A battery management method, device, system and electronic equipment

Abstract

The present application relates to a battery management method, device, system and electronic device, belonging to the field of batteries. The battery management method includes: obtaining the change rate of a specified parameter of the battery during N periodic charges or discharges, the specified parameter including the voltage of the battery and / or the internal resistance of the battery, and N is an integer greater than or equal to 2; adjusting the management strategy of the battery within a preset time period after N periodic charges or discharges according to the change rate of the specified parameter. The change rate of the specified parameter of the battery during N periodic charges or discharges is used as a signal for battery management, and the management strategy of the battery within a preset time period after N periodic charges or discharges is adjusted by obtaining the change rate of the specified parameter to improve the battery cycle life and safety, thereby providing a battery management method with simple calculation and high accuracy to manage the battery.

Description

Technical Field

[0001] The present application belongs to the field of batteries, and specifically relates to a battery management method, device, system and electronic equipment. Background Art

[0002] A battery is a device that can convert chemical energy into electrical energy and is widely used in power fields such as portable electronic devices (such as mobile phones and tablets), electric transportation vehicles (such as electric vehicles, aircraft, ships, submarines), etc.

[0003] After the battery is put into use, it will gradually expand, that is, the surface thickness will increase. The expansion process of the battery is almost irreversible. Under some conditions (such as high temperature, high pressure, etc.), the positive electrode of the battery will continue to undergo oxidation reactions to produce gases such as carbon dioxide, which will accelerate the expansion of the battery. The expansion of the battery will not only reduce the life of the battery itself, but also damage the equipment equipped with the battery after it expands to a certain extent. Therefore, how to manage and protect the battery and extend the service life of the battery is a problem that needs to be considered.

[0004] In the current battery management solution, the battery expansion parameters are calculated by obtaining the working time of the battery at multiple temperatures and multiple voltages, and then the battery charging and discharging strategy is adjusted according to the battery expansion parameters. The formula for calculating the expansion parameters is: B is the recent expansion parameter of the terminal battery, T i is the ith temperature interval, V j is the jth voltage interval, t′(T i , V j ) is the terminal’s recent temperature at T j and the voltage is at V j The duration of a′(T i , V j ) is the terminal battery temperature at T i and the voltage is at V j The expansion coefficient at that time. Wherein, 1≤i≤n, 1≤j≤m, i and j are positive integers. n is the total number of divided temperature intervals, and m is the total number of divided voltage intervals. Although this method can delay the expansion rate of the battery and extend the battery life, it needs to obtain parameters such as the working time of the battery at multiple temperatures and voltages, and use them to calculate the expansion parameters. There are many types of parameters that need to be obtained, and the amount of data calculation is large, which is not conducive to battery management. Summary of the invention

[0005] In view of this, the purpose of the present application is to provide a battery management method, device, system and electronic device to improve the existing battery management solution because there are many types of parameters that need to be obtained and the amount of data calculation is large, which is not conducive to battery management.

[0006] The embodiment of the present application is implemented as follows:

[0007] In a first aspect, an embodiment of the present application provides a battery management method, comprising: obtaining the rate of change of specified parameters of a battery during N periodic charges or discharges, wherein the specified parameters include the voltage of the battery and / or the internal resistance of the battery, and N is an integer greater than or equal to 2; and adjusting the management strategy of the battery within a preset time period after N periodic charges or discharges according to the rate of change of the specified parameters.

[0008] In an embodiment of the present application, the rate of change of a specified parameter (voltage and / or internal resistance) of the battery during N periodic charges or discharges is used as a signal for battery management. The rate of change of the specified parameter is obtained to adjust the management strategy of the battery within a preset time period after N periodic charges or discharges to improve the battery cycle life and safety, thereby providing a battery management method with simple calculation and high accuracy for managing the battery.

[0009] In combination with a possible implementation manner of the embodiment of the first aspect, the specified parameters include voltage, and obtaining the change rate of the specified parameters of the battery includes: periodically obtaining the voltage of the battery after being charged or discharged to a specified state of charge according to a preset current and standing for a preset period of time; determining the voltage change rate based on the N voltages obtained.

[0010] In the embodiment of the present application, each time the voltage is obtained, the voltage of the battery is obtained after it is charged or discharged to a specified state of charge according to a preset current and left to stand for a preset period of time, so that the N voltages obtained are obtained under the same conditions, thereby improving the problem of data errors caused by different acquisition conditions. At the same time, by leaving the battery to stand for a preset period of time before obtaining the required voltage, the obtained voltage is the voltage after the battery is completely depolarized and stabilized, thereby improving the accuracy of the calculation result.

[0011] In combination with a possible implementation manner of the embodiment of the first aspect, the specified parameters include internal resistance, and obtaining the change rate of the specified parameters of the battery includes: periodically obtaining the internal resistance of the battery when charged or discharged according to a preset current; and determining the internal resistance change rate based on the N internal resistances obtained.

[0012] In the embodiment of the present application, since each time the internal resistance is obtained, the internal resistance of the battery when it is charged or discharged according to a preset current is obtained, the N internal resistances obtained are all obtained under the same conditions, thereby improving the problem of data errors caused by different acquisition conditions, thereby improving the accuracy of the calculation results.

[0013] In combination with a possible implementation manner of the embodiment of the first aspect, the internal resistance of a battery when charged or discharged according to a preset current is periodically obtained, including: obtaining an actual curve of the battery when charged or discharged according to a first preset current each time the internal resistance of the battery is obtained, the actual curve representing the corresponding relationship between the residual voltage of the battery and the depth of discharge; obtaining a first voltage on the actual curve and a second voltage on a preset standard curve at the same specified discharge depth, wherein the preset standard curve is a curve when the battery is charged or discharged according to a second preset current when no polarization occurs, and the first preset current is greater than the second preset current; and determining the internal resistance based on the first voltage, the second voltage and the first preset current.

[0014] In the embodiment of the present application, each time the internal resistance of the battery is obtained, the first voltage on the actual curve and the second voltage on the preset standard curve at the same specified discharge depth are obtained, and the internal resistance is calculated based on this. Since the polarization effect of the battery is also taken into account, the calculated internal resistance is more accurate.

