Battery evaluation method and device and vehicle

Abstract

The invention relates to a battery evaluation method and device and a vehicle, relates to the technical field of power batteries, and at least solves the technical problem that a battery evaluation result is not accurate enough in the prior art. The method comprises the following steps: acquiring the running state and the charging and discharging information of a battery, and determining the capacity fading information of the battery based on the running state and the charging and discharging information of the battery; based on the capacity attenuation information, determining a charging and discharging evaluation result of the battery; therefore, the evaluation result of the battery can be more accurate.

Description

Technical Field

[0001] The present application relates to the technical field of power batteries, and in particular to a battery evaluation method, device and vehicle. Background Art

[0002] With the vigorous development of vehicle technology, electric vehicles powered by power batteries have gradually become popular. Electric vehicles are vehicles that use an onboard power source as a power source and use a motor to drive the wheels. During the use of electric vehicles, the capacity of the power battery will decay. By obtaining the capacity decay of the power battery, the power battery can be evaluated.

[0003] One prior art provides a method for predicting the remaining life of a lithium battery, through which a life prediction model is constructed according to the type of battery cell, and the battery evaluation result is obtained based on the life prediction model, the number of charge and discharge cycles, environmental parameters and operating parameters. Another prior art provides a quantitative battery life attenuation prediction method based on a mixed integer programming model, which establishes a nonlinear life model and obtains a mixed integer linear programming model by linearizing it successively through a multivariate Taylor expansion, then calculates the Euclidean distance, and obtains the battery evaluation result based on the battery power.

[0004] However, the battery evaluation results obtained by the above method are not accurate enough. Therefore, a new method is needed to evaluate power batteries. Summary of the invention

[0005] The present application provides a battery evaluation method, device and vehicle to at least solve the technical problem that the battery evaluation results in the related art are not accurate enough.

[0006] According to the first aspect provided by the present application, the technical solution of the present application is applied to a battery evaluation device. The battery evaluation method includes: obtaining the operating state of the battery and the charge and discharge information of the battery. Based on the operating state of the battery and the charge and discharge information, determining the capacity decay information of the battery. Based on the capacity decay information, determining the charge and discharge evaluation result of the battery.

[0007] In a possible implementation, based on the operating state and the charge and discharge information, determining the capacity decay information of the battery includes: determining a capacity decay rate based on the operating state and the charge and discharge information, the capacity decay rate being used to indicate the amount of change of the capacity decay information over time. Based on the capacity decay rate, determining the capacity decay information of the battery.

[0008] In a possible implementation, the operating state includes: battery temperature and battery current. Based on the operating state and charge and discharge information, the capacity decay rate is determined, including: obtaining a first capacity decay influence factor of the battery temperature, a second capacity decay influence factor of the battery current, and a third capacity decay influence factor of the charge and discharge information, the first capacity decay influence factor is used to indicate the degree of influence of the battery temperature on the ability of the battery to store and release electrical energy, the second capacity decay influence factor is used to indicate the degree of influence of the battery current on the ability of the battery to store and release electrical energy, and the third capacity decay influence factor is used to indicate the degree of influence of the charge and discharge information on the ability of the battery to store and release electrical energy. Based on the battery temperature, battery current, charge and discharge information, the first capacity decay influence factor, the second capacity decay influence factor, and the third capacity decay influence factor, the capacity decay rate is determined.

[0009] In a possible implementation, the capacity decay rate is determined based on the battery temperature, the battery current, the charge and discharge information, the first capacity decay influence factor, the second capacity decay influence factor and the third capacity decay influence factor, including: processing the battery current and the second capacity decay influence factor based on the ampere-hour integration method to obtain an ampere-hour integral decay value, and the ampere-hour integral decay value is used to indicate the current charged or discharged by the battery. The battery temperature and the first capacity decay influence factor are calculated to obtain a temperature decay value, and the temperature decay value is used to indicate the decay rate of the battery at the battery temperature. Based on the temperature decay value, the ampere-hour integral decay value, the charge and discharge information and the third capacity decay influence factor, the capacity decay rate is determined.

[0010] In a possible implementation, the number of operating states is at least one. Based on the capacity decay rate corresponding to each operating state, the capacity decay information of the battery is determined, including: obtaining the operating period of each operating state in the target period. For each operating state, based on the capacity decay rate corresponding to the operating state and the operating period corresponding to the operating state, the battery decay information corresponding to the operating state is determined to obtain the battery decay information of each operating state. Based on the battery decay information corresponding to each operating state, the capacity decay information of the battery is determined.

[0011] In a possible implementation, the target time period includes at least one operating period, one operating period corresponds to one operating state, and different operating periods correspond to different operating states.

[0012] In a possible implementation, based on the capacity decay rate corresponding to the operating state and the operating period corresponding to the operating state, determining the battery decay information corresponding to the operating state includes: obtaining the initial capacity of the battery. Based on each capacity decay rate and the operating period, determining the decay ratio corresponding to each operating state. Based on the decay ratio corresponding to each operating state and the initial capacity of the battery corresponding to each operating state, determining the battery decay information corresponding to each operating state.

[0013] In a possible implementation, based on the capacity decay information, determining the evaluation result of the battery includes: if the capacity decay information is greater than a preset capacity decay threshold, determining that the evaluation result of the battery is unqualified, where the preset capacity decay threshold is the decay threshold of the battery in the target period. If the capacity decay information is less than the preset capacity decay threshold, determining that the evaluation result of the battery is qualified.

