Ex-service battery echelon utilization sorting method, system and equipment

Abstract

The invention discloses an ex-service battery echelon utilization sorting method, system and equipment, and the method comprises the steps: carrying out the appearance detection of an ex-service battery, and obtaining a first screening qualified battery; performing an electrical performance parameter test on the first screening qualified battery, and comparing an electrical performance parameter test result with a preset electrical performance parameter threshold to obtain a second screening qualified battery; carrying out charge and discharge test on the battery qualified in the second screening to obtain maximum available capacity attenuation and a first aging characteristic; monitoring the voltage change within a preset time after the charging and discharging test is finished, and obtaining a second aging characteristic; calculating the SOH of the battery by taking the maximum available capacity attenuation as a main component and taking the first aging characteristic and the second aging characteristic as auxiliary components; and according to the SOH of the batteries, carrying out echelon sorting on the retired batteries. By adopting the embodiment of the invention, the deep performance degradation information of the decommissioned battery can be excavated, so that the SOH measurement and calculation of the decommissioned battery better fits the real health state of the battery, and the sorting deviation caused by misjudgment of a single index is reduced.

Description

Technical Field

[0001] The present invention relates to the field of battery detection technology, and in particular to a method, system and equipment for sorting retired batteries for recycling. Background Art

[0002] With the widespread use of various types of batteries in production and daily life, the number of retired batteries continues to rise. Their cascade utilization has attracted widespread attention as an important way to achieve resource recycling and reduce environmental risks. The core premise of cascade utilization is to accurately assess the SOH (State of Health) of retired batteries to select batteries with performance that meets the requirements of secondary application scenarios. The scientific and comprehensive nature of the SOH assessment directly determines the efficiency and safety of cascade utilization.

[0003] Currently, assessments of the SOH of retired batteries often rely on a single metric, with inadequate integration of multiple indicators. Traditional methods primarily assess SOH based on the maximum available capacity decay rate, reflecting only the degradation of the battery's energy storage capacity without considering other battery operating mechanisms. This results in inaccurate sorting of retired batteries. Summary of the Invention

[0004] The embodiments of the present invention aim to provide a method, system and equipment for the cascade utilization and sorting of retired batteries, which incorporate the phase change characteristics reflecting the integrity of the electrochemical reaction inside the battery and the static voltage changes reflecting the stability of the electrode interface and the electrochemical polarity characteristics into the health status assessment of retired batteries. This can mine the deep performance degradation information of retired batteries, make their SOH measurement more in line with the actual health status of the battery, and reduce the sorting deviation caused by the misjudgment of a single indicator.

[0005] To solve the above technical problems, an embodiment of the present invention provides a method for sorting retired batteries for cascade utilization, comprising:

[0006] Perform appearance inspection on retired batteries to obtain first-screen qualified batteries;

[0007] Performing an electrical performance parameter test on the batteries that passed the first screening, and comparing the electrical performance parameter test results with a preset electrical performance parameter threshold to obtain batteries that passed the second screening;

[0008] Performing charge and discharge tests on the second-screened qualified batteries to obtain a maximum available capacity decay and a first aging characteristic; the first aging characteristic is a phase change characteristic;

[0009] Monitor the voltage change within a preset time after the charge and discharge test to obtain a second aging characteristic;

[0010] Calculating the battery SOH using the maximum available capacity decay as a main component and the first aging characteristic and the second aging characteristic as secondary components;

[0011] According to the battery SOH, retired batteries are sorted in stages.

[0012] As an improvement to the above solution, the method of performing appearance inspection on retired batteries to obtain first-screened qualified batteries includes:

[0013] Based on the factory information of the retired battery, check whether the retired battery has any abnormal appearance; the abnormal appearance includes damage, cracks, bulging and electrolyte leakage;

[0014] The retired batteries without any abnormal appearance are regarded as qualified batteries in the first screening.

[0015] As an improvement to the above solution, the method of performing an electrical performance parameter test on the first screened qualified batteries and comparing the electrical performance parameter test results with a preset electrical performance parameter threshold to obtain a second screened qualified battery includes:

[0016] Performing an open circuit voltage test on the first screened qualified battery to obtain a current battery voltage;

[0017] Performing a DC internal resistance test on the first-screened qualified batteries to obtain the current battery internal resistance;

[0018] The first screened qualified battery, whose current battery voltage is within the preset voltage threshold range and whose current battery internal resistance is less than the preset internal resistance threshold, is used as the second screened qualified battery.

