CN114184969A - Method and device for testing reversible self-discharge capacity loss of battery cell - Google Patents
Method and device for testing reversible self-discharge capacity loss of battery cell Download PDFInfo
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- 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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- G01R31/388—Determining ampere-hour charge capacity or SoC involving voltage measurements
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- G—PHYSICS
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- 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]
- G01R31/389—Measuring internal impedance, internal conductance or related variables
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- G—PHYSICS
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- 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]
- G01R31/392—Determining battery ageing or deterioration, e.g. state of health
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- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
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- G01R31/36—Arrangements for testing, measuring or monitoring the electrical condition of accumulators or electric batteries, e.g. capacity or state of charge [SoC]
- G01R31/396—Acquisition or processing of data for testing or for monitoring individual cells or groups of cells within a battery
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Abstract
The invention provides a method and a device for testing reversible self-discharge capacity loss of a battery cell, wherein the method comprises the following steps: acquiring a first maximum capacity of a target battery cell in an initial state; performing self-discharge aging test on the target battery cell based on the set battery cell capacity influence parameters, and calculating the total self-discharge capacity loss of the target battery cell; calculating a second maximum capacity of the target electric core after the self-discharge aging test; and determining the reversible self-discharge capacity loss of the target battery cell under the set battery cell capacity influence parameter based on the first maximum capacity, the second maximum capacity and the total self-discharge capacity loss. Therefore, the loss of the reversible self-discharge capacity is accurately calculated, the reversible self-discharge capacity of the battery cell in any temperature and any SOC state and in any time can be accurately obtained, the battery cell manufacturing process is optimized more efficiently for formulating more reasonable battery use management strategies, more accurately predicting the service life of the battery, and improving the consistency of the battery cell, and an accurate data base is provided.
Description
Technical Field
The invention relates to the technical field of batteries, in particular to a method and a device for testing reversible self-discharge capacity loss of a battery core.
Background
The lithium ion battery has a self-discharge phenomenon in both a storage state and a use state. Self-discharge not only causes the capacity of the battery to be reduced, but also causes the consistency of the battery core to be poor. The battery pack contains dozens or even hundreds of battery cells, and when the capacity of each battery cell and the consistency of the SoC state are deteriorated, the capacity of the whole battery pack is rapidly degraded, and finally the service life of the battery pack is rapidly terminated. The self-discharge of the battery cell is caused by various reasons, such as metal foreign matters introduced in the battery cell manufacturing process, lithium dendrites in the battery cell using process, side reactions between the electrolyte and the positive and negative electrodes, and the like. Self-discharge can be classified into reversible self-discharge and irreversible self-discharge in terms of recoverability after capacity degradation. The capacity loss caused by reversible self-discharge is called reversible capacity loss. The reversible capacity loss is influenced by factors such as a manufacturing process, using conditions and the like, and has strong randomness, so that the reversible capacity loss is difficult to obtain.
At present, there are many methods for detecting the self-discharge of the battery cell, for example, discharging the battery cell to a state of charge SOC equal to 0, then storing the battery cell in different environmental temperatures, recording the change of the voltage value of the battery cell and the time of storage, and calculating the self-discharge rate of the battery by the change of the voltage and the time of storage, etc. However, the self-discharge capacity losses obtained by these methods are all total capacity losses and cannot distinguish between reversible and irreversible self-discharge capacity losses.
Therefore, how to realize the quantitative calculation of the reversible capacity loss caused by the reversible self-discharge has important significance for the work of researching the consistency degradation rule and the life decay rule of the battery, improving the battery core manufacturing process and the like.
Disclosure of Invention
In view of this, embodiments of the present invention provide a method and an apparatus for testing reversible self-discharge capacity loss of a battery cell, so as to overcome a problem in the prior art that a quantitative calculation method for reversible capacity loss caused by reversible self-discharge is not available.