[0014] In a possible implementation, the battery evaluation method further includes: when the evaluation result of the battery is qualified, determining the attenuation level of the battery based on the capacity attenuation information and a preset attenuation level threshold, the battery attenuation levels include a first level, a second level and a third level, the performance of a first level battery is higher than that of a second level battery, and the performance of a second level battery is higher than that of a third level battery.

[0015] In a possible implementation, the battery evaluation method further includes: if the evaluation result of the battery is unqualified, determining the capacity decay rate corresponding to the target state based on the capacity decay rate corresponding to each operating state, and the capacity decay rate corresponding to the target state is greater than a preset state threshold.

[0016] According to a second aspect provided by the present application, a battery evaluation device is provided, the device comprising an acquisition module and a processing module. The acquisition module is used to acquire the operating state of the battery and the charge and discharge information of the battery. The processing module is used to determine the capacity decay information of the battery based on the operating state and the charge and discharge information of the battery. The processing module is also used to determine the charge and discharge evaluation result of the battery based on the capacity decay information.

[0017] In a possible implementation, the processing module is used to determine the capacity decay rate based on the operating state and the charge and discharge information, and the capacity decay rate is used to indicate the amount of change of the capacity decay information over time. The processing module is also used to determine the capacity decay information of the battery based on the capacity decay rate.

[0018] In a possible implementation, the operating state includes: battery temperature and battery current. An acquisition module is used for a first capacity decay influence factor of battery temperature, a second capacity decay influence factor of battery current, and a third capacity decay influence factor of charge and discharge information. The first capacity decay influence factor is used to indicate the degree of influence of battery temperature on the ability of the battery to store and release electrical energy, the second capacity decay influence factor is used to indicate the degree of influence of battery current on the ability of the battery to store and release electrical energy, and the third capacity decay influence factor is used to indicate the degree of influence of charge and discharge information on the ability of the battery to store and release electrical energy. A processing module is used to determine the capacity decay rate based on battery temperature, battery current, charge and discharge information, the first capacity decay influence factor, the second capacity decay influence factor, and the third capacity decay influence factor.

[0019] In a possible implementation, the processing module is used to process the battery current and the second capacity decay influence factor based on the ampere-hour integration method to obtain an ampere-hour integral decay value, and the ampere-hour integral decay value is used to indicate the current charged or discharged by the battery. The processing module is also used to calculate the battery temperature and the first capacity decay influence factor to obtain a temperature decay value, and the temperature decay value is used to indicate the decay rate of the battery at the battery temperature. The processing module is also used to determine the capacity decay rate based on the temperature decay value, the ampere-hour integral decay value, the charge and discharge information, and the third capacity decay influence factor.

[0020] In a possible implementation, the number of operating states is at least one. The acquisition module is used to acquire the operating period of each operating state in the target period. The processing module is used to determine the battery attenuation information corresponding to each operating state based on the capacity decay rate corresponding to the operating state and the operating period corresponding to the operating state, so as to acquire the battery attenuation information of each operating state. The processing module is also used to determine the capacity attenuation information of the battery based on the battery attenuation information corresponding to each operating state.

[0021] In a possible implementation, the target time period includes at least one operating period, one operating period corresponds to one operating state, and different operating periods correspond to different operating states.

[0022] In a possible implementation, the acquisition module is used to acquire the initial capacity of the battery. The processing module is used to determine the attenuation ratio corresponding to each operating state based on each capacity decay rate and operating period. The processing module is also used to determine the battery attenuation information corresponding to each operating state based on the attenuation ratio corresponding to each operating state and the initial capacity of the battery corresponding to each operating state.

[0023] In a possible implementation, the processing module is used to determine that the evaluation result of the battery is unqualified if the capacity decay information is greater than a preset capacity decay threshold, and the preset capacity decay threshold is the decay threshold of the battery in the target period. The processing module is also used to determine that the evaluation result of the battery is qualified if the capacity decay information is less than the preset capacity decay threshold.

[0024] In a possible implementation, the processing module is used to determine the attenuation level of the battery based on capacity attenuation information and a preset attenuation level threshold when the evaluation result of the battery is qualified, the attenuation levels of the battery include a first level, a second level and a third level, the performance of a first level battery is higher than that of a second level battery, and the performance of a second level battery is higher than that of a third level battery.

[0025] In one possible implementation, the processing module is used to determine the capacity decay rate corresponding to the target state based on the capacity decay rate corresponding to each operating state if the evaluation result of the battery is unqualified, and the capacity decay rate corresponding to the target state is greater than a preset state threshold.

[0026] According to a third aspect provided by the present application, a battery evaluation device is provided, comprising: a processor; a memory for storing processor executable instructions; wherein the processor is configured to execute instructions to implement a method as in the first aspect and any possible implementation manner thereof.

[0027] According to a fourth aspect provided by the present application, a vehicle is provided, the vehicle comprising a battery evaluation device as described in the second aspect, and the vehicle is used to implement a method as described in the first aspect and any possible implementation manner thereof.

[0028] According to the fifth aspect provided by the present application, a computer-readable storage medium is provided. When the instructions in the computer-readable storage medium are executed by the processor of a battery evaluation device, the battery evaluation device is enabled to execute the method of the first aspect and any possible implementation manner thereof.

[0029] According to a sixth aspect provided by the present application, a computer program product is provided, the computer program product comprising computer instructions, when the computer instructions are executed on a battery evaluation device, the battery evaluation device implements the method of the first aspect and any possible implementation manner thereof.

