CN-116148676-B - Method and device for judging self-discharge abnormal battery cell and electronic equipment

CN116148676BCN 116148676 BCN116148676 BCN 116148676BCN-116148676-B

Abstract

The application discloses a judging method, a judging device and electronic equipment of a self-discharge abnormal battery cell, the judging method comprises the steps of obtaining a charge state-open circuit voltage curve of the battery cell, determining the open circuit voltage corresponding to any inflection point position in the charge state-open circuit voltage curve as initial voltage of the battery cell, obtaining n target voltages of the battery cell obtained after n times of target operations are circulated on the battery cell, wherein the target operations are in one-to-one correspondence with the target voltages, the target operations are charging the battery cell for a first preset time with preset current, the first preset time is discharging the battery cell with the preset current, n is an integer larger than 1, determining the voltage difference between the initial voltage and the target voltage based on the initial voltage and the target voltage for each target voltage, and judging that the battery cell is the self-discharge abnormal battery cell under the condition that the n sequentially determined voltage differences are in an increasing trend.

Inventors

ZHOU KUAN
SHAO CHANGHONG
ZHANG XINWEI
YIN YONGSHENG
WEI JIEHONG

Assignees

欣旺达电动汽车电池有限公司

Dates

Publication Date: 20260508
Application Date: 20230327

Claims (9)

1. The method for judging the self-discharge abnormal battery cell is characterized by comprising the following steps of: acquiring a charge state-open circuit voltage curve of the battery cell; determining an open-circuit voltage corresponding to any inflection point position in the charge state-open-circuit voltage curve as an initial voltage of the battery cell; Determining an initial state of charge corresponding to the initial voltage based on the state of charge-open circuit voltage curve; Adjusting the state of charge of the battery cell to the initial state of charge, and standing the battery cell for a third preset time; Obtaining n target voltages of the battery cell, which are obtained after n times of target operation are circulated on the battery cell, wherein the target operation corresponds to the target voltages one by one, the target operation is to charge the battery cell for a first preset time with preset current, the battery cell is discharged for the first preset time with the preset current, and n is an integer greater than 1; Determining, for each of the target voltages, a voltage difference between the initial voltage and the target voltage based on the initial voltage and the target voltage; and under the condition that n voltage differences which are determined in sequence are in an increasing trend, judging the battery cell as a self-discharge abnormal battery cell.
2. The method according to claim 1, further comprising, after the charging the battery cell with the preset current for a first preset time: acquiring the charging energy of the battery cell in the first preset time; after the discharging the battery cell with the preset current for the first preset time, the method further comprises: acquiring discharge energy of the battery cell in the first preset time; and before judging that the battery cell is the self-discharge abnormal battery cell under the condition that n voltage differences which are determined in sequence are in an increasing trend, the method further comprises: determining charge-discharge efficiency of the battery cell based on the discharge energy and the charge energy for each set of the charge energy and the discharge energy; under the condition that n differential pressures determined in sequence are in an increasing trend, judging that the battery cell is a self-discharge abnormal battery cell, including: and under the conditions that the n sequentially determined differential pressures are in an increasing trend and the n sequentially determined charge and discharge efficiencies are in a decreasing trend, judging the battery cell as a self-discharge abnormal battery cell.
3. The method according to claim 2, wherein the acquiring the charging energy of the battery cell in the first preset time includes: Acquiring a first current and a first voltage in the process of charging the battery cell; determining charging energy of the battery cell in the first preset time based on the first current and the first voltage; The obtaining the discharge energy of the battery cell in the first preset time comprises the following steps: acquiring a second current and a second voltage in the process of discharging the battery cell; And determining the discharge energy of the battery cell in the first preset time based on the second current and the second voltage.
4. The method of claim 1, wherein the target operation is to charge the cell for a first preset time with a preset current, to rest the cell for a second preset time, to discharge the cell for the first preset time with the preset current, and to rest the cell for the second preset time.
5. The method according to claim 1, wherein the current magnitude of the preset current is determined according to the rated capacity of the battery cell.
6. The method according to claim 1, wherein the determining a differential pressure between the initial voltage and the target voltage based on the initial voltage and the target voltage includes: Determining a differential pressure between the initial voltage and the target voltage by the following formula; differential pressure= (U0-U4) 1000, Wherein U0 is the initial voltage and U4 is the target voltage; under the condition that n differential pressures determined in sequence are in an increasing trend, judging that the battery cell is a self-discharge abnormal battery cell, including: and under the condition that n sequentially determined differential pressures are in an ascending trend, judging the battery cell as a self-discharge abnormal battery cell.
7. The device for judging the self-discharge abnormal battery cell is characterized by comprising the following components: the first acquisition module is used for acquiring a charge state-open circuit voltage curve of the battery cell; The first determining module is used for determining the open-circuit voltage corresponding to any inflection point position in the charge state-open-circuit voltage curve as the initial voltage of the battery cell; the first determining module is further configured to determine an initial state of charge corresponding to the initial voltage based on the state of charge-open circuit voltage curve; The adjusting module is used for adjusting the charge state of the battery cell to the initial charge state and standing the battery cell for a third preset time; The second acquisition module is used for acquiring n target voltages of the battery cell, which are obtained after n times of target operation are circulated on the battery cell, wherein the target operation corresponds to the target voltages one by one, the target operation is to charge the battery cell for a first preset time by using a preset current, the battery cell is discharged for the first preset time by using the preset current, and n is an integer greater than 1; a second determination module configured to determine, for each of the target voltages, a differential pressure between the initial voltage and the target voltage based on the initial voltage and the target voltage; And the judging module is used for judging that the battery cell is a self-discharge abnormal battery cell under the condition that n sequentially determined differential pressures are in an increasing trend.
8. An electronic device comprising a processor and a memory storing a program or instructions executable on the processor, which when executed by the processor, implement the steps of the method of determining a self-discharging abnormal cell according to any one of claims 1-6.
9. A readable storage medium, wherein a program or an instruction is stored on the readable storage medium, and the program or the instruction, when executed by a processor, implements the steps of the method for determining a self-discharge abnormal cell according to any one of claims 1 to 6.

