Lithium ion battery positive electrode doping screening method and device

Abstract

The invention provides a lithium ion battery positive electrode doping screening method and device, and the method comprises the steps: firstly, determining an experiment effective doping element and a positive electrode material, and screening to-be-selected elements according to a preset index; then, constructing an LNMO initial model of the positive electrode material, and generating a plurality of first doping models in combination with the to-be-selected elements; then, a second doping model is screened out by calculating the voltage and the volume strain ratio of the battery; then, the doping concentration and the capacity retention ratio are evaluated, and a third doping model is further screened out; and finally, comprehensively considering the synthesis difficulty and the preparation cost of the doping material, and finally determining a target doping model. According to the method and the device, a plurality of key factors including voltage, strain, concentration, capacity, cost and the like can be comprehensively considered, and the optimal doping scheme is efficiently screened out, so that the energy density and the structural stability of the lithium ion battery positive electrode material are improved, and the requirement of a high-performance battery is met.

Description

Technical Field

[0001] The present application relates to the technical field of lithium batteries, and in particular to a method and device for screening doping of positive electrodes of lithium-ion batteries. Background Art

[0002] Manganese-containing positive electrode materials, especially LNMO, show great potential in the field of lithium-ion batteries, especially in electric vehicles and energy storage systems, due to their high energy density and high operating voltage of about 4.7V. However, LNMO is prone to volume strain and crystal structure collapse during the cycle, resulting in battery performance degradation. To solve this problem, doping technology is usually used to adjust the material properties by introducing other elements to replace part of the nickel or manganese. In the prior art, manual experimental screening methods are usually used to determine the doping combination, which is costly and inefficient, and the selection and combination of doping elements are also lacking in comprehensiveness. Summary of the invention

[0003] The purpose of the embodiments of the present application is to provide a method and device for screening positive electrode doping of lithium-ion batteries, which can efficiently and comprehensively screen out ideal doping combinations with high voltage and low volume strain in a short time, thereby greatly improving the energy density and structural stability of the material and meeting the needs of high-performance lithium-ion batteries.

[0004] The first aspect of the present application provides a method for screening doping of a positive electrode of a lithium-ion battery, comprising:

[0005] Determine the effective doping elements and the positive electrode materials to be doped for experimental verification;

[0006] Preliminarily screening the doping elements according to preset screening indicators to obtain doping elements to be selected;

[0007] Constructing an initial LNMO structural model according to the positive electrode material;

[0008] Generate a plurality of first doping combination models according to the doping element to be selected and the initial LNMO structure model;

[0009] Calculating a battery voltage corresponding to each of the first doping combination models and a volume strain ratio corresponding to each of the first doping combination models;

[0010] Screening a plurality of the first doping combination models according to the battery voltage and the volume strain ratio to obtain a plurality of second doping combination models;

[0011] Calculating the doping concentration and capacity retention rate of each of the second doping combination models;

[0012] Screening a plurality of the second doping combination models according to the doping concentration and the capacity retention rate to obtain a plurality of third doping combination models;

[0013] Obtaining the doping material synthesis difficulty and the doping combination preparation cost of each of the third doping combination models;

[0014] Screening the third doping combination model according to the difficulty of synthesizing the doping material and the preparation cost of the doping combination to obtain a target doping combination model;

[0015] A lithium-ion battery positive electrode doping scheme is generated according to the target doping combination model.

[0016] In the above implementation process, this method can efficiently and comprehensively screen out ideal doping combinations with high voltage and low volume strain in a short time, thereby greatly improving the energy density and structural stability of the material and meeting the needs of high-performance lithium-ion batteries.

[0017] Furthermore, the determination of the effective doping elements and the positive electrode materials to be doped by experimental verification includes:

[0018] Obtain research data on positive electrode materials for lithium-ion batteries and positive electrode materials to be doped;

[0019] The effective doping elements verified by experiments are determined based on the research data of the positive electrode material.

[0020] Furthermore, the preliminarily screening the doping elements according to the preset screening index to obtain the doping elements to be selected includes:

[0021] Obtaining screening indicators; wherein the screening indicators at least include stability indicators, capacity indicators and operating voltage indicators;

[0022] Screening the doping element according to the screening index to obtain a first screening element;

[0023] Screening the first screening element according to the chemical valence balance principle of the positive electrode material and the full lithium state structure to obtain a second screening element;

[0024] Performing a doping simulation according to the positive electrode material and the second screening element to obtain a plurality of doped combination materials; wherein the doping simulation at least includes a one-element doping simulation, a two-element doping simulation, a three-element doping simulation, and a four-element doping simulation;

[0025] Performing lithium extraction capacity analysis on the doped composite material after doping to obtain a capacity change analysis result;

[0026] The second screening element is systematically screened according to the capacity change analysis result to obtain a candidate doping element.

[0027] Further, the calculating the battery voltage corresponding to each of the first doping combination models and the volume strain ratio corresponding to each of the first doping combination models includes:

[0028] Obtaining a first structural system energy of each of the first doping combination models before delithiation, a second structural system energy of each of the first doping combination models after delithiation, a first model volume of the initial LNMO structural model before delithiation, a second model volume of the initial LNMO structural model after delithiation, a third model volume of each of the first doping combination models before delithiation, and a fourth model volume of each of the first doping combination models after delithiation;

[0029] Calculating the energy difference of each of the first doping combination models during the lithium insertion and extraction process according to the first structural system energy and the second structural system energy;

[0030] Calculating the battery voltage corresponding to each of the first doping combination models according to the energy difference of the first doping combination model during the lithium insertion and extraction process;

[0031] A volumetric strain ratio is calculated based on the first model volume, the second model volume, the third model volume, and the fourth model volume.

