Storage battery polarization internal resistance and electrochemical impedance spectroscopy collaborative testing device and method

Abstract

The invention provides a collaborative test device and method for polarization internal resistance and electrochemical impedance spectroscopy of a storage battery, and relates to the technical field of battery management, and the device comprises a polarization internal resistance test unit, an EIS test unit, a sampling unit and a central processing unit. The polarization internal resistance test unit is used for carrying out polarization internal resistance test control on the storage battery and controlling the sampling unit to carry out sampling; and the EIS test unit is used for carrying out electrochemical impedance spectroscopy test control on the storage battery and controlling the sampling unit to carry out sampling. Polarization internal resistance testing and electrochemical impedance spectroscopy testing of the storage battery are integrated in the same testing device, a collaborative testing framework is constructed, collaborative analysis of the polarization internal resistance and polarization impedance of the storage battery can be obtained through one device, combination of the polarization internal resistance reflecting ohmic polarization and EIS data reflecting electrochemical kinetics is achieved, and the testing accuracy is improved. The state of the storage battery is comprehensively described, the problem of large deviation of single alternating-current impedance evaluation capacity / SOH is solved, and the accuracy and the detection speed of capacity and SOH evaluation results are improved.

Description

Technical Field

[0001] The present invention relates to the technical field of battery management, and particularly relates to a device and method for synergistically testing the polarization internal resistance and electrochemical impedance spectrum of a storage battery. Background Art

[0002] With the rapid development of new energy vehicles, smart grids, and portable electronic devices, the performance monitoring and life assessment of secondary batteries such as lead-acid batteries have become the focus of attention in the industry. Among them, the electrochemical characteristics of the storage battery are the key to its performance monitoring and life assessment. At present, the electrochemical characteristics of the storage battery are generally evaluated by calculating the AC impedance of the storage battery. However, only through the AC impedance, important parameters such as the polarization internal resistance of the storage battery cannot be accurately evaluated, which also leads to a large deviation between the parameters such as the capacity and SOH of the storage battery evaluated by this method and the actual situation. Summary of the Invention

[0003] To solve the problem that the detection and evaluation results of the storage battery capacity and SOH in the prior art are inaccurate, the purpose of the present invention is to provide a device and method for synergistically testing the polarization internal resistance and electrochemical impedance spectrum of a storage battery, which can obtain the synergistic analysis of the polarization internal resistance and polarization impedance of the storage battery through a set of devices, can comprehensively quantify the dynamic performance of the battery, avoid the errors caused by the working condition differences of a single method, and thus improve the accuracy rate and detection speed of the evaluation results of the storage battery capacity and SOH.

[0004] To achieve the above purpose, the present invention provides the following technical solutions: In the first aspect, the present invention provides a device for synergistically testing the polarization internal resistance and electrochemical impedance spectrum of a storage battery, including: a polarization internal resistance testing unit for controlling the polarization internal resistance test of the storage battery and controlling the sampling unit to perform sampling; an EIS testing unit for controlling the electrochemical impedance spectrum test of the storage battery and controlling the sampling unit to perform sampling; a sampling unit for contacting the positive electrode post and the negative electrode post of the storage battery through sampling cables and jigs to form a test circuit, and performing sampling according to the control of the polarization internal resistance testing unit or the EIS testing unit to obtain sampling data; and a central processing unit for performing calculations on the sampling data obtained by the sampling unit to obtain the polarization internal resistance and polarization impedance of the storage battery.

[0005] In the first aspect, the present invention provides a preferred solution. The device for synergistically testing the polarization internal resistance and electrochemical impedance spectrum of the storage battery further includes: a temperature testing unit for controlling the temperature test of the storage battery and controlling the temperature sampling unit to perform temperature sampling; a temperature sampling unit for contacting the positive electrode post or the negative electrode post of the storage battery through a temperature sensor and performing temperature sampling according to the control of the temperature testing unit to obtain the pole temperature of the storage battery.

