Gas Venting Management Techniques for EV Battery Thermal Events

Managing thermal energy in battery packs while isolating vent gases from the coolant. The battery pack uses an enclosure with a coolant loop to cool the cells. A vent manifold inside the enclosure captures cell vent gases and routes them separately to outside the pack. This prevents coolant contamination from vent gases. The coolant directly contacts the cells and vent manifold. The coolant manages thermal energy in the cells while the vent manifold isolates vent gases.

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Battery pack and module design with improved safety against thermal runaway, fire, explosion, and the like, that is, thermal safety, for battery packs used in electric vehicles and energy storage systems. The pack and module have a cell cover surrounding some of the pouch-type battery cells directly instead of module cases. The cell cover allows venting gas to escape in a specific direction instead of all directions. This prevents flame propagation between cells if a thermal event occurs in one cell. The cell cover guides discharged gases and flames away from adjacent cells to contain thermal events.

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Early detection of thermal runaway events in batteries, like those used in electric vehicles, by detecting the initial venting of gases during the runaway process. A sensor measures the thermal conductivity of the gas atmosphere inside the battery. Changes in conductivity due to venting can be detected as an indicator of an impending thermal runaway. An apparatus with interface and processing circuitry receives the conductivity measurement and determines if venting has occurred. This allows early warning of potential thermal runaway events to mitigate safety risks.

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Managing thermal energy within a traction battery pack of an electrified vehicle to prevent cell venting debris from spreading to adjacent cells during thermal events. The technique involves securing thermal blockers between adjacent battery cells using an adhesive-backed base assembly that sandwiches between the cells. This prevents vent byproducts from migrating between cells during a thermal event. The base assembly can be an adhesive tape, securing the thermal blockers and adjacent cells together. The adhesive tape also provides mechanical support to the cells. The technique helps contain thermal runaway within cells and prevent cell-to-cell propagation.

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Cylindrical secondary battery design with a vent structure to prevent ignition and reduce deformation during forced discharge. The vent is located in specific areas of the cap plate, like the center or connection, and has reduced thickness compared to surrounding areas. This allows controlled venting to relieve pressure without excessive core deformation. The vent shapes can be circular rings, crosses, spirals, or pinwheels extending from the center. The reduced thickness at the vent areas enables controlled venting while minimizing core deformation.

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Battery pack design to prevent thermal runaway propagation in battery packs by efficiently discharging venting gas while preventing backflow. The pack has a housing with gas channels, a venting plate with a movable cutout, and a restriction member. The cutout moves into the venting opening during normal operation. If pressure rises, the cutout moves out to vent. The restriction blocks reverse movement to prevent backflow. This allows efficient gas discharge while preventing gas reentry during thermal runaway.

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Battery exhaust device, hard-shell battery, and soft-pack battery that allows internal gas to be safely discharged from batteries without damaging the battery. The exhaust device has a valve body with an exhaust channel, an air inlet, and an air outlet. A blocking member and elastic member are used to control gas flow. The valve body connects to the battery cell chamber. When gas pressure builds up, the blocking member moves to allow gas out through the air outlet. This prevents explosions by venting the gas. The hard-shell battery has the exhaust device inside the shell, and the soft-pack battery has it outside the aluminum-plastic film.

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A secondary battery with a venting device to prevent structural collapse and flame propagation during thermal runaway. The venting device has a rupture disk that bursts at a certain pressure. A heat-absorbing porous member is placed upstream or downstream of the rupture disk. This member prevents flames from escaping when the vent opens. The porous member may deform or melt at high temperatures and pressures to allow gas escape. It also absorbs heat to lower the ignition point. By controlling venting and flame propagation, it delays or prevents secondary battery collapse during thermal runaway.

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Battery safety valve with a sealing airbag to prevent external gas from entering the battery during overpressure venting. The valve has an airbag attached to the valve body that collects the vented battery gases. This prevents external air from entering the battery when it vents, allowing continued operation and extending the time before thermal runaway. The airbag seals against the valve body with a gasket. A pressure sensor monitors the airbag pressure.

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Battery pack with improved safety against fire or gas explosion in electric vehicles. The pack has a housing with a sealed gas inlet covered by a venting unit. When internal pressure exceeds a threshold, the venting unit ruptures to allow gas to escape. This prevents explosions spreading between modules by quickly venting gas. The venting unit has a split plate with one section exposed to rupture and the other section supporting. When pressure rises, the exposed section ruptures while the supported section remains fixed.

