3d modeling method for micro-pores of graphite negative electrode

Abstract

The present application relates to the technical field of 3D modeling, in particular to a 3D modeling method for graphite negative micro-pores, comprising the following steps: extracting three-dimensional space coordinate parameters and grid space connection parameters of a three-dimensional entity grid of a graphite negative electrode, combining control points of an initial micro-crack surface non-uniform rational B-spline surface to perform position overlap judgment, and generating an occlusion bounding box intersection boundary node linked list; performing limit value screening according to the occlusion bounding box intersection boundary node linked list, and generating a micro-crack surface intersection grid element set. The present application can reduce the probability of self-intersection or distortion of sharp regions and recessed regions; through additional volume retention constraints, separated boundary position locking, coordinate variation difference updating, and minimum space distance principle bridging reconstruction, the pore volume can be maintained stable and the boundary can be closed and continuous when smoothing the stepped topography of the surface, and finally a three-dimensional micro-pore entity structure with topological coherence and more detailed topography close to the real structure of the graphite negative micro-pores is generated.

Description

Technical Field

[0001] This invention relates to the field of 3D modeling technology, and in particular to a method for 3D modeling of micropores in graphite anodes. Background Technology

[0002] 3D modeling technology refers to the technology of digitally representing, reconstructing, analyzing, and simulating solid objects, microstructures, spatial geometric forms, and their internal structures in three dimensions.

[0003] Existing technologies typically revolve around acquiring 3D spatial coordinates, constructing point clouds or meshes, fitting surfaces, reconstructing solids, establishing topological connections, and correcting local morphology. The processed objects are often treated as outer contours or continuous internal structures, easily classifying microscopic pores, microcracks, and local gaps as ordinary geometric details. This leads to a lack of distinction between spatially overlapping areas, crack boundary nodes, and closed pore edges. When solid meshes have high curvature depressions, sharp corner transitions, or narrow gaps, conventional surface fitting and local smoothing focus more on geometric surface continuity, easily flattening micropore boundaries, causing pore width distortion, crack path offset, and broken connections. During mesh offset or boundary reconstruction, relying solely on a uniform offset distance or overall topological repair can lead to problems such as patch interleaving, vertex reflection, and local volume anomalies at locations with small minimum curvature radii. Therefore, improvements are needed. Summary of the Invention

[0004] The purpose of this invention is to overcome the shortcomings of existing technologies and propose a 3D modeling method for the micropores of graphite anodes.

[0005] To achieve the above objectives, the present invention employs the following technical solution: a 3D modeling method for the micropores of graphite anodes, comprising the following steps: Extract the three-dimensional spatial coordinate parameters and mesh spatial connection parameters of the graphite anode three-dimensional solid mesh, combine them with the control points of the initial microcrack surface non-uniform rational B-spline surface to determine the position overlap, and generate a bounding box intersection boundary node linked list. Based on the bounding box, the intersection boundary node linked list is used for limit filtering to generate a set of intersecting mesh elements of microcrack surfaces; The parameters corresponding to the intersecting mesh element set of the microcrack surface are separated and rearranged to generate constrained mesh re-partitioning patches; Surface fitting is performed on the mesh vertices within the constrained mesh repartition patch, and partial derivative operations are executed to extract the principal curvature and minimum curvature radius parameters, generating a local basic form curvature set; And generate the initial normal offset parameter on one side of each mesh vertex according to the preset gap width; By comparing the minimum radius of curvature parameter with the single-sided initial normal offset parameter, parameters that need to be limited are selected to generate a set of attenuation mesh parameters to be limited; Attenuation operations are applied to the offset parameters within the set of parameters to be limited and attenuated, and the three-dimensional spatial coordinate parameters are updated in combination with the offset parameters of the remaining grid vertices not included in the set of parameters to be limited and attenuated, to generate an anti-self-intersecting offset grid.

[0006] Preferably, the method further includes: Extract the three-dimensional spatial coordinate parameters of the vertices of the surface stepped mesh in the anti-self-intersection offset mesh, perform Laplacian smoothing operation with additional volume preservation constraints and separation boundary position locking, and generate a displacement smoothing mesh set containing coordinate variation differences; update the coordinate parameters according to the variation differences, and bridge and reconstruct the separation boundary according to the minimum spatial distance principle to generate stitched mesh patches and merge them to generate a three-dimensional microporous solid structure.

[0007] Preferably, the step of obtaining the bounding box intersection boundary node linked list is as follows: The vertex number, three-dimensional spatial coordinate parameters, and mesh spatial connection parameters are read one by one from the vertex record of the graphite negative electrode three-dimensional solid mesh. The correspondence between the three-dimensional spatial coordinate parameters and the mesh spatial connection parameters is established according to the vertex number. Then, the control point number and control point coordinate parameters are read from the surface definition record of the initial microcrack surface non-uniform rational B-spline surface. The spatial arrangement order of the control point coordinate parameters is retained according to the control point number, and the correspondence between the three-dimensional spatial coordinate parameters, mesh spatial connection parameters, and control point coordinate parameters is generated. According to the mesh space connection parameters, the vertex numbers associated with the same mesh cell are read. The bounding box boundaries of the mesh cell on the three coordinate axes are determined according to the three-dimensional spatial coordinate parameters of the associated vertices. Local sub-surfaces of the initial microcrack surface non-uniform rational B-spline surface are constructed according to the control point coordinate parameters. The bounding box boundaries of each local sub-surface are determined on the three coordinate axes. The start and end coordinates of the bounding box boundaries of the mesh cell and the bounding box boundaries of each local sub-surface are compared item by item on the three coordinate axes. The boundary node numbers of the three coordinate axes with overlapping coordinate intervals are retained, and a bounding box intersection boundary node linked list is generated.

[0008] Preferably, the step of obtaining the intersecting mesh element set of the microcrack surface is as follows: The three-dimensional spatial coordinate parameters corresponding to each boundary node number in the bounding box intersection boundary node chain list are read. A preset bounding box spatial collision coordinate limit is called. The absolute difference of the three-dimensional spatial coordinate parameters corresponding to the boundary node numbers on the three coordinate axes is compared item by item. Vertex parameters whose absolute difference exceeds the preset bounding box spatial collision coordinate limit and are located in the non-overlapping area outside the three-dimensional spatial coordinate domain are eliminated. Then, the corresponding mesh spatial connection parameters are traced back according to the remaining vertex parameters. The mesh cells to which the remaining vertex parameters belong are included in the intersection range to generate a microcrack surface intersection mesh cell set. The preset bounding box spatial collision coordinate limit is 0.02-0.08 times the average feature size of all mesh cells.