[0015] In combination with a possible implementation manner of the embodiment of the first aspect, the step of determining the value range of the specified discharge depth includes: obtaining a first discharge depth of an actual full charge voltage on the preset standard curve, and obtaining a second discharge depth of an actual full discharge voltage on the preset standard curve; obtaining a capacity ratio of a preset discharge depth on the preset standard curve, wherein the value range of the preset discharge depth is 0% to 100%; and determining the range of the specified discharge depth based on the first discharge depth, the second discharge depth, and the capacity ratio of the preset discharge depth.

[0016] In the embodiment of the present application, since the battery life decays during use, the capacity of the battery becomes smaller, making the full charge or full discharge position points (discharge depths) corresponding to the preset standard curve and the actual curve different. By adopting the above-mentioned method, the determined specified discharge depth is the common part of the preset standard curve and the actual curve, thereby ensuring the accuracy of the subsequent calculation of the internal resistance and improving the problem that the selected specified discharge depth has only corresponding points on the preset standard curve but no corresponding points on the actual curve.

[0017] In combination with a possible implementation manner of the first aspect, the method further includes: obtaining the capacity decay rate of the battery; accordingly, adjusting the management strategy of the battery within a preset time period after N periodic charges or discharges according to the rate of change of the specified parameter, including: adjusting the management strategy of the battery within a preset time period after N periodic charges or discharges according to the rate of change of the specified parameter and the capacity decay rate.

[0018] In an embodiment of the present application, when adjusting the management strategy of the battery within a preset time period after N periodic charges or discharges, the capacity decay rate of the battery is also taken into account, thereby better improving the cycle decay and cycle expansion of the battery, and better extending the battery life and improving the safety of the battery.

[0019] In combination with a possible implementation manner of the embodiment of the first aspect, the management strategy of the battery within a preset time period after N periodic charges or discharges is adjusted according to the change rate of the specified parameter, including: when the change rate of the specified parameter is greater than a first preset threshold and less than a second preset threshold, adjusting the charge and discharge strategy of the battery within a preset time period after N periodic charges or discharges, and the second preset threshold is greater than the first preset threshold.

[0020] In an embodiment of the present application, when the rate of change of a specified parameter is greater than a first preset threshold value and less than a second preset threshold value, the battery's cycle attenuation and cycle expansion are improved by adjusting the battery's charge and discharge strategy within a preset time period after N periodic charges or discharges, thereby better extending the battery's service life and improving the battery's safety.

[0021] In combination with a possible implementation manner of the embodiment of the first aspect, the first preset threshold is the rate of change of the specified parameter corresponding to when the capacity decay rate of the battery is a first specified decay rate, the second preset threshold is the rate of change of the specified parameter corresponding to when the capacity decay rate of the battery is a second specified decay rate, and the first specified decay rate is less than the second specified decay rate.

[0022] In combination with a possible implementation manner of the embodiment of the first aspect, the first specified attenuation rate is any capacity attenuation rate between 5% and 20%, and the second specified attenuation rate is any capacity attenuation rate between 40% and 70%.

[0023] In the embodiments of the present application, since the capacity decay rate is within a range of 5% to 20%, the battery does not experience significant irreversible capacity decay, and the cycle performance of the battery is improved more significantly after adjusting the battery's charge and discharge strategy; while the capacity decay rate is within a range of 40% to 70%, especially when the capacity decay rate is 70%, the battery's endurance and power performance are significantly attenuated, and the experience is poor. The battery may experience interface problems such as lithium plating and purple spots caused by insufficient electrolyte, resulting in safety risks such as thermal runaway.

[0024] In combination with a possible implementation manner of the embodiment of the first aspect, the charge and discharge strategy includes at least one of lowering the upper limit charging voltage, lowering the charging current, lowering the discharge current, or increasing the lower limit discharge voltage.

[0025] In the embodiment of the present application, the battery charge and discharge strategy can be adjusted by adopting at least one of lowering the upper charge limit voltage, lowering the charging current, lowering the discharge current, or increasing the lower discharge limit voltage to extend the battery life and improve the battery safety.

[0026] In combination with a possible implementation manner of the first aspect, when lowering the upper limit charging voltage, lowering the charging current, lowering the discharging current, or increasing the lower limit discharging voltage, the upper limit charging voltage is lowered, the charging current is lowered, the discharging current is lowered, or the lower limit discharging voltage is increased according to a preset relationship between the capacity attenuation degree and the adjustment amount characterizing the battery, wherein different capacity attenuation degrees correspond to different adjustment amounts.

[0027] In the embodiment of the present application, when lowering the upper limit charging voltage, lowering the charging current, lowering the discharge current, or increasing the lower limit discharge voltage, the upper limit charging voltage, the charging current, the discharge current, or the lower limit discharge voltage is lowered according to the adjustment amount corresponding to the degree of battery capacity decay, and the battery capacity decay rate is taken into account, thereby better improving the battery cycle decay and cycle expansion, and better extending the battery service life and improving the battery safety.

[0028] In combination with a possible implementation manner of the embodiment of the first aspect, N is an integer greater than or equal to 2 and less than or equal to 50.

[0029] In the embodiment of the present application, the rate of change is calculated by obtaining relatively more (2 to 50) specified parameters, thereby improving the accuracy and controlling the amount of calculation to better balance performance and cost; if the number is too large (greater than 50), the amount of calculation will increase, but the accuracy will not be significantly increased, but the cost will be increased.

[0030] In the second aspect, an embodiment of the present application also provides a battery management device, including: an acquisition unit and a management unit; the acquisition unit is used to obtain the change rate of specified parameters of the battery during N periodic charging or discharging processes, the specified parameters include the battery voltage and / or the battery internal resistance, and N is an integer greater than or equal to 2; the management unit is used to adjust the management strategy of the battery within a preset time period after N periodic charging or discharging according to the change rate of the specified parameters.

[0031] In a third aspect, an embodiment of the present application further provides a battery management system connected to a battery, wherein the battery management system is used to execute the battery management method provided in the above-mentioned first aspect embodiment and / or any possible implementation method in combination with the first aspect embodiment.

