CN115358042B - Heat production power prediction method, device, computer equipment and storage medium - Google Patents

Abstract

The present application relates to a heat production power prediction method, device, computer equipment, storage medium and computer program product. The method includes: obtaining the current temperature and working current intensity of the target battery; determining the first current intensity of thermal side reactions at the electrode interface according to the current temperature and the maximum rated capacity; , to determine the interference current intensity corresponding to the electrochemical reaction at the electrode interface; the interference current intensity indicates the current intensity corresponding to the charged particles that can participate in the thermal side reaction of the electrode interface among the charged particles participating in the electrode interface electrochemical reaction; according to the first current intensity and the interference current Intensity, to predict the second current intensity of the thermal side reaction at the electrode interface; according to the second current intensity, the maximum rated capacity, and the reaction enthalpy of the thermal side reaction at the electrode interface, calculate the heat production power of the thermal side reaction at the electrode interface. The method can improve the prediction accuracy of heat generation power of thermal side reactions at the electrode interface.

Description

Heat generation power prediction method, device, computer equipment and storage medium

Technical Field

The present application relates to the field of battery technology, and in particular to a method, device, computer equipment, storage medium and computer program product for predicting heat generation power.

Background Art

When the battery is under abuse conditions such as overheating, in addition to the electrochemical reaction at the electrode-electrolyte interface (hereinafter referred to as the electrode interface) that originally supports the normal operation of the battery, thermal side reactions that affect the normal operation of the battery will also occur at the electrode interface. The heat accumulation of this thermal side reaction may cause the battery temperature to continue to rise, triggering other side reactions in the battery and ultimately causing irreversible damage to the battery. Therefore, it is necessary to perform thermal modeling, thermal management or thermal design on the battery based on the heat generation power of the thermal side reaction at the electrode interface to reduce the damage to the battery caused by heat accumulation.

In the related art, a thermal side reaction kinetic model based on the Arrhenius equation can be used to predict the heat generation power of the thermal side reaction at the electrode interface. However, the thermal side reaction kinetic model is established for a static battery system, that is, a battery system in a non-working state. When the battery is in a working state, the electrochemical reaction at the electrode interface will have a certain impact on the thermal side reaction at the electrode interface. Therefore, the thermal side reaction kinetic model established for the static battery system has a low accuracy in predicting the heat generation power of the thermal side reaction at the electrode interface, which is not conducive to the accuracy of the thermal modeling, thermal management or thermal design of the battery.

Summary of the invention

Based on this, it is necessary to provide a heat generation power prediction method, device, computer equipment, computer readable storage medium and computer program product that can improve the accuracy of heat generation power prediction of thermal side reactions at electrode interfaces in order to address the above technical problems.

In a first aspect, the present application provides a method for predicting heat generation power. The method comprises:

Obtain the current temperature and current intensity of the target battery in the current working state;

Determine, according to the current temperature and the maximum rated capacity of the target battery, a first current intensity of a thermal side reaction at an electrode interface of the target battery; the first current intensity is an equivalent current intensity corresponding to the movement of charged particles participating in the thermal side reaction at an electrode interface when the target battery is in a non-working state;

Determine the interference current intensity corresponding to the electrochemical reaction at the electrode interface of the target battery according to the current working current intensity and the electrode interface electro-thermal reaction coupling coefficient corresponding to the target battery; the electrode interface electro-thermal reaction coupling coefficient represents the proportion of charged particles that can participate in thermal side reactions at the electrode interface among the charged particles participating in the electrochemical reaction at the electrode interface when the target battery is in a working state; the interference current intensity represents the current intensity corresponding to the charged particles that can participate in thermal side reactions at the electrode interface among the charged particles participating in the electrochemical reaction at the electrode interface;

Predicting a second current intensity of the thermal side reaction at the electrode interface of the target battery according to the first current intensity and the interference current intensity; the second current intensity is an equivalent current intensity corresponding to the movement of charged particles participating in the thermal side reaction at the electrode interface of the target battery in the current working state;

The heat generation power of the thermal side reaction at the electrode interface of the target battery is calculated according to the second current intensity, the maximum rated capacity, and the reaction enthalpy of the thermal side reaction at the electrode interface of the target battery.

In one embodiment, the process of determining the electro-thermal reaction coupling coefficient of the electrode interface corresponding to the target battery includes:

Performing a first calorimetric test on a sample battery in a non-working state, and establishing a corresponding relationship between heat power generated by a thermal side reaction and temperature based on the result of the first calorimetric test; the sample battery is a battery with the same material composition as the target battery;

Performing a second calorimetric test on the sample battery at a plurality of working current intensities, and establishing a corresponding relationship between the heat generation power and the temperature of the electrode interface at each working current intensity based on the result of the second calorimetric test;

Based on the working current intensity of the sample battery, the reaction enthalpy of the thermal side reaction at the electrode interface of the sample battery, the electrode interface resistance of the sample battery, and the maximum rated capacity of the sample battery, a relationship between the heat generation power at the electrode interface and the heat generation power of the thermal side reaction and the electro-thermal reaction coupling coefficient at the electrode interface is established;

Based on the correspondence between the heat generation power of the thermal side reaction and the temperature, the correspondence between the heat generation power of the electrode interface and the temperature under each of the working current intensities, and the relationship between the heat generation power of the electrode interface, the heat generation power of the thermal side reaction and the electro-thermal reaction coupling coefficient of the electrode interface, the electro-thermal reaction coupling coefficient of the electrode interface corresponding to the target battery is determined.

In one embodiment, the method further comprises:

The heat generation power of the electrochemical reaction at the electrode interface of the target battery is calculated according to the electrode interface resistance of the target battery and the current working current intensity.

In one embodiment, determining the first current intensity of the thermal side reaction at the electrode interface of the target battery according to the current temperature and the maximum rated capacity of the target battery includes:

According to the current temperature, a first electron concentration instantaneous decrease rate of the electrode interface thermal side reaction of the target battery is calculated by using a kinetic model of the electrode interface thermal side reaction corresponding to the target battery, which is pre-established based on the Arrhenius equation; the first electron concentration instantaneous decrease rate is a rate of decrease of the electron concentration in the electrode active material caused by the movement of charged particles participating in the electrode interface thermal side reaction when the target battery is in a non-working state;

The maximum rated capacity and the first electron concentration instantaneous decrease rate are multiplied to obtain a first current intensity of a thermal side reaction at an electrode interface of the target battery.

In one embodiment, the calculating the heat generation power of the thermal side reaction at the electrode interface of the target battery according to the second current intensity, the maximum rated capacity, and the reaction enthalpy of the thermal side reaction at the electrode interface of the target battery includes:

Calculating the ratio of the second current intensity to the maximum rated capacitance to obtain a second electron concentration instantaneous decrease rate of the thermal side reaction at the electrode interface of the target battery; the second electron concentration instantaneous decrease rate is a rate of decrease of the electron concentration in the electrode active material caused by the movement of charged particles participating in the thermal side reaction at the electrode interface of the target battery under the current working state;

The heat generation power of the thermal side reaction at the electrode interface of the target battery is obtained by multiplying the second electron concentration instantaneous decrease rate by the reaction enthalpy of the thermal side reaction at the electrode interface of the target battery.

In one embodiment, determining the interference current intensity corresponding to the electrochemical reaction at the electrode interface of the target battery according to the current working current intensity and the electrode interface electro-thermal reaction coupling coefficient corresponding to the target battery includes:

The current working current intensity is multiplied by the electrode interface electro-thermal reaction coupling coefficient corresponding to the target battery to obtain the interference current intensity corresponding to the electrochemical reaction of the electrode interface of the target battery.

In a second aspect, the present application also provides a heat generation power prediction device. The device comprises:

An acquisition module is used to acquire the current temperature and current working current intensity of the target battery in the current working state;

A first determination module is used to determine a first current intensity of a thermal side reaction at an electrode interface of the target battery according to the current temperature and the maximum rated capacity of the target battery; the first current intensity is an equivalent current intensity corresponding to the movement of charged particles participating in the thermal side reaction at the electrode interface when the target battery is in a non-working state;

A second determination module is used to determine the interference current intensity corresponding to the electrochemical reaction of the electrode interface of the target battery according to the current working current intensity and the electrode interface electro-thermal reaction coupling coefficient corresponding to the target battery; the electrode interface electro-thermal reaction coupling coefficient represents the proportion of charged particles that can participate in thermal side reactions at the electrode interface among the charged particles participating in the electrochemical reaction at the electrode interface when the target battery is in a working state; the interference current intensity represents the current intensity corresponding to the charged particles that can participate in thermal side reactions at the electrode interface among the charged particles participating in the electrochemical reaction at the electrode interface;

A prediction module, used to predict a second current intensity of a thermal side reaction at an electrode interface of the target battery according to the first current intensity and the interference current intensity; the second current intensity is an equivalent current intensity corresponding to the movement of charged particles participating in the thermal side reaction at an electrode interface of the target battery in a current working state;

The first calculation module is used to calculate the heat generation power of the thermal side reaction at the electrode interface of the target battery according to the second current intensity, the maximum rated capacity, and the reaction enthalpy of the thermal side reaction at the electrode interface of the target battery.

