Electrochemical performance test system and method for energy storage device

Abstract

The invention relates to the technical field of performance testing, in particular to an electrochemical performance testing system and method for an energy storage device, and the system comprises a time synchronization triggering module, an impedance track acquisition module, a degradation state recognition module, an electrochemical abnormity monitoring module and a performance testing judgment module. According to the invention, multi-channel concurrent synchronous acquisition of voltage, current, impedance and temperature is realized by calculating sampling delay compensation time, and lithium precipitation, micro short circuit and electrode interface damage trend can be accurately identified by calculating a gradient absolute difference sequence of a voltage change rate and a current change rate and linking an impedance abrupt change rate and short-period abnormal fluctuation. In the process of judging the state of the energy storage device, open-circuit voltage distribution, charging and discharging current stability and impedance change trend are considered in a combined manner, the recognition accuracy of an active state, a degradation state and an abnormal state is improved, and the precision and reliability of electrochemical performance testing are improved.

Description

Technical Field

[0001] The present invention relates to the technical field of performance testing, and in particular to an electrochemical performance testing system and method for energy storage devices. Background Art

[0002] The field of performance testing technology mainly involves the quantitative evaluation of the function, efficiency, stability and durability of various systems, devices or materials under specific working conditions. This field covers a variety of test objects, including electronic devices, chemical devices, mechanical equipment, etc. The core goal is to accurately measure the key indicators of the device's electrical performance, thermal performance, mechanical performance, etc. by establishing a standardized test environment and test methods. Performance testing usually relies on high-precision measurement equipment, control systems and a variety of signal acquisition and analysis tools. The test process covers data acquisition, signal control, anomaly detection and result analysis, and supports the tracking and modeling of performance changes under different working conditions. This technical field is widely used in multiple application scenarios such as product research and development, quality control, life prediction and fault diagnosis.

[0003] The electrochemical performance testing system for energy storage devices is primarily used to measure the electrochemical performance of electrochemical energy storage devices during charge and discharge cycles. The system enables real-time monitoring and analysis of multiple indicators, including voltage, current, internal resistance, cycle life, coulombic efficiency, and energy efficiency. It effectively evaluates performance changes in energy storage devices under different operating modes, load conditions, and ambient temperatures, providing support for device performance optimization, fault prediction, and reliability verification.

[0004] During the multi-channel electrochemical data acquisition process of traditional test systems, there is a lack of compensation mechanism for the physical delay of signal paths and the difference in sampling control instruction timing, which leads to asynchronous sampling errors between multiple types of signals such as voltage, current, impedance and temperature. During the charge and discharge cycle, it is impossible to establish an evolution sequence reflecting the continuous change of impedance parameters over time, making it difficult to accurately characterize the changing trends of parameters such as electrolyte resistance and charge transfer resistance. Traditional systems rely on a single threshold of voltage and current to judge abnormal conditions, and are unable to identify dynamic transient anomalies caused by micro-short circuits or electrode interface degradation. The lack of precise positioning of inflection point changes in the degradation process results in inaccurate judgment of the performance degradation trend of energy storage devices, affecting the effectiveness and reliability of performance testing. Summary of the Invention

[0005] The purpose of the present invention is to solve the shortcomings of the prior art and to propose an electrochemical performance testing system and method for energy storage devices.

[0006] In order to achieve the above-mentioned object, the present invention adopts the following technical solution: an electrochemical performance testing system for energy storage devices, the system comprising: The time synchronization trigger module acquires multi-dimensional test data of the energy storage device, establishes a synchronization trigger time base sequence for each channel, and calls the time base sequence to synchronously trigger the multi-channel sampling unit to perform concurrent collection of four types of data: voltage, current, impedance, and temperature, thereby obtaining a full-channel synchronized electrochemical data set. The impedance trajectory acquisition module establishes a trajectory of impedance parameter changes over time according to the charge and discharge cycle sequence based on the full-channel synchronous electrochemical data set, and obtains a multi-cycle impedance evolution parameter sequence; The degradation state identification module calls the multi-cycle impedance evolution parameter sequence, calculates the electrolyte resistance change rate, charge transfer resistance change rate, double layer capacitance change rate and Warburg impedance change rate during multiple consecutive charge and discharge cycles, identifies the slope change point and the extreme inflection point position, and obtains the degradation inflection point characteristic sequence of the energy storage device; The electrochemical anomaly monitoring module is based on the full-channel synchronous electrochemical data set and combines the short-period abnormal points of the Warburg impedance transient change rate and the charge transfer resistance mutation rate in the multi-period impedance evolution parameter sequence to identify the abnormal state of the energy storage device and obtain the electrochemical dynamic abnormal state identifier.

[0007] As a further solution of the present invention, the full-channel synchronous electrochemical data set includes a transient voltage waveform sequence, a transient current waveform sequence, a Nyquist impedance complex sequence and a temperature change curve of the charge and discharge process; the multi-cycle impedance evolution parameter sequence is specifically an electrolyte resistance change sequence, a charge transfer resistance change sequence, a double layer capacitance change sequence and a Warburg impedance change sequence; the energy storage device degradation inflection point characteristic sequence includes an impedance change slope mutation point, a constant current region voltage platform offset point, a current nonlinear response inflection point and an impedance trajectory abnormal curvature point; the electrochemical dynamic abnormal state identifier specifically refers to a voltage-current gradient mutation identifier, a fluctuation continuous over-limit state label, an impedance transient drastic change abnormal label and a composite failure mode judgment label.

[0008] As a further solution of the present invention, the time synchronization trigger module includes: The clock synchronization submodule obtains the clock pulse frequency value of the crystal oscillator phase-locked loop signal source based on the multi-dimensional test data of the energy storage device, extracts the physical signal path delay parameters of the voltage sampling channel, current sampling channel, impedance measurement channel and temperature monitoring channel, calculates the channel sampling delay time based on the clock pulse frequency value and the physical signal path delay parameters, establishes the channel clock synchronization benchmark, and obtains the channel clock synchronization benchmark information; The timing compensation submodule calls the channel clock synchronization reference information, performs cumulative operation on the channel sampling delay time and the target trigger time of the sampling instruction, calculates the timing offset value of the channel, establishes a synchronization trigger time sequence based on the timing offset value, and obtains a channel timing compensation sequence; The concurrent acquisition submodule calls the channel timing compensation sequence and simultaneously issues acquisition instructions to the voltage sampling channel, current sampling channel, impedance measurement channel, and temperature monitoring channel according to the synchronous trigger time sequence. It collects transient voltage waveforms, transient current waveforms, Nyquist impedance complex sequences, and temperature change curves during the charge and discharge process to generate a full-channel synchronous electrochemical data set.

[0009] As a further solution of the present invention, the impedance trajectory acquisition module includes: The frequency band extraction submodule obtains the full-channel synchronous electrochemical data set, extracts the complex impedance sequences of the high frequency band, the medium frequency band, the low frequency band, and the ultra-low frequency band within the frequency characteristic range of the Nyquist diagram, extracts the amplitude and phase information based on the frequency band impedance sequence, and obtains the frequency band impedance characteristic information; The parameter calculation submodule calls the impedance characteristic information of the frequency band, calculates the electrolyte resistance according to the real part of the high frequency band, calculates the charge transfer resistance according to the semicircle diameter of the medium frequency band, calculates the double layer capacitance according to the slope of the low frequency straight line in the medium and low frequency bands, and calculates the Warburg impedance according to the slope and frequency dependence of the ultra-low frequency band, thereby obtaining a set of impedance characteristic parameters; The trajectory construction submodule calls the impedance characteristic parameter set, arranges the electrolyte resistance, charge transfer resistance, double layer capacitance and Warburg impedance in sequence according to the charge and discharge cycle sequence, constructs a time series trajectory of the four impedance parameters changing with the charge and discharge cycle, and generates a multi-cycle impedance evolution parameter sequence.

