Random-Structure GIC Production via Polar Protic Solvent
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Solution Overview
Problem
Existing methods for producing exfoliated graphite with a small number of stacked layers struggle to achieve stability and sufficient exfoliation due to retained regularity in alkali metal-GIC structures, even after exposure to air or polar aprotic solvents.
Innovation Solution
A method involving the contact of alkali metal-GIC with a polar protic solvent in a non-oxidizing atmosphere to collapse stage structures, followed by potential exposure to an oxygen-containing atmosphere, results in a random-structure GIC, which is then exfoliated using ultrasonic or shear treatments in a solvent, preferably with a surfactant, to obtain exfoliated graphite with reduced regularity and improved conductivity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If alkali metal-GIC is exposed to air or polar aprotic solvent, then the structure changes and stage 2/3 peaks appear, but the regularity of graphene stacked state is not eliminated and stable exfoliation cannot be achieved
Solution Approach 1:
The invention changes the chemical parameter by introducing a polar protic solvent (water or alcohol) instead of polar aprotic solvent, and controls the oxidation state by using non-oxidizing atmosphere initially. This parameter change enables the collapse of stage structures while maintaining regularity, achieving stable exfoliation with controlled oxidation later.
Solution Approach 2:
The invention uses non-oxidizing atmosphere (inert atmosphere) during the initial contact of polar protic solvent with alkali metal-GIC to prevent unwanted oxidation reactions. This protects the integrity of the GIC structure during the critical solvation process, allowing controlled structure collapse without premature oxidation.
2Ease of manufacture
If alkali metal-GIC is dissolved in polar aprotic solvent such as THF, then GIC dissolves, but sufficient exfoliation cannot be achieved and exfoliated graphite with small number of stacked layers cannot be obtained
Solution Approach 1:
The invention changes the solvent parameter from polar aprotic (THF) to polar protic (water or alcohol). This parameter change enables both dissolution and sufficient exfoliation simultaneously, achieving the dual goal of ease of manufacture and high exfoliation degree that was not possible with polar aprotic solvents.
Solution Approach 2:
The polar protic solvent acts as an intermediary that facilitates both dissolution and exfoliation processes. The protic nature of the solvent enables stronger interaction with the alkali metal-GIC structure, mediating the collapse of stage structures and achieving complete exfoliation while maintaining solubility.
3Manufacturing precision
If stage structure is collapsed to obtain random-structure GIC, then regularity is reduced and exfoliation is facilitated, but oxidation may occur and affect the quality of exfoliated graphite
Solution Approach 1:
The invention uses non-oxidizing atmosphere during the critical step of polar protic solvent contact to prevent oxidation while enabling structure collapse. This inert environment protects against harmful oxidation during the vulnerable stage when the GIC structure is most susceptible to degradation.
Solution Approach 2:
The invention later exposes the random-structure GIC to oxygen-containing atmosphere after the structure has collapsed and regularity has been reduced. By timing the oxidation exposure after the critical structure collapse, the harmful oxidation effect is converted into a beneficial process that can be controlled to achieve the desired exfoliated graphite quality.
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 effectively reduces the regularity of graphene stacked states, allowing for the stable production of exfoliated graphite with a small number of layers, maintaining excellent electrical and thermal conductivity, and enabling the formation of tape-shaped or networked exfoliated graphite structures.
Implementation Method 1
bringing a polar erotic solvent into contact with the alkali metal-GIC
Implementation Method 2
graphite is exfoliated by ultrasonic treatment
Implementation Method 3
graphite is exfoliated by ultrasonic treatment, heat treatment, or the like
Data Source
AI summary
The present invention provides a method for producing a random-structure GIC in which exfoliated graphite having a low regularity of a graphene stacked state and a small number of stacked graphene layers can be easily obtained by exfoliation treatment. The method includes the steps of providing an alkali metal-GIC having an alkali metal intercalated between graphene layers and bringing a polar protic solvent into contact with the alkali metal-GIC in a non-oxidizing atmosphere.