Lithium precipitation detection method, device and equipment

Abstract

The invention provides a lithium precipitation detection method, device and equipment, and the method comprises the steps: collecting the voltages of a plurality of charging stages of a to-be-detected battery in a target charging process, obtaining the respective starting voltages and ending voltages of the plurality of charging stages, the starting voltages being the voltages at the charging starting moments of the corresponding charging stages, and the ending voltages being the voltages at the charging ending moments of the corresponding charging stages; the end voltage is the voltage at the charging end moment of the corresponding charging stage; for any target charging stage in the plurality of charging stages, calculating the difference between the ending voltage of the target charging stage and the starting voltage of the next charging stage of the target charging stage to obtain a voltage change value; according to the plurality of voltage change values, judging whether lithium precipitation occurs in the to-be-detected battery or not; wherein the plurality of charging stages correspond to different charging parameters, and the charging parameters comprise a charge state and a charging current or a charging rate corresponding to the charge state. The accuracy and convenience of battery lithium precipitation detection can be improved.

Description

Technical Field

[0001] The embodiments of the present application relate to the field of battery detection technology, and in particular to a lithium plating detection method, device and equipment. Background Art

[0002] With the continuous increase in the number of new energy vehicles, higher requirements are placed on the charging speed of lithium-ion batteries. The increase in battery charging speed will lead to an increase in the battery charging rate, which in turn will lead to an increase in battery polarization. A large amount of lithium ions will accumulate at the negative electrode of the battery, thereby increasing the risk of lithium plating. After lithium plating occurs, the precipitated lithium dendrites react with the electrolyte, generating a large amount of heat or short circuit locally. In severe cases, it may cause thermal runaway of the battery, ultimately threatening the safe use of the battery. Therefore, how to detect whether lithium plating occurs or exists in the battery is a technical problem that needs to be solved. Summary of the invention

[0003] The present application provides a lithium deposition detection method, device and equipment, which can improve the accuracy and convenience of battery lithium deposition detection.

[0004] In a first aspect, the present application provides a lithium plating detection method, the method comprising: collecting voltages of multiple charging stages during a target charging process of a battery to be tested, obtaining a start voltage and an end voltage of each of the multiple charging stages, the start voltage being the voltage at the start time of the corresponding charging stage, and the end voltage being the voltage at the end time of the corresponding charging stage; for any target charging stage in the multiple charging stages, calculating the difference between the end voltage of the target charging stage and the start voltage of the next charging stage of the target charging stage, to obtain a voltage change value; judging whether lithium plating occurs in the battery to be tested based on the multiple voltage change values; wherein the multiple charging stages correspond to different charging parameters, and the charging parameters include the state of charge (SOC, or referred to as the charging state) and the charging current or charging rate corresponding to the state of charge.

[0005] In a second aspect, the present application provides a lithium plating detection device, which includes: a voltage acquisition module, which is used to collect voltages of multiple charging stages during a target charging process of a battery to be tested, and obtain a start voltage and an end voltage of each of the multiple charging stages, wherein the start voltage is the voltage at the start time of the corresponding charging stage, and the end voltage is the voltage at the end time of the corresponding charging stage; a difference calculation module, which is used to calculate the difference between the end voltage of the target charging stage and the start voltage of the next charging stage of the target charging stage for any target charging stage in the multiple charging stages, and obtain a voltage change value; a lithium plating judgment module, which is used to judge whether lithium plating occurs in the battery to be tested based on multiple voltage change values; wherein the multiple charging stages correspond to different charging parameters, and the charging parameters include the state of charge and the charging current or charging rate corresponding to the state of charge.

[0006] In a third aspect, the present application provides an electronic device, comprising: a processor and a memory, the memory being used to store a computer program, the processor being used to call and run the computer program stored in the memory, and executing the method in the first aspect or its various implementations.

[0007] In a fourth aspect, the present application provides a computer-readable storage medium for storing a computer program, wherein the computer program enables a computer to execute the method in the first aspect or its various implementations.

[0008] In a fifth aspect, the present application provides a computer program product, comprising computer program instructions, which enable a computer to execute the method in the first aspect or its various implementations.

[0009] In a sixth aspect, the present application provides a computer program, which enables a computer to execute the method in the first aspect or its various implementations.

[0010] Through the technical solution of the present application, the change in voltage when the charging stage changes during the charging process of the battery to be tested can be detected, and whether lithium plating occurs can be determined based on the change in voltage. It can be understood that in the above process, not only is there no need for additional charge and discharge detection processes or test equipment to participate, the cost of lithium plating detection can be reduced, and non-destructive detection of lithium plating of the battery can be achieved; and the detection is performed during the battery charging process, therefore, the real-time and convenience of lithium plating detection can be achieved, and the safety of the battery during use can be improved. In addition, since the above voltage changes can reflect whether lithium plating occurs, more accurate and sensitive lithium plating detection can also be achieved. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for describing the embodiments are briefly introduced below.