[0032] Further, the calculating of the doping concentration and capacity retention rate of each of the second doping combination models includes:

[0033] Obtaining the number of doping atomic sites, the total number of dopable sites, the total number of lithium atoms, and the capacity loss corresponding to each of the second doping combination models;

[0034] Calculating the doping concentration of each of the second doping combination models according to the number of the doping atomic sites and the total number of the dopable sites;

[0035] The capacity retention rate is calculated based on the total number of lithium atoms and the capacity loss.

[0036] A second aspect of the present application provides a lithium ion battery positive electrode doping screening device, the lithium ion battery positive electrode doping screening device comprising:

[0037] A determination unit, used to determine the effective doping elements verified by experiments and the positive electrode materials to be doped;

[0038] A first screening unit, used to preliminarily screen the doping elements according to preset screening indicators to obtain doping elements to be selected;

[0039] A construction unit, used to construct an initial LNMO structural model according to the positive electrode material;

[0040] A combination unit, used for generating a plurality of first doping combination models according to the doping element to be selected and the initial LNMO structure model;

[0041] A first calculation unit, used for calculating a battery voltage corresponding to each of the first doping combination models and a volume strain ratio corresponding to each of the first doping combination models;

[0042] A second screening unit, configured to screen the plurality of first doping combination models according to the battery voltage and the volume strain ratio to obtain a plurality of second doping combination models;

[0043] A second calculation unit, used for calculating the doping concentration and capacity retention rate of each of the second doping combination models;

[0044] a third screening unit, configured to screen the plurality of the second doping combination models according to the doping concentration and the capacity retention rate to obtain a plurality of third doping combination models;

[0045] An acquisition unit, used for acquiring the difficulty of synthesizing the doping material and the preparation cost of the doping combination of each of the third doping combination models;

[0046] a fourth screening unit, configured to screen the third doping combination model according to the difficulty of synthesizing the doping material and the preparation cost of the doping combination to obtain a target doping combination model;

[0047] A generating unit is used to generate a lithium-ion battery positive electrode doping scheme according to the target doping combination model.

[0048] Furthermore, the determining unit includes:

[0049] A third acquisition subunit is used to acquire research data of positive electrode materials of lithium-ion batteries and positive electrode materials to be doped;

[0050] The determination subunit is used to determine the effective doping elements verified by experiments based on the research data of the positive electrode material.

[0051] Furthermore, the first screening unit includes:

[0052] A fourth acquisition subunit is used to acquire screening indicators; wherein the screening indicators at least include stability indicators, capacity indicators and operating voltage indicators;

[0053] A first screening subunit, used to screen the doping element according to the screening index to obtain a first screening element;

[0054] The first screening subunit is further used to screen the first screening element according to the chemical valence balance principle of the positive electrode material and the full lithium state structure to obtain a second screening element;

[0055] A simulation subunit, configured to perform a doping simulation according to the positive electrode material and the second screening element to obtain a plurality of doped combination materials; wherein the doping simulation includes at least a one-element doping simulation, a two-element doping simulation, a three-element doping simulation, and a four-element doping simulation;

[0056] An analysis subunit, used for analyzing the lithium removal capacity of the doped composite material after doping to obtain a capacity change analysis result;

[0057] The second screening subunit is used to systematically screen the second screening element according to the capacity change analysis result to obtain a doping element to be selected.

[0058] Furthermore, the first computing unit includes:

[0059] A first acquisition subunit is used to acquire a first structural system energy of each of the first doping combination models before delithiation, a second structural system energy of each of the first doping combination models after delithiation, a first model volume of the initial LNMO structural model before delithiation, a second model volume of the initial LNMO structural model after delithiation, a third model volume of each of the first doping combination models before delithiation, and a fourth model volume of each of the first doping combination models after delithiation;

[0060] A first calculation subunit, configured to calculate an energy difference of each of the first doping combination models during a lithium insertion and extraction process according to the first structural system energy and the second structural system energy;

[0061] The first calculation subunit is further used to calculate the battery voltage corresponding to each of the first doping combination models according to the energy difference of the first doping combination model during the lithium insertion and extraction process;

[0062] The first calculation subunit is further used to calculate a volume strain ratio according to the first model volume, the second model volume, the third model volume and the fourth model volume.

[0063] Furthermore, the second computing unit includes:

[0064] A second acquisition subunit, used to acquire the number of doping atomic sites, the total number of dopable sites, the total number of lithium atoms, and the capacity loss corresponding to each of the second doping combination models;

[0065] A second calculation subunit, configured to calculate the doping concentration of each of the second doping combination models according to the number of the doping atomic sites and the total number of the dopable sites;

[0066] The second calculation subunit is further used to calculate the capacity retention rate according to the total number of lithium atoms and the capacity loss.

[0067] The third aspect of the present application provides an electronic device, including a memory and a processor, wherein the memory is used to store a computer program, and the processor runs the computer program to enable the electronic device to perform the lithium-ion battery positive electrode doping screening method described in any one of the first aspect of the present application.

[0068] In a fourth aspect, the present application provides a computer-readable storage medium storing computer program instructions. When the computer program instructions are read and executed by a processor, the lithium-ion battery positive electrode doping screening method described in any one of the first aspect of the present application is executed.

[0069] The beneficial effects of the present application are as follows: the method and device can use the first principles calculation method to ensure the theoretical high voltage output of each doping combination, so that the material can provide a higher energy density in practical applications, which is beneficial to improving the overall performance of lithium-ion batteries and making them suitable for application scenarios with high energy demands.

