First-principles prediction method for structural stability of transition metal layered oxides

Abstract

This invention discloses a first-principles prediction method for the stability of transition metal layered oxide structures. This invention relates to the field of material stability calculation technology. It constructs and optimizes a multi-state structure model according to standardized rules, presets a dual calculation parameter system, calculates multi-dimensional stability indices, establishes specific criteria, and outputs an engineering report containing modification suggestions through automated post-processing. The advantages of this invention are: by employing standardized structure modeling and initial geometry optimization techniques including ideal, doped, defective, and delithiation states, combined with two sets of standardized calculation parameter systems preset for the electronic structure characteristics of transition metal layered oxides, it simultaneously performs multi-dimensional stability calculations of formation energy, decomposition energy, phase transition barrier, mixing energy, and oxygen vacancy formation energy, and establishes specific quantitative criteria for judgment levels. This solves the shortcomings of existing first-principles calculations, such as fragmentation, lack of unified parameter standards, and lack of targeted criteria.

Description

Technical Field

[0001] This invention relates to the field of material stability calculation technology, specifically a first-principles prediction method for the stability of transition metal layered oxide structures. Background Technology

[0002] Transition metal layered oxides, as a class of functional materials with unique crystal structures and excellent physicochemical properties, have shown broad application prospects in several key fields such as lithium-ion battery cathode materials, electrocatalysis, and energy storage devices. Their market demand and application scope continue to expand with the rapid development of the new energy industry. The crystal structure of these materials is characterized by layered stacking, where transition metal atoms and oxygen atoms form a stable layered framework. Lithium ions or other cations can reversibly intercalate and deintercalate in the interlayer channels. This structural characteristic endows the materials with excellent electrochemical activity and ion transport capabilities.

[0003] Existing methods for assessing the stability of transition metal layered oxide structures primarily rely on independent calculations of single indicators using first-principles methods. This approach has several drawbacks. First, the calculations are fragmented, lacking unified parameter standards and targeted quantitative criteria, requiring secondary manual analysis. This makes it difficult to systematically understand the material's stability state and accurately pinpoint the core failure mechanism. Second, it fails to accurately capture material-specific failure mechanisms such as phase transitions, ion mixing, and oxygen release, only outputting raw calculation data. This disconnects the data from engineering applications, resulting in poor practicality and high trial-and-error costs in material development, as well as slow screening and optimization processes. Therefore, we propose a first-principles method for predicting the stability of transition metal layered oxide structures. Summary of the Invention

[0004] The purpose of this invention is to provide a first-principles prediction method for the stability of transition metal layered oxide structures.

[0005] To achieve the above objectives, the present invention provides the following technical solution: a first-principles prediction method for the stability of transition metal layered oxide structures, the prediction method comprising the following steps:

[0006] Step 1: Construct a transition metal layered oxide structure model containing ideal, doped, defective, and delithiation states according to standardized rules and perform initial geometry optimization;

[0007] Step 2: Based on the electronic structure characteristics of layered oxides of transition metals (strong correlation between d electrons of transition metals and p electrons of oxygen), two sets of standardized first-principles calculation parameter systems are pre-set for high-throughput screening and precise verification.

[0008] Step 3: Calculate the two types of thermodynamic stability indices: formation energy and decomposition energy;

[0009] Step 4: Calculate the phase transition barriers from layered phase to spinel phase and from spinel phase to rock salt phase using the NEB method;

[0010] Step 5: Calculate the mixing energy of transition metals and lithium ions under different mixing ratios;

[0011] Step 6: Construct defect structure models of single oxygen vacancies and double oxygen vacancies (adjacent / non-adjacent), and calculate the oxygen vacancy formation energy based on the accurate verification parameters in Step 2;

[0012] Step 7: Establish multi-dimensional stability criteria based on quantization thresholds and determine the level;

[0013] Step 8: Output an engineering report containing failure point location and modification suggestions through an automated post-processing program.

