New Nanoconfined Galvanic Replacement Synthesis of Hollow Sb@C Yolk–Shell Spheres Constituting a Stable Anode for High-Rate Li/Na-Ion Batteries

In the current research project, we have prepared a novel Sb@C nanosphere anode with biomimetic yolk–shell structure for Li/Na-ion batteries via a nanoconfined galvanic replacement route. The yolk–shell microstructure consists of Sb hollow yolk completely protected by a well-conductive carbon thin shell. The substantial void space in the these hollow Sb@C yolk–shell particles allows for the full volume expansion of inner Sb while maintaining the framework of the Sb@C anode and developing a stable SEI film on the outside carbon shell. As for Li-ion battery anode, they displayed a large specific capacity (634 mAh g–1), high rate capability (specific capabilities of 622, 557, 496, 439, and 384 mAh g–1 at 100, 200, 500, 1000, and 2000 mA g–1, respectively) and stable cycling performance (a specific capacity of 405 mAh g–1 after long 300 cycles at 1000 mA g–1). As for Na-ion storage, these yolk–shell Sb@C particles also maintained a reversible capacity of approximate 280 mAh g–1 at 1000 mA g–1 after 200 cycles.