A battery degradation detection method and device, a terminal device, and a medium

Abstract

This application relates to the field of battery technology and provides a method, apparatus, terminal device, and computer-readable storage medium for detecting battery degradation. The method includes: acquiring the battery current and terminal voltage of the battery under test after performing a discharge operation; determining the target initial lithium intercalation quantity of the positive electrode, the target initial lithium intercalation quantity of the negative electrode, the target positive electrode capacity, and the target negative electrode capacity based on the electrical parameters of the battery under test; and performing degradation detection on the battery under test based on the battery current, terminal voltage, target initial lithium intercalation quantity of the positive electrode, target initial lithium intercalation quantity of the negative electrode, target positive electrode capacity, and target negative electrode capacity to obtain degradation detection results. Compared with the prior art, which only combines data such as battery capacity, internal resistance, and voltage, the method of this application requires combining the battery current, terminal voltage, initial lithium intercalation quantity of the positive electrode, initial lithium intercalation quantity of the negative electrode, positive electrode capacity, and negative electrode capacity to perform degradation detection on the battery, thereby improving the accuracy of battery degradation detection.

Description

Technical Field

[0001] This application belongs to the field of battery technology, and in particular relates to a method, apparatus, terminal equipment and computer-readable storage medium for detecting battery degradation. Background Technology

[0002] With the rapid development of the new energy vehicle industry, the demand for batteries will increase, which means the number of retired batteries will also rise. These retired batteries are not entirely without value; on the contrary, their residual capacity still has significant energy value in other scenarios. However, retired batteries exhibit considerable inconsistency, therefore, it is necessary to test the degree of battery degradation to determine which retired batteries are usable.

[0003] However, existing technologies often only rely on observation of surface data such as capacity, internal resistance, and voltage of retired batteries to detect battery degradation, without conducting deeper degradation detection. This lack of comprehensiveness leads to low accuracy in battery degradation detection. Summary of the Invention

[0004] This application provides a method, apparatus, terminal device, and computer-readable storage medium for detecting battery degradation, which can improve the accuracy of battery degradation detection.

[0005] In a first aspect, embodiments of this application provide a method for detecting battery degradation, including:

[0006] The battery current and terminal voltage of the battery under test are obtained after a discharge operation is performed; wherein, the battery current is the current flowing through the battery under test after a load is connected;

[0007] Based on the electrical parameters of the battery under test, determine the initial lithium intercalation amount of the target positive electrode, the initial lithium intercalation amount of the target negative electrode, the target positive electrode capacity, and the target negative electrode capacity of the battery under test.

[0008] The battery under test is subjected to degradation testing based on the battery current, the terminal voltage, the initial lithium intercalation amount of the target positive electrode, the initial lithium intercalation amount of the target negative electrode, the capacity of the target positive electrode, and the capacity of the target negative electrode, so as to obtain the degradation test result of the battery under test.

[0009] Optionally, determining the initial lithium intercalation amount of the target positive electrode, the initial lithium intercalation amount of the target negative electrode, the target positive electrode capacity, and the target negative electrode capacity of the battery under test based on the electrical parameters of the battery under test includes:

[0010] The standard electromotive force of the battery under test is determined based on the preset electrochemical model, the battery current, and the terminal voltage.

[0011] The initial lithium insertion amount and capacity of the first negative electrode are calculated based on the standard electromotive force.

[0012] The first battery health of the battery under test is determined based on the initial lithium intercalation amount of the first negative electrode and the capacity of the first negative electrode.

[0013] The following parameters are obtained: the first maximum lithium-ion concentration, the first electrode porosity, the first electrode effective porosity, and the first electrode thickness corresponding to the positive electrode of the battery under test; the second maximum lithium-ion concentration, the second electrode porosity, the second electrode effective porosity, and the second electrode thickness corresponding to the negative electrode of the battery under test; the active lithium-ion content in the battery under test; and the initial terminal voltage of the battery under test before performing the discharge operation. The maximum lithium-ion concentration represents the maximum value of the electrode lithium-ion concentration generated by the battery under test during the discharge operation.

[0014] Based on the first battery health, the first maximum lithium-ion concentration, the first electrode porosity, the first electrode effective porosity, the first electrode thickness, the second maximum lithium-ion concentration, the second electrode porosity, the second electrode effective porosity, the second electrode thickness, the active lithium-ion content, and the initial terminal voltage, the initial lithium intercalation amount of the first positive electrode, the initial lithium intercalation amount of the second negative electrode, the capacity of the first positive electrode, and the capacity of the second negative electrode are determined.

[0015] Based on the first battery health status and the preset standard battery health status, the initial lithium intercalation amount of the target positive electrode, the initial lithium intercalation amount of the target negative electrode, the target positive electrode capacity, and the target negative electrode capacity are determined.

[0016] Optionally, determining the initial lithium intercalation amount of the target positive electrode, the initial lithium intercalation amount of the target negative electrode, the target positive electrode capacity, and the target negative electrode capacity based on the first battery health and a preset standard battery health includes:

[0017] If the absolute value of the difference between the first battery health and the standard battery health is greater than a set threshold, then the first battery health is updated based on the first battery health and the standard battery health.

[0018] Based on the updated first battery health, the initial lithium intercalation amount of the target positive electrode, the initial lithium intercalation amount of the target negative electrode, the capacity of the target positive electrode, and the capacity of the target negative electrode are determined.

[0019] Optionally, determining the initial lithium intercalation amount of the target positive electrode, the initial lithium intercalation amount of the target negative electrode, the target positive electrode capacity, and the target negative electrode capacity of the battery under test based on the electrical parameters of the battery under test includes:

[0020] The method obtains the first initial lithium-ion concentration, first maximum lithium-ion concentration, first electrode porosity, first electrode effective porosity, and first electrode thickness corresponding to the positive electrode of the battery under test; the second initial lithium-ion concentration, second maximum lithium-ion concentration, second electrode porosity, second electrode effective porosity, second electrode thickness, and effective electrode area corresponding to the negative electrode of the battery under test; wherein, the initial lithium-ion concentration represents the electrode lithium-ion concentration of the battery under test before performing a discharge operation, and the maximum lithium-ion concentration represents the maximum value of the electrode lithium-ion concentration generated by the battery under test during the discharge operation.

[0021] The initial lithium intercalation amount of the target cathode is calculated based on the first initial lithium ion concentration and the first maximum lithium ion concentration.

[0022] The initial lithium intercalation amount of the target negative electrode is calculated based on the second initial lithium ion concentration and the second maximum lithium ion concentration.

[0023] The target positive electrode capacity is calculated based on the first maximum lithium ion concentration, the first electrode porosity, the first electrode effective porosity, the first electrode effective area, and the first electrode thickness.

[0024] The target negative electrode capacity is calculated based on the second maximum lithium ion concentration, the second electrode porosity, the second electrode effective porosity, the electrode effective area, and the second electrode thickness.

[0025] Optionally, the step of performing degradation detection on the battery under test based on the battery current, the terminal voltage, the initial lithium intercalation amount of the target positive electrode, the initial lithium intercalation amount of the target negative electrode, the capacity of the target positive electrode, and the capacity of the target negative electrode to obtain the degradation detection result of the battery under test includes:

[0026] The target battery capacity of the battery under test is calculated based on the target negative electrode capacity and the initial lithium intercalation amount of the target negative electrode.

[0027] Based on the target battery capacity and the target cathode capacity, determine the range of variation in the lithium intercalation amount in the cathode of the battery under test;

[0028] Based on the target battery capacity and the target negative electrode capacity, determine the range of variation in the amount of lithium intercalated in the negative electrode of the battery under test;

[0029] The battery under test is subjected to degradation detection based on the battery current, the terminal voltage, the initial lithium intercalation amount of the target positive electrode, the initial lithium intercalation amount of the target negative electrode, the capacity of the target positive electrode, the capacity of the target negative electrode, the range of variation of the lithium intercalation amount of the positive electrode, and the range of variation of the lithium intercalation amount of the negative electrode, and the degradation detection results are obtained.

[0030] Optionally, the step of performing degradation detection on the battery under test based on the battery current, the terminal voltage, the initial lithium intercalation amount of the target positive electrode, the initial lithium intercalation amount of the target negative electrode, the capacity of the target positive electrode, and the capacity of the target negative electrode to obtain the degradation detection result of the battery under test includes:

[0031] The target battery capacity of the battery under test is calculated based on the target negative electrode capacity and the initial lithium intercalation amount of the target negative electrode.

[0032] Based on the battery current and the terminal voltage, the battery energy and battery power of the battery under test are calculated.

[0033] The second battery health status of the battery under test is calculated based on the target battery capacity and the initial rated capacity of the battery under test.

[0034] The third battery health status of the battery under test is calculated based on the battery energy and the initial rated energy of the battery under test.

[0035] The fourth battery health status of the battery under test is calculated based on the battery power and the initial rated power of the battery under test.

[0036] The degradation detection result is determined based on the health status of the second battery, the health status of the third battery, and the health status of the fourth battery.