[0009] Preferably, the step of obtaining the constrained mesh repartition patch is as follows: The set of intersecting mesh elements of the microcrack surface is called, and the vertex number, three-dimensional spatial coordinate parameters and mesh spatial connection parameters corresponding to each intersecting mesh element of the microcrack surface are read one by one. The surface sampling position and surface normal direction are determined according to the control point coordinate parameters of the initial non-uniform rational B-spline surface of the microcrack surface. The three-dimensional spatial coordinate parameters of each vertex are projected along the surface normal direction. The forward side vertex, reverse side vertex and separation boundary vertex are divided according to the projection sign. The original mesh spatial connection parameters corresponding to the separation boundary vertex are retained. The separation mesh spatial connection parameters are rearranged according to the forward side vertex number and the reverse side vertex number respectively to generate constrained mesh re-partitioning patches.

[0010] Preferably, the step of obtaining the initial normal offset parameter on one side is as follows: The three-dimensional spatial coordinate parameters, adjacent vertex numbers, and rearranged mesh spatial connectivity parameters of the discrete mesh vertices within the constrained mesh repartitioned patch are read item by item. The local neighborhood of each discrete mesh vertex is determined according to the adjacent vertex numbers. A local fitting surface is constructed based on the three-dimensional spatial coordinate parameters within the local neighborhood. The local fitting surface is unfolded along the tangential and normal directions to obtain the first and second basic form partial derivative parameters. The principal curvature and minimum curvature radius parameters corresponding to each discrete mesh vertex are extracted based on the first and second basic form partial derivative parameters to generate a local basic form curvature set. The initial normal offset parameter of each discrete mesh vertex is generated based on half the preset total width of the micro gap.

[0011] Preferably, the step of obtaining the set of parameters for the attenuation grid to be limited is as follows: Extract the vertex number and minimum curvature radius parameter corresponding to each discrete mesh vertex within the local basic curvature set. Call the single-sided initial normal offset parameter corresponding to the same vertex number. Compare each minimum curvature radius parameter with the single-sided initial normal offset parameter under the same vertex number item by item. If the minimum curvature radius parameter is less than the single-sided initial normal offset parameter, retain the corresponding vertex number, minimum curvature radius parameter, single-sided initial normal offset parameter, and surface normal direction. If the minimum curvature radius parameter is greater than or equal to the single-sided initial normal offset parameter, exclude the corresponding vertex number and generate the set of mesh parameters to be limited and attenuated.

[0012] Preferably, the step of obtaining the anti-self-intersecting offset mesh is as follows: The minimum radius of curvature parameter, the initial normal offset parameter on one side, and the normal direction of the surface are read item by item from each vertex number in the parameter set of the mesh to be limited and attenuated. The initial normal offset parameter on one side is gradually attenuated according to the minimum radius of curvature parameter. The offset distance value after each attenuation is compared with the minimum radius of curvature parameter of the additional proportional attenuation safety factor under the same vertex number. If the offset distance value after attenuation is still greater than or equal to the minimum radius of curvature parameter of the additional proportional attenuation safety factor, the offset distance value after attenuation is further reduced. If the offset distance value after attenuation is less than the minimum radius of curvature parameter of the additional proportional attenuation safety factor, the attenuation is stopped, and the three-dimensional spatial coordinate parameters of the corresponding mesh vertex are updated along the normal direction of the surface according to the offset distance value after attenuation to generate the three-dimensional spatial coordinate parameters of the limit attenuation mesh vertex. Based on the three-dimensional spatial coordinate parameters of the vertices of the amplitude-limiting attenuation grid, the vertex number, three-dimensional spatial coordinate parameters, and surface normal direction of the other discrete grid vertices not included in the amplitude-limiting attenuation grid parameter set are read. The single-sided initial normal offset parameter corresponding to the same vertex number is called. The three-dimensional spatial coordinate parameters of the other discrete grid vertices not included in the amplitude-limiting attenuation grid parameter set are updated along the surface normal direction according to the single-sided initial normal offset parameter. Then, the updated three-dimensional spatial coordinate parameters of the other discrete grid vertices not included in the amplitude-limiting attenuation grid parameter set are merged with the three-dimensional spatial coordinate parameters of the amplitude-limiting attenuation grid vertices in the order of vertex number to generate an anti-self-intersection offset grid volume.

[0013] Preferably, the steps for obtaining the three-dimensional microporous solid structure are as follows: Extract the vertex number, three-dimensional spatial coordinate parameters, adjacent vertex number, and adjacent three-dimensional spatial coordinate parameters of the surface stepped mesh vertices in the amplitude-limiting transition zone of the anti-self-crossing offset mesh. Determine the spatial adjacency range of each surface stepped mesh vertex according to the adjacent vertex number. Lock the three-dimensional spatial coordinate parameters of the mesh vertices at the separation boundary. For the unlocked surface stepped mesh vertices, adjust the coordinate variation of the surface stepped mesh vertices in the three-dimensional coordinate axis direction item by item according to the coordinate difference between the three-dimensional spatial coordinate parameters of the surface stepped mesh vertex and the three-dimensional spatial coordinate parameters of the adjacent vertices. Use the difference in local closed volume before and after adjustment as the volume retention constraint parameter to backtrack the coordinate variation. Extract the spatial coordinate variation difference of the mesh vertices after backtracking correction to generate a displacement smoothing mesh set. The three-dimensional spatial coordinate parameters and the difference in spatial coordinate variation of each vertex in the displacement smoothing mesh set are read item by item. The difference in spatial coordinate variation of each vertex is superimposed on the corresponding three-dimensional spatial coordinate parameters according to the vertex number to form the updated three-dimensional spatial coordinate parameters. Then, the spatial connection parameters of the upper edge mesh and the lower edge mesh at the separation boundary are extracted. The pairing relationship between the upper edge vertex and the lower edge vertex is established according to the principle of minimum spatial distance. The boundary connection relationship between adjacent paired vertices is reorganized into a closed connection relationship to generate a stitched mesh patch. Read the stitch vertex number, stitch mesh spatial connection parameters, and updated three-dimensional spatial coordinate parameters of each stitch vertex in the stitched mesh patch. Retrieve the corresponding boundary vertex number in the anti-self-intersecting offset mesh body according to the stitch vertex number. Connect the stitch mesh spatial connection parameters of the stitched mesh patch to the original mesh spatial connection parameters of the anti-self-intersecting offset mesh body. Eliminate duplicate boundary connection relationships and retain the connection relationships that form the outer wall of the closed pore to generate a three-dimensional micro-pore solid structure.