[0012] Figure 1 A flow chart of a lithium deposition detection method provided in an embodiment of the present application;

[0013] Figure 2 A schematic diagram of a lithium precipitation detection method provided in an embodiment of the present application;

[0014] Figure 3 A schematic diagram of another lithium precipitation detection method provided in an embodiment of the present application;

[0015] Figure 4 A schematic diagram of another lithium precipitation detection method provided in an embodiment of the present application;

[0016] Figure 5 A schematic diagram of another lithium precipitation detection method provided in an embodiment of the present application;

[0017] Figure 6 A schematic diagram of a lithium deposition detection device 600 provided in an embodiment of the present application;

[0018] Figure 7 A schematic block diagram of an electronic device 700 provided in an embodiment of the present application. DETAILED DESCRIPTION

[0019] It should be noted that the terms "first", "second", etc. in the specification and claims of the present application and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchangeable where appropriate, so that the embodiments of the present application described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having" and any of their variations are intended to cover non-exclusive inclusions, for example, a process, method, system, product or server that includes a series of steps or units is not necessarily limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0020] It should be understood that the technical solution of the present application can be applied to the following scenarios, but is not limited to:

[0021] In one embodiment, the technical solution of the present application can be applied to the lithium plating detection scenario of lithium-ion power batteries. For example, it can be applied to the lithium plating detection scenario of lithium-ion batteries such as ternary positive electrode batteries and lithium iron phosphate positive electrode batteries. The present application does not impose any restrictions on this.

[0022] After introducing the application scenarios of the embodiments of the present application, the technical solution of the present application will be described in detail below:

[0023] Figure 1 A flow chart of a lithium deposition detection method provided in an embodiment of the present application is as follows: Figure 1 As shown, the method may include the following steps:

[0024] S110: collecting voltages of multiple charging stages during a target charging process of the battery to be tested, and obtaining a start voltage and an end voltage of each of the multiple charging stages, wherein the start voltage is the voltage at the start time of the corresponding charging stage, and the end voltage is the voltage at the end time of the corresponding charging stage;

[0025] S120: for any target charging stage among the multiple charging stages, calculating the difference between the end voltage of the target charging stage and the start voltage of the next charging stage of the target charging stage to obtain a voltage change value;

[0026] S130: Determine whether lithium deposition occurs in the battery to be tested according to the multiple voltage change values.

[0027] Among them, multiple charging stages correspond to different charging parameters, and the charging parameters include the state of charge and the charging current or charging rate corresponding to the state of charge.

[0028] It should be noted that the target charging process can be performed based on a multi-step charging method. Figure 2 As shown, the multi-step charging method is to divide the battery charging process into multiple state of charge intervals, and use different charging rates / charging currents in different state of charge intervals. One state of charge corresponds to one charging stage and one step. Specifically, the charging process can be divided into 3-40 steps, that is, 3-40 charging stages. A larger rate is used for charging in the low state of charge interval, and a relatively small rate is used for charging in the high state of charge interval.

[0029] In addition, the charging temperature of the target charging process may be any constant temperature between -30°C and 60°C, which is not limited in the present application.

[0030] In one embodiment, the technical solution of the present application can be applied to the whole vehicle BMS (battery management system) to detect lithium deposition. Specifically, the voltage of the battery to be tested can be collected through the sensors and dedicated integrated chips included in the BMS, and whether lithium deposition occurs can be determined based on the voltage, so that the whole vehicle application process such as the existing whole vehicle fast charging mode can be matched, and lithium deposition detection can be performed during the use of the whole vehicle (specifically in the whole vehicle fast charging mode).

[0031] The sampling interval of the collected voltage may be 0.1s-10s, which is not limited in this application.

[0032] For example, Figure 3 As shown, taking two charging stages as an example, assuming that the charging current of the target charging stage is current I1, and the charging current of the next charging stage of the target charging stage is current I2. The starting voltage (i.e., the voltage at the moment when charging starts in the target charging stage) and the ending voltage (i.e., the voltage at the moment when charging ends in the target charging stage) of the target charging stage are voltages V0 and V1 respectively; the starting voltage and ending voltage of the next charging stage of the target charging stage are voltages V2 and V3 respectively. The difference between the ending voltage of the target charging stage and the starting voltage of the next charging stage of the target charging stage, i.e., the voltage change value, is V1-V2.

[0033] In one embodiment, judging whether lithium deposition has occurred in the battery to be tested based on multiple voltage change values ​​includes: determining a voltage change threshold; for any adjacent first voltage change value and second voltage change value among the multiple voltage change values, calculating the absolute value of the difference between the first voltage change value and the second voltage change value to obtain a voltage change degree value; if the voltage change degree value is less than or equal to the voltage change threshold, judging that lithium deposition has not occurred in the battery to be tested; if the voltage change degree value is greater than the voltage change threshold, judging that lithium deposition has occurred in the battery to be tested.