[0010] As a further solution of the present invention, the degradation state identification module includes: The change rate extraction submodule obtains the multi-cycle impedance evolution parameter sequence, performs first-order difference operations on the electrolyte resistance, charge transfer resistance, double layer capacitance and Warburg impedance according to the charge and discharge cycle sequence, calculates the change rate sequence of the impedance parameters, and generates impedance change rate information; The trend inflection point identification submodule calls the impedance change rate information, calculates the continuous first-order derivative of the change rate sequence, identifies the extreme value points of the change slope and the change inflection point positions of the derivative sequence, calculates the mutation intensity based on the change gradient distribution, obtains the mutation intensity sequence by operation, and screens the inflection point indexes above the mutation screening threshold to obtain the change trend mutation index; The degradation joint judgment submodule performs a joint matching judgment based on the change trend mutation index, combined with the voltage platform change amplitude and current response nonlinear offset of the constant current region corresponding to each charge and discharge cycle, and selects the periodic nodes where the mutation gradient change is consistent with the voltage and current fluctuations, establishes a set of key turning points in the degradation process, and obtains the degradation inflection point characteristic sequence of the energy storage device.

[0011] As a further solution of the present invention, the formula for calculating and obtaining the mutation intensity sequence is specifically: ; in, Representative The mutation intensity of each charge and discharge cycle, Representative The impedance change rate during the charge and discharge cycle is Representative The impedance change rate during the charge and discharge cycle is Representative Normalized value of voltage platform change in constant current region during each charge and discharge cycle, Representative Normalized value of nonlinear offset of current response during charge and discharge cycle, Representative Normalized value of charge transfer resistance for each charge and discharge cycle, Representative Normalized value of double layer capacitance per charge and discharge cycle, Representative Normalized value of Warburg impedance during charge and discharge cycles, represents the weight coefficient of the difference in rate of change, represents the weight coefficient of voltage change, represents the weight coefficient of the current offset, Represents the threshold for determining mutation intensity.

[0012] As a further solution of the present invention, the electrochemical anomaly monitoring module includes: The gradient difference extraction submodule extracts the voltage change rate sequence and the current change rate sequence at each time point in the charge and discharge process based on the full-channel synchronous electrochemical data set, calculates the absolute value of the difference between the two change rate sequences at the corresponding time points, and accumulates the absolute values ​​of the differences in consecutive time points to obtain the voltage and current gradient difference cumulative amount information; The fluctuation persistence discrimination submodule calls the voltage and current gradient differential cumulative amount information, extracts the periodic fluctuation segments based on the continuous time window length, calculates the fluctuation duration, Warburg impedance transient change rate, and charge transfer resistance mutation rate within each segment, performs normalization on the three parameters, and then performs standardized amplitude aggregation to obtain a sequence of period abnormality amplification coefficients. The period indexes greater than the abnormal amplification threshold are screened to obtain an abnormal fluctuation period index set. The formula for calculating and obtaining the periodic abnormality amplification coefficient sequence is specifically: ; in, Indicates the The abnormal increase coefficient of the cycle, Indicates the Normalized value of the cumulative differential amount of periodic voltage and current gradient, Indicates the Normalized value of the transient rate of change of periodic Warburg impedance, Indicates the Normalized value of the periodic charge transfer resistance mutation rate, It represents the mean value of the accumulated voltage and current gradient differences within the cycle. represents the mean value of the transient change rate of Warburg impedance within a cycle, represents the average value of the charge transfer resistance mutation rate within a cycle, Adjust parameters for gradient differential amplification; Abnormal state identification submodule: Based on the abnormal fluctuation period index set, a joint threshold judgment is performed on the voltage change rate sequence, current change rate sequence, Warburg impedance change rate and charge transfer resistance mutation rate within the corresponding period, and the periodic nodes that simultaneously meet the characteristics of abnormal voltage and current fluctuations and abnormal impedance changes are identified. An abnormal working state label set is established to obtain the electrochemical dynamic abnormal state identification.

[0013] As a further embodiment of the present invention, the system further comprises: The performance test determination module calls the degradation inflection point characteristic sequence and electrochemical dynamic abnormal state identifier of the energy storage device, distinguishes and marks the active state interval, degradation interval and abnormal interval of the energy storage device based on the state classification rule, and obtains the electrochemical performance test state mapping result of the energy storage device; The electrochemical performance test state mapping result of the energy storage device includes an active working state label, a performance degradation state label, a function abnormality state label, and a test cycle performance change trend label.

[0014] As a further solution of the present invention, the performance test determination module includes: The state parameter extraction submodule obtains the degradation inflection point feature sequence and electrochemical dynamic abnormal state identifier of the energy storage device, and extracts each state parameter of the corresponding cycle by combining the open circuit voltage interval distribution, charge and discharge current stability index, charge transfer resistance change trend and double layer capacitance change interval in the current charge and discharge cycle to obtain the state parameter feature set; The state interval division submodule constructs a state interval division standard based on the state parameter feature set and according to the fluctuation amplitude of the open circuit voltage interval distribution, the degree of current stability deviation, and the trend change of the charge transfer resistance and double layer capacitance, divides the periodic state into active state interval, degraded state interval and abnormal state interval, and generates state interval classification labels; The performance map generation submodule calls the state interval classification label and maps each cycle state to the performance label space, forming a bidirectional mapping relationship between the cycle and the state label. Combined with the continuous state change trajectory during the charge and discharge process, a complete performance test state mapping relationship is established to obtain the electrochemical performance test state mapping result of the energy storage device.

[0015] A method for testing the electrochemical performance of an energy storage device, the method being used to implement the above-mentioned electrochemical performance testing system for an energy storage device, comprises the following steps: S1: Acquire multi-dimensional test data of energy storage devices, establish a synchronous trigger time base sequence for each channel, call the time base sequence to synchronously trigger the multi-channel sampling unit to perform concurrent acquisition of four types of data: voltage, current, impedance, and temperature, and obtain a full-channel synchronous electrochemical data set; S2: Based on the full-channel synchronous electrochemical data set, establish a time-varying trajectory of the impedance parameters according to the charge-discharge cycle sequence to obtain a multi-cycle impedance evolution parameter sequence; S3: calling the multi-cycle impedance evolution parameter sequence, calculating the electrolyte resistance change rate, charge transfer resistance change rate, double layer capacitance change rate and Warburg impedance change rate during multiple consecutive charge and discharge cycles, identifying the slope change point and the extreme inflection point position, and obtaining the energy storage device degradation inflection point characteristic sequence; S4: Based on the full-channel synchronous electrochemical data set, combined with the short-period abnormal points of the Warburg impedance transient change rate and the charge transfer resistance mutation rate in the multi-period impedance evolution parameter sequence, the abnormal state of the energy storage device is identified to obtain the electrochemical dynamic abnormal state identifier; S5: calling the energy storage device degradation inflection point characteristic sequence and electrochemical dynamic abnormal state identifier, distinguishing and marking the active state interval, degradation interval and abnormal interval of the energy storage device based on the state classification rule, and obtaining the electrochemical performance test state mapping result of the energy storage device.

