Battery self-discharge screening method and device, electronic equipment and storage medium

Abstract

The application provides a battery self-discharge screening method and device, electronic equipment and storage medium. The full battery to be screened is subjected to at least two high-temperature aging operations, and a first open circuit voltage is obtained. Any two of the at least two high-temperature aging operations comprise a power compensation operation on the battery to be screened. In the case that the first open circuit voltage is higher than a first open circuit voltage standard value, the battery residual capacity of the battery to be screened is adjusted to a preset proportion of the total capacity of the battery. The battery to be screened is subjected to a self-discharge operation, and at least two second open circuit voltages of the battery to be screened in the self-discharge operation are obtained. Based on the at least two second open circuit voltages, a screening result of the battery to be screened is obtained. Through the power compensation on the battery to be screened, multi-stage high-temperature aging is realized. Through the adjustment of the residual capacity of the battery to be screened, the screening result of the battery is obtained based on the open circuit voltage after the self-discharge, the differential pressure monitoring under a specific SOC is realized, and the misjudgment rate of the battery is reduced.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of battery screening, and in particular to a battery self-discharge screening method and device, electronic equipment and a storage medium. BACKGROUND

[0002] In recent years, lithium iron phosphate has been widely used in the energy storage industry due to its excellent cycle life, environmental protection and safety compared to ternary materials. In the electric vehicle industry, due to the safety problems and cost problems of ternary system batteries, lithium iron phosphate system batteries have gradually replaced them. Due to the processing method of lithium iron phosphate, the self-discharge of lithium iron phosphate system batteries is greater than that of ternary materials, and due to the structural characteristics of lithium iron phosphate materials, the self-discharge of lithium iron phosphate system batteries is more difficult to select than ternary system.

[0003] In related technologies, batteries with good self-discharge are usually screened by full-charge long-time high-temperature aging, but due to the different degrees of irreversible side reactions between batteries, the voltage drop of some battery cells coincides with the self-discharge of some battery cells, which indirectly leads to the misjudgment of some batteries as self-discharge defective products, resulting in a high misjudgment rate of battery self-discharge screening. SUMMARY

[0004] The present application provides a battery self-discharge screening method, device, electronic equipment and storage medium to solve the defect of a high misjudgment rate of battery self-discharge screening caused by the misjudgment of some batteries as self-discharge defective products, and to reduce the misjudgment rate of battery self-discharge screening.

[0005] In a first aspect, the present application provides a battery self-discharge screening method, comprising:

[0006] Performing at least two high-temperature aging operations on the full-charge battery to be screened to obtain a first open-circuit voltage, wherein any two of the at least two high-temperature aging operations include a power compensation operation on the battery to be screened;

[0007] If the first open-circuit voltage is higher than a first open-circuit voltage standard value, adjusting the battery remaining capacity of the battery to be screened to a preset proportion of the total battery capacity;

[0008] Performing a self-discharge operation on the battery to be screened to obtain at least two second open-circuit voltages of the battery to be screened during the self-discharge operation;

[0009] Based on the at least two second open-circuit voltages, obtaining a screening result of the battery to be screened.

[0010] According to the battery self-discharge screening method provided by the present application, the battery remaining capacity of the battery to be screened is adjusted to a preset proportion of the total battery capacity, which comprises:

[0011] discharging the battery to be screened to 2.0V using a first rate, and then performing a self-discharge operation;

[0012] discharging the battery to be screened to 2.0V using a second rate, and then performing a self-discharge operation;

[0013] charging the battery to be screened until the remaining capacity of the battery to be screened is within a preset proportion range of the total capacity of the battery;

[0014] wherein the first rate is greater than the second rate.

[0015] According to the battery self-discharge screening method provided by the application, the self-discharge operation of the battery to be screened is performed to obtain at least two second open-circuit voltages of the battery to be screened in the self-discharge operation, which comprises:

[0016] After the battery to be screened is stored at a first temperature for a first time length, the OCV2 in the at least two second open-circuit voltages is tested;

[0017] Based on the OCV2, it is determined that the remaining capacity of the battery to be screened is within a preset proportion range of the total capacity of the battery, the battery to be screened is stored at a second temperature for a second time length, and the OCV3 in the at least two second open-circuit voltages is tested;

[0018] wherein the second time length is greater than the first time length, and the difference between the first temperature and the second temperature is less than a temperature difference threshold.

[0019] According to the battery self-discharge screening method provided by the application, the screening result of the battery to be screened is obtained based on the at least two second open-circuit voltages, which comprises:

[0020] Based on the OCV2 and OCV3, a self-discharge rate is obtained, wherein the self-discharge rate = (OCV2-OCV3) / T, and T is the second time length;

[0021] In the case where the self-discharge rate is determined to be less than a standard self-discharge rate, the screening result of the battery to be screened is determined to be qualified, and in the case where the self-discharge rate is determined to be greater than or equal to the standard self-discharge rate, the screening result of the battery to be screened is determined to be unqualified.

[0022] According to the battery self-discharge screening method provided by the application, the high-temperature aging operation comprises:

[0023] storing the battery to be screened at a third temperature for a third time length, and storing the battery to be screened at a fourth temperature for a fourth time length;

[0024] The third temperature is higher than room temperature, the fourth temperature is lower than the third temperature, and the fourth time length is less than the third time length.

