A method and device for calculating properties of positive electrode materials of lithium battery

Abstract

A method and device for calculating the properties of positive electrode materials of lithium batteries, relating to the technical field of calculating the properties of electrode materials, wherein the method optimizes the configuration of the initial unit cell structure and performs self-consistent calculation processing to obtain the ground state wave function and orbital eigenvalues; according to the orbital eigenvalues ​​and atomic coordinates, the initial electronic screening potential is set, and the Kohn‑sham orbital coefficient matrix, the overlap matrix and the density matrix are initialized; through the tensor calculation strategy, the occupation matrix after summation is calculated; the initial electronic screening potential is iterated by setting formal parameters. Second-order linear perturbation is performed; until the set formal parameters reach the convergence limit, the electronic screening potential and the slope of the corresponding point are obtained at this time; according to the atomic coordinates, the electronic force is calculated; by setting the calculation strategy, the set performance parameters of the positive electrode material are calculated. The present invention can dynamically adjust the electronic screening potential during the calculation process to compensate for the self-interaction error, thereby providing a more accurate electronic structure calculation.

Description

Technical Field

[0001] The present invention relates to the technical field of electrode material property calculation, and in particular to a method and device for calculating the property of a lithium battery positive electrode material. Background Art

[0002] Lithium batteries play a vital role in modern energy storage devices, especially in portable electronic devices and electric vehicles. As one of the core components of lithium batteries, the design and discovery of cathode materials directly affect the performance, life and safety of batteries. In order to develop efficient cathode materials, computer virtual screening and calculations have been widely used, especially the first-principles calculation methods. These calculation methods are based on the basic laws of quantum mechanics and do not rely on experimental parameters. They can accurately predict the electronic structure and related properties of materials theoretically.

[0003] At present, although first-principles calculations have performed well in materials science research, there are some limitations in their application, especially the self-interaction error (SIE). This error is caused by the failure of electrons to be completely offset under self-interaction, resulting in a deviation between the calculated results of the electronic structure and the actual situation. Specifically, the self-interaction error will make the electron density distribution inaccurate, affecting the prediction of energy level distribution and band gap, and thus affecting the conductivity, stability and other key properties of the material.

[0004] Therefore, how to invent a method for calculating the properties of lithium battery positive electrode materials that can dynamically adjust the electron screening potential during the calculation process, compensate for self-interaction errors, and provide more accurate electronic structure calculations has become an urgent problem to be solved. Summary of the invention

[0005] To this end, the present invention provides a method and device for calculating the properties of lithium battery positive electrode materials, which can dynamically adjust the electron screening potential during the calculation process to compensate for the self-interaction error, thereby providing a more accurate electronic structure calculation, and at the same time can significantly improve the accuracy of the calculation results without significantly increasing the amount of calculation.

[0006] In order to achieve the above object, the present invention provides the following technical solution: a method for calculating the properties of positive electrode materials of lithium batteries, comprising:

[0007] Inputting the initial unit cell structure into the set calculation software, optimizing the configuration of the initial unit cell structure by setting the optimization strategy; performing self-consistent calculation processing on the optimized configuration to obtain the ground state wave function and orbital eigenvalue;

[0008] According to the orbital eigenvalues ​​and atomic coordinates, an initial electron screening potential is set, and the Kohn-sham orbital coefficient matrix, overlap matrix, and density matrix are initialized;

[0009] The tensor calculation strategy is used to calculate the occupation matrix after summation; the initial electronic screening potential is subjected to second-order linear perturbation by setting formal parameters; several values ​​of the set formal parameters are substituted to perform iterative calculation until the set formal parameters reach the convergence limit, and the iteration is stopped to obtain the electronic screening potential and the slope of the corresponding point at this time;

[0010] When the second-order linear perturbation processing is completed, the force on the electron is calculated according to the atomic coordinates;

[0011] According to the electronic force, a calculation strategy is set to calculate and obtain the set performance parameters of the positive electrode material.

[0012] As a preferred solution of a method for calculating the properties of a positive electrode material for a lithium battery, in the process of calculating and obtaining the set performance parameters of the positive electrode material by setting a calculation strategy, the calculation steps of the set performance parameters are:

[0013] According to the force on the electron, the self-consistent calculation process is performed to obtain a molecular orbital list; according to the molecular orbital list, a band gap is calculated;

[0014] The equilibrium discharge rate under the set potential difference is calculated by the equilibrium discharge rate calculation strategy; the equilibrium discharge rate is linearly fitted to obtain the final equilibrium discharge rate;

[0015] The mobility is calculated using the mobility calculation strategy.

