Enhanced electrochemical performance of SiO anode material via nitrogen-doped carbon coating in a facile and green route

摘要

Silicon monoxide (SiO) has triggered widespread attention due to its high-energy density and satisfied operating voltage. In this work, the nitrogen-doped carbon-coated SiO (SiO/NC) composite anode material was prepared by a facile and green sintering route. The raw SiO material was modified by using economical and eco-friendly citric acid and melamine as carbon and nitrogen sources. A homogeneous layer of amorphous nitrogen-doped carbon exists in the surface of SiO/NC composite, which is confirmed through XRD, SEM, TEM, EDS, and XPS analysis. The carbon coating in combination with the introduction of nitrogen atoms impels the as-prepared anode material to show better electrochemical performance than raw SiO anode. Specifically, the initial Li-extraction capacity of SiO/NC anode was enhanced to 1280 mAh g(-1) in contrast to 777 mAh g(-1) of the raw SiO electrode, and it still maintains 90.5% of capacity after 150 cycles at 1000 inA g(-1). In addition, the SiO/NC anode achieves an excellent rate-capability of 880 mAh g(-1) at 2000 mA g(-1), while the non-coated SiO offers only 464 mAh g(-1). Above all, this synthesis strategy is beneficial to advance the production and applications of SiO anode materials in future LIBs.