CN115728655A - Battery degradation detection method and device, terminal equipment and medium - Google Patents

Abstract

The application is applicable to the technical field of batteries, and provides a method and a device for detecting battery degradation, a terminal device and a computer readable storage medium, wherein the method comprises the following steps: acquiring battery current and terminal voltage of a battery to be detected after a discharging operation is performed; 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; and performing degradation detection on the battery to be detected according to the battery current, the terminal voltage, 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 to obtain a degradation detection result. Compared with the prior art that only data such as battery capacity, internal resistance and voltage are combined, the method needs to combine battery current, terminal voltage, initial lithium-embedded quantity of the positive electrode, initial lithium-embedded quantity of the negative electrode, positive electrode capacity and negative electrode capacity of the battery to detect degradation of the battery, and improves accuracy of detection of degradation of the battery.

Description

Battery degradation detection method and device, terminal equipment and medium

Technical Field

The present application relates to the field of battery technologies, and in particular, to a method and an apparatus for detecting battery degradation, a terminal device, and a computer-readable storage medium.

Background

With the rapid development of the new energy automobile industry, the demand for batteries is increased, which means that the number of retired batteries is increased. These retired batteries are not completely without value, but their residual capacity still has a high energy value in other scenarios. However, there is a great inconsistency in the retired battery, and therefore, it is necessary to detect the degree of degradation of the battery to determine the available retired battery.

However, in the prior art, the degradation detection of the battery is often simply realized according to the observation of the surface data of the capacity, the internal resistance, the voltage and the like of the retired battery, the battery is not deeply degraded and is not considered fully, and the accuracy of the degradation detection of the battery is low.

Disclosure of Invention

The embodiment of the application provides a battery degradation detection method and device, a terminal device and a computer readable storage medium, which can improve the accuracy of battery degradation detection.

In a first aspect, an embodiment of the present application provides a method for detecting battery degradation, including:

acquiring battery current and terminal voltage of a battery to be detected after a discharging operation is performed; the battery current is the current passing through the battery to be detected after the battery to be detected is connected to a load;

determining the target anode initial lithium intercalation amount, the target cathode initial lithium intercalation amount, the target anode capacity and the target cathode capacity of the battery to be detected according to the electrical parameters of the battery to be detected;

and 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 to obtain a degradation detection result of the battery to be detected.

Optionally, the determining, according to the electrical parameter of the battery to be detected, an initial lithium insertion amount of a target positive electrode, an initial lithium insertion amount of a target negative electrode, a target positive electrode capacity, and a target negative electrode capacity of the battery to be detected includes:

determining the standard electromotive force of the battery to be detected according to a preset electrochemical model, the battery current and the terminal voltage;

calculating to obtain the initial lithium embedding amount of the first negative electrode and the capacity of the first negative electrode according to the standard electromotive force;

determining the first battery health degree of the battery to be detected according to the initial lithium insertion amount of the first negative electrode and the first negative electrode capacity;

acquiring a first maximum lithium ion concentration, a first electrode porosity, a first electrode effective porosity and a first electrode thickness corresponding to the anode 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 the cathode 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 executed; wherein the maximum lithium ion concentration represents a maximum value of an electrode lithium ion concentration generated during the discharge operation of the battery to be tested;

determining a first positive electrode initial lithium intercalation amount, a second negative electrode initial lithium intercalation amount, a first positive electrode capacity, and a second negative electrode capacity as a function of 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;

and determining the target initial lithium embedding amount of the positive electrode, the target initial lithium embedding amount of the negative electrode, the target positive electrode capacity and the target negative electrode capacity according to the first battery health degree and a preset standard battery health degree.

Optionally, the determining, according to the first battery health degree and a preset standard battery health degree, 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 includes:

if the absolute value of the difference between the first battery health degree and the standard battery health degree is larger than a set threshold, updating the first battery health degree according to the first battery health degree and the standard battery health degree;

and determining 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 according to the updated first battery health degree.

Optionally, the determining, according to the electrical parameter of the battery to be detected, an initial lithium insertion amount of a target positive electrode, an initial lithium insertion amount of a target negative electrode, a target positive electrode capacity, and a target negative electrode capacity of the battery to be detected includes:

acquiring 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 anode of the battery to be detected, 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 and an electrode effective area of the battery to be detected corresponding to the cathode of the battery to be detected; the initial lithium ion concentration represents the electrode lithium ion concentration of the battery to be detected before the battery to be detected performs the discharging operation, and the maximum lithium ion concentration represents the maximum value of the electrode lithium ion concentration generated by the battery to be detected during the discharging operation;

calculating to obtain the initial lithium insertion amount of the target anode according to the first initial lithium ion concentration and the first maximum lithium ion concentration;

calculating to obtain the target cathode initial lithium insertion amount according to the second initial lithium ion concentration and the second maximum lithium ion concentration;

calculating to obtain the target positive electrode capacity 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;

and calculating to obtain the target negative electrode capacity 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.

Optionally, the performing degradation detection on the battery to be detected according to the battery current, the terminal voltage, 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 to obtain a degradation detection result of the battery to be detected includes:

calculating to obtain the target battery capacity of the battery to be detected according to the target negative electrode capacity and the target negative electrode initial lithium embedding amount;

determining the variation range of the lithium embedding amount of the anode of the battery to be detected according to the target battery capacity and the target anode capacity;

determining the negative electrode lithium insertion amount variation range of the battery to be detected according to the target battery capacity and the target negative electrode capacity;

and performing degradation detection on the battery to be detected according to the battery current, the terminal voltage, the target initial lithium intercalation amount of the anode, the target initial lithium intercalation amount of the cathode, the target anode capacity, the target cathode capacity, the variation range of the lithium intercalation amount of the anode and the variation range of the lithium intercalation amount of the cathode to obtain a degradation detection result.

Optionally, the performing degradation detection on the battery to be detected according to the battery current, the terminal voltage, 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 to obtain a degradation detection result of the battery to be detected includes:

calculating to obtain the target battery capacity of the battery to be detected according to the target negative electrode capacity and the target negative electrode initial lithium embedding amount;

calculating the battery energy and the battery power of the battery to be detected according to the battery current and the terminal voltage;

calculating to obtain a second battery health degree of the battery to be detected according to the target battery capacity and the initial rated capacity of the battery to be detected;

calculating to obtain a third battery health degree of the battery to be detected according to the battery energy and the initial rated energy of the battery to be detected;

calculating to obtain a fourth battery health degree of the battery to be detected according to the battery power and the initial rated power of the battery to be detected;

and determining the degradation detection result according to the second battery health degree, the third battery health degree and the fourth battery health degree.

Optionally, the performing degradation detection on the battery to be detected according to the battery current, the terminal voltage, 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 to obtain a degradation detection result of the battery to be detected includes:

acquiring 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 the discharging operation is executed;

calculating to obtain the target battery capacity of the battery to be detected according to the target negative electrode capacity and the target negative electrode initial lithium embedding amount;

calculating to obtain a capacity loss value of the battery to be detected according to the target battery capacity and the initial rated capacity of the battery to be detected;

calculating to obtain a first loss value of the battery to be detected according to the original positive electrode initial lithium embedding amount, the original negative electrode initial lithium embedding amount, the original positive electrode capacity, the original negative electrode capacity, the target positive electrode initial lithium embedding amount, the target negative electrode initial lithium embedding amount, the target positive electrode capacity, the target negative electrode capacity and the capacity loss value; the first loss value is capacity loss caused by active lithium ion loss in the battery to be detected;

calculating to obtain a second loss value of the battery to be detected according to a preset electrochemical model, the terminal voltage and the battery current; the second loss value is capacity loss caused by overpotential loss in the battery to be detected;

calculating to obtain a third loss value of the battery to be detected according to the capacity loss value, the first loss value and the second loss value;

determining the degradation detection result according to the first loss value, the second loss value, and the third loss value.