[0034] The voltage change degree value is used to characterize the difference between the first voltage change value and the second voltage change value. When the difference is large, that is, the voltage change degree value is greater than the voltage change threshold, it can be judged that lithium deposition has occurred in the battery under test; when the difference is small, that is, the voltage change degree value is less than or equal to the voltage change threshold, it can be judged that lithium deposition has not occurred in the battery under test.

[0035] Specifically, if the voltage change degree value is less than or equal to the voltage change threshold, it is judged that the adjacent first voltage change value and the second voltage change value corresponding to the voltage change degree value do not cause lithium deposition in the corresponding charging stage; if the voltage change degree value is greater than the voltage change threshold, it is judged that the adjacent first voltage change value and the second voltage change value corresponding to the voltage change degree value do cause lithium deposition in the corresponding charging stage.

[0036] It is understandable that if Figure 4 As shown, the battery to be tested includes: graphite and a solid electrolyte interface membrane (SEI membrane) wrapped in graphite. During the target charging process, when the charging current drops suddenly according to the charging stage, the voltage of the lithium-ion battery also decreases (reference Figure 3 ), that is, the starting voltage of the next charging stage after the target charging stage will be lower than the starting voltage of the target charging stage. Figure 4 During the charging process, when lithium is deposited from the negative electrode of the battery, the battery is in a relaxed state, and the deposited lithium metal is embedded back into the negative electrode. At this time, the battery voltage drops slowly, corresponding to Figure 4 The solid line in the middle indicates the relaxation curve of lithium deposition. When there is no lithium deposition, the battery voltage drops relatively steadily, corresponding to Figure 4 The middle dashed line indicates the relaxation curve without lithium deposition.

[0037] Therefore, it can be determined that: when lithium is not deposited, the voltage reduction is relatively stable, that is, the voltage reduction value when the charging stage changes is relatively stable, that is, the above multiple voltage change values ​​are relatively close, that is, the voltage change degree is less than or equal to the voltage change threshold; when lithium is deposited, the voltage reduction becomes slow, that is, the voltage reduction value when the charging stage changes is less than the voltage reduction value in the state without lithium deposition, that is, the above voltage change value will be lower than the voltage change value in the state without lithium deposition, that is, the voltage change degree value is greater than the voltage change threshold. Therefore, it is possible to determine whether lithium deposition occurs by detecting the voltage drop degree / change trend of the battery voltage (that is, the absolute value of the difference between the adjacent first voltage change value and the second voltage change value, that is, the voltage change degree value) when the charging current changes during the charging process (specifically, it can be the battery charging relaxation stage), that is, when the charging stage changes.

[0038] In one embodiment, the above-mentioned determination of the voltage change threshold may include: determining the voltage change ratio; calculating the product of the first voltage change value and the voltage change ratio to obtain the voltage change threshold corresponding to the first voltage change value and the second voltage change value; wherein the charging time corresponding to the first voltage change value is earlier than the charging time corresponding to the second voltage change value. That is, the target charging stage corresponding to the first voltage change value is earlier than the target charging stage corresponding to the second voltage change value.

[0039] The voltage change ratio may be used to represent a ratio of a decrease in the second voltage change value relative to the first voltage change value.

[0040] In combination with the above content, that is to say, if the absolute value of the difference between the first voltage change value and the second voltage change value, that is, the voltage change degree value, is less than or equal to the product of the first voltage change value and the voltage change ratio, it can be determined that lithium deposition has not occurred in the battery to be tested; if the absolute value of the difference between the first voltage change value and the second voltage change value, that is, the voltage change degree value, is greater than the product of the first voltage change value and the voltage change ratio, it is determined that lithium deposition has occurred in the battery to be tested.

[0041] It is understandable that when the charging stage changes, the charging current will change suddenly, which will cause the battery polarization to decrease and the battery voltage to decrease. The degree of battery polarization decrease corresponding to batteries with different battery capacities is also different (generally, the smaller the battery capacity, the greater the corresponding degree of battery polarization decrease). Therefore, the above voltage change ratio can be determined by the battery capacity and battery polarization degree of the battery to be tested.

[0042] Exemplarily, the battery capacity of the battery to be tested may be first obtained to obtain a target battery capacity; then, the battery polarization degree of the battery to be tested during each charging process may be determined; finally, the voltage change ratio may be determined based on the target battery capacity and each battery polarization degree.