In one embodiment, the device further comprises:

A first establishing module is used to perform a first calorimetric test on a sample battery in a non-working state, and establish a corresponding relationship between the heat power generated by the thermal side reaction and the temperature based on the result of the first calorimetric test; the sample battery is a battery with the same material composition as the target battery;

A second establishing module, used to perform a second calorimetric test on the sample battery at a plurality of working current intensities, and establish a corresponding relationship between the heat generation power and the temperature of the electrode interface at each of the working current intensities based on the results of the second calorimetric test;

A third establishment module is used to establish a relationship between the heat generation power of the electrode interface, the heat generation power of the thermal side reaction, and the electro-thermal reaction coupling coefficient of the electrode interface based on the working current intensity of the sample battery, the reaction enthalpy of the thermal side reaction of the electrode interface of the sample battery, the electrode interface resistance of the sample battery, and the maximum rated capacity of the sample battery;

The third determination module is used to determine the electrode interface electro-thermal reaction coupling coefficient corresponding to the target battery based on the corresponding relationship between the heat power generated by the thermal side reaction and the temperature, the corresponding relationship between the heat power generated by the electrode interface and the temperature under each of the working current intensities, and the relationship between the heat power generated by the electrode interface, the heat power generated by the thermal side reaction, and the electro-thermal reaction coupling coefficient of the electrode interface.

In one of the embodiments, the device further includes a second calculation module for calculating the heat generation power of the electrochemical reaction at the electrode interface of the target battery according to the electrode interface resistance of the target battery and the current working current intensity.

In one embodiment, the first determining module is specifically configured to:

According to the current temperature, a first electron concentration instantaneous decrease rate of the thermal side reaction at the electrode interface of the target battery is calculated by using a kinetic model of thermal side reactions at the electrode interface corresponding to the target battery that is pre-established based on the Arrhenius equation; the first electron concentration instantaneous decrease rate is a rate of decrease of electron concentration in electrode active materials caused by the movement of charged particles participating in the thermal side reaction at the electrode interface when the target battery is in a non-working state; and the maximum rated capacity and the first electron concentration instantaneous decrease rate are multiplied to obtain a first current intensity of the thermal side reaction at the electrode interface of the target battery.

In one embodiment, the first computing module is specifically configured to:

The ratio of the second current intensity to the maximum rated capacitance is calculated to obtain the second electron concentration instantaneous decrease rate of the thermal side reaction at the electrode interface of the target battery; the second electron concentration instantaneous decrease rate is the rate of decrease of the electron concentration in the electrode active material caused by the movement of the charged particles participating in the thermal side reaction at the electrode interface of the target battery under the current working state; the second electron concentration instantaneous decrease rate is multiplied by the reaction enthalpy of the thermal side reaction at the electrode interface of the target battery to obtain the heat generation power of the thermal side reaction at the electrode interface of the target battery.

In one embodiment, the second determining module is specifically configured to:

The current working current intensity is multiplied by the electrode interface electro-thermal reaction coupling coefficient corresponding to the target battery to obtain the interference current intensity corresponding to the electrochemical reaction of the electrode interface of the target battery.

In a third aspect, the present application further provides a computer device, wherein the computer device comprises a memory and a processor, wherein the memory stores a computer program, and when the processor executes the computer program, the steps of the method described in the first aspect are implemented.

In a fourth aspect, the present application further provides a computer-readable storage medium, wherein a computer program is stored on the computer-readable storage medium, and when the computer program is executed by a processor, the steps of the method described in the first aspect are implemented.

In a fifth aspect, the present application further provides a computer program product, wherein the computer program product comprises a computer program, and when the computer program is executed by a processor, the steps of the method described in the first aspect are implemented.

The above-mentioned heat generation power prediction method, device, computer equipment, storage medium and computer program product determine the interference current intensity through the current working current intensity of the target battery and the electro-thermal reaction coupling coefficient, and then predict the second current intensity of the thermal side reaction at the electrode interface according to the first current intensity of the thermal side reaction at the electrode interface and the interference current intensity. Wherein, the first current intensity is the equivalent current intensity corresponding to the movement of the charged particles participating in the thermal side reaction at the electrode interface when the target battery is in a non-working state; the electro-thermal reaction coupling coefficient represents the proportion of the charged particles that can participate in the thermal side reaction at the electrode interface among the charged particles participating in the electrochemical reaction at the electrode interface when the target battery is in a working state; the interference current intensity represents the current intensity corresponding to the charged particles that can participate in the thermal side reaction at the electrode interface among the charged particles participating in the electrochemical reaction at the electrode interface; the second current intensity is the equivalent current intensity corresponding to the movement of the charged particles participating in the thermal side reaction at the electrode interface when the target battery is in a current working state. Since the battery will have electrochemical reactions and thermal side reactions at the electrode interface when it is in working state, and the electrochemical reaction will occupy the charged particles (such as electrons) that could originally participate in the thermal side reaction, the second current intensity predicted based on the first current intensity and the interference current intensity is closer to the actual equivalent current intensity of the thermal side reaction at the electrode interface of the target battery in the current working state, and the heat generation power calculated based on the predicted second current intensity is closer to the actual heat generation power of the thermal side reaction at the electrode interface. Therefore, the method has a higher prediction accuracy for the heat generation power of the thermal side reaction at the electrode interface of the battery in the working state, which is conducive to improving the accuracy of the thermal modeling, thermal management or thermal design of the battery, and thus improving the safety of the battery.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG1 is a schematic diagram of a flow chart of a method for predicting heat generation power in one embodiment;

FIG2 is a schematic diagram of the mechanism of electrode interface reaction in one example;

FIG3 is a schematic diagram of an electrode particle microelement in one example;

FIG4 is a schematic diagram of a process for determining an electro-thermal reaction coupling coefficient at an electrode interface in one embodiment;

FIG5 is a schematic diagram of a flow chart of calculating a first current intensity in one embodiment;

FIG6 is a schematic diagram of a process for calculating the heat generation power of thermal side reactions at an electrode interface in one embodiment;

FIG7 is a schematic diagram of simulation results of simulating heat generation behavior of a battery using a heat generation power prediction method in an example;

FIG8 is a structural block diagram of a heat generation power prediction device in one embodiment;

FIG. 9 is a diagram showing the internal structure of a computer device in one embodiment.

DETAILED DESCRIPTION

In order to make the purpose, technical solution and advantages of the present application more clearly understood, the present application is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

First of all, before specifically introducing the technical solutions of the embodiments of the present application, the technical background or technical evolution context on which the embodiments of the present application are based is introduced. When the battery is under abuse conditions such as overheating, in addition to the electrochemical reaction at the electrode-electrolyte interface (hereinafter referred to as the electrode interface) that originally supports the normal operation of the battery, thermal side reactions that affect the normal operation of the battery will also occur at the electrode interface. The working state of the battery includes a discharge state and a charge state. For example, for a lithium battery in a discharged state, the electrochemical reaction at the interface between the negative electrode and the electrolyte is: an oxidation reaction occurs at the negative electrode, lithium ions escape from the negative electrode into the electrolyte, and pass through the electrolyte to the positive electrode, and the corresponding electrons flow from the negative electrode into the external circuit, and the positive electrode receives electrons from the external circuit and undergoes a reduction reaction with the lithium ions in the electrolyte. The thermal side reaction at the interface between the negative electrode and the electrolyte can be: the lithium-embedded negative electrode directly undergoes an oxidation-reduction reaction with the electrolyte to generate byproducts such as lithium carbonate.

The heat generated by the thermal side reactions at the electrode interface may cause the battery temperature to continue to rise, which in turn may trigger other side reactions within the battery and ultimately cause irreversible damage to the battery. Therefore, it is necessary to perform thermal modeling, thermal management or thermal design on the battery based on the heat generation power of the thermal side reactions at the electrode interface to reduce the damage to the battery caused by heat accumulation. For example, the battery can be thermally modeled based on the heat generation power of the thermal side reactions at the electrode interface, and then the corresponding heat dissipation design can be performed for the battery to balance the heat dissipation and heat generation to reduce heat accumulation.

