Green synthesis of porous graphitic carbons from coal tar pitch templated by nano-CaCO3 for high-performance lithium-ion batteries

Abstract

A green and cost-effective strategy was developed to synthesize porous graphitic carbons from coal tar pitch using commercially available CaCO3 nanoparticles as template without any further activation. The prepared porous graphitic carbons have well-developed hierarchical porous structure with moderate specific surface area (∼236.3 m2 g−1) and large pore volume (∼2.871 cm3 g−1), cross-linked carbon skeleton with relatively high levels of graphitic feature and enriched in oxygen/nitrogen-containing functional groups. Such unique microstructure characteristics of porous graphitic carbons not only can endow sufficient available space or active sites for Li-ions storage, but also can provide favorable and efficient channels for the Li-ions/electrons transportation. The prepared porous graphitic carbon PGC-3 applied as anode for lithium-ion batteries (LIBs) shows a large reversible capacity of 707 mAh g−1 at 0.05 A g−1, and presents a superior rate capability with high reversible capacities of 299 mAh g−1 and 248 mAh g−1 even at the extremely high current densities of 3 A g−1 and 5 A g−1, respectively. Moreover, such porous graphitic carbon also exhibits an outstanding long-term electrochemical stability and excellent cycling performance with over 93.5% capacity retention after 1000 cycles. This study paves a promising and universal way for large-scale production of porous graphitic carbons porous from coal tar pitch for high performance anode materials used in LIBs.