Working condition adjusting method and device of power battery, readable storage medium and vehicle

Abstract

The invention relates to the technical field of new energy, in particular to a working condition adjustment method and device of a power battery, a readable storage medium and a vehicle, and aims to solve the problems of how to perform working condition optimization on the power battery in a more targeted manner so as to effectively delay aging of the power battery and prolong the service life of the power battery. In order to achieve the purpose, the power battery meeting the working condition adjusting condition is determined according to historical state data of the power battery, relaxation time distribution of the power battery is further obtained, the dominant failure mode of the power battery is determined according to the relaxation time distribution, and the matched use working condition of the power battery is determined according to the dominant failure mode. Therefore, the working condition of the power battery is adjusted according to the matched use working condition, targeted working condition adjustment of the power battery in different attenuation states can be realized, so that the problem of aging of the power battery is delayed more effectively, the service life of the power battery is prolonged effectively, and the use experience of a user is improved.

Description

Technical Field

[0001] The present invention relates to the field of new energy technologies, and specifically provides a method and device for adjusting the operating condition of a power battery, a readable storage medium, and a vehicle. Background Art

[0002] The capacity of the power battery of an electric vehicle will decay during use as the cycle and calendar life increase. When it drops to a certain value of the initial capacity, the battery capacity will drop significantly. It is generally believed that the battery should be recycled before the capacity drops. The life cycle of the battery is greatly affected by the environment and operating conditions (such as fast charging capacity, number of fast charging, operating temperature, etc.), and various physical and chemical changes will lead to irreversible capacity loss. Capacity loss will limit the service life of the battery and may reduce the operating reliability of the battery in the operating conditions. Under some special operating conditions and abuse conditions, battery aging may cause serious failures and safety problems. The charge and discharge cycle of the battery will exert mechanical stress on the electrode, resulting in particle rupture, reduced electrode porosity, and loss of connectivity of the active material. Combined with the electrochemical side reactions between the electrode and the dielectric, such as the formation and thickening of the solid electrolyte interface (SEI) layer, the battery capacity gradually decreases.

[0003] The historical operating conditions of power batteries will lead to different aging modes. In most practical applications, power batteries are only charged and discharged in a partial SOC (State of Charge) range rather than in the entire SOC (0%-100%) range. The battery will undergo different electrochemical processes in different cycle intervals, which will cause different mechanisms of capacity decay on the positive and negative electrodes. At the same time, inappropriate operating conditions, such as multiple consecutive fast charges, low-temperature fast charges, etc., will also accelerate battery decay. Therefore, after the battery has experienced a long period of decay, adjusting the battery's operating range and charging mode can effectively extend the battery life.

[0004] In the prior art, after the power battery decays to a certain SOH (State of Health), the battery pack is indiscriminately adjusted for charge and discharge depth and fast charge power is limited, without providing different usage conditions optimization for different battery decay paths, so it cannot effectively alleviate the battery aging problem. In fact, usage conditions that do not match the decay mechanism may accelerate the decay of the battery.

[0005] Therefore, the art needs a new power battery operating condition adjustment solution to solve the above problems. Summary of the invention

[0006] In order to overcome the above-mentioned defects, the present invention is proposed to provide a solution or at least partially solve the problem of how to optimize the operating conditions of the power battery in a more targeted manner to effectively delay the aging of the power battery and extend the service life of the power battery.

[0007] In a first aspect, the present invention provides a method for adjusting an operating condition of a power battery, the method comprising:

[0008] Determining whether the power battery meets a preset operating condition adjustment condition according to the historical status data of the power battery;

[0009] When the power battery meets the operating condition adjustment condition, obtaining the relaxation time distribution of the power battery according to the historical state data;

[0010] Determining a dominant failure mode of the power battery according to the relaxation time distribution;

[0011] According to the dominant failure mode, a matching use condition of the power battery is determined, and the operating condition of the power battery is adjusted according to the matching use condition.

[0012] In a technical solution of the above-mentioned method for adjusting the working condition of the power battery, determining the dominant failure mode of the power battery according to the relaxation time distribution includes:

[0013] comparing the relaxation time distribution with an initial relaxation time distribution of the power battery;

[0014] According to the comparison result, obtaining the change amplitude of the polarization impedance peak at each relaxation time;

[0015] The dominant failure mode of the power battery is determined according to the variation amplitude.

[0016] In a technical solution of the above-mentioned method for adjusting the working condition of the power battery, the polarization impedance peak includes a first polarization impedance peak, a second polarization impedance peak, a third polarization impedance peak and a fourth polarization impedance peak;

[0017] Determining the dominant failure mode of the power battery according to the variation amplitude includes:

[0018] Different dominant failure modes of the power battery are determined according to combinations of different variation amplitudes of the first polarization impedance peak, the second polarization impedance peak, the third polarization impedance peak, and the fourth polarization impedance peak.

[0019] In a technical solution of the above-mentioned method for adjusting the working condition of the power battery, the dominant failure mode includes a first aging model, a second aging mode and a third aging mode;

[0020] Determining different dominant failure modes of the power battery according to combinations of different change amplitudes of the first polarization impedance peak, the second polarization impedance peak, the third polarization impedance peak, and the fourth polarization impedance peak includes:

[0021] When only the change amplitude of the fourth polarization impedance peak is increasing, and the increase amplitude is greater than a preset amplitude threshold, determining that the dominant failure mode of the power battery is the first aging mode;

[0022] When the change amplitudes of the third polarization impedance peak and the fourth polarization impedance peak increase simultaneously, and the increase amplitudes are both greater than the amplitude threshold, it is determined that the dominant failure mode of the power battery is the second aging mode;

[0023] When the change amplitudes of the first polarization impedance peak, the second polarization impedance peak, and the third polarization impedance peak increase simultaneously, and the increase amplitudes are all greater than the amplitude threshold, it is determined that the dominant failure mode of the power battery is the third aging mode;

[0024] The determining, according to the dominant failure mode, the matching use condition of the power battery includes:

[0025] When the dominant failure mode is the first aging mode, determining the matching use condition to be the first use condition;

[0026] When the dominant failure mode is the second aging mode, determining the matching use condition to be the second use condition;

[0027] When the dominant failure mode is the third aging mode, the matching usage condition is determined to be the third usage condition.