[0043] Specifically, based on the lithium plating and reinsertion mechanism, the degree of battery polarization elimination / weakening (i.e., battery polarization degree) of the battery to be tested during the target charging process under the target battery capacity can be tested, and the voltage change values ​​corresponding to multiple charging stages and the reduction ratio of each voltage change value relative to the previous voltage change value (i.e., the reduction ratio of the first voltage change value relative to the second voltage change value) can be recorded simultaneously; then, the corresponding relationship between each reduction ratio and the battery polarization degree is determined, and the reduction ratio corresponding to the battery polarization degree during lithium plating is determined as the voltage change ratio.

[0044] For example, experiments have found that when the voltage change value decreases by more than 5%-100% relative to the previous voltage change value, it is determined that lithium deposition occurs in the battery, that is, the voltage change ratio can be determined to be 5%-100%.

[0045] Exemplarily, a preset voltage change value corresponding to a plurality of voltage change values ​​may be determined by a battery step current difference test; then, whether lithium deposition occurs may be determined based on the plurality of voltage change values ​​and the preset voltage change value. Specifically, it may be calculated whether the difference between the plurality of voltage change values ​​and the preset voltage change value is less than the preset difference. If it is less than or equal to the preset difference, it may be determined that lithium deposition does not occur in the charging stage corresponding to the corresponding voltage change value; if it is greater than the preset difference, it may be determined that lithium deposition occurs in the charging stage corresponding to the corresponding voltage change value.

[0046] Among them, the battery step current difference test refers to the process of determining the voltage change value when no lithium deposition occurs in the adjacent charging stages by calculating the difference in charging current or charging rate corresponding to the adjacent charging stages, that is, the preset voltage change value. It can be understood that the difference in charging current or charging rate corresponding to the adjacent charging stages is related to the voltage change value corresponding to the adjacent charging stages, that is, combined with Figure 3 , there is a corresponding relationship between the difference between current I1 and current I2 and the sudden voltage, that is, the voltage change value V1-V2, that is, the difference between current I1 and current I2 corresponds to a preset voltage change value (that is, a fixed voltage change value V1-V2). When lithium deposition does not occur, V1-V2 is close to the preset voltage change value, that is, the difference between the preset voltage change value and the preset voltage change value is less than or equal to the preset difference; when lithium deposition occurs, the difference between V1-V2 and the preset voltage change value is greater than the preset difference.

[0047] In one embodiment, when it is determined that lithium deposition occurs in the battery to be tested, the battery to be tested may be disassembled to verify whether lithium deposition occurs in the battery to be tested.

[0048] For example, Figure 5As shown in (a) in the figure, the black box represents the graphite in the battery to be tested. When lithium deposition does not occur, the graphite does not contain lithium ions. When lithium deposition occurs, the graphite will contain lithium ions, as shown by the filled diagonal line part in the black box. The white area in the black box represents the lithium ions combined with the graphite.

[0049] In the above embodiment, the battery can be non-destructively, quickly, and highly sensitively detected for lithium deposition by detecting the battery voltage drop trend during multiple current mutations during the charging process. At the same time, the corresponding charging state when lithium deposition occurs, as well as the state of charge and charging current under the charging state, can also be determined, so that real-time and rapid lithium deposition detection can be achieved during the battery charging process, which is convenient for adjusting and correcting the battery charging strategy, improving the safety of the battery use process, and realizing accurate battery state control during the charging process. Moreover, the present application does not need to test the battery resistance and voltage changes through an additional charging static process to perform lithium deposition detection, so the cost of lithium deposition detection can be reduced.

[0050] In one embodiment, the above-mentioned multiple charging stages are multiple continuous charging stages. Before collecting the voltages of multiple charging stages in the target charging process of the battery to be tested, the negative electrode voltage of the battery to be tested in the target charging process can be monitored first; the negative electrode voltage threshold is determined; and it is determined that the charging stage corresponding to the negative electrode voltage being lower than the negative electrode voltage threshold in all charging stages of the target charging process is the first charging stage among the multiple charging stages.

[0051] Since lithium deposition is more likely to occur when the negative electrode voltage is lower than the negative electrode potential threshold (correspondingly, lithium deposition is more likely to occur at the lowest point of the negative electrode voltage during the entire charging process), therefore, detecting the voltages in the charging stage where the probability of lithium deposition is higher and performing lithium deposition detection based on these voltages can improve detection efficiency.

[0052] For example, the target charging process includes 3-40 total charging stages, and the number of multiple charging stages used for lithium plating detection may be 1-40.

[0053] In one embodiment, a voltage change curve can also be constructed based on multiple voltage change values, and the voltage change curve represents the relationship between the multiple voltage change values ​​and the corresponding charging stages; then, based on the positional relationship between the coordinate points corresponding to the multiple voltage change values ​​in the voltage change curve, it can be determined whether lithium deposition occurs in the battery to be tested.

