Electrochemical impedance spectroscopy detection method and system and related equipment

Abstract

The invention discloses an electrochemical impedance spectroscopy detection method and system and related equipment. The electrochemical impedance spectroscopy detection system comprises: a battery pack comprising a plurality of cells; the battery cell management module is connected with the plurality of battery cells and is used for acquiring response voltage of the battery pack and performing discrete Fourier transform on the excitation current and the response voltage to obtain an electrochemical impedance spectrum of the battery pack under the target excitation frequency; the battery management module is connected with the excitation source module and used for sending the target excitation frequency to the excitation source module; and the excitation source module is used for generating excitation current according to the target excitation frequency sent by the battery management module.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of battery control, and particularly relates to an electrochemical impedance spectroscopy (EIS) detection system, an EIS detection method, an electronic device, and a computer-readable storage medium. BACKGROUND

[0002] Currently, an EIS system is mainly implemented on a battery bench and has an independent excitation source. When implemented on a new energy vehicle, an additional excitation source hardware needs to be added, which brings problems such as cost increase and arrangement difficulty. Therefore, selecting an existing vehicle-mounted device becomes a development focus. Meanwhile, during use of the excitation source, the excitation current passing through will cause the system to heat and reduce the overall resistance. In addition, the excitation frequency of the excitation source may not be consistent with the target frequency due to control precision problems. Therefore, the stability of the excitation source in achieving the target demand and related system design become problems to be solved urgently. SUMMARY

[0003] The present application aims to at least solve one of the technical problems existing in the prior art. To this end, the present application provides an EIS detection method, system and related device to realize real-time monitoring of the battery health state.

[0004] In a first aspect, an EIS detection system is provided, which includes: a battery pack including a plurality of battery cells; a battery cell management module connected to the plurality of battery cells, configured to acquire a response voltage of the battery pack, and perform discrete Fourier transform on the excitation current and the response voltage to obtain an EIS of the battery pack at a target excitation frequency; a battery management module connected to the excitation source module, configured to send the target excitation frequency to the excitation source module; an excitation source module configured to generate an excitation current according to the target excitation frequency sent by the battery management module.

[0005] In some embodiments, the excitation source module includes an excitation source management module, a high-frequency switch module and an excitation source. The excitation source management module is connected to the battery management module and configured to control the on-off of the high-frequency switch module according to the target excitation frequency to control the excitation source to generate the excitation current.

[0006] In some embodiments, the excitation source includes a positive temperature coefficient heater or a heating film of the battery pack.

[0007] In some embodiments, the EIS detection system further includes a current sensor configured to detect the excitation current and send the excitation current to the battery cell management module.

[0008] The application provides an electrochemical impedance spectroscopy detection system, comprising: a battery pack comprising a plurality of battery cells; a battery cell management module connected with the plurality of battery cells, configured to detect a response voltage of the battery pack, and perform discrete Fourier transform on the excitation current and the response voltage to obtain an electrochemical impedance spectrum of the battery pack at a target excitation frequency; a battery management module connected with the excitation source module, configured to send the target excitation frequency to the excitation source module; and an excitation source module configured to generate an excitation current according to the target excitation frequency sent by the battery management module. The application uses a positive temperature coefficient heater or a heating film as an excitation source of the vehicle-mounted EIS, can superimpose excitation current disturbance on the whole vehicle high-voltage system without affecting the normal function of the whole vehicle, and enables the EIS test to be performed when the vehicle is driving or charging; the PTC or the heating film used for heating the battery pack in winter is used as the excitation source by adding a software function, without the need of additional physical hardware; and because the excitation source has no inductive element, the waveform and frequency of the excitation source are easy to control.

[0009] In a second aspect, the application provides an electrochemical impedance spectroscopy detection method, comprising: sending a discrete Fourier transform instruction of the target excitation frequency to the excitation source module by the power management module, so that the excitation source module sends a corresponding excitation current according to the discrete Fourier transform instruction of the target excitation frequency; obtaining a response voltage of the battery pack generated under the excitation of the excitation current by the battery cell management module, performing discrete Fourier transform on the excitation current and the response voltage at the target excitation frequency to obtain a corresponding frequency domain current and frequency domain voltage, calculating a ratio of the frequency domain voltage to the frequency domain current, and obtaining the electrochemical impedance spectrum of the battery pack at the target excitation frequency.