[0030] Beneficial effects of the present invention: (1) By obtaining the operating status of each time period in each target time period and the charge and discharge information corresponding to each operating status, the battery evaluation results obtained under different operating conditions can be made more accurate.

[0031] (2) By determining the battery evaluation result by presetting the capacity decay threshold, a clear and objective standard can be obtained. In this way, the quality of the result can be judged more intuitively.

[0032] (3) The capacity decay information of the battery can be determined through the operating status and charge and discharge information of the battery. Afterwards, the charge and discharge evaluation results of the battery can be determined based on the capacity decay information, thereby evaluating the capacity decay of the battery. Traditional methods usually evaluate the capacity decay of the battery by calculating the number of effective charge and discharge times that the battery can complete under specific conditions, or by estimating the health status of the battery by recording the actual mileage of the vehicle or equipment, and then evaluating the capacity decay of the battery. However, the traditional method does not consider the impact of the operating status and charge and discharge information of the battery on the battery capacity decay. This scheme can more fully evaluate the capacity decay of the vehicle battery by considering the impact of the battery operating status of the power battery during the charge and discharge process on the capacity decay information, so that the evaluation results obtained are more accurate, and thus the performance of the vehicle battery can be better evaluated.

[0033] (4) The capacity decay rate can directly reflect the capacity change of the battery from the initial state to the current state. The battery decay information obtained through the capacity decay rate can make the battery aging degree more intuitive. Since the current rate is directly related to the chemical reaction rate inside the battery, the capacity decay rate is obtained by the ampere-hour integral decay value, which can more accurately reflect the actual state of the battery during use, thereby improving the accuracy of the capacity decay rate.

[0034] (5) Through at least one operating state of the battery, the battery attenuation information corresponding to each operating state can be obtained, and the battery capacity attenuation information can be obtained to more accurately evaluate the battery performance of the vehicle under different temperatures and currents.

[0035] (6) The capacity decay rate can be determined based on the operating status and the charge and discharge information. The capacity decay rate is used to indicate the amount of change in the capacity decay information over time. Then, the capacity decay information of the battery can be determined based on the capacity decay rate. Since the capacity decay rate is related to the performance state of the battery, by obtaining the amount of change in the capacity decay information over time, the current performance state of the battery can be accurately evaluated.

[0036] (7) The capacity decay value can directly reflect the battery's ability to store and release electrical energy, and can intuitively reflect the battery's health status. By regularly measuring the battery's capacity decay value, the changing trend of the battery's performance can be obtained, abnormal declines in battery performance can be discovered in time, and corresponding maintenance can be performed.

[0037] (8) By classifying the battery capacity decay information into levels, the results can be made more intuitive and easy to understand.

[0038] (9) By determining the capacity decay rate corresponding to the target state in the unqualified battery, the environment in which the battery capacity decays fastest can be determined, so that the battery environment can be adjusted to reduce the battery capacity decay rate and thereby increase the battery life.

[0039] It should be noted that the technical effects brought about by any implementation method in the second to sixth aspects can refer to the technical effects brought about by the corresponding implementation method in the first aspect, and will not be repeated here.

[0040] It should be understood that the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] The drawings herein are incorporated into the specification and constitute a part of the specification, illustrate embodiments consistent with the present application, and together with the specification are used to explain the principles of the present application, and do not constitute an improper limitation on the present application.

[0042] Figure 1 is a flowchart of a battery evaluation method according to an exemplary embodiment; Figure 2 is a flow chart of another battery evaluation method according to an exemplary embodiment; Figure 3 is a flow chart of another battery evaluation method according to an exemplary embodiment; Figure 4 is a schematic structural diagram of a battery evaluation device according to an exemplary embodiment; Figure 5 It is a schematic structural diagram of another battery evaluation device according to an exemplary embodiment. DETAILED DESCRIPTION

[0043] In order to enable ordinary persons in the art to better understand the technical solution of the present application, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the accompanying drawings.

[0044] It should be noted that the terms "first", "second", etc. in the specification and claims of the present application and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchangeable where appropriate, so that the embodiments of the present application described herein can be implemented in an order other than those illustrated or described herein. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with the present application. On the contrary, they are merely examples of devices and methods consistent with some aspects of the present application as detailed in the attached claims.

[0045] At present, the batteries of new energy vehicles can not only provide vehicle driving power and power supply for high and low voltage electrical appliances, but also discharge to the outside in different scenarios. For example, the vehicle's mobile power station (vehicle to load, V2L) function can convert the power stored in the vehicle battery into household AC power through the on-board inverter and discharge it to the outside. The vehicle's vehicle-to-grid (vehicle to grid, V2G) function can release the power in the battery back to the grid.

[0046] When the vehicle is in vehicle to everything (V2X) mode, it will affect the performance of the battery and increase the degree of battery aging. Therefore, the battery needs to be evaluated.

[0047] Some methods can evaluate the battery through the battery cycle life calculation model and evaluate the battery capacity through the battery cycle charge and discharge depth (DOD). Some methods can evaluate the battery through the electric vehicle (EV) battery capacity degradation model. This method sets the temperature and charge and discharge rate to fixed values, and evaluates the battery capacity through the battery cycle charge and discharge depth and charge and discharge times. However, both methods do not consider the impact of temperature changes and current rate changes during the charge and discharge process of the battery, making the battery evaluation results inaccurate.

[0048] Therefore, a new method is needed to evaluate the battery so that the battery evaluation results are more accurate.