[0019] As an improvement to the above solution, the charging and discharging test is performed on the second qualified battery after screening to obtain the maximum available capacity attenuation and the first aging characteristics, including:

[0020] Performing a charge-discharge test for one cycle on the second screening qualified battery at a preset temperature, while collecting infrared thermal imaging data during the charge-discharge test;

[0021] updating the second screening qualified batteries according to the infrared thermal imaging data;

[0022] According to the updated charge and discharge test results of the second-screened qualified battery, the maximum available capacity attenuation and the first aging characteristics are obtained.

[0023] As an improvement to the above solution, updating the second screened qualified batteries according to the infrared thermal imaging data includes:

[0024] Obtaining, based on the infrared thermal imaging data, the temperature distribution, the temperature extreme value difference, and the temperature change rate of the batteries that passed the second screening;

[0025] According to the temperature distribution at the same time, the area where the abnormal battery group is located is obtained, the abnormal battery group in the second screened qualified battery is removed, and the second screened qualified battery is updated;

[0026] The second-screened qualified batteries are updated according to a preset temperature extreme value difference threshold and a preset temperature change rate threshold.

[0027] As an improvement to the above solution, obtaining the maximum available capacity attenuation and the first aging characteristic based on the updated charge and discharge test results of the second screened qualified battery includes:

[0028] According to the updated charge and discharge test results of the second-screened qualified batteries, retired batteries having a discharge capacity greater than a preset capacity threshold are screened to obtain third-screened qualified batteries;

[0029] Obtaining the current battery capacity of the third screened qualified battery, and calculating the maximum available capacity attenuation based on the battery design capacity;

[0030] The IC curve of the third screened qualified battery is obtained, and the phase change peak attenuation of the IC curve is calculated according to the preset IC curve to obtain the phase change characteristic as the first aging characteristic.

[0031] As an improvement to the above solution, the monitoring of voltage changes within a preset time after the charge and discharge test is completed to obtain the second aging characteristic includes:

[0032] At the end of the charge and discharge test, the first voltage of the retired battery is collected;

[0033] leaving the retired battery to stand for a preset time and collecting a second voltage;

[0034] A difference between the first voltage and the second voltage is calculated, and a second aging characteristic is obtained according to the difference and a preset difference threshold.

[0035] As an improvement to the above solution, the method of calculating the battery SOH using the maximum available capacity decay as a main component and the first aging characteristic and the second aging characteristic as secondary components includes:

[0036] The battery SOH is calculated by SOH=CRR×80%+AC1×10%+AC2×10%; where CRR is the maximum available capacity attenuation, AC1 is the first aging characteristic, and AC2 is the second aging characteristic.

[0037] The embodiment of the present invention further provides a retired battery recycling sorting system, comprising:

[0038] An appearance inspection module is used to perform appearance inspection on retired batteries to obtain first-screen qualified batteries;

[0039] a performance testing module, configured to perform an electrical performance parameter test on the first-screened qualified batteries, compare the electrical performance parameter test results with a preset electrical performance parameter threshold, and obtain a second-screened qualified battery;

[0040] a charge and discharge test module, configured to perform a charge and discharge test on the second screened qualified battery to obtain a maximum available capacity decay and a first aging characteristic; the first aging characteristic being a phase change characteristic;

[0041] A static voltage monitoring module is used to monitor the voltage change within a preset time after the charge and discharge test is completed to obtain a second aging characteristic;

[0042] An SOH calculation module is configured to calculate the battery SOH using the maximum available capacity decay as a main component and the first aging characteristic and the second aging characteristic as secondary components;

[0043] The tiered sorting module is used to tier-sort retired batteries according to the battery SOH.

[0044] An embodiment of the present invention also provides a retired battery recycling sorting device, comprising a processor, a memory, and a computer program stored in the memory and configured to be executed by the processor, wherein when the processor executes the computer program, the retired battery recycling sorting method described above is implemented.