[0025] According to the battery self-discharge screening method provided by the application, the power supplement operation on the battery to be screened includes:

[0026] The battery to be screened is charged using a third rate until a voltage difference between the voltage of the battery to be screened and 3.6V is less than a voltage difference threshold.

[0027] In a second aspect, the application further provides a battery self-discharge screening device, which includes:

[0028] The first obtaining module is configured to perform at least two high-temperature aging operations on the battery to be screened in full power, and obtain a first open-circuit voltage, wherein any two of the at least two high-temperature aging operations include a power supplement operation on the battery to be screened;

[0029] The adjusting module is configured to, in a case where the first open-circuit voltage is higher than a first open-circuit voltage standard value, adjust a battery remaining capacity of the battery to be screened to a preset proportion of a total capacity of the battery.

[0030] The second obtaining module is configured to perform a self-discharge operation on the battery to be screened, and obtain at least two second open-circuit voltages of the battery to be screened in the self-discharge operation.

[0031] The third obtaining module is configured to obtain a screening result of the battery to be screened based on the at least two second open-circuit voltages.

[0032] In a third aspect, the application further provides an electronic device, which includes a memory, a processor, and a computer program stored in the memory and executable on the processor, and the processor implements the battery self-discharge screening method according to any one of the above aspects when executing the program.

[0033] In a fourth aspect, the application further provides a non-transitory computer readable storage medium, which stores a computer program executable by a processor to implement the battery self-discharge screening method according to any one of the above aspects.

[0034] In a fifth aspect, the application further provides a computer program product, which includes a computer program executable by a processor to implement the battery self-discharge screening method according to any one of the above aspects.

[0035] The battery self-discharge screening method, device, electronic equipment and storage medium provided by the application, through at least twice high-temperature aging operation on the full battery to be screened, and supplementing power to the battery to be screened between any two high-temperature aging operations, realizing multi-section high-temperature aging, reducing the cell misjudgment caused by the difference of side reactions of the cell during high-temperature aging; by adjusting the remaining capacity (state of charge, SOC) of the battery to be screened, based on the open circuit voltage (OCV) after self-discharge, the screening result of the battery is obtained, realizing differential pressure monitoring at a specific SOC, improving the recognition rate of self-discharge, and reducing the misjudgment rate of the battery. BRIEF DESCRIPTION OF DRAWINGS

[0036] In order to more clearly illustrate the technical solutions in the application or prior art, the following will briefly introduce the drawings needed to be used in the embodiments or prior art description. Obviously, the drawings in the following description are some embodiments of the application, and other drawings can be obtained by those skilled in the art without creative labor.

[0037] Figure 1 is a flowchart of the battery self-discharge screening method provided by the application;

[0038] Figure 2 is a structural schematic diagram of the battery self-discharge screening device provided by the application;

[0039] Figure 3 is a structural schematic diagram of the electronic equipment provided by the application. DETAILED DESCRIPTION

[0040] In order to make the purpose, technical scheme and advantages of the application more clear, the technical scheme in the application will be described clearly and completely in the following with reference to the drawings in the application. Obviously, the described embodiments are some embodiments of the application, not all embodiments. Based on the embodiments in the application, all other embodiments obtained by those skilled in the art without creative labor belong to the protection scope of the application.

[0041] The following will be explained in detail based on multiple embodiments.

[0042] Figure 1 is a flowchart of the battery self-discharge screening method provided by the application, as Figure 1 shown, the method comprises the following steps:

[0043] At step 100, at least two high-temperature aging operations are performed on a full battery to be screened to obtain a first open-circuit voltage, wherein the at least two high-temperature aging operations include a power supplement operation on the battery to be screened between any two of the at least two high-temperature aging operations.

[0044] Optionally, the battery to be screened can include a lithium iron phosphate battery.

[0045] Optionally, the high-temperature aging operation can include placing a battery with full power, or a battery with power close to full, or a battery with power charged to a preset value, or a battery with power higher than the preset value, or a battery with power close to the preset value in a high-temperature and dry environment for a period of time.

[0046] Optionally, the preset value can be a preset battery capacity, or a self-defined battery capacity, or a battery capacity close to the total capacity of the battery.

[0047] Optionally, the preset value can be 90%, or 98%, or 100% of the total capacity of the battery, and the application is not limited thereto.

[0048] Optionally, the high-temperature aging operation can cause the solid electrolyte interphase (SEI) film of the battery to recombine from a tight and small-pore structure into a loose and porous structure.

[0049] Optionally, the voltage of the battery after the high-temperature aging operation can be more accurate and stable.

[0050] Optionally, after the high-temperature aging operation on the battery, the irreversible side reactions generated can include voltage changes, or thickness changes, or internal resistance changes, etc.

[0051] Optionally, before the at least two high-temperature aging operations on the full battery to be screened, the battery to be screened can be pretreated.

[0052] Optionally, the pretreatment can include fully charging the battery to be screened.