[0016] As a preferred solution of a method for calculating the properties of positive electrode materials of lithium batteries, in the process of calculating and obtaining the summed occupancy matrix through the tensor calculation strategy, the expression of the tensor calculation strategy is:

[0017] ;

[0018] In the formula, For the I The wave functions on the orbital basis constitute the left vector; is the density operator corresponding to spin \sigma; For the I The wave functions on the orbital basis form the right vector; , are the spin\sigma and I The overall wave function on the strip; For the m Track base The wave function of the spin constitutes the left vector; is the center of the ith wave function The combination coefficient of spin; m and i Represents the position coordinates of the center of the wave function.

[0019] As a preferred solution of a method for calculating the properties of positive electrode materials of a lithium battery, in the process of performing a second-order linear perturbation on the initial electron screening potential by setting formal parameters, the expression of the second-order linear perturbation is:

[0020] ;

[0021] In the formula, is the orbital action coefficient; is the spin operator; , ,c,d,e Label the rows and columns of the partially occupied matrix; is the total energy of the system; For Coordinate parameters under orbital action coefficients; for P In the I Matrix elements on the strip wave function; For Q I Matrix elements on the strip wave function; It means distinguishing spins different from σ; is the symbol of partial derivative; for P In the I On the wave function OK, f The value on the column; For Coordinate parameters under orbital action coefficients; for P In the I On the wave function OK, c The value on the column; For Coordinate parameters under orbital action coefficients; for P In the I On the wave function OK, e The value on the column; For Coordinate parameters under orbital action coefficients.

[0022] As a preferred solution for calculating the properties of a lithium battery positive electrode material, the calculation formula for the electron force is:

[0023] ;

[0024] In the formula, is the three-dimensional coordinate; For Under the coordinates, The unit cell force corresponding to the formal parameter value at the convergence limit; is the occupancy number overlap matrix element; is the total energy under the values ​​of P and Q.

[0025] The present invention also provides a device for calculating the properties of a positive electrode material of a lithium battery, based on the above method for calculating the properties of a positive electrode material of a lithium battery, comprising:

[0026] The configuration optimization and self-consistent calculation module is used to input the initial unit cell structure into the set calculation software, and optimize the configuration of the initial unit cell structure by setting the optimization strategy; the optimized configuration is processed by self-consistent calculation to obtain the ground state wave function and orbital eigenvalue;

[0027] A matrix initialization module, used to set the initial electron screening potential according to the orbital eigenvalues ​​and atomic coordinates, and to initialize the Kohn-sham orbital coefficient matrix, overlap matrix and density matrix;

[0028] A second-order linear perturbation iterative calculation module is used to calculate the summed occupation matrix through the tensor calculation strategy; perform second-order linear perturbation on the initial electronic screening potential by setting formal parameters; perform iterative calculation by substituting several values ​​of the set formal parameters until the set formal parameters reach the convergence limit, stop iteration, and obtain the electronic screening potential and the slope of the corresponding point at this time;

[0029] An electron force acquisition module, used to calculate and obtain the electron force according to the atomic coordinates when the second-order linear perturbation processing is completed;

[0030] The material performance parameter calculation module is used to calculate the set performance parameters of the positive electrode material by setting a calculation strategy according to the electronic force.

[0031] As a preferred solution of a lithium battery positive electrode material property calculation device, in the material performance parameter calculation module, the calculation submodule includes:

[0032] A band gap calculation submodule, used to perform the self-consistent calculation process according to the electronic force to obtain a molecular orbital list; and calculate the band gap according to the molecular orbital list;

[0033] The balanced discharge rate calculation submodule is used to calculate the balanced discharge rate under the set potential difference through the balanced discharge rate calculation strategy; and perform linear fitting on the balanced discharge rate to obtain the final balanced discharge rate;

[0034] The mobility calculation submodule is used to calculate the mobility through the mobility calculation strategy.

[0035] As a preferred solution of a lithium battery positive electrode material property calculation device, in the second-order linear perturbation iterative calculation module, in the process of calculating the summed occupancy matrix through the tensor calculation strategy, the expression of the tensor calculation strategy is:

[0036] ;

[0037] In the formula, For the I The wave functions on the orbital basis constitute the left vector; is the density operator corresponding to spin \sigma; For the I The wave functions on the orbital basis form the right vector; , are the spin\sigma and I The overall wave function on the strip; For the m Track base The wave function of the spin constitutes the left vector; is the center of the ith wave function The combination coefficient of spin; m and i Represents the position coordinates of the center of the wave function.

[0038] As a preferred solution of a lithium battery positive electrode material property calculation device, in the second-order linear perturbation iterative calculation module, in the process of performing a second-order linear perturbation on the initial electron screening potential by setting formal parameters, the expression of the second-order linear perturbation is:

[0039] ;

[0040] In the formula, is the orbital action coefficient; is the spin operator; , ,c,d,e Label the rows and columns of the partially occupied matrix; is the total energy of the system; For Coordinate parameters under orbital action coefficients; for P In the I Matrix elements on the strip wave function; For Q I Matrix elements on the strip wave function; It means distinguishing spins different from σ; is the symbol of partial derivative; for P In the I On the wave function OK, f The value on the column; For Coordinate parameters under orbital action coefficients; for P In the I On the wave function OK, c The value on the column; For Coordinate parameters under orbital action coefficients; for P In the I On the wave function OK, e The value on the column; For Coordinate parameters under orbital action coefficients.