[0032] In a fourth aspect, an embodiment of the present application further provides an electronic device, comprising: a main body, a battery management system and a battery connected to the battery management system; the battery is used to power the main body; the battery management system is used to execute the battery management method provided in the above-mentioned first aspect embodiment and / or any possible implementation method combined with the first aspect embodiment.

[0033] Other features and advantages of the present application will be described in the following description, and partly become apparent from the description, or understood by implementing the embodiments of the present application. The purpose and other advantages of the present application can be realized and obtained by the structures specifically pointed out in the written description and the drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can also be obtained based on these drawings without creative work. As shown in the drawings, the above and other purposes, features and advantages of the present application will be clearer. The same reference numerals indicate the same parts in all the drawings. The drawings are not deliberately scaled to the actual size, and the focus is on showing the main purpose of the present application.

[0035] Figure 1 A schematic diagram showing the relationship between the cycle life of a battery and the static voltage of the battery after discharge provided in an embodiment of the present application is shown.

[0036] Figure 2 A schematic diagram showing the relationship between the cycle life of a battery and the static voltage of the battery after charging is provided in an embodiment of the present application.

[0037] Figure 3 A schematic diagram showing the relationship between the cycle life of a battery and the internal resistance of the battery provided in an embodiment of the present application is shown.

[0038] Figure 4 A schematic diagram showing the principle of a battery management method provided in an embodiment of the present application is shown.

[0039] Figure 5 A schematic diagram showing the corresponding relationship between the residual voltage and the discharge depth of a battery provided in an embodiment of the present application is shown.

[0040] Figure 6 A functional module schematic diagram of a battery management device provided in an embodiment of the present application is shown. DETAILED DESCRIPTION

[0041] The technical solutions in the embodiments of the present application will be described below in conjunction with the drawings in the embodiments of the present application.

[0042] It should be noted that similar numbers and letters represent similar items in the following drawings, so once an item is defined in one drawing, it is not necessary to further define and explain it in the subsequent drawings. At the same time, in the description of this application, relational terms such as "first", "second", etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply that there is any such actual relationship or order between these entities or operations. Moreover, the term "include", "comprise" or any other variant thereof is intended to cover non-exclusive inclusion, so that the process, method, article or equipment including a series of elements includes not only those elements, but also includes other elements that are not clearly listed, or also includes elements inherent to such process, method, article or equipment. In the absence of more restrictions, the elements limited by the sentence "including one..." do not exclude the existence of other identical elements in the process, method, article or equipment including the elements.

[0043] Furthermore, the term "and / or" in this application is only a description of the association relationship of associated objects, indicating that there may be three relationships. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. The term "plurality" refers to more than two (including two).

[0044] In the description of the embodiments of the present application, unless otherwise clearly specified and limited, technical terms such as "connection" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can also be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the embodiments of the present application can be understood according to specific circumstances.

[0045] At present, from the perspective of market development, the application of power batteries is becoming more and more extensive. Power batteries are not only used in energy storage power systems such as hydropower, thermal power, wind power and solar power stations, but also widely used in electric vehicles such as electric bicycles, electric motorcycles, electric cars, as well as military equipment and aerospace and other fields. With the continuous expansion of the application field of power batteries, the market demand is also constantly expanding.

[0046] The inventors of the present application have noticed that the expansion of the battery will not only reduce the life of the battery itself, but also damage the equipment equipped with the battery after the expansion reaches a certain extent. Therefore, it is necessary to manage and protect the battery to extend the service life of the battery and improve the safety of the battery. In view of the existing battery management scheme, it is necessary to obtain parameters such as the working time of the battery at multiple temperatures and voltages to calculate the expansion parameters. Because there are many types of parameters that need to be obtained, the amount of data calculation is large, which is not conducive to battery management. Based on this, the embodiment of the present application provides a battery management method with simple calculation and high accuracy to manage the battery to improve the battery cycle life and safety.

[0047] When inventing this application, the inventor discovered that the increase of battery polarization (the phenomenon that the electrode deviates from the equilibrium electrode potential when current flows through the battery is called electrode polarization) is accompanied by the attenuation of the battery cycle life, resulting in the battery voltage becoming lower and lower after being charged and left to rest. Figure 1 As shown, the battery cycle life reflects the relationship between the battery capacity retention rate and the number of battery charge and discharge cycles. Initially, the battery capacity retention rate is 100%. As the number of battery charge and discharge cycles increases, the battery capacity retention rate gradually decreases along with the attenuation of the battery cycle life. The static voltage after charging reflects the relationship between the voltage of the battery after charging and standing still and the number of battery charge and discharge cycles. Initially, the static voltage of the battery after charging is about 4.1V. As the number of cycles increases, the static voltage of the battery after charging gradually decreases. When the number of cycles is 500, the static voltage of the battery after charging is reduced to about 3.8V. The attenuation of the battery cycle life will also cause the voltage after discharge to become higher and higher, such as Figure 2 As shown, the post-discharge static voltage reflects the relationship between the voltage of the battery after discharge and the number of battery charge and discharge cycles. Initially, the battery post-discharge static voltage is about 3.2V. As the number of cycles increases, the battery post-discharge static voltage gradually increases. When the number of cycles is 500, the battery post-discharge static voltage increases to about 3.6V.

[0048] from Figure 1 and Figure 2 It can be seen that there is a linear relationship between the cycle life of the battery and the voltage change of the battery during the charging and discharging process. The inflection point of the cycle attenuation is basically consistent with the inflection point of the voltage change after charging and discharging. Therefore, the voltage change rate of the battery can be used as a signal for battery management.

[0049] The inventors also found when inventing this application that the decay of the cycle life of the battery is accompanied by an increase in the internal resistance of the battery. Figure 3 As shown, the internal resistance of the battery is linearly related to the attenuation of the cycle life, and the inflection point of the internal resistance change is consistent with the inflection point of the attenuation of the battery cycle life. Therefore, the change rate of the internal resistance of the battery can be used as a signal for battery management.

[0050] Based on the relationship between the change rate of the above-mentioned specified parameters (such as the battery voltage and / or the battery internal resistance) and the cycle life attenuation, the present application uses the change rate of the specified parameters of the battery during N periodic charging or discharging as a battery management signal to manage the battery.

[0051] In order to better understand this application, Figure 4 , the battery management method provided in the embodiment of the present application is described.