[0053] Optionally, fully charging the battery to be screened can be charging the battery to be screened to 3.6-3.65V, 0.01C.

[0054] Optionally, pretreating the battery to be screened can calibrate the estimation accuracy of the SOC of the battery.

[0055] Optionally, the specific operation of the pretreatment can include charging the battery to be screened to 10%-20% SOC using 0.03-0.1C constant current, and then charging the battery to be screened to 3.6-3.65V, 0.01C using 0.3-0.75C constant current and constant voltage.

[0056] Optionally, C can be a charge-discharge rate, for example, 1C can be that a battery is charged or discharged in one hour, and 0.1C can be that a battery is charged or discharged in ten hours.

[0057] Optionally, the first open circuit voltage can be OCV1.

[0058] Optionally, the power compensation operation can include using a small current to fully charge the battery to be screened between any two high-temperature aging operations, or to charge the battery to be screened close to full, or to charge the battery to be screened to a preset value, or to charge the battery to be screened to a battery higher than the preset value, or to charge the battery to be screened close to the preset value.

[0059] Optionally, the preset value can be a pre-set battery capacity, or a self-defined battery capacity, or a battery capacity close to the total battery capacity.

[0060] Optionally, the preset value can be 90%, or 98%, or 100% of the total battery capacity, etc., which is not limited by the present application.

[0061] Optionally, the power compensation operation on the battery to be screened can calibrate the estimation accuracy of the battery SOC.

[0062] Specifically, first, the battery to be screened can be pretreated, then the first high-temperature aging operation can be performed on the battery to be screened after pretreatment, then the power compensation operation can be performed on the battery to be screened, then the second high-temperature aging operation can be performed on the battery to be screened after power compensation, and then the first open circuit voltage of the battery to be screened can be tested and obtained, and the number of high-temperature aging operations is not limited by the present application.

[0063] Step 110, in the case that the first open circuit voltage is higher than the first open circuit voltage standard value, adjusting the battery remaining capacity of the battery to be screened to a preset proportion of the total battery capacity;

[0064] Optionally, the first open circuit voltage standard value can be the highest threshold of the open circuit voltage of the battery with unqualified self-discharge after high-temperature aging operation.

[0065] Optionally, the first open circuit voltage standard value can be 3.2V, or 3.3V, or 3.5V, etc., which is not limited by the present application.

[0066] Optionally, in the case that the first open circuit voltage is lower than or equal to the first open circuit voltage standard value, the battery to be screened can be determined as a battery with unqualified self-discharge.

[0067] Optionally, in the case that the first open circuit voltage is higher than the first open circuit voltage standard value, after the SOC test on the battery to be screened, the battery remaining capacity of the battery to be screened can be adjusted to a preset proportion of the total battery capacity.

[0068] Optionally, the preset proportion of the total capacity of the battery can be a preset proportion.

[0069] Optionally, the preset proportion of the total capacity of the battery can be 15%, or 20%, or 28%, etc., and the application does not limit this.

[0070] Optionally, the to-be-screened battery can be charged using constant current or constant current and constant voltage, so that the SOC of the cell of the to-be-screened battery is adjusted to 15%-28% of the total capacity of the battery.

[0071] In step 120, self-discharge operation is performed on the to-be-screened battery to obtain at least two second open-circuit voltages of the to-be-screened battery in the self-discharge operation.

[0072] Specifically, after adjusting the remaining capacity of the to-be-screened battery to the preset proportion of the total capacity of the battery, at least two self-discharge operations can be performed on the to-be-screened battery, and then at least two second open-circuit voltages of the to-be-screened battery in the self-discharge operation can be tested and obtained.

[0073] In step 130, a screening result of the to-be-screened battery is obtained based on the at least two second open-circuit voltages.

[0074] Optionally, after obtaining at least two second open-circuit voltages of the to-be-screened battery in the self-discharge operation, the self-discharge rate of the to-be-screened battery within a second time period can be determined based on the at least two second open-circuit voltages, and then it can be determined whether the to-be-screened battery is a self-discharge qualified battery, so as to obtain the screening result of the to-be-screened battery.

[0075] The battery self-discharge screening method provided by the application can realize multi-stage high-temperature aging by performing at least two high-temperature aging operations on the full battery to-be-screened battery and supplementing power to the to-be-screened battery between any two high-temperature aging operations, reduce the cell misjudgment caused by the difference in side reactions of the cell during high-temperature aging, adjust the remaining capacity of the to-be-screened battery, obtain the screening result of the battery based on the open-circuit voltage after self-discharge, realize differential pressure monitoring at a specific SOC, improve the recognition rate of self-discharge, and reduce the misjudgment rate of the battery.

[0076] Optionally, the adjusting of the remaining capacity of the to-be-screened battery to the preset proportion of the total capacity of the battery comprises:

[0077] discharging the to-be-screened battery to 2.0V using a first rate and then performing self-discharge operation;

[0078] discharging the to-be-screened battery to 2.0V using a second rate and then performing self-discharge operation;

[0079] Charge the battery to be screened until the battery remaining capacity of the battery to be screened is in a preset proportion range of the total capacity of the battery.

[0080] The first rate is greater than the second rate.