[0037] Optionally, the step of performing degradation detection on the battery under test based on the battery current, the terminal voltage, the initial lithium intercalation amount of the target positive electrode, the initial lithium intercalation amount of the target negative electrode, the capacity of the target positive electrode, and the capacity of the target negative electrode to obtain the degradation detection result of the battery under test includes:

[0038] The initial lithium intercalation amount of the positive electrode, the initial lithium intercalation amount of the negative electrode, the original positive electrode capacity, and the original negative electrode capacity of the battery under test before the discharge operation are obtained.

[0039] The target battery capacity of the battery under test is calculated based on the target negative electrode capacity and the initial lithium intercalation amount of the target negative electrode.

[0040] Based on the target battery capacity and the initial rated capacity of the battery under test, the capacity loss value of the battery under test is calculated.

[0041] Based on the initial lithium intercalation amount of the original positive electrode, the initial lithium intercalation amount of the original negative electrode, the original positive electrode capacity, the original negative electrode capacity, the initial lithium intercalation amount of the target positive electrode, the initial lithium intercalation amount of the target negative electrode, the target positive electrode capacity, the target negative electrode capacity, and the capacity loss value, the first loss value of the battery under test is calculated; the first loss value is the capacity loss in the battery under test caused by the loss of active lithium ions.

[0042] Based on the preset electrochemical model, the terminal voltage, and the battery current, the second loss value of the battery under test is calculated; the second loss value is the capacity loss in the battery under test caused by overpotential loss.

[0043] The third loss value of the battery under test is calculated based on the capacity loss value, the first loss value, and the second loss value.

[0044] The degradation detection result is determined based on the first loss value, the second loss value, and the third loss value.

[0045] Secondly, embodiments of this application provide a battery degradation detection device, comprising:

[0046] The first acquisition unit is used to acquire the battery current and terminal voltage of the battery under test after performing a discharge operation; wherein, the battery current is the current flowing through the battery under test after the battery under test is connected to a load;

[0047] The first determining unit is used to determine the initial lithium intercalation amount of the target positive electrode, the initial lithium intercalation amount of the target negative electrode, the target positive electrode capacity, and the target negative electrode capacity of the battery under test based on the electrical parameters of the battery under test.

[0048] The first detection unit is used to perform degradation detection on the battery under test based on the battery current, the terminal voltage, the initial lithium intercalation amount of the target positive electrode, the initial lithium intercalation amount of the target negative electrode, the capacity of the target positive electrode, and the capacity of the target negative electrode, and to obtain the degradation detection result of the battery under test.

[0049] Thirdly, embodiments of this application provide a terminal device, including: a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the computer program to implement the battery degradation detection method as described in any one of the first aspects above.

[0050] Fourthly, embodiments of this application provide a computer-readable storage medium storing a computer program that, when executed by a processor, implements the battery degradation detection method as described in any one of the first aspects above.

[0051] Fifthly, embodiments of this application provide a computer program product that, when run on a terminal device, enables the terminal device to execute the battery degradation detection method described in any one of the first aspects.

[0052] The beneficial effects of the embodiments of this application compared with the prior art are:

[0053] This application provides a battery degradation detection method. It acquires the battery current and terminal voltage of the battery under test after a discharge operation. The battery current is the current flowing through the battery after a load is connected. Based on the battery's electrical parameters, it determines the target initial lithium intercalation amount of the positive electrode, the target initial lithium intercalation amount of the negative electrode, the target positive electrode capacity, and the target negative electrode capacity. Based on the battery current, terminal voltage, target initial lithium intercalation amount of the positive electrode, target initial lithium intercalation amount of the negative electrode, target positive electrode capacity, and target negative electrode capacity, it performs degradation detection on the battery to obtain the degradation detection result. Compared to existing technologies that only observe surface data such as battery capacity, internal resistance, and voltage to detect battery degradation, the detection method provided in this application, in addition to the battery current and terminal voltage, also combines the initial lithium intercalation amount of the positive electrode, the initial lithium intercalation amount of the negative electrode, the positive electrode capacity, and the negative electrode capacity to perform degradation detection, thus improving the accuracy of battery degradation detection. Attached Figure Description

[0054] To more clearly illustrate the technical solutions in the embodiments of this application, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0055] Figure 1 This is a flowchart illustrating the implementation of a battery degradation detection method according to an embodiment of this application.

[0056] Figure 2 This is a flowchart illustrating the implementation of a battery degradation detection method provided in another embodiment of this application;

[0057] Figure 3 This is a flowchart illustrating the implementation of a battery degradation detection method provided in another embodiment of this application;

[0058] Figure 4 This is a flowchart illustrating the implementation of a battery degradation detection method according to another embodiment of this application;

[0059] Figure 5 This is a flowchart illustrating the implementation of a battery degradation detection method according to another embodiment of this application;

[0060] Figure 6 This is a flowchart illustrating the implementation of a battery degradation detection method according to another embodiment of this application;

[0061] Figure 7 This is a graph showing the changes in the first loss value, the second loss value, and the third loss value under different discharge operations provided in the embodiments of this application.

[0062] Figure 8 This is a schematic diagram of the structure of a battery degradation detection device provided in one embodiment of this application;

[0063] Figure 9 This is a schematic diagram of the structure of a terminal device provided in an embodiment of this application. Detailed Implementation

[0064] In the following description, specific details such as particular system architectures and techniques are set forth for illustrative purposes and not for limitation, in order to provide a thorough understanding of the embodiments of this application. However, those skilled in the art will understand that this application may also be implemented in other embodiments without these specific details. In other instances, detailed descriptions of well-known systems, apparatuses, circuits, and methods have been omitted so as not to obscure the description of this application with unnecessary detail.

[0065] It should be understood that, when used in this application specification and the appended claims, the term "comprising" indicates the presence of the described features, integrals, steps, operations, elements and / or components, but does not exclude the presence or addition of one or more other features, integrals, steps, operations, elements, components and / or a collection thereof.

[0066] It should also be understood that the term “and / or” as used in this application specification and the appended claims means any combination of one or more of the associated listed items and all possible combinations, and includes such combinations.

[0067] As used in this application specification and the appended claims, the term "if" may be interpreted, depending on the context, as "when," "once," "in response to determination," or "in response to detection." Similarly, the phrase "if determined" or "if detected [the described condition or event]" may be interpreted, depending on the context, as meaning "once determined," "in response to determination," "once detected [the described condition or event]," or "in response to detection [the described condition or event]."

[0068] Furthermore, in the description of this application and the appended claims, the terms "first," "second," "third," etc., are used only to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0069] References to "one embodiment" or "some embodiments" as described in this specification mean that one or more embodiments of this application include a specific feature, structure, or characteristic described in connection with that embodiment. Therefore, the phrases "in one embodiment," "in some embodiments," "in other embodiments," "in still other embodiments," etc., appearing in different parts of this specification do not necessarily refer to the same embodiment, but rather mean "one or more, but not all, embodiments," unless otherwise specifically emphasized. The terms "comprising," "including," "having," and variations thereof mean "including but not limited to," unless otherwise specifically emphasized.

[0070] Please see Figure 1 , Figure 1 This is a flowchart illustrating the implementation of a battery degradation detection method according to an embodiment of this application. In this embodiment, the execution subject of the battery degradation detection method is a terminal device.

[0071] It should be noted that all the following embodiments will be described in detail using lithium iron phosphate batteries as an example.

[0072] like Figure 1 As shown, a battery degradation detection method provided in one embodiment of this application may include steps S101 to S103, which are detailed below:

[0073] In S101, the battery current and terminal voltage of the battery under test are obtained after the discharge operation is performed; wherein, the battery current is the current flowing through the battery under test after the load is connected.

[0074] In some possible embodiments, the terminal device can acquire the battery current and terminal voltage of the battery under test in real time after a discharge operation via a sampling circuit connected to it via a wired communication connection. The wired communication connection can be a Universal Serial Bus (USB) connection.

[0075] In practical applications, conventional sampling circuits can be used, and there are no restrictions here.

[0076] In this embodiment, performing a discharge operation on the battery under test can specifically be: discharging and then resting the battery under test a set number of times. The set number of times can be set according to actual needs and is not limited here.

[0077] In S102, based on the electrical parameters of the battery under test, the initial lithium intercalation amount of the target positive electrode, the initial lithium intercalation amount of the target negative electrode, the target positive electrode capacity, and the target negative electrode capacity of the battery under test are determined.

[0078] In one embodiment of this application, the electrical parameters of the battery to be detected include, but are not limited to, battery current and terminal voltage. Therefore, the terminal device can specifically detect these parameters through methods such as... Figure 2 Step S102, which is shown in S201 to S206, is described in detail below:

[0079] In S201, the standard electromotive force of the battery under test is determined based on the preset electrochemical model, the battery current, and the terminal voltage.

[0080] In this embodiment, the preset electrochemical model simplifies the battery under test into a system consisting of a positive electrode (i.e., positive electrode), a negative electrode (i.e., negative electrode), a separator, and an electrolyte. The battery model is established based on electrochemical theories such as internal electrochemical reactions, ion diffusion, and polarization effects of the battery under test.