The embodiment of the invention provides a method for testing reversible self-discharge capacity loss of a battery cell, which comprises the following steps:
acquiring a first maximum capacity of a target battery cell in an initial state;
performing self-discharge aging test on the target electric core based on the set electric core capacity influence parameters, and calculating the total self-discharge capacity loss of the target electric core;
calculating a second maximum capacity of the target battery cell after the self-discharge aging test;
and determining the reversible self-discharge capacity loss of the target battery cell under the set battery cell capacity influence parameter based on the first maximum capacity, the second maximum capacity and the total self-discharge capacity loss.
Optionally, the acquiring the first maximum capacity of the target electric core in the initial state includes:
performing a charge-discharge test on the target battery cell in an initial state, and determining a discharge electromotive force curve of the target battery cell in the initial state;
and calculating the first maximum capacity of the target battery cell in the initial state based on the charge cut-off voltage of the target battery cell and the discharge electromotive force curve of the target battery cell in the initial state.
Optionally, the setting of the cell capacity influence parameter includes: the method comprises the following steps of carrying out self-discharge aging test on a target electric core based on set electric core capacity influence parameters, and calculating the total self-discharge capacity loss of the target electric core, wherein the self-discharge aging test comprises the following steps:
discharging the target battery cell at the target temperature in a constant current manner to a discharge cut-off voltage;
performing constant-current charging on the target battery cell to a target charge state, and converting the target battery cell into constant-voltage charging;
recording the total charge capacity after the constant voltage charge reaches the target constant voltage charge time;
discharging the target battery cell again at constant current to a discharge cut-off voltage, and recording the discharge capacity;
and calculating the total self-discharge capacity loss of the target battery cell based on the total charge capacity and the discharge capacity.
Optionally, the calculating a second maximum capacity of the target cell after the self-discharge aging test includes:
performing a charge-discharge test on the target electric core after the self-discharge aging test, and determining a discharge electromotive force curve of the target electric core after the self-discharge aging test;
and calculating a second maximum capacity of the target electric core after the self-discharge aging test based on the charge cut-off voltage of the target electric core and the discharge electromotive force curve of the target electric core after the self-discharge aging test.
Optionally, the determining a reversible self-discharge capacity loss of the target cell under the set cell capacity influence parameter based on the first maximum capacity, the second maximum capacity, and the total self-discharge capacity loss includes:
calculating an irreversible self-discharge capacity loss of the target cell based on the first maximum capacity and the second maximum capacity;
calculating the reversible self-discharge capacity loss based on the total self-discharge capacity loss and the irreversible self-discharge capacity loss.
Optionally, the initial state comprises: the initial temperature, performing a charge-discharge test on the target electric core in an initial state, and determining a discharge electromotive force curve of the target electric core in the initial state, includes:
charging the target cell to a charge cut-off voltage at the initial temperature;
respectively carrying out charging and discharging tests of different discharging currents on the target battery cell to obtain corresponding discharging voltage curves of the target battery cell under different discharging currents;
and calculating a discharge electromotive force curve of the target battery cell in an initial state based on corresponding discharge voltage curves of the target battery cell under different discharge currents.
Optionally, the performing a charge-discharge test on the target electric core after the self-discharge aging test to determine a discharge electromotive force curve of the target electric core after the self-discharge aging test includes:
charging the target battery cell subjected to the self-discharge aging test to a charge cut-off voltage at the initial temperature;
respectively carrying out charge-discharge tests of different discharge currents on the target electric core subjected to the self-discharge aging test to obtain corresponding discharge voltage curves of the aged target electric core under different discharge currents;
and calculating a discharge electromotive force curve of the target electric core after the self-discharge aging test based on corresponding discharge voltage curves of the aged target electric core under different discharge currents.
