CN113805072A - Capacity determination method and device, capacity grading method and power battery system - Google Patents
Capacity determination method and device, capacity grading method and power battery system Download PDFInfo
- Publication number
- CN113805072A CN113805072A CN202110895199.9A CN202110895199A CN113805072A CN 113805072 A CN113805072 A CN 113805072A CN 202110895199 A CN202110895199 A CN 202110895199A CN 113805072 A CN113805072 A CN 113805072A
- Authority
- CN
- China
- Prior art keywords
- capacity
- battery
- charging
- storage battery
- voltage
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
Images
Classifications
-
- 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]
- G01R31/382—Arrangements for monitoring battery or accumulator variables, e.g. SoC
- G01R31/3835—Arrangements for monitoring battery or accumulator variables, e.g. SoC involving only voltage measurements
Landscapes
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Secondary Cells (AREA)
Abstract
A method for determining the capacity of a storage battery, a method for grading the capacity of a storage battery, a power battery system and a device for determining the capacity of a storage battery are provided. The method for determining the capacity of the storage battery comprises the following steps: acquiring a full-battery voltage measured value when the storage battery after complete discharge is incompletely charged and the charging capacity reaches a set charging capacity value; and determining the capacity of the storage battery according to the set charging capacity value, the full battery voltage measured value, the corresponding relation between the charging state SOC and the voltage of the positive half battery of the storage battery and the corresponding relation between the charging capacity and the voltage of the negative half battery of the storage battery. Because only the storage battery needs to be incompletely charged, the capacity determination time can be shortened, the power consumption is reduced, the capacity grading time is further shortened, the capacity grading energy consumption is reduced, and the mass production is facilitated.
Description
Technical Field
The present disclosure relates to the field of battery technologies, and in particular, to a method for determining capacity of a storage battery, a method for classifying capacity of a storage battery, a power battery system, and a device for determining capacity of a storage battery.
Background
With the gradual industrialization of electric automobiles, the output of electric automobiles in China is rapidly increased, and the maintenance quantity of power battery systems of the electric automobiles is sharply increased. The power battery system usually adopts hundreds of batteries or even more batteries to be used in series and in parallel according to a certain mode, and the output energy, the output power and the service life of the whole system depend on the battery with the worst performance in the system. Therefore, the inconsistency of the single battery is the most critical factor affecting the performance of the whole system. And the consistency of the capacities of the single batteries is one of the important expressions of the consistency of the power battery system. Therefore, the batteries need to be capacity-graded before grouping.
In the related art, the storage battery is subjected to capacity grading by adopting a full capacity grading method. Full grading refers to determining the capacity of a battery by fully charging and discharging the battery, and then grading according to the capacity of the battery. The capacity grading mode is long in time consumption and extremely high in energy consumption due to the fact that the batteries are charged and discharged completely and consume time and electricity.
Disclosure of Invention
The embodiment of the application provides a method for determining the capacity of a storage battery, and the capacity of the storage battery can be obtained only by incompletely charging the storage battery, so that the capacity grading time can be shortened, and the capacity grading energy consumption can be reduced.
The application provides a method for determining capacity of a storage battery, which comprises the following steps:
acquiring a full-battery voltage measured value when the storage battery after complete discharge is incompletely charged and the charging capacity reaches a set charging capacity value;
and determining the capacity of the storage battery according to the set charging capacity value, the full battery voltage measured value, the corresponding relation between the charging state SOC and the voltage of the positive half battery of the storage battery and the corresponding relation between the charging capacity and the voltage of the negative half battery of the storage battery.
In an exemplary embodiment, the corresponding relationship between the state of charge SOC and the voltage of the positive half cell is obtained by:
acquiring the corresponding relation between the charging capacity and the voltage of the positive half battery in the charging process of fully charging the fully discharged positive half battery;
converting the charging capacity in the corresponding relation between the charging capacity and the voltage of the positive half battery into a charging state SOC to obtain the corresponding relation between the charging state SOC and the voltage of the positive half battery;
wherein converting the charge capacity to the state of charge SOC comprises: and dividing the charging capacity by the capacity of the positive half battery to obtain the converted charging state SOC, wherein the capacity of the positive half battery is equal to the charging capacity of the positive half battery when the positive half battery reaches a full-charged state.
In an exemplary embodiment, the correspondence between the charge capacity and the voltage of the negative half cell is obtained by:
and acquiring the corresponding relation between the charging capacity and the voltage of the cathode half cell in the charging process of fully charging the cathode half cell after complete discharge, and acquiring the corresponding relation between the charging capacity and the voltage of the cathode half cell.
In an exemplary embodiment, the determining the capacity of the battery according to the set charge capacity value and the full-battery voltage measurement value, the corresponding relationship between the state of charge SOC and the voltage of the positive half-cell of the battery, and the corresponding relationship between the charge capacity and the voltage of the negative half-cell of the battery includes:
determining a negative electrode voltage value when the charge capacity of the storage battery reaches the set charge capacity value according to the set charge capacity value and the corresponding relation between the charge capacity and the voltage of the negative electrode half battery;
adding the negative electrode voltage value when the charging capacity of the storage battery reaches the set charging capacity value and the full battery voltage measured value to obtain a positive electrode voltage value when the charging capacity of the storage battery reaches the set charging capacity value;
determining a state of charge SOC value when the charge capacity of the storage battery reaches the set charge capacity value according to a positive electrode voltage value when the charge capacity of the storage battery reaches the set charge capacity value and a corresponding relation between the state of charge SOC and the voltage of the positive electrode half battery;
and determining the capacity of the storage battery according to the SOC value and the set charging capacity value.
In an exemplary embodiment, one of the set charge capacity values;
obtaining a full-battery voltage measurement value when the charging capacity of the storage battery reaches the set charging capacity value, and determining an SOC value according to the set charging capacity value and the corresponding full-battery voltage measurement value, the corresponding relation between the charging state SOC and the voltage of the positive half battery and the corresponding relation between the charging capacity and the voltage of the negative half battery;
the determining the capacity of the storage battery according to the SOC value and the set charge capacity value includes:
and dividing the set charge capacity value by the determined SOC value to obtain the capacity of the storage battery.