[0081] Based on this, the electrochemical model provided in this embodiment includes mathematical descriptions of the solid-phase diffusion process, liquid-phase diffusion process, reactive polarization process, and ohmic polarization process of the battery under test, as well as the calculation of the terminal voltage.

[0082] Specifically, please refer to Table 1, which is a mathematical description of the electrochemical model provided in the embodiments of this application.

[0083] Table 1

[0084]

[0085]

[0086] Among them, y avg y0 represents the average lithium intercalation amount of the positive electrode of the battery under test, and Q represents the initial lithium intercalation amount of the positive electrode of the battery under test. p Indicates the positive electrode capacity of the battery under test, x avg Q represents the average lithium intercalation amount of the negative electrode of the battery under test, x0 represents the initial lithium intercalation amount of the negative electrode of the battery under test, and Q n Indicates the negative electrode capacity of the battery under test, y surf This indicates the amount of lithium intercalated on the positive electrode surface of the battery under test. This represents the positive electrode solid-phase diffusion time constant of the battery under test. τ represents the negative electrode solid-phase diffusion time constant of the battery under test, c0 represents the initial electrolyte concentration of the battery under test, and τ e P represents the liquid phase diffusion time constant of the battery under test. con R represents the liquid-phase diffusion proportionality coefficient of the battery under test, T represents the temperature of the battery under test, F represents the Faraday constant of the battery under test, and P represents the liquid-phase diffusion proportionality coefficient of the battery under test. act R represents the negative electrode polarization coefficient of the battery under test. ohm U represents the ohmic internal resistance of the battery under test.p U represents the positive terminal voltage of the battery under test. n U represents the negative terminal voltage of the battery under test, I(t) represents the battery current of the battery under test, and U... app This indicates the terminal voltage of the battery to be tested.

[0087] In this embodiment, the standard electromotive force of the battery to be tested can be calculated using the following formula:

[0088]

[0089] Where Emf represents the standard electromotive force of the battery under test, and U p U represents the positive terminal voltage of the battery under test. n y0 represents the negative electrode voltage of the battery under test, y0 represents the initial lithium intercalation amount at the positive electrode of the battery under test, and Q represents the negative electrode voltage of the battery under test. p Q represents the positive electrode capacity of the battery under test, x0 represents the initial lithium intercalation amount of the negative electrode of the battery under test, and Q represents the positive electrode capacity of the battery under test. n I(t) represents the negative electrode capacity of the battery under test, and I(t) represents the battery current of the battery under test.

[0090] In S202, the initial lithium insertion amount and the capacity of the first negative electrode are calculated based on the standard electromotive force.

[0091] In this embodiment, by combining the formula for calculating the standard electromotive force of the battery under test provided in S201, the terminal device can use the least squares method to perform a preliminary fitting of the initial lithium intercalation amount and positive electrode capacity of the battery under test, that is, to obtain the initial lithium intercalation amount and first negative electrode capacity of the battery under test.

[0092] In S203, the first battery health of the battery under test is determined based on the initial lithium intercalation amount of the first negative electrode and the capacity of the first negative electrode.

[0093] In this embodiment, after obtaining the initial lithium intercalation amount and the first negative electrode capacity, the terminal device can calculate the first battery capacity of the battery under test after performing a discharge operation based on the initial lithium intercalation amount and the first negative electrode capacity.

[0094] Specifically, the terminal device can calculate the first battery capacity of the battery under test after performing a discharge operation according to the following formula:

[0095] Q N =Q n1 *x1;

[0096] Among them, Q N Q represents the first battery capacity of the battery under test after a discharge operation, x1 represents the initial lithium intercalation amount of the first negative electrode of the battery under test, and Q represents the first battery capacity after a discharge operation. n1This indicates the capacity of the first negative electrode of the battery to be tested.

[0097] In this embodiment, after obtaining the first battery capacity of the battery under test after performing a discharge operation, the terminal device can calculate the first battery health of the battery under test according to the following formula:

[0098]

[0099] Where SOH_1 represents the first battery health status of the battery under test, and Q N Q0 represents the initial rated capacity of the battery under test after a discharge operation. The initial rated capacity of the battery under test is the same as its rated capacity at the time of manufacture.

[0100] In practical applications, battery state of health (SOH) can be understood as the percentage of the current capacity of the battery under test relative to its factory capacity.

[0101] In S204, the following parameters are obtained: the first maximum lithium-ion concentration, the first electrode porosity, the first electrode effective porosity, and the first electrode thickness corresponding to the positive electrode of the battery under test; the second maximum lithium-ion concentration, the second electrode porosity, the second electrode effective porosity, and the second electrode thickness corresponding to the negative electrode of the battery under test; the active lithium-ion content in the battery under test; and the initial terminal voltage of the battery under test before performing the discharge operation. The maximum lithium-ion concentration represents the maximum value of the electrode lithium-ion concentration generated by the battery under test during the discharge operation.

[0102] In S205, the initial lithium intercalation amount of the first positive electrode, the initial lithium intercalation amount of the second negative electrode, the capacity of the first positive electrode, and the capacity of the second negative electrode are determined based on the first battery health, the first maximum lithium ion concentration, the first electrode porosity, the first electrode effective porosity, the first electrode thickness, the second maximum lithium ion concentration, the second electrode porosity, the second electrode effective porosity, the second electrode thickness, the active lithium ion content, and the initial terminal voltage.

[0103] In this embodiment, the terminal device can specifically calculate the initial lithium intercalation amount of the first positive electrode and the initial lithium intercalation amount of the second negative electrode of the battery to be tested according to the following formula:

[0104] ε s，p L p y1c s，p，max +E s，n L n x2c s，n，max =SOH_1*nL i ;

[0105] U p (y1)-U n (x2)=V(0);

[0106] Where, ε s,p ε represents the effective porosity of the first electrode corresponding to the positive electrode of the battery under test. s,n L represents the effective porosity of the second electrode corresponding to the negative electrode of the battery under test. p L represents the thickness of the first electrode corresponding to the positive electrode of the battery under test. n c represents the thickness of the second electrode corresponding to the positive electrode of the battery under test. s,p,max c represents the first maximum lithium-ion concentration corresponding to the positive electrode of the battery under test. s,n,max n represents the second maximum lithium-ion concentration corresponding to the negative electrode of the battery under test. Li V represents the active lithium-ion content in the battery under test, V(0) represents the initial terminal voltage of the battery under test, SOH_1 represents the first battery health of the battery under test, x2 represents the initial lithium intercalation amount of the second negative electrode of the battery under test, y1 represents the initial lithium intercalation amount of the first positive electrode of the battery under test, and U p U represents the positive terminal voltage of the battery under test. n This indicates the negative terminal voltage of the battery being tested.

[0107] The first maximum lithium-ion concentration can also be referred to as the surface maximum lithium-ion concentration corresponding to the positive electrode of the battery under test, and the second maximum lithium-ion concentration can also be referred to as the surface maximum lithium-ion concentration corresponding to the negative electrode of the battery under test.

[0108] In this embodiment, after obtaining the initial lithium intercalation amount of the second negative electrode of the battery to be tested, the terminal device can calculate the capacity of the second negative electrode of the battery to be tested based on the initial lithium intercalation amount of the second negative electrode and the first battery health of the battery to be tested.

[0109] Based on this, the terminal device can calculate the first positive electrode capacity of the battery under test according to the first positive electrode initial lithium intercalation amount, the second negative electrode initial lithium intercalation amount, and the second negative electrode capacity calculated above.

[0110] In S206, the initial lithium intercalation amount of the target positive electrode, the initial lithium intercalation amount of the target negative electrode, the target positive electrode capacity, and the target negative electrode capacity are determined based on the first battery health status and the preset standard battery health status.

[0111] It should be noted that the preset standard battery health is specifically: the battery health obtained after the battery under test has undergone a low-rate discharge operation at a current of 0.04C.

[0112] In this embodiment, the terminal device can calculate the difference between the first battery health level of the battery to be tested and the preset standard battery health level, and compare the absolute value of the difference with a set threshold. The set threshold can be set according to actual needs and is not limited here; for example, the set threshold can be set to 0.001.

[0113] In one implementation of this embodiment, when the terminal device detects that the absolute value of the difference between the first battery health of the battery under test and the preset standard battery health is less than or equal to a set threshold, it indicates that the battery health of the battery under test meets the requirements, that is, the difference between it and the preset standard battery health can be ignored. Therefore, the terminal device can directly determine the first initial lithium intercalation amount of the positive electrode, the second initial lithium intercalation amount of the negative electrode, the first positive electrode capacity, and the second negative electrode capacity of the battery under test calculated in step S205 as the target initial lithium intercalation amount of the positive electrode, the target initial lithium intercalation amount of the negative electrode, the target positive electrode capacity, and the target negative electrode capacity of the battery under test.