[0028] In a technical solution of the above-mentioned method for adjusting the working condition of the power battery, the step of determining the matching working condition of the power battery according to the dominant failure mode includes:

[0029] Establishing a corresponding relationship between the dominant failure mode and the matching use condition;

[0030] Based on the corresponding relationship, a matching operating condition corresponding to the dominant failure mode is determined.

[0031] In a technical solution of the above-mentioned method for adjusting the working condition of the power battery, the working condition parameters corresponding to the matching use working condition include the state of charge working range and / or charging working condition parameters of the power battery;

[0032] The charging condition parameters include maximum charging current and / or high current charging time and / or charging temperature; and / or,

[0033] The historical status data includes impedance spectrum test data of the power battery.

[0034] In a technical solution of the above-mentioned method for adjusting the working condition of the power battery, the step of obtaining the relaxation time distribution of the power battery according to the historical state data includes:

[0035] Acquire the full life cycle impedance spectrum of the power battery according to the historical status data;

[0036] The relaxation time distribution of the power battery is obtained according to the full life cycle impedance spectrum.

[0037] In a technical solution of the above-mentioned method for adjusting the working condition of the power battery, determining whether the power battery meets the preset working condition adjustment condition according to the historical state data of the power battery includes:

[0038] Acquiring a battery health status of the power battery according to the historical status data of the power battery;

[0039] When the battery health status is less than a preset status threshold, it is determined that the power battery meets the operating condition adjustment condition.

[0040] In a technical solution of the above-mentioned method for adjusting the working condition of the power battery, the historical status data includes the current value and / or voltage value of the power battery in the charging and discharging state, and / or the current value and / or voltage value of the power battery in the static state.

[0041] In a second aspect, a control device is provided, which includes at least one processor and at least one storage device, wherein the storage device is suitable for storing multiple program codes, and the program codes are suitable for being loaded and run by the processor to execute the method for adjusting the operating condition of a power battery described in any one of the technical solutions of the above-mentioned method for adjusting the operating condition of the power battery.

[0042] In a third aspect, a computer-readable storage medium is provided, which stores a plurality of program codes, wherein the program codes are suitable for being loaded and run by a processor to execute the method for adjusting the operating condition of a power battery described in any one of the technical solutions of the above-mentioned method for adjusting the operating condition of a power battery.

[0043] The above one or more technical solutions of the present invention have at least one or more of the following Beneficial effects:

[0044] In the technical solution of the present invention, the present invention determines a power battery that meets the working condition adjustment conditions according to the historical state data of the power battery, further obtains the relaxation time distribution of the power battery according to the historical state data of the power battery, determines the dominant failure mode of the power battery according to the relaxation time distribution, and determines the matching use condition of the power battery according to the dominant failure mode, so as to adjust the working condition of the power battery according to the matching use condition. Through the above configuration, the present invention determines the dominant failure mode of the power battery based on its relaxation time distribution for the power battery that needs to be adjusted in working condition, and can determine the different dominant failure modes corresponding to power batteries in different attenuation states. And based on the dominant failure mode, the matching use condition of the power battery is determined, and the working condition of the power battery is adjusted according to the matching use condition, which can achieve more targeted optimization of the use condition of power batteries in different attenuation states, and can effectively ensure that the optimized use condition is more matched with the attenuation state of the power battery, thereby more effectively delaying the problem of power battery aging, effectively improving the service life of the power battery, and thus improving the user experience.

[0045] Solution 1. A method for adjusting the operating condition of a power battery, characterized in that the method comprises:

[0046] Determining whether the power battery meets a preset operating condition adjustment condition according to the historical status data of the power battery;

[0047] When the power battery meets the operating condition adjustment condition, obtaining the relaxation time distribution of the power battery according to the historical state data;

[0048] Determining a dominant failure mode of the power battery according to the relaxation time distribution;

[0049] According to the dominant failure mode, a matching use condition of the power battery is determined, and the operating condition of the power battery is adjusted according to the matching use condition.

[0050] Solution 2. The method for adjusting the operating condition of a power battery according to Solution 1 is characterized in that:

[0051] Determining the dominant failure mode of the power battery according to the relaxation time distribution includes:

[0052] comparing the relaxation time distribution with an initial relaxation time distribution of the power battery;

[0053] According to the comparison result, obtaining the change amplitude of the polarization impedance peak at each relaxation time;

[0054] The dominant failure mode of the power battery is determined according to the variation amplitude.

[0055] Solution 3. The method for adjusting the operating condition of a power battery according to Solution 2, characterized in that the polarization impedance peak includes a first polarization impedance peak, a second polarization impedance peak, a third polarization impedance peak and a fourth polarization impedance peak;

[0056] Determining the dominant failure mode of the power battery according to the variation amplitude includes:

[0057] Different dominant failure modes of the power battery are determined according to combinations of different variation amplitudes of the first polarization impedance peak, the second polarization impedance peak, the third polarization impedance peak, and the fourth polarization impedance peak.

