CN116148676A - Method and device for judging self-discharge abnormal battery cell and electronic equipment - Google Patents
Method and device for judging self-discharge abnormal battery cell and electronic equipment Download PDFInfo
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- CN116148676A CN116148676A CN202310312496.5A CN202310312496A CN116148676A CN 116148676 A CN116148676 A CN 116148676A CN 202310312496 A CN202310312496 A CN 202310312496A CN 116148676 A CN116148676 A CN 116148676A
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R31/00—Arrangements for testing electric properties; Arrangements for locating electric faults; Arrangements for electrical testing characterised by what is being tested not provided for elsewhere
- G01R31/36—Arrangements for testing, measuring or monitoring the electrical condition of accumulators or electric batteries, e.g. capacity or state of charge [SoC]
- G01R31/367—Software therefor, e.g. for battery testing using modelling or look-up tables
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R31/00—Arrangements for testing electric properties; Arrangements for locating electric faults; Arrangements for electrical testing characterised by what is being tested not provided for elsewhere
- G01R31/36—Arrangements for testing, measuring or monitoring the electrical condition of accumulators or electric batteries, e.g. capacity or state of charge [SoC]
- G01R31/385—Arrangements for measuring battery or accumulator variables
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
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Abstract
The application discloses a judging method, a judging device and electronic equipment of a self-discharge abnormal battery cell, wherein the judging method comprises the following steps: 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; 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.
Description
Technical Field
The present disclosure 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, however, 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 a 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:
in a first aspect, an embodiment of the present application discloses a method for determining a self-discharge abnormal cell, including: 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; 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.
In a second aspect, an embodiment of the present application discloses a device for determining a self-discharge abnormal cell, including: 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 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.
In a third aspect, embodiments of the present application provide 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 aspect.
In a fourth aspect, embodiments of the present application provide a readable storage medium having stored thereon a program or instructions which when executed by a processor implement the steps of the method according to the first aspect.
The embodiment of the application provides a judging method of a self-discharge abnormal battery cell, which comprises the steps of determining an open-circuit voltage corresponding to any inflection point position in a charge state-open-circuit voltage curve as an initial voltage of the battery cell by acquiring the charge state-open-circuit voltage curve of the battery cell, then acquiring n target voltages obtained after the battery cell is charged for a first preset time with preset current and is discharged for a target operation of the first preset time with preset current, determining a pressure difference between the initial voltage and the target voltage according to each target voltage on the basis of the initial voltage and the target voltage, and finally 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. By the method, whether the battery cell is abnormal in self-discharge or not is judged, a specific test value is not needed to be considered, and whether the battery cell is abnormal in self-discharge or not can be judged only on the basis of the change trend of n differential pressures, so that the accuracy of judging the abnormal battery cell in self-discharge can be improved.
Drawings
Fig. 1 is a schematic flow chart of a method for judging a self-discharge abnormal cell according to an embodiment of the present application;
FIG. 2 is a plot of state of charge versus open circuit voltage for a cell as disclosed in embodiments of the present application;
fig. 3a is a trend chart of charge and discharge efficiency of a battery cell according to an embodiment of the present disclosure;
FIG. 3b is a graph showing a variation trend of differential pressure according to the embodiments of the present application;
fig. 4a is a graph showing a change trend of charge and discharge efficiency of another battery cell according to an embodiment of the present disclosure;
FIG. 4b is a graph showing another pressure difference variation trend disclosed in the embodiments of the present application;
fig. 5a is a graph showing a change trend of charge and discharge efficiency of another battery cell according to an embodiment of the present disclosure;
FIG. 5b is a graph showing the trend of pressure difference according to another embodiment of the present disclosure;
fig. 6a is a graph showing a change trend of charge and discharge efficiency of another battery cell according to an embodiment of the present disclosure;
FIG. 6b is a graph showing the trend of pressure difference according to another embodiment of the present disclosure;
fig. 7 is a schematic structural diagram of a device for determining a self-discharge abnormal cell according to an embodiment of the present disclosure;
fig. 8 is a schematic structural diagram of an electronic device according to an embodiment of the present application.
Detailed Description
Technical solutions in the embodiments of the present application will be clearly described below with reference to the drawings in the embodiments of the present application, and it is apparent that the described embodiments are some embodiments of the present application, but not all embodiments. All other embodiments obtained by a person of ordinary skill in the art based on the embodiments in the present application are within the scope of the protection of the present application.
