Sn/FeSn2/FeO@N-doped carbon yolk-shell nanocubes with multi-phase nanocores for highly stable anode materials in lithium-ion battery

Highlights: : • Multi-phase nanocores consist of Sn, FeSn₂ and FeO nanoparticles. • The shell is made of amorphous N-doped carbon. • Enhanced properties are due to the synergetic effects. • Synergy of multiphase cores, in-depth nanocrystallization and C shell confining. -- Abstract: A two-step approach using co-precipitation and thermal reduction treatment strategy is adopted to synthesize Sn/FeSn₂/FeO@nitrogen-doped carbon yolk-shell nanocubes with multi-phase nanocores for highly stable anode materials in lithium-ion battery. In the novel yolk-shell nanostructure, the multi-phase nanocores consist of Sn, FeSn₂ and FeO nanoparticles while the shell is made of amorphous nitrogen-doped carbon. With the synergy of multi-phase nanocores, the confining effect of the carbon shell and the in-depth nanocrystallization of Sn/FeSn₂/FeO nanocores in the yolk-shell nanostructures, Sn/FeSn₂/FeO@C nanocomposites exhibit high capacity of 601 mAh g⁻¹ at 0.1 Ag⁻¹ after the 300th cycle and capacity of 484 mAh g⁻¹ at 0.5 Ag⁻¹ after the 600th cycle. Our work suggests that high-performance battery materials can be produced by rational structure engineering of multi-phase nanocomposites.