In an exemplary embodiment, the set charge capacity value is plural;
for each set charging capacity value, determining an SOC value corresponding to the charging capacity value according to a full battery voltage measurement value corresponding to the charging capacity value and the charging capacity reaching the charging capacity value, a corresponding relation between the charging state SOC and the voltage of the positive half battery and a corresponding relation between the charging capacity and the voltage of the negative half battery;
the determining the capacity of the storage battery according to the SOC value and the set charge capacity value includes:
dividing each set charging capacity value by the SOC value determined according to the charging capacity value to obtain a corresponding capacity initial value;
and taking the average value of all the obtained initial capacity values as the capacity of the storage battery.
In an exemplary embodiment, the method for determining the capacity of the storage battery further includes:
and acquiring the corresponding relation between the charging capacity of the storage battery and the full battery voltage in the charging process of incompletely charging the storage battery after complete discharge.
In an exemplary embodiment, the state of charge SOC and voltage of the positive half-cell are represented by a SOC-V curve;
and the corresponding relation between the charging capacity and the voltage of the negative half battery is represented by a C-V relation curve.
The embodiment of the invention also provides a capacity grading method of the storage battery, which comprises the following steps:
incompletely charging the storage battery after complete discharge;
determining the capacity of the storage battery according to the determination method of the capacity of the storage battery in any one of the above embodiments;
and grading the storage battery according to the capacity of the storage battery.
In an exemplary embodiment, the incompletely charging the fully discharged storage battery includes:
charging the storage battery after complete discharge until a set charging capacity is reached, wherein the set charging capacity is smaller than the rated capacity of the storage battery; or
Charging the storage battery after complete discharge until a set voltage is reached, wherein the set voltage is less than the charge termination voltage of the storage battery; or
Charging the storage battery after complete discharge until a set time length is reached, wherein the set time length is less than the time length required by full charge of the storage battery;
wherein the charge capacity at the end of the incomplete charging of the storage battery is greater than or equal to the charge capacity value set in the method for determining the capacity of the storage battery.
In one exemplary embodiment, the battery is a lithium ion battery; or
The storage battery is a nickel-metal hydride battery.
The embodiment of the invention also provides a power battery system which comprises a plurality of storage batteries, wherein the storage batteries are subjected to capacity grading by adopting the capacity grading method of the storage batteries in any one of the embodiments.
Embodiments of the present invention further provide a device for determining a capacity of a storage battery, including a processor, a memory, and a computer program stored on the memory and executable on the processor, wherein the computer program, when executed by the processor, implements the steps of the method for determining a capacity of a storage battery according to any one of the above embodiments.
Compared with the prior art, the method for determining the capacity of the storage battery can obtain the charging capacity value of the storage battery at the same moment and the full battery voltage measured value at the moment in the incomplete charging process by testing the incomplete charging of the storage battery. And then combining the corresponding relation between the SOC and the voltage of the positive half cell of the storage battery and the corresponding relation between the charging capacity and the voltage of the negative half cell of the storage battery, and adopting a fitting capacity grading method to obtain the capacity of the storage battery. Because only the storage battery needs to be incompletely charged, the capacity determination time can be shortened, the power consumption is reduced, the capacity grading time is further shortened, the capacity grading energy consumption is reduced, and the mass production is facilitated.
Additional features and advantages of the application will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by the practice of the application. Other advantages of the present application may be realized and attained by the instrumentalities and combinations particularly pointed out in the specification and the drawings.
Drawings
The accompanying drawings are included to provide an understanding of the present disclosure and are incorporated in and constitute a part of this specification, illustrate embodiments of the disclosure and together with the examples serve to explain the principles of the disclosure and not to limit the disclosure.
Fig. 1 is a schematic flow chart of a method for determining the capacity of a storage battery according to an embodiment of the present invention;
FIG. 2 is a partial flow diagram of a method for determining battery capacity according to an embodiment of the present invention;
fig. 3 is a schematic flow chart of a capacity grading method for a storage battery according to an embodiment of the present invention;
FIG. 4 is a schematic block diagram of a power battery system provided in accordance with one embodiment of the present invention;
fig. 5 is a schematic block diagram of a storage battery capacity determination apparatus according to an embodiment of the present invention;
fig. 6 is a graph illustrating a relationship between a charging capacity and a voltage of a positive half-cell according to an embodiment of the present invention;
FIG. 7 is a graph illustrating a relationship between a charging capacity and a voltage of a negative half cell according to an embodiment of the present application;
fig. 8 is a graph illustrating a relationship between a charging capacity and a voltage of a battery according to an embodiment of the present application.
Detailed Description
As shown in fig. 1, an embodiment of the present invention provides a method for determining a capacity of a storage battery, including:
step S100: acquiring a full-battery voltage measured value when the storage battery after complete discharge is incompletely charged and the charging capacity reaches a set charging capacity value;
step S200: and determining the capacity of the storage battery according to the set charging capacity value, the full battery voltage measured value, the corresponding relation between the charging state SOC and the voltage of the positive half battery of the storage battery and the corresponding relation between the charging capacity and the voltage of the negative half battery of the storage battery.
According to the method for determining the capacity of the storage battery provided by the embodiment of the invention, the charging capacity value of the storage battery at the same moment in the incomplete charging process and the full battery voltage measured value at the moment can be obtained by performing the incomplete charging test on the storage battery. Then, the capacity of the storage battery can be obtained by adopting a fitting capacity grading method by combining the corresponding relation between the state of charge (SOC) and the voltage of the positive half battery of the storage battery and the corresponding relation between the charge capacity and the voltage of the negative half battery of the storage battery. Because only the storage battery needs to be incompletely charged, the capacity determination time can be shortened, the power consumption is reduced, the capacity grading time is further shortened, the capacity grading energy consumption is reduced, and the mass production is facilitated.
It is understood that fitting the partial capacity refers to partially charging the battery, and the battery capacity is obtained through test data and theoretical calculation. The fitting and capacity grading have the advantages of less time consumption and less energy consumption. "fully charged" refers to charging to a fully charged state. "incomplete charging" refers to partial charging, where the charging is not to a full charge.
