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CN-121995255-A - Battery capacity detection method, detection device, terminal and storage medium

CN121995255ACN 121995255 ACN121995255 ACN 121995255ACN-121995255-A

Abstract

The application discloses a battery capacity detection method, a battery capacity detection device, a terminal and a storage medium. The battery capacity detection method comprises the steps of obtaining thermodynamic discharge data of a reference battery cell and kinetic discharge data of a battery cell to be detected, wherein the reference battery cell and the battery cell to be detected belong to the same battery design of the same battery system, obtaining capacity compensation data based on the thermodynamic discharge data and the kinetic discharge data, and correcting the kinetic capacity data of the battery cell to be detected by utilizing the capacity compensation data to obtain thermodynamic capacity data of the battery cell to be detected. In this way, the application can shorten the detection period of the battery capacity and improve the detection accuracy of the battery capacity.

Inventors

  • Shi Xixiu
  • SU MIN
  • Liang jinding
  • WEI YIMIN

Assignees

  • 宁德时代新能源科技股份有限公司

Dates

Publication Date
20260508
Application Date
20241107

Claims (12)

  1. 1.A method for detecting battery capacity, the method comprising: the thermodynamic discharge data of a reference battery monomer and the thermodynamic discharge data of a battery monomer to be detected are obtained, wherein the reference battery monomer and the battery monomer to be detected belong to the same battery design of the same battery system; acquiring capacity compensation data based on the thermodynamic discharge data and the kinetic discharge data; and correcting the dynamic capacity data of the battery cell to be detected by using the capacity compensation data to obtain the thermodynamic capacity data of the battery cell to be detected.
  2. 2. The method according to claim 1, wherein the thermodynamic discharge data includes an open circuit voltage and a first discharge capacity of the reference cell, and the kinetic discharge data includes a discharge end voltage and a second discharge capacity of the cell to be measured; acquiring capacity compensation data based on the thermodynamic discharge data and the kinetic discharge data, comprising: Acquiring a first relation based on the open-circuit voltage and the first discharge capacity, wherein the first relation is a relation between the residual capacity of the reference battery cell and the open-circuit voltage; And acquiring the residual capacity corresponding to the discharge end voltage as capacity compensation data based on the first relation.
  3. 3. The method of detecting as claimed in claim 2, wherein the first relation includes a functional relation, the obtaining a first relation between the remaining capacity of the reference battery cell and the open circuit voltage based on the open circuit voltage and the first discharge capacity includes: acquiring a first curve based on the open-circuit voltage and the first discharge capacity, wherein the first curve is a relation curve between the open-circuit voltage and the discharge capacity of the reference battery cell; converting the first curve into a second curve, wherein the second curve is a relation curve between the open-circuit voltage and the residual capacity of the reference battery cell; And acquiring the functional relation based on the second curve.
  4. 4. The method according to claim 3, wherein the converting the first curve into a second curve, the second curve being a relation curve between the open circuit voltage and the remaining capacity of the reference battery cell, comprises: acquiring a third curve corresponding to a discharge end stage of the reference battery cell from the first curve based on the discharge end voltage; and converting the third curve into a second curve, wherein the second curve is a relation curve between the open circuit voltage and the residual capacity of the reference battery cell at the discharge end stage.
  5. 5. The method according to claim 3 or 4, wherein the second curve includes a first sub-curve and a second sub-curve, the first sub-curve being a relation between the open-circuit voltage of the reference battery cell and a percentage of the remaining capacity, and the second sub-curve being a relation between the open-circuit voltage of the reference battery cell and an absolute value of the remaining capacity.
  6. 6. The detection method according to any one of claims 3 to 5, characterized in that the detection method further comprises: At least obtaining a third sub-curve corresponding to one circle of discharge of the reference battery monomer, and a fourth sub-curve corresponding to N circles of discharge; comparing at least the third sub-curve and the fourth sub-curve to obtain a comparison result; the obtaining capacity compensation data based on the thermodynamic discharge data and the kinetic discharge data includes: Responding to the comparison result to be matched, and acquiring capacity compensation data of the battery cell to be tested in one circle of discharge based on thermodynamic discharge data of the reference battery cell in one circle of discharge and the kinetic discharge data; the correcting the dynamic capacity data of the battery cell to be measured by using the capacity compensation data to obtain thermodynamic capacity data of the battery cell to be measured includes: and correcting the dynamic capacity data of the battery cell to be tested by utilizing the capacity compensation data of the one circle of discharge, and at least obtaining the thermodynamic capacity data of the one circle of discharge of the battery cell to be tested.
  7. 7. The method according to any one of claims 1 to 6, wherein the capacity compensation data includes first capacity compensation data and second capacity compensation data, and the acquiring capacity compensation data based on the thermodynamic discharge data and the kinetic discharge data includes: responding to the fact that the comparison result is not matched, and at least acquiring first capacity compensation data of one circle of discharge of the battery cell to be tested and second capacity compensation data of the nth circle of discharge based on thermodynamic discharge data of at least one circle of discharge, thermodynamic discharge data of N circles of discharge and the kinetic discharge data of the reference battery cell; the correcting the dynamic capacity data of the battery cell to be measured by using the capacity compensation data to obtain thermodynamic capacity data of the battery cell to be measured includes: correcting the dynamic capacity data of the battery cell to be measured discharged for one circle to (N-1) circle by using the first capacity compensation data, and correcting the dynamic capacity data of the battery cell to be measured discharged for N circles and N circles by using the second capacity compensation data; wherein, N is a natural number greater than 1.
  8. 8. The detection method according to any one of claims 2 to 7, wherein acquiring the discharge end voltage includes: and after the discharge is finished, standing the battery monomer to be tested for a preset time, and obtaining the voltage after the preset time as the discharge finishing voltage.
  9. 9. The detection method according to any one of claims 2 to 7, wherein acquiring the discharge end voltage includes: after discharging, standing the battery to be tested for a preset time period, and obtaining the voltage after the preset time period as a standing voltage; And fitting the rest voltage by using a relaxation formula to obtain the discharge end voltage.
  10. 10. A battery capacity detection device, characterized in that the battery capacity detection device includes: the system comprises a detection module, a reference battery cell, a battery system and a battery system, wherein the detection module is used for acquiring thermodynamic discharge data of the reference battery cell and kinetic discharge data of the battery cell to be detected; The analysis module is used for acquiring capacity compensation data based on the thermodynamic discharge data and the kinetic discharge data; And the correction module is used for correcting the dynamic capacity data of the battery cell to be detected by utilizing the capacity compensation data to obtain the thermodynamic capacity data of the battery cell to be detected.
  11. 11. A terminal comprising a memory, a processor and a computer program stored in the memory and running on the processor, the processor being configured to execute program data to implement the method of detecting battery capacity according to any one of claims 1 to 9.
  12. 12. A computer-readable storage medium, characterized in that the computer-readable storage medium has stored thereon a computer program which, when executed by a processor, implements the method of detecting the battery capacity according to any one of claims 1 to 9.

