Pressure Monitoring of EV Battery Cells

Battery design with external pressure sensor to improve thermal runaway detection. The battery has cell modules, a main control unit, and a pressure sensor outside the main board, like near the switch box or on a secondary board. This allows better thermal event detection without enlarging the main board. A nearby temperature sensor on a cell board completes the setup. The external sensor avoids board size issues, improves data verification, and enables closer proximity to cells for better thermal event detection.

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Detecting abnormal operating conditions of battery packs, like thermal runaway, using external air pressure sensors. The method involves monitoring air pressure inside and outside the battery pack enclosure. If the internal pressure rises rapidly or exceeds normal limits, it indicates a thermal runaway inside the pack. This allows detecting pack failures before internal sensors fail. The method can also stop charging and alarm users when abnormal conditions are detected.

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A device and method to monitor electric vehicle batteries for improved safety and diagnostics. The device has pressure and acceleration sensors inside the battery housing. It processes the sensor data, compresses it, and sends it to the main battery management system (BMS). This offloads the BMS from initial data processing, allowing it to focus on fault response. The device also houses the sensors in a rigid housing attached to the battery to accurately capture accelerations. This allows detecting impacts and potential cell rupture before pressure spikes. The compressed sensor data is then transmitted to the BMS to trigger appropriate fault responses.

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A method for estimating state of charge (SOC) of a battery pack using pressure sensors instead of traditional voltage or current sensors. The method involves calculating the SOC based on the pressure inside the battery pack. It involves constructing a mapping between battery pack pressure and SOC at different currents and temperatures. The mapping is created using charge/discharge curves and voltage correction coefficients at different temperatures. By monitoring the pressure during charging/discharging, the SOC can be estimated without needing voltage or current sensors.

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Battery core design with integrated monitoring system for battery modules in electric vehicles to improve safety and reliability. The battery core has a housing with cell compartments, a heat sink between cells, and a monitoring module inside. The module has temperature, pressure, and air pressure sensors to monitor cell conditions. This enables direct cell-level monitoring inside the core, compared to external sensors. The core can be connected in series/parallel to form a module, which has an external management system. This wirelessly connects to the internal monitoring system of each core to provide comprehensive real-time monitoring of the entire module.

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Accurately measuring internal pressure of secondary batteries like lithium-ion batteries to improve safety and reliability by directly measuring the pressure instead of indirectly through gas injection. The method involves inserting a pressure sensor between the battery and lower plate, monitoring the sensor's reading as gas is injected into the battery, then measuring the sensor value when venting releases pressure. This directly measures the internal battery pressure instead of relying on gas injection.

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Early detection of thermal runaway in a traction battery of an electric vehicle to prevent chain reactions that can lead to battery ignition. The method involves continuously monitoring the pressure inside the battery housing using a pressure sensor. If the pressure variance exceeds a threshold, indicating potential thermal runaway, an event signal is triggered to alert the vehicle's control system. This allows detecting battery failure even if the housing is leaky or venting due to a burst membrane, as the pressure variation becomes more pronounced.

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Estimating pressure distribution inside a battery cell during pressure testing to evaluate uniform pressing. The method involves measuring strains using sensors on the pressure apparatus as it compresses the cell. The strains are used to estimate the pressure distribution inside the cell rather than just the average pressure. This allows analysis of localized pressure imbalances and identification of causes.

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Method to accurately detect and alarm for thermal runaway in electric vehicle battery packs to improve safety and reduce false alarms. The method involves monitoring battery pack parameters like temperature, voltage, humidity, and pressure. If the pack pressure exceeds a threshold at a moment when other parameters indicate abnormality, it indicates thermal runaway. This prevents false alarms due to pressure sensor issues while still catching real thermal runaway events.

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A flexible printed circuit board (FPC) for measuring the internal pressure of pouch-style lithium-ion battery cells. The FPC has a pressure sensor mounted on an extension part that extends from the sensing part to the board. The extension part has a metal protective sheath surrounding the insulation. This allows the FPC to be inserted into the gas pocket inside the pouch cell without cutting or damaging the insulation. The sheath seals against the cell outer layers during welding to enclose the sensor. The FPC can then accurately measure the cell's internal pressure during charging and discharging.