[0041] As a preferred solution of a lithium battery positive electrode material property calculation device, in the electronic force acquisition module, the calculation formula of the electronic force is:

[0042] ;

[0043] In the formula, is the three-dimensional coordinate; For Under the coordinates, The unit cell force corresponding to the formal parameter value at the convergence limit; is the occupancy number overlap matrix element; is the total energy under the values ​​of P and Q.

[0044] The invention has the following advantages: inputting the initial unit cell structure into the set calculation software, optimizing the configuration of the initial unit cell structure by setting the optimization strategy; performing self-consistent calculation processing on the optimized configuration to obtain the ground state wave function and orbital eigenvalues; setting the initial electron screening potential according to the orbital eigenvalues ​​and atomic coordinates, and initializing the Kohn-sham orbital coefficient matrix, the overlap matrix and the density matrix; calculating and obtaining the summed occupancy matrix by the tensor calculation strategy; performing second-order linear perturbation on the initial electron screening potential by setting formal parameters; performing iterative calculation by substituting several set formal parameter values ​​until the set formal parameters reach the convergence limit, stopping the iteration, and obtaining the electron screening potential and the slope of the corresponding point at this time; when the second-order linear perturbation processing is completed, calculating and obtaining the electron force according to the atomic coordinates; and calculating and obtaining the set performance parameters of the positive electrode material by setting the calculation strategy according to the electron force. The calculation steps for setting the performance parameters are: according to the force on the electron, the self-consistent calculation process is performed to obtain a molecular orbital list; according to the molecular orbital list, the band gap is calculated; the equilibrium discharge rate under the set potential difference is calculated by the equilibrium discharge rate calculation strategy; the equilibrium discharge rate is linearly fitted to obtain the final equilibrium discharge rate; the mobility is calculated by the mobility calculation strategy. The present invention dynamically adjusts the electron screening potential during the calculation process to compensate for the self-interaction error, thereby providing a more accurate electronic structure calculation. At the same time, it can significantly improve the accuracy of the calculation results without significantly increasing the amount of calculation. The present invention can not only accurately calculate the electronic structure, but also effectively predict the properties of the positive electrode material related to the electronic structure, such as band gap, equilibrium discharge rate, average electron mobility, etc. This is of great significance for the research and development of positive electrode materials. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] In order to more clearly illustrate the implementation methods of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for the implementation methods or the description of the prior art. Obviously, the drawings in the following description are only exemplary, and for ordinary technicians in this field, other implementation drawings can be derived from the provided drawings without creative work.

[0046] The structures, proportions, sizes, etc. illustrated in this specification are only used to match the contents disclosed in the specification so as to facilitate understanding and reading by persons familiar with the technology. They are not used to limit the conditions under which the present invention can be implemented, and therefore have no substantial technical significance. Any structural modification, change in proportion or adjustment of size shall still fall within the scope of the technical contents disclosed in the present invention without affecting the effects and purposes that can be achieved by the present invention.

[0047] Figure 1A schematic diagram of a method for calculating the properties of a positive electrode material for a lithium battery provided in Example 1 of the present invention;

[0048] Figure 2 This is a schematic diagram of the architecture of a lithium battery positive electrode material property calculation device provided in Example 2 of the present invention. DETAILED DESCRIPTION

[0049] The following is a description of the implementation of the present invention by specific embodiments. People familiar with the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0050] Example 1

[0051] See also Figure 1 Embodiment 1 of the present invention provides a method for calculating the properties of a positive electrode material of a lithium battery, comprising the following steps:

[0052] S1. Inputting the initial unit cell structure into the setting calculation software, optimizing the configuration of the initial unit cell structure by setting the optimization strategy; performing self-consistent calculation processing on the optimized configuration to obtain the ground state wave function and orbital eigenvalue;

[0053] S2. According to the orbital eigenvalues ​​and atomic coordinates, an initial electron screening potential is set, and the Kohn-sham orbital coefficient matrix, overlap matrix and density matrix are initialized;

[0054] S3, by using the tensor calculation strategy, calculate and obtain the occupation matrix after summation; perform a second-order linear perturbation on the initial electronic screening potential by setting formal parameters; perform iterative calculation by substituting several values ​​of the set formal parameters until the set formal parameters reach the convergence limit, stop the iteration, and obtain the electronic screening potential and the slope of the corresponding point at this time;

[0055] S4. When the second-order linear perturbation processing is completed, the electron force is calculated according to the atomic coordinates;

[0056] S5. According to the force on the electrons, a calculation strategy is set to calculate and obtain set performance parameters of the positive electrode material.