The embodiment of the invention also provides a device for testing reversible self-discharge capacity loss of a battery cell, which comprises:
the acquisition module is used for acquiring a first maximum capacity of a target battery cell in an initial state;
the first processing module is used for carrying out self-discharge aging test on the target electric core based on the set electric core capacity influence parameters and calculating the total self-discharge capacity loss of the target electric core;
the second processing module is used for calculating a second maximum capacity of the target battery cell after the self-discharge aging test;
and the third processing module is used for determining the reversible self-discharge capacity loss of the target battery cell under the set battery cell capacity influence parameter based on the first maximum capacity, the second maximum capacity and the total self-discharge capacity loss.
An embodiment of the present invention further provides an electronic device, including: the device comprises a memory and a processor, wherein the memory and the processor are connected with each other in a communication mode, computer instructions are stored in the memory, and the processor executes the computer instructions so as to execute the method provided by the embodiment of the invention.
The embodiment of the invention also provides a computer-readable storage medium, which stores computer instructions for enabling a computer to execute the method provided by the embodiment of the invention.
The technical scheme of the invention has the following advantages:
the embodiment of the invention provides a method and a device for testing reversible self-discharge capacity loss of a battery cell, wherein a first maximum capacity of a target battery cell in an initial state is obtained; performing self-discharge aging test on the target battery cell based on the set battery cell capacity influence parameters, and calculating the total self-discharge capacity loss of the target battery cell; calculating a second maximum capacity of the target electric core after the self-discharge aging test; and determining the reversible self-discharge capacity loss of the target battery cell under the set battery cell capacity influence parameter based on the first maximum capacity, the second maximum capacity and the total self-discharge capacity loss. Therefore, the total self-discharge capacity of the battery core is obtained by performing self-discharge test on the battery core, then the maximum capacity of the battery core in different aging states is tested, the irreversible self-discharge capacity loss of the battery core is obtained, the reversible self-discharge capacity loss is obtained by calculation, accurate calculation of the reversible self-discharge capacity loss is realized, the reversible self-discharge capacity of the battery core in any temperature, any SOC state and any time during storage can be accurately obtained, a more reasonable battery use management strategy is formulated, the service life of the battery is more accurately predicted, the battery core manufacturing process is more efficiently optimized, and accurate data basis is provided for improving the consistency of the battery core.
Drawings
In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, and it is obvious that the drawings in the following description are some embodiments of the present invention, and other drawings can be obtained by those skilled in the art without creative efforts.
Fig. 1 is a flowchart of a cell reversible self-discharge capacity loss test method in an embodiment of the present invention;
FIG. 2 is a schematic diagram of a self-discharge burn-in test according to an embodiment of the present invention;
fig. 3 is a schematic diagram of a specific working process of a reversible self-discharge capacity loss test of a battery cell in the embodiment of the invention;
fig. 4 is a schematic structural diagram of a cell reversible self-discharge capacity loss testing device in an embodiment of the present invention;
fig. 5 is a schematic structural diagram of an electronic device in an embodiment of the present invention.
Detailed Description
In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are some, but not all, embodiments of the present invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
The technical features mentioned in the different embodiments of the invention described below can be combined with each other as long as they do not conflict with each other.
At present, there are many methods for detecting the self-discharge of the battery cell, for example, discharging the battery cell to a state of charge, that is, SOC is 0, then storing the battery cell in different environmental temperatures, recording the change of the voltage value of the battery cell and the time of storage, and calculating the self-discharge rate of the battery by the change of the voltage and the time of storage, etc. However, the self-discharge capacity losses obtained by these methods are all total capacity losses and cannot distinguish between reversible and irreversible self-discharge capacity losses. Therefore, how to realize the quantitative calculation of the reversible capacity loss caused by the reversible self-discharge has important significance for the work of researching the consistency degradation rule and the life decay rule of the battery, improving the battery core manufacturing process and the like.
Based on the above problem, an embodiment of the present invention provides a method for testing reversible self-discharge capacity loss of a battery cell, as shown in fig. 1, the method specifically includes the following steps:
step S101: and acquiring a first maximum capacity of the target battery cell in an initial state.
Wherein, initial state includes: the initial temperature, in the embodiment of the present invention, is described by taking the initial temperature as the ambient temperature T as an example, and in practical applications, the initial temperature may be flexibly set according to the cell test requirement, which is not limited in the present invention.
