CN-122017626-A - Battery abnormal lithium-precipitation nondestructive detection method, system, electronic equipment and storage medium

CN122017626ACN 122017626 ACN122017626 ACN 122017626ACN-122017626-A

Abstract

The application provides a nondestructive testing method, a system, electronic equipment and a storage medium for abnormal lithium precipitation of a battery, and relates to the technical field of battery detection, wherein the method comprises the steps of performing two-stage charging on a target battery, wherein the target battery is charged to a charging cut-off voltage in a first charging stage, and enters a second charging stage after a preset standing time period, the target battery is recharged to the charging cut-off voltage by a target charging current in the second charging stage, and the minimum charging current in the first charging stage is larger than the target charging current; the method comprises the steps of obtaining a voltage change curve of each battery core in a target battery in a charging process of a second charging stage, calculating the voltage change rate of the voltage change of each battery core along with time according to the voltage change curve to obtain a voltage change rate curve, and determining an abnormal lithium-ion battery core according to the outlier change of the voltage change rate curve of each battery core. The application can realize early warning of lithium precipitation risk in real time on line, with low cost and high robustness.

Inventors

Zou Xiaoxi
Cheng Jingkang
ZHANG FANGFANG
JIN ZHONG

Assignees

武汉蔚能电池资产有限公司

Dates

Publication Date: 20260512
Application Date: 20260213

Claims (10)

1. A method for non-destructive detection of abnormal lithium precipitation of a battery, the method comprising: Performing two-stage charging on a target battery, wherein the target battery is charged to a charging cut-off voltage in a first charging stage, and enters a second charging stage after a preset standing time, the target battery is recharged to the charging cut-off voltage in the second charging stage by a target charging current, and the minimum charging current of the first charging stage is larger than the target charging current; Acquiring a voltage change curve of each battery core in the target battery in the charging process of the second charging stage; calculating the voltage change rate of the voltage of each battery cell along with the time change according to the voltage change curve to obtain a voltage change rate curve; and determining abnormal lithium-ion battery cells according to the outlier change of the voltage change rate curve of each battery cell.
2. The method for non-destructive testing of abnormal lithium-ion batteries according to claim 1, wherein said determining abnormal lithium-ion battery cells from an outlier variation of said voltage rate curve of each battery cell comprises: Calculating target confidence intervals of the voltage change rates of all the battery cells under each voltage value according to the voltage change rate curve; Taking the lower limit value of the target confidence interval as an outlier threshold of the voltage change rate; and if the voltage change rate of the target battery cell existing in the continuous voltage interval is always smaller than the outlier threshold, determining the target battery cell as an abnormal lithium precipitation battery cell.
3. The method according to claim 2, wherein the interval length of the continuous voltage interval is 10mV or more, and the target confidence interval is a 95% confidence interval.
4. The method for non-destructive testing of abnormal lithium-ion batteries according to claim 1, wherein said determining abnormal lithium-ion battery cells from an outlier variation of said voltage rate curve of each battery cell comprises: calculating the average value of the voltage change rates of all the battery cells under each voltage value according to the voltage change rate curve; determining an outlier threshold of the voltage change rate according to the average value; and if the voltage change rate of the target battery cell existing in the continuous voltage interval is always smaller than the outlier threshold, determining the target battery cell as an abnormal lithium precipitation battery cell.
5. The method according to claim 4, wherein the continuous voltage interval has an interval length of 10mV or more, and the outlier threshold is 75% of the average value.
6. The method for non-destructive testing of abnormal lithium analysis of a battery according to claim 1, wherein the step of obtaining a voltage change curve of each cell in the target battery during the charging process in the second charging stage comprises the steps of: Collecting the cell voltage of each cell in the target battery in the charging process of the second charging stage at preset time intervals; And constructing the voltage change curve of each battery cell according to the preset time interval and the battery cell voltage.
7. The method for non-destructive testing of abnormal lithium analysis of a battery according to claim 1, wherein the target charging current is 0.1C or less and the preset rest period is 30 minutes or less.
8. A system for non-destructive testing of abnormal lithium analysis of a battery, said system comprising: The charging execution module is used for executing two-stage charging on a target battery, wherein the target battery is charged to a charging cut-off voltage in a first charging stage, and enters a second charging stage after a preset standing time period, the target battery is recharged to the charging cut-off voltage in the second charging stage by a target charging current, and the minimum charging current of the first charging stage is larger than the target charging current; The parameter acquisition module is used for acquiring a voltage change curve of each battery core in the target battery in the second charging stage process; The parameter calculation module is used for calculating the voltage change rate of the voltage change of each battery cell along with time according to the voltage change curve to obtain a voltage change rate curve; and the lithium precipitation detection module is used for determining abnormal lithium precipitation battery cells according to the outlier change of the voltage change rate curve of each battery cell.
9. An electronic device comprising a memory, a processor and a computer program stored on the memory and executable on the processor, wherein execution of the computer program by the processor implements the method for non-destructive lithium analysis from a battery according to any one of claims 1-7.
10. A computer readable storage medium, on which a computer program is stored, characterized in that the computer program, when being executed by a processor, implements the method for non-destructive detection of abnormal lithium-out of a battery according to any one of claims 1-7.

