Battery detection method, electronic equipment and computer program product

Abstract

The invention provides a battery detection method, electronic equipment and a computer program product, and the method comprises the steps: obtaining the target coulombic efficiency of a to-be-detected battery, and the to-be-detected battery comprises a battery which is shelved after a target shelving time; according to the capacity diving detection method and the capacity diving detection device, the diving cell with the abnormal attenuation rate in the to-be-detected battery can be accurately identified according to the target coulombic efficiency, so that the accuracy of identifying the capacity diving detection result of the to-be-detected battery is improved; and meanwhile, the target coulombic efficiency can reflect a capacity diving mechanism in the battery, so that the method is suitable for scenes of online capacity diving early warning and offline attenuation consistency sorting, the practicability of a capacity diving detection result is improved, the safety and performance problems caused by doping the capacity diving battery into the battery module are avoided, and the battery capacity diving early warning method is suitable for large-scale popularization and application. Therefore, the device can be widely landed.

Description

Technical Field

[0001] The present invention relates to the field of battery technology, and in particular to a battery detection method, electronic equipment and computer program product. Background Art

[0002] The number of new energy vehicles in my country has reached new highs. The first batch of power batteries will usher in a "retirement wave", and it is necessary to establish a complete and guaranteed screening mechanism for batteries whose capacity has dropped.

[0003] In the related technology, based on the electrochemical model and data-driven fusion, the battery's attenuation characteristic data and the quantum clustering algorithm are integrated to provide early warning for batteries in the diving degradation mode. However, when the above method is used to detect the battery, since the capacity diving characteristic value is usually only an assessment of the current state, it is a state quantity and cannot identify changes in the battery attenuation mode. The accuracy of identifying whether a capacity dive has occurred is low, resulting in a series of safety and performance issues caused by the incorporation of capacity diving batteries in the battery module. Summary of the invention

[0004] The present invention aims to solve at least one of the technical problems existing in the prior art.

[0005] To this end, an object of the present invention is to propose a battery detection method, which can accurately identify the capacity diving cells with abnormal attenuation rate in the battery to be detected according to the target coulomb efficiency, thereby improving the accuracy of identifying the capacity diving detection results of the battery to be detected. At the same time, the target coulomb efficiency can reflect the capacity diving mechanism inside the battery, so that the present invention is suitable for online capacity diving warning and offline attenuation consistency sorting scenarios, improves the practicality of the capacity diving detection results, avoids the safety and performance problems caused by the addition of capacity diving batteries into the battery module, and thus facilitates the widespread implementation of the present invention.

[0006] To this end, a second objective of the present invention is to provide an electronic device.

[0007] To this end, a third object of the present invention is to provide a non-transitory computer-readable storage medium.

[0008] To this end, a fourth object of the present invention is to provide a computer program product.

[0009] To this end, a fifth objective of the present invention is to provide a battery detection device.

[0010] To this end, a sixth object of the present invention is to provide a controller.

[0011] In order to achieve the above-mentioned purpose, an embodiment of the first aspect of the present invention proposes a battery detection method, which includes: obtaining a target coulombic efficiency of the battery to be detected, wherein the battery to be detected includes a battery that has been shelved for a target shelving time; and determining a capacity dive detection result of the battery to be detected according to the target coulombic efficiency.

[0012] According to the battery detection method of the embodiment of the present invention, by controlling the target shelving time of the battery to be detected, the target coulomb efficiency after the current coulomb efficiency is reacted is determined to determine the change in the attenuation mode of the battery to be detected, and according to the size relationship between the target coulomb efficiency and the judgment parameter of the capacity diving fault occurring under the same set conditions, the capacity diving detection result of the battery to be detected is determined, and the diving battery cell with abnormal attenuation rate in the battery to be detected can be accurately identified, thereby improving the accuracy of identifying the capacity diving detection result of the battery to be detected. At the same time, by utilizing the size of the target coulomb efficiency to reflect the capacity diving mechanism inside the battery, the present invention is suitable for the scenarios of online capacity diving warning and offline attenuation consistency sorting, thereby improving the practicality of the capacity diving detection result, avoiding the safety and performance problems caused by the incorporation of capacity diving batteries into the battery module, thereby facilitating the widespread implementation of the present invention.

[0013] In some embodiments, determining the target coulombic efficiency of the battery to be tested includes: determining a target SOC value of the battery to be tested; and determining the target coulombic efficiency according to the target SOC value and the target shelf time.

[0014] In some embodiments, the target coulombic efficiency is determined according to the target SOC value and the target shelf time, including: obtaining a target charging capacity of the battery to be tested at the target SOC value and a target discharging capacity of the battery to be tested at the target shelf time; and determining the target coulombic efficiency according to the target charging capacity and the target discharging capacity.

[0015] In some embodiments, obtaining the target charging capacity of the battery to be tested at the target SOC value includes: controlling the battery to be tested to discharge to a cut-off voltage at a preset constant current rate, and then controlling the battery to be tested to charge to the target SOC value at the preset constant current rate to obtain the target charging capacity.

[0016] In some embodiments, obtaining the target discharge capacity of the battery to be detected at the target shelf time includes: when the battery to be detected is shelved for the target shelf time, controlling the battery to be detected to discharge to a cut-off voltage at the preset constant current rate to obtain the target discharge capacity.

[0017] In some embodiments, determining the target coulombic efficiency according to the target charging capacity and the target discharging capacity includes: calculating a percentage of the target discharging capacity and the target charging capacity, and using the percentage as the target coulombic efficiency.

[0018] In some embodiments, determining the capacity dive detection result of the battery to be detected according to the target coulombic efficiency includes: obtaining a coulombic efficiency threshold of the battery to be detected; and determining the capacity dive detection result of the battery to be detected according to the coulombic efficiency threshold and the target coulombic efficiency.

[0019] In some embodiments, obtaining the coulombic efficiency threshold of the battery to be detected includes: obtaining a coulombic efficiency threshold database of batteries; and determining the coulombic efficiency threshold of the battery to be detected according to the coulombic efficiency threshold database.

[0020] In some embodiments, obtaining a coulombic efficiency threshold database of a battery includes: obtaining the coulombic efficiency of the battery at a set SOC value at different shelf times and the decay rate of the battery; and establishing a coulombic efficiency threshold database of the battery at a set SOC value and different shelf times according to the coulombic efficiency and the decay rate.

[0021] In some embodiments, a coulombic efficiency threshold database of the battery under a set SOC value and different shelf times is established based on the coulombic efficiency and the decay rate, including: obtaining a correspondence diagram between the coulombic efficiency and the decay rate; determining in the correspondence diagram the coulombic efficiency threshold corresponding to the decay rate distribution within a set range; and establishing a coulombic efficiency threshold database consisting of the set SOC value, different shelf times, and the coulombic efficiency threshold.

[0022] In some embodiments, determining the coulombic efficiency threshold of the battery to be tested according to the coulombic efficiency threshold database includes: determining the coulombic efficiency threshold of the battery to be tested at the target SOC value and the target shelf time in the coulombic efficiency threshold database.