In the related art, a thermal side reaction kinetic model based on the Arrhenius equation can be used to predict the heat generation power of the thermal side reaction at the electrode interface. However, the thermal side reaction kinetic model is established for a static battery system, that is, a battery system in a non-working state. When the battery is in a working state, the electrochemical reaction at its electrode interface will have a certain impact on the thermal side reaction at the electrode interface. Therefore, the thermal side reaction kinetic model established for the static battery system has a low prediction accuracy for the heat generation power of the thermal side reaction at the electrode interface, which is not conducive to the accuracy of the thermal modeling, thermal management or thermal design of the battery. Based on this background, the applicant has proposed a heat generation power prediction method of the present application through long-term research and development and experimental verification, which can improve the accuracy of the heat generation power prediction of the thermal side reaction at the electrode interface when the battery is in a working state, which is conducive to improving the accuracy of the thermal modeling, thermal management or thermal design of the battery, and thus improving the safety of the battery. In addition, it should be noted that the applicant has made a lot of creative work in the discovery of the technical problem of the present application and the technical solutions introduced in the following embodiments.

The heat generation power prediction method provided in the embodiment of the present application can be applied to a terminal to predict the heat generation power of the thermal side reaction of the electrode interface of a real battery or a simulated battery. It is understandable that the method can also be applied to a server, and can also be applied to a system including a terminal and a server, and is implemented through the interaction between the terminal and the server. Among them, the terminal can be but is not limited to various personal computers, laptops, smart phones, tablet computers, Internet of Things devices, etc., and the server can be implemented as an independent server or a server cluster consisting of multiple servers.

In one embodiment, as shown in FIG1 , a heat generation power prediction method is provided, which is described by taking the method applied to a terminal as an example, and includes the following steps:

Step 101, obtaining the current temperature and current working current intensity of the target battery in the current working state.

In implementation, the terminal can obtain the current temperature (which can be recorded as T) and the current working current intensity (which can be recorded as _Ie ) of the target battery in the current working state. Among them, the target battery can be a real battery or a simulated battery simulated by a simulation platform. If it is a real battery, the current temperature and current working current intensity of the target battery in the current working state can be obtained through the battery management system. If it is a simulated battery, the user can set the current temperature and current working current intensity of the battery through the simulation platform on the terminal, and the terminal can obtain the current temperature and current working current intensity from the simulation platform. The current working state of the target battery can be a discharge state or a charging state. If it is a discharge state, the current working current intensity is the discharge current intensity, and if it is a charging state, the current working current intensity is the charging current intensity.

Step 102, determining a first current intensity of a thermal side reaction at an electrode interface of the target battery according to the current temperature and the maximum rated capacity of the target battery.

The first current intensity is an equivalent current intensity corresponding to the movement of charged particles participating in thermal side reactions at the electrode interface when the target battery is in a non-operating state.

)。例如，终端可以根据目标电池的电极材料和电解液材料，确定出目标电池对应的电极界面热副反应类型，然后根据热副反应动力学模型，计算出当前温度下电极界面热副反应的瞬时反应速率，进而根据该瞬时反应速率、以及该热副反应的电子转移数，计算出电极界面热副反应的第一电流强度

。其中，热副反应动力学模型是基于阿伦尼乌斯方程建立的该热副反应类型对应的模型。In practice, if the target battery is a real battery, the maximum rated capacity of the real battery (which can be recorded as CAP) is the performance parameter of the battery, and the terminal can obtain the maximum rated capacity from the pre-stored performance parameters of the target battery; if it is a simulated battery, the maximum rated capacity can be set by the user. Then, the terminal calculates the first current intensity (which can be recorded as ) of the thermal side reaction at the electrode interface of the target battery according to the current temperature T and the maximum rated capacity CAP.

). For example, the terminal can determine the type of thermal side reaction at the electrode interface corresponding to the target battery according to the electrode material and electrolyte material of the target battery, and then calculate the instantaneous reaction rate of the thermal side reaction at the electrode interface at the current temperature according to the thermal side reaction kinetic model, and then calculate the first current intensity of the thermal side reaction at the electrode interface according to the instantaneous reaction rate and the number of electron transfers of the thermal side reaction.

Among them, the thermal side reaction kinetic model is a model corresponding to the thermal side reaction type established based on the Arrhenius equation.

Step 103, determining the interference current intensity corresponding to the electrochemical reaction at the electrode interface of the target battery according to the current working current intensity and the electrode interface electro-thermal reaction coupling coefficient corresponding to the target battery.

Among them, the electrode interface electro-thermal reaction coupling coefficient indicates the proportion of charged particles that can participate in the thermal side reaction of the electrode interface among the charged particles participating in the electrochemical reaction of the electrode interface when the target battery is in the working state. The interference current intensity indicates the current intensity corresponding to the charged particles that can participate in the thermal side reaction of the electrode interface among the charged particles participating in the electrochemical reaction of the electrode interface.

When there are electrochemical reactions and thermal side reactions at the electrode interface at the same time, the electrochemical reaction will occupy charged particles (such as electrons) that can participate in thermal side reactions, so a certain proportion of the electrons participating in the electrochemical reaction are originally electrons that can participate in thermal side reactions. This proportion is defined as the electrode interface electro-thermal reaction coupling coefficient (which can be recorded as η) in this application. The current intensity corresponding to this part of the electrons that can participate in thermal side reactions is the interference current intensity described in this application. The electrode interface electro-thermal reaction coupling coefficient η is related to battery materials (such as electrode materials, electrolyte materials, etc.). The electrode interface electro-thermal reaction coupling coefficient η corresponding to the target battery can be determined in advance by experiments and stored. A detailed description of the process of determining the electrode interface electro-thermal reaction coupling coefficient η will be provided later, which will not be repeated here.

In implementation, the terminal may calculate the interference current intensity corresponding to the electrochemical reaction at the electrode interface of the target battery in the current working state according to the current working current intensity I _e obtained in step 101 and the electrode interface electro-thermal reaction coupling coefficient η corresponding to the target battery stored in advance. For example, the current working current intensity I _e and the electrode interface electro-thermal reaction coupling coefficient η may be multiplied, and the product obtained is the interference current intensity (η·I _e ).

Step 104 , predicting a second current intensity of a thermal side reaction at an electrode interface of a target battery according to the first current intensity and the interference current intensity.

The second current intensity (which may be denoted as I _p ) is the equivalent current intensity corresponding to the movement of charged particles participating in the thermal side reaction at the electrode interface under the current working state of the target battery, that is, the equivalent current intensity corresponding to the movement of electrons actually participating in the thermal side reaction at the electrode interface under the interference of the electrochemical reaction at the electrode interface.

、以及步骤103中得到的干扰电流强度，预测目标电池的电极界面热副反应的第二电流强度I_p，即通过第一电流强度

和干扰电流强度，预测出电极界面热副反应对应的实际的等效电流强度。例如，终端可以计算出第一电流强度

和干扰电流强度(η·I_e)的差值，该差值即为预测出的第二电流强度

。In implementation, the terminal can obtain the first current intensity according to step 102.

, and the interference current intensity obtained in step 103, predict the second current intensity I _p of the thermal side reaction of the electrode interface of the target battery, that is, through the first current intensity

and interference current intensity, predicting the actual equivalent current intensity corresponding to the thermal side reaction at the electrode interface. For example, the terminal can calculate the first current intensity

The difference between the interference current intensity (η·I _e ) and the second current intensity is predicted.

.

Step 105 , calculating the heat generation power of the thermal side reaction at the electrode interface of the target battery according to the second current intensity, the maximum rated capacity, and the reaction enthalpy of the thermal side reaction at the electrode interface of the target battery.

Among them, the reaction enthalpy (which can be recorded as ΔH) of the thermal side reaction at the electrode interface of the target battery can be obtained in advance based on experiments or experience and stored (real battery scenario), or directly set by the user (simulated battery scenario).

In implementation, the terminal may calculate the heat generation power of the thermal side reaction at the electrode interface of the target battery according to the second current intensity _Ip predicted in step 104, the maximum rated capacity CAP of the target battery, and the reaction enthalpy ΔH of the thermal side reaction at the electrode interface. For example, the ratio of the second current intensity _Ip to the maximum rated capacity CAP may be calculated, and then the ratio may be multiplied by the reaction enthalpy ΔH to obtain the heat generation power of the thermal side reaction at the electrode interface.

In the above heat generation power prediction method, the interference current intensity is determined by the current working current intensity of the target battery and the electro-thermal reaction coupling coefficient, and then the second current intensity of the thermal side reaction at the electrode interface is predicted based on the first current intensity of the thermal side reaction at the electrode interface and the interference current intensity. Among them, the first current intensity is the equivalent current intensity corresponding to the movement of the charged particles participating in the thermal side reaction at the electrode interface when the target battery is in a non-working state; the electro-thermal reaction coupling coefficient represents the proportion of the charged particles that can participate in the thermal side reaction at the electrode interface among the charged particles participating in the electrochemical reaction at the electrode interface when the target battery is in a working state; the interference current intensity represents the current intensity corresponding to the charged particles that can participate in the thermal side reaction at the electrode interface among the charged particles participating in the electrochemical reaction at the electrode interface; the second current intensity is the equivalent current intensity corresponding to the movement of the charged particles participating in the thermal side reaction at the electrode interface when the target battery is in the current working state. Since the battery will have electrochemical reactions and thermal side reactions at the electrode interface when it is in working state, and the electrochemical reaction will occupy the charged particles (such as electrons) that could originally participate in the thermal side reaction, the second current intensity predicted based on the first current intensity and the interference current intensity is closer to the actual equivalent current intensity of the thermal side reaction at the electrode interface of the target battery in the current working state, and the heat generation power calculated based on the predicted second current intensity is closer to the actual heat generation power of the thermal side reaction at the electrode interface. Therefore, the method has a higher prediction accuracy for the heat generation power of the thermal side reaction at the electrode interface of the battery in the working state, which is conducive to improving the accuracy of the thermal modeling, thermal management or thermal design of the battery, and thus improving the safety of the battery.

