Structural modification of petroleum needle coke by adding lithium on calcining

Abstract

Petroleum needle coke modified by lithium additives is studied with a view to producing high-strength carbon materials. Modification by calcining with lithium carbonate changes the structure and properties of petroleum coke. Since the atomic radius of lithium is less than the distance between the layers of acicular phase in the petroleum coke, the added lithium is able to penetrate into the structure and form intercalated layers of composition Li x C y . Temperatures ensuring complete dissociation of the carbonate, reduction of the oxides, and intercalation of lithium during various stages in the calcining of petroleum coke are selected. The properties of pressed carbon materials derived from petroleum coke are assessed. Tests show that properties of the modified materials such as the strength and electrical conductivity are 10–15% greater than for standard samples.