Step S102: and performing self-discharge aging test on the target battery cell based on the set battery cell capacity influence parameters, and calculating the total self-discharge capacity loss of the target battery cell.
Wherein, set for electric core capacity influence parameter, include: state of charge, temperature, and constant voltage charge time. Specifically, the specific value of the cell capacity influence parameter can be flexibly set according to the cell reversible self-discharge capacity loss test requirement, and if the cell reversible self-discharge capacity loss of the cell is required to be tested at the ambient temperature T, the state of charge is SOC, and the constant-voltage charging time is N, that is, the cell aging time is the cell placement time, the like.
Step S103: and calculating a second maximum capacity of the target cell after the self-discharge aging test.
In practical application, after the battery cell is placed for a period of time, the maximum capacity of the battery cell is reduced due to the influence of irreversible self-discharge capacity loss, so that the irreversible self-discharge capacity loss of the battery cell can be calculated by calculating the maximum capacity of the battery cell after a self-discharge aging test.
Step S104: and determining the reversible self-discharge capacity loss of the target battery cell under the set battery cell capacity influence parameter based on the first maximum capacity, the second maximum capacity and the total self-discharge capacity loss.
Specifically, the irreversible self-discharge capacity loss of the battery cell is calculated through the maximum capacity of the battery cell before and after the self-discharge aging test, and then the reversible self-discharge capacity loss of the target battery cell under the set battery cell capacity influence parameter can be calculated approximately and accurately by combining the total self-discharge capacity loss.
By executing the steps, the method for testing the reversible self-discharge capacity loss of the battery core provided by the embodiment of the invention obtains the total self-discharge capacity of the battery core by performing the self-discharge test on the battery core, then tests the maximum capacity of the battery core in different aging states to obtain the irreversible self-discharge capacity loss of the battery core, and then calculates to obtain the reversible self-discharge capacity loss, so that the accurate calculation of the reversible self-discharge capacity loss is realized, the reversible self-discharge capacity loss of the battery core at any temperature, in any SOC state and at any time during storage can be accurately obtained, and an accurate data basis is provided for formulating a more reasonable battery use management strategy, more accurately predicting the service life of the battery and more efficiently optimizing a battery core manufacturing process, and improving the consistency of the battery core.
Specifically, in an embodiment, the step S101 specifically includes the following steps:
step S201: and carrying out a charge-discharge test on the target electric core in the initial state, and determining a discharge electromotive force curve of the target electric core in the initial state.
Specifically, the step S201 is performed by charging the target cell to the charge cut-off voltage at the initial temperature; respectively carrying out charge-discharge tests of different discharge currents on the target battery cell to obtain corresponding discharge voltage curves of the target battery cell under different discharge currents; and calculating a discharge electromotive force curve of the target battery cell in the initial state based on the corresponding discharge voltage curves of the target battery cell under different discharge currents.
Illustratively, at ambient temperature T, the cell will be charged at 1/3C constant current to a charge cutoff voltage, and at constant voltage to a current of 0.05C; standing for 0.5 h, and then performing constant current discharge at 0.1C until the discharge cut-off voltage is reached; the above process is repeated, and the discharge current is changed to 0.2C, 0.3C and 0.5C in sequence. After the discharge voltage curves under different multiplying powers are obtained, a voltage curve when the discharge current is constantly equal to 0 is calculated through a regression algorithm, and the voltage curve at the moment is a discharge electromotive force curve, namely EMF, of the battery cell in the initial state.
Step S202: and calculating the first maximum capacity of the target battery cell in the initial state based on the charge cut-off voltage of the target battery cell and the discharge electromotive force curve of the target battery cell in the initial state.
Specifically, the capacity corresponding to the charge cut-off voltage on the EMF curve is the first maximum capacity of the target cell in the initial state.
