Structural and Electrochemical Enhancement of FCC Slurry Oil-Derived Pitch via Asphaltene-Driven Graphitic Ordering

FCC slurry oil, with its high aromatic content, has great potential for producing advanced carbon materials but suffers from low thermal stability and poor graphitic ordering. In this work, we systematically investigated the oxidative modification of FCC slurry oil using two approaches: direct asphaltene addition and mesitylene-assisted dispersion. XRD, Raman, FTIR, and NMR analyses reveal that asphaltene incorporation promotes both aromatic condensation and graphitic ordering, resulting in reduced interlayer spacing (<i>d</i> ₀₀₂ from 0.3597 to 0.3445 nm) and increased crystallite height (<i>L</i> _c from 0.7503 to 0.8743 nm). Simultaneously, the softening point rose from 96 to 213 °C and the quinoline-insoluble (QI) content increased from 0.74 to 4.21%, indicating enhanced molecular rigidity, cross-linking density, and thermal stability. FCC-R-20 exhibited the highest specific capacity (404.8 mA·h·g^-1) and capacity retention (84.63% after 100 cycles), attributed to controlled defect formation (<i>I</i> _D/<i>I</i> _G 1.997 to 2.091) and structural refinement enabled by mesitylene-assisted dispersion. These findings demonstrate that solvent-assisted oxidative modification not only regulates asphaltene aggregation behavior but also improves stacking order and electrochemical durability, making it a promising strategy for tailoring FCC-derived carbon materials for high-performance energy storage applications.