Graphitic Heat Storage Material With Low-Temperature Pressing
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Solution Overview
Problem
Existing heat storage materials face high process requirements and costs due to the use of high-cost binders and high-temperature molding processes, which hinder efficient thermal conductivity and compressive strength.
Innovation Solution
A highly thermally conductive heat storage material comprising a carbonaceous part and a graphitic part, prepared using a specific composition of graphite and mesophase pitch, with controlled microcrystal sizes and graphitization degrees, and a preparation method involving normal temperature pressing, hot press molding, and heat treatment.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If one-step hot press molding is adopted to prepare carbon/ceramic composite material, then high thermal conductivity can be achieved, but high molding temperature and high energy consumption are required
Solution Approach 1:
The preparation process is divided into two distinct stages: (1) cold pressing stage where green bodies are formed at room temperature with low energy input, and (2) hot pressing stage where sintering occurs at elevated temperature to achieve final densification and graphitization. This segmentation allows the high-temperature step to be minimized and optimized separately from the forming step, reducing overall energy consumption while maintaining manufacturing feasibility.
Solution Approach 2:
Cold pressing is performed as a preliminary action before hot pressing to pre-form the green bodies with desired shape and initial density. This preliminary consolidation reduces the burden on the subsequent hot pressing step, allowing lower peak temperatures and shorter holding times, thereby reducing energy consumption while ensuring proper material distribution and green body integrity before sintering.
2Loss of energy
If Japanese naphthalene series AR mesophase pitch is used as binder, then high thermal conductivity can be achieved, but high cost results
Solution Approach 1:
The patent employs inexpensive petroleum-based mesophase pitch as the binder instead of costly Japanese naphthalene series AR mesophase pitch. Although the cheaper pitch may have slightly different performance characteristics, it provides sufficient binding and graphitization functionality for the application, significantly reducing material cost while maintaining acceptable thermal conductivity and mechanical properties in the final carbon/ceramic composite.
Solution Approach 2:
The invention changes the chemical composition parameters of the binder from high-purity naphthalene-based mesophase pitch to petroleum-based mesophase pitch with different molecular structure and composition. This parameter change in raw material selection achieves cost reduction while the hot pressing and graphitization process parameters are optimized to compensate for any performance differences, maintaining the required thermal conductivity.
3Loss of energy
If high purity natural graphite powder is used as heat transfer enhancer, then high thermal conductivity is achieved, but high cost and high process requirements result
Solution Approach 1:
The patent creates a composite material system combining carbonaceous particles (including graphite) with ceramic particles in a matrix, where the graphite serves as thermal conductivity enhancer but is not required to be of ultra-high purity. The composite structure allows moderate-purity graphite to function effectively when combined with other thermally conductive phases and proper matrix material, reducing both material cost and processing complexity while achieving sufficient thermal conductivity for practical applications.
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 material achieves high thermal conductivity and compressive strength with a simplified, cost-effective process, suitable for applications in thermal storage and heat transfer.
Implementation Method 1
the graphitic part is obtained by graphitization transformation of the mesophase pitch
Implementation Method 2
the highly thermally conductive heat storage material comprises a carbonaceous part and a graphitic part... high thermal conductivity and compressive strength
Data Source
AI summary
The present invention relates to the fields of heat storage and thermally conductive materials, and discloses a highly thermally conductive heat storage material, a preparation method therefor, and the application thereof, and a composition for preparing a highly thermally conductive heat storage material and the application thereof. The highly thermally conductive heat storage material comprises 11-41 wt % of a carbonaceous part and 59-89 wt % of a graphitic part; for the carbonaceous part, Lc>18 nm, La>35 nm, d002<0.3388 nm, and the degree of graphitization is 60% to 95%; for the graphitic part, Lc>50 nm; La>80 nm; d002<0.3358 nm, and the degree of graphitization is 95% to 100%. The highly thermally conductive heat storage material comprises a carbonaceous part with a specific structure and a graphitic part with a specific structure, and the heat storage material obtained thereby possesses high thermal conductivity and high compressive strength. Meanwhile, the preparation process of the highly thermally conductive heat storage material is simple and cost-effective.