[0006] The present invention provides a preferred solution in a first aspect. The sampling cable of the sampling unit adopts a four-wire system, including a voltage sampling cable with a positive electrode and a negative electrode, and an overcurrent cable with a positive electrode and a negative electrode.

[0007] The present invention provides a method for collaborative testing of polarization internal resistance and electrochemical impedance spectrum of a storage battery in a second aspect. Based on the above device, it includes: Controlling the polarization internal resistance test of the storage battery and controlling sampling; Controlling the electrochemical impedance spectrum test of the storage battery and controlling sampling; Contacting the positive electrode post and the negative electrode post of the storage battery through the sampling cable and the fixture to form a test circuit, and performing sampling according to the control to obtain sampling data; Performing operations on the obtained sampling data to obtain the polarization internal resistance and polarization impedance of the storage battery.

[0008] The present invention provides a preferred solution in a second aspect. The method for collaborative testing of polarization internal resistance and electrochemical impedance spectrum of the storage battery further includes: Controlling the temperature test of the storage battery and controlling temperature sampling; Contacting the positive electrode post or the negative electrode post of the storage battery through the temperature sensor, and performing temperature sampling according to the control to obtain the post temperature of the storage battery.

[0009] The present invention provides a preferred solution in a second aspect. The polarization internal resistance test control includes: when the storage battery is in a static state, applying an instantaneous current pulse between the positive and negative electrodes of the storage battery to obtain the voltage change amount between the two electrodes.

[0010] The present invention provides a preferred solution in a second aspect. The polarization internal resistance is calculated by the following formula: , where is the voltage change amount, is the amplitude of the instantaneous current pulse.

[0011] The present invention provides a preferred solution in a second aspect. For any one or more of the polarization internal resistance test control, the electrochemical impedance spectrum test control, and the temperature test control, the control is performed at least five times to obtain test results; calculate the error between the five test values, and the maximum error value is used as the test accuracy of the polarization internal resistance or the polarization impedance or the cell temperature.

[0012] The present invention provides a preferred solution in a second aspect. The electrochemical impedance spectrum test control includes: when the storage battery is in a static state, injecting a current excitation signal into the storage battery, and then testing the excitation response signal; obtaining the polarization impedance according to the current excitation signal and the excitation response signal.

[0013] The present invention provides a preferred solution in a second aspect. The method for co-testing the polarization internal resistance and electrochemical impedance spectrum of a storage battery further includes: placing the storage battery in a constant temperature chamber, performing temperature testing through a temperature calibration device to obtain the calibration temperature; and taking the error between the calibration temperature and the terminal temperature of the storage battery as the temperature testing accuracy.

[0014] Compared with the prior art, the present invention has the following advantages: The present invention integrates the polarization internal resistance test and the electrochemical impedance spectrum (EIS) test of the storage battery into the same test device, constructs a co-testing architecture, and can obtain the co-analysis of the polarization internal resistance and polarization impedance of the storage battery through a set of devices, realizing the combination of the polarization internal resistance reflecting ohmic polarization and the EIS data reflecting electrochemical kinetics, comprehensively characterizing the state of the storage battery, solving the problem of large deviation in the evaluation of capacity / SOH by a single AC impedance, avoiding the error caused by working condition differences in a single method, and improving the accuracy and detection speed of evaluation results such as capacity and SOH. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the drawings in the following description are only the embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained according to the provided drawings without creative efforts.

[0016] Figure 1 It is a block diagram of a device for co-testing the polarization internal resistance and electrochemical impedance spectrum of a storage battery provided by a specific embodiment of the present invention; Figure 2 It is a flowchart of a method for co-testing the polarization internal resistance and electrochemical impedance spectrum of a storage battery provided by a specific embodiment of the present invention; Figure 3 It is a sampling wiring diagram during the polarization internal resistance test in a device for co-testing the polarization internal resistance and electrochemical impedance spectrum of a storage battery provided by a specific embodiment of the present invention; Figure 4 It is a sampling wiring diagram during the EIS test in a device for co-testing the polarization internal resistance and electrochemical impedance spectrum of a storage battery provided by a specific embodiment of the present invention.