The following is the theoretical derivation process of this scheme, which proves that the second current intensity of the thermal side reaction at the electrode interface can be accurately predicted by the first current intensity and the interference current intensity of the thermal side reaction at the electrode interface.

When there are electrochemical reactions and thermal side reactions at the electrode-electrolyte interface of the battery at the same time, the rate or intensity of the two reactions can be described by the interface current caused by the reaction. As shown in FIG2 , the interface current caused by the electrochemical reaction is I _e (corresponding to the working current intensity of the battery), and the interface current caused by the thermal side reaction (or thermochemical reaction) is I _p (corresponding to the second current intensity of the thermal side reaction at the electrode interface). The equations will be established below to describe I _e and I _p . The microelement method can be used for analysis. Taking a microelement of a battery in a discharged state and a negative electrode active material particle of the battery as an example, as shown in FIG3 , the volume of the microelement is dV, and the surface area of the microelement is dS. The battery system in a charged state and the principle of the battery positive electrode interface reaction are similar, and will not be repeated here.

The amount of electrons in the microelement that can participate in the reaction (including thermal side reactions and electrochemical reactions) is expressed as Q. The total decrease rate of the amount of electrons in the microelement caused by the two reactions can be expressed as:

为该微元中由热副反应导致的电子电量下降率，

为该微元中由电化学反应导致的电子电量下降率。In the formula,

is the electron charge decrease rate caused by thermal side reactions in the microelement,

is the rate of decrease of electron charge in the microelement caused by the electrochemical reaction.

Among them, the decrease rate of the electron charge in the microelement caused by the thermal side reaction can be expressed as:

Where _jP is the interfacial current density actually caused by the thermal side reaction on the surface of the microelement, that is, the equivalent interfacial current density corresponding to the movement of electrons participating in the thermal side reaction on the surface of the microelement, and dS is the surface area of the microelement.

The rate of decrease of the electron charge caused by the electrochemical reaction can be expressed as:

Where, _je is the interfacial current density caused by the electrochemical reaction on the surface of the microelement.

The electron charge Q in the microelement can also be expressed by the electron concentration c (normalized concentration, initial concentration is 1) that can participate in the reaction (including electrochemical reaction and thermal side reaction) in the microelement and the capacitance cap that can participate in the reaction stored per unit volume in the microelement, the formula is as follows:

Q＝c·cap·dV (4)

Then the total decrease rate of the electron charge caused by the reaction in the microelement can also be expressed as:

表示该微元中由反应(包括电化学反应和热副反应)导致的电子浓度下降率。In the formula,

It represents the electron concentration decrease rate caused by reactions (including electrochemical reactions and thermal side reactions) in the microelement.

Therefore, the decrease rate of the electron charge in the microelement caused by the thermal side reaction can also be expressed as:

The rate of decrease of the electron charge caused by the electrochemical reaction can also be expressed as:

为热副反应导致的电子浓度下降率，

为电化学反应导致的电子浓度下降率。In the formula,

is the electron concentration decrease rate caused by thermal side reactions,

is the rate of decrease of electron concentration caused by electrochemical reaction.

，该微元中的电子电量的下降率仅为由热副反应导致的电子电量下降率，联立公式(1)、(2)、(6)，可得到如下公式：When the battery is in a non-working state, no electrochemical reaction occurs at the battery interface, only thermal side reactions occur, i.e.

, the decrease rate of the electron charge in this microelement is only the decrease rate of the electron charge caused by the thermal side reaction. Combining formulas (1), (2), and (6), we can get the following formula:

表示电池在非工作状态下、由热副反应导致的电子浓度下降率，

表示电池在非工作状态下、由热副反应导致的界面电流密度。in,

It indicates the rate of decrease of electron concentration caused by thermal side reactions when the battery is not working.

It indicates the interfacial current density caused by thermal side reactions when the battery is not working.

的计算公式：According to formula (8), the interfacial current density caused by the thermal side reaction at the electrode interface when the battery is not working can be obtained:

The calculation formula is:

可由式(12)计算，式(10)至(12)可称为电极界面热副反应动力学模型。According to reaction thermodynamics, the thermal side reaction in the battery follows the Arrhenius law. The electron concentration decrease rate caused by the thermal side reaction can be calculated using equations (10) and (11). At this time, the heat generation power of the thermal side reaction is

It can be calculated by formula (12). Formulas (10) to (12) can be called the electrode interface thermal side reaction kinetic model.

f(c)＝(1-c) ⁿ (11)

Where A is the forward factor of the thermal side reaction, E _a is the reaction activation energy, R ⁰ =8.314 J·mol ^-1 ·K ^-1 is the ideal gas constant, and T is the battery temperature (specifically the temperature of the electrode interface). f(c) is the reaction rate function, which usually follows the exponential law in formula (11), and other calculation methods can also be used. ΔH is the reaction enthalpy of the thermal side reaction. Parameters A, E _a , ΔH, and n can be measured based on experience or experiments.

的计算公式：Combining equations (9) and (10), we can obtain the interfacial current density caused by the thermal side reaction at the electrode interface when the battery is not working:

The calculation formula is:

When the battery is in working state, the electrochemical reaction will occupy the electrons that could originally participate in the thermal side reaction, that is, part of the interface current density j _e caused by the electrochemical reaction on the surface of the microelement is contributed by the electrons that could originally participate in the thermal side reaction. The proportion of the electrons that could originally participate in the thermal side reaction among the electrons that participate in the electrochemical reaction is the electrode interface electro-thermal reaction coupling coefficient η. The interface current density caused by the electrons that could originally participate in the thermal side reaction among the electrons that participate in the electrochemical reaction can be recorded as η· _je . The interface current density j _P caused by the electrons that actually participate in the thermal side reaction can be calculated by the following formula:

的计算公式：According to equations (2) and (6), the actual electron concentration decrease rate caused by thermal side reactions can be obtained:

The calculation formula is:

可表示为：Assuming that the negative electrode active material particles of the battery are uniform particles, that is, the internal electron concentration c and the ability to accommodate electrons everywhere in the particles are equal, that is, the capacitance per unit volume cap is the same everywhere, then the interface current density j _e and j _P on the particle surface are also the same everywhere. By integrating equation (15), the actual electron concentration decrease rate caused by thermal side reactions at the negative electrode interface is

It can be expressed as:

CAP＝cap·V (17)

Wherein, V is the volume of the negative electrode active material particles, S is its surface area, and CAP is the maximum capacity of the negative electrode active material (equivalent to the maximum rated capacity of the battery).

According to the definition of current intensity (the amount of electricity passing through the conductor cross section per unit time), and by integrating equation (2), combined with equation (16), it can be known that the current intensity I _p actually caused by the thermal side reaction at the negative electrode interface (corresponding to the second current intensity of the thermal side reaction at the electrode interface) can be expressed as:

According to the definition of current intensity and by integrating equations (3) and (7), it can be seen that the current intensity (corresponding to the working current intensity of the battery) _Ie caused by the electrochemical reaction at the negative electrode interface can be expressed as:

Combining formulas (14), (18) and (19), we can obtain:

，对应于电极界面热副反应的第一电流强度)可以表示为：According to the definition of current intensity and integrating equation (8), we can know that the current intensity caused by thermal side reactions at the negative electrode interface when the battery is not in operation (which can be expressed as

, corresponding to the first current intensity of the thermal side reaction at the electrode interface) can be expressed as:

Therefore, combining equations (20) and (21), we can obtain:

和干扰电流强度(η·I_e)，准确地预测出电极界面热副反应的第二电流强度I_p。Therefore, the first current intensity of the thermal side reaction at the electrode interface can be

and interference current intensity (η·I _e ), and accurately predict the second current intensity I _p of the thermal side reaction at the electrode interface.

In addition, for the working current intensity of the battery, the current rate C _rate can be used to quantitatively describe the applied current. The current rate C _rate satisfies the following formula:

According to equations (19) and (23), we can get:

In one embodiment, as shown in FIG. 4 , a process for determining the electro-thermal reaction coupling coefficient η of the electrode interface corresponding to a target battery is provided, which specifically includes the following steps:

Step 401 : performing a first calorimetric test on a sample battery in a non-operating state, and establishing a corresponding relationship between heat generation power of a thermal side reaction and temperature based on the result of the first calorimetric test.