[0114] In another implementation of this embodiment, when the terminal device detects that the absolute value of the difference between the first battery health level of the battery under test and the preset standard battery health level is greater than a set threshold, the terminal device can specifically determine the initial lithium intercalation amount of the target positive electrode, the initial lithium intercalation amount of the target negative electrode, the target positive electrode capacity, and the target negative electrode capacity of the battery under test through the following steps, detailed below:

[0115] If the absolute value of the difference between the first battery health and the standard battery health is greater than a set threshold, then the first battery health is updated based on the first battery health and the standard battery health.

[0116] Based on the updated first battery health, the initial lithium intercalation amount of the target positive electrode, the initial lithium intercalation amount of the target negative electrode, the capacity of the target positive electrode, and the capacity of the target negative electrode are determined.

[0117] In this embodiment, when the terminal device detects that the absolute value of the difference between the first battery health value of the battery to be tested and the preset standard battery health value is greater than a set threshold, it indicates that the battery health value of the battery to be tested does not meet the requirements, that is, the difference between it and the preset standard battery health value is too large. Therefore, the terminal device can update the first battery health value based on the first battery health value of the battery to be tested and the preset standard battery health value.

[0118] Specifically, the terminal device can update the first battery health status of the battery to be tested according to the following formula:

[0119] SOH_1'=(SOH_1+SOH_2) / 2;

[0120] Wherein, SOH_1' represents the first battery health status after the update of the battery to be tested, SOH_1 represents the first battery health status of the battery to be tested, and SOH_2 represents the standard battery health status of the battery to be tested.

[0121] In this embodiment, the terminal device can determine the initial lithium intercalation amount of the target positive electrode, the initial lithium intercalation amount of the target negative electrode, the target positive electrode capacity, and the target negative electrode capacity of the battery to be tested based on the updated first battery health status.

[0122] Specifically, the terminal device can calculate the initial lithium intercalation amount of the second positive electrode, the initial lithium intercalation amount of the third negative electrode, the capacity of the second positive electrode, and the capacity of the third negative electrode based on the updated first battery health, the first maximum lithium-ion concentration corresponding to the positive electrode of the battery under test, the first electrode porosity, the first electrode effective porosity, the first electrode thickness, the second maximum lithium-ion concentration corresponding to the negative electrode of the battery under test, the second electrode porosity, the second electrode effective porosity, the second electrode thickness, the active lithium-ion content in the battery under test, and the initial terminal voltage of the battery under test.

[0123] Subsequently, when the terminal device detects that the absolute value of the difference between the updated first battery health and the preset standard battery health is less than or equal to a set threshold, it indicates that the battery health of the battery under test meets the requirements, that is, the difference between it and the preset standard battery health can be ignored. Therefore, the terminal device can directly determine the second initial lithium intercalation amount of the positive electrode, the third initial lithium intercalation amount of the negative electrode, the second positive electrode capacity, and the third negative electrode capacity of the battery under test obtained above as the target initial lithium intercalation amount of the positive electrode, the target initial lithium intercalation amount of the negative electrode, the target positive electrode capacity, and the target negative electrode capacity of the battery under test.

[0124] In another embodiment of this application, the electrical parameters of the battery under test may further include: a first initial lithium-ion concentration, a first maximum lithium-ion concentration, a first electrode porosity, a first electrode effective porosity, and a first electrode thickness corresponding to the positive electrode of the battery under test; a second initial lithium-ion concentration, a second maximum lithium-ion concentration, a second electrode porosity, a second electrode effective porosity, a second electrode thickness corresponding to the negative electrode of the battery under test; and an effective electrode area of ​​the battery under test. Wherein, the initial lithium-ion concentration represents the lithium-ion concentration of the electrodes (such as the negative and positive electrodes) of the battery under test before the discharge operation is performed, and the maximum lithium-ion concentration represents the maximum value of the lithium-ion concentration of the electrodes (such as the negative and positive electrodes) generated by the battery under test during the discharge operation.

[0125] Based on this, the terminal device can also be specifically configured through methods such as... Figure 3 The execution steps S102 shown in S301 to S305 are detailed below:

[0126] In S301, the first initial lithium ion concentration, the first maximum lithium ion concentration, the first electrode porosity, the first electrode effective porosity, and the first electrode thickness corresponding to the positive electrode of the battery under test are obtained, as well as the second initial lithium ion concentration, the second maximum lithium ion concentration, the second electrode porosity, the second electrode effective porosity, the second electrode thickness, and the effective electrode area of ​​the battery under test corresponding to the negative electrode of the battery under test.

[0127] In S302, the initial lithium intercalation amount of the target cathode is calculated based on the first initial lithium ion concentration and the first maximum lithium ion concentration.

[0128] In this embodiment, the terminal device can calculate the initial lithium intercalation amount of the target positive electrode of the battery to be tested according to the following formula:

[0129]

[0130] Among them, y d This indicates the initial lithium intercalation amount of the target positive electrode of the battery under test. This indicates the first maximum lithium-ion concentration corresponding to the positive electrode of the battery under test. This indicates the initial lithium-ion concentration corresponding to the positive electrode of the battery under test.

[0131] In S303, the initial lithium intercalation amount of the target negative electrode is calculated based on the second initial lithium ion concentration and the second maximum lithium ion concentration.

[0132]

[0133] Where, x d This indicates the initial lithium intercalation amount of the target negative electrode of the battery under test. This indicates the second maximum lithium-ion concentration corresponding to the negative electrode of the battery under test. This indicates the initial lithium-ion concentration corresponding to the negative electrode of the battery under test.

[0134] In S304, the target positive electrode capacity is calculated based on the first maximum lithium ion concentration, the first electrode porosity, the first electrode effective porosity, the electrode effective area, and the first electrode thickness.

[0135]

[0136] Among them, Q pd ε represents the target positive electrode capacity of the battery under test. p ε represents the porosity of the first electrode corresponding to the positive electrode of the battery under test. f,p L represents the effective porosity of the first electrode corresponding to the positive electrode of the battery under test. pn represents the thickness of the first electrode corresponding to the positive electrode of the battery under test. Li The value of A represents the active lithium ion content in the battery under test, and A represents the effective electrode area in the battery under test.

[0137] In S305, the target negative electrode capacity is calculated based on the second maximum lithium ion concentration, the second electrode porosity, the second electrode effective porosity, the electrode effective area, and the second electrode thickness.

[0138]

[0139] Among them, Q nd ε represents the target negative electrode capacity of the battery under test. n ε represents the porosity of the second electrode corresponding to the negative electrode of the battery under test. f,n L represents the effective porosity of the second electrode corresponding to the negative electrode of the battery under test. n n represents the thickness of the second electrode corresponding to the negative electrode of the battery under test. Li The value of A represents the active lithium ion content in the battery under test, and A represents the effective electrode area in the battery under test.

[0140] In S103, the battery under test is subjected to degradation detection based on the battery current, the terminal voltage, the initial lithium intercalation amount of the target positive electrode, the initial lithium intercalation amount of the target negative electrode, the capacity of the target positive electrode, and the capacity of the target negative electrode, so as to obtain the degradation detection result of the battery under test.

[0141] In one embodiment of this application, the terminal device can specifically be configured as follows: Figure 4 The execution steps S103 shown in S401 to S404 are detailed below:

[0142] In S401, the target battery capacity of the battery under test is calculated based on the target negative electrode capacity and the initial lithium intercalation amount of the target negative electrode.

[0143] In this embodiment, the terminal device can calculate the target battery capacity of the battery to be tested according to the following formula:

[0144] Q Nd =Q nd *x d ;

[0145] Among them, Q Nd x represents the target battery capacity of the battery to be tested. d Q represents the initial lithium intercalation amount of the target negative electrode of the battery under test. nd This indicates the target negative electrode capacity of the battery to be tested.

[0146] In S402, the range of variation in the amount of lithium intercalated in the positive electrode of the battery under test is determined based on the target battery capacity and the target positive electrode capacity.

[0147] In this embodiment, the terminal device can specifically calculate the range of lithium intercalation variation in the positive electrode of the battery under test according to the following formula:

[0148]

[0149] Among them, D x Q represents the range of lithium intercalation amount in the positive electrode of the battery under test. N Q represents the target battery capacity of the battery to be tested. nd This indicates the target positive electrode capacity of the battery to be tested.

[0150] In S403, the range of variation of lithium intercalation in the negative electrode of the battery under test is determined based on the target battery capacity and the target negative electrode capacity.

[0151]

[0152] Among them, D y Q represents the range of lithium intercalation amount on the negative electrode of the battery under test. N Q represents the target battery capacity of the battery to be tested. pd This indicates the target negative electrode capacity of the battery to be tested.

[0153] In S404, the battery under test is subjected to degradation detection based on the battery current, the terminal voltage, the initial lithium intercalation amount of the target positive electrode, the initial lithium intercalation amount of the target negative electrode, the target positive electrode capacity, the target negative electrode capacity, the range of variation of the lithium intercalation amount of the positive electrode, and the range of variation of the lithium intercalation amount of the negative electrode, and the degradation detection result is obtained.