[0010] In some embodiments, the method further comprises: sending discrete Fourier transform instructions of a plurality of different excitation frequencies to the excitation source module by the battery management module, so that the excitation source module sends a plurality of corresponding excitation currents according to the discrete Fourier transform instructions of the plurality of different excitation frequencies; obtaining a plurality of response voltages of the battery pack generated under the excitation of a plurality of excitation currents by the battery cell management module, performing discrete Fourier transform on the excitation current and the response voltage at each excitation frequency to obtain a corresponding frequency domain current and frequency domain voltage, calculating a ratio of the frequency domain voltage to the frequency domain current, and determining that an excitation frequency corresponding to a maximum ratio is the target excitation frequency.

[0011] In some embodiments, the method further comprises: analyzing the health state of the battery pack according to the electrochemical impedance spectrum.

[0012] In some embodiments, the method further comprises: comparing the excitation current generated by the excitation source module with the excitation current detected by the current sensor. decrease the PWM duty cycle of the target excitation frequency in response to the excitation current detected by the current sensor being greater than the excitation current generated by the excitation source module.

[0013] The application provides an electrochemical impedance spectroscopy detection method, comprising: sending a discrete Fourier transform instruction of a target excitation frequency to an excitation source module through a power management module, so that the excitation source module emits a corresponding excitation current according to the discrete Fourier transform instruction of the target excitation frequency; obtaining a response voltage generated by a battery pack under the excitation of the excitation current through a battery management module, performing discrete Fourier transform on the excitation current and the response voltage under the target excitation frequency, obtaining a corresponding frequency domain current and frequency domain voltage, calculating a ratio of the frequency domain voltage to the frequency domain current, and obtaining an electrochemical impedance spectroscopy of the battery pack under the target excitation frequency. The application selects different excitation frequencies for discrete Fourier transform, determines the frequency corresponding to the maximum ratio of the current excitation frequency through the ratio of the discrete Fourier transform of the response voltage and the excitation current of the battery pack, and takes the frequency as the target excitation frequency, and then performs discrete Fourier transform on the response voltage and the excitation current of the battery pack, and thus obtains the electrochemical impedance spectroscopy of the battery pack. The method realizes high precision and high reliability of EIS measurement under the constraint of low-cost hardware through an excitation frequency dynamic screening mechanism.

[0014] In a third aspect, an embodiment of the application provides an electronic device, comprising: a processor and a memory, the memory stores programs or instructions executable on the processor, and the programs or instructions are executed by the processor to implement the steps of the electrochemical impedance spectroscopy detection method according to the first aspect.

[0015] In a fourth aspect, an embodiment of the application provides a computer readable storage medium, the readable storage medium stores programs or instructions, and the programs or instructions are executed by a processor to implement the steps of the electrochemical impedance spectroscopy detection method according to the first aspect.

[0016] Additional aspects and advantages of the application will be made apparent by the following description and the accompanying drawings. BRIEF DESCRIPTION OF DRAWINGS

[0017] The above and / or additional aspects and advantages of the application will become apparent and be readily understood by considering the following detailed description, including the accompanying drawings, in which: Figure 1 An impedance spectroscopy detection system provided by an embodiment of the application is shown in the schematic diagram.

[0018] Figure 2 A flowchart of an electrochemical impedance spectroscopy detection method provided by an embodiment of the application is shown.

[0019] Figure 3The high-frequency switch module provided in the embodiment of the present application generates different frequency sine waves.

[0020] Figure 4 The schematic diagram of the excitation current and the response of the cell voltage is provided in the embodiment of the present application.

[0021] Figure 5 The schematic diagram of the excitation current amplitude under different frequencies is provided in the embodiment of the present application.

[0022] Figure 6 The structural schematic diagram of an electronic device in the embodiment of the present application is provided.

[0023] Reference signs: 1-battery pack, 11-cell, 2-cell management module, 3-battery management module, 4-excitation source module, 41-excitation source management module, 42-high-frequency switch module, 43-excitation source, 5-current sensor, 601-first management module, 602-second management module, 710-processor, 720-memory, 730-input / output interface, 740-communication interface, 750-bus. DETAILED DESCRIPTION

[0024] Embodiments of the present application will be described in more detail by referring to the attached drawings. Although certain embodiments of the present application are shown in the drawings, it is understood that the present application can be implemented in various forms and should not be interpreted as being limited to the embodiments set forth herein, but rather these embodiments are provided to make the present application more thorough and complete. It is understood that the drawings and embodiments of the present application are for exemplary purposes only and are not intended to limit the scope of protection of the present application.