[0070] At the same time, the method and device can also adopt the strategy of transition metal valence change and oxygen defect to ensure the charge balance and phase stability of the material during lithium insertion and extraction, thereby reducing the volume expansion or contraction of the electrode material during the cycle, extending the service life of the battery and reducing performance degradation.

[0071] Finally, the method and device can also significantly reduce the screening time through computational simulation, thereby ensuring the accuracy and reliability of the screening results, thereby finding the optimal doping scheme in a short time, providing a fast and effective path for material development and industrial application. BRIEF DESCRIPTION OF THE DRAWINGS

[0072] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments of the present application will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present application and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying creative work.

[0073] Figure 1 A schematic diagram of a process for screening a positive electrode doping of a lithium-ion battery provided in an embodiment of the present application;

[0074] Figure 2 A schematic diagram of another process for screening a positive electrode doping of a lithium-ion battery provided in an embodiment of the present application;

[0075] Figure 3 A schematic diagram of the structure of a lithium-ion battery positive electrode doping screening device provided in an embodiment of the present application;

[0076] Figure 4 A schematic structural diagram of another lithium-ion battery positive electrode doping screening device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0077] The technical solutions in the embodiments of the present application will be described below in conjunction with the drawings in the embodiments of the present application.

[0078] It should be noted that similar reference numerals and letters represent similar items in the following drawings, so once an item is defined in one drawing, it does not need to be further defined and explained in subsequent drawings. At the same time, in the description of this application, the terms "first", "second", etc. are only used to distinguish the description and cannot be understood as indicating or implying relative importance.

[0079] Example 1

[0080] Please see Figure 1 , Figure 1 A schematic diagram of a process flow of a lithium-ion battery positive electrode doping screening method provided in this embodiment. The lithium-ion battery positive electrode doping screening method comprises:

[0081] S101. Determine the effective doping elements verified by experiments and the positive electrode materials to be doped.

[0082] S102, preliminarily screening the doping elements according to preset screening indicators to obtain doping elements to be selected.

[0083] S103, constructing an initial LNMO structural model based on the positive electrode material.

[0084] S104: Generate a plurality of first doping combination models according to the doping elements to be selected and the initial LNMO structure model.

[0085] S105 , calculating a battery voltage corresponding to each first doping combination model and a volume strain ratio corresponding to each first doping combination model.

[0086] S106. Screening a plurality of first doping combination models according to battery voltage and volume strain ratio to obtain a plurality of second doping combination models.

[0087] S107, calculating the doping concentration and capacity retention rate of each second doping combination model.

[0088] S108. Screen the plurality of second doping combination models according to the doping concentration and the capacity retention rate to obtain a plurality of third doping combination models.

[0089] S109, obtaining the doping material synthesis difficulty and the doping combination preparation cost of each third doping combination model.

[0090] S110. Screen the third doping combination model according to the difficulty of synthesizing the doping material and the preparation cost of the doping combination to obtain a target doping combination model.

[0091] S111. Generate a lithium-ion battery positive electrode doping scheme according to a target doping combination model.

[0092] In this embodiment, the execution subject of the method may be a computing device such as a computer or a server, and no limitation is made in this embodiment.

[0093] In this embodiment, the execution subject of the method may also be a smart device such as a smart phone, a tablet computer, etc., which is not limited in this embodiment.

[0094] It can be seen that the implementation of the lithium-ion battery positive electrode doping screening method described in this embodiment can quickly construct a large number of LNMO models of different element doping combinations through high-throughput calculation and simulation, and use the first-principles calculation method to systematically study the voltage change and volume strain of these doping combinations during the charge and discharge process. Among them, through high-throughput screening technology, it is possible to efficiently screen out ideal doping combinations with high voltage and low volume strain in a short time, thereby greatly improving the energy density and structural stability of the material and meeting the needs of high-performance lithium-ion batteries.

[0095] Example 2

[0096] Please see Figure 2 , Figure 2 A schematic diagram of a process flow of a lithium-ion battery positive electrode doping screening method provided in this embodiment. The lithium-ion battery positive electrode doping screening method comprises:

[0097] S201. Obtain research data on positive electrode materials for lithium-ion batteries and positive electrode materials to be doped.

[0098] S202. Determine the effective doping elements verified by experiments based on the research data of the positive electrode material.

[0099] In this embodiment, the method can collect potential positive electrode material research systems, including the ability to screen out experimentally verified effective doping elements to provide a basis for subsequent high-throughput screening.

[0100] S203, obtaining screening indicators.

[0101] In this embodiment, the screening index includes at least a stability index, a capacity index and an operating voltage index.

[0102] S204, screening the doping elements according to the screening index to obtain the first screening elements.

[0103] In this embodiment, the screening index can ensure that the material has high capacity and high operating voltage, thereby improving the overall energy density. At this time, if the volume strain during the charge and discharge process is reduced, the structural stability of the material can be improved, thereby achieving the effect of extending the battery life.

[0104] S205. Screen the first screening element according to the chemical valence balance principle of the positive electrode material and the full lithium state structure to obtain the second screening element.

[0105] In this embodiment, the method can ensure that the doped structure maintains a balance of chemical valence states when the material is in a fully lithium state, avoid the formation of unstable phases, and ensure the structural stability of the material.

[0106] In this embodiment, the method can achieve charge compensation through the valence change of the transition metal during the lithium ion insertion and extraction process.