The sample battery is a battery with the same material composition as the target battery. For example, a commercial battery of the same model as the target battery can be directly used as the sample battery, or a sample battery can be prepared based on the same material components as the target battery. The sample battery can be a button battery. In order to facilitate the experiment and improve the experimental efficiency, the sample battery can also be assembled with the same components as the key components of the target battery (such as electrode active materials and electrolyte).

In implementation, the terminal can control the calorimetric equipment (such as a microcalorimeter, an adiabatic calorimeter, etc.) to perform a first calorimetric test on the sample battery in a non-working state. Specifically, it can be a scanning calorimetric test on the sample battery at a preset heating rate, and the heating can be stopped when the temperature rises to the preset temperature value. The preset heating rate and the preset temperature value can be set according to experiments or experience. The preset temperature value is generally related to the material of the battery and can be set to 180°C. According to the first calorimetric test, multiple temperature data at a preset heating rate and the heat generation power corresponding to each temperature data (i.e., the result of the first calorimetric test) can be obtained. Since the battery is in a non-working state, the heat generation power measured at this time is mainly the heat generation power of the thermal side reaction at the electrode interface. Then, the terminal can establish a corresponding relationship between the heat generation power of the thermal side reaction and the temperature according to the result of the first calorimetric test (i.e., the heat generation power corresponding to each temperature data). For example, the heat generation power-temperature relationship curve P _O (T) of the thermal side reaction can be fitted according to the heat generation power corresponding to each temperature data. Generally, the temperature T ranges from 50 to 180°C.

Step 402 , performing a second calorimetric test on the sample battery at a plurality of working current intensities, and establishing a corresponding relationship between the heat generation power and the temperature of the electrode interface at each working current intensity based on the result of the second calorimetric test.

In implementation, the terminal can perform a second calorimetric test on the sample battery at multiple working current intensities. For example, the terminal can control the calorimetric device to heat the sample battery and record the temperature data, and control the sample battery to charge or discharge at the first working current intensity when each preset temperature value is reached, and measure the heat generation power corresponding to the preset temperature value through the calorimetric device. The heat generation power measured at this time is mainly the sum of the heat generation power of the thermal side reaction of the electrode interface and the heat generation power (i.e. Joule heat) of the electrochemical reaction of the electrode interface, which can be called the electrode interface heat generation power. Each preset temperature value can be a plurality of temperature values between 50-180°C. Each time a preset temperature value is reached, the sample battery is controlled to charge or discharge at the first working current intensity. Then, a calorimetric test is performed on the sample battery at the second working current intensity to obtain calorimetric test results at multiple working current intensities. The temperature data and the corresponding heat generation power at each working current intensity are the second calorimetric test results. The working current intensity can be described by the current rate (see formula (23)), and the current rate can be set between 0C-8C (unit h ^-1 ). Optionally, before performing the second calorimetric test on the sample battery, the sample battery can be charged to a full-charged state (which can be equivalent to reaching the maximum rated capacity) to perform the second calorimetric test in the fully-charged state. It can be understood that multiple sample batteries can be used, and each sample battery can be subjected to a calorimetric test at a certain working current intensity at the same time. For example, 5 sample batteries can be heated at the same time. When heated to a preset temperature value, the 5 sample batteries are controlled to discharge at current rates of 0.1C, 0.5C, 1C, 5C, and 10C, respectively, and the heat generation power corresponding to each sample battery is measured, thereby simultaneously obtaining temperature data and corresponding heat generation power at 5 working current intensities to improve the test efficiency.

为电流倍率C_rate-i下的电极界面产热功率-温度关系曲线，一般温度T的范围为50-180℃。Then, the terminal can establish the corresponding relationship between the heat generation power and temperature of the electrode interface at each working current intensity according to the results of the second calorimetric test (i.e., the temperature data and the corresponding heat generation power at each working current intensity). For example, the heat generation power-temperature relationship curve of the electrode interface at each current rate can be fitted according to the temperature data and the corresponding heat generation power at each current rate.

This is the heat generation power-temperature relationship curve of the electrode interface under the current rate C _rate-i . The general temperature T ranges from 50 to 180°C.

Step 403, based on the working current intensity of the sample battery, the reaction enthalpy of the thermal side reaction of the electrode interface of the sample battery, the electrode interface resistance of the sample battery, and the maximum rated capacity of the sample battery, a relationship between the heat generation power of the electrode interface and the heat generation power of the thermal side reaction and the electro-thermal reaction coupling coefficient of the electrode interface is established.

和电极界面电-热反应耦合系数η的关系式，其中，热副反应产热功率

为电池在非工作状态时、电极界面热副反应的产热功率。在一个示例中，该关系式如下所示：In implementation, the terminal can establish the electrode interface heat generation power P and the thermal side reaction heat generation power based on the working current intensity _Ie of the sample battery, the reaction enthalpy ΔH of the thermal side reaction of the electrode interface of the sample battery, the electrode interface resistance _RSEI of the sample battery, and the maximum rated capacity CAP of the sample battery.

and the electrode interface electro-thermal reaction coupling coefficient η, where the heat generation power of the thermal side reaction

is the heat generation power of the thermal side reaction at the electrode interface when the battery is not in operation. In an example, the relationship is as follows:

The following is the derivation process of this relationship:

The heat generation power P of the electrode interface satisfies the following formula:

P＝ _PP + _Pe (26)

Where P _P is the actual heat generation power of the thermal side reaction at the electrode interface under the interference of electrochemical translation, and _Pe is the heat generation power of the electrochemical reaction at the electrode interface.

Referring to formula (12), the actual heat generation power _Pp of the thermal side reaction at the electrode interface satisfies the following formula:

According to formula (14), formula (16) and formula (27), we can get

The heat generation power p _e of the electrochemical reaction at the electrode interface satisfies the following formula:

_Pe = _Ie2 ^· _RSEI (29)

Combining formulas (9), (12), (26), (28), and (29), we can obtain:

That is, we get the relationship shown in formula (25).

Step 404, based on the correspondence between the heat power generated by the thermal side reaction and the temperature, the correspondence between the heat power generated by the electrode interface and the temperature at each working current intensity, and the relationship between the heat power generated by the electrode interface, the heat power generated by the thermal side reaction and the electro-thermal reaction coupling coefficient of the electrode interface, determine the electro-thermal reaction coupling coefficient of the electrode interface corresponding to the target battery.

In implementation, the terminal can determine the electrode interface electro-thermal reaction coupling coefficient corresponding to the target battery based on the correspondence between the heat power generated by the thermal side reaction and the temperature established in step 401, the correspondence between the heat power generated by the electrode interface and the temperature under each working current intensity established in step 402, and the relationship between the heat power generated by the electrode interface, the heat power generated by the thermal side reaction, and the electro-thermal reaction coupling coefficient of the electrode interface established in step 403.

。以及，终端可以在电流倍率C_rate-i下的电极界面产热功率-温度关系曲线

得到电流倍率C_rate-i、及温度T_j下的电极界面产热功率

作为关系式(25)中的电极界面产热功率P，并根据电流倍率C_rate-i和最大额定电容量CAP计算得到工作电流强度I_e-i，作为关系式(25)中的工作电流强度I_e。For example, the terminal can obtain the heat generation power P _O (T j ) at temperature T _j according to the heat generation power-temperature relationship curve P _O ( _T ), as in equation (25), the heat generation power of the thermal side reaction of the battery at temperature T _j and in a non-operating state is

. And, the terminal can generate heat at the electrode interface under the current rate C _rate-i power-temperature relationship curve

Get the current rate C _rate-i and the electrode interface heat generation power at temperature T _j

As the electrode interface heat generation power P in the relationship (25), the working current intensity I _ei is calculated according to the current rate C _rate-i and the maximum rated capacity CAP, and is used as the working current intensity I _e in the relationship (25).

Therefore, according to the relationship (25) established in step 403, the following formula can be obtained:

、以及公式(34)，拟合出温度T_j下的电极界面电-热反应耦合系数η(T_j)，得到样本电池在多个温度下的电极界面电-热反应耦合系数η(T)。Then, the terminal can generate heat power-temperature relationship curve P _O (T) of the thermal side reaction heat generation based on the step 401, the electrode interface heat generation power-temperature relationship curve under each working current intensity I _ei (corresponding to the current rate C _rate-i ) established in step 402, and the electrode interface heat generation power-temperature relationship curve

, and formula (34), the electrode interface electro-thermal reaction coupling coefficient η(T _j ) at temperature T _j is fitted, and the electrode interface electro-thermal reaction coupling coefficient η(T) of the sample battery at multiple temperatures is obtained.