[0045] Compared with the prior art, the present invention discloses a method, system, and device for cascade utilization and sorting of retired batteries. The method performs an appearance inspection on retired batteries to obtain first-screen qualified batteries; performs an electrical performance parameter test on the first-screen qualified batteries, and compares the electrical performance parameter test results with a preset electrical performance parameter threshold to obtain second-screen qualified batteries; performs a charge and discharge test on the second-screen qualified batteries to obtain the maximum available capacity decay and the first aging characteristic; the first aging characteristic is a phase change characteristic; monitors the voltage change within a preset time after the charge and discharge test to obtain the second aging characteristic; uses the maximum available capacity decay as the main component and the first and second aging characteristics as secondary components to calculate the battery SOH; and performs cascade sorting on retired batteries based on the battery SOH. By adopting the embodiments of the present invention, it is possible to mine the deep performance degradation information of retired batteries, so that their SOH calculation is more in line with the actual health status of the battery, and reduce sorting deviations caused by misjudgment of a single indicator. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] Figure 1 This is a schematic flow chart of the steps of a method for sorting and recycling retired batteries provided by an embodiment of the present invention;

[0047] Figure 2It is a structural schematic diagram of a retired battery recycling and sorting system provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0048] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.

[0049] In the description of the specification and claims, it should be understood that the terms "first," "second," etc., are used solely for descriptive purposes to distinguish between identical technical features and are not to be construed as indicating or implying relative importance or implicitly specifying the number of technical features being referred to, nor do they necessarily describe a sequential or chronological order. The terms are interchangeable where appropriate. Thus, a feature specified as "first" or "second" may explicitly or implicitly include at least one of those features.

[0050] The embodiment of the present invention provides a method for sorting retired batteries for recycling. Figure 1 In this embodiment, the retired battery recycling sorting method is specifically performed through steps S1 to S6:

[0051] S1. Perform appearance inspection on retired batteries to obtain batteries that pass the first screening.

[0052] Appearance inspection can quickly screen out batteries with obvious physical damage, preventing them from entering subsequent processes and causing safety hazards or testing errors. It is important to note that if only minor damage is observed during appearance inspection, further testing may be determined based on the application scenario.

[0053] S2. Perform an electrical performance parameter test on the batteries that have passed the first screening, and compare the electrical performance parameter test results with a preset electrical performance parameter threshold to obtain batteries that have passed the second screening.

[0054] Similar to appearance inspection, electrical performance parameter testing can be performed quickly. Pre-set thresholds enable rapid screening, allowing retired batteries with lost functionality or severe performance defects to be removed early in the sorting process. This reduces the number of invalid batteries entering subsequent charge and discharge testing, improving overall sorting efficiency.

[0055] S3. Perform charge and discharge tests on the second qualified battery to obtain a maximum available capacity decay and a first aging characteristic; the first aging characteristic is a phase change characteristic.

[0056] The maximum available capacity decay directly reflects the change in the battery's energy storage capacity, while the phase change characteristics can identify the microscopic aging phenomenon of retired battery capacity decay and reflect the integrity of the battery's internal electrochemical reactions.

[0057] S4. Monitor the voltage change within a preset time after the charge and discharge test is completed to obtain a second aging characteristic.

[0058] The second aging characteristic reflects the electrode interface stability and electrochemical polarity characteristics of the battery in a non-working state. The voltage change of retired batteries in a static scenario can reflect the degree of battery aging to a certain extent.

[0059] S5. Calculate the battery SOH using the maximum available capacity decay as a main component and the first aging characteristic and the second aging characteristic as secondary components.

[0060] The maximum available capacity attenuation, the first aging characteristics and the second aging characteristics are used to measure the battery SOH from three dimensions: macroscopic characteristics, microscopic mechanism and dynamic stability.

[0061] S6. Sorting the retired batteries in stages according to the battery SOH.

[0062] Currently, some battery sorting solutions pre-build and train a model for a single battery product to quickly predict the battery's condition with only a short test. However, this battery sorting solution struggles to meet the diverse product testing and screening needs of the battery market, and requires a large amount of data to be accumulated in the early stages, making it less adaptable.

[0063] In this embodiment of the present invention, the retired batteries can be in the form of battery packs, battery modules, or single cells, and are applicable to various types of battery products, such as ternary batteries, lithium cobalt oxide batteries, and lithium iron phosphate batteries. In the retired battery recycling sorting method, a holistic assessment is performed based on the inherent form of the retired batteries. For example, during the appearance inspection of the battery pack, if the battery pack has an abnormal appearance, the entire pack of batteries cannot be recycled.