[0017] The reference numerals are as follows: polarization internal resistance test unit 1, EIS test unit 2, sampling unit 3, voltage sampling cable 31, overcurrent cable 32, central processing unit 4, temperature test unit 5, temperature sampling unit 6, temperature sensor 61, temperature sampling cable 62, storage battery to be tested 7. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0018] The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0019] Please refer to Figure 1 , in one implementation, a co-testing device for the polarization internal resistance and electrochemical impedance spectrum of a storage battery, also known as a tester, can perform polarization internal resistance and electrochemical spectrum tests on lead-acid batteries within 2V to 12V. The test results should not be used as the ultimate standard for measuring the battery quality. It mainly consists of a detection host and a sampling part. The detection host includes a polarization internal resistance test unit, an EIS test unit, a central processing unit, and a temperature test unit. The sampling part mainly consists of a sampling unit and a temperature sampling unit. The polarization internal resistance test unit, the EIS test unit, and the temperature test unit are respectively used to control and obtain the polarization internal resistance, electrochemical impedance spectrum (polarization impedance can be further obtained), and terminal temperature (i.e., the battery cell temperature) of the storage battery to be tested. The central processing unit is used to perform parameter operations on the voltage and current values obtained by the sampling unit (voltage sampling cable and overcurrent cable) to obtain the DC internal resistance value. Connect the voltage sampling cable and the overcurrent cable to the positive and negative electrodes of the cell, and operate the detection host to obtain relevant information including the DC internal resistance value without damaging the battery during rapid testing.

[0020] The polarization internal resistance test unit is used to control the polarization internal resistance test of the storage battery and control the sampling unit to perform sampling. The EIS test unit is used to control the electrochemical impedance spectrum test of the storage battery and control the sampling unit to perform sampling. The sampling unit is used to contact the positive terminal and negative terminal of the storage battery through sampling cables and clamps to form a test circuit, and perform sampling according to the control of the polarization internal resistance test unit or the EIS test unit to obtain sampling data. The central processing unit is used to perform operations on the sampling data obtained by the sampling unit to obtain the polarization internal resistance and polarization impedance of the storage battery. The temperature test unit is used to control the temperature test of the storage battery and control the temperature sampling unit to perform temperature sampling. The temperature sampling unit is used to contact the positive terminal or negative terminal of the storage battery through a temperature sensor and perform temperature sampling according to the control of the temperature test unit to obtain the terminal temperature of the storage battery. The sampling cables of the sampling unit adopt a four-wire system, including a voltage sampling cable with a positive and a negative pole, and an overcurrent cable with a positive and a negative pole, to eliminate the lead impedance. The generation of lead impedance is due to the resistance characteristics of the wire material itself, and the four-wire system realizes accurate measurement by separating the current excitation and voltage detection paths, thus eliminating the lead impedance. And the polarization internal resistance test unit and the EIS test unit share a set of cables.

[0021] Please refer to Figure 2 Accordingly, based on the battery polarization internal resistance and electrochemical impedance spectroscopy collaborative testing device of this embodiment, a battery polarization internal resistance and electrochemical impedance spectroscopy collaborative testing method is provided, which specifically includes the following steps: S11. Perform polarization internal resistance test control on the battery and control sampling; S12. Perform electrochemical impedance spectroscopy test and sampling control on the battery; S20. The positive and negative poles of the battery are contacted by the sampling cable and the clamp to form a test circuit, and sampling is performed according to the control to obtain sampling data; S30. Calculate the acquired sampling data to obtain the polarization internal resistance and polarization impedance of the battery.

[0022] In addition, when conducting polarization internal resistance testing, the battery temperature can also be tested and controlled at the same time to control temperature sampling; the temperature sensor is in contact with the positive or negative pole of the battery, and temperature sampling is performed according to the control to obtain the battery pole temperature.