[0057] In this embodiment, in step S1, the initial unit cell structure is input into the setting calculation software, and the configuration of the initial unit cell structure is optimized by setting the optimization strategy; the optimized configuration is processed by self-consistent calculation to obtain the ground state wave function and orbital eigenvalue;

[0058] Specifically, taking the orthorhombic Cu2O as an example, the unit cell contains 6 atoms, and the lattice constants are a=b=c=4.25A,\alpha=\beta=\gamma=90; the initial unit cell structure is input into the first-principles calculation software CP2K, and the TZV2P basis set and PBE functional are used for configuration optimization, and then a self-consistent calculation is performed to obtain the ground state wave function and orbital eigenvalues.

[0059] In this embodiment, in step S2, the initial electron screening potential is set according to the orbital eigenvalues ​​and atomic coordinates, and the Kohn-sham orbital coefficient matrix, overlap matrix and density matrix are initialized;

[0060] Specifically, the atomic coordinates and the ground state wave function are used as initial conditions, and the initial electronic screening potential is set to 1e-10. At the same time, the Kohn-sham orbital coefficient matrix C, overlap matrix S, and density matrix D are initialized. The Kohn-sham orbital coefficient matrix C is initialized using the isolated atomic orbital coefficients of Cu and O atoms; the overlap matrix S is set to 1.E-20; and the density matrix uses the orbital overlap of Cu and O as an initial value of 0.21.

[0061] In this embodiment, in step S3, the occupancy matrix after summation is calculated by using the tensor calculation strategy;

[0062] Specifically, the expression of the tensor calculation strategy is:

[0063] ;

[0064] In the formula, For the I The wave functions on the orbital basis constitute the left vector; is the density operator corresponding to spin \sigma; For the I The wave functions on the orbital basis form the right vector; , are the spin\sigma and I The overall wave function on the strip; For the m Track base The wave function of the spin constitutes the left vector; is the center of the ith wave function The combination coefficient of spin; m and i Represents the position coordinates of the center of the wave function.

[0065] In this embodiment, the initial electron screening potential is subjected to a second-order linear perturbation by setting formal parameters; by substituting several values ​​of the set formal parameters, an iterative calculation is performed until the set formal parameters reach a convergence limit, the iteration is stopped, and the electron screening potential and the slope of the corresponding point at this time are obtained;

[0066] Specifically, set P The initial value is 1.E-20, set Q The value range of is [0,0.5]; Q The value grid points are set to 20, and are substituted into Q Calculate the electronic screening potential; find the minimum value, find the slope of the corresponding point, and use this point as Q The next initial value of P Perform the same operation and iterate until the convergence limit is 1.E-20. P and Q Iterate until the convergence limit is reached and output the P and Q The values ​​are 0.113 and 0.23.

[0067] Wherein, the expression of the second-order linear perturbation is:

[0068] ;

[0069] In the formula, is the orbital action coefficient; is the spin operator; , ,c,d,e Label the rows and columns of the partially occupied matrix; is the total energy of the system; For Coordinate parameters under orbital action coefficients; for P In the I Matrix elements on the strip wave function; For Q I Matrix elements on the strip wave function; It means distinguishing spins different from σ; is the symbol of partial derivative; for P In the I On the wave function OK, f The value on the column; For Coordinate parameters under orbital action coefficients; for P In the I On the wave function OK, c The value on the column; For Coordinate parameters under orbital action coefficients; for P In the I On the wave function OK, e The value on the column; For Coordinate parameters under orbital action coefficients.

[0070] In this embodiment, in step S4, when the second-order linear perturbation processing is completed, the electron force is calculated according to the atomic coordinates;

[0071] Specifically, the calculation formula of the electron force is:

[0072] ;

[0073] In the formula, is the three-dimensional coordinate; For Under the coordinates, The unit cell force corresponding to the formal parameter value at the convergence limit; is the occupancy number overlap matrix element; is the total energy under the values ​​of P and Q.

[0074] In this embodiment, in step S5, according to the force on the electrons, a calculation strategy is set to calculate and obtain the set performance parameters of the positive electrode material.

[0075] Specifically, the calculation steps for setting the performance parameters are:

[0076] S51, performing the self-consistent calculation process according to the electronic force to obtain a molecular orbital list; and calculating and obtaining a band gap according to the molecular orbital list;

[0077] Specifically, according to the force at this time, a self-consistent calculation is performed to output the molecular orbital list {e_i}; the difference between the eigenvalues ​​of the lowest unoccupied orbital e_m and the highest occupied orbital e_{m-1} is the band gap. In Cu2O, e_m is 0.72eV, e_{m-1} is 0.21eV, the band gap is 0.51eV, and the mobility is =0.013.