[0016] Compared with the prior art, the advantages and positive effects of the present invention are: In the present invention, by calculating the sampling delay compensation time, multi-channel concurrent synchronous acquisition of voltage, current, impedance and temperature is achieved, effectively avoiding data errors caused by asynchronous sampling between channels. The dynamic evolution sequence of electrolyte resistance, charge transfer resistance, double layer capacitance and Warburg impedance is extracted based on the frequency characteristic interval of the Nyquist diagram. The slope change points and extreme inflection points of the electrolyte resistance change rate and the charge transfer resistance change rate are combined to assist in identifying the inflection point characteristics of the energy storage device degradation process. By calculating the gradient absolute difference sequence of the voltage change rate and the current change rate, and linking the impedance mutation rate with short-period abnormal fluctuations, the trends of lithium plating, micro-short circuit and electrode interface damage can be accurately identified. In the process of determining the state of the energy storage device, the open circuit voltage distribution, charge and discharge current stability and impedance change trend are jointly considered to improve the accuracy of identifying the active state, degraded state and abnormal state, and improve the accuracy and reliability of electrochemical performance testing. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0018] Figure 1 is a system flow chart of the present invention; Figure 2 Schematic diagram of the system framework of the present invention; Figure 3 This is a flow chart of the time synchronization trigger module of the present invention; Figure 4 This is a flow chart of the impedance trajectory acquisition module of the present invention; Figure 5 This is a flow chart of the degradation state identification module of the present invention; Figure 6 This is a flow chart of the electrochemical anomaly monitoring module of the present invention; Figure 7 This is a flow chart of the performance test determination module of the present invention; Figure 8 Schematic diagram of the method steps of the present invention. DETAILED DESCRIPTION

[0019] The technical solution of the present invention is described below in conjunction with the accompanying drawings.

[0020] In the embodiments of the present invention, words such as "exemplarily" and "for example" are used to indicate examples, illustrations, or explanations. Any embodiment or design described as an "exemplary" in the present invention should not be interpreted as being preferred or advantageous over other embodiments or designs. Rather, the use of the word "exemplary" is intended to present concepts in a concrete manner. Furthermore, in the embodiments of the present invention, "and / or" can mean both or either of the two.

[0021] In the embodiments of the present invention, the terms "image" and "picture" may sometimes be used interchangeably. It should be noted that, when the distinction is not emphasized, the meanings they convey are the same. The terms "of," "corresponding," and "corresponding" may sometimes be used interchangeably. It should be noted that, when the distinction is not emphasized, the meanings they convey are the same.

[0022] In the embodiments of the present invention, sometimes a subscript such as W1 may be written as a non-subscript such as W1. When the difference is not emphasized, the meanings to be expressed are the same.

[0023] In order to make the technical problems, technical solutions and advantages to be solved by the present invention clearer, a detailed description will be given below with reference to the accompanying drawings and specific embodiments.

[0024] See also Figure 1 The present invention provides a technical solution: an electrochemical performance testing system for energy storage devices, the system comprising: The time synchronization trigger module acquires multi-dimensional test data of the energy storage device, including the clock pulse frequency of the crystal oscillator phase-locked loop signal source, and the physical signal path delay parameters of the energy storage device voltage sampling channel, current sampling channel, impedance measurement channel, and temperature monitoring channel. Based on the clock pulse frequency and channel delay parameters, the sampling delay compensation time is calculated. The compensation time is used to perform timing calibration on the triggering moment of the sampling control instruction, and a synchronous trigger time base sequence is established for each channel. The time base sequence is called to synchronously trigger the multi-channel sampling unit to perform concurrent acquisition of four types of data: voltage, current, impedance, and temperature, thereby obtaining a full-channel synchronous electrochemical data set. The impedance trajectory acquisition module extracts four impedance characteristic parameters of the energy storage device within the Nyquist plot frequency characteristic range based on a full-channel synchronous electrochemical data set: electrolyte resistance, charge transfer resistance, double-layer capacitance, and Warburg impedance. It then establishes a trajectory of impedance parameter changes over time according to the charge-discharge cycle sequence, generating a multi-cycle impedance evolution parameter sequence. The degradation state identification module uses a multi-cycle impedance evolution parameter sequence to calculate the rate of change of the electrolyte resistance, charge transfer resistance, double layer capacitance, and Warburg impedance over multiple consecutive charge and discharge cycles. It then calculates the first-order derivative of the four-item change rate sequence to identify the slope change points and extreme inflection points. The module then combines the voltage platform change amplitude in the constant current region during the charge and discharge process with the nonlinear offset of the current response to determine the characteristic sequence of degradation inflection points of the energy storage device. The electrochemical anomaly monitoring module, based on a full-channel synchronous electrochemical data set, extracts the voltage and current rate of change sequences during the charge and discharge process, calculates the gradient absolute difference sequence at corresponding time points, obtains the fluctuation duration within a continuous time window, and determines whether it exceeds the voltage-current anomaly gradient threshold and time duration threshold. Combining the short-period anomalies of the Warburg impedance transient change rate and charge transfer resistance mutation rate in the multi-period impedance evolution parameter sequence, it identifies the abnormal state of the energy storage device and obtains the electrochemical dynamic abnormal state identifier. The performance test judgment module calls the energy storage device degradation inflection point characteristic sequence and electrochemical dynamic abnormal state identification, combines the open circuit voltage interval distribution, charge and discharge current stability, charge transfer resistance change trend and double layer capacitance change interval in the current cycle, and distinguishes and labels the active state interval, degradation interval and abnormal interval of the energy storage device based on the state classification rules, and obtains the electrochemical performance test state mapping result of the energy storage device; The full-channel synchronous electrochemical data set includes the transient voltage waveform sequence, transient current waveform sequence, Nyquist impedance complex sequence and temperature change curve of the charging and discharging process. The multi-cycle impedance evolution parameter sequence specifically includes the electrolyte resistance change sequence, charge transfer resistance change sequence, double layer capacitance change sequence and Warburg impedance change sequence. The characteristic sequence of energy storage device degradation inflection point includes the impedance change slope mutation point, the constant current region voltage platform offset point, the current nonlinear response inflection point and the impedance trajectory abnormal curvature point. The electrochemical dynamic abnormal state identification specifically includes the voltage-current gradient mutation identification, the fluctuation continuous over-limit state label, the impedance transient drastic change abnormality label and the composite failure mode judgment label. The electrochemical performance test state mapping results of the energy storage device include the active working state label, the performance degradation state label, the functional abnormality state label and the test cycle performance change trend label.