[0058] Solution 4. The method for adjusting the operating condition of a power battery according to Solution 3, characterized in that the dominant failure mode includes a first aging model, a second aging mode and a third aging mode;

[0059] Determining different dominant failure modes of the power battery according to combinations of different change amplitudes of the first polarization impedance peak, the second polarization impedance peak, the third polarization impedance peak, and the fourth polarization impedance peak includes:

[0060] When only the change amplitude of the fourth polarization impedance peak is increasing, and the increase amplitude is greater than a preset amplitude threshold, determining that the dominant failure mode of the power battery is the first aging mode;

[0061] When the change amplitudes of the third polarization impedance peak and the fourth polarization impedance peak increase simultaneously, and the increase amplitudes are both greater than the amplitude threshold, it is determined that the dominant failure mode of the power battery is the second aging mode;

[0062] When the change amplitudes of the first polarization impedance peak, the second polarization impedance peak, and the third polarization impedance peak increase simultaneously, and the increase amplitudes are all greater than the amplitude threshold, it is determined that the dominant failure mode of the power battery is the third aging mode;

[0063] The determining, according to the dominant failure mode, the matching use condition of the power battery includes:

[0064] When the dominant failure mode is the first aging mode, determining the matching use condition to be the first use condition;

[0065] When the dominant failure mode is the second aging mode, determining the matching use condition to be the second use condition;

[0066] When the dominant failure mode is the third aging mode, the matching usage condition is determined to be the third usage condition.

[0067] Solution 5. The method for adjusting the operating condition of a power battery according to Solution 1 is characterized in that:

[0068] The determining, according to the dominant failure mode, the matching use condition of the power battery includes:

[0069] Establishing a corresponding relationship between the dominant failure mode and the matching use condition;

[0070] Based on the corresponding relationship, a matching operating condition corresponding to the dominant failure mode is determined.

[0071] Solution 6. The method for adjusting the operating condition of a power battery according to any one of Solutions 1 to 5, characterized in that the operating condition parameters corresponding to the matching use condition include the state of charge operating range and / or charging condition parameters of the power battery;

[0072] The charging condition parameters include maximum charging current and / or high current charging time and / or charging temperature; and / or,

[0073] The historical status data includes impedance spectrum test data of the power battery.

[0074] Solution 7. The method for adjusting the operating condition of a power battery according to Solution 1 is characterized in that:

[0075] The obtaining the relaxation time distribution of the power battery according to the historical state data includes:

[0076] Acquire the full life cycle impedance spectrum of the power battery according to the historical status data;

[0077] The relaxation time distribution of the power battery is obtained according to the full life cycle impedance spectrum.

[0078] Solution 8. The method for adjusting the operating condition of a power battery according to Solution 1 is characterized in that:

[0079] The determining, based on the historical status data of the power battery, whether the power battery meets a preset operating condition adjustment condition includes:

[0080] Acquiring a battery health status of the power battery according to the historical status data of the power battery;

[0081] When the battery health status is less than a preset status threshold, it is determined that the power battery meets the operating condition adjustment condition.

[0082] Solution 9. The method for adjusting the operating condition of a power battery according to Solution 8 is characterized in that the historical status data includes the current value and / or voltage value of the power battery in a charging and discharging state, and / or the current value and / or voltage value of the power battery in a static state.

[0083] Scheme 10. A control device comprising at least one processor and at least one storage device, wherein the storage device is suitable for storing multiple program codes, and is characterized in that the program codes are suitable for being loaded and run by the processor to execute the operating condition adjustment method of the power battery described in any one of Schemes 1 to 9.

[0084] Solution 11. A computer-readable storage medium storing a plurality of program codes, characterized in that the program codes are suitable for being loaded and run by a processor to execute the method for adjusting the operating condition of a power battery described in any one of Solutions 1 to 9.

[0085] Solution 12. A vehicle, characterized in that the vehicle includes a power battery and the control device described in Solution 10. BRIEF DESCRIPTION OF THE DRAWINGS

[0086] The disclosure of the present invention will become more easily understood with reference to the accompanying drawings. It is easy for those skilled in the art to understand that these drawings are only for illustrative purposes and are not intended to limit the scope of protection of the present invention. Among them:

[0087] Figure 1 is a flow chart of main steps of a method for adjusting the working condition of a power battery according to an embodiment of the present invention;

[0088] Figure 2 is a schematic flow chart of main steps of a method for adjusting the operating condition of a power battery according to an implementation of an embodiment of the present invention;

[0089] Figure 3 is a distribution schematic diagram corresponding to a relaxation time distribution according to an example of the present invention;

[0090] Figure 4 The flowchart of the main steps of establishing the corresponding relationship between the dominant failure mode and the matching use condition is an example according to the present invention;

[0091] Figure 5 is a schematic diagram showing a comparison result of a relaxation time distribution of a power battery according to an example of the present invention and a distribution schematic diagram corresponding to an initial relaxation time distribution;

[0092] Figure 6 It is a schematic diagram of the corresponding capacities of a power battery according to an example of the present invention when the operating condition is adjusted according to matching operating conditions and when the capacity is not adjusted. DETAILED DESCRIPTION

[0093] Some embodiments of the present invention are described below with reference to the accompanying drawings. It should be understood by those skilled in the art that these embodiments are only used to explain the technical principles of the present invention and are not intended to limit the protection scope of the present invention.

[0094] In the description of the present invention, "module" and "processor" may include hardware, software or a combination of the two. A module may include hardware circuits, various suitable sensors, communication ports, and memories, and may also include software parts, such as program codes, or a combination of software and hardware. The processor may be a central processing unit, a microprocessor, an image processor, a digital signal processor, or any other suitable processor. The processor has data and / or signal processing functions. The processor may be implemented in software, hardware, or a combination of the two. Non-temporary computer-readable storage media include any suitable medium that can store program codes, such as a magnetic disk, a hard disk, an optical disk, a flash memory, a read-only memory, a random access memory, and the like. The term "A and / or B" means all possible combinations of A and B, such as only A, only B, or A and B. The term "at least one A or B" or "at least one of A and B" has a similar meaning to "A and / or B", and may include only A, only B, or A and B. The singular terms "one" and "the" may also include plural forms.

