Graphite Thermal Conductivity Tester

Thermal Conductivity Measurement of Graphite Materials Using a Thermal Conductivity Tester

Due to their unique layered crystal structure, graphite materials exhibit very high intrinsic thermal conductivity and are widely used in electronic device heat dissipation, thermal management materials, and new energy batteries. Accurate measurement of the thermal conductivity of graphite materials (especially their anisotropic properties) is essential for performance optimization and application design.

Traditional steady-state thermal conductivity testing methods (such as the laser flash method and t...

I. Experimental Procedure

1. Experimental Sample
- Electrode graphite material.

2. Testing Equipment
- THS200 Thermal Conductivity Tester.
3. Sample Pretreatment
- Sample dimensions: two pieces, each 30 × 30 × 7.5 mm, with uniformly smooth and flat surfaces.
- Surface treatment: polish the sample surface with 600#–2000# sandpaper to remove scratches and improve thermal contact between the probe and sample.

4. Operation Process
- Sample placement: place the probe in the middle of the two samples, ensuring that the probe fully covers the central area of the sample.
- Parameter settings: select test power of 5 W according to the estimated thermal diffusivity of the sample.
- Data acquisition: initiate a heating pulse, and record the temperature variation of the probe over time (sampling interval 0.1 ms, total test duration 10 s).

II. Experimental Results and Analysis
- The purity of electrode graphite is usually lower than that of high-purity graphite. The ash content of industrial-grade electrode graphite generally ranges from 0.1% to 1% (with some lower-end products reaching more than 2%). Impurities scatter phonons and significantly reduce thermal conductivity. For example, every 0.5% increase in ash content may result in a 5%–10% reduction in thermal conductivity.
- At room temperature, the in-plane thermal conductivity of electrode graphite typically ranges from 50–200 W/(m·K), while the through-plane (out-of-plane) conductivity is usually 10–50 W/(m·K). Specific values are mainly determined by purity, density, and porosity.
- The degree of anisotropy of electrode graphite is relatively low, making it a cost-effective thermal and electrical functional material for industrial applications.