CN116455020A

CN116455020A - Battery management method and management device

Info

Publication number: CN116455020A
Application number: CN202310264911.4A
Authority: CN
Inventors: 周建兵; 李文娟; 李瑞生
Original assignee: Huawei Digital Power Technologies Co Ltd
Current assignee: Huawei Digital Power Technologies Co Ltd
Priority date: 2023-03-10
Filing date: 2023-03-10
Publication date: 2023-07-18

Abstract

The application provides a battery management method and a battery management device. In the technical scheme provided by the application, when the SOH of the battery meets a first condition, the charging current of the battery is controlled to be a first current, and/or the charging and discharging SOC interval of the battery is controlled to be a first interval, wherein the first condition comprises that the SOH of the battery is larger than the first SOH; when the SOH of the battery meets a second condition, the charging current of the battery is controlled to be a second current, and/or the charging and discharging SOC interval of the battery is controlled to be a second interval, wherein the second current is smaller than the first current, the second interval is a partial interval in the first interval, and the second condition comprises that the SOH of the battery is smaller than or equal to the first SOH. The technical scheme of this application guarantees the steady operation of battery through the charge mode of regulation and control battery, has avoided the potential safety hazard problem that the battery produced because of ageing.

Description

Battery management method and management device

Technical Field

The present disclosure relates to the field of battery technologies, and in particular, to a method and an apparatus for managing a battery.

Background

The lithium battery is widely applied to the energy storage field due to the advantages of high energy density, long service life, strong endurance capacity and the like. However, as users continue to go deep, the lithium battery inevitably ages, such as battery capacity fading, internal resistance increase, lithium precipitation, and leakage, thereby creating a safety hazard. For the lithium battery module, there may be a potential danger that the battery case deforms, interferes with the cabinet, the tabs between the battery cells break, the battery module severely expands, deforms and squeezes the single plate, so that the single plate fails, even carbonizes, and the like.

In order to prevent potential safety hazards of lithium batteries, a state of health (SOH) is used in industry to represent the aging degree of the battery, and after the SOH reaches a battery quality assurance (EOW), an alarm message is output to prompt a user to replace the battery.

However, the above method cannot effectively avoid the potential safety hazard problem of the lithium battery caused by aging. For example, after the battery SOH reaches EOW, even if the output of the alarm information prompts the user that the battery needs to be replaced, the user still continues to use the battery, so that there is a safety hazard.

Disclosure of Invention

The application provides a battery management method and a management device, so that potential safety hazard problems caused by aging of a battery can be effectively avoided.

In a first aspect, the present application provides a method for managing a battery, including: when the SOH of the battery meets a first condition, controlling the charging current of the battery to be a first current, and/or controlling a charge-discharge battery charge state SOC interval of the battery to be a first interval, wherein the first condition comprises that the SOH of the battery is larger than the first SOH; and when the SOH of the battery meets a second condition, controlling the charging current of the battery to be a second current, and/or controlling the charging and discharging SOC interval of the battery to be a second interval, wherein the second current is smaller than the first current, the second interval is a partial interval in the first interval, and the second condition comprises that the SOH of the battery is smaller than or equal to the first SOH.

The method may be performed by a management device of the battery, which may be a battery management system (battery management system, BMS) in the battery module or may be an energy storage system monitoring unit.

In one implementation, the first SOH may be an end of wall (EOW) given by a manufacturer at the time of battery shipment.

In another implementation, the first SOH may be an SOH less than EOW.

Optionally, when the charging mode of the battery is adjusted, the current running state of the battery can be prompted by outputting indication information.

As an example, the indicator light may include a green indicator light, an orange indicator light, and a red indicator light. For example, a green indicator light is used for prompting a user that the current running state of the battery is stable; the orange indicator lamp is used for prompting the user that the battery is aged and the battery needs to be replaced; the red indicator light is used for prompting the user that the aging degree in the battery is serious, and the battery needs to be replaced as soon as possible.

The voice prompt may include directly outputting the current operating state of the battery, outputting different types of alarm sounds, or outputting different frequencies of alarm sounds, etc.

The text alert may include outputting information that the battery is functioning well, that the battery needs to be replaced, etc.

In the technical scheme, when the health condition of the battery is reduced, the battery aging can be slowed down by limiting the charging current of the battery and/or controlling the charge-discharge state of charge (SOC) interval of the battery, and the service life of the battery is prolonged, so that the running reliability of the battery is improved, and the use safety of a user is further improved.

In addition, through the charging mode of adjustment battery, can reduce the expansion force of battery to reduce the structural design intensity of battery module, reduced design cost and implementation cost.

With reference to the first aspect, in one possible implementation manner, when the state of health SOH of the battery meets a first condition, controlling the charging current of the battery to be a first current, and/or controlling the charge-discharge battery state of charge SOC interval of the battery to be a first interval includes: when the SOH of the battery meets a first condition, controlling the battery to charge until the battery is fully charged, and controlling the battery to discharge until the output voltage of the battery is cut-off voltage; acquiring the current SOH of the battery; and when the current SOH of the battery meets the first condition, controlling the charging current of the battery to be a first current, and/or controlling the charging and discharging SOC interval of the battery to be a first interval.

In the implementation manner, if the method is executed by the BMS battery management system, the BMS battery management system can send request information to the energy storage system monitoring unit so as to request the energy storage system monitoring unit to calculate the current SOH of the battery, thereby realizing calibration of SOH data and improving the accuracy of the data and the robustness of the technical scheme.

The energy storage system monitoring unit controls the BMS battery management system in the target battery module to control the battery to be fully charged according to the request information sent by the BMS battery management system, and then continues to control the target battery to discharge until the output voltage of the battery is cut-off voltage, so that the current SOH of the battery can be obtained.

