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KR-20260067177-A - METHOD FOR REDUCING THERMAL RUNAWAY OF ENERGY STORAGE DEVICE AND SYSTEM THEREOF

KR20260067177AKR 20260067177 AKR20260067177 AKR 20260067177AKR-20260067177-A

Abstract

The present disclosure relates to a method for reducing thermal runaway in an energy storage device and a system for reducing thermal runaway in an energy storage device. A method for reducing thermal runaway in an energy storage device according to one embodiment of the present disclosure may include the steps of: monitoring the state of each cell and collecting state data of each cell; detecting whether each cell is in an abnormal state using the collected state data of each cell; if there is a cell detected to be in an abnormal state, blocking charging and/or discharging for at least the discharge target cell including the detected cell and transmitting an operation signal to a signal transmission unit to connect the discharge target cell with an external discharge resistor; and, when the signal transmission unit receives the operation signal, operating to cause the external discharge resistor and the discharge target cell to be energized, thereby discharging the energy of the discharge target cell through the external discharge resistor.

Inventors

  • 박신호
  • 김성준
  • 박병준
  • 최소연

Assignees

  • 에스케이온 주식회사

Dates

Publication Date
20260512
Application Date
20241105

Claims (20)

  1. A method for reducing thermal runaway in an energy storage device comprising a plurality of cells, A step of monitoring the status of each cell and collecting status data of each cell; A step of detecting whether each cell is in an abnormal state using the state data of each cell collected above; If there is a cell detected in an abnormal state, the step of blocking charging and/or discharging for a discharge target cell including at least the detected cell, and transmitting an operation signal to a signal transmission unit to connect the discharge target cell with an external discharge resistor; A method for reducing thermal runaway in an energy storage device, comprising the step of: the signal transmission unit, upon receiving the operation signal, operating to cause an external discharge resistor and the discharge target cell to conduct current, thereby discharging the energy of the discharge target cell through the external discharge resistor.
  2. In paragraph 1, The above abnormal condition is, A method for reducing thermal runaway in an energy storage device when the cell current increases by more than 50% compared to the normal charging or discharging current.
  3. In paragraph 1, The above abnormal condition is, A method for reducing thermal runaway in an energy storage device in which the difference in SoC between cells is 10% or more.
  4. In paragraph 1, The above abnormal condition is, A method for reducing thermal runaway in an energy storage device when the voltage of the cell exceeds the voltage corresponding to 100% of the SoC.
  5. In paragraph 1, The above abnormal condition is, A method for reducing thermal runaway in an energy storage device when the cell temperature exceeds a preset reference temperature.
  6. In paragraph 5, The above reference temperature is, A method for reducing thermal runaway in an energy storage device, wherein the temperature is the fire-reach margin temperature at the allowable temperature of the separator and the temperature obtained by subtracting the cell temperature rise during discharge.
  7. In paragraph 1, The magnitude of the above external discharge resistance is, A method for reducing thermal runaway in an energy storage device by setting the discharge time to be below the maximum usable C-rate of the cell.
  8. In Paragraph 7, A method for reducing thermal runaway in an energy storage device, wherein the size of an external discharge resistance is set so that the above-mentioned discharge time can be adjusted to a set voltage or SoC.
  9. In paragraph 1, A method for reducing thermal runaway in an energy storage device, comprising the step of blocking the cell after the energy of the cell to be discharged is discharged through the external discharge resistor.
  10. In paragraph 1, A method for reducing thermal runaway in an energy storage device, wherein the energy of the above-mentioned discharge target cell is discharged through the above-mentioned external discharge resistor, and the SoC is maintained at 30% or less.
  11. In paragraph 1, The operation signal of the above signal transmission unit is, A method for reducing thermal runaway of an energy storage device determined according to an abnormal signal calculated based on current, voltage, and temperature data in the above-mentioned control unit.
  12. In a thermal runaway reduction system in an energy storage device comprising a plurality of cells, A control unit that monitors the status of each cell, collects data from each cell to detect whether each cell is in an abnormal state, and if a cell is detected to be in an abnormal state, blocks charging and/or discharging for at least the discharge target cell including the detected cell, and generates an operation signal for connection with the discharge target cell; A signal transmission unit that receives an operation signal from the above control unit and forms a current transmission circuit with the discharge target cell; Including an external discharge resistor formed on a current-carrying circuit formed by the above signal transmission unit, A thermal runaway reduction system for an energy storage device that discharges the energy of the above-mentioned discharge target cell through the above-mentioned external discharge resistor.
  13. In Paragraph 12, The abnormal state detected by the above control unit is, A thermal runaway reduction system for an energy storage device when the cell current increases by more than 50% compared to the normal charging or discharging current.
  14. In Paragraph 12, The abnormal state detected by the above control unit is, A thermal runaway reduction system for an energy storage device in which the difference in SoC between cells is 10% or more.
  15. In Paragraph 12, The abnormal state detected by the above control unit is, A thermal runaway reduction system for an energy storage device in which the cell voltage exceeds the voltage corresponding to 100% of the SoC.
  16. In Paragraph 12, The abnormal state detected by the above control unit is, A thermal runaway reduction system for an energy storage device when the cell temperature exceeds a preset reference temperature.
  17. In Paragraph 16, The above reference temperature is, A thermal runaway reduction system for an energy storage device, wherein the temperature is the fire-reach margin temperature and the cell temperature rise during discharge, subtracted from the allowable temperature of the separator.
  18. In Paragraph 12, The magnitude of the above external discharge resistance is, A thermal runaway reduction system for an energy storage device that secures discharge time by setting the maximum usable C-rate of the cell below a certain level.
  19. In Paragraph 18, A thermal runaway reduction system for an energy storage device in which the size of an external discharge resistance is set so that the above-mentioned discharge time can be adjusted to a set voltage or SoC.
  20. In Paragraph 12, In the above control unit, A thermal runaway reduction system for an energy storage device that blocks the cell after the energy of the cell to be discharged is discharged through the external discharge resistor.