In a second aspect, an embodiment of the present application provides a device for detecting battery degradation, including:

the first acquisition unit is used for acquiring the current and the terminal voltage of the battery to be detected after the battery to be detected performs the discharge operation; the battery current is the current of the battery to be detected passing through the battery to be detected after the battery to be detected is connected to a load;

the first determining unit is used for 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;

and the first detection unit is used for carrying out degradation detection on the battery to be detected according to the battery current, the terminal voltage, the target anode initial lithium embedding amount, the target cathode initial lithium embedding amount, the target anode capacity and the target cathode capacity to obtain a degradation detection result of the battery to be detected.

In a third aspect, an embodiment of the present application provides a terminal device, including: a memory, a processor and a computer program stored in the memory and executable on the processor, the processor implementing the method of detecting battery degradation according to any of the first aspect as described above when executing the computer program.

In a fourth aspect, the present application provides a computer-readable storage medium, which stores a computer program, and when the computer program is executed by a processor, the computer program implements the method for detecting battery degradation according to any one of the first aspect.

In a fifth aspect, the present application provides a computer program product, when the computer program product runs on a terminal device, the terminal device may execute the method for detecting battery degradation according to any one of the first aspect.

Compared with the prior art, the embodiment of the application has the beneficial effects that:

according to the method for detecting the battery degradation, the battery current and the terminal voltage of the battery to be detected after the battery to be detected performs the discharging operation are obtained; the battery current is the current passing 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; and performing degradation detection on the battery to be detected according to the current, the terminal voltage, the target initial lithium intercalation amount of the anode, the target initial lithium intercalation amount of the cathode, the target anode capacity and the target cathode capacity of the battery to obtain a degradation detection result of the battery to be detected. Compared with the prior art that the degradation detection of the battery is realized only according to the observation of the surface data of the battery, such as the capacity, the internal resistance, the voltage and the like, the detection method provided by the application 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 of the battery to perform degradation detection on the battery besides the battery current and the terminal voltage of the battery, so that the accuracy of the degradation detection of the battery is improved.

Drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings needed to be used in the embodiments or the prior art descriptions will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present application, and it is obvious for those skilled in the art to obtain other drawings without creative efforts.

Fig. 1 is a flowchart illustrating an implementation of a method for detecting battery degradation according to an embodiment of the present disclosure;

fig. 2 is a flowchart of an implementation of a method for detecting battery degradation according to another embodiment of the present application;

fig. 3 is a flowchart illustrating an implementation of a method for detecting battery degradation according to still another embodiment of the present application;

fig. 4 is a flowchart illustrating an implementation of a method for detecting battery degradation according to another embodiment of the present disclosure;

fig. 5 is a flowchart illustrating an implementation of a method for detecting battery degradation according to another embodiment of the present disclosure;

fig. 6 is a flowchart illustrating an implementation of a method for detecting battery degradation according to another embodiment of the present disclosure;

fig. 7 is a graph showing a variation of the first loss value, the second loss value, and the third loss value under different times of discharging operations provided in the embodiment of the present application.

Fig. 8 is a schematic structural diagram of a device for detecting battery degradation according to an embodiment of the present application;

fig. 9 is a schematic structural diagram of a terminal device according to an embodiment of the present application.

Detailed Description

In the following description, for purposes of explanation and not limitation, specific details are set forth, such as particular system structures, techniques, etc. in order to provide a thorough understanding of the embodiments of the present application. It will be apparent, however, to one skilled in the art that the present application may be practiced in other embodiments that depart from these specific details. In other instances, detailed descriptions of well-known systems, devices, circuits, and methods are omitted so as not to obscure the description of the present application with unnecessary detail.

It will be understood that the terms "comprises" and/or "comprising," when used in this specification and the appended claims, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof.

It should also be understood that the term "and/or" as used in this specification and the appended claims refers to and includes any and all possible combinations of one or more of the associated listed items.

As used in this specification and the appended claims, the term "if" may be interpreted contextually as "when", "upon" or "in response to" determining "or" in response to detecting ". Similarly, the phrase "if it is determined" or "if a [ described condition or event ] is detected" may be interpreted contextually to mean "upon determining" or "in response to determining" or "upon detecting [ described condition or event ]" or "in response to detecting [ described condition or event ]".

Furthermore, in the description of the present application and the appended claims, the terms "first," "second," "third," and the like are used for distinguishing between descriptions and not necessarily for describing or implying relative importance.

Reference throughout this specification to "one embodiment" or "some embodiments," or the like, means that a particular feature, structure, or characteristic described in connection with the embodiment is included in one or more embodiments of the present application. Thus, appearances of the phrases "in one embodiment," "in some embodiments," "in other embodiments," or the like, in various places throughout this specification are not necessarily all referring to the same embodiment, but rather "one or more but not all embodiments" unless specifically stated otherwise. The terms "comprising," "including," "having," and variations thereof mean "including, but not limited to," unless expressly specified otherwise.

Referring to fig. 1, fig. 1 is a flowchart illustrating an implementation of a method for detecting battery degradation according to an embodiment of the present disclosure. In the embodiment of the application, the main execution body of the detection method for battery degradation is terminal equipment.

It should be noted that all the following embodiments will be described in detail by taking the battery to be detected as a lithium iron phosphate battery as an example.

As shown in fig. 1, the method for detecting battery degradation according to an embodiment of the present application may include steps S101 to S103, which are detailed as follows:

in S101, acquiring a battery current and a terminal voltage of a battery to be detected after a discharging operation is performed; and the battery current is the current of the battery to be detected passing through the battery to be detected after the battery to be detected is connected with a load.

In some possible embodiments, the terminal device may obtain, in real time, the battery current and the terminal voltage of the battery to be detected after performing the discharging operation through a sampling circuit connected in wired communication with the terminal device. The wired communication connection may be a Universal Serial Bus (USB) connection.

In practical applications, the sampling circuit may be a conventional sampling circuit, and is not limited herein.

In the embodiment of the present application, the specific step of performing the discharging operation on the battery to be detected may be: a set number of discharges-rests is performed on the battery to be tested. The set number of times may be set according to actual needs, and is not limited herein.

At S102, according to the electrical parameters of the battery to be detected, determining the target anode initial lithium intercalation amount, the target cathode initial lithium intercalation amount, the target anode capacity and the target cathode capacity of the battery to be detected.

In one embodiment of the present application, the electrical parameters of the battery to be tested include, but are not limited to: battery current and terminal voltage, therefore, the terminal device can specifically execute step S102 through S201 to S206 shown in fig. 2, as detailed below:

in S201, the standard electromotive force of the battery to be detected is determined according to a preset electrochemical model, the battery current and the terminal voltage.

In this embodiment, the preset electrochemical model is a battery model that is created by simplifying the battery to be detected into a system composed of a positive electrode (i.e., a positive electrode), a negative electrode (i.e., a negative electrode), a diaphragm and an electrolyte, and based on electrochemical theories such as an electrochemical reaction, an ion diffusion, and a polarization effect in the battery to be detected.

Based on this, the electrochemical model provided in this embodiment includes mathematical descriptions of the solid-phase diffusion process, the liquid-phase diffusion process, the reactive polarization process, the ohmic polarization process, and the calculation of the terminal voltage of the battery to be detected.

Specifically, please refer to table 1, wherein table 1 is a mathematical description table of the electrochemical model provided in the examples of the present application.