[0049] In order to solve the above problems, the present application provides a battery evaluation method, which includes: the capacity decay information of the battery can be determined through the operating state and charge and discharge information of the battery. Afterwards, the charge and discharge evaluation result of the battery can be determined based on the capacity decay information, so as to evaluate the capacity decay of the battery. Traditional methods usually evaluate the capacity decay of the battery by calculating the number of effective charge and discharge times that the battery can complete under specific conditions, or by estimating the health status of the battery by recording the actual mileage of the vehicle or equipment, and then evaluating the capacity decay of the battery. However, the traditional method does not consider the impact of the operating state of the battery and the charge and discharge information on the battery capacity decay. This solution can more fully evaluate the capacity decay of the vehicle battery by considering the impact of the battery operating state of the power battery during the charge and discharge process on the capacity decay information, so that the obtained evaluation results are more accurate, and thus the performance of the vehicle battery can be better evaluated.

[0050] For ease of understanding, the battery evaluation method provided in this application is specifically introduced below with reference to the accompanying drawings.

[0051] Figure 1is a flowchart of a battery evaluation method according to an exemplary embodiment. Figure 1 As shown, the battery evaluation method includes: S101, obtaining the operating status of the battery and the charging and discharging information of the battery.

[0052] In a possible design, the operating state of the battery includes at least one of the following: battery temperature and battery current. The charge and discharge information of the battery includes at least one of the following: battery discharge depth and battery charge and discharge rate.

[0053] In a possible implementation, the operating state of the battery in each operating period in the target time period and the charging and discharging information of the battery corresponding to each operating state may be obtained.

[0054] Optionally, the target time period includes at least one operating time period, and one operating time period corresponds to one operating state. Different operating time periods correspond to different operating states.

[0055] Exemplarily, the target period is 8 hours, and the target period includes operation period 1, operation period 2, and operation period 3. Operation period 1 is 2 hours, operation period 2 is 4 hours, and operation period 3 is 2 hours. The battery temperature corresponding to operation period 1 is 30 degrees Celsius, and the battery current corresponding to operation period 1 is 13 amperes (A); the battery temperature corresponding to operation period 2 is 35 degrees Celsius, and the battery current corresponding to operation period 1 is 15A; the battery temperature corresponding to operation period 1 is 40 degrees Celsius, and the battery current corresponding to operation period 1 is 15A.

[0056] It should be noted that the target period may be the duration of the vehicle's V2X mode. This application does not limit the target period. For example, the target period may be 1 hour, 8 hours, 12 hours, 24 hours, or 48 hours.

[0057] It can be understood that by obtaining the operating state of each time period in each target time period and the charge and discharge information corresponding to each operating state, the battery evaluation results obtained under different operating states can be made more accurate.

[0058] S102: Determine the capacity attenuation information of the battery based on the operating status and charge and discharge information of the battery.

[0059] The capacity decay information may be a capacity decay value of the battery and / or a capacity decay ratio of the battery.

[0060] For example, the initial capacity is 24 ampere-hours (Ah), and the capacity decay value is 3.6 Ah. For another example, the initial capacity is 24 Ah, and the capacity decay ratio is 0.15.

[0061] In a possible implementation, the battery attenuation information corresponding to each operating state can be determined based on at least one operating state and the charge and discharge information corresponding to each operating state. Then, the capacity attenuation information of the battery can be obtained based on the battery attenuation information corresponding to each operating state, and the capacity attenuation information is the sum of the battery attenuation information corresponding to all operating states.

[0062] Exemplarily, the battery attenuation information 1 is 0.01, the battery attenuation information 2 is 0.05, and the battery attenuation information 3 is 0.02, and the capacity attenuation information is 0.08.

[0063] Optionally, the at least one operating state includes an initial operating state and at least one updated operating state of the battery.

[0064] In one possible design, it is possible to determine whether the operating state of the battery has changed based on the initial operating state. If the operating state of the battery has changed, the operating time period corresponding to the initial operating state is obtained to obtain the battery attenuation information corresponding to the initial operating state. Afterwards, the updated operating state of the battery can be obtained. And based on the updated operating state of the battery, it is determined whether the operating state of the battery has changed. If the operating state of the battery has changed, the operating time period corresponding to the updated operating state of the battery is obtained to obtain the battery attenuation information corresponding to the updated operating state of the battery, until the battery attenuation information corresponding to all operating states in the target time period is obtained.

[0065] S103: Determine a charge and discharge evaluation result of the battery based on the capacity decay information.

[0066] In a possible implementation, the charge and discharge evaluation result of the battery may be determined based on the capacity decay information and a preset capacity decay threshold.

[0067] Optionally, if the capacity decay information is greater than a preset capacity decay threshold, the charge and discharge evaluation result of the battery is determined to be unqualified, and the preset capacity decay threshold is the decay threshold of the battery in the target period. If the capacity decay information is less than the preset capacity decay threshold, the charge and discharge evaluation result of the battery is determined to be qualified.

[0068] It should be noted that the present application does not limit the preset capacity decay threshold. For example, the preset capacity decay threshold may be 0.2, 0.25, 0.3, 0.35 or 0.4.

[0069] It is understandable that by determining the evaluation result of the battery by presetting the capacity decay threshold, a clear and objective standard can be obtained, so that the quality of the result can be judged more intuitively.

