Multiscale free-standing graphene-based scaffolds enabling advanced high-energy and dendrite-free lithium metal anodes

Lithium (Li) metal, considered as the thorny Holy Grail in battery anodes, has attracted unflagging efforts to revolutionize existing energy storage systems. However, the uncontrolled dendrite growth and infinite volume fluctuations of Li metal anodes during cycling severely hinder their practical applications. Herein, a novel multi-scale nitrogen-doped carbon/Mg@reduced graphene oxide (NC/Mg@RGO) composite microsphere (MS) scaffold was developed to simultaneously increase energy density, mitigate huge volume fluctuations, suppress Li dendrite growth, and reduce side reactions via the elaborate 3D spatially confined Li plating/stripping beneath the stable RGO-based SEI layers. The obtained free-standing NC/Mg@RGO-Li composite anodes delivered an excellent cycling stability with an extremely high specific capacity of 1863 mA h gwhole electrode−1, which were far superior to those of the contrast electrodes. Moreover, the corresponding NC/Mg@RGO-Li//LiFePO4 full cells demonstrated excellent rate performance and superior cycling stability with high specific capacity. In summary, this work opens a new avenue to enable the advanced high-energy and dendrite-free LMBs by virtue of the unique graphene-based 3D spatially confined scaffolds.