[0014] As a further aspect of the present invention: the ideal layered structure is selected from either a 1×1×3 or 2×2×2 supercell (containing 12-48 atoms), the doping structure is based on an atomic replacement ratio of 0.5%-10%, and equivalent and non-equivalent doping is performed on one of the transition metal layer and the lithium layer, with the doped atoms occupying equivalent lattice positions. The concentration of oxygen vacancies and transition metal vacancies in the defect structure is 0.1%-5%, and a single / double defect random distribution model is constructed. The delithiation state structure is based on Li X The MO2 gradient sets the delithiation ratio, M is the transition metal, x = 0.1, 0.2...1.0, and the delithiation sites are preferentially selected from the equivalent positions of the lithium layer without adjacent transition metals. The initial geometry optimization only fixes the lattice constant and the coordinates of the relaxed atoms. The modeling software is MaterialsStudio, VASP or CASTEP.

[0015] As a further aspect of the present invention: In step two, the standardized calculation parameter system is as follows: the high-throughput screening system adopts the PBE functional and projected fused wave (PAW) pseudopotential under the generalized gradient approximation (GGA), the k-point grid is ≥3×3×1 (≥5×5×1 when the supercell is ≥2×2×2), the plane wave cutoff energy is 350-400eV, and the structural relaxation convergence criterion is set as: atomic force ≤0.02eV / Å, and total cell energy convergence accuracy ≤1×10⁻⁶. -5 eV / atom, self-consistent iterative convergence criterion ≤1×10 -6 eV / atom;

[0016] The precise verification system employs an HSE06 hybrid functional with 25%-30% Hartree-Fock exchange energy, and optimizes the PAW pseudopotential to an all-electron pseudopotential. The k-point grid is ≥5×5×1, the cutoff energy is 400-450 eV, and the convergence criterion is improved to: atomic force ≤0.01 eV / Å, and the total energy convergence accuracy ≤1×10⁻⁶. -6eV / atom is used for high-throughput screening to initially screen stable systems, and precise verification is used to confirm the performance of core systems, achieving a balance between accuracy and efficiency.

[0017] As a further aspect of the present invention: in step three, the heat is calculated using first-principles calculations of the formation energy, a core indicator of the thermodynamic stability of transition metal layered oxides. and decomposition energy , forming energy and decomposition energy The calculation formula is as follows:

[0018] ;

[0019] in, The total energy (eV) of the unit cell after construction and optimization in step one. The first in the unit cell The number of atoms of the elements Li, transition metal M, and O. For the first Chemical potential of elements (unit: eV / atom), with the chemical potential of Li based on the stable phase of metallic Li ( , (total energy per unit cell of a stable bulk lithium crystal structure), and the chemical potential of the transition metal M. Based on its stable oxides (such as Co3O4, NiO), the chemical potential of O Based on O2 molecules ( );

[0020] ;

[0021] in, This represents the total cell energy of the possible decomposition products of layered oxides (such as Li₂O, MO, M₂O₃, etc.). The numbers represent the sequence numbers of the decomposition products, corresponding to the single products such as Li₂O, MO, and M₂O₃ that may be produced by the decomposition of layered oxides. The total energy of the cell of the original transition metal layered oxide is used to determine whether the material is thermodynamically decomposable.

[0022] As a further aspect of the present invention: In step four, the phase transition stability calculation adopts the NEB method to construct the minimum energy paths from the layered phase to the spinel phase and from the spinel phase to the rock salt phase in the transition metal layered oxide. Each phase transition path has 6-8 intermediate states. The coordinates of the intermediate states are generated by linear interpolation and relaxed (with a fixed lattice constant). The energy of each intermediate state and the phase transition barrier are calculated. The calculation formula is as follows:

[0023] ;

[0024] in, The highest energy point of the minimum energy path (unit: eV). The total energy (unit: eV) after optimization of the initial phase (layered phase or spinel phase) directly reflects whether the material is prone to phase transition failure during service through the phase transition barrier.

