Effect of the binder content on the electrical and thermal conductivity of bulk graphite

Bulk graphite was prepared from starting materials of calcined coke and coal tar pitch by the hot-pressing process. The effect of binder content on the electrical and thermal conductivity of the bulk graphite has been investigated. Based on the experimental results, the interaction mechanism of the calcined coke grain and the binder was proposed with the hot-binding and hot-pressing process. Results show that the electrical and thermal conductivity of the bulk graphite was strongly dependant on the type, granularity and content of the starting materials. The reason why the conduction increased with increasing the binder content up to 25 W/% might be attributed to the filling of pores in the calcined coke by the binder and the resulting densification of the bulk graphite. A binder content more than 25 W/% led to an increase in the porosity and a decrease in electrical and thermal conductivity.