[0025] See also Figure 2 and Figure 3 ,The time synchronization trigger module includes a clock synchronization submodule, a timing compensation submodule, and a concurrent acquisition submodule; The clock synchronization submodule obtains the clock pulse frequency value of the crystal oscillator phase-locked loop signal source based on the multi-dimensional test data of the energy storage device, extracts the physical signal path delay parameters of the voltage sampling channel, current sampling channel, impedance measurement channel and temperature monitoring channel, calculates the channel sampling delay time based on the clock pulse frequency value and the physical signal path delay parameters, establishes the channel clock synchronization benchmark, and obtains the channel clock synchronization benchmark information; Get the clock pulse frequency value of the crystal oscillator phase-locked loop signal source, where the clock pulse frequency is set to The constant temperature crystal oscillator source corresponds to the clock period of , extract the physical signal path delay parameters of the voltage sampling channel, current sampling channel, impedance measurement channel and temperature monitoring channel. After measuring the cable length and calculating the signal transmission time, the physical path delay of the voltage channel is measured to be , the current channel is , the impedance channel is , the temperature channel is , based on the clock cycle Calculate the channel sampling delay time using the formula: , substituted into the voltage channel as clock cycles, the calculated delay time of all channels is less than a full clock cycle. To avoid trigger errors, the benchmark rule is set to round up, so the delay time of the voltage channel, current channel, impedance channel and temperature channel is set to 1 clock cycle, that is, This rule is based on the minimum resolution unit of the crystal oscillator. If the path delay is less than one clock cycle, one clock cycle is used as the minimum synchronization compensation unit. Decimal accumulation is not allowed. Then, based on the delay compensation setting, a channel clock synchronization benchmark is established. A synchronization benchmark table is constructed. The table lists the channel number, physical delay, and delay compensation clock cycle, and finally the channel clock synchronization benchmark information is obtained. The timing compensation submodule calls the channel clock synchronization reference information, accumulates the channel sampling delay time and the target trigger time of the sampling instruction, calculates the channel timing offset value, establishes the synchronization trigger time sequence based on the timing offset value, and obtains the channel timing compensation sequence; Call the channel clock synchronization benchmark information, first extract the delay compensation value of each channel, the voltage sampling channel compensation is 1 clock cycle, the current channel, impedance channel and temperature channel are also 1 clock cycle, the sampling instruction target trigger time is set to As the global start time, the accumulated delay compensation value is used, and the voltage channel triggering time is calculated as The other three channels are calculated similarly as , calculate the timing offset value according to the trigger time, using the formula: Timing offset value = channel trigger time - minimum trigger time, where the minimum trigger time of all channels is , so the timing offset values ​​are The offset rule is based on the synchronous system design standard. The offset lower limit reference value is 0, and the upper limit reference value is equal to the maximum channel trigger time, which is currently 100. This is used to establish the synchronous trigger time sequence. The starting point of the time sequence is set to , the step interval is set according to the crystal oscillator period , the sample time series is 、 、 、 The step interval is set according to the acquisition frequency. If the clock frequency is adjusted to , the step interval is adjusted accordingly to ,Finally a synchronous trigger schedule of the entire charging and discharging process is formed, and the channel timing compensation sequence is obtained; The concurrent acquisition submodule calls the channel timing compensation sequence and simultaneously issues acquisition instructions to the voltage sampling channel, current sampling channel, impedance measurement channel, and temperature monitoring channel according to the synchronous trigger time sequence. It collects transient voltage waveforms, transient current waveforms, Nyquist impedance complex sequences, and temperature change curves during the charge and discharge process to generate a full-channel synchronous electrochemical data set. Call the channel timing compensation sequence, and send acquisition instructions to the voltage sampling channel, current sampling channel, impedance measurement channel and temperature monitoring channel at the same time according to the synchronous trigger time sequence. The sampling rate of the voltage channel is set to , 1000 voltage sampling points are obtained in one charging cycle, and the current channel also has a sampling rate of , obtain 1000 current sampling points, perform frequency scanning on the impedance measurement channel, set the scanning frequency to 1Hz to 1kHz, the number of scanning points to 20, record the Nyquist complex impedance value corresponding to each frequency point, set the sampling rate of the temperature channel to 1Hz, and record the temperature change curve of the entire charging and discharging process. During the acquisition process, the timestamps of all channels are strictly based on the synchronous time series, and the synchronization accuracy benchmark is set to the crystal oscillator period , the upper limit of synchronization error is controlled within one clock cycle, that is, The trigger signal that exceeds the error is determined to be a step-out signal and is marked and removed. All collected data are finally aligned and stored according to the timestamp to form a multi-physical quantity full-channel synchronous electrochemical data package containing transient voltage waveforms, transient current waveforms, Nyquist impedance complex sequences and temperature change curves, and finally a full-channel synchronous electrochemical data set is generated.

[0026] See also Figure 2 and Figure 4 ,The impedance trajectory acquisition module includes a frequency band extraction submodule, a parameter calculation submodule, and a trajectory construction submodule; The frequency band extraction submodule acquires a full-channel synchronous electrochemical data set, extracts the complex impedance sequences of the high-frequency band, mid-frequency band, low-frequency band, and ultra-low-frequency band within the frequency characteristic range of the Nyquist diagram, extracts the amplitude and phase information based on the frequency band impedance sequence, and obtains the frequency band impedance characteristic information; Acquire a full-channel synchronous electrochemical data set. First, extract the complex impedance sequence segmentally based on the frequency characteristic interval of the Nyquist diagram. The Nyquist diagram frequency division standard is the high frequency band. to , mid-band to , low frequency band to and ultra-low frequency band to , according to the four frequency intervals, the corresponding complex impedance sequence is selected. For each frequency band impedance point, the real part and the imaginary part are extracted, and the amplitude is calculated using the formula and phase Calculate, where is the real part, is the imaginary part. For example, if the real part of the high frequency impedance is , the imaginary part is , then the amplitude , phase The calculation is applied to the impedance points in all frequency bands in turn to complete the impedance data amplitude and phase conversion in the high-frequency, medium-frequency, low-frequency and ultra-low-frequency bands. The frequency division is based on the conventional judgment criteria of electrochemical impedance spectroscopy. The ultra-low frequency band mainly reflects the diffusion process, the medium frequency band represents the charge transfer process, the high frequency band reflects the interface resistance, and the low frequency band reflects the double-layer capacitance process. Finally, the frequency band impedance characteristic information is obtained. The parameter calculation submodule calls the frequency band impedance characteristic information, calculates the electrolyte resistance based on the real part of the high frequency band, calculates the charge transfer resistance based on the semicircle diameter of the medium frequency band, calculates the double layer capacitance based on the slope of the low frequency straight line in the medium and low frequency bands, and calculates the Warburg impedance based on the slope and frequency dependence of the ultra-low frequency band, thus obtaining a set of impedance characteristic parameters; Call the frequency band impedance characteristic information and directly calculate the electrolyte resistance based on the real part of the high frequency band. If the average real part of the high frequency band is , then the electrolyte resistance , the charge transfer resistance is determined according to the diameter of the semicircle in the mid-frequency band. The semicircle diameter is calculated by subtracting the minimum real part from the maximum real part in the mid-frequency band. If the maximum real part in the mid-frequency band is The minimum real part is , then the charge transfer resistance , according to the double logarithmic linear relationship between the imaginary part and frequency in the low and medium frequency impedance spectrum, the slope of the straight line is extracted using the formula Calculate, if the frequency from Change to , the imaginary part from changes to , then , according to the relationship between the double-layer capacitance and the imaginary part of the impedance slope at , the Warburg impedance formula is used in the ultra-low frequency band , if the imaginary part of the impedance measured at is , then , the final Warburg impedance parameters are obtained , all parameter calculations are based on the standard theory of electrochemical impedance spectroscopy, without introducing new weights or coefficients, and all reference sources are derived from the physical measurement of the Nyquist diagram, obtaining a set of impedance characteristic parameters; The trajectory construction submodule calls the impedance characteristic parameter set, and arranges the electrolyte resistance, charge transfer resistance, double-layer capacitance and Warburg impedance in sequence according to the order of the charge and discharge cycle, constructs the time sequence trajectory of the change of the four impedance parameters with the charge and discharge cycle, and generates a multi-cycle impedance evolution parameter sequence; The impedance characteristic parameter set is called, and the electrolyte resistance, charge transfer resistance, double-layer capacitance and Warburg impedance are arranged in time sequence according to the order of the charge and discharge cycle, and the impedance change trajectory in the charge and discharge cycle is constructed. In the example cycle, if the impedance parameters of the first charge and discharge cycle are , , , , , the second cycle measures , , , , and so on, the four impedance parameters of each cycle are sequentially sorted to form a sequence curve changing with time, and the trajectory sequence determination standard is set as when the change amplitude of the impedance parameters of adjacent cycles exceeds 5%, it is marked as a mutation point. The 5% variation determination threshold is set according to the allowable deviation of the electrochemical performance test under IEC61960 standard. If the double-layer capacitance of a certain cycle changes from to , the change rate is greater than 5%, it is recorded as a mutation node, and a complete impedance change trajectory is finally formed and a multi-cycle impedance evolution parameter sequence is generated.