[0054] Specifically, in combination with the above content, it can be known that when lithium deposition has not occurred, the positions of the coordinate points corresponding to multiple voltage change values ​​in the voltage change curve are relatively close (specifically, the difference in the coordinate values ​​representing the voltage change values ​​in the corresponding coordinate points is less than or equal to the coordinate value difference threshold); when lithium deposition occurs, the position of the coordinate point corresponding to the voltage change value corresponding to the charging stage where lithium deposition occurs in the voltage change curve is relatively far away from the coordinate point corresponding to where lithium deposition has not occurred (specifically, the difference between the coordinate value representing the voltage change value in the coordinate point corresponding to the charging stage where lithium deposition occurs and the coordinate value representing the voltage change value in the coordinate point corresponding to where lithium deposition has not occurred is greater than the coordinate value difference threshold).

[0055] Among them, the coordinate value difference threshold is similar to the above-mentioned voltage change threshold, and its corresponding determination method and other contents are similar to the contents corresponding to the voltage change threshold. To avoid repetition, this application will not elaborate on this.

[0056] For example, the battery to be tested can be charged multiple times or multiple cycles based on the same charging method, and the voltage change value of each charging stage during each charging cycle can be recorded to obtain the following: Figure 5 It can be seen from the voltage change curve shown in (a) in the figure that before the 19th charging stage (or charging step) of the 183rd cycle of charging, the battery voltage was basically stable at 32mv, while the voltage change value between the 19th charging stage and the 20th charging stage of the 183rd cycle was reduced to 21mv, which indicates that lithium plating occurred at this time.

[0057] The following is an introduction to the technical solution of this application through experimental data:

[0058] Example 1, taking the battery to be tested as a lithium iron phosphate positive electrode-graphite negative electrode lithium ion battery as an example, the battery is a 10Ah soft pack battery, and the target charging process includes 20 charging stages, i.e., charging steps. First, a three-electrode battery corresponding to the battery is made to detect the negative electrode potential. Specifically, a diaphragm can be used to wrap a copper wire with a diameter of 30um, and the side of the battery can be opened, implanted into the battery as a battery three-electrode, and the battery can be packaged; then, the battery is charged for 1.5h using a charging and discharging device with a parameter of 20uA, and the three electrodes are charged and lithium-plated to complete the activation of the three-electrode lithium plating. Then, at a constant temperature (for example, 25°C), a 20-step multi-step constant current step fast charging strategy is used to charge the three-electrode battery, while monitoring the potential difference between the three electrodes and the negative electrode, determining the trend of the negative electrode potential change during the above charging process, and determining the lowest position of the negative electrode potential (i.e., the charging current and the number of steps when the potential is the lowest, i.e., the charging stage). Then, multiple voltage change values ​​between the charging stage corresponding to the position and the subsequent charging stage can be calculated. Afterwards, the battery can be charged and discharged at the constant temperature to cycle at 1C, monitor the voltage change value, i.e., the voltage difference, at each step transition, i.e., the charging stage transition, during each charging process in real time, and construct a voltage distribution model according to the multiple voltage change values. Figure 5 The voltage change curve shown in (a) in FIG. 1 is used to determine the charging stage corresponding to the sudden drop in the voltage value in the voltage change curve as the charging stage corresponding to the occurrence of lithium deposition. At the same time, the above data can be recorded as follows: Figure 5 As shown in the second row of the table shown in (b), the voltage difference represents the voltage change value, and the number of monitoring steps is the charging stage. Figure 5 It can be seen that the voltage difference drop during the 19th to 20th stage conversion process in the 183rd cycle is significantly lower than the voltage difference drop during the 19th to 20th stage conversion process before the 182nd cycle: before the 19th charging stage (or charging step) of the 183rd cycle, the battery voltage is basically stable at 32mv, while the voltage change value between the 19th charging stage and the 20th charging stage of the 183rd cycle is reduced to 21mv, which means that lithium plating occurs at this time, that is, according to the voltage relaxation mechanism ( Figure 4 Corresponding content), it is judged that lithium deposition occurs in the 19th stage charging process of the 183rd cycle, and the voltage difference drops significantly due to the back insertion of deposited lithium when switching to the 20th stage, and it is judged that lithium deposition occurs in the battery when it is cycled to the 183rd cycle. By disassembling the battery, it is found that lithium deposition occurs on the negative electrode sheet, verifying that the lithium deposition phenomenon judged by the technical solution of this application is correct.

[0059] In Example 2, the battery to be tested is a ternary positive electrode-graphite negative electrode 12Ah lithium ion soft pack battery as an example, and the charging strategy used is the ternary battery 18-step ladder (that is, the charging process includes 18 charging stages) fast charging strategy, and the remaining steps refer to Example 1. Figure 5From the third row of the table shown in (b), we can see that at the 128th cycle, that is, the 128th charging process, when the 16th step is converted to the 17th step (that is, the 16th charging stage is converted to the 17th charging stage), the battery voltage difference suddenly drops from the previous stable value of 26mv to 15mv. It can be judged that lithium deposition occurs in the battery at this time. By disassembling the battery for verification, it is found that lithium deposition occurs in the battery.