[0081] Optionally, the first rate can be 0.1C, or 0.2C, or 0.5C, etc., which is not limited in the present application.

[0082] Optionally, when the first open circuit voltage is higher than the first open circuit voltage standard value, after the SOC test of the battery to be screened, the battery to be screened can be discharged to 2.0V using the first rate.

[0083] Optionally, the second rate can be 0.01C, or 0.02C, or 0.05C, etc., which is not limited in the present application.

[0084] Optionally, after discharging the battery to be screened to 2.0V using the first rate, the battery to be screened can be rested for 10 minutes, and then the battery to be screened can be discharged to 2.0V using the second rate.

[0085] Optionally, after discharging the battery to be screened to 2.0V using the first rate, the battery to be screened can be rested for 16 minutes, and then the battery to be screened can be discharged to 2.0V using the second rate.

[0086] Optionally, after discharging the battery to be screened to 2.0V using the first rate, the battery to be screened can be rested for 30 minutes, and then the battery to be screened can be discharged to 2.0V using the second rate.

[0087] Optionally, the preset proportion range of the total capacity of the battery can be 15%-28%, or 18%-28%, or 15%-25%, etc., which is not limited in the present application.

[0088] Optionally, after discharging the battery to be screened to 2.0V using the second rate, the battery to be screened can be rested for 5 minutes, and then the battery to be screened can be charged using constant current or constant current and constant voltage until the battery SOC of the battery to be screened is in the preset proportion range of the total capacity of the battery.

[0089] Optionally, after discharging the battery to be screened to 2.0V using the second rate, the battery to be screened can be rested for 12 minutes, and then the battery to be screened can be charged using constant current or constant current and constant voltage until the battery SOC of the battery to be screened is in the preset proportion range of the total capacity of the battery.

[0090] Optionally, after discharging the battery to be screened to 2.0V using the second magnification, the battery to be screened can be stored for 20 minutes, and then the battery to be screened can be charged using constant current or constant current constant voltage until the battery SOC of the battery to be screened is in the preset proportion range of the total capacity of the battery.

[0091] The battery self-discharge screening method provided by the application realizes the adjustment of a specific SOC by discharging the battery to be screened and charging the battery to be screened to a preset proportion range of the total capacity of the battery using constant current or constant current constant voltage.

[0092] Optionally, the discharging operation on the battery to be screened to obtain at least two second open circuit voltages of the battery to be screened in the discharging operation includes:

[0093] After storing the battery to be screened at the first temperature for a first time, test OCV2 in the at least two second open circuit voltages;

[0094] Based on the OCV2, it is determined that the battery remaining capacity of the battery to be screened is in a preset proportion range of the total capacity of the battery, and the battery to be screened is stored at a second temperature for a second time, and OCV3 in the at least two second open circuit voltages is tested.

[0095] Wherein, the second time is greater than the first time, and the difference between the first temperature and the second temperature is less than a temperature difference threshold.

[0096] Optionally, after adjusting the battery remaining capacity of the battery to be screened to a preset proportion of the total capacity of the battery, a second open circuit voltage can be tested.

[0097] Optionally, the first temperature can be slightly higher than room temperature, or close to room temperature, or close to human body temperature.

[0098] Optionally, the first temperature can be 32℃, or 35℃, or 38℃, etc., which is not limited by the application.

[0099] Optionally, the first time can be 12h, or 24h, or 32h, etc., which is not limited by the application.

[0100] Optionally, after storing the battery to be screened at the first temperature for a first time, OCV2 can be tested.

[0101] Optionally, the second temperature can be slightly higher than room temperature, or close to room temperature, or close to human body temperature.

[0102] Optionally, the second temperature can be 32℃, or 35℃, or 38℃, etc., which is not limited by the application.

[0103] Optionally, the temperature difference threshold can be 0.1 DEG C, or 2 DEG C, or 6 DEG C, etc., which is not limited in the present application.

[0104] Optionally, the second duration can be 72h, or 96h, or 144h, etc., which is not limited in the present application.

[0105] Optionally, based on the OCV2, the SOC of the battery to be screened can be determined, if the SOC is within a preset proportion range of the total capacity of the battery, the battery to be screened can be stored at the second temperature for the second duration, and then the OCV3 can be tested.

[0106] The battery self-discharge screening method provided by the present application adjusts the remaining capacity of the battery to be screened, and realizes the selection of a specific SOC by storing the battery to be screened at a specific temperature and then testing a second open circuit voltage, and continues to store the battery to be screened at a specific temperature to obtain an OCV3, thereby preparing for subsequent pressure difference monitoring at a specific SOC.

[0107] Optionally, the obtaining of the screening result of the battery to be screened based on the at least two second open circuit voltages comprises:

[0108] Based on the OCV2 and the OCV3, a self-discharge rate is obtained, wherein the self-discharge rate=(OCV2-OCV3) / T, and T is the second duration;

[0109] In a case where the self-discharge rate is less than a standard self-discharge rate, it is determined that the screening result of the battery to be screened is qualified, and in a case where the self-discharge rate is greater than or equal to the standard self-discharge rate, it is determined that the screening result of the battery to be screened is unqualified.