[0014] Compared with the prior art, the advantages and positive effects of the present invention are as follows: This invention extracts the 3D spatial coordinate parameters and mesh spatial connection parameters of the graphite negative electrode 3D solid mesh, and performs spatial overlap determination with the control points of the initial microcrack surface non-uniform rational B-spline surface. This allows the intersection range between the microcrack surface and the solid mesh to converge from the global 3D space to the bounding box intersection boundary node list. Then, by filtering with preset bounding box spatial collision coordinate limits, parameters in the outer non-overlapping regions are eliminated, improving the boundary accuracy of the microcrack surface intersecting mesh unit set and reducing the entry of irrelevant mesh units into subsequent processing. By performing normal separation and mesh spatial connection parameter rearrangement on the corresponding parameters of the microcrack surface intersecting mesh unit set, constrained mesh re-partitioning patches are formed, ensuring that the microcrack separation boundary maintains a clear topological relationship. Through surface fitting, partial derivative calculation, principal curvature extraction, and minimum curvature... The radius of curvature parameter generation can transform the local curvature into a geometric parameter that can participate in displacement constraints. Combined with the preset gap width, it forms a single-sided initial normal offset parameter, so that the pore expansion no longer depends on a uniform offset scale. By comparing the minimum radius of curvature parameter with the single-sided initial normal offset parameter, parameters that need to be limited are screened out and attenuation operations are performed. This can constrain the offset distance to be lower than the allowable range of local curvature, reducing the probability of self-intersection or distortion in sharp and concave areas. By adding volume preservation constraints, locking the separation boundary position, updating the coordinate variation difference, and bridging reconstruction based on the minimum spatial distance principle, it can maintain the stability of pore volume and the continuity of boundary closure when the surface is smooth and stepped. Finally, it generates a three-dimensional microporous solid structure with topological coherence and morphological details that are closer to the real microporous structure of graphite anode.

[0015] The three-dimensional microporous solid structure obtained by this invention can be directly used for the simulation analysis of the electrochemical performance of lithium-ion batteries, including but not limited to: calculation of pore tortuosity, simulation of electrolyte wetting path, prediction of effective diffusion coefficient of lithium-ion transport, and analysis of stress distribution at the electrode-electrolyte interface. Attached Figure Description

[0016] Figure 1 This is a graph showing the change in the offset distance after attenuation. Figure 2 A selection chart for bounding box space collision coordinate limits. Detailed Implementation

[0017] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0018] Please see Figure 1-2 This invention provides a technical solution: a 3D modeling method for the micropores of graphite anodes, comprising the following steps: The three-dimensional spatial coordinate parameters and mesh spatial connection parameters of the graphite anode three-dimensional solid mesh are extracted. The position overlap is determined by combining the control points of the initial microcrack surface non-uniform rational B-spline surface, and a bounding box intersection boundary node list is generated. The bounding box intersection boundary node list is then filtered by limit values ​​to generate a microcrack surface intersection mesh element set. The parameters corresponding to the intersecting mesh element set of the microcrack surface are separated and rearranged to generate a constrained mesh re-partitioned patch; the mesh vertices in the constrained mesh re-partitioned patch are surface fitted and partial derivative operations are performed to extract the principal curvature and minimum curvature radius parameters to generate a local basic form curvature set; and the initial normal offset parameters of each mesh vertex are generated according to the preset gap width. By comparing the minimum radius of curvature parameter with the initial normal offset parameter on one side, the parameters that need to be limited are selected to generate the set of parameters for the attenuation mesh to be limited; attenuation operation is applied to the offset parameters in the set of parameters for the attenuation mesh to be limited, and the three-dimensional spatial coordinate parameters are updated by combining the offset parameters of the other mesh vertices not included in the set of parameters for the attenuation mesh to be limited, so as to generate the anti-self-intersection offset mesh volume. The three-dimensional spatial coordinate parameters of the vertices of the stepped mesh on the surface of the anti-self-crossing offset mesh are extracted. Laplacian smoothing operation with additional volume preservation constraints and separation boundary position locking is performed to generate a displacement smoothing mesh set containing coordinate variation differences. The coordinate parameters are updated according to the variation differences, and the separation boundary is bridged and reconstructed according to the minimum spatial distance principle to generate stitched mesh patches and merge them to generate a three-dimensional microporous solid structure.

[0019] The steps to obtain the linked list of intersection boundary nodes for bounding boxes are as follows: The vertex number, three-dimensional spatial coordinate parameters, and mesh spatial connection parameters are read one by one from the vertex record of the graphite negative electrode three-dimensional solid mesh. The correspondence between the three-dimensional spatial coordinate parameters and the mesh spatial connection parameters is established according to the vertex number. Then, the control point number and control point coordinate parameters are read from the surface definition record of the initial microcrack surface non-uniform rational B-spline surface. The spatial arrangement order of the control point coordinate parameters is retained according to the control point number, and the correspondence between the three-dimensional spatial coordinate parameters, mesh spatial connection parameters, and control point coordinate parameters is generated. Read the vertex numbers associated with the same mesh cell according to the mesh space connection parameters, determine the bounding box boundaries of the mesh cell on the three coordinate axes according to the three-dimensional spatial coordinate parameters of the associated vertices, construct local sub-patterns of the initial microcrack surface non-uniform rational B-spline surface according to the control point coordinate parameters, and determine the bounding box boundaries of each local sub-pattern on the three coordinate axes. Compare the start and end coordinates of the bounding box boundaries of the mesh cell with the bounding box boundaries of each local sub-pattern on the three coordinate axes one by one, retain the boundary node numbers where the coordinate intervals of the three coordinate axes overlap, and generate a bounding box intersection boundary node linked list.

[0020] Specifically, based on the three-dimensional solid mesh of graphite anodes acquired by X-ray nano-CT scanning or focused ion beam scanning electron microscopy (FIB-SEM), the vertex numbers, three-dimensional spatial coordinate parameters, and mesh spatial connectivity parameters are read one by one from the vertex records of the three-dimensional solid mesh of graphite anodes. The specific implementation involves first traversing the structured file storing the solid mesh data, and for each row of vertex data, extracting its unique vertex number, usually an integer value, and simultaneously extracting its position in the three-dimensional Cartesian coordinate system. , , Coordinate values ​​are used as 3D spatial coordinate parameters, and the connection information between the vertex and other vertices forming mesh units (e.g., tetrahedrons or hexahedrons) is extracted and recorded; this is the mesh space connection parameter, which usually exists in the form of a list of vertex numbers. Then, to achieve fast retrieval, a hash mapping table is constructed with vertex numbers as keys and composite structures containing 3D spatial coordinate parameters and mesh space connection parameters as values. This establishes a one-to-one or one-to-many correspondence between 3D spatial coordinate parameters and mesh space connection parameters according to vertex numbers. Subsequently, from an independent, initially defined micro-crack... In the non-uniform rational B-spline NURBS surface file, control point data is read. This data includes the control point number and the corresponding control point coordinate parameters. To preserve the original topology of the surface definition, these control point coordinate parameters are stored in an ordered array or linked list according to their number order. The previously established mesh vertex hash mapping table is integrated with this ordered array of control points to form a unified data structure. This structure contains both the geometric and topological information of the mesh and the definition information of the crack surface, generating the correspondence between the three-dimensional spatial coordinate parameters, the mesh spatial connection parameters, and the control point coordinate parameters.