[0078] S52, calculating the equilibrium discharge rate under the set potential difference through the equilibrium discharge rate calculation strategy; performing linear fitting on the equilibrium discharge rate to obtain the final equilibrium discharge rate;

[0079] Specifically, different discharge rate calculation strategies are used to calculateV The equilibrium discharge rate under the value is calculated, and a linear fit is performed to obtain the final equilibrium discharge rate;

[0080] ;

[0081] In the formula, is the migration rate; V is the potential difference, set to 3V; d In order to balance the discharge distance, the value here is the optimized Cu-O bond length of 2.36A.

[0082] S53. Calculate and obtain the mobility using a mobility calculation strategy.

[0083] Specifically, the mobility calculation formula is:

[0084] ;

[0085] In the formula, m is the effective mass, which is obtained from step S51 k The energy band slope at the point is calculated to be 0.33; e is the electron charge constant; is the effective mass of the corresponding electron.

[0086] In one possible implementation, two spinel LiMn2O4 structures containing surface and bulk defects reported in experiments are used for comparative implementation tests:

[0087] First, the TZV2P basis set and PBE functional were used for configuration optimization as a comparison between SASP calculation and ordinary direct calculation of corresponding values. The potential difference was set to 3.5V here. For the accuracy of the calculation, the k-point was set to 3*3*3, and the Monte-Commander-Parker sampling method was used. The calculation method (SASP) was used to compare the band gap, average discharge rate and average electron mobility results of the commonly used PBE functional, HSE functional and the commonly used self-consistent calculation method that directly outputs the molecular orbital list, and the band gap was compared with the experimental value; the results are shown in Tables 1 and 2:

[0088] Table 1 Properties of LiMnO4-1

[0089]

[0090] Table 2 Results of property parameters of LiMnO4-2

[0091]

[0092] The results show that the method of the present invention accurately describes the band gap, equilibrium discharge rate and mobility compared with experimental values, and the calculation time does not increase significantly. The results obtained by the common self-consistent calculation using PBE or HSE functionals are distorted, and there is a certain proportion of output error values, and the calculation time of the HSE functional method is more than 10 times that of the present invention.

[0093] In summary, the present invention inputs the initial unit cell structure into the set calculation software, optimizes the configuration of the initial unit cell structure by setting the optimization strategy; performs self-consistent calculation processing on the optimized configuration to obtain the ground state wave function and orbital eigenvalues; sets the initial electron screening potential according to the orbital eigenvalues ​​and atomic coordinates, and initializes the Kohn-sham orbital coefficient matrix, overlap matrix and density matrix; calculates and obtains the summed occupancy matrix through the tensor calculation strategy; performs second-order linear perturbation on the initial electron screening potential by setting formal parameters; performs iterative calculation by substituting several values ​​of the set formal parameters until the set formal parameters reach the convergence limit, stops iteration, and obtains the electron screening potential and the slope of the corresponding point at this time; when the second-order linear perturbation processing is completed, the electron force is calculated according to the atomic coordinates; according to the electron force, the set performance parameters of the positive electrode material are calculated by setting the calculation strategy. The calculation steps for setting the performance parameters are: according to the force on the electron, the self-consistent calculation process is performed to obtain a molecular orbital list; according to the molecular orbital list, the band gap is calculated; the equilibrium discharge rate under the set potential difference is calculated by the equilibrium discharge rate calculation strategy; the equilibrium discharge rate is linearly fitted to obtain the final equilibrium discharge rate; the mobility is calculated by the mobility calculation strategy. The present invention dynamically adjusts the electron screening potential during the calculation process to compensate for the self-interaction error, thereby providing a more accurate electronic structure calculation. At the same time, it can significantly improve the accuracy of the calculation results without significantly increasing the amount of calculation. The present invention can not only accurately calculate the electronic structure, but also effectively predict the properties of the positive electrode material related to the electronic structure, such as band gap, equilibrium discharge rate, average electron mobility, etc. This is of great significance for the research and development of positive electrode materials.

[0094] It should be noted that the method of the embodiment of the present disclosure can be performed by a single device, such as a computer or a server. The method of the present embodiment can also be applied in a distributed scenario and completed by multiple devices cooperating with each other. In the case of such a distributed scenario, one of the multiple devices can only perform one or more steps in the method of the embodiment of the present disclosure, and the multiple devices will interact with each other to complete the described method.

[0095] It should be noted that some embodiments of the present disclosure are described above. In some cases, the actions or steps recorded can be performed in an order different from that in the above embodiments and still achieve the desired results. In addition, the processes depicted in the accompanying drawings do not necessarily require the specific order or continuous order shown to achieve the desired results. In some embodiments, multitasking and parallel processing are also possible or may be advantageous.