[0060] In addition, for the battery in Test Example 2, during the 50th cycle, i.e. the 50th charging process, the voltage change value of the 19th current conversion process was stable at 26mv, without any obvious sudden drop phenomenon. After the battery was disassembled, no lithium deposition was found. For the battery in Test Example 1, during the 128th cycle, i.e. the 19th current conversion process, the voltage change value was stable at 32mv, without any obvious sudden drop phenomenon. After the battery was disassembled, no lithium deposition was found.

[0061] Through the test results of Example 1 and Example 2 and the battery disassembly verification, it can be proved that the technical solution of the present application is real-time and effective: by detecting the voltage difference change of the battery voltage during the step current conversion process during the multi-step step fast charging process of the lithium-ion power battery, a method for judging whether lithium plating occurs in the lithium-ion battery during the cycle process, i.e., multiple charging processes.

[0062] It should be noted that all the above technical solutions can be combined in any way to form optional embodiments of the present application, which will not be described one by one here.

[0063] Figure 6 Schematic diagram of a lithium deposition detection device 600 provided in an embodiment of the present application. Figure 6 As shown, the lithium deposition detection device 600 includes: a voltage acquisition module 610, a difference calculation module 620, a lithium deposition judgment module 630, a potential monitoring module 640, a threshold determination module 650, and a stage determination module 660.

[0064] In one embodiment, a voltage acquisition module 610 is used to acquire voltages of multiple charging stages during a target charging process of a battery to be tested, and obtain a start voltage and an end voltage of each of the multiple charging stages, where the start voltage is the voltage at the start time of the corresponding charging stage, and the end voltage is the voltage at the end time of the corresponding charging stage; a difference calculation module 620 is used to calculate the difference between the end voltage of the target charging stage and the start voltage of the next charging stage of the target charging stage for any target charging stage in the multiple charging stages, and obtain a voltage change value; a lithium plating judgment module 630 is used to judge whether lithium plating occurs in the battery to be tested based on multiple voltage change values; wherein the multiple charging stages correspond to different charging parameters, and the charging parameters include the state of charge and the charging current or charging rate corresponding to the state of charge.

[0065] In one embodiment, the lithium plating judgment module 630 is specifically used to: determine a voltage change threshold; for any adjacent first voltage change value and second voltage change value among multiple voltage change values, calculate the absolute value of the difference between the first voltage change value and the second voltage change value to obtain a voltage change degree value; if the voltage change degree value is less than or equal to the voltage change threshold, it is determined that lithium plating has not occurred in the battery to be tested; if the voltage change degree value is greater than the voltage change threshold, it is determined that lithium plating has occurred in the battery to be tested.

[0066] In one embodiment, the lithium plating judgment module 630 is specifically used to: determine the voltage change ratio; calculate the product of the first voltage change value and the voltage change ratio to obtain the voltage change threshold corresponding to the first voltage change value and the second voltage change value; wherein the charging time corresponding to the first voltage change value is earlier than the charging time corresponding to the second voltage change value.

[0067] In one embodiment, the lithium deposition judgment module 630 is specifically used to: obtain the battery capacity of the battery to be tested to obtain the target battery capacity; determine the battery polarization degree of the battery to be tested in each charging process; and determine the voltage change ratio according to the target battery capacity and each battery polarization degree.

[0068] In one embodiment, the multiple charging stages are multiple continuous charging stages; the potential monitoring module 640 is used to: monitor the negative electrode voltage of the battery to be tested during the target charging process; the threshold determination module 650 is used to: determine the negative electrode voltage threshold; the stage determination module 660 is used to: determine that among all the charging stages of the target charging process, the charging stage corresponding to the negative electrode voltage being lower than the negative electrode voltage threshold is the first charging stage among the multiple charging stages.

[0069] In one embodiment, the lithium deposition judgment module 630 is specifically used to: construct a voltage change curve based on multiple voltage change values, where the voltage change curve represents the relationship between the multiple voltage change values ​​and the corresponding charging stages; and judge whether lithium deposition occurs in the battery to be tested based on the positional relationship between the coordinate points corresponding to the multiple voltage change values ​​in the voltage change curve.

[0070] It should be understood that the embodiments of the device are similar to the embodiments of the above method, and the contents and effects thereof can refer to the contents and effects of the above method, which will not be described in detail in this application. Figure 6 The device 600 shown can execute the above method embodiments, and the above and other operations and / or functions of each module in the device 600 are respectively for implementing the corresponding processes in the above methods, which will not be repeated here for the sake of brevity.

