Battery control method, management system, battery system, equipment, medium and product

Abstract

The embodiment of the invention discloses a battery control method, a management system, a battery system, equipment, a medium and a product, and the method comprises the steps: obtaining a target thermal condition of a battery in a charging and discharging process; in response to the condition that the current health state value of the battery is attenuated to be below a first state threshold value, adjusting a discharge lower limit in a charge-discharge interval of the battery based on a target thermal condition and a thermal state of the battery in a charge-discharge process to obtain a target discharge lower limit; and performing first-stage charge and discharge control on the battery based on the target discharge lower limit. According to the embodiment of the invention, after the charge-discharge interval of the battery is attenuated, the available residual capacity of the battery can be improved, the damage to the battery is reduced, and the aging rate of the battery is slowed down.

Description

Technical Field

[0001] The present disclosure relates to but is not limited to the field of battery equipment technology, and in particular to a battery control method, management system, battery system, equipment, medium and product. Background Art

[0002] In battery design, it is taken into account that the low voltage range of the battery's charge and discharge interval has a greater risk of gas and heat generation. In related technologies, the use of the low voltage range of the battery's charge and discharge interval is restricted, which makes it impossible to fully utilize the battery capacity, resulting in redundancy and waste. Summary of the invention

[0003] In view of this, the embodiments of the present disclosure at least provide a battery control method, a management system, a battery system, a device, a medium and a product.

[0004] The technical solution of the embodiment of the present disclosure is implemented as follows: The present disclosure provides a battery control method, including: Obtain the target thermal conditions of the battery during the charging and discharging process; In response to the current health state value of the battery decaying below a first state threshold, based on the target thermal condition and the thermal state of the battery during the charge and discharge process, adjusting the lower discharge limit of the battery in the charge and discharge interval to obtain a target lower discharge limit; Based on the target lower discharge limit, the battery is charged and discharged in the first stage.

[0005] In the disclosed embodiment, the target thermal condition of the battery during the charge and discharge process is first obtained; secondly, when the current health state value of the battery decays to below the first state threshold, the lower discharge limit in the charge and discharge interval of the battery is adjusted according to the target thermal condition and the thermal state of the battery during the charge and discharge process to obtain the target discharge lower limit; finally, the battery is subjected to the first stage of charge and discharge control according to the target discharge lower limit. In this way, when it is detected that the current health state value decays to below the first state threshold, the thermal state of the battery during the charge and discharge process and the target thermal condition are comprehensively considered, and the lower discharge limit in the charge and discharge interval of the battery is adjusted, so that after the charge and discharge interval of the battery decays, the available remaining capacity of the battery is increased while reducing damage to the battery and slowing down the aging rate of the battery.

[0006] In some embodiments, based on the target thermal condition and the thermal state of the battery during the charge and discharge process, the lower discharge limit in the charge and discharge interval of the battery is adjusted to obtain the target discharge lower limit, including: lowering the discharge lower limit to a first candidate lower limit; performing a second-stage charge and discharge control on the battery based on the first candidate lower limit, and monitoring the thermal state of the battery during the second-stage charge and discharge control process; in response to the thermal state of the battery during the second-stage charge and discharge control process satisfying the target thermal condition, determining the first candidate lower limit as the target discharge lower limit.

[0007] In the above embodiment, the discharge lower limit is adjusted down to the first candidate lower limit; the battery is controlled for the second stage of charge and discharge according to the first candidate lower limit, and the thermal state of the battery during the second stage of charge and discharge control is monitored; when the thermal state of the battery during the second stage of charge and discharge control meets the target thermal condition, the first candidate lower limit is determined as the target discharge lower limit. In this way, when the thermal state meets the target thermal condition, the first candidate lower limit is determined as the target discharge lower limit to increase the charge and discharge range of the battery.

[0008] In some embodiments, the thermal state of the battery during the second stage of charge and discharge control satisfies the target thermal condition, including at least one of the following: when the target thermal condition includes the target heat production condition and the thermal state includes the heat production state, the heat production state of the battery during the second stage of charge and discharge control satisfies the target heat production condition; when the target thermal condition includes the target stress condition and the thermal state includes the stress state, the stress state of the battery during the second stage of charge and discharge control satisfies the target stress condition; when the target thermal condition includes the target volume condition and the thermal state includes the volume state, the volume state of the battery during the second stage of charge and discharge control satisfies the target volume condition.

[0009] In the above embodiment, when the target thermal condition includes the target heat generation condition and the thermal state includes the heat generation state, the heat generation state of the battery in the second stage of charge and discharge control process meets the target heat generation condition; when the target thermal condition includes the target stress condition and the thermal state includes the stress state, the stress state of the battery in the second stage of charge and discharge control process meets the target stress condition; when the target thermal condition includes the target volume condition and the thermal state includes the volume state, the volume state of the battery in the second stage of charge and discharge control process meets the target volume condition. In this way, whether the heat generation state, stress state, and volume state meet the corresponding target heat generation condition, target stress condition, and target volume condition is considered respectively, which improves the accuracy of determining whether the thermal state meets the target thermal condition.

[0010] In some embodiments, the target thermal condition includes a target change condition of the thermal state; in response to the thermal state of the battery during the second stage of charge and discharge control satisfying the target thermal condition, the first candidate lower limit is determined as the target discharge lower limit, including: in response to the degree of change in the thermal state of the battery during the second stage of charge and discharge control satisfying the target change condition, the first candidate lower limit is determined as the target discharge lower limit.

[0011] In the above embodiment, when the degree of change of the thermal state of the battery during the second stage of charge and discharge control meets the target change condition, the first candidate lower limit is determined as the target discharge lower limit. In this way, since the thermal state of the battery is a cumulative process, whether the condition is met can be determined based on the change amount of the thermal state, and the change of the thermal state can be accurately obtained.

[0012] In some embodiments, the degree of change of the thermal state of the battery during the second stage of charge and discharge control satisfies the target change condition, including at least one of the following: when the target change condition includes a target heat generation change condition, and the degree of change of the thermal state includes the degree of heat generation change, the degree of change of the heat generation of the battery during the second stage of charge and discharge control satisfies the target heat generation change condition; when the target change condition includes a target stress change condition, and the degree of change of the thermal state includes the degree of stress change, the degree of stress change of the battery during the second stage of charge and discharge control satisfies the target stress change condition; when the target change condition includes a target volume change condition, and the degree of change of the thermal state includes the degree of volume change, the degree of volume change of the battery during the second stage of charge and discharge control satisfies the target volume change condition.

[0013] In the above embodiment, when the target change condition includes the target heat generation change condition and the degree of change of the thermodynamic state includes the degree of heat generation change, the degree of heat generation change of the battery in the second stage of charge and discharge control process meets the target heat generation change condition; when the target change condition includes the target stress change condition and the degree of change of the thermodynamic state includes the degree of stress change, the degree of stress change of the battery in the second stage of charge and discharge control process meets the target stress change condition; when the target change condition includes the target volume change condition and the degree of change of the thermodynamic state includes the degree of volume change, the degree of volume change of the battery in the second stage of charge and discharge control process meets the target volume change condition. In this way, whether the degree of heat generation change, the degree of stress change, and / or the degree of volume change meet the corresponding target heat generation change condition, target stress change condition, and target volume change condition is considered respectively, thereby improving the accuracy of determining whether the degree of change of the thermodynamic state meets the target change condition.