[0070] Based on the above technical solution, the capacity decay information of the battery can be determined through the operating status and charge and discharge information of the battery. Afterwards, the charge and discharge evaluation results of the battery can be determined based on the capacity decay information, so as to evaluate the capacity decay of the battery. Traditional methods usually evaluate the capacity decay of the battery by calculating the number of effective charge and discharge times that the battery can complete under specific conditions, or by estimating the health status of the battery by recording the actual mileage of the vehicle or equipment, and then evaluating the capacity decay of the battery. However, the traditional method does not consider the impact of the operating status and charge and discharge information of the battery on the battery capacity decay. This solution can more fully evaluate the capacity decay of the vehicle battery by considering the impact of the battery operating status of the power battery during the charge and discharge process on the capacity decay information, so that the evaluation results obtained are more accurate, and thus the performance of the vehicle battery can be better evaluated.

[0071] Figure 2 is a flow chart of another battery evaluation method according to an exemplary embodiment. Figure 2 As shown, the battery evaluation method includes: S201. Determine a capacity decay rate based on an operating state and charge and discharge information, where the capacity decay rate is used to indicate a change in capacity decay information over time.

[0072] The capacity decay rate is used to indicate the amount of change in capacity decay information over time.

[0073] In a possible implementation, the first capacity decay influence factor of the battery temperature, the second capacity decay influence factor of the battery current, and the third capacity decay influence factor of the charge and discharge information can be obtained. The first capacity decay influence factor is used to indicate the degree of influence of the battery temperature on the ability of the battery to store and release electric energy, the second capacity decay influence factor is used to indicate the degree of influence of the battery current on the ability of the battery to store and release electric energy, and the third capacity decay influence factor is used to indicate the degree of influence of the charge and discharge information on the ability of the battery to store and release electric energy. Afterwards, the capacity decay rate can be determined based on the battery temperature, battery current, charge and discharge information, the first capacity decay influence factor, the second capacity decay influence factor, the charge and discharge information, and the third capacity decay influence factor.

[0074] In a possible design, the battery current and the second capacity decay influencing factor can be processed based on the ampere-hour integration method to obtain an ampere-hour integral decay value, which is used to indicate the current charged or discharged by the battery. Afterwards, the battery temperature and the first capacity decay influencing factor can be calculated to obtain a temperature decay value, which is used to indicate the decay rate of the battery at the battery temperature. Afterwards, the capacity decay rate can be determined based on the temperature decay value, the ampere-hour integral decay value, the charge and discharge information, and the third capacity decay influencing factor.

[0075] In an embodiment of the present application, the third capacity attenuation influencing factor includes a discharge depth influencing factor and a charge and discharge rate factor. The discharge depth influencing factor is used to indicate the degree of influence of the battery discharge depth on the battery's ability to store and release electrical energy. The charge and discharge rate factor is used to indicate the degree of influence of the battery charge and discharge rate on the battery's ability to store and release electrical energy.

[0076] Optionally, a fourth capacity decay influence factor of the capacity decay rate may be obtained, and the fourth capacity decay influence factor is used to indicate the degree of influence of the capacity decay rate on the ability of the battery to store and release electrical energy. Afterwards, the capacity decay rate may be determined based on the first capacity decay influence factor, the second capacity decay influence factor and the charge and discharge information, the third capacity decay influence factor, and the fourth capacity decay influence factor.

[0077] Exemplarily, the capacity decay rate satisfies Formula 1.

[0078] Formula 1.

[0079] Among them, d (SOH loss ) is the capacity decay rate, A is the fourth capacity decay factor, B is the discharge depth factor, C is the charge and discharge rate factor, D is the first capacity decay factor, DOD is the battery discharge depth, C is the charge and discharge rate factor, D is the first capacity decay factor, DOD is the battery discharge depth, C is the charge and discharge rate factor, D is the first capacity decay factor, DOD is the battery discharge depth, D ... rate is the battery charge and discharge rate, Temp is the battery temperature, t is the operating period, I is the battery current, E is the second capacity decay factor, and F is used to indicate the unit conversion of the target period.

[0080] Optionally, the first capacity decay impact factor is a negative number.

[0081] It should be noted that the present application does not limit F. For example, F may be 3600000, 3600, 60 or 1.

[0082] It is understandable that the capacity decay rate can directly reflect the capacity change of the battery from the initial state to the current state. Obtaining battery decay information through the capacity decay rate can make the degree of battery aging more intuitive. Since the current rate is directly related to the chemical reaction rate inside the battery, the capacity decay rate is obtained through the ampere-hour integral decay value, which can more accurately reflect the actual state of the battery during use, thereby improving the accuracy of the capacity decay rate.

[0083] S202: Determine capacity decay information of the battery based on the capacity decay rate.

[0084] In a possible implementation, the operating period of each operating state in the target period may be obtained. Then, for each operating state, the battery attenuation information corresponding to the operating state may be determined based on the capacity decay rate corresponding to the operating state and the operating period corresponding to the operating state, so as to obtain the battery attenuation information of each operating state. Then, the capacity attenuation information of the battery may be determined based on the battery attenuation information corresponding to each operating state.

[0085] Exemplarily, the battery attenuation information of the battery satisfies Formula 2.

[0086] Formula 2.

[0087] Among them, SOH loss It is the battery attenuation information of the battery.

[0088] It is understandable that the battery attenuation information corresponding to each operating state can be obtained through at least one operating state of the battery. In this way, the battery capacity attenuation information obtained can reflect the battery health status of the battery under different operating states, thereby more accurately evaluating the battery performance of the vehicle under different temperatures and currents.