With reference to the first aspect, in a possible implementation manner, the second condition further includes: the SOH of the battery is greater than the second SOH; wherein the method further comprises: and when the SOH of the battery meets a third condition, controlling the charging current of the battery to be a third current, and/or controlling the charging and discharging SOC interval of the battery to be a third interval, wherein the third current is smaller than the second current, the third interval is a partial interval in the second interval, the third condition comprises that the SOH of the battery is smaller than or equal to a second SOH, and the second SOH is smaller than the first SOH.

In this implementation, when the battery meets the third condition, it indicates that the aging degree of the battery is serious, and therefore, it is necessary to further limit the charging current of the battery and/or the charge-discharge SOC interval of the battery to ensure safe operation of the battery.

In the implementation mode, the battery is controlled in a grading manner according to the health condition of the battery, so that the running stability of the battery and the use safety of a user are further improved.

With reference to the first aspect, in a possible implementation manner, the third condition further includes: and the duration that the SOH of the battery is smaller than or equal to the second SOH is the first duration.

Alternatively, the first duration may be one month.

In the implementation manner, in the first duration, the user can be reminded of replacing the battery in the duration by outputting the alarm prompt information, and if the user does not replace the battery in the duration, the charging current of the battery and/or the charging and discharging SOC interval of the current are further limited, so that the use safety of the user is improved.

In the implementation mode, under the condition of ensuring safe operation of the battery, a certain processing time is given to the user, and the use experience of the user is improved.

With reference to the first aspect, in one possible implementation manner, the second SOH is a maximum value of SOH when the battery is at the end of life and SOH when the battery module is at the end of life.

In the implementation mode, the service life end point of the energy storage battery system is determined by considering the service life of the battery and the structural service life of the battery module, and is matched with the charging current of the control battery and/or the charging and discharging SOC interval of the control battery, so that potential safety hazards caused by unrestricted use of the battery by a user are avoided, and the safety and reliability of the energy storage battery system are improved.

With reference to the first aspect, in one possible implementation manner, the battery is at a service life end point when the battery includes at least one of the following states: the alternating current internal resistance of the battery is larger than the internal resistance threshold, the pole piece in the battery is broken, the lithium precipitation area in the battery exceeds the area threshold, and the battery safety test result meets the preset test result.

In this implementation, the SOH at the end of life of the battery may be the maximum of the SOHs of the battery including any of the states described above. For example, if the SOH when the ac internal resistance of the battery is greater than the internal resistance threshold is 40%, the SOH when the pole pieces in the battery are broken is 50%, the SOH when the battery test result satisfies the preset test result is 55%, and the SOH when the battery is at the end-of-life point is 55%.

With reference to the first aspect, in one possible implementation manner, the state of the battery module when the battery module is at the end of life point includes that the maximum deformation displacement of the battery module is greater than the displacement threshold.

The SOH of the battery module at the service life end point is the SOH of the battery when the deformation displacement of the battery module reaches the maximum deformation displacement.

Alternatively, the maximum deformation displacement of the battery may be the minimum value of the lateral distance between the structural members where the battery module is located, the material stress boundary of the structural members where the battery module is located, and the single plate distance between the batteries, and the lateral direction is the expansion direction of the battery.

In this implementation, the structural life of the battery module, i.e., the maximum deformation displacement is taken into account, avoiding the risk of failure of the battery module structure. In addition, the determination of the end-of-life point of the battery module may also be used to guide the early design of the battery module structure.

In a second aspect, the present application provides a battery management device comprising means for implementing the method of the first aspect or any implementation manner thereof, each means being implemented in hardware and/or software.

For example, the apparatus may include: the device comprises a processing module and a receiving and transmitting module. The processing module is used for controlling the charging current of the battery to be a first current and/or controlling the charging and discharging SOC interval of the battery to be a first interval when the SOH of the battery meets a first condition, wherein the first condition comprises that the SOH of the battery is larger than the first SOH; the processing module is further configured to control a charging current of the battery to be a second current and/or control a charging and discharging SOC interval of the battery to be a second interval when the SOH of the battery satisfies a second condition, wherein the second current is smaller than the first current, the second interval is a partial interval in the first interval, and the second condition includes that the SOH of the battery is smaller than or equal to the first SOH.

With reference to the second aspect, in a possible implementation manner, the processing module is further configured to control, when the SOH of the battery meets a first condition, charging the battery until the battery is fully charged, and discharging the battery until an output voltage of the battery is a cutoff voltage; the receiving and transmitting module is used for acquiring the current SOH of the battery; the processing module is further configured to control a charging current of the battery to be a first current and/or control a charging and discharging SOC interval of the battery to be a first interval when the current SOH of the battery satisfies the first condition.

With reference to the second aspect, in one possible implementation manner, the processing module is further configured to control the charge current of the battery to be a third current and/or control the charge-discharge SOC interval of the battery to be a third interval when the SOH of the battery meets a third condition, where the third current is smaller than the second current, and the third interval is a partial interval within the second interval, and the third condition includes that the SOH of the battery is smaller than or equal to a second SOH, and the second SOH is smaller than the first SOH.

In a third aspect, the present application provides a battery management device comprising a processor coupled to a memory, operable to execute instructions in the memory to implement the method of the first aspect or any one of the possible implementations. Optionally, the apparatus further comprises a memory. Optionally, the apparatus further comprises a communication interface, the processor being coupled to the communication interface.

In a fourth aspect, the present application provides a battery management system comprising a battery management device according to the third aspect.

In a fifth aspect, the present application provides a battery module comprising the battery management system according to the fourth aspect.

In a sixth aspect, the present application provides a battery comprising the battery management device according to the second or third aspect, or comprising the battery management system according to the fourth aspect, or comprising the battery module according to the fifth aspect.