[0025] As a further aspect of the present invention: In step five, the mixed-displacement stability calculation constructs mixed-displacement structure models with mixing ratios of 0.1%, 0.5%, 1%, 3%, 5%, and 10%, wherein the mixing method is either transition metal atoms occupying lithium layer lattice sites or lithium ions occupying transition metal layer lattice sites. Based on the accurate verification parameters in step two, the total energy of the mixed-displacement structure is calculated. Total energy of ideal structure The formula for calculating mixed emissions is as follows:

[0026] ;

[0027] in, The unit is eV / atom. The mixing energy is used to determine the material's ability to resist ion mixing. The lower the mixing energy, the easier it is for mixing to occur.

[0028] As a further aspect of the present invention: In step six, the oxygen release stability calculation is achieved by constructing one of the following: a single oxygen vacancy defect model, an adjacent double oxygen vacancy defect model, or a non-adjacent double oxygen vacancy defect model, thereby activating the spin polarization effect, and calculating the total energy of the perfect structure based on accurate verification parameters. Total energy of defective structures Oxygen vacancy formation energy The calculation formula is as follows:

[0029] ;

[0030] in, , gas phase Total energy of a molecule (unit: eV). The unit is eV. The higher the oxygen vacancy formation energy, the more difficult it is for the material to release lattice oxygen, and the stronger the oxygen release stability.

[0031] As a further aspect of the present invention: in step seven, the multi-dimensional quantification criterion is:

[0032] ①Thermodynamic stability: <0 eV / atom and >0 eV / unit cell (unit cell is defined according to the supercell size in step one);

[0033] ② Phase transformation stability: from layered phase to spinel phase ≥1.2eV, spinel phase to rock salt phase ≥0.8eV;

[0034] ③ Stable ion mixing: at a mixing ratio of 10% ≥0.2eV / atom;

[0035] ④ Stable oxygen release: single oxygen vacancy ≥4.0eV;

[0036] A condition is considered comprehensively stable if all four conditions are met, partially stable if two to three conditions are met, and unstable if ≤1 condition is met.

[0037] As a further aspect of the present invention: In step eight, the automated post-processing program integrates Python scripts and Origin visualization modules, and the output engineering report includes basic material information, multi-dimensional stability index values, criterion compliance status, comprehensive stability level, core failure point location, targeted modification suggestions, as well as phase change energy path diagram, stability radar diagram, and mixing energy and mixing ratio relationship curve.

[0038] Compared with the prior art, the beneficial effects of the present invention by adopting the above technical solution are as follows:

[0039] 1. This invention employs standardized structural modeling and initial geometry optimization techniques that include ideal, doped, defective, and delithiation states. Combined with two sets of standardized calculation parameter systems pre-defined for the electronic structure characteristics of transition metal layered oxides, it simultaneously performs multi-dimensional stability calculations of formation energy, decomposition energy, phase transition barrier, mixing energy, and oxygen vacancy formation energy. Furthermore, it establishes a dedicated quantitative criterion for determining the appropriate level of stability. This addresses the shortcomings of existing first-principles calculations, such as fragmentation, lack of standardized parameters, and absence of targeted criteria. It allows for a comprehensive understanding of material stability without the need for secondary manual analysis, accurately pinpointing the core failure mechanism. This achieves the effect of improving the systematic nature and reliability of stability assessment and providing precise theoretical basis for targeted material modification.

[0040] 2. This invention utilizes the NEB method to specifically calculate the phase transition barriers from layered phases to spinel phases and from spinel phases to rock salt phases. It constructs multi-scale mixed-structure models and single / double oxygen vacancy defect models for specialized calculations. Combined with an automated post-processing program integrating Python scripts and the Origin visualization module, it outputs an engineering report containing modification suggestions. This solves the shortcomings of existing technologies, such as the inability to accurately capture unique failure mechanisms and poor results applicability. It achieves direct conversion from computational data to R&D guidance, significantly reducing the trial-and-error costs and time costs of materials R&D, and accelerating the screening and optimization process of new transition metal layered oxide materials. Attached Figure Description

[0041] Figure 1This is a schematic diagram of the method steps in an embodiment of the present invention. Detailed Implementation

[0042] The specific embodiments of the present invention will be further described below with reference to the accompanying drawings. It should be noted that the description of these embodiments is for the purpose of helping to understand the present invention, but does not constitute a limitation of the present invention.