[0027] Please refer to Figure 2 and Figure 5 , the degradation state recognition module includes a change rate extraction submodule, a trend inflection point identification submodule, and a degradation joint determination submodule; The change rate extraction submodule obtains a multi-cycle impedance evolution parameter sequence, performs first-order difference operations on the electrolyte resistance, charge transfer resistance, double-layer capacitance, and Warburg impedance according to the charge and discharge cycle sequence, calculates the change rate sequence of the impedance parameters, and generates impedance change rate information; Obtain multi-cycle impedance evolution parameter sequence, based on the charge and discharge cycle sequence, the electrolyte resistance , charge transfer resistance , electric double layer capacitors and Warburg impedance Perform first-order difference operations respectively, for example, the impedance parameter of cycle 1 is 、 、 、 , the impedance parameter of period 2 is 、 、 、 , using the first-order difference formula Calculate and get 、 、 、 The logic of the change rate calculation is to describe the dynamic trend of impedance change through the absolute difference of impedance values ​​in adjacent charge and discharge cycles, rather than based on percentage change, directly reflecting the transient change amplitude of each physical parameter. The change rate judgment benchmark is 5%. Here, the electrolyte resistance change rate If it is greater than 5%, it is marked as a change, and the double layer capacitance change rate If it is less than 5%, no mark is made and the impedance change rate information is finally obtained; The trend inflection point identification submodule calls the impedance change rate information, calculates the continuous first-order derivative of the change rate sequence, identifies the extreme value points of the change slope and the change inflection point positions of the derivative sequence, calculates the mutation intensity based on the change gradient distribution, obtains the mutation intensity sequence, and screens the inflection point indexes above the mutation screening threshold to obtain the change trend mutation index; The formula for calculating the mutation intensity sequence is as follows: ; in, Representative The mutation intensity of each charge and discharge cycle, Representative The impedance change rate during the charge and discharge cycle is Representative The impedance change rate during the charge and discharge cycle is Representative Normalized value of voltage platform change in constant current region during each charge and discharge cycle, Representative Normalized value of nonlinear offset of current response during charge and discharge cycle, Representative Normalized value of charge transfer resistance for each charge and discharge cycle, Representative Normalized value of double layer capacitance per charge and discharge cycle, Representative Normalized value of Warburg impedance during charge and discharge cycles, represents the weight coefficient of the difference in rate of change, represents the weight coefficient of voltage change, represents the weight coefficient of the current offset, represents the threshold for determining mutation intensity; To call the impedance change rate information, first perform the first-order derivative operation on the change rate sequence. For example, the electrolyte resistance change rate in period 2 is , period 3 is , the derivative is calculated as , similarly calculate the derivative series of charge transfer resistance, double layer capacitance, and Warburg impedance, and then substitute them into the formula: ; Set the parameter value to 、 、 , substitute the example, assuming 、 、 , , charge transfer resistance , double layer capacitance , Warburg impedance , substitute into the formula to calculate: ; Step-by-step calculation: ; ; Molecular part: 、 、 , sum of numerators = 0.2078 + 0.01192 + 0.015 = 0.23472; Denominator: ; Final calculation: ; This calculation result is below the mutation screening threshold , is not judged as a mutation point.

[0028] The meanings of the parameters in the formula are: Representative Cycle mutation intensity, Weight for change rate difference, Weight for voltage fluctuation, Weight for current offset, Indicates the absolute value of the derivative of the adjacent cycle change rate, Normalized value of constant current region voltage change, Normalized value of current response offset, the denominator is the modulus of the charge transfer resistance, double-layer capacitance and Warburg impedance, and the square root operation plays a role in normalization smoothing, the absolute value eliminates the directional influence, the square root balances the large number of items, the multiplication distributes the contribution of different parameters, and the division realizes the normalization processing.

[0029] The advantage of the formula is that by introducing the nonlinear terms of voltage fluctuation And current offset , the detection of nonlinear degradation trend is more sensitive, and the dimension difference between multiple physical quantities is effectively balanced through the square root denominator structure, which improves the stability and adaptability of the mutation intensity determination. The result shows that there is no mutation inflection point in the current cycle, and the value is lower than the threshold value 1.5. If the value is greater than the threshold value, it will be marked as a trend mutation node, which directly affects the key node determination of the subsequent degradation path.

[0030] The degradation joint determination submodule is based on the change trend mutation index, combines the constant current region voltage platform change amplitude and current response nonlinear offset corresponding to each charge and discharge cycle, and performs joint matching judgment to screen the cycle nodes with consistent mutation gradient change, voltage and current fluctuation, establish the key turning point set in the degradation process, and obtain the degradation inflection point feature sequence of the energy storage device.

[0031] Based on the change trend mutation index, the constant current region voltage change And current offset of the current cycle are combined to perform joint determination, and the judgment standard is set as: Greater than 0.03V, Greater than 0.02A, and mutation intensity Greater than 1.5 is determined as a key inflection point. The voltage change threshold is calculated to be 0.108V according to 3% of the average working voltage 3.6V of the battery, and 0.03V is actually used as a more sensitive monitoring value. The current offset threshold is calculated to be 0.02A according to 2% of the average working current 1A, the mutation intensity calculated in the current cycle is 0.2323, which is lower than 1.5, Greater than the threshold, Greater than the threshold, although the voltage and current fluctuations meet the requirements, the mutation intensity is not met, so it is not determined to be a degradation inflection point. This result shows that although there are voltage platform fluctuations and current response offsets in this cycle, they are not enough to form a major mutation in the trend change, so it will not be included in the key nodes of the degradation path, and finally the characteristic sequence of the degradation inflection point of the energy storage device is obtained.

[0032] See also Figure 2 and Figure 6 ,The electrochemical anomaly monitoring module includes a gradient difference extraction submodule, a ,fluctuation persistence discrimination submodule, and an abnormal state recognition submodule; The gradient difference extraction submodule extracts the voltage change rate sequence and current change rate sequence at each time point in the charge and discharge process based on the full-channel synchronous electrochemical data set, calculates the absolute value of the difference between the two change rate sequences at the corresponding time points, and accumulates the absolute values ​​of the differences in consecutive time points to obtain the voltage and current gradient difference cumulative information; Acquire a full-channel synchronous electrochemical data set and extract the voltage change rate series based on the time series during the charge and discharge process and current rate of change series , each rate of change sequence is calculated based on time differential, using the difference formula 、 To solve, assume that the time series has a step of 10ms, and in the first time step The voltage changes from 3.6V to 3.58V, , the current changes from 1.00A to 1.05A, , and then calculate the absolute value of the gradient difference between the two: , continue to perform this calculation for the entire time series, assuming that the absolute value sequence of the difference is obtained in 5 consecutive time steps , and add them up to get the voltage and current gradient differential accumulator The calculation of the gradient difference reflects the degree of synchronization deviation between the voltage and current in the time change trend. The accumulation process is used to quantify the sum of the deviation in a charge and discharge cycle. There is no threshold for the cumulative value calculation. The changes in all time steps are fully included, and finally the voltage and current gradient difference accumulation information corresponding to each charge and discharge cycle is formed; The fluctuation persistence discrimination submodule uses the voltage and current gradient differential accumulation information to extract periodic fluctuation segments based on the continuous time window length. It then calculates the fluctuation duration, Warburg impedance transient change rate, and charge transfer resistance mutation rate within each segment. After normalizing these three parameters, it performs standardized amplitude aggregation and calculates the cycle abnormality amplification coefficient sequence. It then selects the cycle indexes that are greater than the abnormal amplification threshold to obtain the abnormal fluctuation cycle index set. The formula for calculating the periodic abnormality amplification coefficient sequence is as follows: ; in, Indicates the The abnormal increase coefficient of the cycle, Indicates the Normalized value of the cumulative differential amount of periodic voltage and current gradient, Indicates the Normalized value of the transient rate of change of periodic Warburg impedance, Indicates the Normalized value of the periodic charge transfer resistance mutation rate, It represents the mean value of the accumulated voltage and current gradient differences within the cycle. represents the mean value of the transient change rate of Warburg impedance within a cycle, represents the average value of the charge transfer resistance mutation rate within a cycle, Adjust parameters for gradient differential amplification; Call the voltage and current gradient differential accumulation information, combined with the Warburg impedance transient change rate within each cycle Charge transfer resistance mutation rate , first calculate the normalized values ​​of the three parameters, the normalization formula is ,in is the mean of all cycles, assuming that in 10 cycles 、 、 , current cycle 、 、 , substitute into the formula: ; Step-by-step calculation: Gradient difference term ; Warburg impedance term ; Charge transfer resistance term ; Multiplying three terms ; The abnormal increase threshold is set to 2.0, which is calculated based on the average value of the increase coefficient in all cycles plus 1.5 times the standard deviation. If the mean is 1.5 and the standard deviation is 0.33, then ,current It is determined to be an abnormal period. The operation logic in the formula is: the gradient difference term adopts exponential operation The nonlinear amplification of gradient anomalies is emphasized, the square root operation balances the influence of Warburg impedance, the charge transfer resistance uses linear amplification to reflect short-term mutations, the absolute value is used to eliminate the directionality of positive and negative changes, and multiplication aggregates three types of physical indicators to improve the comprehensiveness and accuracy of anomaly detection. The formula is beneficial in that it amplifies the gradient difference term through nonlinear exponential amplification and superimposes the square root function to smooth impedance fluctuations, constructing a multi-dimensional physical parameter joint judgment. This allows anomaly detection to not only focus on sudden changes in voltage and current, but also reflect the changing trends of internal electrochemical processes, thereby effectively improving the recognition sensitivity of abnormal conditions such as micro-short circuits and lithium deposition. The result indicates that there is a comprehensive fluctuation anomaly in this cycle, which will be included in the abnormal cycle index concentration as the judgment basis for subsequent abnormal state identification. Abnormal state identification submodule: Based on the abnormal fluctuation period index set, a joint threshold discrimination is performed on the voltage change rate sequence, current change rate sequence, Warburg impedance change rate, and charge transfer resistance mutation rate within the corresponding period. The periodic nodes that simultaneously meet the characteristics of abnormal voltage and current fluctuations and abnormal impedance changes are identified, and an abnormal working state label set is established to obtain the electrochemical dynamic abnormal state identification.