[0014] In some embodiments, the method also includes: determining a first change rate of the thermal state of the battery during the third stage of charge and discharge control; the third stage is a stage of charge and discharge control of the battery before the health state value decays to a first state threshold; determining a second change rate of the thermal state of the battery during the second stage of charge and discharge control; when the ratio of the second change rate to the first change rate is not greater than the first ratio threshold, determining that the degree of change in the thermal state of the battery during the second stage of charge and discharge control meets the target change condition.

[0015] In the above embodiment, the third stage is a stage in which the battery is charged and discharged before the health state value decays to the first state threshold. When the ratio of the second change rate of the thermal state of the battery during the charge and discharge control process of the second stage to the first change rate of the thermal state during the charge and discharge control process of the third stage is not greater than the first ratio threshold, it is determined that the degree of change of the thermal state of the battery during the charge and discharge control process of the second stage meets the target change condition. In this way, the relationship between the degree of change of the thermal state of the battery during the charge and discharge control process of the second stage and the degree of change of the thermal state of the battery during the charge and discharge control process of the third stage can be determined based on the ratio of the second change rate to the first change rate, so as to determine whether the current degree of change of the thermal state has the risk of damaging the battery, that is, whether the current degree of change of the thermal state meets the target change condition.

[0016] In some embodiments, based on the target thermal conditions and the thermal state of the battery during the charging and discharging process, the discharge lower limit in the charging and discharging interval of the battery is adjusted to obtain the target discharge lower limit, and also includes: in response to the thermal state of the battery during the first stage of charging and discharging control not meeting the target thermal conditions, determining the reference discharge lower limit as the target discharge lower limit, and the reference discharge lower limit is higher than the first candidate lower limit.

[0017] In the above embodiment, in response to the thermal state of the battery in the first stage of charge and discharge control not satisfying the target thermal condition, the reference discharge lower limit is determined as the target discharge lower limit, and the reference discharge lower limit is higher than the first candidate lower limit. In this way, when the thermal state does not satisfy the target thermal condition, the reference discharge lower limit higher than the first candidate lower limit is determined as the target discharge lower limit, thereby reducing the damage to the battery caused by the thermal state.

[0018] In some embodiments, adjusting the discharge lower limit down to the first candidate lower limit includes: determining an adjustment step size of the discharge lower limit; and adjusting the discharge lower limit down to the first candidate lower limit based on the adjustment step size.

[0019] In the above embodiment, the adjustment step length of the discharge lower limit is determined, and based on the adjustment step length, the discharge lower limit is adjusted down to the first candidate lower limit. In this way, the discharge lower limit can be adjusted down to a suitable first candidate lower limit according to a suitable adjustment step length.

[0020] In some embodiments, determining the adjustment step size of the lower discharge limit includes: determining the adjustment step size of the lower discharge limit based on a current health state value of the battery; wherein the adjustment step size is inversely proportional to the current health state value.

[0021] In the above embodiment, the adjustment step of the lower discharge limit is determined according to the current health state value of the battery; wherein the adjustment step is inversely proportional to the current health state value. In this way, when the health state value is large, more consideration is given to minimizing the damage to the battery as much as possible. Therefore, a smaller adjustment step can be set to reduce the damage to the battery caused by excessive reduction of the lower discharge limit and slow down the aging of the battery; and when the health state value is small, more consideration is given to increasing the remaining capacity of the battery. Therefore, a larger adjustment step is set to increase the remaining capacity of the battery. In this way, in the process of the continuous attenuation of the battery health state, the needs of increasing the remaining capacity of the battery and reducing the damage to the battery can be taken into account, thereby improving the overall performance of the battery during use.

[0022] The present disclosure provides a battery management system, the battery management system comprising: An acquisition module is used to obtain the target thermal conditions of the battery during the charging and discharging process; an adjustment module, configured to adjust a lower discharge limit of the battery in a charge and discharge interval based on a target thermal condition and a thermal state of the battery during a charge and discharge process in response to a current health state value of the battery decaying below a first state threshold value, so as to obtain a target lower discharge limit; The control module is used to control the charge and discharge of the battery in the first stage based on the target discharge lower limit.

[0023] An embodiment of the present disclosure provides a battery system, including a battery and the above-mentioned battery management system.

[0024] An embodiment of the present disclosure provides a computer device, including a memory and a processor, wherein the memory stores a computer program that can be run on the processor, and when the processor executes the program, some or all of the steps in the above method are implemented.

[0025] An embodiment of the present disclosure provides a computer-readable storage medium on which a computer program is stored. When the computer program is executed by a processor, some or all of the steps in the above method are implemented.

[0026] An embodiment of the present disclosure provides a computer program product, including a computer program or instructions. When the computer program or instructions are executed by a processor, some or all of the steps in the above method are implemented.

[0027] It should be understood that the above general description and the following detailed description are merely exemplary and explanatory, and are not intended to limit the technical solutions of the present disclosure. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] The drawings herein are incorporated into the specification and constitute a part of the specification. These drawings illustrate embodiments consistent with the present disclosure and are used to illustrate the technical solutions of the present disclosure together with the specification.

[0029] Figure 1 A schematic diagram of an implementation flow of a battery control method provided in an embodiment of the present disclosure; Figure 2 A schematic diagram of the structure of a battery management system provided in an embodiment of the present disclosure; Figure 3 A schematic diagram of the structure of a battery system provided in an embodiment of the present disclosure; Figure 4 A schematic diagram of aging capacity retention rate at different discharge lower limits provided in an embodiment of the present disclosure; Figure 5 A schematic diagram of a test result of dynamically adjusting the lower limit of discharge and a control group test result provided by an embodiment of the present disclosure; Figure 6 A hardware entity schematic diagram of a computer device provided in an embodiment of the present disclosure. DETAILED DESCRIPTION

[0030] In order to make the purpose, technical solutions and advantages of the present disclosure clearer, the technical solutions of the present disclosure are further elaborated in detail below in conjunction with the drawings and embodiments. The described embodiments should not be regarded as limiting the present disclosure. All other embodiments obtained by ordinary technicians in the field without making creative work are within the scope of protection of the present disclosure.

[0031] In the following description, reference is made to “some embodiments”, which describe a subset of all possible embodiments, but it will be understood that “some embodiments” may be the same subset or different subsets of all possible embodiments and may be combined with each other without conflict.

[0032] The terms "first / second / third" involved are merely used to distinguish similar objects and do not represent a specific ordering of the objects. It is understandable that "first / second / third" can be interchanged with a specific order or sequence where permitted so that the embodiments of the present disclosure described herein can be implemented in an order other than that illustrated or described herein.

[0033] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art to which the present disclosure belongs. The terms used herein are only for the purpose of describing the present disclosure and are not intended to limit the present disclosure.

[0034] The present disclosure provides a battery control method. Figure 1A schematic diagram of an implementation flow of a battery control method provided in an embodiment of the present disclosure is shown in FIG. Figure 1 As shown, the method includes the following steps S101 to S103: Step S101: obtaining target thermal conditions of the battery during the charging and discharging process; In some embodiments, the target thermodynamic condition may include, but is not limited to, at least one of a target heat production condition, a target stress condition, a target volume condition, and the like.