The terms first, second and the like in the description and in the claims, are used for distinguishing between similar objects and not necessarily for describing a particular sequential or chronological order. It is to be understood that the data so used may be interchanged, as appropriate, such that embodiments of the present application may be implemented in sequences other than those illustrated or described herein, and that the objects identified by "first," "second," etc. are generally of a type and not limited to the number of objects, e.g., the first object may be one or more. In addition, in the specification and claims, "and/or" means at least one of the electrically connected objects, and the character "/", generally means that the associated object is an "or" relationship.
The method, the device and the electronic equipment for judging the self-discharge abnormal battery cell disclosed in the embodiments of the present application are described in detail below with reference to the accompanying drawings by specific embodiments and application scenarios thereof.
Fig. 1 is a flow chart of a method for judging a self-discharge abnormal cell according to an embodiment of the present application, as shown in fig. 1, the method includes the following steps:
s110, acquiring a State of Charge-open circuit voltage (SOC-OCV) curve of the battery cell.
Exemplary, a plot of SOC-OCV for a cell of a nominal capacity 150Ah is shown in fig. 2. It should be noted that the SOC-OCV curves of different cells may be different, and fig. 2 is only an example.
And S120, 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.
In the method, the open-circuit voltage corresponding to any inflection point position in the SOC-OCV curve is determined as the initial voltage of the battery cell, so that the subsequent determination result is more obvious and visual. Alternatively, the open circuit voltage corresponding to the position of the abrupt and gentle inflection point in the SOC-OCV curve may be determined as the initial voltage of the battery cell.
Taking fig. 2 as an example, the open circuit voltage corresponding to 5% soc may be determined as the initial voltage of the battery cell, or the open circuit voltage corresponding to 50% soc may be determined as the initial voltage of the battery cell.
S130, obtaining n target voltages of the battery cell obtained after n times of target operation on the battery cell.
The target operation is to charge the battery cell for a first preset time with a preset current, and discharge the battery cell for the first preset time with the preset current, wherein n is an integer greater than 1.
That is, after the target operation of charging the battery cell with the preset current for the first preset time and discharging the battery cell with the preset current for the first preset time once per cycle, a target voltage is obtained.
In the application, n target voltages are obtained after n times of target operations are circulated on the battery cell from the initial voltage.
If the battery core has no self-discharge abnormality, after the target operation is performed on the battery core, ignoring temperature rise and polarization, wherein the target voltage of the battery core is equal to or close to the initial voltage of the battery core, and when the difference between the initial voltage of the battery core and the target voltage of the battery core is within +/-1% of the initial voltage of the battery core, the target voltage of the battery core is considered to be close to the initial voltage of the battery core; if the self-discharge of the battery cell is abnormal, repeatedly cycling n times of target operation, the obtained target voltage of the battery cell gradually gets far away from the initial voltage of the battery cell, namely the pressure difference between the initial voltage and the target voltage tends to increase.
S140, for each of the target voltages, determining a differential pressure between the initial voltage and the target voltage based on the initial voltage and the target voltage.
And S150, judging the battery cell as a self-discharge abnormal battery cell under the condition that n sequentially determined differential pressures are in an increasing trend.
The method can be used for more intuitively determining the change trend of the n differential pressures based on the determined n differential pressures by plotting the cycle times as an abscissa and the differential pressures as an ordinate, and further judging that the battery cell is a self-discharge abnormal battery cell under the condition that the n differential pressures which are sequentially determined are in an increasing trend.
The embodiment of the application provides a judging method of a self-discharge abnormal battery cell, which comprises the steps of determining an open-circuit voltage corresponding to any inflection point position in a charge state-open-circuit voltage curve as an initial voltage of the battery cell by acquiring the charge state-open-circuit voltage curve of the battery cell, then acquiring n target voltages obtained after the battery cell is charged for a first preset time with preset current and is discharged for a target operation of the first preset time with preset current, determining a pressure difference between the initial voltage and the target voltage according to each target voltage on the basis of the initial voltage and the target voltage, and finally 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. By the method, whether the battery cell is abnormal in self-discharge or not is judged, a specific test value is not needed to be considered, and whether the battery cell is abnormal in self-discharge or not can be judged only on the basis of the change trend of n differential pressures, so that the accuracy of judging the abnormal battery cell in self-discharge can be improved.