[0023] In some embodiments, determining a capacity dive detection result of the battery to be detected according to the coulombic efficiency threshold and the target coulombic efficiency includes: if the target coulombic efficiency is lower than the coulombic efficiency threshold, determining that the battery to be detected has a capacity dive.

[0024] In some embodiments, obtaining the coulombic efficiency of the battery and the attenuation rate of the battery at different shelf times at the set SOC value of the battery includes: obtaining the charging capacity of the battery at the set SOC value, the discharging capacity of the battery at the set SOC value and the shelf time, the number of charge and discharge cycles of the battery, and the capacity change value of the battery under the number of cycles; determining the coulombic efficiency of the battery according to the charging capacity and the discharging capacity; and obtaining the attenuation rate according to the capacity change value and the number of charge and discharge cycles.

[0025] In some embodiments, obtaining the charging capacity of the battery at the set SOC value includes: controlling the battery to charge at a preset rate constant current to the set SOC value to obtain the corresponding charging capacity at the set SOC value.

[0026] In some embodiments, obtaining the discharge capacity of the battery at the set SOC value and the shelf time includes: placing the battery at the set SOC value until the shelf time is reached; and controlling the battery to discharge at a preset constant current rate to obtain the discharge capacity of the battery at the set SOC value and the shelf time.

[0027] In some embodiments, controlling the battery to discharge at a preset constant current rate includes: controlling the battery to discharge at a preset constant current rate to a cut-off voltage.

[0028] In some embodiments, obtaining the attenuation rate according to the capacity change value and the number of charge and discharge cycles includes: calculating a ratio of the capacity change value to the number of cycles, and using the ratio as the attenuation rate.

[0029] In some embodiments, after determining the capacity dive detection result of the battery to be detected according to the target coulombic efficiency, the method further includes: removing the battery with capacity dive.

[0030] In order to achieve the above-mentioned purpose, an embodiment of the second aspect of the present invention proposes an electronic device, which includes at least one processor; and a memory communicatively connected to the at least one processor; wherein the memory stores a battery detection program that can be executed by the at least one processor, and when the battery detection program is executed by the at least one processor, the at least one processor executes the battery detection method described in the above-mentioned embodiment.

[0031] According to the electronic device of the embodiment of the present invention, by controlling the target shelving time of the battery to be detected, the target coulomb efficiency after the current coulomb efficiency is reacted is determined to determine the change in the attenuation mode of the battery to be detected, and according to the size relationship between the target coulomb efficiency and the judgment parameter of the capacity diving fault under the same set conditions, the capacity diving detection result of the battery to be detected is determined, and the diving battery cell with abnormal attenuation rate in the battery to be detected can be accurately identified, thereby improving the accuracy of identifying the capacity diving detection result of the battery to be detected. At the same time, by utilizing the size of the target coulomb efficiency to reflect the capacity diving mechanism inside the battery, the present invention is suitable for the scenarios of online capacity diving warning and offline attenuation consistency sorting, thereby improving the practicality of the capacity diving detection result, avoiding the safety and performance problems caused by the addition of capacity diving batteries into the battery module, and facilitating the wide implementation of the present invention.

[0032] In order to achieve the above-mentioned purpose, an embodiment of the third aspect of the present invention proposes a non-temporary computer-readable storage medium, on which a battery detection program is stored. When the battery detection program is executed by a processor, the battery detection method described in the above-mentioned embodiment is implemented.

[0033] In order to achieve the above-mentioned purpose, an embodiment of the fourth aspect of the present invention proposes a computer program product, wherein the computer program product includes a computer program, and the computer program includes program instructions. When the program instructions are executed by a computer, the computer executes the battery detection method described in the above-mentioned embodiment.

[0034] According to the computer program product of the embodiment of the present invention, by controlling the target shelving time of the battery to be detected, the target coulomb efficiency after the current coulomb efficiency is reacted is determined to determine the change in the attenuation mode of the battery to be detected, and according to the size relationship between the target coulomb efficiency and the judgment parameter of the capacity diving fault occurring under the same set conditions, the capacity diving detection result of the battery to be detected is determined, and the diving battery cell with abnormal attenuation rate in the battery to be detected can be accurately identified, thereby improving the accuracy of identifying the capacity diving detection result of the battery to be detected. At the same time, by utilizing the size of the target coulomb efficiency to reflect the capacity diving mechanism inside the battery, the present invention is suitable for the scenarios of online capacity diving warning and offline attenuation consistency sorting, thereby improving the practicality of the capacity diving detection result, avoiding the safety and performance problems caused by the incorporation of capacity diving batteries into the battery module, thereby facilitating the widespread implementation of the present invention.

[0035] In order to achieve the above-mentioned purpose, an embodiment of the fifth aspect of the present invention proposes a battery detection device, which includes: an acquisition module, used to obtain the target coulomb efficiency of the battery to be detected, and the battery to be detected includes a battery that has been shelved for a target shelving time; a determination module, used to determine the capacity dive detection result of the battery to be detected according to the target coulomb efficiency.

[0036] According to the battery detection device of the embodiment of the present invention, by controlling the target shelving time of the battery to be detected, the target coulomb efficiency after the current coulomb efficiency is reacted is determined to determine the change in the attenuation mode of the battery to be detected, and according to the size relationship between the target coulomb efficiency and the judgment parameter of the capacity diving fault under the same set conditions, the capacity diving detection result of the battery to be detected is determined, and the diving battery cell with abnormal attenuation rate in the battery to be detected can be accurately identified, thereby improving the accuracy of identifying the capacity diving detection result of the battery to be detected. At the same time, by utilizing the size of the target coulomb efficiency to reflect the capacity diving mechanism inside the battery, the present invention is suitable for the scenarios of online capacity diving warning and offline attenuation consistency sorting, thereby improving the practicality of the capacity diving detection result, avoiding the safety and performance problems caused by the addition of capacity diving batteries into the battery module, and facilitating the widespread implementation of the present invention.

[0037] In order to achieve the above object, an embodiment of a sixth aspect of the present invention provides a controller, wherein the controller includes the battery detection device described in the above embodiment.

[0038] According to the controller of the embodiment of the present invention, by controlling the target shelving time of the battery to be detected, the target coulomb efficiency after the current coulomb efficiency is reacted is determined to determine the change in the attenuation mode of the battery to be detected, and according to the size relationship between the target coulomb efficiency and the judgment parameter of the capacity diving fault occurring under the same set conditions, the capacity diving detection result of the battery to be detected is determined, and the diving battery cell with abnormal attenuation rate in the battery to be detected can be accurately identified, thereby improving the accuracy of identifying the capacity diving detection result of the battery to be detected. At the same time, by utilizing the size of the target coulomb efficiency to reflect the capacity diving mechanism inside the battery, the present invention is suitable for the scenarios of online capacity diving warning and offline attenuation consistency sorting, thereby improving the practicality of the capacity diving detection result, avoiding the safety and performance problems caused by the addition of capacity diving batteries into the battery module, thereby facilitating the widespread implementation of the present invention.

