Ceramic Coated Graphite via Sol-Gel Bonding
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Solution Overview
Problem
The existing methods for manufacturing ceramic coated graphite are complex and costly, leading to low productivity due to the need for surface reforming and drying processes, which hinder the mass production of materials with high thermal conductivity and electric insulation.
Innovation Solution
A sol-gel method is used to chemically bond ceramic to the lateral defect areas of graphite, eliminating the need for surface reforming and incorporating a pyrene derivative as a dispersing agent to enhance dispersion and uniformity of the ceramic coating, thereby simplifying the process and improving thermal conductivity and electric insulation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If surface reforming and drying processes are used to coat graphite with ceramic, then uniform coating and electric insulation are achieved, but process complexity and manufacturing time increase
Solution Approach 1:
The patent combines the ceramic coating process with the graphite synthesis process into a single step. The ceramic precursor is mixed with the graphite precursor before sintering, allowing both materials to be formed and bonded simultaneously without separate surface reforming and drying steps, thus simplifying the manufacturing process while achieving uniform coating.
Solution Approach 2:
The patent performs preliminary mixing of ceramic precursor with graphite precursor before the sintering process. This preliminary action ensures uniform distribution of ceramic particles throughout the graphite structure before densification occurs, eliminating the need for subsequent surface reforming operations and achieving uniform coating in advance.
2Ease of manufacture
If spray coating method is used to apply ceramic to graphite, then coating can be applied, but expenses increase and yield rates decrease due to complex processes
Solution Approach 1:
The patent merges the ceramic coating application with the graphite formation process. Instead of applying ceramic coating separately through spray coating, the ceramic precursor is incorporated into the graphite precursor mixture, and both are sintered together in one step, significantly simplifying the manufacturing process and improving productivity.
Solution Approach 2:
The patent enables the graphite and ceramic to bond with each other through their own sintering process without requiring external coating equipment like spray coating systems. The materials self-assemble and bond during the sintering process, eliminating the need for complex coating equipment and operations.
3Manufacturing precision
If multiple process steps including surface reforming and drying are implemented, then ceramic coating quality is improved, but overall process time increases
Solution Approach 1:
The patent combines multiple process steps (ceramic mixing, graphite formation, surface reforming, and drying) into a single sintering process. The ceramic precursor and graphite precursor are mixed together, formed, and sintered in one continuous operation, eliminating the need for separate surface reforming and drying steps while maintaining coating quality.
Solution Approach 2:
The patent maintains continuous useful action throughout the manufacturing process by performing mixing, forming, and sintering in a continuous sequence without intermediate drying or surface reforming steps. The sintering process itself achieves both densification and surface stabilization, eliminating time-consuming intermediate steps.
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
The method achieves high productivity and economic feasibility by uniformly coating graphite with ceramic, resulting in materials with surface resistances ranging from 10^8 to 10^16 Ω/sq and maintaining excellent thermal conductivity and electric insulation without the need for additional surface reforming processes.
Implementation Method 1
A sol-gel method is used to chemically bond ceramic to the lateral defect areas of graphite
Implementation Method 2
introducing 0.1 to 70 parts by weight of graphite having an average diameter from 10 nm to 1000 pm based on 100 parts by weight of an alcohol solvent and sufficiently dispersing the graphite in the alcohol solvent to obtain a dispersed solution; introducing an alkaline catalyst to the dispersed solution to titrate the dispersed solution to pH9 to pH12
Implementation Method 3
When the graphite is coated with the ceramic, a pyrene derivative may be further added as a dispersing agent
Data Source
AI summary
Disclosed is a method of manufacturing ceramic coated graphite having electric resistance in a range from 108 to 1016 Ω/sq via a sol-gel method, the ceramic coated graphite comprising graphite; and ceramic chemically bonded to a lateral defect area of the graphite, wherein the graphite is oval graphite having an aspect ratio selected from the group consisting of 10:1 to 200:1, and the ceramic is at least one type selected from the group consisting of magnesium oxide, aluminum oxide, zinc oxide, zirconium oxide, and silica.