[0154] In this embodiment, the terminal device can specifically perform degradation detection on the battery under test based on the battery current, terminal voltage, initial lithium intercalation amount of the target positive electrode, initial lithium intercalation amount of the target negative electrode, target positive electrode capacity, target negative electrode capacity, range of change of lithium intercalation amount of the positive electrode, and range of change of lithium intercalation amount of the negative electrode, and obtain the degradation detection result of the battery under test.

[0155] In some possible embodiments, in conjunction with S401 to S403, the terminal device can calculate the initial total lithium-ion content of the battery under test based on the initial lithium intercalation amount of the target positive electrode, the initial lithium intercalation amount of the target negative electrode, the target positive electrode capacity, and the target negative electrode capacity.

[0156] Specifically, the terminal device can calculate the initial total lithium-ion content of the battery under test according to the following formula:

[0157] C = xd *Q nd +y d *Q Pd ;

[0158] Where C represents the initial total lithium-ion content of the battery under test, and x d y represents the initial lithium intercalation amount of the target negative electrode of the battery under test. d Q represents the initial lithium intercalation amount of the target positive electrode of the battery under test. nd Q represents the target positive electrode capacity of the battery under test. pd This indicates the target negative electrode capacity of the battery to be tested.

[0159] The terminal equipment can also determine the lithium-ion ratio of the battery under test based on the initial lithium intercalation amount of the target negative electrode and the range of variation of the negative electrode lithium intercalation amount. This lithium-ion ratio refers to the ratio between the irreversible intercalation / deintercalation lithium-ion content and the reversible intercalation / deintercalation lithium-ion content in the battery under test.

[0160] Specifically, the lithium-ion ratio of the battery under test = the initial lithium intercalation amount of the target negative electrode of the battery under test / the range of variation of the lithium intercalation amount of the negative electrode.

[0161] The terminal equipment can also determine the maximum lithium-ion content of the positive electrode of the battery under test based on the initial lithium intercalation amount of the target negative electrode and the range of variation of the lithium intercalation amount of the negative electrode.

[0162] Specifically, the maximum lithium-ion content mentioned above = the initial lithium intercalation amount of the target negative electrode of the battery under test + the range of variation of the lithium intercalation amount of the negative electrode.

[0163] In another embodiment of this application, the terminal device can specifically be implemented through, as shown in the example below. Figure 5 The execution steps S103 shown in S501 to S506 are detailed below:

[0164] In S501, the target battery capacity of the battery to be tested is calculated based on the target negative electrode capacity and the initial lithium intercalation amount of the target negative electrode.

[0165] In this embodiment, the terminal device can calculate the target battery capacity of the battery to be tested according to the following formula:

[0166] Q Nd =Q nd *x d ;

[0167] Among them, Q Nd x represents the target battery capacity of the battery to be tested. d Q represents the initial lithium intercalation amount of the target negative electrode of the battery under test. nd This indicates the target negative electrode capacity of the battery to be tested.

[0168] In S502, the battery energy and battery power of the battery under test are calculated based on the battery current and the terminal voltage.

[0169] In this embodiment, the terminal device can calculate the battery energy of the battery to be tested according to the following formula:

[0170]

[0171] Among them, E N Let T represent the battery energy of the battery under test, T represent the total duration of the discharge operation of the battery under test, U(t) represent the terminal voltage of the battery under test at time t during the discharge operation, and I(t) represent the battery current of the battery under test at time t during the discharge operation.

[0172] In this embodiment, the terminal device can specifically calculate the battery power of the battery to be tested according to the following formula:

[0173]

[0174] Among them, P N Let T represent the battery power of the battery under test, T represent the total duration of the discharge operation of the battery under test, U(t) represent the terminal voltage of the battery under test at time t during the discharge operation, and I(t) represent the battery current of the battery under test at time t during the discharge operation.

[0175] In S503, the second battery health of the battery under test is calculated based on the target battery capacity and the initial rated capacity of the battery under test.

[0176] In this embodiment, the second battery health specifically refers to the ratio between the target battery capacity and the initial rated capacity of the battery under test, under the capacity degradation method. The initial rated capacity refers to the rated capacity of the battery under test at the time of manufacture.

[0177] In S504, the third battery health of the battery under test is calculated based on the battery energy and the initial rated energy of the battery under test.

[0178] In this embodiment, the third battery health specifically refers to the ratio between the battery energy of the battery under test and its initial rated energy under the energy degradation method. The initial rated energy refers to the rated energy of the battery under test when it left the factory.

[0179] In S505, the fourth battery health of the battery under test is calculated based on the battery power and the initial rated power of the battery under test.

[0180] In this embodiment, the fourth battery health specifically refers to the ratio between the battery power of the battery under test and its initial rated power under the power degradation method. The initial rated power refers to the rated power of the battery under test when it left the factory.

[0181] In S506, the degradation detection result is determined based on the second battery health, the third battery health, and the fourth battery health.

[0182] In this embodiment, the terminal device can calculate the target battery health of the battery to be tested based on the second battery health, third battery health, and fourth battery health calculated above.

[0183] Specifically, the terminal device can calculate the target battery health of the battery under test according to the following formula:

[0184]

[0185] Wherein, SOH represents the target battery health of the battery under test. cap The second battery health indicator, SOH, represents the battery health of the battery under test. eng The third indicator of the battery health, SOH, represents the battery health of the battery under test. pow This indicates the fourth battery health status of the battery being tested.

[0186] Based on this, the terminal device can determine the degradation test result of the battery to be tested according to the above target battery health status.

[0187] It should be noted that when the target battery health level of the battery under test is higher, it indicates that the degree of degradation of the battery under test is lower, that is, the degradation test result of the battery under test is better; when the target battery health level of the battery under test is lower, it indicates that the degree of degradation of the battery under test is higher, that is, the degradation test result of the battery under test is worse.

[0188] In another embodiment of this application, since battery degradation is typically caused by the loss of active lithium ions, loss of active materials, and overpotential loss, the terminal device can specifically address this through methods such as... Figure 6 The execution steps S103 shown in S601 to S607 are detailed below:

[0189] In S601, the initial lithium intercalation amount of the positive electrode, the initial lithium intercalation amount of the negative electrode, the initial positive electrode capacity, and the initial negative electrode capacity of the battery under test are obtained before the discharge operation is performed.

[0190] In S602, the target battery capacity of the battery to be tested is calculated based on the target negative electrode capacity and the initial lithium intercalation amount of the target negative electrode.

[0191] In this embodiment, the terminal device can calculate the target battery capacity of the battery to be tested according to the following formula:

[0192] Q Nd =Q nd *x d ;

[0193] Among them, Q Nd x represents the target battery capacity of the battery to be tested. d Q represents the initial lithium intercalation amount of the target negative electrode of the battery under test. nd This indicates the target negative electrode capacity of the battery to be tested.

[0194] In S603, the capacity loss value of the battery under test is calculated based on the target battery capacity and the initial rated capacity of the battery under test.

[0195] In this embodiment, the capacity loss value of the battery under test specifically refers to the total battery capacity loss value after the battery under test performs a discharge operation.

[0196] Specifically, the capacity loss value of the battery under test = target battery capacity - initial rated capacity.

[0197] In S604, a first loss value of the battery under test is calculated based on the initial lithium intercalation amount of the original positive electrode, the initial lithium intercalation amount of the original negative electrode, the original positive electrode capacity, the original negative electrode capacity, the initial lithium intercalation amount of the target positive electrode, the initial lithium intercalation amount of the target negative electrode, the target positive electrode capacity, the target negative electrode capacity, and the capacity loss value; the first loss value is the capacity loss in the battery under test caused by the loss of active lithium ions.

[0198] In this embodiment, the terminal device can specifically calculate the first loss value of the battery to be tested according to the following formula:

[0199]

[0200] Among them, Q LLI Q represents the first loss value of the battery under test. loss x represents the capacity loss value of the battery under test. d y represents the initial lithium intercalation amount of the target negative electrode of the battery under test. d Q represents the initial lithium intercalation amount of the target positive electrode of the battery under test. Pd Q represents the target positive electrode capacity of the battery under test. nd Let Q represent the target negative electrode capacity of the battery under test, y0(0) represent the initial lithium intercalation amount of the original positive electrode of the battery under test, and x0(0) represent the initial lithium intercalation amount of the original negative electrode of the battery under test. p (0) represents the original positive electrode capacity of the battery under test, Qn (0) indicates the original negative electrode capacity of the battery to be tested.

[0201] In S605, a second loss value of the battery under test is calculated based on a preset electrochemical model, the terminal voltage, and the battery current; the second loss value is the capacity loss in the battery under test caused by overpotential loss.

[0202] In this embodiment, the overpotential loss is the battery capacity loss caused by the presence of concentration polarization overpotential, reaction polarization overpotential, and ohmic polarization overpotential. Therefore, by combining the mathematical description of the overpotential and terminal voltage calculation in the electrochemical model provided by S101, the curves of each of the above overpotentials and terminal voltages can be obtained.

