Yolk-shell tin phosphides composites as superior reversibility and stability anodes for lithium/sodium ion batteries

The rational design of nanostructure is crucial to achieving high-rate and long-term cycling performance for electrodes. Herein, the tin phosphide composites with yolk-shell nanostructure (SnxPy/NG) are designed and synthesized by one-step carbonization and phosphorization from the precursor of Sn6O4(OH)4/NG. The SnxPy/NG electrode with yolk-shell nanostructure shows energy storage properties superior to that of nanoclusters or nanoparticles. The void space in yolk-shell nanostructure relieves the huge volume ex-pansion, and the unique phase hybridization of Sn4P3 and SnP0.94 promotes the reaction kinetics. Thus, SnxPy/NG delivers high-rate long-term cycling stability for Li-half cells (521.2 mA h g-1 maintained after 3000 cycles at 5.0 A g-1) and Na-half cells (203.1 mA h g-1 maintained after 300 cycles at 1.0 A g-1). The design strategy can promote the practical application of Sn-based phosphide and pave the way for designing and exploring other metal-based phosphide electrodes for energy storage.(c) 2022 Published by Elsevier B.V.