Battery SOH Diagnosis Using Differential Peak Voltage Profiles

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Solution Overview

Problem

Existing battery diagnosis technologies fail to provide a non-destructive method for assessing the state of a battery based on voltage and capacity indicators, particularly failing to identify batteries with a sudden drop in State of Health (SOH).

Innovation Solution

An apparatus and method that diagnose the state of a battery by analyzing differential profiles of voltage and capacity, identifying target peaks within a predetermined voltage range, and comparing their voltages and change rates with reference peaks to detect sudden drops in SOH.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If conventional battery diagnosis methods are used, then general battery state can be assessed, but batteries with sudden SOH drop cannot be identified

Engineering Contradiction:
ImproveSOH diagnosis precisionVSAvoidDetection of sudden SOH drop
Core Design Contradiction:
Measurement precisionVSReliability

Solution Approach 1:

The differential profile is segmented into multiple peaks, each corresponding to different electrode reactions. By analyzing individual peak characteristics rather than the overall profile, the method can detect subtle changes indicating sudden SOH drops with higher precision and reliability.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The method performs preliminary diagnosis by comparing target peaks from differential profiles obtained at different states of charge. This preliminary comparison enables early detection of batteries experiencing sudden SOH drops before complete failure occurs, allowing preventive maintenance actions.

Inventive Principle:
Principle #10Preliminary action

2Measurement precision

If detailed differential profile analysis is performed, then accurate SOH diagnosis is achieved, but diagnosis time increases

Engineering Contradiction:
ImproveSOH diagnosis accuracyVSAvoidDiagnosis time
Core Design Contradiction:
Measurement precisionVSLoss of time

Solution Approach 1:

The method extracts only the critical target peaks from the differential profile that are most indicative of SOH status. By focusing analysis on these specific peaks rather than the entire profile, accurate SOH diagnosis is achieved with reduced computation time and faster results.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The method performs partial analysis by examining only the necessary peak characteristics (voltage, area, position) rather than complete profile analysis. This selective approach maintains diagnostic accuracy while significantly reducing the time required for battery state assessment.

Inventive Principle:
Principle #16Partial or excessive action

3Adaptability or versatility

If multiple battery parameters are monitored, then comprehensive diagnosis is achieved, but system complexity increases

Engineering Contradiction:
ImproveDiagnosis comprehensivenessVSAvoidSystem complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The differential profile analysis method serves multiple diagnostic functions simultaneously: it assesses general SOH status, detects sudden drops, and identifies specific degradation patterns. This multi-functional approach provides comprehensive diagnosis without requiring separate systems for each diagnostic purpose, maintaining system simplicity.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Data Source

PatentEP4206706B1Apparatus and method for diagnosing state of battery
Publication Date: 2026.01.21 LG ENERGY SOLUTION LTD
  • EP4206706B1 patent drawingFigure 1
  • EP4206706B1 patent drawingFigure 2
  • EP4206706B1 patent drawingFigure 3~4

AI summary

An apparatus for diagnosing a state of a battery according to an embodiment of the present disclosure includes a profile obtaining unit configured to obtain a plurality of differential profiles representing a corresponding relationship between a differential capacity representing a change rate of a capacity of a battery with respect to a voltage of the battery and the voltage; a peak determining unit configured to determine a target peak located in a predetermined voltage section in each of the plurality of differential profiles; and a state diagnosing unit configured to compare the voltage of a plurality of target peaks determined by the peak determining unit with a voltage of a reference peak preset to correspond to each of the plurality of target peaks, and diagnose a state of the battery based on the voltage comparison result.