[0052] S1: Obtain the rate of change of a specified parameter of the battery during N periodic charging or discharging cycles.

[0053] In the present application, when managing the battery, the voltage change rate of the battery during N periodic charging or discharging of the battery can be regularly obtained, and / or the internal resistance change rate of the battery during N periodic charging or discharging of the battery can be obtained, where N is an integer greater than or equal to 2.

[0054] Considering that too large a value of N will increase the amount of calculation, in one implementation, the value of N is any value between 2 and 50, including endpoints 2 and 50. In a preferred implementation, the value of N is any value between 5 and 20, including endpoints 2 and 20. When the value of N is within the range of 5 to 20, the voltage change rate or the internal resistance change rate is relatively more obvious, and the battery will not undergo irreversible cycle attenuation changes, which can further improve the accuracy.

[0055] S2: adjusting the management strategy of the battery within a preset time period after N periodic charges or discharges according to the change rate of the designated parameter.

[0056] After obtaining the change rate of the specified parameter, the management strategy of the battery within a preset time period after N periodic charges or discharges is adjusted according to the change rate of the specified parameter to improve the battery cycle life and safety.

[0057] The preset time period may refer to the time period from the moment when the battery completes N periodic charges or discharges (recorded as time A) to the moment when the battery completes N periodic charges or discharges next time (recorded as time B). The length of the time period from time A to time B may be set according to management needs.

[0058] In an embodiment of the present application, the rate of change of a specified parameter of the battery during N periodic charges or discharges is used as a signal for battery management. The rate of change of the specified parameter is obtained to adjust the management strategy of the battery within a preset time period after N periodic charges or discharges to improve the battery cycle life and safety, thereby providing a battery management method with simple calculation and high accuracy for managing the battery.

[0059] The following describes how to obtain the rate of change of a specified parameter of a battery during N periodic charging or discharging operations.

[0060] In one embodiment, when the specified parameters include the voltage of a battery, the process of obtaining the rate of change of the specified parameters of the battery may be: periodically obtaining the voltage of the battery after it is charged or discharged to a specified state of charge (SOC) according to a preset current and left to stand for a preset period of time; thereafter, determining the voltage change rate based on the N voltages obtained.

[0061] For a better understanding, an example is given to illustrate that in each cycle, the battery is discharged to a specified state of charge (assuming the first state of charge) at a preset current, such as a constant current of 0.5 to 2C, such as discharging to 10% to 30% SOC, and standing for a preset time, such as standing for 5 to 30 minutes, and then the voltage of the battery when it is discharged to the specified state of charge at the preset current is obtained; the battery is then charged to another specified state of charge (assuming the second state of charge), such as charging to 90% to 100% SOC, and then the voltage of the battery after it is discharged to the specified state of charge at the preset current and standing for a preset time is obtained; the battery is then charged to another specified state of charge, and then the voltage of the battery after it is discharged to the specified state of charge at the preset current and standing for a preset time is obtained; the battery is then charged to another specified state of charge, and then the voltage of the battery after it is discharged to the specified state of charge at the preset current and standing for a preset time is obtained; this is repeated periodically until a specified number of N voltages are obtained, and then the rate of change is calculated based on the obtained N voltages.

[0062] C represents the charge and discharge rate, which is charge and discharge rate = charge and discharge current / rated capacity. Rated capacity test method: After the battery is left at 25°C for 15 minutes, it is charged to 4.45V at a constant current of 0.7C, then charged to 0.05C at a constant voltage of 4.45V, left for 15 minutes, then discharged to 3.0V at a constant current of 0.5C, left for 15 minutes, and the battery discharge capacity is recorded.

[0063] Similarly, for charging, the battery is charged to a specified state of charge (assuming the second state of charge) at a preset current, such as a constant current of 0.5 to 2C, such as charged to 90% to 100% SOC, and left to stand for a preset time, such as 5 to 30 minutes, and the voltage of the battery after being charged to the specified state of charge at the preset current and standing for a preset time is obtained; the battery is then discharged to another specified state of charge (assuming the first state of charge), such as discharged to 10% to 30% SOC, and then the voltage of the battery after being charged to the specified state of charge at the preset current and standing for a preset time is obtained; the battery is then discharged to another specified state of charge, and then the voltage of the battery after being charged to the specified state of charge at the preset current and standing for a preset time is obtained; the battery is then discharged to another specified state of charge, and then the voltage of the battery after being charged to the specified state of charge at the preset current and standing for a preset time is obtained; this process is repeated periodically until a specified number of N voltages are obtained, and then the rate of change is calculated based on the obtained N voltages.

[0064] Among them, the preset current can be any value between 0.5 and 2C, including 0.5C or 2C. The preset duration can be any value between 5 and 30 minutes, including 5 minutes or 30 minutes. After the battery is charged or discharged to a specified state of charge, it is left to stand for a preset time, and then the voltage of the battery is obtained. At this time, the voltage obtained is the voltage after the battery is completely depolarized and stabilized. Preferably, the voltage of the battery is obtained when it is charged or discharged to a specified state of charge and left to stand for 15 minutes.

[0065] When calculating the change rate of the N voltages obtained, the formula (V n -V 1 ) / (N-1) to calculate the voltage change rate. n Indicates the voltage obtained for the Nth time, V 1 Indicates the voltage obtained for the first time. Assuming N is 5, the voltage obtained after the battery is charged or discharged to a specified state of charge according to a preset current and left to rest for a preset time will be obtained five times periodically. The voltages obtained in these five times are respectively represented as V 1 、V 2 、V 3 、V 4 and V 5 .

[0066] In addition to the formula (V n -V 1 ) / (N-1) to calculate the voltage change rate, the voltage change rate of these N voltages can also be calculated based on the least square method.

[0067] It should be noted that if the battery is charged from a first state of charge to a second state of charge according to a preset current, the first state of charge is less than the second state of charge. Conversely, if the battery is discharged from the first state of charge to the second state of charge according to the preset current, the first state of charge is greater than the second state of charge. Therefore, the range of the first state of charge and the second state of charge in the above examples cannot be understood as a limitation of the present application.