[0107] In this embodiment, transition metal valence refers to the change in the oxidation state of the transition metal element to compensate for the loss or gain of electrons during the charge and discharge process of the lithium-ion battery. Among them, this valence change process is an important mechanism for material charge balance and stability. In this method, controlling the valence change behavior of the transition metal is one of the important principles to ensure the performance of the doped material.

[0108] In this embodiment, if charge compensation cannot be achieved by changing the valence state of the transition metal, the following two strategies need to be adopted:

[0109] (1) Reduce lithium extraction capacity: By reducing the amount of lithium ions extracted, the charge compensation is mainly completed by the valence change of the transition metal;

[0110] (2) Constructing oxygen defects: By introducing oxygen defects, we can further ensure that charge compensation is achieved by the valence change of the transition metal.

[0111] In this embodiment, oxygen defects refer to the positions where oxygen atoms are missing in the material lattice, which can affect the electronic structure and physical properties of the material. During the doping process, the introduction of oxygen defects can change the electron density of the material, affect the valence behavior of the transition metal, and thus adjust the performance of the material.

[0112] S206 , performing doping simulation according to the positive electrode material and the second screening element to obtain a plurality of doping combination materials.

[0113] In this embodiment, the doping simulation includes at least one doping simulation, two doping simulations, three doping simulations and four doping simulations.

[0114] For example, unary doping refers to the simulation of doping each single element, and a preliminary understanding and judgment of the doping element is made, so as to prepare for the subsequent element combination. For example:

[0115] type element Capacity increase due to unit doping No loss of capacity Ti (+4, unchanged) 0 Capacity loss Al (unchanged price), Cu (changed price) -1

[0116] Among them, Ti 4+ : No significant change in capacity.

[0117] Al 3+ : Lead to Ni 2+ Raised to Ni 3+ , unit doping results in a capacity reduction of 1.

[0118] In this embodiment, binary doping, ternary doping, and quaternary doping are similar.

[0119] By implementing this embodiment, the method can effectively identify and optimize doped LNMO with high voltage and low volumetric strain, so that it can meet the application requirements of high-performance lithium-ion batteries.

[0120] S207, analyzing the lithium removal capacity of the doped composite material after doping to obtain a capacity change analysis result.

[0121] S208. Systematically screen the second screening elements according to the capacity change analysis results to obtain candidate doping elements.

[0122] S209, constructing an initial LNMO structural model based on the positive electrode material.

[0123] S210 , generating a plurality of first doping combination models according to the doping elements to be selected and the initial LNMO structure model.

[0124] In this embodiment, the method can model the initial LNMO structure (eg, LNMO with a spinel structure), and specifically can model the specific sites of different atoms in the structure.

[0125] In this embodiment, the model is mainly used to replace the main atoms (such as Mn) during the doping process.

[0126] For example, this method can be used to replace one Mn site in the LNMO structure with one Al atom during Al doping.

[0127] The doping method of other metal elements is similar to this. For different elements and their doping concentrations, this method can generate multiple doping combination models.

[0128] S211, obtaining the first structural system energy of each first doping combination model before delithiation, the second structural system energy of each first doping combination model after delithiation, the first model volume of the initial LNMO structural model before delithiation, the second model volume of the initial LNMO structural model after delithiation, the third model volume of each first doping combination model before delithiation, and the fourth model volume of each first doping combination model after delithiation.

[0129] S212. Calculate the energy difference of each first doping combination model during the lithium insertion and extraction process according to the first structural system energy and the second structural system energy.

[0130] S213, calculating the battery voltage corresponding to each first doping combination model according to the energy difference of the first doping combination model during the lithium insertion and extraction process.

[0131] In this embodiment, the battery voltage refers to the potential difference generated by the battery or electrode during the charge and discharge process. In lithium-ion batteries, voltage is one of the key parameters for measuring battery energy output. In this method, it refers to the average voltage before and after the structure is de-liquidated by calculation.

[0132] S214, calculating the volume strain ratio according to the first model volume, the second model volume, the third model volume and the fourth model volume.

[0133] In this embodiment, volume strain refers to the volume change of the material caused by lithium ion insertion and extraction during the charge and discharge process. Excessive volume strain will affect the structural stability of the electrode material and cause the battery performance to decline. Therefore, reducing volume strain is one of the important means to improve the cycle life of lithium ion batteries.

[0134] S215 , screening a plurality of first doping combination models according to the battery voltage and the volume strain ratio to obtain a plurality of second doping combination models.

[0135] In this embodiment, the method can calculate the energy of the structural system before Li removal (obtained by first principle calculation) and the energy of the structural system after Li removal. Then, the energy difference between the two systems during lithium deintercalation is calculated and divided by the number of lithium deintercalation electrons to obtain the corresponding voltage. Among them, the volume strain ratio calculation formula used to calculate the volume strain ratio is as follows:

[0136]

[0137] The minus sign "-" in the formula is because the energy difference needs to be converted into an electrochemical potential, which corresponds to the voltage of the battery;

[0138] and They are the model volumes of the doped composite structure LNMXO before and after Li removal;

[0139] and These are the model volumes of the original LNMO before and after Li removal.

[0140] In this embodiment, the method can quantitatively measure the effect of doping on the volume stability of the material by comparing the volume changes of the doped system and the undoped system before and after delithiation.

[0141] In this embodiment, the volume strain ratio can be used to evaluate the structural stability of the doped material and its effect on the cycle stability.

[0142] In this embodiment, the first principles calculation refers to a calculation method based on the principles of quantum mechanics, which is used to predict the electronic structure and physical properties of materials.

[0143] S216, obtaining the number of doping atomic sites, the total number of dopable sites, the total number of lithium atoms, and the capacity loss corresponding to each second doping combination model.

