Yolk-shelled Sn@C@MnO hierarchical hybrid nanospheres for high performance lithium-ion batteries

Abstract

Metallic tin exhibits great potential as an alternative to commercial graphite anode materials. However, its tremendous volume change during cycles leads to significant capacity fading, which hampers its practical application. In this work, Sn nanoparticles are confined to a carbon nanocage to form Sn@C@MnO yolk-shell hierarchical hybrid nanospheres as anode nanomaterials for Li-ion battery. In the novel nanostructures, the yolk-shell nanostructures can well buffer the volume contraction/expansion of Sn nanocores during cycles; the carbon shell can provide high conductivity and inhibit Sn and MnO nanocrystals from stacking; MnO nanocrystals on the C shell can not only offer sufficient active sites for Li-ion adsorption, but also validly consolidate the structural stability of the shell in the yolk-shell nanostructure. Benefiting from the unique nanostructures, Sn@C@MnO yolk-shell hierarchical hybrid nanospheres exhibit superior electrochemical lithium storage performances (822mAhg−1 after 250 cycles at 0.1Ag-1) and long-term cyclic stability (603mAhg−1 after 500 cycles at 0.5Ag-1). This work offers valuable insight into the synthetic strategy of Sn-based anode materials with novel hierarchical hybrid nanostructures.