Study on preparation of composite carbon rod for high-power electrode from coke with different structural characteristics

Abstract

Different from lithium-ion batteries, composite carbon rod for high-power electrode was widely used in high-end manufacturing industry due to its good conductivity and low CTE. In this study, semi cokes with different structural characteristics was used as aggregate and coal tar pitch was adopted as binder and impregnant to prepare composite carbon rod for high-power electrode, and the bonding and impregnation behavior was also investigated. It was found that calcination promoted ordered stacking of planar aromatic lamellae of acicular domain texture and aggravated the structural defects of mosaic texture. Coal tar pitch with low aromaticity and high toluene insoluble (TI) as bonded and impregnated pitch possessed higher adhesion but low weight gain ratio after calcination. While higher TI content of coal tar pitch enhanced the weight gain ratio, but the adhesion of composite carbon rod declined. In addition, the carbonaceous sheets derived from coal tar pitch gradually extended and covered the surface of orderly graphited sheets generated from acicular domain texture and contributed to the lowest CTE of 1.43 * 10−6·℃−1 as well as the lowest specific resistance of 6.03μΩ·m. While the structural defects and voids generated from disordered mosaic texture could not be completely filled, thereby resulting in highest CTE of 2.20 * 10−6·℃−1 and highest specific resistance of 9.55μΩ·m.