[0095] See attached Figure 1 , Figure 1 FIG. 1 is a flow chart of the main steps of a method for adjusting the working condition of a power battery according to an embodiment of the present invention. Figure 1 As shown, the method for adjusting the working condition of a power battery in the embodiment of the present invention mainly includes the following steps S101 to S104.

[0096] Step S101: determining whether the power battery meets a preset operating condition adjustment condition according to the historical status data of the power battery.

[0097] In this embodiment, it is possible to determine whether the power battery meets the preset operating condition adjustment condition based on the historical status data of the power battery.

[0098] In one implementation, the operating condition adjustment condition may be that the battery state of health (SOH) of the power battery is less than a preset state threshold.

[0099] In one embodiment, the battery health state of the power battery can be calculated based on the historical status data of the power battery. When the battery health state is less than the status threshold, it can be determined that the power battery meets the operating condition adjustment condition. Those skilled in the art can set the status threshold according to the needs of the actual application. For example, it can be set to any value between 70% and 90%.

[0100] In one implementation, the historical status data may include current values ​​and voltage values ​​of the power battery in a charging and discharging state, current values ​​and voltage values ​​of the power battery in a stationary state, and the like.

[0101] In one implementation, a full life cycle database of the power battery may be established in the cloud, historical status data of the power battery may be obtained from the full life cycle database, and the SOH of the power battery may be calculated in the cloud.

[0102] Step S102: when the power battery meets the operating condition adjustment condition, the relaxation time distribution of the power battery is obtained according to the historical state data.

[0103] In this embodiment, if the power battery meets the working condition adjustment conditions, it means that the power battery is attenuated, and the relaxation time distribution of the power battery can be obtained according to its historical state data. Among them, the relaxation time distribution refers to the distribution data obtained by decomposing the electrochemical impedance spectrum using the relaxation time distribution technology (DRT, Distribution of Relaxation Time). The relaxation time distribution technology is a technology for objectively analyzing the time domain information presented in the electrochemical impedance by digitization.

[0104] In one embodiment, the full life cycle impedance spectrum of the power battery can be obtained based on the historical status data of the power battery, and the relaxation time distribution of the power battery can be obtained based on the full life cycle impedance spectrum. As shown in formula (1), the relaxation time distribution can be obtained by integrating the relaxation time function.

[0105]

[0106] Among them, R P is the polarization impedance, γ(τ) is the relaxation time function, and τ is the relaxation time.

[0107] In one embodiment, the historical status data includes impedance spectrum test data of the power battery. The impedance spectrum test data can be impedance spectrum data measured in the battery swap station, or impedance spectrum data reconstructed based on current, voltage and other data in the cloud. Among them, the impedance spectrum test is a non-destructive test that connects the system to a signal source to explore the interaction characteristics between the battery, dielectric and circuit, and conduct a detailed analysis of them.

[0108] Step S103: Determine the dominant failure mode of the power battery according to the relaxation time distribution.

[0109] In this embodiment, the dominant failure mode of the battery can be determined according to the relaxation time distribution, that is, the dominant failure mode causing the power battery attenuation can be determined according to the distribution of the relaxation time distribution of the power battery.

[0110] In one embodiment, the relaxation time distribution includes multiple polarization impedance peaks, and the dominant failure mode of the power battery can be determined according to the distribution of the multiple polarization impedance peaks. The polarization impedance peak refers to the peak value corresponding to the relaxation time in the relaxation time distribution.

[0111] Step S104: determining the matching use condition of the power battery according to the dominant failure mode, and adjusting the working condition of the power battery according to the matching use condition.

[0112] In this embodiment, the matching use condition of the power battery can be determined according to the dominant failure mode, so that the operating condition of the power battery can be adjusted according to the matching use condition.

[0113] In one embodiment, the operating condition parameters corresponding to the matching use condition may include the state of charge operating range and charging condition parameters of the power battery; the charging condition parameters may include parameters such as maximum charging current, high current charging time and charging temperature. When adjusting the operating condition of the power battery according to the matching use condition, one or a combination of the above operating condition parameters may be adjusted.

[0114] In one implementation, the operating condition of the power battery may be adjusted by a power battery management system (BMS) based on matching usage conditions.

[0115] Based on the above steps S101-S104, the embodiment of the present invention determines the power battery that meets the working condition adjustment conditions according to the historical state data of the power battery, further obtains the relaxation time distribution of the power battery according to the historical state data of the power battery, determines the dominant failure mode of the power battery according to the relaxation time distribution, and determines the matching use condition of the power battery according to the dominant failure mode, so as to adjust the working condition of the power battery according to the matching use condition. Through the above configuration, the embodiment of the present invention determines the dominant failure mode of the power battery based on its relaxation time distribution for the power battery that needs to be adjusted in working condition, and can determine the different dominant failure modes corresponding to power batteries in different attenuation states. And based on the dominant failure mode, the matching use condition of the power battery is determined, and the working condition of the power battery is adjusted according to the matching use condition, so as to achieve more targeted optimization of the use condition of the power battery in different attenuation states, and can effectively ensure that the optimized use condition is more matched with the attenuation state of the power battery, so as to more effectively delay the problem of power battery aging, effectively improve the service life of the power battery, and then improve the user experience.

[0116] Step S103 and step S104 are further described below.

[0117] In one implementation of the embodiment of the present invention, step S103 may further include the following steps S1031 to S1033:

[0118] Step S1031: Compare the relaxation time distribution with the initial relaxation time distribution of the power battery.

[0119] In this embodiment, the current relaxation time distribution of the power battery may be compared with its initial relaxation time distribution.