[0064] In the above scheme, through a step-by-step screening process, physical damage or functional failure of batteries are quickly eliminated through appearance inspection and electrical performance parameter testing. Then, qualified batteries are subjected to refined health assessment through in-depth testing. Finally, different application scenarios are matched according to the battery SOH, which can effectively improve the detection efficiency. More importantly, by combining appearance inspection, initial screening of electrical performance parameters with charge and discharge depth testing, and incorporating the phase change characteristics that reflect the integrity of the electrochemical reaction inside the battery and the static voltage changes that reflect the stability of the electrode interface and the electrochemical polarity characteristics into the health status assessment of retired batteries, it is possible to explore the deep performance degradation information of retired batteries, make their SOH measurement more in line with the actual health status of the battery, and reduce the sorting deviation caused by the misjudgment of a single indicator.

[0065] As a preferred embodiment, step S1, performing an appearance inspection on retired batteries to obtain first-screened qualified batteries, includes:

[0066] Based on the factory information of the retired battery, check whether the retired battery has any abnormal appearance; the abnormal appearance includes damage, cracks, bulging and electrolyte leakage;

[0067] The retired batteries without any abnormal appearance are regarded as qualified batteries in the first screening.

[0068] It should be noted that the appearance specifications of batteries of different types and batches may vary when leaving the factory. For example, the bulge detection thresholds may vary due to the shell material and sealing process. In the embodiments of the present invention, the appearance inspection combined with factory information can provide a unified comparison benchmark for retired batteries from different sources, avoiding misscreening due to subjective differences in inspection personnel or incompatibility with universal standards.

[0069] It should also be noted that step S1 can be performed by an image recognition algorithm or manually. When an image recognition algorithm is used, a battery appearance detection model must be trained in advance based on appearance abnormality data.

[0070] As a preferred embodiment, step S2, performing an electrical performance parameter test on the first screened qualified batteries, comparing the electrical performance parameter test results with a preset electrical performance parameter threshold, and obtaining a second screened qualified battery, includes:

[0071] Performing an open circuit voltage test on the first screened qualified battery to obtain a current battery voltage;

[0072] Performing a DC internal resistance test on the first-screened qualified batteries to obtain the current battery internal resistance;

[0073] The first screened qualified battery, whose current battery voltage is within the preset voltage threshold range and whose current battery internal resistance is less than the preset internal resistance threshold, is used as the second screened qualified battery.

[0074] It is understandable that the order of the open circuit voltage test and the DC internal resistance test can be adjusted, and more preferably, the first screening qualified batteries can be preliminarily screened after the open circuit voltage test or the DC internal resistance test is completed to reduce the number of test batteries.

[0075] The open-circuit voltage reflects the potential difference between the positive and negative electrodes of a battery and is a fundamental indicator of whether the battery can properly transfer charge. The DC internal resistance reflects the resistance to ion conduction and charge transfer within the battery and is directly related to the battery's charge and discharge capabilities. Testing and screening these two electrical performance parameters ensures that qualified batteries entering the second screening phase possess basic electrochemical activity. This provides a reliable sample foundation for subsequent, more in-depth charge and discharge testing and aging characteristic analysis, avoiding ineffective in-depth testing of batteries that have lost their core electrochemical functions.

[0076] For example, a high-precision voltmeter is used to test the open-circuit voltage. If the current battery voltage is not within the factory voltage range, the entire pack of batteries cannot be reused. An internal resistance meter is used to test the DC internal resistance of retired batteries. If the current battery internal resistance exceeds the manufacturer's specifications by 1.25 times, the entire pack of batteries cannot be reused.

[0077] As a preferred embodiment, step S3, performing a charge and discharge test on the second screened qualified battery to obtain the maximum available capacity attenuation and the first aging characteristic, includes:

[0078] Performing a charge-discharge test for one cycle on the second screening qualified battery at a preset temperature, while collecting infrared thermal imaging data during the charge-discharge test;

[0079] updating the second screening qualified batteries according to the infrared thermal imaging data;

[0080] According to the updated charge and discharge test results of the second-screened qualified battery, the maximum available capacity attenuation and the first aging characteristics are obtained.

[0081] In a preferred embodiment of the present invention, the infrared thermal imaging monitoring screen is parallel to a plane where the battery cells of the battery pack are most distributed, and the temperature conditions of each area can be obtained through infrared thermal imaging data.

[0082] Preferably, the charge and discharge test conditions are parameters provided by the factory information of the retired battery.