[0089] Based on the above technical solution, the capacity decay rate can be determined based on the operating state and the charge and discharge information. The capacity decay rate is used to indicate the change in the capacity decay information over time. Afterwards, the capacity decay information of the battery can be determined based on the capacity decay rate. Since the capacity decay rate is related to the performance state of the battery, by obtaining the change in the capacity decay information over time, the current performance state of the battery can be accurately evaluated.

[0090] In some embodiments, the initial capacity of the battery may be obtained. Then, the attenuation ratio corresponding to each operating state may be determined based on each capacity decay rate and operating period. Then, the battery attenuation information corresponding to each operating state may be determined based on the attenuation ratio corresponding to each operating state and the initial capacity of the battery corresponding to each operating state.

[0091] Optionally, the battery attenuation information may be a capacity attenuation value, where the capacity attenuation value is used to indicate a reduction in battery capacity during a target period of time.

[0092] Exemplarily, the battery attenuation information satisfies Formula 3.

[0093] Formula three.

[0094] Among them, Q loss is the capacity attenuation value, Q start is the initial capacity.

[0095] It is understandable that the capacity decay value can directly reflect the battery's ability to store and release electrical energy, and can intuitively reflect the battery's health status. By regularly measuring the battery's capacity decay value, the changing trend of battery performance can be obtained, abnormal battery performance decline can be discovered in time, and corresponding maintenance can be performed.

[0096] In some embodiments, a target capacity decay value can be obtained based on the capacity decay value corresponding to each operating state, and the target capacity decay value is the sum of the capacity decay values ​​corresponding to all operating states. Thereafter, a charge and discharge evaluation result of the battery can be determined based on the target capacity decay value and the target capacity decay threshold.

[0097] In a possible implementation, if the target capacity decay value is greater than the target capacity decay threshold, the battery charge and discharge evaluation result is determined to be unqualified, and the target capacity decay threshold is the decay threshold of the battery capacity in the target period. If the target capacity decay value is less than the preset capacity decay threshold, the battery charge and discharge evaluation result is determined to be qualified.

[0098] In some embodiments, when the evaluation result of the battery is qualified, the attenuation level of the battery is determined based on the capacity attenuation information and a preset attenuation level threshold, and the attenuation level of the battery includes a first level, a second level, and a third level. The performance of a first level battery is higher than that of a second level battery, and the performance of a second level battery is higher than that of a third level battery.

[0099] It should be noted that the present application does not limit the preset attenuation level threshold. For example, the preset attenuation level threshold may be 0.05, 0.08, 0.1, 0.13 or 0.15.

[0100] It can be understood that by classifying the capacity decay information of the battery, the result can be made more intuitive and easier to understand.

[0101] In some embodiments, if the evaluation result of the battery is unqualified, the capacity decay rate corresponding to the target state is determined based on the capacity decay rate corresponding to each operating state, and the capacity decay rate corresponding to the target state is greater than a preset state threshold.

[0102] It should be noted that the present application does not limit the preset state threshold. For example, the preset state threshold may be 0.003, 0.005, 0.008, 0.01 or 0.02.

[0103] In this way, by determining the capacity decay rate corresponding to the target state in the unqualified battery, the environment in which the battery capacity decays the fastest can be determined, so that the battery environment can be adjusted to reduce the battery capacity decay rate and thereby increase the battery life.

[0104] The embodiments of the present application are introduced below with reference to specific examples.

[0105] For example, Figure 3 As shown, it is a flow chart of another battery evaluation method according to an exemplary embodiment. The operating state of the battery and the charge and discharge information of the battery can be obtained. Afterwards, the operating state of the battery and the charge and discharge information of the battery can be input into formula one to obtain the capacity decay rate corresponding to the operating state. Afterwards, the capacity decay rate corresponding to the operating state and the operating period corresponding to the operating state can be input into formula two to obtain the battery decay information corresponding to the operating state. Afterwards, the initial capacity of the battery can be obtained, and the initial capacity of the battery and the battery decay information corresponding to the operating state can be input into formula three to obtain the capacity decay information of the operating period. Afterwards, it can be determined whether the operating state of the battery has changed. If the operating state of the battery has changed, the updated operating state of the battery and the charge and discharge information of the battery are obtained, and based on the updated operating state of the battery and the charge and discharge information of the battery, the capacity decay information corresponding to the updated operating state of the battery is obtained. It is iterated in this way until the capacity decay information corresponding to all operating states in the target period is obtained. Afterwards, the capacity decay information corresponding to all operating states can be added to obtain the total capacity decay information. Afterwards, the charge and discharge evaluation result of the battery can be determined based on the total decay information.

[0106] The above mainly introduces the solution provided by the embodiment of the present application from the perspective of the method. In order to achieve the above functions, the battery evaluation device includes a hardware structure and / or software module corresponding to each function. Those skilled in the art should easily realize that, in combination with the units and algorithm steps of each example described in the embodiments disclosed herein, the present application can be implemented in the form of hardware or a combination of hardware and computer software. Whether a function is executed in the form of hardware or computer software driving hardware depends on the specific application and design constraints of the technical solution. Professional and technical personnel can use different methods to implement the described functions for each specific application, but such implementation should not be considered to be beyond the scope of this application.

[0107] The embodiment of the present application can divide the functional modules of the battery evaluation device according to the above method. For example, the battery evaluation device can include various functional modules corresponding to the various functional divisions, or two or more functions can be integrated into one processing module. The above integrated modules can be implemented in the form of hardware or in the form of software functional modules. It should be noted that the division of modules in the embodiment of the present application is schematic and is only a logical functional division. There may be other division methods in actual implementation.