[0120] In one embodiment, the initial relaxation time distribution may be a relaxation time distribution of a fresh cell of the power battery in a BOL (Beginning of Life) state.

[0121] Step S1032: According to the comparison result, the variation amplitude of the polarization impedance peak at each relaxation time is obtained.

[0122] In this embodiment, the variation amplitude of the polarization impedance peak at each relaxation time can be determined according to the comparison result, that is, each polarization impedance peak of the current relaxation time distribution is compared with the corresponding polarization impedance peak of the initial relaxation time distribution to obtain the variation amplitude of each polarization impedance peak.

[0123] Step S1033: Determine the dominant failure mode of the power battery according to the variation range.

[0124] In this embodiment, the dominant failure mode of the power battery can be determined according to the variation amplitude, that is, the dominant failure mode of the power battery can be determined according to the variation amplitude of different polarization impedance peaks.

[0125] In one embodiment, the polarization impedance peak may include a first polarization impedance peak, a second polarization impedance peak, a third polarization impedance peak, and a fourth polarization impedance peak. Step S1033 may further include the following steps S10331 to S10333:

[0126] Step S10331: When only the change amplitude of the fourth polarization impedance peak increases, and the increase amplitude is greater than a preset amplitude threshold, it is determined that the dominant failure mode of the power battery is the first aging mode.

[0127] Step S10332: When the change amplitudes of the third polarization impedance peak and the fourth polarization impedance peak increase simultaneously, and the increase amplitudes are both greater than the amplitude threshold, it is determined that the dominant failure mode of the power battery is the second aging mode.

[0128] Step S10333: When the change amplitudes of the first polarization impedance peak, the second polarization impedance peak, and the third polarization impedance peak increase simultaneously, and the increase amplitudes are all greater than the amplitude threshold, it is determined that the dominant failure mode of the power battery is the third aging mode.

[0129] Furthermore, step S104 may further include:

[0130] Step S1041: When the dominant failure mode is the first aging mode, determining the matching usage condition to be the first usage condition.

[0131] Step S1042: When the dominant failure mode is the second aging mode, determining that the matching usage condition is the second usage condition.

[0132] Step S1043: When the dominant failure mode is the third aging mode, determining that the matching usage condition is the third usage condition.

[0133] In this implementation, the matching use conditions corresponding to different dominant failure modes can be determined.

[0134] In one embodiment, the first operating condition, the second operating condition, and the third operating condition may be a combination of a state of charge operating range and a charging operating condition parameter. The state of charge operating range may be selected from any range of 0-100% according to actual needs, and the range width may be greater than or equal to 70%. The charging operating condition parameter may include one or a combination of the maximum charging current, the maximum current charging time limit, and the charging temperature.

[0135] For example, the first operating condition includes a first state of charge operating range and a first charging condition parameter;

[0136] The second operating condition includes a second state of charge operating range and a second charging condition parameter;

[0137] The third operating condition includes a third state of charge operating range and a third charging condition parameter.

[0138] Among them, the first state of charge working range, the second state of charge working range and the third state of charge working range may have the same situation; the first charging condition parameters, the second charging condition parameters and the third charging condition parameters may also have the same situation; but the first usage condition, the second usage condition and the third usage condition respectively composed of them are different.

[0139] It should be noted that the present application not only includes the above-mentioned three aging modes and the three judgment conditions corresponding to the above-mentioned first to fourth polarization impedance peaks and each aging mode, but also includes combinations of other change amplitudes of the first polarization impedance peak, the second polarization impedance peak, the third polarization impedance peak and the fourth polarization impedance peak. These combinations of change amplitudes may also have corresponding aging modes that are considered to be the dominant failure mode of the power battery.

[0140] As an example: when the fourth polarization impedance peak increases by the first amplitude, and the third polarization impedance peak increases by the second amplitude, it can correspond to the fourth aging mode. That is to say, there are multiple different combination modes of change amplitudes for the first to fourth polarization impedance peaks mentioned above: the change amplitude not only includes the situation where one of the polarization impedance peaks increases, but also the situation where one of the polarization impedance peaks decreases; the threshold condition for judgment is not a single threshold; it can also be that the change of a certain polarization impedance peak exceeds multiple levels of different thresholds, which will also correspond to different aging modes; it can also be that the second polarization impedance peak and the fourth polarization impedance peak in the aforementioned steps produce super-threshold changes. The above-mentioned combinations of different types of change amplitudes, different thresholds, and different objects may all correspond to different aging modes.

[0141] The key is: the division of different aging modes is based on better matching operating conditions. Therefore, when a certain operating condition is suitable for a combination of amplitude changes of a certain polarization impedance peak to produce a better match, effectively extending the service life of the power battery, it can be identified as a specific aging mode and the operating condition can be defined as the corresponding matching operating condition.

[0142] Therefore, the present application can determine different dominant failure modes of the power battery according to the combination of different change amplitudes of the first polarization impedance peak, the second polarization impedance peak, the third polarization impedance peak and the fourth polarization impedance peak.

[0143] It should also be noted that the number of polarization impedance peaks in the relaxation time distribution is not limited to the above four. There may be more polarization impedance peaks, such as five or six. Different dominant failure modes of the power battery can be determined based on the different changes and trends of more polarization impedance peaks.

[0144] Please refer to the attached Figure 3 , Figure 3 Schematic diagram of the distribution of relaxation time corresponding to an example of the present invention. Figure 3 A typical relaxation time distribution diagram of a power battery is given in Figure 3 As shown, P1 is the first polarization impedance peak, P2 is the second polarization impedance peak, P3 is the third polarization impedance peak, and P4 is the fourth polarization impedance peak. Among them, P0 is the high-frequency end information, which is greatly affected by the measurement method, and therefore is not used as a parameter to determine the dominant failure mode.

