Key Words:HIGH-PERFORMANCE ANODE; HIGH-CAPACITY; ENERGY-STORAGE; POROUS CARBON; ION BATTERIES; GRAPHENE; NANOSHEETS; PHOSPHORUS
Abstract:Tin-based composites are accepted as one kind of feasible anode material in sodium batteries. But they often suffer from their weak electrochemical stability and sluggish interface charge transfer process, limiting their practical application significantly. Herein, a multidimensional structure of SnSe is designed to enhance their performance. In this structure, SnSe nanoparticles are co-supported by '' inner '' sandwich-like r-GO and '' outer '' nitrogen-doped carbon (SnSe/NC@r-GO). These '' inner '' and '' outer '' structures could synergistically form multidimensional charge transfer pathways. The '' inner '' r-GO builds a fast charge migration path as an '' expressway ''. The '' outer '' nitrogen-doped carbon provides stable and strong interaction as a '' ramp '' for charge transfer between SnSe and r-GO. DFT calculations further reveal that the nitrogen-doped carbon could stabilize the SnSe/ NC@r-GO structure and enhance the interfacial charge transfer via electrochemical interaction. The above excellent behaviors achieve efficient kinetic performance of SnSe in sodium batteries (smaller charge migration resistance and high sodium ion diffusion rate). Finally, this composite could realize superior electrochemical reversibility (448 mAh center dot g-1 after 500 cycles with 12.7% capital capacity fading) and favorable rate property (306 mAh center dot g-1 at 5 A center dot g-1). The design of multidimensional charge transfer paths could provide ideas for synergistically improving electrochemical performance in energy storage fields.
Volume:10
Issue:44
Translation or Not:no