[0025] It is understood that each step described in the method embodiment of the present application can be executed in different order and / or in parallel. In addition, the method embodiment can include additional steps and / or omit the execution of the steps shown. The scope of the present application is not limited in this respect.

[0026] As described in the background section, electrochemical impedance spectroscopy (EIS) as an important electrochemical analysis method, by applying a small amplitude sine wave potential (or current) perturbation and measuring the response current (or potential), the spectrum reflecting the impedance of the electrochemical system with frequency change can be obtained, which provides rich information for electrode process dynamics and surface phenomenon research. Its analysis is usually based on the equivalent circuit model composed of resistance (R), capacitance (C), inductance (L) and other elements, and the impedance data is often represented by Nyquist plot and Bode plot.

[0027] EIS technology is widely used in electrode process dynamics, battery materials, solid electrolytes, conductive polymers, and corrosion protection. Especially in battery performance evaluation, health status monitoring and aging analysis, EIS can evaluate the health status by monitoring the change of battery resistance, identify internal failure modes, optimize battery management system algorithms, and evaluate the electrochemical performance in new material research and development, providing key support for battery technology development.

[0028] However, existing EIS systems usually conduct tests on battery benches equipped with independent excitation sources. When implementing EIS on new energy vehicles, additional excitation source hardware is required, which inevitably leads to increased costs and complex arrangements. Therefore, using existing vehicle-mounted equipment has become a key direction for current research and development. Meanwhile, the excitation current flowing through the excitation source generates heat, causing the overall resistance of the system to decrease. Moreover, due to control accuracy issues, the actual frequency of the excitation source may not match the target frequency. Therefore, the stability of the excitation source in achieving the target requirements and related system design are the core problems that this invention aims to solve.

[0029] Reference Figure 1 The impedance spectrum detection system provided by the embodiments of the present application is shown in the schematic diagram.

[0030] The impedance spectrum detection system provided by the embodiments of the present application includes a battery pack 1, a cell management module 2, a battery management module 3, and an excitation source module 4.

[0031] The battery pack 1 is composed of several cells 11 connected in a specific manner (such as series, parallel, or mixed connection) to provide the system with the electrochemical energy storage unit to be tested. The battery pack 1, as the object being tested, directly affects the measurement results of the impedance spectrum due to its electrochemical performance and state.

[0032] The cell management module 2 can include high-precision voltage and current sensors, signal conditioning circuits, analog-to-digital converters (ADCs), and microprocessors. The cell management module 2 is closely connected to each cell 11 of the battery pack 1, ensuring accurate acquisition of the response voltage of each cell 11 and the entire battery pack 1.

[0033] The battery management module 3 can be composed of high-performance microcontrollers, memories, communication interfaces, etc. The battery management module 3 is connected to the cell management module 2 through a specific communication protocol (such as CAN bus, SPI bus, etc.), realizing data transmission and control instruction sending.

[0034] Optionally, the excitation source module 4 includes an excitation source management module 41, a high-frequency switching module 42, and an excitation source 43; the excitation source management module 41 is connected to the battery management module 3, used to control the on-off of the high-frequency switching module 42 according to the target excitation frequency sent by the battery management module 3, to control the excitation current generated by the excitation source 43.

[0035] Specifically, the excitation source module 4 includes an excitation source management module 41, a high-frequency switch module 42, and an excitation source 43. The excitation source management module 41 can adopt a microcontroller or a special control chip, and has a digital signal processing and communication interface function. It is connected with the battery management module 3 to receive control instructions, and is connected with the high-frequency switch module 42 to control the on-off thereof. The high-frequency switch module 42 can be composed of a power semiconductor device (such as MOSFET, IGBT, etc.) and a driving circuit thereof. It is connected between the excitation source 43 and the battery pack 1, and is controlled by the excitation source management module 41. The high-frequency switch module 42 can be a metal oxide semiconductor field effect transistor (MOSFET) or an insulated gate bipolar transistor (IGBT). The MOSFET or IGBT can be multiple, and can be in series or parallel in structure.

[0036] Optionally, the excitation source 43 includes a positive temperature coefficient heater or a heating film of the battery pack.

[0037] Specifically, the excitation source 43 can be a heating film provided by the battery pack, a combination of an external power supply and a specific circuit, etc. It is connected with the high-frequency switch module 42 to provide excitation energy for the battery pack 1.