[0145] In one embodiment, the relaxation time distribution of the power battery can be obtained multiple times, and the relaxation time distributions obtained multiple times can be compared with the initial relaxation time distribution of the power battery to obtain the overall change trend of each polarization impedance peak of the power battery. This overall change trend is used as the change amplitude of the polarization impedance peak to determine the dominant failure mode of the power battery.

[0146] In one implementation of the embodiment of the present invention, step S104 may further include the following steps S1041 and S1042:

[0147] Step S1041: Establishing a correspondence between the dominant failure mode and the matching operating condition.

[0148] In this embodiment, a characteristic operating condition table can be established, power batteries with different dominant failure modes can be combined with different operating conditions, and aging experiments can be carried out to obtain matching operating conditions corresponding to different dominant failure modes, thereby establishing a corresponding relationship between the dominant failure modes and the matching operating conditions.

[0149] In one embodiment, please refer to the attached Figure 4 , Figure 4 The figure is a flowchart of the main steps of establishing the correspondence between the dominant failure mode and the matching use condition according to the present invention. The working conditions of the power batteries with different dominant failure modes can be combined to obtain the combined characteristics, which include the optimized working range (0-90%, 5-95%, 10-100%), the optimized charging conditions (charging condition 1, charging condition 2, charging condition 3, ...) and the typical aging characteristics of batteries with different aging modes. The different combined characteristics are subjected to aging experiments to obtain the matching use conditions of the battery after experiencing different aging modes.

[0150] Step S1042: Based on the corresponding relationship, determine the matching operating condition corresponding to the dominant failure mode.

[0151] In this embodiment, the matching use condition corresponding to the current dominant failure mode of the power battery can be determined according to the corresponding relationship. For example, the corresponding relationship between the dominant failure mode and the matching use condition can be a corresponding relationship table, and the matching use condition corresponding to the dominant failure mode can be obtained by looking up the table.

[0152] It should be pointed out that due to the differences in the types of cell materials, cell structure types, and even the cell assembly methods in power batteries, the same state of charge working range and charging condition parameters have different effects on power batteries. Therefore, the establishment of characteristic condition tables (corresponding relationship tables) and operating conditions is based on the same power battery.

[0153] In one embodiment, see the attached Figure 2 , Figure 2 FIG. 1 is a flow chart of the main steps of a method for adjusting the operating condition of a power battery according to an embodiment of the present invention. Figure 2 As shown, the method for adjusting the working condition of the power battery may include the following steps S201 to S208:

[0154] Step S201: Obtain historical status data of the power battery monitored by the cloud.

[0155] In this embodiment, the historical status data of the power battery can be obtained from the cloud.

[0156] Step S202: Determine whether the battery cell has reached the SOH threshold that needs to be adjusted; if so, jump to step S203; if not, jump to step S208.

[0157] In this embodiment, the method described in step S202 is similar to the aforementioned step S101, and for the sake of simplicity, it will not be repeated here.

[0158] Step S203: Failure mode recognition algorithm.

[0159] In this implementation, a failure mode recognition algorithm may be applied to calculate the dominant failure mode of the power battery.

[0160] Step S204: Classify battery failure modes.

[0161] In this embodiment, the dominant failure modes of the power battery may be classified according to the calculation results of the failure mode identification algorithm.

[0162] Step S205: Experimentally establish a failure mode-optimal operating condition table.

[0163] In this implementation, a correspondence table between dominant failure modes and optimal operating conditions (matching operating conditions) may be established through experiments.

[0164] Step S206: Look up a table to obtain the best adjustment conditions for the battery cells under different failure modes.

[0165] In this implementation, the optimal adjustment conditions corresponding to different dominant failure modes can be determined by searching the corresponding relationship table.

[0166] Step S207: Adaptive battery operating condition adjustment.

[0167] In this embodiment, adaptive battery operating condition adjustment can be achieved according to the optimal adjustment operating condition.

[0168] Step S208: No battery adjustment is required.

[0169] In this embodiment, when the SOH threshold is not reached, there is no need to adjust the battery operating condition.

[0170] In one example, for a 125Ah ternary lithium battery, a correspondence table between the dominant failure mode of the power battery and the matching use condition is constructed through a large number of aging experiments. As shown in Table 1, when the dominant failure mode of the power battery is the first aging mode, the corresponding matching use condition is the first use condition, that is, the state of charge working range is 10%-90%, the charging condition parameters are limited to a maximum charging rate of 2C, and the fast charging temperature is 15-40°C; when the dominant failure mode of the power battery is the second aging mode, the corresponding matching use condition is the second use condition, that is, the state of charge working range is 5%-85%, the charging condition parameters are limited to a maximum charging rate of 1.5C, and the fast charging temperature is 15-40°C; when the dominant failure mode of the power battery is the third aging mode, the corresponding matching use condition is the third use condition, that is, the state of charge working range is 0%-80%, the charging condition parameters are limited to a maximum charging rate of 1C, and the fast charging temperature is 20-35°C.

[0171] Table 1 Correspondence between dominant failure modes and matching operating conditions

[0172] Two 125Ah ternary lithium batteries (marked as C1 and C2) of the same model and batch were subjected to aging experiments under the same conditions. In order to simulate the actual vehicle working conditions to accelerate the aging of the battery cells, the high-rate and pulse discharge and fast charging processes were increased, and a 5000N preload force was applied during the test. The capacity was calibrated every 100 turns, and its impedance spectrum was measured. Among them, the impedance spectrum was measured by applying a 3.5mV voltage disturbance with a frequency of 2000Hz to 0.01Hz. The obtained impedance spectrum was converted to a relaxation time distribution to obtain a DRT curve (relaxation time distribution).

