Mechanism and application in lithium ion batteries of ferrocene catalyzed coal tar pitch to prepare fibrous carbon material with soft and hard carbon hybrid structure

Coal tar pitch (CTP) is a significant by-product of the coal chemical industry, characterized by its high aromaticity, high carbon residue content, low cost, and its role as a high-quality precursor for carbon materials. Exploring more potential applications of CTP is the only way to realize its high-value materialization. In this study, ferrocene (Fc)-catalyzed CTP is utilized to efficiently prepare hybrid fibrous carbon consisting of soft and hard carbon by rapid chemical vapor deposition (RCVD). Density functional theory (DFT) verifies that Fc undergoes pyrolysis and deposition prior to CTP due to the lower binding of Fc-CTP compared to CTP-CTP. The features of soft and hard carbon hybridization are ultimately revealed by the variations in the way catalyst particles interact with pyrolyzed carbon. When used as an anode material for lithium-ion batteries (LIBs), the hybridized fibrous carbon demonstrates excellent electrochemical performance with a capacity of around 600 mA h g−1 at first discharge, 220 mA h g−1 at 5 A/g, and exhibits excellent cycling stability with increased capacity after 1000 cycles at 1 A/g. This study proves the feasibility of converting CTP to soft and hard carbon hybridized fibrous carbon materials and provides a facile pathway to synthesize fibrous carbon materials for electrochemical lithium-ion storage.