Specifically, in an embodiment, the step S102 specifically includes the following steps:
discharging the target battery cell at a target temperature in a constant current manner to a discharge cut-off voltage; the target battery cell is charged at a constant current to a target charge state and then is charged at a constant voltage; recording the total charge capacity after the constant voltage charge reaches the target constant voltage charge time; discharging the target battery cell again at constant current to a discharge cut-off voltage, and recording the discharge capacity; and calculating the total self-discharge capacity loss of the target battery cell based on the total charge capacity and the discharge capacity.
The target temperature, the target charge state and the target constant voltage charging time can be flexibly set according to the test requirement of the reversible self-discharge capacity of the battery cell, and the invention is not limited to the above.
Illustratively, as shown in fig. 2, at an ambient temperature T, the cell was discharged to a cut-off voltage at a constant current of 1/3C, and after standing for 5 minutes, was charged to any SoC (x)i) The state is changed to constant voltage charging, and the constant voltage charging is carried out for N days (N)>30 days), the total charge capacity is recorded, the charging current is smaller and smaller during constant voltage charging, and the battery is closer and closer to the equilibrium state. If the self-discharge process does not exist in the battery, the current of the constant voltage charging is reduced to 0; if there is a self-discharge process in the battery, the current during constant voltage charging is greater than 0, and the charging current is used to compensate the voltage drop caused by self-discharge. After charging at constant voltage for N days, the discharge capacity was recorded by discharging at constant current 1/3C to the cut-off voltage.
The total self-discharge capacity loss of the target cell was calculated by the following formula (1):
ΔQt＝Qoh-Qd (1)
wherein, is Δ QtDenotes total self-discharge capacity loss, QchRepresenting the total charge capacity, QdThe discharge capacity is shown.
Therefore, the total self-discharge capacity loss of the target battery cell is calculated through the self-discharge aging test, an accurate data basis is provided for the subsequent calculation of the reversible self-discharge capacity loss of the target battery cell, and the accuracy of the final calculation result of the reversible self-discharge capacity loss is further improved.
Specifically, in an embodiment, the step S103 specifically includes the following steps:
step S401: and carrying out a charge-discharge test on the target electric core after the self-discharge aging test, and determining a discharge electromotive force curve of the target electric core after the self-discharge aging test.
Specifically, in step S401, the target battery cell after the self-discharge aging test is charged to the charge cut-off voltage at the initial temperature; respectively carrying out charge-discharge tests of different discharge currents on the target electric core subjected to the self-discharge aging test to obtain corresponding discharge voltage curves of the aged target electric core under different discharge currents; and calculating a discharge electromotive force curve of the target battery cell after the self-discharge aging test based on the corresponding discharge voltage curves of the aged target battery cell under different discharge currents.
Exemplarily, at an ambient temperature T, the cell after the self-discharge aging test is charged at a constant current of 1/3C to a charge cut-off voltage, and the charge at a constant voltage is changed to a current of 0.05C; standing for 0.5 h, and then performing constant current discharge at 0.1C until the discharge cut-off voltage is reached; the above process is repeated, and the discharge current is changed to 0.2C, 0.3C and 0.5C in sequence. And after the discharge voltage curves under different multiplying powers are obtained, calculating a voltage curve when the discharge current is constantly equal to 0 through a regression algorithm, wherein the voltage curve at the moment is a discharge electromotive force curve of the target battery cell after the self-discharge aging test. The specific process is the same as the principle of the discharge electromotive force curve of the target electric core in the initial state, and is not described herein again.
Step S402: and calculating a second maximum capacity of the target electric core after the self-discharge aging test based on the charge cut-off voltage of the target electric core and the discharge electromotive force curve of the target electric core after the self-discharge aging test.
Specifically, the capacity corresponding to the charge cut-off voltage on the discharge electromotive force curve of the battery cell after the self-discharge aging test is the second maximum capacity of the target battery cell after the self-discharge aging test.