[0039] Additional aspects and advantages of the present invention will be given in part in the following description and in part will be obvious from the following description, or will be learned through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] The above and / or additional aspects and advantages of the present invention will become apparent and easily understood from the description of the embodiments in conjunction with the following drawings, in which:

[0041] Figure 1 It is a schematic diagram showing the change of the capacity of a normal decay cell and a diving cell with the number of cycles according to an embodiment of the present invention;

[0042] Figure 2is a schematic diagram of the cycle life decay rate of a normal decay battery cell and a water-degradation battery cell according to an embodiment of the present invention;

[0043] Figure 3 is a flow chart of a battery detection method according to an embodiment of the present invention;

[0044] Figure 4 is a corresponding relationship diagram between coulombic efficiency and decay rate according to an embodiment of the present invention;

[0045] Figure 5 is a schematic diagram showing the change in capacity of a normal decay battery cell with the number of cycles according to an embodiment of the present invention;

[0046] Figure 6 is a schematic diagram showing the change in capacity of a diving battery cell with the number of cycles according to an embodiment of the present invention;

[0047] Figure 7 is a flow chart of a battery detection method according to a specific embodiment of the present invention;

[0048] Figure 8 is a structural block diagram of a battery detection device according to an embodiment of the present invention;

[0049] Fig. 9 is a structural block diagram of a controller according to an embodiment of the present invention.

[0050] Reference numerals:

[0051] Battery testing device 2;

[0052] Acquisition module 21; Determination module 22;

[0053] Controller 3. DETAILED DESCRIPTION

[0054] Embodiments of the present invention are described in detail below. The embodiments described with reference to the accompanying drawings are exemplary. Embodiments of the present invention are described in detail below.

[0055] In the relevant technologies, the power batteries equipped in new energy vehicles are mainly based on positive electrode materials such as ternary and lithium iron phosphate. The power stage has extremely high requirements on the power, energy and safety performance of the battery. When the battery capacity decays to a certain extent, its power and endurance will not be able to meet the requirements. Therefore, these batteries need to be retired. According to research reports, 19.4 million new energy vehicles will reach the retirement standards in the next eight years. The remaining life of these batteries is still very high and can be used in communication base stations, energy storage, low-speed electric vehicles and other fields in tiered applications, mainly lithium iron phosphate batteries, on the premise of establishing a complete and guaranteed screening mechanism.

[0056] Due to the complex operating conditions of batteries in the power stage, the attenuation patterns of batteries are not the same even at the same capacity. Some batteries will experience a rapid drop in capacity in a short time or a short cycle, which is called capacity diving. If these diving cells cannot be identified and detected, the module performance will be greatly reduced when they are combined with normal attenuation cells to form a module, and may even cause serious safety problems. Traditional electrochemical parameters such as capacity and internal resistance make it difficult to identify capacity diving cells and study the capacity diving mechanism. Therefore, sorting cannot be based solely on simple electrochemical parameters, and a screening strategy that can effectively identify diving cells should be developed.

[0057] In related technologies, based on electrochemical models, the characteristics of the battery's QV differential curve are compared with those of a standard new battery to determine whether the battery has a capacity dive and the cause of the dive, identify the capacity dive cells and study the dive mechanism. However, engineering applications are difficult, and the complicated differential processing cannot adapt to all equipment. Alternatively, based on data-driven, the attenuation threshold is determined through algorithm clustering, and the battery capacity dive point and attenuation degree are identified based on the attenuation threshold and the battery capacity attenuation. The calculation is simple and the identification is rapid, but the diving mechanism inside the battery cannot be explained. In short, the current research on battery capacity dive identification technology has not been widely implemented, and its practicality and accuracy are low.

[0058] like Figure 1 The figure shows the capacity change of the normal decay battery cell and the decommissioned battery cell with the number of cycles. Each curve shows the capacity change of the retired battery cell with different SOH (state of healthy) with the number of cycles, where SOH reflects the current available capacity of the battery, which is numerically defined as the ratio of the current available capacity to the initial available capacity. The battery cell with normal decay after about 500 cycles has basically the same decay pattern even if the SOH is different (in Figure 1 The thinner curve in the figure shows that the decay mode of the diving cell is uneven (in Figure 1 The method of the present invention can identify the battery cells with different attenuation, thereby preventing them from flowing into the next process.

[0059] Since the loss of lithium cation Li+ in each cycle or storage in the coulombic efficiency reaction is usually less affected by SOC, capacity loss is usually caused by two major reasons: LAM, i.e., loss of active materials, and LLI, i.e., loss of active lithium. Among them, LAM, i.e., loss of active materials, is usually caused by structural damage to positive and negative electrode materials, loss of electrical contact, etc.; LLI, i.e., loss of active lithium, is usually caused by SEI film growth consumption, lithium deposition to form dead lithium, etc. The coulombic efficiency of the diving cell drops sharply, which is essentially a change in the attenuation mode, from the normal attenuation cell LI-dominated to LLI and LAM-dominated. The difference in the attenuation proportions of LLI and LAM will produce the following results: Figure 2 As shown in the phenomenon, the attenuation patterns of the failed cells are uneven, so the failed cells need to be sorted and eliminated.

[0060] The method of the present invention is applicable to all types of retired lithium iron phosphate batteries. A certain type of retired lithium iron phosphate battery is now taken as an example. The initial capacity of the new battery of this type is 270Ah, and the constant current charging current is 80A.

[0061] Combine the following Figure 1-Figure 7 The battery detection method according to the embodiment of the present invention is described with examples.

[0062] like Figure 3 As shown, the battery detection method of the embodiment of the present invention at least includes steps S1 to S3.

[0063] Step S1, obtaining a target coulombic efficiency of a battery to be tested, wherein the battery to be tested includes a battery that has been left for a target rest time.

[0064] Among them, the battery to be detected includes a battery that has been shelved for a period of time, such as a target shelving time, and its attenuation mode within the target shelving time needs to be detected. It is judged whether the battery to be detected has a capacity dive based on the change state of the attenuation mode. It can be understood that when the attenuation modes of the batteries to be detected within the target shelving time are uneven, it is considered that the capacity attenuation of the batteries to be detected is relatively fluctuating and a capacity dive occurs, and the battery to be detected meets the retirement standard; when the attenuation modes of the batteries to be detected within the target shelving time are basically the same, it is considered that the capacity attenuation of the batteries to be detected is relatively stable, and no capacity dive occurs, then the battery to be detected does not meet the retirement standard, and the target coulomb efficiency of the batteries to be detected is obtained so that the batteries to be detected can be screened according to the target coulomb efficiency.

[0065] In an embodiment, the battery to be tested is controlled to perform a coulombic efficiency reaction under set conditions, i.e., a certain SOC value and a target shelf time. That is, after the battery to be tested is charged to a certain SOC value of the battery capacity, the battery to be tested is shelf-stored at room temperature. When the shelf time reaches the target shelf time, the target coulombic efficiency of the battery to be tested under the same set conditions is obtained to determine the parameters of the battery to be tested after the coulombic efficiency reaction, thereby realizing the screening of the battery to be tested.

[0066] Step S2, determining the capacity drop detection result of the battery to be detected according to the target coulombic efficiency.