[0035] The target heat generation condition is the condition that the heat generation state of the battery satisfies when the battery is operating safely during the charging and discharging process, that is, the upper heat generation threshold value is set in consideration of the damage to the battery caused by heat generation during the battery charging and discharging control process. The upper heat generation threshold value can be pre-set by those skilled in the art according to actual conditions, and the embodiments of the present disclosure do not limit this. Here, the heat generation state of the battery may include the heat generated by the DC internal resistance of the battery.

[0036] The target stress condition is the condition that the stress state of the battery satisfies when the battery operates safely during the charging and discharging process, that is, the upper stress limit threshold value set in consideration of the damage to the battery caused by stress during the battery charging and discharging control process. The upper stress limit threshold value can be pre-set by those skilled in the art according to actual conditions, and the embodiments of the present disclosure do not limit this. Here, the stress state may include the expansion force generated by the gas produced by the electrochemical reaction in the battery.

[0037] The target volume condition is a condition that the volume state of the battery satisfies when the battery operates safely during the charge and discharge process, that is, an upper volume threshold value set in consideration of the damage to the battery caused by volume expansion during the battery charge and discharge control process. The upper volume threshold value may be pre-set by a person skilled in the art based on actual conditions, and the embodiments of the present disclosure are not limited thereto.

[0038] Step S102: in response to the current health state value of the battery decaying to below the first state threshold, based on the target thermal condition and the thermal state of the battery during the charge and discharge process, adjusting the lower discharge limit of the battery in the charge and discharge interval to obtain a target lower discharge limit; Here, the State of Health (SOH) is an important indicator for evaluating battery performance and service life. It is the ratio between the maximum available capacity that can be discharged by the battery when it is fully charged and its initial capacity or rated capacity.

[0039] The first state threshold may be preset by those skilled in the art according to actual conditions, and the embodiments of the present disclosure are not limited thereto.

[0040] In some embodiments, the first state threshold can generally be set to 85% to 90%. When the health state value is above the first state threshold, the battery attenuation is less and the charge and discharge range is relatively large. In order to reduce the damage to the battery caused by lowering the discharge lower limit, the discharge lower limit can be adjusted when the health state value decays below the first state.

[0041] In some embodiments, the charge and discharge interval of the battery is an open voltage interval, not a theoretically available voltage interval of the battery. For example, the theoretically available voltage lower limit of the battery is 2.0V, and the discharge lower limit can be set to 2.6V, but in some scenarios, the battery can be allowed to continue to discharge to 2.0V.

[0042] The battery's charge and discharge interval can also be an open charge and discharge state of charge (SOC) interval. For example, the theoretically available SOC lower limit of the battery is 0%, and the state of charge interval can be set to 30% to 100%, that is, the discharge lower limit is 30%, but in some scenarios, it can continue to discharge to an SOC of 20%.

[0043] In some embodiments, if the lower discharge limit of all batteries is set to 2.6V, the use of the low voltage range is directly restricted, while the battery can continue to be discharged to 2V in some scenarios. This means that the capacity of the lithium iron phosphate battery cannot be fully utilized, resulting in redundancy and waste. Not all batteries will produce gas and heat during aging, so the lower discharge limit can be lowered by detecting the gas and heat production of the battery.

[0044] In some embodiments, in order not to damage the performance of the battery, a portion of the low voltage range can be restricted and unavailable, that is, the lowest threshold value of the adjustable lower discharge limit is determined. When the lowest threshold value is reached, the adjustment of the lower discharge limit is completed. For example, the initial lower discharge limit of the battery is 2.6V, which can be adjusted to a minimum of 2V.

[0045] In some embodiments, the thermodynamic state may include, but is not limited to, at least one of a heat generation state, a stress state, a volume state, and the like.

[0046] In some embodiments, during the charge and discharge process of the battery, the battery is more likely to generate heat and gas in the low voltage interval of the charge and discharge interval, and the volume increases due to expansion, and gas and heat generation are cumulative processes. If the gas and heat generation accumulate too much, it will affect the performance, safety and service life of the battery. Therefore, when adjusting the lower limit of discharge, the target thermal conditions and the thermal state of the battery during the charge and discharge process should be comprehensively considered.

[0047] In some embodiments, if the lower discharge limit in the charge and discharge interval is lowered when the health status value is large, the battery performance may decline faster due to gas and heat production. Therefore, after the battery decays below the first state threshold, the lower discharge limit is adjusted by comprehensively considering the target thermal conditions and the thermal state of the battery during the charge and discharge process.

[0048] Step S103: Based on the target lower discharge limit, the battery is charged and discharged in the first stage.

[0049] Here, the first stage is a stage in which, after the adjustment of the discharge lower limit is completed, the target discharge lower limit obtained is used as the discharge lower limit to control the charge and discharge of the battery.

[0050] In some implementations, two cells with good consistency are selected, namely cell 1 and cell 2, for testing, wherein cell 1 dynamically adjusts the lower limit of discharge according to the above method and performs charge and discharge control; cell 2 does not adjust the lower limit of discharge and performs charge and discharge control, such as Figure 5 As shown, under the same number of cycles, the health state value of battery cell 1 is greater than the health state value of battery cell 2. Therefore, it can be concluded that adjusting the lower discharge limit can slow down the aging rate of the battery.

[0051] The embodiments of the present disclosure do not limit the chemical system of the above-mentioned battery. For example, the battery may include but is not limited to at least one of a lithium iron phosphate battery, a ternary lithium battery, a lithium manganese oxide battery, a lithium cobalt oxide battery, a nickel metal hydride battery, and the like.

[0052] In some embodiments, the discharge lower limit is adjusted stepwise according to an adjustment step. For example, the discharge lower limit is lowered to a first candidate lower limit. In the process of controlling charge and discharge according to the first candidate lower limit, when the thermal state meets the target thermal condition, the current discharge lower limit is determined to be the first candidate lower limit. The current discharge lower limit is further adjusted to a second candidate lower limit according to the current discharge lower limit and the adjustment step. In the process of controlling charge and discharge according to the second candidate lower limit, when the thermal state meets the target thermal condition, the current discharge lower limit is determined to be the second candidate lower limit. The discharge lower limit is continued to be adjusted until it is adjusted to the lowest threshold value of the adjustable discharge lower limit, thereby completing the adjustment of the discharge lower limit.

[0053] In the disclosed embodiment, the target thermal condition of the battery during the charge and discharge process is first obtained; secondly, when the current health state value of the battery decays to below the first state threshold, the lower discharge limit in the charge and discharge interval of the battery is adjusted according to the target thermal condition and the thermal state of the battery during the charge and discharge process to obtain the target discharge lower limit; finally, the battery is subjected to the first stage of charge and discharge control according to the target discharge lower limit. In this way, when it is detected that the current health state value decays to below the first state threshold, the thermal state of the battery during the charge and discharge process and the target thermal condition are comprehensively considered, and the lower discharge limit in the charge and discharge interval of the battery is adjusted, so that after the charge and discharge interval of the battery decays, the available remaining capacity of the battery is increased while reducing damage to the battery and slowing down the aging rate of the battery.

[0054] Among them, adjusting the lower discharge limit can slow down the aging rate of the battery. The reason is that when the negative electrode potential of the battery is low (that is, the lower discharge limit of the battery is low), the main reaction of the negative electrode solid electrolyte interface film (Solid Electrolyte Interphase, SEI) changes, generating a denser SEI film component, which effectively slows down the reaction rate of the electrolyte, lithium ions and the negative electrode. Therefore, lowering the lower discharge limit can slow down the aging rate of the battery.