The positive half cell of the storage battery is a half cell made of the same positive electrode component and material as the storage battery, and the half cell is called as the positive half cell of the storage battery. For a batch of batteries of the same specification, a positive half-cell can be made to represent the positive properties of the batch of batteries.
Similarly, the negative half cell of the storage battery is a half cell made of the same negative electrode component and material as the storage battery, and the half cell is called the negative half cell of the storage battery. For a batch of batteries of the same specification, a negative half-cell can be made to represent the negative performance of the batch.
Such as: for lithium ion batteries: the positive electrode assembly, electrolyte and diaphragm of a batch of storage batteries with the same specification can be adopted, and a lithium metal sheet is matched as a counter electrode to prepare a positive electrode half battery; negative electrode components, electrolyte and diaphragms of a batch of storage batteries with the same specification are adopted, and a lithium metal sheet is matched to be used as a counter electrode to manufacture a negative electrode half battery.
In an exemplary embodiment, further, the corresponding relationship between the state of charge SOC and the voltage of the positive electrode half cell is obtained by:
acquiring the corresponding relation between the charging capacity and the voltage of the positive half battery in the charging process of fully charging the fully discharged positive half battery;
and converting the charging capacity in the corresponding relation between the charging capacity and the voltage of the positive half battery into a charging state SOC to obtain the corresponding relation between the charging state SOC and the voltage of the positive half battery.
Wherein converting the charge capacity to the state of charge SOC comprises: and dividing the charging capacity by the capacity of the positive half battery to obtain the converted charging state SOC, wherein the capacity of the positive half battery is equal to the charging capacity of the positive half battery when the positive half battery reaches a full-charged state.
Since the charge capacity and the voltage are physical quantities, they can be directly measured by an instrument. The charge capacity can be measured by a capacity meter and the voltage can be measured by a voltmeter. And the state of charge SOC (or state of charge SOC) represents the percentage of the remaining capacity to the full capacity, the remaining capacity of the positive half-cell being equal to the charge capacity of the positive half-cell after full discharge. Thus, the state of charge SOC can be obtained by measuring the charge capacity of the positive half cell and then converting by dividing the charge capacity of the positive half cell by the charge capacity (or nominal capacity) at which the positive half cell reaches a full charge.
Further, the correspondence between the charge capacity and the voltage of the negative electrode half cell is obtained by:
and acquiring the corresponding relation between the charging capacity and the voltage of the cathode half cell in the charging process of fully charging the cathode half cell after complete discharge, and acquiring the corresponding relation between the charging capacity and the voltage of the cathode half cell.
The corresponding relation between the charging capacity and the voltage of the positive half battery is obtained by completely discharging and then completely charging the positive half battery, and the positive performance of the storage batteries in the same batch can be accurately reflected. Therefore, the corresponding relation between the charging capacity and the voltage of the positive half battery is used as the basis for the fitting and capacity grading of the same batch of storage batteries, and the accuracy is high.
Similarly, the corresponding relation between the charging capacity and the voltage of the negative half-cell is obtained by completely discharging and then completely charging the negative half-cell, and the negative performance of the storage batteries in the same batch can be accurately reflected. Therefore, the corresponding relation between the charging capacity and the voltage of the negative half battery is used as the basis for the fitting and capacity grading of the same batch of storage batteries, and the accuracy is high.
In an exemplary embodiment, further, as shown in FIG. 2, step 200 includes:
step S202: determining a negative electrode voltage value when the charge capacity of the storage battery reaches the set charge capacity value according to the set charge capacity value and the corresponding relation between the charge capacity and the voltage of the negative electrode half battery;
step S204: adding the negative electrode voltage value when the charging capacity of the storage battery reaches the set charging capacity value and the full battery voltage measured value to obtain a positive electrode voltage value when the charging capacity of the storage battery reaches the set charging capacity value;
step S206: determining a state of charge SOC value when the charge capacity of the storage battery reaches the set charge capacity value according to a positive electrode voltage value when the charge capacity of the storage battery reaches the set charge capacity value and a corresponding relation between the state of charge SOC and the voltage of the positive electrode half battery;
step S208: and determining the capacity of the storage battery according to the SOC value and the set charging capacity value.
Since the full cell voltage is equal to the difference between the positive and negative voltages, the positive voltage is equal to the sum of the full cell voltage and the negative voltage. The corresponding relation between the charge capacity and the voltage of the negative half cell reflects the relation between the negative voltage and the negative capacity, the change of the negative voltage in the charging process is small, and the negative electrode is usually overcharged, so the negative voltage value when the charge capacity of the storage battery reaches the set charge capacity value can be determined according to the set charge capacity value in the incomplete charging process of the storage battery and by combining the corresponding relation between the charge capacity and the voltage of the negative half cell. And adding the voltage value of the negative electrode and the voltage measured value of the full battery to obtain the voltage value of the positive electrode when the charging capacity of the storage battery reaches a set charging capacity value.
Since the corresponding relationship between the state of charge SOC and the voltage of the positive electrode half cell reflects the corresponding relationship between the positive electrode voltage and the positive electrode state of charge SOC, the positive electrode state of charge SOC when the charge capacity of the battery reaches the set charge capacity value can be determined by combining the corresponding relationship between the positive electrode voltage and the state of charge SOC of the positive electrode half cell according to the positive electrode voltage value when the charge capacity of the battery reaches the set charge capacity value, and the positive electrode state of charge SOC is equal to the state of charge SOC value of the full cell.
Since the state of charge SOC (or state of charge SOC) represents the percentage of the remaining capacity to the full capacity, the remaining capacity of the battery is equal to the charge capacity of the battery after full discharge. Therefore, the capacity of the battery can be determined from the state of charge SOC value and the set charge capacity value.
It is worth noting that during battery production, the negative electrode capacity is generally greater than the positive electrode capacity. For a fresh battery, the negative electrode capacity is excessive. The size of the battery capacity depends on how much the positive electrode capacity is, i.e. the full battery capacity equals the positive electrode capacity. Accordingly, the positive electrode state of charge SOC is equal to the state of charge SOC of the full battery.
In one example, there is one of the set charge capacity values.
And obtaining a full-battery voltage measured value when the charging capacity of the storage battery reaches the set charging capacity value, and determining an SOC value according to the set charging capacity value and the corresponding full-battery voltage measured value, the corresponding relation between the charging state SOC and the voltage of the positive half battery and the corresponding relation between the charging capacity and the voltage of the negative half battery.