[0144] S217. Calculate the doping concentration of each second doping combination model according to the number of doping atomic sites and the total number of dopable sites.

[0145] S218. Calculate the capacity retention rate based on the total number of lithium atoms and the capacity loss.

[0146] S219, screening the plurality of second doping combination models according to the doping concentration and the capacity retention rate to obtain a plurality of third doping combination models.

[0147] In this embodiment, the method is preferably helpful in reducing the cost with respect to the doping concentration.

[0148] In this embodiment, the doping concentration refers to the ratio of the number of doping atoms doped in the material to the number of all available doping sites in the material. The calculation formula of the doping concentration is as follows:

[0149] Doping concentration = total number of doping sites / number of doping atomic sites

[0150] Among them, the number of doping atomic sites refers to the number of sites occupied by doping atoms in the material structure;

[0151] The total number of dopable sites refers to the total number of sites in the material structure that can be occupied by doping atoms.

[0152] In this embodiment, the capacity retention rate of this method is preferably greater than 70%.

[0153] In this embodiment, the capacity retention rate refers to the ratio of the battery capacity retained during the material doping process to the total capacity. The calculation formula of the capacity retention rate is as follows:

[0154] Capacity retention rate = (total number of Li atoms - capacity loss) / total number of Li atoms

[0155] Among them, the total number of Li atoms refers to the total number of lithium atoms that can be stored in the structure of the material when it is undoped;

[0156] Capacity loss refers to the capacity that is lost due to the inability of the doping elements to effectively participate in the electrochemical reaction or the formation of irreversible loss during the doping process.

[0157] S220, obtaining the doping material synthesis difficulty and the doping combination preparation cost of each third doping combination model.

[0158] S221. Screen the third doping combination model according to the difficulty of synthesizing the doping material and the preparation cost of the doping combination to obtain a target doping combination model.

[0159] S222. Generate a lithium-ion battery positive electrode doping scheme according to a target doping combination model.

[0160] In this embodiment, high-throughput computing is a systematic computing method, which is embodied in the process of rapid screening and optimization of material or compound combinations. Specifically, the method is embodied in the process of simultaneously calculating and analyzing a large number of candidate materials through an automated computing process. By adopting this computing method, the method can greatly improve the efficiency and accuracy of material screening. In short, high-throughput computing is used to screen a large number of doping combinations, and the optimal LNMO positive electrode material combination can be quickly found.

[0161] For example, the doping combination structure is as follows:

[0162]

[0163] Among them, this method can experimentally verify the potential doping combinations screened. Specifically, LiNi 0.5 Mn 1.5 O4 and doped Li8Ni4Mn9Al1Mg1Fe1O 32 .

[0164] In the raw material mixing process, the method can weigh the raw materials according to the stoichiometric ratio, and mix them by ball milling in a high-energy ball mill for 12 hours; then, the mixed powder is pre-sintered at 600°C for 4 hours; then, the pre-sintered powder is sintered at 900°C for 12 hours. Cooling and grinding; after naturally cooling to room temperature, the sintered sample is ground into fine powder to obtain a uniform positive electrode material.

[0165] On this basis, the method begins to prepare for electrochemical performance testing. Specifically, the method selects a test electrode material prepared by mixing active material, conductive carbon black and PVDF in a ratio of 8:1:1, and sets the test conditions as follows:

[0166] (1) Electrolyte: LiPF6 with a concentration of 1 mol / L dissolved in EC / DMC (1:1) solution;

[0167] (2) Battery test: The first cycle discharge test was performed at a rate of 0.1C in the voltage range of 2.5-4.9V, followed by 100 cycles at a rate of 1C.

[0168] After electrochemical performance testing, the following test results can be obtained:

[0169]

[0170] In this embodiment, the execution subject of the method may be a computing device such as a computer or a server, and no limitation is made in this embodiment.

[0171] In this embodiment, the execution subject of the method may also be a smart device such as a smart phone, a tablet computer, etc., which is not limited in this embodiment.

[0172] It can be seen that the implementation of the lithium-ion battery positive electrode doping screening method described in this embodiment can quickly construct a large number of LNMO models of different element doping combinations through high-throughput calculation and simulation, and use the first-principles calculation method to systematically study the voltage changes and volume strains of these doping combinations during the charge and discharge process. Among them, through high-throughput screening technology, it is possible to efficiently screen out ideal doping combinations with high voltage and low volume strain in a short time, thereby greatly improving the energy density and structural stability of the material and meeting the needs of high-performance lithium-ion batteries.

[0173] Example 3

[0174] Please see Figure 3 , Figure 3 This is a schematic diagram of the structure of a lithium-ion battery positive electrode doping screening device provided in this embodiment. Figure 3 As shown, the lithium-ion battery positive electrode doping screening device comprises:

[0175] A determination unit 310, used to determine the effective doping elements verified by experiments and the positive electrode material to be doped;

[0176] The first screening unit 320 is used to preliminarily screen the doping elements according to the preset screening index to obtain the doping elements to be selected;

[0177] A construction unit 330 is used to construct an initial LNMO structure model according to the positive electrode material;

[0178] A combination unit 340, configured to generate a plurality of first doping combination models according to the doping elements to be selected and the initial LNMO structure model;

[0179] A first calculation unit 350, used to calculate a battery voltage corresponding to each first doping combination model and a volume strain ratio corresponding to each first doping combination model;

[0180] A second screening unit 360 is used to screen the plurality of first doping combination models according to the battery voltage and the volume strain ratio to obtain a plurality of second doping combination models;

[0181] A second calculation unit 370, used to calculate the doping concentration and capacity retention rate of each second doping combination model;

[0182] A third screening unit 380 is used to screen the plurality of second doping combination models according to the doping concentration and the capacity retention rate to obtain a plurality of third doping combination models;

[0183] An acquisition unit 390 is used to acquire the doping material synthesis difficulty and the doping combination preparation cost of each third doping combination model;

[0184] A fourth screening unit 400 is used to screen the third doping combination model according to the difficulty of synthesizing the doping material and the preparation cost of the doping combination to obtain a target doping combination model;

[0185] The generating unit 410 is used to generate a lithium-ion battery positive electrode doping scheme according to a target doping combination model.