[0043] Furthermore, the technical features involved in the various embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0044] Please see the appendix Figure 1 The present invention provides a first-principles method for predicting the stability of transition metal layered oxide structures. The prediction method includes the following steps:

[0045] Step 1: Construct a transition metal layered oxide structure model containing ideal, doped, defective, and delithiation states according to standardized rules and perform initial geometry optimization;

[0046] Step 2: Based on the electronic structure characteristics of layered oxides of transition metals (strong correlation between d electrons of transition metals and p electrons of oxygen), two sets of standardized first-principles calculation parameter systems are pre-set for high-throughput screening and precise verification.

[0047] Step 3: Calculate the two types of thermodynamic stability indices: formation energy and decomposition energy;

[0048] Step 4: Calculate the phase transition barriers from layered phase to spinel phase and from spinel phase to rock salt phase using the NEB method;

[0049] Step 5: Calculate the mixing energy of transition metals and lithium ions under different mixing ratios;

[0050] Step 6: Construct defect structure models of single oxygen vacancies and double oxygen vacancies (adjacent / non-adjacent), and calculate the oxygen vacancy formation energy based on the accurate verification parameters in Step 2;

[0051] Step 7: Establish multi-dimensional stability criteria based on quantization thresholds and determine the level;

[0052] Step 8: Output an engineering report containing failure point location and modification suggestions through an automated post-processing program.

[0053] Example 1

[0054] Standardized structural modeling and implementation of a two-parameter system

[0055] With NCM811 (LiNi 0.8 Co 0.1 Mn 0.1Using O2 as the target material, a structural model was constructed: the ideal structure was selected as a 2×2×2 supercell containing 32 atoms, modeled using Materials Studio software. The doped structure was designed with a 3% atomic replacement ratio, and Mg was added to the transition metal layer. 2+ Non-equivalent doping was used, with Mg occupying equivalent sites in the Ni lattice. A 1.5% oxygen vacancy concentration was set for the defect structure, and a random distribution model of two defects was constructed. The delithiation ratio was set in gradients of x=0.2, 0.4, 0.6, and 0.8. Delithiation sites were preferentially selected from equivalent sites in the lithium layer without adjacent transition metals. After modeling, only the coordinates of the relaxed atoms in the lattice constant were fixed. A two-parameter system was preset: high-throughput screening used GGA-PBE functionals and PAW pseudopotentials, with a k-point grid of 5×5×1, a cutoff energy of 370 eV, and convergence criteria of atomic force ≤0.02 eV / Å and total energy ≤1×10⁻⁶. -5 eV / atom, precise verification was performed using the HSE06 functional with 27% Hartree-Fock exchange energy, an all-electron PAW pseudopotential, a 6×6×1 k-point grid, a cutoff energy of 430 eV, and convergence criteria improved to atomic force ≤0.01 eV / Å and total energy ≤1×10 -6 eV / atom, the formation energy and decomposition energy are calculated using VASP software. The formation energy is calculated according to the formula... Calculation, where The optimized total cell energy is -156.82 eV. , =6.4、 =0.8、 =0.8、 =16, = =−3.04eV, Based on NiO, -5.21 eV / atom, =0.5 =−4.92eV / atom, finally obtained =−0.35eV / atom, the decomposition energy is according to the formula calculate, =−156.82eV, the decomposition products are Li2O, NiO, CoO, and MnO. The values ​​were -58.63 eV, -52.10 eV, -30.45 eV, and -41.28 eV, respectively, resulting in... =0.79eV / unitcell, achieving a balance between accuracy and efficiency in calculations.

[0056] Example 2

[0057] Implementation of multi-dimensional quantitative criteria

[0058] Using LiMnO2 as the target material, after completing structural modeling and multi-dimensional calculations, stability assessment was conducted.