[0068] In another embodiment, when the specified parameters include the internal resistance of the battery, the process of obtaining the change rate of the specified parameters of the battery can be: periodically obtaining the internal resistance of the battery when it is charged or discharged according to a preset current; and then determining the internal resistance change rate based on the N internal resistances obtained.

[0069] The process of periodically obtaining the internal resistance of a battery when it is charged or discharged according to a preset current may be: each time the internal resistance of the battery is obtained, the internal resistance of the battery when it is charged or discharged from a first state of charge to a second state of charge according to a preset current may be obtained. For example, the internal resistance of the battery when it is discharged from a fully charged state (100% SOC) to a fully discharged state (0% SOC) according to a preset current (such as 0.5-2C) may be obtained, or the internal resistance of the battery when it is charged from a fully discharged state to a fully discharged state according to a preset current may be obtained.

[0070] In addition, the process of periodically obtaining the internal resistance of the battery when it is charged or discharged according to a preset current can also be: each time the internal resistance of the battery is obtained, the actual curve when the battery is charged or discharged according to a first preset current (such as 0.5-2C) is obtained, and the actual curve represents the corresponding relationship between the residual voltage of the battery and the depth of discharge (Depth Of Discharge, DOD); the first voltage on the actual curve and the second voltage on the preset standard curve at the same specified depth of discharge are obtained; the internal resistance is determined based on the first voltage, the second voltage and the first preset current. Wherein, the preset standard curve is a curve when the battery is charged or discharged according to a second preset current (such as 0.1-0.5C) when polarization does not occur, and the first preset current is greater than the second preset current.

[0071] For a better understanding, the following Figure 5 The schematic diagram showing the corresponding relationship between the remaining voltage of the battery and the depth of discharge is used for explanation. Figure 5 The dotted line in the figure represents the preset standard curve, and the solid line represents the actual curve. x ) The voltage on the two curves, if the specified discharge depth DOD x The first voltage on the actual curve is denoted as V x , the second voltage on the preset standard curve is represented as V cx , and the corresponding internal resistance is represented by R x , then the internal resistance Rx =(V cx -V x ) / first preset current.

[0072] In order to improve data accuracy, each time the internal resistance of the battery is obtained, the first voltage on the actual curve and the second voltage on the preset standard curve are obtained for the same specified discharge depth. And each time the actual curve is obtained, the actual curve when the battery is charged or discharged according to the same first preset current is obtained. This ensures that each time the internal resistance of the battery is obtained, it is obtained under the same conditions, which can reduce the data errors caused by different acquisition conditions.

[0073] As the battery life decays during use, the battery capacity will decrease, making the full charge or full discharge position points corresponding to the preset standard curve and the actual curve different. Figure 5 As shown, for example, for the preset standard curve, the full charge voltage on the vertical coordinate will be greater than the full charge voltage corresponding to the actual curve; the discharge depth on the horizontal coordinate will be greater than the discharge depth corresponding to the actual curve. Therefore, it is necessary to ensure that the selected specified discharge depth is in the overlapping DOD part of the two curves.

[0074] The value range of the specified discharge depth can be determined in the following manner: obtaining a first discharge depth of an actual full charge voltage on a preset standard curve, and obtaining a second discharge depth of an actual full discharge voltage on a preset standard curve; obtaining a capacity ratio of a preset discharge depth on the preset standard curve, wherein the value range of the preset discharge depth is 0% to 100%; and determining the range of the specified discharge depth based on the first discharge depth, the second discharge depth, and the capacity ratio of the preset discharge depth.

[0075] For a better understanding, combine Figure 5 The process of determining the range of values ​​for a given depth of discharge is described. s Indicates the first discharge depth of the actual full charge voltage on the preset standard curve, expressed as DOD e Indicates the second discharge depth of the actual full discharge voltage on the preset standard curve. The remaining battery capacity corresponding to the preset discharge depth x is expressed as capacity x. The capacity ratio of the preset discharge depth x is: capacity x / total capacity. The value range of the specified discharge depth DOD is x =DOD s +(DOD e -DOD s )×capacity x / total capacity. The preset discharge depth x ranges from 0% to 100%. When the preset discharge depth is 0%, capacity x = total capacity, DOD x =DOD e , when the preset discharge depth is 100%, the capacity x = 0, then DODx =DODs. Then the specified discharge depth DOD x The value range is DOD e ~DOD s In a preferred embodiment, the designated discharge depth ranges from 30% to 80% DOD. At this discharge depth, the damage to the battery is minimal, which can better extend the battery life.

[0076] When calculating the change rate of the N internal resistances obtained, the formula (R n -R 1 ) / (N-1) to calculate the internal resistance change rate. n Represents the internal resistance obtained for the Nth time, R 1 Indicates the internal resistance obtained for the first time. Assuming N is 5, the internal resistance of the battery when it is charged or discharged according to the preset current will be obtained five times periodically. The voltages obtained in these five times are respectively represented as R 1 , R 2 , R 3 , R 4 and R 5 .

[0077] In addition to the formula (R n -R 1 ) / (N-1) to calculate the internal resistance change rate, the internal resistance change rate of these N internal resistances can also be calculated based on the least squares method.

[0078] The following describes a process of how to adjust the management strategy of the battery within a preset time period after N periodic charges or discharges according to the change rate of the specified parameter.

[0079] In one implementation, the rate of change of the specified parameter may be compared with a preset threshold, and the battery management strategy may be adjusted according to the comparison result. For example, when the rate of change of the specified parameter is greater than a first preset threshold and less than a second preset threshold, the battery charge and discharge strategy is adjusted, and the second preset threshold is greater than the first preset threshold. When the rate of change of the specified parameter is less than the first preset threshold, the battery charge and discharge strategy is adjusted to remain unchanged, that is, the battery charge and discharge strategy is not adjusted. When the rate of change of the specified parameter is greater than the second preset threshold, an alarm is issued. In addition, while issuing an alarm, the battery charge and discharge strategy may be further adjusted.