Specifically, in an embodiment, the step S104 specifically includes the following steps:
step S501: and calculating the irreversible self-discharge capacity loss of the target battery cell based on the first maximum capacity and the second maximum capacity.
Specifically, the irreversible self-discharge capacity loss of the target cell is calculated by the following formula (2):
wherein, DeltaQirRepresents the irreversible loss of self-discharge capacity,
the first maximum capacity is represented by the first maximum capacity,
representing the second maximum capacity.
Step S502: the reversible self-discharge capacity loss was calculated based on the total self-discharge capacity loss and the irreversible self-discharge capacity loss.
Specifically, the reversible self-discharge capacity loss of the target cell is calculated by the following formula (3):
ΔQre＝ΔQt-ΔQir (3)
wherein, is Δ QreDenotes the loss of reversible self-discharge capacity,. DELTA.QtDenotes total self-discharge capacity loss,. DELTA.QirIndicating irreversible self-discharge capacity loss.
Since the EMF curve is a voltage curve when the battery is in an equilibrium state (at which the current is equal to 0), the capacity calculated from the EMF curve can be regarded as the true capacity of the cell and the maximum capacity that the cell can release. And calculating to obtain the irreversible self-discharge capacity of the battery according to the maximum capacity in the initial state and the maximum capacity after the self-discharge aging test.
In the embodiment of the invention, in the self-discharge aging test, constant-voltage charging is carried out under different SoC states, so that the self-discharge capacity of the battery cell under different SoCs can be obtained; the self-discharge capacity of the battery cell at different time can be obtained by adjusting the constant voltage charging time; and selecting different test temperatures, and obtaining the self-discharge capacity of the battery cell at different temperatures. As shown in fig. 3, the reversible self-discharge capacity loss test methods of the battery cells provided by the embodiment of the invention can obtain corresponding reversible self-discharge capacities under the above conditions. The flexibility of the loss test of the reversible self-discharge capacity of the core is greatly improved, and an accurate data base is further provided for formulating a more reasonable battery use management strategy, more accurately predicting the service life of the battery and more efficiently optimizing the battery core manufacturing process, and improving the consistency of the battery core.
By executing the steps, the method for testing the reversible self-discharge capacity loss of the battery core provided by the embodiment of the invention obtains the total self-discharge capacity of the battery core by performing the self-discharge test on the battery core, then tests the maximum capacity of the battery core in different aging states to obtain the irreversible self-discharge capacity loss of the battery core, and then calculates to obtain the reversible self-discharge capacity loss, so that the accurate calculation of the reversible self-discharge capacity loss is realized, the reversible self-discharge capacity loss of the battery core at any temperature, in any SOC state and at any time during storage can be accurately obtained, and an accurate data basis is provided for formulating a more reasonable battery use management strategy, more accurately predicting the service life of the battery and more efficiently optimizing a battery core manufacturing process, and improving the consistency of the battery core.
An embodiment of the present invention further provides a device for testing reversible self-discharge capacity loss of a battery cell, as shown in fig. 4, the device for testing reversible self-discharge capacity loss of a battery cell includes:
the obtaining module 101 is configured to obtain a first maximum capacity of a target cell in an initial state. For details, refer to the related description of step S101 in the above method embodiment, and no further description is provided here.
The first processing module 102 is configured to perform a self-discharge aging test on the target electric core based on the set electric core capacity influence parameter, and calculate a total self-discharge capacity loss of the target electric core. For details, refer to the related description of step S102 in the above method embodiment, and no further description is provided here.
And the second processing module 103 is configured to calculate a second maximum capacity of the target cell after the self-discharge aging test. For details, refer to the related description of step S103 in the above method embodiment, and no further description is provided here.
And the third processing module 104 is configured to determine a reversible self-discharge capacity loss of the target cell under the set cell capacity influence parameter, based on the first maximum capacity, the second maximum capacity, and the total self-discharge capacity loss. For details, refer to the related description of step S104 in the above method embodiment, and no further description is provided here.