[0108] Figure 4FIG. 1 is a schematic diagram showing the structure of a battery evaluation device according to an exemplary embodiment. Figure 4 The battery evaluation device includes an acquisition module 401 and a processing module 402 .

[0109] The acquisition module 401 is used to acquire the operating status of the battery and the charging and discharging information of the battery.

[0110] The processing module 402 is used to determine the capacity decay information of the battery based on the operating state and the charge and discharge information of the battery. The processing module 402 is also used to determine the charge and discharge evaluation result of the battery based on the capacity decay information.

[0111] Regarding the device in the above embodiment, the specific manner in which each module performs operations has been described in detail in the embodiment of the method, and will not be elaborated here.

[0112] Figure 5 FIG. 1 is a schematic diagram showing the structure of another battery evaluation device according to an exemplary embodiment. Figure 5 As shown, the battery evaluation device includes but is not limited to: a processor 501 and a memory 502 .

[0113] The memory 502 is used to store executable instructions of the processor 501. It can be understood that the processor 501 is configured to execute instructions to implement the battery evaluation method in the above embodiment.

[0114] It should be noted that those skilled in the art can understand that Figure 5 The battery evaluation device structure shown in the figure does not constitute a limitation on the battery evaluation device, and the battery evaluation device may include Figure 5 More or fewer components may be shown, or certain components may be combined, or the components may be arranged differently.

[0115] The processor 501 is the control center of the battery evaluation device. It uses various interfaces and lines to connect the various parts of the entire battery evaluation device. By running or executing the software programs and / or modules stored in the memory 502, and calling the data stored in the memory 502, it performs various functions of the battery evaluation device and processes data, thereby monitoring the battery evaluation device as a whole. The processor 501 may include one or more processing units. Optionally, the processor 501 may integrate an application processor and a modem processor, wherein the application processor mainly processes the operating system, user interface, and application programs, and the modem processor mainly processes wireless communications. It is understandable that the above-mentioned modem processor may not be integrated into the processor 501.

[0116] The memory 502 may be used to store software programs and various data. The memory 502 may mainly include a program storage area and a data storage area, wherein the program storage area may store an operating system, an application program required by at least one functional module (such as a determination unit, a processing unit, etc.), etc. In addition, the memory 502 may include a high-speed random access memory, and may also include a non-volatile memory, such as at least one disk storage device, a flash memory device, or other volatile solid-state storage devices.

[0117] In an exemplary embodiment, the present application also provides a vehicle, which includes a battery evaluation device. The vehicle can execute the method in the above embodiment through the battery evaluation device.

[0118] In an exemplary embodiment, a computer-readable storage medium including instructions is also provided, such as a memory 502 including instructions, and the instructions can be executed by a processor 501 of a battery evaluation device to implement the method in the above embodiment.

[0119] In actual implementation, Figure 4 The functions of the acquisition module 401 and the processing module 402 in Figure 5 The processor 501 in the embodiment calls the computer program stored in the memory 502. The specific execution process can refer to the description of the method part in the above embodiment, which will not be repeated here.

[0120] Optionally, the computer-readable storage medium may be a non-temporary computer-readable storage medium, for example, the non-temporary computer-readable storage medium may be a read-only memory (ROM), a random access memory (RAM), a CD-ROM, a magnetic tape, a floppy disk, an optical data storage device, etc.

[0121] In an exemplary embodiment, the present application also provides a computer program product including one or more instructions, and the one or more instructions can be executed by the processor 501 of the battery evaluation device to complete the method in the above embodiment.

[0122] It should be noted that when the instructions in the above-mentioned computer-readable storage medium or one or more instructions in the computer program product are executed by the processor of the battery evaluation device, the various processes of the above-mentioned method embodiment are implemented, and the same technical effect as the above-mentioned method can be achieved. In order to avoid repetition, they will not be repeated here.

[0123] Through the description of the above implementation methods, technical personnel in the relevant field can clearly understand that for the convenience and simplicity of description, only the division of the above-mentioned functional modules is used as an example. In actual applications, the above-mentioned functions can be assigned to different functional modules as needed, that is, the internal structure of the device can be divided into different functional modules to complete all or part of the functions described above.

[0124] In the several embodiments provided in the present application, it should be understood that the disclosed devices and methods can be implemented in other ways. For example, the device embodiments described above are only schematic, for example, the division of modules or units is only a logical function division, and there may be other division methods in actual implementation, such as multiple units or components can be combined or integrated into another device, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some interfaces, indirect coupling or communication connection of devices or units, which can be electrical, mechanical or other forms.

[0125] The units described as separate components may or may not be physically separated, and the components shown as units may be one physical unit or multiple physical units, that is, they may be located in one place or distributed in multiple different places. Some or all of the units may be selected according to actual needs to achieve the purpose of the present embodiment.

[0126] In addition, each functional unit in each embodiment of the present application may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit. The above-mentioned integrated unit may be implemented in the form of hardware or in the form of software functional units.

[0127] If the integrated unit is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a readable storage medium. Based on this understanding, the technical solution of the embodiment of the present application is essentially or the part that contributes to the prior art or the full classification part or part of the technical solution can be embodied in the form of a software product, which is stored in a storage medium and includes several instructions for a device (which can be a single-chip microcomputer, chip, etc.) or a processor (processor) to execute the full classification part or part of the steps of each embodiment method of the present application. The aforementioned storage medium includes: U disk, mobile hard disk, ROM, RAM, disk or CD and other media that can store program code.