[0080] Among them, the first preset threshold and the second preset threshold are both set in advance according to needs. For example, the first preset threshold is the change rate of the specified parameter corresponding to the first specified decay rate when the capacity decay rate of the battery is the first specified decay rate, and the second preset threshold is the change rate of the specified parameter corresponding to the second specified decay rate when the capacity decay rate of the battery is the second specified decay rate. The first specified decay rate is less than the second specified decay rate. For example, when the specified parameter is the voltage of the battery, the first preset threshold is the change rate of the voltage corresponding to the first specified decay rate when the capacity decay rate of the battery is the second specified decay rate, and the second preset threshold is the change rate of the voltage corresponding to the second specified decay rate when the capacity decay rate of the battery is the second specified decay rate. Similarly, when the specified parameter is the internal resistance of the battery, the first preset threshold is the change rate of the internal resistance corresponding to the first specified decay rate when the capacity decay rate of the battery is the second specified decay rate, and the second preset threshold is the change rate of the internal resistance corresponding to the second specified decay rate when the capacity decay rate of the battery is the second specified decay rate.

[0081] Among them, the first specified attenuation rate is preferably any capacity attenuation rate between 5% and 20%. Within this range, the battery does not experience significant irreversible capacity attenuation, and the battery cycle performance is more significantly improved after adjusting the battery's charge and discharge strategy. The second specified attenuation rate is preferably any capacity attenuation rate between 40% and 70%. Within this range, especially when the capacity attenuation rate is 70%, the battery's endurance and power performance are significantly attenuated, the customer experience is poor, and the battery may have interface problems such as lithium plating and purple spots caused by insufficient electrolyte, resulting in safety risks such as thermal runaway.

[0082] It should be noted that the first specified attenuation rate is not limited to any capacity attenuation rate between 5% and 20%, for example, it can be any capacity attenuation rate between 4% and 30%; similarly, the second specified attenuation rate is not limited to any capacity attenuation rate between 40% and 70%, it can be any capacity attenuation rate between 35% and 75%. Therefore, the above preferred capacity attenuation rate cannot be understood as a limitation on the first specified attenuation rate and the second specified attenuation rate.

[0083] Among them, the capacity decay rate and the capacity retention rate are a pair of relative concepts. For example, if the capacity decay rate is 5%, the capacity retention rate is 95%, which means that the battery capacity decays to 95%. Therefore, the first preset threshold value can also be regarded as the change rate of the specified parameter corresponding to the first specified retention rate when the battery capacity retention rate is the first specified retention rate, and the second preset threshold value is the change rate of the specified parameter corresponding to the second specified retention rate when the battery capacity retention rate is the second specified retention rate. The first specified retention rate is greater than the second specified retention rate.

[0084] Among them, the first specified retention rate is preferably any capacity retention rate between 80% and 95%. Within this range, the battery does not experience significant irreversible capacity decay, and the battery cycle performance is more significantly improved after adjusting the battery's charge and discharge strategy. The second specified retention rate is preferably any capacity retention rate between 30% and 60%. Within this range, especially when the capacity retention rate is 30%, the battery's endurance and power performance are significantly attenuated, the experience is poor, and the battery may have interface problems such as lithium plating and purple spots caused by insufficient electrolyte, resulting in safety risks such as thermal runaway.

[0085] The above-mentioned charge and discharge strategy includes at least one of lowering the upper charge limit voltage, lowering the charge current, lowering the discharge current, or increasing the lower discharge limit voltage. When adjusting the charge and discharge strategy of the battery, it can be at least one of lowering the upper charge limit voltage, lowering the charge current, lowering the discharge current, or increasing the lower discharge limit voltage.

[0086] When lowering the upper limit voltage of charging, lowering the charging current, lowering the discharge current, or increasing the lower limit voltage of discharge, the adjustment amount may be increased or decreased by a preset ratio on the original basis, or increased or decreased by a preset fixed size on the existing basis. For example, the preset ratio is 1%. Assuming that the current upper limit voltage of charging is 4.5V, then 4.5V×1%=0.045, then when lowering the upper limit voltage of charging, the upper limit voltage of charging can be lowered to 4.5-0.045=4.455V, and similarly, when increasing the lower limit voltage of discharge, the voltage of the preset ratio may be increased on the existing basis. When lowering the charging current and lowering the discharge current according to the preset ratio, the principle is similar to the principle of lowering the upper limit voltage of charging or increasing the lower limit voltage of discharge according to the preset ratio. Similarly, when adjusting according to the preset fixed size, the principle is similar to adjusting according to the preset ratio. For example, assuming that the current upper limit voltage of charging is 4.5V, assuming that the preset fixed size is 50mV, then when lowering the upper limit voltage of charging, the upper limit voltage of charging can be lowered to 4.5-0.05=4.45V.

[0087] In one implementation, when managing the battery, the capacity decay rate (or capacity retention rate) of the current battery is also taken into account. At this time, the battery management method also includes obtaining the capacity decay rate of the battery; accordingly, the process of adjusting the management strategy of the battery within a preset time period after N periodic charges or discharges according to the change rate of the specified parameter can be: adjusting the management strategy of the battery within a preset time period after N periodic charges or discharges according to the change rate and capacity decay rate of the specified parameter. For example, when the change rate of the specified parameter is greater than the first preset threshold and less than the second preset threshold, the charge and discharge strategy of the battery within the preset time period after N periodic charges or discharges is adjusted according to the capacity decay rate.

[0088] At this time, when lowering the upper limit voltage of charging, lowering the charging current, lowering the discharging current, or increasing the lower limit voltage of discharging, the upper limit voltage of charging, the charging current, the discharging current, or the lower limit voltage of discharging may be lowered according to the relationship between the preset capacity attenuation degree and the adjustment amount that characterizes the battery, wherein different capacity attenuation degrees correspond to different adjustment amounts. The upper limit voltage of charging, the charging current, the discharging current, or the lower limit voltage of discharging may be lowered according to the adjustment amount corresponding to the capacity attenuation rate of the current battery.

[0089] Based on the same inventive concept, the embodiment of the present application also provides a battery management system (BMS), which is connected to the battery and is used to manage the battery. The battery management system is used to receive information from the battery and various external interfaces, analyze and process the information, and issue execution instructions to complete the battery's charging, discharging, protection, balancing, fault detection and fault warning functions to ensure the normal, efficient, reasonable and safe operation of the battery. For example, the battery management system can obtain the rate of change of a specified parameter of the battery during N periodic charging or discharging processes, and adjust the management strategy of the battery within a preset time period after N periodic charging or discharging according to the rate of change of the specified parameter.