Description

Method and device for judging self-discharge abnormal battery cell and electronic equipment Technical Field The present application relates to the field of batteries, and in particular, to a method and an apparatus for determining a self-discharge abnormal cell, and an electronic device. Background At the beginning of new forms of energy consumer production such as electric automobile, energy storage power station and in the use, generally can carry out uniformity screening and management and control to electric core or group battery to make the consumer can reach better result of use. At present, common control items include battery capacity, voltage, internal resistance, self-discharge and the like, wherein the self-discharge is the most difficult to control, and the result caused by the self-discharge is the most serious. In the related art, each enterprise mainly carries out self-discharge sorting on the battery cells through a standing method, the main process is to stand for different days from capacity division of the battery cells, test the voltage drop of the battery cells every day, count the mean value and standard deviation (sigma) of the voltage drop of the battery cells, determine a sorting threshold value based on the mean value and standard deviation (sigma) of the voltage drop of the battery cells, and then judge whether the battery cells are abnormal in self-discharge according to the determined sorting threshold value, but because the single voltage of the battery cells is generally between 0 and 5V, and the voltage drop of the battery cells every day is not obvious in many times, a certain error exists in the voltage measuring device when testing the voltage drop, so the problem that the accuracy of judgment is lower exists in judging whether the battery cells are abnormal in self-discharge or not through the scheme. Disclosure of Invention The application discloses a judging method and device for a self-discharge abnormal battery cell and electronic equipment, which can improve the accuracy of judging the self-discharge abnormal battery cell. In order to solve the problems, the application adopts the following technical scheme: The embodiment of the application discloses a judging method of a self-discharge abnormal battery cell, which comprises the steps of obtaining a charge state-open circuit voltage curve of the battery cell, determining the open circuit voltage corresponding to any inflection point position in the charge state-open circuit voltage curve as initial voltage of the battery cell, obtaining n target voltages of the battery cell obtained after n times of target operations are circulated on the battery cell, wherein the target operations are in one-to-one correspondence with the target voltages, the target operations are to charge the battery cell for a first preset time with preset current, the first preset time is to discharge the battery cell with the preset current, n is an integer larger than 1, determining the pressure difference between the initial voltage and the target voltage based on the initial voltage and the target voltage for each target voltage, and judging the battery cell as the self-discharge abnormal battery cell under the condition that the n sequentially determined pressure differences are in an increasing trend. The embodiment of the application discloses a judging device of a self-discharge abnormal battery cell, which comprises a first acquiring module, a first determining module and a second acquiring module, wherein the first acquiring module is used for acquiring a charge state-open circuit voltage curve of the battery cell, the first determining module is used for determining the open circuit voltage corresponding to any inflection point position in the charge state-open circuit voltage curve as an initial voltage of the battery cell, the second acquiring module is used for acquiring n target voltages of the battery cell obtained after n times of target operations are circulated on the battery cell, the target operations are in one-to-one correspondence with the target voltages, the target operations are charging the battery cell for a first preset time with preset current, the first preset time is discharging the battery cell with the preset current, n is an integer larger than 1, the second determining module is used for determining the pressure difference between the initial voltage and the target voltage based on the initial voltage and the target voltage for each target voltage, and the judging module is used for judging the battery cell to be the abnormal in the case that the n determined pressure differences are in sequence and are in an increasing trend. In a third aspect, an embodiment of the present application provides an electronic device comprising a processor and a memory storing a program or instructions executable on the processor, which when executed by the processor, implement the steps of the method as described in the first