Preparation of mesocarbon microbeads as anode material for lithium-ion battery by co‑carbonization of FCC decant oil and conductive carbon black

Abstract

Low yield and unremarkable electrochemical performance of MCMB prepared from conventional thermal polymerization are inevitable, which limits its large-scale application as anode material for lithium-ion batteries. Hence, in this work, MCMBs were prepared by co‑carbonization of low-valued FCC decant oil and conductive carbon black (CCB). CCB can enhance the nucleation, inhibit the growth of the mesophase spheres and adhere on the surface of spheres, thereby increasing the yields (38.9 wt%), influencing the microstructure and subsequent electrochemical performance of MCMB. The MCMBs prepared by doping with 3 wt% CCB exhibited a small particle size (15.0 μm) and moderate structural disorder degree with wide interlayer spacing (AD3/Aall = 18.15%, d002 = 3.5342 Å), which shortened the transport pathway of Li+ inside the microbeads. Besides, chain-like conductive carbon black connected to the surface of the MCMBs, forming a continuous and developed conductive network, which was benefit for increasing of electron conduction and enhancing the Li+ transport rate outside the microbead. Such MCMB delivered the superior long-term cyclability with specific capacity of 394.5 mAh g−1 at 0.5 A g−1 (over 400 cycles) and presented a high-rate capability with reversible capacity of 276.0 mAh g−1 at an ultra-high current density of 3 A g−1.