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A battery cell monitoring system that provides direct measurement of electrical, pressure, and temperature distributions inside a battery cell to improve battery design and charging. The system involves a segmented current collector array with uniform or varying density of current collectors directly contacting the cell electrode. Temperature sensors, pressure sensors, and reference electrodes are also collocated on a PCB. This allows capturing localized current, impedance, and temperature data during cell operation to understand distribution patterns and locate potential faults. The isolated data bus and controller capture the signals from the arrays without connecting to the cell electrodes.

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Battery module for electric vehicles with improved thermal runaway prevention using pressure sensing and cooling system adjustment. The module has a sensing pad on the cell sidewall connected to a battery management system (BMS). The BMS receives cell pressure measurements. If pressure exceeds a threshold, indicating swelling, it reduces cooling water flow rate to prevent overheating. This prevents cell damage and runaway from pressure buildup during charging/discharging cycles.

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Leak detection system for checking the tightness of objects like batteries by measuring pressure variations. The system involves pressurizing the object's internal space, measuring pressure inside and outside, and calculating leak size based on normalized pressure differences. The system uses multiple pressure sensors inside and outside the object, along with temperature sensors, to accurately determine leaks even in environments with large pressure and temperature variations. The normalized pressure differences account for environmental effects on the internal pressure. This allows more reliable and repeatable leak detection in industrial environments where object temperatures and pressures can fluctuate.

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Battery module design with integrated strain monitoring to improve safety by detecting internal pressure changes without internal sensors. The module has a battery cell array sandwiched between end plates connected by tensioned tie rods. Strain sensors on the tie rods measure expansion/contraction as cells swell/shrink due to pressure changes. By correlating strain with internal pressure from factory testing, this allows monitoring for issues like overpressure, thermal runaway, and cell failure without internal sensors.

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Estimating battery cell swelling behavior and space requirements in a battery pack using a pressure model. The model takes cell parameters like current and SOC to predict cell pressure. By applying determined parameters during operation, the cell pressure can be estimated. This allows determining cell swelling and space requirements based on the predicted pressure. The model enables more accurate estimation of cell swelling, aging, capacity loss, and SOC compared to just measuring cell dimensions.

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Battery pack with a pressure sensor to detect cell swelling and damage after assembly. The sensor is placed inside the pack during manufacture, initialized after assembly, and its pressure readings are used to control charging/discharging. This allows inspection of swelling and damage after transportation and installation. The sensor is positioned where cells are pressurized during pack assembly. The initial pressure reading is zeroed after assembly. If subsequent readings exceed thresholds, charging stops to prevent overpressure. Below thresholds indicates damage.

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A battery pack with integrated pressure sensing cells for detecting swelling and thermal runaway in lithium-ion battery packs. The pack has a pressure sensing cell sandwiched between battery cells. The cell has a fluid-filled, flexible container with pins that sense pressure. By placing the cell between cells, it directly detects swelling and gassing forces. The cell provides a compact, integrated way to monitor cell health and safety without complex algorithms or external devices.

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A pressure sensing cell for accurately detecting pressure changes in battery packs to prevent thermal runaway and monitor battery health. The cell is a flexible pouch filled with fluid and has pressure-sensitive pins inside. It is placed between battery cells in the pack. When cells swell or deform, the pouch compresses and the pins deform, generating electrical signals. These are read by circuitry to detect pressure changes and evaluate battery safety and health.

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Early and accurate detection of thermal chain (thermal runaway) in battery packs to improve safety. The method involves monitoring both cell voltage and pack pressure, and determining thermal chain when both are abnormal. This prevents false positives from just cell voltage issues, and accounts for pressure contributors like leaks or exhaust gas. If pack pressure or cell voltage becomes abnormal, it's monitored for a set time even if values return to normal to catch short-lived thermal chain events.

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Battery monitoring system for electric vehicles that accurately detects abnormal battery conditions. The system uses a pressure sensor between the battery module and enclosure to measure the pressure change. By also monitoring voltage and temperature, it can more accurately determine if the battery is failing compared to just using voltage and temperature. This is because some battery issues, like leaks or thermal runaway, have distinct pressure signatures. The system collects battery data, analyzes it, and alerts if the battery is abnormal.

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