[0021] The process involves reading the vertex numbers associated with the same mesh cell according to the mesh space connectivity parameters. First, each mesh cell is traversed, and the vertex numbers constituting that cell are obtained using the mesh space connectivity parameters. Then, based on these vertex numbers, the 3D spatial coordinate parameters of each vertex are retrieved from the previously established correspondence. These coordinate parameters are then used to... , , Take the maximum and minimum values ​​in each of the three dimensions, that is... , , , , , To determine the axis-aligned bounding box (AABB) boundary of the mesh element, and simultaneously construct a local sub-patch of the initial microcrack surface non-uniform rational B-spline surface based on the control point coordinate parameters, the specific construction method is as follows: using the geometric center of the current mesh element as the query point, the nearest N control points (e.g., N=16) are quickly retrieved from all control points using spatial indexing structures such as kd-trees. A local sub-patch is generated using these N control points and their associated node vectors and weights, and the bounding box boundary of this sub-patch is calculated. This boundary is also determined by finding the maximum and minimum values ​​of each axis of the coordinates of these N control points. The bounding box boundary of the mesh element is then intersected with the bounding box boundary of each local sub-patch. This intersecting process involves comparing the coordinate intervals of the two bounding boxes on the three coordinate axes to determine whether the following conditions are simultaneously met: the mesh element's... Axis intervals and sub-patterns The axis intervals overlap, and Axis interval and The axis intervals overlap, and Axis interval and If the intervals of the three coordinate axes overlap, then the two bounding boxes are determined to intersect. The vertex numbers of all the grid cells that make up the grid cell are recorded and stored in a linked list. After traversing all grid cells and combining all local sub-faces, a linked list of bounding box intersection boundary nodes is generated.

[0022] The steps for obtaining the intersecting mesh element set of microcrack surfaces are as follows: Read the 3D spatial coordinate parameters corresponding to each boundary node number in the bounding box intersection boundary node chain list, call the preset bounding box spatial collision coordinate limit, compare the absolute difference of the 3D spatial coordinate parameters corresponding to the boundary node number on the three coordinate axes one by one, remove the vertex parameters whose absolute difference exceeds the preset bounding box spatial collision coordinate limit and are located in the non-overlapping area outside the 3D spatial coordinate domain, and then backtrack the corresponding mesh spatial connection parameters according to the remaining vertex parameters, and classify the mesh cells to which the remaining vertex parameters belong into the intersection range to generate the microcrack surface intersection mesh cell set.

[0023] Specifically, the three-dimensional spatial coordinate parameters corresponding to the boundary node number in the bounding box intersection boundary node linked list are read. First, the linked list is traversed to obtain the number of each boundary node that may intersect with the crack surface, and its three-dimensional spatial coordinate parameters are queried based on this number. Then, a preset bounding box spatial collision coordinate limit is called. This limit is used to filter out more accurate intersecting elements from the coarse bounding box intersection detection results. The method for setting it is to calculate the average feature size of all graphite negative electrode three-dimensional solid mesh elements. (e.g., the average side length of all grid cells), and limit the value. Set to a smaller proportion of that average size, for example Taking a case study, if the average side length of all mesh cells is calculated to be 2.5 micrometers, then the collision coordinate limit can be set as follows: Next, for each boundary node's three-dimensional spatial coordinates, calculate the shortest distance from it to the initial microcrack surface's non-uniform rational B-spline surface. This distance is typically calculated using a geometric iterative projection algorithm. Then, compare this shortest distance with a preset bounding box space collision coordinate limit. The comparison is performed. If the calculated shortest distance is greater than 0.125 micrometers, it is determined that although the vertex is within the bounding box of its element, it is too far from the actual crack surface and belongs to the vertex of the non-overlapping outer region. Therefore, its parameters are removed from the candidate set. After traversing all boundary nodes and completing the removal operation, based on the remaining vertex parameters, the original mesh elements composed of these vertices are found by backtracking and querying the mesh space connection parameters to which they belong. The unique identifiers (IDs) of these mesh elements are added to a Set data structure and automatically deduplicated and included in the intersection range. Finally, the intersecting mesh element set of the microcrack surface is generated.

[0024] The steps for obtaining the constrained mesh repartitioned patches are as follows: The set of intersecting mesh elements of the microcrack surface is called, and the vertex number, three-dimensional spatial coordinate parameters and mesh spatial connection parameters corresponding to each intersecting mesh element of the microcrack surface are read one by one. The surface sampling position and surface normal direction are determined according to the control point coordinate parameters of the initial non-uniform rational B-spline surface of the microcrack surface. The three-dimensional spatial coordinate parameters of each vertex are projected along the surface normal direction. The forward side vertex, reverse side vertex and separation boundary vertex are divided according to the projection sign. The original mesh spatial connection parameters corresponding to the separation boundary vertex are retained. The separation mesh spatial connection parameters are rearranged according to the forward side vertex number and the reverse side vertex number respectively to generate constrained mesh re-partitioning patches.

[0025] Specifically, the process involves calling the intersecting mesh element set of microcrack surfaces. First, it iterates through each intersecting mesh element in the set, reading its vertex number, the 3D spatial coordinates of each vertex, and the mesh space connectivity parameters defining the element topology. Then, based on the complete control point coordinates and node vectors of the initial microcrack surface's non-uniform rational B-spline surface, it determines the surface sampling positions within each intersecting mesh element that require refinement. Typically, uniform or adaptive sampling is performed within the element to obtain a series of sampling points. At each sampling point, the tangent plane is determined by calculating the first-order partial derivative of the NURBS surface, and then the normal direction vector of the surface at that point is obtained. Then, for each vertex within the intersecting grid cell, its vertex coordinate vector is... The coordinate vector of the surface sampling point closest to the vertex Subtracting them gives us the vector. Then the vector and the normal direction of the surface at that sampling point Perform dot product, i.e. calculate Vertex types are classified based on the sign of the dot product result. A positive dot product indicates the vertex is located on the side of the surface normal, classified as a positive-side vertex. A negative result indicates the vertex is located on the opposite side of the normal, classified as a negative-side vertex. If the result is within a very small tolerance range near zero (e.g., ...), the vertex is classified as a negative-side vertex. If the vertex is located on the surface, it is classified as a separated boundary vertex. After processing all vertices, the original mesh space connection parameters of the separated boundary vertex are retained for subsequent stitching. At the same time, all positive side vertices and their connection relationships, and all negative side vertices and their connection relationships are collected and recombined to generate two new and independent sets of mesh patches, that is, to generate constrained mesh repartition patches.