Then, the terminal can calculate the average value of the electrode interface electro-thermal reaction coupling coefficient η(T) of the sample battery at multiple temperatures, and determine the average value as the electrode interface electro-thermal reaction coupling coefficient η corresponding to the target battery. The terminal can also establish a corresponding relationship between the electrode interface electro-thermal reaction coupling coefficient η and the temperature T, and then the terminal can determine the electrode interface electro-thermal reaction coupling coefficient η of the target battery at the current temperature based on the corresponding relationship.

The electrode interface electro-thermal reaction coupling coefficient η obtained according to this embodiment can accurately reflect the degree of interference of the electrochemical reaction on the thermal side reaction when the target battery is in a working state, and thus can more accurately predict the equivalent current intensity corresponding to the movement of charged particles participating in the thermal side reaction of the electrode interface in the current working state of the target battery, thereby improving the prediction accuracy of the heat generation power of the thermal side reaction of the electrode interface.

In one embodiment, the method further includes a Joule heat calculation step: calculating the heat generation power of the electrochemical reaction at the electrode interface of the target battery according to the electrode interface resistance of the target battery and the current working current intensity.

In implementation, the terminal can calculate the heat generation power _Pe of the electrochemical reaction at the electrode interface of the target battery according to the electrode interface resistance R _SEI and the current working current intensity I _e of the target battery (as shown in the above formula (29)). Thus, the electrode interface heat generation power P can be calculated according to the heat generation power _Pe of the electrochemical reaction at the electrode interface and the actual heat generation power P _P of the thermal side reaction at the electrode interface (as shown in the above formula (26)).

The heat generation power P of the electrode interface calculated in this embodiment is closer to the actual heat generation power of the electrode system, that is, this method can more accurately predict the heat generation power of the battery in different electrochemical processes (such as at different current rates), which is of great significance to the thermal modeling, thermal management, and thermal design applications of the battery.

In one embodiment, as shown in FIG. 5 , the method for determining the first current intensity of the thermal side reaction at the electrode interface in step 102 specifically includes the following steps:

Step 501, according to the current temperature, using the electrode interface thermal side reaction kinetic model corresponding to the target battery established in advance based on the Arrhenius equation, calculate the instantaneous decrease rate of the first electron concentration of the electrode interface thermal side reaction of the target battery.

。其中，第一电子浓度瞬时下降率

为目标电池在非工作状态下、参与电极界面热副反应的带电粒子的运动导致的电极材料中电子浓度的下降速率。In implementation, the terminal can calculate the instantaneous decrease rate of the first electron concentration of the thermal side reaction at the electrode interface of the target battery according to the current temperature T, using the electrode interface thermal side reaction kinetic model (such as the aforementioned equations (10) to (12)) that is pre-established based on the Arrhenius equation. Specifically, the terminal can substitute the current temperature T into equation (10) to calculate the instantaneous decrease rate of the first electron concentration of the thermal side reaction at the electrode interface of the target battery.

Among them, the instantaneous decrease rate of the first electron concentration is

It is the rate of decrease of electron concentration in the electrode material caused by the movement of charged particles participating in thermal side reactions at the electrode interface when the target battery is not in operation.

Step 502: multiply the maximum rated capacity and the first electron concentration instantaneous decrease rate to obtain a first current intensity of a thermal side reaction at an electrode interface of a target battery.

Among them, by integrating the above formula (9) and combining formula (21), the following formula is obtained:

相乘，即得到电极界面热副反应的第一电流强度

。Therefore, in implementation, the terminal can set the maximum rated capacity CAP and the first electron concentration instantaneous decrease rate

Multiply them to get the first current intensity of the thermal side reaction at the electrode interface.

.

In one embodiment, as shown in FIG. 6 , the process of calculating the heat generation power of the thermal side reaction at the electrode interface in step 105 specifically includes the following steps:

Step 601, calculating the ratio of the second current intensity to the maximum rated capacitance to obtain the instantaneous decrease rate of the second electron concentration of the thermal side reaction at the electrode interface of the target battery.

The second electron concentration decrease rate is the rate of decrease of the electron concentration in the electrode material caused by the movement of charged particles participating in the thermal side reaction at the electrode interface under the current working state of the target battery.

In implementation, based on the definition of current intensity and the above formula (16), the following formula can be obtained:

。Therefore, the terminal can substitute the second current intensity _Ip and the maximum rated capacity CAP into formula (36) to calculate the ratio of the two and obtain the instantaneous decrease rate of the second electron concentration of the thermal side reaction at the electrode interface of the target battery:

.

Step 602 , multiplying the second electron concentration instantaneous decrease rate and the reaction enthalpy of the thermal side reaction at the electrode interface of the target battery to obtain the heat generation power of the thermal side reaction at the electrode interface of the target battery.

和目标电池的电极界面热副反应的反应焓ΔH，即根据公式(27)，计算得到目标电池的电极界面热副反应的产热功率P_P。In the implementation, the terminal will be the second electron concentration instantaneous decrease rate

and the reaction enthalpy ΔH of the thermal side reaction at the electrode interface of the target battery, that is, according to formula (27), the heat generation power P _P of the thermal side reaction at the electrode interface of the target battery is calculated.

The heat generation power prediction methods provided in the above embodiments can be applied to simulate and predict the heat generation behavior of the battery in different electrochemical processes, so as to predict the heat generation performance of the battery system in different electrochemical processes.

In a simulation example, the heat generation power of the battery system in the constant power heating mode can be simulated and predicted to predict the temperature of the battery system. In the constant power heating mode, the temperature rise of the battery system (specifically the temperature rise of the negative electrode active material particles) comes from its own heat generation power, heating power and heat exchange power. The temperature T of the electrode active material particles at time t can be calculated by equations (37) to (40).

P _ALL ＝P _P +P _e +P _H -P _D (39)

P _D (t)＝h _partial ·A _partial ·(TT _env ) (40)

Wherein, _Pe is the heat generation power of the electrochemical reaction at the electrode interface, P _P is the actual heat generation power of the thermal side reaction at the electrode interface, which can be calculated according to the heat generation power prediction method in the above-mentioned embodiment; P _H is the heating power, which is set to 0.2 mW in this simulation example; P _D is the heat exchange power (or heat dissipation power), which can be calculated according to formula (40). Wherein, h _partical is the heat exchange coefficient between the negative electrode active material particles and the environment, which is set to 0.01 W·K ^-1 ·m ^-2 in this simulation example; A _partical is the heat exchange area between the negative electrode active material particles and the environment, which is calculated with the particles as squares in this simulation example, and the particle surface area corresponding to 1g of material is about 2.118 cm ² ; T _env is the ambient temperature, which is set to 25°C in this simulation example. C _h is the specific heat capacity, T ₀ is the starting temperature, and the discharge current is applied when the temperature rises to 40°C in this example. The specific values of the relevant parameters are shown in Table 1, assuming that the mass of the negative electrode active material particles in the simulated battery system is 1g, and the electrode interface electric-thermal reaction coupling coefficient η of the battery system is 1. Under the heating and heat dissipation power conditions in this example, the thermal equilibrium temperature of the negative electrode active material particles is about 120°C.

Table 1 Parameter value table

The simulation results of this simulation example are shown in Figure 7. It can be seen that applying different discharge current rates (i.e., different discharge current intensities) to the negative electrode active material particles will affect the reaction rate and heat generation behavior of the negative electrode active material particles during the constant power heating thermal failure process. As the applied discharge current rate increases, the maximum temperature of the battery during the thermal failure process first decreases and then increases. According to Figure 7, at a 0C rate discharge current, that is, when the battery is in a non-working state, only the electrode interface thermal side reaction occurs at the interface, and the maximum temperature of the negative electrode active material particles can reach about 170°C, and then slowly decreases to the heating-heat dissipation equilibrium temperature (about 120°C) due to heat dissipation; the discharge current within the range of 0.01C to 0.1C can effectively inhibit the heat generation of the electrode interface thermal side reaction, and the particles slowly heat up to the heating and heat dissipation equilibrium temperature (about 120°C) under constant power heating conditions; continuing to increase the discharge current rate to 5C or 10C, the temperature will rise instantly after the short-circuit current is connected due to the influence of Joule heat, and the maximum temperature of the particles can reach about 200°C, which is not conducive to the thermal stability of the battery. The above simulation results show that the discharge current in the range of 0.01C to 0.1C can effectively inhibit the thermal side reactions at the electrode interface, improve the thermal stability of the battery, and increase the discharge rate. On the contrary, the thermal failure hazard of the battery increases due to the effect of Joule heat.

It should be understood that, although the various steps in the flowcharts involved in the above-mentioned embodiments are displayed in sequence according to the indication of the arrows, these steps are not necessarily executed in sequence according to the order indicated by the arrows. Unless there is a clear explanation in this article, the execution of these steps does not have a strict order restriction, and these steps can be executed in other orders. Moreover, at least a part of the steps in the flowcharts involved in the above-mentioned embodiments can include multiple steps or multiple stages, and these steps or stages are not necessarily executed at the same time, but can be executed at different times, and the execution order of these steps or stages is not necessarily carried out in sequence, but can be executed in turn or alternately with other steps or at least a part of the steps or stages in other steps.

