Ionogel Electrode Paste Mixing for Leak-Safe Room-Temperature Cells

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Solution Overview

Problem

The use of liquid electrolytes in electrochemical accumulators poses challenges such as leakage and chemical reactions leading to thermal runaway, while solid alternatives like lithium-ion conductive glass or ceramic require complex synthesis and have low ionic conductivity at room temperature, necessitating higher temperatures for effective ion diffusion.

Innovation Solution

A method of manufacturing electrodes with a polymer matrix that traps a liquid electrolyte, using a specific mixer with co-rotating interpenetrating screws to create a high-viscosity paste composition, reducing the need for solvents and enabling efficient ionogel electrode production at room temperature.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If liquid electrolyte is used in electrochemical accumulators, then electrochemical performance and ion conductivity are improved, but safety issues arise including leakage and thermal runaway

Engineering Contradiction:
Improveelectrochemical performanceVSAvoidleakage and thermal runaway
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The liquid electrolyte is trapped inside a polymeric matrix, creating a nested structure where the electrolyte is contained within the polymer network. This prevents leakage while maintaining ion conductivity, as the electrolyte remains confined within the polymer channels.

Inventive Principle:
Principle #7Nested doll (Nesting)

Solution Approach 2:

The invention creates a composite material by combining a polymeric matrix with a liquid electrolyte to form an ionogel. This composite structure integrates the advantages of both components: the polymer provides structural integrity and containment, while the liquid electrolyte maintains high ion conductivity.

Inventive Principle:
Principle #40Composite materials

2Object-affected harmful factors

If solid electrolytes like glass or ceramic are used, then safety is improved by eliminating leakage, but manufacturing complexity increases and ionic conductivity decreases at room temperature

Engineering Contradiction:
Improveleakage preventionVSAvoidsynthesis complexity
Core Design Contradiction:
Object-affected harmful factorsVSDevice complexity

Solution Approach 1:

The invention changes the physical state parameter of the electrolyte system by trapping liquid electrolyte within a polymer matrix at room temperature, creating a gel-like ionogel. This avoids the need for high-temperature processing required by solid glass or ceramic electrolytes, simplifying manufacturing while maintaining safety.

Inventive Principle:
Principle #35Parameter changes

3Object-affected harmful factors

If solid electrolytes like glass or ceramic are used, then leakage is prevented, but ion conductivity at room temperature is reduced requiring higher operating temperatures

Engineering Contradiction:
Improveleakage preventionVSAvoidoperating temperature requirement
Core Design Contradiction:
Object-affected harmful factorsVSTemperature

Solution Approach 1:

By creating an ionogel composite that combines polymeric matrix with liquid electrolyte, the invention maintains the liquid electrolyte's high ion conductivity at room temperature while the polymer matrix provides leakage prevention, eliminating the need for elevated operating temperatures required by solid electrolytes.

Inventive Principle:
Principle #40Composite materials

4Ease of manufacture

If conventional mixing methods are used for electrode preparation, then manufacturing is simple, but solvent usage increases leading to higher effluent management costs

Engineering Contradiction:
Improvemanufacturing simplicityVSAvoidsolvent usage
Core Design Contradiction:
Ease of manufactureVSLoss of substance

Solution Approach 1:

The invention replaces conventional mechanical mixing methods with a twin-screw extruder system that uses mechanical intermeshing screws to mix and process the electrode slurry. This extrusion-based approach reduces solvent requirements while maintaining manufacturing efficiency and simplifying effluent management.

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

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

This approach minimizes solvent usage, reduces effluent management costs, and maintains electrochemical performance equivalent to liquid electrolyte-based lithium-ion accumulators at room temperature, enhancing safety and scalability.

Implementation Method 1

a polymer matrix trapping an electrolyte, more specifically, a liquid electrolyte capable of forming a gel with the polymer matrix (in which case the electrode can be described as an ionogel electrode)

Methodology Applied
Scientific EffectGel formation: Gel

Implementation Method 2

a composition in the form of a paste having a dynamic viscosity greater than 5000 Pa.s measured at a shear gradient of 0.1 s−1 and at ambient temperature

Methodology Applied
Scientific EffectViscosity:

Implementation Method 3

the electrodes comprising specific materials capable of reacting according to an oxidation-reduction reaction, whereby there is an exchange of electrons which gives rise to the electric current

Methodology Applied
Scientific EffectOxidation-reduction reaction: Redox Reactions

Implementation Method 4

an electrolyte, which will allow the movement of ions (usually from a metallic salt present in the electrolyte) from the positive electrode to the negative electrode during charging and vice versa during discharging

Methodology Applied
Scientific EffectIon diffusion: Diffusion

Data Source

PatentEP4008031B1Method for manufacturing an electrode comprising a polymer matrix trapping an electrolyte
Publication Date: 2023.09.06 SOLVAY SA
  • EP4008031B1 patent drawingFigure 1
  • EP4008031B1 patent drawingFigure 2~3
  • EP4008031B1 patent drawing

AI summary

The invention relates to a method for manufacturing an electrode comprising a polymer matrix trapping an electrolyte, the method comprising the following steps: a) a step of preparing a composition comprising the ingredients intended to be included in the constitution of the electrode; b) a step of forming the electrode, from the composition, on a support; characterised in that: - the composition prepared in step a) is a composition in paste form having a dynamic viscosity greater than 5000 Pa.s measured at a shear gradient of 0.1 s-1 and at ambient temperature; and - the preparation step consists in introducing the ingredients intended to be included in the constitution of the electrode into a mixer with two co-rotating interpenetrating screws rotating in a closed sleeve, and mixing the ingredients therein, the preparation step being implemented at a temperature less than 100°C.