Through the cooperative cooperation of the components, the device for testing the reversible self-discharge capacity loss of the battery core provided by the embodiment of the invention obtains the total self-discharge capacity of the battery core by testing the self-discharge of the battery core, then tests the maximum capacity of the battery core in different aging states to obtain the irreversible self-discharge capacity loss of the battery core, and further calculates to obtain the reversible self-discharge capacity loss, so that the accurate calculation of the reversible self-discharge capacity loss is realized, the reversible self-discharge capacity of the battery core in any temperature, any SOC state and any storage time can be accurately obtained, a more reasonable battery use management strategy is formulated, the service life of the battery is more accurately predicted, the battery core manufacturing process is more efficiently optimized, and an accurate data basis is provided for improving the consistency of the battery core.
Further functional descriptions of the modules are the same as those of the corresponding method embodiments, and are not repeated herein.
There is also provided an electronic device according to an embodiment of the present invention, as shown in fig. 5, the electronic device may include a processor 901 and a memory 902, where the processor 901 and the memory 902 may be connected by a bus or in another manner, and fig. 5 takes the example of being connected by a bus as an example.
The memory 902, which is a non-transitory computer readable storage medium, may be used for storing non-transitory software programs, non-transitory computer executable programs, and modules, such as program instructions/modules corresponding to the methods in the method embodiments of the present invention. The processor 901 executes various functional applications and data processing of the processor by executing non-transitory software programs, instructions and modules stored in the memory 902, that is, implements the methods in the above-described method embodiments.
The memory 902 may include a storage program area and a storage data area, wherein the storage program area may store an application program required for operating the device, at least one function; the storage data area may store data created by the processor 901, and the like. Further, the memory 902 may include high speed random access memory, and may also include non-transitory memory, such as at least one magnetic disk storage device, flash memory device, or other non-transitory solid state storage device. In some embodiments, the memory 902 may optionally include memory located remotely from the processor 901, which may be connected to the processor 901 via a network. Examples of such networks include, but are not limited to, the internet, intranets, local area networks, mobile communication networks, and combinations thereof.
One or more modules are stored in the memory 902, which when executed by the processor 901 performs the methods in the above-described method embodiments.
The specific details of the electronic device may be understood by referring to the corresponding related descriptions and effects in the above method embodiments, and are not described herein again.
It will be understood by those skilled in the art that all or part of the processes of the methods of the embodiments described above can be implemented by hardware related to instructions of a computer program, and the program can be stored in a computer readable storage medium, and when executed, can include the processes of the embodiments of the methods described above. The storage medium may be a magnetic Disk, an optical Disk, a Read-Only Memory (ROM), a Random Access Memory (RAM), a Flash Memory (Flash Memory), a Hard Disk (Hard Disk Drive, abbreviated as HDD) or a Solid State Drive (SSD), etc.; the storage medium may also comprise a combination of memories of the kind described above.
Although the embodiments of the present invention have been described in conjunction with the accompanying drawings, those skilled in the art may make various modifications and variations without departing from the spirit and scope of the invention, and such modifications and variations fall within the scope defined by the appended claims.
Claims (10)
1. A method for testing reversible self-discharge capacity loss of a battery cell is characterized by comprising the following steps:
acquiring a first maximum capacity of a target battery cell in an initial state;
performing self-discharge aging test on the target electric core based on the set electric core capacity influence parameters, and calculating the total self-discharge capacity loss of the target electric core;
calculating a second maximum capacity of the target battery cell after the self-discharge aging test;
and determining the reversible self-discharge capacity loss of the target battery cell under the set battery cell capacity influence parameter based on the first maximum capacity, the second maximum capacity and the total self-discharge capacity loss.
2. The method of claim 1, wherein the obtaining the first maximum capacity of the target cell in the initial state comprises:
performing a charge-discharge test on the target battery cell in an initial state, and determining a discharge electromotive force curve of the target battery cell in the initial state;
and calculating the first maximum capacity of the target battery cell in the initial state based on the charge cut-off voltage of the target battery cell and the discharge electromotive force curve of the target battery cell in the initial state.