Further, step S208 includes: and dividing the set charge capacity value by the determined SOC value to obtain the capacity of the storage battery.
In this example, only one charge capacity value is set, and the corresponding full-battery voltage measurement value, negative-electrode voltage value, positive-electrode voltage value, and SOC value are all only one. In other words, the present example uses only data from one time during the incomplete charging of the battery for fitting calculations to determine the capacity of the battery. Because the data is less and the algorithm is simple, the calculation program is simplified.
In another example, the set charge capacity value is plural.
And for each set charging capacity value, determining an SOC value corresponding to the charging capacity value according to a full battery voltage measured value corresponding to the charging capacity value and the charging capacity reaching the charging capacity value, the corresponding relation between the charging state SOC and the voltage of the positive half battery and the corresponding relation between the charging capacity and the voltage of the negative half battery.
Further, step S208 includes:
dividing each set charging capacity value by the SOC value determined according to the charging capacity value to obtain a corresponding capacity initial value;
and taking the average value of all the obtained initial capacity values as the capacity of the storage battery.
In this example, there are a plurality of charge capacity values, such as two, three, four, or more, and there are a plurality of corresponding full-battery voltage measurement values, negative-electrode voltage values, positive-electrode voltage values, and SOC values. In other words, in this example, the capacity of the storage battery can be determined by performing fitting calculation using data at a plurality of different times during incomplete charging of the storage battery, determining a plurality of initial capacity values, and then adding and averaging all the initial capacity values. And the data is more, so that the accuracy of fitting and grading is improved.
The charging capacity and the battery voltage of the storage battery can be measured in real time in the full battery testing process, so that no matter data at several moments are taken for fitting calculation, the testing duration of the full battery is not influenced, only certain influence is exerted on the subsequent calculation process, the capacity grading duration and the capacity grading energy consumption of the storage battery are not greatly influenced, and the accuracy is favorably improved.
In an exemplary embodiment, further, the method for determining the capacity of the storage battery further includes:
and acquiring the corresponding relation between the charging capacity of the storage battery and the full battery voltage in the charging process of incompletely charging the storage battery after complete discharge.
Normally, in the charging process of the fully discharged storage battery, the corresponding relationship between the charging capacity and the full battery voltage should have a certain regularity, for example, as the charging capacity increases, the full battery voltage increases rapidly and then slowly. Therefore, in the charging process in which the secondary battery is not fully charged, when it is found that the correspondence relationship between the charging capacity and the full battery voltage does not clearly conform to the rule that it should have, it indicates that some aspect may be problematic, such as a failure of the secondary battery or the charging device or the capacity measuring device or the voltage measuring device, etc.
Therefore, the corresponding relation between the charging capacity of the storage battery after complete discharge in the incomplete charging process and the full battery voltage is obtained, a better reminding effect can be achieved, and certain research value and reference value are achieved.
The corresponding relation between the charging capacity of the storage battery after complete discharge in the incomplete charging process and the full battery voltage can be represented by a C-V relation curve, so that the storage battery is relatively intuitive. Meanwhile, the representing mode of the relation curve is adopted, the charging capacity and the corresponding full-battery voltage measured value at the same moment can be conveniently obtained directly on the relation curve in a query mode, and the obtaining of one group or multiple groups of data is convenient.
Specifically, as shown in fig. 8, the abscissa of the C-V relationship curve may be the charge capacity value, and the ordinate may be the negative electrode voltage value.
Of course, the corresponding relationship between the charging capacity of the fully discharged storage battery in the incomplete charging process and the full battery voltage can also be represented by recording multiple sets of data. Each set of data includes charge capacity and full cell voltage measurements at the same time.
In an exemplary embodiment, further, the corresponding relationship between the state of charge SOC and the voltage of the positive half-cell is represented by a SOC-V relationship curve.
This is also intuitive. Meanwhile, the expression mode of the relation curve is adopted, the positive voltage value and the corresponding SOC value at the same moment can be conveniently obtained directly on the relation curve in a query mode, and the acquisition of one or more groups of data is convenient.
Specifically, as shown in fig. 6, the abscissa of the SOC-V relationship curve may be the SOC value, and the ordinate is the positive electrode voltage value.
Furthermore, the corresponding relation between the charging capacity and the voltage of the negative half cell is represented by a C-V relation curve. This is also intuitive. Meanwhile, the expression mode of the relation curve is adopted, the cathode voltage value and the corresponding charge capacity value at the same moment can be conveniently obtained directly on the relation curve in a query mode, and the acquisition of one or more groups of data is convenient.
Specifically, as shown in fig. 7, the abscissa of the C-V relationship curve may be the charge capacity value, and the ordinate may be the negative electrode voltage value.
As shown in fig. 3, an embodiment of the present invention further provides a capacity grading method for a storage battery, including:
step S302: incompletely charging the storage battery after complete discharge;
step S304: determining the capacity of the storage battery according to a determination method of the capacity of the storage battery;
step S306: and grading the storage battery according to the capacity of the storage battery.
In step S304, the method for determining the capacity of the storage battery is the method for determining the capacity of the storage battery in any one of the foregoing embodiments.
In the capacity grading method of the embodiment, the capacity of the storage battery is determined by adopting the method for determining the capacity of the storage battery in any one of the embodiments, so that the capacity grading time is shortened, and the capacity grading energy consumption is reduced.
In one example, step S302 includes: and charging the storage battery after complete discharge until a set charging capacity is reached, wherein the set charging capacity is smaller than the rated capacity of the storage battery. Wherein the charge capacity at the end of the incomplete charging of the storage battery is greater than or equal to the charge capacity value set in the method for determining the capacity of the storage battery.
In another example, step S302 includes: and charging the storage battery after complete discharge until a set voltage is reached, wherein the set voltage is less than the charge termination voltage of the storage battery. Wherein the charge capacity at the end of the incomplete charging of the storage battery is greater than or equal to the charge capacity value set in the method for determining the capacity of the storage battery.