[0026] The steps for obtaining the initial normal offset parameter on one side are as follows: The three-dimensional spatial coordinate parameters, adjacent vertex numbers, and rearranged mesh spatial connectivity parameters of discrete mesh vertices within the constrained mesh repartitioned patch are read item by item. The local neighborhood of each discrete mesh vertex is determined according to the adjacent vertex numbers. A local fitting surface is constructed based on the three-dimensional spatial coordinate parameters within the local neighborhood. The local fitting surface is unfolded along the tangential and normal directions to obtain the first and second basic form partial derivative parameters. The principal curvature and minimum curvature radius parameters corresponding to each discrete mesh vertex are extracted based on the first and second basic form partial derivative parameters to generate a local basic form curvature set. The initial normal offset parameter of each discrete mesh vertex is generated based on half the preset total width of the micro gap.

[0027] Specifically, the 3D spatial coordinate parameters, adjacent vertex numbers, and rearranged mesh spatial connectivity parameters of the discrete mesh vertices within the constrained mesh repartitioned patch are read item by item. First, for each discrete mesh vertex, a local neighborhood is determined using its adjacent vertex number information. This neighborhood consists of the vertex and all its first-order neighboring vertices directly connected by edges. Then, based on the 3D spatial coordinate parameters of all vertices in this local neighborhood, a quadratic or higher-order local fitting surface is constructed using the least squares method, such as a quadratic polynomial surface. This is used to smoothly approximate a discrete mesh point cloud near the vertex. After construction, a surface function is fitted to this local area. Differentiate along its parameter direction (tangential direction) and calculate its first-order partial derivative ( , ) and second-order partial derivatives ( , , These partial derivative values ​​constitute the coefficients of the first and second fundamental forms in differential geometry. Specifically, based on the partial derivative parameters of the first and second fundamental forms, the Gaussian curvature and mean curvature at each discrete grid vertex are calculated using standard differential geometry formulas, and the two principal curvatures are further solved. and Among them, the minimum radius of curvature parameter That is, the reciprocal of the larger of the two principal curvatures, i.e. After completing the curvature calculation for all vertices, the vertex number is stored together with its corresponding principal curvature and minimum curvature radius parameters to generate a local basic form curvature set, based on a preset total width of micro-slits representing the final target width of the pore. Half of it is taken as the base distance for unilateral offset, that is This generates the initial one-sided normal offset parameter for each discrete mesh vertex.

[0028] The steps for obtaining the set of parameters for the amplitude-limiting attenuation grid are as follows: Extract the vertex number and minimum curvature radius parameter corresponding to each discrete mesh vertex within the local basic curvature set. Call the single-sided initial normal offset parameter corresponding to the same vertex number. Compare each minimum curvature radius parameter with the single-sided initial normal offset parameter under the same vertex number item by item. If the minimum curvature radius parameter is less than the single-sided initial normal offset parameter, retain the corresponding vertex number, minimum curvature radius parameter, single-sided initial normal offset parameter, and surface normal direction. If the minimum curvature radius parameter is greater than or equal to the single-sided initial normal offset parameter, exclude the corresponding vertex number and generate the set of mesh parameters to be limited and attenuated.

[0029] Specifically, the vertex ID and minimum radius of curvature parameter corresponding to each discrete mesh vertex within the local basic form curvature set are extracted. The specific operation involves traversing the curvature set data structure and, for each record, simultaneously detecting its unique vertex identifier and the associated minimum radius of curvature parameter. Then, using the same vertex number, call and retrieve the one-sided initial normal offset parameter generated for that vertex in the previous step. Then, the two values ​​are directly compared, which is the judgment condition. Whether this holds true or not, the purpose of this comparison is to identify regions where the local curvature is too large (radius of curvature too small) to be directly offset without self-intersection. If the comparison result is true, meaning the minimum radius of curvature is less than the required offset, this means that if direct offset is performed... The distance to this point is crucial because the newly generated surface may fold or intersect near this point. Therefore, it's necessary to restrict the offset operation on this vertex. In this case, the vertex number and the current minimum radius of curvature parameter should be retained. 1 / 2 Initial normal offset parameter and the surface normal direction vector at the location of the vertex. And store this information as a data unit in a new set; conversely, if the minimum radius of curvature parameter is greater than or equal to the initial normal offset parameter on one side ( If the value is zero, it indicates that offsetting at that vertex is safe and will not immediately lead to self-intersection. Therefore, the vertex is excluded from the set that requires special processing and no operation is performed on it. After completing the investigation and screening of all vertices in the local basic curvature set, the final new set is the set of mesh parameters to be limited and attenuated.

[0030] The steps for obtaining the anti-self-intersecting offset mesh are as follows: The minimum radius of curvature parameter, the initial normal offset parameter on one side, and the normal direction of the surface are read item by item for each vertex number in the parameter set of the mesh to be limited and attenuated. The initial normal offset parameter on one side is gradually attenuated according to the minimum radius of curvature parameter. The offset distance value after each attenuation is compared with the minimum radius of curvature parameter of the additional proportional attenuation safety factor under the same vertex number. If the offset distance value after attenuation is still greater than or equal to the minimum radius of curvature parameter of the additional proportional attenuation safety factor, the offset distance value after attenuation is reduced. If the offset distance value after attenuation is less than the minimum radius of curvature parameter of the additional proportional attenuation safety factor, the attenuation is stopped, and the three-dimensional spatial coordinate parameters of the corresponding mesh vertex are updated along the normal direction of the surface according to the offset distance value after attenuation to generate the three-dimensional spatial coordinate parameters of the vertex of the limited attenuation mesh. Based on the three-dimensional spatial coordinate parameters of the vertices of the amplitude-limiting attenuation grid, the vertex number, three-dimensional spatial coordinate parameters, and surface normal direction of the other discrete grid vertices not included in the amplitude-limiting attenuation grid parameter set are read. The single-sided initial normal offset parameter corresponding to the same vertex number is called. The three-dimensional spatial coordinate parameters of the other discrete grid vertices not included in the amplitude-limiting attenuation grid parameter set are updated along the surface normal direction according to the single-sided initial normal offset parameter. Then, the updated three-dimensional spatial coordinate parameters of the other discrete grid vertices not included in the amplitude-limiting attenuation grid parameter set are merged with the three-dimensional spatial coordinate parameters of the amplitude-limiting attenuation grid vertices in the order of vertex number to generate an anti-self-intersection offset grid volume.

