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CN-121995258-A - Method, device and equipment for detecting thermal runaway of battery

CN121995258ACN 121995258 ACN121995258 ACN 121995258ACN-121995258-A

Abstract

The embodiment of the invention discloses a method, a device and equipment for detecting thermal runaway of a battery. The battery thermal runaway detection method comprises the steps of obtaining residual electric quantity of each electric core in a target battery, detecting internal resistance of the electric core based on a preset period and a preset frequency when the residual electric quantity is higher than a preset electric quantity threshold value, determining an internal resistance change rate of the electric core according to the internal resistance of the electric core and the preset period, and determining whether the target battery is in thermal runaway or not according to the internal resistance change rate. The method, the device and the equipment for detecting the thermal runaway of the battery can ensure the detection reliability.

Inventors

  • SUN JINGBAO
  • WANG ZHENG

Assignees

  • 杭州协能科技股份有限公司

Dates

Publication Date
20260508
Application Date
20241231
Priority Date
20241105

Claims (10)

  1. 1. A method for detecting thermal runaway of a battery, comprising: Obtaining the residual electric quantity of each electric core in a target battery, wherein the target battery comprises a plurality of electric cores; detecting the internal resistance of the battery cell based on a preset period and a preset frequency when the residual electric quantity is higher than a preset electric quantity threshold value; Determining the internal resistance change rate of the battery cell according to the internal resistance of the battery cell and the preset period; And determining whether the target battery is out of control thermally according to the internal resistance change rate.
  2. 2. The method for detecting thermal runaway of a battery according to claim 1, wherein the determining the rate of change of the internal resistance of the battery cell according to the internal resistance of the battery cell and the preset period includes: The internal resistance of the battery cell in the current period is differed from the internal resistance of the battery cell in the previous period to obtain a difference value; And taking the ratio of the difference value to the preset period as the internal resistance change rate of the battery cell.
  3. 3. The method of detecting thermal runaway of a battery according to claim 1, wherein the rate of change of internal resistance, determining whether thermal runaway of the target battery occurs, comprises: according to the internal resistance change rate, determining a mean value S_ agv and a standard deviation S_std of the internal resistance change rates of all the battery cells in the target battery; If the internal resistance change rate of at least one cell is greater than S_ agv +nS_std or less than S_ agv-nS_std, determining that the target battery is out of control, wherein n is a positive integer greater than or equal to 3, and S_ agv-nS_std is less than zero.
  4. 4. A method of detecting thermal runaway of a battery as defined in claim 3, wherein determining that the target battery is thermally runaway if there is at least one cell having a rate of change of internal resistance greater than s_ agv +ns_std or less than s_ agv-ns_std comprises: and if the internal resistance change rate of at least one cell in m continuous times is greater than S_ agv +nS_std or less than S_ agv-nS_std, determining that the target battery is out of control, wherein m is a positive integer.
  5. 5. The method of detecting thermal runaway of a battery according to claim 1, wherein after said determining the target thermal runaway of the battery, comprising: And sending out an early warning prompt of the thermal runaway of the target battery.
  6. 6. The method for detecting thermal runaway of a battery according to claim 1, wherein the target battery is a lithium battery, the preset period ranges from 5s to 200s, and the preset frequency is greater than 1Hz.
  7. 7. A battery thermal runaway detection device, characterized by comprising: the power acquisition module is used for acquiring the residual power of each battery core in the target battery, wherein the target battery comprises a plurality of battery cores; The internal resistance detection module is used for detecting the internal resistance of the battery cell based on a preset period and a preset frequency when the residual electric quantity is higher than a preset electric quantity threshold value; the rate determining module is used for determining the internal resistance change rate of the battery cell according to the internal resistance of the battery cell and the preset period; and a thermal runaway determining module for determining whether thermal runaway of the target battery occurs according to the internal resistance change rate.
  8. 8. The apparatus for detecting thermal runaway of a battery of claim 7, wherein the thermal runaway determination module comprises: the average value determining unit is used for determining an average value S_ agv and a standard deviation S_std of the internal resistance change rates of all the battery cells in the target battery according to the internal resistance change rate; And the thermal runaway determining unit is used for determining that the target battery is in thermal runaway if at least one cell has an internal resistance change rate greater than S_ agv +nS_std or less than S_ agv-nS_std, n is a positive integer greater than or equal to 3, and S_ agv-nS_std is less than zero.
  9. 9. An apparatus, the apparatus comprising: One or more processors; a storage means for storing one or more programs; When the one or more programs are executed by the one or more processors, the one or more processors are caused to implement the method of detecting thermal runaway of a battery as claimed in any one of claims 1 to 6.
  10. 10. A computer-readable storage medium, on which a computer program is stored, characterized in that the program, when executed by a processor, implements the method for detecting thermal runaway of a battery according to any one of claims 1 to 6.