TABLE 1

Wherein, y _avg Represents the average lithium intercalation amount, y, of the positive electrode of the battery to be tested ₀ Represents the initial lithium insertion quantity, Q, of the positive electrode of the battery to be detected _p Representing the positive electrode capacity, x, of the battery to be tested _avg Represents the average inserted lithium amount, x, of the negative electrode of the battery to be tested ₀ Represents the initial lithium insertion quantity, Q, of the negative electrode of the battery to be tested _n Indicating the negative electrode capacity, y, of the battery to be tested _surf Indicating the lithium embedding amount of the positive electrode surface of the battery to be detected,

represents the solid phase diffusion time constant of the anode of the battery to be detected,

represents the time constant of solid phase diffusion of the negative electrode of the cell to be tested, c ₀ Indicating the initial electrolyte concentration, τ, of the cell to be tested _e Represents the liquid phase diffusion time constant, P, of the cell to be tested _con The liquid phase diffusion proportionality coefficient of the battery to be detected is represented, R represents the universal gas constant of the battery to be detected, T represents the temperature of the battery to be detected, F represents the Faraday constant of the battery to be detected, and P represents the Faraday constant of the battery to be detected _act Representing the negative reaction polarization coefficient, R, of the cell to be tested _ohm Indicates the ohmic internal resistance, U, of the battery to be tested _p Indicating the voltage of the positive electrode, U, of the battery to be tested _n Representing the negative voltage of the battery to be tested, I (t) representing the battery current of the battery to be tested, U _app Indicating the terminal voltage of the battery to be tested.

In this embodiment, the standard electromotive force of the battery to be detected can be specifically calculated according to the following formula:

where Emf denotes the standard electromotive force, U, of the battery to be tested _p Indicating the voltage of the positive electrode, U, of the battery to be tested _n Indicating the voltage of the negative electrode, y, of the battery to be tested ₀ Represents the initial lithium insertion quantity, Q, of the positive electrode of the battery to be detected _p Representing the positive electrode capacity, x, of the battery to be tested ₀ Represents the initial lithium insertion quantity, Q, of the negative electrode of the battery to be tested _n The negative electrode capacity of the battery to be detected is represented, and I (t) represents the battery current of the battery to be detected.

In S202, the first negative electrode initial lithium intercalation amount and the first negative electrode capacity are calculated from the standard electromotive force.

In this embodiment, in combination with the formula for calculating the standard electromotive force of the battery to be detected provided in S201, the terminal device may perform preliminary fitting on the initial lithium insertion amount and the positive electrode capacity of the positive electrode of the battery to be detected by using a least square method, so as to obtain the initial lithium insertion amount and the first negative electrode capacity of the first negative electrode of the battery to be detected.

In S203, determining a first battery health degree of the battery to be detected according to the initial lithium intercalation amount of the first negative electrode and the first negative electrode capacity.

In this embodiment, after obtaining the initial lithium insertion amount of the first negative electrode and the first negative electrode capacity, the terminal device may calculate the first battery capacity of the battery to be detected after performing the discharging operation according to the initial lithium insertion amount of the first negative electrode and the first negative electrode capacity.

Specifically, the terminal device may calculate a first battery capacity of the battery to be detected after the discharging operation is performed according to the following formula:

Q _N ＝Q _n1 *x ₁ ；

wherein Q _N Representing a first battery capacity, x, of the battery to be tested after performing a discharge operation ₁ Represents the initial lithium insertion quantity, Q, of the first negative electrode of the battery to be detected _n1 Indicating the first negative capacity of the battery to be tested.

In this embodiment, when the terminal device obtains the first battery capacity of the battery to be detected after the battery to be detected performs the discharging operation, the first battery health degree of the battery to be detected may be calculated according to the following formula:

wherein SOH _1 represents a first battery health degree, Q, of the battery to be detected _N Representing a first battery capacity, Q, of the battery to be tested after performing a discharge operation ₀ Indicating the initial rated capacity of the battery to be tested. The initial rated capacity of the battery to be detected is the rated capacity of the battery to be detected when the battery leaves the factory.

In practical applications, the state of health (SOH) of a battery may be understood as the percentage of the current capacity of the battery to be detected to the factory capacity.

In S204, obtaining 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 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 the 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 electrode lithium ion concentrations generated during the discharge operation of the battery to be tested.

In S205, a first positive electrode initial lithium intercalation amount, a second negative electrode initial lithium intercalation amount, a first positive electrode capacity, and a second negative electrode capacity are determined according to 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.

In this embodiment, the terminal device may specifically calculate the first initial lithium insertion amount of the positive electrode and the second initial lithium insertion amount of the negative electrode of the battery to be detected according to the following formulas:

ε _s，p L _p y ₁ c _s，p，max +E _s，n L _n x ₂ c _s，n，max ＝SOH_1*nL _i ；

U _p (y ₁ )-U _n (x ₂ )＝V(0)；

wherein epsilon _s,p Represents the effective porosity of the first electrode corresponding to the anode of the battery to be detected, epsilon _s,n Indicates the effective porosity, L, of the second electrode corresponding to the negative electrode of the battery to be tested _p Indicates the thickness of the first electrode corresponding to the anode of the battery to be detected, L _n Represents the thickness of the second electrode corresponding to the positive electrode of the battery to be tested, c _s,p,max Represents to beDetecting a first maximum lithium ion concentration, c, corresponding to the positive electrode of the battery _s,n,max Indicating a second maximum lithium ion concentration, n, corresponding to the negative electrode of the battery to be tested _Li Indicating the active lithium ion content in the battery to be detected, V (0) indicating the initial terminal voltage of the battery to be detected, SOH _1 indicating the first battery health of the battery to be detected, x ₂ Indicating the initial amount of lithium inserted into the second negative electrode of the battery to be tested, y ₁ Represents the initial lithium insertion amount, U, of the first positive electrode of the battery to be tested _p Indicating the voltage of the positive electrode, U, of the battery to be tested _n Representing the voltage of the negative electrode of the battery to be tested.

The first maximum lithium ion concentration may also be referred to as a surface maximum lithium ion concentration corresponding to a positive electrode of the battery to be detected, and the second maximum lithium ion concentration may also be referred to as a surface maximum lithium ion concentration corresponding to a negative electrode of the battery to be detected.

In this embodiment, the terminal device may calculate the second negative electrode capacity of the battery to be detected according to the second negative electrode initial lithium insertion amount and the first battery health degree of the battery to be detected when obtaining the second negative electrode initial lithium insertion amount of the battery to be detected.

Based on this, the terminal device may calculate the first positive electrode capacity of the battery to be detected according to the first positive electrode initial lithium insertion amount, the second negative electrode initial lithium insertion amount and the second negative electrode capacity of the battery to be detected, which are obtained through the above calculation.

In S206, 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 according to the first battery health degree and a preset standard battery health degree.

It should be noted that the preset standard battery health specifically includes: and (4) obtaining the health degree of the battery after the battery to be detected performs the battery low-rate discharge operation under the current of 0.04C.

In this embodiment, the terminal device may calculate a difference between a first battery health degree of the battery to be detected and a preset standard battery health degree, and compare an absolute value of the difference with a set threshold. The set threshold may be set according to actual needs, and is not limited herein, and for example, the set threshold may be set to 0.001.

In an implementation manner of this embodiment, when the terminal device detects that the absolute value of the difference between the first battery health degree of the battery to be detected and the preset standard battery health degree is less than or equal to the set threshold, it indicates that the battery health degree of the battery to be detected meets the requirement, that is, the difference between the first battery health degree and the preset standard battery health degree is negligible, so that the terminal device may 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 to be detected, which are obtained by the calculation 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 to be detected.

