Bi nanorods anchored in N-doped carbon shell as anode for high-performance magnesium ion batteries

•Successfully developed a facile route to synthesize core-shell Bi@NC nanorods.•Core-shell Bi@NC nanorods were firstly applied as anode for MIBs.•Micropores in carbon matrix mitigate the large volume change of inner core Bi.•Excellent Mg storage performance, especially in rate performance. The rechargeable magnesium batteries are potentially applicable in large-scale energy storage systems because of the low costs and rich sources. But the alternative anodes for magnesium ion batteries have not been fully developed. In this work, a novel bismuth-carbon composite with bismuth nanorods anchored in nitrogen-doped mesoporous carbon matrix (Bi@NC), was prepared as anode for magnesium ion batteries by carbonizing the dopamine-coated bismuth metal precursors. The matrix facilitated the magnesiation/de-magnesiation of bismuth due to its highly electronic conductive network. Moreover, it restrained the aggregation of bismuth nanorods and serves as a buffer layer to alleviate the mechanical strain of bismuth nanorods upon magnesium insertion/extraction. As the anode for magnesium ion batteries, the Bi@NC core-shell nanorods delivered a reversible capacity of 360 mAh g−1 at the current density of 100 mA g−1, and 87 % of the initial capacity was achieved after 100 cycles. The standout rate performance is 275 mAh g−1 at the current density of 1 A g−1. Such a good electrochemical property demonstrated the great application potential of Bi@NC as anode in magnesium ion batteries. [Display omitted]