[0083] Traditional battery temperature monitoring technologies rely primarily on battery management systems, using temperature sensors to obtain temperature parameters. However, these technologies struggle to accurately locate faulty batteries. In an embodiment of the present invention, nondestructive testing technology is integrated into a retired battery recycling and sorting method. By combining infrared thermal imaging with charge and discharge testing, not only can accurate battery information be collected, but also effective safety testing and the location of abnormal battery packs can be achieved.

[0084] Furthermore, preferably, the updating of the second screening qualified batteries according to the infrared thermal imaging data includes:

[0085] Obtaining, based on the infrared thermal imaging data, the temperature distribution, the temperature extreme value difference, and the temperature change rate of the batteries that passed the second screening;

[0086] According to the temperature distribution at the same time, the area where the abnormal battery group is located is obtained, the abnormal battery group in the second screened qualified battery is removed, and the second screened qualified battery is updated;

[0087] The second-screened qualified batteries are updated according to a preset temperature extreme value difference threshold and a preset temperature change rate threshold.

[0088] For example, if the temperature difference between different areas of the retired battery is greater than 5°C within the same period of time, it is determined that there is an abnormal battery pack. The abnormal battery pack is removed and the infrared thermal imaging data is re-obtained. When the infrared thermal imaging data is normal, the second screening qualified battery is updated; if the difference between the maximum temperature and the minimum temperature of the retired battery in a charge and discharge cycle is greater than 15°C, the entire pack of batteries cannot be reused in a cascade manner; if the temperature rise of the retired battery is greater than 8°C within 10s, the entire pack of batteries cannot be reused in a cascade manner.

[0089] Preferably, obtaining the maximum available capacity attenuation and the first aging characteristic according to the updated charge and discharge test results of the second screened qualified battery includes:

[0090] According to the updated charge and discharge test results of the second-screened qualified batteries, retired batteries having a discharge capacity greater than a preset capacity threshold are screened to obtain third-screened qualified batteries;

[0091] Obtaining the current battery capacity of the third screened qualified battery, and calculating the maximum available capacity attenuation based on the battery design capacity;

[0092] The IC curve of the third screened qualified battery is obtained, and the phase change peak attenuation of the IC curve is calculated according to the preset IC curve to obtain the phase change characteristic as the first aging characteristic.

[0093] Preferably, in the embodiment of the present invention, the maximum available capacity decay is obtained by dividing the current battery capacity by the battery design capacity.

[0094] For example, a charge-discharge test is performed on the batteries that have passed the second screening at room temperature (25°C) for one cycle. The charge-discharge test conditions are the parameters provided by the factory information of the retired batteries. Infrared thermal imaging data is used to screen out the entire battery and removable parts of the batteries that cannot be reused in the second screening, so as to update the batteries that have passed the second screening. If the discharge capacity of the retired battery is not greater than 50% of the rated capacity, the entire pack of batteries cannot be reused in a cascade; and if the charge-discharge curve in a cycle is abnormal, the entire pack of batteries cannot be reused in a cascade.

[0095] In some preferred embodiments, an IC curve, i.e., a capacity increment curve, is obtained through charge and discharge tests. The characteristics of the IC curve can reflect the phase change reaction of the battery material. Battery aging is judged based on the characteristic difference from the preset curve. The degree of aging is evaluated based on the attenuation degree of the phase change peak to obtain a first aging index.

[0096] As a preferred embodiment, step S4, monitoring the voltage change within a preset time after the charge and discharge test is completed to obtain the second aging characteristic, includes:

[0097] At the end of the charge and discharge test, the first voltage of the retired battery is collected;

[0098] leaving the retired battery to stand for a preset time and collecting a second voltage;

[0099] A difference between the first voltage and the second voltage is calculated, and a second aging characteristic is obtained according to the difference and a preset difference threshold.

[0100] For example, the voltage difference of a retired battery before and after standing for 30 minutes is used to reflect its electrochemical polarity characteristics and serve as a measure of the battery health status.

[0101] As a preferred embodiment, step S5, using the maximum available capacity decay as a main component and the first aging characteristic and the second aging characteristic as secondary components to calculate the battery SOH, includes:

[0102] The battery SOH is calculated by SOH=CRR×80%+AC1×10%+AC2×10%; where CRR is the maximum available capacity attenuation, AC1 is the first aging characteristic, and AC2 is the second aging characteristic.

[0103] In the above solution, the main component coefficient is 80%, and the secondary component coefficients are all 10%. In some preferred embodiments, the component coefficients can also be determined through training according to different battery models and manufacturers.