[0071] The above describes the device 600 of the embodiment of the present application from the perspective of the functional module in conjunction with the accompanying drawings. It should be understood that the functional module can be implemented in hardware form, can be implemented by instructions in software form, and can also be implemented by a combination of hardware and software modules. Specifically, the steps of the method embodiment in the embodiment of the present application can be completed by the hardware integrated logic circuit and / or software form instructions in the processor, and the steps of the method disclosed in the embodiment of the present application can be directly embodied as a hardware decoding processor to perform, or a combination of hardware and software modules in the decoding processor to perform. Optionally, the software module can be located in a mature storage medium in the field such as a random access memory, a flash memory, a read-only memory, a programmable read-only memory, an electrically erasable programmable memory, a register, etc. The storage medium is located in a memory, and the processor reads the information in the memory, and completes the steps in the above method embodiment in conjunction with its hardware.

[0072] Figure 7 A schematic block diagram of an electronic device 700 provided in an embodiment of the present application.

[0073] like Figure 7 As shown, the electronic device 700 may include:

[0074] The memory 710 and the processor 720, the memory 710 is used to store the computer program and transmit the program code to the processor 720. In other words, the processor 720 can call and run the computer program from the memory 710 to implement the method in the embodiment of the present application.

[0075] For example, the processor 720 may be configured to execute the above method embodiments according to instructions in the computer program.

[0076] In some embodiments of the present application, the processor 720 may include but is not limited to:

[0077] General-purpose processor, digital signal processor (DSP), application-specific integrated circuit (ASIC), field programmable gate array (FPGA) or other programmable logic device, discrete gate or transistor logic device, discrete hardware components, etc.

[0078] In some embodiments of the present application, the memory 710 includes but is not limited to:

[0079] Volatile memory and / or non-volatile memory. Among them, the non-volatile memory can be a read-only memory (ROM), a programmable read-only memory (PROM), an erasable programmable read-only memory (EPROM), an electrically erasable programmable read-only memory (EEPROM) or a flash memory. The volatile memory can be a random access memory (RAM), which is used as an external cache. By way of example and not limitation, many forms of RAM are available, such as static random access memory (SRAM), dynamic random access memory (DRAM), synchronous dynamic random access memory (SDRAM), double data rate synchronous dynamic random access memory (DDR SDRAM), enhanced synchronous dynamic random access memory (ESDRAM), synchronous link DRAM (SLDRAM) and direct RAM bus random access memory (DR RAM).

[0080] In some embodiments of the present application, the computer program may be divided into one or more modules, which are stored in the memory 710 and executed by the processor 720 to complete the method provided by the present application. The one or more modules may be a series of computer program instruction segments capable of completing specific functions, and the instruction segments are used to describe the execution process of the computer program in the electronic device.

[0081] like Figure 7 As shown, the electronic device may also include:

[0082] The transceiver 730 may be connected to the processor 720 or the memory 710 .

[0083] The processor 720 may control the transceiver 730 to communicate with other devices, specifically, to send information or data to other devices, or to receive information or data sent by other devices. The transceiver 730 may include a transmitter and a receiver. The transceiver 730 may further include an antenna, and the number of antennas may be one or more.

[0084] It should be understood that the various components in the electronic device are connected via a bus system, wherein the bus system includes not only a data bus but also a power bus, a control bus and a status signal bus.

[0085] The present application also provides a computer storage medium on which a computer program is stored, and when the computer program is executed by a computer, the computer can perform the method of the above method embodiment. In other words, the present application embodiment also provides a computer program product containing instructions, and when the instructions are executed by a computer, the computer can perform the method of the above method embodiment.

[0086] When software is used for implementation, it can be implemented in whole or in part in the form of a computer program product. The computer program product includes one or more computer instructions. When the computer program instruction is loaded and executed on a computer, the computer can be made to perform the corresponding flow in each method in the embodiment of the present application in whole or in part, and generate the functions that can be realized by each method in the embodiment of the present application. The computer can be a general-purpose computer, a special-purpose computer, a computer network, or other programmable devices. The computer instruction can be stored in a computer-readable storage medium, or transmitted from one computer-readable storage medium to another computer-readable storage medium, for example, the computer instruction can be transmitted from a website site, computer, server or data center by wired (such as coaxial cable, optical fiber, digital subscriber line (Digital Subscriber Line, DSL)) or wireless (such as infrared, wireless, microwave, etc.) mode to another website site, computer, server or data center. The computer-readable storage medium can be any available medium that a computer can access or a data storage device such as a server, a data center, etc. that contains one or more available media integrations. The available medium may be a magnetic medium (eg, a floppy disk, a hard disk, a magnetic tape), an optical medium (eg, a digital video disk (DVD)), or a semiconductor medium (eg, a solid state disk (SSD)).

[0087] Those skilled in the art will appreciate that the modules and algorithm steps of each example described in conjunction with the embodiments disclosed herein can be implemented by electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution.