[0067] In an embodiment, after determining the target coulombic efficiency of the battery to be detected, a judgment parameter for the occurrence of a capacity diving fault under the same set conditions, namely, a coulombic efficiency threshold, is extracted from a preset database, such as a coulombic efficiency threshold database, and a capacity diving detection result of the battery to be detected is determined according to the size relationship between the target coulombic efficiency and the coulombic efficiency threshold. According to the capacity diving detection result, the capacity diving cell is identified and the diving mechanism is studied, so as to perform corresponding processing on the battery with the capacity diving fault and the battery without the capacity diving fault.

[0068] In the related art, the batteries to be tested are screened based on the coulomb efficiency calculated under full charge and discharge conditions. Since the coulomb efficiency of the batteries to be tested is easily affected by the charge and discharge time, charge and discharge temperature and number of cycles, the accuracy of the capacity diving result is low. When the present invention uses the target coulomb efficiency to screen the batteries to be tested, the target coulomb efficiency is determined based on the target SOC and the target shelving time. By shelving the batteries to be tested, a more accurate target coulomb efficiency can be obtained, so that when the batteries to be tested are screened based on the target coulomb efficiency, the accuracy of the capacity diving detection of the batteries to be tested can be improved.

[0069] According to the battery detection method of the embodiment of the present invention, by controlling the target shelving time of the battery to be detected, the target coulomb efficiency after the current coulomb efficiency is reacted is determined to determine the change in the attenuation mode of the battery to be detected, and according to the size relationship between the target coulomb efficiency and the judgment parameter of the capacity diving fault occurring under the same set conditions, the capacity diving detection result of the battery to be detected is determined, and the diving battery cell with abnormal attenuation rate in the battery to be detected can be accurately identified, thereby improving the accuracy of identifying the capacity diving detection result of the battery to be detected. At the same time, by utilizing the size of the target coulomb efficiency to reflect the capacity diving mechanism inside the battery, the present invention is suitable for the scenarios of online capacity diving warning and offline attenuation consistency sorting, thereby improving the practicality of the capacity diving detection result, avoiding the safety and performance problems caused by the incorporation of capacity diving batteries into the battery module, thereby facilitating the widespread implementation of the present invention.

[0070] In some embodiments, determining a target coulombic efficiency of the battery to be tested includes: determining a target SOC value of the battery to be tested; and determining the target coulombic efficiency according to the target SOC value and the target shelf time.

[0071] In an embodiment, the set condition of the battery to be tested is determined to be a target SOC value, and the battery to be tested is controlled to perform a coulombic efficiency reaction under the corresponding set condition, i.e., the target SOC value and the target shelf time. That is, after the battery to be tested is charged to the target SOC value of the battery capacity, the battery to be tested is shelf-raised at room temperature, and when the shelf time reaches the target shelf time, the target coulombic efficiency of the battery to be tested under the same set condition, i.e., the target SOC value and the target shelf time is obtained to determine the parameters of the battery to be tested after the coulombic efficiency reaction.

[0072] In some embodiments, the target coulombic efficiency is determined according to the target SOC value and the target shelf time, including: obtaining the target charging capacity of the battery to be tested at the target SOC value and the target discharging capacity of the battery to be tested at the target shelf time; determining the target coulombic efficiency according to the target charging capacity and the target discharging capacity.

[0073] In the embodiment, the battery to be tested is controlled to be charged at a constant current to a target SOC value of the battery capacity, and a target charging capacity of the battery to be tested at the target SOC value is obtained, for example, recorded as Q3, and the battery to be tested is controlled to be shelved for a target shelving time, and a target discharge capacity Q of the battery to be tested at the target shelving time is obtained. b ; Get the target charging capacity Q3 and the target discharging capacity Q b After that, according to the target charging capacity Q3 and the target discharge capacity Q b The target coulombic efficiency is determined as a percentage of, for example, denoted as η 3b .

[0074] In some embodiments, obtaining a target charging capacity of a battery to be tested under a target SOC value and a target shelf time includes: controlling the battery to be tested to discharge to a cutoff voltage at a preset constant current rate, and then controlling the battery to be tested to charge to a target SOC value at a preset constant current rate to obtain the target charging capacity.

[0075] In an embodiment, at room temperature, the battery to be tested is controlled to discharge at a preset constant current rate, for example, a constant current rate of ≤1C to a cut-off voltage of 2.5V, and then the battery to be tested is controlled to charge at a preset constant current rate, for example, a constant current rate of ≤1C to a target SOC value of the battery capacity, for example, 75% SOC; or the battery to be tested is controlled to discharge at a constant current of 80A to a cut-off voltage of 2.5V, and then the battery to be tested is controlled to charge at a constant current of 80A to a target SOC value of the battery capacity, for example, 75% SOC, to obtain a target charging capacity Q3.

[0076] In some embodiments, obtaining a target discharge capacity of the battery to be tested at a target shelf time includes: when the battery to be tested is shelf-raised for the target shelf time, controlling the battery to be tested to discharge at a preset constant current rate to a cut-off voltage to obtain the target discharge capacity.

[0077] In an embodiment, at room temperature, when the battery to be tested is placed for a target placement time, such as 3 days, the battery to be tested after placement is controlled to be discharged at the same preset constant current rate, such as a rate of ≤1C, to a cut-off voltage of 2.5V, or the battery to be tested is controlled to be discharged at a current of 80A to a cut-off voltage of 2.5V, so as to obtain a target discharge capacity Q b .

[0078] In some embodiments, determining the target coulombic efficiency according to the target charging capacity and the target discharging capacity includes: calculating the percentage of the target discharging capacity and the target charging capacity, and using the percentage as the target coulombic efficiency.

[0079] In the embodiment, the target charging capacity Q3 and the target discharging capacity Q b Then, calculate the target charging capacity Q3 and the target discharge capacity Q b The percentage is taken as the target coulomb efficiency η 3b , that is, η 3b =Q b / Q3×100%.

[0080] In some embodiments, determining a capacity dive detection result of a battery to be detected according to a target coulombic efficiency includes: obtaining a coulombic efficiency threshold of the battery to be detected; and determining a capacity dive detection result of the battery to be detected according to the coulombic efficiency threshold and the target coulombic efficiency.

[0081] Among them, the coulomb efficiency threshold is a parameter for judging whether the battery has a capacity diving failure. This threshold can effectively identify capacity diving cells and analyze the internal diving mechanism with an accuracy rate of almost 100%. It is suitable for online capacity diving warning and offline attenuation consistency sorting scenarios.

[0082] In an embodiment, the coulombic efficiency threshold of the battery to be tested corresponding to a specific SOC and a shelf time is extracted from a preset database, such as a coulombic efficiency threshold database. The method for extracting the characteristic threshold is relatively simple, and is a conclusion drawn through effective identification of life dives of multiple batteries.

[0083] After obtaining the coulombic efficiency threshold of the battery to be tested, the size relationship between the target coulombic efficiency and the coulombic efficiency threshold is compared, and the capacity diving detection result of the battery to be tested is judged according to the size relationship between the target coulombic efficiency and the coulombic efficiency threshold, so as to perform corresponding processing on the battery with capacity diving fault and the battery without capacity diving fault.