[0033] Based on the abnormal fluctuation period index set, the period The voltage change rate sequence and current change rate sequence in the period were retrospectively detected, confirming that within the continuous time window, the voltage change rate sequence had a peak offset of 0.04V / s, and the current change rate sequence had an offset of 0.035A / s. The absolute value of the gradient difference between the two was continuously higher than 0.07 for three time steps. In addition, the Warburg impedance change rate of this period was detected to be 0.28, which was greater than the average of 0.24 for the entire period, and the charge transfer resistance mutation rate was 0.35, which was greater than the average of 0.31 for the entire period. All abnormal joint judgment rules were met, and the joint threshold rule was set to a voltage change rate peak higher than 0.03 V / s, the peak current change rate is higher than 0.025A / s, and the cumulative gradient difference is greater than 0.18 (based on G_avg) and lasts for more than two time steps. All indicators of this period are met and it is determined to be an electrochemical abnormal state period. It is included in the abnormal working state label set and ultimately forms an electrochemical dynamic abnormal state identification. This judgment logic avoids misjudgment caused by a single voltage or current anomaly through dual cross-validation of gradient fluctuations and impedance mutations, ensuring that the abnormal state not only reflects external signal fluctuations, but also simultaneously captures deep electrochemical anomalies such as interface degradation and ion diffusion barriers within the energy storage device.

[0034] See also Figure 2 and Figure 7 ,The performance test determination module includes a state parameter extraction submodule, a state interval division submodule, and a performance map generation submodule; The state parameter extraction submodule obtains the characteristic sequence of the degradation inflection point and the electrochemical dynamic abnormal state identification of the energy storage device. Combined with the open circuit voltage interval distribution, charge and discharge current stability index, charge transfer resistance change trend and double layer capacitance change interval in the current charge and discharge cycle, it extracts each state parameter of the corresponding cycle and obtains the state parameter feature set. Obtain the characteristic sequence of the degradation inflection point of the energy storage device and the electrochemical dynamic abnormal state identification, extract the open circuit voltage interval distribution for the current charge and discharge cycle, and detect the stable fluctuation range of the open circuit voltage at the end of charge and the beginning of discharge, such as The open circuit voltage in the cycle is measured to range from 3.58V to 3.65V, with a fluctuation of 0.07V. Combined with the stability of the charge and discharge current, the standard deviation of the current fluctuation in the constant current section is monitored. If the constant current target is 1A, the standard deviation in the current cycle is measured to be 0.015A. The charge transfer resistance change trend is further extracted. If the charge transfer resistance in this cycle is , the previous cycle was , the rate of change is , synchronously obtain the double layer capacitance change interval, this cycle , last cycle , the rate of change is The judgment criteria for each change rate are set as follows: if the change amplitude exceeds 5%, it is marked as a trend mutation. The 5% threshold is derived from the IEC61960 standard's provisions on the tolerance of electrochemical parameter fluctuations. The above four parameters are combined as the state description of the current cycle to form a state parameter feature set; The state interval division submodule is based on the state parameter feature set. It constructs a state interval division standard according to the fluctuation amplitude of the open circuit voltage interval distribution, the degree of current stability deviation, and the trend change of charge transfer resistance and double layer capacitance. It divides the periodic state into active state interval, degraded state interval and abnormal state interval, and generates state interval classification labels. Based on the state parameter feature set, the judgment is first made according to the open circuit voltage fluctuation amplitude. If the fluctuation amplitude is less than 0.05V, it is judged as active state, between 0.05V and 0.1V is judged as degraded state, and greater than 0.1V is judged as abnormal state. The open circuit voltage fluctuation of the current cycle is 0.07V, which is classified as degraded interval. Then, according to the current stability index, if the standard deviation is less than 0.01A, it is classified as active, greater than 0.02A is classified as abnormal, between 0.01A and 0.02A is judged as degraded, and the current 0.015A is in degraded state. Continue to analyze the charge transfer circuit. The resistance change trend is judged. If the change rate is less than 3%, it is active; if it is greater than 7%, it is abnormal; if it is between 3% and 7%, it is degraded. A change rate of 5.88% in this cycle is classified as degraded. The same applies to the change of double-layer capacitance. A change rate of less than -3% is degraded, greater than -7% is abnormal, and a change rate of -5% in this cycle is classified as degraded. The above judgment rules are set based on the distribution mean of the measured energy storage device within 500 charge and discharge cycles and are aligned with the common fault judgment intervals in industry standards. The judgment results of the four indicators consistently fall into the degradation interval, generating a state interval classification label; The performance mapping generation submodule calls the state interval classification label and maps each cycle state to the performance label space, forming a bidirectional mapping relationship between the cycle and the state label. Combined with the continuous state change trajectory during the charge and discharge process, a complete performance test state mapping relationship is established to obtain the electrochemical performance test state mapping results of the energy storage device.

[0035] The state interval classification label is called to map the cycle state to the performance label space. If the current cycle is marked as a degraded state, the corresponding performance label is "moderately degraded", forming a bidirectional mapping relationship between the cycle number and the state label. For example, cycle j corresponds to "moderately degraded", cycle j-1 corresponds to "active", and cycle j+1 detects abnormal current fluctuations and a sudden change in charge transfer resistance, which is marked as "abnormal failure". Combined with the continuous state change trajectory of the entire charging and discharging process, a sequence mapping curve of the cycle and state label over time is drawn. The mapping relationship not only shows the state of a single cycle, but also reflects the dynamic trend of state transition, such as the evolution path from active to degraded, and then to abnormality, and finally generates the state mapping result of the electrochemical performance test of the energy storage device.

[0036] See also Figure 8 A method for testing the electrochemical performance of an energy storage device is provided. The method is used to implement the above-mentioned electrochemical performance testing system for an energy storage device, comprising the following steps: S1: Acquire multi-dimensional test data of energy storage devices, establish a synchronous trigger time base sequence for each channel, call the time base sequence to synchronously trigger the multi-channel sampling unit to perform concurrent acquisition of four types of data: voltage, current, impedance, and temperature, and obtain a full-channel synchronous electrochemical data set; S2: Based on the full-channel synchronous electrochemical data set, the impedance parameter change trajectory with time is established according to the charge and discharge cycle sequence, and a multi-cycle impedance evolution parameter sequence is obtained; S3: The multi-cycle impedance evolution parameter sequence is called to calculate the electrolyte resistance change rate, charge transfer resistance change rate, double-layer capacitance change rate and Warburg impedance change rate in the continuous multiple charge and discharge cycles, identify the slope change point and extreme inflection point position, and obtain the degradation inflection point feature sequence of the energy storage device; S4: Based on the full-channel synchronous electrochemical data set, the short-cycle abnormal points of the Warburg impedance transient change rate and the charge transfer resistance mutation rate in the multi-cycle impedance evolution parameter sequence are combined to identify the abnormal state of the energy storage device, and an electrochemical dynamic abnormal state identifier is obtained. S5: The degradation inflection point feature sequence of the energy storage device and the electrochemical dynamic abnormal state identifier are called, and the active state interval, degradation interval and abnormal interval of the energy storage device are distinguished and labeled based on the state classification rule, and an electrochemical performance test state mapping result of the energy storage device is obtained.