[0203] The terminal device can determine the first discharge cutoff time of the battery under test based on the above multiple curves, and determine the second discharge cutoff time of the battery under test when the overpotential is initially 0.

[0204] Based on this, the terminal device can calculate the second loss value of the battery to be tested according to the following formula:

[0205]

[0206] Among them, Q η Let t1 represent the second loss value of the battery under test, t2 represent the first discharge cutoff time of the battery under test, and I(t) represent the battery current at time t when the battery under test is performing a discharge operation.

[0207] In S606, a third loss value of the battery under test is calculated based on the capacity loss value, the first loss value, and the second loss value.

[0208] It should be noted that the third loss value of the battery under test is the capacity loss caused by the loss of active materials in the battery under test.

[0209] In this embodiment, the terminal device can specifically calculate the third loss value of the battery to be tested according to the following formula:

[0210] Q LAM =Q Ioss -Q LLI -Q η ;

[0211] Among them, Q LAM Q represents the third loss value of the battery under test. loss Q represents the capacity loss value of the battery under test. LLI Q represents the first loss value of the battery under test. ηThis represents the second loss value of the battery under test.

[0212] In S607, the degradation detection result is determined based on the first loss value, the second loss value, and the third loss value.

[0213] In this embodiment, the smaller the first loss value of the battery under test, the lower the degree of degradation of the battery under test, that is, the better the degradation test result of the battery under test; the lower the second loss value of the battery under test, the lower the degree of degradation of the battery under test, that is, the better the degradation test result of the battery under test; the lower the third loss value of the battery under test, the lower the degree of degradation of the battery under test, that is, the better the degradation test result of the battery under test.

[0214] Please see Figure 7 , Figure 7 This is a graph showing the variation of different loss values ​​under different discharge operations, as provided in the embodiments of this application. Specifically, Figure 7 (a) and Figure 7 (b) is a graph showing the variation of the second loss value under different discharge operations. Figure 7 (c) is a graph showing the variation of different first loss values ​​under different discharge operations. Figure 7 (d) Curves showing the variation of the third loss value under different discharge operations.

[0215] As can be seen from the above, the battery degradation detection method provided in this application obtains the battery current and terminal voltage of the battery under test after a discharge operation; wherein, the battery current is the current flowing through the battery under test after a load is connected; based on the electrical parameters of the battery under test, the target initial lithium intercalation amount of the positive electrode, the target initial lithium intercalation amount of the negative electrode, the target positive electrode capacity, and the target negative electrode capacity are determined; based on the battery current, terminal voltage, target initial lithium intercalation amount of the positive electrode, target initial lithium intercalation amount of the negative electrode, target positive electrode capacity, and target negative electrode capacity, degradation detection is performed on the battery under test to obtain the degradation detection result of the battery under test. Compared with the prior art, which only relies on the observation of surface data such as battery capacity, internal resistance, and voltage to detect battery degradation, the detection method provided in this application, in addition to the battery current and terminal voltage, also needs to combine the initial lithium intercalation amount of the positive electrode, the initial lithium intercalation amount of the negative electrode, the positive electrode capacity, and the negative electrode capacity to detect the battery degradation, thereby improving the accuracy of battery degradation detection.

[0216] It should be understood that the sequence number of each step in the above embodiments does not imply the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of this application.

[0217] Corresponding to the battery degradation detection method described in the above embodiments, Figure 8 This diagram illustrates a structural block diagram of a battery degradation detection device according to an embodiment of this application. For ease of explanation, only the parts relevant to the embodiment of this application are shown. (Refer to...) Figure 8 The battery degradation detection device 800 includes: a first acquisition unit 81, a first determination unit 82, and a first detection unit 83. Wherein:

[0218] The first acquisition unit 81 is used to acquire the battery current and terminal voltage of the battery under test after performing a discharge operation; wherein, the battery current is the current flowing through the battery under test after the battery under test is connected to a load.

[0219] The first determining unit 82 is used to determine the initial lithium intercalation amount of the target positive electrode, the initial lithium intercalation amount of the target negative electrode, the target positive electrode capacity, and the target negative electrode capacity of the battery under test based on the electrical parameters of the battery under test.

[0220] The first detection unit 83 is used to perform degradation detection on the battery under test based on the battery current, the terminal voltage, the initial lithium intercalation amount of the target positive electrode, the initial lithium intercalation amount of the target negative electrode, the capacity of the target positive electrode, and the capacity of the target negative electrode, and to obtain the degradation detection result of the battery under test.

[0221] In one embodiment of this application, the first determining unit 82 specifically includes: a second determining unit, a first calculation unit, a third determining unit, a second acquisition unit, a fourth determining unit, and a fifth determining unit.

[0222] in:

[0223] The second determining unit is used to determine the standard electromotive force of the battery to be tested based on a preset electrochemical model, the battery current, and the terminal voltage.

[0224] The first calculation unit is used to calculate the initial lithium insertion amount and the capacity of the first negative electrode based on the standard electromotive force.

[0225] The third determining unit is used to determine the first battery health of the battery under test based on the initial lithium intercalation amount of the first negative electrode and the capacity of the first negative electrode.

[0226] The second acquisition unit is used to acquire the first maximum lithium-ion concentration, first electrode porosity, first electrode effective porosity, and first electrode thickness corresponding to the positive electrode of the battery under test; the second maximum lithium-ion concentration, second electrode porosity, second electrode effective porosity, and second electrode thickness corresponding to the negative electrode of the battery under test; the active lithium-ion content in the battery under test; and the initial terminal voltage of the battery under test before performing the discharge operation; wherein, the maximum lithium-ion concentration represents the maximum value of the electrode lithium-ion concentration generated by the battery under test during the discharge operation.

[0227] The fourth determining unit is used to determine the initial lithium intercalation amount of the first positive electrode, the initial lithium intercalation amount of the second negative electrode, the capacity of the first positive electrode, and the capacity of the second negative electrode based on the first battery health, the first maximum lithium ion concentration, the first electrode porosity, the first electrode effective porosity, the first electrode thickness, the second maximum lithium ion concentration, the second electrode porosity, the second electrode effective porosity, the second electrode thickness, the active lithium ion content, and the initial terminal voltage.

[0228] The fifth determining unit is used to determine the initial lithium intercalation amount of the target positive electrode, the initial lithium intercalation amount of the target negative electrode, the target positive electrode capacity, and the target negative electrode capacity based on the first battery health status and the preset standard battery health status.

[0229] In one embodiment of this application, the fifth determining unit specifically includes: an updating unit and a sixth determining unit. Wherein:

[0230] The update unit is used to update the first battery health based on the first battery health and the standard battery health if the absolute value of the difference between the first battery health and the standard battery health is greater than a set threshold.

[0231] The sixth determining unit is used to determine the initial lithium intercalation amount of the target positive electrode, the initial lithium intercalation amount of the target negative electrode, the capacity of the target positive electrode, and the capacity of the target negative electrode based on the updated first battery health.

[0232] In one embodiment of this application, the first determining unit 82 specifically includes: a third acquiring unit, a second calculating unit, a third calculating unit, a fourth calculating unit, and a fifth calculating unit. Wherein:

[0233] The third acquisition unit is used to acquire the first initial lithium-ion concentration, the first maximum lithium-ion concentration, the first electrode porosity, the first electrode effective porosity, and the first electrode thickness corresponding to the positive electrode of the battery under test; the second initial lithium-ion concentration, the second maximum lithium-ion concentration, the second electrode porosity, the second electrode effective porosity, and the second electrode thickness corresponding to the negative electrode of the battery under test; wherein, the initial lithium-ion concentration represents the electrode lithium-ion concentration of the battery under test before performing the discharge operation, and the maximum lithium-ion concentration represents the maximum value of the electrode lithium-ion concentration generated by the battery under test during the discharge operation.

[0234] The second calculation unit is used to calculate the initial lithium intercalation amount of the target cathode based on the first initial lithium ion concentration and the first maximum lithium ion concentration.

[0235] The third calculation unit is used to calculate the initial lithium intercalation amount of the target negative electrode based on the second initial lithium ion concentration and the second maximum lithium ion concentration.

[0236] The fourth calculation unit is used to calculate the target positive electrode capacity based on the first maximum lithium ion concentration, the first electrode porosity, the first electrode effective porosity, the electrode effective area, and the first electrode thickness.

[0237] The fifth calculation unit is used to calculate the target negative electrode capacity based on the second maximum lithium ion concentration, the second electrode porosity, the second electrode effective porosity, the electrode effective area, and the second electrode thickness.

[0238] In one embodiment of this application, the first detection unit 83 specifically includes: a first capacity determination unit, a first range determination unit, a second range determination unit, and a second detection unit. Wherein:

[0239] The first capacity determination unit is used to calculate the target battery capacity of the battery under test based on the target negative electrode capacity and the initial lithium intercalation amount of the target negative electrode.

[0240] The first range determination unit is used to determine the range of variation of the positive electrode lithium intercalation amount of the battery under test based on the target battery capacity and the target positive electrode capacity.

