Tunable Synthesis of Yolk-Shell Porous Silicon@Carbon for Optimizing Si/C-Based Anode of Lithium-Ion Batteries.

Significant "breathing effect" calls for exploring efficient strategies to address the intrinsic issues of silicon anode of lithium-ion batteries (LIBs). We here report a controllable synthetic route to fabricate the silicon-carbon hybrids, in which porous silicon nanoparticles (p-SiNPs) are loaded in void carbon spheres by forming the yolk-shell p-SiNPs@hollow carbon (HC) nanohybrids tunable. A set of controlled experiments accompanying with systematic characterizations demonstrate that the void space and mass loading of Si can be adjusted in an effective way so that the nanostructure can be optimized with achieving improved electrochemical performance as anode of lithium-ion batteries (LIBs). The optimized p-SiNPs@HC nanohybrids show excellent performance as anode for Li-ion battery, delivering a capacity of more than 1400 mA h g after 100 cycles at 0.2 A g and 720 mA h g at a high current density of 4 A g. The present work may provide us with an attractive and promising strategy for advancing Si-based anode materials due to advantages of tunable structure of silicon-carbon nanohybrids for optimizing electrochemical performance.