[0031] Specifically, the minimum radius of curvature parameter, the initial normal offset parameter on one side, and the surface normal direction corresponding to each vertex number in the parameter set of the mesh to be limited and attenuated are read item by item. For each vertex in the set, based on its minimum radius of curvature parameter... For the initial normal offset parameter on one side Perform a step-by-step decay calculation, which introduces a decay rate. (For example ) and an additional proportional attenuation safety factor This coefficient is used to ensure a safety margin between the final offset distance and the radius of curvature. Its setting is based on experience and is typically between 0.8 and 0.98. For example, it can be set to... The decay process is an iterative loop: first, the upper limit of the target offset is calculated. Set the current offset Initialize to Then enter the loop and check if... Then update the current offset to And repeat this judgment and update step until... When the loop stops, it calculates a single instance. , , , ,but After the first iteration After the second iteration After the third iteration At this point, the value is less than 7.6, so the loop terminates, and the decayed offset distance is 7.29. Then, the original three-dimensional spatial coordinate parameters of this vertex are... Along its surface normal direction The offset distance after movement decay is updated to the coordinates. The updated coordinates of all vertices that have undergone this amplitude limiting and attenuation process are summarized to generate the three-dimensional spatial coordinate parameters of the amplitude limiting and attenuation mesh vertices.

[0032] Based on the 3D spatial coordinate parameters of the vertices of the attenuation-limiting mesh, all remaining discrete mesh vertices not included in the parameter set of the attenuation-limiting mesh are first identified. These vertices were determined to be offset-safe vertices in the previous step. Then, the numbers and original 3D spatial coordinate parameters of these safe vertices are read one by one. and the corresponding surface normal direction It then calls the one-sided initial normal offset parameters corresponding to these vertex numbers, without any attenuation. Then, the coordinates of these safe vertices are updated directly according to the initial normal offset parameter on one side. Specifically, the original coordinates of each safe vertex are updated. Along its normal direction move The distance is used to obtain the updated coordinates. After this operation is performed on all unlimited vertices, a data set containing the new coordinates of all safe vertices is obtained. This new coordinate set is then merged with the 3D spatial coordinate parameters of the vertices in the limited attenuation mesh generated in the previous step. The merging is based on the vertex number. That is, the updated 3D spatial coordinate parameters of the two parts of vertices (one part is attenuated offset, and the other part is directly offset without attenuation) are reorganized into a unified and complete vertex coordinate list according to their respective vertex numbers. The order of this list is consistent with the vertex order of the original repartitioned patch. This complete mesh entity containing the updated coordinates of all vertices is the anti-self-intersection offset mesh.

[0033] The steps for obtaining a three-dimensional microporous solid structure are as follows: Extract the vertex number, 3D spatial coordinate parameters, adjacent vertex number, and adjacent 3D spatial coordinate parameters of the surface stepped mesh vertices in the amplitude-limited transition zone of the anti-self-crossing offset mesh. Determine the spatial adjacency range of each surface stepped mesh vertex according to the adjacent vertex number. Lock the 3D spatial coordinate parameters of the mesh vertices at the separation boundary. For the unlocked surface stepped mesh vertices, adjust the coordinate variation of the surface stepped mesh vertices in the 3D coordinate axis direction item by item according to the coordinate difference between the 3D spatial coordinate parameters of the surface stepped mesh vertex and the 3D spatial coordinate parameters of the adjacent vertices. Use the difference in local closed volume before and after adjustment as the volume preservation constraint parameter to backtrack the coordinate variation. Extract the spatial coordinate variation difference of the mesh vertices after backtracking correction to generate a displacement smoothing mesh set. The three-dimensional spatial coordinate parameters and the difference in spatial coordinate variation of each vertex in the displacement smoothing mesh set are read item by item. The difference in spatial coordinate variation of each vertex is superimposed on the corresponding three-dimensional spatial coordinate parameters according to the vertex number to form the updated three-dimensional spatial coordinate parameters. Then, the spatial connection parameters of the upper edge mesh and the lower edge mesh at the separation boundary are extracted. The pairing relationship between the upper edge vertex and the lower edge vertex is established according to the principle of minimum spatial distance. The boundary connection relationship between adjacent paired vertices is reorganized into a closed connection relationship to generate the stitched mesh patch. Read the stitch vertex number, stitch mesh spatial connection parameters, and updated 3D spatial coordinate parameters of each stitched mesh patch. Retrieve the corresponding boundary vertex number in the anti-self-intersecting offset mesh according to the stitch vertex number. Connect the stitch mesh spatial connection parameters of the stitched mesh patch to the original mesh spatial connection parameters of the anti-self-intersecting offset mesh. Eliminate duplicate boundary connection relationships and retain the connection relationships that form the outer wall of the closed pore to generate a 3D microporous solid structure.

[0034] Specifically, the vertex numbers, 3D spatial coordinate parameters, adjacent vertex numbers, and adjacent 3D spatial coordinate parameters of the surface stepped mesh vertices in the amplitude-limited transition zone of the anti-self-crossing offset mesh are extracted. The amplitude-limited transition zone refers to a local area that simultaneously contains vertices that have undergone amplitude-limited attenuation and vertices that have not been attenuated by offset. Its surface exhibits a stepped shape due to different offset distances. First, the spatial adjacency range of each surface stepped mesh vertex is determined by the adjacent vertex numbers, i.e., its set of first-order neighbor vertices. Then, mesh vertices located on the original separation boundary are locked, and their 3D spatial coordinate parameters remain unchanged in subsequent smoothing operations. For the unlocked surface stepped mesh vertices, an improved Laplacian smoothing algorithm is executed. This algorithm is based on each vertex... The three-dimensional spatial coordinate parameters are the same as those of all its adjacent vertices. Calculate an initial displacement vector based on the coordinate differences between the three-dimensional spatial coordinate parameters. Where N is the number of adjacent vertices, an additional volume preservation constraint is introduced before applying this displacement vector. This constraint is calculated by measuring the volume change of the local infinitesimal element (e.g., triangular or tetrahedral element) formed by the vertex and its neighbors before and after smoothing. To achieve this, a volume change tolerance limit is set. For example, setting it to 1% of the original local volume, if Exceeding this limit will affect the coordinate variation. Perform backtracking correction, for example, by multiplying it by a coefficient less than 1 (such as 0.8) and recalculating the volume change until the constraint is met. After the correction is completed, extract the final backtracked mesh vertex spatial coordinate variation difference, and collect the difference values ​​of all vertices to generate a displacement smoothing mesh set.