[0037] It should be understood that the term "and / or" herein is only a description of the association relationship of the associated objects, which means that there can be three relationships, for example, A and / or B can represent: A exists alone, A and B exist together, and B exists alone, where A and B can be singular or plural. In addition, the character " / " herein generally represents an "or" relationship between the front and rear associated objects, but it can also represent an "and / or" relationship, which can be understood in the context before and after.

[0038] In the present application, "at least one" means one or more, and "multiple" means two or more. "At least one of the following" or the like means any combination of these items, including any combination of single or multiple items. For example, at least one of a, b, or c can mean a, b, c, a-b, a-c, b-c, or a-b-c, where a, b, and c can be single or multiple.

[0039] It should be understood that in various embodiments of the present application, the size of the serial number of the above processes does not mean the order of execution, and the execution order of the processes should be determined by their functions and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present application.

[0040] Those skilled in the art can clearly understand that the units and algorithm steps of each example described in combination with the embodiments disclosed herein can be realized by electronic hardware or a combination of computer software and electronic hardware. Whether the functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of the present application.

[0041] Those skilled in the art can clearly understand that, for the convenience and brevity of the description, the specific working processes of the devices, apparatuses and units described above can refer to the corresponding processes in the foregoing method embodiments, which will not be repeated here.

[0042] In several embodiments provided by the present application, it should be understood that the disclosed devices, apparatuses and methods can be implemented in other ways. For example, the apparatus embodiments described above are merely schematic, for example, the division of the units is only a logical function division, and actual implementation can have another division manner, for example, multiple units or components can be combined or integrated into another device, or some features can be ignored or not executed. In addition, the coupling or direct coupling or communication connection between the units shown or discussed can be indirect coupling or communication connection through some interfaces, devices or units, which can be electrical, mechanical or other forms.

[0043] The units described as separate components can or can not be physically separated, and the components shown as units can or can not be physical units, that is, they can be located in one place, or can be distributed on multiple network units. Part or all of the units can be selected according to actual needs to achieve the purpose of the embodiment scheme.

[0044] In addition, each functional unit in each embodiment of the present application can be integrated into a processing unit, or each unit can exist physically independently, or two or more units can be integrated into one unit.

[0045] If the functions are realized in the form of software function units and sold or used as independent products, they can be stored in a computer readable storage medium. Based on this understanding, the technical solutions of the present application or the parts of the present application that essentially contribute to the prior art or the parts of the technical solutions can be embodied in the form of software products. The computer software product is stored in a storage medium and includes a plurality of instructions for causing a computer device (which can be a personal computer, a server, or a network device, etc.) to execute all or part of the steps of the method described in the various embodiments of the present application. The aforementioned storage medium includes a U disk, a mobile hard disk, a read-only memory (ROM), a random access memory (RAM), a magnetic disk or an optical disk, and various media that can store program codes.

[0046] The above is only a specific implementation of the present application, but the protection scope of the present application is not limited thereto. Any person skilled in the art can easily think of changes or replacements within the technical range disclosed by the present application, which should be covered within the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.

Claims

1. An electrochemical performance testing system for energy storage devices, characterized in that: The system comprises: The time synchronization trigger module acquires multi-dimensional test data of the energy storage device, establishes a synchronization trigger time base sequence for each channel, and calls the time base sequence to synchronously trigger the multi-channel sampling unit to perform concurrent collection of four types of data: voltage, current, impedance, and temperature, thereby obtaining a full-channel synchronized electrochemical data set. The impedance trajectory acquisition module establishes a trajectory of impedance parameter changes over time according to the charge and discharge cycle sequence based on the full-channel synchronous electrochemical data set, and obtains a multi-cycle impedance evolution parameter sequence; The degradation state identification module calls the multi-cycle impedance evolution parameter sequence, calculates the electrolyte resistance change rate, charge transfer resistance change rate, double layer capacitance change rate and Warburg impedance change rate during multiple consecutive charge and discharge cycles, identifies the slope change point and the extreme inflection point position, and obtains the degradation inflection point characteristic sequence of the energy storage device; The electrochemical anomaly monitoring module is based on the full-channel synchronous electrochemical data set and combines the short-period abnormal points of the Warburg impedance transient change rate and the charge transfer resistance mutation rate in the multi-period impedance evolution parameter sequence to identify the abnormal state of the energy storage device and obtain the electrochemical dynamic abnormal state identifier.

2. The electrochemical performance testing system for energy storage devices according to claim 1, characterized in that: The full-channel synchronous electrochemical data set includes a transient voltage waveform sequence, a transient current waveform sequence, a Nyquist impedance complex sequence and a temperature change curve during the charge and discharge process. The multi-cycle impedance evolution parameter sequence is specifically an electrolyte resistance change sequence, a charge transfer resistance change sequence, a double-layer capacitance change sequence and a Warburg impedance change sequence. The energy storage device degradation inflection point characteristic sequence includes an impedance change slope mutation point, a constant current region voltage platform offset point, a current nonlinear response inflection point and an impedance trajectory abnormal curvature point. The electrochemical dynamic abnormal state identifier specifically refers to a voltage-current gradient mutation identifier, a fluctuation continuous over-limit state label, an impedance transient drastic change abnormal label and a composite failure mode judgment label.

3. The electrochemical performance testing system for energy storage devices according to claim 2, characterized in that: The time synchronization trigger module includes: The clock synchronization submodule obtains the clock pulse frequency value of the crystal oscillator phase-locked loop signal source based on the multi-dimensional test data of the energy storage device, extracts the physical signal path delay parameters of the voltage sampling channel, current sampling channel, impedance measurement channel and temperature monitoring channel, calculates the channel sampling delay time based on the clock pulse frequency value and the physical signal path delay parameters, establishes the channel clock synchronization benchmark, and obtains the channel clock synchronization benchmark information; The timing compensation submodule calls the channel clock synchronization reference information, performs cumulative operation on the channel sampling delay time and the target trigger time of the sampling instruction, calculates the timing offset value of the channel, establishes a synchronization trigger time sequence based on the timing offset value, and obtains a channel timing compensation sequence; The concurrent acquisition submodule calls the channel timing compensation sequence and simultaneously issues acquisition instructions to the voltage sampling channel, current sampling channel, impedance measurement channel, and temperature monitoring channel according to the synchronous trigger time sequence. It collects transient voltage waveforms, transient current waveforms, Nyquist impedance complex sequences, and temperature change curves during the charge and discharge process to generate a full-channel synchronous electrochemical data set.

4. The electrochemical performance testing system for energy storage devices according to claim 3, characterized in that: The impedance trajectory acquisition module includes: The frequency band extraction submodule obtains the full-channel synchronous electrochemical data set, extracts the complex impedance sequences of the high frequency band, the medium frequency band, the low frequency band, and the ultra-low frequency band within the frequency characteristic range of the Nyquist diagram, extracts the amplitude and phase information based on the frequency band impedance sequence, and obtains the frequency band impedance characteristic information; The parameter calculation submodule calls the impedance characteristic information of the frequency band, calculates the electrolyte resistance according to the real part of the high frequency band, calculates the charge transfer resistance according to the semicircle diameter of the medium frequency band, calculates the double layer capacitance according to the slope of the low frequency straight line in the medium and low frequency bands, and calculates the Warburg impedance according to the slope and frequency dependence of the ultra-low frequency band, thereby obtaining a set of impedance characteristic parameters; The trajectory construction submodule calls the impedance characteristic parameter set, arranges the electrolyte resistance, charge transfer resistance, double layer capacitance and Warburg impedance in sequence according to the charge and discharge cycle sequence, constructs a time series trajectory of the four impedance parameters changing with the charge and discharge cycle, and generates a multi-cycle impedance evolution parameter sequence.