[0110] Optionally, after the test of the OCV3 is completed, a self-discharge rate (self-discharge K value) is obtained based on the OCV2 and the OCV3.

[0111] Optionally, T can be the storage duration of the OCV2 to obtain the OCV3 at a specific temperature.

[0112] Optionally, T can be the second duration.

[0113] Optionally, T can be 72h, or 96h, or 144h, etc., which is not limited in the present application.

[0114] Optionally, in a case where the self-discharge K value is less than a standard self-discharge K value, it can be determined that the screening result of the battery to be screened is qualified.

[0115] Optionally, in a case where the self-discharge K value is greater than or equal to the standard self-discharge K value, it can be determined that the screening result of the battery to be screened is unqualified.

[0116] The battery self-discharge screening method provided by the application adjusts the remaining capacity of the battery to be screened, obtains the screening result of the battery based on the open circuit voltage after self-discharge, realizes differential pressure monitoring at a specific SOC, improves the recognition rate of self-discharge, and reduces the misjudgment rate of the battery.

[0117] Optionally, the high-temperature aging operation once includes:

[0118] The battery to be screened is stored at a third temperature for a third time length, and the battery to be screened is stored at a fourth temperature for a fourth time length.

[0119] The third temperature is higher than room temperature, the fourth temperature is lower than the third temperature, and the fourth time length is less than the third time length.

[0120] Optionally, the third temperature can be a temperature slightly higher than the human body temperature, or a temperature higher than the room temperature.

[0121] Optionally, the third temperature can be 40℃, or 44℃, or 50℃, etc., which is not limited by the application.

[0122] Optionally, the third time length can be 48h, or 72h, or 96h, etc., which is not limited by the application.

[0123] Optionally, the fourth temperature can be a temperature close to the room temperature.

[0124] Optionally, the fourth temperature can be 20℃, or 22℃, or 28℃, etc., which is not limited by the application.

[0125] Optionally, the fourth time length can be 6h, or 12h, or 32h, etc., which is not limited by the application.

[0126] Optionally, the high-temperature aging operation once can include placing the battery to be screened at a third temperature for a third time length, and then placing the battery to be screened at a fourth temperature for a fourth time length.

[0127] Optionally, the battery to be screened can be pretreated, and the battery to be screened can be charged to 10%-20% SOC by using 0.03-0.1C constant current, and then charged to 3.6-3.65V by using 0.3-0.75C constant current and constant voltage until the charge-discharge rate of the battery to be screened is 0.01C.

[0128] Optionally, the first high-temperature aging operation can include: after the full-charge battery to be screened is left to stand at 44 DEG C for 72h, the battery to be screened is left to stand at 22 DEG C for 6h, then the battery to be screened can be charged to 3.6V using 0.1C constant current constant voltage, until the charge-discharge rate is 0.01C, then the second high-temperature aging operation can be performed, after the battery to be screened is left to stand at 44 DEG C for 72h, the battery to be screened is left to stand at 22 DEG C for 6h.

[0129] The battery self-discharge screening method provided by the application realizes multi-section high-temperature aging by performing at least two high-temperature aging operations on the full-charge battery to be screened, reduces the wrong judgment of the battery cell due to the difference in the side reaction of the battery cell during high-temperature aging, improves the recognition rate of the self-discharge, and reduces the misjudgment rate of the battery.

[0130] Optionally, the power supplement operation on the battery to be screened includes:

[0131] The battery to be screened is charged using the third rate until the voltage difference between the voltage of the battery to be screened and 3.6V is less than the voltage difference threshold.

[0132] Optionally, the third rate can be 0.1C, or 0.2C, or 0.3C, etc., which is not limited in the application.

[0133] Optionally, the voltage difference threshold can be 0.01V, or 0.02V, or 0.05V, etc., which is not limited in the application.

[0134] Optionally, after the first high-temperature aging operation is performed on the battery to be screened, the battery to be screened can be charged using the third rate until the voltage difference between the voltage of the battery to be screened and 3.6V is less than the voltage difference threshold, and the charge-discharge rate of the battery to be screened is 0.01C.

[0135] Optionally, if the number of high-temperature aging operations is three, after the second high-temperature aging operation is performed on the battery to be screened, the battery to be screened can be charged using the third rate until the voltage difference between the voltage of the battery to be screened and 3.6V is less than the voltage difference threshold, and the charge-discharge rate of the battery to be screened is 0.01C.

[0136] The battery self-discharge screening method provided by the application realizes multi-section high-temperature aging by performing power supplement on the battery to be screened between any two high-temperature aging operations, reduces the wrong judgment of the battery cell due to the difference in the side reaction of the battery cell during high-temperature aging, improves the recognition rate of the self-discharge, and reduces the misjudgment rate of the battery.