In addition, through the judging method disclosed by the application, whether the battery cell is abnormal in self-discharge or not is judged, and as the battery cell is circularly charged and discharged for n times, the battery cell with the abnormal self-discharge (such as stress puncture of a diaphragm after foreign matter circulation) after charging and discharging for a certain times can be screened out. In addition, by adopting the judging method disclosed by the application, corresponding parameters can be adjusted according to actual project conditions, so that judging accuracy is improved, for example, for a battery cell with a low self-discharge rate, cycle times can be increased, preset current is reduced, and the duration of the first preset time is increased, so that judging accuracy is improved.
Considering the influence of the sampling precision of the cell voltage on the judgment result, in this embodiment of the present application, after the charging the cell with the preset current for the first preset time, the method may further include: 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 may further include: acquiring discharge energy of the battery cell in the first preset time; before the determining that the cell is the self-discharge abnormal cell under the condition that the n sequentially determined differential pressures are in an increasing trend, the method may further include: 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 can comprise: 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.
It should be noted that, each time the target operation is executed, a set of charging energy to the battery cell in the first preset time and a set of discharging energy to the battery cell in the first preset time can be obtained, so as to obtain charging and discharging efficiency of one battery cell, that is, the target operation corresponds to the charging and discharging efficiency one by one. If the battery cell has no self-discharge abnormality, the charge-discharge efficiency of the battery cell is a relatively stable value, if the battery cell has self-discharge abnormality, when a charge or discharge pulse is applied to the battery cell, the rate of rise or fall of the voltage is different, for example, an open circuit voltage corresponding to 5% SOC as shown in fig. 2 is selected as an initial voltage of the battery cell, at this time, the voltage change in the discharge process is amplified, specifically, at this time, the battery cell discharge current=self-discharge current-preset current, and at this time, the voltage change in the charge process is reduced, specifically, at this time, the total charge current=preset current-self-discharge current of the battery cell, and the external appearance is that the charge-discharge efficiency of the battery cell is continuously reduced.
The method can be used for more intuitively determining the change trend of the n charge-discharge efficiencies based on the determined n charge-discharge efficiencies by plotting the cycle times as the abscissa and the charge-discharge efficiencies as the ordinate, and if the n charge-discharge efficiencies are in a decreasing trend, the battery cell is a self-discharge abnormal battery cell.
In one implementation, the determining, for each set of the charging energy and the discharging energy, the charging and discharging efficiency of the battery cell based on the discharging energy and the charging energy may include: determining the charge and discharge efficiency of the battery cell through the following formula; charge-discharge efficiency = discharge energy/charge energy 100%.
According to the judging method disclosed by the application, through combining the change trend of n differential pressures obtained by cycling n times of target operation with the change trend of n charge and discharge efficiencies, whether the battery cell is abnormal in self-discharge or not is judged, and the accuracy of judging the battery cell with abnormal self-discharge can be further improved.
In one implementation, the acquiring the charging energy of the battery cell in the first preset time may include: 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 acquiring the discharge energy of the battery cell in the first preset time may include: 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.
Illustratively, the determining the charging energy of the battery cell within the first preset time based on the first current and the first voltage may include: determining the charging energy of the battery cell in the first preset time through the following formula; e (E) c1 ＝∫I 2 *U 2 ＝∑I 2 *U 2 Wherein E is c1 To charge the battery cell within the first preset time, I 2 For the first current, U 2 Is the first voltage. The determining, based on the second current and the second voltage, a discharge energy to the cell within the first preset time may include: determining the discharge energy of the battery cell in the first preset time through the following formula; e (E) c2 ＝∫I 3 *U 3 ＝∑I 3 *U 3 Wherein E is c2 To discharge energy of the battery cell within the first preset time, I 3 For the second current, U 3 Is the second voltage.
In this embodiment of the present application, the target operation may be charging the battery cell for a first preset time with a preset current, standing the battery cell for a second preset time, discharging the battery cell for the first preset time with the preset current, and standing the battery cell for the second preset time. That is, after the battery cell is charged for a first preset time by the preset current, the battery cell is kept stand for a second preset time, after the voltage of the battery cell tends to be stable, the battery cell is discharged for the first preset time by the preset current, then the battery cell is kept stand for the second preset time, after the voltage of the battery cell tends to be stable, the voltage of the battery cell at the moment is obtained as a target voltage, so that the accuracy of the obtained target voltage is improved, and the accuracy of judging whether the battery cell is abnormal in self-discharge or not is further improved. It should be noted that, the value of the second preset time is not specifically limited in this application, and the specific value of the second preset time may be determined according to actual needs.
