Thermal Runaway Prevention Techniques for EV Batteries

Thermal vent management system to isolate and control gas discharges from rechargeable energy storage systems like vehicle batteries. The system captures and directs the gases away from the battery housing to prevent the build-up of explosive concentrations. It uses a one-way valve vent that connects to a chamber with an air inlet. The inlet draws ambient air using a Venturi effect to dilute and safely exhaust any vented gases.

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Battery pack design for electric vehicles to safely vent gases during thermal runaway without releasing debris or particles. The battery cells have vents to release gases during overheating. The battery pack enclosure contains a passageway with inlet ports aligned to the cell vents. This allows vent gases to be routed through the passageway, preventing hot gases from directly contacting the enclosure. The passageway can have frangible sections that break during thermal events to further separate the gases from the enclosure.

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Explosion-proof valve for discharging gases from a battery pack to prevent pressure buildup during runaway conditions. The valve has a flame arresting member and air permeable membrane to allow gas exchange while extinguishing flames and cooling gases. This prevents explosions and fires if a lithium ion battery overheats. The valve opens to release gases when pressure spikes during thermal runaway. The flame arrestor inside blocks flames and sparks.

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Battery cell venting system for battery packs to vent gases from battery cells to avoid overpressure. The venting system has a vent port, a vent tube inside the cell, and a spacer plate between the tube and the electrodes. This provides multiple flow pathways for gases to escape the cell. The tube and plate create vertical and lateral paths. The tube is shorter than the cell height.

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Battery design with enhanced thermal management and safety features for preventing thermal runaway propagation. The design uses a thermally conductive filler material between the battery cell stack and the housing inner surface to provide improved heat transfer from cells to the housing for cooling. This filler contains thermally conductive particles in a polymer matrix. The filler also includes a thermal runaway containment feature where the polymer is formulated to thermally decompose at runaway temperatures, creating a barrier that inhibits further propagation of runaway between cells.

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Battery pack that provides thermal management, detection of abnormal heating, detection of thermal runaway, thermal runaway propagation prevention, and fire spread prevention in batteries. The pack uses a coolant system that can discharge coolant directly onto overheating cells to rapidly cool them and prevent thermal runaway. The system uses deformation elements attached to each cell that bend if the cell overheats to unlock coolant tubes.

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Battery system for electric vehicles that has a unique venting system to safely exhaust gases in the event of a battery thermal runaway. The system uses a cover element attached to the battery pack housing with a venting channel to redirect and cool the hot gases. The channel has obstacles and curves to lengthen the path and increase contact with the cover to extract heat. This prevents the hot gases from rapidly exiting the pack and potentially igniting, instead cooling them before release.

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Vehicle battery system that reduces risk of fires caused by thermal runaway by safely venting hot gases and separating out solid debris. The battery system includes a housing with sidewalls that have channels and apertures. During thermal runaway, gases flow out of the battery cells through the apertures into the channels. The channels slow down the gases and cause solid debris to settle to the bottom while allowing the gases to escape the housing. A centrifugal separator may also be used downstream to separate any remaining debris. This prevents the debris from short circuiting other cells while still venting the gases.

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Detecting thermal runaway in electric vehicle batteries to protect against fire and explosion risks. The system uses pressure sensors inside battery cells to detect swelling indicative of thermal runaway. This early warning system can detect thermal runaway before it reaches the point of fire or explosion.

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A battery design for mitigating thermal runaway in electric vehicle batteries, improving safety. The battery cells are grouped into subgroups and surrounded by dynamic enclosures that can close around a subgroup if it starts to overheat, contain any thermal runaway, and prevent spread to other subgroups. The enclosures have pivoting covers that can open and close, forming thermal and physical barriers as needed.

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Detection system for identifying thermal runaway events in batteries to prevent fires and explosions. The system uses gas sensors inside the battery enclosure to detect gases released during initial cell venting and thermal runaway. By analyzing the gas composition and levels, the system can identify when a battery is undergoing thermal runaway. This allows early detection and intervention to prevent further propagation of the runaway. The system analyzes gases like CO2, CO, H2, etc., and triggers an alarm if levels exceed predetermined thresholds.

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Early detection of thermal runaway in battery packs to prevent propagation, using graphite sheets and sensors positioned near cell vents. The graphite has high in-plane thermal conductivity but low through-plane conductivity, so it absorbs and conducts away heat from a venting cell to stop runaway propagation. Sensors monitor the graphite temperature for signs of abnormal heat.

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Fast and robust detection of thermal runaway in batteries to prevent catastrophic failures like fire or explosion. The detection system uses shared attributes of initial cell venting that are common between different battery designs and respond to venting gases from a failing cell. The system utilizes gas sensors and processing devices to monitor the battery enclosure for elevated gas levels indicating thermal runaway.