[0055] In some embodiments, the above step S102 may include the following steps S111 to S113: Step S111: lowering the discharge lower limit to a first candidate lower limit; Here, the first candidate lower limit is determined according to the current discharge lower limit and the adjustment step size of the discharge lower limit.

[0056] Step S112: performing charge and discharge control of the battery in the second stage based on the first candidate lower limit, and monitoring the thermal state of the battery in the charge and discharge control process in the second stage; Here, the second stage is a stage in which the charge and discharge of the battery is controlled using the first candidate lower limit as the discharge lower limit during the adjustment of the discharge lower limit.

[0057] In some embodiments, the discharge lower limit is first adjusted down to a first candidate lower limit, and the battery is charged and discharged with the first candidate lower limit as the discharge lower limit. During the second stage of charge and discharge control of the battery, the thermal state of the battery is monitored in real time, and whether the target thermal conditions are met is determined based on the detected thermal state to determine whether the battery can operate safely with the first candidate lower limit as the discharge lower limit.

[0058] Step S113: in response to the thermal state of the battery in the second stage of charge and discharge control satisfying the target thermal condition, determining the first candidate lower limit as the target discharge lower limit.

[0059] In some embodiments, during the second stage of charge and discharge control of the battery, when the thermal state always satisfies the target thermal condition, the first candidate lower limit is determined as the target discharge lower limit.

[0060] In some embodiments, after the discharge lower limit is lowered to the first candidate lower limit each time, the battery is subjected to a second stage of charge and discharge control, and during the charge and discharge control process, the thermal state of the battery is monitored in real time, and when the thermal state meets the target thermal condition, the first candidate lower limit is determined as the target discharge lower limit. Here, the target discharge lower limit is not lower than the lowest discharge lower limit threshold.

[0061] In the disclosed embodiment, the discharge lower limit is adjusted down to the first candidate lower limit; the battery is controlled for the second stage of charge and discharge according to the first candidate lower limit, and the thermal state of the battery during the second stage of charge and discharge control is monitored; when the thermal state of the battery during the second stage of charge and discharge control meets the target thermal condition, the first candidate lower limit is determined as the target discharge lower limit. In this way, when the thermal state meets the target thermal condition, the first candidate lower limit is determined as the target discharge lower limit to increase the charge and discharge range of the battery.

[0062] In some embodiments, the above step S113 may include at least one of the following steps S121 to S123: Step S121: when the target thermal condition includes the target heat generation condition and the thermal state includes the heat generation state, the heat generation state of the battery during the second stage of charge and discharge control satisfies the target heat generation condition; In some embodiments, when the heat generated by the battery during the second stage of charge and discharge control is not greater than the heat represented by the target heat generation condition, it is determined that the heat generation state of the battery during the second stage of charge and discharge control meets the target heat generation condition.

[0063] In some embodiments, when the temperature of the battery during the second stage of charge and discharge control is not higher than the temperature represented by the target heat generation condition, it is determined that the heat generation state of the battery during the second stage of charge and discharge control meets the target heat generation condition.

[0064] Step S122: when the target thermal condition includes the target stress condition and the thermal state includes the stress state, the stress state of the battery during the second stage of charge and discharge control satisfies the target stress condition; In some embodiments, when the expansion force of the battery during the second stage of charge and discharge control is not greater than the expansion force represented by the target stress condition, it is determined that the stress state of the battery during the second stage of charge and discharge control meets the target stress condition.

[0065] In some embodiments, when the internal pressure of the battery during the second stage of charge and discharge control is not greater than the internal pressure represented by the target stress condition, it is determined that the stress state of the battery during the second stage of charge and discharge control meets the target stress condition.

[0066] Step S123: When the target thermodynamic condition includes the target volume condition and the thermodynamic state includes the volume state, the volume state of the battery during the second stage of charge and discharge control satisfies the target volume condition.

[0067] In some embodiments, when the volume of the battery during the second stage of charge and discharge control is not greater than the volume represented by the target volume condition, it is determined that the volume state of the battery during the second stage of charge and discharge control meets the target volume condition.

[0068] In the embodiment of the present disclosure, when the target thermal condition includes the target heat generation condition and the thermal state includes the heat generation state, the heat generation state of the battery in the second stage of charge and discharge control process meets the target heat generation condition; when the target thermal condition includes the target stress condition and the thermal state includes the stress state, the stress state of the battery in the second stage of charge and discharge control process meets the target stress condition; when the target thermal condition includes the target volume condition and the thermal state includes the volume state, the volume state of the battery in the second stage of charge and discharge control process meets the target volume condition. In this way, whether the heat generation state, stress state, and volume state meet the corresponding target heat generation condition, target stress condition, and target volume condition is considered respectively, which improves the accuracy of determining whether the thermal state meets the target thermal condition.

[0069] In some embodiments, the target thermal condition includes a target change condition of the thermal state; the above step S113 may include the following step S131: Step S131: in response to the degree of change in the thermal state of the battery during the second stage of charge and discharge control satisfying the target change condition, determining the first candidate lower limit as the target discharge lower limit.

[0070] Here, the target change condition is a condition that the degree of change in the thermal state of the battery satisfies when the battery operates safely during the second stage of charge and discharge control.

[0071] In some embodiments, the degree of change of the thermal state may include, but is not limited to, at least one of an increment, an increase rate, etc. of the thermal state.

[0072] In the embodiment of the present disclosure, when the degree of change of the thermal state of the battery during the second stage of charge and discharge control meets the target change condition, the first candidate lower limit is determined as the target discharge lower limit. In this way, since the thermal state of the battery is a cumulative process, whether the condition is met can be determined based on the change amount of the thermal state, and the change of the thermal state can be accurately obtained.

[0073] In some embodiments, the above step S131 may include the following steps S141 to S143: Step S141: when the target change condition includes the target heat generation change condition and the degree of change of the thermal state includes the degree of heat generation change, the degree of heat generation change of the battery during the second stage of charge and discharge control satisfies the target heat generation change condition; In some embodiments, when the heat generation variation degree includes the heat generation increase / increase rate, the heat generation increase / increase rate of the battery during the second stage of charge and discharge control satisfies the target heat generation variation condition.

[0074] In some embodiments, when the degree of heat generation variation includes a heat generation variation rate, the heat generation variation rate of the battery during the charge and discharge control process of the second stage satisfies a target heat generation variation condition.

[0075] Step S142: when the target change condition includes the target stress change condition and the degree of change of the thermal state includes the degree of stress change, the degree of stress change of the battery during the second stage of charge and discharge control satisfies the target stress change condition; In some embodiments, when the stress change degree includes the stress increase amount / increase rate, the stress increase amount / increase rate of the battery during the charge and discharge control process of the second stage meets the target stress change condition.

[0076] In some embodiments, when the stress change degree includes a stress change rate, the stress change rate of the battery during the charge and discharge control process of the second stage meets the target stress change condition.

[0077] Step S143: When the target change condition includes a target volume change condition and the degree of change in the thermal state includes a volume change degree, the volume change degree of the battery during the second stage of charge and discharge control satisfies the target volume change condition.

[0078] In some embodiments, when the volume change degree includes a volume increase amount / increase rate, the volume increase amount / increase rate of the battery during the second stage of charge and discharge control meets the target volume change condition.