[0088] In the several embodiments provided in the present application, it should be understood that the disclosed systems, devices and methods can be implemented in other ways. For example, the system embodiments described above are only schematic. For example, the division of the modules is only a logical function division. There may be other division methods in actual implementation, such as multiple modules or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some interfaces, and the indirect coupling or communication connection of the system, device or module can be electrical, mechanical or other forms.

[0089] The modules described as separate components may or may not be physically separated, and the components displayed as modules may or may not be physical modules, that is, they may be located in one place, or they may be distributed on multiple network units. Some or all of the modules may be selected according to actual needs to achieve the purpose of the scheme of this embodiment. For example, each functional module in each embodiment of the present application may be integrated into a processing module, or each module may exist physically separately, or two or more modules may be integrated into one module.

Claims

1. A lithium precipitation detection method, characterized in that: include: Collecting voltages of multiple charging stages during the target charging process of the battery to be tested, and obtaining a start voltage and an end voltage of each of the multiple charging stages, wherein the start voltage is the voltage at the start time of the corresponding charging stage, and the end voltage is the voltage at the end time of the corresponding charging stage; For any target charging stage among the multiple charging stages, calculating a difference between an end voltage of the target charging stage and a start voltage of a charging stage next to the target charging stage, to obtain a voltage change value; Determining whether lithium deposition occurs in the battery to be tested according to the multiple voltage change values; The multiple charging stages correspond to different charging parameters, and the charging parameters include a state of charge and a charging current or a charging rate corresponding to the state of charge.

2. The method according to claim 1, characterized in that The step of judging whether lithium deposition occurs in the battery to be tested according to the plurality of voltage change values ​​comprises: Determine a voltage change threshold; For any adjacent first voltage change value and second voltage change value among the plurality of voltage change values, calculating the absolute value of the difference between the first voltage change value and the second voltage change value to obtain a voltage change degree value; If the voltage change degree value is less than or equal to the voltage change threshold, it is determined that lithium deposition does not occur in the battery to be tested; If the voltage change degree value is greater than the voltage change threshold, it is determined that lithium deposition occurs in the battery to be tested.

3. The method according to claim 2, characterized in that The step of determining the voltage change threshold comprises: Determine the voltage change ratio; Calculating the product of the first voltage change value and the voltage change ratio to obtain voltage change thresholds corresponding to the first voltage change value and the second voltage change value; The charging time corresponding to the first voltage change value is earlier than the charging time corresponding to the second voltage change value.

4. The method according to claim 3, characterized in that The determining of the voltage change ratio comprises: Obtaining the battery capacity of the battery to be tested to obtain a target battery capacity; Determining the battery polarization degree of the battery to be tested during each charging process; The voltage change ratio is determined according to the target battery capacity and the polarization degree of each of the batteries.

5. The method according to claim 1, characterized in that: The step of judging whether lithium deposition occurs in the battery to be tested according to the plurality of voltage change values ​​includes: constructing a voltage change curve according to the plurality of voltage change values, wherein the voltage change curve represents a relationship between the plurality of voltage change values ​​and corresponding charging stages; According to the positional relationship between the coordinate points corresponding to the multiple voltage change values ​​in the voltage change curve, it is determined whether lithium deposition occurs in the battery to be tested.

6. The method according to any one of claims 1 to 5, characterized in that: The multiple charging stages are multiple continuous charging stages; Before collecting the voltages of multiple charging stages during the target charging process of the battery to be tested, the method further includes: Monitoring the negative electrode voltage of the battery under test during the target charging process; Determining a negative voltage threshold; It is determined that, among all charging stages of the target charging process, the charging stage corresponding to the negative electrode voltage being lower than the negative electrode voltage threshold is the first charging stage of the multiple charging stages.

7. A lithium deposition detection device, characterized in that: include: A voltage acquisition module is used to acquire voltages of multiple charging stages during the target charging process of the battery to be tested, and obtain the start voltage and end voltage of each of the multiple charging stages, wherein the start voltage is the voltage at the start time of the corresponding charging stage, and the end voltage is the voltage at the end time of the corresponding charging stage; a difference calculation module, configured to calculate, for any target charging stage among the plurality of charging stages, a difference between an end voltage of the target charging stage and a start voltage of a charging stage next to the target charging stage, to obtain a voltage change value; A lithium deposition judging module, used for judging whether lithium deposition occurs in the battery to be tested according to the plurality of voltage change values; The multiple charging stages correspond to different charging parameters, and the charging parameters include a state of charge and a charging current or a charging rate corresponding to the state of charge.

8. An electronic device, characterized in that: include: processor; as well as A memory, configured to store executable instructions of the processor; The processor is configured to perform the method of any one of claims 1 to 6 by executing the executable instructions.

9. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the method according to any one of claims 1 to 6 is implemented.

10. A computer program product comprising instructions, characterized in that When the computer program product is run on an electronic device, the electronic device is enabled to execute the method according to any one of claims 1 to 6.

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