Description

Battery capacity detection method, detection device, terminal and storage medium Technical Field The present application relates to the field of battery technologies, and in particular, to a battery capacity detection method, a battery capacity detection device, a terminal, and a computer readable storage medium. Background With the development of battery technology, battery devices are applied to more and more fields, such as automobile power, energy storage and other fields, and gradually replace traditional petrochemical energy sources. With the rise of the battery market, the long-life performance of the battery device is focused, however, the test period of the battery cell is long, particularly the battery cell for energy storage, and the long-life parameter of the battery cell is not practical to detect through the cycle of the full life cycle. In the related art, the service life of the battery cell is predicted by testing a small amount of cyclic data and extrapolating or modeling the cyclic data, but the prediction mode by extrapolating or modeling the cyclic data is extremely dependent on the quality and the length of the tested data, and the data with the quality or the length not reaching the standard can cause great errors in prediction, so that the accuracy of the detected battery capacity is lower. Disclosure of Invention In view of the above, the present application provides a method for detecting battery capacity, a device for detecting battery capacity, a terminal and a computer readable storage medium, so as to shorten the detection period of battery capacity and improve the detection accuracy of battery capacity. The application provides a battery capacity detection method, which comprises the steps of obtaining thermodynamic discharge data of a reference battery monomer and kinetic discharge data of a battery monomer to be detected, wherein the reference battery monomer and the battery monomer to be detected belong to the same battery design of the same battery system, obtaining capacity compensation data based on the thermodynamic discharge data and the kinetic discharge data, and correcting the kinetic capacity data of the battery monomer to be detected by utilizing the capacity compensation data to obtain the thermodynamic capacity data of the battery monomer to be detected. By the method, thermodynamic capacity data of the battery to be measured can be obtained only by obtaining thermodynamic discharge data of one single battery under the same battery design of the same battery system and kinetic discharge data of the battery to be measured. Compared with the dynamic discharge data, the thermodynamic discharge data has long acquisition period and high reliability, and the embodiment does not need to acquire the thermodynamic discharge data of the battery to be detected, so that the embodiment can shorten the detection period of the battery capacity and acquire the thermodynamic capacity data with high reliability, thereby improving the detection accuracy of the battery capacity. In some embodiments, the thermodynamic discharge data comprises an open circuit voltage and a first discharge capacity of the reference battery cell, the kinetic discharge data comprises a discharge end voltage and a second discharge capacity of the battery cell to be tested, the capacity compensation data are obtained based on the thermodynamic discharge data and the kinetic discharge data, the capacity compensation data are obtained based on the open circuit voltage and the first discharge capacity, the first relation is a relation between the residual capacity of the reference battery cell and the open circuit voltage, and the residual capacity corresponding to the discharge end voltage is obtained based on the first relation to serve as the capacity compensation data. The open circuit voltage and the discharge capacity are important data related to the battery capacity in the battery cell and are easy to obtain, the first relation is determined through the two data, and the residual capacity corresponding to the discharge end voltage of the battery cell to be tested is obtained as capacity compensation data based on the first relation, so that the residual capacity corresponding to the discharge end voltage can represent unreleased battery capacity caused by factors such as polarization after the discharge of the battery cell to be tested is ended, and the capacity compensation data of the battery cell to be tested can be accurately obtained. In some embodiments, the first relationship comprises a functional relationship, the obtaining a first relationship between the residual capacity and the open-circuit voltage of the reference battery cell based on the open-circuit voltage and the first discharge capacity comprises obtaining a first curve based on the open-circuit voltage and the first discharge capacity, the first curve being a relationship between the open-circuit voltage and the discharge capacit