[0241] The second range determination unit is used to determine the range of variation in the amount of lithium intercalated in the negative electrode of the battery under test based on the target battery capacity and the target negative electrode capacity.

[0242] The second detection unit is used to perform degradation detection on the battery under test based on the battery current, the terminal voltage, the initial lithium intercalation amount of the target positive electrode, the initial lithium intercalation amount of the target negative electrode, the target positive electrode capacity, the target negative electrode capacity, the range of change of the lithium intercalation amount of the positive electrode, and the range of change of the lithium intercalation amount of the negative electrode, and to obtain the degradation detection result.

[0243] In one embodiment of this application, the first detection unit 83 specifically includes: a sixth calculation unit, a seventh calculation unit, a first health calculation unit, a second health calculation unit, a third health calculation unit, and a third detection unit. Wherein:

[0244] The sixth calculation unit is used to calculate the target battery capacity of the battery under test based on the target negative electrode capacity and the initial lithium intercalation amount of the target negative electrode.

[0245] The seventh calculation unit is used to calculate the battery energy and battery power of the battery under test based on the battery current and the terminal voltage.

[0246] The first health calculation unit is used to calculate the second battery health of the battery under test based on the target battery capacity and the initial rated capacity of the battery under test.

[0247] The second health calculation unit is used to calculate the third battery health of the battery under test based on the battery energy and the initial rated energy of the battery under test.

[0248] The third health calculation unit is used to calculate the fourth battery health of the battery under test based on the battery power and the initial rated power of the battery under test.

[0249] The third detection unit is used to determine the degradation detection result based on the health status of the second battery, the health status of the third battery, and the health status of the fourth battery.

[0250] In one embodiment of this application, the first detection unit 83 specifically includes: a fourth acquisition unit, a second capacity determination unit, a first loss value calculation unit, a second loss value calculation unit, a third loss value calculation unit, and a fourth detection unit. Wherein:

[0251] The fourth acquisition unit is used to acquire the initial lithium intercalation amount of the original positive electrode, the initial lithium intercalation amount of the original negative electrode, the original positive electrode capacity, and the original negative electrode capacity of the battery under test before performing the discharge operation.

[0252] The second capacity determination unit is used to calculate the target battery capacity of the battery under test based on the target negative electrode capacity and the initial lithium intercalation amount of the target negative electrode.

[0253] The first loss value calculation unit is used to calculate the capacity loss value of the battery under test based on the target battery capacity and the initial rated capacity of the battery under test.

[0254] The second loss value calculation unit is used to calculate the first loss value of the battery under test based on the initial lithium intercalation amount of the original positive electrode, the initial lithium intercalation amount of the original negative electrode, the original positive electrode capacity, the original negative electrode capacity, the initial lithium intercalation amount of the target positive electrode, the initial lithium intercalation amount of the target negative electrode, the target positive electrode capacity, the target negative electrode capacity, and the capacity loss value; the first loss value is the capacity loss in the battery under test caused by the loss of active lithium ions.

[0255] The third loss value calculation unit is used to calculate the second loss value of the battery under test based on the preset electrochemical model, the terminal voltage and the battery current; the second loss value is the capacity loss in the battery under test caused by overpotential loss.

[0256] The fourth loss value calculation unit is used to calculate the third loss value of the battery under test based on the capacity loss value, the first loss value, and the second loss value.

[0257] The fourth detection unit is used to determine the degradation detection result based on the first loss value, the second loss value, and the third loss value.

[0258] It should be noted that the information interaction and execution process between the above-mentioned devices / units are based on the same concept as the method embodiments of this application. For details on their specific functions and technical effects, please refer to the method embodiments section, and they will not be repeated here.

[0259] Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the above-described division of functional units and modules is merely an example. In practical applications, the above functions can be assigned to different functional units and modules as needed, that is, the internal structure of the device can be divided into different functional units or modules to complete all or part of the functions described above. The functional units and modules in the embodiments can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The integrated unit can be implemented in hardware or as a software functional unit. Furthermore, the specific names of the functional units and modules are only for easy differentiation and are not intended to limit the scope of protection of this application. The specific working process of the units and modules in the above system can be referred to the corresponding process in the foregoing method embodiments, and will not be repeated here.

[0260] Figure 9This is a schematic diagram of the structure of a terminal device provided in an embodiment of this application. Figure 9 As shown, the terminal device 9 of this embodiment includes: at least one processor 90 ( Figure 9 (Only one is shown) a processor, a memory 91, and a computer program 92 stored in the memory 91 and executable on the at least one processor 90, wherein the processor 90 executes the computer program 92 to implement the steps in any of the above-described battery degradation detection method embodiments.

[0261] The terminal device may include, but is not limited to, a processor 90 and a memory 91. Those skilled in the art will understand that... Figure 9 This is merely an example of terminal device 9 and does not constitute a limitation on terminal device 9. It may include more or fewer components than shown in the figure, or combine certain components, or different components, such as input / output devices, network access devices, etc.

[0262] The processor 90 may be a Central Processing Unit (CPU), or it may be other general-purpose processors, digital signal processors (DSPs), application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. A general-purpose processor may be a microprocessor or any conventional processor.

[0263] In some embodiments, the memory 91 may be an internal storage unit of the terminal device 9, such as the RAM of the terminal device 9. In other embodiments, the memory 91 may be an external storage device of the terminal device 9, such as a plug-in hard drive, Smart Media Card (SMC), Secure Digital (SD) card, or Flash Card equipped on the terminal device 1. Furthermore, the memory 91 may include both internal and external storage units of the terminal device 9. The memory 91 is used to store the operating system, applications, bootloader, data, and other programs, such as the program code of the computer program. The memory 91 can also be used to temporarily store data that has been output or will be output.

[0264] This application also provides a computer-readable storage medium storing a computer program that, when executed by a processor, implements the steps described in the various method embodiments above.

[0265] This application provides a computer program product that, when run on a terminal device, enables the terminal device to implement the steps described in the various method embodiments above.

[0266] If the integrated unit is implemented as a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, all or part of the processes in the methods of the above embodiments of this application can be implemented by a computer program instructing related hardware. The computer program can be stored in a computer-readable storage medium, and when executed by a processor, it can implement the steps of the various method embodiments described above. The computer program includes computer program code, which can be in the form of source code, object code, executable files, or certain intermediate forms. The computer-readable medium can include at least: any entity or device capable of carrying computer program code to a terminal device, a recording medium, a computer memory, a read-only memory (ROM), a random access memory (RAM), an electrical carrier signal, a telecommunication signal, and a software distribution medium. Examples include USB flash drives, portable hard drives, magnetic disks, or optical disks. In some jurisdictions, according to legislation and patent practice, computer-readable media cannot be electrical carrier signals or telecommunication signals.

[0267] In the above embodiments, the descriptions of each embodiment have different focuses. For parts that are not described in detail or recorded in a certain embodiment, please refer to the relevant descriptions of other embodiments.

[0268] The above-described embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this application, and should all be included within the protection scope of this application.

Claims

1. A method of detecting deterioration of a battery, characterized by, The method comprises the following steps: obtaining the battery current and the terminal voltage of a battery to be detected after performing a discharge operation; wherein the battery current is the current flowing through the battery to be detected after the battery to be detected is connected to a load; determining the target positive electrode initial lithium intercalation amount, the target negative electrode initial lithium intercalation amount, the target positive electrode capacity and the target negative electrode capacity of the battery to be detected according to the electrical parameters of the battery to be detected; performing degradation detection on the battery to be detected according to the battery current, the terminal voltage, the target positive electrode initial lithium intercalation amount, the target negative electrode initial lithium intercalation amount, the target positive electrode capacity and the target negative electrode capacity, and obtaining the degradation detection result of the battery to be detected; determining the target positive electrode initial lithium intercalation amount, the target negative electrode initial lithium intercalation amount, the target positive electrode capacity and the target negative electrode capacity of the battery to be detected according to the electrical parameters of the battery to be detected, comprising: determining the standard electromotive force of the battery to be detected according to the preset electrochemical model, the battery current and the terminal voltage; calculating the first negative electrode initial lithium intercalation amount and the first negative electrode capacity according to the standard electromotive force; determining the first battery health degree of the battery to be detected according to the first negative electrode initial lithium intercalation amount and the first negative electrode capacity; obtaining the first maximum lithium ion concentration corresponding to the positive electrode of the battery to be detected, the first electrode porosity, the first electrode effective porosity, the first electrode thickness, the second maximum lithium ion concentration corresponding to the negative electrode of the battery to be detected, the second electrode porosity, the second electrode effective porosity, the second electrode thickness, the active lithium ion content in the battery to be detected and the initial terminal voltage of the battery to be detected before performing the discharge operation; wherein the maximum lithium ion concentration represents the maximum value of the electrode lithium ion concentration generated during the discharge operation of the battery to be detected; determining the first positive electrode initial lithium intercalation amount, the second negative electrode initial lithium intercalation amount, the first positive electrode capacity and the second negative electrode capacity according to the first battery health degree, the first maximum lithium ion concentration, the first electrode porosity, the first electrode effective porosity, the first electrode thickness, the second maximum lithium ion concentration, the second electrode porosity, the second electrode effective porosity, the second electrode thickness, the active lithium ion content and the initial terminal voltage; determining the target positive electrode initial lithium intercalation amount, the target negative electrode initial lithium intercalation amount, the target positive electrode capacity and the target negative electrode capacity according to the first battery health degree and the preset standard battery health degree.