In another implementation manner of this embodiment, when the terminal device detects that an absolute value of a difference between a first battery health degree of a battery to be detected and a preset standard battery health degree is greater than a set threshold, the terminal device may specifically determine a target positive electrode initial lithium insertion amount, a target negative electrode initial lithium insertion amount, a target positive electrode capacity, and a target negative electrode capacity of the battery to be detected by the following steps, which are detailed as follows:

if the absolute value of the difference between the first battery health degree and the standard battery health degree is larger than a set threshold, updating the first battery health degree according to the first battery health degree and the standard battery health degree;

and determining 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 according to the updated first battery health degree.

In this embodiment, when detecting that the absolute value of the difference between the first battery health degree of the battery to be detected and the preset standard battery health degree is greater than the set threshold, the terminal device indicates that the battery health degree of the battery to be detected does not meet the requirement, that is, the difference between the first battery health degree of the battery to be detected and the preset standard battery health degree is too large, and therefore, the terminal device can specifically update the first battery health degree according to the first battery health degree of the battery to be detected and the preset standard battery health degree.

Specifically, the terminal device may update the first battery health degree of the battery to be detected according to the following formula:

SOH_1'＝(SOH_1+SOH_2)/2；

the SOH _1' represents the first battery health degree of the battery to be detected after being updated, the SOH _1 represents the first battery health degree of the battery to be detected, and the SOH _2 represents the standard battery health degree of the battery to be detected.

In this embodiment, the terminal device may determine the target initial lithium insertion amount of the positive electrode, the target initial lithium insertion amount of the negative electrode, the target capacity of the positive electrode, and the target capacity of the negative electrode of the battery to be detected according to the updated first battery health degree.

Specifically, the terminal device may calculate a second positive electrode initial lithium intercalation amount, a third negative electrode initial lithium intercalation amount, a second positive electrode capacity and a third negative electrode capacity of the battery to be detected according to the updated first battery health degree, a first maximum lithium ion concentration corresponding to the positive electrode of the battery to be detected, a first electrode porosity, a first electrode effective porosity, a first electrode thickness, a second maximum lithium ion concentration corresponding to the negative electrode of the battery to be detected, a second electrode porosity, a second electrode effective porosity, a second electrode thickness, an active lithium ion content in the battery to be detected and an initial terminal voltage of the battery to be detected.

Then, when the terminal device detects that the absolute value of the difference between the updated first battery health degree and the preset standard battery health degree is smaller than or equal to the set threshold, it indicates that the battery health degree of the battery to be detected meets the requirement, that is, the difference between the updated first battery health degree and the preset standard battery health degree is negligible, so that the terminal device can directly determine the calculated second positive electrode initial lithium intercalation amount, third negative electrode initial lithium intercalation amount, second positive electrode capacity and third negative electrode capacity of the battery to be detected as the target positive electrode initial lithium intercalation amount, target negative electrode initial lithium intercalation amount, target positive electrode capacity and target negative electrode capacity of the battery to be detected.

In another embodiment of the present application, the electrical parameters of the battery to be detected may further include: the method comprises the steps of detecting 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 anode of the battery to be detected, and detecting 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 electrode effective area of the battery to be detected corresponding to the cathode of the battery to be detected. Wherein, the initial lithium ion concentration represents the lithium ion concentration of the electrode (such as the negative electrode and the positive electrode) of the battery to be detected before the discharging operation is performed, and the maximum lithium ion concentration represents the maximum value of the lithium ion concentration of the electrode (such as the negative electrode and the positive electrode) of the battery to be detected during the discharging operation is performed.

Based on this, the terminal device may specifically execute step S102 through S301 to S305 as shown in fig. 3, which is detailed as follows:

in S301, 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 to be detected, 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, and an electrode effective area corresponding to the negative electrode of the battery to be detected are obtained.

In S302, the target initial lithium insertion amount of the positive electrode is calculated according to the first initial lithium ion concentration and the first maximum lithium ion concentration.

In this embodiment, the terminal device may specifically calculate the initial lithium insertion amount of the target positive electrode of the battery to be detected according to the following formula:

wherein, y _d Indicating the target initial lithium intercalation amount of the positive electrode of the battery to be tested,

indicating a first maximum lithium ion concentration corresponding to the positive electrode of the battery to be tested,

indicating a first initial lithium ion concentration corresponding to the positive electrode of the battery to be tested.

In S303, the target negative electrode initial lithium insertion amount is calculated according to the second initial lithium ion concentration and the second maximum lithium ion concentration.

Wherein x is _d Indicating the target initial lithium intercalation amount of the negative electrode of the battery to be detected,

indicating a second maximum lithium ion concentration corresponding to the negative electrode of the battery to be tested,

indicating a first initial lithium ion concentration corresponding to the negative electrode of the battery to be tested.

In S304, the target positive electrode capacity 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.

Wherein Q is _pd Indicates the target positive electrode capacity of the battery to be tested, epsilon _p Denotes the porosity of the first electrode corresponding to the positive electrode of the cell to be tested, ε _f,p Indicates the effective porosity, L, of the first electrode corresponding to the positive electrode of the battery to be detected _p Indicating the thickness of the first electrode, n, corresponding to the positive electrode of the battery to be tested _Li The method is characterized by comprising the following steps of (1) representing the active lithium ion content in a battery to be detected, and (A) representing the effective area of an electrode in the battery to be detected.

In S305, the target negative 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.

Wherein Q _nd Indicates the target negative electrode capacity, epsilon, of the battery to be tested _n Indicates the porosity of the second electrode corresponding to the negative electrode of the battery to be detected, epsilon _f,n Indicating the effective porosity, L, of the second electrode corresponding to the negative electrode of the battery to be tested _n Indicating the thickness of the second electrode corresponding to the negative electrode of the battery to be tested, n _Li The active lithium ion content in the battery to be detected is represented, and A represents the effective area of an electrode in the battery to be detected.

In S103, performing degradation detection on the battery to be detected according to the battery current, the terminal voltage, 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, so as to obtain a degradation detection result of the battery to be detected.

In an embodiment of the present application, the terminal device may specifically execute step S103 through S401 to S404 shown in fig. 4, which are detailed as follows:

in S401, calculating the target battery capacity of the battery to be detected according to the target negative electrode capacity and the target negative electrode initial lithium insertion amount.

In this embodiment, the terminal device may specifically calculate the target battery capacity of the battery to be detected according to the following formula:

Q _Nd ＝Q _nd *x _d ；

wherein Q is _Nd Representing the target battery capacity, x, of the battery to be tested _d Represents the target initial lithium insertion amount, Q, of the negative electrode of the battery to be tested _nd Indicating the target negative capacity of the battery to be tested.

In S402, determining a variation range of the lithium insertion amount of the positive electrode of the battery to be detected according to the target battery capacity and the target positive electrode capacity.

In this embodiment, the terminal device may specifically calculate the variation range of the positive electrode lithium insertion amount of the battery to be detected according to the following formula:

wherein D is _x Represents the variation range of the lithium insertion quantity of the positive electrode of the battery to be detected, Q _N Representing the target battery capacity, Q, of the battery to be tested _nd Indicating the target positive electrode capacity of the battery to be tested.

In S403, determining a variation range of the lithium insertion amount of the negative electrode of the battery to be detected according to the target battery capacity and the target negative electrode capacity.

Wherein D is _y Represents the variation range of the lithium insertion quantity of the negative electrode of the battery to be detected, Q _N Representing the target battery capacity, Q, of the battery to be tested _pd Indicating the target negative capacity of the battery to be tested.

In S404, performing degradation detection on the battery to be detected according to the battery current, the terminal voltage, 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, the target negative electrode capacity, the variation range of the lithium intercalation amount of the positive electrode, and the variation range of the lithium intercalation amount of the negative electrode, so as to obtain the degradation detection result.