[0090] Among them, BMS can be mainly divided into three parts of closed-loop feedback: information collection, information analysis and processing, and output decision execution instructions. For information collection, BMS needs to monitor the status of the battery in real time, so various sensors are needed to collect the battery's voltage, current, temperature and other physical parameters. Information analysis and processing means that after BMS collects relevant information, it needs to analyze and process the information to determine the actions that need to be taken. Output decision execution instructions means that BMS outputs decision execution instructions to the interactive object (such as charging equipment) that interacts with it through the external interactive interface.

[0091] The battery management system may adopt an existing battery management system. For example, for a laptop computer, the battery management system is a battery management system currently used in a laptop computer, and its structure is well known in the art and will not be described here.

[0092] The battery management principle and technical effects provided by the battery management system embodiment are the same as those of the aforementioned method embodiment. For the sake of brief description, for matters not mentioned in the battery management system embodiment, reference may be made to the corresponding contents in the aforementioned method embodiment.

[0093] Based on the same inventive concept, an embodiment of the present application also provides an electronic device, which includes a main body, a battery management system and a battery connected to the battery management system. The battery is used to power the main body; the battery management system is used to execute the above-mentioned battery management principle method to achieve online management of the battery. The electronic device can be a laptop computer, a tablet computer, an electric toy, a smart phone, and the like. Among them, the electric toy can include fixed or mobile electric toys, such as game consoles, electric car toys, electric ship toys, and electric airplane toys, and the like. It can be understood that the electronic device is not limited to this, and can also be an electric device with a power battery, for example, it can be an electric vehicle, such as an electric bicycle, an electric motorcycle, an electric car, and the like.

[0094] The battery management principle and technical effects provided by the electronic device embodiment are the same as those of the aforementioned method embodiment. For the sake of brief description, for matters not mentioned in the electronic device embodiment, reference may be made to the corresponding contents in the aforementioned method embodiment.

[0095] Based on the same inventive concept, the present application also provides a battery management device, such as Figure 6 The battery management device includes: an acquisition unit and a management unit.

[0096] The acquisition unit is used to acquire the change rate of a specified parameter of the battery during N periodic charging or discharging processes, where the specified parameter includes the battery voltage and / or the battery internal resistance, and N is an integer greater than or equal to 2.

[0097] The management unit is used to adjust the management strategy of the battery within a preset time period after N periodic charges or discharges according to the change rate of the specified parameter.

[0098] Optionally, the specified parameters include voltage, and the acquisition unit is specifically used to periodically acquire the voltage of the battery after it is charged or discharged to a specified state of charge according to a preset current and left to stand for a preset period of time; and determine the voltage change rate based on the N voltages acquired.

[0099] The specified parameters include an internal resistance, and an acquisition unit is specifically used to periodically acquire the internal resistance of the battery when it is charged or discharged according to a preset current; and determine the internal resistance change rate according to the acquired N internal resistances.

[0100] The acquisition unit is specifically used to acquire an actual curve when the battery is charged or discharged according to a first preset current each time the internal resistance of the battery is acquired, wherein the actual curve represents the corresponding relationship between the residual voltage of the battery and the discharge depth; acquire a first voltage on the actual curve and a second voltage on a preset standard curve at the same specified discharge depth, wherein the preset standard curve is a curve when the battery is charged or discharged according to a second preset current when no polarization occurs, and the first preset current is greater than the second preset current; and determine the internal resistance based on the first voltage, the second voltage and the first preset current.

[0101] The step of determining the value range of the specified discharge depth includes: obtaining a first discharge depth of an actual full charge voltage on a preset standard curve, and obtaining a second discharge depth of an actual full discharge voltage on a preset standard curve; obtaining a capacity ratio of a preset discharge depth on the preset standard curve, wherein the value range of the preset discharge depth is 0% to 100%; and determining the range of the specified discharge depth based on the first discharge depth, the second discharge depth, and the capacity ratio of the preset discharge depth.

[0102] Optionally, the acquisition unit is further used to acquire the capacity decay rate of the battery; accordingly, the management unit is used to adjust the management strategy of the battery within a preset time period after N periodic charges or discharges according to the change rate of the specified parameters and the capacity decay rate.

[0103] The management unit is specifically used to adjust the charge and discharge strategy of the battery within a preset time period after N periodic charges or discharges when the change rate of the specified parameter is greater than a first preset threshold and less than a second preset threshold, and the second preset threshold is greater than the first preset threshold.

[0104] The battery management device provided in the embodiment of the present application has the same implementation principle and technical effects as those of the aforementioned method embodiment. For the sake of brief description, for matters not mentioned in the device embodiment, reference may be made to the corresponding contents in the aforementioned method embodiment.

[0105] An embodiment of the present application further provides a non-volatile computer-readable storage medium (hereinafter referred to as storage medium), on which a computer program is stored. When the computer program is run by a computer such as the above-mentioned electronic device, the battery management method shown above is executed.

[0106] It should be noted that the various embodiments in this specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the various embodiments can be referenced to each other.

[0107] In several embodiments provided in the present application, it should be understood that the disclosed devices and methods can also be implemented in other ways. The device embodiments described above are merely schematic. For example, the flowcharts and block diagrams in the accompanying drawings show the possible architecture, functions and operations of the devices, methods and computer program products according to multiple embodiments of the present application. In this regard, each box in the flowchart or block diagram can represent a module, a program segment or a part of a code, and the module, a program segment or a part of a code contains one or more executable instructions for implementing the specified logical function. It should also be noted that in some alternative implementations, the functions marked in the box can also occur in a different order from the order marked in the accompanying drawings. For example, two consecutive boxes can actually be executed substantially in parallel, and they can sometimes be executed in the opposite order, depending on the functions involved. It should also be noted that each box in the block diagram and / or flowchart, and the combination of boxes in the block diagram and / or flowchart can be implemented with a dedicated hardware-based system that performs a specified function or action, or can be implemented with a combination of dedicated hardware and computer instructions.

[0108] In addition, the functional modules in the various embodiments of the present application may be integrated together to form an independent part, or each module may exist separately, or two or more modules may be integrated to form an independent part.