[0035] The process involves sequentially reading the 3D spatial coordinate parameters and the spatial coordinate variation difference of each vertex in the displacement smoothing mesh set. First, the set is traversed, and the spatial coordinate variation difference vector of each vertex is superimposed onto its corresponding 3D spatial coordinate parameters in the anti-self-intersection offset mesh volume. This completes the final smoothing update of the coordinates, forming the updated 3D spatial coordinate parameters. This step effectively eliminates the surface step effect caused by the amplitude limiting process, making the transition zone surface smoother. Next, the topological information of the upper and lower edge meshes located at the original separation boundary is extracted, namely the spatial connection parameters of the upper edge mesh and the lower edge mesh. These two sets of parameters define the open boundaries of the two meshes separated by the crack surface. Then, according to the minimum spatial distance principle, for each vertex of the upper edge, a vertex with the closest spatial distance among all vertices of the lower edge is found, establishing a one-to-one pairing relationship. For example, for each vertex of the upper edge... With the lower edge vertex Pairing, if It is the distance among all vertices of the lower edge. The most recent one, after establishing a pairing relationship, reorganizes the original open boundary connections. By creating new connections between paired vertices and between adjacent paired vertices (e.g., generating triangles or quadrilaterals), the open boundary connections are transformed into closed connections. In this way, the gaps between the upper and lower meshes are bridged, generating stitched mesh patches.

[0036] The process reads the stitching vertex number, stitching mesh spatial connectivity parameters, and updated 3D spatial coordinate parameters of each stitched mesh patch. First, it iterates through the newly generated stitched patch to obtain all its geometric and topological information. Then, based on the vertex numbers in the stitched patch, it retrieves and locates the corresponding boundary vertex numbers in the previously generated anti-self-intersection offset mesh. This is to accurately "weld" the stitched patch to the boundary of the main mesh. Next, the stitching mesh spatial connectivity parameters of the stitched mesh patch (i.e., defining the vertex connection relationships of the newly created bridging elements) are merged into the original mesh spatial connectivity parameter set of the anti-self-intersection offset mesh. During the merging process, a deduplication and cleanup operation is performed, specifically checking for duplicates caused by stitching... The resulting duplicate boundary connections, such as if two vertices were already edges of a surface element before stitching, and a new edge is attempted to be created between them during stitching, need to be eliminated. At the same time, edge connections that originally belonged to open boundaries also need to be identified and deleted after being covered by the new stitched surface element. Only those connections that together form a complete and closed outer wall of the pore are retained. This process ensures that the final generated model is topologically manifold, that is, each edge is exactly shared by two surfaces, and there are no open boundaries or non-manifold structures. After the integration, cleaning and optimization of the connection relationships, the final data structure containing the updated coordinates and the complete closed topology is the three-dimensional microporous solid structure.

[0037] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention in any other way. Any person skilled in the art may make changes or modifications to the above-disclosed technical content to create equivalent embodiments that can be applied to other fields. However, any simple modifications, equivalent changes, and modifications made to the above embodiments based on the technical essence of the present invention without departing from the scope of the present invention shall still fall within the protection scope of the present invention.

Claims

1. A 3D modeling method for the micropores of graphite anodes, characterized in that, Includes the following steps: Extract the three-dimensional spatial coordinate parameters and mesh spatial connection parameters of the graphite anode three-dimensional solid mesh, combine them with the control points of the initial microcrack surface non-uniform rational B-spline surface to determine the position overlap, and generate a bounding box intersection boundary node linked list. Based on the bounding box, the intersection boundary node linked list is used for limit filtering to generate a set of intersecting mesh elements of microcrack surfaces; The parameters corresponding to the intersecting mesh element set of the microcrack surface are separated and rearranged to generate constrained mesh re-partitioning patches; Surface fitting is performed on the mesh vertices within the constrained mesh repartition patch, and partial derivative operations are executed to extract the principal curvature and minimum curvature radius parameters, generating a local basic form curvature set; And generate the initial normal offset parameter on one side of each mesh vertex according to the preset gap width; By comparing the minimum radius of curvature parameter with the single-sided initial normal offset parameter, parameters that need to be limited are selected to generate a set of attenuation mesh parameters to be limited; Attenuation operation is applied to the offset parameters in the set of parameters to be limited and attenuated, and the three-dimensional spatial coordinate parameters are updated in combination with the offset parameters of the remaining grid vertices not included in the set of parameters to be limited and attenuated, to generate an anti-self-intersecting offset grid. Extract the three-dimensional spatial coordinate parameters of the vertices of the surface stepped mesh in the anti-self-intersection offset mesh, perform Laplacian smoothing operation with additional volume preservation constraints and separation boundary position locking, and generate a displacement smoothing mesh set containing coordinate variation differences; update the coordinate parameters according to the variation differences, and bridge and reconstruct the separation boundary according to the minimum spatial distance principle to generate stitched mesh patches and merge them to generate a three-dimensional microporous solid structure.

2. The 3D modeling method for micropores in graphite anodes according to claim 1, characterized in that, The steps for obtaining the bounding box intersection boundary node linked list are as follows: The vertex number, three-dimensional spatial coordinate parameters, and mesh spatial connection parameters are read one by one from the vertex record of the graphite negative electrode three-dimensional solid mesh. The correspondence between the three-dimensional spatial coordinate parameters and the mesh spatial connection parameters is established according to the vertex number. Then, the control point number and control point coordinate parameters are read from the surface definition record of the initial microcrack surface non-uniform rational B-spline surface. The spatial arrangement order of the control point coordinate parameters is retained according to the control point number, and the correspondence between the three-dimensional spatial coordinate parameters, mesh spatial connection parameters, and control point coordinate parameters is generated. According to the mesh space connection parameters, the vertex numbers associated with the same mesh cell are read. The bounding box boundaries of the mesh cell on the three coordinate axes are determined according to the three-dimensional spatial coordinate parameters of the associated vertices. Local sub-surfaces of the initial microcrack surface non-uniform rational B-spline surface are constructed according to the control point coordinate parameters. The bounding box boundaries of each local sub-surface are determined on the three coordinate axes. The start and end coordinates of the bounding box boundaries of the mesh cell and the bounding box boundaries of each local sub-surface are compared item by item on the three coordinate axes. The boundary node numbers of the three coordinate axes with overlapping coordinate intervals are retained, and a bounding box intersection boundary node linked list is generated.

3. The 3D modeling method for micropores in graphite anodes according to claim 1, characterized in that, The steps for obtaining the intersecting mesh element set of the microcrack surface are as follows: The three-dimensional spatial coordinate parameters corresponding to each boundary node number in the bounding box intersection boundary node chain list are read. A preset bounding box spatial collision coordinate limit is called. The absolute difference of the three-dimensional spatial coordinate parameters corresponding to the boundary node numbers on the three coordinate axes is compared item by item. Vertex parameters whose absolute difference exceeds the preset bounding box spatial collision coordinate limit and are located in the non-overlapping area outside the three-dimensional spatial coordinate domain are eliminated. Then, the corresponding mesh spatial connection parameters are traced back according to the remaining vertex parameters. The mesh cells to which the remaining vertex parameters belong are included in the intersection range to generate a microcrack surface intersection mesh cell set. The preset bounding box spatial collision coordinate limit is 0.02-0.08 times the average feature size of all mesh cells.