[0173] Please refer to the attached Figure 5 , Figure 5 FIG. 1 is a schematic diagram showing a comparison result of a relaxation time distribution of a power battery according to an example of the present invention and a distribution schematic diagram corresponding to an initial relaxation time distribution. Figure 5 As shown, the two cells experience the same cycling conditions and therefore have the same aging pattern. Figure 5 The comparison of DRT curves before and after C1 aging is shown in Figure 1. It can be seen that the P4 peak increases significantly, while other peaks remain unchanged. Corresponding to the first aging mode in Table 1, the corresponding matching operating conditions are obtained by looking up the table: the SOC working range is adjusted to 10-90%, the maximum charging rate should be limited to 2C, and the fast charging temperature is higher than 15-40℃.

[0174] Please refer to the attached Figure 6 , Figure 6The figure is a schematic diagram of the corresponding capacity of a power battery according to an example of the present invention when the operating condition is adjusted according to the matching operating condition and when the capacity is not adjusted. The operating condition of C1 is adjusted to the matching operating condition corresponding to the first aging mode. At the same time, in order to verify that the battery cycle life is effectively improved after the operating condition is adjusted, the SOC operating range of the C2 battery is adjusted to 15-95% (the same range width as C1), and the charging condition is not restricted. Figure 6 As shown, after the working condition is adjusted in a targeted manner, the attenuation of C1 is better alleviated than that of C2. This proves that the working condition adjustment method of the power battery of the present invention can effectively delay the aging of the power battery and extend the service life of the power battery.

[0175] It should be pointed out that although the various steps in the above embodiments are described in a specific order, those skilled in the art can understand that in order to achieve the effects of the present invention, different steps do not have to be performed in such an order. They can be performed simultaneously (in parallel) or in other orders. These changes are within the scope of protection of the present invention.

[0176] It is understood by those skilled in the art that the present invention implements all or part of the processes in the method of the above embodiment, and can also be completed by instructing the relevant hardware through a computer program, and the computer program can be stored in a computer-readable storage medium, and the computer program can implement the steps of the above-mentioned various method embodiments when executed by the processor. Among them, the computer program includes computer program code, and the computer program code can be in source code form, object code form, executable file or some intermediate form. The computer-readable storage medium may include: any entity or device, medium, U disk, mobile hard disk, disk, optical disk, computer memory, read-only memory, random access memory, electric carrier signal, telecommunication signal and software distribution medium that can carry the computer program code. It should be noted that the content contained in the computer-readable storage medium can be appropriately increased or decreased according to the requirements of legislation and patent practice in the jurisdiction. For example, in some jurisdictions, according to legislation and patent practice, computer-readable storage media do not include electric carrier signals and telecommunication signals.

[0177] Furthermore, the present invention also provides a control device. In an embodiment of a control device according to the present invention, the control device includes a processor and a storage device, the storage device can be configured to store a program for executing the method for adjusting the working condition of the power battery of the above method embodiment, and the processor can be configured to execute the program in the storage device, which includes but is not limited to the program for executing the method for adjusting the working condition of the power battery of the above method embodiment. For ease of explanation, only the parts related to the embodiment of the present invention are shown. For specific technical details not disclosed, please refer to the method part of the embodiment of the present invention. The control device can be a control device device formed by various electronic devices.

[0178] In the embodiment of the present invention, the control device may be a control device device formed by various electronic devices. In some possible implementations, the control device may include multiple storage devices and multiple processors. The program for executing the operating condition adjustment method of the power battery of the above method embodiment can be divided into multiple subprograms, and each subprogram can be loaded and run by the processor to execute different steps of the operating condition adjustment method of the power battery of the above method embodiment. Specifically, each subprogram can be stored in different storage devices, and each processor can be configured to execute the program in one or more storage devices to jointly implement the operating condition adjustment method of the power battery of the above method embodiment, that is, each processor executes different steps of the operating condition adjustment method of the power battery of the above method embodiment, to jointly implement the operating condition adjustment method of the power battery of the above method embodiment.

[0179] The above-mentioned multiple processors may be processors deployed on the same device. For example, the above-mentioned control device may be a high-performance device composed of multiple processors, and the above-mentioned multiple processors may be processors configured on the high-performance device. In addition, the above-mentioned multiple processors may also be processors deployed on different devices. For example, the above-mentioned control device may be a server cluster, and the above-mentioned multiple processors may be processors on different servers in the server cluster.

[0180] Furthermore, the present invention also provides a computer-readable storage medium. In a computer-readable storage medium embodiment according to the present invention, the computer-readable storage medium may be configured to store a program for executing the operating condition adjustment method of the power battery of the above-mentioned method embodiment, and the program may be loaded and run by the processor to implement the above-mentioned operating condition adjustment method of the power battery. For ease of explanation, only the parts related to the embodiment of the present invention are shown. For specific technical details not disclosed, please refer to the method part of the embodiment of the present invention. The computer-readable storage medium may be a storage device formed by various electronic devices. Optionally, the computer-readable storage medium in the embodiment of the present invention is a non-temporary computer-readable storage medium.

[0181] Furthermore, the present invention also provides a vehicle. In one embodiment of a vehicle according to the present invention, the vehicle includes a power battery and the control device in the above control device embodiment.

[0182] Further, it should be understood that since the setting of each module is only for illustrating the functional units of the device of the present invention, the physical devices corresponding to these modules may be the processor itself, or a part of the software in the processor, a part of the hardware, or a part of the combination of software and hardware. Therefore, the number of each module in the figure is only schematic.

[0183] It is understood by those skilled in the art that the modules in the device can be adaptively split or merged. Such splitting or merging of specific modules will not cause the technical solution to deviate from the principle of the present invention, and therefore, the technical solutions after splitting or merging will fall within the protection scope of the present invention.