[0137] In one embodiment, the battery to be screened can be a 2000PCS battery, first pre-treatment can be performed, 0.1C constant current constant voltage can be used to charge the battery to 3.6V, 0.01C cutoff; after the pre-treatment is completed, the first high temperature aging operation can be performed, the battery can be placed at 45°C for 2 days, and then the battery is placed at 25°C for 12h; after the first high temperature aging operation is completed, the power compensation operation can be performed, 0.3C constant current constant voltage can be used to charge the battery to 3.65V, 0.01C cutoff; after the power compensation operation is completed, the second high temperature aging operation can be performed, the battery can be placed at 45°C for 4 days, and then the battery is placed at 25°C for 16h; after the second high temperature aging operation is completed, the remaining capacity of the battery can be tested, OCV1 can be tested; after determining that OCV1 is higher than the first open circuit voltage standard value, the self-discharge operation can be performed, 0.1C can be used to discharge the battery to 2.0V, and stand for 10min, then 0.05C can be used to discharge the battery to 2.0V, and stand for 20min; after the self-discharge operation is completed, the remaining capacity of the battery can be adjusted, constant current can be used to charge the battery to 25% of the total capacity of the battery; after the remaining capacity is adjusted, the battery can be stored at 35°C for 28h, OCV2 is tested, if the remaining capacity of the battery is between 15%-28% of the total capacity, the battery can be placed at 35°C for 144h, after the storage is completed, OCV3 can be tested, based on OCV2 and OCV3, the self-discharge K value of the battery = (OCV2-OCV3) / 144h can be calculated, if the self-discharge K value of the battery is less than the standard self-discharge K value, the screening result of the battery can be determined as qualified, if the self-discharge K value of the battery is greater than or equal to the standard self-discharge K value, the screening result of the battery can be determined as unqualified.

[0138] In one embodiment, the battery to be screened can be a 2000PCS battery, first pre-treatment can be performed, 0.1C constant current constant voltage can be used to charge the battery to 3.6V, 0.01C cutoff; after the pre-treatment is completed, the first high temperature aging operation can be performed, the battery can be placed at 45℃ for 3 days, and then the battery can be placed at 25℃ for 8h; after the first high temperature aging operation is completed, the power compensation operation can be performed, 0.1C constant current constant voltage can be used to charge the battery to 3.65V, 0.01C cutoff; after the power compensation operation is completed, the second high temperature aging operation can be performed, the battery can be placed at 45℃ for 3 days, and then the battery can be placed at 25℃ for 24h; after the second high temperature aging operation is completed, the remaining capacity of the battery can be tested, OCV1 can be tested; after determining that OCV1 is higher than the first open circuit voltage standard value, the self-discharge operation can be performed, 0.2C can be used to discharge the battery to 2.0V, and the battery is placed for 20min, then 0.02C can be used to discharge the battery to 2.0V, and the battery is placed for 20min; after the self-discharge operation is completed, the remaining capacity of the battery can be adjusted, constant current can be used to charge the battery to 27% of the total capacity of the battery; after the remaining capacity is adjusted, the battery can be stored at 35℃ for 32h, OCV2 is tested, if the remaining capacity of the battery is between 15% and 28% of the total capacity, the battery can be placed at 35℃ for 144h, after the placement is completed, OCV3 can be tested, based on OCV2 and OCV3, the self-discharge K value of the battery = (OCV2-OCV3) / 144h can be calculated, if the self-discharge K value of the battery is less than the standard self-discharge K value, it can be determined that the screening result of the battery is qualified, if the self-discharge K value of the battery is greater than or equal to the standard self-discharge K value, it can be determined that the screening result of the battery is unqualified.

[0139] The battery self-discharge screening device provided by the application is described below, and the battery self-discharge screening device described below can be referred to in correspondence with the battery self-discharge screening method described above.

[0140] Figure 2 is a structural schematic diagram of the battery self-discharge screening device provided by the application, as Figure 2 shown, the device 200 comprises a first acquisition module 201, an adjustment module 202, a second acquisition module 203 and a third acquisition module 204; wherein:

[0141] The first acquisition module 201 is configured to perform at least two high temperature aging operations on the full battery to be screened, and obtain a first open circuit voltage, wherein any two of the at least two high temperature aging operations comprise a power compensation operation on the battery to be screened;

[0142] The adjusting module 202 is configured to adjust the remaining capacity of the battery to be screened to a preset proportion of the total capacity of the battery in the case that the first open circuit voltage is higher than a first open circuit voltage standard value.

[0143] The second obtaining module 203 is configured to perform self-discharge operation on the battery to be screened to obtain at least two second open circuit voltages of the battery to be screened in the self-discharge operation.

[0144] The third obtaining module 204 is configured to obtain a screening result of the battery to be screened based on the at least two second open circuit voltages.

[0145] Specifically, the battery self-discharge screening device is configured to perform at least two high-temperature aging operations on the full battery to be screened through the first obtaining module 201 to obtain a first open circuit voltage, wherein the at least two high-temperature aging operations include a power compensation operation on the battery to be screened between any two high-temperature aging operations; then adjust the remaining capacity of the battery to be screened to a preset proportion of the total capacity of the battery in the case that the first open circuit voltage is higher than a first open circuit voltage standard value through the adjusting module 202; then perform self-discharge operation on the battery to be screened through the second obtaining module 203 to obtain at least two second open circuit voltages of the battery to be screened in the self-discharge operation; and finally obtain a screening result of the battery to be screened based on the at least two second open circuit voltages through the third obtaining module 204.

