Electrical Conductivity of Carbon Materials Based on Coal-Tar Pitch with Added Graphite Foam

Resumo

Attention focuses on the structure and electrical conductivity of carbon materials produced by the carbonization (at 900°C) of coal-tar pitch with the addition of 0.03–0.3% graphite foam and oxidized graphite foam. In these quantities, the additives do not change the X-ray diffraction characteristics but considerably increase the conductivity of the product over the whole temperature range. With increase in concentration of the additives, the conductivity of the carbon material increases. At room temperature, it is 14–20 S/cm, which is at least 2–3 times the value in the absence of the additives. The influence on the conductivity is greater for the oxidized graphite foam. This may be attributed to the smaller size of the crystallites and the greater distance between the planes, resulting in greater accessible surface area of the graphite layers orienting the pitch molecules on carbonization.