[0128] The above are only specific implementations of the present application, but the protection scope of the present application is not limited thereto, and any changes or substitutions within the technical scope disclosed in the present application 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 evaluation method, characterized in that: The method comprises: Acquire the operating state of the battery and the charge and discharge information of the battery, wherein the charge and discharge information of the battery includes at least one of the following: battery discharge depth and battery charge and discharge rate; Determine a capacity decay rate based on the operating state and the charge and discharge information, where the capacity decay rate is used to indicate a change in the capacity decay information over time; Determining capacity decay information of the battery based on the capacity decay rate; Based on the capacity fade information, a charge and discharge evaluation result of the battery is determined.

2. The battery evaluation method according to claim 1, characterized in that: The operating state includes: battery temperature and battery current; and determining the capacity decay rate based on the operating state and the charge and discharge information includes: Acquire a first capacity decay influence factor of the battery temperature, a second capacity decay influence factor of the battery current, and a third capacity decay influence factor of the charge and discharge information, wherein the first capacity decay influence factor is used to indicate the degree of influence of the battery temperature on the ability of the battery to store and release electric energy, the second capacity decay influence factor is used to indicate the degree of influence of the battery current on the ability of the battery to store and release electric energy, and the third capacity decay influence factor is used to indicate the degree of influence of the charge and discharge information on the ability of the battery to store and release electric energy; The capacity decay rate is determined based on the battery temperature, the battery current, the charge and discharge information, the first capacity decay influence factor, the second capacity decay influence factor, and the third capacity decay influence factor.

3. The battery evaluation method according to claim 2, characterized in that: The determining the capacity decay rate based on the battery temperature, the battery current, the charge and discharge information, the first capacity decay influence factor, the second capacity decay influence factor, and the third capacity decay influence factor includes: Processing the battery current and the second capacity decay influencing factor based on an ampere-hour integration method to obtain an ampere-hour integral decay value, wherein the ampere-hour integral decay value is used to indicate the current charged or discharged by the battery; Calculating the battery temperature and the first capacity decay influencing factor to obtain a temperature decay value, where the temperature decay value is used to indicate a decay rate of the battery at the battery temperature; The capacity decay rate is determined based on the temperature decay value, the ampere-hour integrated decay value, the charge and discharge information, and the third capacity decay influencing factor.

4. The battery evaluation method according to claim 1, characterized in that: The number of the operating states is at least one; The determining the capacity decay information of the battery based on the capacity decay rate corresponding to each of the operating states includes: Obtaining the operating time period of each operating state in the target time period; For each of the operating states, determining the battery attenuation information corresponding to the operating state based on the capacity decay rate corresponding to the operating state and the operating period corresponding to the operating state, so as to obtain the battery attenuation information of each of the operating states; Based on the battery attenuation information corresponding to each operating state, the capacity attenuation information of the battery is determined.

5. The battery evaluation method according to claim 4, characterized in that: The target time period includes at least one operating period, one operating period corresponds to one operating state, and different operating periods correspond to different operating states.

6. The battery evaluation method according to claim 4, characterized in that: Determining battery attenuation information corresponding to the operating state based on the capacity decay rate corresponding to the operating state and the operating period corresponding to the operating state includes: Obtaining the initial capacity of the battery; Determining a decay ratio corresponding to each operating state based on each of the capacity decay rates and the operating time period; Based on the attenuation ratio corresponding to each operating state and the initial capacity of the battery corresponding to each operating state, the battery attenuation information corresponding to each operating state is determined.

7. The battery evaluation method according to any one of claims 4 to 6, characterized in that: The determining, based on the capacity decay information, an evaluation result of the battery includes: If the capacity decay information is greater than a preset capacity decay threshold, determining that the evaluation result of the battery is unqualified, the preset capacity decay threshold is a decay threshold of the battery in the target period; If the capacity decay information is less than a preset capacity decay threshold, it is determined that the evaluation result of the battery is qualified.

8. The battery evaluation method according to claim 7, characterized in that: The battery evaluation method further comprises: When the evaluation result of the battery is qualified, the attenuation level of the battery is determined based on the capacity attenuation information and a preset attenuation level threshold, and the attenuation levels of the battery include a first level, a second level and a third level. The performance of the battery at the first level is higher than that of the battery at the second level, and the performance of the battery at the second level is higher than that of the battery at the third level.

9. The battery evaluation method according to claim 7, characterized in that: The battery evaluation method further comprises: If the evaluation result of the battery is unqualified, the capacity decay rate corresponding to the target state is determined based on the capacity decay rate corresponding to each operating state, and the capacity decay rate corresponding to the target state is greater than a preset state threshold.

10. A battery evaluation device, characterized in that: The device comprises an acquisition module and a processing module; The acquisition module is used to acquire at least one operating state of the battery and the charge and discharge information of the battery within the target period, wherein the charge and discharge information of the battery includes at least one of the following: battery discharge depth and battery charge and discharge rate; The processing module is further used to determine a capacity decay rate based on the operating state and the charge and discharge information, wherein the capacity decay rate is used to indicate a change amount of the capacity decay information over time; The processing module is further used to determine the capacity decay information of the battery based on the capacity decay rate; the processing module is further used to determine the charge and discharge evaluation result of the battery based on the capacity decay information.

11. A battery evaluation device, characterized in that: include: processor; a memory for storing instructions executable by the processor; The processor is configured to execute the instructions to implement the battery evaluation method according to any one of claims 1 to 9.

12. A vehicle, characterized in that: The vehicle includes the battery evaluation device according to claim 10 .

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