[0038] Optionally, the impedance spectrum detection system provided by the embodiment of the present application is further provided with a current sensor 5 on the main circuit, which is used to detect the excitation current and send the excitation current to the cell management module 2.

[0039] The electrochemical impedance spectrum detection system provided by the present application adopts a positive temperature coefficient heater or a heating film as an excitation source of the vehicle-mounted EIS, can superimpose an excitation current disturbance on the whole vehicle high-voltage system without affecting the normal function of the whole vehicle, and enables the vehicle to perform EIS testing when driving and charging; uses the existing PTC or heating film for heating the battery pack in winter, and can be used as an excitation source by increasing a software function without additional physical hardware; and because it has no inductive element, the waveform and frequency of the excitation source are easy to control.

[0040] Reference Figure 2 The flowchart of the electrochemical impedance spectrum detection method provided by the embodiment of the present application.

[0041] In step S201, the power management module sends a discrete Fourier transform instruction of a target excitation frequency to the excitation source module, so that the excitation source module sends a corresponding excitation current according to the discrete Fourier transform instruction of the target excitation frequency.

[0042] In step S202, the battery management module obtains the response voltage generated by the battery pack under the excitation current excitation, performs discrete Fourier transform on the excitation current and the response voltage under the target excitation frequency, obtains the corresponding frequency domain current and frequency voltage, calculates the ratio of the frequency domain voltage to the frequency domain current, and obtains the electrochemical impedance spectrum of the battery pack under the target excitation frequency.

[0043] As an optional embodiment, the method further comprises: sending, by the battery management module, discrete Fourier transform instructions of a plurality of different excitation frequencies to the excitation source module, so that the excitation source module sends a plurality of corresponding excitation currents according to the discrete Fourier transform instructions of the plurality of different excitation frequencies; and obtaining, by the battery management module, a plurality of response voltages generated by the battery pack under a plurality of excitation currents, performing discrete Fourier transform on the excitation current and the response voltage under each excitation frequency, obtaining the corresponding frequency domain current and frequency voltage, calculating the ratio of the frequency domain voltage to the frequency domain current, and determining the excitation frequency corresponding to the maximum ratio as the target excitation frequency.

[0044] Specifically, the battery management module (Battery Management Controller, BMC) sends discrete Fourier transform (Discrete Fourier Transform, DFT) instructions of different excitation frequencies to the cell management module (Cell Management Controller, CMC) to guide the CMC to perform frequency domain analysis on the response voltage and the excitation current of the battery pack to obtain signal characteristics under different frequencies.

[0045] The BMC determines the frequency range and frequency points that need to be analyzed according to a preset test scheme or algorithm. For example, if the frequency range is set to 1 Hz to 30 Hz and the frequency interval is 10 Hz, three DFT instructions of different frequencies need to be sent. The BMC generates a DFT instruction containing information of each frequency point. The instruction format usually includes parameters such as frequency value, number of sampling points, sampling time, etc. to ensure that the CMC can accurately perform DFT transformation. Then, the BMC sends the DFT instruction to the CMC through a communication bus (such as CAN bus, SPI bus, etc.). During the sending process, the integrity and correctness of the instruction need to be ensured to avoid data loss or errors.

[0046] Specifically, the CMC performs frequency domain analysis on the response voltage and the excitation current of the battery pack according to the DFT instruction sent by the BMC, extracts the signal amplitude under different frequencies, and selects the excitation frequency corresponding to the excitation current with the highest amplitude as the target excitation frequency, which provides a basis for subsequent battery performance evaluation and fault diagnosis.

[0047] The CMC collects the response voltage and excitation current of the battery pack in real time through the voltage collection line and the current collection line. During the collection process, the sampling frequency and sampling time need to meet the requirements of DFT transformation to ensure the accuracy of frequency domain analysis. The CMC performs DFT transformation on the collected response voltage and excitation current signals according to the received DFT instructions, converts the time domain signals into frequency domain signals, i.e., converts the response voltage into frequency domain voltage and converts the excitation current into frequency domain current, and calculates the ratio (impedance modulus) of the response voltage to the excitation current at each excitation frequency. The frequency corresponding to the maximum impedance modulus is selected as the target excitation frequency. The target excitation frequency is fed back to the test system for subsequent electrochemical impedance spectroscopy (EIS) test.