[0079] In some embodiments, when the volume change degree includes a volume change rate, the volume change rate of the battery during the charge and discharge control process of the second stage meets the target volume change condition.

[0080] In the embodiment of the present disclosure, when the target change condition includes the target heat generation change condition, and the degree of change of the thermodynamic state includes the degree of heat generation change, the degree of heat generation change of the battery in the second stage of charge and discharge control process meets the target heat generation change condition; when the target change condition includes the target stress change condition, and the degree of change of the thermodynamic state includes the degree of stress change, the degree of stress change of the battery in the second stage of charge and discharge control process meets the target stress change condition; when the target change condition includes the target volume change condition, and the degree of change of the thermodynamic state includes the degree of volume change, the degree of volume change of the battery in the second stage of charge and discharge control process meets the target volume change condition. In this way, whether the degree of heat generation change, the degree of stress change, and / or the degree of volume change meet the corresponding target heat generation change condition, target stress change condition, and target volume change condition is considered respectively, and the accuracy of determining whether the degree of change of the thermodynamic state meets the target change condition is improved.

[0081] In some embodiments, the above method may further include the following steps S181 to S183: Step S181: determining a first rate of change of the thermal state of the battery during the charge and discharge control process of the third stage; the third stage is a stage of performing charge and discharge control on the battery before the health state value decays to the first state threshold; Here, the third stage is a stage of controlling the charge and discharge of the battery before the health state value decays to the first state threshold, that is, the process of controlling the charge and discharge of the battery before adjusting the lower discharge limit.

[0082] Exemplarily, based on the thermal state of the battery during charge and discharge control before the health state value decays to the first state threshold, a straight line of the thermal state is fitted, and the first slope of the straight line is determined, and the first slope is used as the first change rate of the thermal state of the battery during the charge and discharge control process in the third stage.

[0083] Exemplarily, the ratio of the thermal state at the first moment during the charge and discharge control of the battery before the health state value decays to the first state threshold and the thermal state at the previous moment is determined as a first ratio, and the first ratio is used as the first change rate of the thermal state of the battery during the charge and discharge control process in the third stage.

[0084] Step S182: determining a second change rate of the thermal state of the battery during the second stage of charge and discharge control; Exemplarily, based on the thermal state of the battery during charge and discharge control as the health state value decays from a first state threshold to a current health state value, a real-time change curve of the thermal state is fitted, and based on the real-time change curve, a real-time second slope is determined, and the real-time second slope is used as the real-time second change rate of the thermal state of the battery during the second stage of charge and discharge control.

[0085] Exemplarily, when the health state value decays from a first state threshold to a current health state value, the ratio of the thermal state at a current moment to the moment before the current moment is determined in real time during the charge and discharge control of the battery, a real-time second ratio is determined, and the real-time second ratio is used as the real-time second change rate of the thermal state of the battery during the second stage of charge and discharge control.

[0086] Step S183: when the ratio of the second change rate to the first change rate is not greater than the first ratio threshold, determine that the degree of change in the thermal state of the battery during the second stage of charge and discharge control meets the target change condition.

[0087] In some embodiments, by real-time monitoring of the ratio of the second change rate to the first change rate, it is measured whether the thermal state of the battery during the charge and discharge control process meets the target change condition.

[0088] In the embodiment of the present disclosure, the third stage is a stage in which the battery is charged and discharged before the health state value decays to the first state threshold. When the ratio of the second change rate of the thermal state of the battery during the charge and discharge control process of the second stage to the first change rate of the thermal state during the charge and discharge control process of the third stage is not greater than the first ratio threshold, it is determined that the degree of change of the thermal state of the battery during the charge and discharge control process of the second stage meets the target change condition. In this way, the relationship between the degree of change of the thermal state of the battery during the charge and discharge control process of the second stage and the degree of change of the thermal state of the battery during the charge and discharge control process of the third stage can be determined based on the ratio of the second change rate to the first change rate, so that it can be determined whether the current degree of change of the thermal state has a risk of damaging the battery, that is, it can be determined whether the current degree of change of the thermal state meets the target change condition.

[0089] In some embodiments, the above step S102 may include the following step S151: Step S151: in response to the thermal state of the battery in the first stage of charge and discharge control not satisfying the target thermal condition, determining a reference discharge lower limit as the target discharge lower limit, the reference discharge lower limit being higher than the first candidate lower limit.

[0090] In some embodiments, when it is detected that the thermal state of the battery during the first stage of charge and discharge control does not meet the target thermal condition, a reference discharge lower limit higher than the first candidate lower limit may be used as the target discharge lower limit.

[0091] In some embodiments, when it is detected that the thermal state of the battery during the first stage of charge and discharge control does not meet the target thermal conditions, it indicates that the battery is sensitive to gas and heat production. Therefore, the reference discharge lower limit can be the initial discharge lower limit when the discharge lower limit is not adjusted, making the battery safer during operation.

[0092] In the embodiment of the present disclosure, in response to the thermal state of the battery in the first stage of charge and discharge control not meeting the target thermal condition, the reference discharge lower limit is determined as the target discharge lower limit, and the reference discharge lower limit is higher than the first candidate lower limit. In this way, when the thermal state does not meet the target thermal condition, the reference discharge lower limit higher than the first candidate lower limit is determined as the target discharge lower limit, thereby reducing the damage to the battery caused by the thermal state.

[0093] In some embodiments, the above step S111 may include the following steps S161 and S162: Step S161: determining the adjustment step length of the discharge lower limit; Here, the adjustment step size is the value by which the lower discharge limit is lowered every time the battery health status value decays by 1%.

[0094] In some embodiments, the lower discharge limit can be adjusted proportionally. The lower discharge limit can be evenly adjusted according to the decay interval of the health state value (i.e., the SOH interval of the battery life cycle) and the interval in which the lower discharge limit can be lowered. That is, the decay interval is divided by the interval in which the lower discharge limit can be lowered to obtain the adjustment step size. This method is simpler and easier to implement.

[0095] In some embodiments, when the health status value is large, the battery performance is better. If the lower discharge limit is lowered too much at this time, it may cause the battery to decay faster. Therefore, a smaller adjustment step size can be set in the early stage of health status value decay, and a larger step size can be set in the later stage of health status value decay to slow down the battery aging.

[0096] Step S162: based on the adjustment step size, adjusting the discharge lower limit down to the first candidate lower limit.

[0097] In some implementations, a first candidate lower limit is determined according to the current discharge lower limit and the adjustment step size, and the discharge lower limit is adjusted down to the first candidate lower limit.

[0098] In the embodiment of the present disclosure, the adjustment step length of the discharge lower limit is determined; based on the adjustment step length, the discharge lower limit is adjusted down to the first candidate lower limit. In this way, the discharge lower limit can be adjusted down to a suitable first candidate lower limit according to a suitable adjustment step length.

[0099] In some embodiments, the above step S161 may include the following step S171: Step S171: Based on the current health state value of the battery, determine the adjustment step size of the lower discharge limit; wherein the adjustment step size is inversely proportional to the current health state value.

[0100] In some embodiments, an adjustment step size of a lower discharge limit corresponding to a health state value is determined, and a smaller adjustment step size is set for a larger health state value, and a larger adjustment step size is set for a smaller health state value.