In a seventh aspect, the present application provides a computer readable medium storing program code for execution by a device, the program code comprising instructions for performing the method of the first aspect or any one of the possible implementations thereof.

In an eighth aspect, the present application provides a computer program product comprising instructions which, when run on a computer, cause the computer to perform the method according to the first aspect or any one of the possible implementations thereof.

Drawings

Fig. 1 is a schematic view of an application scenario provided in an embodiment of the present application;

FIG. 2 is a schematic diagram of a battery management method according to one embodiment of the present application;

Fig. 3 is a schematic diagram of determining a charge-discharge SOC interval of a battery according to an embodiment of the present disclosure;

fig. 4 is a schematic diagram of a battery management method according to another embodiment of the present application;

FIG. 5 is a schematic diagram of a battery life cycle provided in one embodiment of the present application;

FIG. 6 is a schematic diagram of a method for determining SOH threshold according to one embodiment of the present application;

fig. 7 is a schematic structural diagram of a battery management device according to an embodiment of the present application;

fig. 8 is a schematic structural diagram of a battery management device according to another embodiment of the present application.

Specific embodiments thereof have been shown by way of example in the drawings and will herein be described in more detail. These drawings and the written description are not intended to limit the scope of the inventive concepts in any way, but to illustrate the concepts of the present application to those skilled in the art by reference to specific embodiments.

Detailed Description

Reference will now be made in detail to exemplary embodiments, examples of which are illustrated in the accompanying drawings. When the following description refers to the accompanying drawings, the same numbers in different drawings refer to the same or similar elements, unless otherwise indicated. The implementations described in the following exemplary examples are not representative of all implementations consistent with the present application. Rather, they are merely examples of apparatus and methods consistent with some aspects of the present application as detailed in the accompanying claims.

The technical scheme provided by the application can be applied to battery systems in different fields. Fig. 1 is a schematic view of an application scenario provided in an embodiment of the present application. As shown in fig. 1, the energy storage battery system 10 includes an energy storage system monitoring unit 120, a cabinet 130, a plurality of battery modules 110, and other components.

The battery module 110 includes a plurality of batteries, a case structure, a battery management system (battery management system, BMS), and the like as core devices of the system.

In the battery module 110, a plurality of batteries may be grouped together and one battery module may be formed by structural members in order to safely and effectively manage the respective batteries, so that the stability and safety of the batteries may be ensured.

The BMS battery management system can be used for dynamically detecting the working state of the battery module, and acquiring information such as terminal voltage, temperature, charge and discharge current and the like of each battery in the battery module in real time in the process of charging and discharging the battery; the method can also be used for realizing estimation of the state of charge (SOC) and the state of health (SOH) of the battery according to the acquired information, thereby realizing charge management, discharge management, balance management, fault diagnosis and protection of the battery.

The SOC of the battery refers to a percentage of the remaining battery power. Soc=0 indicates that the battery is completely discharged, and soc=1 indicates that the battery is completely charged. SOH of a battery refers to the percentage of the ratio of the capacity discharged from the battery discharged to the cut-off voltage at a certain rate from the full charge operating state to the nominal capacity of the battery. The greater SOH indicates a lower degree of aging of the battery.

The energy storage system monitoring unit 120 is used for managing the battery module 110.

For example, the energy storage system monitoring unit 120 may send indication information to the battery module 110 to instruct the BMS battery management system in the battery module 110 to report the collected relevant information in the battery module 110 to the energy storage system monitoring unit 120, where the relevant information may include SOH, SOC, voltage, current, and the like of the battery.

As another example, the energy storage system monitoring unit 120 may transmit control information to the battery module 110 to instruct the BMS battery management system in the battery module 110 to perform charge and discharge management on the battery, so that accurate estimation of the SOH of the battery may be achieved.

The cabinet 130 may be a secondary cabinet, and the battery module 110, the energy storage system monitoring unit 120 may be integrated into the cabinet 130.

Other components may include air conditioning modules, fuses, etc., and other components may also be located in the cabinet 130.

However, with the continuous deep use of the energy storage battery system, aging can inevitably occur, for example, problems such as battery capacity attenuation, internal resistance increase, lithium precipitation, liquid leakage and the like can occur in the battery in the system; there may be a potential danger in the battery module that the deformation of the battery case interferes with the cabinet, the tabs between the battery cells are broken, the battery module severely expands, deforms and squeezes the single board, so that the single board fails, even carbonizes, and the like.

In view of this, the application provides a management method and a management device of battery, when the health condition of battery descends, slow down the ageing of battery through adjusting the charge mode of battery, extension battery's life, in addition can also report to the police and indicate the user to change the battery to can guarantee that the battery runs safe and reliable, and then improve user's safety in utilization.

Fig. 2 is a schematic diagram illustrating a battery management method according to an embodiment of the present application. As shown in fig. 2, the method includes S201, S202, and S203.

The method may be performed by a management device of the battery, which may be a BMS battery management system in the battery module or may be an energy storage system monitoring unit.

S201, judging whether SOH of the battery is larger than first SOH. If the SOH of the battery is greater than the first SOH, then S202 is performed, otherwise S203 is performed.

In this embodiment, alternatively, the SOH of the battery may be obtained by the BMS battery management system according to the battery information collected in real time.

Alternatively, the first SOH may be adjusted according to the actual situation. The first SOH may be preset in advance in the energy storage battery system, for example, in the BMS battery management system, or in the energy storage system monitoring unit.

As an example, the first SOH may be an end of wall (EOW) given by a manufacturer at the time of battery shipment.

The battery manufacturer considers that the battery achieves a quality assurance point when the SOH of the battery is 70-80%. Thus, the first SOH may be any value between 70% and 80%.

As another example, the first SOH may be an SOH less than EOW, e.g., the first SOH may be 60%.