In this application, after determining the open-circuit voltage corresponding to any inflection point position in the state of charge-open-circuit voltage curve as the initial voltage of the battery cell, the method may further include: determining an initial state of charge corresponding to the initial voltage based on the state of charge-open circuit voltage curve; and adjusting the charge state of the battery cell to the initial charge state, and standing the battery cell for a third preset time. That is, after the state of charge of the battery cell is adjusted to an initial state of charge corresponding to the selected initial voltage and the battery cell is left for a third preset time, a target operation is performed on the battery cell to obtain a target voltage. It should be noted that, the value of the third preset time is not specifically limited in this application, and the specific value of the third preset time may be determined according to actual needs.
In addition, in order to avoid causing the temperature rise and polarization accumulation of the battery cells, the preset current and the first preset time are not too large. In this application, the current level of the preset current may be determined according to the rated capacity of the battery cell. In one implementation, the current corresponding to 1/10 of the rated capacity of the battery cell may be determined as the current of the preset current, and for example, the current of the preset current is 15A when the rated capacity of the battery cell is 150Ah, and the current of the preset current is 0.6A when the rated capacity of the battery cell is 6 Ah. In addition, the current magnitude of the preset current can be adjusted according to the precision of the device for executing the target operation, and when the precision of the device for executing the target operation is high, a relatively smaller preset current can be selected, and the duration of the selected first preset time is relatively longer. In the application, the duration of the first preset time can be determined according to the rated capacity of the battery cell and the severity of the self-discharge of the battery cell, the duration of the first preset time can be shorter under the condition that the capacity of the battery cell is smaller, the duration of the first preset time can be longer under the condition that the capacity of the battery cell is larger, the duration of the first preset time can be shorter under the condition that the severity of the self-discharge of the battery cell is higher, and the duration of the first preset time can be longer under the condition that the severity of the self-discharge of the battery cell is lower. For example, in case that the rated capacity of the battery cell is 150Ah, the first preset time may be 1 minute to 3 minutes.
In one implementation, the determining the voltage difference between the initial voltage and the target voltage based on the initial voltage and the target voltage may include: determining a differential pressure between the initial voltage and the target voltage by the following formula; differential pressure= (U0-U4) ×1000, where 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 can comprise: 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. The formula can amplify the pressure difference between the initial voltage and the target voltage by multiplying the difference between the initial voltage and the target voltage by 1000, and further can more intuitively determine the change trend of n pressure differences.
The embodiment of the application provides a judging method of a self-discharge abnormal battery cell, which comprises the steps of determining an open-circuit voltage corresponding to any inflection point position in a charge state-open-circuit voltage curve as an initial voltage of the battery cell, adjusting the charge state of the battery cell to the initial charge state corresponding to the initial voltage, standing the battery cell for a third preset time, then obtaining a first preset time for charging the battery cell with preset current for n times, standing the battery cell for a second preset time for discharging the battery cell with preset current, and determining the voltage difference between n initial voltages and target voltages obtained after target operation of the second preset time and the charge and discharge efficiency of n battery cells when n voltage differences are in an increasing trend and n charge and discharge efficiencies are in a decreasing trend.
For example, after the state of charge of the battery cell is adjusted to the initial state of charge corresponding to the initial voltage, and the battery cell is kept stand for 2 hours, 100 times of charging the battery cell with 15A current for 2 minutes at a sampling frequency of 1 second at each cycle interval are performed, the battery cell is kept stand for 1 minute, then is discharged with 15A current for 2 minutes, and the battery cell is kept stand for 1 minute under a cycle condition, and the whole process takes 12 hours, so that a lot of time can be saved compared with the judging method of the self-discharge abnormal battery cell in the related art, and further the labor cost is saved.
In addition, when the whole self-discharge abnormal battery pack is required to be analyzed, but no corresponding reference data exists, the judging method disclosed by the application is adopted, and the judgment can be carried out only by checking whether the suspected objects are consistent with the trends represented by other battery cells.
