Battery EOL Diagnosis Through Differential Voltage-Capacity Peaks

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Solution Overview

Problem

Existing battery management systems struggle to diagnose the state of a battery in a non-destructive manner, which can lead to the misuse of batteries in end-of-life (EOL) states, potentially causing accidents.

Innovation Solution

A battery management apparatus and method that utilizes differential profile analysis to diagnose the state of a battery by generating a differential profile representing the relationship between voltage and capacity, and comparing the differential values of criterion and target peaks to determine the battery's usability.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If conventional battery state estimation methods (capacity change or internal resistance) are used, then the diagnosis process is simple, but the measurement precision and reliability of battery state diagnosis deteriorates

Engineering Contradiction:
Improvebattery state diagnosis precisionVSAvoiddiagnosis method complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent transforms the battery profile from voltage-capacity relationship to differential voltage-capacity relationship by calculating differential voltage (dV/dQ). This parameter transformation enables more precise battery state diagnosis through differential profile analysis, where feature points in the differential profile provide accurate indicators of battery health state without requiring complex additional hardware

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent replaces physical-destructive battery testing methods with non-destructive differential profile analysis. By analyzing the differential voltage curve characteristics during normal charging/discharging operations, the system can diagnose battery state without subjecting the battery to additional stress or degradation, substituting mechanical/physical testing with mathematical analysis

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

2Reliability

If battery state diagnosis is delayed or contains errors, then the device complexity remains low, but the reliability and safety of battery usage deteriorates

Engineering Contradiction:
Improvebattery usage safetyVSAvoiddiagnosis system complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent implements continuous feedback through differential profile analysis during battery charging and discharging operations. By continuously monitoring differential voltage characteristics and comparing them against reference profiles, the system provides real-time feedback on battery health state, enabling timely detection of degradation and prevention of unsafe usage without requiring complex additional sensing hardware

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The patent performs preliminary diagnosis actions by analyzing differential profile features during normal battery operations before critical failures occur. The system identifies early signs of battery degradation through characteristic changes in the differential voltage profile, enabling preventive maintenance and avoiding situations where batteries reach dangerous failure states

Inventive Principle:
Principle #10Preliminary action

Data Source

PatentEP4224182B1Battery management apparatus and method
Publication Date: 2025.05.07 LG ENERGY SOLUTION LTD
  • EP4224182B1 patent drawingFigure 1~2
  • EP4224182B1 patent drawingFigure 3~4
  • EP4224182B1 patent drawingFigure 5

AI summary

A battery management apparatus according to an embodiment of the present disclosure includes a profile generating unit configured to generate a differential profile for a battery profile representing a corresponding relationship between voltage and capacity of a battery; and a control unit configured to determine a criterion peak and a target peak in the differential profile received from the profile generating unit, and diagnose a state of the battery based on a result of comparing a differential value of the criterion peak and a differential value of the target peak.