In the embodiment of the application, the SOH of the battery is greater than the first SOH, which may be referred to as a first condition; the SOH of the battery being less than or equal to the first SOH may be referred to as a second condition.

S202, controlling the charging current of the battery to be a first current and/or controlling the charging and discharging SOC interval of the battery to be a first interval.

In one possible implementation, the charge current of the battery may be set to the first current when the SOH of the battery satisfies the first condition.

The first current can be set according to actual requirements. For example, the first current may be 0.5c, c representing the nominal capacity of the battery.

It should be noted that, the magnitude of the charging current is generally expressed as a charging rate, for example, the charging rate is a ratio of the charging current to the nominal capacity of the battery.

For example, if a battery having a nominal capacity of 100 ampere hours (Ah) is charged with a current of 20 ampere hours (a), its charging rate is 0.2C.

In another possible implementation, when the SOH of the battery satisfies the first condition, the charge-discharge SOC interval of the battery may be set to the first interval.

The first section is a first section of a charge-discharge SOC of the battery, and the first section can be set according to actual requirements.

As one example, the first interval may be 0% to 100%. For example, when the first SOH is greater than or equal to the SOH corresponding to the quality assurance point of the battery, the first interval may be 0% to 100%.

As another example, the first interval may be 40% to 90%. For example, when the first SOH is less than the SOH corresponding to the quality assurance point of the battery, the first interval may be 40% to 90%.

Alternatively, when the SOH of the battery satisfies the first condition, the charge current of the battery may be simultaneously controlled to be the first current and the charge-discharge SOC interval of the battery to be the first interval.

S203, controlling the charging current of the battery to be a second current and/or controlling the charging and discharging SOC interval of the battery to be a second interval, wherein the second current is smaller than the first current, and the second interval is a partial interval of the first interval.

The second section is a second section of the charge-discharge SOC of the battery.

It will be appreciated that the state of health of the battery is worse when the SOH of the battery meets the second condition than when the SOH of the battery meets the first condition.

In this embodiment, when the SOH of the battery meets the second condition, the charging current of the battery needs to be reduced, and/or the charge-discharge SOC interval of the battery needs to be reduced, so as to slow down the aging of the battery and prolong the service life of the battery.

Optionally, the second current and the second interval may be set according to actual requirements. For example, the second current may be half the first current.

As one example, when the first interval is 0% to 100%, the second interval may be 40% to 90%.

As another example, when the first interval is 40% to 90%, the second interval may be 50% to 80%.

In this embodiment, the battery management device may periodically execute the method shown in fig. 2, and the execution period may be preconfigured.

Alternatively, the second current and the second interval may be determined according to a correspondence relationship between a charge-discharge SOC interval of the battery and a battery swelling force.

As an example, fig. 3 is a schematic diagram of determining a charge-discharge SOC interval of a battery according to an embodiment of the present application. The three curves shown in fig. 3 are the relationship curves between the expansion force of the battery and the charge/discharge SOC interval of the battery when the charge current of the battery is 1C, 0.5C, and 0.1C, respectively.

As shown in fig. 3, the larger the charging current of the battery is, the larger the swelling force of the battery is, so that the aging speed of the battery is faster; the larger the charge-discharge SOC interval of the battery is, the larger the expansion force of the battery is, so that the aging speed of the battery is higher.

Therefore, when controlling the charge/discharge SOC section of the battery, the SOC section can be determined centering on the SOC corresponding to the peak-to-valley value of the expansion force. For example, the SOC corresponding to the peak-to-valley value of the expansion force in fig. 3 is 65%, and thus the charge-discharge SOC interval of the battery may be 50% to 80%.

Alternatively, when S202 and S203 are performed, the current operation state of the battery may be prompted to the user by outputting indication information.

As an example, the indication information may be output by means of an indication lamp, a voice prompt, or a text prompt.

As one example, the indicator lights may include a green indicator light, an orange indicator light, and a red indicator light. For example, a green indicator light is used for prompting a user that the current running state of the battery is stable; the orange indicator lamp is used for prompting the user that the battery is aged and the battery needs to be replaced; the red indicator light is used for prompting the user that the aging degree in the battery is serious, and the battery needs to be replaced as soon as possible.

In this embodiment, when the health condition of the battery decreases, the battery aging may be slowed down by limiting the charging current of the battery and/or controlling the charging and discharging SOC interval of the battery, so as to prolong the service life of the battery, thereby improving the reliability of the battery operation. Compared with the mode of directly prohibiting the user from using the battery, the technical scheme provided by the application improves the use experience of the user. In addition, through the charging mode of adjusting the battery, the expansion force of the battery can be reduced, so that the design strength of the battery module structure can be reduced, and the design cost and implementation cost are reduced.

Fig. 4 is a schematic diagram of a battery management method according to another embodiment of the present application. As shown in fig. 4, the method includes S401 to S406.

S401, SOH of the battery is obtained.

The BMS battery management system can acquire SOH of the battery according to the battery information acquired in real time.

For example, the BMS battery management system may determine SOH of the battery, which is a percentage of the discharge capacity of the battery to the nominal capacity of the battery, from the collected discharge capacity data of the battery.

If the method is performed by a device other than the BMS battery management system, the device may acquire SOH of the battery from the BMS battery management system.

S402, judging whether SOH of the battery is larger than the first SOH. If the SOH of the battery is greater than the first SOH, S403 is executed, otherwise S404 is executed.

The specific implementation of S402 may refer to S201, and will not be described herein.

In this embodiment, alternatively, when the SOH of the battery is greater than the first SOH, the battery operation state may be considered good, otherwise, the battery operation state may be considered bad.

Whether the SOH of the battery is greater than the first SOH is a determination manner of whether the battery operation state is good, and in the embodiment of the present application, the determination manner of whether the battery operation state is good is not limited to this.