[0048] It should be noted that the quality of the collected response voltage and excitation current signals directly affects the results of DFT transformation. It is necessary to ensure that there is no noise interference during signal collection and that the sampling frequency and sampling time meet the requirements of DFT transformation. The selection of frequency range can be reasonably set according to the characteristics of the battery pack and the test requirements. A too wide frequency range may result in excessive calculation, and a too narrow frequency range may not fully reflect the frequency response characteristics of the battery pack. The selection of the target excitation frequency can be considered comprehensively in combination with the actual application scenario. For example, in some special cases, more attention can be paid to the signal characteristics in a specific frequency range rather than the signal with the highest amplitude.

[0049] As an optional embodiment, the method further comprises analyzing the state of health of the battery pack according to electrochemical impedance spectroscopy.

[0050] Specifically, key features such as mid-frequency impedance, high-frequency phase angle change, and low-frequency diffusion impedance can be extracted from the impedance spectrum. The extracted features are compared with the reference model of healthy batteries to identify deviations. Finally, based on the degree of deviation, the threshold judgment or machine learning algorithm (such as support vector machine, neural network) is used to evaluate the state of health (SOH) of the battery pack.

[0051] As an optional embodiment, the method further comprises comparing the excitation current generated by the excitation source module with the excitation current detected by the current sensor; and in response to the excitation current detected by the current sensor being greater than the excitation current generated by the excitation source module, reducing the PWM duty cycle of the target excitation frequency.

[0052] Controlling the average value of the current through the duty cycle of PWM (Pulse Width Modulation) to keep it consistent in all cycles is an effective closed-loop control method, especially suitable for the requirement of current stability in electrochemical impedance spectroscopy (EIS) test. The duty cycle of the PWM signal determines the average value of the output voltage, thereby indirectly controlling the average value of the load current. By adjusting the PWM duty cycle, the current can be dynamically adjusted to remain constant.

[0053] Specifically, the duty cycle of the PWM signal can be dynamically adjusted according to the comparison result to control the output power of the excitation source. Real-time adjustment of the PWM output through a microcontroller or FPGA or the use of a PID control algorithm to dynamically adjust the duty cycle according to the current deviation can achieve closed-loop control. Through closed-loop control of the PWM duty cycle, the average value of the current can be effectively adjusted to remain consistent in EIS testing. This method not only improves the accuracy of the test but also enhances the robustness of the system, making it suitable for various electrochemical impedance spectroscopy testing scenarios.

[0054] The present application provides a more specific embodiment, and the operation flow of this embodiment aims to comprehensively evaluate the performance of a battery pack using an electrochemical impedance spectroscopy (EIS) test system through a series of precise control and measurement steps. By starting EIS testing, generating a pulse current, selecting an excitation current frequency, collecting and analyzing data, and controlling the size of the excitation current, impedance spectrum information of the battery pack is obtained, and the health status of the battery is analyzed, temperature changes are predicted, and scientific basis is provided for the maintenance and management of the battery.

[0055] First, in the specific implementation, it is necessary to ensure that the impedance spectroscopy detection system components (battery pack, cell management module, battery management module, excitation source management module, high-frequency switching module, excitation source, and various circuit connection lines, etc.) are installed firmly, connected normally, and have no looseness, short circuit, or open circuit phenomenon. Check the stability of the power supply of each component, and the indicator light shows normal, no abnormal alarm information.

[0056] Further, start the control software matched with the EIS test system and enter the operation interface. Set relevant parameters in the software, such as preset conditions (charging completion, vehicle start, time timing, etc.), pulse current models (sine wave, square wave, triangle wave, etc.), measurement frequency range, sampling frequency, data storage path, etc., to ensure that the parameter settings meet the actual measurement requirements.

[0057] In addition, it is also necessary to ensure that the measurement environment temperature, humidity, and other conditions are within the working range allowed by the battery pack and the test system to avoid the influence of environmental factors on the measurement results. Reduce electromagnetic interference in the measurement environment, such as staying away from strong magnetic fields, high-power electrical appliances, and other interference sources.

[0058] Further, when the preset conditions (such as charging completion, vehicle start, or time timing) are met, the battery controller cell management module, battery management module, and excitation source module work and preset relevant parameters.

[0059] Firstly, the excitation source management module controls the switching frequency and duration of the high-frequency switching module according to the frequency and waveform information from the battery management module, so that the excitation source generates an excitation current. The excitation current passes through the battery cells in the battery pack, and the battery cells generate a corresponding voltage fluctuation. Among them, the pulse current model can be a sine wave, a square wave, a triangular wave, etc.