[0146] The battery self-discharge screening device provided by the application realizes multi-stage high-temperature aging by performing at least two high-temperature aging operations on the full battery to be screened and performing power compensation on the battery to be screened between any two high-temperature aging operations, reduces the wrong judgment of the battery caused by the difference in side reactions of the battery during high-temperature aging, adjusts the remaining capacity of the battery to be screened, obtains the screening result of the battery based on the open circuit voltage after self-discharge, realizes pressure difference monitoring at a specific SOC, improves the recognition rate of self-discharge, and reduces the misjudgment rate of the battery.

[0147] Figure 3 is a structural schematic diagram of an electronic device provided by the application, as Figure 3 shown, the electronic device can include: a processor 310, a communications interface 320, a memory 330 and a communications bus 340, wherein the processor 310, the communications interface 320, the memory 330 complete mutual communication through the communications bus 340. The processor 310 can call the logic instructions in the memory 330 to execute the battery self-discharge screening method, which includes:

[0148] performing at least two high-temperature aging operations on the full-charged battery to be screened to obtain a first open circuit voltage, wherein any two of the at least two high-temperature aging operations include a power compensation operation on the battery to be screened;

[0149] in a case where the first open circuit voltage is higher than a first open circuit voltage standard value, adjusting a battery remaining capacity of the battery to be screened to a preset proportion of a total capacity of the battery;

[0150] performing a self-discharge operation on the battery to be screened to obtain at least two second open circuit voltages of the battery to be screened in the self-discharge operation;

[0151] obtaining a screening result of the battery to be screened based on the at least two second open circuit voltages.

[0152] In addition, the logic instructions in the memory 330 described above can be implemented in the form of a software function unit and sold or used as an independent product, and can be stored in a computer readable storage medium. Based on such understanding, the technical solutions of the present application essentially or the parts that contribute to the prior art or parts of the technical solutions can be embodied in the form of a software product. 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 methods 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, Read-Only Memory), a random access memory (RAM, Random Access Memory), a magnetic disk or an optical disk, and various media that can store program codes.

[0153] On the other hand, the present application also provides a computer program product, the computer program product includes a computer program, the computer program can be stored on a non-transitory computer readable storage medium, when the computer program is executed by a processor, the computer can execute the battery self-discharge screening method provided by the above-mentioned methods, the method includes:

[0154] performing at least two high-temperature aging operations on the full-charged battery to be screened to obtain a first open circuit voltage, wherein any two of the at least two high-temperature aging operations include a power compensation operation on the battery to be screened;

[0155] in a case where the first open circuit voltage is higher than a first open circuit voltage standard value, adjusting a battery remaining capacity of the battery to be screened to a preset proportion of a total capacity of the battery;

[0156] perform self-discharge operation on the battery to be screened to obtain at least two second open-circuit voltages of the battery to be screened in the self-discharge operation;

[0157] obtain a screening result of the battery to be screened based on the at least two second open-circuit voltages.

[0158] In another aspect, the present application also provides a non-transitory computer-readable storage medium having a computer program stored thereon, the computer program being executed by a processor to implement the battery self-discharge screening method provided by the above method, the method comprising:

[0159] perform at least two high-temperature aging operations on the full battery to be screened to obtain a first open-circuit voltage, wherein any two of the at least two high-temperature aging operations comprise a power compensation operation on the battery to be screened;

[0160] if the first open-circuit voltage is higher than a first open-circuit voltage standard value, adjust a battery remaining capacity of the battery to be screened to a preset proportion of a total battery capacity;

[0161] perform self-discharge operation on the battery to be screened to obtain at least two second open-circuit voltages of the battery to be screened in the self-discharge operation;

[0162] obtain a screening result of the battery to be screened based on the at least two second open-circuit voltages.

[0163] The device embodiments described above are merely illustrative, wherein the units illustrated as separate components can or can not be physically separated, and the components illustrated as units can or can not be physical units, i.e., can be located in one place or distributed on multiple network units. Part or all of the modules can be selected to achieve the purpose of the embodiment according to actual needs. Those skilled in the art can understand and implement without creative labor.

[0164] From the above description of the embodiments, those skilled in the art can clearly understand that the embodiments can be implemented by means of software plus necessary general hardware platforms, and of course can also be implemented by hardware. Based on such understanding, the above technical solutions can be embodied in the form of a software product, which can be stored in a computer readable storage medium, such as ROM / RAM, magnetic disk, optical disk, etc., and includes a plurality of instructions to make a computer device (which can be a personal computer, a server, or a network device, etc.) execute the methods described in each embodiment or some parts of the embodiments.

[0165] It should be pointed out finally that the above embodiments are only used to illustrate the technical solutions of the present application, but not to limit the same; and although the present application has been described in detail with reference to the foregoing embodiments, it should be appreciated by those skilled in the art that the technical solutions recorded in the foregoing embodiments can be modified, or some technical features thereof can be replaced equivalently; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present application.

