Inline IR Spectrometry for Battery Electrolyte Filling Control

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Solution Overview

Problem

Current methods for monitoring electrolyte solution composition and quality in battery production are unreliable, delayed, and result in material waste due to cleaning residue disposal, lacking real-time process control and efficient quality assurance.

Innovation Solution

A measuring device with an IR spectrometer and flow cell for inline monitoring of electrolyte solutions, allowing continuous, non-destructive real-time analysis of electrolyte composition and contaminants using individually controlled IR emitters and detectors for precise spectral acquisition.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If offline laboratory analysis is used to check electrolyte solution composition, then measurement accuracy can be achieved, but time delay and loss of real-time process control occur

Engineering Contradiction:
Improveelectrolyte composition analysis accuracyVSAvoidanalysis time delay
Core Design Contradiction:
Measurement precisionVSLoss of time

Solution Approach 1:

The patent replaces the mechanical/chemical offline laboratory analysis system with an optical measurement system (infrared spectrometer) that can perform analysis in-line and in real-time. The IR spectrometer uses light absorption spectroscopy to identify and quantify electrolyte components and contaminants without requiring physical sampling and transport to a laboratory, thereby eliminating time delays while maintaining measurement capability.

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

Solution Approach 2:

The patent introduces an infrared spectrometer as an intermediary measurement device between the electrolyte storage and filling processes. This intermediary system continuously monitors electrolyte composition and quality parameters, providing real-time feedback without interrupting the production flow, thus resolving the contradiction between accurate measurement and real-time control requirements.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Reliability

If generous pre-rinse volume is used after cleaning to ensure quality, then contamination risk is reduced, but material waste and disposal costs increase

Engineering Contradiction:
Improveelectrolyte solution quality assuranceVSAvoidelectrolyte material waste
Core Design Contradiction:
ReliabilityVSLoss of substance

Solution Approach 1:

The patent implements a feedback control system where the infrared spectrometer continuously monitors electrolyte quality in real-time. After cleaning and rinsing operations, the system immediately detects whether contaminants are present and provides feedback on solution quality. This allows the process to determine the actual need for discarding rinsing volumes based on measured quality parameters rather than using fixed generous volumes, thereby reducing material waste while maintaining quality standards.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The patent changes the monitoring parameter from indirect quality indicators to direct spectral analysis of electrolyte composition. By measuring actual quality parameters (contaminant concentrations, solution composition) in real-time, the system can dynamically adjust rinsing and discarding decisions based on measured values, optimizing the balance between quality assurance and material conservation.

Inventive Principle:
Principle #35Parameter changes

3Measurement precision

If multiple measurement paths with different detection ranges are used, then measurement precision and coverage are improved, but device complexity increases

Engineering Contradiction:
Improvespectral analysis accuracyVSAvoidspectrometer structure complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent segments the spectral detection range into multiple distinct measurement paths, each optimized for specific detection ranges. The infrared spectrometer incorporates multiple detectors or detector arrays, each responsible for specific wavelength regions, allowing simultaneous measurement of different electrolyte components and contaminants across the full infrared spectrum. This segmentation enables comprehensive analysis while managing device complexity through modular detector design.

Inventive Principle:
Principle #1Segmentation

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 reliable, real-time monitoring of electrolyte quality, reducing material waste and improving process efficiency by ensuring immediate compliance with quality standards during battery production.

Implementation Method 1

an IR spectrometer (infrared spectrometer) coupled to the flow cell and interacting with the electrolyte solution for spectroscopic analysis of the electrolyte solution

Methodology Applied
Scientific EffectInfrared spectroscopy: Absorption Spectroscopy

Implementation Method 2

The IR spectrometer can be configured for either transmission spectroscopy (i.e., as a transmission spectrometer) or attenuated total reflection (ATR) spectroscopy

Methodology Applied
Scientific EffectInfrared radiation interaction: Absorption (EM radiation)

Data Source

PatentEP4671733A1Measuring device, electrolyte filling system and method for inline monitoring of an electrolyte solution
Publication Date: 2025.12.31 IRPC INFRARED PROCESS CONTROL GMBH
  • EP4671733A1 patent drawingFigure 1~2
  • EP4671733A1 patent drawingFigure 3~4
  • EP4671733A1 patent drawing

AI summary

The invention relates to a measuring device for the inline monitoring of an electrolyte solution (3), an electrolyte filling system for filling battery bodies (7) with an electrolyte solution (3), and a method for the inline monitoring of an electrolyte solution (3) during the filling of battery bodies (7). The measuring device comprises an IR spectrometer (1) with several IR emitters (10), at least one IR detector (11) with several detection ranges, and a control unit (12), wherein each of the IR emitters (10) is assigned to a separate detection range of the IR detector (11). Together, these form a measurement path of the IR spectrometer (1).The power of the IR emitters (10) can be individually controlled by the control unit (12) as a function of a detection range-specific wavenumber interval, such that the radiation intensity in the respective measurement path lies within an intensity operating range that remains above the signal noise level and below the saturation limit of the IR detector (11). The invention enables real-time spectral-analytical monitoring of the electrolyte composition and is particularly suitable for process control during the filling of battery bodies (7) with lithium or sodium-ion electrolyte solutions.