Search

CN-121995246-A - Method, device and equipment for detecting OH area ratio of battery cell

CN121995246ACN 121995246 ACN121995246 ACN 121995246ACN-121995246-A

Abstract

The application discloses a detection method, a device and equipment for an OH area ratio of a battery cell, relates to the technical field of battery detection, and discloses a detection method for the OH area ratio of the battery cell, wherein a target corresponding relation between the OH area ratio of a first battery cell and a leakage current integral value, which is established in advance, is obtained, the leakage current integral value is an integral value obtained by integrating the leakage current of the first battery cell with time, first leakage current data of a second battery cell to be detected are measured, the integral value of the leakage current in the first leakage current data is calculated, the first integral value is obtained, the second battery cell is identical with other design parameters of the first battery cell except the OH area ratio, and the OH area ratio of the second battery cell is determined according to the first integral value and the target corresponding relation. The application has the advantages of simple test flow and data processing without depending on photographic imaging technology, can realize quantitative analysis of the OH area occupation ratio by measuring the leakage current integral value and comparing with the corresponding relation, and has high reliability.

Inventors

  • WU YUTING
  • SU MIN

Assignees

  • 宁德时代新能源科技股份有限公司

Dates

Publication Date
20260508
Application Date
20241104

Claims (10)

  1. 1. The method for detecting the OH area ratio of the battery cell is characterized by comprising the following steps of: acquiring a target corresponding relation between an OH area occupation ratio of a first battery core and a leakage current integral value, wherein the leakage current integral value is an integral value obtained by integrating the leakage current of the first battery core with time; measuring first leakage current data of a second battery cell to be measured, and calculating integration of leakage current in the first leakage current data to time to obtain a first integration value, wherein the second battery cell is identical to the first battery cell in other design parameters except the OH area occupation ratio; and determining the OH area ratio of the second battery cell according to the first integral value and the target corresponding relation.
  2. 2. The method of claim 1, wherein measuring the first leakage current data of the second cell under test comprises: Adjusting the residual electric quantity SOC of the second battery cell to a target SOC, wherein the voltage variation amplitude of the second battery cell under the target SOC is larger than a first value; and under the target SOC, measuring first leakage current data of the second battery cell to be measured.
  3. 3. The method according to claim 1 or 2, wherein measuring the first leakage current data of the second cell to be measured comprises: Setting the second electric core in an oven, and adjusting the temperature of the oven to a preset temperature interval, wherein the leakage current of the second electric core in the preset temperature interval is larger than a second value, and the preset temperature interval is determined according to the capacity of the second electric core; and measuring first leakage current data of the second battery cell to be measured in the preset temperature interval.
  4. 4. The method according to claim 1 or 2, wherein measuring the first leakage current data of the second cell to be measured comprises: measuring an open circuit voltage of the second cell; Charging the second battery cell to the open circuit voltage through a current of a target constant value, wherein the target constant value is determined according to the capacity of the second battery cell; and under the condition that the voltage of the second battery cell is kept to be the open-circuit voltage, collecting the change data of the charging current along with time as the first leakage current data.
  5. 5. The method of claim 1, wherein the method further comprises: Dividing a change interval of the OH area ratio in the target corresponding relation into N first subintervals, wherein N is an integer greater than 1; according to the target corresponding relation, N second sub-intervals of leakage current integral values corresponding to the N first sub-intervals are determined; Determining at least one first target interval from the N first subintervals as a screening condition; Determining at least one second target interval corresponding to the at least one first target interval in the N second sub-intervals; and screening out the second battery cells of the first integral value in the at least one second target interval as target battery cells.
  6. 6. The method of claim 1, wherein prior to said obtaining a target correspondence between the OH area occupancy of the first cell and the leakage current integral value, the method further comprises: Preparing M groups of first electric cores with different OH area occupation ratios, wherein M is an integer larger than 1, and other design parameters of the M groups of first electric cores except the OH area occupation ratios are the same; For each first cell in the M groups of first cells, measuring second leakage current data corresponding to the first cell, and calculating integration of leakage current in the second leakage current data to time to obtain a second integration value; And establishing the target corresponding relation according to the OH area occupation ratio and the second integral value respectively corresponding to the M groups of first electric cores.
  7. 7. A device for detecting the OH area ratio of a battery cell, the device comprising: The acquisition module is used for acquiring a target corresponding relation between the OH area occupation ratio of the first battery cell and the leakage current integral value, wherein the leakage current integral value is an integral value obtained by integrating the leakage current of the first battery cell with time; The measuring module is used for measuring first leakage current data of a second battery cell to be measured and calculating integration of leakage current in the first leakage current data to time to obtain a first integrated value, wherein the second battery cell is identical to the first battery cell in design parameters except for the OH area occupation ratio; and the determining module is used for determining the OH area occupation ratio of the second battery cell according to the first integral value and the target corresponding relation.
  8. 8. A device for detecting the OH area fraction of a cell, characterized in that the device comprises a memory, a processor and a computer program stored on the memory and executable on the processor, the computer program being configured to implement the steps of the method for detecting the OH area fraction of a cell according to any one of claims 1 to 6.
  9. 9. A storage medium, characterized in that the storage medium is a computer-readable storage medium, on which a computer program is stored, which computer program, when being executed by a processor, realizes the steps of the method for detecting the OH area fraction of a cell according to any one of claims 1 to 6.
  10. 10. A computer program product, characterized in that it comprises a computer program which, when executed by a processor, implements the steps of the method for detecting the OH area fraction of a cell according to any one of claims 1 to 6.

