Remarkable performance of Co3O4 anode coated with hard-soft carbon 2D nanosheets prepared from single pavement petroleum asphalt precursor

Abstract

Incorporating extraneous carbonaceous materials to coat transitional metal oxide (TMO) anodes emerges as a viable strategy to mitigate the pulverization of TMO anode during Li-ion insertion/extraction processes. Herein, hard-soft carbon coated Co3O4 (HC-SC@Co3O4) composites were synthesized by employing a facile NaCl-mediated pyrolysis with Co(NO3)2·6 H2O as the oxide precursor and pavement petroleum asphalt as the single hard-soft carbon source. Microscopic structure characterizations revealed that HC-SC@Co3O4 exhibited a core-shell structure with a fluffy nanoflower-like S/O co-doped carbon shell. Benefiting from its distinctive coating structure, the HC-SC@Co3O4 anode demonstrated remarkable cycling stability and significant initial coulombic efficiency (ICE) of 71 %, after 150 cycles at 100 mA g−1, it still maintained a capacity of 742 mAh g−1. Moreover, introduction of soft carbon delivered outstanding rate capability upon HC-SC@Co3O4 anode, evidenced by discharge capacities of 1108 and 571 mA h g−1 at 100 and 1000 mA g−1, respectively. This study not only presents the potential to effectively solve the challenge of TMO anodes in lithium-ion batteries (LIBs), but also introduces an economically and environmentally approach for the efficient utilization of pavement petroleum asphalt.