Claims

1. A battery self-discharge screening method, characterized by, The method comprises the following steps: carrying out at least two high-temperature aging operations on a full-charge battery to be screened to obtain a first open-circuit voltage, wherein any two of the at least two high-temperature aging operations comprise a power compensation operation on the battery to be screened; in the case where the first open-circuit voltage is higher than a first open-circuit voltage standard value, adjusting a battery residual capacity of the battery to be screened to a preset proportion of a total battery capacity; carrying out a self-discharge operation on the battery to be screened to obtain at least two second open-circuit voltages of the battery to be screened in the self-discharge operation; obtaining a screening result of the battery to be screened based on the at least two second open-circuit voltages; the step of carrying out a self-discharge operation on the battery to be screened to obtain at least two second open-circuit voltages of the battery to be screened in the self-discharge operation comprises: after storing the battery to be screened at a first temperature for a first time length, testing an OCV2 in the at least two second open-circuit voltages; based on the OCV2, determining that the battery residual capacity of the battery to be screened is within a preset proportion range of the total battery capacity, storing the battery to be screened at a second temperature for a second time length, and testing an OCV3 in the at least two second open-circuit voltages; wherein the second time length is greater than the first time length, and a difference between the first temperature and the second temperature is less than a temperature difference threshold value; the step of obtaining a screening result of the battery to be screened based on the at least two second open-circuit voltages comprises: based on the OCV2 and the OCV3, obtaining a self-discharge rate, wherein the self-discharge rate = (OCV2-OCV3) / T, and T is the second time length; in the case where the self-discharge rate is determined to be less than a standard self-discharge rate, determining that the screening result of the battery to be screened is qualified, and in the case where the self-discharge rate is determined to be greater than or equal to the standard self-discharge rate, determining that the screening result of the battery to be screened is unqualified.

2. The battery self-discharge screening method of claim 1, wherein, the step of adjusting the battery residual capacity of the battery to be screened to a preset proportion of the total battery capacity comprises: carrying out a self-discharge operation on the battery to be screened after discharging the battery to be screened at a first rate to 2.0V; carrying out a self-discharge operation on the battery to be screened after discharging the battery to be screened at a second rate to 2.0V; charging the battery to be screened until the battery residual capacity of the battery to be screened is within a preset proportion range of the total battery capacity; wherein the first rate is greater than the second rate.

3. The battery self-discharge screening method of claim 1, wherein, one of the high-temperature aging operations comprises: storing the battery to be screened at a third temperature for a third time length, and storing the battery to be screened at a fourth temperature for a fourth time length; wherein the third temperature is higher than room temperature, the fourth temperature is lower than the third temperature, and the fourth time length is less than the third time length.

4. The battery self-discharge screening method of claim 1, wherein, the power compensation operation on the battery to be screened comprises: charging the battery to be screened at a third rate until a voltage difference between the voltage of the battery to be screened and 3.6V is less than a voltage difference threshold value.

5. A battery self-discharge screening apparatus, characterized by, The method comprises the following steps: The first obtaining module is configured to perform at least two high-temperature aging operations on the full-electric battery to be screened to obtain a first open-circuit voltage, wherein the at least two high-temperature aging operations include a power compensation operation on the battery to be screened between any two of the at least two high-temperature aging operations. The adjusting module is configured to adjust a battery residual capacity of the battery to be screened to a preset proportion of a total capacity of the battery if the first open-circuit voltage is higher than a first open-circuit voltage standard value. The second obtaining module is configured to perform a self-discharge operation on the battery to be screened to obtain at least two second open-circuit voltages of the battery to be screened in the self-discharge operation. The third obtaining module is configured to obtain a screening result of the battery to be screened based on the at least two second open-circuit voltages. The self-discharge operation on the battery to be screened to obtain the at least two second open-circuit voltages of the battery to be screened in the self-discharge operation includes: After the battery to be screened is stored at a first temperature for a first time length, an OCV2 in the at least two second open-circuit voltages is tested. Based on the OCV2, it is determined that a battery residual capacity of the battery to be screened is within a preset proportion range of the total capacity of the battery, the battery to be screened is stored at a second temperature for a second time length, and an OCV3 in the at least two second open-circuit voltages is tested. The second time length is greater than the first time length, and a difference between the first temperature and the second temperature is less than a temperature difference threshold. The obtaining of the screening result of the battery to be screened based on the at least two second open-circuit voltages includes: Based on the OCV2 and the OCV3, a self-discharge rate is obtained, where the self-discharge rate = (OCV2-OCV3) / T, and T is the second time length. If it is determined that the self-discharge rate is less than a standard self-discharge rate, it is determined that the screening result of the battery to be screened is qualified, and if it is determined that the self-discharge rate is greater than or equal to the standard self-discharge rate, it is determined that the screening result of the battery to be screened is unqualified.

6. An electronic device comprising a memory, a processor, and a computer program stored on the memory and executable on the processor, characterized in that, The processor executes the program to implement the steps of the battery self-discharge screening method according to any one of claims 1 to 4.

7. A non-transitory computer-readable storage medium having stored thereon a computer program, characterized in that, The computer program is executed by the processor to implement the steps of the battery self-discharge screening method according to any one of claims 1 to 4.

8. A computer program product comprising a computer program, characterized in that, The computer program is executed by the processor to implement the steps of the battery self-discharge screening method according to any one of claims 1 to 4.

Images