Alternatively, to improve the data accuracy of the present solution, the SOH of the battery may be calibrated.

In one possible implementation manner, the BMS battery management system may send request information to the energy storage system monitoring unit to request the energy storage system monitoring unit to recalculate the current SOH of the battery, so as to implement calibration of the SOH of the battery; and the energy storage system monitoring unit regulates and controls the BMS battery management system in the target battery module to control the battery to be fully charged according to the request information sent by the BMS battery management system, and then continuously controls the target battery to discharge until the output voltage of the battery is cut-off voltage, so that the current SOH of the battery can be obtained.

In this implementation, if the obtained size relationship between the current SOH of the battery and the first SOH is the same as the size relationship between the SOH of the battery and the first SOH, S403 or S404 is executed. For example, if the SOH of the battery is greater than the first SOH, S403 is performed; if the SOH of the battery is less than or equal to the first SOH, S404 is performed.

S403, controlling the charging current of the battery to be the first current and/or controlling the charging and discharging SOC interval of the battery to be the first interval.

In this embodiment, when the battery is in good operation, the charging current of the battery may be the first current, and/or the charge-discharge SOC interval of the battery may be the first interval.

The specific implementation of S403 may refer to S202, which is not described herein.

S404, judging whether the SOH of the battery is larger than the second SOH. If the SOH of the battery is greater than the second SOH, S405 is executed, otherwise S406 is executed.

In this embodiment, the second SOH may be understood as a lifetime end point of the energy storage battery system, and the second SOH is smaller than the first SOH.

Alternatively, when the SOH of the battery is less than or equal to the first SOH and greater than the second SOH, the battery operating state may be considered poor, and when the SOH of the battery is less than or equal to the second SOH, the battery operating state may be considered poor.

Alternatively, the second SOH may be the maximum value of the SOH when the battery is at the end of life (EOL) and the SOH when the battery module is at the end of life.

Optionally, the battery is at an end-of-life point when the battery comprises at least one of: the alternating current internal resistance of the battery is larger than the internal resistance threshold, the pole piece in the battery is broken, the lithium precipitation area in the battery exceeds the area threshold, and the battery safety test result meets the preset test result.

The SOH at the end of life of the battery may be the maximum of the SOHs of the battery including any of the states described above. For example, if the SOH when the ac internal resistance of the battery is greater than the internal resistance threshold is 40%, the SOH when the pole pieces in the battery are broken is 50%, the SOH when the battery test result satisfies the preset test result is 55%, and the SOH when the battery is at the end-of-life point is 55%.

Optionally, the state of the battery module when the battery module is at the end-of-life point includes a maximum deformation displacement of the battery module being greater than a displacement threshold.

The maximum deformation displacement of the battery can be the minimum value of the transverse distance between structural members where the battery module is located, the material stress boundary of the structural members where the battery module is located and the single plate distance between the batteries, and the transverse direction is the expansion direction of the battery.

SOH when the battery module is at the service life end point is SOH of the battery when the deformation displacement of the battery module reaches the maximum deformation displacement.

Alternatively, the second SOH may be preset in advance in the energy storage battery system, for example, in the BMS battery management system, or in the energy storage system monitoring unit.

Illustratively, fig. 5 is a schematic diagram of a battery life cycle provided by one embodiment of the present application. As shown in fig. 5, when the SOH of the battery is greater than the first SOH, the battery is in the safe operating region; when the SOH of the battery is smaller than the first SOH and larger than the second SOH, the battery is in a risk operation area; when the SOH of the battery is less than the second SOH, the battery is in a dangerous operation region.

Optionally, in this embodiment, the current SOH of the battery may also be obtained, and the magnitude relation between the current SOH of the battery and the second SOH may be determined, so as to calibrate the SOH of the battery, and improve the accuracy. The specific implementation manner may be referred to the relevant content in the foregoing embodiments, which is not described herein again.

S405, controlling the charging current of the battery to be a second current and/or controlling the charge-discharge SOC interval of the battery to be a second interval, where the second current is smaller than the first current, and the second interval is a partial interval of the first interval.

In this embodiment, when the battery is in a poor running state, the charging current of the battery may be controlled to be the second current, and/or the charging/discharging SOC interval of the battery may be controlled to be the second interval.

The specific implementation of S405 may refer to S203, which is not described herein.

S406, controlling the charging current of the battery to be a third current and/or controlling the charging and discharging SOC interval of the battery to be a third interval, wherein the third current is smaller than the second current, and the third interval is a partial interval of the second interval.

The third section is a third section of the charge/discharge SOC of the battery.

In this embodiment, when the battery is in a very poor running state, the charging current of the battery needs to be further reduced, and/or the charging/discharging SOC interval of the battery needs to be reduced, so as to ensure the use safety of the user.

Alternatively, the third current and the third interval may be set according to actual requirements. For example, the third current may be 0.1 times the first current.

As one example, when the second interval is 40% to 90%, the third interval may be 50% to 80%.

As another example, when the second interval is 50% to 80%, the third interval may be 55% to 75%.

In this embodiment, the battery has a certain standby power capability when running in this state, but the user is prompted to replace the battery as soon as possible by using the field Jing Shouxian.

Alternatively, the third current and the third interval may be further determined according to a correspondence relationship between a charge-discharge SOC interval of the battery and a battery swelling force. Reference may be made specifically to the embodiment shown in fig. 3, and details are not repeated here.

In the embodiment, the battery is controlled in a grading manner according to the health condition of the battery, so that the running stability of the battery and the use safety of a user are further improved; by calibrating the SOH of the battery, the accuracy of the data and the robustness of the method are improved.

Optionally, in one possible implementation, before S406 is performed, the user may be reminded to replace the battery in a specific time by outputting an alarm prompt. If the user does not change the battery for a prescribed time, S406 is performed.