[0023] Please refer to Figure 3 In a preferred embodiment of the polarization internal resistance test, the sampling unit of the test device is specifically configured as follows: a voltage sampling cable with positive and negative poles (i.e., two thin signal wires) is marked with a voltage terminal at the lead-out point of the test device, and an overcurrent cable with positive and negative poles (i.e., two thick power wires) is marked with a current terminal at the lead-out point of the test device. Figure 3 In the figure, L0: voltage sampling cable; L0+: positive pole of voltage sampling cable; L0-: negative pole of voltage sampling cable; L1: overcurrent cable; L1+: positive pole of overcurrent cable; L1-: negative pole of overcurrent cable. Connect the two thin signal wires marked with voltage terminals to the positive and negative poles of the battery pack under test, and connect the two thick power wires marked with current terminals to the positive and negative poles of the battery pack under test. While performing the polarization internal resistance test, a temperature test is also performed. For the temperature sampling unit, a temperature sensor (such as a temperature probe) is specifically used. The temperature probe that comes with the test device is connected to the negative pole of the battery pack under test. After forming a test circuit, the polarization internal resistance test can be performed. More specifically, the process and principle of the polarization internal resistance test are as follows: Polarization internal resistance test: Connect the voltage sampling cable and the overcurrent cable, and use the DC pulse method. That is, when the battery is in a static state, apply a transient current pulse between the positive and negative electrodes of the battery to obtain the voltage change between the two electrodes. When the pulse action time is short (much shorter than the time constant of the battery), the battery response can be approximately considered linear. At this time, the polarization internal resistance Calculated by the following formula: ,in, is the voltage change amount, i.e., the floating voltage, is the amplitude of the instantaneous current pulse. In a preferred embodiment, at least five tests are performed using a test device, the test results are read, and the error between the five test values is calculated. The maximum test error is the polarization internal resistance test accuracy of the test device. In a preferred embodiment, by quantifying the internal resistance change, the obtained data is imported into the Luenberger observer, and then the corresponding output is obtained, that is, the obtained data is imported into the closed-loop algorithm model in the Luenberger observer for state estimation calculation to obtain the key state variables that cannot be directly measured inside the system. By using the obtained data to drive this auxiliary model - the closed-loop algorithm model, the state of the Luenberger observer gradually approaches the actual state.

[0024] Battery aging will cause loss of internal chemical active substances, which is directly manifested as an increase in polarization internal resistance. The DC pulse method maps to SOH by quantifying the internal resistance change. The main feature of the polarization internal resistance test in this embodiment is that there is no need to inject a signal with a specific frequency into the battery, and only pulse modulation is performed on the battery within the safe range in milliseconds. This test method will not cause physical damage to the battery, and the entire measurement process to data display can be completed within one second.

[0025] Cell voltage test: Connect the voltage sampling cable to perform the cell voltage test. In a preferred embodiment, at least five tests are performed using a test device, the test results are read, and the error between the five test values is calculated. The maximum test error is the cell voltage test accuracy of the test device.

[0026] Cell temperature test: Considering that temperature and internal resistance are extremely sensitive, during the polarization internal resistance test, temperature test is synchronized, and thus a temperature compensation mechanism and correction are introduced: by real-time monitoring the cell temperature, a temperature-internal resistance correlation model is established to dynamically correct the test results. In a preferred embodiment, at least five maximum values are used for the cell temperature test using a detection device, the test results are read, and the error between the five test values is calculated. The maximum measurement error is the cell temperature test accuracy of the test device.

[0027] In another embodiment, the temperature test accuracy is obtained in the following way: The storage battery is placed statically in a constant temperature box, and the temperature test is performed through a temperature calibration device to obtain the calibration temperature; the error between the calibration temperature and the terminal temperature of the storage battery is defined as the temperature test accuracy. Specifically as follows: A stable temperature environment is provided by the constant temperature box, and temperature measurements are respectively performed through a temperature calibrator (or other temperature measurement devices that have passed standard verification) and the test device of this embodiment, and the measurement results are read. The error between the measurement result of the test device and the measurement result of the temperature calibrator is the device temperature measurement accuracy, and the specific formula is as follows: ; is the indicated temperature error of the test device, in percentage (%); is the temperature value of the battery cell measured by the test device, in degrees Celsius (°C); is the temperature value of the thermostat or the temperature value of the battery cell under test measured by the temperature calibrator, in degrees Celsius (°C).

