Battery Lithium Plating Detection Without a Reference Electrode

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Solution Overview

Problem

Existing methods for detecting lithium plating in rechargeable batteries suffer from inaccuracies due to the influence of reference electrode materials and locations, leading to poor detection results.

Innovation Solution

A method that utilizes open-circuit voltage, negative electrode open-circuit voltage, and polarization voltage, obtained from state of charge, terminal voltage, and polarization proportion, to determine lithium plating without requiring a reference electrode, ensuring accuracy and ease of implementation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If a reference electrode is used to measure the electrical potential of the negative electrode, then the lithium plating detection method can be implemented, but the accuracy of the detection result is poor due to factors such as reference electrode material and location

Engineering Contradiction:
Improvelithium plating detection accuracyVSAvoidreference electrode requirements
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent extracts and eliminates the reference electrode from the detection system. Instead of measuring the negative electrode potential relative to a reference electrode, the method calculates the negative electrode potential by subtracting the positive electrode potential from the terminal voltage, thereby removing the source of measurement inaccuracy while maintaining the ability to detect lithium plating

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent introduces the terminal voltage as an intermediary measurement. By measuring the terminal voltage and the positive electrode potential separately, and using their difference to represent the negative electrode potential, the method achieves accurate lithium plating detection without directly measuring the negative electrode potential against a reference electrode

Inventive Principle:
Principle #24Intermediary (Mediator)

2Reliability

If traditional lithium plating detection methods are used, then detection can be performed, but additional hardware costs and system modifications are required

Engineering Contradiction:
Improvelithium plating detection capabilityVSAvoidsystem compatibility and hardware requirements
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The patent makes the detection method universal by designing it to work with existing battery management system hardware. The method uses terminal voltage and positive electrode potential measurements that are already available in conventional systems, allowing lithium plating detection without requiring additional sensors or hardware modifications

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

Solution Approach 2:

The method enables the battery management system to perform lithium plating detection using its own existing measurement capabilities. By utilizing the terminal voltage and positive electrode potential data that the system already collects for other functions, the detection capability is achieved through self-service without external assistance or additional hardware

Inventive Principle:
Principle #25Self-service

Data Source

PatentEP4130767B1Lithium plating detection method and apparatus
Publication Date: 2025.07.02 YINWANG INTELLIGENT TECHNOLOGIES CO LTD
  • EP4130767B1 patent drawingFigure 1
  • EP4130767B1 patent drawingFigure 2
  • EP4130767B1 patent drawingFigure 3~4

AI summary

A method and apparatus for detecting lithium plating, and a method and apparatus for obtaining a polarization proportion are provided, and belong to the field of rechargeable battery technologies. The method includes: obtaining an open-circuit voltage of a rechargeable battery and a negative electrode open-circuit voltage of the rechargeable battery based on a state of charge of the rechargeable battery (205); obtaining a negative electrode polarization voltage of the rechargeable battery based on the open-circuit voltage of the rechargeable battery, a terminal voltage of the rechargeable battery, and a polarization proportion of the rechargeable battery (206), where the polarization proportion of the rechargeable battery represents a proportion that is of a negative electrode polarization voltage of the rechargeable battery to a polarization voltage of the rechargeable battery and that is obtained when the rechargeable battery is at a lithium plating critical point; obtaining a negative electrode voltage of the rechargeable battery based on the negative electrode open-circuit voltage of the rechargeable battery and the negative electrode polarization voltage of the rechargeable battery (207); and determining, based on the negative electrode voltage of the rechargeable battery, whether lithium plating occurs in the rechargeable battery (208). This method improves accuracy of lithium plating detection.