Description

Method for Reducing Thermal Runaway of Energy Storage Device and System Thereof The present disclosure relates to a method for reducing thermal runaway of an energy storage device and a system thereof. With the rapid increase in the use of lithium-ion batteries, safety issues regarding energy storage devices containing them are emerging as a critical topic. In particular, for electric vehicles (EVs) and similar devices utilizing high-capacity energy storage systems, thermal runaway caused by cell abnormalities is becoming a major concern. Thermal runaway is a phenomenon where the temperature inside a cell rises rapidly, potentially causing fires or explosions. This poses a risk of a chain reaction of explosions as heat transfers to adjacent cells. Therefore, it is necessary for battery management systems to detect cell abnormalities early and implement preventive measures. The Battery Management System (BMS) monitors the state of cells based on data such as voltage, current, and temperature, and operates by stopping charging or discharging under specific conditions. However, even after a cell abnormality is detected, the energy remaining inside the cell can cause thermal runaway, and safety devices are required to prevent heat transfer, particularly to adjacent cells. In the case of fire spread prevention in conventional energy storage devices, serial fires have been prevented by using walls that block heat transfer between cells or by using liquid fire extinguishing agents. However, this method involves installing barrier walls and fire extinguishing agents inside modules containing energy storage devices, which leads to a decrease in cell mounting density and results in increased costs for installing fire extinguishing agents or barrier walls. FIG. 1 is a flowchart illustrating a method for reducing thermal runaway of an energy storage device according to one embodiment of the present disclosure. FIG. 2 is a drawing illustrating an example of a thermal runaway reduction system for an energy storage device according to one embodiment of the present disclosure. FIG. 3 is a result graph showing the temperature rise and voltage change during the discharge of a cell according to one embodiment of the present disclosure. FIG. 4 is a drawing illustrating an electric vehicle that uses a thermal runaway reduction method for an energy storage device according to one embodiment of the present disclosure and includes a thermal runaway reduction system for an energy storage device. Hereinafter, the present disclosure will be described in detail with reference to the attached drawings. However, this is merely illustrative and the present disclosure is not limited to the specific embodiments described illustratively. Although terms such as "first," "second," etc. are used to describe various elements, components, and/or sections, it goes without saying that these elements, components, and/or sections are not limited by these terms. These terms are used merely to distinguish one element, component, or section from another. Accordingly, the first element, first component, or first section mentioned below may, within the technical scope of the present disclosure, be a second element, second component, or second section. The terms used herein are for describing the embodiments and are not intended to limit the disclosure. In this specification, the singular form includes the plural form unless specifically stated otherwise in the text. As used herein, "comprises" and/or "made of" do not exclude the presence or addition of one or more other components, steps, actions, and/or elements to the mentioned components, steps, actions, and/or elements. Unless otherwise defined, all terms used in this specification (including technical and scientific terms) may be used in a meaning commonly understood by those skilled in the art to which this disclosure pertains. Additionally, terms defined in commonly used dictionaries are not to be interpreted ideally or excessively unless explicitly and specifically defined otherwise. FIG. 1 is a flowchart illustrating a method for reducing thermal runaway of an energy storage device according to one embodiment of the present disclosure, and FIG. 2 is a drawing illustrating an example of a system for reducing thermal runaway of an energy storage device according to one embodiment of the present disclosure. Referring to FIGS. 1 and 2, a method for reducing thermal runaway in an energy storage device according to one embodiment of the present disclosure may include the steps of: monitoring the state of each cell and collecting state data of each cell; detecting whether each cell is in an abnormal state using the collected state data of each cell; if there is a cell detected to be in an abnormal state, blocking charging and/or discharging for at least the discharge target cell (100) including the detected cell, and transmitting an operation signal to a signal transmission unit (300) to connect the di