Description

Battery abnormal lithium-precipitation nondestructive detection method, system, electronic equipment and storage medium Technical Field The application relates to the technical field of battery detection, in particular to a method, a system, electronic equipment and a storage medium for nondestructive detection of abnormal lithium precipitation of a battery. Background With the popularization of new energy automobiles, the market demand of lithium ion batteries continues to rise. However, during the use of the lithium ion battery, lithium precipitation is an unavoidable evolution process, and potential safety hazards such as thermal runaway and the like may be caused when serious, so that abnormal lithium precipitation monitoring and early warning are extremely important during the use of the lithium ion battery. The traditional lithium separation detection method generally needs to disassemble the battery for destructive detection, and is low in efficiency and difficult to timely feed back abnormal conditions. At present, the detection means based on the expansion force change trend, ultrasonic waves, impedance and the like are suitable for cell test verification in a laboratory environment, but the rapid response to the abnormal lithium precipitation cannot be realized in an actual application scene. Therefore, how to efficiently and conveniently monitor lithium ion battery lithium precipitation in practical application scenes is a problem to be solved. Disclosure of Invention In view of the defects in the prior art, the application provides a method, a system, electronic equipment and a storage medium for nondestructive detection of abnormal lithium precipitation of a battery, which effectively solve the problem that lithium precipitation of a lithium ion battery cannot be monitored efficiently and conveniently in a practical application scene. In a first aspect, the present application provides a method for non-destructive detection of abnormal lithium precipitation of a battery, the method comprising: Performing two-stage charging on a target battery, wherein the target battery is charged to a charging cut-off voltage in a first charging stage, and enters a second charging stage after a preset standing time, the target battery is recharged to the charging cut-off voltage in the second charging stage by a target charging current, and the minimum charging current of the first charging stage is larger than the target charging current; Acquiring a voltage change curve of each battery core in the target battery in the charging process of the second charging stage; calculating the voltage change rate of the voltage of each battery cell along with the time change according to the voltage change curve to obtain a voltage change rate curve; and determining abnormal lithium-ion battery cells according to the outlier change of the voltage change rate curve of each battery cell. In an alternative embodiment, the determining abnormal lithium-out cell according to the outlier variation of the voltage variation rate curve of each cell includes: Calculating target confidence intervals of the voltage change rates of all the battery cells under each voltage value according to the voltage change rate curve; Taking the lower limit value of the target confidence interval as an outlier threshold of the voltage change rate; and if the voltage change rate of the target battery cell existing in the continuous voltage interval is always smaller than the outlier threshold, determining the target battery cell as an abnormal lithium precipitation battery cell. In an alternative embodiment, the interval length of the continuous voltage interval is greater than or equal to 10mV, and the target confidence interval is a 95% confidence interval. In an alternative embodiment, the determining abnormal lithium-out cell according to the outlier variation of the voltage variation rate curve of each cell includes: calculating the average value of the voltage change rates of all the battery cells under each voltage value according to the voltage change rate curve; determining an outlier threshold of the voltage change rate according to the average value; and if the voltage change rate of the target battery cell existing in the continuous voltage interval is always smaller than the outlier threshold, determining the target battery cell as an abnormal lithium precipitation battery cell. In an alternative embodiment, the interval length of the continuous voltage interval is 10mV or more, and the outlier threshold is 75% of the average value. In an alternative embodiment, the acquiring the voltage change curve of each cell in the target battery during the charging process of the second charging stage includes: Collecting the cell voltage of each cell in the target battery in the charging process of the second charging stage at preset time intervals; And constructing the voltage change curve of each battery cell according to the preset time interv