[0059] ①Thermodynamic stability: The formation energy is calculated using the formula. =−0.29eV / atom (<0eV / atom), decomposition energy =0.56eV / unitcell (>0eV / unitcell), which meets the criterion;

[0060] ② Phase transition stability: The NEB method was used to calculate the minimum energy paths from the layered phase to the spinel phase and from the spinel phase to the rock salt phase. Seven intermediate states were set for each layer path. The coordinates of the intermediate states were generated by linear interpolation and relaxed (with fixed lattice constants). The phase transition barrier was calculated according to the formula. Calculations show that the layered phase to the spinel phase... =−128.35eV、 =−129.72eV, therefore =1.37eV (≥1.2eV), spinel phase to rock salt phase =−127.98eV、 =−128.85eV, therefore =0.87eV (≥0.8eV), which meets the criterion;

[0061] ③ Ion mixing stability: Construct a mixing ratio model of 0.1%-10%, according to the formula Calculations show that under a 10% mixing ratio... =−129.43eV、 =−129.72eV, therefore =0.29eV / atom (≥0.2eV / atom), which meets the criterion;

[0062] ④ Oxygen release stability: Construct a single oxygen vacancy defect model (enabling spin polarization effect), according to the formula calculate, =−127.65eV、 =−129.72eV、 =−4.92eV / atom, therefore =4.23eV (≥4.0eV), which meets the criterion, and is therefore judged as "overall stable".

[0063] Example 3

[0064] Implementation of Automated Post-Processing and Engineering Reporting

[0065] Lithium-rich manganese-based materials (Li 1.1 Mn 0.6 Ni 0.2 Co0.1 Using O2 as the target material, after completing the aforementioned modeling and calculations, an automated post-processing program is launched. Integrating Python scripts and the Origin visualization module, the program automatically extracts multi-dimensional data: formation energy... =−0.27eV / atom, decomposition energy =0.48eV / unitcell, layered phase to spinel phase transformation barrier =1.12eV, 10% mixing energy =0.17 eV / atom, single oxygen vacancy formation energy =3.76eV, criteria indicated: phase transition barrier, mixing energy, and oxygen release stability did not meet the standards. The core failure point was identified as "easy phase transition + strong tendency for ion mixing + high risk of oxygen release". Based on the failure mechanism, the report output targeted modification recommendation: "Use Zr..." 4+ The doping of a transition metal layer (5% doping ratio) enhances lattice bonding strength to suppress ion mixing and phase transition, regulates the oxygen coordination environment, and increases the oxygen vacancy formation energy to above 4.0 eV. At the same time, it automatically generates a phase transition energy path diagram (marking the energy distribution of intermediate states), a stability radar chart (intuitively showing the achievement of four criteria), and a mixing energy-mixing ratio relationship curve (showing the trend of mixing energy changing with the ratio), directly providing engineering guidance for material research and development.

[0066] Specifically, the core of the structural modeling rules is to fit the actual application scenarios of layered oxides of transition metals: the selection of supercells needs to balance the accuracy of interlayer interaction characterization and computational efficiency. 1×1×3 or 2×2×2 supercells can accurately reflect the layered stacking characteristics. The doped atoms occupying equivalent positions in the lattice are based on lattice symmetry and bonding stability to avoid distortion of calculation results due to random occupancy. The delithiation sites are preferentially selected from equivalent positions without adjacent transition metals, which is the preferred deintercalation and deintercalation path of lithium ions in the actual electrochemical process. The initial geometry optimization only fixes the lattice constant, which is to eliminate the geometric stress of the initial modeling while preserving the essential characteristics of the layered structure, and to ensure the accuracy of subsequent calculations.

[0067] Specifically, the design of the two standardized computational parameter systems is based on the electronic structure characteristics of transition metal layered oxides: the d electrons of transition metals are strongly correlated with the p electrons of oxygen, the PBE functional can efficiently describe conventional electronic interactions, and it is suitable for the efficiency requirements of high-throughput screening. The HSE06 hybrid functional introduces part of the Hartree-Fock exchange energy, which can accurately correct the electronic correlation effect and meet the accuracy requirements of the core system. The gradient setting of the parameter convergence standard is to balance the reliability of the results and the computational cost at different computational stages. The limitation of the k-point grid and the cutoff energy is based on the two-dimensional periodicity characteristics of the layered structure to ensure the integrity of the electronic state integral and avoid computational deviations caused by insufficient parameters.