[0060] Reference Figure 3 The high-frequency switching module provided in the embodiment of the present application generates different frequency sine waves. That is, the square waves with different duty cycles are coupled with the inherent characteristics of the system to generate sine waves.

[0061] Referring to FIG. 4, a schematic diagram of the excitation current provided in the embodiment of the present application is a square wave and the voltage response of the battery cell.

[0062] After the excitation current is generated, the battery management module sends a discrete Fourier transform (DFT) instruction of three frequency points A, B and C to the battery cell management module.

[0063] Reference Figure 5 The excitation current amplitude diagram under different frequencies provided in the embodiment of the present application is shown in the figure. Among them, point A is the desired excitation frequency, point B frequency = point A frequency - 1 Hz, and point C frequency = point A frequency + 1 Hz. The battery cell management module performs DFT transformation according to the DFT instruction and the measured current, and simultaneously obtains the amplitudes PA, PB and PC corresponding to the frequencies, and sends them to the battery management module.

[0064] The battery management module selects the frequency corresponding to the maximum value of PA, PB and PC as the frequency for calculating DFT. The battery cell management module acquires the voltage of the battery cell and the working current information of the battery pack in real time through the battery cell voltage acquisition harness and the battery pack current acquisition harness. The battery cell management module performs discrete Fourier transform (DFT) to output the frequency domain voltage U(k) and the frequency domain current I(k). Among them, the frequency corresponding to k is the frequency corresponding to the maximum amplitude.

[0065] Further, when the first frequency point test is started, the current value of the system is recorded .

[0066] During the step test cycle, according to the size of the current sensor and , the duty cycle of the PWM wave is adjusted. When > , the duty cycle is reduced to offset the resistance change of the heating resistor caused by the working heat, so as to avoid further causing the current change.

[0067] Finally, the battery management module performs a discrete Fourier transform (DFT) on the voltage and current data collected over a period of time to calculate the impedance spectrum R(k)=U(k) / I(k) of the battery cell. Based on the impedance spectrum, the battery management module further performs state of health analysis, temperature prediction, and the like. For example, the aging degree, internal resistance change, and the like of the battery can be determined by comparing the impedance value changes at different frequencies.

[0068] To sum up, the application provides an electrochemical impedance spectrum detection method, which comprises the following steps: sending a discrete Fourier transform instruction of a target excitation frequency to an excitation source module through a power management module, so that the excitation source module sends corresponding excitation current according to the discrete Fourier transform instruction of the target excitation frequency; obtaining a response voltage generated by a battery pack under the excitation of the excitation current through a battery cell management module, performing a discrete Fourier transform on the excitation current and the response voltage at the target excitation frequency, obtaining corresponding frequency domain current and frequency domain voltage, calculating the ratio of the frequency domain voltage to the frequency domain current, and obtaining the electrochemical impedance spectrum of the battery pack at the target excitation frequency. The application selects different excitation frequencies for discrete Fourier transform, determines the frequency corresponding to the maximum ratio of the current excitation frequency through the ratio of the discrete Fourier transform of the response voltage and the excitation current of the battery pack, and takes the frequency as the target excitation frequency. The response voltage and the excitation current of the battery pack are subjected to discrete Fourier transform again, and then the electrochemical impedance spectrum of the battery pack is obtained. The method realizes high precision and high reliability of EIS measurement under the constraint of low-cost hardware through an excitation frequency dynamic screening mechanism.

[0069] It should be noted that the method of the embodiments of the application can be executed by a single device, such as a computer or a server. The method of the embodiments can also be applied to a distributed scenario, and completed by multiple devices in cooperation. In the case of such a distributed scenario, one of the multiple devices can only execute one or more steps in the method of the embodiments of the application, and the multiple devices can interact with each other to complete the above method.

[0070] It should be noted that some embodiments of the application have been described above. Other embodiments are within the scope of the appended claims. In some cases, the actions or steps recited in the claims can be performed in a different order than the order described above and still achieve desirable results. In addition, the processes depicted in the figures do not necessarily require the particular order shown or sequential order to achieve the desired results. In certain implementations, multitasking and parallel processing can be advantageous.

[0071] Corresponding to the above embodiments, the application further provides an electronic device.

[0072] Reference Figure 6Fig. 6 is a block diagram of an electronic device according to some embodiments of the present application, which shows a more specific hardware structure of an electronic device according to some embodiments of the present application. The electronic device can include a processor 610, a memory 620, an input / output interface 630, a communication interface 640, and a bus 650. The processor 610, the memory 620, the input / output interface 630, and the communication interface 640 are connected to each other via the bus 650.

