US-20260126498-A1 - Thermal Runaway Detection System

US20260126498A1US 20260126498 A1US20260126498 A1US 20260126498A1US-20260126498-A1

Abstract

A system and method for early detection of thermal runaway and electrochemical degradation in battery cells and packs includes a sensor with at least two conductive electrodes separated by a sub-millimeter gap and biased by a controlled voltage. When thermal runaway byproducts enter the gap, current between the electrodes is altered to produce a measurable signal, conditioned by onboard or remote circuitry through amplification/filtering to generate a processed signal. This signal is transmitted to a battery control system to initiate protective actions (e.g., shutdown, cooling activation, or cell isolation). The sensor may be implemented on a printed circuit board or as discrete electrodes and may include a gas-permeable filter that admits vapors and fine aerosols while blocking liquids and debris. The disclosed system enables real-time, sub-second detection of early thermal runaway precursors before temperature rise or combustion occurs, enhancing safety and reliability of lithium-ion and other electrochemical energy storage systems.

Inventors

Youssef Mansour
John Gelmisi

Assignees

IC Technologies, LLC

Dates

Publication Date: 20260507
Application Date: 20251103

Claims (20)

1 . A thermal runaway detection system, comprising: a processing unit; a sensor in communication with the processing unit, the sensor comprising a first electrode, a second electrode, and a gap between the first electrode and the second electrode; wherein the first electrode and/or the second electrode are electrically charged with a voltage such that, upon one or more thermal runaway byproducts entering the gap, a change in current between the sensor electrodes produces a signal indicative of a thermal runaway event.
2 . The thermal runaway detection system of claim 1 , wherein the gap is between 0.05 millimeters and 2.0 millimeters, thereby providing sufficient sensitivity for detection of a conductive gas.
3 . The thermal runaway detection system of claim 1 , wherein the voltage ranges from 500 volts to 1,000 volts depending on a selected detection mode.
4 . The thermal runaway detection system of claim 1 , wherein a source of the voltage is selected from a group consisting of a direct current source, an alternative current source, and a microwave source, each configured to bias the first electrode and second electrode so as to enable gas ionization or conductivity-based sensing.
5 . The thermal runaway detection system of claim 1 , wherein, in a low-voltage sensing configuration for detection of conductivity change, the voltage ranges from 3 volts to 500 volts.
6 . The thermal runaway detection system of claim 1 , wherein the one or more thermal runaway byproducts comprise lithium ions, particulates, electrons, hydrocarbons, and/or hydrogen gases that alter electrical conductivity within the gap between the first electrode and the second electrode.
7 . The thermal runaway detection system of claim 1 , wherein the sensor is comprised of a rigid PCB, a flexible PCB, or separate electrodes each including conductive tracks defining the first electrode, the second electrode, and the gap.
8 . The thermal runaway detection system of claim 7 , wherein the PCB sensor comprises tracks up to 10 millimeters in height to increase exposed sensing area and gas interaction.
9 . The thermal runaway detection system of claim 1 , wherein the sensor is attached to at least partially cover a vented opening of a battery cell such that gases vented from the cell directly enter a sensing region of the sensor.
10 . The thermal runaway detection system of claim 1 , wherein the sensor is integrated with the processing unit so as to enable local signal conditioning and reduce transmission noise.
11 . The thermal runaway detection system of claim 1 , wherein the sensor is separate from the processing unit.
12 . The thermal runaway detection system of claim 1 , wherein the sensor comprises a gas-permeable filter positioned over the gap between the first electrode and the second electrode.
13 . The thermal runaway detection system of claim 12 , wherein the gas-permeable filter is configured to admit vapors and/or fine aerosols while rejecting liquid electrolyte splash, condensate, and/or debris.
14 . The thermal runaway detection system of claim 1 , wherein the system comprises a thermal runaway prevention feedback control mechanism configured to initiate protective measures upon receiving the signals from the sensor, the protective measures comprising at least one of system shutdown, activation of cooling systems, isolation of affected battery cells, cessation of battery charging, and cessation of battery discharging.
15 . A method of detecting thermal runaway in a battery cell, comprising: mounting a sensor to an access opening of the battery cell such that a sensor is exposed to an internal headspace of the cell, the sensor comprising a first electrode, a second electrode, and a gap between the first electrode and the second electrode; producing a raw signal by closing a circuit between the first electrode and the second electrode due to a presence of a thermal runaway indicator; processing the raw signal by a conditioning circuit to produce a processed signal; and transmitting the processed signal to a battery control system.
16 . The method of claim 15 , wherein the sensor is operable to detect internal electrochemical changes in lithium ion batteries and battery deterioration as well as battery thermal runaway so as to enable detection of gases prior to external venting.
17 . The method of claim 15 , wherein the conditioning circuit is integrated with the sensor and wherein the conditioning circuit performs local amplification, filtering, and signal stabilization prior to transmission to the battery control system.
18 . The method of claim 15 , wherein the sensor comprises a gas-permeable filter configured to allow passage of gasses while restricting passage of liquids.
19 . The method of claim 15 , wherein the step of processing the raw signal comprises amplifying, filtering the raw signal, and applying a threshold algorithm to discriminate early venting or decomposition signals from normal operating variations.
20 . A method of detecting thermal runaway in a module or battery pack, comprising: mounting a sensor at a gas-venting location of the module or within a pack enclosure, the sensor comprising a first electrode, a second electrode, and a gap between the first electrode and the second electrode, and the battery pack comprising a plurality of battery cells; producing a raw signal by closing a circuit between the first electrode and the second electrode due to a presence of a thermal runaway indicator; processing the raw signal by a conditioning circuit to produce a processed signal; and transmitting the processed signal to a battery control system configured to initiate safety responses including isolation of affected cells, activation of cooling, or system shutdown.