[0101] In some embodiments, the decay interval of the health state value and the downward adjustment interval of the discharge lower limit are determined; the decay interval is divided into multiple sub-decay intervals, and the downward adjustment interval includes multiple sub-downward adjustment intervals; the sub-downward adjustment intervals corresponding to the multiple sub-decay intervals are determined; based on the multiple sub-decay intervals and the sub-downward adjustment intervals corresponding to the multiple sub-decay intervals, the adjustment step lengths of the discharge lower limits corresponding to the multiple sub-decay intervals are determined. Here, the adjustment step lengths of the discharge lower limits corresponding to the health state values ​​in the same sub-decay interval are the same, and each sub-decay interval may include one or more health state values; the larger the health state value in the multiple sub-decay intervals, the smaller the corresponding adjustment step length.

[0102] In the disclosed embodiment, the adjustment step size of the lower discharge limit is determined according to the current health state value of the battery; wherein the adjustment step size is inversely proportional to the current health state value. In this way, when the health state value is large, more consideration is given to minimizing the damage to the battery. Therefore, a smaller adjustment step size can be set to reduce the damage to the battery caused by excessive reduction of the lower discharge limit and slow down the aging of the battery; and when the health state value is small, more consideration is given to increasing the remaining capacity of the battery. In this way, in the process of the continuous attenuation of the battery health state, the needs of increasing the remaining capacity of the battery and reducing the damage to the battery can be taken into account, thereby improving the overall performance of the battery during use.

[0103] The present disclosure provides a battery management system. Figure 2 A schematic diagram of the structure of a battery management system provided in an embodiment of the present disclosure is shown in FIG. Figure 2 As shown, the battery management system 200 includes: An acquisition module 201 is used to acquire a target thermal condition of the battery during the charging and discharging process; An adjustment module 202 is configured to adjust a lower discharge limit of the battery in a charge and discharge interval based on a target thermal condition and a thermal state of the battery during a charge and discharge process in response to the current health state value of the battery decaying below a first state threshold value, so as to obtain a target lower discharge limit; The control module 203 is used to perform a first stage of charge and discharge control on the battery based on the target lower discharge limit.

[0104] In the disclosed embodiment, the target thermal condition of the battery during the charge and discharge process is first obtained; secondly, when the current health state value of the battery decays to below the first state threshold, the lower discharge limit in the charge and discharge interval of the battery is adjusted according to the target thermal condition and the thermal state of the battery during the charge and discharge process to obtain the target discharge lower limit; finally, the battery is subjected to the first stage of charge and discharge control according to the target discharge lower limit. In this way, when it is detected that the current health state value decays to below the first state threshold, the thermal state of the battery during the charge and discharge process and the target thermal condition are comprehensively considered, and the lower discharge limit in the charge and discharge interval of the battery is adjusted, so that after the charge and discharge interval of the battery decays, the available remaining capacity of the battery is increased while reducing damage to the battery and slowing down the aging rate of the battery.

[0105] In some embodiments, the adjustment module includes: a downward adjustment unit, used to lower the discharge lower limit to a first candidate lower limit; a control unit, used to perform a second stage of charge and discharge control on the battery based on the first candidate lower limit, and monitor the thermal state of the battery during the second stage of charge and discharge control; a first determination unit, used to determine the first candidate lower limit as the target discharge lower limit in response to the thermal state of the battery during the second stage of charge and discharge control satisfying the target thermal condition.

[0106] In some embodiments, the first determination unit includes at least one of the following: when the target thermal condition includes a target heat generation condition and the thermal state includes a heat generation state, the heat generation state of the battery during the second stage of charge and discharge control satisfies the target heat generation condition; when the target thermal condition includes a target stress condition and the thermal state includes a stress state, the stress state of the battery during the second stage of charge and discharge control satisfies the target stress condition; when the target thermal condition includes a target volume condition and the thermal state includes a volume state, the volume state of the battery during the second stage of charge and discharge control satisfies the target volume condition.

[0107] In some embodiments, the first determination unit further includes: a first determination subunit, configured to determine the first candidate lower limit as the target discharge lower limit in response to the degree of change in the thermal state of the battery during the second stage of charge and discharge control satisfying the target change condition.

[0108] In some embodiments, the first determination subunit includes at least one of the following: when the target change condition includes a target heat generation change condition and the degree of change of the thermal state includes the degree of heat generation change, the degree of heat generation change of the battery during the second stage of charge and discharge control meets the target heat generation change condition; when the target change condition includes a target stress change condition and the degree of change of the thermal state includes the degree of stress change, the degree of stress change of the battery during the second stage of charge and discharge control meets the target stress change condition; when the target change condition includes a target volume change condition and the degree of change of the thermal state includes the degree of volume change, the degree of volume change of the battery during the second stage of charge and discharge control meets the target volume change condition.

[0109] In some embodiments, the battery management system further comprises: A first determination module is used to determine a first change rate of the thermal state of the battery during the charge and discharge control process of the third stage; the third stage is a stage of controlling the charge and discharge of the battery before the health state value decays to the first state threshold; A second determination module, used to determine a second change rate of the thermal state of the battery during the charge and discharge control process of the second stage; The third determination module is used to determine whether the degree of change of the thermal state of the battery during the second stage of charge and discharge control meets the target change condition when the ratio of the second change rate to the first change rate is not greater than the first ratio threshold.

[0110] In some embodiments, the adjustment module also includes: a second determination unit, which is used to determine the reference discharge lower limit as the target discharge lower limit in response to the thermal state of the battery during the first stage of charge and discharge control not meeting the target thermal condition, and the reference discharge lower limit is higher than the first candidate lower limit.

[0111] In some embodiments, the downward adjustment unit includes: a second determining subunit, configured to determine an adjustment step length of the discharge lower limit; and a downward adjustment subunit, configured to adjust the discharge lower limit downward to the first candidate lower limit based on the adjustment step length.

[0112] In some embodiments, the second determination subunit is further used to: determine an adjustment step size of the lower discharge limit based on a current health state value of the battery; wherein the adjustment step size is inversely proportional to the current health state value.

[0113] The present disclosure provides a battery system. Figure 3 A schematic diagram of the structure of a battery system provided in an embodiment of the present disclosure is shown in FIG. Figure 3 As shown, the battery system 300 includes a battery 301 and the above-mentioned battery management system 200 .

[0114] The following describes the application of the embodiments of the present disclosure in actual scenarios.

[0115] The voltage open range (corresponding to the charge and discharge range in the aforementioned embodiment) of lithium iron phosphate batteries is not the maximum voltage range of the whole battery. In battery design, considering that the low voltage range has a greater risk of gas production and heat generation, the low voltage range is generally avoided in the open range, directly limiting the use of the low voltage range, which makes the capacity of the lithium iron phosphate battery unable to be fully utilized, resulting in redundancy and waste. In actual battery use, the effects of different aging paths on gas production and direct current resistance (DCR) are more complicated. Not all low voltage ranges under all aging paths will have safety issues such as gas production and heat generation. By designing a suitable algorithm in the battery management system (BMS) to monitor the gas production and heat generation of the battery, the lower limit of the cycle range can be appropriately released when conditions are right to increase the previously redundant capacity of the low voltage part and improve the capacity decay rate of the battery.