[0028] In a preferred embodiment, the temperature provided by the thermostat should select at least 5 temperature points within the temperature measurement range of the test device. The temperature measurement repeatability test and the measurement accuracy test are carried out simultaneously, so as to systematically separate the sources of device errors and achieve a comprehensive performance evaluation.

[0029] Furthermore, the degradation level is generally expressed by the state of health (SOH). The calculation of SOH can be divided into capacity-based SOH (the ratio of the current ampere-hour capacity to the initial ampere-hour capacity), or power-based SOH (the ratio of the initial internal resistance to the current internal resistance), or comprehensive type (comprehensively calculated by combining factors such as capacity, internal resistance, and efficiency). In a preferred embodiment of the present invention, the degradation level is estimated by using the polarization internal resistance. The specific principle and process are as follows: Calculate the ratio of the polarization voltage difference to the current through the voltage curves before and after the discharge pulse to approximate the polarization resistance.

[0030] Perform an accelerated aging experiment on the battery, such as high-temperature aging or cyclic charge and discharge. In this case, record the polarization internal resistance at different times and different degradation levels (SOH).

[0031] Model the obtained polarization resistances at different SOH values. The established SOH prediction model is optimized through methods such as AI learning or neural network algorithms. Combine the polarization internal resistance with other parameters (temperature, number of cycles) and input them into the model, and the output can predict the SOH, so as to achieve the purpose of estimating the degradation level.

[0032] Extract the polarization internal resistance through millisecond-level pulse testing, construct a polarization internal resistance - SOH mapping dataset by combining the accelerated aging experiment, and use an AI model to fuse multi-parameters to dynamically predict the SOH, realizing online diagnosis of battery life without complete charge and discharge. The polarization internal resistance is more sensitive to aging than the ohmic internal resistance, especially can capture the interface impedance change caused by the growth of SEI. At the same time, fuse temperature / cycle number to compensate for environmental interference, further improving the SOH prediction accuracy. Moreover, a single polarization internal resistance test can be completed within one second, meeting the real-time requirement of online monitoring. This solution embeds the laboratory-level aging analysis ability into a portable device, solves the problems of time-consuming traditional capacity testing and high complexity of the EIS model, and provides an industrial-level tool for battery health management.

[0033] Please refer to Figure 4, For the sampling unit of the test device in Electrochemical Impedance Spectroscopy (EIS) test (EIS test, EIS impedance test), the following specific settings are made: The voltage sampling cable with a positive electrode and a negative electrode (i.e., two thin signal wires) is marked with voltage terminals at the connection point in the test device, and the over-current cable with a positive electrode and a negative electrode (i.e., two thick power wires) is marked with current terminals at the connection point in the test device. Figure 4 In Figure 4 , L0: voltage sampling cable; L0+: positive electrode of voltage sampling cable; L0-: negative electrode of voltage sampling cable; L1: over-current cable; L1+: positive electrode of over-current cable; L1-: negative electrode of over-current cable; L2: temperature sampling cable. Briefly speaking, the same set of sampling unit is used for both EIS test and polarization internal resistance test. Connect the two thin signal wires marked with voltage terminals to the positive and negative electrodes of the battery pack to be tested respectively, and connect the two thick power wires marked with current terminals to the positive and negative electrodes of the battery pack to be tested respectively. After forming the test circuit, the EIS test can be carried out. More specifically, the process and principle of polarization impedance test are as follows: Electrochemical Impedance Spectroscopy (EIS) test (EIS test, EIS impedance test): When the storage battery is in a static state, inject a current excitation signal into the storage battery , and then test the excitation response signal ; Inject a small-amplitude current into the static storage battery, and the excitation signal can be generated. This signal will disturb the electrochemical equilibrium state of the battery, causing processes such as internal ion migration, charge transfer, and double-layer charging and discharging to be activated. Obtain the polarization impedance based on the current excitation signal and the excitation response signal. The polarization impedance z is calculated by the following formula: ; ; ; Where, is the phasor of the port voltage, is the phasor of the port current, is the impedance angle, is the phase of the voltage phasor, is the phase of the current phasor. The modulus |z| of the polarization impedance z is equal to the ratio of the effective value of the voltage to the effective value of the current .