Optionally, if the SOH of the battery continues to decay to the third SOH, the user may still not replace the battery, and/or the charge-discharge SOC interval of the battery may be further limited, where the third SOH is smaller than the second SOH.

In this embodiment, the SOH of the battery being greater than the first SOH may be referred to as a first condition, the SOH of the battery being less than or equal to the first SOH and greater than the second SOH may be referred to as a second condition, and the SOH of the battery being less than the first SOH and less than or equal to the second SOH may be referred to as a third condition.

Thus, in this embodiment, it can be understood as follows: the step S403 is executed when the SOH of the battery satisfies the first condition, the step S405 is executed when the SOH of the battery satisfies the second condition, and the step S406 is executed when the SOH of the battery satisfies the third condition.

In any of the foregoing embodiments of the present application, the first SOH or the second SOH may be referred to as an SOH threshold.

In some implementations of this embodiment, the battery management device may periodically execute the method shown in fig. 4, where the execution period may be preconfigured.

Alternatively, the management device of the battery may set an identification bit for the battery, the identification bit being used to identify which state of the SOH of the battery in the previous cycle is the first state including the SOH of the battery being greater than the first SOH and the second state including the SOH of the battery being less than the first SOH and greater than the second SOH or equal to the first SOH.

For example, the identification bit may occupy 1 bit, with a value of "0" indicating a first state and "1" indicating a second state.

In this implementation manner, the battery management device may determine the SOH state of the battery in the previous period based on the identification bit, and if the state is the first state, execute S401, and then continue executing from S402; if the second state is set, the execution starts from S404 after S401 is executed.

Alternatively, the identification bit may indicate which of the first state, the second state, and the third state the SOH of the battery in the previous cycle is, the third state including the SOH of the battery being less than or equal to the second SOH.

For example, the flag bit may occupy 2 bits, with a value of "00" indicating a first state, a value of "01" indicating a second state, and a value of "10" indicating a third state.

If the SOH state of the battery of the previous cycle is the third state, the execution starts from S404 after S401 is executed, or the execution of S402 to S406 may not be executed, and the alarm information may be directly output.

In the above implementation manner, because the management device of the battery determines the SOH state based on the value of the identification bit, compared with the comparison of the SOH of the battery and the magnitude relation of each SOH threshold value, the management efficiency of the battery can be improved.

Illustratively, FIG. 6 illustrates a method of determining an SOH threshold. As shown in fig. 6, the method includes S601 to S607.

And S601, performing aging cycle test on the battery.

The aging cycle test of the battery comprises a charge and discharge cycle test of the battery.

Alternatively, the temperature of the aging cycle test of the battery may be set according to actual demands. For example, the test may be performed at a normal temperature of 25 degrees Celsius (DEG C) or a high temperature of 55 degrees Celsius.

S602, acquiring expansion force data corresponding to batteries of different SOHs and batteries of different SOHs.

In this embodiment, optionally, during the battery aging cycle test, discharge capacity data of each cycle of each battery is collected, so that a change of SOH of each battery can be monitored, and when SOH of the battery is attenuated to a preset SOH, the aging cycle test is stopped, so that batteries with different SOHs can be obtained. It should be appreciated that the number of batteries for different SOHs is at least 1.

In this implementation, the preset SOH may be set according to actual requirements. Illustratively, the preset SOH may include 60%, 50%, …, 0%.

Optionally, before the battery aging cycle test, expansion force detection clamps may be installed at two sides of the battery, so as to monitor the change data of expansion force in the battery aging cycle test process in real time, determine expansion force data corresponding to batteries with different SOHs, and further determine a relationship curve between the expansion force of the battery and the health state of the battery.

And S603, acquiring aging data of batteries of different SOHs.

In this embodiment, the aging data of the battery includes ac internal resistance of the battery, breaking condition of the pole piece in the battery, lithium precipitation area in the battery, and the like.

The breaking condition of the pole piece in the battery and the lithium precipitation area in the battery need to be determined by disassembling the battery.

S604, determining a first service life end point of the battery according to the aging data of the battery.

In one possible implementation, the first end-of-life point of the battery may be determined in order of SOH from greater to lesser. For example, determining whether a state of a certain battery exists in the battery with the maximum SOH includes at least one of: the alternating current internal resistance of the battery is larger than the internal resistance threshold, the pole piece in the battery is broken, and the lithium precipitation area in the battery exceeds the area threshold.

If the state of a certain battery in the battery with the largest SOH comprises at least one of the states, the SOH is a first service life end point of the battery; otherwise, judging whether the state of a certain battery exists in the batteries of each SOH in sequence from big to small according to the SOH sequence, and determining at least one of the states until the first service life end point of the battery is determined.

S605, performing safety test on the battery at the first service life end point, and determining SOH when the battery is at the service life end point.

The safety test may include an overcharge test and a short circuit test, among others.

In this embodiment, if the battery at the first life end point passes the safety test, the first life end point is the SOH of the battery at the life end point; otherwise, increasing SOH on the basis of the first service life end point, and carrying out safety test on the battery with the increased SOH until the battery passes the safety test, wherein the SOH of the battery passing the safety test is used as the SOH when the battery is at the service life end point.

Alternatively, the battery at the first end-of-life point passing the safety test may be understood as the safety test result of the battery at the first end-of-life point satisfying the preset test result. The preset test result can be set according to actual requirements.

Alternatively, SOH may be increased by a magnitude of 5% on the basis of the first lifetime end point.

Thus far, SOH at the end of life of the battery was determined and noted as SOH _EOL,cell 。

In this embodiment, by determining the first lifetime end point of the battery, the battery at the first lifetime end point is subjected to a safety test, so that SOH when the battery is at the lifetime end point is determined, and resources are saved.

S606, determining SOH when the battery module is at the service life end point.