[0084] In some embodiments, obtaining the coulombic efficiency threshold of the battery to be detected includes: obtaining a coulombic efficiency threshold database of the battery; and determining the coulombic efficiency threshold of the battery to be detected according to the coulombic efficiency threshold database.

[0085] In an embodiment, the selection of the characteristic coulombic efficiency threshold is determined based on its relationship with the attenuation rate at a specific SOC and shelf time, and the coulombic efficiency thresholds of different set SOC values ​​and different shelf times are traversed to establish a database of coulombic efficiency thresholds of the battery at different set SOC values ​​and different shelf times.

[0086] After establishing the coulombic efficiency threshold database, the set conditions of the battery to be tested, i.e., a set SOC value and a certain standby time, are determined, and the coulombic efficiency threshold of the battery under the set conditions is obtained from the coulombic efficiency threshold database to determine the judgment parameters for the capacity diving failure under the set conditions.

[0087] In some embodiments, obtaining a coulombic efficiency threshold database of a battery includes: obtaining the coulombic efficiency of the battery at a set SOC value at different shelf times and the decay rate of the battery; and establishing a coulombic efficiency threshold database of the battery at a set SOC value and different shelf times according to the coulombic efficiency and the decay rate.

[0088] Among them, Coulomb efficiency, also known as discharge efficiency, refers to the ratio of the battery discharge capacity to the charging capacity in the same cycle, that is, the percentage of discharge capacity to charging capacity. It is a quantitative indicator of battery reversibility and can be used to estimate the life of retired lithium iron phosphate batteries.

[0089] In the embodiment, since the size of the coulomb efficiency can well identify the change in the attenuation mode of the diving cell, it can be used for the sorting of capacity diving. As shown in Table 1, taking 4 set SOC values ​​and 3 shelf times as an example, the battery is controlled to charge to different set SOC values ​​of the battery capacity, and the charging capacity of the battery at the set SOC value is obtained, for example, recorded as Q 充电 ; and at different set SOC values, the battery corresponding to the set SOC value is placed at room temperature for different shelf times, and the discharge capacity of the battery at the set SOC value and different shelf times is obtained, for example, recorded as Q 放电 , the discharge capacity Q 放电 With charging capacity Q 充电 The percentage of Coulomb efficiency is recorded as η, that is, η = Q 放电 / Q 充电 ×100%.

[0090] Table 1

[0091]

[0092] At the same time, the battery decay rate is determined according to the changes of the battery before and after the coulombic reaction. By obtaining the coulombic efficiency and decay rate, a coulombic efficiency threshold database of the battery under set SOC values ​​and different shelf times is established according to the coulombic efficiency and decay rate, providing data support for the subsequent determination of parameters causing capacity diving failures.

[0093] After obtaining the coulombic efficiency and the decay rate, the relationship between the coulombic efficiency and the decay rate under the same set conditions, i.e., a certain set SOC value and a certain shelf time, is obtained. When the decay rate is relatively concentrated and almost all lower than the preset value, it is considered that the battery has not experienced a capacity diving fault. When the decay rate is relatively dispersed and significantly greater than the preset value, it is considered that the battery has experienced a capacity diving fault. The coulombic efficiency corresponding to the range is distinguished as the coulombic efficiency threshold. The threshold is a process quantity that can effectively identify the change in the decay mode. That is, for the battery tested under the set conditions, when the coulombic efficiency is less than the coulombic efficiency threshold, the battery will experience a capacity diving. The coulombic efficiency thresholds for different set SOC values ​​and different shelf times are determined in a similar way, and a coulombic efficiency threshold database for the battery under different set SOC values ​​and different shelf times is established. By extracting the coulombic efficiency threshold under the set SOC value and different shelf time, the extraction method is relatively simple, and the size of the coulombic efficiency threshold can accurately and effectively identify the diving battery cell, with an accuracy rate of almost 100%.

[0094] In some embodiments, a coulombic efficiency threshold database of the battery under set SOC values ​​and different shelf times is established based on the coulombic efficiency and the decay rate, including: obtaining a correspondence diagram between the coulombic efficiency and the decay rate; determining in the correspondence diagram the coulombic efficiency threshold corresponding to the decay rate distribution within a set range; and establishing a coulombic efficiency threshold database consisting of the set SOC value, different shelf times and the coulombic efficiency threshold.

[0095] In the embodiment, after obtaining the coulombic efficiency and the decay rate, a corresponding relationship diagram of the coulombic efficiency and the decay rate under the same set conditions, i.e., a set SOC value and a certain standby time, is obtained, such as Figure 4 As shown in the figure, the retired batteries with different SOH are charged with 100% SOC, left for 3 days, and then discharged to 2.5V to obtain the relationship between the coulombic efficiency and the decay rate. It can be seen from the corresponding relationship diagram that when the coulombic efficiency is greater than 99%, the decay rate of the battery is more concentrated, almost all of which are lower than the preset value, i.e., 0.01Ah / Cycle. On the contrary, when the coulombic efficiency is less than 99%, the decay rate of the battery is more dispersed and the rate is significantly increased. Therefore, the coulombic efficiency threshold corresponding to the decay rate distribution in the set range is determined to be 99%, that is, for the batteries tested under the set conditions, the batteries with a coulombic efficiency less than 99% will experience a capacity dive. The coulombic efficiency thresholds for different set SOC values ​​and different shelf times are determined in a similar way, thereby establishing a database of coulombic efficiency thresholds for batteries under set SOC values ​​and different shelf times.

[0096] In fact, as shown in Table 2, the coulombic efficiency changes of calendar and cycle life diving cells after being stored for 60 days. The coulombic efficiency is also significantly lower than that of cells with normal attenuation. Therefore, this method is suitable for the identification of calendar and cycle life diving cells.

[0097] Table 2

[0098]

[0099]

[0100] In some embodiments, determining the coulombic efficiency threshold of the battery to be tested according to the coulombic efficiency threshold database includes: determining the coulombic efficiency threshold of the battery to be tested at a target SOC value and a target shelf time in the coulombic efficiency threshold database.

[0101] In an embodiment, after establishing a coulombic efficiency threshold database, the target SOC value of the battery to be tested, for example, 75% SOC and the target shelf time, i.e., 3 days, are obtained, and the coulombic efficiency threshold corresponding to the target SOC value 75% SOC and the target shelf time 3 days is obtained in the coulombic efficiency threshold database to determine the judgment parameters of whether the battery has a capacity diving failure, thereby accurately and effectively identifying the diving battery cells.

[0102] In some embodiments, the capacity dive detection result of the battery to be detected is determined according to the coulombic efficiency threshold and the target coulombic efficiency, including: if the target coulombic efficiency is lower than the coulombic efficiency threshold, determining that the battery to be detected has a capacity dive.