[0034] Reasons for improving the accuracy of battery capacity and SOH assessment through the collaborative analysis of polarization internal resistance and polarization impedance: The polarization internal resistance quickly captures ohmic losses, such as SEI thickening and current collector corrosion, and EIS analyzes the kinetic process, such as charge transfer resistance and Warburg diffusion impedance. The two cover the entire chain of battery degradation, namely: ohmic loss → electrochemical reaction retardation → ion diffusion hindrance. Further, the polarization impedance reflects interface degradation earlier than capacity attenuation; the growth ratios of the ohmic internal resistance and the polarization internal resistance are analyzed collaboratively to distinguish aging types such as SEI thickening and lithium deposition. The polarization internal resistance is significantly affected by the current rate, and EIS can separate the differential effects of temperature on interface reactions (low frequency) and ionic conductivity (high frequency); a single internal resistance index is easily interfered by operating condition fluctuations, such as a sharp increase in concentration polarization caused by an instantaneous large current. Combining with the relaxation time constant analysis of EIS can distinguish reversible polarization and irreversible aging.

[0035] Based on the above embodiments, the present invention can achieve the following beneficial technical effects: On the basis of calculating the AC impedance, the present invention adds the calculation of the polarization impedance of the battery, integrates the measurement of the polarization internal resistance of the battery and the electrochemical impedance spectroscopy (EIS) measurement into the same test device, constructs a collaborative test architecture, combines the polarization internal resistance reflecting ohmic polarization with the EIS data reflecting electrochemical kinetics, comprehensively depicts the state of the battery, solves the problem of large deviation in the evaluation of capacity / SOH by a single AC impedance, and improves the accuracy and detection speed of evaluation results such as capacity and SOH. The polarization internal resistance test is completed within 1 second by the DC pulse method + four-wire design, and the efficiency is significantly improved compared with traditional EIS (the laboratory-level EIS equipment is large in volume and time-consuming in testing, requiring minute-level frequency sweeping).

[0036] The test device of the present invention shares a set of four-wire sampling unit to achieve hardware reuse of data acquisition. At the same time, independent positive and negative voltage sampling cables (thin signal cables) and over-current cables (thick power cables) are used to eliminate the influence of lead impedance on the measurement accuracy through physical separation, that is, the interference of lead (cable) resistance can be eliminated to ensure the sampling accuracy of small-signal voltage.

[0037] The present invention performs ≥5 repeated tests on the polarization internal resistance, EIS, and temperature, and takes the maximum error value as the final test accuracy index to improve the test accuracy. At the same time, a temperature calibration mechanism is introduced. By comparing the readings of the standard device and the device in a thermostat, the temperature error is dynamically calibrated to achieve real-time temperature compensation, avoid parameter misjudgment caused by temperature drift, and expand the applicable environment range of the device.

[0038] The technical features of the above-described embodiments can be combined arbitrarily. For the sake of brevity of description, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, it should be considered as the scope described in this specification. Moreover, the above embodiments only represent several implementation manners of the present invention, and the description is relatively specific and detailed, but it should not be construed as a limitation on the scope of the present invention. For those of ordinary skill in the art, without departing from the concept of the present invention, several modifications and improvements can still be made, and these all belong to the protection scope of the present invention.

