Preparation and study on the storage sodium performance of coumarone resin/petroleum asphalt composite hard carbon anode material

Abstract

Petroleum asphalt has been regarded as a potential precursor for the preparation of hard carbon in sodium-ion batteries (SIBs) due to its advantages of abundant resources, low cost, and high carbon content. It is understood that the disordered carbon atoms (sp3 hybrid carbon) existing in the graphene plane in hard carbon will lead to 3D space defects, then cause 2D space deformities of the graphene layer, and hinder the expansion of the graphite carbon atoms (sp2 hybrid carbon) plane. In this work, we have developed a simple and commercially available hard carbon material based on petroleum asphalt. The asphalt is cross-linked with five-membered heterocyclic aromatic molecules, and a 3D cross-linked skeleton structure is formed locally in the hard carbon after pre-oxidation and high-temperature thermal polycondensation, thus expanding the distance between the graphite layers and forming a holding site. The experimental results show that the hard carbon (GPHC44–1300) obtained from the crosslinking treatment of five-membered hetero-rings shows a reversible specific capacity of 325.5 mAh g⁻¹ at a current density of 15 mA g⁻¹. Moreover, the reversible specific capacity of 287 mAh g⁻¹ level is maintained at a high current density of 0.3 A g⁻¹ for 100 cycles. These excellent rate performance and cycle stability indicate that the five-membered heterocyclic crosslinking treatment has a positive impact on the preparation of high-performance hard carbon.