Machine Learning Prediction of Lithium Compound C-Axis Length

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Solution Overview

Problem

Current methods for predicting the c-axis length of lithium compound crystal structures are time-consuming and require significant computational resources, limiting the efficiency of lithium-ion battery development, as they rely heavily on first-principles calculations with high parameter loads, and there is a lack of effective methods using machine learning to accurately describe and predict the physical properties of lithium compounds.

Innovation Solution

A method and system utilizing a learning model, specifically a machine learning model such as a Gaussian process regression or convolutional neural network, that converts crystal structures into binary data descriptors and uses these to predict the c-axis length of lithium compounds like NCM (lithium composite oxides) with manganese substitution, reducing the need for extensive first-principles calculations by leveraging training data from Vienna Ab initio Simulation Package (VASP) or other optimization programs.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If first-principles calculation is used for c-axis length calculation, then reliability of calculation result is improved, but calculation time and computational load increase significantly

Engineering Contradiction:
Improvereliability of calculation resultVSAvoidcalculation time
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The patent applies preliminary action by pre-calculating c-axis lengths for various NCM crystal structures with different metal atom substitutions using first-principles calculation, then storing these results as training data. This allows the machine learning model to make rapid predictions without performing time-consuming first-principles calculations for each new material composition, thus resolving the contradiction between reliability and calculation time.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent creates a computational copy by training a machine learning model on first-principles calculation results. The model learns the relationship between crystal structure parameters and c-axis length, then uses this learned knowledge to predict c-axis lengths for new compositions. This copying approach maintains the reliability of first-principles calculations while eliminating their time consumption for routine predictions.

Inventive Principle:
Principle #26Copying

2Productivity

If machine learning method is used for prediction, then calculation time is reduced, but accuracy and reliability of prediction decrease

Engineering Contradiction:
Improveprediction speedVSAvoidprediction accuracy
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The patent performs preliminary action by extensively training the machine learning model using a comprehensive dataset generated from first-principles calculations covering various metal atoms (Mg, Al, Sc, Ti, V, Cr, Fe, Cu, Zn, Ga, Ge) and substitution sites. This thorough preliminary training ensures the model achieves high prediction accuracy while maintaining fast inference speed for new compositions.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent optimizes prediction accuracy by carefully selecting and adjusting model parameters including the descriptor types (binary data representation of crystal structures), the number of training samples, and the specific machine learning algorithm configuration. These parameter changes enable the model to achieve reliability comparable to first-principles calculations while maintaining computational efficiency.

Inventive Principle:
Principle #35Parameter changes

3Measurement precision

If comprehensive first-principles calculation with multiple parameters is used, then prediction accuracy is improved, but computational resources and processing capability requirements increase

Engineering Contradiction:
Improveprediction accuracyVSAvoidcomputational resource requirements
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent creates a simplified computational model that copies the essential predictive capability of complex first-principles calculations. The machine learning model, trained on comprehensive first-principles data, captures the relationship between crystal structure parameters and c-axis length without requiring the full computational machinery of first-principles methods, thus reducing device complexity while maintaining prediction accuracy.

Inventive Principle:
Principle #26Copying

Solution Approach 2:

The patent transforms the computational approach by changing from direct first-principles calculation parameters to machine learning model parameters. The model uses descriptor vectors representing crystal structure features and metal atom characteristics as inputs, replacing the need for complex quantum mechanical calculations. This parameter transformation maintains measurement precision while significantly reducing computational resource requirements.

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentUS20230012643A1Method for predicting c-axis length of lithium compound crystal structure, method for building learning model, and system for predicting crystal structure having maximum c-axis length
Publication Date: 2023.01.19 SEMICON ENERGY LAB CO LTD
  • US20230012643A1 patent drawing
  • US20230012643A1 patent drawing
  • US20230012643A1 patent drawing

AI summary

To provide a method for predicting the c-axis length of a lithium compound crystal structure, a method for building a learning model for predicting a c-axis length, and a system for predicting a crystal structure having the maximum c-axis length. A method for predicting the c-axis length of a crystal structure of a lithium compound containing cobalt, nickel, and manganese includes preparing a descriptor including n values (n is an integer greater than or equal to 0) obtained by converting a crystal structure of the lithium compound in which manganese at any one or more of n sites is substituted by a metal atom among crystal structures of the lithium compound into binary data and a characteristic value of the metal atom; inputting the descriptor into a learned learning model; and outputting a predicted value of c-axis length of an optimized crystal structure and a descriptor corresponding to the optimized crystal structure as an output value of the learning model.