In yet another example, step S302 includes: and charging the storage battery after complete discharge until a set time length is reached, wherein the set time length is less than the time length required by full charge of the storage battery. Wherein the charge capacity at the end of the incomplete charging of the storage battery is greater than or equal to the charge capacity value set in the method for determining the capacity of the storage battery.
In the process of testing the full battery, the charging capacity value and the full battery voltage value of the storage battery can be measured in real time. Therefore, when the storage battery after complete discharge is incompletely charged, the storage battery is not fully charged, the storage battery can be used as the ending basis of incomplete charging of the storage battery no matter the charging capacity, the charging voltage or the charging time, and the storage battery can be reasonably selected according to factors such as convenience and accuracy in the specific production process.
As for the set charging capacity value in the method for determining the capacity of the storage battery, the charging capacity of the storage battery at the end of incomplete charging can be taken, which is more convenient; of course, the charging capacity of the battery during incomplete charging may be used.
In an exemplary embodiment, further, the capacity grading method of the storage battery further includes:
and discharging the storage battery to the discharge termination voltage of the storage battery to obtain the completely discharged storage battery.
Further, the discharging the storage battery to the discharge termination voltage of the storage battery to obtain the completely discharged storage battery includes:
discharging the storage battery for multiple times, and controlling the discharge current of the next time to be smaller than that of the previous time;
and carrying out standing treatment on the storage battery between two adjacent discharging processes of the storage battery.
Wherein the discharge current of the secondary battery may be in a range of, but not limited to, 0.1C to 2C. The length of the standing time may be in the range of, but not limited to, 1 minute to 10 minutes.
Further, the capacity grading method of the storage battery further comprises the following steps:
discharging the positive half cell to the discharge termination voltage of the positive half cell to obtain the completely discharged positive half cell;
charging the fully discharged positive half battery until the fully charged state is reached;
discharging the negative half cell to the discharge termination voltage of the negative half cell to obtain the completely discharged negative half cell;
and charging the fully discharged negative half battery until the fully charged state is reached.
Further, discharging the positive half-cell to a discharge end voltage of the positive half-cell to obtain the fully discharged positive half-cell, comprising:
discharging the positive half cell for multiple times, and controlling the discharge current of the next time to be smaller than that of the previous time;
and carrying out standing treatment on the positive half cell between two adjacent discharging processes of the positive half cell.
Wherein the discharge current of the positive half cell may be in the range of, but is not limited to, 0.1C to 2C. The length of the standing time may be in the range of, but not limited to, 1 minute to 10 minutes.
Further, the discharging the negative half-cell to the discharge termination voltage of the negative half-cell to obtain the fully discharged negative half-cell includes:
discharging the negative electrode half cell for multiple times, and controlling the discharge current of the next time to be smaller than that of the previous time;
and carrying out standing treatment on the negative half cell between two adjacent discharging processes of the negative half cell.
Wherein the discharge current of the negative half cell may be in the range of, but not limited to, 0.1C to 2C. The length of the standing time may be in the range of, but not limited to, 1 minute to 10 minutes.
Before the positive half cell and the negative half cell are fully charged, the positive half cell and the negative half cell are fully discharged so as to ensure the data accuracy of the positive half cell and the negative half cell in the full charging process. Moreover, the positive half cell and the negative half cell are discharged for multiple times, so that the discharging sufficiency is improved, and the electric quantity is ensured to be fully discharged.
Here, the discharge current per time can be set as needed. The standing time period can also be set according to needs.
Illustratively, the secondary battery may be a lithium ion battery, such as a cylindrical lithium ion battery or a soft-packed lithium ion battery or a hard-packed prismatic lithium ion battery.
Alternatively, the battery may be a nickel metal hydride battery.
As shown in fig. 4, an embodiment of the present invention further provides a power battery system 600, which includes a plurality of storage batteries 602, and the storage batteries 602 are subjected to capacity division by using the capacity division method of the storage batteries, so that all the beneficial effects of any of the above embodiments are achieved, and are not described herein again.
As shown in fig. 5, an embodiment of the present invention further provides a device 700 for determining a capacity of a storage battery, which includes a processor 704, a memory 702, and a computer program stored on the memory 702 and executable on the processor, where the computer program, when executed by the processor 704, implements the steps of the method for determining a capacity of a storage battery according to any of the foregoing embodiments, and thus all beneficial effects of any of the foregoing embodiments are achieved, and are not described herein again.
One embodiment is described below.
The specific embodiment provides a capacity grading method for a lithium ion battery, which comprises three stages.
The first stage is as follows: half cell test and full cell test
The half cell test part includes the steps of:
step S400: manufacturing a positive electrode half cell and a negative electrode half cell;
step S402: discharging the positive half cell to an end-of-discharge voltage (i.e., 0% SOC voltage) at 0.5C;
step S404: standing for 5 minutes;
step S406: discharging the positive half cell to an end-of-discharge voltage (i.e., 0% SOC voltage) at 0.05C;
step S408: standing for 5 minutes;
step S410: charging the positive half cell to the end-of-charge voltage (i.e., 100% SOC voltage) at 0.5C;
step S412: obtaining a relation curve of the positive electrode SOC-Voltage (namely the relation curve of the positive electrode half battery SOC-V) according to the step S410;
step S502: discharging the negative half-cell to an end-of-discharge voltage (i.e., 0% SOC voltage) at 0.5C;
step S505: standing for 5 minutes;
step S506: discharging the negative half-cell to an end-of-discharge voltage (i.e., 0% SOC voltage) at 0.05C;
step S508: standing for 5 minutes;
step S510: charging the negative half cell to the end-of-charge voltage (i.e., 100% SOC voltage) at 0.5C;
step S512: obtaining a relation curve of the negative electrode Charge Ah-Voltage (namely a C-V relation curve of the negative electrode half cell) according to the step S510;
the full battery test part includes the following steps:
step S502: discharging the full cell to a discharge end voltage (i.e., 0% SOC voltage) at 0.5C;
step S505: standing for 5 minutes;
step S506: discharging the full cell to a discharge end voltage (i.e., 0% SOC voltage) at 0.05C;
step S508: standing for 5 minutes;
step S510: charging the full cell to a charge termination voltage (i.e., 100% SOC voltage) at 0.5C;
step S512: obtaining a relation curve of the full battery Charge Ah-Voltage (namely a C-V relation curve of the full battery) according to the step S510;
and a second stage: computing capacity
The negative electrode Voltage of the Charge X Ah (i.e. the set Charge capacity value) is inquired according to the negative electrode Charge Ah-Voltage relation.