[0186] In this embodiment, the explanation of the lithium-ion battery positive electrode doping screening device can refer to the description in Example 1 or Example 2, and will not be further elaborated in this embodiment.

[0187] It can be seen that the lithium-ion battery positive electrode doping screening device described in this embodiment can quickly construct a large number of LNMO models of different element doping combinations through high-throughput calculation and simulation, and use the first-principles calculation method to systematically study the voltage change and volume strain of these doping combinations during the charge and discharge process. Among them, through high-throughput screening technology, it is possible to efficiently screen out ideal doping combinations with high voltage and low volume strain in a short time, thereby greatly improving the energy density and structural stability of the material and meeting the needs of high-performance lithium-ion batteries.

[0188] Example 4

[0189] Please see Figure 4 , Figure 4 This is a schematic diagram of the structure of a lithium-ion battery positive electrode doping screening device provided in this embodiment. Figure 4As shown, the lithium-ion battery positive electrode doping screening device comprises:

[0190] A determination unit 310, used to determine the effective doping elements verified by experiments and the positive electrode material to be doped;

[0191] The first screening unit 320 is used to preliminarily screen the doping elements according to the preset screening index to obtain the doping elements to be selected;

[0192] A construction unit 330 is used to construct an initial LNMO structure model according to the positive electrode material;

[0193] A combination unit 340, configured to generate a plurality of first doping combination models according to the doping elements to be selected and the initial LNMO structure model;

[0194] A first calculation unit 350, used to calculate a battery voltage corresponding to each first doping combination model and a volume strain ratio corresponding to each first doping combination model;

[0195] A second screening unit 360 is used to screen the plurality of first doping combination models according to the battery voltage and the volume strain ratio to obtain a plurality of second doping combination models;

[0196] A second calculation unit 370, used to calculate the doping concentration and capacity retention rate of each second doping combination model;

[0197] A third screening unit 380 is used to screen the plurality of second doping combination models according to the doping concentration and the capacity retention rate to obtain a plurality of third doping combination models;

[0198] An acquisition unit 390 is used to acquire the doping material synthesis difficulty and the doping combination preparation cost of each third doping combination model;

[0199] A fourth screening unit 400 is used to screen the third doping combination model according to the difficulty of synthesizing the doping material and the preparation cost of the doping combination to obtain a target doping combination model;

[0200] The generating unit 410 is used to generate a lithium-ion battery positive electrode doping scheme according to a target doping combination model.

[0201] As an optional implementation manner, the determining unit 310 includes:

[0202] The third acquisition subunit 311 is used to acquire the research data of the positive electrode material of the lithium-ion battery and the positive electrode material to be doped;

[0203] The determination subunit 312 is used to determine the effective doping elements verified by experiments according to the positive electrode material research data.

[0204] As an optional implementation, the first screening unit 320 includes:

[0205] The fourth acquisition subunit 321 is used to acquire screening indicators, wherein the screening indicators at least include stability indicators, capacity indicators and operating voltage indicators;

[0206] A first screening subunit 322, used to screen the doping elements according to the screening index to obtain the first screening elements;

[0207] The first screening subunit 322 is further used to screen the first screening element according to the chemical valence balance principle of the positive electrode material and the full lithium state structure to obtain the second screening element;

[0208] The simulation subunit 323 is used to perform doping simulation according to the positive electrode material and the second screening element to obtain a plurality of doped combination materials; wherein the doping simulation includes at least one-element doping simulation, two-element doping simulation, three-element doping simulation and four-element doping simulation;

[0209] An analysis subunit 324 is used to analyze the lithium removal capacity of the doped composite material after doping to obtain a capacity change analysis result;

[0210] The second screening subunit 325 is used to systematically screen the second screening elements according to the capacity change analysis result to obtain the doping elements to be selected.

[0211] As an optional implementation, the first calculation unit 350 includes:

[0212] A first acquisition subunit 351 is used to acquire a first structural system energy of each first doping combination model before delithiation, a second structural system energy of each first doping combination model after delithiation, a first model volume of the initial LNMO structural model before delithiation, a second model volume of the initial LNMO structural model after delithiation, a third model volume of each first doping combination model before delithiation, and a fourth model volume of each first doping combination model after delithiation;

[0213] A first calculation subunit 352, for calculating the energy difference of each first doping combination model during the lithium insertion and extraction process according to the first structural system energy and the second structural system energy;

[0214] The first calculation subunit 352 is further used to calculate the battery voltage corresponding to each first doping combination model according to the energy difference of the first doping combination model during the lithium insertion and extraction process;

[0215] The first calculation subunit 352 is further used to calculate the volume strain ratio according to the first model volume, the second model volume, the third model volume and the fourth model volume.