Description

Method, device and equipment for detecting thermal runaway of battery The application claims priority to application date 2024.11.05, application number 202411568766X and patent name "a method, a device and equipment for detecting thermal runaway of a battery". Technical Field The embodiment of the invention relates to a battery technology, in particular to a method, a device and equipment for detecting thermal runaway of a battery. Background The battery such as a lithium battery applied to a new energy automobile has the problem that the thermal runaway detection of the battery relates to the battery safety of the new energy automobile. With the popularization of new energy automobiles, lithium batteries are becoming a mainstream choice of power batteries for automobiles, and the safety problem thereof is becoming an increasing concern. The high active electrode materials and flammable electrolyte materials of lithium batteries are such that the risk of thermal runaway, a progressive process usually caused by severe side reactions of the electrolyte, which can lead to elevated internal pressures and temperatures of the battery, eventually leading to possible fires or explosions. At present, the existing battery thermal runaway detection method is characterized by monitoring the characteristics of the voltage, the surface temperature, the gas, the smoke and the like of the battery, alarming at the later occurrence stage of the thermal runaway, wherein the later occurrence stage of the thermal runaway is very short, and the manual intervention is not performed, or the battery thermal runaway risk probability is detected when the thermal runaway does not occur by analyzing based on a large amount of data obtained in advance, so that the battery is replaced to avoid the risk, but the battery is influenced by missing data, the accuracy is low, errors are easy to occur, and the detection reliability is influenced. Disclosure of Invention The embodiment of the invention provides a method, a device and equipment for detecting thermal runaway of a battery, so as to ensure detection reliability. In a first aspect, an embodiment of the present invention provides a method for detecting thermal runaway of a battery, including: Obtaining the residual electric quantity of each electric core in a target battery, wherein the target battery comprises a plurality of electric cores; detecting the internal resistance of the battery cell based on a preset period and a preset frequency when the residual electric quantity is higher than a preset electric quantity threshold value; Determining the internal resistance change rate of the battery cell according to the internal resistance of the battery cell and the preset period; And determining whether the target battery is out of control thermally according to the internal resistance change rate. Optionally, the determining, according to the internal resistance of the battery cell and the preset period, the internal resistance change rate of the battery cell includes: The internal resistance of the battery cell in the current period is differed from the internal resistance of the battery cell in the previous period to obtain a difference value; And taking the ratio of the difference value to the preset period as the internal resistance change rate of the battery cell. Optionally, the determining whether the target battery is thermally out of control according to the internal resistance change rate includes: according to the internal resistance change rate, determining a mean value S_ agv and a standard deviation S_std of the internal resistance change rates of all the battery cells in the target battery; If the internal resistance change rate of at least one cell is greater than S_ agv +nS_std or less than S_ agv-nS_std, determining that the target battery is out of control, wherein n is a positive integer greater than or equal to 3, and S_ agv-nS_std is less than zero. Optionally, if there is at least one cell whose internal resistance change rate is greater than s_ agv +ns_std or less than s_ agv-ns_std, determining that the target battery is thermally out of control includes: and if the internal resistance change rate of at least one cell in m continuous times is greater than S_ agv +nS_std or less than S_ agv-nS_std, determining that the target battery is out of control, wherein m is a positive integer. Optionally, after the determining that the target battery is thermally out of control, the determining includes: And sending out an early warning prompt of the thermal runaway of the target battery. Optionally, the target battery is a lithium battery, the preset period ranges from 5s to 200s, and the preset frequency is greater than 1Hz. In a second aspect, an embodiment of the present invention provides a detection apparatus for thermal runaway of a battery, including: the power acquisition module is used for acquiring the residual power of each battery core in the target batte