[0184] The relevant user personal information that may be involved in the various embodiments of this application is strictly in accordance with the requirements of laws and regulations, following the principles of legality, legitimacy and necessity, based on the reasonable purposes of business scenarios, to process the personal information that users actively provide during the use of products / services or generated due to the use of products / services, as well as the personal information obtained with the user's authorization.

[0185] The user personal information processed by the applicant will vary depending on the specific product / service scenario, and shall be based on the specific scenario in which the user uses the product / service, which may involve the user's account information, device information, driving information, vehicle information or other related information. The applicant will treat the user's personal information and its processing with a high degree of diligence.

[0186] The Applicant attaches great importance to the security of user personal information and has adopted reasonable and feasible security protection measures that comply with industry standards to protect user information and prevent personal information from being accessed, disclosed, used, modified, damaged or lost without authorization.

[0187] So far, the technical solutions of the present invention have been described in conjunction with the preferred embodiments shown in the accompanying drawings. However, it is easy for those skilled in the art to understand that the protection scope of the present invention is obviously not limited to these specific embodiments. Without departing from the principle of the present invention, those skilled in the art can make equivalent changes or substitutions to the relevant technical features, and the technical solutions after these changes or substitutions will fall within the protection scope of the present invention.

Claims

1. A method for adjusting the working condition of a power battery, characterized in that: The method comprises: Determining whether the power battery meets a preset operating condition adjustment condition according to the historical status data of the power battery; When the power battery meets the operating condition adjustment condition, obtaining the relaxation time distribution of the power battery according to the historical state data; Determining a dominant failure mode of the power battery according to the relaxation time distribution; According to the dominant failure mode, a matching use condition of the power battery is determined, and the operating condition of the power battery is adjusted according to the matching use condition.

2. The method for adjusting the operating condition of a power battery according to claim 1, characterized in that: Determining the dominant failure mode of the power battery according to the relaxation time distribution includes: comparing the relaxation time distribution with an initial relaxation time distribution of the power battery; According to the comparison result, obtaining the change amplitude of the polarization impedance peak at each relaxation time; The dominant failure mode of the power battery is determined according to the variation amplitude.

3. The method for adjusting the operating condition of a power battery according to claim 2, characterized in that: The polarization impedance peaks include a first polarization impedance peak, a second polarization impedance peak, a third polarization impedance peak and a fourth polarization impedance peak; Determining the dominant failure mode of the power battery according to the variation amplitude includes: Different dominant failure modes of the power battery are determined according to combinations of different variation amplitudes of the first polarization impedance peak, the second polarization impedance peak, the third polarization impedance peak, and the fourth polarization impedance peak.

4. The method for adjusting the operating condition of a power battery according to claim 3, characterized in that: The dominant failure modes include a first aging model, a second aging model, and a third aging model; Determining different dominant failure modes of the power battery according to combinations of different change amplitudes of the first polarization impedance peak, the second polarization impedance peak, the third polarization impedance peak, and the fourth polarization impedance peak includes: When only the change amplitude of the fourth polarization impedance peak is increasing, and the increase amplitude is greater than a preset amplitude threshold, determining that the dominant failure mode of the power battery is the first aging mode; When the change amplitudes of the third polarization impedance peak and the fourth polarization impedance peak increase simultaneously, and the increase amplitudes are both greater than the amplitude threshold, it is determined that the dominant failure mode of the power battery is the second aging mode; When the change amplitudes of the first polarization impedance peak, the second polarization impedance peak, and the third polarization impedance peak increase simultaneously, and the increase amplitudes are all greater than the amplitude threshold, it is determined that the dominant failure mode of the power battery is the third aging mode; The determining, according to the dominant failure mode, the matching use condition of the power battery includes: When the dominant failure mode is the first aging mode, determining the matching use condition to be the first use condition; When the dominant failure mode is the second aging mode, determining the matching use condition to be the second use condition; When the dominant failure mode is the third aging mode, the matching usage condition is determined to be the third usage condition.

5. The method for adjusting the operating condition of a power battery according to claim 1, characterized in that: The determining, according to the dominant failure mode, the matching use condition of the power battery includes: Establishing a corresponding relationship between the dominant failure mode and the matching use condition; Based on the corresponding relationship, a matching operating condition corresponding to the dominant failure mode is determined.

6. The method for adjusting the operating condition of a power battery according to any one of claims 1 to 5, characterized in that: The operating condition parameters corresponding to the matching use operating condition include the state of charge working range and / or charging operating condition parameters of the power battery; The charging condition parameters include maximum charging current and / or high current charging time and / or charging temperature; and / or, The historical status data includes impedance spectrum test data of the power battery.

7. The method for adjusting the operating condition of a power battery according to claim 1, characterized in that: The obtaining the relaxation time distribution of the power battery according to the historical state data includes: Acquire the full life cycle impedance spectrum of the power battery according to the historical status data; The relaxation time distribution of the power battery is obtained according to the full life cycle impedance spectrum.

8. The method for adjusting the operating condition of a power battery according to claim 1, characterized in that: The determining, based on the historical status data of the power battery, whether the power battery meets a preset operating condition adjustment condition includes: Acquiring a battery health status of the power battery according to the historical status data of the power battery; When the battery health state is less than a preset state threshold, it is determined that the power battery meets the operating condition adjustment condition.

9. The method for adjusting the operating condition of a power battery according to claim 8, characterized in that: The historical status data includes the current value and / or voltage value of the power battery in a charging and discharging state, and / or the current value and / or voltage value of the power battery in a stationary state.

10. A control device, comprising at least one processor and at least one storage device, wherein the storage device is suitable for storing a plurality of program codes, characterized in that: The program code is suitable for being loaded and run by the processor to execute the operating condition adjustment method of the power battery according to any one of claims 1 to 9.

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