Based on the same inventive concept, the embodiment of the present application also provides a heat generation power prediction device for implementing the heat generation power prediction method involved above. The implementation scheme for solving the problem provided by the device is similar to the implementation scheme recorded in the above method, so the specific limitations in one or more heat generation power prediction device embodiments provided below can refer to the limitations of the heat generation power prediction method above, and will not be repeated here.

In one embodiment, as shown in FIG8 , a heat generation power prediction device 800 is provided, comprising: an acquisition module 801, a first determination module 802, a second determination module 803, a prediction module 804 and a first calculation module 805, wherein:

The acquisition module 801 is used to acquire the current temperature and current working current intensity of the target battery in the current working state.

The first determination module 802 is used to determine the first current intensity of the thermal side reaction at the electrode interface of the target battery according to the current temperature and the maximum rated capacity of the target battery; the first current intensity is the equivalent current intensity corresponding to the movement of charged particles participating in the thermal side reaction at the electrode interface when the target battery is in a non-working state.

The second determination module 803 is used to determine the interference current intensity corresponding to the electrochemical reaction of the electrode interface of the target battery according to the current working current intensity and the electrode interface electro-thermal reaction coupling coefficient corresponding to the target battery; the electrode interface electro-thermal reaction coupling coefficient represents the proportion of charged particles that can participate in thermal side reactions at the electrode interface among the charged particles participating in the electrochemical reaction at the electrode interface when the target battery is in a working state; the interference current intensity represents the current intensity corresponding to the charged particles that can participate in thermal side reactions at the electrode interface among the charged particles participating in the electrochemical reaction at the electrode interface.

The prediction module 804 is used to predict the second current intensity of the thermal side reaction at the electrode interface of the target battery based on the first current intensity and the interference current intensity; the second current intensity is the equivalent current intensity corresponding to the movement of charged particles participating in the thermal side reaction at the electrode interface of the target battery under the current working state.

The first calculation module 805 is used to calculate the heat generation power of the thermal side reaction at the electrode interface of the target battery according to the second current intensity, the maximum rated capacity, and the reaction enthalpy of the thermal side reaction at the electrode interface of the target battery.

In one embodiment, the device further includes a first establishing module, a second establishing module, a third establishing module and a third determining module, wherein:

The first establishment module is used to perform a first calorimetric test on the sample battery in a non-working state, and establish a corresponding relationship between the heat power generated by the thermal side reaction and the temperature based on the result of the first calorimetric test; the sample battery is a battery with the same material composition as the target battery.

The second establishing module is used to perform a second calorimetric test on the sample battery at multiple working current intensities, and establish a corresponding relationship between the heat generation power and the temperature of the electrode interface at each working current intensity based on the result of the second calorimetric test.

The third establishment module is used to establish a relationship between the heat generation power of the electrode interface, the heat generation power of the thermal side reaction, and the electro-thermal reaction coupling coefficient of the electrode interface based on the working current intensity of the sample battery, the reaction enthalpy of the thermal side reaction of the electrode interface of the sample battery, the electrode interface resistance of the sample battery, and the maximum rated capacity of the sample battery.

The third determination module is used to determine the electrode interface electro-thermal reaction coupling coefficient corresponding to the target battery based on the corresponding relationship between the heat generation power of the thermal side reaction and the temperature, the corresponding relationship between the heat generation power of the electrode interface and the temperature under each working current intensity, and the relationship between the heat generation power of the electrode interface, the heat generation power of the thermal side reaction, and the electro-thermal reaction coupling coefficient of the electrode interface.

In one embodiment, the device further includes a second calculation module for calculating the heat generation power of the electrochemical reaction at the electrode interface of the target battery according to the electrode interface resistance of the target battery and the current working current intensity.

In one embodiment, the first determining module 802 is specifically configured to:

According to the current temperature, a kinetic model of electrode interface thermal side reactions corresponding to the target battery, which is pre-established based on the Arrhenius equation, is used to calculate the instantaneous decrease rate of the first electron concentration of the thermal side reactions at the electrode interface of the target battery. The instantaneous decrease rate of the first electron concentration is the rate of decrease of the electron concentration in the electrode active material caused by the movement of charged particles participating in the thermal side reactions at the electrode interface when the target battery is not in a working state. The maximum rated capacity and the instantaneous decrease rate of the first electron concentration are multiplied to obtain the first current intensity of the thermal side reactions at the electrode interface of the target battery.

In one embodiment, the first calculation module 805 is specifically used for:

The ratio of the second current intensity and the maximum rated capacitance is calculated to obtain the instantaneous decrease rate of the second electron concentration of the thermal side reaction at the electrode interface of the target battery; the instantaneous decrease rate of the second electron concentration is the rate of decrease of the electron concentration in the electrode active material caused by the movement of the charged particles participating in the thermal side reaction at the electrode interface of the target battery under the current working state; the instantaneous decrease rate of the second electron concentration and the reaction enthalpy of the thermal side reaction at the electrode interface of the target battery are multiplied to obtain the heat generation power of the thermal side reaction at the electrode interface of the target battery.

In one embodiment, the second determining module 803 is specifically configured to:

The interference current intensity corresponding to the electrochemical reaction at the electrode interface of the target battery is obtained by multiplying the current working current intensity and the electrode interface electro-thermal reaction coupling coefficient corresponding to the target battery.

Each module in the above-mentioned heat generation power prediction device can be implemented in whole or in part by software, hardware and a combination thereof. Each of the above-mentioned modules can be embedded in or independent of a processor in a computer device in the form of hardware, or can be stored in a memory in a computer device in the form of software, so that the processor can call and execute the operations corresponding to each of the above modules.

In one embodiment, a computer device is provided, which may be a terminal, and its internal structure diagram may be shown in FIG9. The computer device includes a processor, a memory, a communication interface, a display screen, and an input device connected via a system bus. Among them, the processor of the computer device is used to provide computing and control capabilities. The memory of the computer device includes a non-volatile storage medium and an internal memory. The non-volatile storage medium stores an operating system and a computer program. The internal memory provides an environment for the operation of the operating system and the computer program in the non-volatile storage medium. The communication interface of the computer device is used to communicate with an external terminal in a wired or wireless manner, and the wireless manner may be implemented through WIFI, a mobile cellular network, NFC (near field communication) or other technologies. When the computer program is executed by the processor, a method for predicting heat generation power is implemented. The display screen of the computer device may be a liquid crystal display screen or an electronic ink display screen, and the input device of the computer device may be a touch layer covered on the display screen, or a key, a trackball or a touch pad provided on the housing of the computer device, or an external keyboard, touch pad or mouse, etc.

Those skilled in the art will understand that the structure shown in FIG. 9 is merely a block diagram of a partial structure related to the solution of the present application, and does not constitute a limitation on the computer device to which the solution of the present application is applied. The specific computer device may include more or fewer components than shown in the figure, or combine certain components, or have a different arrangement of components.

In one embodiment, a computer device is provided, including a memory and a processor, wherein a computer program is stored in the memory, and the processor implements the steps in the above-mentioned method embodiments when executing the computer program.

In one embodiment, a computer-readable storage medium is provided, on which a computer program is stored. When the computer program is executed by a processor, the steps in the above-mentioned method embodiments are implemented.

In one embodiment, a computer program product is provided, including a computer program, which implements the steps in the above method embodiments when executed by a processor.

It should be noted that the user information (including but not limited to user device information, user personal information, etc.) and data (including but not limited to data used for analysis, stored data, displayed data, etc.) involved in this application are all information and data authorized by the user or fully authorized by all parties.

Those of ordinary skill in the art can understand that all or part of the processes in the above-mentioned embodiment methods can be completed by instructing the relevant hardware through a computer program, and the computer program can be stored in a non-volatile computer-readable storage medium. When the computer program is executed, it can include the processes of the embodiments of the above-mentioned methods. Among them, any reference to the memory, database or other medium used in the embodiments provided in the present application can include at least one of non-volatile and volatile memory. Non-volatile memory can include read-only memory (ROM), magnetic tape, floppy disk, flash memory, optical memory, high-density embedded non-volatile memory, resistive random access memory (ReRAM), magnetic random access memory (MRAM), ferroelectric random access memory (FRAM), phase change memory (PCM), graphene memory, etc. Volatile memory can include random access memory (RAM) or external cache memory, etc. As an illustration and not limitation, RAM can be in various forms, such as static random access memory (SRAM) or dynamic random access memory (DRAM). The database involved in each embodiment provided in this application may include at least one of a relational database and a non-relational database. Non-relational databases may include distributed databases based on blockchains, etc., but are not limited to this. The processor involved in each embodiment provided in this application may be a general-purpose processor, a central processing unit, a graphics processor, a digital signal processor, a programmable logic device, a data processing logic device based on quantum computing, etc., but are not limited to this.