[0096] Example 2

[0097] See also Figure 2 Embodiment 2 of the present invention further provides a device for calculating the properties of a positive electrode material of a lithium battery, comprising:

[0098] The configuration optimization and self-consistent calculation module 001 is used to input the initial unit cell structure into the set calculation software, and optimize the configuration of the initial unit cell structure by setting the optimization strategy; and perform self-consistent calculation processing on the optimized configuration to obtain the ground state wave function and orbital eigenvalue;

[0099] Matrix initialization module 002, used to set the initial electron screening potential according to the orbital eigenvalues ​​and atomic coordinates, and initialize the Kohn-sham orbital coefficient matrix, overlap matrix and density matrix;

[0100] The second-order linear perturbation iterative calculation module 003 is used to calculate the occupation matrix after summation through the tensor calculation strategy; perform second-order linear perturbation on the initial electronic screening potential by setting formal parameters; perform iterative calculation by substituting several values ​​of the set formal parameters until the set formal parameters reach the convergence limit, stop iteration, and obtain the electronic screening potential and the slope of the corresponding point at this time;

[0101] The electron force acquisition module 004 is used to calculate and obtain the electron force according to the atomic coordinates when the second-order linear perturbation processing is completed;

[0102] The material performance parameter calculation module 005 is used to calculate and obtain the set performance parameters of the positive electrode material by setting a calculation strategy according to the electronic force.

[0103] In this embodiment, in the material performance parameter calculation module 005, the calculation submodule includes:

[0104] The band gap calculation submodule 051 is used to perform the self-consistent calculation process according to the electronic force to obtain a molecular orbital list; and calculate the band gap according to the molecular orbital list;

[0105] The balanced discharge rate calculation submodule 052 is used to calculate the balanced discharge rate under the set potential difference through the balanced discharge rate calculation strategy; perform linear fitting on the balanced discharge rate to obtain the final balanced discharge rate;

[0106] The mobility calculation submodule 053 is used to calculate and obtain the mobility through the mobility calculation strategy.

[0107] In this embodiment, in the second-order linear perturbation iterative calculation module 003, in the process of calculating and obtaining the summed occupancy matrix through the tensor calculation strategy, the expression of the tensor calculation strategy is:

[0108] ;

[0109] In the formula, For the I The wave functions on the orbital basis constitute the left vector; is the density operator corresponding to spin \sigma; For the I The wave functions on the orbital basis form the right vector; , are the spin\sigma and I The overall wave function on the strip; For the m Track base The wave function of the spin constitutes the left vector; is the center of the ith wave function The combination coefficient of spin; m and i Represents the position coordinates of the center of the wave function.

[0110] In this embodiment, in the second-order linear perturbation iterative calculation module 003, in the process of performing second-order linear perturbation on the initial electron screening potential by setting formal parameters, the expression of the second-order linear perturbation is:

[0111] ;

[0112] In the formula, is the orbital action coefficient; is the spin operator; , ,c,d,e Label the rows and columns of the partially occupied matrix; is the total energy of the system; For Coordinate parameters under orbital action coefficients; for P In theI Matrix elements on the strip wave function; For Q I Matrix elements on the strip wave function; It means distinguishing spins different from σ; is the symbol of partial derivative; for P In the I On the wave function OK, f The value on the column; For Coordinate parameters under orbital action coefficients; for P In the I On the wave function OK, c The value on the column; For Coordinate parameters under orbital action coefficients; for P In the I On the wave function OK, e The value on the column; For Coordinate parameters under orbital action coefficients.

[0113] In this embodiment, in the electronic force acquisition module 004, the calculation formula of the electronic force is:

[0114] ;

[0115] In the formula, is the three-dimensional coordinate; For Under the coordinates, The unit cell force corresponding to the formal parameter value at the convergence limit; is the occupancy number overlap matrix element; is the total energy under the values ​​of P and Q.

[0116] It should be noted that the information interaction, execution process and other contents between the modules of the above-mentioned system are based on the same concept as the method embodiment in Example 1 of the present application, and the technical effects they bring are the same as those of the method embodiment of the present application. For specific contents, please refer to the description in the method embodiment shown above in the present application, and will not be repeated here.

[0117] Example 3

[0118] Embodiment 3 of the present invention provides a non-transitory computer-readable storage medium, in which a program code for a method for calculating the properties of a positive electrode material of a lithium battery is stored. The program code includes instructions for executing a method for calculating the properties of a positive electrode material of a lithium battery of Embodiment 1 or any possible implementation thereof.

[0119] Computer-readable storage media can be any available media that can be accessed by a computer or a data storage device such as a server or data center that includes one or more available media. The available media can be magnetic media (e.g., floppy disks, hard disks, tapes), optical media (e.g., DVDs), or semiconductor media (e.g., solid-state drives (SSDs)).