2. The detection method of claim 1, wherein, determining the target positive electrode initial lithium intercalation amount, the target negative electrode initial lithium intercalation amount, the target positive electrode capacity and the target negative electrode capacity according to the first battery health degree and the preset standard battery health degree, comprising: if the absolute value of the difference between the first battery health degree and the standard battery health degree is greater than a set threshold, updating the first battery health degree according to the first battery health degree and the standard battery health degree; According to the updated first battery health, the target positive electrode initial lithium intercalation amount, the target negative electrode initial lithium intercalation amount, the target positive electrode capacity and the target negative electrode capacity are determined.

3. The method of claim 1, wherein the detecting is performed by a method selected from the group consisting of mass spectrometry, nuclear magnetic resonance, and chromatography. According to the electrical parameters of the battery to be detected, the target positive electrode initial lithium intercalation amount, the target negative electrode initial lithium intercalation amount, the target positive electrode capacity and the target negative electrode capacity of the battery to be detected are determined, comprising: Obtaining the first initial lithium ion concentration, the first maximum lithium ion concentration, the first electrode porosity, the first electrode effective porosity, the first electrode thickness corresponding to the positive electrode of the battery to be detected, the second initial lithium ion concentration, the second maximum lithium ion concentration, the second electrode porosity, the second electrode effective porosity, the second electrode thickness corresponding to the negative electrode of the battery to be detected, and the electrode effective area of the battery to be detected; wherein the initial lithium ion concentration represents the electrode lithium ion concentration of the battery to be detected before performing the discharging operation, and the maximum lithium ion concentration represents the maximum value of the electrode lithium ion concentration generated during the discharging operation of the battery to be detected; According to the first initial lithium ion concentration and the first maximum lithium ion concentration, the target positive electrode initial lithium intercalation amount is calculated; According to the second initial lithium ion concentration and the second maximum lithium ion concentration, the target negative electrode initial lithium intercalation amount is calculated; According to the first maximum lithium ion concentration, the first electrode porosity, the first electrode effective porosity, the electrode effective area and the first electrode thickness, the target positive electrode capacity is calculated; According to the second maximum lithium ion concentration, the second electrode porosity, the second electrode effective porosity, the electrode effective area and the second electrode thickness, the target negative electrode capacity is calculated.

4. The detection method according to any one of claims 1 to 3, characterized in that, According to the battery current, the terminal voltage, the target positive electrode initial lithium intercalation amount, the target negative electrode initial lithium intercalation amount, the target positive electrode capacity and the target negative electrode capacity, the battery to be detected is subjected to degradation detection to obtain the degradation detection result of the battery to be detected, comprising: According to the target negative electrode capacity and the target negative electrode initial lithium intercalation amount, the target battery capacity of the battery to be detected is calculated; According to the target battery capacity and the target positive electrode capacity, the positive electrode lithium intercalation amount variation range of the battery to be detected is determined; According to the target battery capacity and the target negative electrode capacity, the negative electrode lithium intercalation amount variation range of the battery to be detected is determined; According to the battery current, the terminal voltage, the target positive electrode initial lithium intercalation amount, the target negative electrode initial lithium intercalation amount, the target positive electrode capacity, the target negative electrode capacity, the positive electrode lithium intercalation amount variation range and the negative electrode lithium intercalation amount variation range, the battery to be detected is subjected to degradation detection to obtain the degradation detection result.

5. The detection method according to any one of claims 1 to 3, wherein According to the battery current, the terminal voltage, the target positive electrode initial lithium intercalation amount, the target negative electrode initial lithium intercalation amount, the target positive electrode capacity and the target negative electrode capacity, the battery to be detected is subjected to degradation detection to obtain the degradation detection result of the battery to be detected, comprising: According to the target negative electrode capacity and the target negative electrode initial lithium intercalation amount, a target battery capacity of the battery to be detected is calculated; According to the battery current and the terminal voltage, a battery energy and a battery power of the battery to be detected are calculated; According to the target battery capacity and an initial rated capacity of the battery to be detected, a second battery health degree of the battery to be detected is calculated; According to the battery energy and an initial rated energy of the battery to be detected, a third battery health degree of the battery to be detected is calculated; According to the battery power and an initial rated power of the battery to be detected, a fourth battery health degree of the battery to be detected is calculated; According to the second battery health degree, the third battery health degree and the fourth battery health degree, the degradation detection result is determined.

6. The assay of any one of claims 1-3, wherein, The degradation detection of the battery to be detected according to the battery current, the terminal voltage, the target positive electrode initial lithium intercalation amount, the target negative electrode initial lithium intercalation amount, the target positive electrode capacity and the target negative electrode capacity, to obtain the degradation detection result of the battery to be detected, includes: obtaining the original positive electrode initial lithium intercalation amount, the original negative electrode initial lithium intercalation amount, the original positive electrode capacity and the original negative electrode capacity of the battery to be detected before performing the discharging operation; According to the target negative electrode capacity and the target negative electrode initial lithium intercalation amount, a target battery capacity of the battery to be detected is calculated; According to the target battery capacity and an initial rated capacity of the battery to be detected, a second battery health degree of the battery to be detected is calculated; According to the original positive electrode initial lithium intercalation amount, the original negative electrode initial lithium intercalation amount, the original positive electrode capacity, the original negative electrode capacity, the target positive electrode initial lithium intercalation amount, the target negative electrode initial lithium intercalation amount, the target positive electrode capacity, the target negative electrode capacity and the capacity loss value, a first loss value of the battery to be detected is calculated; the first loss value is the capacity loss of the battery to be detected due to the loss of active lithium ions; According to a preset electrochemical model, the terminal voltage and the battery current, a second loss value of the battery to be detected is calculated; the second loss value is the capacity loss of the battery to be detected due to the loss of overpotential; According to the capacity loss value, the first loss value and the second loss value, a third loss value of the battery to be detected is calculated; According to the first loss value, the second loss value and the third loss value, the degradation detection result is determined.

7. A battery deterioration detecting device characterized by comprising: includes: The first acquisition unit is configured to acquire the battery current and the terminal voltage of the battery to be detected after performing the discharging operation; wherein the battery current is the current of the battery to be detected after connecting the load through the battery to be detected; The first determination unit is configured to determine the target positive electrode initial lithium intercalation amount, the target negative electrode initial lithium intercalation amount, the target positive electrode capacity and the target negative electrode capacity of the battery to be detected according to the electrical parameters of the battery to be detected; The first detection unit is configured to perform a degradation detection on the battery to be detected according to the battery current, the terminal voltage, the target positive initial lithium intercalation amount, the target negative initial lithium intercalation amount, the target positive capacity, and the target negative capacity, and obtain a degradation detection result of the battery to be detected. The first determination unit specifically includes: The second determination unit is configured to determine a standard electromotive force of the battery to be detected according to a preset electrochemical model, the battery current, and the terminal voltage. The first calculation unit is configured to calculate a first negative initial lithium intercalation amount and a first negative capacity according to the standard electromotive force. The third determination unit is configured to determine a first battery health degree of the battery to be detected according to the first negative initial lithium intercalation amount and the first negative capacity. The second acquisition unit is configured to acquire a first maximum lithium ion concentration, a first electrode porosity, a first electrode effective porosity, and a first electrode thickness corresponding to a positive electrode of the battery to be detected, a second maximum lithium ion concentration, a second electrode porosity, a second electrode effective porosity, and a second electrode thickness corresponding to a negative electrode of the battery to be detected, an active lithium ion content in the battery to be detected, and an initial terminal voltage of the battery to be detected before the discharging operation is performed; wherein the maximum lithium ion concentration represents a maximum value of an electrode lithium ion concentration generated in the battery to be detected during the discharging operation. The fourth determination unit is configured to determine a first positive initial lithium intercalation amount, a second negative initial lithium intercalation amount, a first positive capacity, and a second negative capacity according to the first battery health degree, the first maximum lithium ion concentration, the first electrode porosity, the first electrode effective porosity, the first electrode thickness, the second maximum lithium ion concentration, the second electrode porosity, the second electrode effective porosity, the second electrode thickness, the active lithium ion content, and the initial terminal voltage. The fifth determination unit is configured to determine the target positive initial lithium intercalation amount, the target negative initial lithium intercalation amount, the target positive capacity, and the target negative capacity according to the first battery health degree and a preset standard battery health degree.

8. A terminal device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that, The processor executes the computer program to implement the battery degradation detection method in any one of claims 1 to 6.

9. A computer-readable storage medium storing a computer program, the computer-readable storage medium comprising: The computer program is executed by the processor to implement the battery degradation detection method in any one of claims 1 to 6.

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