Description

Method, device and equipment for detecting OH area ratio of battery cell Technical Field The application relates to the technical field of battery detection, in particular to a detection method, a detection device and detection equipment for the OH area ratio of a battery cell. Background Because of the advantages of high energy density, recycling charging, safety, environmental protection and the like, the power battery is widely applied to the fields of new energy automobiles, consumer electronics, energy storage systems and the like, and for example, the power battery comprises a lithium battery. In the design of a lithium battery, the cathode of the lithium battery needs to be provided with area allowance in the length and width directions than the anode, a parameter of Overhang (abbreviated as OH) area occupation ratio is generally set to represent that the cathode pole piece is more than the anode pole piece in the length and width directions, and the battery cell is detected and screened according to the parameter of the OH area occupation ratio. At present, detection of the OH area ratio is mostly based on a photographic imaging technology, for example, an x-ray image is adopted to calculate the OH area ratio of a battery, the detection method is single, the selectivity is low, the calculation universality is low, the calculation is complex, the requirement on equipment algorithm is high, and the detection requirement of a lithium battery is difficult to meet. Therefore, how to provide a simpler and effective OH area ratio detection method is a problem to be solved. Disclosure of Invention The application mainly aims to provide a detection method, a detection device and detection equipment for the OH area ratio of a battery cell, and aims to provide a simpler and effective detection method for the OH area ratio. In order to achieve the above purpose, the present application provides a method for detecting an OH area ratio of a battery cell, the method comprising: acquiring a target corresponding relation between an OH area occupation ratio of a first battery core and a leakage current integral value, wherein the leakage current integral value is an integral value obtained by integrating the leakage current of the first battery core with time; measuring first leakage current data of a second battery cell to be measured, and calculating integration of leakage current in the first leakage current data to time to obtain a first integration value, wherein the second battery cell is identical to the first battery cell in other design parameters except the OH area occupation ratio; and determining the OH area ratio of the second battery cell according to the first integral value and the target corresponding relation. In an embodiment, the measuring the first leakage current data of the second cell to be measured includes: Adjusting the residual electric quantity SOC of the second battery cell to a target SOC, wherein the voltage variation amplitude of the second battery cell under the target SOC is larger than a first value; and under the target SOC, measuring first leakage current data of the second battery cell to be measured. In this embodiment, in the process of measuring the first leakage current data of the second battery cell, the SOC of the second battery cell can be adjusted to the target SOC and then measured, so that the voltage variation amplitude of the second battery cell is larger than the first value, thus the leakage current measured subsequently can be similarly amplified, the leakage current data can be measured more accurately, and the battery cell with a certain OH area ratio can be screened more accurately. In an embodiment, the measuring the first leakage current data of the second cell to be measured includes: Setting the second electric core in an oven, and adjusting the temperature of the oven to a preset temperature interval, wherein the leakage current of the second electric core in the preset temperature interval is larger than a second value, and the preset temperature interval is determined according to the capacity of the second electric core; and measuring first leakage current data of the second battery cell to be measured in the preset temperature interval. In this embodiment, in the process of measuring the first leakage current data of the second battery cell, the second battery cell may be set in the oven and adjusted to a preset temperature interval for measurement, so that the measured leakage current may be greater than the second value, and considered to be in a monitorable range, and a specific preset temperature interval may be determined according to the capacity of the second battery cell, for example, when the capacity of the battery cell is smaller, a higher preset temperature interval may be set, so as to amplify the leakage current, so that effective monitoring is facilitated, leakage current data is measured more accurately, and further, a battery cell wit