Constructing atomically dispersed Snδ+ sites in porous carbon nanosheets to boost lithium-/sodium-storage capability

Nanoscale carbon-supported single atomic metal active centers (Mδ+) have recently caught much attention as a high-efficient catalyst in energy-conversion/-storage fields. Further works extended to employ these materials as the lithium-/sodium-storage anode. Inspired by the progresses, porous carbon nanosheets with abundant Snδ+ sites (Sn-PCNS) are prepared by easy-controllable template-directed method and post carbonization process in this work. Here, atomically dispersed Snδ+ is stabilized mainly by O/N moieties in carbon framework, which can enhance the electron transfer and Li+-/Na+-diffusion kinetics, thus benefiting the Li+-/Na+-storage capabilities. As a result, the Sn-PCNS electrode can deliver a high lithium-storage capacity of 428 mA h g−1 at 10 A g−1 and show a long-term cycling performance for sodium storage at high rate (∼ 120 mA h g−1 at 5 A g−1 after 1000 cycles). This work not only provides a strategy for the preparation of new sheet-like carbon-based nanomaterials, but also offer an opportunity to promote the application of carbon-supported single atomic metal active centers in energy conversion and storage.