[0116] For example, in the case of gas production by electrochemical reaction and heat generation by DCR, the lower discharge limit is considered to be set at 2.6V. However, in some scenarios, it can continue to discharge to 2V. The difference in discharge capacity from 2.6V to 2V is the incremental capacity benefit generated by the voltage range opening strategy.

[0117] Design a cycle flow with the same upper limit and different lower limits, such as 0%-100%, 10%-100%, and 20%-100% cycles, control other conditions to be the same, and test the same battery cell for aging experiments, and convert the number of cycles to the equivalent full cycle number, such as Figure 4 As shown, the aging capacity retention rate of a certain battery at the discharge lower limit is 0%, 10%, 20%, and 30% respectively. It can be seen that with the decrease of the charging lower limit, the aging rate of the equivalent full-range cycle number decreases, and the battery capacity retention rate is higher after the same equivalent full cycle number (that is, the battery decay slows down).

[0118] Due to some aging conditions, it is not suitable to open the low voltage section of power, so it is necessary to monitor battery gas production, DCR and other parameters in the BMS to determine whether to open the low voltage section of capacity depending on the battery condition. The specific principles are as follows: When the BMS estimates that the battery SOH is lower than 85%, the low voltage segment can be turned on, and the amount turned on is proportional to the SOH. For example, for every 2% attenuation of the SOH, the low voltage segment is reduced by 0.1V until it reaches the 2.0V limit and no longer decreases. At the same time, the BMS monitors the DCR and the internal pressure of the battery, and measures the risk of gas production by the slope of the gas pressure increase before and after the low voltage segment is turned on. If the BMS determines that there is a risk of abnormal gas production, the low voltage segment should be turned off.

[0119] A certain type of lithium iron phosphate battery was tested, and the open voltage range was designed to be 2.5~3.65V. Two cells with good consistency were selected for hanging test, the ambient temperature was set to 45 degrees Celsius, and the capacity data was tested every 500 cycles. One of them dynamically adjusted the lower limit of discharge. After the SOH decayed to 90%, the special BMS control system was used to dynamically adjust the lower limit of discharge. For every 1% decay, the lower limit of discharge of the battery was reduced by 0.02V until the lower limit reached 2.0V. At the same time, the battery pressure and expansion force were monitored. If there was no abnormality, the lower limit would continue to be lowered, otherwise the lower limit would be restored to 2.5V. No abnormality occurred in this test. After the SOH of the test group with dynamic adjustment of the lower limit of discharge decayed to around 85%, its cycle lower limit voltage was 2.2V. The other battery was tested as a control group without adjusting the lower limit of discharge.

[0120] By comparing the test results of the dynamic adjustment of the lower limit of discharge with those of the control group, Figure 5 As shown in the figure, it can be observed that after adjusting the dynamic voltage around 4000 cycles (SOH is 90%), the capacity has been improved to a certain extent (increasing the previously redundant capacity of the low voltage part), and the subsequent attenuation trend of the battery has slowed down and the aging slope has been significantly reduced (improving the capacity attenuation rate of the battery). When the SOH decays to 85%, the battery gas production and expansion force monitoring did not alarm, and no abnormal over-threshold problem occurred. This shows that dynamically adjusting the lower limit of discharge can effectively increase the available remaining capacity of the battery and extend the battery life.

[0121] In the disclosed embodiment, by detecting the heat generation or heat generation condition of the battery and dynamically adjusting the lower discharge limit, the originally redundant capacity of the low voltage part can be increased, the available remaining capacity of the battery can be effectively improved, and the battery life can be extended.

[0122] It should be noted that in the embodiments of the present disclosure, if the above method is implemented in the form of a software function module and sold or used as an independent product, it can also be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the embodiments of the present disclosure is essentially or the part that contributes to the relevant technology can be embodied in the form of a software product, which is stored in a storage medium and includes several instructions for a computer device (which can be a personal computer, a server, or a network device, etc.) to execute all or part of the methods of each embodiment of the present disclosure. The aforementioned storage medium includes: various media that can store program codes, such as a U disk, a mobile hard disk, a read-only memory (ROM), a disk or an optical disk. In this way, the embodiments of the present disclosure are not limited to any specific hardware, software or firmware, or any combination of hardware, software, and firmware.

[0123] An embodiment of the present disclosure provides a computer device, including a memory and a processor, wherein the memory stores a computer program that can be run on the processor, and when the processor executes the program, some or all of the steps in the above method are implemented.

[0124] The embodiment of the present disclosure provides a computer-readable storage medium on which a computer program is stored, and when the computer program is executed by a processor, some or all of the steps in the above method are implemented. The computer-readable storage medium can be transient or non-transient.

[0125] An embodiment of the present disclosure provides a computer program, including a computer-readable code. When the computer-readable code is run in a computer device, a processor in the computer device executes some or all of the steps for implementing the above method.

[0126] The embodiments of the present disclosure provide a computer program product, which includes a non-transitory computer-readable storage medium storing a computer program, and when the computer program is read and executed by a computer, some or all of the steps in the above method are implemented. The computer program product can be implemented in hardware, software, or a combination thereof. In some embodiments, the computer program product is specifically embodied as a computer storage medium, and in other embodiments, the computer program product is specifically embodied as a software product, such as a software development kit (SDK), etc.

[0127] It should be noted here that the description of the various embodiments above tends to emphasize the differences between the various embodiments, and the same or similar aspects can be referenced to each other. The description of the above device, storage medium, computer program and computer program product embodiments is similar to the description of the above method embodiment, and has similar beneficial effects as the method embodiment. For technical details not disclosed in the embodiments of the device, storage medium, computer program and computer program product disclosed in the present invention, please refer to the description of the method embodiment disclosed in the present invention for understanding.

[0128] It should be noted that Figure 6 is a schematic diagram of a hardware entity of a computer device in an embodiment of the present disclosure, such as Figure 6 As shown, the hardware entity of the computer device 600 includes: a processor 601, a communication interface 602 and a memory 603, wherein: Processor 601 generally controls the overall operation of computer device 600 .

[0129] The communication interface 602 enables the computer device to communicate with other terminals or servers through a network.

[0130] The memory 603 is configured to store instructions and applications executable by the processor 601, and can also cache data to be processed or processed by the processor 601 and each module in the computer device 600 (for example, image data, audio data, voice communication data, and video communication data), which can be implemented by flash memory (FLASH) or random access memory (Random Access Memory, RAM). Data can be transmitted between the processor 601, the communication interface 602, and the memory 603 through the bus 604.

[0131] It should be understood that "one embodiment" or "an embodiment" mentioned throughout the specification means that specific features, structures or characteristics related to the embodiment are included in at least one embodiment of the present disclosure. Therefore, "in one embodiment" or "in an embodiment" appearing throughout the specification does not necessarily refer to the same embodiment. In addition, these specific features, structures or characteristics can be combined in one or more embodiments in any suitable manner. It should be understood that in the various embodiments of the present disclosure, the size of the serial numbers of the above-mentioned steps / processes does not mean the order of execution. The execution order of each step / process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present disclosure. The serial numbers of the embodiments of the present disclosure are for description only and do not represent the advantages and disadvantages of the embodiments.

[0132] It should be noted that, in this article, the terms "include", "comprises" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, an element defined by the sentence "comprises a ..." does not exclude the existence of other identical elements in the process, method, article or device including the element.