[0216] As an optional implementation, the second calculation unit 370 includes:

[0217] A second acquisition subunit 371 is used to obtain the number of doping atomic sites, the total number of dopable sites, the total number of lithium atoms, and the capacity loss corresponding to each second doping combination model;

[0218] A second calculation subunit 372, configured to calculate the doping concentration of each second doping combination model according to the number of doping atomic sites and the total number of dopable sites;

[0219] The second calculation subunit 372 is further used to calculate the capacity retention rate according to the total number of lithium atoms and the capacity loss.

[0220] In this embodiment, the explanation of the lithium-ion battery positive electrode doping screening device can refer to the description in Example 1 or Example 2, and will not be further elaborated in this embodiment.

[0221] It can be seen that the lithium-ion battery positive electrode doping screening device described in this embodiment can quickly construct a large number of LNMO models of different element doping combinations through high-throughput calculation and simulation, and use the first-principles calculation method to systematically study the voltage change and volume strain of these doping combinations during the charge and discharge process. Among them, through high-throughput screening technology, it is possible to efficiently screen out ideal doping combinations with high voltage and low volume strain in a short time, thereby greatly improving the energy density and structural stability of the material and meeting the needs of high-performance lithium-ion batteries.

[0222] An embodiment of the present application provides an electronic device, including a memory and a processor, wherein the memory is used to store a computer program, and the processor runs the computer program to enable the electronic device to execute the lithium-ion battery positive electrode doping screening method in Embodiment 1 or Embodiment 2 of the present application.

[0223] An embodiment of the present application provides a computer-readable storage medium storing computer program instructions. When the computer program instructions are read and executed by a processor, the lithium-ion battery positive electrode doping screening method in Embodiment 1 or Embodiment 2 of the present application is executed.

[0224] In several embodiments provided in the present application, it should be understood that the disclosed devices and methods can also be implemented in other ways. The device embodiments described above are merely schematic. For example, the flowcharts and block diagrams in the accompanying drawings show the possible architecture, functions and operations of the devices, methods and computer program products according to multiple embodiments of the present application. In this regard, each box in the flowchart or block diagram can represent a module, a program segment or a part of a code, and the module, a program segment or a part of a code contains one or more executable instructions for implementing the specified logical function. It should also be noted that in some alternative implementations, the functions marked in the box can also occur in a different order from the order marked in the accompanying drawings. For example, two consecutive boxes can actually be executed substantially in parallel, and they can sometimes be executed in the opposite order, depending on the functions involved. It should also be noted that each box in the block diagram and / or flowchart, and the combination of boxes in the block diagram and / or flowchart can be implemented with a dedicated hardware-based system that performs a specified function or action, or can be implemented with a combination of dedicated hardware and computer instructions.

[0225] In addition, the functional modules in the various embodiments of the present application may be integrated together to form an independent part, or each module may exist separately, or two or more modules may be integrated to form an independent part.

[0226] If the functions are implemented in the form of software function modules and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present application can be essentially or partly embodied in the form of a software product that contributes to the prior art. The computer software product is stored in a storage medium, including several instructions to enable a computer device (which can be a personal computer, a server, or a network device, etc.) to perform all or part of the steps of the methods described in each embodiment of the present application. The aforementioned storage medium includes: various media that can store program codes, such as a USB flash drive, a mobile hard disk, a read-only memory (ROM), a random access memory (RAM), a magnetic disk or an optical disk.

[0227] The above description is only an embodiment of the present application and is not intended to limit the scope of protection of the present application. For those skilled in the art, the present application may have various changes and variations. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present application should be included in the scope of protection of the present application. It should be noted that similar reference numerals and letters represent similar items in the following drawings, so once an item is defined in one drawing, it does not need to be further defined and explained in the subsequent drawings.

[0228] The above is only a specific implementation of the present application, but the protection scope of the present application is not limited thereto. Any technician familiar with the technical field can easily think of changes or substitutions within the technical scope disclosed in the present application, which should be included in the protection scope of the present application. Therefore, the protection scope of the present application should be based on the protection scope of the claims.

[0229] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the sentence "comprise a ..." do not exclude the existence of other identical elements in the process, method, article or device including the elements.

Claims

1. A method for screening doping of positive electrodes of lithium-ion batteries, characterized in that: include: Determine the effective doping elements and the positive electrode materials to be doped for experimental verification; Preliminarily screening the doping elements according to preset screening indicators to obtain doping elements to be selected; Constructing an initial LNMO structural model according to the positive electrode material; Generate a plurality of first doping combination models according to the doping element to be selected and the initial LNMO structure model; Calculating a battery voltage corresponding to each of the first doping combination models and a volume strain ratio corresponding to each of the first doping combination models; Screening a plurality of the first doping combination models according to the battery voltage and the volume strain ratio to obtain a plurality of second doping combination models; Calculating the doping concentration and capacity retention rate of each of the second doping combination models; Screening a plurality of the second doping combination models according to the doping concentration and the capacity retention rate to obtain a plurality of third doping combination models; Obtaining the doping material synthesis difficulty and the doping combination preparation cost of each of the third doping combination models; Screening the third doping combination model according to the difficulty of synthesizing the doping material and the preparation cost of the doping combination to obtain a target doping combination model; A lithium-ion battery positive electrode doping scheme is generated according to the target doping combination model.

2. The method for screening the positive electrode doping of a lithium ion battery according to claim 1, characterized in that: The determination of the effective doping elements and the positive electrode materials to be doped by experimental verification comprises: Obtain research data on positive electrode materials for lithium-ion batteries and positive electrode materials to be doped; The effective doping elements verified by experiments are determined based on the research data of the positive electrode material.