[0104] In some preferred embodiments, the battery SOH is divided into several levels, and the retired battery level is determined according to the battery SOH, so as to allocate the retired batteries to different application scenarios to maximize value utilization.

[0105] For example, retired batteries with a SOH ≥ 70% are classified as high-grade retired batteries, retired batteries with a SOH ≥ 60% are classified as medium-grade retired batteries, and retired batteries with a SOH ≥ 50% are classified as low-grade retired batteries. Preferably, high-grade retired batteries are used for power energy storage, medium-grade retired batteries are used for low-speed electric vehicles, and low-grade retired batteries are used for grid peak regulation.

[0106] A retired battery recycling sorting method provided by an embodiment of the present invention uses a step-by-step screening process to first quickly eliminate physically damaged or functionally failed batteries through appearance inspection and electrical performance parameter testing, and then conducts a refined health assessment of qualified batteries through in-depth testing. Finally, different tiered application scenarios are matched according to the battery SOH, which can effectively improve the detection efficiency. More importantly, by combining appearance inspection, initial screening of electrical performance parameters with charge and discharge depth testing, and incorporating the phase change characteristics that reflect the integrity of the electrochemical reaction inside the battery and the static voltage changes that reflect the stability of the electrode interface and the electrochemical polarity characteristics into the retired battery health status assessment, it is possible to mine the deep performance degradation information of retired batteries, make their SOH measurement more in line with the actual health status of the battery, and reduce the sorting deviation caused by the misjudgment of a single indicator.

[0107] The embodiment of the present invention provides a sorting system for the recycling of retired batteries. Figure 2 The retired battery recycling and sorting system includes an appearance inspection module 11, a performance testing module 12, a charge and discharge testing module 13, a static voltage monitoring module 14, a SOH calculation module 15 and a cascade sorting module 16, wherein:

[0108] Appearance inspection module 11, used to perform appearance inspection on retired batteries to obtain first screening qualified batteries;

[0109] A performance testing module 12 is configured to perform an electrical performance parameter test on the first-screened qualified batteries, and compare the electrical performance parameter test results with a preset electrical performance parameter threshold to obtain a second-screened qualified battery;

[0110] a charge and discharge test module 13, configured to perform a charge and discharge test on the second screened qualified battery to obtain a maximum available capacity decay and a first aging characteristic; the first aging characteristic being a phase change characteristic;

[0111] The static voltage monitoring module 14 is used to monitor the voltage change within a preset time after the charge and discharge test is completed to obtain the second aging characteristics;

[0112] An SOH calculation module 15 is configured to calculate the battery SOH using the maximum available capacity decay as a main component and the first aging characteristic and the second aging characteristic as secondary components;

[0113] The tiered sorting module 16 is configured to tier-sort retired batteries according to the battery SOH.

[0114] As a preferred embodiment, the appearance detection module 11 is specifically used to:

[0115] Based on the factory information of the retired battery, check whether the retired battery has any abnormal appearance; the abnormal appearance includes damage, cracks, bulging and electrolyte leakage;

[0116] The retired batteries without any abnormal appearance are regarded as qualified batteries in the first screening.

[0117] As a preferred embodiment, the performance testing module 12 is specifically configured to:

[0118] Performing an open circuit voltage test on the first screened qualified battery to obtain a current battery voltage;

[0119] Performing a DC internal resistance test on the first-screened qualified batteries to obtain the current battery internal resistance;

[0120] The first screened qualified battery, whose current battery voltage is within the preset voltage threshold range and whose current battery internal resistance is less than the preset internal resistance threshold, is used as the second screened qualified battery.

[0121] As a preferred embodiment, the charge and discharge test module 13 includes:

[0122] an infrared data acquisition unit, configured to perform a charge-discharge test on the second qualified battery in a cycle at a preset temperature, and simultaneously acquire infrared thermal imaging data during the charge-discharge test;

[0123] A battery updating unit, configured to update the second-screened qualified battery according to the infrared thermal imaging data;

[0124] The test result acquisition unit is used to obtain the maximum available capacity attenuation and the first aging characteristic according to the updated charge and discharge test results of the second-screened qualified battery.

[0125] Furthermore, preferably, the battery renewal unit is specifically used to:

[0126] Obtaining, based on the infrared thermal imaging data, the temperature distribution, the temperature extreme value difference, and the temperature change rate of the batteries that passed the second screening;

[0127] According to the temperature distribution at the same time, the area where the abnormal battery group is located is obtained, the abnormal battery group in the second screened qualified battery is removed, and the second screened qualified battery is updated;

[0128] The second-screened qualified batteries are updated according to a preset temperature extreme value difference threshold and a preset temperature change rate threshold.