[0103] In an embodiment, after obtaining the target coulomb efficiency, the target coulomb efficiency is compared with the coulomb efficiency threshold of the corresponding state in the coulomb efficiency threshold database, and the capacity diving detection result of the battery to be detected is judged according to the size relationship between the target coulomb efficiency and the coulomb efficiency threshold. If the target coulomb efficiency is lower than the coulomb efficiency threshold, it is determined that the battery to be detected has a capacity diving fault; if the target coulomb efficiency is greater than or equal to the coulomb efficiency threshold, it is determined that the battery to be detected has not had a capacity diving, and the identification and classification of batteries with capacity diving and batteries with normal attenuation are realized, so that the batteries with capacity diving faults and the batteries without capacity diving faults can be processed accordingly, and a series of problems such as safety and performance caused by the combination of two battery cells can be avoided.

[0104] For example, if the target coulombic efficiency of the battery under test is 98% under the set conditions of 100% SOC and 3 days of storage, which is lower than the coulombic efficiency threshold of 99% under the set conditions, then it is determined that the battery has a capacity dive.

[0105] In some embodiments, obtaining the coulombic efficiency of the battery and the attenuation rate of the battery at a set SOC value at different shelf times includes: obtaining the charge capacity of the battery at the set SOC value, the discharge capacity of the battery at the set SOC value and shelf time, the number of charge and discharge cycles of the battery, and the capacity change value of the battery under the number of cycles; determining the coulombic efficiency of the battery based on the charge capacity and the discharge capacity; and obtaining the attenuation rate based on the capacity change value and the number of charge and discharge cycles.

[0106] In the embodiment, the battery is controlled to be charged at a constant current to different set SOC values ​​of the battery capacity. Taking 4 set SOC values ​​as an example, the charging capacity of the battery at the set SOC value is obtained, for example, recorded as Q1, Q2, Q3 and Q4; at different set SOC values, the battery corresponding to the set SOC value is placed at room temperature for different shelf times. Taking 3 shelf times as an example, the discharge capacity of the battery at the set SOC value and shelf time is obtained, for example, recorded as Q a , Q b and Q c , and simultaneously obtain the number of charge and discharge cycles of the battery and the capacity change value of the battery under the number of cycles.

[0107] The charge capacity and discharge capacity of the battery with different SOH at 4 set SOC values ​​and 3 shelf times are divided to determine the coulombic efficiency of the battery, which is recorded as η 1a , η 1b , η 1c ,......,η 4c , such as the Coulomb efficiency η 1a =Q a / Q1×100%.

[0108] After obtaining the number of charge and discharge cycles of the battery and the capacity change value of the battery under the number of cycles, calculate the ratio of the capacity change value to the number of cycles, and use the ratio as the decay rate. For example, the initial capacity of the battery is 117Ah, and the capacity after 100 cycles is 116Ah. The capacity change value is 116-117=-1Ah, and the decay rate is -1 / 100=-0.01Ah / Cycle.

[0109] It is understandable that if Figure 2 As shown, the decay rate of cells with normal attenuation of this type of battery is lower than 0.01Ah / Cycle, while the decay rate of cells with serious attenuation is even higher than 0.1Ah / Cycle. It only takes about 1000 cycles for the cells with severe attenuation to decay to 80% of the initial capacity, which seriously affects the warranty period of the entire module. Therefore, they need to be identified and classified to avoid being assembled with cells with normal attenuation.

[0110] In some embodiments, obtaining the charging capacity of the battery at a set SOC value includes: controlling the battery to charge at a preset rate constant current to the set SOC value to obtain the corresponding charging capacity at the set SOC value.

[0111] In an embodiment, as shown in Table 1, batteries with different SOH are controlled to be charged at a preset rate, for example, a constant current charge rate of ≤1C to a set SOC value of the battery capacity, such as 10% SOC, 25% SOC, 75% SOC and 100% SOC, to obtain the charging capacity Q1, Q2, Q3 and Q4 of the corresponding charge state at the set SOC value.

[0112] For example, the capacity of a battery of this model is 200Ah. The battery is controlled to be charged with 10% SOC, 25% SOC, 75% SOC and 100% SOC of the battery capacity at a charging current of 80A, that is, the corresponding charging capacities are: Q1=20Ah, Q2=50Ah, Q3=150Ah and Q4=200Ah. The charging current of 80A is fixed in a similar way and extended to batteries of all SOH.

[0113] In some embodiments, obtaining the discharge capacity of a battery at a set SOC value and a shelf time includes: placing the battery at the set SOC value until the battery reaches the shelf time; controlling the battery to discharge at a preset rate constant current to a cut-off voltage to obtain the discharge capacity of the battery at the set SOC value and the shelf time.

[0114] In the embodiment, as shown in Table 1, taking a certain set SOC value as an example, the battery corresponding to the set SOC value is placed at room temperature until the battery reaches the placement time, for example, 1 day, 3 days and 7 days, and the placed battery is controlled to discharge at the same preset rate constant current to the cut-off voltage to obtain the discharge capacity Q of the battery at the set SOC value and placement time. a , Q b and Q c .

[0115] For example, a battery charged to 25% SOC is placed at room temperature for 1 day, 3 days, and 7 days, and the battery is discharged at a constant current of 80A to a cut-off voltage of 2.5V. The discharge capacity Q at the corresponding placement time is recorded. a , Q b and Q c , and extend it to other batteries with set SOC values ​​in a similar way.

[0116] In some embodiments, after determining the capacity dive detection result of the battery to be detected according to the target coulombic efficiency, the method further includes: removing the battery with capacity dive.

[0117] In an embodiment, after the capacity diving detection result of the battery to be tested is determined according to the target coulombic efficiency, the batteries with capacity diving are eliminated, and the batteries with the same SOH and no capacity diving are grouped together to obtain batteries with relatively stable capacity decay. The above batteries can be reused after testing, screening, and reorganization, avoiding a series of safety and performance problems caused by the combination of two battery cells: batteries with capacity diving and batteries with relatively stable capacity decay.

[0118] like Figure 5 As shown in FIG. 1 , the capacity of the normally decayed battery cell identified by the present invention changes little with the number of cycles. Even if the SOH is different, the decay mode shown after about 500 cycles is basically the same; Figure 6 As shown, the capacity of the diving battery cell identified by the present invention varies greatly with the number of cycles, and the attenuation patterns displayed within 500 cycles are uneven. The normal attenuation battery cell identified by the present invention based on coulomb efficiency remains basically stable during 500 cycles, indicating the effectiveness of this method.

[0119] Reference below Figure 7 The battery detection method according to the embodiment of the present invention is described with examples.

[0120] like Figure 7 As shown, the battery detection method of the embodiment of the present invention at least includes steps S11 to S26.

[0121] Step S11, suspending the battery to be tested for a target suspension time.

[0122] Step S12, determining the target SOC value of the battery to be tested.

[0123] Step S13, after controlling the battery to be tested to discharge at a preset constant current rate to a cut-off voltage, controlling the battery to be tested to charge at a preset constant current rate to a target SOC value to obtain a target charging capacity.

[0124] Step S14, when the battery to be tested has been placed for a target placement time, the battery to be tested is controlled to discharge at a preset constant current rate to a cut-off voltage to obtain a target discharge capacity.

[0125] Step S15, calculating the percentage of the target discharge capacity and the target charge capacity, and taking the percentage as the target coulomb efficiency.