[0068] Specifically, the selection of the chemical potential benchmark in the formation energy formula has a clear physical significance: using the stable phase of bulk lithium metal, stable oxides of transition metals, and gaseous O2 molecules as benchmarks is to unify the reference standard of elemental energy and ensure the comparability of the formation energies of different material systems. The limitation of decomposition products in the decomposition energy formula is based on the common thermodynamic decomposition paths of layered oxides of transition metals during service, covering typical products such as Li2O, MO, and M2O3, which can comprehensively reflect the thermodynamic stability trend of the material. By calculating the two types of indicators together, the one-sidedness of judging by a single indicator can be avoided, and the stability of the material at the thermodynamic level can be fully evaluated.

[0069] Specifically, the implementation logic of the NEB method is to accurately capture the energy barrier of the phase transition process: constructing the minimum energy paths from the layered phase to the spinel phase and from the spinel phase to the rock salt phase, because these two types of phase transitions are the most important structural failure forms of transition metal layered oxides. The number of intermediate states is set to 6-8 to ensure the continuity of the energy path and avoid missing key transition state structures. The intermediate state coordinates are relaxed after being generated by linear interpolation and the lattice constant is fixed to focus on the energy change of the phase transition itself and eliminate the additional energy interference caused by lattice distortion. The phase transition barrier formula directly reflects the energy difference from the initial phase to the transition state, which can quantitatively assess the material's ability to resist phase transitions and provide a core basis for stability determination.

[0070] Specifically, the core design principle of mixed-packing structure modeling and mixed-packing energy calculation is to align with actual failure mechanisms: the mixed-packing ratio covers 0.1%-10% because this range includes low- to high-occurrence mixed-packing scenarios during material service, enabling a comprehensive assessment of the impact of mixed-packing on stability. Two mixed-packing methods are limited because transition metal atoms occupying lithium layer lattice sites and lithium ions occupying transition metal layer lattice sites are the most common mixed-packing types for this type of material, conforming to the actual structural evolution law. By calculating the mixed-packing energy through the energy difference between the mixed-packing structure and the ideal structure, the material's ability to resist ion mixed-packing can be quantitatively reflected. The physical meaning of the mixed-packing energy is directly related to the material's cycle stability, providing a crucial reference for engineering applications.

[0071] Specifically, the construction and calculation logic of the oxygen vacancy defect model is aimed at the oxygen release failure problem of transition metal layered oxides: single oxygen vacancy and adjacent / non-adjacent double oxygen vacancy models correspond to two typical mechanisms: oxygen atom release by individual release and oxygen atom release by aggregation, respectively, covering the main forms of oxygen release in actual service. The spin polarization effect is enabled because transition metal atoms have unpaired d electrons, and the spin characteristics will significantly affect the bonding strength between transition metal and oxygen. Ignoring spin polarization will lead to the distortion of the oxygen vacancy formation energy calculation. The calculation of oxygen vacancy formation energy directly reflects the ease with which the material releases lattice oxygen. Its value is closely related to the material's cycle stability and thermal stability, and is the core indicator for evaluating oxygen release stability.

[0072] Working principle:

[0073] First, for the target transition metal layered oxide, a structural model including ideal, doped, defective, and delithiation states was constructed according to standardized rules. After model building using specified modeling software, only the lattice constant was fixed for initial geometric optimization to ensure that the model closely matches the actual structural characteristics of the material. Next, considering the strong correlation between d electrons and p electrons of the transition metal in this type of material, two sets of standardized first-principles calculation parameters were preset for high-throughput screening and precise verification to achieve a balance between computational accuracy and efficiency. Subsequently, based on the constructed model and preset parameters, two thermodynamic stability indices, formation energy and decomposition energy, were calculated sequentially. The NEB method was used to calculate the phase transition barriers from the layered phase to the spinel phase and from the spinel phase to the rock salt phase, and a multi-scale mixed-structure model was constructed. The process involves calculating the mixing energy of transition metals and lithium ions, building defect models for single oxygen vacancies and adjacent / non-adjacent double oxygen vacancies, and calculating the oxygen vacancy formation energy by activating spin polarization. This completes the comprehensive acquisition of core stability indicators across multiple dimensions. Subsequently, based on preset quantification thresholds, specific criteria are matched from four dimensions: thermodynamics, phase transition, ion mixing, and oxygen release, to determine the overall stability level of the material. Finally, through an automated post-processing program integrating Python scripts and the Origin visualization module, all calculation data and criterion results are integrated to output an engineering report containing basic material information, stability index values, compliance status, level determination, core failure point location, targeted modification suggestions, and related visualization charts. This concludes the entire workflow.

[0074] While the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the invention. Any variations and modifications can be made by those skilled in the art without departing from the spirit and scope of the invention. Therefore, any modifications, equivalent changes, and alterations made to the above embodiments based on the technical essence of the present invention, without departing from the scope of the invention, fall within the protection scope defined by the claims of the present invention.

Claims

1. A first-principles method for predicting the stability of transition metal layered oxide structures, characterized in that, The prediction method includes the following steps: Step 1: Construct a transition metal layered oxide structure model containing ideal, doped, defective, and delithiation states according to standardized rules and perform initial geometry optimization; Step 2: Based on the electronic structure characteristics of transition metal layered oxides, two standardized first-principles calculation parameter systems are pre-set for high-throughput screening and precise verification; Step 3: Calculate the two types of thermodynamic stability indices: formation energy and decomposition energy; Step 4: Calculate the phase transition barriers from layered phase to spinel phase and from spinel phase to rock salt phase using the NEB method; Step 5: Calculate the mixing energy of transition metals and lithium ions under different mixing ratios; Step 6: Construct defect structure models of single and double oxygen vacancies, and calculate the oxygen vacancy formation energy based on the accurate verification parameters obtained in Step 2. Step 7: Establish multi-dimensional stability criteria based on quantization thresholds and determine the level; Step 8: Output an engineering report containing failure point location and modification suggestions through an automated post-processing program.

2. The first-principles prediction method for the stability of transition metal layered oxide structures according to claim 1, characterized in that: The ideal layered structure is selected from either a 1×1×3 or 2×2×2 supercell. The doping structure uses an atomic replacement ratio of 0.5%-10%, with equivalent and non-equivalent doping performed on one of the transition metal or lithium layers, ensuring that the doped atoms occupy equivalent lattice positions. The concentration of oxygen vacancies and transition metal vacancies in the defect structure is 0.1%-5%. A single / double defect random distribution model is constructed, and the delithiation state structure follows the Li... X The MO2 gradient sets the delithiation ratio, M is the transition metal, x = 0.1, 0.2...1.0, and the delithiation sites are preferentially selected from the equivalent positions of the lithium layer without adjacent transition metals. The initial geometry optimization only fixes the lattice constant and the coordinates of the relaxed atoms. The modeling software is MaterialsStudio, VASP or CASTEP.

3. The first-principles prediction method for the stability of transition metal layered oxide structures according to claim 2, characterized in that: In step two, the standardized calculation parameter system is as follows: the high-throughput screening system adopts the PBE functional under the generalized gradient approximation, the projected fused wave pseudopotential, the k-point grid ≥ 3×3×1, the plane wave cutoff energy is 350-400eV, and the structural relaxation convergence criteria are set as follows: atomic force ≤ 0.02eV / Å, and total cell energy convergence accuracy ≤ 1×10⁻⁶. -5 eV / atom, self-consistent iterative convergence criterion ≤1×10 -6 eV / atom; The precise verification system employs an HSE06 hybrid functional with 25%-30% Hartree-Fock exchange energy, and optimizes the PAW pseudopotential to an all-electron pseudopotential. The k-point grid is ≥5×5×1, the cutoff energy is 400-450 eV, and the convergence criterion is improved to: atomic force ≤0.01 eV / Å, and the total energy convergence accuracy ≤1×10⁻⁶. -6 eV / atom.