For example, SOH may be SOH _EOL,cell The battery of the battery pack is subjected to back pressure test, and the corresponding battery expansion force when the battery is retracted for 1mm displacement is recorded, so that a relation curve of the battery expansion force and the battery expansion displacement can be obtained.

The relation curve of the battery expansion force and the battery health state, the relation curve of the battery expansion force and the battery expansion displacement, the target battery module structure design model and the material characteristics of the structural member where the battery module is positioned are input into the structure simulation analysis model, so that the relation curve of the battery health state and the battery module structure deformation displacement can be determined.

It should be noted that, the structural simulation analysis model may be any model of a general analysis method in the art, which is not limited herein.

According to the health of the batteryDetermining SOH of the battery module at the service life end point according to the relation curve of state and deformation displacement of the battery module structure and the maximum deformation displacement of the battery, and marking as SOH _{EOL,structure} 。

S607, determining the SOH threshold.

The SOH threshold is the maximum value of SOH when the battery is at the end-of-life point and SOH when the battery module is at the end-of-life point, i.e., SOH threshold=max (SOH _EOL,cell ，SOH _{EOL,structure} )。

In this embodiment, the service life end point of the energy storage battery system is determined by considering the service life of the battery and the service life of the battery module, and is matched with the charging current of the control battery and/or the charging and discharging SOC interval of the battery, so that potential safety hazards caused by unrestricted use of the battery by a user are avoided, and the safety and reliability of the energy storage battery system are improved. Wherein, the determination of the end-of-life point of the battery module may also be used to guide the early design of the battery module structure.

Fig. 7 is a schematic structural diagram of a battery management device according to an embodiment of the present application. The apparatus 700 shown in fig. 7 may be used to implement the various steps of fig. 2, 4, or 6. As shown in fig. 7, the apparatus 700 of the present embodiment may include: a processing module 710 and a transceiver module 720.

When the apparatus 700 is used to implement the method shown in fig. 2, the processing module 710 may be used to implement S201, S202, and S203.

When the apparatus 700 is used to implement the method shown in fig. 4, the processing module 710 may be used to implement S402, S403, S404, S405, and S406. The transceiver module 720 may be used to implement S401.

When the apparatus 700 is used to implement the method shown in fig. 6, the processing module 710 may be used to implement S601, S604, S605, S606, and S607. The transceiver module 720 may be used to implement S602, S603.

It should be appreciated that the apparatus 700 is embodied in the form of functional modules. The term "module" may refer to an application specific integrated circuit (application specific integrated circuit, ASIC), an electronic circuit, a processor (e.g., a shared, dedicated, or group processor, etc.) and memory that execute one or more software or firmware programs, a combinational logic circuit, and/or other suitable components that support the described functionality. In an alternative example, it will be understood by those skilled in the art that the apparatus 700 may be specifically a battery management apparatus in the above method embodiment, or the functions of the battery management apparatus in the above method embodiment may be integrated in the apparatus 700, and the apparatus 700 may be used to execute each flow and/or step corresponding to the battery management apparatus in the above method embodiment, which is not repeated herein for avoiding repetition.

Fig. 8 is a schematic structural diagram of a battery management device according to another embodiment of the present application. The apparatus 800 shown in fig. 8 may be used to implement the method performed by the battery management apparatus in any of the foregoing embodiments.

As shown in fig. 8, the apparatus 800 of the present embodiment includes: memory 810, processor 820, communication interface 830, and bus 840. The memory 810, the processor 820, and the communication interface 830 are communicatively coupled to each other via a bus 840.

The memory 810 may be a Read Only Memory (ROM), a static storage device, a dynamic storage device, or a random access memory (random access memory, RAM). The memory 810 may store a program, and the processor 820 is configured to perform various steps performed by the battery management device in the method shown in fig. 2, 4, or 6 when the program stored in the memory 810 is executed by the processor 820.

Processor 820 may employ a general-purpose central processing unit (central processing unit, CPU), microprocessor, application specific integrated circuit (application specific integrated circuit, ASIC), or one or more integrated circuits for executing the relevant programs.

Processor 820 may also be an integrated circuit chip with signal processing capabilities. In implementation, various relevant steps in embodiments of the present application may be accomplished through integrated logic circuitry in hardware in processor 820 or through instructions in the form of software.

The processor 820 may also be a general purpose processor, a digital signal processor (digital signal processing, DSP), an Application Specific Integrated Circuit (ASIC), an off-the-shelf programmable gate array (field programmable gate array, FPGA) or other programmable logic device, discrete gate or transistor logic device, discrete hardware components. The disclosed methods, steps, and logic blocks in the embodiments of the present application may be implemented or performed. A general purpose processor may be a microprocessor or the processor may be any conventional processor or the like.

The steps of a method disclosed in connection with the embodiments of the present application may be embodied directly in hardware, in a decoded processor, or in a combination of hardware and software modules in a decoded processor. The software modules may be located in a random access memory, flash memory, read only memory, programmable read only memory, or electrically erasable programmable memory, registers, etc. as well known in the art. The storage medium is located in the memory 810, and the processor 820 reads information in the memory 810 and performs functions necessary for the unit included in the apparatus of the present application in combination with hardware.

Communication interface 830 may enable communication between apparatus 800 and other devices or apparatuses using, but is not limited to, a transceiver or the like.

Bus 840 may include a path to transfer information between various components of device 800 (e.g., memory 810, processor 820, communication interface 830).

Also provided in some embodiments of the present application is a computer program product, for example, when executed on a processor, for implementing the method implemented by the battery management device in any of the embodiments described above. Some embodiments of the present application further provide a computer readable storage medium, where the computer readable storage medium contains computer instructions, where the computer instructions, when executed on a processor, may implement a method implemented by a battery management device in any of the embodiments described above.

