Lithium Secondary Battery Lifetime Prediction via Impedance Analysis

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Solution Overview

Problem

Current methods for predicting the lifespan characteristics of lithium secondary batteries are inefficient, relying on trial and error due to the difficulty in anticipating the impact of electrode materials, electrolytes, and battery structures on battery performance, necessitating extensive testing and long development times.

Innovation Solution

A method involving impedance spectroscopic analysis of lithium secondary batteries in a blocking cell form, followed by data collection and analysis to derive charge amount and capacity predictions for each cycle, with artificial neural network learning to correct and enhance prediction accuracy, allowing for reliable prediction of capacity change patterns without actual battery manufacturing.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If conventional trial and error methods with actual battery production and long-term testing are used, then lifespan characteristics can be evaluated, but the research and development process becomes excessively long and inefficient

Engineering Contradiction:
Improvelifespan characteristics evaluationVSAvoidresearch and development process duration
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The patent applies preliminary action by performing impedance spectroscopic analysis on blocking cells before actual battery production and long-term testing. This preliminary characterization of electrode materials and electrolytes allows prediction of lifespan characteristics in advance, eliminating the need for extensive trial and error cycles and significantly reducing the R&D timeline while maintaining evaluation reliability

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent uses blocking cells as simplified copies or models of actual lithium secondary batteries. These blocking cells contain the same electrode materials and electrolytes but have a modified structure that prevents actual electrochemical reactions. By measuring impedance characteristics in these blocking cells, the patent can predict the lifespan behavior of full batteries without needing to manufacture and test actual operating batteries repeatedly

Inventive Principle:
Principle #26Copying

2Measurement precision

If actual battery manufacturing and long-term testing are conducted to evaluate lifespan characteristics, then accurate prediction is possible, but the process requires extensive resources and multiple trials

Engineering Contradiction:
Improvelifespan characteristics prediction accuracyVSAvoiddevelopment efficiency
Core Design Contradiction:
Measurement precisionVSProductivity

Solution Approach 1:

The patent replaces the mechanical/physical process of actual battery manufacturing and long-term operational testing with an electrochemical measurement system. By using impedance spectroscopy on blocking cells, the method substitutes direct observation of battery aging with indirect electrical measurements that correlate to lifespan characteristics, achieving the same predictive accuracy without the resource-intensive testing process

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent introduces impedance spectroscopic analysis as an intermediary measurement technique. Instead of directly observing battery lifespan through long-term testing, the method uses impedance characteristics of blocking cells as an intermediate indicator that correlates with actual battery performance. This intermediary measurement provides accurate predictions without requiring the battery to undergo actual aging processes

Inventive Principle:
Principle #24Intermediary (Mediator)

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

This approach enables the reliable prediction of lithium secondary battery lifespan characteristics, significantly shortening the development process by reducing the need for extensive testing and minimizing trial and error, while ensuring high accuracy in forecasting capacity changes over cycles.

Implementation Method 1

a first step of subjecting a lithium secondary battery in a form of a blocking cell to an impedance spectroscopic analysis under application of multiple frequencies

Methodology Applied
Scientific EffectImpedance spectroscopy: Electrical Impedance Tomography

Data Source

PatentEP4202459B1Method for predicting lifetime characteristics of lithium secondary battery
Publication Date: 2024.08.07 LG ENERGY SOLUTION LTD
  • EP4202459B1 patent drawingFigure 1~2
  • EP4202459B1 patent drawingFigure 3a~3b
  • EP4202459B1 patent drawingFigure 4

AI summary

The present disclosure relates to a method for predicting lifespan characteristics of a lithium secondary battery that can reliably predict the lifespan characteristics of a lithium secondary battery, specifically, the mode of variation in cycle capacity in advance.