[0109] If the functions are implemented in the form of software function modules and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present application can be essentially or partly embodied in the form of a software product that contributes to the prior art. The computer software product is stored in a computer-readable storage medium, including several instructions for enabling a computer device (which can be a personal computer, a laptop, a server, or an electronic device, etc.) to perform all or part of the steps of the methods described in each embodiment of the present application. The aforementioned computer-readable storage medium includes: various media that can store program codes, such as a USB flash drive, a mobile hard disk, a read-only memory (ROM), a random access memory (RAM), a magnetic disk or an optical disk.

[0110] The above is only a specific implementation of the present application, but the protection scope of the present application is not limited thereto. Any technician familiar with the technical field can easily think of changes or substitutions within the technical scope disclosed in the present application, which should be included in the protection scope of the present application. Therefore, the protection scope of the present application should be based on the protection scope of the claims.

Claims

1. A battery management method, It is characterized in that include: Obtaining a change rate of a specified parameter of the battery during N periodic charging or discharging processes, where the specified parameter includes the voltage of the battery and / or the internal resistance of the battery, and N is an integer greater than or equal to 2; adjusting the management strategy of the battery within a preset time period after N periodic charges or discharges according to the change rate of the specified parameter; Wherein, the specified parameter includes voltage, and obtaining the change rate of the specified parameter of the battery includes: Periodically obtaining the voltage of the battery after it is charged or discharged to a specified state of charge according to a preset current and left to rest for a preset period of time; determining the voltage change rate based on the N voltages obtained; The specified parameter includes internal resistance, and obtaining the change rate of the specified parameter of the battery includes: The internal resistance of the battery when it is charged or discharged according to a preset current is periodically obtained; and the internal resistance change rate is determined according to the N internal resistances obtained.

2. The method according to claim 1, It is characterized in that Periodically obtaining the internal resistance of the battery when it is charged or discharged according to a preset current, including: Each time the internal resistance of the battery is obtained, an actual curve of the battery when it is charged or discharged according to a first preset current is obtained, wherein the actual curve represents a corresponding relationship between the residual voltage of the battery and the depth of discharge; Obtaining a first voltage on the actual curve and a second voltage on a preset standard curve at the same specified discharge depth, wherein the preset standard curve is a curve when the battery is charged or discharged according to a second preset current when polarization does not occur, and the first preset current is greater than the second preset current; An internal resistance is determined based on the first voltage, the second voltage, and the first preset current.

3. The method according to claim 2, It is characterized in that The step of determining the value range of the specified discharge depth comprises: Acquire a first discharge depth of an actual full charge voltage on the preset standard curve, and acquire a second discharge depth of an actual full discharge voltage on the preset standard curve; Obtaining a capacity ratio of a preset discharge depth on the preset standard curve, wherein the preset discharge depth has a value range of 0% to 100%; The range of the designated discharge depth is determined based on the capacity ratio of the first discharge depth, the second discharge depth, and the preset discharge depth.

4. The method according to claim 1, It is characterized in that The method further comprises: Obtain the capacity attenuation rate of the battery; accordingly, Adjusting the management strategy of the battery within a preset time period after N periodic charges or discharges according to the change rate of the specified parameter includes: The management strategy of the battery within a preset time period after N periodic charges or discharges is adjusted according to the change rate of the specified parameter and the capacity decay rate.

5. The method according to claim 1, It is characterized in that Adjusting the management strategy of the battery within a preset time period after N periodic charges or discharges according to the change rate of the specified parameter includes: When the change rate of the specified parameter is greater than a first preset threshold and less than a second preset threshold, the charge and discharge strategy of the battery within a preset time period after N periodic charges or discharges is adjusted, and the second preset threshold is greater than the first preset threshold.

6. The method according to claim 5, It is characterized in that The first preset threshold is the change rate of the specified parameter corresponding to when the capacity decay rate of the battery is a first specified decay rate, and the second preset threshold is the change rate of the specified parameter corresponding to when the capacity decay rate of the battery is a second specified decay rate, and the first specified decay rate is less than the second specified decay rate.

7. The method according to claim 6, It is characterized in that The first specified attenuation rate is any capacity attenuation rate between 5% and 20%, and the second specified attenuation rate is any capacity attenuation rate between 40% and 70%.

8. The method according to claim 5, It is characterized in that The charge and discharge strategy includes at least one of lowering the upper charge limit voltage, lowering the charge current, lowering the discharge current, or increasing the lower discharge limit voltage.

9. The method according to claim 7, It is characterized in that When lowering the upper limit charging voltage, lowering the charging current, lowering the discharge current, or increasing the lower limit discharge voltage, the upper limit charging voltage, lowering the charging current, lowering the discharge current, or increasing the lower limit discharge voltage is lowered according to a preset relationship between the capacity attenuation degree and the adjustment amount that characterizes the battery, wherein different capacity attenuation degrees correspond to different adjustment amounts.

10. The method according to any one of claims 1 to 9, It is characterized in that N is an integer less than or equal to 50.

11. A battery management device, It is characterized in that include: an acquisition unit, used to acquire a change rate of a specified parameter of the battery during N periodic charging or discharging processes, wherein the specified parameter includes the voltage of the battery and / or the internal resistance of the battery, and N is an integer greater than or equal to 2; A management unit, configured to adjust a management strategy of the battery within a preset time period after N periodic charges or discharges according to a change rate of the specified parameter; The specified parameter includes a voltage, and the acquisition unit is used to: periodically acquire the voltage of the battery after it is charged or discharged to a specified state of charge according to a preset current and left to stand for a preset period of time; determine the voltage change rate according to the N voltages acquired; The specified parameters include internal resistance, an acquisition unit, and are used to: The internal resistance of the battery when it is charged or discharged according to a preset current is periodically obtained; and the internal resistance change rate is determined according to the N internal resistances obtained.

12. A battery management system, It is characterized in that Connected to a battery, the battery management system is used to execute the battery management method according to any one of claims 1 to 10.

13. An electronic device, It is characterized in that include: A main body, a battery management system and a battery connected to the battery management system; The battery is used to supply power to the body; The battery management system is used to execute the battery management method according to any one of claims 1 to 10.

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