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Battery explosion-proof valve and battery design with stepped pressure relief to prevent battery pack explosions during thermal runaway. The valve has three stages of pressure relief: a primary valve connected to the outside for normal venting, and secondary and tertiary valves with higher opening pressures. This allows controlled pressure relief as internal pressure rises during thermal runaway, preventing explosive overpressure. The valve also has features like waterproof breathable membranes, sand filters, and magnetic levitation to prevent clogging and sticking. The stepped relief design ensures safety during thermal runaway events.

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Preventing thermal runaway propagation in battery packs by allowing heat and gas to escape when a cell experiences thermal runaway. The device has a dedicated discharge passage and valve for each cell. If a cell temperature exceeds a threshold, the valve opens to release heat and gas outside. This prevents the runaway from spreading to adjacent cells. A battery management system selectively opens valves for cells with runaway. Simultaneous valve opening prevents runaway chain reactions.

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Battery housing for electric vehicle batteries that allows hot gas discharge while preventing environmental contamination. The housing has a valve device with a valve body that moves outward when internal pressure rises. When pressure exceeds a threshold due to hot gases, the valve body lifts and secures to expel hot gases. It cannot return when pressure drops. This prevents hot gases from venting into the environment unless pressure is high enough. The valve body is also designed to fix in place when lifted to prevent external forces from closing it.

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Pressure relief mechanism for batteries that improves safety by guiding discharged gas away from the battery and preventing it from damaging other components. The mechanism has an airflow blocking member around the pressure relief port that restricts gas flow through the port. High-temperature gas discharged during battery thermal runaway is directed out of the blocking member's exhaust port instead of scattering through the port. This prevents gas from hitting and damaging nearby components like wiring harnesses. The blocking member also expands and contracts with the valve cover to maintain gas flow guidance during pressure relief.

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Explosion-proof valve, battery module, and battery pack for lithium-ion batteries that provide safe pressure relief to prevent explosions. The valve has an electrochemical energy storage component that can be ignited by a control circuit when the internal battery pressure exceeds a threshold. This component pierces a diaphragm to rapidly relieve pressure inside the battery pack. The pack has a thermal management module connected to a pressure sensor that triggers the valve when pressure rises.

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A housing for battery modules with improved gas venting capabilities. The housing has a main body that mates with the lower housing containing the battery cells. It has two types of vents: burst vents that rapidly release excess gases when pressure reaches a threshold, and slow vents with gas-selective permeability layers that enable gas exchange between the chamber and exterior. This allows directed rapid venting of excessive gases while allowing slower venting of other gases to maintain cell breathing. The burst vents prevent overpressure rupture, and the slow vents prevent condensation buildup.

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Venting assembly for traction battery packs that allows controlled release of gases and debris from venting battery cells into a sealed enclosure. The venting assembly uses a valve that opens in response to a cell venting to provide a path for the vented gases and debris into a passageway in the battery pack structure. This prevents buildup of pressure and prevents explosive venting of the cells. The valve can be a simple perforated area or a more complex mechanism like a reed valve. Multiple valves can be used to vent individual cells or cell stacks separately.

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Battery pack venting assembly for electrified vehicles that cools the vented gas before discharging it to the environment. The venting assembly has a shielded vent path with internal passages for ambient air. The shields surround the vented gas path. Prior to discharge, ambient air is mixed with the vented gas within the shielded path. This cools the gas before release, preventing excessive heat buildup in the pack. The air mixing passages are positioned between the inlet and outlet to mix the gases during venting.

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Battery pack design with improved gas venting and waterproofing for electric vehicles. The pack has a case with multiple battery cells, each cell having a pressure relief valve. The case has vent holes to prevent expansion/contraction due to temperature changes. It also has enlarged smoke exhausts with fragile joints. The joints have a weakened section that peels off when internal pressure rises, allowing quick gas release through the exhausts instead of box deformation.

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Power battery pack design to prevent explosions by improving gas release efficiency. The battery pack has a unique configuration that allows quick and efficient gas venting during thermal runaway. The pack has a compartmentalized structure with the battery modules spaced apart and connected to the pack frame. This creates a direct gas exhaust path between the modules and the explosion-proof valve. When a module vents gas during runaway, it flows through the module's exhaust channel and directly out the valve, preventing pressure buildup and explosion risk.

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