Taking a battery pack with a certain nominal capacity 150Ah as an example, fig. 3a is a trend chart of battery charging and discharging efficiency obtained by determining an open-circuit voltage corresponding to 5% soc in fig. 2 as an initial voltage of the battery, performing 100 times of cycling, fig. 3b is a trend chart of battery charging and discharging efficiency obtained by determining an open-circuit voltage corresponding to 5% soc in fig. 2 as an initial voltage of the battery, performing 100 times of cycling, fig. 4a is a trend chart of battery charging and discharging efficiency obtained by determining an open-circuit voltage corresponding to 50% soc in fig. 2 as an initial voltage of the battery, performing 100 times of cycling, fig. 4b is a trend chart of battery charging and discharging efficiency obtained by determining an open-circuit voltage corresponding to 50% soc in fig. 2 as an initial voltage of the battery, performing 100 times of cycling, determining an open-circuit voltage corresponding to 35% soc in fig. 2 as an initial voltage of the battery, performing 100 times of cycling, determining a trend chart of voltage corresponding to 100 times of cycling, performing a trend chart of voltage corresponding to 6% soc in fig. 2 as an initial voltage of the battery, performing 100 times of cycling, performing a graph of determining a trend chart of voltage of the battery charge and performing 100 times of cycling, performing a change of the battery corresponding to 6% soc corresponding to the battery is obtained as an initial voltage of the battery, and performing a voltage of the battery is determined to be obtained. 5% SOC and 50% SOC are inflection points in the SOC-OCV curve, and 35% SOC and 80% SOC are locations in the SOC-OCV curve where no inflection point is apparent.
As can be seen from fig. 3a to fig. 4b, the voltage difference trend and the charge/discharge efficiency trend of the battery cell 1 are significantly different from those of other battery cells, and compared with other battery cells, the charge/discharge efficiency of the battery cell 1 is the lowest, and continuously decreases along with the circulation, and the voltage difference of the battery cell 1 is the rising trend along with the circulation, and the change trend of the charge/discharge efficiency and the change trend of the voltage difference of other battery cells are very stable. Compared with fig. 3a to 4b, the change trend of fig. 5a to 6b is not obvious enough, and the charge and discharge efficiency does not obviously decrease, so that the open-circuit voltage corresponding to any inflection point position in the charge state-open-circuit voltage curve is determined as the initial voltage of the battery cell, and the accuracy of judging the self-discharge abnormal battery cell can be improved.
According to the method for judging the self-discharge abnormal battery cell provided by the embodiment of the application, the execution main body can be a device for judging the self-discharge abnormal battery cell. In the embodiment of the present application, a method for determining a self-discharge abnormal cell by using a determination device for a self-discharge abnormal cell is taken as an example, and the determination device for a self-discharge abnormal cell provided in the embodiment of the present application is described.
Fig. 7 is a schematic structural diagram of a device for determining a self-discharge abnormal cell according to an embodiment of the present disclosure. As shown in fig. 7, the determination device 700 for a self-discharge abnormal cell includes: the first acquisition module 710, the first determination module 720, the second acquisition module 730, the second determination module 740, and the determination module 750.
In the present application, the first obtaining module 710 is configured to obtain a state of charge-open circuit voltage curve of the battery cell; a first determining module 720, configured to determine an open-circuit voltage corresponding to any inflection point position in the state of charge-open-circuit voltage curve as an initial voltage of the electrical core; a second obtaining module 730, configured to obtain n target voltages of the battery cell obtained after n times of target operations are circulated on the battery cell, where the target operations correspond to the target voltages one by one, the target operations are to charge the battery cell for a first preset time with a preset current, and discharge the battery cell for the first preset time with the preset current, and n is an integer greater than 1; a second determination module 740 for determining, 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 750 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.
In one implementation, the second obtaining module 730 is further configured to obtain, after the charging the battery cell with the preset current for a first preset time, charging energy of the battery cell within the first preset time; the second obtaining module 730 is further configured to obtain, after the first preset time for discharging the battery cell with the preset current, discharge energy for the battery cell within the first preset time; the second determining module 740 is further configured to determine, for each set of the charging energy and the discharging energy, a charging efficiency and a discharging efficiency of the battery cell based on the discharging energy and the charging energy, before determining that the battery cell is a self-discharging abnormal battery cell in the case that the n differential pressures determined in sequence are in an increasing trend; the determining module 750 determines that the cell is a self-discharge abnormal cell when the n sequentially determined differential pressures are in an increasing trend, 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.
In one implementation, the second obtaining module 730 obtains the charging energy of the battery cell within the first preset time, including: 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 second obtaining module 730 obtains the discharge energy of the battery cell within the first preset time, including: 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.
In one implementation, the target operation is to charge the battery cell for a first preset time with a preset current, to stand the battery cell for a second preset time, to discharge the battery cell for the first preset time with the preset current, and to stand the battery cell for the second preset time.