Since the full-cell voltage is equal to the negative-electrode voltage — the negative-electrode voltage, the positive-electrode voltage is equal to the full-cell voltage + the negative-electrode voltage. Therefore, the anode voltage is calculated according to the full battery voltage and the cathode voltage.
And inquiring the positive pole SOC when charging X Ah according to the calculated positive pole Voltage and the positive pole SOC-Voltage relation.
Positive electrode capacity X/positive electrode SOC.
Since the capacity of the full battery is equal to the positive electrode capacity, the capacity of the full battery is equal to the positive electrode capacity X/positive electrode SOC.
And a third stage: grading
And grading the storage batteries according to different capacities.
The capacity grading method for the lithium ion battery provided by the specific embodiment has the following beneficial effects: the capacity of the battery cell can be calculated and obtained only through a small segment of charging data, and the storage battery is graded according to the capacity of the battery cell, so that the grading time and the consumed energy are reduced.
In summary, the embodiment of the present invention develops a capacity grading method for calculating the capacity of a full battery by using the corresponding relationship between the charging data of the positive half battery and the negative half battery and combining the charging data of the full battery, so as to grade the full battery, and the capacity grading method has the advantages of short capacity grading time and low capacity grading energy consumption.
The present application describes embodiments, but the description is illustrative rather than limiting and it will be apparent to those of ordinary skill in the art that many more embodiments and implementations are possible within the scope of the embodiments described herein. Although many possible combinations of features are shown in the drawings and discussed in the detailed description, many other combinations of the disclosed features are possible. Any feature or element of any embodiment may be used in combination with or instead of any other feature or element in any other embodiment, unless expressly limited otherwise.
The present application includes and contemplates combinations of features and elements known to those of ordinary skill in the art. The embodiments, features and elements disclosed in this application may also be combined with any conventional features or elements to form a unique inventive concept as defined by the claims. Any feature or element of any embodiment may also be combined with features or elements from other inventive aspects to form yet another unique inventive aspect, as defined by the claims. Thus, it should be understood that any of the features shown and/or discussed in this application may be implemented alone or in any suitable combination. Accordingly, the embodiments are not limited except as by the appended claims and their equivalents. Furthermore, various modifications and changes may be made within the scope of the appended claims.
Further, in describing representative embodiments, the specification may have presented the method and/or process as a particular sequence of steps. However, to the extent that the method or process does not rely on the particular order of steps set forth herein, the method or process should not be limited to the particular sequence of steps described. Other orders of steps are possible as will be understood by those of ordinary skill in the art. Therefore, the particular order of the steps set forth in the specification should not be construed as limitations on the claims. Further, the claims directed to the method and/or process should not be limited to the performance of their steps in the order written, and one skilled in the art can readily appreciate that the sequences may be varied and still remain within the spirit and scope of the embodiments of the present application.
It will be understood by those of ordinary skill in the art that all or some of the steps of the methods, systems, functional modules/units in the devices disclosed above may be implemented as software, firmware, hardware, and suitable combinations thereof. In a hardware implementation, the division between functional modules/units mentioned in the above description does not necessarily correspond to the division of physical components; for example, one physical component may have multiple functions, or one function or step may be performed by several physical components in cooperation. Some or all of the components may be implemented as software executed by a processor, such as a digital signal processor or microprocessor, or as hardware, or as an integrated circuit, such as an application specific integrated circuit. Such software may be distributed on computer readable media, which may include computer storage media (or non-transitory media) and communication media (or transitory media). The term computer storage media includes volatile and nonvolatile, removable and non-removable media implemented in any method or technology for storage of information such as computer readable instructions, data structures, program modules or other data, as is well known to those of ordinary skill in the art. Computer storage media includes, but is not limited to, RAM, ROM, EEPROM, flash memory or other memory technology, CD-ROM, Digital Versatile Disks (DVD) or other optical disk storage, magnetic cassettes, magnetic tape, magnetic disk storage or other magnetic storage devices, or any other medium which can be used to store the desired information and which can accessed by a computer. In addition, communication media typically embodies computer readable instructions, data structures, program modules or other data in a modulated data signal such as a carrier wave or other transport mechanism and includes any information delivery media as known to those skilled in the art.
Claims (13)
1. A method of determining battery capacity, comprising:
acquiring a full-battery voltage measured value when the storage battery after complete discharge is incompletely charged and the charging capacity reaches a set charging capacity value;
and determining the capacity of the storage battery according to the set charging capacity value, the full battery voltage measured value, the corresponding relation between the charging state SOC and the voltage of the positive half battery of the storage battery and the corresponding relation between the charging capacity and the voltage of the negative half battery of the storage battery.
2. The storage battery capacity determination method according to claim 1, wherein the correspondence between the state of charge SOC and the voltage of the positive electrode half cell is obtained by:
acquiring the corresponding relation between the charging capacity and the voltage of the positive half battery in the charging process of fully charging the fully discharged positive half battery;
converting the charging capacity in the corresponding relation between the charging capacity and the voltage of the positive half battery into a charging state SOC to obtain the corresponding relation between the charging state SOC and the voltage of the positive half battery;
wherein converting the charge capacity to the state of charge SOC comprises: and dividing the charging capacity by the capacity of the positive half battery to obtain the converted charging state SOC, wherein the capacity of the positive half battery is equal to the charging capacity of the positive half battery when the positive half battery reaches a full-charged state.
3. The method for determining the capacity of a secondary battery according to claim 1, wherein the correspondence between the charge capacity and the voltage of the negative half-cell is obtained by:
and acquiring the corresponding relation between the charging capacity and the voltage of the cathode half cell in the charging process of fully charging the cathode half cell after complete discharge, and acquiring the corresponding relation between the charging capacity and the voltage of the cathode half cell.