Description

This application claims benefit of and priority to U.S. Provisional Application Ser. No. 63/852,512 filed Jul. 28, 2025 entitled Method for Detection of Internal Electrochemical Degradation and Thermal Runaway of Lithium Ion Batteries and U.S. Provisional Application Ser. No. 63/716,073 filed Nov. 4, 2024 entitled Method for Detection of Internal Electrochemical Degradation and Thermal Runaway of Lithium Ion Batteries, both of which are hereby incorporated herein by reference in their entireties. BACKGROUND Certain power sources, such as lithium-ion and lithium-metal battery cells, can undergo various types of failures. Such failures have been known to initiate a process commonly referred to “thermal runaway”. Thermal runaway may result in a rapid increase in battery cell temperature accompanied by the release of flammable byproducts, such as electrolytes, particulates, and/or chemical gases. These flammable byproducts may pose a significant ignition risk which can potentially lead to fires; endangering occupants and bystanders. Flammable byproducts resulting from thermal runaway, such as flammable gases, will often be ignited by the battery's high temperature. Such an ignition may result in a fire which, in turn, may spread to other cells, thus causing the thermal runaway. In light of the widespread use of such battery cells in applications such as electric vehicles, portable electronics, and energy storage systems, early detection of thermal runaway is crucial for ensuring safety of such battery systems. Traditional detection methods for thermal runaway typically rely on a combination of sensor technologies that may be integrated into a battery management system. These systems monitor factors such as temperature, voltage, gas emissions, and pressure changes to detect early signs of thermal runaway. Temperature sensors may be used to detect local hotspots within the battery pack, but their effectiveness is limited by response times and the potential for undetected localized heating. Voltage sensors may detect overcharging or discharging by measuring terminal voltage changes. Thermistors, thermocouples, and digital temperature sensors may also be used despite limitations in detection accuracy and environmental sensitivity. Gas sensors, such as for detecting hydrogen, carbon monoxide, and carbon dioxide, may provide early warning signs of thermal runaway by detecting the release of volatile organic compounds and gasses during the initial stages of exothermic reactions. However, these approaches have limitations in terms of early detection and reliability, as they often respond to later stages of the thermal runaway process. It would be beneficial to provide a system in which thermal runaway is detected at an earlier stage so as to provide rapid and precise alerts for mitigating potential hazards effectively. SUMMARY Disclosed herein are systems, devices, and methods for efficiently and rapidly detecting thermal runaway events and hydrogen leakage, enabling early intervention and mitigation measures. The systems, devices, and methods disclosed herein may utilize a sensor having a pair of electrodes separated by a predefined gap of sufficient width to prevent closing of a circuit between the electrodes absent presence of gasses and electrochemical species or the like which are indicative of thermal runaway conditions. A sensor may be attached to a specific prismatic cell or to a module or pack of multiple cells. The sensor may be attached to a gas-venting location of a battery module or to a dedicated access opening in a lid of a prismatic cell. In either case, a gas-permeable filter or membrane may be positioned between the gas-venting location or dedicated access opening and the electrodes that admits vapors and/or fine aerosols while rejecting liquid electrolyte splash, condensate, and/or debris. Upon the circuit between the electrodes being closed due to the presence of any such thermal runaway indicators, a raw voltage signal may be transmitted by the sensor to a conditioning circuit or onboard measurement and diagnostic module for filtering, amplification, and/or other processing. The processing of the raw signal may be performed for each such sensor, or a plurality of sensors may be transmitted to a common conditioning circuit. The processed signal may then be transmitted to a battery control system for further action (e.g., cutoff, alarms, etc.) so as to quickly react to the thermal runaway conditions. In some aspects, the techniques described herein relate to a sensor system configured for thermal runaway mitigation through feedback control, enabling dynamic responses based on sensor data. In some aspects, the techniques described herein relate to a sensor system incorporating sensitivity calibration capable of predicting early or late-stage thermal runaway events based on selected detection modes such as low voltage sensing, high voltage sensing, and calibratable thresholds. The sensor may include sp