[0129] Preferably, the test result acquisition unit is specifically used to:

[0130] According to the updated charge and discharge test results of the second-screened qualified batteries, retired batteries having a discharge capacity greater than a preset capacity threshold are screened to obtain third-screened qualified batteries;

[0131] Obtaining the current battery capacity of the third screened qualified battery, and calculating the maximum available capacity attenuation based on the battery design capacity;

[0132] The IC curve of the third screened qualified battery is obtained, and the phase change peak attenuation of the IC curve is calculated according to the preset IC curve to obtain the phase change characteristic as the first aging characteristic.

[0133] As a preferred embodiment, the static voltage monitoring module 14 is specifically used to:

[0134] At the end of the charge and discharge test, the first voltage of the retired battery is collected;

[0135] leaving the retired battery to stand for a preset time and collecting a second voltage;

[0136] A difference between the first voltage and the second voltage is calculated, and a second aging characteristic is obtained according to the difference and a preset difference threshold.

[0137] As a preferred implementation, the SOH calculation module 15 is specifically configured to:

[0138] The battery SOH is calculated by SOH=CRR×80%+AC1×10%+AC2×10%; where CRR is the maximum available capacity attenuation, AC1 is the first aging characteristic, and AC2 is the second aging characteristic.

[0139] The retired battery recycling sorting system provided by the embodiment of the present invention uses a step-by-step screening process to first quickly eliminate physically damaged or functionally failed batteries through appearance inspection and electrical performance parameter testing, and then conducts a refined health assessment of qualified batteries through in-depth testing. Finally, different tiered application scenarios are matched according to the battery SOH, which can effectively improve the detection efficiency. More importantly, by combining appearance inspection, initial screening of electrical performance parameters with charge and discharge depth testing, and incorporating the phase change characteristics that reflect the integrity of the electrochemical reaction inside the battery and the static voltage changes that reflect the stability of the electrode interface and the electrochemical polarity characteristics into the retired battery health status assessment, it is possible to mine the deep performance degradation information of retired batteries, make their SOH measurement more in line with the actual health status of the battery, and reduce the sorting deviation caused by the misjudgment of a single indicator.

[0140] An embodiment of the present invention also provides a retired battery recycling and sorting device, comprising a processor, a memory, and a computer program stored in the memory and configured to be executed by the processor. When the processor executes the computer program, a retired battery recycling and sorting method as described above is implemented. The working principles and beneficial effects of the two correspond one to one, and therefore will not be repeated here.

[0141] Those skilled in the art will appreciate that all or part of the processes in the above-described method embodiments can be implemented by instructing related hardware through a computer program. The program can be stored in a computer-readable storage medium, and when executed, the program can include the processes in the above-described method embodiments. The storage medium can be a magnetic disk, an optical disk, a read-only memory (ROM), or a random access memory (RAM).

[0142] The above is a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present invention. These improvements and modifications are also considered to be within the scope of protection of the present invention.

Claims

1. A method for sorting retired batteries for cascade utilization, characterized in that: include: Perform appearance inspection on retired batteries to obtain first-screen qualified batteries; Performing an electrical performance parameter test on the batteries that passed the first screening, and comparing the electrical performance parameter test results with a preset electrical performance parameter threshold to obtain batteries that passed the second screening; Performing a charge and discharge test on the second-screened qualified battery to obtain a maximum available capacity attenuation and a first aging characteristic; The first aging characteristic is a phase change characteristic; Monitor the voltage change within a preset time after the charge and discharge test to obtain a second aging characteristic; Calculating the battery SOH using the maximum available capacity decay as a main component and the first aging characteristic and the second aging characteristic as secondary components; According to the battery SOH, retired batteries are sorted in stages.

2. A method for sorting and recycling retired batteries according to claim 1, characterized in that: The performing of appearance inspection on the retired batteries to obtain first screening qualified batteries includes: Based on the factory information of the retired battery, check whether the retired battery has any abnormal appearance; the abnormal appearance includes damage, cracks, bulging and electrolyte leakage; The retired batteries without any abnormal appearance are regarded as qualified batteries in the first screening.