4. The first-principles prediction method for the stability of transition metal layered oxide structures according to claim 3, characterized in that: In step three, the heat is calculated using first-principles calculations of the formation energy, a core indicator of the thermodynamic stability of transition metal layered oxides. and decomposition energy , forming energy and decomposition energy The calculation formula is as follows: ； in, The total energy of the unit cell after construction and optimization in step one. The first in the unit cell The number of atoms of the elements Li, transition metal M, and O. For the first The chemical potentials of the elements, with the chemical potential of Li based on the stable phase of metallic Li, and the chemical potentials of transition metals M. Based on its stable oxide, the chemical potential of O Based on O2 molecules; ； in, This represents the total cell energy of the possible decomposition products of layered oxides. The sequence number is the decomposition product. This represents the total energy of the unit cell of the original transition metal layered oxide.

5. The first-principles prediction method for the stability of transition metal layered oxide structures according to claim 4, characterized in that: In step four, the phase transition stability calculation employs the NEB method, constructing minimum energy paths from the layered phase to the spinel phase and from the spinel phase to the rock salt phase in the transition metal layered oxide. Each phase transition path contains 6-8 intermediate states. The coordinates of these intermediate states are generated through linear interpolation and then relaxed. The energy of each intermediate state and the phase transition barrier are then calculated. The calculation formula is as follows: ； in, The highest energy point is the path with the minimum energy. This represents the total energy after initial phase optimization.

6. The first-principles prediction method for the stability of transition metal layered oxide structures according to claim 5, characterized in that: In step five, the mixed-displacement stability calculation constructs mixed-displacement structure models with mixing ratios of 0.1%, 0.5%, 1%, 3%, 5%, and 10%. The mixing method is either transition metal atoms occupying lithium layer lattice sites or lithium ions occupying transition metal layer lattice sites. Based on the accurate verification parameters in step two, the total energy of the mixed-displacement structure is calculated. Total energy of ideal structure The formula for calculating mixed emissions is as follows: ； in, The unit is eV / atom. The mixing energy is used to determine the material's ability to resist ion mixing. The lower the mixing energy, the easier it is for mixing to occur.

7. The first-principles prediction method for the stability of transition metal layered oxide structures according to claim 6, characterized in that: In step six, the oxygen release stability calculation is performed by constructing one of the following models: a single oxygen vacancy defect model, an adjacent double oxygen vacancy defect model, or a non-adjacent double oxygen vacancy defect model. This activates the spin polarization effect, and the total energy of the perfect structure is calculated based on accurate verification parameters. Total energy of defective structures Oxygen vacancy formation energy The calculation formula is as follows: ； in, , gas phase The higher the total energy of the molecules and the higher the oxygen vacancy formation energy, the more difficult it is for the material to release lattice oxygen, and the stronger the oxygen release stability.

8. The first-principles prediction method for the stability of transition metal layered oxide structures according to claim 7, characterized in that: In step seven, the multi-dimensional quantification criterion is: ①Thermodynamic stability: <0 eV / atom and >0 eV / unit cell; ② Phase transformation stability: from layered phase to spinel phase ≥1.2eV, spinel phase to rock salt phase ≥0.8eV; ③ Stable ion mixing: at a mixing ratio of 10% ≥0.2eV / atom; ④ Stable oxygen release: single oxygen vacancy ≥4.0eV; A condition is considered comprehensively stable if all four conditions are met, partially stable if two to three conditions are met, and unstable if ≤1 condition is met.

9. The first-principles prediction method for the stability of transition metal layered oxide structures according to claim 8, characterized in that: In step eight, the automated post-processing program integrates Python scripts and the Origin visualization module. The output engineering report includes basic material information, multi-dimensional stability index values, criterion compliance status, comprehensive stability level, core failure point location, targeted modification suggestions, as well as phase change energy path diagram, stability radar diagram, and mixing energy and mixing ratio relationship curve.

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