[0126] Step S16, controlling the battery to charge at a preset rate constant current to a set SOC value, so as to obtain a corresponding charging capacity under the set SOC value.

[0127] Step S17, leaving the battery at the set SOC value until the leaving time is reached.

[0128] Step S18, controlling the battery to discharge at a preset rate constant current to a cut-off voltage, so as to obtain the discharge capacity of the battery under the set SOC value and shelf time.

[0129] Step S19, determining the coulombic efficiency of the battery according to the charging capacity and the discharging capacity; and obtaining the attenuation rate according to the coulombic efficiency.

[0130] Step S20, obtaining the number of charge and discharge cycles of the battery and the capacity change value of the battery under the number of cycles.

[0131] Step S21, calculating the ratio of the capacity change value to the number of cycles, and taking the ratio as the attenuation rate.

[0132] Step S22, obtaining a corresponding relationship diagram between coulombic efficiency and attenuation rate; determining the coulombic efficiency threshold corresponding to the attenuation rate distribution within a set range in the corresponding relationship diagram; and establishing a coulombic efficiency threshold database consisting of a set SOC value, different standby times and coulombic efficiency thresholds.

[0133] Step S23, determining whether the target coulombic efficiency is lower than the coulombic efficiency threshold, if so, executing step S24; otherwise, executing step S25.

[0134] Step S24, determining whether the capacity of the battery to be tested has dropped.

[0135] Step S25, determining that the capacity of the battery to be tested does not drop.

[0136] Step S26, removing batteries with reduced capacity.

[0137] According to the battery detection method of the embodiment of the present invention, by controlling the target shelving time of the battery to be detected, the target coulomb efficiency after the current coulomb efficiency is reacted is determined to determine the change in the attenuation mode of the battery to be detected, and according to the size relationship between the target coulomb efficiency and the judgment parameter of the capacity diving fault occurring under the same set conditions, the capacity diving detection result of the battery to be detected is determined, and the diving battery cell with abnormal attenuation rate in the battery to be detected can be accurately identified, thereby improving the accuracy of identifying the capacity diving detection result of the battery to be detected. At the same time, by utilizing the size of the target coulomb efficiency to reflect the capacity diving mechanism inside the battery, the present invention is suitable for the scenarios of online capacity diving warning and offline attenuation consistency sorting, thereby improving the practicality of the capacity diving detection result, avoiding the safety and performance problems caused by the incorporation of capacity diving batteries into the battery module, thereby facilitating the widespread implementation of the present invention.

[0138] The electronic device according to the embodiment of the present invention is described below.

[0139] The electronic device of an embodiment of the present invention includes at least one processor; and a memory connected to the at least one processor in communication; wherein the memory stores a battery detection program that can be executed by the at least one processor, and when the battery detection program is executed by the at least one processor, the at least one processor executes the battery detection method of the above embodiment.

[0140] According to the electronic device of the embodiment of the present invention, by controlling the target shelving time of the battery to be detected, the target coulomb efficiency after the current coulomb efficiency is reacted is determined to determine the change in the attenuation mode of the battery to be detected, and according to the size relationship between the target coulomb efficiency and the judgment parameter of the capacity diving fault occurring under the same set conditions, the capacity diving detection result of the battery to be detected is determined, and the diving battery cell with abnormal attenuation rate in the battery to be detected can be accurately identified, thereby improving the accuracy of identifying the capacity diving detection result of the battery to be detected. At the same time, by utilizing the size of the target coulomb efficiency to reflect the capacity diving mechanism inside the battery, the present invention is suitable for the scenarios of online capacity diving warning and offline attenuation consistency sorting, thereby improving the practicality of the capacity diving detection result, avoiding the safety and performance problems caused by the incorporation of capacity diving batteries into the battery module, thereby facilitating the widespread implementation of the present invention.

[0141] The following describes a non-transitory computer-readable storage medium according to an embodiment of the present invention.

[0142] A battery detection program is stored on a computer-readable storage medium in an embodiment of the present invention. When the battery detection program is executed by a processor, the battery detection method of the above embodiment is implemented.

[0143] The following describes a computer program product according to an embodiment of the present invention.

[0144] The computer program product of the embodiment of the present invention includes a computer program, and the computer program includes program instructions. When the program instructions are executed by a computer, the computer executes the battery detection method of the above embodiment.

[0145] According to the computer program product of the embodiment of the present invention, by controlling the target shelving time of the battery to be detected, the target coulomb efficiency after the current coulomb efficiency is reacted is determined to determine the change in the attenuation mode of the battery to be detected, and according to the size relationship between the target coulomb efficiency and the judgment parameter of the capacity diving fault occurring under the same set conditions, the capacity diving detection result of the battery to be detected is determined, and the diving battery cell with abnormal attenuation rate in the battery to be detected can be accurately identified, thereby improving the accuracy of identifying the capacity diving detection result of the battery to be detected. At the same time, by utilizing the size of the target coulomb efficiency to reflect the capacity diving mechanism inside the battery, the present invention is suitable for the scenarios of online capacity diving warning and offline attenuation consistency sorting, thereby improving the practicality of the capacity diving detection result, avoiding the safety and performance problems caused by the incorporation of capacity diving batteries into the battery module, thereby facilitating the widespread implementation of the present invention.

[0146] Reference below Figure 8 A battery testing device 2 according to an embodiment of the present invention is described.

[0147] like Figure 8 As shown, the battery detection device 2 of the embodiment of the present invention includes: an acquisition module 21 and a determination module 22, wherein:

[0148] The acquisition module 21 is used to acquire the target coulomb efficiency of the battery to be detected, and the battery to be detected includes a battery that has been shelved for a target shelving time; the determination module 22 is used to determine the capacity drop detection result of the battery to be detected according to the target coulomb efficiency.

[0149] According to the battery detection device 2 of the embodiment of the present invention, by controlling the target shelving time of the battery to be detected, the target coulomb efficiency after the current coulomb efficiency is reacted is determined to determine the change in the attenuation mode of the battery to be detected, and according to the size relationship between the target coulomb efficiency and the judgment parameter of the capacity diving fault under the same set conditions, the capacity diving detection result of the battery to be detected is determined, and the diving battery cell with abnormal attenuation rate in the battery to be detected can be accurately identified, thereby improving the accuracy of identifying the capacity diving detection result of the battery to be detected. At the same time, by utilizing the size of the target coulomb efficiency to reflect the capacity diving mechanism inside the battery, the present invention is suitable for the scenarios of online capacity diving warning and offline attenuation consistency sorting, thereby improving the practicality of the capacity diving detection result, avoiding the safety and performance problems caused by the addition of capacity diving batteries to the battery module, thereby facilitating the widespread implementation of the present invention.

[0150] Reference below Fig. 9 The controller 3 according to the embodiment of the present invention is described.

[0151] like Fig. 9 As shown, the controller 3 of the embodiment of the present invention includes the battery detection device 2 of the above embodiment.