3. The method for sorting retired batteries for cascade utilization according to claim 1, characterized in that: The step of performing an electrical performance parameter test on the first-screened qualified batteries and comparing the electrical performance parameter test results with a preset electrical performance parameter threshold to obtain a second-screened qualified battery includes: Performing an open circuit voltage test on the first screened qualified battery to obtain a current battery voltage; Performing a DC internal resistance test on the first-screened qualified batteries to obtain the current battery internal resistance; The first screened qualified battery, whose current battery voltage is within the preset voltage threshold range and whose current battery internal resistance is less than the preset internal resistance threshold, is used as the second screened qualified battery.

4. The method for sorting retired batteries for cascade utilization according to claim 1, characterized in that: The performing of a charge and discharge test on the second screened qualified battery to obtain a maximum available capacity attenuation and a first aging characteristic includes: Performing a charge-discharge test for one cycle on the second screening qualified battery at a preset temperature, while collecting infrared thermal imaging data during the charge-discharge test; updating the second screening qualified batteries according to the infrared thermal imaging data; According to the updated charge and discharge test results of the second-screened qualified battery, the maximum available capacity attenuation and the first aging characteristics are obtained.

5. A method for sorting and recycling retired batteries according to claim 4, characterized in that: The updating of the second screening qualified batteries according to the infrared thermal imaging data includes: Obtaining, based on the infrared thermal imaging data, the temperature distribution, the temperature extreme value difference, and the temperature change rate of the batteries that passed the second screening; According to the temperature distribution at the same time, the area where the abnormal battery group is located is obtained, the abnormal battery group in the second screened qualified battery is removed, and the second screened qualified battery is updated; The second-screened qualified batteries are updated according to a preset temperature extreme value difference threshold and a preset temperature change rate threshold.

6. A method for sorting and recycling retired batteries according to claim 4, characterized in that: Obtaining the maximum available capacity attenuation and the first aging characteristic according to the updated charge and discharge test results of the second-screened qualified battery includes: According to the updated charge and discharge test results of the second-screened qualified batteries, retired batteries having a discharge capacity greater than a preset capacity threshold are screened to obtain third-screened qualified batteries; Obtaining the current battery capacity of the third screened qualified battery, and calculating the maximum available capacity attenuation based on the battery design capacity; The IC curve of the third screened qualified battery is obtained, and the phase change peak attenuation of the IC curve is calculated according to the preset IC curve to obtain the phase change characteristic as the first aging characteristic.

7. The method for sorting and recycling retired batteries according to claim 1, characterized in that: The monitoring of the voltage change within a preset time after the charge and discharge test to obtain the second aging characteristic includes: At the end of the charge and discharge test, the first voltage of the retired battery is collected; leaving the retired battery to stand for a preset time and collecting a second voltage; A difference between the first voltage and the second voltage is calculated, and a second aging characteristic is obtained according to the difference and a preset difference threshold.

8. The method for sorting and recycling retired batteries according to claim 1, characterized in that: The calculating the battery SOH by using the maximum available capacity decay as a main component and the first aging characteristic and the second aging characteristic as secondary components includes: The battery SOH is calculated by SOH=CRR×80%+AC1×10%+AC2×10%; where CRR is the maximum available capacity attenuation, AC1 is the first aging characteristic, and AC2 is the second aging characteristic.

9. A retired battery recycling sorting system, characterized in that: include: An appearance inspection module is used to perform appearance inspection on retired batteries to obtain first-screen qualified batteries; a performance testing module, configured to perform an electrical performance parameter test on the first-screened qualified batteries, compare the electrical performance parameter test results with a preset electrical performance parameter threshold, and obtain a second-screened qualified battery; a charge and discharge test module, configured to perform a charge and discharge test on the second-screened qualified battery to obtain a maximum available capacity attenuation and a first aging characteristic; The first aging characteristic is a phase change characteristic; A static voltage monitoring module is used to monitor the voltage change within a preset time after the charge and discharge test is completed to obtain a second aging characteristic; An SOH calculation module is configured to calculate the battery SOH using the maximum available capacity decay as a main component and the first aging characteristic and the second aging characteristic as secondary components; The tiered sorting module is used to tier-sort retired batteries according to the battery SOH.

10. A retired battery recycling and sorting device, characterized in that: The method comprises a processor, a memory, and a computer program stored in the memory and configured to be executed by the processor, wherein when the processor executes the computer program, a method for sorting and recycling retired batteries as claimed in any one of claims 1 to 8 is implemented.

Images