4. The 3D modeling method for micropores in graphite anodes according to claim 1, characterized in that, The steps for obtaining the constrained mesh repartitioned patches are as follows: The set of intersecting mesh elements of the microcrack surface is called, and the vertex number, three-dimensional spatial coordinate parameters and mesh spatial connection parameters corresponding to each intersecting mesh element of the microcrack surface are read one by one. The surface sampling position and surface normal direction are determined according to the control point coordinate parameters of the initial non-uniform rational B-spline surface of the microcrack surface. The three-dimensional spatial coordinate parameters of each vertex are projected along the surface normal direction. The forward side vertex, reverse side vertex and separation boundary vertex are divided according to the projection sign. The original mesh spatial connection parameters corresponding to the separation boundary vertex are retained. The separation mesh spatial connection parameters are rearranged according to the forward side vertex number and the reverse side vertex number respectively to generate constrained mesh re-partitioning patches.

5. The 3D modeling method for micropores in graphite anodes according to claim 1, characterized in that, The steps for obtaining the initial normal offset parameter on one side are as follows: The three-dimensional spatial coordinate parameters, adjacent vertex numbers, and rearranged mesh spatial connectivity parameters of the discrete mesh vertices within the constrained mesh repartitioned patch are read item by item. The local neighborhood of each discrete mesh vertex is determined according to the adjacent vertex numbers. A local fitting surface is constructed based on the three-dimensional spatial coordinate parameters within the local neighborhood. The local fitting surface is unfolded along the tangential and normal directions to obtain the first and second basic form partial derivative parameters. The principal curvature and minimum curvature radius parameters corresponding to each discrete mesh vertex are extracted based on the first and second basic form partial derivative parameters to generate a local basic form curvature set. The initial normal offset parameter of each discrete mesh vertex is generated based on half the preset total width of the micro gap.

6. The 3D modeling method for micropores in graphite anodes according to claim 1, characterized in that, The steps for obtaining the set of parameters for the attenuation grid to be limited are as follows: Extract the vertex number and minimum curvature radius parameter corresponding to each discrete mesh vertex within the local basic curvature set. Call the single-sided initial normal offset parameter corresponding to the same vertex number. Compare each minimum curvature radius parameter with the single-sided initial normal offset parameter under the same vertex number item by item. If the minimum curvature radius parameter is less than the single-sided initial normal offset parameter, retain the corresponding vertex number, minimum curvature radius parameter, single-sided initial normal offset parameter, and surface normal direction. If the minimum curvature radius parameter is greater than or equal to the single-sided initial normal offset parameter, exclude the corresponding vertex number and generate the set of mesh parameters to be limited and attenuated.

7. The 3D modeling method for micropores in graphite anodes according to claim 1, characterized in that, The steps for obtaining the anti-self-intersection offset mesh are as follows: The minimum radius of curvature parameter, the initial normal offset parameter on one side, and the normal direction of the surface are read item by item from each vertex number in the parameter set of the mesh to be limited and attenuated. The initial normal offset parameter on one side is gradually attenuated according to the minimum radius of curvature parameter. The offset distance value after each attenuation is compared with the minimum radius of curvature parameter of the additional proportional attenuation safety factor under the same vertex number. If the offset distance value after attenuation is still greater than or equal to the minimum radius of curvature parameter of the additional proportional attenuation safety factor, the offset distance value after attenuation is further reduced. If the offset distance value after attenuation is less than the minimum radius of curvature parameter of the additional proportional attenuation safety factor, the attenuation is stopped, and the three-dimensional spatial coordinate parameters of the corresponding mesh vertex are updated along the normal direction of the surface according to the offset distance value after attenuation to generate the three-dimensional spatial coordinate parameters of the limit attenuation mesh vertex. Based on the three-dimensional spatial coordinate parameters of the vertices of the amplitude-limiting attenuation grid, the vertex number, three-dimensional spatial coordinate parameters, and surface normal direction of the other discrete grid vertices not included in the amplitude-limiting attenuation grid parameter set are read. The single-sided initial normal offset parameter corresponding to the same vertex number is called. The three-dimensional spatial coordinate parameters of the other discrete grid vertices not included in the amplitude-limiting attenuation grid parameter set are updated along the surface normal direction according to the single-sided initial normal offset parameter. Then, the updated three-dimensional spatial coordinate parameters of the other discrete grid vertices not included in the amplitude-limiting attenuation grid parameter set are merged with the three-dimensional spatial coordinate parameters of the amplitude-limiting attenuation grid vertices in the order of vertex number to generate an anti-self-intersection offset grid volume.

8. The 3D modeling method for micropores in graphite anodes according to claim 1, characterized in that, The steps for obtaining the three-dimensional microporous solid structure are as follows: Extract the vertex number, three-dimensional spatial coordinate parameters, adjacent vertex number, and adjacent three-dimensional spatial coordinate parameters of the surface stepped mesh vertices in the amplitude-limiting transition zone of the anti-self-crossing offset mesh. Determine the spatial adjacency range of each surface stepped mesh vertex according to the adjacent vertex number. Lock the three-dimensional spatial coordinate parameters of the mesh vertices at the separation boundary. For the unlocked surface stepped mesh vertices, adjust the coordinate variation of the surface stepped mesh vertices in the three-dimensional coordinate axis direction item by item according to the coordinate difference between the three-dimensional spatial coordinate parameters of the surface stepped mesh vertex and the three-dimensional spatial coordinate parameters of the adjacent vertices. Use the difference in local closed volume before and after adjustment as the volume retention constraint parameter to backtrack the coordinate variation. Extract the spatial coordinate variation difference of the mesh vertices after backtracking correction to generate a displacement smoothing mesh set. The three-dimensional spatial coordinate parameters and the difference in spatial coordinate variation of each vertex in the displacement smoothing mesh set are read item by item. The difference in spatial coordinate variation of each vertex is superimposed on the corresponding three-dimensional spatial coordinate parameters according to the vertex number to form the updated three-dimensional spatial coordinate parameters. Then, the spatial connection parameters of the upper edge mesh and the lower edge mesh at the separation boundary are extracted. The pairing relationship between the upper edge vertex and the lower edge vertex is established according to the principle of minimum spatial distance. The boundary connection relationship between adjacent paired vertices is reorganized into a closed connection relationship to generate a stitched mesh patch. Read the stitch vertex number, stitch mesh spatial connection parameters, and updated three-dimensional spatial coordinate parameters of each stitch vertex in the stitched mesh patch. Retrieve the corresponding boundary vertex number in the anti-self-intersecting offset mesh body according to the stitch vertex number. Connect the stitch mesh spatial connection parameters of the stitched mesh patch to the original mesh spatial connection parameters of the anti-self-intersecting offset mesh body. Eliminate duplicate boundary connection relationships and retain the connection relationships that form the outer wall of the closed pore to generate a three-dimensional micro-pore solid structure.

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