In this embodiment, the terminal device may specifically perform degradation detection on the battery to be detected according to the battery current, the terminal voltage, the target initial lithium insertion amount of the positive electrode, the target initial lithium insertion amount of the negative electrode, the target positive electrode capacity, the target negative electrode capacity, the positive electrode lithium insertion amount variation range, and the negative electrode lithium insertion amount variation range of the battery to be detected, so as to obtain a degradation detection result of the battery to be detected.

In some possible embodiments, with reference to S401 to S403, the terminal device may calculate the total initial lithium ion content of the battery to be detected according to 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 detected.

Specifically, the terminal device may calculate the initial total lithium ion content of the battery to be detected according to the following formula:

C＝x _d *Q _nd +y _d *Q _Pd ；

wherein C represents the initial total lithium ion content of the battery to be detected, and x _d Indicates the target initial lithium intercalation amount, y, of the battery to be tested _d Represents the initial lithium insertion amount, Q, of the target positive electrode of the battery to be detected _nd Indicating the target positive electrode capacity, Q, of the battery to be tested _pd Indicating the target negative capacity of the battery to be tested.

The terminal equipment can also determine the lithium ion ratio of the battery to be detected according to the target initial lithium intercalation amount of the negative electrode of the battery to be detected and the change range of the lithium intercalation amount of the negative electrode. Wherein, the 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 to be detected.

Specifically, the lithium ion ratio of the battery to be detected = target negative electrode initial lithium intercalation amount/negative electrode lithium intercalation amount variation range of the battery to be detected.

The terminal equipment can also determine the maximum lithium ion content of the embedded anode of the battery to be detected according to the target initial lithium embedding amount of the cathode of the battery to be detected and the variation range of the lithium embedding amount of the cathode.

Specifically, the maximum lithium ion content = the target initial lithium intercalation amount of the negative electrode + the variation range of the lithium intercalation amount of the negative electrode of the battery to be detected.

In another embodiment of the present application, the terminal device may specifically execute step S103 through S501 to S506 shown in fig. 5, which are detailed as follows:

in S501, the target battery capacity of the battery to be detected is calculated according to the target negative electrode capacity and the target negative electrode initial lithium insertion amount.

In this embodiment, the terminal device may specifically calculate the target battery capacity of the battery to be detected according to the following formula:

Q _Nd ＝Q _nd *x _d ；

wherein Q is _Nd Representing the target battery capacity, x, of the battery to be tested _d Represents the target initial lithium insertion amount, Q, of the negative electrode of the battery to be tested _nd Indicating the target negative capacity of the battery to be tested.

In S502, the battery energy and the battery power of the battery to be detected are calculated according to the battery current and the terminal voltage.

In this embodiment, the terminal device may specifically calculate the battery energy of the battery to be detected according to the following formula:

wherein E is _N The battery energy of the battery to be detected is represented, T represents the total time length of the battery to be detected for performing the discharging operation, U (T) represents the terminal voltage of the battery to be detected at the T-th moment when the discharging operation is performed, and I (T) represents the battery current of the battery to be detected at the T-th moment when the discharging operation is performed.

In this embodiment, the terminal device may specifically calculate the battery power of the battery to be detected according to the following formula:

wherein, P _N The battery power of the battery to be detected is represented, T represents the total time length of the battery to be detected for performing the discharging operation, U (T) represents the terminal voltage of the battery to be detected at the T-th moment when the discharging operation is performed, and I (T) represents the battery current of the battery to be detected at the T-th moment when the discharging operation is performed.

In S503, calculating a second battery health degree of the battery to be detected according to the target battery capacity and the initial rated capacity of the battery to be detected.

In this embodiment, the second battery health degree specifically refers to a ratio between a target battery capacity and an initial rated capacity of the battery to be detected under a capacity fading method. Wherein, the initial rated capacity refers to the rated capacity of the battery to be detected when the battery leaves the factory.

In S504, a third battery health degree of the battery to be detected is calculated according to the battery energy and the initial rated energy of the battery to be detected.

In this embodiment, the third battery health degree specifically refers to a ratio between the battery energy of the battery to be detected and the initial rated energy under the energy decay method. Wherein, the initial rated energy refers to the rated energy of the battery to be detected when the battery leaves the factory.

In S505, a fourth battery health degree of the battery to be detected is calculated according to the battery power and the initial rated power of the battery to be detected.

In this embodiment, the fourth battery health degree specifically refers to a ratio between the battery power of the battery to be detected and the initial rated power under the power fading method. Wherein, the initial rated power refers to the rated power of the battery to be detected when the battery leaves the factory.

In S506, the degradation detection result is determined according to the second battery health degree, the third battery health degree, and the fourth battery health degree.

In this embodiment, the terminal device may calculate the target battery health degree of the battery to be detected according to the second battery health degree, the third battery health degree and the fourth battery health degree obtained through the calculation.

Specifically, the terminal device may calculate the target battery health degree of the battery to be detected according to the following formula:

wherein SOH represents the target battery health of the battery to be detected, SOH _cap Indicating a second battery health, SOH, of the battery to be tested _eng Indicating battery to be testedThird battery health degree, SOH _pow Indicating a fourth battery health of the battery to be tested.

Based on the above, the terminal device may determine the degradation detection result of the battery to be detected according to the target battery health degree.

It should be noted that, when the target battery health degree of the battery to be detected is higher, it indicates that the degradation degree of the battery to be detected is lower, that is, the degradation detection result of the battery to be detected is better; when the target battery health degree of the battery to be detected is lower, it indicates that the deterioration degree of the battery to be detected is higher, i.e., the deterioration detection result of the battery to be detected is worse.

In yet another embodiment of the present application, since the battery degradation is generally caused by active lithium ion loss, active material loss and over-potential loss of the battery, the terminal device may specifically perform step S103 through S601 to S607 as shown in fig. 6, which is detailed as follows:

in S601, an original positive electrode initial lithium insertion amount, an original negative electrode initial lithium insertion amount, an original positive electrode capacity, and an original negative electrode capacity of the battery to be detected before the battery to be detected performs a discharging operation are obtained.

In S602, calculating a target battery capacity of the battery to be detected according to the target negative electrode capacity and the target negative electrode initial lithium insertion amount.

In this embodiment, the terminal device may specifically calculate the target battery capacity of the battery to be detected according to the following formula:

Q _Nd ＝Q _nd *x _d ；

wherein Q is _Nd Representing the target battery capacity, x, of the battery to be tested _d Represents the target initial lithium insertion amount, Q, of the negative electrode of the battery to be tested _nd Indicating the target negative capacity of the battery to be tested.

In S603, a capacity loss value of the battery to be detected is calculated according to the target battery capacity and the initial rated capacity of the battery to be detected.

In this embodiment, the capacity loss value of the battery to be detected specifically refers to a total battery capacity loss value after the battery to be detected performs a discharging operation.

Specifically, the capacity loss value of the battery to be detected = target battery capacity-initial rated capacity.

In S604, calculating a first loss value of the battery to be detected according to the original initial lithium intercalation amount of the anode, the original initial lithium intercalation amount of the cathode, the original anode capacity, the original cathode capacity, the target initial lithium intercalation amount of the anode, the target initial lithium intercalation amount of the cathode, the target anode capacity, the target cathode capacity and the capacity loss value; the first loss value is a capacity loss in the battery to be tested due to loss of active lithium ions.

In this embodiment, the terminal device may specifically calculate the first loss value of the battery to be detected according to the following formula:

wherein Q _LLI Representing a first loss value, Q, of the battery to be tested _loss Representing the value of capacity loss, x, of the battery to be tested _d Indicates the target initial lithium intercalation amount, y, of the battery to be tested _d Represents the target initial lithium insertion amount, Q, of the positive electrode of the battery to be tested _Pd Representing the target positive electrode capacity, Q, of the battery to be tested _nd Indicating the target negative electrode capacity, y, of the battery to be tested ₀ (0) Represents the initial lithium insertion amount, x, of the original positive electrode of the battery to be tested ₀ (0) Represents the initial lithium insertion amount, Q, of the original cathode of the battery to be tested _p (0) Representing the original positive capacity, Q, of the battery to be tested _n (0) Representing the original negative capacity of the battery to be tested.