The technical features of the above embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

The above-described embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the present application. It should be pointed out that, for a person of ordinary skill in the art, several modifications and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the protection scope of the present application shall be subject to the attached claims.

Claims (10)

1. A method of heat generation power prediction, the method comprising:

acquiring the current temperature and the current working current intensity of a target battery in a current working state;

determining a first current intensity of an electrode interface thermal side reaction of the target battery according to the current temperature and the maximum rated capacitance of the target battery; the first current intensity is equivalent current intensity corresponding to the movement of charged particles participating in electrode interface thermal side reaction when the target battery is in a non-working state;

Determining the interference current intensity corresponding to the electrochemical reaction of the electrode interface of the target battery according to the current working current intensity and the electric-thermal reaction coupling coefficient of the electrode interface corresponding to the target battery; the electrode interface electric-thermal reaction coupling coefficient represents the duty ratio of charged particles which can participate in the electrode interface thermal side reaction among charged particles which participate in the electrode interface electrochemical reaction when the target battery is in a working state; the interference current intensity represents the current intensity corresponding to the charged particles which can participate in the electrode interface thermal side reaction among the charged particles which participate in the electrode interface electrochemical reaction;

predicting a second current intensity of an electrode interface thermal side reaction of the target battery according to the first current intensity and the interference current intensity; the second current intensity is equivalent current intensity corresponding to the movement of charged particles which participate in the electrode interface thermal side reaction of the target battery in the current working state;

calculating the heat generation power of the electrode interface thermal side reaction of the target battery according to the second current intensity, the maximum rated capacitance and the reaction enthalpy of the electrode interface thermal side reaction of the target battery;

The determining process of the electrode interface electric-thermal reaction coupling coefficient corresponding to the target battery comprises the following steps:

performing a first calorimetric test on the sample battery in a non-working state, and establishing a corresponding relation between heat generation power of a thermal side reaction and temperature based on a result of the first calorimetric test; the sample battery is a battery with the same material composition as the target battery;

performing a second calorimetric test on the sample battery under a plurality of working current intensities respectively, and establishing a corresponding relation between the heat generating power and the temperature of an electrode interface under each working current intensity based on the result of the second calorimetric test;

based on the working current intensity of the sample battery, the reaction enthalpy of the thermal side reaction of the electrode interface of the sample battery, the electrode interface resistance of the sample battery and the maximum rated capacitance of the sample battery, establishing a relational expression of the thermal power generated by the electrode interface, the thermal power generated by the thermal side reaction and the electric-thermal reaction coupling coefficient of the electrode interface;

and determining the electrode interface electric-thermal reaction coupling coefficient corresponding to the target battery based on the corresponding relation between the heat generating power of the thermal side reaction and the temperature, the corresponding relation between the heat generating power of the electrode interface and the temperature under the working current intensity, and the relational expression between the heat generating power of the electrode interface and the heat generating power of the thermal side reaction and the electrode interface electric-thermal reaction coupling coefficient.

2. The method according to claim 1, wherein the method further comprises:

and calculating the heat generation power of the electrochemical reaction of the electrode interface of the target battery according to the electrode interface resistance of the target battery and the current working current intensity.

3. The method of claim 1, wherein determining a first amperage of an electrode interface thermal side reaction of the target battery based on the current temperature and a maximum rated capacity of the target battery comprises:

according to the current temperature, calculating a first electron concentration instantaneous drop rate of the electrode interface thermal side reaction of the target battery by adopting an electrode interface thermal side reaction dynamics model which is established in advance based on an Arrhenius equation and corresponds to the target battery; the first electron concentration instantaneous drop rate is the drop rate of the electron concentration in the electrode active material caused by the movement of charged particles participating in the electrode interface thermal side reaction when the target battery is in a non-working state;

multiplying the maximum rated capacitance by the first electron concentration instantaneous drop rate to obtain the first current intensity of the electrode interface thermal side reaction of the target battery.

4. The method of claim 3, wherein calculating the heat generation power of the electrode interface thermal side reaction of the target battery based on the second amperage, the maximum rated capacity, and the reaction enthalpy of the electrode interface thermal side reaction of the target battery comprises:

calculating the ratio of the second current intensity to the maximum rated capacitance to obtain the second electron concentration instantaneous drop rate of the electrode interface thermal side reaction of the target battery; the second electron concentration instantaneous drop rate is the drop rate of the electron concentration in the electrode active material caused by the movement of charged particles which participate in the electrode interface thermal side reaction of the target battery in the current working state;

and multiplying the second electron concentration instantaneous drop rate by the reaction enthalpy of the electrode interface thermal side reaction of the target battery to obtain the heat generation power of the electrode interface thermal side reaction of the target battery.

5. The method of claim 1, wherein determining the disturbance current intensity corresponding to the electrochemical reaction of the electrode interface of the target battery according to the current operation current intensity and the electrode interface electro-thermal reaction coupling coefficient corresponding to the target battery comprises:

Multiplying the current working current intensity by an electrode interface electric-thermal reaction coupling coefficient corresponding to the target battery to obtain an interference current intensity corresponding to the electrode interface electrochemical reaction of the target battery.

6. A heat generation power prediction apparatus, the apparatus comprising:

the acquisition module is used for acquiring the current temperature and the current working current intensity of the target battery in the current working state;

the first determining module is used for determining a first current intensity of an electrode interface thermal side reaction of the target battery according to the current temperature and the maximum rated capacitance of the target battery; the first current intensity is equivalent current intensity corresponding to the movement of charged particles participating in electrode interface thermal side reaction when the target battery is in a non-working state;

the second determining module is used for determining the interference current intensity corresponding to the electrochemical reaction of the electrode interface of the target battery according to the current working current intensity and the electric-thermal reaction coupling coefficient of the electrode interface corresponding to the target battery; the electrode interface electric-thermal reaction coupling coefficient represents the duty ratio of charged particles which can participate in the electrode interface thermal side reaction among charged particles which participate in the electrode interface electrochemical reaction when the target battery is in a working state; the interference current intensity represents the current intensity corresponding to the charged particles which can participate in the electrode interface thermal side reaction among the charged particles which participate in the electrode interface electrochemical reaction;

The prediction module is used for predicting a second current intensity of the electrode interface thermal side reaction of the target battery according to the first current intensity and the interference current intensity; the second current intensity is equivalent current intensity corresponding to the movement of charged particles which participate in the electrode interface thermal side reaction of the target battery in the current working state;

the calculation module is used for calculating the heat generation power of the electrode interface thermal side reaction of the target battery according to the second current intensity, the maximum rated capacitance and the reaction enthalpy of the electrode interface thermal side reaction of the target battery;

the apparatus further comprises:

the first establishing module is used for carrying out a first calorimetric test on the sample battery in a non-working state and establishing a corresponding relation between heat generation power of a thermal side reaction and temperature based on a result of the first calorimetric test; the sample battery is a battery with the same material composition as the target battery;

the second establishing module is used for respectively carrying out a second calorimetric test on the sample battery under a plurality of working current intensities, and establishing the corresponding relation between the heat generating power and the temperature of the electrode interface under each working current intensity based on the result of the second calorimetric test;

The third establishing module is used for establishing a relational expression of the heat generating power of the electrode interface, the heat generating power of the thermal side reaction and the electric-thermal reaction coupling coefficient of the electrode interface based on the working current intensity of the sample battery, the reaction enthalpy of the thermal side reaction of the electrode interface of the sample battery, the electrode interface resistance of the sample battery and the maximum rated capacitance of the sample battery;

and the third determining module is used for determining the electrode interface electric-thermal reaction coupling coefficient corresponding to the target battery based on the corresponding relation between the heat generating power of the thermal side reaction and the temperature, the corresponding relation between the heat generating power of the electrode interface under the working current intensity and the temperature and the relational expression between the heat generating power of the electrode interface, the heat generating power of the thermal side reaction and the electrode interface electric-thermal reaction coupling coefficient.

7. The apparatus of claim 6, wherein the apparatus further comprises:

and the second calculation module is used for calculating the heat generation power of the electrochemical reaction of the electrode interface of the target battery according to the electrode interface resistance of the target battery and the current working current intensity.

8. A computer device comprising a memory and a processor, the memory storing a computer program, characterized in that the processor implements the steps of the method of any one of claims 1 to 5 when the computer program is executed.

9. A computer readable storage medium, on which a computer program is stored, characterized in that the computer program, when being executed by a processor, implements the steps of the method of any of claims 1 to 5.

10. A computer program product comprising a computer program, characterized in that the computer program, when being executed by a processor, implements the steps of the method according to any one of claims 1 to 5.

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