Fiber Optic Battery Probe for Temperature and Lithiation Sensing

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Solution Overview

Problem

Current fiber optic sensors are unable to simultaneously measure internal temperature and the lithiation state of a battery electrode with a single sensor, which is essential for accurate state of charge estimation and optimal battery management.

Innovation Solution

A fiber optic sensor with a thermoluminescent material probe that emits light at two distinct wavelengths, allowing for simultaneous temperature measurement and lithiation state monitoring by ratiometry and luminescence absorption techniques.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If a single fiber optic sensor is used to measure both temperature and lithiation state, then device complexity is reduced, but measurement precision deteriorates due to the inability to simultaneously capture both parameters with adequate accuracy

Engineering Contradiction:
Improvesensor system complexityVSAvoidtemperature and lithiation measurement precision
Core Design Contradiction:
Device complexityVSMeasurement precision

Solution Approach 1:

The patent combines temperature measurement and lithiation state measurement into a single fiber optic sensor system. The sensor simultaneously detects both parameters by measuring the intensity ratio of two luminescence peaks (one sensitive to temperature, one sensitive to lithiation), thereby reducing device complexity while maintaining measurement precision through multi-parameter detection capability.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The fiber optic sensor is designed with multi-functionality to perform both temperature measurement and lithiation state monitoring using the same sensing probe. The luminescent material exhibits dual sensitivity characteristics, allowing the single sensor to serve multiple measurement purposes without requiring separate specialized sensors for each parameter.

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

2Quantity of substance

If conventional fiber optic sensors are used, then temperature measurement is achieved, but the lithiation state of the battery electrode cannot be measured simultaneously

Engineering Contradiction:
Improvemeasurement parameters obtainedVSAvoidsensor application versatility
Core Design Contradiction:
Quantity of substanceVSAdaptability or versatility

Solution Approach 1:

The sensor system achieves universality by enabling a single fiber optic probe to measure both temperature and lithiation state. The luminescent material is selected to have emission peaks with different sensitivities - one peak intensity ratio provides temperature information while another provides lithiation state information, allowing the same sensor to adapt to multiple measurement needs.

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

Solution Approach 2:

The invention utilizes changes in luminescence parameters (intensity ratios of different peaks) to encode multiple measurement information. By monitoring how the luminescence spectrum changes in response to both temperature variations and lithiation state changes, the system extracts multiple parameters from a single sensing output, increasing the quantity of measurable substances.

Inventive Principle:
Principle #35Parameter changes

3Measurement precision

If separate sensors are used for temperature and lithiation measurement, then measurement precision is maintained, but device complexity and installation difficulty increase

Engineering Contradiction:
Improveparameter measurement precisionVSAvoidsensor system complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent merges temperature sensing and lithiation state sensing into a single integrated fiber optic probe. The luminescent material layer on the fiber tip simultaneously provides both measurement functions, eliminating the need for multiple separate sensors and their associated installation complexity while preserving measurement precision through independent signal processing channels for each parameter.

Inventive Principle:
Principle #5Merging (Combining)

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

Enables precise and simultaneous measurement of internal temperature and lithiation state of a battery electrode, facilitating real-time state of charge estimation and improving battery management systems.

Implementation Method 1

one free end of which forms an optical probe with thermoluminescent material(s) capable of emitting a peak of light at at least two wavelengths, at least one of the peaks being adapted to be in at least one zone of variation of the optical absorption spectrum

Methodology Applied
Scientific EffectThermoluminescence: Thermoluminescence

Implementation Method 2

the capacity of a material to emit almost instantaneously, at a given temperature and under the effect of light radiation called absorption or excitation radiation, light radiation of the same wavelength or of a different wavelength called emission radiation

Methodology Applied
Scientific EffectPhotoluminescence: Photoluminescence

Implementation Method 3

A sensor as described above can be implemented in any industrial, medical or biological application requiring, at one time or another, the determination of a temperature

Methodology Applied
Scientific EffectOptical fiber transmission: Optical Fibre

Data Source

PatentEP4571280A1Temperature measurement device and state of charge (SOC) measurement device for a battery
Publication Date: 2025.06.18 COMMISSARIAT A LENERGIE ATOMIQUE ET AUX ENERGIES ALTERNATIVES
  • EP4571280A1 patent drawingFigure 1~2
  • EP4571280A1 patent drawingFigure 3~4
  • EP4571280A1 patent drawingFigure 5~6

AI summary

Temperature and state of charge (SOC) sensor for an optical fiber accumulator with thermoluminescent material(s), at the emission peak(s) in a variation zone of the optical absorption spectrum of the insertion material of an electrode The invention relates to a temperature and state of charge (SOC) sensor (7) for a metal-ion accumulator, comprising an optical fiber (8) of which a free end (82) forms an optical probe (9) with thermoluminescent material(s) (91) capable of emitting a light peak at at least two wavelengths, at least one of the two peaks being adapted to be in at least one variation zone of the optical absorption spectrum of the metal ion insertion material of at least one electrode of the accumulator, the ratio of the two peaks being a function of the temperature of the accumulator and the variation in intensity of at least one of the two peaks being a function of the insertion of metal ions into the electrode.