3. The method of claim 1, wherein the setting of the cell capacity influencing parameter comprises: the method comprises the following steps of carrying out self-discharge aging test on a target electric core based on set electric core capacity influence parameters, and calculating the total self-discharge capacity loss of the target electric core, wherein the self-discharge aging test comprises the following steps:
discharging the target battery cell at the target temperature in a constant current manner to a discharge cut-off voltage;
performing constant-current charging on the target battery cell to a target charge state, and converting the target battery cell into constant-voltage charging;
recording the total charge capacity after the constant voltage charge reaches the target constant voltage charge time;
discharging the target battery cell again at constant current to a discharge cut-off voltage, and recording the discharge capacity;
and calculating the total self-discharge capacity loss of the target battery cell based on the total charge capacity and the discharge capacity.
4. The method of claim 2, wherein the calculating the second maximum capacity of the target cell after the self-discharge aging test comprises:
performing a charge-discharge test on the target electric core after the self-discharge aging test, and determining a discharge electromotive force curve of the target electric core after the self-discharge aging test;
and calculating a second maximum capacity of the target electric core after the self-discharge aging test based on the charge cut-off voltage of the target electric core and the discharge electromotive force curve of the target electric core after the self-discharge aging test.
5. The method of claim 1, wherein determining the reversible self-discharge capacity loss of the target cell at a set cell capacity influencing parameter based on the first maximum capacity, the second maximum capacity, and the total self-discharge capacity loss comprises:
calculating an irreversible self-discharge capacity loss of the target cell based on the first maximum capacity and the second maximum capacity;
calculating the reversible self-discharge capacity loss based on the total self-discharge capacity loss and the irreversible self-discharge capacity loss.
6. The method of claim 4, wherein the initial state comprises: the initial temperature, performing a charge-discharge test on the target electric core in an initial state, and determining a discharge electromotive force curve of the target electric core in the initial state, includes:
charging the target cell to a charge cut-off voltage at the initial temperature;
respectively carrying out charging and discharging tests of different discharging currents on the target battery cell to obtain corresponding discharging voltage curves of the target battery cell under different discharging currents;
and calculating a discharge electromotive force curve of the target battery cell in an initial state based on corresponding discharge voltage curves of the target battery cell under different discharge currents.
7. The method of claim 6, wherein the performing a charge-discharge test on the target cell after the self-discharge aging test to determine a discharge electromotive force curve of the target cell after the self-discharge aging test comprises:
charging the target battery cell subjected to the self-discharge aging test to a charge cut-off voltage at the initial temperature;
respectively carrying out charge-discharge tests of different discharge currents on the target electric core subjected to the self-discharge aging test to obtain corresponding discharge voltage curves of the aged target electric core under different discharge currents;
and calculating a discharge electromotive force curve of the target electric core after the self-discharge aging test based on corresponding discharge voltage curves of the aged target electric core under different discharge currents.
8. The utility model provides a reversible self-discharge capacity loss testing arrangement of electricity core which characterized in that includes:
the acquisition module is used for acquiring a first maximum capacity of a target battery cell in an initial state;
the first processing module is used for carrying out self-discharge aging test on the target electric core based on the set electric core capacity influence parameters and calculating the total self-discharge capacity loss of the target electric core;
the second processing module is used for calculating a second maximum capacity of the target battery cell after the self-discharge aging test;
and the third processing module is used for determining the reversible self-discharge capacity loss of the target battery cell under the set battery cell capacity influence parameter based on the first maximum capacity, the second maximum capacity and the total self-discharge capacity loss.
9. An electronic device, comprising:
a memory and a processor, the memory and the processor being communicatively coupled to each other, the memory having stored therein computer instructions, the processor performing the method of any of claims 1-7 by executing the computer instructions.
10. A computer-readable storage medium having stored thereon computer instructions for causing a computer to perform the method of any one of claims 1-7.
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