3. The method for screening the positive electrode doping of a lithium ion battery according to claim 1, characterized in that: The preliminarily screening the doping elements according to the preset screening index to obtain the doping elements to be selected includes: Obtaining screening indicators; wherein the screening indicators at least include stability indicators, capacity indicators and operating voltage indicators; Screening the doping element according to the screening index to obtain a first screening element; Screening the first screening element according to the chemical valence balance principle of the positive electrode material and the full lithium state structure to obtain a second screening element; Performing a doping simulation according to the positive electrode material and the second screening element to obtain a plurality of doped combination materials; wherein the doping simulation at least includes a one-element doping simulation, a two-element doping simulation, a three-element doping simulation, and a four-element doping simulation; Performing lithium extraction capacity analysis on the doped composite material after doping to obtain a capacity change analysis result; The second screening element is systematically screened according to the capacity change analysis result to obtain a candidate doping element.

4. The method for screening the positive electrode doping of a lithium-ion battery according to claim 1, characterized in that: The calculating the battery voltage corresponding to each of the first doping combination models and the volume strain ratio corresponding to each of the first doping combination models includes: Obtaining a first structural system energy of each of the first doping combination models before delithiation, a second structural system energy of each of the first doping combination models after delithiation, a first model volume of the initial LNMO structural model before delithiation, a second model volume of the initial LNMO structural model after delithiation, a third model volume of each of the first doping combination models before delithiation, and a fourth model volume of each of the first doping combination models after delithiation; Calculating the energy difference of each of the first doping combination models during the lithium insertion and extraction process according to the first structural system energy and the second structural system energy; Calculating the battery voltage corresponding to each of the first doping combination models according to the energy difference of the first doping combination model during the lithium insertion and extraction process; A volumetric strain ratio is calculated based on the first model volume, the second model volume, the third model volume, and the fourth model volume.

5. The method for screening positive electrode doping of a lithium ion battery according to claim 1, characterized in that: The calculating the doping concentration and capacity retention rate of each of the second doping combination models comprises: Obtaining the number of doping atomic sites, the total number of dopable sites, the total number of lithium atoms, and the capacity loss corresponding to each of the second doping combination models; Calculating the doping concentration of each of the second doping combination models according to the number of the doping atomic sites and the total number of the dopable sites; The capacity retention rate is calculated based on the total number of lithium atoms and the capacity loss.

6. A lithium-ion battery positive electrode doping screening device, characterized in that: The lithium-ion battery positive electrode doping screening device comprises: A determination unit, used to determine the effective doping elements verified by experiments and the positive electrode materials to be doped; A first screening unit, used to preliminarily screen the doping elements according to preset screening indicators to obtain doping elements to be selected; A construction unit, used to construct an initial LNMO structural model according to the positive electrode material; A combination unit, used for generating a plurality of first doping combination models according to the doping element to be selected and the initial LNMO structure model; A first calculation unit, used for calculating a battery voltage corresponding to each of the first doping combination models and a volume strain ratio corresponding to each of the first doping combination models; A second screening unit, configured to screen the plurality of first doping combination models according to the battery voltage and the volume strain ratio to obtain a plurality of second doping combination models; A second calculation unit, used for calculating the doping concentration and capacity retention rate of each of the second doping combination models; a third screening unit, configured to screen the plurality of the second doping combination models according to the doping concentration and the capacity retention rate to obtain a plurality of third doping combination models; An acquisition unit, used for acquiring the doping material synthesis difficulty and the doping combination preparation cost of each of the third doping combination models; a fourth screening unit, configured to screen the third doping combination model according to the difficulty of synthesizing the doping material and the preparation cost of the doping combination to obtain a target doping combination model; A generating unit is used to generate a lithium-ion battery positive electrode doping scheme according to the target doping combination model.

7. The lithium-ion battery positive electrode doping screening device according to claim 6, characterized in that: The first computing unit comprises: A first acquisition subunit is used to acquire a first structural system energy of each of the first doping combination models before delithiation, a second structural system energy of each of the first doping combination models after delithiation, a first model volume of the initial LNMO structural model before delithiation, a second model volume of the initial LNMO structural model after delithiation, a third model volume of each of the first doping combination models before delithiation, and a fourth model volume of each of the first doping combination models after delithiation; A first calculation subunit, configured to calculate an energy difference of each of the first doping combination models during a lithium insertion and extraction process according to the first structural system energy and the second structural system energy; The first calculation subunit is further used to calculate the battery voltage corresponding to each of the first doping combination models according to the energy difference of the first doping combination model during the lithium insertion and extraction process; The first calculation subunit is further used to calculate a volume strain ratio according to the first model volume, the second model volume, the third model volume and the fourth model volume.

8. The lithium-ion battery positive electrode doping screening device according to claim 6, characterized in that: The second computing unit comprises: A second acquisition subunit, used to acquire the number of doping atomic sites, the total number of dopable sites, the total number of lithium atoms, and the capacity loss corresponding to each of the second doping combination models; A second calculation subunit, configured to calculate the doping concentration of each of the second doping combination models according to the number of the doping atomic sites and the total number of the dopable sites; The second calculation subunit is further used to calculate the capacity retention rate according to the total number of lithium atoms and the capacity loss.

9. An electronic device, characterized in that: The electronic device comprises a memory and a processor, the memory is used to store a computer program, and the processor runs the computer program to enable the electronic device to perform the lithium ion battery positive electrode doping screening method according to any one of claims 1 to 5.

10. A readable storage medium, characterized in that: The readable storage medium stores computer program instructions, and when the computer program instructions are read and executed by a processor, the method for screening positive electrode doping of a lithium-ion battery according to any one of claims 1 to 5 is executed.

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