5. The electrochemical performance testing system for energy storage devices according to claim 4, characterized in that: The degradation state identification module includes: The change rate extraction submodule obtains the multi-cycle impedance evolution parameter sequence, performs first-order difference operations on the electrolyte resistance, charge transfer resistance, double layer capacitance and Warburg impedance according to the charge and discharge cycle sequence, calculates the change rate sequence of the impedance parameters, and generates impedance change rate information; The trend inflection point identification submodule calls the impedance change rate information, calculates the continuous first-order derivative of the change rate sequence, identifies the extreme value points of the change slope and the change inflection point positions of the derivative sequence, calculates the mutation intensity based on the change gradient distribution, obtains the mutation intensity sequence by operation, and screens the inflection point indexes above the mutation screening threshold to obtain the change trend mutation index; The degradation joint judgment submodule performs a joint matching judgment based on the change trend mutation index, combined with the voltage platform change amplitude and current response nonlinear offset of the constant current region corresponding to each charge and discharge cycle, and selects the periodic nodes where the mutation gradient change is consistent with the voltage and current fluctuations, establishes a set of key turning points in the degradation process, and obtains the degradation inflection point characteristic sequence of the energy storage device.

6. The electrochemical performance testing system for energy storage devices according to claim 5, characterized in that: The formula for calculating the mutation intensity sequence is as follows: ； in, Representative The mutation intensity of each charge and discharge cycle, Representative The impedance change rate during the charge and discharge cycle is Representative The impedance change rate during the charge and discharge cycle is Representative Normalized value of voltage platform change in constant current region during each charge and discharge cycle, Representative Normalized value of nonlinear offset of current response during charge and discharge cycle, Representative Normalized value of charge transfer resistance for each charge and discharge cycle, Representative Normalized value of double layer capacitance per charge and discharge cycle, Representative Normalized value of Warburg impedance during charge and discharge cycles, represents the weight coefficient of the difference in rate of change, represents the weight coefficient of voltage change, represents the weight coefficient of the current offset, Represents the threshold for determining mutation intensity.

7. The electrochemical performance testing system for energy storage devices according to claim 6, characterized in that: The electrochemical anomaly monitoring module includes: The gradient difference extraction submodule extracts the voltage change rate sequence and the current change rate sequence at each time point in the charge and discharge process based on the full-channel synchronous electrochemical data set, calculates the absolute value of the difference between the two change rate sequences at the corresponding time points, and accumulates the absolute values ​​of the differences in consecutive time points to obtain the voltage and current gradient difference cumulative amount information; The fluctuation duration discrimination submodule calls the voltage and current gradient differential cumulative amount information, extracts the periodic fluctuation segments based on the continuous time window length, calculates the fluctuation duration, Warburg impedance transient change rate, and charge transfer resistance mutation rate within each segment, performs normalization processing on the three parameters, and then performs standardized amplitude aggregation to obtain a sequence of period abnormality amplification coefficients. The period index greater than the abnormal amplification threshold is screened to obtain an abnormal fluctuation period index set. The formula for calculating and obtaining the periodic abnormality amplification coefficient sequence is specifically: ； in, Indicates the The abnormal increase coefficient of the cycle, Indicates the Normalized value of the cumulative differential amount of periodic voltage and current gradient, Indicates the Normalized value of the transient rate of change of periodic Warburg impedance, Indicates the Normalized value of the periodic charge transfer resistance mutation rate, It represents the mean value of the accumulated voltage and current gradient differences within the cycle. represents the mean value of the transient change rate of Warburg impedance within a cycle, represents the average value of the charge transfer resistance mutation rate within a cycle, Adjust parameters for gradient differential amplification; Abnormal state identification submodule: Based on the abnormal fluctuation period index set, a joint threshold judgment is performed on the voltage change rate sequence, current change rate sequence, Warburg impedance change rate and charge transfer resistance mutation rate within the corresponding period, and the periodic nodes that simultaneously meet the characteristics of abnormal voltage and current fluctuations and abnormal impedance changes are identified. An abnormal working state label set is established to obtain the electrochemical dynamic abnormal state identification.

8. The electrochemical performance testing system for energy storage devices according to claim 7, characterized in that: The system further comprises: The performance test determination module calls the degradation inflection point characteristic sequence and electrochemical dynamic abnormal state identifier of the energy storage device, distinguishes and marks the active state interval, degradation interval and abnormal interval of the energy storage device based on the state classification rule, and obtains the electrochemical performance test state mapping result of the energy storage device; The electrochemical performance test state mapping result of the energy storage device includes an active working state label, a performance degradation state label, a function abnormality state label, and a test cycle performance change trend label.

9. The electrochemical performance testing system for energy storage devices according to claim 8, characterized in that: The performance test determination module includes: The state parameter extraction submodule obtains the degradation inflection point feature sequence and electrochemical dynamic abnormal state identifier of the energy storage device, and extracts each state parameter of the corresponding cycle by combining the open circuit voltage interval distribution, charge and discharge current stability index, charge transfer resistance change trend and double layer capacitance change interval in the current charge and discharge cycle to obtain the state parameter feature set; The state interval division submodule constructs a state interval division standard based on the state parameter feature set and according to the fluctuation amplitude of the open circuit voltage interval distribution, the degree of current stability deviation, and the trend change of the charge transfer resistance and double layer capacitance, divides the periodic state into active state interval, degraded state interval and abnormal state interval, and generates state interval classification labels; The performance map generation submodule calls the state interval classification label and maps each cycle state to the performance label space, forming a bidirectional mapping relationship between the cycle and the state label. Combined with the continuous state change trajectory during the charge and discharge process, a complete performance test state mapping relationship is established to obtain the electrochemical performance test state mapping result of the energy storage device.

10. A method for testing the electrochemical performance of an energy storage device, characterized in that: The method is used to implement the electrochemical performance testing system for energy storage devices according to any one of claims 1 to 9, comprising the following steps: S1: Acquire multi-dimensional test data of energy storage devices, establish a synchronous trigger time base sequence for each channel, call the time base sequence to synchronously trigger the multi-channel sampling unit to perform concurrent acquisition of four types of data: voltage, current, impedance, and temperature, and obtain a full-channel synchronous electrochemical data set; S2: Based on the full-channel synchronous electrochemical data set, establish a time-varying trajectory of the impedance parameters according to the charge-discharge cycle sequence to obtain a multi-cycle impedance evolution parameter sequence; S3: calling the multi-cycle impedance evolution parameter sequence, calculating the electrolyte resistance change rate, charge transfer resistance change rate, double layer capacitance change rate and Warburg impedance change rate during multiple consecutive charge and discharge cycles, identifying the slope change point and the extreme inflection point position, and obtaining the energy storage device degradation inflection point characteristic sequence; S4: Based on the full-channel synchronous electrochemical data set, combined with the short-period abnormal points of the Warburg impedance transient change rate and the charge transfer resistance mutation rate in the multi-period impedance evolution parameter sequence, the abnormal state of the energy storage device is identified to obtain the electrochemical dynamic abnormal state identifier; S5: calling the energy storage device degradation inflection point characteristic sequence and electrochemical dynamic abnormal state identifier, distinguishing and marking the active state interval, degradation interval and abnormal interval of the energy storage device based on the state classification rule, and obtaining the electrochemical performance test state mapping result of the energy storage device.

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