4. The method of determining the capacity of a storage battery according to any one of claims 1 to 3, the determining the capacity of the storage battery according to the set charge capacity value and the full-battery voltage measurement value, the correspondence of the state of charge SOC and the voltage of the positive half-cell of the storage battery, and the correspondence of the charge capacity and the voltage of the negative half-cell of the storage battery, comprising:
determining a negative electrode voltage value when the charge capacity of the storage battery reaches the set charge capacity value according to the set charge capacity value and the corresponding relation between the charge capacity and the voltage of the negative electrode half battery;
adding the negative electrode voltage value when the charging capacity of the storage battery reaches the set charging capacity value and the full battery voltage measured value to obtain a positive electrode voltage value when the charging capacity of the storage battery reaches the set charging capacity value;
determining a state of charge SOC value when the charge capacity of the storage battery reaches the set charge capacity value according to a positive electrode voltage value when the charge capacity of the storage battery reaches the set charge capacity value and a corresponding relation between the state of charge SOC and the voltage of the positive electrode half battery;
and determining the capacity of the storage battery according to the SOC value and the set charging capacity value.
5. The method for determining the capacity of a secondary battery according to claim 4, wherein there is one of the set charge capacity values;
obtaining a full-battery voltage measurement value when the charging capacity of the storage battery reaches the set charging capacity value, and determining an SOC value according to the set charging capacity value and the corresponding full-battery voltage measurement value, the corresponding relation between the charging state SOC and the voltage of the positive half battery and the corresponding relation between the charging capacity and the voltage of the negative half battery;
the determining the capacity of the storage battery according to the SOC value and the set charge capacity value includes:
and dividing the set charge capacity value by the determined SOC value to obtain the capacity of the storage battery.
6. The method for determining the capacity of a secondary battery according to claim 4, wherein there are a plurality of the set charge capacity values;
for each set charging capacity value, determining an SOC value corresponding to the charging capacity value according to a full battery voltage measurement value corresponding to the charging capacity value and the charging capacity reaching the charging capacity value, a corresponding relation between the charging state SOC and the voltage of the positive half battery and a corresponding relation between the charging capacity and the voltage of the negative half battery;
the determining the capacity of the storage battery according to the SOC value and the set charge capacity value includes:
dividing each set charging capacity value by the SOC value determined according to the charging capacity value to obtain a corresponding capacity initial value;
and taking the average value of all the obtained initial capacity values as the capacity of the storage battery.
7. The storage battery capacity determination method according to any one of claims 1 to 3, further comprising:
and acquiring the corresponding relation between the charging capacity of the storage battery and the full battery voltage in the charging process of incompletely charging the storage battery after complete discharge.
8. The method of determining battery capacity according to any one of claims 1 to 3,
the corresponding relation between the SOC and the voltage of the positive half battery is represented by an SOC-V relation curve;
and the corresponding relation between the charging capacity and the voltage of the negative half battery is represented by a C-V relation curve.
9. A method of grading a battery comprising:
incompletely charging the storage battery after complete discharge;
the determination method of the capacity of the storage battery according to any one of claims 1 to 8, determining the capacity of the storage battery;
and grading the storage battery according to the capacity of the storage battery.
10. The method for grading a battery according to claim 9, wherein the incompletely charging the battery after complete discharge comprises:
charging the storage battery after complete discharge until a set charging capacity is reached, wherein the set charging capacity is smaller than the rated capacity of the storage battery; or
Charging the storage battery after complete discharge until a set voltage is reached, wherein the set voltage is less than the charge termination voltage of the storage battery; or
Charging the storage battery after complete discharge until a set time length is reached, wherein the set time length is less than the time length required by full charge of the storage battery;
wherein the charge capacity at the end of the incomplete charging of the storage battery is greater than or equal to the charge capacity value set in the method for determining the capacity of the storage battery.
11. The capacity classifying method of a secondary battery according to claim 9 or 10,
the storage battery is a lithium ion battery; or
The storage battery is a nickel-metal hydride battery.
12. A power battery system comprising a plurality of batteries, said batteries being sized using the method of sizing the batteries of any of claims 9 to 11.
13. A determination device of a capacity of a storage battery, comprising a processor, a memory and a computer program stored on the memory and executable on the processor, the computer program, when being executed by the processor, implementing the steps of the determination method of a capacity of a storage battery according to any one of claims 1 to 8.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
CN202110895199.9A CN113805072B (en) | 2021-08-03 | 2021-08-03 | Capacity determining method and device, capacity dividing method and power battery system |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
CN202110895199.9A CN113805072B (en) | 2021-08-03 | 2021-08-03 | Capacity determining method and device, capacity dividing method and power battery system |
Publications (2)
Publication Number | Publication Date |
---|---|
CN113805072A true CN113805072A (en) | 2021-12-17 |
CN113805072B CN113805072B (en) | 2023-10-20 |
Family
ID=78893403
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
CN202110895199.9A Active CN113805072B (en) | 2021-08-03 | 2021-08-03 | Capacity determining method and device, capacity dividing method and power battery system |
Country Status (1)
Country | Link |
---|---|
CN (1) | CN113805072B (en) |