[0152] According to the controller 3 of the embodiment of the present invention, by controlling the target shelving time of the battery to be detected, the target coulomb efficiency after the current coulomb efficiency is reacted is determined to determine the change in the attenuation mode of the battery to be detected, and according to the size relationship between the target coulomb efficiency and the judgment parameter of the capacity diving failure under the same set conditions, the capacity diving detection result of the battery to be detected is determined, and the diving battery cell with abnormal attenuation rate in the battery to be detected can be accurately identified, thereby improving the accuracy of identifying the capacity diving detection result of the battery to be detected. At the same time, by utilizing the size of the target coulomb efficiency to reflect the capacity diving mechanism inside the battery, the present invention is suitable for the scenarios of online capacity diving warning and offline attenuation consistency sorting, thereby improving the practicality of the capacity diving detection result, avoiding the safety and performance problems caused by the addition of capacity diving batteries into the battery module, thereby facilitating the widespread implementation of the present invention.

[0153] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "illustrative embodiments", "examples", "specific examples", or "some examples" means that the specific features, structures, materials, or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example.

[0154] Although the embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the claims and their equivalents.

Claims

1. A battery detection method, characterized in that: include: Obtaining a target coulombic efficiency of the battery to be tested, wherein the battery to be tested comprises a battery that has been shelved for a target shelving time; A capacity drop detection result of the battery to be detected is determined according to the target coulombic efficiency.

2. The battery detection method according to claim 1, characterized in that: Determining the target coulombic efficiency of the battery to be tested, including: Determining a target SOC value of the battery to be tested; The target coulombic efficiency is determined according to the target SOC value and the target rest time.

3. The battery detection method according to claim 2, characterized in that: Determining the target coulombic efficiency according to the target SOC value and the target shelf time includes: Obtaining a target charging capacity of the battery to be tested at the target SOC value and a target discharging capacity of the battery to be tested at the target shelf time; The target coulombic efficiency is determined according to the target charging capacity and the target discharging capacity.

4. The battery detection method according to claim 3, characterized in that: Obtaining a target charging capacity of the battery to be tested at the target SOC value includes: After controlling the battery to be detected to discharge to a cut-off voltage at a preset constant current rate, controlling the battery to be detected to charge to the target SOC value at the preset constant current rate to obtain the target charging capacity.

5. The battery detection method according to claim 3, characterized in that: Obtaining the target discharge capacity of the battery to be tested during the target shelf time includes: When the battery to be detected is left for the target rest time, the battery to be detected is controlled to discharge to a cut-off voltage at the preset constant current rate to obtain the target discharge capacity.

6. The battery detection method according to claim 3, characterized in that: Determining the target coulombic efficiency according to the target charging capacity and the target discharging capacity includes: The percentage of the target discharge capacity and the target charge capacity is calculated, and the percentage is used as the target coulomb efficiency.

7. The battery detection method according to claim 1, characterized in that: Determining a capacity drop detection result of the battery to be detected according to the target coulombic efficiency includes: Obtaining a coulombic efficiency threshold of the battery to be tested; A capacity drop detection result of the battery to be detected is determined according to the coulombic efficiency threshold and the target coulombic efficiency.

8. The battery detection method according to claim 7, characterized in that: Obtaining the coulombic efficiency threshold of the battery to be detected includes: Obtain the Coulombic efficiency threshold database of the battery; The coulombic efficiency threshold of the battery to be tested is determined according to the coulombic efficiency threshold database.

9. The battery detection method according to claim 8, characterized in that: Get the Coulombic efficiency threshold database of batteries, including: Obtaining the coulombic efficiency of the battery and the attenuation rate of the battery at different storage times when the battery has a set SOC value; A coulombic efficiency threshold database of the battery under set SOC value and different shelf time is established according to the coulombic efficiency and the decay rate.

10. The battery detection method according to claim 9, characterized in that: A coulombic efficiency threshold database of the battery under a set SOC value and different shelf times is established according to the coulombic efficiency and the decay rate, including: Obtaining a corresponding relationship diagram between the coulomb efficiency and the decay rate; Determine in the corresponding relationship diagram the coulomb efficiency threshold corresponding to when the attenuation rate distribution is within a set range; A coulombic efficiency threshold database consisting of the set SOC value, different holding times and the coulombic efficiency thresholds is established.

11. The battery detection method according to claim 8, characterized in that: Determining the coulombic efficiency threshold of the battery to be detected according to the coulombic efficiency threshold database includes: The coulombic efficiency threshold of the battery to be tested under a target SOC value and a target shelf time is determined in the coulombic efficiency threshold database.

12. The battery detection method according to claim 7, characterized in that: Determining a capacity drop detection result of the battery to be detected according to the coulombic efficiency threshold and the target coulombic efficiency includes: If the target coulombic efficiency is lower than the coulombic efficiency threshold, it is determined that the capacity of the battery to be detected has dropped.

13. The battery detection method according to claim 9, characterized in that: Obtaining the coulombic efficiency of the battery and the attenuation rate of the battery at different storage times at the set SOC value of the battery, including: Obtaining the charging capacity of the battery at the set SOC value, the discharging capacity of the battery at the set SOC value and the shelf time, the number of charge and discharge cycles of the battery, and the capacity change value of the battery under the number of cycles; Determining the coulombic efficiency of the battery according to the charging capacity and the discharging capacity; The attenuation rate is obtained according to the capacity change value and the number of charge and discharge cycles.

14. The battery detection method according to claim 13, characterized in that: Obtaining the charging capacity of the battery at the set SOC value includes: The battery is controlled to be charged at a preset rate constant current to the set SOC value to obtain a corresponding charging capacity under the set SOC value.

15. The battery detection method according to claim 13, characterized in that: Obtaining the discharge capacity of the battery under the set SOC value and shelf time, including: placing the battery at the set SOC value until the placement time is reached; The battery is controlled to discharge at a preset rate constant current to obtain the discharge capacity of the battery under the set SOC value and the shelf time.

16. The battery detection method according to claim 15, characterized in that: Controlling the battery to discharge at a preset rate constant current includes: The battery is controlled to discharge at a preset rate constant current to a cut-off voltage.

17. The battery detection method according to claim 13, characterized in that: Obtaining the attenuation rate according to the capacity change value and the number of charge and discharge cycles includes: The ratio of the capacity change value to the number of cycles is calculated, and the ratio is used as the attenuation rate.

18. The battery detection method according to claim 1, characterized in that: After determining the capacity dive detection result of the battery to be detected according to the target coulombic efficiency, the method further includes: removing the battery with capacity dive.

19. An electronic device, characterized in that: include: at least one processor; as well as a memory communicatively connected to the at least one processor; wherein, The memory stores a battery detection program executable by the at least one processor. When the battery detection program is executed by the at least one processor, the at least one processor executes the battery detection method according to any one of claims 1 to 18.

20. A non-transitory computer-readable storage medium, characterized in that The computer-readable storage medium stores a battery detection program, and when the battery detection program is executed by the processor, the battery detection method according to any one of claims 1 to 18 is implemented.

21. A computer program product, characterized in that The computer program product comprises a computer program, and the computer program comprises program instructions. When the program instructions are executed by a computer, the computer is enabled to execute the battery detection method according to any one of claims 1 to 18.

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