It should be noted that the modules or components shown in the above embodiments may be one or more integrated circuits configured to implement the above methods, for example: one or more application specific integrated circuits (application specific integrated circuit, ASIC), or one or more microprocessors (digital signal processor, DSP), or one or more field programmable gate arrays (field programmable gate array, FPGA), or the like. For another example, when a module above is implemented in the form of a processing element calling program code, the processing element may be a general-purpose processor, such as a central processing unit (central processing unit, CPU) or other processor, such as a controller, that may call the program code. For another example, the modules may be integrated together and implemented in the form of a system-on-a-chip (SOC).

In the above embodiments, it may be implemented in whole or in part by software, hardware, firmware, software modules or any combination thereof. When implemented in software, may be implemented in whole or in part in the form of a computer program product. The computer program product includes one or more computer instructions. When the computer program instructions are loaded and executed on a computer, the processes or functions in accordance with embodiments of the present application are produced in whole or in part. The computer may be a general purpose computer, a special purpose computer, a computer network, or other programmable apparatus. The computer instructions may be stored in or transmitted from one computer-readable storage medium to another, for example, by wired (e.g., coaxial cable, fiber optic, digital Subscriber Line (DSL)), or wireless (e.g., infrared, wireless, microwave, etc.) means from one website, computer, server, or data center. Computer readable storage media can be any available media that can be accessed by a computer or data storage devices, such as servers, data centers, etc., that contain an integration of one or more available media. The usable medium may be a magnetic medium (e.g., floppy Disk, hard Disk, magnetic tape), an optical medium (e.g., DVD), or a semiconductor medium (e.g., solid State Disk (SSD)), etc.

The term "plurality" herein refers to two or more. The term "and/or" is herein merely an association relationship describing an associated object, meaning that there may be three relationships, e.g., a and/or B, may represent: a exists alone, A and B exist together, and B exists alone. In addition, the character "/" herein generally indicates that the front and rear associated objects are an "or" relationship; in the formula, the character "/" indicates that the front and rear associated objects are a "division" relationship. In addition, it should be understood that in the description of this application, the words "first," "second," and the like are used merely for distinguishing between the descriptions and not for indicating or implying any relative importance or order.

It will be appreciated that the various numerical numbers referred to in the embodiments of the present application are merely for ease of description and are not intended to limit the scope of the embodiments of the present application.

It should be understood that, in the embodiments of the present application, the sequence number of each process described above does not mean that the execution sequence of each process should be determined by the function and the internal logic of each process, and should not constitute any limitation on the implementation process of the embodiments of the present application.

Claims

1. A battery management method, comprising:

when the state of health SOH of the battery meets a first condition, controlling the charging current of the battery to be a first current, and/or controlling a charge-discharge battery state of charge (SOC) interval of the battery to be a first interval, wherein the first condition comprises that the SOH of the battery is larger than the first SOH;

and when the SOH of the battery meets a second condition, controlling the charging current of the battery to be a second current, and/or controlling the charging and discharging SOC interval of the battery to be a second interval, wherein the second current is smaller than the first current, the second interval is a partial interval in the first interval, and the second condition comprises that the SOH of the battery is smaller than or equal to the first SOH.

2. The method according to claim 1, wherein controlling the charge current of the battery to be the first current and/or controlling the charge-discharge battery state of charge, SOC, interval of the battery to be the first interval when the state of health, SOH, of the battery satisfies the first condition comprises:

when the SOH of the battery meets a first condition, controlling the battery to charge until the battery is fully charged, and controlling the battery to discharge until the output voltage of the battery is cut-off voltage;

Acquiring the current SOH of the battery;

and when the current SOH of the battery meets the first condition, controlling the charging current of the battery to be a first current, and/or controlling the charging and discharging SOC interval of the battery to be a first interval.

3. The method according to claim 1 or 2, wherein the second condition further comprises: the SOH of the battery is greater than the second SOH;

wherein the method further comprises:

and when the SOH of the battery meets a third condition, controlling the charging current of the battery to be a third current, and/or controlling the charging and discharging SOC interval of the battery to be a third interval, wherein the third current is smaller than the second current, the third interval is a partial interval in the second interval, the third condition comprises that the SOH of the battery is smaller than or equal to a second SOH, and the second SOH is smaller than the first SOH.

4. A method according to claim 3, wherein the third condition further comprises: and the duration that the SOH of the battery is smaller than or equal to the second SOH is the first duration.

5. The method according to claim 3 or 4, wherein the second SOH is the maximum value of the SOH when the battery is at the end-of-life point and the SOH when the battery module is at the end-of-life point.

6. The method of claim 5, wherein the battery is at an end-of-life point when the battery comprises at least one of: the alternating current internal resistance of the battery is larger than the internal resistance threshold, the pole piece in the battery is broken, the lithium precipitation area in the battery exceeds the area threshold, and the battery safety test result meets the preset test result.

7. The method of claim 5 or 6, wherein the state of the battery module at the end of life comprises a maximum deformation displacement of the battery module greater than a displacement threshold.

8. Battery management device, characterized by comprising respective functional modules for implementing the method according to any of claims 1 to 7.

9. A battery management apparatus, comprising: a processor coupled to a memory for storing a computer program which, when invoked by the processor, causes the apparatus to perform the method of any one of claims 1 to 7.

10. A battery management system comprising the battery management apparatus according to claim 9.

11. A battery module comprising the battery management system of claim 10.

12. A battery comprising the battery management device according to claim 8 or 9, or comprising the battery management system according to claim 10, or comprising the battery module according to claim 11.

13. A computer readable medium, characterized in that the computer readable medium stores a program code for computer execution, the program code comprising instructions for performing the method of any of claims 1 to 7.

14. A computer program product comprising computer program code which, when run on a computer, causes the computer to implement the method of any one of claims 1 to 7.