In S605, calculating a second loss value of the battery to be detected according to a preset electrochemical model, the terminal voltage and the battery current; the second loss value is capacity loss caused by over potential loss in the battery to be detected.

In this embodiment, the overpotential loss is a battery capacity loss caused by the presence of a concentration polarization overpotential, a reaction polarization overpotential, and an ohmic polarization overpotential, and therefore, the curves of the respective overpotentials and terminal voltages can be obtained by combining the mathematical description about the calculation of the overpotentials and the terminal voltages in the electrochemical model provided in S101.

The terminal device can determine a first discharge cutoff time of the battery to be detected according to the plurality of curves, and determine a second discharge cutoff time of the battery to be detected when the overpotential is the initial value 0.

Based on this, the terminal device may specifically calculate the second loss value of the battery to be detected according to the following formula:

wherein Q is _η Representing a second loss value, t, of the battery to be tested ₁ First discharge cutoff time, t, of the battery to be tested ₂ And a second discharge cut-off time of the battery to be detected, wherein I (t) represents the current of the battery at the t-th moment when the battery to be detected performs a discharge operation.

In S606, a third loss value of the battery to be detected is calculated according to the capacity loss value, the first loss value, and the second loss value.

It should be noted that the third loss value of the battery to be tested is a capacity loss caused by the loss of the active material in the battery to be tested.

In this embodiment, the terminal device may specifically calculate a third loss value of the battery to be detected according to the following formula:

Q _LAM ＝Q _Ioss -Q _LLI -Q _η ；

wherein Q is _LAM Representing a third loss value, Q, of the battery to be tested _loss Representing the capacity loss value, Q, of the battery to be tested _LLI Representing a first loss value, Q, of the battery to be tested _η Representing a second loss value of the battery to be tested.

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

In this embodiment, when the first loss value of the battery to be detected is smaller, it indicates that the degradation degree of the battery to be detected is lower, that is, the degradation detection result of the battery to be detected is better; when the second loss value of the battery to be detected is lower, the lower the degradation degree of the battery to be detected is, namely the better the degradation detection result of the battery to be detected is; when the third loss value of the battery to be detected is lower, it indicates that the deterioration degree of the battery to be detected is lower, i.e., the deterioration detection result of the battery to be detected is better.

Referring to fig. 7, fig. 7 is a graph illustrating a variation of different loss values when different discharging operations are performed according to an embodiment of the present disclosure. Specifically, fig. 7 (a) and 7 (b) are graphs showing the variation of the second loss value in the case of different numbers of discharge operations, fig. 7 (c) is a graph showing the variation of the first loss value in the case of different numbers of discharge operations, and fig. 7 (d) is a graph showing the variation of the third loss value in the case of different numbers of discharge operations.

As can be seen from the above, the method for detecting battery degradation provided by the embodiment of the present application obtains the battery current and the terminal voltage of the battery to be detected after the battery performs the discharging operation; the battery current is the current passing 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; and performing degradation detection on the battery to be detected according to the current, the terminal voltage, the target initial lithium intercalation amount of the anode, the target initial lithium intercalation amount of the cathode, the target anode capacity and the target cathode capacity of the battery to obtain a degradation detection result of the battery to be detected. Compared with the prior art that the degradation detection of the battery is realized only according to the observation of the surface data of the battery, such as the capacity, the internal resistance, the voltage and the like, the detection method provided by the application 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 of the battery to perform degradation detection on the battery besides the battery current and the terminal voltage of the battery, so that the accuracy of the degradation detection of the battery is improved.

It should be understood that, the sequence numbers of the steps in the foregoing embodiments do not imply an execution sequence, and the execution sequence of each process should be determined by its function and inherent logic, and should not constitute any limitation to the implementation process of the embodiments of the present application.

Fig. 8 shows a block diagram of a device for detecting battery degradation according to an embodiment of the present application, which corresponds to the method for detecting battery degradation according to the foregoing embodiment, and only the relevant parts of the embodiment of the present application are shown for convenience of description. Referring to fig. 8, the battery degradation detection apparatus 800 includes: a first acquisition unit 81, a first determination unit 82, and a first detection unit 83. Wherein:

the first acquiring unit 81 is used for acquiring a battery current and a terminal voltage of a battery to be detected after a discharging operation is performed; the battery current is the current passing through the battery to be detected after the battery to be detected is connected to a load.

The first determining unit 82 is configured to determine a target initial lithium insertion amount of the positive electrode, a target initial lithium insertion amount of the negative electrode, a target capacity of the positive electrode, and a target capacity of the negative electrode of the battery to be detected according to the electrical parameter of the battery to be detected.

The first detection unit 83 is configured to perform degradation detection on the battery to be detected according to the battery current, the terminal voltage, the target initial lithium insertion amount of the positive electrode, the target initial lithium insertion amount of the negative electrode, the target positive electrode capacity, and the target negative electrode capacity, so as to obtain a degradation detection result of the battery to be detected.

In an embodiment of the present application, the first determining unit 82 specifically includes: the device comprises a second determining unit, a first calculating unit, a third determining unit, a second acquiring unit, a fourth determining unit and a fifth determining unit.

Wherein:

and the second determination unit is used for determining the standard electromotive force of the battery to be detected according to a preset electrochemical model, the battery current and the terminal voltage.

And the first calculating unit is used for calculating to obtain the initial lithium embedding amount of the first negative electrode and the first negative electrode capacity according to the standard electromotive force.

The third determining unit is used for determining the first battery health degree of the battery to be detected according to the initial lithium embedding amount of the first negative electrode and the first negative electrode capacity.

The second obtaining unit is used for obtaining a first maximum lithium ion concentration, a first electrode porosity, a first electrode effective porosity and a first electrode thickness corresponding to the anode 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 the cathode 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 executed; wherein the maximum lithium ion concentration represents a maximum value of electrode lithium ion concentrations generated during the discharge operation of the battery to be tested.

A fourth determination unit is configured to determine a first positive electrode initial lithium intercalation amount, a second negative electrode initial lithium intercalation amount, a first positive electrode capacity, and a second negative electrode capacity according to 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.

And the fifth determining unit is used for determining the target initial lithium embedding amount of the positive electrode, the target initial lithium embedding amount of the negative electrode, the target capacity of the positive electrode and the target capacity of the negative electrode according to the first battery health degree and a preset standard battery health degree.

In an embodiment of the application, the fifth determining unit specifically includes: an updating unit and a sixth determining unit. Wherein:

the updating unit is used for updating the first battery health degree according to the first battery health degree and the standard battery health degree if the absolute value of the difference between the first battery health degree and the standard battery health degree is larger than a set threshold value.

The sixth determining unit is configured to determine 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 according to the updated first battery health degree.

In an embodiment of the present application, the first determining unit 82 specifically includes: the device comprises a third acquisition unit, a second calculation unit, a third calculation unit, a fourth calculation unit and a fifth calculation unit. Wherein:

the third acquiring unit is used for acquiring 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 anode of the battery to be detected, 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 and an electrode effective area of the battery to be detected corresponding to the cathode 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 the discharging operation is performed, and the maximum lithium ion concentration represents the maximum value of the electrode lithium ion concentration generated by the battery to be detected during the discharging operation is performed.

And the second calculating unit is used for calculating the target initial lithium insertion amount of the positive electrode according to the first initial lithium ion concentration and the first maximum lithium ion concentration.

