DC Switching Power Supply for Graphene Exfoliation

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Current methods for manufacturing graphene, such as mechanical exfoliation, chemical exfoliation, exfoliation-reinsertion-expansion, and chemical vapor deposition, face challenges in achieving high purity and large-scale production due to low yield, irregular shapes, and high interlayer contact resistance, while electrochemical methods suffer from reduced yield and purity when using constant DC power supplies.

Innovation Solution

A method involving a DC switching power supply is used to alternately apply positive and negative voltages between a cathode and an anode dipped in an electrolyte, allowing for efficient insertion and discharge of ions between graphite layers, facilitating the peeling of high purity graphene.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If a constant DC power supply is used in electrochemical exfoliation, then the process is simple to operate, but the yield and purity of graphene are reduced due to ion stacking between graphite layers

Engineering Contradiction:

Improveease of operationVSAvoidyield

Core Design Contradiction:

Ease of operationVSProductivity

Solution Approach 1:

The patent applies periodic reversal of DC voltage polarity to prevent ion stacking between graphite layers. By alternating the voltage direction, ions are discharged from the interlayer spaces during the reverse voltage phase, enabling continuous exfoliation cycles that significantly improve graphene yield and purity compared to constant DC voltage application.

Inventive Principle:

Principle #19Periodic action

2Ease of manufacture

If mechanical exfoliation is used to obtain graphene, then the process is simple, but the graphene is formed in irregular shapes with micrometer size and extremely low final yield

Engineering Contradiction:

Improveease of manufactureVSAvoidfinal yield

Core Design Contradiction:

Ease of manufactureVSProductivity

Solution Approach 1:

The patent replaces the mechanical exfoliation method with an electrochemical exfoliation method using DC switching power supply. This substitution enables controlled ion insertion and discharge between graphite layers, producing high-purity graphene with significantly higher yield and more uniform morphology compared to the irregular micrometer-sized flakes from mechanical exfoliation.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

3Productivity

If chemical exfoliation is used to produce graphene oxide and reduce it, then graphene can be obtained, but the excellent physical and electrical properties are dropped due to incomplete reduction and remaining defects

Engineering Contradiction:

Improvegraphene productionVSAvoidphysical and electrical properties

Core Design Contradiction:

ProductivityVSReliability

Solution Approach 1:

The patent replaces chemical exfoliation and reduction methods with direct electrochemical exfoliation using DC switching. This approach produces high-purity graphene without the need for oxidation and reduction steps, preserving the excellent physical and electrical properties of graphene while achieving high production yield and minimal defects.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

4Quantity of substance

If graphite is used as the starting material, then the material cost is very low, but conventional methods achieve low yield and require complex purification processes

Engineering Contradiction:

Improvematerial costVSAvoidyield

Core Design Contradiction:

Quantity of substanceVSProductivity

Solution Approach 1:

The patent employs periodic DC voltage reversal to enable efficient and continuous exfoliation of graphite into graphene. This method maintains the advantage of using inexpensive graphite as starting material while dramatically improving the yield and eliminating the need for complex purification processes required by conventional methods.

Inventive Principle:

Principle #19Periodic action

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 enables the mass production of high purity graphene by controlling ion stacking and discharge, resulting in improved peeling efficiency and reduced sheet resistance, with yields significantly higher than conventional methods.

Implementation Method 1

applying a DC power supply between the cathode and the anode, wherein the DC power supply is a DC switching power supply applying a positive (+) voltage and a negative (−) voltage alternately and repetitively

Methodology Applied

Scientific EffectIon insertion and discharge: Ion Repulsion/Attraction

Implementation Method 2

a method of manufacturing graphene using electrochemistry

Methodology Applied

Scientific EffectElectrochemical exfoliation: Electrolysis

Data Source

PatentUS10858746B2Method of manufacturing graphene by DC switching

Publication Date: 2020.12.08 ZIO HLDG LLC

AI summary

The present inventive concept provides a method of manufacturing graphene using electrochemistry, the method including dipping a cathode including metal and an anode including graphite into an electrolyte and applying a DC power supply between the cathode and the anode, wherein the DC power supply is a DC switching power supply applying a positive (+) voltage and a negative (−) voltage alternately and repetitively. The method according to the present inventive concept can simply mass-produce high purity graphene by applying the DC switching power supply, thereby efficiently controlling the ions to peel the graphite.