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Apparatus and method for predicting thermal runaway of lithium-ion batteries. It analyzes temperature, gas concentration, and pressure readings from sensors inside battery modules. It compares these values to thresholds and looks for specific patterns such as pressure falling after exceeding a threshold or gas concentration exceeding a threshold while temperature is high. These indicate thermal runaway.

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Detecting thermal runaway of electric vehicle batteries to prevent fires and warn occupants. The system uses sensors on battery cells to detect swelling indicative of thermal runaway. When detected, a warning is given to occupants.

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A composite material thermal shielding device to protect compartments from heat and flames during extreme events like battery fires. The device has metal layers separated by a polymer core. The polymer expands, increasing separation between the metal layers and thickness of the device when heated. This reduces heat flow through the device compared to solid metal shields. The polymer contains compounds that release gas when heated to activate expansion.

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Battery pack design with thermal barriers to contain thermal runaway and prevent cascading failures in battery packs. The design involves dividing the battery pack into groups of cells separated by thermal barrier elements. These barriers inhibit the spread of thermal runaway from one cell group to adjacent groups. The barriers are made of materials with high melting points and low thermal conductivity to withstand and isolate runaway conditions. They may also have integrated coolant channels for active cooling.

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Minimizing the propagation of thermal runaway within a battery pack by using a spacer assembly to maintain battery positions and the minimum spacing between them during a thermal event. The spacer assembly is made of a material with a higher melting temperature than the cell mounting bracket, so it remains intact after the bracket melts or vaporizes. This prevents cells from moving closer together and maintains proper cooling between them during a thermal runaway event, reducing the risk of propagation.

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Battery assembly that reduces the risk of thermal runaway by delaying or preventing the spread of heat from a defective cell to adjacent cells. The assembly wraps the cell in a thermal management multilayer sheet. This sheet includes a thermally-insulating layer sandwiched between two heat-spreading layers. This reduces thermal conductivity between cells and can prevent a thermal runaway chain reaction.

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Battery module design that suppresses thermal runaway propagation and explosion risk in battery packs. The module has a connector with a movable interrupting part that can close gaps when pressure rises inside during thermal runaway. This prevents high temperature gas and flames from being ejected.

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Battery module and pack design for mitigating thermal runaway or explosion of one battery cell from propagating to adjacent cells. A thermal barrier is placed between cells that has heat resistant layers to block heat/flame transfer and a rigid mechanical layer to maintain integrity in a runaway event. This contains any thermal event within one cell and prevents chain reactions through the pack.

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Insulation system for vehicle components that selectively insulates the components during heat up and allows heat dissipation once the components reach operating temperature. The insulation system uses an enclosed chamber filled with carbon dioxide that has different thermal conductivity in liquid/gas vs supercritical gas phase. This allows the insulation to change its thermal properties as the component temperature increases.

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Preventing battery thermal runaway by transferring energy from cells at risk to the battery pack to mitigate the runaway potential. It detects cells at risk of thermal runaway in a battery pack and then transfers the energy from those cells to the battery pack using existing systems like coolant loops, heating elements, and charging circuits. This dissipates the energy from the risky cells into the larger pack, preventing thermal runaway.

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Battery with passive thermal runaway prevention and recovery mechanism. The battery has resealable valves that let the battery release pressure to prevent an explosion. It also has a fluid reservoir above the battery cells that can gravity feed coolant into the cells to quench overheating. This system automatically douses and vents overheating cells to prevent thermal runaway. The valves can be resealed after an incident to reuse the cell.

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Thermal runaway detection method and battery management system that can effectively detect thermal runaway in batteries and mitigate the risks of fire and explosion. The method involves monitoring parameters of the battery cooling medium, such as pressure, flow rate, level, and temperature. When these parameters satisfy certain conditions, it indicates thermal runaway is occurring. This allows early detection before catastrophic failure. The method uses sensors on the heat conducting apparatus to monitor cooling medium parameters.

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Battery charging control method and device to mitigate thermal runaway of the battery during charging. The method involves monitoring the battery voltage during charging and stopping charging if the voltage does not monotonically increase over a sampling period and the voltage trend of at least one cell unit does not rise. Charging can also be stopped if the voltage drops and both the preset charging current and actual battery currents are below a threshold. This allows detection of internal short circuits causing voltage drops and prevents thermal runaway.

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Mitigation system for preventing thermal runaway propagation in electric vehicle battery packs by actively and passively cooling the cells and detecting overheating conditions to take necessary actions to counteract them.

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