And the third calculating unit is used for calculating the target negative electrode initial lithium insertion amount according to the second initial lithium ion concentration and the second maximum lithium ion concentration.

And the fourth calculating unit is used for calculating the target anode capacity 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.

And the fifth calculating unit is used for calculating to obtain the target negative electrode capacity 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.

In an embodiment of the present application, the first detecting unit 83 specifically includes: the device comprises a first capacity determining unit, a first range determining unit, a second range determining unit and a second detecting unit. Wherein:

and the first capacity determining unit is used for calculating the target battery capacity of the battery to be detected according to the target negative electrode capacity and the target negative electrode initial lithium embedding amount.

The first range determining unit is used for determining the variation range of the lithium embedding amount of the positive electrode of the battery to be detected according to the target battery capacity and the target positive electrode capacity.

And the second range determining unit is used for determining the variation range of the lithium insertion amount of the negative electrode of the battery to be detected according to the target battery capacity and the target negative electrode capacity.

And the second detection unit is used for carrying out degradation detection on the battery to be detected according to the battery current, the terminal voltage, 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, the target negative electrode capacity, the change range of the lithium intercalation amount of the positive electrode and the change range of the lithium intercalation amount of the negative electrode, so as to obtain a degradation detection result.

In an embodiment of the present application, the first detecting unit 83 specifically includes: the health degree detection device comprises a sixth calculation unit, a seventh calculation unit, a first health degree calculation unit, a second health degree calculation unit, a third health degree calculation unit and a third detection unit. Wherein:

and the sixth calculating unit is used for calculating the target battery capacity of the battery to be detected according to the target negative electrode capacity and the target negative electrode initial lithium insertion amount.

And the seventh calculating unit is used for calculating the battery energy and the battery power of the battery to be detected according to the battery current and the terminal voltage.

The first health degree calculation unit is used for calculating and obtaining a second battery health degree of the battery to be detected according to the target battery capacity and the initial rated capacity of the battery to be detected.

The second health degree calculation unit is used for calculating and obtaining a third battery health degree of the battery to be detected according to the battery energy and the initial rated energy of the battery to be detected.

The third health degree calculation unit is used for calculating and obtaining a fourth battery health degree of the battery to be detected according to the battery power and the initial rated power of the battery to be detected.

The third detection unit is configured to determine the degradation detection result according to the second battery health degree, the third battery health degree, and the fourth battery health degree.

In an embodiment of the present application, the first detecting unit 83 specifically includes: the device comprises 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:

the fourth obtaining unit is used for obtaining an original positive electrode initial lithium embedding amount, an original negative electrode initial lithium embedding amount, an original positive electrode capacity and an original negative electrode capacity of the battery to be detected before the battery to be detected performs the discharging operation.

And the second capacity determining unit is used for calculating the target battery capacity of the battery to be detected according to the target negative electrode capacity and the target negative electrode initial lithium embedding amount.

And the first loss value calculating unit is used for calculating and obtaining the capacity loss value of the battery to be detected according to the target battery capacity and the initial rated capacity of the battery to be detected.

The second loss value calculation unit is used for calculating and obtaining a first loss value of the battery to be detected according to the original positive electrode initial lithium embedding amount, the original negative electrode initial lithium embedding amount, the original positive electrode capacity, the original negative electrode capacity, the target positive electrode initial lithium embedding amount, the target negative electrode initial lithium embedding amount, the target positive electrode capacity, the target negative electrode capacity and the capacity loss value; the first loss value is a capacity loss in the battery to be tested due to loss of active lithium ions.

The third loss value calculation unit is used for calculating a second loss value of the battery to be detected according to a preset electrochemical model, the terminal voltage and the battery current; the second loss value is capacity loss caused by over potential loss in the battery to be detected.

And the fourth loss value calculating unit is used for calculating a third loss value of the battery to be detected according to the capacity loss value, the first loss value and the second loss value.

The fourth detection unit is configured to determine the degradation detection result according to the first loss value, the second loss value, and the third loss value.

It should be noted that, for the information interaction, execution process, and other contents between the above-mentioned devices/units, the specific functions and technical effects thereof are based on the same concept as those of the embodiment of the method of the present application, and specific reference may be made to the part of the embodiment of the method, which is not described herein again.

It will be apparent to those skilled in the art that, for convenience and brevity of description, only the above-mentioned division of the functional units and modules is illustrated, and in practical applications, the above-mentioned function distribution may be performed by different functional units and modules according to needs, that is, the internal structure of the apparatus is divided into different functional units or modules to perform all or part of the above-mentioned functions. Each functional unit and module in the embodiments may be integrated in one processing unit, or each unit may exist alone physically, or two or more units are integrated in one unit, and the integrated unit may be implemented in a form of hardware, or in a form of software functional unit. In addition, specific names of the functional units and modules are only for convenience of distinguishing from each other, and are not used for limiting the protection scope of the present application. For the specific working processes of the units and modules in the system, reference may be made to the corresponding processes in the foregoing method embodiments, which are not described herein again.

Fig. 9 is a schematic structural diagram of a terminal device according to an embodiment of the present application. As shown in fig. 9, the terminal device 9 of this embodiment includes: at least one processor 90 (only one shown in fig. 9), a memory 91, and a computer program 92 stored in the memory 91 and executable on the at least one processor 90, the processor 90 implementing the steps in any of the various battery degradation detection method embodiments described above when executing the computer program 92.

The terminal device may include, but is not limited to, a processor 90, a memory 91. Those skilled in the art will appreciate that fig. 9 is only an example of the terminal device 9, and does not constitute a limitation to the terminal device 9, and may include more or less components than those shown in the drawings, or may combine some components, or different components, and may further include, for example, an input/output device, a network access device, and the like.

The Processor 90 may be a Central Processing Unit (CPU), and the Processor 90 may be other general purpose Processor, a Digital Signal Processor (DSP), an Application Specific Integrated Circuit (ASIC), an off-the-shelf Programmable Gate Array (FPGA) or other Programmable logic device, discrete Gate or transistor logic, discrete hardware components, etc. A general purpose processor may be a microprocessor or the processor may be any conventional processor or the like.

The memory 91 may in some embodiments be an internal storage unit of the terminal device 9, such as a memory of the terminal device 9. The memory 91 may also be an external storage device of the terminal device 9 in other embodiments, such as a plug-in hard disk, a Smart Media Card (SMC), a Secure Digital (SD) Card, a Flash memory Card (Flash Card), and the like provided on the terminal device 1. Further, the memory 91 may also include both an internal storage unit and an external storage device of the terminal device 9. The memory 91 is used for storing an operating system, an application program, a BootLoader (BootLoader), data, and other programs, such as program codes of the computer program. The memory 91 may also be used to temporarily store data that has been output or is to be output.

The embodiments of the present application further provide a computer-readable storage medium, where a computer program is stored, and when the computer program is executed by a processor, the computer program implements the steps in the above-mentioned method embodiments.

The embodiments of the present application provide a computer program product, which when running on a terminal device, enables the terminal device to implement the steps in the above method embodiments when executed.

The integrated unit, if implemented in the form of a software functional unit and sold or used as a stand-alone product, may be stored in a computer readable storage medium. Based on such understanding, all or part of the flow in the method of the embodiments described above can be implemented by a computer program, which can be stored in a computer readable storage medium and can implement the steps of the embodiments of the methods described above when the computer program is executed by a processor. Wherein the computer program comprises computer program code, which may be in the form of source code, object code, an executable file or some intermediate form, etc. The computer-readable medium may include at least: any entity or apparatus capable of carrying computer program code to a terminal device, recording medium, computer Memory, read-Only Memory (ROM), random-Access Memory (RAM), electrical carrier wave signals, telecommunications signals, and software distribution medium. Such as a usb-drive, a removable hard drive, a magnetic or optical disk, etc. In certain jurisdictions, computer-readable media may not be an electrical carrier signal or a telecommunications signal in accordance with legislative and patent practice.