Citations (13)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2005265801A (en) * | 2004-03-22 | 2005-09-29 | Sharp Corp | Battery capacity detecting apparatus, electronic apparatus or vehicle comprising the same, battery capacity detecting method |
CN101285874A (en) * | 2007-04-10 | 2008-10-15 | 三洋电机株式会社 | Battery full charge capacity detection method |
CN106030893A (en) * | 2013-12-20 | 2016-10-12 | 丰田自动车株式会社 | Electrical storage system |
CN107102263A (en) * | 2016-02-22 | 2017-08-29 | 华为技术有限公司 | Detect method, device and the battery management system of cell health state |
CN108072845A (en) * | 2017-12-20 | 2018-05-25 | 上海理工大学 | Lithium battery capacity method of estimation based on imperfect charging voltage curve |
US20190126770A1 (en) * | 2017-10-26 | 2019-05-02 | GM Global Technology Operations LLC | Battery state estimation control logic and architectures for electric storage systems |
CN109814041A (en) * | 2019-01-16 | 2019-05-28 | 上海理工大学 | A kind of lithium ion battery double card Kalman Filtering capacity estimation method |
US10371753B1 (en) * | 2013-12-20 | 2019-08-06 | Hrl Laboratories, Llc | Methods for online estimation of battery capacity and state of health |
CN110165314A (en) * | 2019-04-30 | 2019-08-23 | 蜂巢能源科技有限公司 | Battery battery core performance parameter acquisition methods and acquisition device |
US10511050B1 (en) * | 2018-12-31 | 2019-12-17 | Sf Motors, Inc. | Battery state of health estimation by tracking electrode and cyclable lithium capacities |
CN111077465A (en) * | 2019-12-25 | 2020-04-28 | 欣旺达电动汽车电池有限公司 | Battery characteristic parameter extraction method and device, computer equipment and storage medium |
CN111175653A (en) * | 2020-01-06 | 2020-05-19 | 国网内蒙古东部电力有限公司电力科学研究院 | Method for identifying and prejudging capacity 'water-jumping' fault of ternary battery |
CN111398833A (en) * | 2020-03-13 | 2020-07-10 | 浙江大学 | Battery health state evaluation method and evaluation system |
-
2021
- 2021-08-03 CN CN202110895199.9A patent/CN113805072B/en active Active
Patent Citations (13)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2005265801A (en) * | 2004-03-22 | 2005-09-29 | Sharp Corp | Battery capacity detecting apparatus, electronic apparatus or vehicle comprising the same, battery capacity detecting method |
CN101285874A (en) * | 2007-04-10 | 2008-10-15 | 三洋电机株式会社 | Battery full charge capacity detection method |
US10371753B1 (en) * | 2013-12-20 | 2019-08-06 | Hrl Laboratories, Llc | Methods for online estimation of battery capacity and state of health |
CN106030893A (en) * | 2013-12-20 | 2016-10-12 | 丰田自动车株式会社 | Electrical storage system |
CN107102263A (en) * | 2016-02-22 | 2017-08-29 | 华为技术有限公司 | Detect method, device and the battery management system of cell health state |
US20190126770A1 (en) * | 2017-10-26 | 2019-05-02 | GM Global Technology Operations LLC | Battery state estimation control logic and architectures for electric storage systems |
CN108072845A (en) * | 2017-12-20 | 2018-05-25 | 上海理工大学 | Lithium battery capacity method of estimation based on imperfect charging voltage curve |
US10511050B1 (en) * | 2018-12-31 | 2019-12-17 | Sf Motors, Inc. | Battery state of health estimation by tracking electrode and cyclable lithium capacities |
CN109814041A (en) * | 2019-01-16 | 2019-05-28 | 上海理工大学 | A kind of lithium ion battery double card Kalman Filtering capacity estimation method |
CN110165314A (en) * | 2019-04-30 | 2019-08-23 | 蜂巢能源科技有限公司 | Battery battery core performance parameter acquisition methods and acquisition device |
CN111077465A (en) * | 2019-12-25 | 2020-04-28 | 欣旺达电动汽车电池有限公司 | Battery characteristic parameter extraction method and device, computer equipment and storage medium |
CN111175653A (en) * | 2020-01-06 | 2020-05-19 | 国网内蒙古东部电力有限公司电力科学研究院 | Method for identifying and prejudging capacity 'water-jumping' fault of ternary battery |
CN111398833A (en) * | 2020-03-13 | 2020-07-10 | 浙江大学 | Battery health state evaluation method and evaluation system |
Non-Patent Citations (2)
Title |
---|
D. RAKHMATOV 等: "Battery lifetime prediction for energy-aware computing", 《BATTERY LIFETIME PREDICTION FOR ENERGY-AWARE COMPUTING》, pages 154 - 159 * |
刘军伟 等: "基于可用容量估算和电量增量曲线的安时积分荷电状态估算方法", 《仪表技术》, no. 3, pages 33 - 37 * |
Also Published As
Publication number | Publication date |
---|---|
CN113805072B (en) | 2023-10-20 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
CN107991623B (en) | Battery ampere-hour integral SOC estimation method considering temperature and aging degree | |
CN111812531B (en) | Battery state detection method, device and storage medium | |
CN110109030B (en) | Battery pack consistency evaluation method and battery pack balancing strategy | |
CN109964137B (en) | Apparatus and method for estimating capacity retention rate of secondary battery | |
CN104051810B (en) | A kind of lithium-ion energy storage battery system SOC estimates rapid correction method | |
JP5474993B2 (en) | Method for determining the state of charge of a battery in the charge or discharge phase | |
CN109975715B (en) | Method for obtaining residual electric quantity of lithium ion battery module of electric vehicle | |
CN112526352B (en) | SOH estimation method for retired lithium ion battery | |
CN112689934A (en) | Charging method, electronic device, and storage medium | |
CN115754736A (en) | SOC calibration method and device for charging and discharging tail ends of energy storage system | |
CN113484783B (en) | Battery SOH detection method, device, system, medium and program product | |
CN113075558B (en) | Battery SOC estimation method, device and system | |
CN117970158A (en) | Method for determining battery state of health, vehicle and storage medium | |
CN112415399B (en) | Battery cell OCV-SOC curve correction method, device and storage medium | |
CN112924869B (en) | Method and device for determining health state of battery pack | |
CN113176516A (en) | Capacity prediction method, capacity prediction device, electronic device, and storage medium | |
CN113805072B (en) | Capacity determining method and device, capacity dividing method and power battery system | |
CN115902653A (en) | Method and device for determining battery aging degree, storage medium and electronic equipment | |
CN114879053A (en) | Method for predicting service life of energy storage lithium iron phosphate battery | |
CN113097582B (en) | Method and device for estimating SOH value of battery monomer | |
CN115097325A (en) | Battery detection method, device, equipment and storage medium | |
CN112327176B (en) | Battery performance detection method, system and storage medium | |
CN114646892A (en) | Method and device for obtaining SOC-OCV curve and lithium intercalation-OCV curve of secondary battery | |
CN114966453A (en) | Method and related device for acquiring remaining available energy of lithium battery | |
CN112666471A (en) | Lithium ion battery consistency sorting method and sorting system |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
PB01 | Publication | ||
PB01 | Publication | ||
SE01 | Entry into force of request for substantive examination | ||
SE01 | Entry into force of request for substantive examination | ||
GR01 | Patent grant | ||
GR01 | Patent grant |