[0073] The processor 610 can be implemented by a general-purpose CPU (Central Processing Unit), a microprocessor, an ASIC (Application Specific Integrated Circuit), or one or more integrated circuits, and is configured to execute related programs to implement the technical solutions provided by the embodiments of the present application.

[0074] The memory 620 can be implemented by a ROM (Read Only Memory), a RAM (Random Access Memory), a static storage device, a dynamic storage device, or the like. The memory 620 can store an operating system and other application programs. When the technical solutions provided by the embodiments of the present application are implemented by software or firmware, the related program codes are stored in the memory 620 and are invoked and executed by the processor 610.

[0075] The input / output interface 630 is configured to connect to an input / output module to implement information input and output. The input / output module can be configured as a component in the device (not shown in the figure) or can be externally connected to the device to provide corresponding functions. The input device can include a keyboard, a mouse, a touch screen, a microphone, various sensors, and the like, and the output device can include a display, a speaker, a vibrator, an indicator, and the like.

[0076] The communication interface 640 is configured to connect to a communication module (not shown in the figure) to implement communication interaction between the device and other devices. The communication module can implement communication by a wired manner (for example, a USB, a network cable, or the like) or by a wireless manner (for example, a mobile network, WIFI, Bluetooth, or the like).

[0077] The bus 650 includes a channel to transmit information between various components (for example, the processor 610, the memory 620, the input / output interface 630, and the communication interface 640) of the device.

[0078] It should be noted that although the above device only shows the processor 610, the memory 620, the input / output interface 630, the communication interface 640 and the bus 650, in the specific implementation process, the device can also include other components necessary for normal operation. In addition, those skilled in the art can understand that the above device can also only contain components necessary to implement the embodiments of the present application, and does not necessarily contain all the components shown in the figure.

[0079] The electronic device of the above embodiment is used to implement the corresponding method in any of the preceding embodiments, and has the beneficial effects of the corresponding method embodiment, which will not be repeated here.

[0080] Based on the same inventive concept, the present application also provides a computer readable storage medium corresponding to the method of any of the above embodiments, the computer readable storage medium stores computer instructions for causing a computer to execute the method of any of the above embodiments.

[0081] The above computer readable storage medium can be any available medium or data storage device accessible by a computer, including but not limited to magnetic storage (such as floppy disk, hard disk, magnetic tape, magneto-optical disk (MO) and the like), optical storage (such as CD, DVD, BD, HVD and the like), and semiconductor storage (such as ROM, EPROM, EEPROM, non-volatile memory (NAND FLASH), solid state disk (SSD)) and the like.

[0082] The computer instructions stored in the storage medium of the above embodiment are used to cause a computer to execute the method of any of the above exemplary method embodiments, and have the beneficial effects of the corresponding method embodiment, which will not be repeated here.

[0083] In addition, although the operations of the method of the present application are described in a specific order in the accompanying drawings, this does not require or imply that the operations must be performed in that specific order, or that all of the shown operations must be performed to achieve the desired result. On the contrary, the steps depicted in the flowchart can change the order of execution. Additionally or alternatively, some steps can be omitted, a plurality of steps can be combined into one step, and / or one step can be divided into a plurality of steps.

[0084] It should be understood that aspects of the application can be implemented in hardware, software, firmware or combinations thereof, as desired. In the embodiments described above, various steps or methods can be implemented, in software or firmware which are stored in memory and executed by a suitable instruction execution system. For example, if implemented in hardware, as in another embodiment, any of the following technologies, known in the art, or combinations thereof, can be employed: discrete logic circuitry having logic gates for implementing logic functions upon data signals, application specific integrated circuits having appropriate combinational logic gates, programmable gate arrays (PGA), field programmable gate arrays (FPGA), and so forth.

[0085] It should be noted that, unless otherwise defined, technical terms or scientific terms used in the embodiments of the application shall have the common meaning understood by one of ordinary skill in the art to which the application pertains. The terms "first", "second", and similar terms used in the embodiments of the application do not denote any order, quantity, or importance, but are used to distinguish different components. The terms "include", "comprise", and similar terms mean that the elements or objects before the term encompass the elements or objects listed after the term and equivalents thereof, and do not exclude other elements or objects. The terms "connected", "coupled", and similar terms do not mean only physical or mechanical connections, but can include electrical connections, whether direct or indirect. The terms "upper", "lower", "left", "right", and the like are used only to indicate relative positions, and when the absolute positions of the described objects are changed, the relative positions can also be changed accordingly.

