuracy.

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Thermal management system for battery packs, particularly electric vehicle battery packs, that provides improved cooling and heat distribution compared to existing systems. The system uses a framework with encapsulated graphite plates sandwiched between battery pouches. The plates extend between adjacent pouches to form a network of thermal paths. Working fluid flows through channels in the framework and plates to extract heat from the batteries. This allows uniform cooling across the pack and prevents hotspots. The plates also spread the heat across the pouch surface for more even temperature distribution.

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Supporting housing for battery compartments of electric vehicles that uses flat metal sheets for cost-effective mass production, while integrating passive thermal management and other functions. The housing consists of deep-drawn shells that fit together to form a double-floor compartment. The batteries sit on the double-floor separated from the thermal management system. Coolant channels in the outer shell indirectly cool/heat the compartment. Sensors can be integrated into the double-floor for battery status monitoring. The double-floor design isolates the batteries from the cooling system to prevent short circuits. The thin metal sheets have high thermal conductivity for efficient heat transfer.

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Thermal management system for fuel cell vehicles with improved cold-start performance, longer coolant temperature rise time, simplified coolant loop, and reduced valve count compared to conventional systems. The system uses a phase change material (PCM) to store and release heat during cold starts. A coolant pump, stack, heater, PCM, and radiator are connected in loops. The PCM is heat-exchanged with the heater. During cold starts, the heater is used to warm the PCM. When PCM temperature reaches a phase change point, coolant circulates through the PCM loop. For high stack loads, the second loop is used. This allows longer coolant temperature rise time and simplified loop vs conventional systems.

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Battery module for uniform cooling of multiple secondary battery cells while preventing overcooling of adjacent cells. The module has a housing with secondary battery cells, a cooling plate, and a heat conductive member between the cells and plate to transfer heat. The heat conductive member has a central portion with high thermal conductivity and an edge portion with lower conductivity. This gradual conductivity decrease near the module edges prevents supercooling of adjacent cells when one is exposed to external air. The lower conductivity edge portion can have lower metal content in the resin, or pores, compared to the central portion.

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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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Battery system for electric aircraft that prevents thermal runaway propagation between modules to avoid total system failure. The system uses thermal barriers that transition to a lower conductivity state when cells exceed a certain temperature. This reduces heat transfer from compromised cells to the shared cooling structure, preventing thermal runaway spread. The barriers transition from a high initial thermal conductivity state to a lower state when cell temperatures exceed a threshold. This prevents thermal runaway propagation between modules by limiting heat transfer from overheated cells. The shared cooling structure is thermally coupled to all modules to dissipate cell heat.

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Battery pack for electric/hybrid vehicles that has an integrated cooling/heating system to maintain optimal operating temperature for the cells. The battery pack uses a stack of thermally conductive heat sink plates sandwiched between inner and outer frames. The plates have fins with different configurations to transfer heat to/from the cells. Rods connect the plates to form the battery pack. The frames retain the cells mechanically and can be disengaged for service. This provides efficient thermal management to prevent performance degradation due to temperature variations between cells.

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Battery design to mitigate thermal runaway and internal shorting during mechanical abuse. The technique involves adding materials and configuring components in the battery to increase impedance and prevent thermal runaway before it can occur. Damage initiators like passive particles, fibers, or coatings in electrodes deform and fracture during impact to cause widespread damage. Active additives like chemicals, foams, or elastic materials release, absorb, or displace during loading to increase impedance. Shape changes in separator or case promote bending, shear, or debonding in electrodes. By intentionally weakening and deforming parts, damage propagation is promoted to mitigate thermal runaway before it starts.

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Cooling system for electric vehicle charging ports to prevent high pin temperatures during fast charging. The cooling is achieved without complex liquid cooling loops. The charging pins are surrounded by porous metallic cages filled with phase change material. A vapor chamber is between the base of the pins and the cages. The phase change material absorbs heat from the pins during charging, preventing high temperatures, while the vapor chamber further dissipates heat. This simplified cooling method avoids the need for complicated liquid cooling loops.

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Thermal energy storage system for capturing and storing variable renewable energy (VRE) like solar or wind power, and providing continuous heat output for industrial processes and power generation. The system uses a storage medium like solid blocks that can absorb and release heat. It charges by radiatively heating the blocks from the inside with electrical resistance heaters, and discharges by convectively cooling the blocks with air. The system provides uniform temperature delivery through structured media layout and controls. This allows efficient storage of VRE, prevents thermal runaway, and enables reliable, flexible, and scalable thermal energy storage for VRE integration.

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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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Battery assembly for electric aircraft that prevents thermal runaway propagation and mitigates fire risk. The battery has angled sides to contain the cells, insulation sleeves, and cooling plates between rows. The cooling plates facing the insulation are coated in flame retardant paint to prevent thermal runaway in one cell from spreading to adjacent cells. This helps contain any cell failures and prevent cascading failures.

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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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Heat management system for removing heat from electric vehicle batteries using a vapor chamber and phase change material (PCM) to improve cooling efficiency. The system has a vapor chamber with an evaporator surface on the battery cell and a condenser surface. The vapor chamber contains a working fluid that absorbs battery heat and condenses on the PCM-filled shell. The PCM has a lower melting temperature than the working fluid's boiling point, allowing the PCM to reject heat to the air. This prevents reverse heat transfer from the condenser to the evaporator. The PCM provides additional heat storage capacity compared to the vapor chamber alone. The combined vapor chamber and PCM system improves heat absorption and rejection from the battery compared to just active cooling or vapor chambers.

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A thermal management system for electric vehicle batteries that uses multiple phase change materials (PCMs) to effectively remove heat from the batteries. The system consists of an array of unit cells, each containing a primary PCM in direct contact with the battery cell and a separate secondary PCM thermally coupled to the primary PCM via a heat bridge. This allows the PCMs to absorb and store a large amount of heat from the battery cells, reducing their operating temperature and improving performance and lifespan.

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