[0120] Example 4

[0121] Embodiment 4 of the present invention provides an electronic device, including: a memory and a processor;

[0122] The processor and the memory communicate with each other via a bus; the memory stores program instructions that can be executed by the processor, and the processor calls the program instructions to execute a method for calculating the properties of lithium battery positive electrode materials in embodiment 1 or any possible implementation thereof.

[0123] Specifically, the processor can be implemented by hardware or by software. When implemented by hardware, the processor can be a logic circuit, an integrated circuit, etc.; when implemented by software, the processor can be a general-purpose processor implemented by reading software codes stored in a memory. The memory can be integrated in the processor or can be located outside the processor and exist independently.

[0124] In the above embodiments, it can be implemented in whole or in part by software, hardware, firmware or any combination thereof. When implemented using software, it can be implemented in whole or in part in the form of a computer program product. The computer program product includes one or more computer instructions. When the computer program instructions are loaded and executed on a computer, the process or function described in the embodiment of the present invention is generated in whole or in part. The computer can be a general-purpose computer, a special-purpose computer, a computer network, or other programmable systems. The computer instructions can be stored in a computer-readable storage medium, or transmitted from a computer-readable storage medium to another computer-readable storage medium, for example, the computer instructions can be transmitted from a website site, computer, server or data center by wired (e.g., coaxial cable, optical fiber, digital subscriber line (DSL)) or wireless (e.g., infrared, wireless, microwave, etc.) mode to another website site, computer, server or data center.

[0125] Obviously, those skilled in the art should understand that the above modules or steps of the present invention can be implemented by a general computing system, they can be concentrated on a single computing system, or distributed on a network composed of multiple computing systems, and optionally, they can be implemented by a program code executable by a computing system, so that they can be stored in a storage system and executed by the computing system, and in some cases, the steps shown or described can be executed in a different order than here, or they can be made into individual integrated circuit modules, or multiple modules or steps therein can be made into a single integrated circuit module for implementation. Thus, the present invention is not limited to any specific combination of hardware and software.

[0126] Although the present invention has been described in detail above by general description and specific embodiments, it is obvious to those skilled in the art that some modifications or improvements can be made to the present invention. Therefore, these modifications or improvements made without departing from the spirit of the present invention all belong to the scope of protection claimed by the present invention.

Claims

1. A method for calculating the properties of positive electrode materials for lithium batteries, characterized in that: include: Inputting the initial unit cell structure into the set calculation software, optimizing the configuration of the initial unit cell structure by setting the optimization strategy; performing self-consistent calculation processing on the optimized configuration to obtain the ground state wave function and orbital eigenvalue; According to the orbital eigenvalues ​​and atomic coordinates, an initial electron screening potential is set, and the Kohn-sham orbital coefficient matrix, overlap matrix, and density matrix are initialized; The tensor calculation strategy is used to calculate the occupation matrix after summation; the second-order linear perturbation is performed on the initial electronic screening potential by setting formal parameters; by substituting several set formal parameter values, iterative calculation is performed until the set formal parameters reach the convergence limit, the iteration is stopped, and the electronic screening potential and the slope of the corresponding point at this time are obtained; When the second-order linear perturbation processing is completed, the force on the electron is calculated according to the atomic coordinates; According to the electronic force, a calculation strategy is set to calculate and obtain the set performance parameters of the positive electrode material; In the process of calculating the summed occupancy matrix through the tensor calculation strategy, the expression of the tensor calculation strategy is: In the formula, The wave function on the basis of the Ith orbit forms a left vector; is the density operator corresponding to spin \sigma; The wave function on the basis of the Ith orbit forms the right vector; are the spin \sigma and the overall wave function on the Ith bar respectively; The wave function of the σ spin on the mth orbital basis constitutes the left vector; f i (σ) is the combined coefficient of the σ spin at the center of the i-th wave function; m and i represent the position coordinates of the center of the wave function; In the process of performing a second-order linear perturbation on the initial electron screening potential by setting formal parameters, the expression of the second-order linear perturbation is: Where βγ is the orbital interaction coefficient; σ is the spin operator; f, α, c, d, e are the position labels of the rows and columns of the partial occupancy matrix; E +U+J is the total energy of the system; D (σ)βγ is the coordinate parameter under the βγ orbital action coefficient; P (I) is the matrix element of P on the Ith wave function; Q (I) is the matrix element of Q on the Ith wave function; σ′ represents the distinction between spins different from σ; is the symbol of partial derivative; is the value of P in row α and column f on the Ith wave function; D (σ′)fα is the coordinate parameter under the fα orbital action coefficient; is the value of P in row α and column c on the Ith wave function; D (σ′)cd is the coordinate parameter under the cd orbital action coefficient; is the value of P in row d and column e on the Ith wave function; D (σ′)eα is the coordinate parameter under the ea orbital action coefficient; The calculation formula of the electron force is: In the formula, is the three-dimensional coordinate; For coordinates, P, Q are the unit cell forces corresponding to the values ​​of the formal parameters at the convergence limit; is the occupancy number overlap matrix element; E P,Q is the total energy under the values ​​of P and Q.