In the above embodiments, the descriptions of the respective embodiments have respective emphasis, and reference may be made to the related descriptions of other embodiments for parts that are not described or illustrated in a certain embodiment.

The above-mentioned embodiments are only used for illustrating the technical solutions of the present application, and not for limiting the same; although the present application has been described in detail with reference to the foregoing embodiments, it should be understood by those of ordinary skill in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some technical features may be equivalently replaced; such modifications and substitutions do not substantially depart from the spirit and scope of the embodiments of the present application and are intended to be included within the scope of the present application.

Claims (10)

1. A method for detecting battery degradation, comprising:

acquiring battery current and terminal voltage of a battery to be detected after discharge operation is executed; the battery current is the current of the battery to be detected passing 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;

and performing degradation detection on the battery to be detected according to the battery current, the terminal voltage, the target initial lithium intercalation amount of the anode, the target initial lithium intercalation amount of the cathode, the target anode capacity and the target cathode capacity to obtain a degradation detection result of the battery to be detected.

2. The detection method according to claim 1, wherein the determining 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 to be detected according to the electrical parameters of the battery to be detected comprises:

determining the standard electromotive force of the battery to be detected according to a preset electrochemical model, the battery current and the terminal voltage;

calculating to obtain the initial lithium embedding amount of the first negative electrode and the capacity of the first negative electrode according to the standard electromotive force;

determining the first battery health degree of the battery to be detected according to the initial lithium insertion amount of the first negative electrode and the first negative electrode capacity;

acquiring a first maximum lithium ion concentration, a first electrode porosity, a first electrode effective porosity and a first electrode thickness corresponding to the anode 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 the cathode 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 executed; wherein the maximum lithium ion concentration represents a maximum value of an electrode lithium ion concentration generated during the discharge operation of the battery to be tested;

determining a first positive electrode initial lithium intercalation amount, a second negative electrode initial lithium intercalation amount, a first positive electrode capacity, and a second negative electrode capacity as a function of 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;

and determining the target initial lithium intercalation amount of the positive electrode, the target initial lithium intercalation amount of the negative electrode, the target capacity of the positive electrode and the target capacity of the negative electrode according to the first battery health degree and a preset standard battery health degree.

3. The detection method according to claim 2, wherein the determining 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 according to the first battery health degree and a preset standard battery health degree comprises:

if the absolute value of the difference between the first battery health degree and the standard battery health degree is larger than a set threshold, updating the first battery health degree according to the first battery health degree and the standard battery health degree;

and determining 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 according to the updated first battery health degree.

4. The method as claimed in claim 1, wherein the determining 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 to be detected according to the electrical parameters of the battery to be detected comprises:

acquiring 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 anode of the battery to be detected, 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 and an electrode effective area of the battery to be detected corresponding to the cathode of the battery to be detected; the initial lithium ion concentration represents the electrode lithium ion concentration of the battery to be detected before the battery to be detected performs the discharging operation, and the maximum lithium ion concentration represents the maximum value of the electrode lithium ion concentration generated by the battery to be detected during the discharging operation;

calculating to obtain the initial lithium insertion amount of the target anode according to the first initial lithium ion concentration and the first maximum lithium ion concentration;

calculating to obtain the target cathode initial lithium insertion amount according to the second initial lithium ion concentration and the second maximum lithium ion concentration;

calculating to obtain the target positive electrode capacity 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;

and calculating to obtain the target negative electrode capacity 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.

5. The detection method according to any one of claims 1 to 4, wherein the detecting degradation of the battery to be detected according to the battery current, the terminal voltage, 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 to obtain a degradation detection result of the battery to be detected comprises:

calculating to obtain the target battery capacity of the battery to be detected according to the target negative electrode capacity and the target negative electrode initial lithium embedding amount;

determining the variation range of the lithium embedding amount of the anode of the battery to be detected according to the target battery capacity and the target anode capacity;

determining the negative electrode lithium insertion amount variation range of the battery to be detected according to the target battery capacity and the target negative electrode capacity;

and performing degradation detection on the battery to be detected according to the battery current, the terminal voltage, the target initial lithium intercalation amount of the anode, the target initial lithium intercalation amount of the cathode, the target anode capacity, the target cathode capacity, the variation range of the lithium intercalation amount of the anode and the variation range of the lithium intercalation amount of the cathode to obtain a degradation detection result.

6. The detection method according to any one of claims 1 to 4, wherein the detecting degradation of the battery to be detected according to the battery current, the terminal voltage, 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 to obtain a degradation detection result of the battery to be detected comprises:

calculating to obtain the target battery capacity of the battery to be detected according to the target negative electrode capacity and the target negative electrode initial lithium embedding amount;

calculating the battery energy and the battery power of the battery to be detected according to the battery current and the terminal voltage;

calculating to obtain a second battery health degree of the battery to be detected according to the target battery capacity and the initial rated capacity of the battery to be detected;

calculating to obtain a third battery health degree of the battery to be detected according to the battery energy and the initial rated energy of the battery to be detected;

calculating to obtain a fourth battery health degree of the battery to be detected according to the battery power and the initial rated power of the battery to be detected;

and determining the degradation detection result according to the second battery health degree, the third battery health degree and the fourth battery health degree.

7. The detection method according to any one of claims 1 to 4, wherein the detecting degradation of the battery to be detected according to the battery current, the terminal voltage, 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 to obtain a degradation detection result of the battery to be detected comprises:

acquiring 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 the discharging operation is executed;

calculating to obtain the target battery capacity of the battery to be detected according to the target negative electrode capacity and the target negative electrode initial lithium embedding amount;

calculating to obtain a capacity loss value of the battery to be detected according to the target battery capacity and the initial rated capacity of the battery to be detected;

calculating to obtain a first loss value of the battery to be detected according to the original positive electrode initial lithium embedding amount, the original negative electrode initial lithium embedding amount, the original positive electrode capacity, the original negative electrode capacity, the target positive electrode initial lithium embedding amount, the target negative electrode initial lithium embedding amount, the target positive electrode capacity, the target negative electrode capacity and the capacity loss value; the first loss value is capacity loss caused by active lithium ion loss in the battery to be detected;

calculating to obtain a second loss value of the battery to be detected according to a preset electrochemical model, the terminal voltage and the battery current; the second loss value is capacity loss caused by overpotential loss in the battery to be detected;

calculating to obtain a third loss value of the battery to be detected according to the capacity loss value, the first loss value and the second loss value;

determining the degradation detection result according to the first loss value, the second loss value, and the third loss value.

8. A battery degradation detection apparatus, comprising:

the first acquisition unit is used for acquiring the current and the terminal voltage of the battery to be detected after the battery to be detected performs the discharge operation; the battery current is the current of the battery to be detected passing through the battery to be detected after the battery to be detected is connected to a load;

the first determination unit is used for determining the target anode initial lithium intercalation amount, the target cathode initial lithium intercalation amount, the target anode capacity and the target cathode capacity of the battery to be detected according to the electrical parameters of the battery to be detected;

and the first detection unit is used for carrying out degradation detection on the battery to be detected according to the battery current, the terminal voltage, the target anode initial lithium embedding amount, the target cathode initial lithium embedding amount, the target anode capacity and the target cathode capacity to obtain a degradation detection result of the battery to be detected.

9. 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 implements the method of detecting battery degradation according to any one of claims 1 to 7 when executing the computer program.

10. A computer-readable storage medium storing a computer program, wherein the computer program, when executed by a processor, implements the method of detecting battery degradation according to any one of claims 1 to 7.

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