In one implementation, the method further comprises: the first determining module 720 is further configured to determine, based on the state of charge-open circuit voltage curve, an initial state of charge corresponding to the initial voltage after determining the open circuit voltage corresponding to any inflection point position in the state of charge-open circuit voltage curve as the initial voltage of the battery cell; and 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.
In one implementation, the current magnitude of the preset current is determined according to the rated capacity of the battery cell.
In one implementation, the second determination module 740 determines a voltage difference between the initial voltage and the target voltage based on the initial voltage and the target voltage, including: determining a differential pressure between the initial voltage and the target voltage by the following formula; differential pressure= (U0-U4) ×1000, where U0 is the initial voltage and U4 is the target voltage; the determining module 750 determines that the cell is a self-discharge abnormal cell when the n sequentially determined differential pressures are in an increasing trend, 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.
The device for judging the self-discharge abnormal cell in the embodiment of the present application may be an electronic device, or may be a component in the electronic device, for example, an integrated circuit or a chip. The electronic device may be a terminal, or may be other devices than a terminal.
The device for judging the self-discharge abnormal battery cell provided by the embodiment of the application can realize each process realized by the embodiment of the method for judging the self-discharge abnormal battery cell, and in order to avoid repetition, the description is omitted here.
Optionally, as shown in fig. 8, the embodiment of the present application further provides an electronic device 800, including a processor 801 and a memory 802, where a program or an instruction capable of running on the processor 801 is stored in the memory 802, and the program or the instruction implements each step of the above embodiment of the method for determining a self-discharging abnormal cell when executed by the processor 801, and the steps can achieve the same technical effects, so that repetition is avoided and no redundant description is made here.
The electronic device in the embodiment of the application includes the mobile electronic device and the non-mobile electronic device described above.
The embodiment of the application further provides a readable storage medium, on which a program or an instruction is stored, where the program or the instruction realizes each process of the above embodiment of the method for determining the self-discharge abnormal cell when executed by a processor, and the same technical effect can be achieved, so that repetition is avoided, and no detailed description is given here.
Wherein the processor is a processor in the electronic device described in the above embodiment. The readable storage medium includes computer readable storage medium such as computer readable memory ROM, random access memory RAM, magnetic or optical disk, etc.
The embodiment of the application further provides a chip, the chip includes a processor and a communication interface, the communication interface is coupled with the processor, the processor is used for running a program or an instruction, implementing each process of the above embodiment of the method for judging the self-discharge abnormal cell, and achieving the same technical effect, so as to avoid repetition, and no further description is provided here.
It should be understood that the chips referred to in the embodiments of the present application may also be referred to as system-on-chip chips, chip systems, or system-on-chip chips, etc.
The embodiment of the present application provides a computer program product, which is stored in a storage medium, and the program product is executed by at least one processor to implement each process of the above embodiment of the method for determining a self-discharging abnormal cell, and the same technical effects can be achieved, so that repetition is avoided, and no description is repeated here.
In the embodiments described above, the differences between the embodiments are mainly described, and as long as there is no contradiction between the different optimization features between the embodiments, the different optimization features may be combined to form a better embodiment, and in consideration of brevity of line text, the description is omitted here.
The foregoing is merely exemplary of the present application and is not intended to limit the present application. Various modifications and changes may be made to the present application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc. which are within the spirit and principles of the present application are intended to be included within the scope of the claims of the present application.
Claims (10)
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;
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, further comprising, after the determining the open-circuit voltage corresponding to any inflection point position in the state-of-charge-open-circuit voltage curve as the initial voltage of the cell:
determining an initial state of charge corresponding to the initial voltage based on the state of charge-open circuit voltage curve;
and adjusting the charge state of the battery cell to the initial charge state, and standing the battery cell for a third preset time.
6. 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.
7. 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, where 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.
8. 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 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.
9. 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 1-7.
10. 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 7.
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|---|---|---|---|
| CN202310312496.5A CN116148676A (en) | 2023-03-27 | 2023-03-27 | Method and device for judging self-discharge abnormal battery cell and electronic equipment |
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| CN202310312496.5A CN116148676A (en) | 2023-03-27 | 2023-03-27 | Method and device for judging self-discharge abnormal battery cell and electronic equipment |
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| CN202310312496.5A Pending CN116148676A (en) | 2023-03-27 | 2023-03-27 | Method and device for judging self-discharge abnormal battery cell and electronic equipment |
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