2. A method for calculating the properties of positive electrode materials for lithium batteries according to claim 1, characterized in that: In the process of calculating and obtaining the set performance parameters of the positive electrode material by setting the calculation strategy, the calculation steps of the set performance parameters are as follows: According to the force on the electron, the self-consistent calculation process is performed to obtain a molecular orbital list; according to the molecular orbital list, a band gap is calculated; The equilibrium discharge rate under the set potential difference is calculated by the equilibrium discharge rate calculation strategy; the equilibrium discharge rate is linearly fitted to obtain the final equilibrium discharge rate; The mobility is calculated using the mobility calculation strategy.

3. A device for calculating the properties of a positive electrode material of a lithium battery, using a method for calculating the properties of a positive electrode material of a lithium battery according to any one of claims 1 to 2, characterized in that: include: The configuration optimization and self-consistent calculation module is used to input the initial unit cell structure into the set calculation software, and optimize the configuration of the initial unit cell structure by setting the optimization strategy; the optimized configuration is processed by self-consistent calculation to obtain the ground state wave function and orbital eigenvalue; A matrix initialization module, used to set the initial electron screening potential according to the orbital eigenvalues ​​and atomic coordinates, and to initialize the Kohn-sham orbital coefficient matrix, overlap matrix and density matrix; A second-order linear perturbation iterative calculation module is used to calculate the summed occupation matrix through the tensor calculation strategy; perform second-order linear perturbation on the initial electronic screening potential by setting formal parameters; perform iterative calculation by substituting several values ​​of the set formal parameters until the set formal parameters reach the convergence limit, stop iteration, and obtain the electronic screening potential and the slope of the corresponding point at this time; An electron force acquisition module, used to calculate and obtain the electron force according to the atomic coordinates when the second-order linear perturbation processing is completed; A material performance parameter calculation module, used to calculate and obtain the set performance parameters of the positive electrode material by setting a calculation strategy according to the electronic force; In the second-order linear perturbation iterative calculation module, in the process of calculating and obtaining the summed occupancy matrix through the tensor calculation strategy, the expression of the tensor calculation strategy is: In the formula, The wave function on the basis of the Ith orbit forms a left vector; is the density operator corresponding to spin \sigma; The wave function on the basis of the Ith orbit forms the right vector; are the spin \sigma and the overall wave function on the Ith bar respectively; The wave function of the σ spin on the mth orbital basis constitutes the left vector; f i (σ) is the combined coefficient of the σ spin at the center of the i-th wave function; m and i represent the position coordinates of the center of the wave function; In the second-order linear perturbation iterative calculation module, in the process of performing second-order linear perturbation on the initial electron screening potential by setting formal parameters, the expression of the second-order linear perturbation is: Where βγ is the orbital interaction coefficient; σ is the spin operator; f, α, c, d, e are the position labels of the rows and columns of the partial occupancy matrix; E +U+J is the total energy of the system; D (σ)βγ is the coordinate parameter under the βγ orbital action coefficient; P (I) is the matrix element of P on the Ith wave function; Q (I) is the matrix element of Q on the Ith wave function; σ′ represents the distinction between spins different from σ; is the symbol of partial derivative; is the value of P in row α and column f on the Ith wave function; D (σ′)fα is the coordinate parameter under the fα orbital action coefficient; is the value of P in row α and column c on the Ith wave function; D (σ′)cd is the coordinate parameter under the cd orbital action coefficient; is the value of P in row d and column e on the Ith wave function; D (σ′)eα is the coordinate parameter under the ea orbital action coefficient; In the electronic force acquisition module, the calculation formula of the electronic force is: In the formula, is the three-dimensional coordinate; For coordinates, P, Q are the unit cell forces corresponding to the values ​​of the formal parameters at the convergence limit; is the occupancy number overlap matrix element; E P,Q is the total energy under the values ​​of P and Q.

4. A lithium battery positive electrode material property calculation device according to claim 3, characterized in that: In the material performance parameter calculation module, the calculation submodule includes: A band gap calculation submodule, used to perform the self-consistent calculation process according to the electronic force to obtain a molecular orbital list; and calculate the band gap according to the molecular orbital list; The balanced discharge rate calculation submodule is used to calculate the balanced discharge rate under the set potential difference through the balanced discharge rate calculation strategy; and perform linear fitting on the balanced discharge rate to obtain the final balanced discharge rate; The mobility calculation submodule is used to calculate the mobility through the mobility calculation strategy.

Images