[0086] While the principles and spirit of the application have been described with reference to several specific embodiments, it is to be understood that the application is not limited to the specific embodiments disclosed, and that the division of aspects is not meant to imply that features from these aspects cannot be combined to benefit, but is merely for ease of presentation. The application is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims. The scope of the appended claims is to be construed in the broadest sense, encompassing all such modifications and equivalent structures and functions.

Claims

1. An electrochemical impedance spectroscopy detection system, characterized in that: include: A battery pack (1), comprising a plurality of battery cells (11); A cell management module (2) is connected to the plurality of cells (11) and is used to obtain a response voltage of the battery pack (1), and to perform a discrete Fourier transform on the excitation current and the response voltage to obtain an electrochemical impedance spectrum of the battery pack at a target excitation frequency; A battery management module (3) is connected to the excitation source module (4) and is used to send a target excitation frequency to the excitation source module (4); The excitation source module (4) is used to generate an excitation current according to the target excitation frequency sent by the battery management module (3).

2. The electrochemical impedance spectroscopy detection system according to claim 1, characterized in that: The excitation source module (4) includes an excitation source management module (41), a high-frequency switch module (42) and an excitation source (43); The excitation source management module (41) is connected to the battery management module (3) and is used to control the on / off of the high-frequency switch module (42) according to the target excitation frequency, so as to control the excitation source (43) to generate an excitation current.

3. The electrochemical impedance spectroscopy detection system according to claim 2, characterized in that: The excitation source (43) includes a positive temperature coefficient heater or a heating film of the battery pack.

4. The electrochemical impedance spectroscopy detection system according to claim 1, characterized in that: Also includes: A current sensor (5) is used to detect the excitation current and send the excitation current to the battery cell management module (2).

5. A method for detecting electrochemical impedance spectroscopy, characterized in that: Applied to the electrochemical impedance spectroscopy detection system according to any one of claims 1 to 4, the method comprising: Sending a discrete Fourier transform instruction of the target excitation frequency to the excitation source module through the power management module, so that the excitation source module emits a corresponding excitation current according to the discrete Fourier transform instruction of the target excitation frequency; The response voltage generated by the battery pack under the excitation of the excitation current is obtained through the battery cell management module, and the excitation current and response voltage at the target excitation frequency are discrete Fourier transformed to obtain the corresponding frequency domain current and frequency voltage. The ratio of the frequency domain voltage to the frequency domain current is calculated to obtain the electrochemical impedance spectrum of the battery pack at the target excitation frequency.

6. The method for detecting electrochemical impedance spectroscopy according to claim 5, characterized in that: The method further comprises: Sending a plurality of discrete Fourier transform instructions of different excitation frequencies to the excitation source module through the battery management module, so that the excitation source module emits a plurality of corresponding excitation currents according to the plurality of discrete Fourier transform instructions of different excitation frequencies; The battery cell management module obtains multiple response voltages generated by the battery pack under the excitation of multiple excitation currents, performs discrete Fourier transform on the excitation current and response voltage at each excitation frequency, obtains the corresponding frequency domain current and frequency voltage, calculates the ratio of the frequency domain voltage to the frequency domain current, and determines that the excitation frequency corresponding to the largest ratio is the target excitation frequency.

7. The method for detecting electrochemical impedance spectroscopy according to claim 6, characterized in that: The method further comprises: The health status of the battery pack is analyzed according to the electrochemical impedance spectroscopy.

8. The method for detecting electrochemical impedance spectroscopy according to claim 7, characterized in that: The method further comprises: comparing the excitation current generated by the excitation source module with the excitation current detected by the current sensor; In response to the excitation current detected by the current sensor being greater than the excitation current generated by the excitation source module, the PWM duty cycle of the target excitation frequency is reduced.

9. An electronic device, characterized in that: include: A processor and a memory, wherein the memory stores a program or instruction that can be run on the processor, and when the program or instruction is executed by the processor, the steps of the electrochemical impedance spectroscopy detection method according to any one of claims 5 to 8 are implemented.

10. A computer-readable storage medium, characterized in that The readable storage medium stores a program or instruction, and when the program or instruction is executed by the processor, the steps of the electrochemical impedance spectroscopy detection method according to any one of claims 5 to 8 are implemented.

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