Claims

1. A device for jointly testing the polarization internal resistance and electrochemical impedance spectrum of a storage battery, characterized in that Comprising: A polarization internal resistance test unit, configured to control the polarization internal resistance test of the storage battery and control the sampling unit to perform sampling; An EIS test unit, configured to control the electrochemical impedance spectroscopy test of the storage battery and control the sampling unit to perform sampling; A sampling unit, configured to contact the positive and negative electrode posts of the storage battery through sampling cables and clamps to form a test loop, and perform sampling according to the control of the polarization internal resistance test unit or the EIS test unit to obtain sampling data; A central processing unit, configured to perform operations on the sampling data obtained by the sampling unit to obtain the polarization internal resistance and polarization impedance of the storage battery.

2. The co - testing device for the polarization internal resistance and electrochemical impedance spectrum of the storage battery according to claim 1, characterized in that, It further comprises: A temperature test unit, configured to control the temperature test of the storage battery and control the temperature sampling unit to perform temperature sampling; A temperature sampling unit, configured to contact the positive or negative electrode post of the storage battery through a temperature sensor and perform temperature sampling according to the control of the temperature test unit to obtain the electrode post temperature of the storage battery.

3. The polarization internal resistance and electrochemical impedance spectroscopy collaborative testing device for a storage battery according to claim 1, wherein The sampling cable of the sampling unit adopts a four-wire system, including a voltage sampling cable with a positive electrode and a negative electrode, and an overcurrent cable with a positive electrode and a negative electrode.

4. A co - testing method for the polarization internal resistance and electrochemical impedance spectrum of a storage battery, based on the device described in any one of the above - mentioned claims 1 to 3, characterized in that, Comprising: Control the polarization internal resistance test of the storage battery and control sampling; Control the electrochemical impedance spectroscopy test of the storage battery and control sampling; Contact the positive and negative electrode posts of the storage battery through sampling cables and clamps to form a test loop, and perform sampling according to the control to obtain sampling data; Perform operations on the obtained sampling data to obtain the polarization internal resistance and polarization impedance of the storage battery.

5. The method for co - testing the polarization internal resistance and electrochemical impedance spectrum of a storage battery according to claim 4, wherein, It further comprises: Control the temperature test of the storage battery and control temperature sampling; Contact the positive or negative electrode post of the storage battery through a temperature sensor and perform temperature sampling according to the control to obtain the electrode post temperature of the storage battery.

6. The co - testing method for battery polarization internal resistance and electrochemical impedance spectrum according to claim 4, characterized in that, The polarization internal resistance test control includes: when the storage battery is in a static state, applying an instantaneous current pulse between the positive and negative electrodes of the storage battery to obtain the voltage change amount between the two electrodes.

7. The method for synergistically testing the polarization internal resistance and electrochemical impedance spectrum of a storage battery according to claim 6, characterized in that, The polarization internal resistance is calculated by the following formula: , where is the voltage change amount, is the amplitude of the instantaneous current pulse.

8. The co - testing method for the polarization internal resistance and electrochemical impedance spectrum of a storage battery according to claim 5, characterized in that, Any one or more of the polarization internal resistance test control, electrochemical impedance spectroscopy test control, and temperature test control controls at least five tests to obtain test results; calculate the error between the five test values, and the maximum error value is used as the test accuracy of the polarization internal resistance or polarization impedance or cell temperature.

9. The method for synergistically testing the polarization internal resistance and electrochemical impedance spectrum of a storage battery according to claim 4, characterized in that The electrochemical impedance spectroscopy test control includes: when the storage battery is in a static state, injecting a current excitation signal into the storage battery, and then testing the excitation response signal; obtaining the polarization impedance according to the current excitation signal and the excitation response signal.

10. The method for collaborative testing of the polarization internal resistance and electrochemical impedance spectrum of a storage battery according to claim 5, characterized in that It further comprises: Place the storage battery in a constant temperature oven, perform temperature test through a temperature calibration device to obtain the calibration temperature; The error between the calibration temperature and the electrode post temperature of the storage battery is the temperature test accuracy.

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