[0133] In the several embodiments provided in the present disclosure, it should be understood that the disclosed devices and methods can be implemented in other ways. The device embodiments described above are only schematic. For example, the division of units is only a logical function division. There may be other division methods in actual implementation, such as: multiple units or components can be combined, or can be integrated into another system, or some features can be ignored or not executed. In addition, the coupling, direct coupling, or communication connection between the components shown or discussed can be through some interfaces, and the indirect coupling or communication connection of devices or units can be electrical, mechanical or other forms.

[0134] The units described above as separate components may or may not be physically separated, and the components displayed as units may or may not be physical units; they may be located in one place or distributed on multiple network units; some or all of the units may be selected according to actual needs to achieve the purpose of the scheme of this embodiment. In addition, the functional units in the various embodiments of the present disclosure may all be integrated into one processing unit, or each unit may be separately used as a unit, or two or more units may be integrated into one unit; the above integrated units may be implemented in the form of hardware or in the form of hardware plus software functional units.

[0135] A person skilled in the art can understand that: all or part of the steps of implementing the above method embodiment can be completed by hardware related to program instructions, and the aforementioned program can be stored in a computer-readable storage medium. When the program is executed, it executes the steps of the above method embodiment; and the aforementioned storage medium includes: various media that can store program codes, such as mobile storage devices, read-only memories (ROM), magnetic disks or optical disks.

[0136] Alternatively, if the above-mentioned integrated unit of the present disclosure is implemented in the form of a software function module and sold or used as an independent product, it can also be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present disclosure can essentially or in other words, the part that contributes to the relevant technology can be embodied in the form of a software product, and the computer software product is stored in a storage medium, including a number of instructions for a computer device (which can be a personal computer, a server, or a network device, etc.) to execute all or part of the methods of each embodiment of the present disclosure. The aforementioned storage medium includes: various media that can store program codes, such as mobile storage devices, ROMs, magnetic disks, or optical disks.

[0137] The above are only implementation modes of the present disclosure, but the protection scope of the present disclosure is not limited thereto. Any changes or substitutions that can be easily conceived by any technician familiar with the technical field within the technical scope disclosed in the present disclosure should be covered by the protection scope of the present disclosure.

Claims

1. A battery control method, characterized in that: The method comprises: Obtaining target thermal conditions of the battery during charging and discharging; In response to the current health state value of the battery decaying below a first state threshold, based on the target thermal condition and the thermal state of the battery during the charge and discharge process, adjusting a lower discharge limit in the charge and discharge interval of the battery to obtain a target lower discharge limit; Based on the target lower discharge limit, the battery is subjected to a first stage of charge and discharge control.

2. The method according to claim 1, characterized in that The step of adjusting the lower discharge limit in the charge and discharge interval of the battery based on the target thermal condition and the thermal state of the battery during the charge and discharge process to obtain the target lower discharge limit includes: adjusting the discharge lower limit to a first candidate lower limit; performing a second-stage charge and discharge control on the battery based on the first candidate lower limit, and monitoring a thermal state of the battery during the second-stage charge and discharge control process; In response to the thermal state of the battery during the second stage of charge and discharge control satisfying the target thermal condition, the first candidate lower limit is determined as the target discharge lower limit.

3. The method according to claim 2, characterized in that The thermal state of the battery during the charge and discharge control process of the second stage satisfies the target thermal condition, including at least one of the following: When the target thermal condition includes a target heat generation condition and the thermal state includes a heat generation state, the heat generation state of the battery during the charge and discharge control process of the second stage satisfies the target heat generation condition; When the target thermal condition includes a target stress condition and the thermal state includes a stress state, the stress state of the battery during the charge and discharge control process of the second stage satisfies the target stress condition; When the target thermodynamic condition includes a target volume condition and the thermodynamic state includes a volume state, the volume state of the battery during the charge and discharge control process of the second stage satisfies the target volume condition.

4. The method according to claim 2, characterized in that The target thermal conditions include target change conditions of thermal state; In response to the thermal state of the battery in the second stage of charge and discharge control satisfying the target thermal condition, determining the first candidate lower limit as the target discharge lower limit includes: In response to the degree of change in the thermal state of the battery during the second stage of charge and discharge control satisfying the target change condition, the first candidate lower limit is determined as the target discharge lower limit.

5. The method according to claim 4, characterized in that The degree of change in the thermal state of the battery during the charge and discharge control process of the second stage satisfies the target change condition, including at least one of the following: When the target change condition includes a target heat generation change condition and the degree of change of the thermal state includes a degree of heat generation change, the degree of heat generation change of the battery during the charge and discharge control process of the second stage satisfies the target heat generation change condition; When the target change condition includes a target stress change condition and the degree of change of the thermal state includes a stress change degree, the stress change degree of the battery during the charge and discharge control process of the second stage satisfies the target stress change condition; When the target change condition includes a target volume change condition and the degree of change in the thermal state includes a degree of volume change, the degree of volume change of the battery during the charge and discharge control process of the second stage satisfies the target volume change condition.

6. The method according to claim 4, characterized in that The method further comprises: determining a first change rate of the thermal state of the battery during the charge and discharge control process of the third stage; the third stage is a stage of performing charge and discharge control on the battery before the health state value decays to the first state threshold; determining a second rate of change of the thermal state of the battery during the charge and discharge control process of the second stage; When the ratio of the second change rate to the first change rate is not greater than a first ratio threshold, it is determined that the degree of change in the thermal state of the battery during the second stage of charge and discharge control meets the target change condition.

7. The method according to any one of claims 2 to 6, characterized in that The step of adjusting the lower discharge limit in the charge and discharge interval of the battery based on the target thermal condition and the thermal state of the battery during the charge and discharge process to obtain the target lower discharge limit further includes: In response to the thermal state of the battery during the first stage of charge and discharge control not satisfying the target thermal condition, a reference discharge lower limit is determined as the target discharge lower limit, the reference discharge lower limit being higher than the first candidate lower limit.

8. The method according to any one of claims 2 to 6, characterized in that The step of lowering the discharge lower limit to a first candidate lower limit includes: Determining an adjustment step size of the discharge lower limit; Based on the adjustment step size, the discharge lower limit is adjusted down to the first candidate lower limit.

9. The method according to claim 8, characterized in that The step of determining the adjustment step of the lower discharge limit includes: Based on the current health state value of the battery, an adjustment step size of the lower discharge limit is determined; wherein the adjustment step size is in inverse proportion to the current health state value.

10. A battery management system, characterized in that: The battery management system comprises: An acquisition module, used to acquire target thermal conditions of the battery during the charging and discharging process; an adjustment module, configured to adjust a lower discharge limit in a charge and discharge interval of the battery based on the target thermal condition and the thermal state of the battery during the charge and discharge process in response to the current health state value of the battery decaying to below a first state threshold, so as to obtain a target lower discharge limit; A control module is used to perform a first-stage charge and discharge control on the battery based on the target lower discharge limit.

11. A battery system, characterized in that: The battery system comprises a battery and the battery management system as claimed in claim 9.

12. A computer device comprising a memory and a processor, wherein the memory stores a computer program executable on the processor, wherein: When the processor executes the program, the steps in the method according to any one of claims 1 to 9 are implemented.

13. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the steps in the method according to any one of claims 1 to 9 are implemented.

14. A computer program product comprising a computer program or instructions, characterized in that When the computer program or instruction is executed by a processor, the steps in the method according to any one of claims 1 to 9 are implemented.

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